Thermal efficiency improvement of an LPG gas cooker by a swirling central flame

The present study proposes a swirling central flame technique to improve th e thermal efficiency of a conventional open-flame atmospheric gas cooker wh ich is now widely used as a domestic appliance. More extensive studies were done in an effort to improve the thermal efficiency of the cooker by reduc ing thermal inertia of the pan support and using the proposed porous medium technology to recover heat from flame radiation to preheat the secondary a ir entrained from the bottom of the burner. The experimental results showed that the thermal efficiency of the swirling central flame burner with conv entional support is approximately 15 per cent higher than that of the conve ntional radial flow burner. This can be attributed to the higher heat trans fer coefficient between hot flue gas and vessel surface of the swirl burner than that of the conventional one. By replacing the conventional support o f the developed swirl burner with a lighter one, whose mass was reduced by a factor of 3.7, the thermal efficiency could be increased by about 3 per c ent. By using the proposed preheating secondary air support instead of the light support, the thermal efficiency could be further improved by 3 per ce nt. The predicted thermal efficiency obtained from the proposed model showe d good agreement with the experiment. Copyright (C) 2001 John Wiley & Sons, Ltd.