120 A Study on the Refrigerant Charge Quantity of Ground Source Heat Pump System

Ground source heat pump has the advantages of high efficiency, energy saving and environmental protection, which fully develop and utilize the shallow ground heat energy and other renewable energy. For the better using of ground source heat pump, there are still many issues need to study. Because of the low evaporation temperature of ground source heat pump system, the quantity of refrigerant charge has a greater effect on the COP of heat pump. In this study, an experimental setup of ground source heat pump system is established, and the effects of different refrigerant charge on the operation performance of the heat pump unit are investigated by varying the refrigerant charge quantity of R22. Through analyzing the experimental results and reasons in thermodynamics theories, the influence degree of refrigerant charge quantity on the performance of ground source heat pump system and the optimal refrigerant charge quantity for the existing heat pump are obtained. The experimental results can provide theoretical and application bases for the ground source heat pump system efficiently running and the sufficient use of energy.