Experimental Study On Design And Application Effect Of Heat Collection,Heat Dissipation And Temperature Increase System Of Solar Greenhouse In Hetian Area

a number of solar greenhouses in Hetian area increases rapidly,but due to the large temperature difference between day and night,the heat storage and release capacity of the wall of solar greenhouses is limited,and the temperature at night in winter is low,which is not suitable for crop growth.In this study,the solar greenhouse heat collection and heating system is designed,and a series of night temperature increase verification tests are carried out.Using the unique light and heat resources,the night temperature of the greenhouse is effectively improved.The main contents and conclusions of this paper are as follows:（1）The development status and existing problems of solar greenhouse in Hetian area were investigated.Based on the investigation of the basic growth parameters of facility vegetables mainly planted in Hetian area,a solar greenhouse heat collection and heating system is designed by using the unique light and heat resources in Hetian area.The system is mainly composed of heat collection radiator,heat storage part,circulation part and control part.Considering the service life,Due to the factors such as input cost and popularization and application,PE pipe is selected as the water pipe of radiator collector.（2）The results show that the average temperature of the test greenhouse can be increased by 1.7℃～2.1℃and the relative humidity can be reduced by 5.81%in sunny days,and the average temperature of the test greenhouse can be increased by 1.6℃～1.8℃in cloudy days,The average relative humidity can be reduced by 4.63%,the average heat storage capacity of the system is 226.8mj～302.4mj,and the heat release at night is 151.2mj～201.6mj.（3）On the basis of（2）,the structure of the heat collection,heat dissipation and temperature increase system is optimized and the pipeline is added,the heat storage tank is insulated,and the comparative test is carried out.The results show that the temperature of the test greenhouse can be increased by 3.3℃in sunny days and the average relative humidity of the test greenhouse can be reduced by 8.65%compared with the control greenhouse.Compared with the control greenhouse,the average temperature of the cloudy weather test greenhouse increased by 2.4℃and the average relative humidity decreased by 6.8%.The comprehensive average heat collection efficiency of the system is 52.6%.This shows that the optimized experimental greenhouse uses the rich light and heat resources in Hotan area to significantly improve the heat collection performance and thermal insulation performance of the system.The solar greenhouse has the effect of significantly increasing temperature and reducing humidity,and basically meets the needs of greenhouse vegetables for temperature and humidity.（4）Compared with the traditional coal-fired hot blast stove,the optimized heat collection and heating system can save 2253 yuan in terms of investment cost.According to the later use cost analysis,the heat collection and heating system can save 7872.6 yuan in a quarter（three months）than the coal-fired hot blast stove.The heat collection and heating system has no pollutant emission,The coal-fired hot blast stove will cause the emission of smoke,NO_x,SO₂,CO₂and other pollutants.The solar greenhouse heat collection and heating system has a better application and promotion prospect in Hetian area.