Investigation and development of improved methods for the design of ejector

Abstract

The ejector is a simple mechanical device having no moving parts has the characteristics of being fixed, reliable, inexpensive, simple to keep up and handle. An ejector is a device that allows a fluid at low pressure flow (secondary fluid flow) by speed up some other fluid at high pressure flow (primary fluid flow) through nozzle. It is used in lot of industrial processes, particularly with air or steam as operating fluid. The ejector system has a vast range of applications. They reduce pollution compared to fossil fuel power plants. The geometry of the ejector has a remarkable impact on the performance of the ejector. A steam ejector can effectively make use of unused heat resources, which is mainly used in air conditioning, refrigeration, and seawater desalination sectors. The geometry of mixing chamber of the steam ejector features a critical effect on its outcome. The numerical simulation results shows that the entrainment ratio and critical back pressure of the steam ejector initially increases and then decreases with the increase in mixing chamber length for different mach numbers. Mixing chamber length of 40 mm to 80 mm and nozzle throat diameter 2.5 mm provides high performance of steam ejector for steam ejector refrigeration.Ejector with converging-area chamber has higher performance than ejector with constant area section. Hydrocarbon ejector cooling applications is highly recommended.