International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056
Volume: 03 Issue: 05 | May-2016 www.irjet.net p-ISSN: 2395-0072
© 2016, IRJET | Impact Factor value: 4.45 | ISO 9001:2008 Certified Journal | Page 2441
Development Practices in Ejector Technology for Refrigeration and Air
Conditioning Applications
DR K. Ashok Reddy
Professor, Dept of Mechanical Engineering, MLR Institute of Technology , Dundegal (V) , Hyderabad-43
Abstract : This paper presents a comprehensive literature
review on ejector refrigeration systems and working fluids.
It deeply analyzes ejector technology and behavior,
refrigerant properties and their influence over ejector
performance and all of the ejector refrigeration
technologies, with a focus on past, present and future trends.
Ejector technology was described and description of the
refrigerant properties and their influence over ejector
performance was highlighted. A review on development
practices in ejector technology for refrigeration and air
conditioning applications have been presented by various
researchers was made available in this paper.
Keywords: ejector, refrigerant, air conditioning, vapor
compression etc.
I. INTRODUCTION
Hasan Sh. Majdi [1] presented in their paper to develop a
computer simulation program to evaluate the performance
of solar-assited combined ejector absorption (single-
effect) cooling system using LiBr/H2O as a working fluid
and operating under steady-state conditions. The ejector
possess no moving parts and is simple and reliable, which
makes it attractive for combination with single-stage
absorption cycle for further improvement to the system's
performance. In this research, improvement to the system
is achieved by utilizing the potential kinetic energy of the
ejector to enhance refrigeration efficiency. The effects of
the entrainment ratio of the ejector, operating
temperature, on the thermal loads, and system
performance have been investigated. The results showed
that the evaporator and condenser loads, post-addition of
the ejector, is found to be permanently higher than that in
the basic cycle, which indicates a significant enhancement
of the proposed cycle and the cooling capacity of the
system increasing with the increase in evaporator
temperature and entrainment ratio. The COP of the
modified cycle is improved by up to 60 % compared with
that of the basic cycle at the given condition. This process
stabilizes the refrigeration system, enhanced its function,
and enabled the system to work under higher condenser
temperatures.
Giorgio Besagni et al [2] presented in their paper the
increasing need for thermal comfort has led to a rapid
increase in the use of cooling systems and, consequently,
electricity demand for air-conditioning systems in
buildings. Heat-driven ejector refrigeration systems
appear to be a promising alternative to the traditional
compressor-based refrigeration technologies for energy
consumption reduction. M. Hassanain et al [3] presented in
their paper use of a two-phase flow ejector as an
expansion device in vapor compression refrigeration
systems was one of the efficient ways to enhance its
performance. The present work aims to design a constant-
area two phase flow ejector and to evaluate performance
characteristics of the ejector expansion refrigeration
system working with R134a. In order to achieve these
objectives, a simulation program was developed and
effects of operating conditions and ejector internal
efficiencies on the system performance are investigated
using EES software. Comparison between present results
and published experimental data revealed that the
developed model can predict the system COP with a
maximum error of 2.3%. The system COP increased by
ͺ.ͷ% as evaporation temperature changed from −ͳͲ °C to
10 °C. Tao Bai at al [4] presented in their paper an ejector
enhanced vapor injection CO2 transcritical heat pump cycle
with sub-cooler (ESCVI) for heating application in cold
regions was proposed.
The thermodynamic analysis using energetic and exegetic
methods is carried out to predict the performance
characteristics of the ejector enhanced cycle, and then
compared with those of the conventional vapor injection
heat pump cycle with sub-cooler (SCVI). The simulation
results demonstrate that the ejector enhanced cycle
exhibits better performance than the conventional vapor
injection cycle under the specified operating conditions.
The improvements of the maximum system COP and
volumetric heating capacity could reach up to 7.7% and
9.5%, respectively. Exergetic analysis indicates that the
largest exergy destruction ratio is generated at the
compressor followed by the evaporator and gas cooler.
Additionally, the exergy efficiency of the ejector is
introduced to quantify the effectiveness of the exergy
recovery process, which may be a new criterion to
evaluate the performance of the ejector enhanced vapor