SNiP 2.04.01-85*
Building regulations
Internal water supply and sewerage of buildings.
Internal cold and hot water supply systems
WATER PIPES
8. Calculation of the water supply network hot water
8.1. Hydraulic calculations of hot water supply systems should be made based on the estimated hot water flow
Taking into account the circulation flow, l/s, determined by the formula
(14)
where is the coefficient accepted: for water heaters and the initial sections of systems up to the first water riser according to the mandatory Appendix 5;
for other sections of the network - equal to 0.
8.2. The circulating flow rate of hot water in the system, l/s, should be determined by the formula
(15)
where is the circulation misregulation coefficient;
Heat loss from hot water supply pipelines, kW;
Temperature difference in the supply pipelines of the system from the water heater to the most distant water supply point, °C.
Values and depending on the hot water supply scheme should be taken:
for systems that do not provide for water circulation through water risers, the value should be determined from the supply and distribution pipelines at = 10°C and = 1;
for systems in which water circulation is provided through water risers with variable resistance of the circulation risers, the value should be determined from the supply distribution pipelines and water risers at = 10°C and = 1; with the same resistance of sectional units or risers, the value should be determined by water risers at = 8.5 ° C and = 1.3;
for a water riser or sectional unit, heat loss should be determined from the supply pipelines, including the ring jumper, taking = 8.5°C and = 1.
8.3. Pressure losses in sections of pipelines of hot water supply systems should be determined:
for systems where it is not necessary to take into account the overgrowing of pipes - in accordance with clause 7.7;
for systems taking into account pipe overgrowth - according to the formula
where i is the specific pressure loss, taken in accordance with the recommended appendix 6;
Coefficient taking into account pressure loss in local resistance, the values of which should be taken:
0.2 - for supply and circulation distribution pipelines;
0.5 - for pipelines within heating points, as well as for pipelines of water risers with heated towel rails;
0.1 - for pipelines of water risers without heated towel rails and circulation risers.
8.4. The speed of water movement should be taken in accordance with clause 7.6.
8.5. The pressure loss in the supply and circulation pipelines from the water heater to the most remote water-drawn or circulation risers of each branch of the system should not differ for different branches by more than 10%.
8.6. If it is impossible to coordinate the pressures in the pipeline network of hot water supply systems by appropriately selecting pipe diameters, it is necessary to install temperature regulators or diaphragms on the circulation pipeline of the system.
The diaphragm diameter should not be taken less than 10 mm. If, according to calculations, the diameter of the diaphragms must be less than 10 mm, then it is permissible to install taps instead of the diaphragm to regulate the pressure.
It is recommended to determine the diameter of the holes of the control diaphragms using the formula
(17)
8.7. In systems with the same resistance of sectional units or risers, the total pressure loss along the supply and circulation pipelines between the first and last risers at circulation flow rates should be 1.6 times higher than the pressure loss in the sectional unit or riser with circulation deregulation = 1.3.
The diameters of the pipelines of the circulation risers should be determined in accordance with the requirements of clause 7.6, provided that at circulation flow rates in the risers or sectional units determined in accordance with clause 8.2, the pressure losses between the points of their connection to the distribution supply and collection circulation pipelines do not differ more than 10%.
8.8. In hot water supply systems connected to closed heating networks, the pressure loss in sectional units at the calculated circulation flow rate should be taken as 0.03-0.06 MPa (0.3-0.6 kgf/sq.cm).
8.9. In hot water supply systems with direct water withdrawal from the pipelines of the heating network, the pressure loss in the pipeline network should be determined taking into account the pressure in the return pipeline of the heating network.
The pressure loss in the circulation ring of the system pipelines at circulation flow should, as a rule, not exceed 0.02 MPa (0.2 kgf/sq.cm).
8.10. In showers with more than three shower screens, the distribution pipeline should, as a rule, be provided in a loop.
One-way supply of hot water may be provided for manifold distribution.
8.11. When zoning hot water supply systems, it is allowed to provide for the possibility of organizing natural circulation of hot water in the upper zone at night.
2.2 Determination of heat loss and circulation flow rates in the supply pipelines of the hot water supply system
Circulation flow rate of hot water in the system, l/s:
,(2.14)
where> is the total heat loss by the supply pipelines of the hot water supply system, kW;
The temperature difference in the supply pipelines of the system to the most remote water collection point, , is assumed to be 10;
Circulation misregulation coefficient, accepted 1
For a system with variable resistance of circulation risers, the value is determined from the supply pipelines and water risers at = 10 and = 1
Heat loss in areas, kW, are determined by the formula
Where: q is the heat loss of 1 m of pipeline, W/m, taken according to Appendix 7 AAAAAAAAAAAAAAAAAAAAAAAAAAA
l - length of the pipeline section, m, taken according to the drawing
When calculating the heat loss of sections of water risers, the heat loss of a heated towel rail is taken to be 100 W, while its length is excluded from the length of the floor riser. For convenience, the calculation of heat loss is summarized in one table 2 with hydraulic calculation networks.
Let us determine the heat loss for the entire system as a whole. For convenience, it is accepted that risers located on the plan in mirror image are equal to each other. Then the heat loss of the risers located to the left of the input will be equal to:
1.328*2+0.509+1.303*2+2.39*2+2.432*2+2.244=15.659 kW
And the risers located on the right:
1.328*2+(0.509-0.144) +2.39*2+(0.244-0.155) =7.89 kW
The total heat loss per house will be 23.55 kW.
Let's determine the circulation flow:
l/s
Let us determine the calculated second consumption of hot water, l/s, in sections 45 and 44. To do this, we determine the ratio qh/qcir; for sections 44 and 45 it is equal to 4.5 and 5.5, respectively. According to Appendix 5, the coefficient Kcir = 0 in both cases, therefore, the preliminary calculation is final.
Provided for circulation circulation pump brand WILO Star-RS 30/7
2.3 Selection of water meter
acc. from clause a) clause 3.4, we check the condition 1.36m<5м, условие выполняется, принимаем крыльчатый водомер METRON Ду 50 мм.
3. Calculation and design of the sewerage system
The sewerage system is designed to remove from the building contaminants generated during sanitary and hygienic procedures, economic activities, as well as atmospheric and melt water. Internal sewer network consists of outlet pipelines, risers, outlets, exhaust part, and cleaning devices. Discharge pipes are used to drain Wastewater from sanitary fixtures and transferring them to the riser. The outlet pipes are connected to the water seals of sanitary fixtures and laid with a slope towards the riser. Risers are designed to transport wastewater to the sewer outlet. They collect wastewater from drainage pipes and must have a diameter of at least largest diameter outlet pipe or outlet of a device connected to the riser.
In this project, the internal wiring is made of socket PVC pipes with a diameter of 50 mm, risers with a diameter of 100 mm are made of cast iron, also connected by sockets. Connection to risers is made using crosses and tees. The network is subject to inspections and cleaning to remove blockages.
3.1 Determination of estimated sewerage costs
Total maximum design water flow:
Where: - water consumption by the device is assumed to be 0.3 l/s, respectively. from app. 4; - coefficient depending on the total number of devices and the probability of their use Рtot
, (7)
Where: - general norm consumption per hour of greatest water consumption, l, taken in accordance with Appendix 4 to be equal to 20
Number of water consumers equal to 104 * 4.2 people
Number of sanitary fixtures, accepted 416 as ordered
Then, the product N*=416*0.019=7.9, therefore =3.493
The resulting value is less than 8 l/s, therefore, the maximum second wastewater flow:
Where: - consumption from sanitary - technical device with the highest water drainage, l/s, adopted according to Appendix 2 for a toilet with a flush tank equal to 1.6
3.2 Calculation of risers
The water consumption for risers K1-1, K1-2, K1-5, K1-6 will be the same, since an equal number of devices are connected to these risers, each with 52 devices.
We assume the diameter of the riser is 100 mm, the diameter of the floor outlet is 100 mm, the angle of the floor outlet is 90°. Maximum throughput 3.2 l/s. Estimated flow rate 2.95 l/s. Consequently, the riser operates in normal hydraulic mode.
The water consumption for risers K1-3, K1-4 will be the same, since an equal number of devices are connected to these risers, each with 104 devices.
To maintain a constant temperature at water taps in residential and public buildings, hot water is circulated between the tap points and the heat generator. The amount of circulation flow is determined during the thermal calculation of the central heating system network. Depending on the magnitude of the circulation flow rate in the design sections, the diameters of the circulation pipelines are assigned. The amount of heat loss by the central heating system is determined as the sum of heat losses in network sections according to the formula
where is the specific heat loss of 1 running meter of pipeline.
When designing central heating systems with sectional units, heat loss of 1 linear meter of a pipeline can be assumed, depending on the type of pipeline, location and method of its installation. The heat loss of 1 running meter of pipes is given in Appendix 2. Heat loss by insulated pipelines of a quarterly network under various installation conditions is given in Appendix 3.
The circulating flow of hot water, according to clause 8.2, in the system is determined by the formula:
, l/s,
where Q ht – heat loss by hot water supply pipelines, kW;
t – temperature difference in the supply pipelines of the system from the water heater to the most remote water distribution point, С;
– circulation misregulation coefficient.
The values of Q ht and are taken at the same resistance of sectional units
Dt = 8.5С and b = 1.3.
In accordance with the recommendations of clause 9.16, we provide thermal insulation of supply and circulation pipelines, including risers, except for connections to appliances and heated towel rails. As thermal insulation, we use molded mineral wool cylinders produced by Rokwool Russia.
Heat losses are determined for all supply pipelines of the hot water supply system. The calculation is carried out in the form of table 4. Specific heat losses are taken according to appendices 2 and 3.
Table 4. Calculation of heat loss through supply pipelines |
|||||||||
Pipe diameter, mm |
Number of risers or towel dryers |
Riser or pipeline length, m |
Total pipe length, m |
Specific heat loss, W |
Heat loss of risers, W |
Heat loss of main pipelines, W |
|||
Water risers |
|||||||||
Heated towel rails |
|||||||||
Main pipes in the basement |
|||||||||
Total for one house: | |||||||||
Total for two houses: | |||||||||
Main pipes in the channel |
|||||||||
Total heat loss: Q ht = 29342 + 3248 = 32590 W = 32.59 kW |
3.3. Hydraulic calculation of supply pipelines when supplying circulation calculations
Hydraulic calculations of supply pipelines for passing circulation flows through them are carried out in the absence of water intake. The amount of circulation flow is determined by the formula
, l/s.
For sectional units with the same resistance, we take Dt = 8.5°C and b = 1.3.
l/s,
l/s*.
The circulation flow from the water heater is supplied through supply pipelines and water risers and discharged through circulation risers and circulation main pipelines to the water heater. Since the risers are the same, in order to replenish heat loss by pipes, the same circulation flow must pass through each water riser.
We determine the amount of circulation flow passing through the riser:
, l/s,
where n st is the number of water risers in a residential building.
