Water cooling of high power Light Emitting Diode

Abstract

The development in light technologies for entertainment is moving towards LED based solutions. This progress is not without problems, when more than a single LED is used. The amount of generated heat is often in the same order as in a conventional discharge lamp, but the allowable operating temperature is much lower. In order to handle the higher specific power (W/m 3 ) inside the LED based lamps cold plates were designed and manufactured.6 different designs were analyzed through laboratory experiments and their performances were compared. 5 designs cover; traditional straight mini channel, S-shaped mini channel, straight mini channel with swirl, threaded mini channel with swirl and 2 parallel mini channels with swirl. In the 6 th design traditional mini channels were used. Based on the experimentally obtained heat transfer inside the cold plates, it was concluded that the mini channels utilizing swirling flow were much more efficient than channels with traditional flow without swirl. Similar conclusion was made for the design utilizing mini channels. Considering the pressure difference across the cold plate in addition to heat transfer properties, it turned out that two solutions were preferable; axial flow through mini channels or a s-channel. Experiments showed that the channel design utilizing swirling flows had up to 4 times the pressure loss as the mini channel/s-channel.

Research on thermal characteristics of heat pipes for led lightning devices

“…Для обеспечеíèя зàдàííого темпеðàтуðíого ðежèмà СД в ðяде ðàбот пðедлàгàется èспользо-вàть воздушíые сèстемы охлàждеíèя с пðèмеíе-íèем высоêотеплопðоводíых подложеê [7], ðàз-ëèчíîãî âèдà ðàдèàòîðîâ [8], âåíòèëÿòîðîâ [9], à тàêже жèдêостíые сèстемы с зàмêíутым во-дÿíым êîíòóðîм [10]. Нàèбîëåå ðàñïðîñòðàíåí-íымè являются воздушíые сèстемы охлàжде-íèя с пðèмеíеíèем ðàдèàтоðов в условèях есте-ñòâåííîé èëè âыíóждåííîé êîíâåêцèè âîздóõà.…”