初始含水率对土壤储/取热特性影响的试验研究

An experimental investigation of the influence of initial water content on charging/discharging heat in wet soil

介绍了高温储热条件下土壤初始含水率对土壤储热和取热特性的试验结果.在实验室试验装置中,以不同含水率的非饱和湿土壤为研究对象,进行了79℃储热和8℃取热试验研究.试验结果表明:在储热过程中,水分逐渐向远离换热壁面迁移,低初始含水率的土壤径向湿度梯度更高,不利于储热.高含水率时,受重力作用影响明显,水分从内向外迁移的同时也从上向下迁移.高初始含水率的砂土有利于热量的传递,表现出更高的储热功率和取热功率.

In this paper,the experimental results of the influence of the initial water content on the heat transmission in soil during charging or discharging processes are presented.The experiments were conducted in lab on charging heat in and discharging heat from soil storage under the water temperature of 79 ℃ and 8 ℃ respectively,while the unsaturated soil has different initial water content.Results show that the moisture gradually migrates away from the wall of heat exchange tube during the charging process.In the end,the moisture gradient in the radial direction of the case of lower initial water content is larger than that of the case of higher initial water content.It is not in favor of heat charging.The significant moisture migration downward under the action of gravity in the case of higher initial water content was observed during charging process.The high initial water content is favorable to heat transmission,and results in much higher heat injection and extraction ability.