Hydraulic calculations of supply and circulation pipelines are carried out according to the calculated direction relative to the dictating point. Specific pressure losses are taken according to Appendix 1. The calculation results are given in Table 5.
Table 5. Hydraulic calculation of supply pipelines for passage |
|||||||||
circulation flow |
|||||||||
Plot number |
Pipe diameter, mm |
Circulation flow, l/s |
Speed, m/s |
Pressure loss, mm |
|||||
Location on |
H= il(1+Kl) |
||||||||
∑h l = 970.14 mm = |
On payment of thermal energy during the inter-heating period
In the summer, the line “loss of thermal energy in hot water” appeared in receipts of St. Petersburg residents for housing and communal services. The wording of the position may differ, but the essence is the same - with the transition to seasonal heating payments, it became necessary to pay for the consumption of thermal energy associated with heat transfer through risers and heated towel rails. For example, in a letter from the Housing Committee of St. Petersburg, an explanation is given “about the procedure for paying for thermal energy for the circulation of hot water supply through heated towel rails.” The problem is that, in accordance with the existing legislation and regulatory framework, tariffs for thermal energy, including for hot water supply, can only be set in rubles/Gcal. Heat supply organizations (SUE "TEK SPb", TGK) do just that, issuing bills for heat energy according to the readings of metering units in Gcal at established tariffs (prices). Residents are charged for hot water supply according to apartment meter readings or consumption standards in cubic meters, which leads to a significant difference between the cost of thermal energy and the cost of hot water. This difference can be more than 30%. But what was it like before? During the period when the heating fee was calculated, the additional consumption of thermal energy for risers and heated towel rails was taken into account in the heating fee, the so-called ODN. But according to the Rules approved by the Decree of the Government of the Russian Federation dated April 16, 2013 No. 344, the heating fee for ODN has been cancelled. In accordance with the Rules, the calculation of the amount of payment for utility services is made based on the actual volumes of consumption of utility resources in accordance with the readings of common house meters. From which it follows that all thermal energy must be paid in full. As they say, bills have to be paid. The rules developed by the Ministry of Regional Development do not provide for the procedure for paying these costs. Currently, the Ministry of Regional Development of the Russian Federation is developing appropriate changes related to the specified heat consumption to include them in the Decrees of the Government of the Russian Federation No. 306 and No. 354. Before introducing these changes, the Tariff Committee of St. Petersburg recommended that amounts exceeding the consumption of thermal energy for hot water supply be attributed to design consumption 0.06 Gcal/cubic. m for the article “thermal energy for heating water for hot water supply.” (Letter No. 01-14-1573/13-0-1 dated June 17, 2013) Thus, the line that appears in the receipt is legal and fully complies with the requirements of Article 7 and Article 39 of the Housing Code of the Russian Federation.
This is published on the website of the Criminal Code.
SNiP 2.04.01-85*
Building regulations
Internal water supply and sewerage of buildings.
Internal cold and hot water supply systems
WATER PIPES
8. Calculation of the hot water supply network
8.1. Hydraulic calculations of hot water supply systems should be made based on the estimated hot water flow
Taking into account the circulation flow, l/s, determined by the formula
(14)
where is the coefficient accepted: for water heaters and the initial sections of systems up to the first water riser according to the mandatory Appendix 5;
for other sections of the network - equal to 0.
8.2. The circulating flow rate of hot water in the system, l/s, should be determined by the formula
(15)
where is the circulation misregulation coefficient;
Heat loss from hot water supply pipelines, kW;
Temperature difference in the supply pipelines of the system from the water heater to the most distant water supply point, °C.
Values and depending on the hot water supply scheme should be taken:
for systems that do not provide for water circulation through water risers, the value should be determined from the supply and distribution pipelines at = 10°C and = 1;
for systems in which water circulation is provided through water risers with variable resistance of the circulation risers, the value should be determined from the supply distribution pipelines and water risers at = 10°C and = 1; with the same resistance of sectional units or risers, the value should be determined by water risers at = 8.5 ° C and = 1.3;
for a water riser or sectional unit, heat loss should be determined from the supply pipelines, including the ring jumper, taking = 8.5°C and = 1.
8.3. Pressure losses in sections of pipelines of hot water supply systems should be determined:
for systems where it is not necessary to take into account the overgrowing of pipes - in accordance with clause 7.7;
for systems taking into account pipe overgrowth - according to the formula
where i is the specific pressure loss, taken in accordance with the recommended appendix 6;
A coefficient that takes into account pressure losses in local resistances, the values of which should be taken:
0.2 - for supply and circulation distribution pipelines;
0.5 - for pipelines within heating points, as well as for pipelines of water risers with heated towel rails;
0.1 - for pipelines of water risers without heated towel rails and circulation risers.
8.4. The speed of water movement should be taken in accordance with clause 7.6.
8.5. The pressure loss in the supply and circulation pipelines from the water heater to the most remote water-drawn or circulation risers of each branch of the system should not differ for different branches by more than 10%.
8.6. If it is impossible to coordinate the pressures in the pipeline network of hot water supply systems by appropriately selecting pipe diameters, it is necessary to install temperature regulators or diaphragms on the circulation pipeline of the system.
The diaphragm diameter should not be taken less than 10 mm. If, according to calculations, the diameter of the diaphragms must be less than 10 mm, then it is permissible to install taps instead of the diaphragm to regulate the pressure.
It is recommended to determine the diameter of the holes of the control diaphragms using the formula
(17)
8.7. In systems with the same resistance of sectional units or risers, the total pressure loss along the supply and circulation pipelines between the first and last risers at circulation flow rates should be 1.6 times higher than the pressure loss in the sectional unit or riser with circulation deregulation = 1.3.
The diameters of the pipelines of the circulation risers should be determined in accordance with the requirements of clause 7.6, provided that at circulation flow rates in the risers or sectional units determined in accordance with clause 8.2, the pressure losses between the points of their connection to the distribution supply and collection circulation pipelines do not differ more than 10%.
8.8. In hot water supply systems connected to closed heating networks, the pressure loss in sectional units at the calculated circulation flow rate should be taken as 0.03-0.06 MPa (0.3-0.6 kgf/sq.cm).
8.9. In hot water supply systems with direct water withdrawal from the pipelines of the heating network, the pressure loss in the pipeline network should be determined taking into account the pressure in the return pipeline of the heating network.
The pressure loss in the circulation ring of the system pipelines at circulation flow should, as a rule, not exceed 0.02 MPa (0.2 kgf/sq.cm).
8.10. In showers with more than three shower screens, the distribution pipeline should, as a rule, be provided in a loop.
One-way supply of hot water may be provided for manifold distribution.
8.11. When zoning hot water supply systems, it is allowed to provide for the possibility of organizing natural circulation of hot water in the upper zone at night.
A new column has appeared in receipts for utility services - hot water supply. It caused confusion among users, since not everyone understands what it is and why it is necessary to make payments on this line. There are also apartment owners who cross out the box. This entails the accumulation of debt, penalties, fines and even litigation. In order not to take matters to extreme measures, you need to know what DHW is, DHW heat energy and why you need to pay for these indicators.
What is DHW on the receipt?
DHW - this designation stands for hot water supply. Its goal is to provide apartments in apartment buildings and other residential premises with hot water at an acceptable temperature, but hot water supply is not the hot water itself, but the thermal energy that is spent on heating the water to an acceptable temperature.
Experts divide hot water supply systems into two types:
- Central system. Here the water is heated at a heating station. After this, it is distributed to apartments in multi-apartment buildings.
- Autonomous system. It is usually used in private homes. The principle of operation is the same as in the central system, but here the water is heated in a boiler or boiler and is used only for the needs of one specific room.
Both systems have the same goal - to provide home owners with hot water. In apartment buildings, a central system is usually used, but many users install a boiler in case the hot water is turned off, as has happened more than once in practice. An autonomous system is installed where it is not possible to connect to the central water supply. Only those consumers who use the central heating system pay for hot water supply. Users of an autonomous circuit pay for utility resources that are spent to heat the coolant - gas or electricity.
Important! Another column in the receipt related to DHW is DHW at one unit. Decoding ODN - general house needs. This means that the DHW column on one unit is the expenditure of energy on heating water used for the general needs of all residents of an apartment building.
These include:
- technical work that is performed before the heating season;
- pressure testing of the heating system carried out after repair;
- repair work;
- heating of common areas.
Hot water law
The law on hot water supply was adopted in 2013. Government Decree No. 406 states that users of a central heating system are required to pay a two-part tariff. This suggests that the tariff was divided into two elements:
- thermal energy;
- cold water.
This is how DHW appeared on the receipt, that is, the thermal energy spent on heating cold water. Housing and communal services specialists came to the conclusion that risers and heated towel rails, which are connected to the hot water supply circuit, consume thermal energy to heat non-residential premises. Until 2013, this energy was not taken into account in receipts, and consumers used it free of charge for decades, since the air in the bathroom continued to be heated outside the heating season. Based on this, officials divided the tariff into two components, and now citizens have to pay for hot water.
Water heating equipment
The equipment that heats the liquid is a water heater. Its breakdown does not affect the hot water tariff, but users are required to pay the cost of repairing the equipment, since water heaters are part of the property of homeowners in an apartment building. The corresponding amount will appear in the receipt for the maintenance and repair of the property.
Important! This payment should be carefully considered by the owners of those apartments that do not use hot water, since their housing has an autonomous heating system installed. Housing and communal services specialists do not always pay attention to this, simply distributing the amount for water heater repairs among all citizens.
As a result, these apartment owners have to pay for equipment they did not use. If you discover an increase in the tariff for repairs and maintenance of property, you need to find out what this is connected with and contact the management company for recalculation if the payment was calculated incorrectly.
Thermal energy component
What is this - a coolant component? This is heating cold water. The thermal energy component does not have a meter installed, unlike hot water. For this reason, it is impossible to calculate this indicator using a counter. How, in this case, is the thermal energy for hot water calculated? When calculating the payment, the following points are taken into account:
- tariff set for hot water supply;
- expenses spent on maintaining the system;
- cost of heat loss in the circuit;
- costs spent on coolant transfer.
Important! The cost of hot water is calculated taking into account the volume of water consumed, which is measured in 1 cubic meter.
The size of the energy fee is usually calculated based on the readings of the common hot water meter and the amount of energy in the hot water. Energy is also calculated for each individual apartment. To do this, water consumption data is taken, which is learned from the meter readings, and multiplied by the specific heat energy consumption. The received data is multiplied by the tariff. This figure is the required contribution, which is indicated on the receipt.
How to make your own calculation
Not all users trust the payment center, which is why the question arises of how to calculate the cost of hot water supply yourself. The resulting figure is compared with the amount on the receipt and on the basis of this a conclusion is made about the correctness of the charges.
To calculate the cost of hot water supply, you need to know the tariff for thermal energy. The amount is also affected by the presence or absence of a meter. If there is one, then readings are taken from the meter. In the absence of a meter, the standard for the consumption of thermal energy used to heat water is taken. This standard indicator is established by an energy saving organization.
