【摘要】 微通道沸腾换热在电子器件散热和新能源等领域有着极佳的应用前景，其性能提升广受关注．针对烧结并联微通道，以去离子水为工质，研究了烧结底厚效应对沸腾换热性能的影响，测试质量通量为41 kg/（m2·s），入口温度是60℃．并联微通道采用30μm粒径树枝型铜粉烧结而成，烧结底层厚度分别为200、400、600和1 000μm．研究发现：30μm粒径系列，200μm底厚样品沸腾换热系数最大，其临界热流密度（citical heat flux,CHF）可达到120 W/cm2，并可在中高热流维持较高的换热系数．压力脉动和可视化观察表明：过大或过小底厚的样品会引起较大的压力和温度脉动，易造成爆炸沸腾和供液的严重不畅，而较优的底厚则可大大抑制压力和温度脉动．烧结微通道存在最佳的底厚粒径比范围．更多还原

【Abstract】 Microchannel boiling heat transfer has excellent application prospects in the fields of heat dissipation of electronic devices and new energy, and its performance enhancement has attracted much attention. In this paper,the effect of sintered bottom thickness on the performance of boiling heat transfer was investigated for sintered parallel microchannels using deionized water as the work medium, with a mass flux of 41 kg/（m2·s） and an inlet temperature of 60 ℃． The parallel microchannels were made of sintered dendritic copper powders of 30 μm particle size, and the thicknesses of sintered bottoms were 200, 400, 600, and 1 000 μm. It was found that the boiling heat transfer coefficients of the samples were the largest for the 30 μm and 200 μm thickness size series of which CHF could reach 136 W/cm2, and could maintain a high heat transfer coefficient in the middle and high heat flow. Pressure pulsation and visualization observations show that samples with too large or too small bottom thicknesses cause large pressure and temperature pulsations, which can lead to explosive boiling and severe malfunctioning of the liquid supply, while optimal bottom thicknesses can greatly suppress pressure and temperature pulsations. An optimal range of bottom thickness to particle size ratios exists for sintered microchannels.更多还原