Thermodynamic modeling and performance evaluation of the economizer effect on increasing the efficiency of air-cooled compression chillers

Mollakazemi, Ahmad Reza; Pirkandi, Jamasb; Hashem Abadi, Mahdi; Tabatabaei Zadeh, Seyed Mohammad Navid

doi:10.22034/jrenew.2026.247782

Thermodynamic modeling and performance evaluation of the economizer effect on increasing the efficiency of air-cooled compression chillers

Document Type : Original Article

Authors

Ahmad Reza Mollakazemi ¹

Jamasb Pirkandi ²

Mahdi Hashem Abadi ³

Seyed Mohammad Navid Tabatabaei Zadeh ⁴

¹ M.Sc Student, Faculty of Aerospace, Malek Ashtar University of Technology, Tehran, Iran

² Associate Professor, Faculty of Aerospace, Malek Ashtar University of Technology, Tehran, Iran.

³ Assistant Professor, Faculty of Aerospace, Malek Ashtar University of Technology, Tehran, Iran.

⁴ M.Sc Student, Energy Systems Engineering, University of Tehran, Tehran, Iran

10.22034/jrenew.2026.247782

Abstract

Since the invention of refrigeration systems, human living standards have increased rapidly. Air conditioners have provided people with comfort regardless of external conditions, and refrigerators have significantly improved the quality of human food. Since refrigeration systems with high energy efficiency require less energy for the same amount of cooling or heating capacity, they reduce electricity demand. Therefore, improving the performance of the refrigeration system can be a valid approach to preserving the environment. In this study, the thermodynamic performance of an air-cooled vapor compression chiller equipped with an economizer was investigated. The main objective was to evaluate the effect of the economizer on the coefficient of performance (COP), compressor power reduction, and overall energy efficiency improvement. Two models—a two-stage vapor compression cycle and a single-stage cycle with an economizer were developed and simulated using EES software. Eight different refrigerants were analyzed. The simulation results showed that employing an economizer enhanced the COP by 10–15% compared with the conventional system. Among the studied refrigerants, R1234ze(Z) exhibited the highest thermal efficiency and environmental compatibility, while R407C demonstrated the lowest performance. Parametric analysis revealed that an increase in condenser temperature leads to a reduction in COP and a higher compressor power requirement.

Keywords

Air-cooled chiller

Economizer

Coefficient of performance

Refrigerant

Thermodynamic analysis

Subjects

Renewable Energy

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