Heat losses DQ, (W), at the calculated section of the supply pipeline or riser are determined by the standard specific heat losses or by calculation using the formula:

where TO - heat transfer coefficient of an insulated pipeline, K = 11.6 W / (m 2 - ° С); t g av - average water temperature in the system, t g cf, = (t n + t k) / 2,° C; t n, - temperature at the outlet of the heater (temperature of hot water at the entrance to the building), ° С; t to - temperature at the most distant water-folding device, ° С; h - Thermal insulation efficiency (0.6); / is the length of the pipeline section, m; d H - outer diameter of the pipeline, m; t 0 - ambient temperature, ° С.

Water temperature at the most remote water-folding device t to should be taken 5 ° C below the water temperature at the entrance to the building or at the exit from the heater.

Ambient temperature t 0 when laying pipelines in furrows, vertical channels, communication shafts and shafts of sanitary cabins, it should be taken equal to 23 ° С, in bathrooms - 25 ° С, in kitchens and toilet rooms of residential buildings, hostels and hotels - 21 ° С.

Heating of bathrooms is carried out by heated towel rails, therefore, heat losses by heated towel rails are added to the heat loss of the riser 100p(W), where 100 W is the average heat transfer from one heated towel rail, NS - the number of heated towel rails attached to the riser.

When determining the circulating water flow rates, heat losses by circulating 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 sum of heat losses by supplying heat lines. This increases the circulating water consumption, improves the heating of heated towel rails and heating of bathrooms. The calculation results are entered in the table.

№	l, m	D, m	t 0, о С	t g cf -t 0, о С	1-n	q, W / m	DQ, W	åDQ, W	Note

Stand 6
1-3	0,840	0,0213	21,00	36,50	0,30	8,4996	7,139715	7,139715
2-3	1,045	0,0268	21,00	36,50	0,30	10,6944	11,17566	18,31537
3-4	2,9	0,0268	21,00	36,50	0,30	10,6944	31,01379	49,32916
4-5	2,9	0,0335	21,00	36,50	0,30	13,3680	38,76723	88,09639	åDQ = 497.899 + 900 =
5-6	2,9	0,0423	21,00	36,50	0,30	16,8796	48,95086	137,0473	= 1397.899 W
6-7	2,9	0,0423	21,00	36,50	0,30	16,8796	48,95086	185,9981
7-8	2,9	0,0423	21,00	36,50	0,30	16,8796	48,95086	234,9490
8-9	2,9	0,0423	21,00	36,50	0,30	16,8796	48,95086	283,8998
9-10	2,9	0,0423	21,00	36,50	0,30	16,8796	48,95086	332,8507
10-11	2,9	0,0423	21,00	36,50	0,30	16,8796	48,95086	381,8016
11-12	4,214	0,048	5,00	52,50	0,30	27,5505	116,0979	497,8994
12-13	4,534	0,048	5,00	52,50	0,30	27,5505	124,9140	622,8134
13-14	13,156	0,048	5,00	52,50	0,30	27,5505	362,4545	985,2680
14-15	4,534	0,060	5,00	52,50	0,30	34,4381	156,1425	1141,4105
15-Enter	6,512	0,060	5,00	52,50	0,30	34,4381	224,2612	1365,6716
Stand 1

1a-3a	0,840	0,0213	21,00	36,50	0,30	8,4996	7,139715	7,139715	åDQ = 407.504 + 900 = = 1307.504 W
2a-3a	1,045	0,0268	21,00	36,50	0,30	10,6944	11,17566	18,31537
3a-4a	2,9	0,0268	21,00	36,50	0,30	10,6944	31,01379	49,32916
4a-5a	2,9	0,0268	21,00	36,50	0,30	10,6944	31,01379	80,34294
5a-6a	2,9	0,0268	21,00	36,50	0,30	10,6944	31,01379	111,3567
6a-7a	2,9	0,0335	21,00	36,50	0,30	13,3680	38,76723	150,1240
7a-8a	2,9	0,0335	21,00	36,50	0,30	13,3680	38,76723	188,8912
8a-9a	2,9	0,0335	21,00	36,50	0,30	13,3680	38,76723	227,6584
9a-10a	2,9	0,0335	21,00	36,50	0,30	13,3680	38,76723	266,4257
10a-11a	2,9	0,0335	21,00	36,50	0,30	13,3680	38,76723	305,1929
11a-15	4,214	0,0423	5,00	52,50	0,30	24,2789	102,3112	407,5041
15-Enter	6,512	0,060	5,00	52,50	0,30	34,4381	224,2612	631,7652

åQp = 5591.598 W

Hydraulic calculation of circulation pipelines

The circulating water consumption in the hot water supply system G c (kg / h), is distributed in proportion to the total heat losses:

where åQ c - total heat loss by all supply pipelines, W; Dt is the difference in water temperature in the supply pipelines of the hot water supply system, Dt = t g -t to = 5 ° C; с - heat capacity of water, J / (kg ° С).

The circulation flow rates of water in the main sections of the hot water supply system consist of the circulation flow rates of the sections and risers, which are located in front of the water flow.

Stand 1:

Plot 2

Stand 2:

Section 3:

Stand 3:

Section 4:

Hydraulic calculation of circulation pipelines of an open hot water supply system.

№	l, m	G, l / s	D, mm	w, m / s	R, Pa / m	K m	DP, Pa	åDP, Pa
Circulation ring through riser 1
15-16	6,512	0,267093	0,040	0,21367	44,719	0,2	1954,602	1954,602
11-15	4,214	0,073767	0,020	0,2313	123,301	0,2	2293,472	4248,074
1-11		0,073767	0,015	0,4326	579,868	0,5	399529,12	403777,20
1’-11’		0,073767	0,015	0,4326	579,868	0,5	399529,12	803306,32
11’-15’	4,214	0,073767	0,020	0,2313	123,301	0,2	2293,472	805599,79
15’-16’	6,512	0,267093	0,040	0,21367	44,719	0,2	1954,602	807554,39
Circulation ring through riser 2
15-16	6,512	0,267093	0,040	0,21367	44,719	0,2	1954,602	1954,602
14-15	4,534	0,181492	0,032	0,1915	44,4186	0,2	953,399	2908,001
11-14	4,214	0,073767	0,020	0,2313	123,301	0,2	2293,472	5201,473
1-11		0,073767	0,015	0,4326	579,868	0,5	399529,12	404730,59
1’-11’		0,073767	0,015	0,4326	579,868	0,5	399529,12	804259,72
11’-14’	4,214	0,073767	0,020	0,2313	123,301	0,2	2293,472	806553,19
14’-15’	4,534	0,181492	0,032	0,1915	44,4186	0,2	953,399	807506,59
15’-16’	6,512	0,267093	0,040	0,21367	44,719	0,2	1954,602	809461,19
Circulation ring through riser 3
15-16	6,512	0,267093	0,040	0,21367	44,719	0,2	1954,602	1954,602
14-15	4,534	0,181492	0,032	0,1915	44,4186	0,2	953,399	2908,001
13-14	13,156	0,099485	0,020	0,3085	209,147	0,2	36749,54	39657,542
11-13	4,214	0,073767	0,020	0,2313	123,301	0,2	2293,472	41951,014
1-11		0,073767	0,015	0,4326	579,868	0,5	399529,12	441480,07
1’-11’		0,073767	0,015	0,4326	579,868	0,5	399529,12	841009,12
11’-13’	4,214	0,073767	0,020	0,2313	123,301	0,2	2293,472	843320,59
13’-14’	13,156	0,099485	0,020	0,3085	209,147	0,2	36749,54	880052,13
14’-15’	4,534	0,181492	0,032	0,1915	44,4186	0,2	953,399	881005,53
15’-16’	6,512	0,267093	0,040	0,21367	44,719	0,2	1954,602	882960,13
Circulation ring through riser 4
15-16	6,512	0,267093	0,040	0,21367	44,719	0,2	1954,602	1954,602
14-15	4,534	0,181492	0,032	0,1915	44,4186	0,2	953,399	2908,001
13-14	13,156	0,099485	0,020	0,3085	209,147	0,2	36749,54	39657,542
12-13	4,534	0,006592	0,020	0,0201	11,2013	0.2	240,4178	39897,960
11-12	4,214	0,073767	0,020	0,2313	123,301	0,2	2293,472	42191,432
1-11		0,073767	0,015	0,4326	579,868	0,5	399529,12	441720,48
1’-11’		0,073767	0,015	0,4326	579,868	0,5	399529,12	841249,54
11’-12’	4,214	0,073767	0,020	0,2313	123,301	0,2	2293,472	843543,01
12’-13’	4,534	0,006592	0,020	0,0201	11,2013	0.2	240,4178	843783,43
13’-14’	13,156	0,099485	0,020	0,3085	209,147	0,2	36749,54	880532,87
14’-15’	4,534	0,181492	0,032	0,1915	44,4186	0,2	953,399	881486,37
15’-16’	6,512	0,267093	0,040	0,21367	44,719	0,2	1954,602	883440,97

