全玻璃真空管太阳能阵列供暖系统性能试验
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摘要
为了研究实际工况下全玻璃真空管太阳能集热器系统的动态供暖性能,通过试验研究和理论分析得出了储热水箱总热损系数、太阳能集热器阵列集热效率的回归方程以及系统太阳能利用率的计算公式,结果表明:2015年11月24日至2015年12月5日,储热水箱总热损系数为25.82~31.53 W/℃,全玻璃真空管太阳能集热器阵列的集热效率为38%~72%。以2015年11月30日为例,系统的太阳能利用率为37.1%,太阳能集热器所收集的热量仅有54.6%被利用,系统热损过大。通过对比系统供热量和建筑逐时耗热量发现:在供暖期间,系统所提供的热量远大于该段时间的建筑耗热量,特别是在供暖初期,供热量达到了该时段建筑耗热量的10倍以上,供热量和供暖时间过于集中;针对此问题提出了单户太阳能供暖系统运行策略的改进建议。
As a kind of conversion device of solar energy,the solar collector is the most important part of the solar heating system.Among various solar collectors,all-glass vacuum tube solar collector is regarded as more favourable than other collectors in both technical and economic perspectives,so domestic and foreign experts have studied several aspects of it.But the current studies usually focus on the heating performance of the solar system during the whole heating season and the influence factors of the collecting efficiency of the all-glass vacuum tube solar collector,and there is barely research on the hourly and dynamic heating performance of solar heating system in a monomer building under different operating ways.With the purpose of studying the above problems,an all-glass tube solar heating system is fabricated on a monomer building,combined with a low-temperature floor radiation heating.The system is composed of 6 groups of standpipe all-glass vacuum tube solar collectors which have uniform structure parameters,a low-temperature floor radiation heating device,a circulating pump,a valve,a conductor and other accessories.Every group of solar collector comprises 40 all-glass vacuum tubes with the external diameter of 58 mm and the length of 1 800 mm,and a storage tank with the volume of 400 L,which is installed on a rack with an angle of 45° facing south.The contour aperture area of solar collector is about 3.85 m~2,so the total contour aperture area of the array is about 23.1 m~2.The monomer building locates in Minqin County,Gansu Province,China.Its building area is 117 m~2 and actual heating area is 87 m~2.The operation mode of system is as follows:Daily 17:30-23:00 is set to be heating time;during this period,the controller controls the water pump to circulate hot water at a constant flow rate,stop for 5 min every operating for 8 min.In the experiment,the values of various parameters,such as the solar irradiance,the inlet and outlet temperatures of collector array,the tank water temperature,the ambient temperature,the circulating water flow rate and the wind speed,are measured by different sensors.All measured variables are collected and recorded automatically by Agilent 34970 A data acquisition instrument every 10 s.The testing period was from November 24 th to December 5th,2015.Then,many important parameters such as the total heat loss coefficient of storage tank,the collection efficiency of solar collector array,the solar energy utilization and the solar heating fraction of the system,and hourly variation of building heat load are theoretically and experimentally investigated.Furthermore,in the actual operation state,the heating effect of the solar heating system is analyzed,and the improvement proposals of operating strategy are provided.The results show that the total heat loss coefficient of storage tank in this system is 25.82-31.53 W/℃,the collection efficiency of solar collector array is 38%-72%,and the solar energy utilization and the solar heating fraction of the system are 37.1% and 48.3%,respectively;only 54.6% of heat collected by the solar collector is used,the remaining heat is emitted to the environment,and thus the heat loss of system accounts for a large proportion of the total collected heat;under the actual operating state,the heat supply is much more than the heat consumption of building,and especially in the initial period of heating,heat supply reaches more than 10 times that consumed by building,and heat supply and heating time are excessively concentrated.As a consequence,improvement proposals of operating strategy are provided for the solar heating system of the monomer building to reduce the water flux of heating system and advance the heating time.
