Development of hybrid cooling unit with thermoelectric module and heat pipe for high power LEDs

While LEDs, which have many advantages, can convert about 20% of the electrical energy they consume into light energy, the remaining 80% of the energy is released as heat energy. Optimum efficiency from LEDs and long service life of LEDs are directly proportional to the removal of heat from the environment. When it comes to the use of LEDs, especially in areas where high luminous flux is required, the use of systems for removing heat from the environment becomes mandatory. It becomes inevitable to integrate more than one cooling system for cases where a single cooling method is insufficient for the solution of thermal problems in high power LED lighting systems. For this purpose, two different models were designed, primarily a heat pipe cooler and a thermoelectric module cooler. Then, a hybrid cooling system was designed, which includes the two coolers in question. The hybrid cooling system consists of two different designs: heat pipe priority and thermoelectric module priority. The LED cooling performances of the designed models were investigated by numerical analysis and experimental measurements. In the numerical part of the study, CFD analyzes of four different cooler models were made. The obtained CFD simulation results were supported by experimental tests and system validation was carried out. Thus, the compatibility and performance of the system were determined when two different cooling methods are used together. Among the cooler models, the lowest junction temperature and therefore the best cooling performance were obtained in the thermoelectric module priority hybrid cooling unit.