影响平板式太阳能热水器热效率诸因素的研究  

THE EFFECTS OF MULTI VARIABLES ON EFFICIENCY OF A FLAT PLATE SOLAR COLLECTOR

作　　者：范貌宏 RobertC.Brown 范秀英[2] 杨建洲 张微[2] 

机构地区：[1]依阿华州大学可持续环境技术中心,埃姆斯依阿华美国50011 [2]中国科学院生态环境研究中心,北京100085

出　　处：《环境科学进展》1999年第6期122-126,共5页

摘　　要：本文根据辐射传热和对流传热理论，利用Ｍａｔｌａｂ 程序结合太阳能热水器本身的尺寸以及与其有关的水和空气的物理弹性详细分析了影响平板式太阳能热水器热效率的因素包括太阳能热水器表面的太阳光辐射的吸收率αｓ 和辐射系数ε，太阳能热水器的水进口温度Ｔｃ，ｉｎ和流量ｍｃ 太阳辐射能力Ｇｓ，，环境大气温度Ｔｅ，大气辐射系数εｓｋｙ 以及太阳能热水器内部的总传热系数Ｕ。分析结果表明较高的太阳照射能力、环境温度和总传热系数有利于提高集热效率，而增加水量和水进口温度、热水器辐射系数和大气辐射系数则有相反的效果。This paper is intended to estimate the radiation and convection heat transfer from a plat-plate solar collector used to heat water and evaluate the effects of the factors including solar absorptance α s ,emittance ε , entrance temperature of water T c,in , flow rate of water m c , solar irradiation G s , environmental temperature T e , sky emittance ε sky and overall heat transfer coefficient from the absorbing surface to the bulk water U on the collector efficiency η . Based on the related laws of radiation, convection, energy conservation, thermal properties of air and water and physical characteristics of referred flat-plate solar collector, a numerical MATLAB program is applied for calculating the temperature of absorbing surface T s , the exit temperature T c , and consequently η under the different conditions of factors mentioned above. The numerical method has shown that the increase of G s, T e or U will improve the collector efficiency but increase of m c ,ε, T c,in , and ε sky will inversely affect the collector efficiencies.

关 键 词：太阳能收集器 辐射 对流 传热 辐射系数 热水器 

分 类 号：TU832.17[建筑科学—供热、供燃气、通风及空调工程] TK513[动力工程及工程热物理—热能工程]