As a kind of conversion device of solar energy,the solar collector is the most important part of the solar heating system.Among various solar collectors,all-glass vacuum tube solar collector is regarded as more favourable than other collectors in both technical and economic perspectives,so domestic and foreign experts have studied several aspects of it.But the current studies usually focus on the heating performance of the solar system during the whole heating season and the influence factors of the collecting efficiency of the all-glass vacuum tube solar collector,and there is barely research on the hourly and dynamic heating performance of solar heating system in a monomer building under different operating ways.With the purpose of studying the above problems,an all-glass tube solar heating system is fabricated on a monomer building,combined with a low-temperature floor radiation heating.The system is composed of 6 groups of standpipe all-glass vacuum tube solar collectors which have uniform structure parameters,a low-temperature floor radiation heating device,a circulating pump,a valve,a conductor and other accessories.Every group of solar collector comprises 40 all-glass vacuum tubes with the external diameter of 58 mm and the length of 1 800 mm,and a storage tank with the volume of 400 L,which is installed on a rack with an angle of 45° facing south.The contour aperture area of solar collector is about 3.85 m~2,so the total contour aperture area of the array is about 23.1 m~2.The monomer building locates in Minqin County,Gansu Province,China.Its building area is 117 m~2 and actual heating area is 87 m~2.The operation mode of system is as follows:Daily 17:30-23:00 is set to be heating time;during this period,the controller controls the water pump to circulate hot water at a constant flow rate,stop for 5 min every operating for 8 min.In the experiment,the values of various parameters,such as the solar irradiance,the inlet and outlet temperatures of collector array,the tank water temperature,the ambient temperature,the circulating water flow rate and the wind speed,are measured by different sensors.All measured variables are collected and recorded automatically by Agilent 34970 A data acquisition instrument every 10 s.The testing period was from November 24 th to December 5th,2015.Then,many important parameters such as the total heat loss coefficient of storage tank,the collection efficiency of solar collector array,the solar energy utilization and the solar heating fraction of the system,and hourly variation of building heat load are theoretically and experimentally investigated.Furthermore,in the actual operation state,the heating effect of the solar heating system is analyzed,and the improvement proposals of operating strategy are provided.The results show that the total heat loss coefficient of storage tank in this system is 25.82-31.53 W/℃,the collection efficiency of solar collector array is 38%-72%,and the solar energy utilization and the solar heating fraction of the system are 37.1% and 48.3%,respectively;only 54.6% of heat collected by the solar collector is used,the remaining heat is emitted to the environment,and thus the heat loss of system accounts for a large proportion of the total collected heat;under the actual operating state,the heat supply is much more than the heat consumption of building,and especially in the initial period of heating,heat supply reaches more than 10 times that consumed by building,and heat supply and heating time are excessively concentrated.As a consequence,improvement proposals of operating strategy are provided for the solar heating system of the monomer building to reduce the water flux of heating system and advance the heating time.
引文
[1]马超,刘艳峰,王登甲,等.西北农村住宅建筑热工性能及节能策略分析[J].西安建筑科技大学学报:自然科学版,2015(3):427-432.Ma Chao,Liu Yanfeng,Wang Dengjia,et al.Analysis of thermal performance and energy saving strategy of rural residence building in northwest China[J].Journal of Xi'an University of Architecture and Technology:Natural Science Edition,2015(3):427-432.(in Chinese with English abstract)
[2]朱轶韵,刘加平.西北农村建筑冬季室内热环境研究[J].土木工程学报,2010,43(2):400-404.Zhu Yiyun,Liu Jiaping.Research on the indoor thermal environment of rural architecture in winter in northwestern areas[J].China Civil Engineering Journal,2010,43(2):400-404.(in Chinese with English abstract)
[3]Rekstad J,Meir M,Murtnes E,et al.A comparison of the energy consumption in two passive houses,one with a solar heating system and one with an air-water heat pump[J].Energy and Buildings,2015,96:149-161.
[4]Yu Z,Ji J,Sun W,et al.Experiment and prediction of hybrid solar air heating system applied on a solar demonstration building[J].Energy and Buildings,2014,78:59-65.
[5]Mehdaoui F,Hazami M,Naili N,et al.Energetic performances of an optimized passive solar heating prototype used for Tunisian buildings air-heating application[J].Energy Conversion and Management,2014,87:285-296.
[6]Chung M,Park J U,Yoon H K.Simulation of a central solar heating system with seasonal storage in Korea[J].Solar Energy,1998,64(4):163-178.
[7]Ren J,Zhu L,Wang Y,et al.Very low temperature radiant heating/cooling indoor end system for efficient use of renewable energies[J].Solar Energy,2010,84(6):1072-1083.
