Sistema adattivo ad alta efficienza per il comfort del passeggero della mobilità elettrica

In traditional vehicles, the internal combustion engine generates a large amount of waste heat that can be recovered to heat up the passengers' cabin. In Electric Vehicles (EVs) this waste heat is not available due to the high efficiency of the traction motor. Thus, to heat the cabin, alternative methods must be used. Current heating technologies, namely Positive Temperature Coefficient (PTC) effect heaters and heat pumps, are responsible for a reduction of up to 50% in range during cold climate conditions, aggravating the so-called "range anxiety" problem and thus representing one of the major obstacles to the process of electrification of the mobility sector. This work aims at investigating and developing an alternative heating system based on surface heating panels for reducing the power consumption as well as improving the passengers' comfort. The first chapter of the thesis gives an overview on the latest trends in the transportation sector, from government policies and incentives to promote the adoption of electric vehicles to the analysis of the available data on various topics, such as vehicles registrations and shares per type and geographical region. The second chapter focuses on the current heating technologies employed in electric vehicles. Here, a detailed description of the working principle of ceramic PTC heaters and heat pump systems is given along with the main advantages and limitations of these technologies. The third chapter is dedicated to an overview of the proposed heating system based on resistive surface heaters. The chapter starts from a general description of the concept and deals with its scientific background. Furthermore, some relevant details about the ergonomics of the thermal environment found in standards and technical regulations are reported. The fourth chapter deals with the finite element simulations of the novel heating concept, describing all the study steps and analyzing the results in detail. The geometrical dimensions utilized for the finite element model are based on a real test vehicle, namely a Volkswagen ID.3, that was also used for the subsequent experimental phase. In the fifth chapter, the design of etched foil heating elements for the Volkswagen ID.3 is discussed, starting from a brief description of the design process and following with the detailed explanation of each phase of the process, including analytical design, finite element simulations, manufacturing and testing of the prototypes in the laboratory. The sixth chapter focuses on the experimental tests of the Volkswagen ID.3 equipped with the etched foil heating system. The tests were conducted in controlled climate conditions recreated inside a custom climatic chamber. Experimental results are reported and discussed at the end of the chapter. The seventh chapter is dedicated to the development of a second type of resistive surface heaters based on the positive temperature coefficient (PTC) ink technology. After a brief explanation of the working principles, the manufacturing process and the effects of each design choice are described. Then, a custom test sequence for the quality control of PTC ink heaters is detailed, together with some practical examples. In the last part of the chapter, the focus shifts to a new co-printing / thermoforming process that was developed to integrate PTC ink heaters into car interior parts made of sustainable materials. Also, the main motivations behind the choice of PTC ink heaters over other heating technologies is given. Finally, chapter eight draws some conclusions and describes possible future developments of the project.