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喷雾相变冷却是一种具有高热流密度散热特点的冷却方式。采用紫铜棒加热器作为热源,通过调节背压阀改变喷淋室压力,重点研究了在高热流密度散热需求下,以液氨为工质的双喷嘴阵列在不同饱和压力下的喷雾相变冷却传热特性。实验结果表明,随着液氨饱和压力的增大,液氨气化潜热的降低有利于喷雾相变由单相强制对流换热向核态沸腾换热的转变;在相同热流密度下,随着液氨饱和压力的增加,热表面温度升高,过热度降低,换热系数增大,冷却能力得到大幅度提高;当热流密度为310 W/cm2,喷淋室压力为4.01×105Pa时,热表面温度仅为19.5℃,换热系数可达1.48×105W/(m2.K),为高热流密度散热实现较低温度的冷却技术提供了参考。
Spray phase change cooling is a cooling method with high heat flux density and heat dissipation characteristics. A copper rod heater was used as a heat source to change the pressure in the spray booth by adjusting the backpressure valve. The spray cooling of the dual nozzle array with liquid ammonia as the working fluid at different saturation pressures was mainly studied under the requirement of high heat flux density. Heat transfer characteristics. The experimental results show that with the increase of the liquid ammonia saturation pressure, the reduction of the latent heat of vaporization of liquid ammonia favors the transformation from single-phase forced convective heat transfer to nucleate boiling heat transfer. Under the same heat flux, When the heat flux is 310 W / cm2 and the pressure in the spray chamber is 4.01 × 105 Pa, the hot liquid temperature increases, the superheat decreases, the heat transfer coefficient increases, and the cooling capacity is greatly increased. The surface temperature is only 19.5 ℃, the heat transfer coefficient is up to 1.48 × 105W / (m2.K), which provides a reference for the cooling technology of high heat flux density to achieve lower temperature.