Flame Deflector Modification for Improved Combustion Efficiency in Domestic Gas Ovens

Abstract

ABSTRACT This research aimed to examine the effect of port placements in the flame deflector on the combustion efficiency of the grill burner within a domestic gas oven. Six different configurations of the flame deflector were designed for this purpose. Emission tests of the grill burner were carried out at two different pressures for 1 h according to EN30 standard for all types of flame deflectors. The reduction in the C O N content by %11.3 was observed in the flame deflector of No_6 as compared to default deflector. The CFD analysis of the No_6 flame deflector was also carried out to examine the air flow pattern of the flame deflector through the grill burner. Results showed that the air flow from the flame deflector into the grill burner was more uniform than that of the default flame deflector. The temperature, the mass fraction of fuel/air, and CO and CO2 distribution in the grill burner through combustion process were numerically simulated using commercial CFD program, FloEFD. The most appropriate chimney position was recommended based on the distribution of CO2 content. Emission tests and efficiency tests of two different chimney prototypes with different chimney areas (1260 mm2 and 1400 mm2) were tested to evaluate the effect of the chimney area on the combustion quality and combustion efficiency in terms of combustion products and gas consumption. Experimental results showed that reduction in the emission was realized by approximately 50% at both pressures of 17 mbar and 25 mbar when using higher chimney area. However, the gas consumption increased by approximately 0.67%, 1%, and 7% per m3 when the chimney with higher area was used at the burning temperature of 140 K, 180 K, and 220 K, respectively.