摘要
采用数值模拟方法对IGCC(整体煤气化联合循环发电系统)发电系统中主要的显热回收设备废热锅炉(以下简称"废锅")进行了分析,其中合成气连续相采用组分输运方程并结合Realizable k-ε湍流模型进行求解,颗粒相采用DPM模拟,两相间的相互作用采用双向耦合模型求解,温度场基于离散坐标法及灰气体加权和模型进行求解。结果表明:废锅环形通道中心线上速度呈周期性分布,提高了废锅内部的湍流强度;随着径向节距的增大,通道中心线上速度的周期性变化减弱,环形通道的阻力系数逐渐降低并趋于定值;而随着轴向节距的增加,废锅环形通道的阻力系数则逐渐增大,并最终稳定为定值。废锅内环堵板上的速度较小,是积灰严重的重点区域。螺旋环隙内存在涡流,会使得飞灰颗粒的停留时间增加,增大了积灰的可能性,而随着轴向节距的增大,环隙内的涡流逐渐减弱,因此环隙内的积灰将会减弱。
The numerical simulation method was employed to conduct an analysis of the main apparent heat recovery equipment item,a waste heat boiler in an IGCC power generation system,among which the constituent transmission equations in combination with the realizable k- ε turbulent flow model were used to seek solutions to the continuous phase and the discrete phase model was used to seek solutions to the particle phase while a dual direction coupling model was utilized to seek solutions to the interaction between the two phases. In addition,the discrete coordinate method as well as the ash and gas weighted model were used to seek solutions to the temperature field. It has been found that the speed along the centerline of the annular passage in the waste heat boiler assumes a periodical distribution,thus enhancing the turbulent flow intensity inside the waste heat boiler. With an increase of the pitch along the radial direction,the resistance coefficient of the annular passage in the waste heat boiler will gradually decrease and finally tend to be a fixed value. With an increase of the pitch along the axial direction,the resistance coefficient of the annular passage in the waste heat boiler will gradually decrease and finally stabilize at a fixed value.The speed on the block plate in the inner ring of the waste boiler is relatively small,therefore,it is regarded as the key zone of serious ash deposition. Vortexes exist in the helical annular gaps,thus making the residence time duration of flying ash particles increase and heightening the possibility of ash deposition. With an increase of the pitch along the axial direction,the vortexes in the annular gaps will gradually become weakened,thus lessening the ash deposition in the annular gaps.
出处
《热能动力工程》
CAS
CSCD
北大核心
2016年第7期98-102,138,共5页
Journal of Engineering for Thermal Energy and Power
基金
上海市基础研究重点项目(14JC1404800)
国家科技支撑计划项目(2015BAA04B03)
上海理工大学准东煤高效利用协同创新平台项目
关键词
IGCC
废热锅炉
积灰特性
数值模拟
IGCC
waste heat boiler
numerical simulation
ash deposition characteristics
