Study On Ground Soil Heat Pump Under The Intermittent Operation Condition

Ground source heat pump (GSHP) air-conditioning systems utilize soil as a cold or heat source, achieve heat transfer between soil and a working fluid circulating in a closed loop buried in the ground, and then provide the cold and heat energy by heat pump. Compared with the conventional air-conditioning system, The GSHP boasts the features of protecting environment and energy saving. It has become a popular way of air-conditioning abroad. However, our country is in the course of research and application. Therefore, It has great development potential.This thesis focuses on vertical double U-tube heat exchanger. according to the heat transfer characteristics of double U-tube buried heat exchanger. Build the transient heat transfer model. Simulate the soil temperature distribution surrounding the buried heat exchanger under the intermittent operating condition of GSHP with VB program. The results show that the change of soil temperature is different in different depths and different radial distance.The change of soil temperature is big near to buried heat exchanger wall.However, The soil temperature away from the heat exchanger wall doesn't change significantly.At the same time, we get the data of operating in winter and both in summer by experiment.By comparing the data of experiment with the data of theory.its correctness can be verified. Use the heat flux of per meter and the average heat transfer coefficient as the standard of evaluation,give the comparison between intermittent operation condition and continuous operation condition. Meanwhile, the corresponding curves are provided,which can lay the foundation for further research.