【作者】 许英杰；

【导师】 张勇；

【作者基本信息】 西北农林科技大学 ， 农业硕士（专业学位）， 2021， 硕士

【摘要】 在温室中维持适宜的温度对于农作物的健康生长来说至关重要,但现在我国大多温室中均存在一定的问题,如夏季白天温度过高需要通风降温,冬季夜间温度过低需要采取加热措施。在夏季降温方面,目前的技术体系尚未完善;冬季保温方面,前人已进行了诸多研究,取得了突出成果,已基本能够确保农作物安全实现越冬生产,但存在能源利用低下,建造成本较高等问题。相变材料是一种高效储能材料,将其应用到温室中,可以很好的调控温室温度环境。本研究根据课题组前人的研究,针对温室生产实际情况,选取F1、F2和F3三种较适宜温室生产的复合相变材料体系,将其制备成长1.2 m,高为0.3 m,厚度为0.08 m的水泥模块,研究其蓄放热性能,结果表明三种相变材料水泥模块蓄放热性能均较高为良好;而后将其固定到装配式日光温室后墙骨架上,相变材料水泥模块面积为墙体面积的一半,测试其在冬夏两季对温室气温的调控作用。本研究得到的主要结论如下:(1)一块F1、F2、F3相变材料水泥模块温度由8.3℃升到32℃单位体积蓄热量分别为74.5 MJ/m~3、88.0 MJ/m~3、95.1 MJ/m~3;一块F1、F2、F3相变材料水泥模块温度由32℃降到7.8℃单位体积放热量分别为59.8 MJ/m~3、67.8 MJ/m~3、84.2 MJ/m~3;(2)在缓解夏季温室温度过高问题试验中,典型晴天条件下F1相变材料水泥模块共吸收热量35614.8 k J,F2相变材料水泥模块共吸收热量72788.4 k J,F3相变材料水泥模块共吸收热量57153.6 k J;典型阴天条件下F1相变材料水泥模块共吸收热量12589.2 k J,F2相变材料水泥模块共吸收热量24310.8 k J,F3相变材料水泥模块共吸收热量22338.0 k J。三种相变材料均可在温室白天升温期间吸收温室内部大量多余的热量,降低温室气温峰值,使温室气温在晴天条件下维持在40.5℃以下,在阴天条件下维持在31.2℃以下。(3)在提高温室冬季气温,防止温室气温过低试验中,典型晴天条件下F1相变材料水泥模块共释放热量36442.8 k J,F2相变材料水泥模块共释放热量49993.2 k J,F3相变材料水泥模块共释放热量51333 k J;典型阴天条件下F1相变材料水泥模块共释放热量17035.2 k J,F2相变材料水泥模块共释放热量37260 k J,F3相变材料水泥模块共释放热量49542 k J。三种相变材料均可在温室夜晚降温期间向温室内部释放一部分白天储存的热量,提高温室夜间温度,防止温室内部温度过低对植物造成不可逆的伤害。(4)将相变材料墙体与其他墙体材料进行对比,选取冬季晴天数据进行比较,F1、F2、F3相变材料水泥模块单位体积蓄热量分别是土墙的10.2倍、10.4倍和11倍,单位体积放热量分别是土墙的15.6倍、21.5倍和26.4倍。F1、F2、F3相变材料水泥模块单位体积蓄热量分别是红砖墙的4.9倍、5.0倍和5.3倍,单位体积放热量分别是红砖墙的6.6倍、9.0倍和11.1倍。综上所述,本研究所使用的三种相变材料,均具有良好的蓄放热性能,将其应用到温室后墙,可以对温室温度调控发挥重要的作用,其中F3相变材料综合表现最佳,F2相变材料次之,F1相变材料最差。更多还原

【Abstract】 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.更多还原