热管传热性能对小型热管换热器散热效能影响

在零重力辅助下,小热管热阻是小型热管换热器散热效能的重要影响因素之一。基于集总参数法对于换热器系统数值计算的高效性思想,建立了热管、热管换热器的集总参数模型。对同一热管换热器选用不同传热性能的热管,在不同传热温差和流体质量流速下,就其散热效能进行了数值计算。计算结果表明,在零重力辅助下,热管换热器管内热阻存在一临界值Rcri。当热阻RHP≤Rcri时,管外热阻起主导作用,热管换热器的散热效能εh几乎不随热管管内热阻的值而变化。

Effect of heat transfer performance of heat pipe on heat rejection efficiency of the miniature heat pipe heat exchanger

Under the assistance of zero gravity,the thermal resistance of miniature heat pipe(MHP)is one of the most vital factors of the heat rejection efficiency of the miniature heat pipe heat exchanger(MHPHE).The lumped parameter models of MHP and MHPHE are established based on the high-efficiency conception of the lumped parameter method for the numerical calculation of the heat exchanger system.The heat rejection efficiency of MHPHE is calculated by selecting heat pipes with different heat transfer properties for the same heat pipe exchanger under the various temperature differences and flow mass velocities.The calculation results indicate that the thermal resistance of heat pipe in MHPHE has a critical value Rcri under the assistance of zero gravity.When the thermal resistance RHP ≤Rcri,the thermal resistance outside the heat pipe is a dominant factor,so the heat rejection efficiency of the heat pipe exchanger nearly doesn't change with the thermal resistance inside the heat pipe.