Experimental investigation on thermal characteristics of a capillary pumped loop with different reservoir locations

Abstract

This paper presents an effect of reservoir location on heat transfer characteristics of a capillary pumped loop (CPL). The designed CPL has a cylindrical evaporator with a diameter of 12 mm and a length of 65 mm. A stainless steel porous medium that has a pore radius of 4.4 μm is used as a wick. Heat transport length is designed as 1000 mm. The experiments were conducted with four types of reservoir location such as (1) Distance from the evaporator, L = 150 mm, (2) L = 250 mm, (3) L = 750 mm, (4) L = 1450 mm. As results, it was found that the CPL of case (1) showed high operating temperature and much smaller heat transfer capability such as 10 W. For cases of (2) – (4), the maximum heat transfer capability reached 140 – 160 W and showed the good controllability of the operating temperatures ranging from 60 to 100°C. The reason for the low heat transfer performance of case (1) and the difference in operational characteristics are discussed. It was found that there is a design limitation of the reservoir location of CPLs. In addition, the operation of the CPL that reservoir was located much far from the evaporator was successfully demonstrated.