Capacity control of a heat pump system applying a fuzzy control method

This paper presents the capacity control of a heat pump system using the discharge superheating of the compressor, concerns the design of a fuzzy controller for a heat pump at the outlet of a compressor and compares an optimized fuzzy controller with one that is not optimized. The design of a controller is based on a proper system identification model which determines the system modeling from inputs and outputs and completes the state-space system modeling. The type of input signals is pseudo-random binary sequence and the order of system is 7. The fuzzy controller is selected to modulate the discharge superheating of the compressor, and then, genetic algorithm is used as a searching tool for obtaining the optimized fuzzy rule table. The experiment results show that the optimized fuzzy controller makes undershoot and overshoot alleviated significantly in the discharge superheating, outlet temperature of secondary fluid and refrigerant mass flow rate.