Linear Compressor, Dynamic Characteristics, Numerical Study
Compared to other types of compressors, linear compressors have drawn much attention for this application due to low friction, low power losses and compactness. Very little work was found in the open literature related to the comprehensive dynamic compressor modeling of linear compressors coupled with mechanical and electrical sub-models. This paper presents a comprehensive and generalized simulation model that is used to simulate the dynamic performance of a linear compressor. The model is based on mass and energy balance equations applied to open control volumes. The overall model is composed of several sub-models that include a piston dynamic model, an electrical motor model, a valve dynamic model, and a heat transfer model. When integrated together with an overall energy flow model for the compressor, it is possible to predict piston vibration, temperatures, and pressures within the compressor as well as overall performance. The results of the compressor model are being validated using experimental data from a commercially available linear compressor used in domestic refrigerator/freezers. The predictions by the compressor model have been compared to the measured mass flow rate, motor power and overall efficiencies. The comparisons indicate that the simulation model accurately predicts the compressor performance and can be used to study the performance of this type of compressor. The model will be used to improve the compressor design via parametric studies and to identify key parameters affecting the system transients.