重力热管单线内螺纹分布强化换热实验研究

Experimental Study on Heat Enhancement of Gravity Heat Pipe with Single-line Internal Helical Microfin

采用实验方法,研究了不同的内螺纹分布和油浴温度等因素对热管换热特性的影响。实验选用的热管材料为紫铜,外径16 mm,壁厚3 mm,长度为200 mm,传热工质为水,充液率为20%。实验结果表明:在同一油浴温度下,内螺纹重力管的启动特性要优于光滑重力热管。对比不同油浴温度下,布置内螺纹能够有效地降低热管的工作温度。实验选型的内螺纹仅布置在蒸发段不会提高热管的换热系数,而在绝热段和冷凝段布置内螺纹则能够使换热系数显著提升,且随油浴温度的增加,换热系数线性增加。

The effects on the heat transfer characteristics of the heat pipe from different single-line internal helical microfin distribution,oil bath temperature and other factors were studied experimentally. The tested gravity heat pipes were fabricated with red copper tubes with outer diameter of 16 mm,thickness of 3 mm and length of 200 mm. The working liquid was water with filling rate of 20%. Experimental results showed that under the same oil bath temperature,the starting characteristic of the gravity heat pipe with internal helical microfin is better than that of the smooth gravity heat pipe. Under the different oil bath temperatures,the pipes with internal helical microfin can reduce the working temperature effectively. During the experiment,internal helical microfin does not increase heat transfer coefficient in evaporator section,while it can improve the heat transfer coefficient significantly in the adiabatic and condensation sections. And the heat transfer coefficient increases linearly with oil temperature.