埋管换热器阵列系统的转移载荷行为

In the process of development and utilization of large-scale borehole heat exchangers array system, it can be observed the shifted load behaviors when the borehole heat exchanger array runs for a long time. OpenGeoSys coupled with TESPy software was used to establish a comprehensive numerical model of shallow ground source heat pump system, and the behaviors of load shifting between borehole heat exchangers were studied under different inter-borehole spacing and different number of borehole heat exchanger array. The results show that with the operation of the borehole heat exchanger system, the heat load gradually shifts from the center borehole heat exchanger to the edge of the array, and there is obvious shifted load behavior. With the increase of the distance between the borehole, the shifted load behaviors is gradually weakened. With the increase of the number of borehole heat exchangers, the load shifting phenomenon is further enhanced in the larger system model. At the same time, by comparing the shifted load of 5-U and 9-U system, it is found that the maximum shifted load of central borehole heat exchanger changes linearly with the distance between borehole heat exchangers. The proportion of the shifted thermal load is used to express the shifting situation, and it is found that increasing the number of borehole heat exchangers will take more time for the system to achieve thermal equilibrium. Therefore, closing part of the borehole heat exchanger in the center of the array within a certain period of time may help to improve the efficiency of the whole large-scale shallow ground source heat pump system.