GB 50495-2019 English PDFGB 50495: Historical versions
Basic dataStandard ID: GB 50495-2019 (GB50495-2019)Description (Translated English): Technical code for solar heating system Sector / Industry: National Standard Classification of Chinese Standard: P46 Classification of International Standard: 91.140.01 Word Count Estimation: 149,126 Date of Issue: 2019-05-24 Date of Implementation: 2019-12-01 Issuing agency(ies): Ministry of Housing and Urban-Rural Development of the People's Republic of China; State Administration for Market Regulation GB 50495-2019: Technical code for solar heating system---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.1 General 1.0.1 This standard is formulated in order to standardize the design, construction, acceptance and evaluation of solar heating projects, make solar heating projects safe and applicable, economical and reasonable, advanced and reliable, and improve project quality. 1.0.2 This standard applies to the use of solar heating and heating in newly built, expanded and rebuilt buildings, as well as the addition or renovation of solar heating and heating facilities and system engineering design, construction, acceptance and evaluation of existing buildings. 1.0.3 The solar heating system should be included in the construction management of construction projects, and should be planned, designed, constructed, checked and accepted in a unified manner, and put into use at the same time. 1.0.4 The solar heating system should be comprehensively utilized throughout the year. During the non-heating period, it should supply domestic hot water, summer refrigeration and air conditioning or other heat according to demand. 1.0.5 When adding or renovating solar heating systems in existing buildings, the building structure safety review should be carried out and the safety requirements should be met. 1.0.6 It is advisable to carry out building energy-saving renovation for existing buildings with solar heating systems. 1.0.7 Energy saving and environmental protection benefit analysis and evaluation should be carried out for solar heating and heating projects. 1.0.8 The design, construction, acceptance and evaluation of solar heating projects shall not only comply with this standard, but also comply with the current relevant national standards. 2 terms2.0.1 Solar heating Convert solar energy into heat energy to meet certain heating needs of buildings in winter, or supply buildings with winter heating and other heat throughout the year, which can be divided into passive solar heating and solar heating heating systems. 2.0.2 passive solar heating Through the reasonable selection and treatment of building orientation and surrounding environment layout, building internal and external space layout, building materials, and envelope structure, the building itself can collect, store and distribute solar heat in winter, and shield solar radiation and dissipation in summer. Function of indoor heat. 2.0.3 solar heating system Set up special equipment such as solar collectors, and provide heating for buildings in winter and other heat throughout the year through circulation pipelines. 2.0.4 solar thermal combined heat and power generation system A system that converts solar energy into thermal energy, generates electricity through the thermal power conversion process, and uses waste heat for heating. 2.0.5 Solar heating system with short-term heat storage The heat storage device can store the heat obtained from the sun for several days in a solar heating and heating system. 2.0.6 Solar heating system with seasonal heat storage The thermal storage device can store the solar energy heat gained from the sun in the non-heating season. 2.0.7 solar liquid collector A device that absorbs solar radiation and transfers the generated heat energy to a liquid heat transfer medium. 2.0.8 solar air collector A device that absorbs solar radiation and transfers the generated heat energy to the air heat transfer medium. 2.0.9 solar collector system A system that collects solar energy and converts it into thermal energy that is transferred to a heat storage device. 2.0.10 direct solar heat collection system solar direct system The heated working fluid in the solar heat collector is directly supplied to the user's solar heat collection system. 2.0.11 solar indirect system The heat transfer working medium is heated in the solar collector, and then the heat transfer working medium is heated by the heat exchanger to supply the user's solar heat collection system with water. 2.0.12 Closed solar heat collection system solar closed system The solar heat collection system in which the heat transfer medium in the heat collection system is not connected to the atmosphere. 2.0.13 drain down system When the working medium may be frozen, all the working medium can be emptied to prevent the direct solar heat collection system from freezing damage. 2.0.14 drain back system When the working medium may be frozen, all the working medium can be discharged back to the indoor liquid storage tank to prevent the indirect solar heat collection system from freezing damage. 