조수기용 이젝터 최적설계에 관한 연구

Abstract

Performance analysis of an ejector in a fresh water generator about the optimal design

Jin Ho Kim

Interdisciplinary Promgram of Marin-Bio, Electrical & Mechanical Engineering, The Graduate School, Pukyong National University

Abstract An Ejector is an important equipment to create low pressure by fluid injection. A pressure difference is created with water and air entering through the water suction and air suction pipes respectively. In order to maintain vacuum, the Ejector uses the Kinetic Energy of the fluid flow. To evaluate the performance of the Ejector in different types of Fresh Water Generator, the CFD analysis is used on the ejector at different boundary conditions of the suction pipe, namely, 1 atm, 0.5 atm and 0.1 atm. The analysis on the effects of the results of Fluid flow, Velocity, Pressure difference on the performance of the Ejector in different Fresh Water Generators can be used for the Design Optimization of the Fresh Water Generator A normal ejector uses only one suction pipe. In this paper, we introduce two suction pipes, where air & water are inhaled simultaneously, which can be used in Fresh Water Generating System. The performance of the ejector was evaluated using ANSYS CFX 13.0 commercial version. We also calculated the time taken to reach the vacuum pressure in the tank from 1 atm to 0.1 atm at different boundary condition. The result shows the flow rates at different pressure boundary conditions. The time taken to reach 0.1 atm vacuum pressure in the tank is 126s. Results were obtained inlet pressure is raised due to the angle variation of the diffuser. This data from the pressure control was set on the basis of the ejector pipe to connect the diffuser and the outlet. We analyzed the effect on performance of the ejector.