Work

A novel auto-cascade refrigeration system integrated with vapor injection and fractionation: Energy efficiency improvement and economic evaluation

Year: 2026

Type: article

Abstract: The auto-cascade refrigeration cycle (ARC) has become a highly regarded technical approach for achieving ultra-low temperature refrigeration due to its simple structure and reliable operation. The compressor performance and the separation efficiency of refrigerant mixtures are key limiting factors in improving system performance. This paper proposed the improved cycle that combines vapor injection technology and fractionation separation technology with the aim of enhancing the coefficient of performance (COP). By comparing the performance of different environmentally friendly refrigerant mixtures, R600a/R170 is selected as the working fluid. Under the optimal design parameters, the energy, exergy and exergo-economic performance of the improved cycle were analyzed and compared with the basic cycle. The results show that the COP increased from 0.45 to 0.82, the exergy efficiency improved from 24.9% to 36.9% and the total economic cost rate decreased from 2.8358 [[EQUATION]] to 2.4320 [[EQUATION]], which indicates that the overall performance of the improved system has been greatly improved. The performance improvement is mainly due to improved compressor performance and reduced irreversible losses in the cascade heat exchanger. Moreover, the parametric analysis reveals that the system performance enhancement tends to result in a decrease in the pinch point temperature difference in the cascade heat exchangers. Herein, these findings are expected to provide relevant references for refrigerant selection and structural design of auto-cascade refrigeration systems.

Source: Thermal Science and Engineering Progress

DOI: 10.1016/j.tsep.2026.104704

Authors: Zijun Dong, Ningbo Wang, Bo Tian, Shuangquan Shao, Hainan Zhang

Institutions: Huazhong University of Science and Technology, University of Science and Technology Beijing

Language: English

Topic: Refrigeration and Air Conditioning Technologies

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Affordable and clean energy, Industry, innovation and infrastructure, Responsible consumption and production, Climate action

Open Access status: hybrid

Estimated APC paid: $3,000