变截面微通道散热器流动和传热特性

为了解决电子芯片散热问题,通过数值模拟的方法,研究了去离子水流经微通道散热器时的流动和传热特性.微通道散热器由无氧铜层叠焊接而成,散热器内微通道当量直径为0.23 mm,去离子水流经散热器时平均雷诺数为252~1 060,加热面热流密度为2×106W/m2.结果表明:不同雷诺数时,三角凹穴周期性变截面微通道散热器的传热性能明显优于矩形等截面直通道散热器;前者加热面平均温度和最高温度均比后者低2~3℃,且两者压降相差不大;随着去离子水流量的增加,散热器加热面平均温度降低,但当流量增加到一定程度后,加热面温度变化不明显,说明不能单靠增大泵功来强化传热.

Fluid Flow and Heat Transfer on Microchannel Heat Sink With Changeable Cross-sections

To slove the heat transfer problem of electronic chips, this paper studied the fluid flow and heat transfer condition when deionized water flew through the microchannel heat sink. The heat sink was welded by cooper and the microchannel had a hydraulic diameter of 0. 23 mm. The heating flux was 2 × 106 W/m2 and the Re was between 252 and 1 060. Results show that the periodically changeable cross-sections microchannel heat sink with triangular reentrant cavities has a better performance than conventional rectangular microchannel heat sink, and both the heating surface’s average temperature and maximum temperature of the former is 2-3℃ lower than the later one and the pressure loss difference between the two heat sinks is small; with the increase of the flow rate the heating surface’s average temperature is reduced;when the flow rate increases to a appropriate degree, the temperature change will not be obvious, and it suggests that the heat transfer performance cannot be enhanced only by increasing the power of pumps.