Experiment And System Simulation Study Of Multi-ground Source Heat Pump Exchangers

In recent years, alone with the importance and strengthen of energy conservation and renewable energy-applications, ground source heat pump technology is becoming more and more popular. How to design ground heat exchanger reasonably is a necessary condition for an economic and reliable system, and the premise of design buried tube heat exchanger reasonably is establishing an accurate model of buried tube heat exchanger. The current research of ground source heat pump is mainly about the model of single tube heat exchanger. Although the research of ground source heat pump system has increased gradually in recent years, there are few studies on buried pipe heat exchanger tube group and long-term performance of the buried pipe. Therefore, the following contents are studied in this paper.Firstly, a multi-ground source heat pump test platform was built according to the engineering standards, then an single-well and muti-well heat storage experiment was conducted on this experimental platform; Secondly, establish the heat transfer model for multi-well based on the single-well heat transfer theory by using the principle of superposition. Then by comparing the experimental data and simulation data, the reliability of the model can be proved; Finally, simulation analysis are conducted according to different affecting factors, different operation modes and the soil temperature resuming rate based on the established ground source heat pump multi-well model. The results show that the larger of the borehole spacing and the smaller of heat flow intensity the smaller of thermal effect between boreholes; compared to the continuous mode of operation, the intermittent operation mode has higher efficiency of heat pump Operation; the smaller of intermittent ratio and the smaller of intermittent operation cycle the higher of the efficient operation of the heat pump.At the same time, the hourly cooling load was simulated for a residential building in Beijing with the software Dest, according to the climate characteristic in Beijing which is heating-dominated, then build the solar-ground source heat pump seasonal storage model using the software of Trnsys. The results show that the heating and cooling annual accumulative load ratio is 2.3 for residential building in Beijing, yearly accumulative ground heat exchanger of heating and cooling ratio is 1.5, To keep the ground heat exchanger heating and cooling balance, the building area and the collector area ratio should be 25.3.