We determine the discrepancy of pressure losses in two directions through the near and far risers according to the formula: DH count - pressure loss in the water meter, m; H sv - available free head at the bath mixer (3m); DH cm - mixer losses (5 m); H g - the geometrical height of water rise from the axis of the pipeline at the inlet to the axis of the highest located water-folding device (24.2 m).

The water meter is selected according to the water flow rate at the inlet G and nominal diameter D y on . Head loss in the water meter DH mid(m), are determined by the formula:

where S is the hydraulic resistance of the water meter, taken by, (0.32 m / (l / s 2)). We accept the water meter VK-20.

Excessive head at the inlet:

Bibliography.

1. Building codes and regulations. SNiP 3.05.01-85. Internal sanitary systems. M: Stroyizdat, 1986.

2. Building codes and regulations. SNiP 2.04.01-85. Internal water supply and sewerage of buildings. Moscow: Stroyizdat, 1986.

3. Building codes and regulations. SNiP II-34-76. Hot water supply. Moscow: Stroyizdat, 1976.

4. Designer handbook. Heating, plumbing, sewerage / Ed. I. G. Staroverova. - M .: Stroyizdat, 1976. Part 1.

5. Handbook of heat supply and ventilation / R.V. Shchekin, S.M. Korenevsky, G.E.Behm and others - Kiev: Budivelnik, 1976. Part 1.

6. Heat supply: Textbook for universities / A. A. Ionin, B. M. Khlybov and others; Ed. A. A. Ionina. Moscow: Stroyizdat, 1982.

7. Heat supply (course design): Textbook for universities on spec. "Heat and gas supply and ventilation" / V. M. Kopko, N. K. Zaitseva and others; Ed. V. M. Kopko. - Mn .: Higher. shk., 1985.

8. Heat supply: a textbook for university students / V. E. Kozin, T. A. Levina, A. P. Markov and others - M .: Higher. school, 1980.

9. Singer NM Hydraulic and thermal modes of heating systems. - M .: Energoatomizdat, 1986.

10. Sokolov E.Ya. Heating and heating networks. - M .: Publishing house MEI, 2001.

11. Adjustment and operation of water heating networks: Handbook / V. I. Manyuk, Ya. I. Kaplinsky, E. B. Khizh et al. - M .: Stroyizdat, 1988.

UDC 621.64 (083.7)

Developed by: JSC Scientific and Production Complex "Vector", Moscow Power Engineering Institute (Technical University)

Performers: Tishchenko A.A., Shcherbakov A.P.

Under the general editorship of V.G. Semenov

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 the actual losses of heat energy through the thermal insulation of pipelines of water heating networks of district heating systems, some of whose consumers are equipped with metering devices. Actual losses of heat energy for consumers with measuring devices are determined based on the readings of heat meters, and for consumers not equipped with metering devices - by calculation.

Heat losses determined according to this Methodology should be considered as the initial basis for compiling the energy characteristics of the heat network, as well as for the development of technical measures to reduce the actual losses of heat energy.

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 inspection 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 the actual losses of heat energy 1 through the thermal insulation of pipelines of water heating networks of centralized heat supply systems, some of whose consumers are equipped with metering devices. Actual losses of heat energy for consumers with 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 calculation and experimental method for assessing heat losses, set forth in Art.

"Methodology ..." is intended for organizations carrying out energy inspection of heat supply enterprises, as well as for enterprises and organizations operating heat networks, regardless of their departmental affiliation and ownership.

Heat losses determined according to this "Methodology ..." should be considered as the starting point for compiling the energy characteristics of the heating network, as well as for the development of technical measures to reduce the actual heat losses.

1. GENERAL PROVISIONS

The purpose of this "Methodology ..." is to determine the actual losses of heat energy through the thermal insulation of pipelines of water heating networks of district heating systems without special tests. Heat losses are determined for the entire heat network connected to a single source of heat energy. Determination of actual losses of heat energy for individual sections of the heat network is not carried out.

Determination of heat energy losses according to this "Methodology ..." presupposes the presence of certified heat metering units at the heat source and at the heat consumers. The number of consumers equipped with metering devices must be at least 20% of the total number of consumers of a given heating network.

Metering devices must have an archive with hourly and daily registration of parameters. The depth of the hourly archive must be at least 720 hours, 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 are not available for some reason.

Determination of the actual losses of heat energy is carried out on the basis of measurements of the flow rate and temperature of the network water in the supply pipeline 1 for consumers with metering devices, and the temperature of the network water at the source of thermal energy. Losses of heat energy for consumers who do not have measuring devices are determined by calculation according to this "Methodology ...".

__________________

1 Symbols of quantities are given in Appendix B.

Sources and consumers of heat energy in this "Methodology ..." are:

1. in the absence of metering devices directly in buildings: sources of thermal energy - thermal power plants, boiler houses, etc .; heat energy consumers - central (RTP) or individual (ITP) heating points;

2. in the presence of metering devices directly in buildings(in addition to item 1): sources of heat energy - central (CHP) heat points; heat energy consumers - directly buildings.

For the convenience of calculating heat energy losses through thermal insulation, the supply pipeline in this "Methodology ..." is delimited into: the main pipeline and a branch from the main pipeline.

Main pipeline- this is a part of the supply pipeline from the source of thermal energy to the thermal chamber, from which there is a branch to the consumer of thermal energy.

Branch from the main pipeline- this is a part of the supply pipeline from the corresponding heat chamber to the consumer of heat energy.

When determining the actual losses of heat energy, standard values of losses are used, determined according to the norms of heat losses for heating networks, the thermal insulation of which was carried out according to the design standards or (the standards are specified according to the design and executive documentation).

Before making calculations:

collection of initial data on the heating network;

a design diagram of the heating network is drawn up, which indicates the nominal bore (nominal diameter), length and type of pipelines for all sections of the heating network;

data is collected on the connected load of all network consumers;

the type of metering devices is established, the availability of hourly and daily archives for them.

In the absence of a centralized collection of data from heat metering devices, the corresponding devices for collection are prepared: an adapter or a laptop. The laptop must be equipped with a special program supplied with the metering device, which allows you to read the hourly and daily archives from the installed heat meters.

To improve the accuracy of determining heat energy losses, it is preferable to collect data from metering devices for a certain time interval in a non-heating period, when the flow of network water is minimal, having previously specified in the heat supply organization about planned outages of heat energy supply to consumers in order to exclude this time from the data collection period of measuring devices ...

2. COLLECTION AND PROCESSING OF INITIAL DATA

2.1. COLLECTION OF INITIAL DATA ON THE HEAT 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 drawn up (Table B.1 of Appendix B).

A section of a heating network is a section of a pipeline that differs from others in one of the following features (which are indicated in Table B.1 of Appendix B):

nominal pipeline bore (nominal pipeline diameter);

type of laying (aboveground, underground channel, underground channelless);

the material of the main layer of the thermal insulation structure (thermal insulation);

year of laying.

Also in table. B.1 Appendix B specifies:

the name of the initial and final nodes of the site;

section length.