2.0.15 antifreeze system antifreeze system A solar heat collection system that uses antifreeze as a heat transfer medium to prevent freezing damage. 2.0.16 freeze-proofing system with circulation A solar heat collection system that prevents freezing damage through working medium circulation. 2.0.17 efficiency of solar collector system The ratio of the heat gain of a solar thermal collection system to the total solar radiation incident on the total area of the system collectors during a specified period of time. 2.0.18 The ratio of electricity consumption to transferred heat quantity for solar collector system Under design conditions, the ratio of the total power consumption of the circulating water pump or fan of the solar thermal collection system to the heat gain of the solar thermal collection system. 2.0.19 Solar fraction The percentage of heat supplied by solar energy in the solar heating system to the design load of the solar collector system. 2.0.20 cost-benefit ratio of the system The ratio of the increased investment of the solar heating system to the total energy saving of the system during the normal service life indicates the investment cost per kWh of conventional energy heat saved by using solar energy. 2.0.21 heat consumption of building Under the condition of calculating the average outdoor air temperature during the heating period, in order to maintain the calculated indoor design temperature, the heat consumed by the building within a unit time must be supplied by indoor heating facilities. 2.0.22 Building heating design heat load heating load for space heating of building Under the condition of the calculated temperature outside the heating, in order to maintain the calculated temperature of the indoor design, the heat consumed by the building in a unit time and needs to be supplied by the heating facility. 2.0.23 gross collector area The maximum projected area of the entire collector, excluding those components that fix and connect the heat transfer pipes.3 Basic Regulations3.1 General provisions 3.1.1 The application of solar heating technology in new buildings should follow the principles of passive technology priority and active system optimization. 3.3.7 The solar heat and power cogeneration system shall be equipped with a heat exchange machine room, and shall provide indirect heat supply through the heat exchanger. 3.3.8 When the thermal network of the solar cogeneration system uses hot water as the heating medium, the design pressure of the pipe network shall not exceed 2.5MPa, and the design temperature shall not exceed.200°C; when steam is used as the heating medium, the pipe network shall The design pressure should not be greater than 1.6MPa, and the design temperature should not be greater than 350°C.4 Load calculation and type selection design of solar heating system4.1 General provisions 4.1.1 The load calculation of the solar heating system shall include the load calculation of the solar heat collection system and the load calculation of other energy-assisted heating or heat exchange equipment. 4.1.2 The selection and design of the solar heating system should be carried out according to the requirements of construction installation, operation and use, operation management, component replacement and maintenance, etc., and should be safe, reliable, applicable, economical and beautiful. 4.2 Load calculation 4.2.1 The design load of the solar heat collection system should choose the larger value of the heating heat load and domestic hot water supply load it bears. 4.2.2 The heating heat load borne by the solar collector system should be determined by calculating the hourly heat load in the heating season; when the simplified calculation method is adopted, the heating heat load should be the heat consumption of the building under the average outdoor temperature during the heating period, and should meet the following requirements. 1 The heating heat load borne by the solar heat collection system shall be calculated according to the following formula. QH＝QHT＋QINF－QIH (4.2.2-1) In the formula. QH——the heating heat load borne by the solar heat collection system (W); QHT——heat consumption through the envelope structure (W); QINF——heat consumption of air infiltration (W); QIH—Heat gain inside the building, including lighting, electrical appliances, cooking, heat dissipation from the human body and heat gain from passive solar heat-collecting components, etc. (W). 2 The heat consumption of heat transfer through the enclosure structure shall be calculated according to the following formula. QHT＝εKT(ti－te)(1＋Ф) (4.2.2-2) In the formula. QHT——the heat consumption of heat transfer through the envelope structure (W); ti—calculated indoor air temperature (°C), selected according to the lower limit of the range specified in the "Code for Design of Heating, Ventilation and Air Conditioning in Civil Buildings" GB 50736-2012; te——average outdoor temperature (°C) during the heating period, which should be selected according to Appendix A of this standard; ε—the temperature difference correction coefficient of the enclosure structure, which should be selected according to the provisions of GB 50736-2012 in the "Code for Design of Heating, Ventilation and Air Conditioning in Civil Buildings"; K——The heat transfer coefficient of the envelope structure [W/(m2·℃)]; F—area of enclosure structure (m2); Ф——The percentage (%) of the additional heat consumption of the enclosure structure to the basic heat consumption, which should be selected according to the provisions of the "Code for Design of Heating, Ventilation and Air Conditioning in Civil Buildings" GB 50736-2012. 