New Phase Change Material Heat Storage And Release Performance Test And Research On Its Application Performance In Prefabricated Solar Greenhouse

Maintaining a suitable temperature in a greenhouse is essential for the healthy growth of crops.However,at present,most greenhouses in my country have the problems of excessively high temperature during the day in summer and low temperature at night in winter.In terms of cooling in summer,the current technical system is not yet perfect;in terms of winter insulation,predecessors have conducted many studies and achieved outstanding results.They have basically ensured the safety of crops to achieve overwintering production,but there are low energy utilization and high construction costs.problem.Phase change material is a kind of high-efficiency energy storage material,and its application in the greenhouse can well regulate the temperature environment of the greenhouse.In this research,based on the research of the predecessors of the research group,according to the actual situation of greenhouse production,three kinds of composite phase change material systems,F1,F2 and F3,which are more suitable for greenhouse production,were selected and prepared to grow 1.2m,height 0.3m and thickness 0.08 The heat storage and release performance of the mud module of m,the results show that the heat storage and release performance of the three phase change material cement modules are high;then they are fixed to the back wall skeleton of the assembled solar greenhouse,and the area of the phase change material cement module is Half of the wall area,to test its regulating effect on greenhouse temperature in winter and summer.The main conclusions of this research are as follows:(1)The temperature of a F1,F2,F3 phase change material cement module increased from 8.3℃to 32℃and the heat storage per unit volume was 74.5 MJ/m~3,88.0 MJ/m~3,and95.1 MJ/m~3 respectively;the temperature of a F1,F2,F3 phase change material cement module decreased from 32℃to 7.8℃The heat output per unit volume is 59.8 MJ/m~3,67.8MJ/m~3,84.2 MJ/m~3;(2)In the test to alleviate the problem of excessively high greenhouse temperature in summer,under typical sunny conditions,the F1 phase change material cement module absorbs a total of 3,5614.8 k J,the F2 phase change material cement module absorbs a total of 72788.4 k J,and the F3 phase change material cement module absorbs total heat.Heat is 57153.6 k J;under typical cloudy conditions,the F1 phase change material cement module absorbs a total of 1,2589.2 k J,the F2 phase change material cement module absorbs a total of 24310.8 k J,and the F3 phase change material cement module absorbs a total of22338.0 k J.The three phase change materials can absorb a large amount of excess heat inside the greenhouse during the daytime warming up of the greenhouse,reduce the peak temperature of the greenhouse,and maintain the greenhouse temperature below 40.5℃under sunny conditions and below 31.2℃under cloudy conditions.(3)In the experiment of increasing the temperature in the greenhouse in winter to prevent the greenhouse temperature from being too low,the F1 phase change material cement module released a total of 36442.8k k J,and the F2 phase change material cement module released a total of 49993.2 k J under typical sunny conditions.F3 phase change material The cement module released a total of 51333 k J of heat;under typical cloudy conditions,the F1 phase change material cement module released a total of 1,7035.2 k J,the F2 phase change material cement module released a total of 37260 k J,and the F3 phase change material cement module released a total of 49542 k J.The three phase change materials can release part of the heat stored during the day into the greenhouse during the night cooling period,increase the temperature of the greenhouse at night,and prevent the low temperature inside the greenhouse from causing irreversible damage to the plants.(4)The phase change material wall is compared with other wall materials,and the data of sunny days in winter is selected for comparison.The heat storage per unit volume of F1,F2,and F3 phase change material cement modules are 10.2 times,10.4 times and 11 times that of earth walls,respectively.The heat output per unit volume is 15.6 times,21.5 times and 26.4 times that of soil walls.The heat storage per unit volume of the F1,F2,and F3phase change material cement modules are 4.9,5.0,and 5.3 times that of the red brick wall,respectively,and the heat output per unit volume is 6.6,9.0 and 11.1 times that of the red brick wall,respectively.To sum up,the three phase change materials used in this research all have good heat storage and release performance.Applying them to the back wall of the greenhouse can play an important role in the temperature control of the greenhouse.Among them,the F3 phase change material has a comprehensive performance The best,followed by F2 phase change materials,and F1 phase change materials the worst.