http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
한영배(Youngbae Han) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11
Heat engine using oscillating flow in a micro tube is experimentally investigated. Pressure change due to boiling and condensation causes oscillating flow in a micro tube. Rotational work can be obtained from the oscillating flow using piston-crank system. The effects of design parameter such as driving frequency, tube diameter, heating section temperature are experimentally evaluated. As the driving frequency is increased, the indicated work increases, takes a maximum and then decreases at higher driving frequency. Cycle efficiency shows an almost constant value a low frequencies, and then decreases as the driving frequency. Indicated work and cycle efficiency increase as the heating section temperature increases. The present heat engine shows the best performance in a D = 1.0 mm tube.
3차원 구조를 갖는 진동형 히트파이프에 대한 실험적 연구
한영배(Youngbae Han) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11
Oscillating heat pipe is one of the emerging heat transfer technologies that have received much attention from people. The general structure of the oscillating heat pipe is a close loop consisting of a meandering capillary tube over two-dimensional plane. In this study, the performance of oscillating heat pipe with three-dimensional structure is investigated experimentally. Four glass tubes are connected to the heating and cooling aluminum plates perpendicularly. The inner diameter of glass tube is 1.2 mm. Ethanol, water and Novec(HFE-7100) are used as working fluids. Flow pattern and thermal resistance are investigated as changing heating power and filling ratio of working fluids. The thermal resistance of oscillating heat pipe decreases with increasing heating power. Oscillation in capillary tube starts earlier at smaller filling ratio, however dryout also occurs earlier. Among three working fluids, Novec shows the highest thermal performance.
3차원 구조를 갖는 진동형 히트파이프에 대한 실험적 연구
한영배(Youngbae Han),권영진(Youngjin Kwon),김웅식(Woong Sik Kim),나양호(Yang Ho Na) 대한기계학회 2018 大韓機械學會論文集B Vol.42 No.12
진동형 히트파이프의 일반적인 구조는 모세관을 여러 번 구부린 폐루프 형태로 2차원 구조이다. 본 연구에서는 3차원 구조를 갖는 진동형 히트파이프의 성능을 실험적으로 연구하였다. 4개의 유리관을 가열부과 냉각부 사이에 수직으로 연결하였다. 유리관의 직경은 1.2 mm이며 작동유체로서 에탄올, 증류수, 노벡(Novec, HFE-7100)을 사용하였다. 가열량과 작동유체의 충전율을 변화시키면서 유동 양식과 열저항의 특성을 고찰하였다. 진동형 히트파이프의 열저항은 가열량이 증가함에 따라 감소하였다. 충전율이 낮은 경우, 유리관 내에서 더 낮은 가열량에도 작동유체의 진동이 일어났으나 드라이아웃도 빠르게 일어나 작동 가능한 범위가 줄어들었다. 작동유체가운데 노벡이 가장 좋은 열전달 성능을 보였다. The general structure of an oscillating heat pipe is a closed loop consisting of a meandering capillary tube over a two-dimensional (2D) plane. In this study, the performance of an oscillating heat pipe with a three-dimensional (3D) structure is investigated experimentally. Four glass tubes are connected perpendicular to the heating and cooling aluminum plates. The inner diameter of the glass tube is 1.2 mm. Ethanol, water, and Novec (HFE-7100) are used as working fluids. The flow pattern and thermal resistance are investigated as the heating power and filling ratio of working fluids are varied. The results show that the thermal resistance of the oscillating heat pipe decreases with increasing heating power. Oscillations in the capillary tube start earlier for a smaller filling ratio; however, dry-outs also occur earlier. Of the three working fluids, Novec shows the highest thermal performance.