双U型地埋管换热器模型的建立及实验验证

The Establishment and Experimental Validation of the Double U-ground Heat Exchanger Model

地埋管换热器与土壤的换热状况,直接影响到土壤源热泵系统的运行性能.因而建立恰当的地埋管换热器模型,对埋管与土壤的传热研究至关重要.根据钻孔内外传热的不同特点,建立了钻孔内准三维稳态导热数学模型和钻孔外二维非稳态导热数学模型;并以钻孔壁为纽带,将内、外模型组建成完整的地埋管换热器模型.进而利用Ansys有限元法建立其物理模型并进行求解.通过热响应实验,充分验证了该模型的可靠性.这为建立土壤源热泵系统模型,模拟系统长期变负荷工况运行下土壤热堆积情况奠定了坚实基础.

The heat transfer between the ground heat exchanger and the soil has a direct impact on the performance of the ground based heat-pump system.So it is important to establish an appropriated model and study the heat transfer between them.According to the different characteristics of the internal and external drilling,the quasi-three-dimensional steady-state model of the internal drilling and the two-dimensional unsteady-state model of the external drilling are established.Besides,they are formed into the complete ground heat exchanger model,which is solved by the Ansys finite element method.Thermal response test fully verifies the accuracy of heat transfer model.Therefore It's useful to establish the ground-based heat pump system model,which simulates heat accumulation under the long-term varying load conditions of the system.