水平螺旋地埋管群换热器"热短路"效应及控制机理OA

To enhance the utilization efficiency of shallow geothermal energy,a horizontal spiral ground heat exchanger array system was designed,with the Chengdu region as the research area.The"thermal short-circuiting"effect and its control mechanism were systematically investigated from three aspects:heat exchanger structure,external environment,and operation mode.The results indicate that,a smaller pipe spacing leads to more significant thermal short-circuiting but higher soil utilization efficiency,while a larger pipe spacing improves system stability.When the burial depth is less than 3 m,ambient temperature has a significant influence.Soil thermal conductivity determines heat exchange efficiency,while thermal diffusivity dominates soil thermal recovery,with sandy soil exhibiting the most severe thermal short-circuiting losses.Groundwater seepage promotes temperature field migration,increasing heat exchange by 91.6％,9.7％,and 62.3％under vertical,horizontal,and vertical-horizontal seepage conditions,respectively,compared to the no-seepage scenario.Intermittent operation reduces the thermal short-circuiting loss coefficient by 40.0％and increases heat transfer per linear meter by 74.4％,effectively enhancing system stability.This study provides theoretical support for the optimal design of ground source heat pump pipe array systems.