Based on the data of the meteorological service, a table of average monthly temperatures of outside air, ° С, and soil, ° С, at various depths of pipelines, averaged over the past five years, is compiled (Table D.1 Appendix D). Average annual temperatures of outside air, ° С, and soil, ° С, are determined as arithmetic mean from monthly average values for the entire period of operation of the heating network.

On the basis of the approved temperature schedule for the supply of thermal energy at the source of thermal energy, the average monthly temperatures of network water in the supply, ° C, and return, ° C, pipelines are determined (Table D.1 Appendix D). The average monthly temperatures of the supply water are determined by the average monthly outdoor temperature. The average annual temperatures of network water in the supply, ° C, and return, ° C, pipelines are determined as arithmetic mean from the average monthly values, taking into account the duration of the network operation by months and per year.

Based on the data of the heat consumption accounting service of the heat supply organization, a table is drawn up, in which for each consumer it is indicated (Table E.1 Appendix E):

name of the consumer of heat energy;

type of heat supply system (open or closed);

connected average load of the 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 data collection, based on the measurement results, a period is selected for which heat energy losses will be determined. In doing so, the following must be taken into account:

to improve the accuracy of determining heat energy losses, it is advisable to choose a period with a minimum consumption of network water (usually this is a non-heating period);

during the selected period, there should be no planned disconnections of consumers from the heating network;

measurement data are collected at least 30 calendar days in advance.

In the absence of centralized data collection, it is necessary to collect hourly and daily archives of metering devices from heat consumers and at a heat energy source within 3-5 days using an adapter or a laptop with an installed program to read data from the corresponding type of heat meter.

To determine heat energy losses, you must have the following data:

network water consumption in the supply pipeline for heat consumers;

temperature of network water in the supply pipeline for heat consumers;

network water consumption in the supply pipeline at the heat source;

temperature of the network water in the supply and return pipelines at the heat source;

make-up water consumption at the heat source.

2.2. PROCESSING INITIAL DATA OF METERING DEVICES

The main task of processing meter data is to convert the source files read directly from heat meters into a single format that allows subsequent verification (plausibility check) of the measured values of heat consumption parameters and calculations.

For different types of heat meters, data are read in different formats and require 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 for bringing the initial data to uniform physical values. The difference between these coefficients is determined by the diameter of the flow transducer and the characteristics of the pulse inputs of the calculator. Therefore, the initial processing of measurement results requires an individual approach for each initial data file.

Daily and hourly values of the heat carrier parameters are used to verify the measured values. When carrying out this procedure, the main attention should be paid to the following:

the values of temperatures and flow rates of the coolant should not go beyond physically justified limits;

in the daily file there should be no sharp changes in the flow rate of the coolant;

the values of the average daily temperature of the coolant in the supply pipeline for consumers should not exceed the average daily temperature in the supply pipeline at the source of thermal energy;

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 source.

Based on the results of verification of the initial data of metering devices, a table is drawn up in which for each consumer of heat energy with metering devices and for a 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 heat source, the number of hours in the measurement period is determined n and, the data for which will be used for further processing.

Before determining the measurement period, the time of filling all supply pipelines with a coolant t p, s, is calculated according to the formula:

where V

Average for the entire period of measurements, the flow rate of the coolant through the supply pipeline at the source of thermal energy, kg / s.

The measurement period must satisfy the following conditions: the average temperature of the supply water in the supply pipe at the heat source during the time t p preceding the start of the measurement period, and the average temperature of the supply water in the supply pipeline at the heat source for the 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 several consumers, then the data of metering devices of these consumers are not used in the further calculation.

The number of remaining consumers who have metering device data 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%, it is necessary to select another period for data collection and repeat the verification procedure.

For the data obtained at the source of thermal energy, the average temperature of the network water in the supply pipeline, ° С, and the average temperature of the network water in the return pipeline, ° С over the measurement period, are determined:

where

n and - the number of hours in the measurement period.

For the measurement period, the average temperature of the soil at the average depth of the pipeline axis, ° С, and the average temperature of the outside air, ° С are determined.

3. DETERMINATION OF REGULATORY LOSS OF THERMAL ENERGY

3.1. DETERMINATION OF ANNUAL REGULATORY LOSSES

THERMAL ENERGY

For each section of the heating network, the average annual normative specific (per 1 meter of the pipeline length) values of heat energy losses are determined according to the design standards or, in accordance with which the thermal insulation of the heating network pipelines is performed.

Average annual specific heat 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.

The values of the average annual specific heat losses at the difference in the average annual temperatures of the network water and the environment that differ from the values given in the standards are determined by linear interpolation or extrapolation.

For sections of heating networks of underground laying with thermal insulation, made in accordance with (Table E.1 of Appendix E), the standard specific losses of thermal energy are determined in total along the supply and return pipelines q n, W / m, according to the formula:

(3.1)

where are the specific losses of heat energy in total through the supply and return pipelines at a lower than for this network, the tabular value of the difference in the average annual temperatures of the network water and soil, W / m;

Larger than for a given network, the tabular value of the difference between the average annual temperatures of network water and soil, ° С.

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 the supply water in the supply and return pipelines, respectively, ° С;

Average annual soil temperature at the average depth of the pipeline axis, ° С.

To distribute the specific losses of heat energy in the areas of underground laying between the supply and return pipelines, the average annual standard specific losses of heat energy in the return pipeline are determined q but, W / m, which are taken equal to the values of the standard specific losses in the return pipeline given in table. E.1 Appendix E.

q np = q n - q but. (3.3)

For sections of heating networks of underground laying with thermal insulation, made in accordance with (Table I.1 of Appendix I, Table K.1 of Appendix K, Table H.1 of Appendix H), before determining the standard specific losses of thermal energy, it is necessary to additionally determine the difference in average annual temperatures, ° С, 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 appendix I, table. K.1 appendix K and table. H.1 Appendix H:

(3.4)

where, respectively, are the tabular values of the average annual temperatures of network water in the supply (65, 90, 110 ° С) and return (50 ° С) pipelines, ° С;

The standard value of the average annual soil temperature, ° С (taken equal to 5 ° С).

For each pair of average annual temperatures of network water in the supply and return pipelines, the total standard specific losses of thermal energy are determined, W / m:

where, respectively, the values of the standard specific heat losses for underground laying in the supply and return pipelines, given in table. I.1 appendix I, table. K.1 appendix K and table. H.1 appendix H.

The values of the average annual specific heat losses for the heat network under consideration at the difference in the average annual temperatures of the network water and the environment that differ from the values determined by formula 3.4 are determined by linear interpolation or extrapolation.

The values of the total specific losses of heat energy q n, W / m, are determined by formulas 3.1 and 3.2.

Average annual standard specific losses of heat energy in the supply pipeline q np, W / m, are determined by the formula:

(3.6)

where, - specific losses of heat energy through the supply pipeline at two adjacent, respectively, smaller and larger than for this network, tabular values of the difference between the average annual temperatures of the network water and soil, W / m;

Adjacent, respectively, smaller and larger than for a given network, tabular values of the difference between the average annual temperatures of the network water in the supply pipeline and the ground, ° С.

The average annual values of the temperature difference between the supply 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, ° С.

The tabular values of the difference between the average annual temperatures of the supply water in the supply pipeline and the soil are determined by the formula:

Average annual standard specific losses of heat energy 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 above ground with thermal insulation made in accordance with, (Table G.1 of Appendix G, Table L.1 of Appendix A, Table A.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)

The value of the difference between the average annual temperatures of network water and outdoor air, respectively, for the supply and return pipelines for a given heating network, ° С;

Adjacent, respectively, smaller and larger than for this network, tabular values of the difference between the average annual temperatures of the network water in the return pipeline and the outside air, ° С.

The values of the difference between the average annual temperatures of the supply water and the outside air for the supply and return pipelines are determined by the formulas:

where is the average annual outside air temperature, ° С.

For laying in through and semi-through channels, tunnels, basements specific heat losses of the sections are determined according to the relevant standards for laying in rooms (Table M.1 of Appendix M, Table P.1 of Appendix P) at average annual ambient temperatures: tunnels and passageways - +40 ° С, for basements - + 20 ° C.

