Numerical simulation study on the influence of primary nozzle deviation on the steam ejector performance

Abstract

Steam ejector is widely used in the chemical industry, electric power, refrigeration and other fields. However, the ejector performance is usually poor, and the deviation far from the design performance limits its application range. During the actual installation and operation process, the primary nozzle of the ejector will deviate from the axis due to assembly error and vibration, which will affect the ejector performance. In this research, the ejector with a deviation of the primary nozzle is numerically simulated, and the variation law of ejector performance under different displacement and the inclination angle is obtained. It is found that the deviation of the primary nozzle will deteriorate the ejector performance. At the critical mode, large displacement will significantly reduce the entrainment ratio. When the displacement is 26.32%, the entrainment ratio will decrease by 18.0%. However, small displacement has no effect on the entrainment ratio. At the sub-critical mode, the deterioration impact of the primary nozzle inclination on the ejector performance is higher than that of the primary nozzle displacement. At the same time, the deviation of the primary nozzle reduces the critical back pressure, and the small displacement and inclination angle reduces the critical back pressure by up to 8.9% and 20.0%.