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建立了真空集热管中吸收管与玻璃管之间热辐射和残余气体热对流、玻璃管与外界环境之间热对流和玻璃管对天空热辐射的数学模型,提出了模型的计算方法,并通过和实验数据的比较验证了模型的准确性。同时利用模型分析了几种影响热损失的主要因素,分析结果表明:吸收管温度越高,热损失越大;环境温度越低,风速越大,热损失越大,但影响很小;选择性吸收涂层的发射率是影响热损失的主要因素;真空度对热损失也有很大影响。
The mathematical model of the heat radiation and the convection of residual gas between the absorption tube and the glass tube, the convection between the glass tube and the external environment and the heat radiation of the glass tube to the sky were established, and the calculation method of the model was established. The comparison with experimental data verifies the accuracy of the model. At the same time, using the model to analyze several main factors affecting the heat loss, the results show that: the higher the temperature of the absorber tube, the greater the heat loss; the lower the ambient temperature, the greater the wind speed, the greater the heat loss, Absorption coating emissivity is the main factor affecting the heat loss; the degree of vacuum also has a great impact on heat loss.