太阳能平板空气集热器内部流动与传热分析  

Numerical Study of the Flow and Heat Transfer Inside a Solar Energy Flat-plate-based Air Heat Accumulator

作　　者：胡建军[1] 孙喜山[1] 徐进良[2] 

机构地区：[1]燕山大学建筑环境与设备工程系,河北秦皇岛066004 [2]华北电力大学新能源与可再生能源北京市重点实验室,北京102206

出　　处：《热能动力工程》2011年第5期615-620,637-638,共6页Journal of Engineering for Thermal Energy and Power

基　　金：秦皇岛市科学技术研究与发展计划(200901A017)基金资助项目;河北省自然科学基金青年基金(E2011203094)资助项目;国家自然科学基金杰出青年基金资助项目(50825603)

摘　　要：基于雷诺时均的三维定常粘性N-S方程及能量方程,对内设挡流板的太阳能平板空气集热器内部流动和传热特性进行数值分析和实验验证,模拟结果与实验测量结果显示出良好的一致性。研究表明:挡流板的存在致使内部流动非常复杂,挡流板背侧发生显著的流动分离与再附着现象,同时对温度场产生重要影响,因此消除各种涡流是提高集热效率的有效途径之一;气流在挡流板末端发生180°偏转形成的二次流增加了流动损失,但同时实现了冷热流体的掺混,强化了换热;集热板的多种换热方式中对流换热占主导,辐射换热占总换热量的1/7,为提高集热效率,应设法进一步降低集热板平均温度。Through seeking solutions to the Reynolds-time-average-based 3D steady viscid N-S equation and energy equation,numerically analyzed and experimentally verified were the flow and heat transfer characteristics inside a solar energy flat-plate-based air heat accumulator with baffle plates being provided inside.The simulation and test measuring results were in good agreement.The simulation results indicate that the presence of baffle plates results in a very complex inner flow and a remarkable flow separation and re-attachment phenomenon appear on the back of the baffle plates.In the meantime,an important influence on the temperature field is produced.Therefore,to eliminate various vortexes is regarded as one of effective approaches to improve the heat accumulation efficiency.The secondary air flow formed by a 180-degree deflection at the end of the baffle plates increases the flow losses,realizing a mixing and dilution of the cold and hot fluid simultaneously and intensifying the heat exchange.Among multifarious heat exchange modes of heat accumulation plates,the convection heat exchange will dominate and the radiation heat exchange quantity will account for 1/7 of the total heat exchange quantity.To enhance the heat accumulation efficiency,one should manage to further lower the average temperature of the heat accumulation plates.

关 键 词：太阳能 空气集热器 流动与传热 

分 类 号：TK513[动力工程及工程热物理—热能工程]