Effect of phosphor distribution on junction temperature reduction in white LEDs

Author(s):  
Sayeda Ashrafun Nesa ◽  
Md. Osman Ali ◽  
Ashraful Ghani Bhuiyan ◽  
Md. Rafiqul Islam ◽  
Md. Sherajul Islam
2013 ◽  
Vol 49 (2) ◽  
pp. 750-760 ◽  
Author(s):  
David Gacio ◽  
J. Marcos Alonso ◽  
Jorge Garcia ◽  
Marina S. Perdigao ◽  
E. Sousa Saraiva ◽  
...  

2016 ◽  
Vol 55 (22) ◽  
pp. 5909 ◽  
Author(s):  
Hong-Liang Ke ◽  
Lei Jing ◽  
Jian Hao ◽  
Qun Gao ◽  
Yao Wang ◽  
...  

Author(s):  
Rinaldo Miorini ◽  
Darin J Sharar ◽  
Arun V. Gowda ◽  
Cathleen Hoel ◽  
Bryan Whalen ◽  
...  

Abstract In order for electronics packaging power density to increase, innovations and improvements in heat transfer are required. Electrification of transportation has the potential for significant fuel and energy savings. Changing to an electrified drive train requires reliable and efficient power electronics to provide power conversion between AC motors and DC energy storage. For high power transportation systems like aircraft or heavy vehicles, the power density of these power electronics needs to be improved. Power density is also an enabler for high power military devices that must be used and transported via air, ground, and sea. This paper summarizes the outcome of a collaborative and multi-disciplinary research effort aimed at co-designing novel electronics cooling device that utilizes two-phase fluid flow. Two-phase flow cooling has been known for decades as well as the risks associated with it: critical heat flux, dry-out and thermal runaway. Our research de-risks the two-phase cooling phenomenon by swirling the flow to remove the bubbles from the wall and confining them at the core of the cooler. The combined effects of gas phase removal, enhanced nucleation and dramatic liquid film agitation and rupture have been quantified by our experiments: double the heat transfer coefficient with only 13% increase in pressure drop. Besides advanced fluid-dynamics, our Package Integrated Cyclone Cooler (PICCO) utilizes cutting edge packaging and additive manufacturing technology such as direct deposition of a metal substrate and circuits (dies) on a complex helical cooler that can only be manufactured via 3D printing. By co-designing and testing the cooler we have quantified the impact of the swirled flow on the junction temperature with respect to a conventional (non-swirl) two-phase-flow-cooled power electronics package. At steady state, our post-test thermal simulations predict a junction temperature reduction from 185°C to 75°C at the same power dissipation. When the heat load is unsteady (EPA Urban Drive Cycle), the junction temperature reduction is 140°C to 60°C.


2004 ◽  
Author(s):  
Nadarajah Narendran ◽  
Yimin Gu ◽  
R. Hosseinzadeh

2010 ◽  
Author(s):  
Jijun Li ◽  
Lihua Zhang ◽  
Anxiang Wang ◽  
Chunwang Zhao ◽  
Lin Lin

2013 ◽  
Vol 11 (9) ◽  
pp. 091204-91206 ◽  
Author(s):  
Jingjing Zhang Jingjing Zhang ◽  
Tao Zhang Tao Zhang ◽  
Shishen Liu Shishen Liu ◽  
Shidong Yuan Shidong Yuan ◽  
Yafang Jin Yafang Jin ◽  
...  

2019 ◽  
pp. 75-85
Author(s):  
Canan Perdahci ◽  
Hamdi Ozkan

Turkey is rich in terms of renewable energy sources and, therefore, is now encouraging the use of sustainable clean lighting systems in road applications. High pressure sodium lamp is the most widely used type in main roads, but other types of lamps such as mercury vapour lamps or metal halide lamps can be utilized for street lighting. Since it enables energy and money saving, LED light technology has replaced high pressure sodium lamps nowadays. Once solar power system (PV) is integrated with LED lamp for street lighting, the amount of saving and local impact might be enriched. LEDs used as light sources in road lighting luminaires with rising lumen values, decreasing junction temperature, higher colour rendering efficiency, longer lifetime have become more efficient than many light sources with the latest developments. Since the structure of the luminaires in which the LED light sources are used differs from that of the conventional light sources, the optical, thermal and electrical design of the LED luminaires must be considered differently. Thus, this study concentrates upon design considerations and the operating principle of solarpowered LED road lighting luminaire in details. Also, a simple solar panel system was designed and the economical values obtained at the end of 20 years were compared when using the ongrid system and the off-grid system.


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