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Electric vehicles have never been more popular, yet fears around being left stranded by an exhausted battery remain a key reason why some car buyers resist making a purchase. Bigger batteries are not always the solution because of the direct link with higher costs and high impact on weight. A re-engineering of the most energy-consuming auxiliaries is mandatory and the thermal management function is on top of the redesign request list. Heat pump solutions are considered one of the best options to save energy and reduce the impact on vehicle range of heating and cooling functions, but the automotive application requires a careful definition of the system features to avoid unjustified increase of complexity as well as an unneeded system oversizing.

With the passage of the Kigali Amendment to the Montreal Protocol, HFC-134a refrigerant will be phased down in all markets worldwide, including those where automotive companies have been slow to embrace HFO-1234yf. Engineers are currently being challenged to design MAC systems using alternate low GWP refrigerants that are allowed by regulations, and are simultaneously cost-effective to manufacture, energy efficient, safe, reliable, affordable for consumers, and also suitable in electrified vehicles.

The CO2 emission regulations ask a dramatic fuel consumption reduction worldwide. In this scenario, the market penetration of BEVs and PHEVs is strictly related to their electrical driving range, which is strongly affected by the ambient conditions and the passenger comfort asking for an effective thermal management that becomes an opportunity for overcoming these barriers. In this context, a virtual analysis comparing different cooling and heating architectures has been conducted; efficiency and costs aspects have been considered as driving factors as well as the lay-out aspects and vehicle integration constrains which drive component selection and influence the performance. In order to perform a robust architecture comparison and obtain more reliable results, a vehicle thermal model has been developed. The model takes into account the main thermal load contributes and the simulations which have been performed considering different selected cases.

Automotive world is rapidly changing driven by the CO2 emission regulations [1], [2] worldwide asking for a dramatic fuel consumption reduction. The on board thermal management has a relevant role influencing the front vehicle design and sizing to assure the right heat rejection capacity and being crucial to guarantee the on board system efficiency and reliability. In this context the dual level cooling system with water cooled charge air cooling is a clear trend leading to a new generation of systems [3, 4]. This paper describes a compact solution to effectively implement a dual cooling loop system with water cooled charge air cooler and water cooled condenser on small/subcompact cars giving the opportunity to integrate additional modules (e.g. in case of hybrid powertrain) to the secondary loop.

In perspective of the incoming CO₂ emission regulation, the on-board heat management is becoming even more relevant to assure the engine performance improvement minimizing the impact on the vehicle lay out, cooling drag and cost. The paper highlights the benefit of dual-level heat rejection system where the conventional front module is replaced by two coolant-to-air exchangers and where the charge air cooler and condenser are liquid-cooled. This approach allows to review the engine bay design allowing a deeper integration level: the charge air cooler can be integrated in the air intake manifold while the condenser can be placed near the compressor minimizing the tube lengths and refrigerant charge. In addition, the coolant thermal inertia reduces the temperature fluctuations of the engine intake air temperature.