摘要
焦炉上升管余热回收系统是焦化行业节能减排的重要举措,产生的饱和蒸汽经气液分离可供使用或发电,但存在上升管管壁结焦积石墨、蒸汽端品质不稳定等亟需解决的问题。本文由入炉煤推算荒煤气产率,研究荒煤气混合物的热物性参数随温度变化的回归方程,热平衡方程探索上升管传热机理。并采用Fluent仿真模拟软件模拟动态过程下荒煤气的传热过程,耦合了所计算的物性参数回归方程,进一步验证计算结果,通过改变不同荒煤气侧、水侧入口条件确定了上升管换热最佳工况。结果表明,上升管稳态工况下热力计算的传热系数为65.58 W/(m^(2)·℃),荒煤气侧对流换热系数占总换热系数的52.8%,对流换热占据主导,辐射换热也不可忽视;荒煤气侧流量控制在500~650 m^(3)/h,出口温度高于550℃不会导致焦油析出,并能确保蒸汽侧质量流量达到0.0156 kg/s、出口温度升至209.2℃,产出的蒸汽品质好,可为后续荒煤气余热回收系统提供参考依据。
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/(m^(2)·℃)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 m^(3)/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.
作者
周宁玲
王晓佳
孟晓东
沈来宏
ZHOU Ningling;WANG Xiaojia;MENG Xiaodong;SHEN Laihong(School of Energy and Environment,Southeast University,Nanjing 210096,Jiangsu China;Jiangsu Longye Energy Saving Technology Co.,Ltd.,Changzhou 213000,Jiangsu China)
出处
《电力科技与环保》
2024年第4期388-396,共9页
Electric Power Technology and Environmental Protection
基金
国家重点研发计划项目(2020YFC1910000)。
关键词
荒煤气
稳定产出
热力计算
数值模拟
coke oven gas
stable output
thermodynamic calculation
numerical simulation
