A Graph-Based Approach for Dynamic Compressor Modeling in Vapor Compression Systems

Vapor compression systems are widely used as thermal management systems. To satisfy thermal demands, models are used to control and optimize the system’s performance, reliability, and efficiency. Significant effort has been made to model the condenser and evaporator, while there has been minimal focus on control-oriented modeling of the compressor. Initial work illustrates that during transient behavior, the working fluid exhibits a fast dynamic. However, during a startup and shutdown sequence, the working fluid follows a slower dynamic believed to be associated with heat transfer to the shell. To address both thermal dynamics, a graph-based modeling approach is used to incorporate the compressor shell’s thermal capacitance into the model. Experimental and simulation data are compared for a range of operating conditions including shutdown and startup dynamics.