| Summary: | 碩士 === 國立成功大學 === 機械工程學系 === 85 === In this work, combustion characteristics of a double-annular slot domestic cooktop burner were investigated. First, U tube was used to measure the pressure of LPG regulator, and bubble meter was used to measure the flow rate of nozzle. Subsequently image processing techniques were used to study the flame structure of single slot flame under various switch scales being 45°and 90°, and six kinds of air shutter scale being 0°, 10°, 20°, 30°, 40°and 50°. Furthermore, gray levels were measured for three different flame heights. Then, gas chromatography was used to measure the LPG concentration istribution at different port positions for constant switch scale being 90°and four kinds of air shutter scale being 0°, 10°, 20°and 30°. Finally, the temperature distribution at six ifferent positions were measured at two kinds of switch scale being 45°and 90°, and three kinds of air shutter scale being 20°, 30° and 40°.
Results show that, the lowest pressure is achieved when switch scale is 90°, thus flame height is higher than that obtained under other switch scales. Smaller air shutter scale resulting in lower entrainment of ambient air (secondary air). Changes the inner rich premixed flame to undergo weakly burning accompanied by tip-opening of premixed flame, and that the concentration distribution is independent of position that measured at outer annular port, but is dependent of position measured at inner annular port, because premixed mixture is not well mixed at the inner annular port. Finally, in the temperature measurement, it was found that, temperature distribution''s measured near to ambient air affected by convection, resulting in narrower high temperature zone and lower maximum temperature.
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