Heat Transfer Characteristics of Impinging of Flame Jet on Flat Plate: Investigation of Heat Transfer Characteristics in Spiral Flow Heat Exchanger

Abstract

Spiral flow heat exchangers are known as excellent heat exchanger because of far compact and high heat transfer efficiency. Spiral type heat exchanger is a unique design where it consists of single fluid as working fluid for heat exchange. Here heat transfer takes place between solid and fluid, and hence can be called as conjugate heat transfer. Heat transfer characteristics are observed at various Reynolds number and base temperature. The concept of K-type thermoelectric effect is used which is direct conversion of temperature difference to electric voltage, to measure temperature at various point in the heat exchanger. This study investigates the heat transfer from Liquid Petroleum Gas (LPG) flames impinging normal to the water cooled copper metal disc (150mm*150mm*6mm*10mm*2mm) segmented into two spiral channels. The correlates that are apply to the small region on the target, such as the stagnation point, are referred to as the local heat flux. Correlations that apply to a large region of the target, such as the whole area of heating region is referred as the average heat flux by measuring heat transfer over the target. Next the correlations are arranged by the type of heat transfer, for natural convection with low Reynolds number, here for this experimental work only the natural convection is considered. Finally the correlations are arranged by the flow type, either laminar or turbulent and heating height (z/d ratio).