本文關(guān)鍵詞： V 形翅片管換熱器 氣流分布 不均勻性分布　出處：《華中科技大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：翅片管式換熱器極大地提高了管式換熱器的換熱系數(shù),因此廣泛的應(yīng)用于暖通空調(diào)和化工等領(lǐng)域。隨著近年來對能源消耗要求的提高,制冷用翅片管式換熱器性能的提升也成為空調(diào)制造企業(yè)面臨的一個(gè)重大課題。本文首先對空氣經(jīng)過開縫翅片的流動(dòng)與換熱情況進(jìn)行了數(shù)值模擬,然后針對一款美式風(fēng)管機(jī)中使用的V形翅片管式換熱器,利用基于計(jì)算流體力學(xué)CFD原理的Fluent軟件中的多孔介質(zhì)模型,模擬計(jì)算了美式風(fēng)管機(jī)中使用的V形翅片管式換熱器中空氣流動(dòng)的不均勻分布情況。數(shù)值計(jì)算分析結(jié)果顯示,在一定的進(jìn)風(fēng)量情況下,換熱器迎風(fēng)面的風(fēng)速70%的區(qū)域流速集中在0.5-2.0m/s,有一些區(qū)域的流速高達(dá)4.2m/s,風(fēng)速分布差別比較明顯,并且模型計(jì)算出來的壓差為26.2Pa,與實(shí)驗(yàn)實(shí)測值的24.0Pa相差只有9.1%,表明該模型能夠較準(zhǔn)確的計(jì)算出V形翅片管式換熱器空氣側(cè)風(fēng)速的不均勻分布情況。在得到的氣流分布情況的基礎(chǔ)上,進(jìn)一步分析氣流不均勻分布對V形翅片管式換熱器換熱性能的影響。結(jié)合翅片管式換熱器設(shè)計(jì)計(jì)算軟件CoilDesigner軟件,計(jì)算出換熱器換熱情況及制冷劑的出口狀態(tài),結(jié)果顯示換熱器上中下三個(gè)環(huán)路制冷劑出口的過熱度分別為9.3℃、7.3℃和5.2℃,與實(shí)驗(yàn)測試值相差最大只有0.7℃,而且換熱量的誤差在0.5%以內(nèi),驗(yàn)證了計(jì)算結(jié)果的正確性。為后續(xù)合理安排管路布置,保證各個(gè)管路出口制冷劑狀態(tài)能滿足壓縮機(jī)進(jìn)口的要求提供了依據(jù)。通過模擬及對比分析,較準(zhǔn)確的計(jì)算出了V形翅片管式換熱器空氣側(cè)風(fēng)速的不均勻分布情況。本文研究內(nèi)容可以為翅片管式換熱器的優(yōu)化設(shè)計(jì)提供一種可行的新方法,對后續(xù)的實(shí)驗(yàn)研究及結(jié)構(gòu)優(yōu)化有一定的指導(dǎo)意義。
[Abstract]:Finned tube heat exchanger greatly improves the heat transfer coefficient of tube heat exchanger, so it is widely used in HVAC and chemical industry. The improvement of the performance of finned tube heat exchanger for refrigeration has also become a major issue for air conditioning manufacturers. In this paper, the flow and heat transfer of air through slit fin are numerically simulated. Then for a V-shaped finned tube heat exchanger used in an American-style air duct machine, the porous medium model in Fluent software based on the CFD principle of computational fluid dynamics is used. The non-uniform distribution of air flow in the V-shaped finned tube heat exchanger used in the American air duct machine is simulated and calculated. The regional velocity of 70% on the upwind side of the heat exchanger is concentrated at 0.5-2.0 m / s, and in some areas the velocity is as high as 4.2 m / s, and the distribution of the wind speed is quite distinct. The pressure difference calculated by the model is 26.2Pa, which is only 9.1 from the measured value of 24.0Pa, which shows that the model can accurately calculate the non-uniform distribution of wind velocity on the air side of V-shaped finned tube heat exchanger. On the basis of the situation, The influence of uneven distribution of air flow on the heat transfer performance of V-shaped finned tube heat exchanger is further analyzed. The heat transfer situation and refrigerant outlet state of the heat exchanger are calculated by using the software CoilDesigner for the design and calculation of finned tube heat exchanger. The results show that the superheat of the upper, middle and lower loop refrigerant outlet of the heat exchanger is 9.3 鈩，

本文編號：1547454