MODELING AND EXPERIMENTAL STUDY OF AN EJECTOR FOR A TRANSCRITICAL CO_2 REFRIGERATION SYSTEM

摘要

An ejector is proposed to improve the performance of the basic transcritical CO_2 refrigeration system by reducing the expansion process losses. During the first step of the present work, a constant section mixing model was developed for the ejector, based on conservation of mass, energy and momentum. This modeling made it possible to simulate the variation of the relative performance of the cycle over a wide range of the cycle operating conditions: inlet parameters such as source temperatures, discharge pressure of compressor and compression ratio of the ejector. This model enabled us to understand and gain insights of the various physics phenomena occurring. In a second step, the ejector was manufactured and incorporated into an instrumented test bench (with pressure, temperature, mass flow, and power data acquisition). This allowed ejector performance prediction and model validation.