VRF, electric buses, variable capacity, dynamic simulation, public transportation
Based on test data from an electric bus manufacturer, HVAC systems will consume nearly 30% of the available energy in fully electrically operated public transport buses, which heavily decreases the bus mileage. Therefore, improvements for the bus HVAC system structure are needed. In contrast to conventional electric bus HVAC systems, a VRV (variable-refrigerant-volume) system will be simulated as HVAC system. The compressors provide adequate power depending on the requirements from the different heat exchanger units inside the bus cabin. This system will provide either cooling or heating capacity depending on the needs of the target space. Therefore, the energy consumption of the compressors will be reduced This paper will present a dynamic EES simulation model of a VRV system applied in an electric public transportation bus. Goal of this simulation is, to simulate and design the specifications of the VRV HVAC system with given system performance requirements. The bus model and the simulation results will be described in detail in this publication. This project has been developed in collaboration between the Automotive Research and Testing Center of Taiwan (ARTC) and the University of Applied Sciences in Buchs (NTB).