VRF System, Simulation, COP, Heat pump, Optimization
Due to worldwide demand for energy saving, many new technologies have been developed in the air conditioning field. Packaged indoor unit and outdoor unit vapor compression refrigerating heat pump system using the change of refrigerant’s condition between liquid and gas is a recently developed air conditioning system. The cooling cycle is composed of an evaporator, a condenser, a compressor, an accumulator, pipe and an expansion valve. These components are controlled by the equation of continuity, the equation of energy and the equation of motion and so on. We can solve these equations by giving numerical boundary conditions. In this study, we create the simulation model applied the cooling cycle using theory of modular analysis. In this theory we classify the components into some kinds of module and we structure equations of each component individually and connect by physical continuity and initial condition. To verify the accuracy of simulation model, we tested this system in the stable environmental facility. We set more than 300 sensors of temperature, pressure and quantity of flow. We can analyze the change of the conditions of refrigerant per a couple of seconds. Compared to experimental data and the solution of simulation model, we certain accuracy of model and analyze the influence of the ability of machinery and COP. As a result, we made sure that the constructed simulation model could predict actual behavior of systems. Now we focused the heat exchangers at indoor units and outdoor unit, and we calculated the adequate foam of refrigerant flowing paths by cooling cycle and heating cycle.