Integrated Cooling/HVAC System Design and Control Strategy for Light Fuel Cell Electric Vehicle

<div>In the recent years, the use of conventional passenger vehicles has been increasingly discouraged, from European-level policies to local municipal regulations, due to the urgent need to reduce greenhouse gas emissions and urban pollution. In response to these challenges, the PRIN2020 project HySUM (<i>Hybrid SUstainable Mobility platform</i>) explores innovative hybrid powertrain solutions for light and heavy quadricycles to achieve near-zero pollutant emissions, focusing on internal combustion engine hybrid electric vehicles and fuel cell hybrid electric vehicles. Taking all these aspects into consideration, this article proposes an integrated solution for cooling/HVAC circuits, to improve energy efficiency and occupants’ comfort, while focusing on proper battery operation, with a recuperator heat exchanger used to recover the available heat at the powertrain output, in order to reduce the HVAC heater energy consumption. The complexity of the circuit requires a specific control logic to be implemented to simultaneously ensure cabin comfort, effective thermal management of the battery, and minimize energy consumption. The study is applied to the HySUM fuel cell/battery hybrid L-class electric vehicle. A thermal and electrical model for predicting the heat generation and the state of charge of the battery under dynamic load profiles is employed to better understand the potential of the thermal integration of the battery cooling with the HVAC system. The simulation results are encouraging and demonstrate the effectiveness of the proposed thermal load management. Significant energy savings are achieved through the use of the recuperator during driving, while battery thermal management is accomplished without the need for a dedicated circuit, by utilizing conditioned air from the HVAC/cabin system. Unlike traditional lightweight electrified vehicles, which often lack efficient HVAC systems, this solution enhances energy efficiency and guarantees reliable component operation in varying environmental conditions.</div>