The purpose of this research is to investigate thermoeconomic optimization and exergy analysis of transcritical CO2 refrigeration cycle with an ejector. After modeling thermodynamic equations of elements and considering optimization parameters of emerging temperature of gas of cooler (Tgc) , emerging pressure of cooler's gas (Pgc) , and eva...

Compared to mechanical compressors, ejector-based refrigeration systems can make direct use of many forms thermal energy, including waste heat, solar thermal, or biogases. It is known that SE have a lower efficiency compared compressors because their performance at high compression ratios. In the present work, binary fluid ejector heat pumps with are presented based on proper selection fluids a...

This paper presents the analysis of a two phase flow ejector for the transcritical CO2 cycle. A detailed simulation model of a two phase flow ejector was developed. A controllable ejector expansion device was designed, constructed, and installed in a transcritical CO2 experimental air conditioning system. System-level experimental results were obtained at different operation conditions and vari...

The objective of this paper is to explore whether the use of an internal heat exchanger can further improve the performance of transcritical ejector systems with C02 as the working fluid. Instead of using a simplified thermodynamic cycle analysis, the approach taken here is based on a more elaborated and experimentally validated system model for a real mobile air-conditioning system for a typic...

Liquid recirculation is a method of improving evaporator performance by supplying the evaporator with more liquid than is evaporated. The excess liquid, which is generally provided by means of an externally-driven, mechanical pump, eliminates dryout and increases overall heat transfer coefficient in the evaporator. Liquid recirculation is common in large-scale industrial refrigeration systems, ...

A semi-empirical control-volume approach to ejector modeling for transient performance prediction is presented. This new approach is motivated by the need for a predictive real-time ejector sub-system simulation for STOVL integrated flight and propulsion controls design applications. Emphasis is laced on discussion of the approximate characterization of the suggests transient flow predictions a...