운전조건 및 노즐위치에 따른 이젝터 성능특성에 관한 실험적 연구

Abstract

In this study, the performance of an ejector in the refrigeration cycle was experimentally studied using R600a. The performance of the ejector is analyzed according to the inlet pressure and nozzle position. The increase in the primary nozzle pressure decreased the pressure difference across the ejector. In the low entrainment region, the increased suction flow pressure led to an increase in the pressure difference. In the high entrainment region, the pressure difference was inversely proportional to the suction pressure. The effects of nozzle position (<TEX>$L_n$</TEX>) were also analyzed and for <TEX>$L_n</TEX><TEX><</TEX><TEX>0$</TEX>, the decreased suction chamber volume led to a large pressure drop with the small increase in the suction mass flow rate. For <TEX>$L_n</TEX><TEX>></TEX><TEX>0$</TEX>, the increased <TEX>$L_n$</TEX> disturbed the primary nozzle flow and thus an increase in the primary nozzle flow increased the pressure lifting effect. In contrast, the increased suction mass flow rate decreased the pressure difference. When the nozzle outlet was located at the mixing part entrance (<TEX>$L_n=0$</TEX>), the ejector showed the highest pressure lifting effect.