Experimental study on the refrigerant charging in ground source heat pump system

The evaporation temperature of ground source heat pump system is low, so the refrigerant charging quantity has a greater impact on the EER.On bench scale ground source heat pump system, the experiment tests the inner refrigerant side together with the external water circle side by using an actual ground source heat pump under different refrigerant charging quantity of R22.The paper analyses the experiment result and the reasons by thermodynamics theories.Then the influence of the refrigerant charging quantity on the performance of ground source heat pump system and the optimal refrigerant charging quantity for the existing heat pump are ascertained.It supplies theoretical and application bases for efficiently running and the sufficient use of energy in the ground source heat pump system.