Heat Transfer and Natural Ventilation Airflow Rates from Single-sided Heated Solar Chimney for Buildings
Heat Transfer and Natural Ventilation Airflow Rates from Single-sided Heated Solar Chimney for Buildings
复制标题
建筑物单面加热太阳能烟囱的传热和自然通风气流速率
DOI：
10.3130/jaabe.3.233
复制
发表时间：
2004
影响因子：
1.3
通讯作者：
Liping Wang
中科院分区：
文献类型：
--
作者：
Angui Li;P. Jones;Pingge Zhao;Liping Wang
摘要利用计算流体力学（MITFLOW）技术，对建筑物侧壁太阳能烟囱的传热过程和自然通风进行了详细的研究。在本文中，在建模研究的条件和参数是空腔宽度的太阳能烟囱，壁温，高度和宽度的太阳能烟囱，出口面积与入口面积的比例，以及出口位置的太阳能烟囱。针对单面集热器（单面加热墙）太阳能烟囱，计算参数的取值范围为：太阳能烟囱长度L = 0.5 m ~ 5.0 m，宽度B= 0.1 m ~ 0.5 m，高度H= 2.0 m ~ 5.0 m，B/H=0.05~0.25。受热壁面温度Tw在30°C~70°C范围内变化;出口面积与入口面积之比Ar在0.6~1.0范围内变化。研究发现，对于给定的建筑几何形状和入口面积，存在一个最佳空腔宽度，在该宽度处可以获得最大的气流速率。根据预测，当B/H约为1/10时，风量达到最大。研究还发现，对于给定的烟囱几何形状，太阳能烟囱通风流量可以增加与烟囱高度的增加只有横截面积不超过临界面积，因为横截面积有很强的过渡和/或湍流对流传热的封闭。从经济技术的角度出发，可以根据最佳截面宽高比和实用宽度来确定太阳能烟囱的最佳高度。通过对CFD预测结果的分析，指出当出风口面积与进风口面积相同时，可以得到最优的通风量。一般来说，有很好的协议之间的数值计算结果，现有的文献中的实验数据和理论分析的自然通风从太阳能烟囱。
Abstract Heat transfer process and natural ventilation driven by a solar chimney attached to a sidewall of building are investigated with CFD technique (MITFLOW) in detail. In this paper, conditions and parameters studied in the modelling study are the cavity width of the solar chimney, the wall temperature, the height and breadth of the solar chimney, the ratio of outlet area to inlet area as well as the outlet location of the solar chimney. The ranges of calculation parameters focused on a solar chimney with single-sided solar collector (single-sided heated wall) cover following conditions: solar chimney length L = 0.5m~5.0m, breadth B=0.1m~0.5m, height H=2.0m~5.0m, and B/H=0.05~0.25. Heated wall surface temperature Tw is changed in the range of 30°C~70°C; the ratio of the outlet area to inlet area Ar is changed in the range of 0.6~1.0. It is found that for given building geometry and inlet areas, there is an optimum cavity width at which a maximum airflow rate can be achieved. Based on the prediction, the airflow rate reaches maximum when B/H is approximately 1/10. It is also found that for given chimney geometry, solar chimney ventilation flow rate can be increased with the enhancement of chimney height only the cross sectional area no more than the critical area, because cross section area has a strong effect on the transitional and/or turbulent convective heat transfer in an enclosure. From the view of economy technology, the optimized height of a solar chimney can be determined according to the optimized section ratio of breadth to height and available breadth in practice. On the analysis of CFD prediction, it is noted that optimized ventilation flow rate can be obtained when the outlet area takes the same area as the inlet area. Generally, there is good agreement among the numerical results, available experimental data from literature and theoretical analysis of natural ventilation from the solar chimney.