焦炉上升管套管换热器的数值模拟研究
发布时间：2018-07-27 21:09
【摘要】：研发荒煤气余热回收新技术是近些年来焦化生产降低工序能耗、提高能源利用率的重要举措之一,但是该技术在实际应用中存在余热回收困难、易产生结焦的问题。在解决上述问题过程中,需要对上升管内部的换热规律进行深入的探究,因此本文针对焦炉上升管、换热器上升管的换热规律进行了数值模拟研究,具体如下:(1)采用FLUENT软件对焦炉上升管、换热器上升管进行了数值模拟研究,使用ICEM-CFD软件建立了三维结构模型,为了提高计算的准确性,在模拟过程中采用了流固耦合边界条件,选用了DO热辐射模型,使用了k-?湍流模型;(2)针对荒煤气的物性参数采取多项式的形式进行处理,采用MATLAB软件依据文献中荒煤气的物性参数数据,分别回归出荒煤气的密度、导热系数、动力黏度、比热容、吸收系数的曲线公式;(3)选取现场内径为400 mm的焦炉上升管进行验证,结果表明:现场拍摄的上升管红外摄像中管外壁平均温度约为230℃,而数值模拟截取的温度场分布云图中管外壁平均温度约为226℃,二者较为接近,从而验证了模型基本可靠;(4)选取工程中内径为500 mm的焦炉上升管与换热器上升管的几何模型,针对焦炉上升管、蒸汽换热器上升管、水换热器上升管的换热规律进行了数值模拟研究,结果表明:三种上升管的管内壁温度波动区间分别为576-684℃、242-436℃、130-237℃,而我们采用的防止荒煤气结焦的高温涂层最佳适用温度区间为120-300℃,从而得出采用高压水作为实际生产中的余热回收介质为最佳方案;(5)针对换热器上升管在一个炼焦周期内的换热规律进行了数值模拟研究,结果表明:在介质为水蒸汽、高压水、导热油三种工况下,管内壁最高温度的波动区间分别为437-570℃、241-323℃、377-503℃,热量回收率的波动区间分别为8.48%-41.54%、12.15%-47.99%、9.83%-43.89%,故采用高压水作为上升管中的余热回收介质为最佳方案。此外,可以适当提高换热介质的进口速度来提高换热器上升管一个炼焦周期内的余热回收效率。
[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，
本文编号：2149143
[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，
本文编号：2149143
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