摘要
采用数值模拟方法研究了辐射激冷流程中不同鳍片结构对辐射废锅(radiant syngas cooler,RSC)内传热传质的影响.基于Euler坐标系,采用Realizable k-ε湍流模型计算辐射废锅内气相流场.在Lagrange坐标系中采用随机轨道模型计算颗粒粒径分布及其运动轨迹,并通过双向耦合法求解气相与颗粒相间的能量传递.采用P-1模型计算辐射传热,合成气辐射特性参数通过WSGGM模型(weight-sum-of-gray-gas model)加权求解.通过对比模拟结果与工业测量结果,得到最大相对误差为3.7%,验证了计算模型的可靠性.对比辐射废锅内不同鳍片布置方式发现,鳍片径向长度越大,中心流道越小,顶部回流越强.靠近中心轴线处的鳍片灰渣表面温度最高,高度为12m^15m位置处的灰渣表面温度则高达1 080K.随着轴向高度的增加,鳍片径向长度越小,含汽率越大.鳍片径向长度越小,相同径向位置处的含汽率越大,最大值可达0.214.不同径向长度的鳍片交错布置,有利于提高辐射废锅筒体水冷壁的换热量,改善筒体表面温度分布.鳍片表面高温区域减小,水冷壁管吸热趋于均衡,避免局部过冷过热所引起的交变热应力,才能使水冷壁管使用寿命延长.
Effects of different division wall structures on heat and mass transfer in the radiant syngas cooler(RSC)of the radiant syngas cooler process with water quench were carried out by a numerical method.The gas phase flow field was calculated by Realizable k-εmodel in Euler coordinates while the discrete random walk was applied to trace the particles,and the interaction between gas and particles was considered by two-way coupling model.The radiation heat transfer was simulated by the P-1 radiation model,and the radiative properties of syngas were calculated by weighted-sum-of-gray-gas model(WSGGM).The simulated values were compared with the industrial measured values,and it is found that the maximum relative error is 3.7%and the reliability and accuracy of the mathematic models are validated.Compared with different arrangements of fin membrane wall tubes,simulation results indicate that increased radical length of the division wall decreases the central heat exchange region,which results in the enhancement of the recirculation in the top region of RSC.The surface temperature of division wall reaches the maximum value near the axis of RSC,especially at 12 m to 15 m height in which the temperature reaches as high as 1 080 K.With the increase of axial height and decrease of radical length,the steam quality gets higher.At the same radical position,the smaller the radical length of the division wall is,the greater the steam quality gets and the maximum value of the steam quality reaches 0.214.The staggered arrangement of different radical length of fin membrane tubes decreases the high-temperature region,and prominently improves the distribution of surface temperature and heat transfer capacity of the annular water wall which can avoid alternating thermal stress caused by local overheating and undercooling,and the service life of membrane tubes is prolonged.
作者
王蕾
郭庆华
许建良
邱剑勇
于广锁
WANG Lei;GUO Qinghua;XU Jianliang;QIU Jianyong;YU Guangsuo(Key Laboratory of Coal Gasification and Energy Chemical Engineering of Ministry of Education,East China University of Science and Technology,200237 Shanghai,China)
出处
《煤炭转化》
CAS
CSCD
北大核心
2018年第5期65-72,共8页
Coal Conversion
基金
国家重点研发计划项目(2017YFB0602601)
关键词
辐射激冷流程
辐射废锅
鳍片
数值模拟
含汽率
radiant syngas cooler process with water quench
radiant syngas cooler
division wall
numerical simulation
steam quality
