1 General provisions
1.0.1 This standard is formulated with a view to saving energy, protecting the environment, developing urban central heating in China, and improving the design level of central heating engineering, so as to achieve advanced technology, economic rationality, safety and applicability.
1.0.2 This standard is applicable to the design of constructed, extended or renovated urban heating network from the heat source outlet to the heat inlet of building, which has a design pressure of less than or equal to 2.5MPa and a design temperature of less than or equal to 200℃ (hot water as heating medium) and 350℃ (steam as heating medium).
1.0.3 The design of urban heating network shall conform to the requirements of urban planning and township planning, and shall be harmonized with the environment.
1.0.4 In addition to this standard, the design of urban heating network in seismic, collapsible loess, expansive soil, saline soil and other regions shall also comply with the requirements of the current national standards GB 50032 Code for seismic design of outdoor water supply, sewerage, gas and heating engineering, GB 50025 Standard for building construction in collapsible loess regions, GB 50112 Technical code for buildings in expansive soil regions and GB/T 50942 Technical code for building in saline soil regions.
1.0.5 In addition to this standard, the design of urban heating network shall also comply with the requirements of the current relevant standards of the nation.
2 Terms
2.0.1 heating network
pipeline system for conveying and distributing heating medium from heat sources to heat consumers
2.0.2 transmission mains
mainline from the heat source to the main load area, with a length of more than 2km and without branch pipes
2.0.3 distribution pipelines
main pipelines with branch pipes
2.0.4 long distance pipeline
hot water pipeline from the heat source to the main load area, with a length of more than 20km
2.0.5 block hot-water heating network
hot-water heating network with a design pressure of not more than 1.6MPa and a design temperature of not more than 85℃, which extends from the outlet of heat sources such as heating substation or consumer's boiler room, heat pump room and direct combustion engine room to the heat inlet of building and is directly connected to the indoor system of the heat consumer
2.0.6 dynamical hydraulic analysis
analysis of transient pressure changes in a heating network due to sudden changes in operating state
2.0.7 heating system with multi-heat sources
heating system with multiple heat sources
2.0.8 independently operation of multi-heat sources
operation mode of a heating system with multi-heat sources, in which valves are used to separate the heating range of each heat source so that each heat source can supply heat independently
2.0.9 separately operation of multi-heat sources
operation mode of a heating system with multi-heat sources, in which the base-load heat source is put into operation first, and then the heating range of the base-load heat source and peak-shaving heat source is gradually adjusted with valves as the temperature changes
2.0.10 pooled operation of multi-heat sources
operation mode of a heating system with multi-heat sources, in which the base-load heat source is put into operation first, and then the peak-shaving heat source and the base-load heat source jointly supply heat in the heating network as the temperature changes
2.0.11 minimum heating rate
ratio of the minimum heating load required to prevent freezing of the consumer's heating equipment to the design heating load under accident states
2.0.12 installation without compensator
installation method of directly buried hot-water pipeline, in which the straight pipe sections are not provided with any artificial compensation measures
2.0.13 heating substation
facility for converting the type of heating medium, changing the parameters of heating medium, and distributing, controlling and metering the heat supplied to consumers
2.0.14 boosting pump station
pumps and other facilities installed on the transmission mains or distribution pipelines in the hot-water heating network according to the hydraulic regime
2.0.15 pressure isolation station
facilities for dividing a pipe network into independent pressure systems on a heating mainline
2.0.16 combined type expansion joint
compensator which is combined with pipe elbow into a group for compensation of thermal expansion
3 Heat consumption
3.1 Heating load
3.1.1 In the design of branch lines of heating network, block hot-water heating network and consumer's heating substation, the heating load for heating, ventilation, air conditioning and domestic hot water should be the verified design heating load of the building, and the heat loss of heating network in transmission shall be considered at the same time.
3.1.2 When no information on the design heating load of building is available, the heating load for heating, ventilation, air conditioning and domestic hot water of civil buildings shall be determined according to the following requirements:
1 The design heating load for space heating shall be calculated using the following formula:
(3.1.2-1)
where,
Qh——the design heating load for space heating, kW;
qh——the heating load index for space heating, W/m2, which may be taken according to Table 3.1.2-1;
Ah——the floor area of the heated building, m2.
.... ....
3.1.4 When no design information on the heating load for heating, ventilation, air conditioning, living and production process of industrial buildings is available, the actual heat consumption data of production buildings and production processes shall be adopted for existing enterprises, and possible changes in the future shall be taken into account; for industrial enterprises planned for construction, the heating load may be estimated according to the typical scale of production in the estimation indexes of projects in different industries, or may be calculated according to the design information or actual heat consumption quota of enterprises of the same type and in the same region.
3.1.5 The maximum heating load for production process shall be determined according to the superposition of typical daily load curves of heat consumers. When it is not possible to draw the typical daily load curve, the maximum load may be taken as the sum of the verified maximum heating loads of heat consumers multiplied by the diversity factor. The diversity factor may be taken as 0.6~0.9.