For each section of the heating network, standard average annual values of heat energy losses are determined separately for the supply and return pipelines:

where is the average annual standard heat loss through the supply pipeline, W;

b - coefficient of local losses of heat energy, taking into account the loss of heat energy by fittings, compensators and supports, taken in accordance with equal to 1.2 for underground duct and aboveground laying for nominal pipelines up to 150 mm and 1.15 for nominal diameters of 150 mm and more , as well as for all nominal sizes with channelless laying.

3.2. DETERMINATION OF REGULATORY LOSS OF THERMAL ENERGY

DURING THE PERIOD OF MEASUREMENT

For each section of the heating network, the standard averages for the measurement period of heat energy losses in the supply, W, and return, W, pipelines are determined.

For sections of the heating network of underground laying

For sections of the heating network of overhead laying standard averages for the measurement period heat energy losses are determined by the formulas:

(3.18)

(3.19)

where, is the average temperature of the network water during the measurement period in the supply and return pipelines at the heat source, ° С;

Average annual temperature of network water in the supply and return pipelines, respectively, ° С;

Average temperature of soil and outside air for the period of measurements, respectively, ° С;

Average annual temperature of the ground and outside air, respectively, ° С.

For sections laid in through and semi-through channels, tunnels, basements the normative average for the period of measurements of heat energy losses are determined by formulas (3.18) and (3.19) at an average outside air temperature equal to the average annual: for tunnels and passageways - +40 ° С, for basements - +20 ° С.

For the entire network, the standard averages for the measurement period are determined for the loss of heat energy in the supply pipeline, W:

The standard averages for the measurement period are determined for the loss of heat energy in the supply pipeline for all sections of the underground installation, W:

(3.21)

The standard averages for the measurement period of heat energy losses in the return pipeline are determined for all sections of the underground installation, W:

(3.22)

The standard averages for the measurement period of heat energy losses in the supply pipeline for all sections of the above-ground installation are determined, W:

(3.23)

The standard averages for the measurement period of heat energy losses in the return pipeline for all sections of the above-ground installation, W are determined:

(3.24)

The standard averages for the measurement period of heat 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 heat 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 heat energy losses in the supply pipeline are determined for all sections located in the basements, W:

(3.27)

The standard averages for the measurement period of heat energy losses in the return pipeline are determined for all sections located in the basements, W:

(3.28)

4. DETERMINATION OF THE ACTUAL LOSS OF THERMAL ENERGY

4.1. DETERMINATION OF THE ACTUAL LOSS OF THERMAL ENERGY

DURING THE PERIOD OF MEASUREMENT

At the source of thermal energy and for all consumers of thermal energy with metering devices ( i-th consumers of thermal energy), the average flow rate of the coolant in the supply pipeline is determined for the entire measurement period:

where is the average for the entire measurement period the flow rate of the coolant through the supply pipeline at the source of thermal energy, kg / s;

Measured during the measurement period the values of the flow rate of the heat carrier at the source of thermal energy, taken from the hour file, t / h;

i th consumer of thermal energy, kg / s;

The values of the coolant flow rate measured during the measurement period i-th consumer of thermal energy, taken from the hour file, t / h.

For a closed heating system the average consumption of make-up water at the heat source is determined for the entire measurement period:

(4.3)

where is the average for the entire period of measurements the consumption of make-up water at the source of thermal energy, kg / s;

The measured values of the coolant flow rate for make-up at the heat energy source during the measurement period, taken from the hour file, t / h.

Average for the entire measurement period the flow rate of the coolant in the supply pipeline, kg / s, for all consumers of thermal energy that do not have metering devices ( j consumers of thermal energy), for closed heat supply systems is determined by the formula:

For open heating systems that do not have round-the-clock heat carrier consumers, the average consumption of make-up water at the heat source at night is determined for the entire measurement period.

To do this, for each day from the measurement period, the night (from 1:00 to 3:00) hourly average make-up consumption at the heat source is selected. For the data obtained, the arithmetic mean of the flow rate is determined, which is the average hourly feed 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 who consume the heat carrier around the clock and have metering devices, the average hourly consumption of the heat carrier at night is determined. To do this, for each day from the measurement period, the night (from 1:00 to 3:00) average hourly flow rate of the coolant 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 for the entire measurement period coolant flow rate in the supply pipeline for all j-th consumers is determined by the formula 4.4.

Average for the entire measurement period coolant flow rate in the supply pipeline for each j-th consumer, kg / s, is determined by distributing the total flow rate of the coolant among consumers in proportion to the hourly average connected load:

(4.7)

where is the hourly average connected load during the measurement period j th consumer, GJ / h;

j consumers without metering devices during the measurement period, GJ / h.

For each i-th consumer, the average losses of heat energy through the thermal insulation of the supply pipeline are determined over the measurement period, W:

(4.8)

where with p- specific heat capacity of water, with p= 4.187 × 10 3 J / (kg × K);

Measured values of the temperature of the supply water in the supply pipeline at the source of thermal energy, taken from the hour file, ° С;

i th consumer, taken from the hour file, ° С.

The total heat losses in the supply pipelines averaged over the measurement period are determined for all i-th consumers with metering devices, W:

(4.9)

The average losses of heat energy over the measurement period, W, through the thermal insulation of the supply pipeline, referred to i- to the consumer, minus the losses of thermal energy in the branch from the main pipeline:

(4.10)

In the first approximation, the losses of thermal energy in the branch from the main pipeline are taken to be equal to the standard average for the period of measurements of thermal energy losses:

(4.11)

where are the normative averages for the measurement period of heat energy losses in the branch from the main supply pipeline to i to the consumer, W.

Total losses of heat energy, W, in the main supply pipelines for all i-th consumers with metering devices:

Heat loss coefficient of the network r losses n, J / (kg × m), in the main supply pipelines is determined according to measurement data for consumers with metering devices:

(4.13)

where l i- the smallest 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 for the period of measurement of heat energy losses, W, y j consumers without metering devices, the ratio is used:

where l j j- to the consumer without metering devices, m.

The total losses of heat energy, W, averaged over the measurement period, in the supply pipelines for j-th consumers who do not have metering devices:

(4.15)

Actual average over the measurement period total heat energy losses, W, in all supply pipelines:

After determining the actual losses of heat 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 repeated (second approximation), starting with formula 4.10, and the losses in the branches from the main pipelines are determined by the formula:

(4.18)

After determining the value of the actual heat energy losses in the supply pipeline for all consumers in the second approximation, its value is compared with the value of the actual heat energy losses 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 made to determine the value, i.e. the whole calculation, starting with formula 4.10, is repeated.

Usually, two or three approximations are sufficient to obtain a satisfactory result. The heat loss value obtained by formula 4.16 in the last approximation is used in the further calculation.

Another method of accounting for the influence of the branches is possible. Having performed calculations according to 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 t to - the time of movement of the coolant on a homogeneous section of the heating network, s;

l k

W k

r is the density of water at the average temperature of the network water in the supply pipeline at the heat 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, m 2;

G k- coolant consumption in a homogeneous area, kg / s.

A homogeneous section of a heating network is a section where the flow rate of the coolant and the conditional passage of the pipeline do not change, i.e. the constancy of the speed of the coolant is ensured.

The coefficient of heat energy losses, 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 losses of thermal energy over the measurement period through thermal insulation in the supply pipeline, W, referred to j- to the consumer without metering devices:

(4.23)

where t j j-th consumer without metering devices, p.

Having determined by the formula 4.15, we calculate by the formula 4.16. The value of heat energy losses, obtained according to the formula 4.16, is used in the further calculation.

