Application of cage-type heat exchanger to a surface water-source heat pump system

Aiming at the phenomena of surface water temperature stratification, proposes a cage-type heat exchanger to achieve longitudinal cascade utilization of surface water. Taking the shallow surface water of Hefei area as a research object, measures the yearly changes of water temperature in different depth, and analyses the influences of cage-type heat exchanger’s pipe length and the flow rate of circulating water on the heat transfer effect. Tests and simulates the influence of heat exchange pipe operation on water temperature outside the tube. The results show that: 1) increasing the pipe length can enhance the heat transfer, but to a certain length no longer strengthen the heat transfer; 2) increasing the flow rate of circulating water can enhance the heat transfer in the same depth, but when flow rate increases to a certain extent, it will reduce the heat transfer effect; 3) when the flow rate of circulating water is the same, the deeper the water, the better the heat transfer effect; 4) the more closer to the surface, the more obvious the heat transfer effect between heat exchanger pipes, therefore, equal space between the upper and lower pipes shall not be used.