第3期 宋小飞等：地源热泵U型管地下换热器的FD数值模拟 .333 效率的影响变弱，在使用的回填土材料热导率变大 参考文献 时，支管间距的变化对U型管地下换热器换热效率 [1]曾和义，刁乃仁，方肇洪，竖直埋管地热换热器钻孔内的传热分 影响变大，因此建议在使用高热导率材料的同时应 析-太阳能学报，2004,25(3)：399 该适当加大U型管两支管的间距， [2]Gu Yian,O'Neal Dennis L.An analytical solution to transient (2)地源热泵U型管地下换热器的换热效率 heat conduction in a composite region with a cylindrical heat source.Trans ASME,1995.117:242 随回填土材料热导率的增加而增大·为了提高U [3]柳晓雷，王德林，方肇洪·垂直埋管地源热泵的圆柱面传热模型 型管地下换热器效率，应该努力提高回填土层的热 及简化计算.山东建筑工程学院学报，2001,16(1)：47 导率. [4]Yavuzturk C.Spitler J D.A short time step response factor model (③)在钴孔深度增加时，出水口出水温度几乎 for vertical ground loop heat exchangers.ASHREAE Trans. 成线性下降；但是当钻孔深度超过80m时，两支管 1999,105(2):475 [5]Muraya N K.O'Neal D L.Heffington W M.Thermal interfer- 的温升比急剧增加，从80m的2急剧增加100m的 ence of adjacent legs in a vertical UTube heat exchanger for a 3,支管间的热损失加剧，从而降低了单位管长的换 ground-coupled heat pump.ASHREAE Trans,1996.102(2):12 热效率。因此，在实际操作中建议钻孔深度不要太 [5]刁乃仁，曾和义，方肇洪.竖直U型管地热换热器的准三维传 深，对要求较低出水温度的工况可以使用两个U型 热模型.热能动力工程，2003,18(4)：387 管并联工作来减小支管间的温升比，提高单位管长 [7]黄俊惠，时晓燕，唐志伟，地源热泵U型管地下换热器的准三 维模型.中国农业大学学报，2004,9(5)：51 的换热效率 CFD numerical simulation of a Utube ground heat exchanger used in ground source heat pumps SONG Xiaofei,WEN Zhi,SI Junlong Mechanical Engineering School.University of Science and Technology Beijing.Beijing 100083.China ABSTRACI To provide a theory for the optimized design of a Utube ground heat exchanger used in ground source heat pumps,CFD software was used to simulate the processes of flow and heat transfer in the Utube ground heat exchanger.The results show that the heat transfer efficiency of the U-tube ground heat exchanger increases with the increasing distance between two tubes and with the increasing heat conductivity of backfilling soil.The effect of the distance between two tubes and the heat conductivity of backfilling soil on the U-tube ground heat exchanger's efficiency are a very complex nonlinear relation.When the hole-depth is deeper than 80 m,the temperature rise ratio of two tubes increases rapidly and the heat losing between two tubes increases.In practical operation,the hole-depth is better not to be too deep. KEY WORDS ground source heat pump;ground heat exchanger:CFD numerical simulation;heat transfer model效率的影响变弱．在使用的回填土材料热导率变大 时‚支管间距的变化对 U 型管地下换热器换热效率 影响变大‚因此建议在使用高热导率材料的同时应 该适当加大 U 型管两支管的间距． （2） 地源热泵 U 型管地下换热器的换热效率 随回填土材料热导率的增加而增大．为了提高 U 型管地下换热器效率‚应该努力提高回填土层的热 导率． （3） 在钻孔深度增加时‚出水口出水温度几乎 成线性下降；但是当钻孔深度超过80m 时‚两支管 的温升比急剧增加‚从80m 的2急剧增加100m 的 3‚支管间的热损失加剧‚从而降低了单位管长的换 热效率．因此‚在实际操作中建议钻孔深度不要太 深‚对要求较低出水温度的工况可以使用两个 U 型 管并联工作来减小支管间的温升比‚提高单位管长 的换热效率． 参 考 文 献 ［1］ 曾和义‚刁乃仁‚方肇洪．竖直埋管地热换热器钻孔内的传热分 析．太阳能学报‚2004‚25（3）：399 ［2］ Gu Yian‚O’Neal Dennis L．An analytical solution to transient heat conduction in a composite region with a cylindrical heat source．Trans ASME‚1995‚117：242 ［3］ 柳晓雷‚王德林‚方肇洪．垂直埋管地源热泵的圆柱面传热模型 及简化计算．山东建筑工程学院学报‚2001‚16（1）：47 ［4］ Yavuzturk C‚Spitler J D．A short time step response factor model for vertical ground loop heat exchangers．ASHREAE Trans‚ 1999‚105（2）：475 ［5］ Muraya N K‚O’Neal D L‚Heffington W M．Thermal interfer￾ence of adjacent legs in a vertical U-tube heat exchanger for a ground-coupled heat pump．ASHREAE Trans‚1996‚102（2）：12 ［6］ 刁乃仁‚曾和义‚方肇洪．竖直 U 型管地热换热器的准三维传 热模型．热能动力工程‚2003‚18（4）：387 ［7］ 黄俊惠‚时晓燕‚唐志伟‚地源热泵 U 型管地下换热器的准三 维模型．中国农业大学学报‚2004‚9（5）：51 CFD numerical simulation of a U-tube ground heat exchanger used in ground source heat pumps SONG Xiaofei‚WEN Zhi‚SI Junlong Mechanical Engineering School‚University of Science and Technology Beijing‚Beijing100083‚China ABSTRACT To provide a theory for the optimized design of a U-tube ground heat exchanger used in ground source heat pumps‚CFD software was used to simulate the processes of flow and heat transfer in the U-tube ground heat exchanger．The results show that the heat transfer efficiency of the U-tube ground heat exchanger increases with the increasing distance between two tubes and with the increasing heat conductivity of backfilling soil．The effect of the distance between two tubes and the heat conductivity of backfilling soil on the U-tube ground heat exchanger’s efficiency are a very complex nonlinear relation．When the hole-depth is deeper than80 m‚the temperature rise ratio of two tubes increases rapidly and the heat losing between two tubes increases．In practical operation‚the hole-depth is better not to be too deep． KEY WORDS ground source heat pump；ground heat exchanger；CFD numerical simulation；heat transfer model 第3期 宋小飞等： 地源热泵 U 型管地下换热器的 CFD 数值模拟 ·333·