流体机械2012，Vol.40Issue(4)：56-62,7.DOI:10.3969/j.issn.1005-0329.2012.04.014
基于准三维模型的垂直U型埋管换热特性影响因素的分析
Analysis on Influence Factors of Heat Exchange Characteristics of Vertical U-bend Ground Heat Exchanger Based on Quasi-three Dimensional Model
摘要
Abstract
In grder to investigate the influences of various factors on heat exchange characteristics of ground h?st exchangers (GHE) , a quasi-three dimensional heal transfer analytics) model was developed for the vertical l)-bend GHE. The variation of fluid temperature along the U-tube and the thermal interference between two adjacent legs of U-lube were considered in this model. Based on the solution of the model, the influences of various factors, which include the thermal conductivity of grout and pipe, spacing between the two legs of U-tube, flow rate of circulated fluid and borehole depth, on the heat exchange characteristics of GHE were discussed. The results indictate that the increase in the thermal conductivity of grout and pipe, spacing between the two legs and fluid flow rate can all improve heat exchange effectiveness of GHE. But the thermal conductivity of grout should not be increased unrestrictedly, the decision of its value has to take into account the influence of increased thermal interference between the two-legs and its correlation with the spacing of two legs, and should be further optimized for them. At the same time, the increase of fluid flow rate can lead to the increase of heat flow per unit buried coil length, hut the increasing degree become more and more small, a restriction in flow resistance increase must be taken into account to optimize it by a "variable flaw rate design method. Addionally, the depth of a borehole should nol be too large in case that the heat exchange rate per unit coil length should decrease. The experimental validation shows that the predicted relative error is less than 3%. This means that the modeldeveloped can provide references for the analysis of heat exchange characteristic and optimization design of GHE.关键词
地源热泵/垂直U型埋管换热特性/准三维模型/影响因素/试验验证Key words
ground source heat pump/ heat exchange characteristics of vertical U-bend ground heat exchanger/ quasi -three dimensional model/ influence factors/ experimental validation分类
建筑与水利引用本文复制引用
杨卫波,施明恒,陈振乾..基于准三维模型的垂直U型埋管换热特性影响因素的分析[J].流体机械,2012,40(4):56-62,7.基金项目
国家"十一五"科技支撑计划项目资助(2008BAJ12B04) （2008BAJ12B04）
中国博士后科学基金项目资助(20090461050) （20090461050）
住房与城乡建设部科技计划项目资助(2008-K1-26) （2008-K1-26）
扬州大学"新世纪人才工程"优秀青年骨干教师计划项目(2008年度) （2008年度）
扬州大学科技创新培育基金项目(2010CXJ030) （2010CXJ030）
江苏省科技支撑计划项目(BE2010699) （BE2010699）
