本文關(guān)鍵詞：碳氫燃料流動傳熱研究及物性測量與評估　出處：《西安建筑科技大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 碳氫燃料 矩形通道 傳熱 燃料結(jié)焦 物性

【摘要】：本文以高超聲速飛行器吸氣式發(fā)動機的再生主動冷卻為研究背景,冷卻時采用飛行器自身攜帶的燃料作為冷卻劑。碳氫燃料應(yīng)用于再生主動冷卻時,吸熱之后的碳氫燃料進入燃燒室燃燒釋放熱量,不僅對發(fā)動機很好的進行了熱防護,而且還可以對熱量進行回收利用。為了有效的研制和設(shè)計發(fā)動機的再生冷卻熱防護結(jié)構(gòu),必須對碳氫燃料的流動傳熱特性進行研究。本文主要以電加熱的實驗方法模擬了碳氫燃料在矩形小通道內(nèi)流動吸熱的過程,對燃料冷卻過程中的流動換熱特性進行了實驗研究。本文首先利用伽馬射線密度計和熱平衡的原理對本次流動傳熱研究實驗所用A碳氫燃料在高壓高溫下的密度和比熱進行了測量;密度測量時的壓力范圍為2~6MPa,溫度范圍為10~660℃,比熱測量時的壓力范圍為2~4MPa,溫度范圍為15~660℃。其次主要研究分析了燃料在臨界參數(shù)點附近的傳熱變化規(guī)律,燃料臨界參數(shù)為:臨界壓力2.3MPa左右,臨界溫度420℃左右。本文流動傳熱研究的主要實驗參數(shù)范圍如下:壓力范圍為2~4MPa、溫度范圍為100℃~750℃、熱流密度范圍為0.1MW/m2~2.5MW/m2。研究結(jié)果表明:燃料的吸熱冷卻性能受溫度、壓力、以及管型的影響;壓力3MPa時,燃料入口溫度低于臨界溫度時會經(jīng)歷傳熱惡化和傳熱強化的現(xiàn)象,傳熱惡化發(fā)生在臨界溫度點附近,傳熱強化發(fā)生在高熱負荷條件下,由壁溫和主流溫度共同影響決定;當(dāng)燃料溫度超過臨界溫度時,浮升力作用對傳熱影響比較明顯。當(dāng)壓力超過臨界壓力在超臨界壓力范圍內(nèi)溫度和壓力對燃料的傳熱影響是相互的,溫度低于臨界溫度時,壓力高傳熱效果好;溫度高于臨界溫度時,壓力低傳熱效果好。燃料在超臨界下的流動換熱努謝爾數(shù)與經(jīng)典換熱關(guān)聯(lián)式計算結(jié)果進行比較,解釋了燃料在催化裂解時的換熱機理會發(fā)生明顯的變化。通過測量燃料的熱沉、燃料結(jié)焦的情況以及高溫燃料的轉(zhuǎn)化率,建立了燃料評估的方法。
[Abstract]:In this paper, the regenerative active cooling of hypersonic air-breathing engine is studied, and the fuel carried by the vehicle itself is used as the coolant. The hydrocarbon fuel is applied to regenerative active cooling. After heat absorption, the hydrocarbon fuel enters the combustion chamber to release heat, which not only provides a good thermal protection for the engine. In order to effectively develop and design the regenerative cooling thermal protection structure of the engine, the heat can be recycled and utilized. It is necessary to study the flow and heat transfer characteristics of hydrocarbon fuel. In this paper, the flow and heat transfer process of hydrocarbon fuel in rectangular channel is simulated by electric heating. The flow heat transfer characteristics during fuel cooling are studied experimentally. Firstly, the density of A hydrocarbon fuel used in this flow heat transfer experiment at high pressure and high temperature is studied by using the principle of gamma ray densitometer and heat balance. And specific heat was measured. The pressure range of density measurement is 2 ~ 6 MPA, the temperature range is 10 ~ 660 鈩，

本文編號：1368133