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The dynamic performances of the cooling circuit have a great impact on ICE efficiency and CO2 emissions. Engine thermal management is among the most promising technologies able to offer a sensible reduction in terms of engine fuel consumption and CO2 emission. These aspects are widely treated in literature and many technologies are already on the market or ready to be used. A reduced attention in literature, has been done on the pump performances during the real operating conditions. Homologation cycles try to reproduce these conditions. In light duty vehicles these cycles consist in accelerating and decelerating the engine following a specified velocity-time sequence. According to this procedure, the propulsion power requested by the vehicle is low, and the power absorbed by the auxiliaries became significant. The pump of the cooling fluid is the most important component among the auxiliaries.

The growing interest on environmental issues related to vehicles is pushing up the research on reciprocating internal combustion engines which seems to be endless and able to insure to combustion engines a long future. Euro standards imposed a significant reduction of pollutant emissions and were the stimulus to favor the conception of technologies which represented real breakthroughs; the recent directives on greenhouse gases emissions further reinforced the concept of reducing fuel consumption and, consequently, carbon dioxide emissions. So, new technological efforts have to be made on internal combustion engines in order to achieve this additional target: several technological options are already available or under studying, but only a few of these are suitable, in particular, in terms of costs attendance per unit of CO2 saved. Among these technologies, a revision of engine cooling system seems to have good potentiality.

Waste Heat Recovery (WHR) is one of the most viable opportunities to reduce fuel consumption and CO2 emissions from internal combustion engines in the transportation sector. Hybrid thermal and electrical propulsion systems appear particularly interesting because of the presence of an electric battery that simplifies the management of the electrical energy produced by the recovery system. The different technologies proposed for WHR can be categorized into direct and indirect ones, if the working fluid operating inside the recovery system is the exhaust gas itself or a different one whose sequence of transformations follows a thermodynamic cycle. In this paper, a turbocharged diesel engine (F1C Iveco) equipped with a Variable Geometry Turbine (VGT) has been tested to assess the energy recoverable from the exhaust gases both for direct and indirect recovery.

In the perspective of fuel saving and emissions reduction, engine oil thermal management has not yet received the attention it deserves. Lubricating oil, in fact, should be the focus of a specific warmup action: the expected benefits is on friction reduction – mechanical efficiency improvement – but also on a positive interaction with the cooling fluid thermal dynamics. The lower thermal capacity of the circulating oil (with respect to the cooling fluid) and the instantaneous reduction of the viscosity due to temperature increase produces a faster engine overall efficiency benefit: this invites to focus specific actions on its thermal management in the direction of speeding up the temperature rise during a cold engine starting.

Fuel saving and, consequently, CO2 emissions reduction are the main driver of internal combustion engine development for the transportation sector. Among the several technological options presently available for this purpose, those related to thermal management and, in particular, engine cooling optimization, seem to have additional value thanks to their easiness to be applied on board, without invasive modification of the engine and the vehicle. Typically, centrifugal pumps are adopted, but their efficiency is highly dependent on their revolution speed, suffering of it during real operation. Volumetric pumps can overcome this issue, having an efficiency ideally independent on rotational speed. In this work, triple-screw pump has been considered as a technological replacement for the centrifugal one, since it is a consolidated technology in other sectors, but never considered in engine cooling.

In modern turbocharged internal combustion engines the cooling of the air after the compression stage is the standard technique to reduce temperature of the engine intake air aimed at improving cylinder filling (volumetric efficiency) and, therefore, overall global efficiency. At present, standard values for the intake air temperature are in the range 30-70°C, dependently on engine load, external air conditions and vehicle speed and the adoption of a dedicated cooling fluid operating at low temperatures (-10-0°C) is addressed as the most viable option to achieve an effective temperature reduction. This paper investigates a pilot engine set-up, featuring an evaporator on the intake line of a turbocharged diesel engine, tested on a high speed dynamometer bench: the evaporator was a part of an air refrigeration unit – the same used for cabin cooling - composed also by a compressor, a condenser and a thermostatic expansion valve.

The need for even more efficient internal combustion engines in the road transportation sector is a mandatory step to reduce the related CO2 emissions. In fact, this sector impacts significantly on greenhouse gases worldwide, and the path toward hybrid and electric powertrains has just begun. In particular, in heavy-duty vehicles the full electrification of the powertrain is far to be considered as a really feasible alternative. So, internal combustion engines will still play a significant role in the near/medium future. Hence, technologies having a low cost to benefits (CO2 reduction) ratio will be favorably introduced in existing engines. Thermal management of engines is today a recognized area of research. Inside this area, the interest toward the lubricant oil has a great potential but not yet fully exploited. Engine oil is responsible of the mechanical efficiency of the engine which has a significant potential of improvement.

Reducing CO2 emissions in on-the-road transport is important to limit global warming and follow a green transition towards net zero Carbon by 2050. In a long-term scenario, electrification will be the future of transportation. However, in the mid-term, the priority should be given more strongly to other technological alternatives (e.g., decarbonization of the electrical energy and battery recharging time). In the short- to mid-term, the technological and environmental reinforcement of ICEs could participate in the effort of decarbonization, also matching the need to reduce harmful pollutant emissions, mainly during traveling in urban areas. Engine thermal management represents a viable solution considering its potential benefits and limited implementation costs compared to other technologies. A variable flow coolant pump actuated independently from the crankshaft represents the critical component of a thermal management system.