Structure optimization, optical design and thermal management of UVC LED photoreactor to improve its inactivation efficiency

Compared with the chlorine disinfection, ultraviolet light emitting diode (UV LED) has attracted extensive interest due to its advantages of environmental friendliness, wide inactivation range and easy automation. However, there are still some challenges on how to apply UV LED to water disinfection more effectively by designing and optimizing some parameters. In this manuscript, the optimal numbers, spacing and configuration of UVC LEDs are systematically studied using the thermal and optical software simulation and experiment methods. Then, the influence of the reactor shape and reflective material on inactivation efficiency of the photoreactor was studied in detail. The results show that the appropriate numbers and spacing of UVC LEDs is helpful not only to increase the average irradiance and petri factor of reactor surface but also to keep a low chip junction temperature. The simulation results of three UVC LED configurations indicate the four corners configuration exhibits the highest average irradiance and petri factor value. The introduction of reflective materials can enhance the inactivation performance, and especially the polytetrafluoroethylene (PTFE) material can effectively increase the inactivation efficiency of module by ∼42% because of higher reflectivity and light uniformity. The further inactivation experiments reveal that the designed cylinder reactor covered with PTFE materials has the maximum log inactivation value. The current research results can provide some reliable suggestions for the design and optimization of UVC LED photoreactor to improve its inactivation effect through optical simulation and experimental methods.