Hogging Ejector의 설계 및 성능에 관한 연구

Abstract

Research on energy has been continuing various studies on these day. Because the global environment in the future will change depending on how we used an energy in the present. So, various studies have been carried out by various scholars including research on new systems and improvement of efficiency in existing systems. In the field of industry also, many application for improvement of efficiency are considered and applied. Ejector systems also are a lot related to this. Low-pressure working fluid, which is a secondary working fluid, is sucked into the ejector and mixed with each other due to the pressure drop and shearing effect that occurs when the primary working fluid, high pressure and high temperature gas, is released from the nozzle. This mixed fluid are released to the atmosphere through a diffuser. That is, the energy of the primary working fluid causes the secondary working fluid to move. And no electrical power is introduced in this process. If user don’t want to apply the ejector system, user should consider to apply a device such as a pump using electricity to move the secondary working fluid. Of course, Ejector system also, the electrical power is required when primary working fluid is made by compressor. But this fluid is not made only for the ejector system. This steam is for an operation of utilizes in the plant. Namely, The advantage of the ejector system is that it doesn’t need to use electrical power. On the other hand, the design of ejector system is a very difficult problem. Because it deals with compressible fluid. Then the properties change continuously according to temperature and pressure. In addition, normal shock wave and chocking occurs when passing through a narrow area in the nozzle. It is necessary to design it in consideration of this. This often leads to performance failures during performance testing. In this study, I analyzed the major cause of performance failure based on the accumulated database and proposed a new design which can increase the design accuracy. And I confirmed the validity of the new design through experiments with two kinds of ejector to be designed by new design method and original design method.