Thermodynamic investigation of a booster-assisted ejector refrigeration system

• COP based on thermal input increases with booster outlet pressure.
• Both entrainment ratio and area ratio increase with booster outlet pressure.
• COP based on work is larger than compressor-based refrigeration system.
• An optimum booster outlet pressure obtains maximum COP based on work.
• Exergy destruction occurs mainly in ejector, condenser, evaporator and generator.

In order to improve performance of ejector refrigeration system, a booster is added before an ejector to enhance secondary flow pressure, which is called a booster assisted refrigeration system. Based on mass, momentum and energy conservation, a 1D model of ejector for optimal performance prediction was presented and validated with experimental data. A detailed study of working characteristics of the booster assisted ejector refrigeration system was carried out and compared against conventional ejector refrigeration system and compressor based refrigeration system, on the basis of first and second laws of thermodynamics. Effects of booster outlet pressure on COPth based on thermal energy and COPw based on work input, and also on entrainment ratio and area ratio of ejector were studied. The exergy destruction rates were also computed and analyzed for components of the booster-assisted ejector refrigeration system. Ways to reduce exergy destruction were discussed.