If an energy consumption meter is installed in a multi-storey building and the housing has a hot water meter, then the amount for hot water supply is calculated based on general building metering data and the subsequent proportional distribution of the coolant among apartments. If there is no meter, the rate of energy consumption per 1 cubic meter of water and the readings of individual meters are taken.
Complaint due to incorrect calculation of receipt
If, after independently calculating the amount of contributions for hot water supply, a difference is identified, you must contact the management company for clarification. If the organization's employees refuse to provide explanations on this matter, a written complaint must be submitted. Company employees have no right to ignore it. The response must be received within 13 working days.
Important! If no response is received or it is not clear from it why this situation arose, then the citizen has the right to file a claim with the prosecutor’s office or a statement of claim in court. The authority will consider the case and make an appropriate objective decision. You can also contact organizations that control the activities of the management company. Here the subscriber's complaint will be considered and an appropriate decision will be made.
Electricity used to heat water is not a free service. Payment for it is charged on the basis of the Housing Code of the Russian Federation. Each citizen can independently calculate the amount of this payment and compare the data obtained with the amount on the receipt. If any inaccuracy occurs, you should contact the management company. In this case, the difference will be compensated if the error is recognized.
2.2 Determination of heat loss and circulation flow rates in the supply pipelines of the hot water supply system
Circulation flow rate of hot water in the system, l/s:
,(2.14)
where> is the total heat loss by the supply pipelines of the hot water supply system, kW;
The temperature difference in the supply pipelines of the system to the most remote water collection point is assumed to be 10;
Circulation misregulation coefficient, accepted 1
For a system with variable resistance of circulation risers, the value is determined from the supply pipelines and water risers at = 10 and = 1
Heat loss in areas, kW, is determined by the formula
Where: q - heat loss of 1 m of pipeline, W/m, taken according to Appendix 7
l - length of the pipeline section, m, taken according to the drawing
When calculating the heat loss of sections of water risers, the heat loss of a heated towel rail is taken to be 100 W, while its length is excluded from the length of the riser. For convenience, the calculation of heat loss is summarized in one table 2 with a hydraulic calculation of the network.
Let us determine the heat loss for the entire system as a whole. For convenience, it is assumed that the risers located on the plan in a mirror image are equal to each other. Then the heat loss of the risers located to the left of the input will be equal to:
1.328*2+0.509+1.303*2+2.39*2+2.432*2+2.244=15.659 kW
And the risers located on the right:
1.328*2+(0.509-0.144) +2.39*2+(0.244-0.155) =7.89 kW
The total heat loss per house will be 23.55 kW.
Let's determine the circulation flow:
l/s
Let us determine the calculated second consumption of hot water, l/s, in sections 45 and 44. To do this, we determine the ratio qh/qcir; for sections 44 and 45 it is equal to 4.5 and 5.5, respectively. According to Appendix 5, the coefficient Kcir = 0 in both cases, therefore, the preliminary calculation is final.
To ensure circulation, a WILO Star-RS 30/7 circulation pump is provided
2.3 Selection of water meter
acc. from clause a) clause 3.4, we check the condition 1.36m
3. Calculation and design of the sewerage system
The sewerage system is designed to remove from the building contaminants generated during sanitary and hygienic procedures, economic activities, as well as atmospheric and melt water. The internal sewer network consists of outlet pipelines, risers, outlets, exhaust parts, and cleaning devices. Discharge pipes are used to drain wastewater from sanitary fixtures and transfer it to the riser. The outlet pipes are connected to the water seals of sanitary fixtures and laid with a slope towards the riser. Risers are designed to transport wastewater to the sewer outlet. They collect wastewater from outlet pipes and their diameter must be no less than the largest diameter of the outlet pipe or the outlet of the device connected to the riser.
In this project, the intra-apartment wiring is made of bell-shaped PVC pipes with a diameter of 50 mm, risers with a diameter of 100 mm are made of cast iron, also connected by sockets. Connection to risers is made using crosses and tees. The network is subject to inspections and cleaning to remove blockages.
3.1 Determination of estimated sewerage costs
Total maximum design water flow:
Where: - water consumption by the device is assumed to be 0.3 l/s, respectively. from app. 4; - coefficient depending on the total number of devices and the probability of their use Рtot
, (7)
Where: - the total rate of consumption per hour of greatest water consumption, l, is taken in accordance with Appendix 4 to be equal to 20
Number of water consumers equal to 104 * 4.2 people
Number of sanitary fixtures, accepted 416 as ordered
Then, the product N*=416*0.019=7.9, therefore =3.493
The resulting value is less than 8 l/s, therefore, the maximum second wastewater flow:
Where: - flow rate from the sanitary-technical device with the greatest drainage, l/s, taken according to Appendix 2 for a toilet with a flush tank equal to 1.6
3.2 Calculation of risers
The water consumption for risers K1-1, K1-2, K1-5, K1-6 will be the same, since an equal number of devices are connected to these risers, each with 52 devices.
We assume the diameter of the riser is 100 mm, the diameter of the floor outlet is 100 mm, the angle of the floor outlet is 90°. Maximum throughput 3.2 l/s. Estimated flow rate 2.95 l/s. Consequently, the riser operates in normal hydraulic mode.
The water consumption for risers K1-3, K1-4 will be the same, since an equal number of devices are connected to these risers, each with 104 devices.
UDC 621.64 (083.7)
Developed by: CJSC Research and Production Complex "Vector", Moscow Energy Institute (Technical University)
Performers: Tishchenko A.A., Shcherbakov A.P.
Under the general editorship of Semenov V.G.
Approved by the Head of the Department of State Energy Supervision of the Ministry of Energy of the Russian Federation on February 20, 2004.
The methodology establishes the procedure for determining actual losses thermal energy through thermal insulation of pipelines of water heating networks of centralized heating systems, some of the consumers of which are equipped with metering devices. Actual losses of thermal energy for consumers who have measuring devices are determined based on the readings of heat meters, and for consumers not equipped with metering devices - by calculation.
Thermal energy losses determined according to this Methodology should be considered as the initial basis for compiling the energy characteristics of the heating network, as well as for developing technical measures to reduce actual thermal energy losses.
The methodology was approved by the Head of the Department of State Energy Supervision of the Ministry of Energy of the Russian Federation on February 20, 2004.
For organizations carrying out energy inspections of heat supply enterprises, as well as for enterprises and organizations operating heating networks, regardless of their departmental affiliation and forms of ownership.
This “Methodology...” establishes the procedure for determining actual losses of thermal energy 1 through thermal insulation of pipelines of water heating networks of centralized heating systems, some of whose consumers are equipped with metering devices. Actual losses of thermal energy for consumers who have measuring devices are determined based on the readings of heat meters, and for consumers not equipped with metering devices - by calculation.
1 Terms and definitions are given in Appendix A.
The “Methodology...” is based on the computational and experimental method for assessing thermal energy losses, set out in.
“Methodology...” is intended for organizations carrying out energy inspections of heat supply enterprises, as well as for enterprises and organizations operating heating networks, regardless of their departmental affiliation and forms of ownership.
Thermal energy losses determined according to this “Methodology...” should be considered as the initial basis for compiling the energy characteristics of the heating network, as well as for developing technical measures to reduce actual thermal energy losses.
1. GENERAL PROVISIONS
The purpose of this “Methodology...” is to determine the actual losses of thermal energy through the thermal insulation of pipelines of water heating networks of centralized heating systems without special tests. Thermal energy losses are determined for the entire heating network connected to a single source of thermal energy. The actual losses of thermal energy are not determined for individual sections of the heating network.
Determination of thermal energy losses according to this “Methodology...” assumes the presence of certified thermal energy metering units at the thermal energy source and at thermal energy consumers. The number of consumers equipped with metering devices must be at least 20% of total number consumers of this heating network.
Metering devices must have an archive with hourly and daily recording of parameters. The depth of the hourly archive must be at least 720 hours, and the daily archive must be at least 30 days.
The main thing when calculating heat energy losses is the hourly archive of heat meters. The daily archive is used if hourly data is missing for some reason.
Determination of actual losses of thermal energy is carried out on the basis of measurements of the flow rate and temperature of network water in the supply pipeline 1 for consumers who have metering devices, and the temperature of network water at the source of thermal energy. Heat energy losses for consumers who do not have measuring instruments, are determined by calculation using this “Methodology...”.
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1 Legend values are given in Appendix B.
In this “Methodology...” the following are considered sources and consumers of thermal energy:
1. in the absence of metering devices directly in buildings: sources of thermal energy - thermal power plants, boiler houses, etc.; consumers of thermal energy - central (DTP) or individual (ITP) heating points;
2. if there are metering devices directly in buildings(in addition to point 1): sources of thermal energy - central heating points; consumers of thermal energy are the buildings themselves.
For the convenience of calculating thermal energy losses through thermal insulation, the supply pipeline in this “Methodology...” is divided into: the main pipeline and a branch from the main pipeline.
Main pipeline- this is part of the supply pipeline from the thermal energy source to the thermal chamber, from which there is a branch to the thermal energy consumer.
Branch from the main pipeline- this is part of the supply pipeline from the corresponding thermal chamber to the thermal energy consumer.
When determining the actual losses of thermal energy, standard values of losses are used, determined according to the norms of thermal energy losses for heating networks, the thermal insulation of which was carried out according to design standards or (the standards are specified according to the design and as-built documentation).
Before making calculations:
initial data on the heating network is collected;
a design diagram of the heating network is drawn up, which indicates the nominal diameter (nominal diameter), length and type of pipeline installation for all sections of the heating network;
data is collected on the connected load of all network consumers;
the type of metering devices and whether they have hourly and daily archives are established.
In the absence of a centralized collection of data from thermal energy metering devices, the appropriate devices for collection are prepared: an adapter or a laptop computer. The laptop computer must be equipped with a special program supplied with the metering device, which allows you to read hourly and daily archives from installed heat meters.
To increase the accuracy of determining thermal energy losses, it is preferable to collect data from metering devices for a certain time interval during the non-heating period, when the flow of network water is minimal, having previously checked with the heat supply organization about planned shutdowns of heat supply to consumers in order to exclude this time from the period of collecting data from measuring devices .
2. COLLECTION AND PROCESSING OF INITIAL DATA
2.1. COLLECTION OF INITIAL DATA ON THE HEATING NETWORK
Based on the design and as-built documentation for the heating network, a table of characteristics of all sections of the heating network is compiled (Table B.1, Appendix B).
A section of a heating network is considered to be a section of a pipeline that differs from others in one of the following characteristics (which are indicated in Table B.1 of Appendix B):
conditional diameter of the pipeline ( nominal diameter pipeline);
type of installation (overground, underground channel, underground non-channel);
material of the main layer of the thermal insulation structure (thermal insulation);
year of laying.
Also in table. Clause 1 of Appendix B indicates:
name of the starting and ending nodes of the section;
length of the section.
