Most industrial processes use a significant amount of thermal energy, mostly by
burning fossil fuels. Some part of the energy released in combustion is inevitably
rejected to the surroundings as waste. This waste heat can be utilized in certain
types of refrigeration system such a jet refrigeration cycle.
With the use of the jet refrigeration cycle, the amount of electricity purchased
from utility companies, required for conventional vapour compression in the
refrigeration cycle, is reduced. Thus, utilization of the waste heat in refrigeration
systems promotes mitigating the problems related to the environment, particularly
by reduction of CO2 emission from combustion of fossil fuels in boilers of utility
power plants.
Although jet refrigeration systems seem to provide many advantages, vapour
compression systems still dominate in all of the market sectors. In order to promote
the use of jet refrigeration systems, further development is required to
improve their performance and reduce the unit cost.
The aimof this paper is to provide basic background knowledge and a review of
existing literature on ejectors and their applications in refrigeration cycles. The
concepts and interesting points of each study were linked and grouped to other
related studies and described as overview summaries. These differentiate this paper
fromother existing review papers [1,2]. It is hoped that this paper will be useful for
any newcomer in this field of refrigeration technologies.