Simulation and optimization on thermal performance of LED filament light bulb

In the present study, a computational model of LED filament light bulb was established by the ANSYS Icepak software based on the finite element method (FEM) and was compared with the experimental data as well. With the developed model, the effects of the filling gas and the filament substrate on the steady-state thermal performance were investigated. The simulation results revealed that the thermal conductivity of the filling gas in the bulb had a significant influence on the heat dissipation of the bulb. Compared with air filling, helium can reduce the average junction temperature of LED chips bonded on the sapphire substrate by 54.6 °C. With a glass filament substrate and helium filling in the bulb as the base case, the average junction temperature reductions of LED chips bonded on transparent ceramics, sapphire and perforated copper were 9.6 °C, 11.4 °C, and 22.4 °C, respectively. It was found that the higher the thermal conductivity of the filling gas, the less junction temperature change would be resulted from different filament substrates. In conclusion, this model can benefit the optimization of thermal design for a LED filament light bulb.