気泡駆動形熱輸送デバイスの熱輸送特性に関する研究 [in Japanese] Study of Thermal Characteristics of Bubble-Driven Heat-Transport Device [in Japanese]
Search this Article
In the present paper, heat transport rates and fluid flow patterns of a bubble-driven heat-transport device (BD-HTD) made of glass were experimentally investigated by using water, soapsuds, ethanol, and R141b as an operating liquid. In this type of HTD, heating and cooling sections are connected with each other by a closed loop of tube meandering between them, and operating liquid of a volume fraction is enclosed in the meandering loop. The BD-HTD was set vertically, and it was heated at the bottom by heating water and cooled at the top by cooling water. Experimental parameters were the inner diameter of the tube (D=1.8, 2.4, 5.0 mm), the total temperature difference of the heating and cooling water (ΔT=20-60 K), and the liquid volume fraction (α=18-98%). The main results are summarized as follows. The heat transfer coefficient of the operating liquid at the heating and cooling sections, h_<fi>, is not strongly dependent on α and ΔT. Among the present test liquids, the effective thermal conductivity, k_<ef>, is highest for R141b but the heat transfer coefficient, h_<fi>, is highest for water. As k_<ef> is sufficiently high even for water, the heat transport rate, Q, is highest for water. Q of the BD-HTD using water can exceed the maximum heat transport rate of the conventional heat pipes of the same geometry with the present HTD. For R141b, the BD-HTD operated for D/λ_0=1.5 to 4.2 (λ_0; the capillary length) and Q is not srongly dependent on the tube diameter. This result indicates that the BD-HTD is suittable for micro HTDs, but for water the BD-HTD did not operate for D/λ_0=0.65.
- Transactions of the Japan Society of Mechanical Engineers. Series B.
Transactions of the Japan Society of Mechanical Engineers. Series B. 00065(00640), 4077-4083, 1999-12-25
The Japan Society of Mechanical Engineers