| China’s northern region has vast land and abundant feed resources,but the winter is cold and long,and heating pig barns will consume a lot of electricity,coal and other energy,which not only increases the cost of pig breeding,but also affects the health of pigs and pollutes the environment at the same time.Making full use of solar energy can not only save energy,but also reduce environmental pressure and economic losses.Therefore,this paper takes a certain experimental collector shed pig barn in Qianguoeruo Mongolia Autonomous County,Songyuan City,Jilin Province as the research object to explore the impact of collector shed on the internal thermal environment of pig barn and to analyse how to use collector shed in winter to enhance the efficiency of the use of solar energy in northern pig barn,as follows:(1)Calculation of temperature changes and winter energy compensation in pig barns in heat collection sheds.The temperature inside the pig barn,outside the pig barn and inside the collector shed were continuously collected and analysed for changes and abnormalities.The temperature inside the pig barn changed with the temperature outside the pig barn and inside the collector shed,but there was an obvious lag,with the highest temperature lagging more than 4 hours behind the temperature outside the pig barn,and the temperature inside the pig barn started to fall below the average temperature of-3.8 ℃ during the day(6:00-18:00)after19:40.The phenomenon of "inverse temperature" in which the temperature inside the pig barn is lower than the temperature outside the pig barn mainly occurs at night in early spring when it is clear and windless;establish the heat balance equation of the pig barn,calculate the average daily solar energy utilization efficiency of the pig barn heat collection shed as 54.36%according to the actual temperature change,analyse the energy compensation of the pig barn in winter and draw the energy compensation curve and the energy compensation curve of the pig barn in the coldest month of winter.The energy compensation curve and the supplementary heat supply required by the pig house in the coldest month of winter at different feeding densities were analysed.(2)Simulation study of heat collection shed to improve the solar energy utilisation efficiency of pig barn.The optimal lighting orientation of the pig barn building in Song Yuan area was determined to be 25° south by west and the optimal lighting roof inclination was determined to be 40°.Among the different structures of pig barn roofs during the heating period,the equal-slope pig barn roof received the highest solar radiation at the bottom of the heat collection shed,followed by the staggered unequal-slope pig barn roofs at the top and bottom,the unequal-slope pig barn roofs at the front and back,while the four-slope pig barn roofs were the least conducive to receiving solar radiation at the bottom of the heat collection shed.(3)Analysis of energy consumption and economy of pig shed with heat collection shed.The analysis of heat gain and loss of the enclosure structure and monthly energy consumption of different structures and different light-transmitting materials of pig shed roofs during the heating period showed that the order of choosing four different structures of pig shed roofs was four equal slope pig shed roofs,front and rear unequal slope pig shed roofs,equal slope pig shed roofs,staggered unequal slope pig shed roofs;the order of choosing four different materials of pig shed roofs was double-layer PC board pig shed roofs,FRP light-transmitting board pig shed roofs The order of the four different materials is double-layer PC roof,FRP light board roof,plexiglass roof,flat glass roof.According to the relationship between construction cost and heating cost,the annual air-conditioning electricity cost is the lowest for a four-slope pigsty roof and the annual air-conditioning electricity cost is the lowest for a double-layer PC board pigsty roof of existing light-transmitting material during the service life of the pigsty. |
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