基于荒煤气物性参数的上升管换热计算与模拟研究OA

The coke oven ascension pipe waste heat recovery system has been put into industrial use since the 1970s,which is a favorable initiative for energy saving and emission reduction in the coking industry. The saturated steam generated can be used by users or generate electricity through gas-liquid separation,but there are still urgent problems such as coking and graphite accumulation on the wall of the ascension pipe and unstable quality of the steam end. As a complex mixture of gases,the yield of coke oven gas were deduced from the incoming coal,the regression equations of the thermophysical parameters of the mixture with the change of temperature were studied,and the heat transfer mechanism of the ascension pipe was explored by the heat balance equation. The Fluent simulation software was used to simulate the heat transfer process of the coke oven gas under the dynamic process,coupled with the regression equation of the calculated physical parameters,to further verify the calculation results,and the optimal working condition of heat transfer in the ascension pipe was determined by changing the inlet conditions of different coke oven gas side and water side. The heat transfer coefficient of 65.58 W/(m2·℃) was calculated under the steady state condition of the ascension pipe,which provides a reference basis for the waste heat recovery of the coke oven gas. The convective heat transfer coefficient of the coke oven gas side accounts for 52.8％ of the total heat transfer coefficient,so the convective heat transfer is dominant,but the radiant heat transfer should not be neglected. The flow rate of the gas side is controlled at 500-650 m3/h,so that the exit temperature higher than 550 ℃ does not lead to tar precipitation,and at the same time,it can ensure that the mass flow rate of the steam side reaches 0.0156 kg/h,and the exit temperature rises to 209.2 ℃,so that the quality of the steam produced is good.