Modeling, analysis, and experimental validation of a swash plate compressor for automotive air conditioning

This paper presents a comprehensive study of a swash plate compressor, integrating both theoretical modeling and experimental validation. A mathematical model is developed to precisely describe the swash plate's motion and to derive the average power input to the compressor. This derivation considers the compressor's geometric parameters and angular speed under various operating conditions. Complementary to the theoretical analysis, an experimental investigation of an automotive air conditioning system equipped with a swash plate compressor was conducted. Both theoretical and experimental findings consistently demonstrate that the average power consumed by the swash plate compressor is primarily dependent on the swash plate inclination angle, rotational speed, and system pressure. A key conclusion drawn from this research is the critical importance of a small swash plate inclination angle. Such an angle is shown to be essential for minimizing power losses attributed to friction between the slipper and the swash plate, thereby reducing the overall shaft power required by the compressor. Furthermore, for design scenarios demanding both a long stroke and minimal shaft power for the swash plate compressor, the present analysis provides a crucial framework for selecting the optimal inclination angle and stroke length. Experimental results indicate that achieving high coefficients of performance (COP) and volumetric efficiencies necessitates low rotational speeds, high cooling capacities, and a reduced shaft power per unit mass flow rate of refrigerant. The coefficient of performance relative to the corresponding Carnot cycle is observed to decrease hyperbolically with an increase in the shaft power per unit mass flow rate of refrigerant. Importantly, the calculated shaft power values from the theoretical model provides a reasonable approximations agreement with those obtained from a simulation program developed by the compressor's manufacturer [8] across various operating conditions.