摘要
空气–沙子移动床换热器作为塔式太阳能沙子储热系统中的重要附属设备,其较优的运行性能可使整个发电系统的经济效益得到提升。因此,基于多孔介质中的局部非热平衡模型,建立了空气–沙子移动床换热器的二维稳态数值模型,并以㶲变化作为评价指标研究了主要运行参数即雷诺数和沙空速比对空气–沙子移动床换热器传热能力的影响。研究结果表明:空气侧㶲变化的绝对值随雷诺数和沙空速比的增大而增大。当沙空速比值大于0.0035时,空气侧㶲变化的绝对值增长速度趋于0,结合工业应用中对冷热介质温度的要求,最佳的沙空速比可选择为0.003。研究结果对空气–沙子移动床换热器的参数优化提供了一定的理论依据和数据基础。
As the core equipment of tower solar energy sand heat storage system,operational performance of air-sand moving bed heat exchanger directly affects the overall economic benefits of the power generation system.Therefore,based on the local non-thermal equilibrium model in porous media,a two-dimensional steady-state numerical model of the air-sand moving bed heat exchanger is established.The influence of the main operating parameters such as Reynolds number and velocity ratio of sand to air on the heat transfer capacity of the air-sand moving bed heat exchanger is studied,taking the exergy change as the evaluation index.The results show that the absolute value of exergy change increases with the increase of Reynolds number and velocity ratio of sand to air.When the velocity ratio of sand to air is greater than 0.0035,the absolute value of the air side exergy change increases to 0.Considering the requirements on the temperature of hot and cold medium in industrial application,the best velocity ratio of sand to air is 0.003.The results provide theoretical and data basis for the parameter optimization of the air-sand moving bed heat exchanger.
作者
孙源敏
杨建蒙
李斌
SUN Yuanmin;YANG Jianmeng;LI Bin(School of Energy,Power and Mechanical Engineering,North China Electric Power University,Baoding 071003,China)
出处
《电力科学与工程》
2020年第11期64-69,共6页
Electric Power Science and Engineering
关键词
空气–沙子移动床换热器
多孔介质
局部非热平衡
㶲
数值模拟
air-sand moving bed heat exchanger
porous media
local non-thermal equilibrium
exergy
numerical simulation
