Performance Evaluation of an Ejector-Enhanced Modified Cascade–Auto-Cascade Refrigeration System for Ultra-Low-Temperature Cooling

Makaleler > Tam Makale · 2026

Yazarlar: İbrahim KARAÇAYLI, Lütfiye ALTAY, Arif Hepbaşlı

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART E-JOURNAL OF PROCESS MECHANICAL ENGINEERING, SCI Expanded İndekslerine Giren Dergi, Uluslararası, Scopus, 2026, cilt 240, ss 1-10

DOI: 10.1177/09544089261424171

Özet

<p class="ql-align-justify"> Auto-cascade&nbsp;refrigeration&nbsp;(ACR)&nbsp;systems&nbsp;can&nbsp;reach&nbsp;ultra-low&nbsp;temperatures&nbsp;but&nbsp;often&nbsp;suffer&nbsp;from&nbsp;two&nbsp;major&nbsp;drawbacks:&nbsp;high&nbsp;compressor&nbsp;exit&nbsp;(discharge)&nbsp;temperatures&nbsp;and&nbsp;low&nbsp;system&nbsp;performance.&nbsp;Many&nbsp;previous&nbsp;studies&nbsp;have&nbsp;focused&nbsp;on&nbsp;performance&nbsp;enhancement&nbsp;while&nbsp;neglecting&nbsp;the&nbsp;critical&nbsp;issue&nbsp;of&nbsp;compressor&nbsp;exit&nbsp;temperature.&nbsp;Although&nbsp;techniques&nbsp;such&nbsp;as&nbsp;vapor&nbsp;injection,&nbsp;two-stage&nbsp;compression,&nbsp;and&nbsp;additional&nbsp;heat&nbsp;exchangers&nbsp;can&nbsp;enhance&nbsp;system&nbsp;efficiency,&nbsp;they&nbsp;also&nbsp;introduce&nbsp;structural&nbsp;complexity&nbsp;and&nbsp;higher&nbsp;costs.&nbsp;To&nbsp;address&nbsp;these&nbsp;challenges,&nbsp;this&nbsp;study&nbsp;proposes&nbsp;a&nbsp;novel&nbsp;hybrid&nbsp;refrigeration&nbsp;cycle&nbsp;that&nbsp;integrates&nbsp;a&nbsp;cascade&nbsp;cycle&nbsp;with&nbsp;an&nbsp;ACR&nbsp;system.&nbsp;The&nbsp;objective&nbsp;is&nbsp;to&nbsp;lower&nbsp;the&nbsp;compressor&nbsp;exit&nbsp;temperature&nbsp;and&nbsp;improve&nbsp;the&nbsp;overall&nbsp;performance&nbsp;while&nbsp;maintaining&nbsp;simplicity&nbsp;through&nbsp;the&nbsp;use&nbsp;of&nbsp;environmentally&nbsp;friendly&nbsp;refrigerant&nbsp;mixtures.&nbsp;Four&nbsp;different&nbsp;configurations&nbsp;were&nbsp;studied:&nbsp;three&nbsp;modified&nbsp;cascade&nbsp;refrigeration&nbsp;(MCR)&nbsp;cycles&nbsp;and&nbsp;one&nbsp;ejector-&nbsp;enhanced&nbsp;cascade&nbsp;refrigeration&nbsp;(MECR)&nbsp;cycle.&nbsp;The&nbsp;MECR&nbsp;system&nbsp;achieved&nbsp;the&nbsp;best&nbsp;results,&nbsp;with&nbsp;a&nbsp;coefficient&nbsp;of&nbsp;performance&nbsp;(COP)&nbsp;of&nbsp;0.894&nbsp;and&nbsp;an&nbsp;exergy&nbsp;efficiency&nbsp;of&nbsp;30.1%&nbsp;at&nbsp;evaporator&nbsp;exit&nbsp;and&nbsp;condensation&nbsp;temperatures&nbsp;of&nbsp;–60&nbsp;°C&nbsp;and&nbsp;30&nbsp;°C,&nbsp;respectively.&nbsp;The&nbsp;compressor&nbsp;exit&nbsp;temperature&nbsp;was&nbsp;reduced&nbsp;by&nbsp;36.9%,&nbsp;improving&nbsp;safety&nbsp;when&nbsp;using&nbsp;low-GWP&nbsp;refrigerants.&nbsp;Relative&nbsp;to&nbsp;comparable&nbsp;systems&nbsp;reported&nbsp;in&nbsp;the&nbsp;literature,&nbsp;the&nbsp;proposed&nbsp;design&nbsp;improved&nbsp;exergy&nbsp;efficiency&nbsp;by&nbsp;up&nbsp;to&nbsp;58.2%&nbsp;without&nbsp;compromising&nbsp;structural&nbsp;simplicity.&nbsp;These&nbsp;findings&nbsp;demonstrate&nbsp;that&nbsp;the&nbsp;MECR&nbsp;configuration&nbsp;provides&nbsp;a&nbsp;practical&nbsp;balance&nbsp;between&nbsp;the&nbsp;performance&nbsp;improvement,&nbsp;safety,&nbsp;and&nbsp;system&nbsp;simplicity,&nbsp;offering&nbsp;meaningful&nbsp;advantages&nbsp;for&nbsp;ultra-low-temperature&nbsp;applications&nbsp;without&nbsp;increasing&nbsp;the&nbsp;system&nbsp;complexity.</p>

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