【摘要】：研發(fā)荒煤氣余熱回收新技術(shù)是近些年來(lái)焦化生產(chǎn)降低工序能耗、提高能源利用率的重要舉措之一,但是該技術(shù)在實(shí)際應(yīng)用中存在余熱回收困難、易產(chǎn)生結(jié)焦的問(wèn)題。在解決上述問(wèn)題過(guò)程中,需要對(duì)上升管內(nèi)部的換熱規(guī)律進(jìn)行深入的探究,因此本文針對(duì)焦?fàn)t上升管、換熱器上升管的換熱規(guī)律進(jìn)行了數(shù)值模擬研究,具體如下:(1)采用FLUENT軟件對(duì)焦?fàn)t上升管、換熱器上升管進(jìn)行了數(shù)值模擬研究,使用ICEM-CFD軟件建立了三維結(jié)構(gòu)模型,為了提高計(jì)算的準(zhǔn)確性,在模擬過(guò)程中采用了流固耦合邊界條件,選用了DO熱輻射模型,使用了k-?湍流模型;(2)針對(duì)荒煤氣的物性參數(shù)采取多項(xiàng)式的形式進(jìn)行處理,采用MATLAB軟件依據(jù)文獻(xiàn)中荒煤氣的物性參數(shù)數(shù)據(jù),分別回歸出荒煤氣的密度、導(dǎo)熱系數(shù)、動(dòng)力黏度、比熱容、吸收系數(shù)的曲線(xiàn)公式;(3)選取現(xiàn)場(chǎng)內(nèi)徑為400 mm的焦?fàn)t上升管進(jìn)行驗(yàn)證,結(jié)果表明:現(xiàn)場(chǎng)拍攝的上升管紅外攝像中管外壁平均溫度約為230℃,而數(shù)值模擬截取的溫度場(chǎng)分布云圖中管外壁平均溫度約為226℃,二者較為接近,從而驗(yàn)證了模型基本可靠;(4)選取工程中內(nèi)徑為500 mm的焦?fàn)t上升管與換熱器上升管的幾何模型,針對(duì)焦?fàn)t上升管、蒸汽換熱器上升管、水換熱器上升管的換熱規(guī)律進(jìn)行了數(shù)值模擬研究,結(jié)果表明:三種上升管的管內(nèi)壁溫度波動(dòng)區(qū)間分別為576-684℃、242-436℃、130-237℃,而我們采用的防止荒煤氣結(jié)焦的高溫涂層最佳適用溫度區(qū)間為120-300℃,從而得出采用高壓水作為實(shí)際生產(chǎn)中的余熱回收介質(zhì)為最佳方案;(5)針對(duì)換熱器上升管在一個(gè)煉焦周期內(nèi)的換熱規(guī)律進(jìn)行了數(shù)值模擬研究,結(jié)果表明:在介質(zhì)為水蒸汽、高壓水、導(dǎo)熱油三種工況下,管內(nèi)壁最高溫度的波動(dòng)區(qū)間分別為437-570℃、241-323℃、377-503℃,熱量回收率的波動(dòng)區(qū)間分別為8.48%-41.54%、12.15%-47.99%、9.83%-43.89%,故采用高壓水作為上升管中的余熱回收介質(zhì)為最佳方案。此外,可以適當(dāng)提高換熱介質(zhì)的進(jìn)口速度來(lái)提高換熱器上升管一個(gè)煉焦周期內(nèi)的余熱回收效率。
[Abstract]:Developing a new technology for recovering waste heat from waste gas is one of the important measures to reduce energy consumption and improve energy efficiency in coking production in recent years. However, it is difficult to recover waste heat in practical application and coking is easy to occur. In the process of solving the above problems, it is necessary to probe into the heat transfer law inside the riser tube, so the heat transfer law of the rising tube and heat exchanger in the coke oven has been studied numerically in this paper. The details are as follows: (1) numerical simulation of rising tube and heat exchanger riser in coke oven is carried out by using FLUENT software. In order to improve the accuracy of calculation, the fluid-solid coupling boundary condition is adopted in the simulation process, and the three-dimensional structure model is established by using ICEM-CFD software. The do thermal radiation model is selected, and the k-ray model is used. (2) the physical property parameters of waste gas are treated in polynomial form, and the density, thermal conductivity, dynamic viscosity, specific heat capacity of waste gas are regressed by MATLAB software according to the data of physical property parameters of waste gas in the literature. The curve formula of absorption coefficient; (3) selecting the riser of coke oven with an internal diameter of 400mm to verify, the result shows that the average temperature of the outer wall of the tube is about 230 鈩，

本文編號(hào)：2149143