[8]Lundh M,Dalenb?ck J O.Swedish solar heated residential area with seasonal storage in rock:Initial evaluation[J].Renewable Energy,2008,33(4):703-711.
[9]王岳人,毛宏迪,宋延丽.主动式太阳能供暖系统保证率定量分析[J].沈阳建筑大学学报:自然科学版,2013,29(6):1078-1084.Wang Yueren,Mao Hongdi,Song Yanli.Quantitative study on the solar fraction of active solar heating system[J].Journal of Shenyang Jianzhu University:Natural Science,2013,29(6):1078-1084.(in Chinese with English abstract)
[10]赵薇,张于峰,邓娜,等.太阳能-低温热管地板辐射供热系统试验研究[J].太阳能学报,2008,29(6):637-643.Zhao Wei,Zhang Yufeng,Deng Na,et al.Experimental investigation on the performance of solar-thermosyphon embedded radiant floor heating system[J].Acta Energiae Solaris Sinica,2008,29(6):637-643.(in Chinese with English abstract)
[11]李宏燕,何建国,李明滨.银川地区太阳能地板辐射供暖性能测试分析[J].暖通空调,2015(10):86-90.Li Hongyan,He Jianguo,Li Mingbin.Performance test and analysis of solar floor radiation heating in Yinchuan region[J].Heating Ventilating&Air Conditioning,2015(10):86-90.(in Chinese with English abstract)
[12]崔成辽,张叶,焦浩,等.严寒地区太阳能地板辐射供暖系统试验研究[J].建筑节能,2015(6):40-46.Cui Chengliao,Zhang Ye,Jiao Hao,et al.Experimental research of solar radiant floor heating system in cold area[J].Building Energy Efficiency,2015(6):40-46.(in Chinese with English abstract)
[13]李金平,王磊磊,王立璞,等.传统采暖房内热环境的三维数值模拟[J].兰州理工大学学报,2008,34(1):45-49.Li Jinping,Wang Leilei,Wang Lipu,et al.Three-dimensional numerical simulation of thermal environment in traditional radiator-heated houses[J].Journal of Lanzhou University of Technology,2008,34(1):45-49.(in Chinese with English abstract)
[14]李金平,冷小超,马思聪,等.基于可再生能源的农村绿色建筑的能量分析[J].兰州理工大学学报,2014,40(1):50-53.Li Jinping,Leng Xiaochao,Ma Sicong,et al.Energy consumption analysis of a new rural green building based on relying on renewable energy[J].Journal of Lanzhou University of Technology,2014,40(1):50-53.(in Chinese with English abstract)
[15]李金平,曲婧,刁荣丹.太阳能单户建筑室内热性能分析[J].兰州理工大学学报,2015,41(5):62-66.Li Jinping,Qu Jing,Diao Rongdan.Indoor thermal performance analsis of solar single residential building[J].Journal of Lanzhou University of Technology,2015,41(5):62-66.(in Chinese with English abstract)
[16]Sabiha M A,Saidur R,Mekhilef S,et al.Progress and latest developments of evacuated tube solar collectors[J].Renewable and Sustainable Energy Reviews,2015,51:1038-1054.
[17]Daghigh R,Shafieian A.Theoretical and experimental analysis of thermal performance of a solar water heating system with evacuated tube heat pipe collector[J].Applied Thermal Engineering,2016,103:1219-1227.
[18]Budihardjo I,Morrison G L,Behnia M.Natural circulation flow through water-in-glass evacuated tube solar collectors[J].Solar Energy,2007,81(12):1460-1472.
[19]Morrison G L,Budihardjo,Behnia M.Measurement and simulation of flow rate in a water-in glass evacuated tube solarwate heater[J].Solar Energy,2005,78(3):257-267.
[20]Budillarolzo I.Natural circulation flow through water in glass evacuated tube solar collectors[J].Solar Energy,2007,81(12):1460-1472.
[21]Kim Y,Seo T.Thermal performance comparisons of the glass evacuated tube solar collectors with shapes of absorber tube[J].Renewable Energy,2007,32(5):775-778.
[22]Mazarrón F R,Porras-Prieto C J,García J L,et al.Feasibility of active solar water heating systems with evacuated tube collector at different operational water temperatures[J].Energy Conversion and Management,2016,113:16-26.