Based on the weather service data, a table of average monthly temperatures of outside air, °C, and soil, °C, at various pipeline depths, averaged over the last five years, is compiled (Table D.1, Appendix D). Average annual temperatures of outside air, °C, and soil, °C, are determined as the arithmetic average of the monthly average values for the entire period of operation of the heating network.
Based on the approved temperature chart For the release of thermal energy at the thermal energy source, the average monthly temperatures of network water in the supply, °C, and return, °C, pipelines are determined (Table D.1, Appendix D). Average monthly temperatures of network water are determined by the average monthly temperature of outside air. The average annual temperatures of network water in the supply, °C, and return, °C, pipelines are determined as the arithmetic average of the monthly average values, taking into account the duration of the network operation by month and year.
Based on data from the heat supply metering service of the heat supply organization, a table is compiled in which for each consumer it is indicated (Table E.1, Appendix E):
name of the thermal energy consumer;
type of heating system (open or closed);
connected average load of hot water supply system;
name (brand) of metering devices;
depth of archives (daily and hourly);
presence or absence of centralized data collection.
If there is a centralized collection of data based on measurement results, a period is selected for which thermal energy losses will be determined. The following must be taken into account:
To increase the accuracy of determining thermal energy losses, it is advisable to choose a period from minimum consumption network water (usually during the non-heating period);
during the selected period there should be no planned disconnections of consumers from the heating network;
measurement data is collected for at least 30 calendar days.
In the absence of centralized data collection, it is necessary to collect hourly and daily archives of metering devices from consumers of thermal energy and at the source of thermal energy within 3-5 days, using an adapter or laptop computer with an installed program for reading data from the corresponding type of heat meter.
To determine thermal energy losses, you must have the following data:
consumption of network water in the supply pipeline for thermal energy consumers;
temperature of network water in the supply pipeline for thermal energy consumers;
consumption of network water in the supply pipeline at the thermal energy source;
supply water temperature and return pipelines on a source of thermal energy;
consumption of make-up water at the thermal energy source.
2.2. PROCESSING INITIAL DATA OF METERING DEVICES
The main task of processing data from metering devices is to convert source files read directly from heat meters into single format, allowing for subsequent verification (reliability check) of the measured values of heat consumption parameters and calculations.
For different types Heat meter data is read in various formats and requires special processing procedures. For one type of heat meters for different consumers, the parameters stored in the archive may require the use of different coefficients to bring the initial data to a single one physical quantities. The difference between these coefficients is determined by the diameter of the flow converter and the characteristics of the pulse inputs of the computer. Therefore, initial processing of measurement results requires individual approach for each source data file.
Daily and hourly values of the coolant parameters are used to verify the measured values. When carrying out this procedure, main attention should be paid to the following:
temperatures and coolant flow rates should not exceed physically justified limits;
should not be in the daily file sudden changes coolant flow;
the average daily temperature of the coolant in the supply pipeline at consumers should not exceed the average daily temperature in the supply pipeline at the heat source;
the change in the average daily temperature of the coolant in the supply pipeline at consumers must correspond to the change in the average daily temperature in the supply pipeline at the heat energy source.
Based on the results of verification of the initial data of metering devices, a table is compiled in which for each consumer of thermal energy who has metering devices and for the source of thermal energy, the period is indicated when the reliability of the initial data is beyond doubt. Based on this table, a general period is selected for which reliable measurement results are available for all consumers and at the heat source (data availability period).
Using the hourly data file obtained at the thermal energy source, the number of hours in the measurement period is determined n and, the data for which will be used for subsequent processing.
Before determining the measurement period, the time of filling all supply pipelines with coolant t p, s is calculated using the formula:
Where V
Average coolant flow rate through the supply pipeline at the thermal energy source for the entire measurement period, kg/s.
The measurement period must satisfy the following conditions: the average temperature of network water in the supply pipeline at the thermal energy source for time t p preceding the start of the measurement period, and the average temperature of network water in the supply pipeline at the thermal energy source for time t p at the end of the measurement period does not differ more than 5 °C;
the measurement period is completely contained in the data availability period;
The measurement period must be continuous and be at least 240 hours.
If such a period cannot be selected due to the lack of data from one or more consumers, then the data from the metering devices of these consumers is not used in further calculations.
The number of remaining consumers who have data from metering devices must be at least 20% of the total number of consumers of this heating network.
If the number of consumers with metering devices has become less than 20%, you must select another period for data collection and repeat the verification procedure.
For the data obtained at the thermal energy source, the average temperature of the network water in the supply pipeline over the measurement period, °C, and the average temperature of the network water in the return pipeline over the measurement period, °C are determined:
Where
n and - the number of hours in the measurement period.
For the measurement period, the average soil temperature at the average depth of the pipeline axis, °C, and the average outside air temperature, °C, are determined.
3. DETERMINATION OF NORMATIVE THERMAL ENERGY LOSSES
3.1. DETERMINATION OF AVERAGE ANNUAL STANDARD LOSSES
THERMAL ENERGY
For each section of the heating network, the average annual standard specific (per 1 meter of pipeline length) values of thermal energy losses are determined according to design standards or, in accordance with which the thermal insulation of heating network pipelines is performed.
Average annual specific heat energy losses are determined at average annual temperatures of network water in the supply and return pipelines and average annual temperatures of outside air or soil.
Values of average annual specific heat energy losses at the difference between average annual temperatures of network water and environment, different from the values given in the standards, are determined linear interpolation or extrapolation.
For sections of underground heating networks with thermal insulation made in accordance with (Table E.1 of Appendix E), the standard specific losses of thermal energy are determined in total for the supply and return pipelines q n, W/m, according to the formula:
(3.1)
where are the specific losses of thermal energy in total along the supply and return pipelines with a table value of the difference in the average annual temperatures of the network water and soil, W/m, that is lower than for a given network;
The table value of the difference between the average annual temperatures of network water and soil, °C, is greater than for a given network.
The difference between the average annual temperatures of network water and soil is determined by the formula:
(3.2)
where , is the average annual temperature of network water in the supply and return pipelines, respectively, °C;
Average annual soil temperature at the average depth of the pipeline axis, °C.
To distribute specific heat energy losses in the underground laying sections between the supply and return pipelines, the average annual standard specific heat energy losses in the return pipeline are determined q but, W/m, which are taken to be equal to the values of standard specific losses in the return pipeline given in Table. E.1 of Appendix E.
q
q np = q n - q But. (3.3)
For sections of underground heating networks with thermal insulation made in accordance with (Table I.1 of Appendix I, Table K.1 of Appendix K, Table N.1 of Appendix H), before determining the standard specific losses of thermal energy, it is necessary to additionally determine difference in average annual temperatures, °C, for each pair of values of average annual temperatures of network water in the supply and return pipelines and soil, given in table. I.1 of Appendix I, table. K.1 of Appendix K and Table. N.1 of Appendix N:
(3.4)
where , - respectively, the tabulated values of the average annual temperatures of network water in the supply (65, 90, 110 °C) and return (50 °C) pipelines, °C;
Standard value of the average annual soil temperature, °C (assumed to be 5°C).
For each pair of average annual temperatures of network water in the supply and return pipelines, the total standard specific heat energy losses, W/m, are determined:
where , respectively, are the values of standard specific heat energy losses for underground installation in the supply and return pipelines, given in Table. I.1 of Appendix I, table. K.1 of Appendix K and Table. N.1 of Appendix N.
The values of the average annual specific heat energy losses for the heating network under consideration when the difference between the average annual temperatures of the network water and the environment differs from the values determined by formula 3.4 are determined by linear interpolation or extrapolation.
Values of total specific thermal energy losses q n, W/m, are determined by formulas 3.1 and 3.2.
Average annual standard specific heat energy losses in the supply pipeline q np, W/m, are determined by the formula:
(3.6)
where , - specific losses of thermal energy through the supply pipeline at two adjacent, respectively smaller and larger than for a given network, tabulated values of the difference between the average annual temperatures of network water and soil, W/m;
Adjacent, respectively smaller and larger than for a given network, tabulated values of the difference in the average annual temperatures of the network water in the supply pipeline and the soil, °C.
The average annual values of the temperature difference between the network water and the soil for the supply pipeline are determined by the formula:
where is the average annual soil temperature at the average depth of the pipeline axis, °C.
Table values of the difference between the average annual temperatures of network water in the supply pipeline and the soil are determined by the formula:
Average annual standard specific heat energy losses in the return pipeline q but, W/m, are determined by the formula:
q but = q n - q np. (3.9)
For all sections of heating networks overhead laying with thermal insulation made in accordance with (Table G.1 of Appendix G, Table L.1 of Appendix L, Table P.1 of Appendix P), the standard specific losses of thermal energy are determined separately for the supply and return pipelines, respectively, q np and q but, W/m, according to the formulas:
(3.10)
(3.11)
where , - specific losses of thermal energy through the supply pipeline at two adjacent, respectively smaller and larger than for a given network, tabulated values of the difference between the average annual temperatures of the network water and the outside air, W/m;
The difference between the average annual temperatures of network water and outside air, respectively, for the supply and return pipelines for a given heating network, °C;
Adjacent, respectively smaller and larger than for a given network, tabulated values of the difference between the average annual temperatures of the network water in the return pipeline and the outside air, °C.
The values of the difference between the average annual temperatures of network water and outside air for the supply and return pipelines are determined by the formulas:
where is the average annual outdoor temperature, °C.
For laying in through and semi-through channels, tunnels, basements specific heat energy losses of sections are determined according to the relevant standards for installations in premises (Table M.1 of Appendix M, Table P.1 of Appendix P) at average annual ambient temperatures: tunnels and passage channels - +40 °C, for basements - + 20 °C.
For each section of the heating network, the standard average annual values of thermal energy losses are determined separately for the supply and return pipelines:
where is the average annual standard heat loss through the supply pipeline, W;
L
b - coefficient of local thermal energy losses, taking into account the loss of thermal energy by fittings, compensators and supports, taken in accordance with equal to 1.2 for underground channel and above-ground installations for nominal diameters of pipelines up to 150 mm and 1.15 for nominal diameters of 150 mm and more , as well as for all conditional passages at channelless installation.
3.2. DETERMINATION OF NORMATIVE THERMAL ENERGY LOSSES
DURING THE MEASUREMENT PERIOD
For each section of the heating network, the standard average losses of thermal energy in the supply, W, and return, W, pipelines over the measurement period are determined.
For underground heating network sections
For sections of the heating network above ground laying standard average thermal energy losses over the measurement period are determined by the formulas:
(3.18)
(3.19)
where , is the average temperature of the network water over the measurement period in the supply and return pipelines at the thermal energy source, °C;
Average annual temperature of network water in the supply and return pipelines, respectively, °C;
Average soil and outside air temperatures over the measurement period, respectively, °C;
Average annual temperature of soil and outside air, respectively, °C.
