The Hydrogen Vehicle in the Context of the Sustainable Development of the Green Road Transport System

Abstract

Abstract The scientific work presents concrete research carried out by the authors to implement some concepts of technical and managerial nature, so that those interested in this field can get acquainted with a certain way of exposing the problems concerning the hydrogen-powered vehicle, in the context of the sustainable development of the ecological road transport system. At the moment, the car whose energy for propulsion is generated by means of hydrogen or hydrogen fuel cells does not enjoy a high popularity among users, due to the very high purchase price (where we have high technology, we also have a price to match - a fuel cell is more expensive than an electric battery), the reluctance of the population to use this type of fuel, defined by the danger of explosions and fires generated by hydrogen, and the lack of hydrogen refueling stations in Romania and in some European countries. The use of alternative fuels in internal combustion piston engines has the advantage of significantly reducing pollution due to combustion products. With regard to the direct use of hydrogen as a fuel in internal combustion piston engines, we can say that it has proved its inefficiency, because the hydrogen injected or sucked directly into the engine cylinders is unstable, produces uncontrolled burns and detonations, and in the liquid state it is very difficult to store, it requires special transport methods, hydrogen tanks must be armored with Kevlar because hydrogen in the event of a car accident can explode. For example, if we use it as a fuel in a diesel engine, hydrogen may not ignite itself because the self-ignition temperature in the cylinders of compression-ignition engines is high (600°C). However, at a normal stoichiometric ratio, hydrogen has a high flame rate, much higher than gasoline. This creates a thermodynamic cycle of the thermal engine almost perfectly, but ideally, let us not forget that in poor mixtures of air-hydrogen the flame propagation speed is considerably reduced. The compression ratio of the engine is of utmost importance because it is finally defining the thermal efficiency of the engine. In the following, we present a technical and managerial study with engineering nuances, through which readers can look and understand the stage of development, place and role of the vehicle propelled by hydrogen fuel cells. Finally, the conclusions and further directions of research and development in the field addressed are presented.