Study of the migration behavior of mixed refrigerants and energy efficiency during actuators action process in auto-cascade refrigeration systems

IF 6.1 2区工程技术 Q2 ENERGY & FUELS

Applied Thermal Engineering Pub Date : 2025-04-28 DOI:10.1016/j.applthermaleng.2025.126548

Li Yinlong , Jing Dongliang , Liu Guoqiang , Yan Gang

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引用次数: 0

Abstract

The auto-cascade refrigeration cycle (ARC) using mixed refrigerants is widely used to produce temperatures below −40℃. Due to the vapor–liquid separation at the condenser outlet, the ARC system contains three distinct streams: the total stream, the vapor stream and the liquid stream. The three streams exhibit diverse variations in mass flow rates and composition circulation concentrations. The composition distribution and migration behavior in any stream undergoes complex variations with the actuation operation. Existing research only obtained the composition concentration shift relationship or inferred composition migration behavior from the pressure and temperature variations. The underlying causes of changes in thermodynamic parameters have not been revealed. This article experimentally investigates composition migration behavior during the actuator regulation in the ARC system using R600a/R170. From the perspective of composition migration behavior, this study elucidates the variations of thermodynamic parameters during actuators’ operation. The results show that the compressor speed variations lead to an increase in the circulating flow rate. The composition circulating concentration exhibits non-monotonic variation. The increased fan speed accelerates the condensation of mixed refrigerants. The circulating concentration of R170 decreases from 50.4% to 48.38%. The expansion valve before the evaporator regulates the compositions and flow rate, while the other valve primarily manages the total flow rate. The optimal energy efficiency corresponds to a compressor speed of 3000r, fan speed of 1980r and valve openings of 30% and 50%. Studying composition migration behavior provides actuators with optimization regulation strategies for ARC systems.

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自串级制冷系统执行器作用过程中混合制冷剂迁移行为及能效研究

使用混合制冷剂的自串级制冷循环（ARC）广泛用于产生低于- 40℃的温度。由于在冷凝器出口汽液分离，ARC系统包含三个不同的流：总流、蒸气流和液体流。这三条河流在质量流速和成分循环浓度上表现出不同的变化。在任何一种流体中，组分分布和运移行为都会随着驱动操作而发生复杂的变化。现有研究仅从压力和温度的变化中获得组分浓度变化关系或推断组分迁移行为。热力学参数变化的根本原因尚未揭示。本文通过实验研究了R600a/R170电弧系统作动器调节过程中成分迁移行为。本研究从成分迁移行为的角度，阐明了执行器运行过程中热力学参数的变化。结果表明，压缩机转速的变化导致循环流量的增大。成分循环浓度呈非单调变化。风机转速的增加加速了混合制冷剂的冷凝。R170的循环浓度从50.4%下降到48.38%。蒸发器前的膨胀阀调节成分和流量，另一个阀门主要控制总流量。当压缩机转速3000r，风机转速1980r，阀门开度分别为30%和50%时，节能效果最佳。研究组分迁移行为为ARC系统的执行机构优化调节策略提供了依据。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Applied Thermal Engineering 工程技术-工程：机械

CiteScore

11.30

自引率

15.60%

发文量

1474

审稿时长

57 days

期刊介绍： Applied Thermal Engineering disseminates novel research related to the design, development and demonstration of components, devices, equipment, technologies and systems involving thermal processes for the production, storage, utilization and conservation of energy, with a focus on engineering application. The journal publishes high-quality and high-impact Original Research Articles, Review Articles, Short Communications and Letters to the Editor on cutting-edge innovations in research, and recent advances or issues of interest to the thermal engineering community.