Comparative Analysis of Typical Improvement Methods in Transcritical Carbon Dioxide Refrigeration Cycle

In this paper, five kinds of typical improvement methods for the performance of SC cycle are compared and analyzed using the developed thermodynamic model based on the first and second laws of thermodynamics. The results shows that SCE cycle has a most positive effect. The COP of SCSLHX cycle only has an increase of 15% in high temperature conditions, conversely TCFGB cycle can improve by 15% and 28% in common and low temperature conditions. TCIGc cycle has a middle but stable increase of 14%similar to 21%, and margin improvement of TCIC cycle is less than 10% in research conditions. The exergy analysis reveals that SCE, SCSLHX, TCFGB and TCIGc cycles improve the COP mainly by reducing throttling losses, while the improvement of COP for TCIC cycle is mainly achieved by reducing the loss of gas coolers. Furthermore, the exergy loss of each component in each cycle is also quantified. (C) 2017 The Authors. Published by Elsevier Ltd.