新型农村地源热泵地埋管换热器的传热模拟

Heat Transfer Simulation of Underground Pipeline Heat Exchanger in New Rural Ground-Source Heat Pump

[目的]更好地模拟地源热泵地埋换热器的换热状况。[方法]介绍了3种地源热泵地埋管换热器的传热模型（线热源模型、圆柱热源模型和Eskilson模型）,以宁波市鄞州区冬天供热为例,选择适当的传热模型进行数据模拟,得出了地埋管周围土壤温度场分布。[结果]地源热泵系统连续运行一段时间后,地埋管周围半径为0.8m的范围内温度场会呈现强烈的变化,该区域以外的地方温度变化越来越小,直至接近于土壤的原始温度;浅层地表土壤原始温度场分布与深度呈指数关系,当深度达到一定程度后,土壤基本上维持恒温状态,比当地年平均气温高1～2℃。[结论]该研究为新型农村地源热泵中央空调工程设计和运行提供了理论参考。

[Objective] The research aimed to better stimulate the heat exchange status of underground tube heat exchange.[Method] Three kinds of heat transfer models of underground pipeline heat exchanger in ground-source heat pump（including line heat sources model,cylindrical heat sources model and Eskilson model） were introduced.Taking winter heat supply in Qinzhou district of Ningbo city as an example,the appropriate heat transfer model was selected to make data stimulation and educe the temperature field distribution in the surrounding soil of underground pipeline.[Result] After the ground-source heat pump system ran continuously for a period of time,the temperature field in the range with the semidiameter of 0.8 m around the underground pipeline showed intensive changes.The changes of the temperature field in the area outside this region became smaller till it was close to the original temperature of soil.The original temperature field in the soil of shallow ground surface showed an exponential correlation with the depth.When the depth reached to certain extent,the soil basically maintained the constant-temperature state and it was 1～2 ℃ higher than the annual average temperature.[Conclusion] This research provided the theoretical references for the engineering design and operation of the central air-conditioning I new heat pump of rural ground source.