【摘要】 本文采用气体辅助雾化喷嘴,以液氨为冷却工质,氮气为辅助气体,研究了高热流密度条件下的氨喷雾相变冷却换热特性,分析了气液配比对换热特性的影响,并与液压式喷嘴喷雾相变冷却换热进行了对比。结果表明:气雾喷嘴在气助力作用下其雾化特性得到较大改善,气、液相配比率对喷雾相变冷却换热特性影响较大;气相流量一定时,随着液相流量增加,热表面温度降低,临界热流密度值增大。当实验工况维持不变时,热流密度为280 W/cm~2时,氮气雾化喷嘴换热系数可达儿3717 W/(m~2·K),比液压式提高了69%。更多还原

【Abstract】 In this paper,the heat transfer characteristics of spray cooling with ammonia for high heat flux devices were investigated,in which an air-atomized nozzle was employed with ammonia as coolant and nitrogen as auxiliary gas.The effects of gas-liquid ratio upon the heat transfer characteristic were studied,and the results were compared to spray cooling using pressure atomization nozzle at the same conditions.Experimental results showed that the atomization of spray was enhanced by using nitrogen assisted,and the heat transfer characteristics were intensively affected by the gas-liquid ratio.While the gas flow rate remained constant,the surface temperatures decreased and the critical heat flux values increased with increasing liquid flows,respectively.When the spray conditions were the same,the heat transfer coefficient in an air- atomized nozzle reached 113717 W/(m~2·K) at 280 W/cm~2,increasing 69%over pressure nozzle.更多还原