For sections laid in through and semi-through channels, tunnels, basements standard average thermal energy losses over the measurement period are determined by formulas (3.18) and (3.19) at an average outside air temperature equal to the annual average: for tunnels and passage channels - +40 °C, for basements - +20 °C.
For the entire network, the standard average thermal energy losses in the supply pipeline over the measurement period are determined, W:
The standard averages for the measurement period of thermal energy losses in the supply pipeline are determined for all sections of underground installation, W:
(3.21)
The standard averages for the measurement period of thermal energy losses in the return pipeline are determined for all sections of underground installation, W:
(3.22)
The standard averages for the measurement period of thermal energy losses in the supply pipeline are determined for all sections of above-ground installation, W:
(3.23)
The standard averages for the measurement period of thermal energy losses in the return pipeline are determined for all sections of the above-ground installation, W:
(3.24)
The standard averages for the measurement period of thermal energy losses in the supply pipeline are determined for all sections located in through and semi-through channels, tunnels, W:
(3.25)
The standard averages for the measurement period of thermal energy losses in the return pipeline are determined for all sections located in through and semi-through channels, tunnels, W:
(3.26)
The standard averages for the measurement period of thermal energy losses in the supply pipeline are determined for all sections located in basements, W:
(3.27)
The standard averages for the measurement period of thermal energy losses in the return pipeline are determined for all sections located in basements, W:
(3.28)
4. DETERMINATION OF ACTUAL THERMAL ENERGY LOSSES
4.1. DETERMINATION OF ACTUAL THERMAL ENERGY LOSSES
DURING THE MEASUREMENT PERIOD
At the source of thermal energy and for all consumers of thermal energy with metering devices ( i-th consumers of thermal energy), the average coolant flow rate in the supply pipeline over the entire measurement period is determined:
where is the average coolant flow rate through the supply pipeline at the thermal energy source over the entire measurement period, kg/s;
Measured values of coolant flow rate at the thermal energy source during the measurement period, taken from the hourly file, t/h;
i-th consumer of thermal energy, kg/s;
The values of coolant flow measured during the measurement period i th consumer of thermal energy, taken from the hourly file, t/h.
For a closed heating system The average flow rate of make-up water at the thermal energy source over the entire measurement period is determined:
(4.3)
where is the average flow rate of make-up water at the thermal energy source over the entire measurement period, kg/s;
Values of coolant consumption for make-up at the thermal energy source measured over the measurement period, taken from the hourly file, t/h.
Average coolant flow rate in the supply pipeline for the entire measurement period, kg/s, for all thermal energy consumers who do not have metering devices ( j-th consumers of thermal energy), for closed systems heat supply is determined by the formula:
For open systems heat supply, which do not have round-the-clock coolant consumers, the average consumption of make-up water at the thermal energy source at night is determined over the entire measurement period.
To do this, for each day from the measurement period, the nightly (from 1:00 to 3:00) average hourly recharge consumption at the thermal energy source is selected. For the data obtained, the arithmetic mean value of the flow rate is determined, which is the average hourly recharge of the heating network at night, t/h. To determine the value, kg/s, the formula is used:
(4.5)
For open heat supply systems that have industrial consumers that consume coolant around the clock and have metering devices, the average hourly coolant consumption at night is determined. To do this, for each day from the measurement period, the nightly (from 1:00 to 3:00) average hourly coolant flow rate for each such consumer is selected. For the data obtained, the arithmetic mean value of the flow rate is determined, t/h. To determine the value, kg/s, the formula is used:
(4.6)
Average coolant flow rate in the supply pipeline for the entire measurement period for all j th consumers are determined by formula 4.4.
Average coolant flow rate in the supply pipeline for the entire measurement period for each j th consumer, kg/s, is determined by distributing the total coolant flow among consumers in proportion to the average hourly connected load:
(4.7)
where is the average hourly connected load during the measurement period j-th consumer, GJ/h;
j-th consumers without metering devices during the measurement period, GJ/h.
For each i of the th consumer, the average thermal energy loss over the measurement period through the thermal insulation of the supply pipeline is determined, W:
(4.8)
Where with p - specific heat water, with p= 4.187×10 3 J/(kg×K);
Measured values of the network water temperature in the supply pipeline at the thermal energy source, taken from the hourly file, °C;
i th consumer, taken from the hourly file, °C.
The average total losses of thermal energy in the supply pipelines over the measurement period are determined for all i th consumers with metering devices, , W:
(4.9)
The average thermal energy loss over the measurement period, W, through the thermal insulation of the supply pipeline, related to i-th consumer, minus thermal energy losses in the branch from the main pipeline:
(4.10)
As a first approximation, thermal energy losses in a branch from the main pipeline are assumed to be equal to the standard average thermal energy losses over the measurement period:
(4.11)
where are the standard average losses of thermal energy over the measurement period in the branch from the main supply pipeline to i th consumer, W.
Total losses of thermal energy, W, in the main supply pipelines for all i-th consumers with metering devices:
Network thermal energy loss coefficient r losses p, J/(kg×m), in the main supply pipelines are determined based on measurement data for consumers with metering devices:
(4.13)
Where l i- the shortest distance from the source of thermal energy to the branch from the main pipeline to the consumer with metering devices, m.
When determining the average thermal energy losses over the measurement period, W, y j-th consumers without metering devices the following ratio is used:
Where l j j-th consumer without metering devices, m.
The average total losses of thermal energy, W, in the supply pipelines for j-th consumers who do not have metering devices:
(4.15)
Actual average for the measurement period total losses of thermal energy, W, in all supply pipelines:
After determining the actual losses of thermal energy in the supply pipeline for all consumers, the ratio of these losses of thermal energy to the standard losses of thermal energy in the supply pipeline is determined:
and the entire calculation is carried out again (second approximation), starting with formula 4.10, and losses in branches from the main pipelines are determined by the formula:
(4.18)
After determining the value of the actual losses of thermal energy in the supply pipeline for all consumers in the second approximation, its value is compared with the value of the actual losses of thermal energy in the supply pipeline for all consumers, obtained in the first approximation, and the relative difference is determined:
(4.19)
If the value is > 0.05, then another approximation is carried out to determine the value, i.e. the entire calculation, starting with formula 4.10, is repeated.
Usually two or three approximations are sufficient to obtain a satisfactory result. The value of heat losses obtained from formula 4.16 in the last approximation is used in further calculations.
Another method for taking into account the influence of branches is possible. Having performed calculations using formulas 4.1 - 4.9, the time of movement of the coolant t, s, from the source of thermal energy to each of the consumers is determined:
(4.21)
where tk is the time of movement of the coolant in a homogeneous section of the heating network, s;
l k
Wk
r is the density of water at the average temperature of the network water in the supply pipeline at the thermal energy source for the first day of the data availability period, kg/m 3 ;
F k- cross-sectional area of the pipeline in a homogeneous area, m2;
Gk- coolant flow in a homogeneous area, kg/s.
A homogeneous section of a heating network is a section where the coolant flow rate and the nominal diameter of the pipeline do not change, i.e. a constant coolant speed is ensured.
Thermal energy loss coefficient, determined by the time of movement of the coolant in the supply pipelines, J/(kg×s):
(4.22)
where t i i-th consumer with metering devices, p.
Average thermal energy losses over the measurement period through thermal insulation in the supply pipeline, W, referred to j-th consumer without metering devices:
(4.23)
where t j j-th consumer without metering devices, p.
Having determined using formula 4.15, we calculate using formula 4.16. The value of thermal energy losses obtained from formula 4.16 is used in further calculations.
The average actual losses of thermal energy in the supply pipelines for all sections of underground installation, W, over the measurement period are determined:
(4.24)
The average actual losses of thermal energy in the supply pipelines for all sections of overhead installation, W, over the measurement period are determined:
(4.25)
The average actual losses of thermal energy in the supply pipelines for all sections located in through and semi-through channels, tunnels, , W are determined over the measurement period:
(4.26)
The average actual losses of thermal energy in the supply pipelines for all sections located in the basements, , W, over the measurement period are determined:
(4.27)
The average actual losses of thermal energy in the return pipelines for all sections of underground installation, W, are determined over the measurement period:
(4.28)
The average actual losses of thermal energy in the return pipelines for all sections of overhead installation, W, over the measurement period are determined:
(4.29)
The average actual losses of thermal energy in the return pipelines for all sections located in through and semi-through channels, tunnels, , W are determined over the measurement period:
(4.30)
The average actual losses of thermal energy in the return pipelines for all sections located in the basements, , W, over the measurement period are determined:
(4.31)
The actual total losses of thermal energy in the return pipelines, averaged over the measurement period, are determined:
The actual total losses of thermal energy, W, in the network, averaged over the measurement period, are determined:
4.2. DETERMINATION OF ACTUAL THERMAL ENERGY LOSSES FOR THE YEAR
Actual thermal energy losses for the year are determined as the sum of actual thermal energy losses for each month of operation of the heating network.
Actual losses of thermal energy per month are determined under average monthly operating conditions of the heating network.
For all underground installation sites the actual average monthly losses of thermal energy are determined in total along the supply and return pipelines, W, according to the formula:
For all overhead installation areas The actual average monthly losses of thermal energy are determined separately for the supply, W, and return, W, pipelines using the formulas:
(4.35)
(4.36)
For all areas located in through and semi-through channels and tunnels
(4.37)
(4.38)
For all areas located in basements, the actual average monthly losses of thermal energy are determined separately for the supply, W, and return, W, pipelines using the formulas:
(4.39)
(4.40)
Actual losses of thermal energy in the entire network per month, GJ, are determined by the formula:
Where n months - duration of operation of the heating network in the month under consideration, hours.
Actual losses of thermal energy in the entire network per year, GJ, are determined by the formula:
(4.42)
APPENDIX A
Terms and Definitions
Water heating system- a heat supply system in which the coolant is water.
Closed water system heat supply- a water heat supply system that does not provide for the use of network water by consumers by taking it from the heating network.
Individual heating point- a heating point designed to connect heat consumption systems of one building or part of it.
As-built documentation - a set of working drawings developed by the design organization, with inscriptions on the compliance of the work performed in kind with these drawings or changes made to them by the persons responsible for the work.
Source of thermal energy (heat)- a heat-generating power plant or a combination of them, in which the coolant is heated by transferring the heat of burned fuel, as well as by electric heating or other, including non-traditional methods, participating in the heat supply to consumers.
Commercial metering (metering) of thermal energy- determination, based on measurements and other regulated procedures, of thermal power and the amount of thermal energy and coolant for the purpose of carrying out commercial settlements between energy supply organizations and consumers.
Boiler room- a complex of technologically connected thermal power plants located in separate industrial buildings, built-in, attached or superstructured premises with boilers, water heaters (including installations unconventional way obtaining thermal energy) and boiler and auxiliary equipment designed to generate heat.
Thermal energy loss rate (the rate of heat flux density through an insulated surface)- the value of specific losses of thermal energy by pipelines of the heating network through their thermal insulation structures at the calculated average annual temperatures of the coolant and the environment.
