Control characterization research on compressor in variable refrigerant volume air conditionings

Variable refrigerant volume (VRV) air conditionings have been employed in small and medium-sized buildings recently for its advantages of comfort, energy conservation and easy maintenance. However, the optimal control of VRV air conditionings is very difficult due to cross-coupling system parameters and time-variant operating conditions. In order to study the regulation and disturbance characteristics of indoor and outdoor units in VRV air conditionings, as well as to disclose the inherent laws and coupling features among operating parameters, the flow and heat transfer models of components are built, then the numerical simulations are implemented by using modern calculation method, the responses of operating parameters under the step changes of compressor frequency are presented. Results show efficiency and feasibility of the system modeling, which can make a theory foundation for performance analysis, optimum design and control of VRV air conditionings.