3 The heat consumption of air infiltration should be calculated according to the following formula. QINF＝CpρL(ti－te) (4.2.2-3) In the formula. QINF——air permeation heat consumption (W); Cp——air specific heat capacity, [W·h/(kg·℃)], take 0.28W·h/(kg·℃); ρ——air density (kg/m3), take the value under te condition; L——The amount of infiltrated cold air, (m3/h), which should be calculated according to the provisions of Appendix F in the "Code for Design of Heating, Ventilation and Air Conditioning in Civil Buildings" GB 50736-2012. 4.2.3 The domestic hot water supply load borne by the solar heat collection system should be the average daily heat consumption of the building’s domestic hot water, and the calculation of the average daily heat consumption of hot water should comply with the current national standard "Code for Design of Water Supply and Drainage for Buildings" GB 50015 Regulation. 4.2.4 The design load of other energy-assisted heating or heat exchange equipment shall be determined according to the larger value of the building heating design heat load and building hot water design hourly heat consumption. 4.2.5 The calculation of building heating design heat load shall meet the following requirements. 1 The calculation of heating design heat load shall comply with the provisions of the current national standard "Code for Design of Heating Ventilation and Air Conditioning in Civil Buildings" GB 50736. 2 The current national standard "Code for Design of Heating, Ventilation and Air Conditioning in Civil Buildings" GB 50736 stipulates that areas or buildings with central heating may not be set up, and it is advisable to reduce the calculated temperature of indoor air according to the actual local conditions. 4.2.6 Calculation of heat consumption per design hour for domestic hot water shall comply with the provisions of the current national standard "Code for Design of Water Supply and Drainage in Buildings" GB 50015. 4.3 Selection design 4.3.1 When the site conditions for solar collector installation are available, the ground-mounted solar heating system should be selected. 4.3.2 The type of solar heating system combined with the building should be determined according to Table 4.3.2 according to the climate zone of the building and the type of building. 4.3.3 The liquid working fluid solar heating system should adopt terminal heating facilities such as low-temperature hot water radiation, water-air treatment equipment and radiators. 4.3.4 The air-solar heating system should be used in the area of the building that needs hot air heating. 4.3.5 The operating noise of terminal heating equipment shall comply with the provisions of relevant current national standards.5 Design and construction of solar heat collection system5.1 General provisions 5.1.1 The installation of solar heat collection systems on buildings shall not reduce the sunshine standard of adjacent buildings 5.1.2 The solar heat collection system should adopt technical measures such as antifreeze, anti-overheating, anti-hail, anti-wind, anti-seismic, lightning protection and electricity safety according to the construction area and operating conditions 5.1.3 The direct solar heat collection system should be used in areas with high ambient temperature in winter and no serious frost protection problem; the indirect solar heat collection system should be used in areas with low winter ambient temperature. 5.1.4 The performance of the solar collector in the solar heating system shall comply with the current national standards "Flat Solar Collector" GB/T 6424, "Evacuated Tube Solar Collector" GB/T 17581 and "Solar Air Collector Technical Conditions" GB/T 26976, and the normal service life should not be less than 15 years. 5.1.5 The construction and installation of the solar heat collection system must not damage the structure, roof, ground waterproof layer and auxiliary facilities of the building, and must not weaken the ability of the building to bear the load 5.1.6 The pipes and insulation materials of the solar heat collection system should be corrosion-resistant, compatible with the heat transfer medium, able to withstand the maximum operating temperature of the system, and convenient and reliable for installation and connection. 5.1.7 The solar heat collection system shall be equipped with automatic control and shall comply with the following regulations. 1.The function of automatic control shall include the operation control and safety protection control of the solar heat collection system, the work switching control of the heat collection system and other auxiliary heat source equipment. The functions of the safety protection control of the solar thermal collection system shall include antifreeze protection and anti-overheating protection. 