Open water heating system- a water heating system in which all or part of the network water is used by taking it from the heating network to meet the needs of consumers for hot water.
Heating season - time in hours or days per year during which thermal energy is supplied for heating.
Make-up water- specially prepared water supplied to the heating network to replenish coolant losses (network water), as well as water withdrawal for heat consumption.
Thermal energy losses- thermal energy lost by the coolant through the insulation of pipelines, as well as thermal energy lost with the coolant during leaks, accidents, drains, and unauthorized water withdrawals.
Thermal energy consumer- legal or individual, which uses thermal energy (power) and coolants.
- the total design maximum heat load (power) of all heat consumption systems at the calculated outside air temperature for each type of load, or the total design maximum hourly coolant flow rate for all heat consumption systems connected to the heat networks (heat energy source) of the heat supply organization.Network water- specially prepared water, which is used in the water heating system as a coolant.
Heat consumption system- a complex of thermal power plants with connecting pipelines and (or) heating networks that are designed to satisfy one or more types of heat load.
Heating system- a set of interconnected heat sources, heat networks and heat consumption systems.
District heating system- united by common technological process sources of thermal energy, heating networks and consumers of thermal energy.
Thermal load of the heating system (thermal load)- the total amount of thermal energy received from thermal energy sources, equal to the sum of the heat consumption of thermal energy receivers and losses in heating networks per unit time.
Heat network- a set of devices designed for the transfer and distribution of coolant and thermal energy.
Heating point- a set of devices located in a separate room, consisting of elements of thermal power plants that ensure the connection of these plants to the heating network, their operability, control of heat consumption modes, transformation, regulation of coolant parameters.
Thermal power plant coolant, coolant- a moving medium used to transfer thermal energy in a thermal power plant from a more heated body to a less heated body.
Heat consuming installation- a thermal power plant or a set of devices designed to use heat and coolant for heating, ventilation, air conditioning, hot water supply and technological needs.
Heat supply- providing consumers with thermal energy (heat).
Combined heat and power plant (CHP)- a steam turbine power plant designed to produce electrical and thermal energy.
Knot commercial accounting thermal energy and (or) coolants- a set of duly certified measuring instruments and systems and other devices intended for commercial accounting of the amount of thermal energy and (or) coolants, as well as to ensure quality control of thermal energy and heat consumption modes.
District heating- heat supply to consumers from a thermal energy source through a common heating network.
Central heating point (CHP)- a heating point designed to connect two or more buildings.
Operational documentation- documents intended for use during operation, maintenance and repair during operation.
Energy supply (heat supply) organization- an enterprise or organization that is legal entity and having ownership or full economic management installations that generate electrical and (or) thermal energy, electrical and (or) thermal networks and ensure the transfer of electrical and (or) thermal energy to consumers on a contractual basis.
APPENDIX B
Symbols of quantities
Actual thermal energy losses in the entire network per year, GJ;
Actual losses of thermal energy in the entire network per month, GJ;
Actual average monthly losses of thermal energy in total through the supply and return pipelines for all sections of underground installation, W;
Actual average monthly losses of thermal energy separately through the supply pipeline for all sections of above-ground installation, W;
Actual average monthly losses of thermal energy separately through the return pipeline for all sections of above-ground installation, W;
Actual average monthly losses of thermal energy separately through the supply pipeline for all sections located in through and semi-through channels, tunnels, W;
Actual average monthly losses of thermal energy separately through the return pipeline for all sections located in through and semi-through channels, tunnels, W;
Actual average monthly losses of thermal energy separately through the supply pipeline for all areas located in the basements, W;
Actual average monthly losses of thermal energy separately through the return pipeline for all areas located in the basements, W;
The actual total losses of thermal energy in the network are average for the measurement period, W;
The actual losses of thermal energy in the supply pipelines for all sections of underground installation are average for the measurement period, W;
The actual losses of thermal energy in the supply pipelines for all sections of above-ground installation are average for the measurement period, W;
Actual losses of thermal energy in supply pipelines for all sections located in through and semi-through channels, tunnels, average for the measurement period, W;
Actual losses of thermal energy in supply pipelines for all sections located in basements are average for the measurement period, W;
Actual losses of thermal energy in return pipelines for all sections of underground installation are average for the measurement period, W;
Actual losses of thermal energy in return pipelines for all sections of above-ground installation are average for the measurement period, W;
Actual losses of thermal energy in return pipelines for all sections located in through and semi-through channels, tunnels are average for the measurement period, W;
Actual losses of thermal energy in return pipelines for all sections located in basements are average for the measurement period, W;
The actual total losses of thermal energy in all supply pipelines are average for the measurement period, W;
The actual total losses of thermal energy in all return pipelines are average for the measurement period, W;
Total losses of thermal energy in supply pipelines for j th consumers who do not have metering devices, average for the measurement period, W;
Thermal energy losses j th consumers without metering devices average for the measurement period, W;
Total losses of thermal energy in supply pipelines for all i th consumers having metering devices, average for the measurement period, W;
Thermal energy losses through the thermal insulation of the supply pipeline for each i-th consumer with metering devices average for the measurement period, W;
Average hourly connected load during the measurement period j-th consumer, GJ/h;
Average hourly connected load of all j th consumers without metering devices during the measurement period, GJ/h;
Average thermal energy losses over the measurement period through the thermal insulation of the supply pipeline, referred to i-th consumer, minus thermal energy losses in the branch from the main pipeline, W;
Thermal energy losses in a branch from the main pipeline, W;
Standard average for the measurement period of thermal energy losses in the branch from the main supply pipeline to i-th consumer, W;
Total losses of thermal energy in the main supply pipelines for all i th consumers with metering devices, W;
Standard losses of thermal energy in the supply pipeline are average for the measurement period, W;
Standard losses of thermal energy in the return pipeline are average for the measurement period, W;
Standard average for the measurement period of thermal energy losses in the supply pipeline for the entire network, W;
Standard average for the measurement period of thermal energy losses in the supply pipeline for all sections of underground installation, W;
Standard average for the measurement period of thermal energy losses in the return pipeline for all sections of underground installation, W;
Standard average for the measurement period of thermal energy losses in the supply pipeline for all sections of above-ground installation, W;
Standard average for the measurement period of thermal energy losses in the return pipeline for all sections of above-ground installation, W;
Standard average for the measurement period of thermal energy losses in the supply pipeline for all sections located in through and semi-through channels, tunnels, W;
Standard average for the measurement period of thermal energy losses in the return pipeline for all sections located in through and semi-through channels, tunnels, W;
Standard average for the measurement period of thermal energy losses in the supply pipeline for all areas located in basements, W;
Standard average for the measurement period of thermal energy losses in the return pipeline for all sections located in basements, W;
Average annual standard losses of thermal energy through the supply pipeline, W;
Average annual standard losses of thermal energy through the return pipeline, W;
Relative difference comparing the value of actual losses of thermal energy in the supply pipeline for all consumers in the second approximation with the value of actual losses of thermal energy in the supply pipeline for all consumers, obtained in the first approximation;
q n - standard specific losses of thermal energy in total along the supply and return pipelines for sections of underground heating networks, W/m;
Specific losses of thermal energy in total along the supply and return pipelines with a table value of the difference between the average annual temperatures of network water and soil, W/m, that is lower than for a given network;
Specific losses of thermal energy in total along the supply and return pipelines with a table value of the difference between the average annual temperatures of network water and soil greater than for a given network, W/m;
q but - average annual standard specific heat energy losses in the return pipeline, W/m;
q np - average annual standard specific losses of thermal energy in the supply pipeline, W/m;
Total standard specific heat energy losses for underground installation, W/m;
Accordingly, the tabulated values of the standard specific heat energy losses for underground installation in the supply and return pipelines, W/m;
Specific losses of thermal energy through the supply pipeline with two adjacent, respectively smaller and larger than for a given network, tabulated values of the difference in the average annual temperatures of network water and soil, W/m;
Specific heat energy losses through the supply pipeline with two adjacent, respectively smaller and larger than for a given network, tabulated values of the difference between the average annual temperatures of the network water and the outside air, W/m;
Specific losses of thermal energy through the return pipeline with two adjacent, respectively smaller and larger than for a given network, tabulated values of the difference between the average annual temperatures of the network water and the outside air, W/m;
Average coolant flow rate through the supply pipeline at the thermal energy source for the entire measurement period, kg/s;
Measured values of coolant flow rate at the thermal energy source, taken from the hourly file, t/h;
The average coolant flow rate through the supply pipeline for the entire measurement period is i-th consumer of thermal energy with metering devices, kg/s;
Measured values of coolant flow rate i-th consumer of thermal energy, taken from the hourly file, t/h;
Average consumption of make-up water at the thermal energy source for the entire measurement period, kg/s;
Measured values of coolant flow rate for make-up at the thermal energy source, taken from the hourly file, t/h;
Average coolant flow rate in the supply pipeline for the entire measurement period for all thermal energy consumers who do not have metering devices, kg/s;
Average hourly recharge of the heating network at night, t/h;
Average hourly coolant consumption for each i-th consumer who has metering devices at night for each day of the measurement period, t/h;
Average coolant flow rate in the supply pipeline for the entire measurement period for each j-th consumer who does not have metering devices, kg/s;
Gk- coolant flow in a homogeneous area, kg/s;
Average monthly outdoor temperature, °C;
Average monthly soil temperature at the average depth of the pipeline axis, °C;
Average annual outdoor temperature, °C;
Average annual soil temperature at the average depth of the pipeline axis, °C;
Average monthly temperature of network water in the supply pipeline, °C;
Average monthly temperature of network water in the return pipeline, °C;
Average annual temperature of network water in the supply pipeline, °C;
Average annual temperature of network water in the return pipeline, °C;
Average temperature of network water in the supply pipeline at the heat source over the measurement period, °C;
The average temperature of the network water in the return pipeline at the thermal energy source over the measurement period, °C;
Measured values of the network water temperature in the supply pipeline at the thermal energy source, taken from the hourly file, °C;
Measured values of the network water temperature in the return pipeline at the thermal energy source, taken from the hourly file, °C;
Average soil temperature at the average depth of the pipeline axis during the measurement period, °C;
Average outside air temperature for the measurement period, °C;
Accordingly, the tabulated values of the average annual temperatures of network water in the supply (65, 90, 110 °C) and return (50 °C) pipelines, °C;
Standard value of average annual soil temperature, °C;
Measured values of the temperature of the network water in the supply pipeline at i-th consumer, taken from the hourly file, °C;
The difference between the average annual temperatures of network water and soil for a given heating network, °C;
The table value of the difference between the average annual temperatures of network water and soil, °C, is lower than for this network;
The table value of the difference between the average annual temperatures of network water and soil, °C, is greater than for a given network;
The difference in average annual temperatures for each pair of values of average annual temperatures in the supply and return pipelines and soil, °C;
The difference between the average annual temperatures of network water and soil for the supply pipeline of the heating network under consideration, °C;
Adjacent, respectively smaller and larger than for a given network, tabulated values of the difference in the average annual temperatures of the network water in the supply pipeline and the soil, °C;
The difference between the average annual temperatures of network water and outside air, respectively, for the supply and return pipelines for a given heating network, °C;
Adjacent, respectively smaller and larger than for a given network, tabulated values of the difference between the average annual temperatures of the network water in the supply pipeline and the outside air, °C;
Adjacent, respectively smaller and larger than for a given network, tabulated values of the difference between the average annual temperatures of the network water in the return pipeline and the outside air, °C;
V n is the total volume of all supply pipelines of the heating network, m 3 ;
L- length of the heating network section, m;
l i- the shortest distance from the source of thermal energy to the branch from the main pipeline to i-th consumer with metering devices, m;
l j- the shortest distance from the source of thermal energy to the branch to j-th consumer without metering devices, m (page 18);
l k- length of a homogeneous section, m;
r is the density of water at the average temperature of the network water in the supply pipeline at the thermal energy source for the first day of the data availability period, kg/m 3 ;
c p- specific heat capacity of water, J/(kg×K);
Wk- coolant speed in a homogeneous area, m/s;
F k- pipeline passage area in a homogeneous area, m2;
b - coefficient of local thermal energy losses, taking into account the loss of thermal energy by fittings, compensators and supports;
r losses n - coefficient of losses of thermal energy of the network in the main supply pipelines, J/(kg × m);
Thermal energy loss coefficient, determined by the time of movement of the coolant in the supply pipelines, J/(kg × s);
n and - number of hours in the measurement period;
n months - duration of operation of the heating network in the month under consideration, hours;
t p - time of filling all supply pipelines with coolant, s;
t is the time of movement of the coolant from the source of thermal energy to each of the consumers, s;
tk is the time of movement of the coolant in a homogeneous section of the heating network, s;
t i- time of movement of the coolant through the supply pipeline from the source of thermal energy to i-th consumer with metering devices, s;
t j- time of movement of the coolant along the shortest distance from the source of thermal energy to j-th consumer without metering devices, s;
K- the ratio of the actual losses of thermal energy in the supply pipeline for all consumers to the standard losses of thermal energy in the supply pipeline.