The actual losses of heat energy in the supply pipelines for all sections of the underground installation, W, averaged over the measurement period, are determined:

(4.24)

The actual losses of heat energy in the supply pipelines averaged over the measurement period for all sections of the above-ground laying are determined, W:

(4.25)

The actual losses of heat energy in the supply pipelines averaged over the measurement period are determined for all sections located in through and semi-through channels, tunnels,, W:

(4.26)

The actual losses of heat energy in the supply pipelines for all sections located in the basements, averaged over the measurement period, are determined, W:

(4.27)

The actual losses of heat energy in return pipelines averaged over the measurement period are determined for all sections of the underground installation, W:

(4.28)

The actual losses of heat energy in return pipelines averaged over the measurement period are determined for all sections of the above-ground installation, W:

(4.29)

The actual losses of heat energy in return pipelines averaged over the measurement period are determined for all sections located in through and semi-through channels, tunnels,, W:

(4.30)

The actual losses of heat energy in the return pipelines for all sections located in the basements, averaged over the measurement period, are determined, W:

(4.31)

The actual total losses of heat energy in return pipelines, W, averaged over the measurement period, are determined:

The actual total losses of heat energy, W, in the network, averaged over the measurement period, are determined:

4.2. DETERMINATION OF THE ACTUAL LOSS OF THERMAL ENERGY PER YEAR

Actual losses of heat energy for the year are determined as the sum of actual losses of heat energy for each month of operation of the heat network.

The actual losses of heat energy per month are determined under the average monthly operating conditions of the heat network.

For all areas of underground installation the actual average monthly losses of heat energy are determined in total along the supply and return pipelines, W, according to the formula:

For all areas of aboveground installation the actual average monthly losses of heat energy are determined separately for the supply, W, and return, W, pipelines according to the formulas:

(4.35)

(4.36)

For all sections located in through and semi-through channels and tunnels

(4.37)

(4.38)

For all plots located in basements, the actual average monthly losses of heat energy are determined separately for the supply, W, and return, W, pipelines according to the formulas:

(4.39)

(4.40)

Actual losses of heat energy in the entire network for a month, GJ, are determined by the formula:

where n month - the duration of the heating network operation in the considered month, h.

Actual losses of heat energy in the entire network for the year, GJ, are determined by the formula:

(4.42)

APPENDIX A

Terms and Definitions

Water heating system- a heat supply system in which water is the heat carrier.

Closed water heating system- water heating system, which does not provide for the use of network water by consumers by taking it from the heating network.

Individual heating point- heat point intended for connection of heat consumption systems of one building or its part.

Executive 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.

Heat source (heat)- a heat-generating power plant or their combination, in which the heat carrier is heated by transferring the heat of the combusted fuel, as well as by electric heating or by other, including non-traditional methods, participating in heat supply to consumers.

Commercial metering (metering) of heat energy- determination, on the basis of measurements and other regulated procedures, of heat power and the amount of heat energy and heat carrier in order to carry out commercial settlements between energy supplying organizations and consumers.

Boiler room- a complex of technologically connected thermal power plants located in separate industrial buildings, built-in, attached or built-on premises with boilers, water heaters (including installations of an unconventional method of generating thermal energy) and boiler-auxiliary equipment, designed to generate heat.

Heat loss rate (rate of heat flux density through an insulated surface)- the value of the specific losses of thermal energy by pipelines of the heating network through their heat-insulating structures at the calculated average annual values of the temperature of the coolant and the environment.

Open water heating system- 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 in hot water.

Heating period- time in hours or days per year during which heat energy is supplied for heating.

Make-up water- specially prepared water supplied to the heating network to replenish the losses of the heat carrier (network water), as well as draw-off for heat consumption.

Heat 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, unauthorized water intake.

Thermal energy consumer- a legal entity or individual that uses thermal energy (power) and heat carriers.

- the total design maximum heat load (power) of all heat consumption systems at the ambient air temperature calculated for each type of load or the total design maximum hourly flow rate of the heat carrier for all heat consumption systems connected to the heat networks (heat source) of the heat supply organization.

Mains water- specially prepared water, which is used in the water heating system as a heat carrier.

Heat consumption system- a complex of thermal power plants with connecting pipelines and (or) heating networks, which are designed to satisfy one or several types of heat load.

Heat supply system- a set of interconnected heat sources, heating networks and heat consumption systems.

District heating system- sources of heat energy, heat networks and consumers of heat energy united by a common technological process.

Heat load of the heating system (heat load)- the total amount of thermal energy received from heat sources, equal to the sum of heat consumption of heat receivers and losses in heat networks per unit of time.

Heating network- a set of devices designed for the transmission and distribution of heat carrier and heat energy.

Heat point- a complex 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.

Heat carrier heat power plant, heat carrier- a moving medium used to transfer thermal energy in a heat-power plant from a more heated body to a less heated body.

Heat-consuming installation- thermal power plant or a set of devices designed to use heat and coolant for the needs of heating, ventilation, air conditioning, hot water supply and technological needs.

Heat supply- providing consumers with heat energy (heat).

Combined Heat and Power Plant (CHP)- a steam turbine power plant designed for the production of electrical and thermal energy.

Node for commercial metering of heat energy and (or) heat carriers- a set of duly certified measuring instruments and systems and other devices intended for commercial metering of the amount of heat energy and (or) heat carriers, as well as to ensure quality control of heat energy and heat consumption modes.

District heating- heat supply to consumers from a heat source through a common heating network.

Central heating station (CTP)- a heat 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 an organization that is a legal entity and owns or is in full economic control of installations that generate electrical and (or) heat energy, electrical and (or) heat networks and provides, on a contractual basis, the transfer of electrical and (or) heat energy to consumers.

APPENDIX B

Legend for quantities

Actual losses of heat energy in the entire network for the year, GJ;

Actual losses of heat energy in the entire network for a month, GJ;

Actual average monthly losses of heat energy in total through the supply and return pipelines for all sections of the underground installation, W;

Actual average monthly losses of heat energy separately along the supply pipeline for all sections of the above-ground laying, W;

Actual average monthly losses of heat energy separately for the return pipeline for all sections of the above-ground installation, W;

Actual average monthly losses of heat energy separately along the supply pipeline for all sections located in through and semi-through channels, tunnels, W;

Actual average monthly losses of heat energy separately along the return pipeline for all sections located in through and semi-through channels, tunnels, W;

Actual average monthly losses of heat energy separately along the supply pipeline for all sections located in the basements, W;

Actual average monthly losses of heat energy separately through the return pipeline for all sections located in the basements, W;

Actual total losses of heat energy in the network are average over the measurement period, W;

The actual losses of heat energy in the supply pipelines for all sections of the underground installation are average over the measurement period, W;

The actual losses of heat energy in the supply pipelines for all sections of the above-ground installation are average over the measurement period, W;

Actual losses of heat energy in the supply pipelines for all sections located in through and semi-through channels, tunnels, average over the measurement period, W;

Actual losses of heat energy in the supply pipelines for all sections located in the basements, average over the measurement period, W;

Actual losses of heat energy in return pipelines for all sections of the underground installation are average over the measurement period, W;

Actual losses of heat energy in return pipelines for all sections of the above-ground installation are average over the measurement period, W;

Actual losses of heat energy in return pipelines for all sections located in through and semi-through channels, tunnels, average over the measurement period, W;

Actual losses of heat energy in return pipelines for all sections located in basements are average over the measurement period, W;

The actual total losses of heat energy in all supply pipelines are average over the measurement period, W;

The actual total losses of heat energy in all return pipelines are average over the measurement period, W;

The total losses of heat energy in the supply pipelines for j-th consumers without metering devices, average over the measurement period, W;

Heat loss from j-th consumers without metering devices averaged over the measurement period, W;

Total losses of heat energy in supply pipelines for all i-th consumers with metering devices, average over the measurement period, W;

Losses of heat energy through the thermal insulation of the supply pipeline for each i-th consumer with metering devices averages 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 consumers without metering devices during the measurement period, GJ / h;

Average losses of heat energy over the period of measurements through the thermal insulation of the supply pipeline, referred to i- to the consumer, minus the losses of thermal energy in the branch from the main pipeline, W;

Heat energy losses in the branch from the main pipeline, W;

Normative averages for the measurement period of heat energy losses in the branch from the main supply pipeline to i-th consumer, W;

Total losses of heat energy in the main supply pipelines for all i-th consumers with metering devices, W;

