摘要
为确定地下水渗流对埋地换热器的影响,建立了考虑地下水渗流的三维有限长线热源模型,综合虚拟热源法、移动热源法和格林函数法得出了有渗流时半无限大介质中有限长线热源产生的非稳态温度响应的表达式。通过matlab编程模拟温度场,分析了单个钻孔周围土壤过余温度场。模拟结果发现:地下水渗流引起水平面上温度场的变形,当量渗流速度在10-6量级时,能有效缓解热堆积;沿钻孔不同深度处的土壤过余温度不同,在钻孔中部过余温度达到最大。该文中的三维模型可用来研究不同地区、不同土壤分层构造和分层地下水流速等复杂问题,从而更准确地预测分析实际工程运行后的地下温度场变化,具有重要意义,为进一步研究考虑土壤分层和地下水分层流动下地埋管周围温度场奠定了基础。
In order to estimate the impact of groundwater flow on performance of ground heat exchanger in groundsource heat pump systems, a three-dimensional finite line source model with groundwater advection was developed. A formula of the non-steady temperature response in a semi-infinite medium with a line source of finite length was derived by means of setting a virtual line sink, using moving line source solution and the Green function method. The characteristics of temperature field around a single borehole were studied by virtue of Mablab program. Simulation results showed that the groundwater flow would cause a distortion of the original symmetrical temperature field and the magnitude of equivalent groundwater flow rate at 10-6 level could effectively alleviate the underground heat imbalance. It was also found that the temperature was not constant along the borehole, and maximum temperature occurred near the mid level of borehole. The proposed three-dimensional model can be used to investigate the problem of various regions with multi-layer soil and different groundwater flow, which is the basis for the following study on the temperature field around the ground heat exchanger considering multi-layer soil level and groundwater flow.
出处
《太阳能学报》
EI
CAS
CSCD
北大核心
2011年第6期862-867,共6页
Acta Energiae Solaris Sinica
关键词
地源热泵
地下水渗流
埋地换热器
三维传热模型
geothermal-source heat pump
groundwater flow
ground source heat exchanger
three-dimensional heat transfer model
