流化床横向波动特性实验研究  

Experimental study on lateral pressure fluctuation properties of fluidized bed

作　　者：胡南 刘世杰 徐梦 张缦[2] 杨海瑞[2] 赵冰 巩太义 王家林 HU Nan;LIU Shijie;XU Meng;ZHANG Man;YANG Hairui;ZHAO Bing;GONG Taiyi;WANG Jialin(Jilin Province S&T Innovation Center for Physical Simulation and Security of Water Resources and Electric Power Engineering,Changchun Institute of Technology,Changchun 130012,China;Key Laboratory for Thermal Science and Power Engineering of Ministry of Education,Tsinghua University,Beijing 100084,China;TEDA Branch,Huadian Power International Co.,Ltd.,Tianjin 300270,China)

机构地区：[1]长春工程学院吉林省水利电力工程物理级仿真与安全科技创新中心,吉林长春130012 [2]清华大学热科学与动力工程教育部重点实验室,北京100084 [3]华电国际电力股份有限公司天津开发区分公司,天津300270

出　　处：《热力发电》2020年第12期65-70,共6页Thermal Power Generation

基　　金：吉林省产业技术研究与开发专项项目(2019C056-3);吉林省教育厅科研规划项目(JJKH20200616KJ);电力系统国家重点实验室资助课题(SKLD19KZ07)。

摘　　要：大型循环流化床锅炉在低负荷运行时存在床压横向波动的现象。为了分析气固流化床横向波动的产生机理及影响因素,搭建可加载横向扰动的冷态鼓泡流化床实验装置,通过调速电机和连杆机构带动流化床本体产生横向周期运动,使气固两相流系统在受迫状态下产生横向波动,探究在不同扰动频率和流化风速下床压波动特性。实验结果表明:流化风速为0.72 m/s,无横向扰动时,床层压力和风室压力存在频率相同且相位一致的压力波动;随着扰动频率的提高,床层压力波动幅度明显增加,但是当扰动频率超过1.13 Hz后,压力波动出现下降趋势,说明此时扰动频率在气固流态化系统波动的固有频率处,床压波动幅度达到最大值;实验结果与固有频率机理模型计算结果吻合较好;风速降低到最小流化风速以下,由于布风均匀性差,床层两侧压力波动特性出现明显差异。本文研究结果对循环流化床锅炉布风系统设计和一次风量控制具有一定的参考价值。Lateral pressure fluctuation occurs in large scale circulating fluidized bed(CFB)boilers operating at lower load.In order to analyze the mechanism and influencing factors of lateral pressure fluctuation,a cold bubbling bed test rig with lateral disturbance was built up.In this device,the speed regulating motor and linkage mechanism drive the body of the fluidized bed to generate lateral periodic motion,which makes the gas-solid two-phase flow system generate lateral fluctuation under the forced state.The characteristics of bed pressure fluctuation at different disturbance frequencies and fluidization wind speeds were explored.The experimental results show that,when the gas velocity is 0.72 m/s and with no lateral disturbance,the bed pressure and wind box pressure have the same fluctuation frequency.With the increase of disturbing frequency,the bed pressure fluctuation amplitude increases significantly.But when the disturbing frequency is higher than 1.13 Hz,the bed pressure fluctuation amplitude shows a downward trend,indicating this disturbing frequency equals the natural frequency of lateral bed pressure fluctuation in gas-solid flow system,and the bed pressure fluctuation amplitude reaches the maximum value.The experimental results agrees well with the natural frequency mechanism model.When the wind speed is lower than the minimum fluidized wind speed,the pressure fluctuation characteristics on both sides of the bed are obviously different due to the poor uniformity of wind distribution.The research results have certain reference value for the design of air distribution system and primary air volume control of CFB boilers.

关 键 词：流化床 鼓泡流态化 压力波动 扰动频率 流化风速 固有频率 布风均匀性 

分 类 号：TK224[动力工程及工程热物理—动力机械及工程]