土壤初始温度及地下水渗流对多供一回中心回水管换热器的影响

为研究地下水渗流对多供一回中心回水管换热器与周围岩土体换热情况的影响,以黄土高原地区实际土壤环境为依托,采用DesignMoldeler软件建立多供一回中心回水管换热器及周围土壤的三维热渗耦合传热模型,利用Meshing软件对模型进行网格划分,并采用Fluent软件对其进行数值模拟.分析岩土体分层条件下,沿埋深方向变化的土壤初始温度、不同地下水渗流方向及间歇运行模式对多供一回中心回水管换热器换热的影响.研究结果表明:分层土壤初始温度不同对不同类型的多供一回中心回水管换热器影响较大,故不可忽略;不同地下水渗流方向对不同类型的多供一回中心回水管换热器影响不同,存在一个最佳渗流方向使得换热效率达到最高;间歇运行模式可提高热泵运行效率,减小埋管的设计长度,从而减少初投资.

Influence of Initial Soil Temperature and Groundwater Seepage on Several Supply Pipes and One Central Return Pipe Heat Exchanger

In order to study the influence of groundwater seepage on the heat exchange between the several supply pipes and one central return pipe heat exchanger and surrounding rock and soil, a three-dimensional coupled thermo-seepage heat transfer model of several supply pipes and one central return pipe heat exchanger and surrounding soil was established by DesignMoldeler software, based on the actual soil environment in the Loess Plateau. The model was meshed by Meshing software, and numerically simulated by Fluent software. Under the condition of rock and soil stratification, the effects of soil initial temperature varying along the buried depth, different groundwater seepage directions and intermittent operation modes on the heat transfer of several supply pipes and one central return pipe heat exchanger were analyzed. The research results show that layered soil with different initial temperatures has a greater impact that can not be ignored. Different groundwater seepage directions have different influence on different types of several supply pipes and one central return pipe heat exchangers, there is an optimal seepage direction to maximize the heat transfer efficiency. The intermittent operation mode can improve operation efficiency of the heat pump, and can reduce the design length of the buried pipe, thereby reduce the initial investment.