APPENDIX B
Characteristics of heating network sections
Table B.1
APPENDIX D
Average monthly and average annual ambient and network water temperatures
Table D.1
Months | Average temperature for 5 years, °C | Network water temperature, °C | ||
soil | outside air | in the supply line | in the return pipeline | |
January | ||||
February | ||||
March | ||||
April | ||||
May | ||||
June | ||||
July | ||||
August | ||||
September | ||||
October | ||||
November | ||||
December | ||||
Average annual temperature, °C |
APPENDIX D
Characteristics of thermal energy consumers and metering devices
Table E.1
Consumer name | Type of heating system (open, closed) | Meter brand | Archive depth | Availability of centralized data collection (yes, no) | |||||
heating | ventilation | DHW | Total | daily | hourly | ||||
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
APPENDIX E
Norms of thermal energy loss by insulated water heat pipes located in non-passing channels and during channelless installation (with a design soil temperature of +5 °C at the depth of the heat pipes) according to
Table E.1
Outer diameter of pipes, mm | ||||
Return heat pipe at average water temperature ( t o =50 °C) | Two-pipe installation with a difference in average annual temperatures of water and soil of 52.5 ° C ( t n =65°C) | Two-pipe laying with a difference in average annual temperatures of water and soil of 65 ° C ( t p =90°C) | Two-pipe installation with a difference in average annual temperatures of water and soil of 75 ° C ( t p =110°C) | |
32 | 23 | 52 | 60 | 67 |
57 | 29 | 65 | 75 | 84 |
76 | 34 | 75 | 86 | 95 |
89 | 36 | 80 | 93 | 102 |
108 | 40 | 88 | 102 | 111 |
159 | 49 | 109 | 124 | 136 |
219 | 59 | 131 | 151 | 165 |
273 | 70 | 154 | 174 | 190 |
325 | 79 | 173 | 195 | 212 |
377 | 88 | 191 | 212 | 234 |
426 | 95 | 209 | 235 | 254 |
478 | 106 | 230 | 259 | 280 |
529 | 117 | 251 | 282 | 303 |
630 | 133 | 286 | 321 | 345 |
720 | 145 | 316 | 355 | 379 |
820 | 164 | 354 | 396 | 423 |
920 | 180 | 387 | 433 | 463 |
1020 | 198 | 426 | 475 | 506 |
1220 | 233 | 499 | 561 | 591 |
1420 | 265 | 568 | 644 | 675 |
APPENDIX G
Norms of thermal energy loss by one isolated water
heat pipe for above-ground installation
(with an estimated average annual outdoor temperature of +5 °C) according to
Table G.1
Outer diameter of pipes, mm | Norms of thermal energy loss, W/m | |||
Difference between the average annual temperature of the network water in the supply or return pipelines and the outside air, °C | ||||
45 | 70 | 95 | 120 | |
32 | 17 | 27 | 36 | 44 |
49 | 21 | 31 | 42 | 52 |
57 | 24 | 35 | 46 | 57 |
76 | 29 | 41 | 52 | 64 |
89 | 32 | 44 | 58 | 70 |
108 | 36 | 50 | 64 | 78 |
133 | 41 | 56 | 70 | 86 |
159 | 44 | 58 | 75 | 93 |
194 | 49 | 67 | 85 | 102 |
219 | 53 | 70 | 90 | 110 |
273 | 61 | 81 | 101 | 124 |
325 | 70 | 93 | 116 | 139 |
377 | 82 | 108 | 132 | 157 |
426 | 95 | 122 | 148 | 174 |
478 | 103 | 131 | 158 | 186 |
529 | 110 | 139 | 168 | 197 |
630 | 121 | 154 | 186 | 220 |
720 | 133 | 168 | 204 | 239 |
820 | 157 | 195 | 232 | 270 |
920 | 180 | 220 | 261 | 302 |
1020 | 209 | 255 | 296 | 339 |
1420 | 267 | 325 | 377 | 441 |
APPENDIX AND
Norms of heat flux density through the insulated surface of pipelines of two-pipe water heating networks when laid in non-passing channels, W/m, according to
Table I.1
Pipeline | ||||||
server | back | server | back | server | back | |
65 | 50 | 90 | 50 | 110 | 50 | |
25 | 16 | 11 | 23 | 10 | 28 | 9 |
30 | 17 | 12 | 24 | 11 | 30 | 10 |
40 | 18 | 13 | 26 | 12 | 32 | 11 |
50 | 20 | 14 | 28 | 13 | 35 | 12 |
65 | 23 | 16 | 34 | 15 | 40 | 13 |
80 | 25 | 17 | 36 | 16 | 44 | 14 |
100 | 28 | 19 | 41 | 17 | 48 | 15 |
125 | 31 | 21 | 42 | 18 | 50 | 16 |
150 | 32 | 22 | 44 | 19 | 55 | 17 |
200 | 39 | 27 | 54 | 22 | 68 | 21 |
250 | 45 | 30 | 64 | 25 | 77 | 23 |
300 | 50 | 33 | 70 | 28 | 84 | 25 |
350 | 55 | 37 | 75 | 30 | 94 | 26 |
400 | 58 | 38 | 82 | 33 | 101 | 28 |
450 | 67 | 43 | 93 | 36 | 107 | 29 |
500 | 68 | 44 | 98 | 38 | 117 | 32 |
600 | 79 | 50 | 109 | 41 | 132 | 34 |
700 | 89 | 55 | 126 | 43 | 151 | 37 |
800 | 100 | 60 | 140 | 45 | 163 | 40 |
900 | 106 | 66 | 151 | 54 | 186 | 43 |
1000 | 117 | 71 | 158 | 57 | 192 | 47 |
1200 | 144 | 79 | 185 | 64 | 229 | 52 |
1400 | 152 | 82 | 210 | 68 | 252 | 56 |
APPENDIX K
Norms of heat flux density through the insulated surface of pipelines for two-pipe underground ductless installation of water heating networks, W/m, according to
Table K.1
Conditional diameter of the pipeline, mm | With more than 5,000 operating hours per year | |||
Pipeline | ||||
server | back | server | back | |
Average annual coolant temperature, °C | ||||
65 | 50 | 90 | 50 | |
25 | 33 | 25 | 44 | 24 |
50 | 40 | 31 | 54 | 29 |
65 | 45 | 34 | 60 | 33 |
80 | 46 | 35 | 61 | 34 |
100 | 49 | 38 | 65 | 35 |
125 | 53 | 41 | 72 | 39 |
150 | 60 | 46 | 80 | 43 |
200 | 66 | 50 | 89 | 48 |
250 | 72 | 55 | 96 | 51 |
300 | 79 | 59 | 105 | 56 |
350 | 86 | 65 | 113 | 60 |
400 | 91 | 68 | 121 | 63 |
450 | 97 | 72 | 129 | 67 |
500 | 105 | 78 | 138 | 72 |
600 | 117 | 87 | 156 | 80 |
700 | 126 | 93 | 170 | 86 |
800 | 140 | 102 | 186 | 93 |
Coefficient taking into account changes in heat flux density standards when using a thermal insulation layer made of polyurethane foam, polymer concrete, FL phenolic foam
Table K.2
APPENDIX L
Norms of heat flux density through the insulated surface of pipelines of water heating networks when located on outdoors, W/m, by
Table L.1
Conditional diameter of the pipeline, mm | With more than 5,000 operating hours per year | ||
Average annual coolant temperature, °C | |||
50 | 100 | 150 | |
15 | 10 | 20 | 30 |
20 | 11 | 22 | 34 |
25 | 13 | 25 | 37 |
40 | 15 | 29 | 44 |
50 | 17 | 31 | 47 |
65 | 19 | 36 | 54 |
80 | 21 | 39 | 58 |
100 | 24 | 43 | 64 |
125 | 27 | 49 | 70 |
150 | 30 | 54 | 77 |
200 | 37 | 65 | 93 |
250 | 43 | 75 | 106 |
300 | 49 | 84 | 118 |
350 | 55 | 93 | 131 |
400 | 61 | 102 | 142 |
450 | 65 | 109 | 152 |
500 | 71 | 119 | 166 |
600 | 82 | 136 | 188 |
700 | 92 | 151 | 209 |
800 | 103 | 167 | 213 |
900 | 113 | 184 | 253 |
1000 | 124 | 201 | 275 |
35 | 54 | 70 |
APPENDIX M
Norms of heat flux density through the insulated surface of pipelines of water heating networks when located in a room or tunnel, W/m, according to
Table M.1
Conditional diameter of the pipeline, mm | With more than 5,000 operating hours per year | ||
Average annual coolant temperature, °C | |||
50 | 100 | 150 | |
15 | 8 | 18 | 28 |
20 | 9 | 20 | 32 |
25 | 10 | 22 | 35 |
40 | 12 | 26 | 41 |
50 | 13 | 28 | 44 |
65 | 15 | 32 | 50 |
80 | 16 | 35 | 54 |
100 | 18 | 39 | 60 |
125 | 21 | 44 | 66 |
150 | 24 | 49 | 73 |
200 | 29 | 59 | 88 |
250 | 34 | 68 | 100 |
300 | 39 | 77 | 112 |
350 | 44 | 85 | 124 |
400 | 48 | 93 | 135 |
450 | 52 | 101 | 145 |
500 | 57 | 109 | 156 |
600 | 67 | 125 | 176 |
700 | 74 | 139 | 199 |
800 | 84 | 155 | 220 |
900 | 93 | 170 | 241 |
1000 | 102 | 186 | 262 |
Curved surfaces with an external nominal bore of more than 1020 mm and flat | Norms of surface heat flux density, W/m 2 | ||
29 | 50 | 68 |
APPENDIX H
Norms of heat flux density through the insulated surface of pipelines of two-pipe water heating networks when laid in non-passing channels and underground channelless installation, W/m, according to
Table H.1
Conditional diameter of the pipeline, mm | With more than 5,000 operating hours per year | |||||
Pipeline | ||||||
server | back | server | back | server | back | |
Average annual coolant temperature, °C | ||||||
65 | 50 | 90 | 50 | 110 | 50 | |
25 | 14 | 9 | 20 | 9 | 24 | 8 |
30 | 15 | 10 | 20 | 10 | 26 | 9 |
40 | 16 | 11 | 22 | 11 | 27 | 10 |
50 | 17 | 12 | 24 | 12 | 30 | 11 |
65 | 20 | 13 | 29 | 13 | 34 | 12 |
80 | 21 | 14 | 31 | 14 | 37 | 13 |
100 | 24 | 16 | 35 | 15 | 41 | 14 |
125 | 26 | 18 | 38 | 16 | 43 | 15 |
150 | 27 | 19 | 42 | 17 | 47 | 16 |
200 | 33 | 23 | 49 | 19 | 58 | 18 |
250 | 38 | 26 | 54 | 21 | 66 | 20 |
300 | 43 | 28 | 60 | 24 | 71 | 21 |
350 | 46 | 31 | 64 | 26 | 80 | 22 |
400 | 50 | 33 | 70 | 28 | 86 | 24 |
450 | 54 | 36 | 79 | 31 | 91 | 25 |
500 | 58 | 37 | 84 | 32 | 100 | 27 |
600 | 67 | 42 | 93 | 35 | 112 | 31 |
700 | 76 | 47 | 107 | 37 | 128 | 31 |
800 | 85 | 51 | 119 | 38 | 139 | 34 |