Standard losses of heat energy in the supply pipeline, average over the measurement period, W;

Standard losses of heat energy in the return pipeline, average over the measurement period, W;

Normative averages for the measurement period of heat energy losses in the supply pipeline for the entire network, W;

Normative average for the period of measurements of heat energy losses in the supply pipeline for all sections of the underground installation, W;

Normative averages for the measurement period of heat energy losses in the return pipeline for all sections of the underground installation, W;

Normative averages for the measurement period of heat energy losses in the supply pipeline for all sections of the above-ground installation, W;

Normative averages for the measurement period of heat energy losses in the return pipeline for all sections of the above-ground installation, W;

Normative averages for the measurement period of heat energy losses in the supply pipeline for all sections located in through and semi-through channels, tunnels, W;

Normative averages for the measurement period of heat energy losses in the return pipeline for all sections located in through and semi-through channels, tunnels, W;

Standard averages for the measurement period of heat energy losses in the supply pipeline for all sections located in basements, W;

Normative averages for the measurement period of heat energy losses in the return pipeline for all sections located in the basements, W;

Average annual standard heat energy losses through the supply pipeline, W;

Average annual standard heat losses through the return pipeline, W;

The relative difference between the comparison of the value of the actual heat losses in the supply pipeline for all consumers in the second approximation with the value of the actual heat losses in the supply pipeline for all consumers, obtained in the first approximation;

q n - normative specific losses of heat energy in total along the supply and return pipelines for sections of heating networks of underground laying, W / m;

Specific heat losses in total through the supply and return pipelines at a lower than for this network, the tabular value of the difference in the average annual temperatures of the network water and soil, W / m;

Specific losses of heat energy in total through the supply and return pipelines at a tabular value of the difference between the average annual temperatures of the network water and the ground, greater than for this network, W / m;

q but - the average annual standard specific losses of heat energy in the return pipeline, W / m;

q np - average annual standard specific losses of heat energy in the supply pipeline, W / m;

Total standard specific losses of heat energy for underground laying, W / m;

Accordingly, the tabular values of the standard specific heat losses for underground laying in the supply and return pipelines, W / m;

Specific losses of heat energy through the supply pipeline at two adjacent, respectively, smaller and larger than for this network, tabular values of the difference between the average annual temperatures of the network water and soil, W / m;

Specific heat energy losses through the return pipeline at two adjacent, respectively, smaller and larger than for this network, tabular values of the difference between the average annual temperatures of the network water and outdoor air, W / m;

Average for the entire measurement period the flow rate of the coolant through the supply pipeline at the source of thermal energy, kg / s;

Measured values of the flow rate of the heat carrier at the source of thermal energy, taken from the hour file, t / h;

Average for the entire period of measurements the flow rate of the coolant through the supply pipeline at i-th consumer of thermal energy with metering devices, kg / s;

The measured values of the flow rate of the heating medium at i-th consumer of thermal energy, taken from the hour file, t / h;

Average consumption of make-up water for the entire period of measurements at the source of thermal energy, kg / s;

Measured values of the flow rate of the coolant for make-up at the source of thermal energy, taken from the hour file, t / h;

Average for the entire measurement period the flow rate of the coolant in the supply pipeline for all consumers of heat energy without metering devices, kg / s;

Average hourly recharge of the heating network at night, t / h;

Average hourly flow rate of the heat carrier for each i th consumer with metering devices at night for every day from the measurement period, t / h;

Average for the entire measurement period coolant flow rate in the supply pipeline for each j th consumer who does not have metering devices, kg / s;

G k- coolant consumption in a homogeneous area, kg / s;

Average monthly outdoor air temperature, ° С;

Average monthly soil temperature at the average depth of the pipeline axis, ° С;

Average annual outside air temperature, ° С;

Average annual soil temperature at the average depth of the pipeline axis, ° С;

Average monthly temperature of the supply water in the supply pipeline, ° С;

Average monthly temperature of supply water in the return pipeline, ° С;

Average annual temperature of network water in the supply pipeline, ° С;

Average annual temperature of supply water in the return pipeline, ° С;

The average temperature of the supply water for the period of measurements in the supply pipeline at the source of thermal energy, ° С;

The average temperature of the network water in the return pipeline at the heat source during the measurement period, ° С;

Measured values of the temperature of the supply water in the supply pipeline at the source of thermal energy, taken from the hour file, ° С;

Measured values of the temperature of the supply water in the return pipeline at the source of thermal energy, taken from the hour file, ° С;

Average soil temperature at the average depth of the pipeline axis during the measurement period, ° С;

Average temperature of the outside air during the measurement period, ° С;

Accordingly, the tabular values of the average annual temperatures of network water in the supply (65, 90, 110 ° С) and return (50 ° С) pipelines, ° С;

Standard value of the average annual soil temperature, ° С;

The measured values of the temperature of the supply water in the supply pipe at i th consumer, taken from the hour file, ° С;

The value of the difference in the average annual temperatures of network water and soil for a given heating network, ° С;

Less than for this network, the tabular value of the difference between the average annual temperatures of the network water and soil, ° С;

Larger than for a given network, the tabular value of the difference between the average annual temperatures of network water and soil, ° С;

The difference in average annual temperatures for each pair of values of average annual temperatures in the supply and return pipelines and soil, ° С;

The value of the difference in the average annual temperatures of network water and soil for the supply pipeline of the considered heating network, ° С;

Adjacent, respectively, less and more than for this network, tabular values of the difference in the average annual temperatures of the network water in the supply pipeline and the ground, ° С;

The value of the difference between the average annual temperatures of network water and outdoor air, respectively, for the supply and return pipelines for a given heating network, ° С;

Adjacent, respectively, less and more than for this network, tabular values of the difference between the average annual temperatures of the network water in the supply pipeline and outside air, ° С;

Adjacent, respectively, less and more than for this network, tabular values of the difference between the average annual temperatures of the network water in the return pipeline and the outside air, ° С;

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 smallest distance from the source of thermal energy to the branch from the main pipeline to i- to the consumer with metering devices, m;

l j- the smallest distance from the source of thermal energy to the branch to j- to the consumer without metering devices, m (p. 18);

l k- length of a homogeneous area, m;

r is the density of water at the average temperature of the network water in the supply pipeline at the heat source for the first day of the data availability period, kg / m 3;

c p- specific heat capacity of water, J / (kg × K);

W k- speed of the coolant in a homogeneous area, m / s;

F k- the area of the pipeline passage on a homogeneous section, m 2;

b - coefficient of local losses of thermal energy, taking into account the losses of thermal energy by fittings, compensators and supports;

r losses n - coefficient of heat losses of the network in the main supply pipelines, J / (kg × m);

The coefficient of heat energy losses, determined by the time of movement of the coolant in the supply pipelines, J / (kg × s);

n and - the number of hours in the measurement period;

n month - the duration of the heating network operation in the considered month, h;

t p - filling time of all supply pipelines with a coolant, s;

t is the time of movement of the heat carrier from the source of thermal energy to each of the consumers, s;

t to - the time of movement of the coolant on a homogeneous section of the heating network, s;

t i- the 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- the time of movement of the coolant at the smallest distance from the source of thermal energy to j th consumer without metering devices, s;

K- the ratio of 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 sections of the heating network

Table B.1

APPENDIX D

Average monthly and average annual temperatures of the environment and network water

Table D.1

Months	Average temperature over 5 years, ° С		Supply water temperature, ° С
Months	soil	outside air	in the supply pipeline	in the return pipeline
January
February
March
April
May
June
July
August
September
October
November
December
Average annual temperature, ° С

APPENDIX E

Characteristics of heat consumers and metering devices

Table E.1

Consumer name	Heat supply system type (open, closed)	Metering device brand	Archive depth		Centralized data collection (yes, no)
Consumer name	Heat supply system type (open, closed)	Metering device brand	heating	ventilation	Centralized data collection (yes, no)	DHW	Total	daily	hourly
1	2	3	4	5	6	7	8	9	10