[23]Gao Y,Zhang Q,Fan R,et al.Effects of thermal mass and flow rate on forced-circulation solar hot-water system:Comparison of water-in-glass and U-pipe evacuated-tube solar collectors[J].Solar Energy,2013,98:290-301.
[24]Li Jinping,Li Xiuzhen,Wang Na,et al.Experimental research on indoor thermal environment of new rural residence with active solar water heating system and external wall insulation[J].Applied Thermal Engineering,2016,95:35-41.
[25]李金平,司泽田,孔莹,等.西北农村单体住宅太阳能主动采暖效果试验[J].农业工程学报,2016,32(21):217-222.Li Jinping,Si Zetian,Kong Ying,et al.Experiment on active solar heating for the monomer building in northwest region[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2016,32(21):217-222.(in Chinese with English abstract)
[26]农村居住建筑节能设计标准:GB 50824-2013[S].
[27]太阳能供热采暖工程技术规范:GB 50495-2009[S].
[28]严寒和寒冷地区居住建筑节能设计标准:JGJ26-2010[S].
[29]孙刚,贺平,王飞,等.供热工程[M].北京:中国建筑工业出版社,2009:10-11.
[30]岑幻霞.关于太阳能保证率f的计算[J].太阳能学报,1981(1):59-68.Cen Huanxia.Calculation of the fraction“f”of the heating load supplied by solar energy[J].Acta Energiae Solaris Sinica,1981(1):59-68.(in Chinese with English abstract)
[2]朱轶韵,刘加平.西北农村建筑冬季室内热环境研究[J].土木工程学报,2010,43(2):400-404.Zhu Yiyun,Liu Jiaping.Research on the indoor thermal environment of rural architecture in winter in northwestern areas[J].China Civil Engineering Journal,2010,43(2):400-404.(in Chinese with English abstract)
[3]Rekstad J,Meir M,Murtnes E,et al.A comparison of the energy consumption in two passive houses,one with a solar heating system and one with an air-water heat pump[J].Energy and Buildings,2015,96:149-161.
[4]Yu Z,Ji J,Sun W,et al.Experiment and prediction of hybrid solar air heating system applied on a solar demonstration building[J].Energy and Buildings,2014,78:59-65.
[5]Mehdaoui F,Hazami M,Naili N,et al.Energetic performances of an optimized passive solar heating prototype used for Tunisian buildings air-heating application[J].Energy Conversion and Management,2014,87:285-296.
[6]Chung M,Park J U,Yoon H K.Simulation of a central solar heating system with seasonal storage in Korea[J].Solar Energy,1998,64(4):163-178.
[7]Ren J,Zhu L,Wang Y,et al.Very low temperature radiant heating/cooling indoor end system for efficient use of renewable energies[J].Solar Energy,2010,84(6):1072-1083.
[8]Lundh M,Dalenb?ck J O.Swedish solar heated residential area with seasonal storage in rock:Initial evaluation[J].Renewable Energy,2008,33(4):703-711.
[9]王岳人,毛宏迪,宋延丽.主动式太阳能供暖系统保证率定量分析[J].沈阳建筑大学学报:自然科学版,2013,29(6):1078-1084.Wang Yueren,Mao Hongdi,Song Yanli.Quantitative study on the solar fraction of active solar heating system[J].Journal of Shenyang Jianzhu University:Natural Science,2013,29(6):1078-1084.(in Chinese with English abstract)
[10]赵薇,张于峰,邓娜,等.太阳能-低温热管地板辐射供热系统试验研究[J].太阳能学报,2008,29(6):637-643.Zhao Wei,Zhang Yufeng,Deng Na,et al.Experimental investigation on the performance of solar-thermosyphon embedded radiant floor heating system[J].Acta Energiae Solaris Sinica,2008,29(6):637-643.(in Chinese with English abstract)
[11]李宏燕,何建国,李明滨.银川地区太阳能地板辐射供暖性能测试分析[J].暖通空调,2015(10):86-90.Li Hongyan,He Jianguo,Li Mingbin.Performance test and analysis of solar floor radiation heating in Yinchuan region[J].Heating Ventilating&Air Conditioning,2015(10):86-90.(in Chinese with English abstract)
