A New Variable Refrigerant Flow System Simulation Approach in EnergyPlus

Abstract

A variable refrigerant flow (VRF) system is widely applied to build air conditioning systems. Literature review of previous VRF modeling studies was conducted, and it was found that the current calculation approach in EnergyPlus can result in more than 20% deviation in both heat transfer capacity and power consumption. Therefore, a new VRF model is proposed in this study, which includes an improved thermal zone distribution concept, new indoor unit types, and a new thermodynamic model. The developed model is validated with experimental data within 10% in heat transfer capacity and 5% in power consumption. Based on the proposed model, the operation control strategy is also discussed. The results show that the proposed model could also simulate the current control strategy in the VRF system.