含空气层冷辐射板的改进分析及其防结露控制

发布时间：2018-07-01 15:19

  本文选题：含空气层冷辐射板 + 供冷能力　； 参考：《湖南大学》2015年硕士论文

【摘要】：对于一些常见的冷辐射板类型,其冷冻水铜管跟辐射板金属面板直接接触,容易导致冷辐射板表面形成条状的低温区域,表面温度分布很不均匀。为了克服这个问题,某公司研发出一种含空气层的模块化冷辐射板,很好地解决了冷辐射板表面温度分布不均匀的缺点。但由于空气本身的热阻较大,空气层的存在阻碍了热量的传递,大大降低了冷辐射板的供冷能力。文章介绍了辐射供冷系统的分类,分析其各自的优缺点,借助热辐射和辐射换热的机理来阐明辐射供冷的原理,研究冷辐射板辐射换热量和对流换热量的计算方法。为了提升含空气层冷辐射板的性能,本文建立一种新型含空气层冷辐射板的数学传热模型,由模型计算得到的辐射板供冷能力和表面平均温度与实验结果的误差分别为9.20%和-4.00%,证明该传热模型的可靠性较高。对辐射板冷冻水铜管与导热板的接触形式进行两种改造,利用已验证的传热模型对改进后的冷辐射板进行分析计算。计算结果表明:在最优参数条件下,空气层厚度减小为1mm时两种辐射板的供冷能力分别提高了36.92W/m2和33.19 W/m2;冷冻水平均温度每降低1℃、室内温度每升高1℃辐射板供冷能力分别平均提高7.46 W/m2和7.54W/m2;辐射板表面最大温差几乎不变,抗结露能力良好。此外,在与常见冷辐射板类型比较后可以发现,在各自的最优运行参数下,改进后含超薄空气层冷辐射板的供冷能力与抗结露能力都优于常见的冷辐射板。可见,改进后含空气薄层的冷辐射板供冷和抗结露性能良好,适合推广使用。文章分析了表面结露的本质问题,得到冷辐射板表面结露需要满足的条件。根据计算得到的数据拟合出冷冻水平均温度、室内温度以及冷辐射板表面温度三者之间的函数关系,进而提出了三种防止冷辐射板表面出现结露的控制策略并分析了其各自的优缺点。
[Abstract]:For some common cold radiation plate types, the chilled water copper tube is in direct contact with the radiation plate metal panel, which can easily lead to the formation of a strip low temperature area on the surface of the cold radiation plate, and the surface temperature distribution is very uneven. In order to overcome this problem, a modular cold radiation plate with air layer has been developed by a company, which can solve the disadvantage of uneven surface temperature distribution. However, due to the large thermal resistance of the air itself, the existence of the air layer hinders the heat transfer and greatly reduces the cooling capacity of the cooling radiating plate. This paper introduces the classification of radiation cooling system, analyzes their advantages and disadvantages, clarifies the principle of radiation cooling by means of the mechanism of heat radiation and radiation heat transfer, and studies the calculation method of radiation heat transfer and convection heat transfer of cold radiation plate. In order to improve the performance of air-cooled radiating plate, a new mathematical heat transfer model of air-cooled radiating plate is established in this paper. The errors between the cooling capacity and the average surface temperature of the radiating plate calculated by the model are 9.20% and -4.00%, respectively. It is proved that the heat transfer model is reliable. Two kinds of modification were carried out on the contact form between the cooling water copper tube and the heat conduction plate of the radiation plate, and the improved cold radiation plate was analyzed and calculated by using the verified heat transfer model. The results show that the cooling capacity of the two radiating plates increases by 36.92 W / m ~ 2 and 33.19 W / m ~ 2 when the thickness of the air layer decreases to 1mm, and the average freezing temperature decreases by 1 鈩，

本文编号：2088201