单井循环地下换热系统健康运行的研究

Study on the Healthy Operation for Standing Column Well Ground Heat Exchange System

单井循环地下换热系统的热源井现阶段共有三种:循环单井、抽灌同井和填砾抽灌同井。数值计算表明,渗透系数是传统回灌井和抽灌同井回灌难易程度的决定因素,填砾抽灌同井显著降低了灌压,循环单井没有回灌困难的问题。单井循环地下换热系统运行时会产生热贯通问题,尤其是填砾抽灌同井和循环单井。抽灌同井运行时的季节性储能很大程度地减轻了对含水层作为热源(汇)的依赖,而让其作为一种蓄热的载体。回灌问题、热贯通问题和季节性储能问题是单井循环地下换热系统能否长期健康稳定运行的关键影响因素。

The heat source wells of standing column well ground heat exchange system（SCWGHES） have three types now： standing column well（SCW）,pumping ＆ recharging well（PRW） and gravel-backfill PRW（GB-PRW）.The results of numerical simulation showed the coefficient of permeability was critical to injection for traditional recharging well and PRW.The GB-PRW remarkably reduced the pressure of injection.And SCW didn＇t have the trouble of recharging.There was the problem of thermal transfixion for SCWGHES,epically for GB-PRW and SCW.For PRW,the seasonal thermal energy storage（STES） alleviated the dependency on aquifer for heat source or sink,and made aquifer as a carrier for heat storage.The problems of injection,thermal transfixion and STES were the key factors to the healthy operation for SCWGHES.