Exergy analysis and energy output improvement of the micro-thermophotovoltaic system via investigating the fractal angles of secondary Y-shaped fins in the micro combustor

Aiming to improve the energy output of micro thermophotovoltaic systems, and the thermal performance of the embedded bionic Y-shaped fins(BYF) micro-combustor is further explored, the influence of different fractal angles (30 degrees, 60 degrees and 90 degrees) of the BYF are studied. The results show that the thermal performance of the novel one at different fractal angles are superior to traditional one. The novel one can reach 1309.2 K, 1315.1 K and 1332.2 K for outer wall temperature when the fractal angles are 30 degrees, 60 degrees, and 90 degrees, respectively. However, the traditional one is 1129.8 K. Moreover, the energy efficiency and energy output of the novel micro combustor are also much higher than the conventional ones. The exergy efficiency of the novel one can reach 44.19 %, 44.80 % and 44.80 % when the fractal angle is 30., 60. and 90., respectively, while the traditional one is 27.26 %. However, the temperature uniformity of the novel one decreases with the increase of the fractal angle. In addition, the silicon carbide solid wall material exhibits excellent outer wall temperature uniformity due to its high thermal conductivity.