3.1.6 The design heating load for domestic hot water shall be taken according to the following requirements:
1 For the heating mainlines, the daily average heating load for domestic hot water shall be adopted;
2 For the heating branch lines, if the heat consumer has water storage tank of enough volume, the daily average heating load for domestic hot water shall be adopted; if not, the maximum hourly heating load for domestic hot water shall be adopted, and the diversity factor shall be taken into account in the superposition of the maximum hourly heating loads.
3.1.7 When it is technically and economically feasible for the heating network with thermal power plant as heat source, the heating loads of non-heating period shall be developed, including heating load for cooling and that for seasonal production.
3.2 Annual heat consumption
3.2.1 The annual heat consumption of civil buildings shall be calculated using the following formulae:
1 The annual heat consumption for heating:
1 General provisions
2 Terms
3 Heat consumption
3.1 Heating load
3.2 Annual heat consumption
4 Heating medium
4.1 Heating mediums selection
4.2 Parameters of heating medium
4.3 Water quality
5 Heating network types
6 Heat-supply regulation
7 Hydraulic calculation
7.1 General requirements
7.2 Design flow
7.3 Parameters of calculation
7.4 Pressure state
7.5 Pump selection
8 Network layout and bury method
8.1 Network layout
8.2 Bury method of pipeline
8.3 Materials and connecting of pipeline
8.4 Compensation of thermal expansion
8.5 Accessories and components
9 Calculation of stresses and actions
10 Station
10.1 General requirements
10.2 Boosting pump station
10.3 Hot-water heating substation and pressure isolation station
10.4 Steam heating substation
11 Insulation and anticorrosion
11.1 General requirements
11.2 Insulation calculation
11.3 Insulation construction
11.4 Anticorrosion
12 Power supply and lighting
12.1 General requirements
12.2 Power supply and distributing
12.3 Lighting
13 Thermal monitoring and control
13.1 General requirements
13.2 Parameter monitoring and control of pipe network
13.3 Parameter monitoring and control of boosting pump station
13.4 Parameter monitoring and control of heating substation and pressure isolation station
13.5 Monitoring system of pipe network
Annex A Distance between heating network and building (structure) or other pipelines
Annex B Stress analysis for steel pipes installed aboveground or in ducts
Annex C Insulation calculation of heating pipeline
Explanation of wording in this standard
List of quoted standards
Explanation of provisions
Standard
CJJ/T 34-2022 Design standard for urban heating network (English Version)
1 General provisions
1.0.1 This standard is formulated with a view to saving energy, protecting the environment, developing urban central heating in China, and improving the design level of central heating engineering, so as to achieve advanced technology, economic rationality, safety and applicability.
1.0.2 This standard is applicable to the design of constructed, extended or renovated urban heating network from the heat source outlet to the heat inlet of building, which has a design pressure of less than or equal to 2.5MPa and a design temperature of less than or equal to 200℃ (hot water as heating medium) and 350℃ (steam as heating medium).
1.0.3 The design of urban heating network shall conform to the requirements of urban planning and township planning, and shall be harmonized with the environment.
1.0.4 In addition to this standard, the design of urban heating network in seismic, collapsible loess, expansive soil, saline soil and other regions shall also comply with the requirements of the current national standards GB 50032 Code for seismic design of outdoor water supply, sewerage, gas and heating engineering, GB 50025 Standard for building construction in collapsible loess regions, GB 50112 Technical code for buildings in expansive soil regions and GB/T 50942 Technical code for building in saline soil regions.
1.0.5 In addition to this standard, the design of urban heating network shall also comply with the requirements of the current relevant standards of the nation.
