平行管超临界流体流动不均匀特性试验研究  

Experimental research on flow uniformity of supercritical fluid in parallel tubes

作　　者：彭宇[1] 程乐鸣[1] 张维国 王勤辉[1] 方梦祥[1] 骆仲泱 PENG Yu;CHENG Leming;ZHANG Weiguo;WANG Qinhui;FANG Mengxiang;LUO Zhongyang(School of Energy Engineering,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学能源工程学院,浙江杭州310027

出　　处：《热力发电》2020年第5期58-64,共7页Thermal Power Generation

基　　金：国家重点研发计划项目(2016YFB0600202-2)。

摘　　要：为了解超临界循环流化床(CFB)锅炉炉膛中悬吊屏平行管束内工质流动不均匀性,基于流体模化理论,设计超临界工质平行管束试验系统,以R-134a模化超临界水蒸气进行试验研究。试验在工质质量流率500~700 kg/(m^2·s),入口温度503~543 K,入口压力4.0~4.3 MPa,CFB颗粒浓度3.9~15.0 kg/m^3下进行,研究了上述参数对平行管束中工质流动不均匀性的影响。结果表明:影响工质在管束内流动不均匀性的主要因素包括管外的换热特性、管内的换热特性和管内压降;工质入口温度增加,其在平行管束内的流动不均匀性降低;当工质入口压力高于其临界压力时,入口压力变化对工质整体流动不均匀性影响较小;工质质量流率增加,其流动不均匀性增加;管束外侧颗粒浓度增加,工质流动不均匀性增强;试验条件下,平行管束两侧流动不均系数相对较小。To investigate the flow uniformity of working fluid in parallel tubes in furnace of supercritical fluidized bed(CFB)boiler,an experimental system of parallel tube bundles was designed by using R-134a as working fluid to simulate the supercritical water according to the fluid-to-fluid modeling method.The influence of mass flow rate of working fluid,inlet temperature,inlet pressure and solids suspension density on the flow uniformity in parallel tubes were studied at mass flow rate of 500~700 kg/(m^2·s),inlet temperature of 503~543 K,inlet pressure of 4.0~4.3 MPa and solids suspension density of 3.9~15.0 kg/m^3.The results show that,the mainly factors influencing the flow uniformity of working fluid in parallel tubes include the heat transfer inside and outside the tubes and the pressure drop inside the tubes.The flow uniformity decreases with the increase of inlet temperature.The change of inlet pressure has less effect on flow uniformity when the inlet pressure is higher than the critical pressure.The flow uniformity increases with mass flow rate of the working fluid and solid suspension density.The flow uniformity coefficient on both sides of the parallel tubes is relatively low under the experimental conditions.

关 键 词：超临界 CFB锅炉 悬吊屏 平行管束 流体模化理论 流动不均匀性 

分 类 号：TK124[动力工程及工程热物理—工程热物理]