本文選題：含空氣層冷輻射板 + 供冷能力�。� 參考：《湖南大學》2015年碩士論文

【摘要】：對于一些常見的冷輻射板類型,其冷凍水銅管跟輻射板金屬面板直接接觸,容易導致冷輻射板表面形成條狀的低溫區(qū)域,表面溫度分布很不均勻。為了克服這個問題,某公司研發(fā)出一種含空氣層的模塊化冷輻射板,很好地解決了冷輻射板表面溫度分布不均勻的缺點。但由于空氣本身的熱阻較大,空氣層的存在阻礙了熱量的傳遞,大大降低了冷輻射板的供冷能力。文章介紹了輻射供冷系統(tǒng)的分類,分析其各自的優(yōu)缺點,借助熱輻射和輻射換熱的機理來闡明輻射供冷的原理,研究冷輻射板輻射換熱量和對流換熱量的計算方法。為了提升含空氣層冷輻射板的性能,本文建立一種新型含空氣層冷輻射板的數(shù)學傳熱模型,由模型計算得到的輻射板供冷能力和表面平均溫度與實驗結果的誤差分別為9.20%和-4.00%,證明該傳熱模型的可靠性較高。對輻射板冷凍水銅管與導熱板的接觸形式進行兩種改造,利用已驗證的傳熱模型對改進后的冷輻射板進行分析計算。計算結果表明:在最優(yōu)參數(shù)條件下,空氣層厚度減小為1mm時兩種輻射板的供冷能力分別提高了36.92W/m2和33.19 W/m2;冷凍水平均溫度每降低1℃、室內(nèi)溫度每升高1℃輻射板供冷能力分別平均提高7.46 W/m2和7.54W/m2;輻射板表面最大溫差幾乎不變,抗結露能力良好。此外,在與常見冷輻射板類型比較后可以發(fā)現(xiàn),在各自的最優(yōu)運行參數(shù)下,改進后含超薄空氣層冷輻射板的供冷能力與抗結露能力都優(yōu)于常見的冷輻射板�？梢�,改進后含空氣薄層的冷輻射板供冷和抗結露性能良好,適合推廣使用。文章分析了表面結露的本質(zhì)問題,得到冷輻射板表面結露需要滿足的條件。根據(jù)計算得到的數(shù)據(jù)擬合出冷凍水平均溫度、室內(nèi)溫度以及冷輻射板表面溫度三者之間的函數(shù)關系,進而提出了三種防止冷輻射板表面出現(xiàn)結露的控制策略并分析了其各自的優(yōu)缺點。
[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，

本文編號：2088201