A SIMULATION STUDY OF MIXED REFRIGERANT ABSORPTION REFRIGERATION SYSTEM USING DIFFERENT ABSORBENTS

Abstract

The performance of a mixed refrigerant absorption refrigeration cycle was studied to explore the feasibility to achieve an ultra-low range of chiller temperatures. The use of ethane-propene refrigerant mixtures with different compositions in combination with a wide range of hydrocarbon solvents were simulated using ASPEN HYSYS software. A parametric study was conducted for identifying the optimal operating conditions for each targeted evaporator temperature. The results revealed that the performance of the studied mixed refrigerant is generally enhanced at conditions of low absorption temperature and/or low condenser temperature. Chiller temperature in the range of -60 to -90 °C was revealed to be achievable using a cascade refrigeration system with a COP in the range of (0.18 to 0.32). The optimal absorbent for most of the studied mixture compositions, regarding maximal COP, and minimal (PP/QE), was found to be MCC5. However, commercial solvents in the same carbon atom range were proved to offer about the same performance at the optimal disclosed operating conditions. The proposed system was found to achieve electrical power savings in the range of 15-53% of that would be consumed by a VCRS for the same chiller duty and temperature as operating under the same conditions, depending on %ethane in the