Application of medium-depth double U-tube ground-source heat pump systems to severe cold zone

Taking a residential district in Fuxin city, Liaoning province as an example, establishes a simulation model by using TRNSYS software. Studies the factors affecting the annual cost of medium-depth double U-tube ground-source heat pump systems by simulation and orthogonal experiment, and analyses the influence degree of these factors. The results show that the borehole spacing and the nominal diameter of the buried pipe have a greater influence on the annual cost of the system, and the increase of the nominal diameter of the buried pipe should be considered when the spacing cannot be increased due to the limitation of the buried pipe area. According to the characteristics of the severe cold zone, carries out the technical and economic analysis between the optimal solution obtained from orthogonal experiment and the common solar assisted ground-source heat pump system. For the areas dominated by heating load, the system has a smaller annual cost in the life cycle and is stable and efficient during long-term operating.