Thermodynamic analysis of ejector cooling cycles with heat-driven feed pumping devices

The paper presents the results of thermodynamic analysis of ejector cooling cycles with heat pumping devices which supply the working fluid to the vapor generator. Two variants of heat pumping devices are considered in which the feed pump is driven by (1) an expander and a turbine and (2) a turbine. A mathematical model for determining the energy and exergy characteristics of the pumping devices and ejector systems as a whole is proposed. Refrigerant R245ca is selected as an environmentally friendly low-boiling working fluid of the ejector cooling cycles. The paper analyzes the effect of condensing and generating temperatures on the characteristics of ejector cooling cycles for the air conditioning systems. It is shown that the use of the work obtained in the expander and turbine taking into account the irreversibility of the working processes in the pumping devices leads to a slight decrease in the energy efficiency of the proposed systems, and, at the same time, it significantly increases their exergic efficiency. (C) 2019 Elsevier Ltd. All rights reserved.