Transient Simulation Study of Direct Expansion Surface Water Source Heat Exchanger

In recent years, soil source heat pump technology is an emerging technology of energy conservation and environmental protection, with great development potential. Our research group has established a ground-source heat pump system of direct expansion downhole heat exchanger with as working fluid, which has the advantages of high heat exchange energy efficiency ratio, small footprint, natural working fluid and environmental friendliness of the . Among them, water is used as backfill, and natural convection is used to enhance the heat exchange effect, and the problem of hot and cold accumulation can also be solved, thereby improving the heat exchange temperature difference. Taking this paper as a starting point, this paper proposes to combine the direct expansion heat pump system with the surface water source, and uses MATLAB software to establish a direct expansion surface water source heat exchanger model based on the thermal resistance heat capacity method, and applies this model to the winter heating conditions, and gives the key parameters such as heat exchange and unit COP at different temperatures at the entrance of the heat exchanger, and the results show that compared with the traditional surface water source heat pump system, the heat transfer of linear meters is 1.55 times higher.