Hydrogen-powered refrigeration system for environmentally friendly transport and delivery in the food supply chain

Abstract

Urban population and the trend towards online commerce leads to an increase in delivery solution in cities. The growth of the transport sector is very harmful to the environment, being responsible for approximately 40% of greenhouse gas emissions in the European Union. The problem is aggravated when transporting perishable foodstuffs, as the vehicle propulsion engine (VPE) must power not only the vehicle but also the refrigeration unit. This means that the VPE must be running continuously, both on the road and stationary (during delivery), as the cold chain must be preserved. The result is costly (high fuel consumption) and harmful to the environment. At present, refrigerated transport does not support full-electric solutions, due to the high energy consumption required, which motivates the work presented in this article. It presents a turnkey solution of a hydrogen-powered refrigeration system (HPRS) to be integrated into standard light trucks and vans for short-distance food transport and delivery. The proposed solution combines an air-cooled polymer electrolyte membrane fuel cell (PEMFC), a lithium-ion battery and low-weight pressurised hydrogen cylinders to minimise cost and increase autonomy and energy density. In addition, for its implementation and integration, all the acquisition, power and control electronics necessary for its correct management have been developed. Similarly, an energy management system (EMS) has been developed to ensure continuity and safety in the operation of the electrical system during the working day, while maximizing both the available output power and lifetime of the PEMFC. Experimental results on a real refrigerated light truck provide more than 4 h of autonomy in intensive intercity driving profiles, which can be increased, if necessary, by simply increasing the pressure of the stored hydrogen from the current 200 bar to whatever is required. The correct operation of the entire HPRS has been experimentally validated in terms of functionality, autonomy and safety; with fuel savings of more than 10% and more than 3650 kg of CO2/year avoided.