本文選題：氣化器　切入點(diǎn)：螺旋擾流桿　出處：《西安石油大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著我國天然氣產(chǎn)業(yè)的高速發(fā)展,對(duì)LNG生產(chǎn)工藝也提出了更高的要求。氣化器是LNG氣化站的核心設(shè)備,而我國對(duì)其研究與發(fā)達(dá)國家相比還存在較大差異,尤其是對(duì)開架式氣化器的傳熱機(jī)理認(rèn)識(shí)尚淺,所有關(guān)鍵設(shè)備均從國外進(jìn)口。因此非常有必要對(duì)開架式氣化器的強(qiáng)化傳熱機(jī)理進(jìn)行深入研究,開發(fā)出一種國產(chǎn)的新型氣化器,以擺脫對(duì)國外技術(shù)和承包商的依賴。本文在現(xiàn)有超級(jí)開架式氣化器(SUPERORV)傳統(tǒng)結(jié)構(gòu)的基礎(chǔ)上,設(shè)計(jì)了一種新型超級(jí)開架式氣化器,即在傳統(tǒng)氣化器傳熱管內(nèi)管中加入一個(gè)十字螺旋擾流桿。發(fā)現(xiàn)擾流桿的存在,不僅能夠加強(qiáng)流體的湍流強(qiáng)度,還能有效減小邊界層厚度,產(chǎn)生強(qiáng)烈的二次流,加強(qiáng)了流體在徑向上的熱交換,提高了傳熱管的換熱能力。本文采用數(shù)值模擬的手段,對(duì)影響換熱效果的不同因素(螺距、壓力、材質(zhì))進(jìn)行了數(shù)值計(jì)算分析,結(jié)果顯示：與目前現(xiàn)行的SUPERORV相比,新型傳熱管擾流桿的存在,不僅增大了換熱面積,還提高了流體的湍流強(qiáng)度,有效破壞了溫度邊界層,提高了換熱管的整體換熱能力。在相同雷諾數(shù)Re下,新型傳熱管內(nèi)流體的平均溫度明顯高于普通傳熱管內(nèi)管流體的溫度；當(dāng)壓力為5MPa,雷諾數(shù)為6000時(shí),隨著螺距的增加,管內(nèi)流體的湍流度減小,出口處流體平均溫度逐漸降低；當(dāng)在同一雷諾數(shù)和螺距時(shí),新型傳熱管內(nèi)流體的溫度隨著壓力的升高逐漸降低,且努賽爾數(shù)Nu和傳熱系數(shù)h也隨其逐漸減�。划�(dāng)依次采用材質(zhì)不銹鋼、鋁、銅時(shí),隨著雷諾數(shù)的增大,新型傳熱管的努賽爾數(shù)Nu也逐漸增大,且采用銅時(shí)的努賽爾數(shù)最大,傳熱系數(shù)也最大。最后對(duì)文獻(xiàn)中的實(shí)驗(yàn)進(jìn)行數(shù)值模擬,并對(duì)比了同一質(zhì)量流速下不同熱流密度對(duì)傳熱的影響,得到了與文獻(xiàn)中實(shí)驗(yàn)結(jié)果相同的結(jié)論,驗(yàn)證了數(shù)值模擬手段的可靠性和正確性。本文的研究成果為超級(jí)開架式氣化器國產(chǎn)化提供了一定的理論依據(jù),對(duì)實(shí)現(xiàn)我國自主研發(fā)國產(chǎn)氣化器具有一定的工程應(yīng)用意義。
[Abstract]:With the rapid development of natural gas industry in China, higher requirements have been put forward for LNG production process. Gasifier is the core equipment of LNG gasification station, but the research on it in our country is different from that in developed countries. In particular, the heat transfer mechanism of the open-shelf gasifier is not well understood, and all the key equipments are imported from abroad. Therefore, it is necessary to deeply study the mechanism of enhanced heat transfer of the open-shelf type gasifier and to develop a new type of gasifier made in China. In order to get rid of the dependence on foreign technology and contractors, this paper designs a new type of super open-shelf gasifier based on the traditional structure of the existing super-open-shelf gasifier SUPERORV. It is found that the existence of the spoiler rod can not only enhance the turbulence intensity of the fluid, but also effectively reduce the thickness of the boundary layer and produce a strong secondary flow. The heat exchange of fluid in the radial direction is strengthened and the heat transfer capacity of the heat transfer pipe is improved. In this paper, different factors (pitch, pressure, material) that affect the heat transfer effect are numerically calculated and analyzed by numerical simulation. The results show that compared with the current SUPERORV, the existence of the new heat transfer tube spoiler not only increases the heat transfer area, but also increases the turbulence intensity of the fluid and effectively destroys the temperature boundary layer. Under the same Reynolds number re, the average temperature of the fluid in the new heat transfer tube is obviously higher than that of the ordinary tube fluid, and when the pressure is 5 MPA and the Reynolds number is 6 000, the average temperature of the fluid in the new heat transfer tube increases with the increase of the pitch. At the same Reynolds number and pitch, the temperature of the fluid in the new heat transfer tube decreases with the increase of pressure. The Nussel number Nu and the heat transfer coefficient h also decrease with the increase of Reynolds number, and the Nusselle number of the new heat transfer tube increases with the increase of Reynolds number, and the Nussel number of the new heat transfer tube increases with the increase of the Reynolds number, and the Nussel number of the new heat transfer tube is the largest when copper is used. The heat transfer coefficient is also the largest. Finally, the experiments in the literature are numerically simulated, and the effects of different heat flux on heat transfer under the same mass velocity are compared, and the results are the same as the experimental results in the literature. The research results in this paper provide a theoretical basis for the localization of super open-shelf gasifier, and have a certain engineering application significance for the independent development of domestic gasifier in China.
【學(xué)位授予單位】：西安石油大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TE96

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本文編號(hào)：1604515