[12]崔成辽,张叶,焦浩,等.严寒地区太阳能地板辐射供暖系统试验研究[J].建筑节能,2015(6):40-46.Cui Chengliao,Zhang Ye,Jiao Hao,et al.Experimental research of solar radiant floor heating system in cold area[J].Building Energy Efficiency,2015(6):40-46.(in Chinese with English abstract)
[13]李金平,王磊磊,王立璞,等.传统采暖房内热环境的三维数值模拟[J].兰州理工大学学报,2008,34(1):45-49.Li Jinping,Wang Leilei,Wang Lipu,et al.Three-dimensional numerical simulation of thermal environment in traditional radiator-heated houses[J].Journal of Lanzhou University of Technology,2008,34(1):45-49.(in Chinese with English abstract)
[14]李金平,冷小超,马思聪,等.基于可再生能源的农村绿色建筑的能量分析[J].兰州理工大学学报,2014,40(1):50-53.Li Jinping,Leng Xiaochao,Ma Sicong,et al.Energy consumption analysis of a new rural green building based on relying on renewable energy[J].Journal of Lanzhou University of Technology,2014,40(1):50-53.(in Chinese with English abstract)
[15]李金平,曲婧,刁荣丹.太阳能单户建筑室内热性能分析[J].兰州理工大学学报,2015,41(5):62-66.Li Jinping,Qu Jing,Diao Rongdan.Indoor thermal performance analsis of solar single residential building[J].Journal of Lanzhou University of Technology,2015,41(5):62-66.(in Chinese with English abstract)
[16]Sabiha M A,Saidur R,Mekhilef S,et al.Progress and latest developments of evacuated tube solar collectors[J].Renewable and Sustainable Energy Reviews,2015,51:1038-1054.
[17]Daghigh R,Shafieian A.Theoretical and experimental analysis of thermal performance of a solar water heating system with evacuated tube heat pipe collector[J].Applied Thermal Engineering,2016,103:1219-1227.
[18]Budihardjo I,Morrison G L,Behnia M.Natural circulation flow through water-in-glass evacuated tube solar collectors[J].Solar Energy,2007,81(12):1460-1472.
[19]Morrison G L,Budihardjo,Behnia M.Measurement and simulation of flow rate in a water-in glass evacuated tube solarwate heater[J].Solar Energy,2005,78(3):257-267.
[20]Budillarolzo I.Natural circulation flow through water in glass evacuated tube solar collectors[J].Solar Energy,2007,81(12):1460-1472.
[21]Kim Y,Seo T.Thermal performance comparisons of the glass evacuated tube solar collectors with shapes of absorber tube[J].Renewable Energy,2007,32(5):775-778.
[22]Mazarrón F R,Porras-Prieto C J,García J L,et al.Feasibility of active solar water heating systems with evacuated tube collector at different operational water temperatures[J].Energy Conversion and Management,2016,113:16-26.
[23]Gao Y,Zhang Q,Fan R,et al.Effects of thermal mass and flow rate on forced-circulation solar hot-water system:Comparison of water-in-glass and U-pipe evacuated-tube solar collectors[J].Solar Energy,2013,98:290-301.
[24]Li Jinping,Li Xiuzhen,Wang Na,et al.Experimental research on indoor thermal environment of new rural residence with active solar water heating system and external wall insulation[J].Applied Thermal Engineering,2016,95:35-41.
[25]李金平,司泽田,孔莹,等.西北农村单体住宅太阳能主动采暖效果试验[J].农业工程学报,2016,32(21):217-222.Li Jinping,Si Zetian,Kong Ying,et al.Experiment on active solar heating for the monomer building in northwest region[J].Transactions of the Chinese Society of Agricultural Engineering(Transactions of the CSAE),2016,32(21):217-222.(in Chinese with English abstract)
[26]农村居住建筑节能设计标准:GB 50824-2013[S].
[27]太阳能供热采暖工程技术规范:GB 50495-2009[S].
[28]严寒和寒冷地区居住建筑节能设计标准:JGJ26-2010[S].
[29]孙刚,贺平,王飞,等.供热工程[M].北京:中国建筑工业出版社,2009:10-11.
[30]岑幻霞.关于太阳能保证率f的计算[J].太阳能学报,1981(1):59-68.Cen Huanxia.Calculation of the fraction“f”of the heating load supplied by solar energy[J].Acta Energiae Solaris Sinica,1981(1):59-68.(in Chinese with English abstract)