APPENDIX E

Norms of heat energy losses by insulated water heat pipelines located in non-passable channels and with channelless laying (with an estimated soil temperature of +5 ° C at the depth of the heat pipelines) according to

Table E.1

Outside diameter of pipes, mm
Outside diameter of pipes, mm	Heat return pipe at average water temperature ( t o = 50 ° C)	Two-pipe laying with a difference in the average annual temperatures of water and soil of 52.5 ° C ( t n = 65 ° C)	Two-pipe laying with a difference in the average annual temperatures of water and soil 65 ° C ( t n = 90 ° C)	Two-pipe laying with a difference in the average annual temperatures of water and soil 75 ° C ( t n = 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 heat energy losses by one insulated water

heat conductor for overhead laying

(with an estimated average annual outside air temperature of +5 ° С)

Table G.1

Outside diameter of pipes, mm	Heat loss rates, W / m
	The difference between the average annual temperature of the supply water in the supply or return pipelines and the outside air, ° С
	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 laying in non-passable channels, W / m, according to

Table I.1


	Pipeline
	serving	back	serving	back	serving	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 with two-pipe underground channelless laying of water heating networks, W / m, according to

Table K.1

Conditional passage of the pipeline, mm	When the number of hours of work per year is more than 5000
	Pipeline
	serving	back	serving	back
	Average annual temperature of the heat carrier, ° С
	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 the change in the norms of heat flux density when using a heat-insulating layer of polyurethane foam, polymer concrete, phenolic foam PL

Table K.2

APPENDIX L

Norms of heat flux density through the insulated surface of pipelines of water heating networks when located in the open air, W / m, by

Table L.1

Conditional passage of the pipeline, mm	When the number of hours of work per year is more than 5000
	Average annual temperature of the heat carrier, ° С
	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 and a tunnel, W / m, by

Table M.1

Conditional passage of the pipeline, mm	When the number of hours of work per year is more than 5000
	Average annual temperature of the heat carrier, ° С
	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 laying in non-passable channels and underground channelless laying, W / m, by

Table H.1

Conditional passage of the pipeline, mm	When the number of hours of work per year is more than 5000
	Pipeline
	serving	back	serving	back	serving	back
	Average annual temperature of the heat carrier, ° С
	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 in the open air along

Table A.1

Conditional passage of the pipeline, mm	When the number of hours of work per year is more than 5000
	Average annual temperature of the heat carrier, ° С
	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 in a room and a tunnel along

Table P.1

Conditional passage of the pipeline, mm	When the number of hours of work per year is more than 5000
	Average annual temperature of the heat carrier, ° С
	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 isolated surfaces are located in a tunnel (through and semi-through channels), a coefficient of 0.85 should be introduced to the density standards.

APPENDIX C

List of referenced normative and technical documents

1. Determination of actual heat losses through thermal insulation in district heating networks / Semenov VG - M .: News of heat supply, 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 .: GUP TsPP Gosstroy of Russia, 1999.

4. Methodology for calculating heat losses in heating networks during transportation. - M .: Firma ORGRES, 1999.

5. Rules for the technical operation of thermal power plants. - M .: Publishing house NTs ENAS, 2003.

6. Typical instructions for the technical operation of systems for transport and distribution of heat energy (heating networks): RD 153-34.0-20.507-98. - M .: SPO ORGRES, 1986.

7. Methodology for determining the standard values of indicators of the functioning of water heating networks of communal heat supply systems. - M .: Roskommunenergo, 2002.

9.GOST 26691-85. Heat power engineering. Terms and Definitions.

10. GOST 19431-84. Energy and electrification. Terms and Definitions.

11. Rules for the development of prescriptions, circulars, operational instructions, guidance documents and information letters 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 REGULATORY LOSS OF THERMAL ENERGY

3.1. Determination of the average annual standard heat losses

3.2. Determination of standard heat energy losses for the measurement period

4. DETERMINATION OF THE ACTUAL LOSS OF THERMAL ENERGY

4.1. Determination of actual losses of heat energy during the measurement period

4.2. Determination of the actual losses of heat energy for the year

ANNEXES

Appendix A. Terms and definitions

Appendix B. Symbols of quantities

Appendix B. Characteristics of sections of the heating network

Appendix D. Average monthly and average annual temperatures of the environment and network water

Appendix D. Characteristics of heat consumers and metering devices

Appendix E. Norms of heat energy losses by insulated water heat pipelines located in non-passable channels and with channelless laying

Appendix G. Norms of heat energy losses by one insulated water heat pipe during overhead laying

Appendix I. Norms of heat flux density through the insulated surface of pipelines of two-pipe water heating networks when laying in non-passage channels

Appendix K. Norms of heat flux density through the insulated surface of pipelines with two-pipe underground channelless laying of water heating networks

Appendix L. Norms of heat flux density through the insulated surface of pipelines of water heating networks when located in the open air

Appendix M. Norms of heat flux density through the insulated surface of pipelines of water heating networks when located in a room and a tunnel

Appendix H. Norms of heat flux density through the insulated surface of pipelines of two-pipe water heating networks when laying in non-passable channels and underground channelless laying

Appendix P. Norms of heat flux density through the insulated surface of pipelines of water heating networks when located in the open air

Appendix P. Norms of heat flux density through the insulated surface of pipelines of water heating networks when located in a room and a tunnel

Appendix C. List of referenced normative and technical documents

2.2 Determination of heat loss and circulation costs in the supply pipelines of the hot water supply system

Circulating hot water consumption in the system, l / s:

,(2.14)

where> - total heat loss by supply pipelines of the DHW system, kW;

The temperature difference in the supply pipelines of the system to the most distant draw-off point,, accepted 10;

Circulation misalignment factor, accepted 1

For a system with variable resistance of circulation risers, the value is determined by the supply pipelines and water-folding risers at = 10 and = 1

Heat losses in the sections, kW, are determined by the formula

Where: q - heat loss of 1 m of the pipeline, W / m, taken according to Appendix 7 AAAAAAAAAAAAAAAAAAAAAAAAAAA

l - the length of the pipeline section, m, taken according to the drawing

When calculating the heat loss of the sections of the water-folding risers, the heat loss of the heated towel rail is taken equal to 100 W, while its length is excluded from the length of the floor stand. For convenience, the calculation of heat loss is summarized in one table 2 with the hydraulic calculation of the network.

Let's 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:

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 for the house will be 23.55 kW.

Let's determine the circulation flow:

l / s

Let us determine the calculated second hot water consumption, l / s, in sections 45 and 44. To do this, we will determine the ratio qh / qcir, for sections 44 and 45 it is respectively equal to 4.5 and 5.5. According to Appendix 5, the coefficient Kcir = 0 in both cases, therefore, the preliminary calculation is final.

To ensure circulation, a circulation pump of the WILO Star-RS 30/7 brand is provided.

2.3 Selection of a water meter

Acc. with item a) item 3.4 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 in the process of sanitary and hygienic procedures, economic activities, as well as atmospheric and melt water. The internal sewerage network consists of branch pipelines, risers, outlets, an exhaust part, and cleaning devices. Drainage pipes are used to drain wastewater from sanitary appliances and transfer them to the riser. Branch pipes are connected to the hydraulic seals of sanitary devices and laid with a slope towards the riser. Risers are designed to transport wastewater to the sewer outlet. They collect drains from the branch pipes and the diameter should be at least the largest diameter of the branch pipe or the outlet of the device connected to the riser.

In this project, the inter-apartment wiring is made of PVC socket pipes with a diameter of 50 mm, the risers with a diameter of 100 mm are made of cast iron, also connected with sockets. Connection to the risers is carried out using crosses and tees. The network provides for revisions and cleanings to remove blockages.

