發(fā)布時間：2018-02-26 17:08

  本文關鍵詞： 超音速 低溫 脫水 Laval噴管 分離效率 壓損比　出處：《青島科技大學》2017年碩士論文　論文類型：學位論文

【摘要】：近年來我國的空氣污染嚴重影響著國民的日常生活,因此天然氣作為一種清潔能源需求量在不斷增加。超音速低溫分離是將氣體動力學與熱力學應用到實際工程中的一種先進工藝技術。氣體在通過收縮—擴張管(Laval噴管)后,會形成低溫低壓的超音速流場。研究表明:當氣體溫度低于水及重烴組分的露點溫度后會凝結成為液態(tài)水滴,在旋流發(fā)生裝置后產生離心加速度將液滴分離出來。該裝置在工作中未使用,因此節(jié)能環(huán)保的同時還降低了一定的運行成本。本文選用氮氣為實驗介質,以符合天然氣實際操作工況的13.2MPa,處理量2000Nm3/h為設計依據。首先開展了超音速低溫天然氣脫水及重烴實驗裝置的核心部件的結構設計,在此基礎上,采用大型商業(yè)流體力學計算軟件FLUENT對實驗裝置的本體結構(入口旋流器及Laval噴管及后續(xù)的脫水裝置)進行了流體特性模擬。最后依據本文的結構設計,完成了實驗裝置的搭建,并進行了相應的實驗工作,實驗內容主要包括不同操作參數以及不同噴管裝置尺寸結構對超音速低溫分離裝置工作效率影響。一方面驗證數值模擬的可行性和正確性,另一方面也為該項技術的進一步工業(yè)化推廣應用提供實驗數據。本文的研究結果如下:(1)實驗結果與數值模擬結果比較,兩者誤差較小,數值模擬結果可以用于對裝置內流場的預測。(2)本實驗裝置在設計工況下,入口壓力13.2MPa,出口壓力9.25MPa(壓損比30%)入口溫度28℃時,裝置進出口溫度差6.3℃,露點降7℃。當進出口壓損比為54%時,該裝置實驗中得到的最大露點降為15℃。(3)實驗結果表明:在高壓環(huán)境下,隨著壓損比的升高,進出口露點降溫度不斷升高。(4)模擬結果顯示,在高壓環(huán)境下,進口壓力一定時,出口壓力升高,裝置內的激波位置向喉口處移動,不利于水蒸氣的凝結分離。同時進出口的溫差升高,超音速噴管內最大馬赫數降低。在Laval噴管入口直徑和喉口直徑一定的情況下,噴管出口直徑對裝置內的流場影響較大。當噴管出口直徑增大時,激波位置向喉口移動,但氣體在Laval噴管內可以達到更低的溫度。而擴壓段入口的徑向尺寸叫噴管出口直徑對裝置內流場影響較小。
[Abstract]:In recent years, air pollution in our country has seriously affected the daily life of the people. As a result, the demand for natural gas as a clean energy is increasing. Supersonic cryogenic separation is an advanced technology that applies gas dynamics and thermodynamics to practical projects. A supersonic flow field at low temperature and low pressure is formed. Studies show that when the gas temperature is below the dew point temperature of water and heavy hydrocarbon components, it condenses into a liquid water droplet. The liquid droplets are separated by centrifugal acceleration after the swirl generator. The device is not used in work, so the operation cost is reduced while saving energy and environmental protection. In this paper, nitrogen is chosen as the experimental medium. According to the design basis of 13.2 MPA and 2000Nm ~ 3 / h, the structural design of the core components of the supersonic low-temperature natural gas dehydration and heavy hydrocarbon experimental device is carried out. The fluid characteristics of the main structure of the experimental device (inlet cyclone, Laval nozzle and subsequent dehydration device) are simulated by the large-scale commercial fluid dynamics calculation software FLUENT. Finally, according to the structure design of this paper, the experimental device is constructed. The experimental work includes the effect of different operating parameters and nozzle size structure on the working efficiency of supersonic cryogenic separation device. On the one hand, the feasibility and correctness of numerical simulation are verified. On the other hand, it also provides experimental data for the further industrial application of this technology. The results of this paper are as follows: 1) the experimental results are smaller than those of the numerical simulation results. The numerical simulation results can be used to predict the flow field in the device. (2) under the design condition, the inlet pressure is 13.2MPa, the outlet pressure is 9.25MPa (pressure loss ratio is 30) and the inlet temperature is 28 鈩，

本文編號：1538924