| 摘要: |
| 地埋管换热器周围温度场随着运行时间变长不断向远处扩散，地下水流动使得埋管热作用距离沿流动方向大大增加。通过饱和含水层内地埋管换热模型，得到了地下水流动作用下埋管热作用距离的近似表达式，分析了地下水流速、土壤导热系数和孔隙率对热作用距离的影响。借助于地埋管热作用测试平台，分析了地下水流动作用下埋管热作用距离和热恢复特性，结果表明：地下水流动使得埋管热作用距离远大于纯导热模式，且热作用距离在埋管轴向不同埋深处大小不一，建议在地下水流速大于1×10-6m/s的地质区域，沿地下水流动方向设置埋管间距为8~10m。 |
| 关键词: 地下水流动 地埋管换热器 热作用距离 |
| DOI： |
|
|
| 基金项目:“十二五”国家科技支撑计划（2012BAJ01B00）资助项目。 |
|
| Evaluation of Temperature Plume Distance under Effects of Groundwater Flow on Borehole Heat Exchanger |
|
Mao Jinfeng, Li Yong, Zhang Hua, Geng Shibin, Han Xu
|
| (PLA University of Science & Technology) |
| Abstract: |
| In the ground source heat pump (GSHP) system, the temperature around the borehole heat exchangers (BHEs) would continue to spread further with running time, in addition the groundwater flow would have an important impact on the thermal dispersion. Based on the heat transfer model considering groundwater flow in aquifers, the approximate analytical expression of temperature plume distance was obtained, the factors including groundwater flow velocity，subsurface thermal conductivity and porosity affecting on the temperature plume distance were analyzed by comparing with infinite line source (ILS) model. The results from test platform showed that the temperature plume distance under the groundwater flow velocity was greatly larger than the distance under the pure conductive model and it was different along the axial direction of BHE. In the zone with the groundwater velocity larger than 1×10-6m/s, the distance of 8-10m between the boreholes was recommended for design along the groundwater flow direction. |
| Key words: groundwater flow borehole exchanger temperature plume distance |