3.1 Determination of the estimated sewage costs

Total maximum design water flow:

Where: - the water consumption by the device, taken equal to 0.3 l / s acc. with appendix 4; - coefficient depending on the total number of devices and the probability of their use Рtot

, (7)

Where: - the total consumption rate per hour of the greatest water consumption, l, taken in accordance with Appendix 4 equal to 20

The number of water consumers equal to 104 * 4.2 people

Number of sanitary appliances, accepted 416 on assignment

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 rate:

Where: - consumption from a sanitary-technical device with the highest drainage capacity, l / s, taken according to Appendix 2 for a toilet with a flush cistern equal to 1.6

3.2 Calculation of risers

The water consumption for the 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 accept the diameter of the riser 100 mm, the diameter of the floor outlet 100 mm, the angle of the floor outlet 90 °. Maximum flow rate 3.2 l / s. Estimated flow rate 2.95 l / s. Consequently, the riser is operating in normal hydraulic mode.

The water consumption for the risers K1-3, K1-4 will be the same, since an equal number of devices are connected to these risers, each with 104 devices.

A new column appeared in receipts for utilities - hot water supply. It caused bewilderment among users, since not everyone understands what it is and why it is necessary to make payments on this line. There are also such apartment owners who cross out the column. This entails the accumulation of debt, interest, fines and even litigation. In order not to take matters to extreme measures, you need to know what is hot water supply, hot water supply and why you need to pay for these indicators.

What is DHW on a receipt?

DHW - this designation stands for hot water supply. Its purpose is to provide apartments in apartment buildings and other residential premises with hot water at an acceptable temperature, but DHW is not hot water itself, but thermal energy that is spent on heating water to an acceptable temperature.

Experts divide hot water supply systems into two types:

Central system. Here the water is heated in a heating plant. After that, it is distributed to apartments in apartment buildings.
Autonomous system. It is commonly 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 one goal - to provide homeowners 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 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 DHW. Autonomous circuit users pay for utility resources that are spent to heat the heat carrier - gas or electricity.

Important! Another one in the column in the receipt related to DHW is DHW at ONE. Decoding ODN - general house needs. This means that the DHW column for ONE is the consumption of energy for heating water used for the general needs of all residents of an apartment building.

These include:

technical work that is carried out before the heating season;
pressure testing of the heating system, carried out after repair;
repair work;
heating of common areas.

Hot water law

The DHW Law was adopted in 2013. Government Decree No. 406 states that users of the district heating system are obliged to pay at a two-component tariff. This suggests that the tariff was divided into two elements:

thermal energy;
cold water.

So hot water supply appeared in 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 for decades free of charge, since outside the heating season, air heating in the bathroom continued. Based on this, officials divided the tariff into two components, and now citizens have to pay for hot water supply.

Water heating equipment

The equipment for heating the liquid is a water heater. Its breakdown does not affect the tariff for hot water, but users must pay the cost of repairing equipment, since water heaters are part of the property of homeowners in an apartment building. The corresponding amount will appear on 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 an autonomous heating system is installed in their homes. Housing and communal services specialists do not always pay attention to this, simply distributing the amount for the repair of the water heater among all citizens.

As a result, these apartment owners have to pay for equipment they did not use. If you find an increase in the rate for the repair and maintenance of property, you need to find out what this is connected with and contact the management company for a recalculation if the payment is calculated incorrectly.

Thermal energy component

What is this - a component for a coolant? This is the heating of cold water. A metering device is not installed on the thermal energy component, unlike hot water. For this reason, it is impossible to calculate this indicator by the counter. How is the heat energy for DHW calculated in this case? When calculating the payment, the following points are taken into account:

the tariff that is set for DHW;
costs spent on maintaining the system;
the cost of heat loss in the circuit;
costs spent on the transfer of the coolant.

Important! The calculation of the cost of hot water is carried out taking into account the volume of consumed water, which is measured in 1 cubic meter.

The amount of the energy charge is usually calculated based on the value of the readings of the general hot water meter and the amount of energy in the hot water. Energy is calculated for each individual apartment. For 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 an independent calculation

Not all users trust the settlement center, therefore, the question arises of how to calculate the cost of hot water supply yourself. The resulting indicator is compared with the amount in 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 heat energy. The amount is also affected by the presence or absence of a metering device. If it is, then readings are taken from the meter. In the absence of a meter, the standard for the consumption of thermal energy used for heating water is taken. Such a normative indicator is established by an energy-saving organization.

If an energy consumption meter is installed in a multi-storey building and there is a meter for hot water in the house, then the amount for hot water supply is calculated on the basis of the data of general housekeeping and the subsequent proportional distribution of the coolant among the apartments. In the absence of a meter, the rate of energy consumption per 1 cubic meter of water and the readings of individual meters are taken.

Complaint about incorrect receipt calculation

If, after self-calculating the amount of contributions for hot water supply, a difference is revealed, you must contact the management company for clarification. If the employees of the organization refuse to give explanations about this, it is necessary to submit a written claim. Its employees of the company have no right to ignore. The answer must be received within 13 working days.

Important! If no answer was received or it is not clear from it why such a situation arose, then the citizen has the right to file a claim with the prosecutor's office or a statement of claim to the court. The instance will consider the case and make an appropriate objective decision. You can also contact the organizations that control the activities of the management company. Here the subscriber's complaint will be considered and an appropriate decision will be made.

The electricity used to heat the water is not a free service. The 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 received data with the amount in the receipt. If any inaccuracies arise, you should contact the management company. In this case, the difference will be compensated if the error is acknowledged.

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 calculation of hot water supply systems should be carried out for the estimated consumption of hot water

Taking into account the circulation flow rate, l / s, determined by the formula

(14)

where is the coefficient taken: for water heaters and the initial sections of systems up to the first standpipe according to mandatory Appendix 5;

for other parts 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 coefficient of misalignment of circulation;

Heat loss by hot water pipelines, kW;

The temperature difference in the supply pipelines of the system from the water heater to the most distant draw-off point, ° С.

The values and, depending on the hot water supply scheme, should be taken:

for systems that do not provide for the circulation of water through the risers, the value should be determined by the supply and distribution pipelines at = 10 ° C and = 1;

for systems that provide for the circulation of water through the risers with variable resistance of the circulating risers, the value should be determined by the supply distribution pipelines and risers at = 10 ° C and = 1; with the same resistance of sectional nodes or risers, the value should be determined by the water-folding risers at = 8.5 ° C and = 1.3;

for a standpipe or a sectional unit, heat loss should be determined along the supply pipelines, including the ringing bulkhead, taking = 8.5 ° C and = 1.

8.3. The head loss in the sections of pipelines of hot water supply systems should be determined:

for systems where it is not required to take into account the overgrowth of pipes - in accordance with clause 7.7;

for systems taking into account overgrowth of pipes - according to the formula

where i is the specific pressure loss taken according to the recommended Appendix 6;

Coefficient that takes into account the head loss 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-folding risers with heated towel rails;

0.1 - for pipelines of water-folding 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 head loss in the supply and circulation pipelines from the water heater to the most distant water 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 match the pressures in the pipeline network of hot water supply systems by appropriate selection of pipe diameters, it is necessary to provide for the installation of 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 the calculation, the diameter of the diaphragms must be taken less than 10 mm, then instead of the diaphragm, it is allowed to provide for the installation of valves to regulate the pressure.

The diameter of the holes in the regulating diaphragms is recommended to be determined by the formula

(17)

8.7. In systems with the same resistance of sectional units or risers, the total pressure loss in the supply and circulation pipelines within the limits between the first and the last risers at circulating flow rates should be 1.6 times higher than the pressure loss in the sectional unit or riser when the circulation is unregulated = 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 the circulation flows in the risers or sectional units determined in accordance with clause 8.2, the pressure loss between the points of their connection to the distribution supply and collection circulation pipelines does not differ more than 10%.

8.8. In hot water supply systems connected to closed heating networks, the pressure loss in the sectional nodes 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 intake from pipelines of the heating network, the pressure loss in the pipeline network should be determined taking into account the pressure in the return pipe of the heating network.

The pressure loss in the circulation ring of the system pipelines at the circulation flow rate should not, as a rule, exceed 0.02 MPa (0.2 kgf / sq.cm).

8.10. In shower rooms with more than three shower nets, the distribution pipeline should, as a rule, be provided in a loop.

One-way hot water supply is allowed to be provided for collector 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.