Experimental and numerical investigation of the design and control of vapor-compression systems with integration of two-phase ejectors for performance enhancement through expansion work recovery
type: CreativeWork
description: The use of ejectors to improve the efficiency and capacity of vapor-compression refrigeration cycles by means of expansion work recovery has received significant attention in the past decade. Research has focused primarily on the design and performance of the ejector and the effect the ejector has on cycle performance. However, recent research has shown that additional factors, such as cycle architecture, improvement in evaporator performance, and cycle control, can also have significant influence on ejector cycle performance. While these factors have been noted in several studies, they have yet to be thoroughly investigated. Thus, the objective of this research is to investigate how to properly integrate an ejector into a vapor-compression cycle (how to choose the proper cycle architecture and proper use of the ejector) and how to design and operate other system components in addition to the ejector, such as the evaporator and cycle controls, in order to gain the maximum benefit from the ejector in the given system. Two ejector cycles are investigated through the use of numerical modeling and experiments. The cycles of interest are the standard ejector cycle, which uses the ejector pressure increase to directly increase compressor suction pressure and reduce compressor power, and the ejector recirculation cycle, which uses the ejector to recirculate excess liquid through the evaporator and improve evaporator performance. The numerical results have shown that refrigerants and systems with inherently high throttling loss, such as transcritical CO2 (R744) systems, should use the ejector to directly supplement compressor power using the pressure increase provided by the ejector, while systems using lower-pressure refrigerants should use the ejector to improve the performance of the evaporator by means of liquid recirculation (overfeed). An experimental investigation of the two ejector cycles using R410A has been performed; two different microchannel evaporators with th…
abstract: The use of ejectors to improve the efficiency and capacity of vapor-compression refrigeration cycles by means of expansion work recovery has received significant attention in the past decade. Research has focused primarily on the design and performance of the ejector and the effect the ejector has on cycle performance. However, recent research has shown that additional factors, such as cycle architecture, improvement in evaporator performance, and cycle control, can also have significant influence on ejector cycle performance. While these factors have been noted in several studies, they have yet to be thoroughly investigated. Thus, the objective of this research is to investigate how to properly integrate an ejector into a vapor-compression cycle (how to choose the proper cycle architecture and proper use of the ejector) and how to design and operate other system components in addition to the ejector, such as the evaporator and cycle controls, in order to gain the maximum benefit from the ejector in the given system. Two ejector cycles are investigated through the use of numerical modeling and experiments. The cycles of interest are the standard ejector cycle, which uses the ejector pressure increase to directly increase compressor suction pressure and reduce compressor power, and the ejector recirculation cycle, which uses the ejector to recirculate excess liquid through the evaporator and improve evaporator performance. The numerical results have shown that refrigerants and systems with inherently high throttling loss, such as transcritical CO2 (R744) systems, should use the ejector to directly supplement compressor power using the pressure increase provided by the ejector, while systems using lower-pressure refrigerants should use the ejector to improve the performance of the evaporator by means of liquid recirculation (overfeed). An experimental investigation of the two ejector cycles using R410A has been performed; two different microchannel evaporators with th…
author: Lawrence, Neal D
language: en
keywords: Ejector, expansion work recovery, vapor-compression technology, evaporator design, carbon dioxide
date published: 2017-03-01T15:46:18Z
date modified: 2026-07-22T22:26:37Z
provider: University of Illinois - Urbana-Champaign
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Illinois at Urbana-Champaign

PropertyValue
property ID: Handle
value: http://hdl.handle.net/2142/95306