地下连续墙内埋管地热换热器传热模型

Heat Transfer Model of Geothermal Heat Exchangers Embedded in Diaphragm Walls

摘要:

地下连续墙内埋管技术是地源热泵技术的一个新的发展方向，它是基于地下连续墙本身具有一定的深度，且处于温度常年保持恒定的地层中的性质，将热交换管植入地下连续墙内形成地下换热器，利用换热器内部循环介质的流动吸收浅层地温能，经热泵提升后供上部建筑物使用。根据地下连续墙内埋管的结构形式和传热特点，建立了开挖面以上和开挖面以下两部分的地下连续墙内埋管传热模型，并采用格林函数法推导了其解析解。该模型能求解带有随时间变化的内热源、非齐次边界条件的复合介质热传导问题，可用于地下连续墙及周围土体内的温度场分析，也可用于地下连续墙内埋管布置形式、埋管间距以及间歇运行时间等参数的优化分析。

Abstract:

The technology of embedding absorber tubes in diaphragm walls is a new developing direction of Ground Source Heat Pump. As the diaphragm walls are located in the ground where temperature remains constant all year around, the shallow geothermal energy may be obtained for space cooling and heating by circulating the medium in absorber tubes. According to the structure and heat transfer characteristics of geothermal heat exchangers, two heat transfer models and their analytical solutions were obtained. One model is for the section over the excavation surface, and the other is for the section under the excavation surface. The models may be employed to calculate the temperature field of diaphragm walls and the surrounding soil under non-homogeneous boundary conditions and varying internal heat source. The models may also be used to optimize the system parameters, including the layout and spacing of heat exchangers, the running time of intermittent operation.