分离式热管凝结换热特性的研究

Study on the Condensation Heat exchange Characteristic of a Separate type Heat pipe

建立了空气冷却实验台 ,热管的加热方式为电加热 ,工质为蒸馏水 .在 1∶ 1模型上对分离式热管管内凝结换热特性、不凝性气体对凝结换热的影响及不凝性气体的扩散规律进行了试验 ,得出分离式热管有一最佳充液率 ,其值为 45%左右 ;凝结换热系数随着蒸汽压力的增加略有降低 ,在实验的压力范围内 ,降低了 9.5% ;不凝性气体对分离式热管的凝结换热仅影响冷凝段下部较小部分 ,通过排气阀排出不凝性气体可有效地改善冷凝段下部的凝结换热 ;随着压力的增加 ,不凝性气体对分离式热管冷凝段的影响减少 .

The condensation heat exchange characteristic of a separate type heat pipe was studied on a 1:1 model.The heat pipe is heated by electricity,and working fluid is distilled water,and it is cooled by air.The experimental results show that,(1)when charging liquid ratio is 45%,condensation heat exchange coefficient reaches to maxium;(2)when there is not non condensing gas,the coeffcient decreases a little with the increase of vapour pressure,and it decreases by 9.5% when the pressure increases from 0.16MPa to 0.36MPa;(3)when there is non condensing gas,the coefficient decreases a little,but when the gas is discharged by an exhaust value,it can be improved,when the volume content of the gas is 2.5%,itcan increased by 22%; (4)the effect ofthenon condensing gas on the coefficientdecreases withtheincreaseof the pressure,and when the volume content of the gas is 5% and the pressure increases from 0.16MPa to 0.36MPa,the coefficient increases by 6%.The relative curves are given between condensation heat exchange coefficient and air flowrate,charging liquid ratio and vapour pressure.