Influence of pressure on the circumferential diffusion characteristics of fuel vapor and combustion performance in a pressurized burner

Abstract

To discuss the circumferential diffusion characteristics of the fuel vapor and combustion performance, a 15 kW pressurized burner fueled by diesel is first proposed in this research. And then, combustion experiments and cool-state numerical simulations are conducted at different pressures (P) and thermal loads (Q). The ratio (F) of the aerodynamic to buoyancy forces and the circumferential diffusion uniformity (σ) of the fuel vapor are constructed through pollutant emissions, fuel vapor concentration distribution and velocity field. The results show that under a Q of 3.55 kW, the burner has a relatively low F, and the buoyancy force has a more obvious effect as P increases, further causing circumferential fuel vapor distribution uniformity to suffer. When the burner operates at a Q of 10.64 kW, the undesired circumferential diffusion uniformity of the fuel vapor is only found at 0.3 MPa. For a Q of 15.37 kW, the fuel vapor has a great circumferential diffusion uniformity in the forward end of the liner at each P. A proper F of 89–278 and σ of 0–3.6% are recommended for diesel vapor circumferential diffusion and pollutant emissions, in which the buoyancy force has a relatively lower effect than the aerodynamic force.