Approaching the performance limit for economized cycles using simplified cycles

作者：Mathison Margaret M^*; Braun James E; Groll Eckhard A

来源：International Journal of Refrigeration, 2014, 45: 64-72.

DOI：10.1016/j.ijrefrig.2014.05.025

• Multistage system
• Modeling
• Injection
• Energy saving
• Thermodynamic cycle

Modifications such as economization aim to improve the efficiency of vapor compression equipment by cooling the refrigerant during the compression process. A previous study (Mathison et al., 2010) explored the theoretical limit to cycle performance with economizing, which was defined as the performance when a saturated vapor state was maintained in the compressor by continuously injecting a two-phase mixture. However, achieving continuous injection and controlling the quality of the injected refrigerant poses a substantial challenge. Therefore, the current paper investigates the ability of an economized cycle with saturated vapor injection through a finite number of ports to approach the limiting cycle performance. For an air-conditioner using R-410A with an evaporation temperature of 5 degrees C and a condensing temperature of 40 degrees C, the model predicts that injecting saturated vapor through three ports will improve the COP by 12%, which is approximately 67% of the maximum benefit provided by economizing in the limiting case.

• 出版日期2014-9