Photovoltaic Collectors And Study On The Application Of Heating Technology In Rural Buildings In Gansu

Traditional heating methods such as stoves and ondols based on coal and firewood fuel have the disadvantages of high heating energy consumption,low fuel thermal efficiency,large pollutant emissions,and poor heating comfort in heating rooms.proportion.Therefore,exploring suitable clean heating technologies and systems is related to the implementation of energy conservation and emission reduction in China,and the construction of new rural areas.It has become a problem that the national and local governments and technicians in related fields urgently need to solve.In order to promote the exploration of clean heating technology in Gansu,the Gansu government has successively issued relevant policies and measures.However,due to the characteristics of Gansu that spans multiple climatic regions,the economy is relatively backward,and has relatively rich solar energy resources,it is suitable for exploring various areas in Gansu Work on clean heating technology for farm house construction has been on the way.Photovoltaic collector is a kind of integrated device of photovoltaic light and heat comprehensive utilization combining solar photovoltaic cell and solar collector.Compared with a single photovoltaic or light-to-heat conversion technology,photovoltaic collector technology can not only generate heat energy and electrical energy at the same time,to achieve efficient use of solar energy resources,but also improve the photovoltaic cell due to excessively high operating temperature caused by problems such as photoelectric efficiency and life drop.At present,the achievements of photovoltaic collector technology are focused on the research of the structure and performance optimization of photovoltaic collectors,but its engineering applications,especially the engineering attempts to solve the problem of clean heating of rural house buildings in various regions of Gansu,are very lacking.Based on the demand for participation in the Lanzhou government clean heating demonstration project,this paper first uses the TRNSYS simulation method and Lanzhou district heating season and non-heating season typical operating conditions parameters to simulate and analyze the performance of the PV collector of the given structure,including the establishment of a simulation model 1.Select the best installation angle,simulate and analyze the influence of inlet water temperature and flow rate on its outlet water temperature,photoelectric efficiency,solar thermal efficiency,photovoltaic cell temperature,etc.;Secondly,based on the current situation of photovoltaic collectors and Gansu farm buildings,establish typical farm buildings Model,design clean heating system,establish heating system simulation model,heat load for hourly heating of the coldest day farmhouses in five cities in Gansu region,hourly heating room temperature in the coldest day,coldest day solar collector array power generation Simulation and analysis of the quantity and heat collection,etc.,obtained the suitability and operation effect of the clean heating system of photovoltaic collectors in Gansu.Finally,by participating in the implementation and engineering of the clean heating demonstration project,the test and analysis obtained the solar radiation intensity,outdoor ambient temperature,indoor temperature of the heating farm house,the temperature of the water supply and return water of the photovoltaic collector,the air source heat pump COP,and the system consumption Results such as electricity and power generation,system energy consumption,economic and environmental benefits.Through the study of this article,the main conclusions are as follows:1)The best installation inclination angle of photovoltaic collectors in Lanzhou area is30°throughout the year,the best installation inclination angle in heating season is 50°,the best installation inclination angle in non-heating season is 10°,and the best installation azimuth angle is in the south direction.2)Under the same meteorological conditions,when the inlet flow of the photovoltaic collector is constant,the increase of the inlet water temperature will increase the outlet water temperature,but the increase of the water temperature will gradually decrease as the inlet water temperature increases,and the collector The overall photoelectric conversion efficiency and light-to-heat conversion efficiency will be reduced to a certain extent;when the inlet water temperature of the photovoltaic collector is constant,the increase of the inlet flow will enhance the photoelectric and photothermal performance of the collector.3)In the target farmhouse buildings with the same building layout and enclosure structure in the five regions of Gansu,the cumulative heat loads in the heating season are Jiuquan 27760.01kWh,Zhangye 27241.93kWh,Pingliang 23437.81kWh,Lanzhou22323.28kWh,and Tianshui 21389.47kWh.Farm buildings in Jiuquan area have the highest heating load in the coldest day,but the region has the most abundant solar energy resources.It is possible to increase the proportion of the photovoltaic collector heating system in the photovoltaic collector array to improve the heating effect.4)According to the simulation results,the use of the photovoltaic collector heating system to simulate the heating operation of typical rural house buildings in five regions,the indoor temperature can reach more than 14℃,which meets the design requirements.According to the measured results,the temperature of the bedroom of the heating farm house is between 16.1～20.9℃,which basically meets the requirements of the specification.During the test period,the maximum effluent water temperature of the photovoltaic collector can reach 47.5℃on the day when the solar radiation intensity is maximum,and the maximum effluent water temperature on the coldest day can reach 45℃,reaching the required water temperature on the heating side of the system.5)During the test period,the cumulative power generation of PV collector modules is662.9kWh,and the average daily power generation is 11.2kWh,which is equivalent to the total annual power generation of 4088kWh.According to the current policy of Gansu,the grid-connected photovoltaic price is 0.3 yuan/kWh,and the pilot farmers will Profits greater than 1226.4 yuan are used for system operating expenses.6)Compared with the traditional coal-fired furnace heating system,the photovoltaic collector heating system greatly reduces pollutant emissions throughout the heating season,reducing CO₂ emissions by 35.76kg/m²,SO₂ emissions by 0.116kg/m²,and NO_x emissions by0.101kg/m2.