Ottimizzazione dei componenti ausiliari nei MCI finalizzata alla riduzione degli inquinanti e delle specie climalteranti

The mean concentration of dioxide carbon and methane gas reached in 2022 the value of 417 ppm and 1894 ppb, respectively; these values are greater with respect of the previous year of about 2.1 ppm and 12 ppb, respectively. The constant growth of global energy demand determinates an increase on pollutants, especially related to fossil fuels usage. The BAU (Business As Usual) scenarios on energy demand show a constant increase of renewable sources and natural gas, while carbon, nuclear and petrol tend to stabilize. From a juridical point of view, Montreal protocol (1987), Kyoto protocol (1997), Paris agreement (2015), Kigali amendment (2016), and pact of Glasgow (2021), have been established limits and gave standards to pollutant emissions; in particular, a set of pollutant chemical families have been detected: carbon dioxide, methane gas, perfluorocarbons, nitrous oxide, hydrofluorocarbons, sulfur hexafluoride. The European regulation on vehicle homologation has been recently changed, with the introduction of WLTC (Worldwide harmonized Light vehicles Test Cycle) procedure, and RDE (Real Drive Emission) test, in order to strictly verify the respect of limits. In this scenario, the present work traduces the sustainability in the Automotive sector into the importance of the electrification of engine auxiliaries, in the transition towards a full electric mobility; in particular, the possibility of substituting the mechanical pump with an electrical driven one. In this way, the pump becomes independent from the engine rotation, and thermal management strategies can be actuated to reduce pollutant concentration. In this work a Jeep Compass has been tested, by installing a complete measure system made of temperature and pressure sensors, and a PEMS (Portable Emissions Measurement System). The tests have been carried out to fully investigate the thermal behavior of the engine during the warm-up phase, dividing two different conditions: cold-start and warm-start. The results show some differences, that can be attributed to the initial thermal state of the engine; in facts, while the initial engine temperature during the cold-start test was about 20 degrees, during the warm-start test the initial engine temperature of about 75 degrees contributes to reduce the duration of the warm-up phase. Consequences on pollutants have been evaluated and related to the engine thermal state. Further considerations have been made on the substitution of the engine pump with an electrically actuated one. The electrical pump presented has been designed with a numerical optimization procedure, that generates the geometry of the impeller and the volute of the pump; with a CFD analysis, the design point has been verified. In this purpose, only a theoretical evaluation on pump control strategies has been discussed. A control strategy has been presented, with the use of a numerical matrix that generates an output value of voltage to the driven pump; the input parameters selected have been cooling fluid temperature and engine velocity. In this way, engine thermal necessities drive directly the pump state. Among the future developments, the possibility of implementing this control matrix take place, together with the evaluation of the consequences on pollutant emissions on RDE tests.