Effect analysis on combustion performance enhancement of the hydrogen-fueled micro-cylindrical combustors with twisted tapes for micro-thermophotovoltaic applications

Abstract

The main part of a micro-thermophotovoltaic (MTPV) system is the micro combustor (MC). In this work, the performance of the traditional micro combustor (TMC) and the micro combustor with twisted tape (MCTT) is investigated numerically under various inlet velocities (9 m/s-12 m/s), H2/air equivalence ratios (0.7–1.0), lengths of the twisted tape (4 mm–16mm), and pitches (4 mm, 5.33 mm and 8 mm). The results show that compared with the TMC, the MCTT with a 16 mm long twisted tape has a 114.7 K, 12.2 W and 15.0% increase in the mean outer wall temperature T¯w, radiation power Pemitter and emitter efficiency ηmc, respectively, at vin = 9 m/s. The outer wall temperature Tow is more uniform when the length of the twisted tape is 4 mm or 8 mm, the maximum drop in temperature standard deviation is 38.9 K when vin = 9 m/s. When the equivalence ratio φha is less than 0.9, the ηmc is not significantly improved with the increase of the length of the twisted tape. Overall, the MCTT offers better promise for applications in MTPV systems than the TMC.