Analysis on effective pipe length of earth-air heat exchanger based on annual cooling/heating capacities

被引:0
作者
Su H. [1 ]
Wei S. [1 ]
Li Q. [1 ]
Fu H. [1 ]
Guo T. [1 ]
机构
[1] School of Architecture and Civil Engineering, Xihua University, Chengdu
来源
Li, Qian (cyqlq@mail.xhu.edu.cn) | 1600年 / Science Press卷 / 42期
关键词
Annual heating/cooling capacities; Earth-air heat exchanger; Effective pipe length; Grid independence; Numerical model of heat transfer; Passive building;
D O I
10.19912/j.0254-0096.tynxb.2019-1026
中图分类号
学科分类号
摘要
In this paper, a two dimensional transient numerical model of heat transfer with an equivalent square pipe was used to simulate the dynamic thermal performance of Earth-air heat exchangers (EAHE). At first, grids independence tests were carried out and Δz≤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, diameter and flow velocity on the effective pipe length and annual heating/cooling capacities, under intermittent operation mode, taking an office building as an example in Chengdu. The annual heating/cooling capacities were used to determine the effective pipe length. Results show that the new method for determining the effective pipe length is feasible. The diameter and flow velocity affect the effective pipe length and annual heating/cooling capacities significantly. The depth affects the effective pipe length slightly and affects the heating/cooling capacities significantly. It is recommended that the depth is within 4 m underneath the ground surface. © 2021, Solar Energy Periodical Office Co., Ltd. All right reserved.
引用
收藏
页码:470 / 477
页数:7
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