1 dimensional design and optimization, Micro-centrifugal compressor, R600a
Miniature compressors play an important role in compact air conditioning systems. Its small size means smaller weight and less material cost. Centrifugal compressors do not have displacement volume and has only one major moving part, which makes it a good candidate for miniature compressor. Typical residential air conditioning systems use R410A as refrigerant due to its good thermodynamic properties and no ozone depletion potential. However, its global warming potential is even higher than that of R22. In addition, it requires high operating speed for a centrifugal compressor. One alternative for R410A is R600a. It has good thermodynamic performance and low impact on environment. Also, its operating pressure is much lower than that of R410A and it requires lower rotational speed. In this paper, a one-dimensional design was performed for a micro-centrifugal compressor for an air conditioning system which has 7 kW cooling capacity and uses R600a as the refrigerant. Furthermore, a single-objective optimization was performed to improve its efficiency using the genetic algorithm. The simulation result shows that the obtained design has 69.7% isentropic efficiency and 2.74 pressure ratio at 250 KRPM.