【摘要】：為了考察在一定設(shè)計尺寸下液化天然氣(LNG)浸沒燃燒式氣化系統(tǒng)的天然氣出口溫度能否達到生產(chǎn)要求,建立了對整個浸沒燃燒式氣化器(包含燃燒室、下氣管和LNG換熱器3部分)中一系列流動和傳熱的數(shù)值計算模型。在燃燒室中,采用灰氣體加權(quán)和模型(WSGGM)計算煙氣的吸收系數(shù),利用DO模型求解輻射傳遞方程,并在考慮對流和輻射的混合傳熱作用下計算出火焰罩的壁面溫度以及煙氣、二次空氣出口的平均溫度;在LNG換熱器中,對流體物性劇烈變化的管程進行分段處理并采用兩相流體模型來模擬殼程中氣液兩相的流動和傳熱過程,在分別獲得管殼兩側(cè)的平均傳熱系數(shù)后用以計算總的換熱系數(shù)。所獲得的管程和殼程對流換熱系數(shù)和關(guān)聯(lián)式與已有的文獻值符合良好。殼程入口氣體溫度在500~700℃的范圍內(nèi)變動時,殼程出口氣體溫度與殼程水浴平均溫度略微升高,同時殼程水浴湍動能降低,換熱系數(shù)稍有減小。模擬獲得的天然氣出口溫度可維持在15℃左右,能滿足生產(chǎn)需要。
[Abstract]:In order to investigate whether the outlet temperature of liquefied natural gas (LNG) (LNG) submerged combustion gasification system can meet the production requirements under a certain design size, the whole submerged combustion gasifier (including combustion chamber) is established. The numerical model of a series of flow and heat transfer in the lower tube and LNG heat exchanger. In the combustion chamber, the ash gas weighted sum model (WSGGM) is used to calculate the absorption coefficient of flue gas, the do model is used to solve the radiation transfer equation, and the wall temperature and smoke of the flame cover are calculated by considering the heat transfer of convection and radiation. The average temperature of the secondary air outlet, in the LNG heat exchanger, the pipe side with dramatically changing fluid properties is treated in sections and the two-phase fluid model is used to simulate the gas-liquid two-phase flow and heat transfer process in the shell side. After obtaining the average heat transfer coefficient on both sides of the tube and shell, the total heat transfer coefficient is calculated. The convection heat transfer coefficient and correlation obtained in tube and shell are in good agreement with the available data. When the inlet gas temperature of the shell side changes in the range of 500 ~ 700 鈩，

本文編號：2167450