跨季节土壤蓄热太阳能数值模拟研究

Numerical Simulation of Solar Energy Storage in Trans-seasonal Soils

为减少太阳能利用所受的季节性限制,以太阳能跨季节蓄热为背景,土壤为蓄热介质,利用ANSYS软件对水平地埋管与土壤的非稳态换热过程进行三维数值模拟。在流速、管径、土壤初始温度以及运行时间等条件相同的情况下,分别讨论埋管深度、管内流体温度、土壤热物性参数以及埋管间距对土壤蓄热效果的影响。结果表明:对于埋深为1.5m、2.0m、2.5m这三种工况,埋深2.5m的土壤蓄热量最大,埋深1.5m的蓄热量最小。对于流体温度为60℃、70℃、80℃这三种工况,温度为80℃的土壤蓄热量最大,60℃的蓄热量最小。对于沙土、粘土、褐土和花岗岩这四种土壤,褐土是最有利于蓄热的,沙土是最不利的。对于埋管间距为2.8m、3.2m、3.6m、4m这四种工况,土壤蓄热量随埋管间距的增大而增大,管间距为4m的土壤蓄热量最大,2.8m的蓄热量最小。

In order to reduce the seasonal limitation of solar energy utilization,this paper takes solar energy as a background of seasonal heat storage,and the soil is a heat storage medium.The ANSYS software is used to simulate the unsteady heat exchange process of horizontal buried pipe and soil.Under the conditions of the same flow rate,pipe diameter,initial soil temperature and running time,the effects of buried pipe depth,pipe fluid temperature,soil thermal property parameters and buried pipe spacing on soil heat storage were discussed.The results show that for the three working conditions of buried depth of 1.5m,2.0m and 2.5m,the soil with a buried depth of 2.5m has the largest heat storage capacity and the minimum buried heat of 1.5m.For the three working conditions of fluid temperature of 60℃,70℃,and 80℃,the temperature of the soil at 80℃is the largest,and the heat storage at 60℃is the smallest.For the four soils of sand,clay,cinnamon and granite,cinnamon is the most favorable for heat storage,and sand is the most unfavorable.For the four working conditions of buried pipe spacing of 2.8m,3.2m,3.6m and 4m,the soil heat storage increases with the increase of the buried pipe spacing.When the pipe spacing is 4m,the soil heat storage is the largest while 2.8m is the smallest.