Assessment of effective parameters on ejector performance in refrigeration system

Document Type : Original Article

Authors

1 Department of Mechanical Engineering Vali-e-Asr University of Rafsanjan Iran

2 Department of mechanical engineering Vali-e-Asr university of Rafsanjan Iran

3 Department of mechanical engineering Vali-e-Asr University of Rafsanjan Iran

Abstract

In this research, the performance of the ejector in the ejector refrigeration system (ERS) with water vapor operating fluid, has been investigated. To analyze the results, axi-symmetric modeling in Fluent software was used and thermodynamic analysis of the cycle was performed using MATLAB software. Ejector entrainment ratio (ER) and ejector refrigeration system performance coefficient (COP) are evaluated according to the input conditions of primary and secondary fluid, condenser conditions and the effect of ejector geometry. The boundary condition of the wall is considered for the momentum equation. On the other hand, in the energy equation, the condition of non-slip is applied. The turbulent flow modeling method is considered k-ε REA in Fluent software. For proper meshing and more accurate focusing on the walls, the creation of boundary layers uses an unstructured mesh that allows for the non-uniform distribution of the elements. Also, to improve the quality of the grid, the meshing modification capability in Fluent software is used. The results show that increasing the primary fluid pressure causes a large expansion in the mixing chamber that has a larger expansion angle than the corresponding lower pressure state. This increases the Mach number, decreases the secondary fluid adsorption, and consequently reduces the ER of ejector and COP of ERS. Also, by moving the primary nozzle exit position (NXP) to the right, the ER of ejector and COP of ERS decrease about 6.86%, 7.5%, respectively.

Keywords

Files

Share

How to cite

Statistics