In-Sung Her

Analysis of the Thermoelectric Devices' Power Generation Performance for Utilizing the Waste Heat of LED Tunnel Lighting Module

In this paper, we propose the LED(Light-Emitting-Diode) emergency lighting in a tunnel by using the thermoelectric devices. To achieve high generated power, thermoelectric device should be have high Seebeck coefficient and small contact area. Also, we reveal that a moderate heatsink required for high generated power. From the waste heat of LED tunnel lighting module (25W), the generated power was 0.062W by thermoelectric device, and it could illuminate for 1hour after charge the battery of emergency lighting during about 101hours.

Characteristic Analysis of a Ex Circuit of Ex LED Signal Lamp Operating with AC/DC 12~254 V

In this paper, we develop a explosion-proof LED lighting (Ex circuit) circuit of Explosion-proof LED Signal Lamp (Ex LSL) to utilize the core module of the explosion-proof Local Control System (Ex LCS) for offshore plant applications. And then analyzed its electrical, optical and thermal characteristics. Ex circuit was applied input voltage from AC/DC(12~254) V. In this experiments, stable light-on characteristics were confirmed by eyes for the every input voltages with min. 78,462 and max. 517,975  of luminance. also Output current and output luminance was made proportional. Because the measured maximum surface temperature of Ex circuit was 54.23°C at AC 48 V, Ex circuit was rated with T6 of temperature class. Finally, Ex circuit was shown stable light on characteristics under the–50°C and 60°C during 12 hours of test period.

Analysis of Heat Dissipation Characteristics for Standard 25 (W) LED Module of Korea Expressway Corporation: Using CFD Analysis

Department of LED Fusion Engineering, Pukyong National University, Busan 608-739, Korea(Received June 5, 2014; Revised July 3, 2014; Accepted July 4, 2014)Abstract: Korea Expressway Corporation established standard of LED lighting fixture in Dec. 2013. To raise compatibility, the standard requires a fixed form and it is applied to street lights and tunnel lights, etc. Because streetlight has different circumstance condition from tunnel light that is down light and exposed to constant wind velocity over height of 8 meters, in case of LED module which has the same shape, characteristic of radiant heat can be different. In this paper, we designed 25 [W] LED Module that is designated by standard of Korea Expressway Corporation and analyzed characteristics of radiant heat about natural convection and forced convection. It is dropped 10.12[℃] that max temperature is decreased by increasing 20 mm of bended height of heatsink at the condition of natural convection. Radiant heat characteristic of bended height 35 mm became 78.08[℃] at the condition of natural convection, 55.30[℃] at the condition of forced convection so that 22.78[℃] is decreased that is 29.1[%] decrease. Bended height 55mm became 67.96[℃] at the condition of natural convection, 48.04[℃] at the condition of forced convection so that 19.92[℃] is decreased that is 29.3% decrease.Keywords: LED module, Heatsink, Standard, Forced convection, Natural convection

A Study of Characteristics of the LED Heat Dissipation According to the Changes in Composition of Die-casting Aluminum

Because of the development of LED technology, products due to high output and compact, the material with high thermal conductivity has been developed. Now that heat radiating part of the LED lamp is currently used for die casting of aluminum. The development of aluminum with excellent thermal conductivity is required. In this study, we measured the thermal properties and compared them while we produced the alloy by changing the component of die casting aluminum. From this study, the thermal conductivity and thermal resistance of the developed alloy were superior to die casting aluminum.