氧化铜纳米流体喷雾冷却传热性能实验研究

Experimental study on influence of spray cooling on heat transfer of copper oxide nano-fluid

为了研究纳米流体在舰载大功率定向能武器喷雾冷却中的传热规律,以氧化铜纳米流体为工质,采用实验与仿真相结合的方法,分析了工质参数及系统参数影响下喷雾冷却的传热特性。分析结果表明:单相区传热阶段,纳米流体传热均优于纯水,且粒径越小,效果越明显,但是当加热功率超过1 000 W时纳米流体对传热的强化作用逐渐削弱,且粒径越小强化作用越小甚至导致换热恶化;纳米流体密度及喷雾流量对传热的影响均呈现出先促进后削弱的变化规律;纳米流体在散热表面温度分布更加均匀方面起到了一定的促进作用;添加质量分数0.004%的分散剂可以降低纳米溶液发泡现象;提升传热系数1.77%,但是当质量分数增至0.007%以上,会使纳米颗粒板结,导致传热弱化。

In order to study the heat transfer law of nanofluids in spray cooling of shipborne power directional energy weapons,the heat transfer characteristics of spray cooling under the in-fluence of working medium parameters and system parameters are analyzed by means of experi-ments and simulations with copper oxide nanofluids as working medium.The results show that the heat transfer of nanofluids is better than that of pure water,and the smaller the particle size is,the more obvious the effect is.However,when the heating power exceeds 1000 W,the enhance-ment effect of nanofluids on heat transfer gradually weakens.The smaller the particle size,the smaller the enhancement effect and even the deterioration of heat transfer.The effects of nanofluid density and spray flow rate on heat transfer have a change law of first promoting and then weake-ning.Nanofluids play a certain role in promoting the uniform temperature distribution on the heat dissipation surface.It can reduce the foaming phenomenon of nano-solution by adding 0.004%dispersant.The heat transfer coefficient is increased by 1.77%,but when the mass fraction in-creases to more than 0.007%,the nanoparticles harden and the heat transfer is weakened.