A Study of Natural Convection Heat Transfer for LED High Thermal Conductive Plastic Heat Sink With Flow Ducts

• Main Authors: YOU,JYUN-KAI, 游竣凱
• Other Authors: YANG,SHIE-CHEN
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/4vfdap

碩士 === 建國科技大學 === 機械工程系暨製造科技研究所 === 105 === In this study,the natural convection heat transfer analysis of fin-typethermal conductive plastics heat sink of LED lamps was investigated by means of numerical simulation. The heat transfer characteristics and temperature variations for heat sink materials of aluminum alloy, pure thermal conductive plastics and thermal conductive plastics/aluminum are compared. The accuracy of numerical simulation results are verified by experimental measurements and comparison. For thermal conductive plastics/aluminum heat sink, the aluminum thin tube effectively transfers the chip heat to the heat sink, and then through convection and radiation heat transfer to the ambient air, which achieves good heat dissipation efficiency. As compared with the aluminum alloy heat sink, the chip junction temperature reduced up to 4~7 ℃, and the heat sink temperature reduced up to 11~20 ℃. The design of the flow ducts of heat sink with chimney effect are also considered to enhance the air flowing and natural convection heat transfer. The influences of the geometrical parameters(flow duct aperture, flow duct height and number of flow duct) on the heat dissipation effect are investigated. For the case of flow duct diameter of 3mm, flow duct height of 31mm, flow duct number of one,the thermal efficiency is the best. As compared with the case without flow ducts, the chip junction temperature can reduce up to 6~11 ℃, heat sink temperature reduce up to 6~9℃.