基于全年冷热量的地道风埋管有效长度的分析  

ANALYSIS ON EFFECTIVE PIPE LENGTH OF EARTH-AIR HEAT EXCHANGER BASED ON ANNUAL COOLING/HEATING CAPACITIES

作　　者：苏华[1] 魏四清 李茜 付红玉 郭婷婷 Su Hua;Wei Siqing;Li Qian;Fu Hongyu;Guo Tingting(School of Architecture and Civil Engineering,Xihua University,Chengdu 610039,China)

机构地区：[1]西华大学建筑与土木工程学院,成都610039

出　　处：《太阳能学报》2021年第10期470-477,共8页Acta Energiae Solaris Sinica

基　　金：教育部“春晖计划”(Z2016158)。

摘　　要：采用等效方管二维非稳态传热数值模型对地道风进行全年动态换热性能计算。首先进行网格独立性检验,建议计算网格为Δz=3 m、Δx=Δy=0.3 m;其次对等效方法进行误差分析,表明方管模型可以接受;然后基于成都地区的气象条件及办公建筑的间隙运行模式,计算分析深度、流速、管径对有效长度以及全年冷热量的影响;最后提出以全年冷热量作为有效长度的判定指标。结果表明,全年冷热量确定有效长度的方法可行。对埋管有效长度影响较大的因素是流速、管径;埋深对全年冷热量的影响明显,但对管长的影响不明显。地表下4 m以内埋管比较合适。Absrtact:In this paper,a two dimensional transient numerical model of heat transfer with an equivalent square pipe was used tosimulate the dynamic thermal performance of Earth-air heat exchangers(EAHE).At first,grids independence tests were carried out andΔz≤3 m,Δx=Δy≤0.3 m is recommended.Secondly,analysis was performed on error of the equivalent square tube model.It show that the equivalent square tube model is acceptable.Thirdly,hourly simulations were conducted to analyze the impacts of depth,diameterand flow velocity on the effective pipe length and annual heating/cooling capacities,under intermittent operation mode,taking an officebuilding as an example in Chengdu.The annual heating/cooling capacities were used to determine the effective pipe length.Results showthat the new method for determining the effective pipe length is feasible.The diameter and flow velocity affect the effective pipe lengthand annual heating/cooling capacities significantly.The depth affects the effective pipe length slightly and affects the heating/coolingcapacities significantly.It is recommended that the depth is within 4 m underneath the ground surface.

关 键 词：地道风 传热数值模型 有效长度 全年冷热量 网格独立性 被动建筑 

分 类 号：TK51[动力工程及工程热物理—热能工程]