蓄取热条件下地埋管钻孔适宜间距模拟研究

Simulation Study on Appropriate Distance between Drill Holes for Buried Pipes under Condition of Heat Storage and Extraction

根据GB 50366—2005《地源热泵系统工程技术规范》(2009年版)的相关规定,选取钻孔热作用半径1.5、2.0、2.5、3.0 m,在非供暖期蓄热、供暖期取热工况下,采用数值模拟方法(模拟时间为10 a),分别对地埋管换热器蓄取热稳定性(评价指标为取蓄热比)、蓄取热工况换热效果(评价指标为地埋管换热器换热效率、地埋管进出水温差温差区持续时间)进行计算分析。热作用半径1.5、2.0 m时,蓄热、取热工况下地埋管换热器具有良好的蓄取热稳定性。蓄热、取热工况下,热作用半径为2.0 m的地埋管换热器具有更高的换热效率且能保持比较稳定且较大的进出水温差。对于哈尔滨地区,钻孔的热作用半径宜选取2.0 m,即钻孔间距宜为4.0 m。

According to the relevant provisions of the Technical Code for Ground-source Heat Pump System （ GB 50366 - 2005 ） （ edition 2009 ）, under conditions of heat storage during non-heating period and heat extraction during heating period, the heat storage and extraction stability of buried pipe heat exchanger （the heat storage and extraction ratio as evaluation index） and the heat transfer effect under conditions of heat storage and extraction （the thermal efficiency of buried pipe heat exchanger and the duration of water temperature difference at inlet and outlet of buried pipe as evaluation indexes） are calculated and analyzed by numerical simulation method （simulation time of 10 a） with thermal effect radius of 1.5, 2.0, 2.5 and 3.0 m. When the thermal effect radius is 1.5 m and 2 m, buried pipe heat exchanger has good heat storage and extraction stability under conditions of heat storage and extraction. The buried pipe heat exchanger with thermal effect radius 2 m has higher heat transfer efficiency and can keep the stable and large water temperature difference between inlet and outlet under conditions of heat storage and extraction. For the Harbin area, the thermal effect radius of 2 m should be selected, that is, the distance between drill holes should be 4m.