2 The control method should be simple, reliable and easy to operate. 3 The measurement uncertainty of the temperature sensor used in the automatic control system shall not be greater than 0.5°C. 5.2 Design of solar heat collection system 5.2.1 The setting of solar collectors should meet the following requirements. 1.The solar collector should be oriented to the south, or set within a range of 20° to the east or west of the south; the installation inclination should be the local latitude + 10°; when limited by actual conditions, the area compensation of the Standard Appendix B is implemented, and an economic benefit analysis should be carried out. 2 For the solar collectors placed on the building envelope, the sunshine hours on the daylighting surface of the collectors on the winter solstice shall not be less than 6h. There should be a space between the front and rear heat collectors for installation and maintenance operations, and the arrangement should be neat and orderly. 3 The sunlight interval at which the solar collector is not blocked by the obstacles in front at a certain moment shall be calculated according to the following formula. D = Hcothcosγ0 (5.2.1) In the formula. D——sunshine spacing (m); H - the height of the obstacle in front (m); h——The altitude angle of the sun at the time of calculation (°). γ0——the angle (°) between the projection line of the sun's rays on the horizontal plane and the projection line of the collector surface normal on the horizontal plane at the calculation time. 4 Solar collectors shall not be installed across building deformation joints. 5.2.2 The total area of solar collectors should be determined through dynamic simulation calculations. When the simplified calculation method is adopted, the following provisions shall be complied with. 1 The total area of the heat collector of the short-term heat storage direct system shall be calculated according to the following formula. In the formula. Ac - the total area of the short-term heat storage direct system collector (m2); QJ——Design load of solar heat collection system (W); JT——The average daily solar radiation in December on the daylighting surface of the local collector [J/(m2·d)], which should be selected according to Appendix A of this standard; f——solar energy guarantee rate (%), which should be selected according to Appendix A of this standard; ηcd——the average heat collection efficiency (%) of the heat collector based on the total area, which should be calculated according to Appendix C of this standard; ηL——the heat loss rate (%) of pipelines and heat storage devices, which should be calculated according to Appendix D of this standard. 2 The total area of the collectors of the direct system of seasonal heat storage shall be calculated according to the following formula. In the formula. Ac.s - the total area of the collector of the seasonal heat storage direct system (m2); Ja - the annual average daily solar radiation [J(m2·d)] on the daylighting surface of the local collector, which should be selected according to Appendix A of this standard; f——solar energy guarantee rate (%), selected according to Appendix A of this standard; Ds——the number of days in the local heating period (d); ηs——seasonal heat storage system efficiency, which can be 0.7~0.9. 3 The total area of heat collectors in the indirect system shall be calculated according to the following formula. In the formula. AIN - the total area of the indirect system collector (m2); Ac - the total area of the direct system collector (m2); UL——The total heat loss coefficient of the collector [W/(m2 ℃)], obtained from the test; Uhx——heat transfer coefficient of heat exchanger [W/(m2 ℃)], obtained from product samples; Ahx——the heat transfer area of the indirect system heat exchanger (m2), which should be calculated according to Appendix E of this standard. 5.2.3 Determine the pipe diameter, length, layout and hydraulic balance device of the system pipeline through hydraulic calculation, which shall meet the hydraulic balance requirements of the pipe network. 5.2.4 The design flow rate of the working fluid of a single solar collector should be calculated according to the following formula. Gs = gA (5.2.4) In the formula. Gs——the design flow rate of the working fluid of the single solar collector (m3/h); A - the total area of a single solar collector (m2); g——the flow rate per unit area of the working fluid of the solar collector [m3/(h m2)], which should be determined acco......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of GB 50495-2019_English be delivered?Answer: Upon your order, we will start to translate GB 50495-2019_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.Question 2: Can I share the purchased PDF of GB 50495-2019_English with my colleagues?Answer: Yes. The purchased PDF of GB 50495-2019_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.Question 3: Does the price include tax/VAT?Answer: Yes. 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