Thermal and luminous investigations of a pcLED based refrigerating liquid prototype

The heat management plays a key role for high performance operation of LEDs. The increase of junction temperature determines the decrease of LEDs' lifetime, the failure of these devices, the shift of color spectrum, and lower operational efficiency. The paper deals with the thermal management and luminous experimental analysis of a new fabricated LED prototype using refrigerating oil as cooling agent. The dielectric cooling liquid represents an effective thermal management solution for high-power LEDs due to their superior heat transfer characteristics compared with air. The new proposed configuration, based on phosphor converted blue LEDs, is investigated by setting up a thermal model and validated through performed experimental tests. A series of experiments were performed on four LED configurations (air/silicon oil as cooling agent, and with/without heat sink) in steady state and heating/cooling transient processes to evaluate the heat dissipation performances. The thermal modeling and experimental results were compared and highlighted, demonstrating good agreement. In addition, the laboratory luminous tests were conducted to analyze if the fabricated guarantees higher luminous efficiency. The experiments indicated that the proposed pcLED based refrigerating liquid prototype efficiently dissipates heat and has good luminous performances. © 2014 Elsevier Ltd. All rights reserved.