Figure 2: Water source heat pump unit works Water source heat pump technology is the use of solar energy and geothermal energy absorbed by the shallow surface of the Earth's surface water source of low-temperature low heat resources, the use of heat pump principle, through a small amount of high energy input, low heat to high A technology of heat transfer. The general principle of a water source heat pump unit is that the heat in a building is transferred to a water source in the summer, and the heat can be efficiently removed due to the low temperature of the water source, and the heat is extracted from the water source in winter. The specific working principle is as follows: In the cooling mode, high temperature and pressure refrigerant gas from the compressor out into the condenser, the refrigerant to the cooling water (groundwater) in the heat, the formation of high temperature and pressure liquid, and the cooling water temperature . The refrigerant is then expanded into low-temperature and low-pressure liquid through the expansion valve, enters the evaporator to absorb the heat in the frozen water (building refrigeration water), evaporates into low-pressure steam, and reduces the water temperature of the frozen water. Low-pressure refrigerant vapor into the compressor and compressed into high temperature and pressure gas, so cycle in the evaporator to obtain chilled water. In heating mode, high temperature and high pressure refrigerant gas flows out of the compressor into the condenser. The refrigerant releases heat to the hot water (building heating water) and cools into high pressure liquid, and the hot water temperature rises. The refrigerant is then expanded into low-temperature and low-pressure liquid through the expansion valve, enters the evaporator to absorb the heat in the low-temperature heat source water (groundwater), evaporates into low-pressure steam, and lowers the water temperature of the low-temperature heat source water. Low-pressure refrigerant vapor into the compressor and compressed into high-temperature high-pressure gas, so the cycle to obtain hot water in the condenser Figure 1: Ground source heat pump technology diagram