纳米悬浮液热虹吸管的传热性能试验研究

Experimental Study of the Heat Transfer Performance of a Nano-suspension-based Thermosyphon Pipe

在相同的试验条件下,对比研究了纳米CuO-去离子水(DW)悬浮液重力热管与普通DW重力热管的启动性和等温性,研究了纳米工质热管的充液率和颗粒浓度对热管工作特性的影响,对纳米工质热管的强化传热机理进行了初步探讨。研究表明:纳米工质热管比普通热管启动快;纳米工质热管蒸发段外壁温的高低与充液率、纳米浓度和加热条件有关;纳米颗粒浓度和充液率对热管的传热性能影响较大,且存在最佳浓度(本研究为5%)和最佳充液率(本研究为44.3%);高浓度纳米工质热管比普通DW重力热管易于达到传热极限;试验中纳米悬浮液重力热管的传热强化率为16.19%～146.27%。

Under the same test conditions, contrasted and studied were the startup and isothermal characteristics of a gravity heat pipe filled with nano-CuO-deioned water (DW) suspension and a common DW gravity heat pipe. Moreover, the influence of the liquid-filling rate and the particle concentration of the nano-working medium heat pipe on its working characteristics was studied with a preliminary exploration of the mechanism governing the intensified heat transfer of the heat pipe. It has been found that the nano-working medium heat pipe can start up quicker than a common heat pipe. The exterior wall surface temperature of the evaporative section of the nano-working medium heat pipe depends on its liquid filling rate, nano-working medium concentration and heating conditions. The nano-particle concentration and the liquid filling rate exercise a relatively big influence on the heat transfer performance of the heat pipe and there exist an optimum concentration (5%) and an optimum liquid filling rate (44.3%). It is easier for the high concentration nano-working medium heat pipe to reach its heat transfer limits than the common DW heat pipe. The intensified heat transfer rate of the nano-suspension gravity heat pipe is within a range from -16.19% to 146.27% for the present test.