2 Terms
2.0.1 heating network
pipeline system for conveying and distributing heating medium from heat sources to heat consumers
2.0.2 transmission mains
mainline from the heat source to the main load area, with a length of more than 2km and without branch pipes
2.0.3 distribution pipelines
main pipelines with branch pipes
2.0.4 long distance pipeline
hot water pipeline from the heat source to the main load area, with a length of more than 20km
2.0.5 block hot-water heating network
hot-water heating network with a design pressure of not more than 1.6MPa and a design temperature of not more than 85℃, which extends from the outlet of heat sources such as heating substation or consumer's boiler room, heat pump room and direct combustion engine room to the heat inlet of building and is directly connected to the indoor system of the heat consumer
2.0.6 dynamical hydraulic analysis
analysis of transient pressure changes in a heating network due to sudden changes in operating state
2.0.7 heating system with multi-heat sources
heating system with multiple heat sources
2.0.8 independently operation of multi-heat sources
operation mode of a heating system with multi-heat sources, in which valves are used to separate the heating range of each heat source so that each heat source can supply heat independently
2.0.9 separately operation of multi-heat sources
operation mode of a heating system with multi-heat sources, in which the base-load heat source is put into operation first, and then the heating range of the base-load heat source and peak-shaving heat source is gradually adjusted with valves as the temperature changes
2.0.10 pooled operation of multi-heat sources
operation mode of a heating system with multi-heat sources, in which the base-load heat source is put into operation first, and then the peak-shaving heat source and the base-load heat source jointly supply heat in the heating network as the temperature changes
2.0.11 minimum heating rate
ratio of the minimum heating load required to prevent freezing of the consumer's heating equipment to the design heating load under accident states
2.0.12 installation without compensator
installation method of directly buried hot-water pipeline, in which the straight pipe sections are not provided with any artificial compensation measures
2.0.13 heating substation
facility for converting the type of heating medium, changing the parameters of heating medium, and distributing, controlling and metering the heat supplied to consumers
2.0.14 boosting pump station
pumps and other facilities installed on the transmission mains or distribution pipelines in the hot-water heating network according to the hydraulic regime
2.0.15 pressure isolation station
facilities for dividing a pipe network into independent pressure systems on a heating mainline
2.0.16 combined type expansion joint
compensator which is combined with pipe elbow into a group for compensation of thermal expansion
3 Heat consumption
3.1 Heating load
3.1.1 In the design of branch lines of heating network, block hot-water heating network and consumer's heating substation, the heating load for heating, ventilation, air conditioning and domestic hot water should be the verified design heating load of the building, and the heat loss of heating network in transmission shall be considered at the same time.
3.1.2 When no information on the design heating load of building is available, the heating load for heating, ventilation, air conditioning and domestic hot water of civil buildings shall be determined according to the following requirements:
1 The design heating load for space heating shall be calculated using the following formula:
(3.1.2-1)
where,
Qh——the design heating load for space heating, kW;
qh——the heating load index for space heating, W/m2, which may be taken according to Table 3.1.2-1;
Ah——the floor area of the heated building, m2.
.... ....
3.1.4 When no design information on the heating load for heating, ventilation, air conditioning, living and production process of industrial buildings is available, the actual heat consumption data of production buildings and production processes shall be adopted for existing enterprises, and possible changes in the future shall be taken into account; for industrial enterprises planned for construction, the heating load may be estimated according to the typical scale of production in the estimation indexes of projects in different industries, or may be calculated according to the design information or actual heat consumption quota of enterprises of the same type and in the same region.
3.1.5 The maximum heating load for production process shall be determined according to the superposition of typical daily load curves of heat consumers. When it is not possible to draw the typical daily load curve, the maximum load may be taken as the sum of the verified maximum heating loads of heat consumers multiplied by the diversity factor. The diversity factor may be taken as 0.6~0.9.
3.1.6 The design heating load for domestic hot water shall be taken according to the following requirements:
1 For the heating mainlines, the daily average heating load for domestic hot water shall be adopted;
2 For the heating branch lines, if the heat consumer has water storage tank of enough volume, the daily average heating load for domestic hot water shall be adopted; if not, the maximum hourly heating load for domestic hot water shall be adopted, and the diversity factor shall be taken into account in the superposition of the maximum hourly heating loads.
3.1.7 When it is technically and economically feasible for the heating network with thermal power plant as heat source, the heating loads of non-heating period shall be developed, including heating load for cooling and that for seasonal production.
3.2 Annual heat consumption
3.2.1 The annual heat consumption of civil buildings shall be calculated using the following formulae:
1 The annual heat consumption for heating:
Contents of CJJ/T 34-2022
1 General provisions
2 Terms
3 Heat consumption
3.1 Heating load
3.2 Annual heat consumption
4 Heating medium
4.1 Heating mediums selection
4.2 Parameters of heating medium
4.3 Water quality
5 Heating network types
6 Heat-supply regulation
7 Hydraulic calculation
7.1 General requirements
7.2 Design flow
7.3 Parameters of calculation
7.4 Pressure state
7.5 Pump selection
8 Network layout and bury method
8.1 Network layout
8.2 Bury method of pipeline
8.3 Materials and connecting of pipeline
8.4 Compensation of thermal expansion
8.5 Accessories and components
9 Calculation of stresses and actions
10 Station
10.1 General requirements
10.2 Boosting pump station
10.3 Hot-water heating substation and pressure isolation station
10.4 Steam heating substation
11 Insulation and anticorrosion
11.1 General requirements
11.2 Insulation calculation
11.3 Insulation construction
11.4 Anticorrosion
12 Power supply and lighting
12.1 General requirements
12.2 Power supply and distributing
12.3 Lighting
13 Thermal monitoring and control
13.1 General requirements
13.2 Parameter monitoring and control of pipe network
13.3 Parameter monitoring and control of boosting pump station
13.4 Parameter monitoring and control of heating substation and pressure isolation station
13.5 Monitoring system of pipe network
Annex A Distance between heating network and building (structure) or other pipelines
Annex B Stress analysis for steel pipes installed aboveground or in ducts
Annex C Insulation calculation of heating pipeline
Explanation of wording in this standard
List of quoted standards
Explanation of provisions
