K. Baran

Radiation studies of the illumination lighting luminaires with LED technology

Semiconductor LED sources currently represent the most rapidly growing group of light sources and thanks to their numerous advantages, they have been applied in many areas of light technology. One of these application areas of LED sources is the area of illumination, and the illumination luminaires based on the said light sources, enable the much broader use, compared to the discharge sources, among others, the creation of the dynamic illumination with the possibility to adjust the colour or light output. The key element ensuring the correct operation of the luminaires, stability of its light parameters and the long life is the correct selection of the heat sink, which task is the effective dissipation of heat from the luminaire. Currently, among the available solutions, the vast majority are the passive heat sinks, where the main heat flow path is the convention between the heat sink and the environment. The article presented the results of the thermal analysis for the sample illumination luminaire of high power. The analysis was performed for several heat sink variants, where the number, geometry and arrangement of the fins was changing. Based on the conducted analysis the most effective solution was presented and the conclusions were formulated.

Influence of luminaire aiming on LED sources junction temperature

The correct selection of the radiator and ensuring the optimal cooling of the LEDs is the key element associated with the long life and stability of LEDs parameters. Currently, the most widely used radiation system in luminaries with LEDs is the passive system, where the main flow path of heat is the free convention between the radiator and the environment. In the above radiation system, apart from the geometry and size of the radiator, the junction temperature of the LED of the luminaire can also be affected by the angle of inclination of the luminaire relative to the gravity vector. The article presents the results of simulation studies, related to the designation of the junction temperature of the exemplary luminaire in the LED technology, for a different location of the fixture relative to the gravity vector.