Thermal performance of cooling system for red, green and blue LED light source for rear projection TV

The problem of climate change poses a challenge for humanity: it is necessary to reduce harmful emissions into the atmosphere, caused mainly by the burning of coal in thermal power plants. Partially, this problem can be solved by the use of energy-saving devices and equipment, including the replacement of traditional light sources with more efficient LEDs. This, however, causes the problem of ensuring normal thermal modes of the LEDs, since the more powerfull the LED is, the more heat is released in their semiconductor crystals, which leads to an increase in the temperature of the crystals and a decrease in the reliability of the device. This problem becomes especially urgent when using powerful multi-chip LED light sources, the so-called SOB matrices, whose power even now exceeds 500 W. This article presents a new design of a powerful LED lamp for indoor illumination of rooms with low ceilings. The heat from the LED is transferred via heat pipes to the heat exchanger rings looped around the light source. The heat exchanger rings are cooled by the natural convection of the surrounding air (at an ambient air temperature of 20°C). Computer simulation allowed evaluating the ability of the proposed cooling system to provide a normal thermal mode of the LED light source. The results on the computer simulations of the temperature field of light source`s cooling system showed that when the LED power is 300 W, the temperature of the light source`s base at the point where it is connected to the light source does not exceed 67.6°C. When the contact zone is covered with a 0.1 mm layer of heat-conducting paste (Arctiс Silver 5 type) with a thermal conductivity coefficient of 8.7 W/(m•°C), the temperature of the LED case reaches 70°C. If the thermal resistance of the LED light source is 0.1°C/W, then the temperature of its semiconductor crystals will be 100°C, well below the allowable temperature value of 150°C. The total thermal resistance of the cooling system is 0.159°C/W.

Download Full-text

Experimental study of a compact cooling system with heat pipes for powerful LED matrices

Технология и конструирование в электронной аппаратуре ◽

10.15222/tkea2020.3-4.35 ◽

2020 ◽

pp. 35-41 ◽

Cited By ~ 2

Author(s):

D. V. Pekur ◽

V. M. Sorokin ◽

Yu. E. Nikolaenko

Keyword(s):

Heat Exchanger ◽

Light Source ◽

Cooling System ◽

Heat Pipes ◽

Ambient Air ◽

Working Fluid ◽

Light Sources ◽

Measured Temperature ◽

Led Light ◽

Led Matrix

LED light sources, and powerful multichip light sources in particular, are currently widely used for lighting household and industrial premises. With an increase in power, the amount of heat increases as well, which leads to an increase in the temperature of semiconductor crystals and, accordingly, to a decrease in the reliability of LEDs and a change in their photometric characteristics. Therefore, when developing the design of LED lighting devices, special attention is paid to thermal management. Since the early 2000s, heat pipes have been widely used to efficiently remove heat from powerful electronic components. They do not require power for moving the working fluid and are most suitable for use in LED luminaires. In this study, the authors carry out a computer simulation of a cooling system based on heat pipes, which is then used to design and test a powerful compact LED lamp with a thermal load of up to 100 W. Heat pipes with a length of 150 mm are used to remove heat from the LED light source to the heat exchanger rings located concentrically around it. The heat exchanger rings are cooled by natural convection of the ambient air. The results of computer modeling of the temperature field of the developed cooling system show that at a power of the LED light source of 140.7 W, the temperature of the LED matrix case is 60.5°C, and the experimentally measured temperature is 61.3°C. The experimentally determined thermal power of the LED matrix is 91.5 W. The p–n junction temperature is 79.6°C. The total thermal resistance of the cooling system is 0.453°C/W. The obtained results indicate the effectiveness of the developed design.

Download Full-text

High-power blue LED light source system

10.1117/12.837725 ◽

2009 ◽

Author(s):

Ping Liang ◽

Yibo Zheng ◽

Qiang Liu

Keyword(s):

Light Source ◽

High Power ◽

Blue Led ◽

Led Light

Download Full-text

Electro-optical characteristics of an innovative LED luminaire with an LED matrix cooling system based on heat pipes

Semiconductor Physics Quantum Electronics & Optoelectronics ◽

10.15407/spqeo23.04.415 ◽

2020 ◽

Vol 23 (04) ◽

pp. 415-423

Author(s):

D.V. Pekur ◽

◽

V.M. Sorokin ◽

Yu.E. Nikolaenko ◽

V.P. Kostylyov ◽

...

Keyword(s):

Light Source ◽

Cooling System ◽

Renewable Energy Sources ◽

Heat Pipes ◽

Luminous Flux ◽

Optical Characteristics ◽

Led Light ◽

Lighting Systems ◽

Led Matrix ◽

Led Luminaire

Widespread use of energy-saving LED lighting systems powered by renewable energy sources, solar energy in particular, will contribute to the improvement of global ecology. One of the structural elements of such lighting systems is LED luminaire. The authors of this article perform a first ever experimental study of electro-optical characteristics of the basic version of a compact high-power LED luminaire for indoor use. The particular feature of this lighting device is that its cooling system for the LED light source is based on heat pipes and concentric cooling rings. Such design allows ensuring the required cooling efficiency of the LED matrix. The revealed trends in optical and electrical parameters during temperature stabilization indicate that the proposed cooling system is highly efficient in maintaining normal thermal conditions of LED light sources with a power of up to 140.7 W and a luminous flux of up to 15083 lm. The results on determining spatial distribution of luminous flux of these luminaires indicate that they may be used for lighting large rooms with high ceilings. Scaling the basic modular design version of the cooling system allows increasing the power of the LED light source up to 600 W.

Download Full-text