900 | 90 | 56 | 128 | 43 | 150 | 37 |
1000 | 100 | 60 | 140 | 46 | 163 | 40 |
1200 | 114 | 67 | 158 | 53 | 190 | 44 |
1400 | 130 | 70 | 179 | 58 | 224 | 48 |
APPENDIX P
Norms of heat flux density through the insulated surface of pipelines of water heating networks when located outdoors
Table A.1
Conditional diameter of the pipeline, mm | With more than 5,000 operating hours per year | ||
Average annual coolant temperature, °C | |||
50 | 100 | 150 | |
25 | 11 | 20 | 30 |
40 | 12 | 24 | 36 |
50 | 14 | 25 | 38 |
65 | 15 | 29 | 44 |
80 | 17 | 32 | 47 |
100 | 19 | 35 | 52 |
125 | 22 | 40 | 57 |
150 | 24 | 44 | 62 |
200 | 30 | 53 | 75 |
250 | 35 | 61 | 86 |
300 | 40 | 68 | 96 |
350 | 45 | 75 | 106 |
400 | 49 | 83 | 115 |
450 | 53 | 88 | 123 |
500 | 58 | 96 | 135 |
600 | 66 | 110 | 152 |
700 | 75 | 122 | 169 |
800 | 83 | 135 | 172 |
900 | 92 | 149 | 205 |
1000 | 101 | 163 | 223 |
Curved surfaces with an external nominal bore of more than 1020 mm and flat | Norms of surface heat flux density, W/m 2 | ||
28 | 44 | 57 |
APPENDIX P
Norms of heat flux density through the insulated surface of pipelines of water heating networks when located indoors and in tunnels according to
Table R.1
Conditional diameter of the pipeline, mm | With more than 5,000 operating hours per year | ||
Average annual coolant temperature, °C | |||
50 | 100 | 150 | |
Norms of linear heat flux density, W/m | |||
25 | 8 | 18 | 28 |
40 | 10 | 21 | 33 |
50 | 10 | 22 | 35 |
65 | 12 | 26 | 40 |
80 | 13 | 28 | 43 |
100 | 14 | 31 | 48 |
125 | 17 | 35 | 53 |
150 | 19 | 39 | 58 |
200 | 23 | 47 | 70 |
250 | 27 | 54 | 80 |
300 | 31 | 62 | 90 |
350 | 35 | 68 | 99 |
400 | 38 | 74 | 108 |
450 | 42 | 81 | 116 |
500 | 46 | 87 | 125 |
600 | 54 | 100 | 143 |
700 | 59 | 111 | 159 |
800 | 67 | 124 | 176 |
900 | 74 | 136 | 193 |
1000 | 82 | 149 | 210 |
Curved surfaces with an external nominal bore of more than 1020 mm and flat | Norms of surface heat flux density, W/m 2 | ||
23 | 40 | 54 |
Note. When placing isolated surfaces in a tunnel (through and semi-through channels), a coefficient of 0.85 should be added to the density standards.
APPENDIX C
List of normative and technical documents to which there are links
1. Determination of actual heat losses through thermal insulation in centralized heating networks / Semenov V. G. - M.: Heat supply news, 2003 (No. 4).
2. Standards for the design of thermal insulation for pipelines and equipment of power plants and heating networks. - M.: Gosstroyizdat, 1959.
3. SNiP 2.04.14-88*. Thermal insulation of equipment and pipelines. - M.: State Unitary Enterprise TsPP Gosstroy of Russia, 1999.
4. Methodology for calculating heat losses in heating networks during transportation. - M.: Firm ORGRES, 1999.
5. Rules technical operation thermal power plants. - M.: Publishing house NC ENAS, 2003.
6. Standard instructions on technical operation of thermal energy transport and distribution systems (heating networks): RD 153-34.0-20.507-98. - M.: SPO ORGRES, 1986.
7. Methodology for determining standard values of performance indicators of water heating networks of public heating systems. - M.: Roskommunenergo, 2002.
9. GOST 26691-85. Thermal power engineering. Terms and Definitions.
10. GOST 19431-84. Energy and electrification. Terms and Definitions.
11. Rules for the development of regulations, circulars, operational instructions, guidance documents and newsletters in the electric power industry: RD 153-34.0-01.103-2000. - M.: SPO ORGRES, 2000.
1. GENERAL PROVISIONS
2. COLLECTION AND PROCESSING OF INITIAL DATA
2.1. Collection of initial data on the heating network
2.2. Processing of initial data of metering devices
3. DETERMINATION OF NORMATIVE THERMAL ENERGY LOSSES
3.1. Determination of annual averages standard losses thermal energy
3.2. Determination of standard thermal energy losses for the measurement period
4. DETERMINATION OF ACTUAL THERMAL ENERGY LOSSES
4.1. Determination of actual thermal energy losses during the measurement period
4.2. Determination of actual thermal energy losses per year
APPLICATIONS
Appendix A. Terms and Definitions
Appendix B. Symbols of quantities
Appendix B. Characteristics of heating network sections
Appendix D. Average monthly and average annual ambient and network water temperatures
Appendix D. Characteristics of thermal energy consumers and metering devices
Appendix E. Norms of thermal energy loss by insulated water heat pipelines located in non-passing channels and for channelless installation
Appendix G. Norms of thermal energy loss by one insulated water heat pipeline when laid above ground
Appendix I. Norms of heat flux density through the insulated surface of pipelines of two-pipe water heating networks when laid in non-passing channels
Appendix K. Norms of heat flux density through the insulated surface of pipelines for two-pipe underground ductless installation of water heating networks
Appendix L. Norms of heat flux density through the insulated surface of pipelines of water heating networks when located outdoors
Appendix M. Norms of heat flux density through the insulated surface of pipelines of water heating networks when located in a room or tunnel
Appendix H. Norms of heat flux density through the insulated surface of pipelines of two-pipe water heating networks when laid in non-passage channels and underground channelless installation
Appendix P. Norms of heat flux density through the insulated surface of pipelines of water heating networks when located outdoors
Appendix R. Norms of heat flux density through the insulated surface of pipelines of water heating networks when located in a room or tunnel
Appendix C. List of normative and technical documents to which there are links
We determine the discrepancy of pressure losses in two directions through the near and far risers using the formula:
where ΣΔp1, ΣΔp2 are, respectively, pressure losses when calculating directions through the far and near risers.
5. Calculation of heat losses by pipelines of the hot water supply system
Heat losses DQ, (W), in the calculated section of the supply pipeline or riser are determined according to the standard specific losses heat or by calculation using the formula:
where K is the heat transfer coefficient insulated pipeline, K=11.6 W/(m2-°C); tгср - average water temperature in the system, tгср,=(tн +tк)/2, °С; tн, - temperature at the outlet of the heater (temperature of hot water at the entrance to the building), °C; tk is the temperature at the most distant water tap, °C; h- Thermal efficiency insulation (0.6); / - length of the pipeline section, m; dH- outside diameter pipeline, m; t0 - ambient temperature, °C.
The water temperature at the most remote water tap tk should be taken 5 °C lower than the water temperature at the entrance to the building or at the outlet of the heater.
The ambient temperature t0 when laying pipelines in furrows, vertical channels, communication shafts and sanitary cabin shafts should be taken equal to 23 ° C, in bathrooms - 25 ° C, in kitchens and toilet rooms of residential buildings, dormitories and hotels - 21 ° WITH .
Heating of bathrooms is carried out by heated towel rails, therefore, to the heat loss of the riser, heat loss from heated towel rails is added in the amount of 100p (W), where 100 W is the average heat transfer by one heated towel rail, n is the number of heated towel rails connected to the riser.
When determining circulation water flow rates, heat losses through circulation pipelines are not taken into account. However, when calculating hot water supply systems with heated towel rails on circulation risers, it is advisable to add the heat transfer of heated towel rails to the amount of heat loss by the supply heat pipes. This increases the circulation flow of water, improves the heating of heated towel rails and heating of bathrooms. The calculation results are entered into the table.
(tсрг-t0), °С |
Heat loss, W |
Notes |
||||||
q at a length of 1 m |
ΔQ on the site |
|||||||
Highway |
||||||||
ΔQ=1622.697W |
||||||||
Total riser losses ΔQ=459.3922 W |
||||||||
Total losses of the riser, including heated towel rails ΔQ=1622.284 W |
||||||||
Total riser losses ΔQ=459.3922 W |
||||||||