Author(s)

D. Dvorak, H. Lacher, D. Simic, T. Bäuml

Abstract

In the pursuit of higher energy efficiency, reduced usage of fossil fuels and lower emissions in urban areas, hybrid vehicle technologies are a promising basis for the transportation of refrigerated goods. The goal of the project, described in this contribution, is to develop a refrigerated vehicle for the delivery of goods in urban areas and to design an optimized operating strategy based on hybrid electric technology.

The electrically operated cooling system will be powered by the traction battery of the hybrid vehicle. Independent of the vehicle’s operating mode, the electric energy is always generated at high efficiency. Even in idle periods, or during stop-and-go traffic, full cooling performance can be delivered continuously. The design and optimization will be conducted by a multiphysical simulation of the entire vehicle including all relevant cooling components.

This paper describes the development of a Toyota hybrid vehicle model and the implementation and validation of the operational strategy of the considered vehicle. Efficiency and power of the vehicle are calculated using efficiency maps of the internal combustion engine and the two motor generators. Measured real-life driving cycle data of a company, which distributes fresh organic vegetables and food in Vienna directly to the customer, will be used to compare the performance of the new vehicle concept with ordinary diesel driven refrigerated vehicles.

The proposed hybrid refrigerated vehicle enables significantly higher energy efficiency than the ordinary system. This can be explained by the advantages of a hybrid electric vehicle itself, especially in the setting of urban traffic. Furthermore, the energy generation for the cooling system always works at highest efficiency of the internal combustion engine due to the operating strategy of the hybrid system. The decreased environmental impact and fuel cost savings of the proposed system will be quantified using the developed simulation model.

Keywords

hybrid electric vehicle, urban freight transport, simulation, energy efficiency, driving range