Numerical investigations on the performance of a hydrogen-fueled micro planar combustor with tube outlet for thermophotovoltaic applications

As the practical application of the micro thermophotovoltaic system is limited by its low output power and energy conversion efficiency, optimizing the structure of micro combustor to enhance the thermal performance of micro combustors is an effective method. In this work, the tube outlet is proposed to enhance the heat transfer between the burned gas and combustor wall. A three-dimensional model including fluid flow, heat transfer and combustion is constructed to investigate effects of tube length, tube diameter and solid wall materials on the performance of a hydrogen-fueled micro planar combustor with tube outlet. The findings show that the tube outlet can effectively improve mean outer wall temperature and outer wall temperature uniformity of micro planar combustor, and the energy output and energy conversion efficiency of MTPV system, but the pressure loss is higher. The energy output and energy conversion efficiency of MTPV system is increased with the reduction of tube length and the increment of tube diameter, while the pressure loss is slowly decreased. Moreover, when nickel is used as the solid wall material, the energy output and energy conversion efficiency of MTPV system can reaches to 6.14 W and 3.54%, respectively.

Automated summary

Optimizing the structure of micro combustors to enhance their thermal performance can effectively improve the output power and energy conversion efficiency of micro thermophotovoltaic systems. The introduction of a tube outlet can effectively increase the mean outer wall temperature and temperature uniformity of micro planar combustors, as well as the energy output and energy conversion efficiency of MTPV system, but it also leads to higher pressure loss. The energy output and energy conversion efficiency of MTPV system can be further increased by reducing the tube length and increasing the tube diameter, while the pressure loss decreases slowly. When nickel is used as the solid wall material, the energy output and energy conversion efficiency of MTPV system can reach 6.14 W and 3.54%, respectively.