Bubble Jet Loop Heat Pipe의 열전달 및 유동특성에 관한 실험적 연구

Abstract

Bubble jet loop heat pipe is a newly devised variation of heat pipe in which heat is effectively transported by the latent heat of evaporation and condensation as well as the heat capacity of circulating working fluid. The circulatory and oscillating motion of working fluid becomes possible by the motion of bubble jet which is generated at a narrow circular gap. These bubbles are condensed at the condensing section. Bubble jet loop heat pipe makes it possible to carry heat long distances upward and horizontal directions. The purpose of this study is to research the performance of heat transfer of bubble jet loop heat pipe and to visualize bubble jet loop heat pipe. First, we measured the temperature profile of heater, evaporating section and condensing section of BJLHP according to refrigerant charging rate and input power rate respectively. When input power is 100W and working fluid charging rate 50%, temperature difference between evaporating section and condensing section measured 1.7 ℃. In case of 150w input power and working fluid charging rate 50%, temperature difference between evaporating section and condensing section measured 3.6 ℃. In general, BJLHP which has 50% of charging rate showed the highest temperature distribution. On the other hand, we have know that BJLHP which has charging rate 30% didn’t operate well at condensing parts due to rack of refrigerant. Second, flow visualization of bubble jet heat pipe was not known. we take a photograph of flow visualization of bubble jet loop heat pipe using high-speed camera.