EXPERIMENTAL STUDY ON ENHANCING ENERGY EFFICIENCY AND MITIGATING ENVIRONMENTAL IMPACT OF AN AUTOMOTIVE ENGINE THROUGH HYDROGEN INJECTION INTO THE AIR INTAKE SYSTEM

Abstract

Currently, global energy demands are primarily met by fossil fuels, which are expected to be depleted in the near future. Additionally, the cost of these fuels has been rising due to increased demand and improved economic conditions in some countries. The growing reliance on fossil fuels has significantly contributed to the escalation of global warming and air pollution. Hydrogen, with its high-octane rating and substantial calorific value, enhances thermal efficiency in internal combustion engines. Moreover, hydrogen’s lack of carbon bonds means that it reduces carbon monoxide (CO) and carbon dioxide (CO₂) emissions when mixed with gasoline. Therefore, the research and development of hydrogen-gasoline-powered internal combustion engines (ICE) holds promising potential. In this context, the present study proposes an experimental investigation aimed at enhancing energy efficiency and reducing the environmental impact of a gasoline-powered automotive engine through the injection of hydrogen into the air intake system. The primary challenge faced by the automotive industry is the development of efficient propulsion systems that emit lower levels of pollutants, which serves as the motivation for this study. For this work, an experimental test bench was constructed using a Ford Zetec Rocam 1.0 gasoline engine (1000cc), incorporating hydrogen injection into the air intake manifold. The engine was not modified for the gasoline-hydrogen mixture, and the ignition timing was left unchanged, remaining consistent with that of gasoline. Performance evaluations were conducted at 1000, 2000, and 3000 rpm, with air parameters set at 30°C dry bulb temperature and 77% relative humidity. The addition of hydrogen increased the total energy and accelerated the combustion reaction of the mixture, resulting in an improvement in thermal efficiency of 10%, 9% and 9% for 1000, 2000, and 3000 rpm, respectively. This enhancement led to higher peak combustion pressure and elevated temperatures, which, in turn, increased specific NOx emissions of 47%, 33% and 36% for 1000, 2000, and 3000 rpm, respectively. However, emissions of CO were reduced of 15%, 13% and 13% for 1000, 2000, and 3000 rpm, respectively, emissions of CO₂ were reduced of 10%, 13% and 13% for 1000, 2000, and 3000 rpm, respectively, and emissions of HC were reduced of 14%, 15% and 17% for 1000, 2000, and 3000 rpm, respectively. A technical analysis of the engine revealed that the combustion of the gasoline-hydrogen mixture generates high thermal loads, which can damage the catalyst, the upper piston region, cylinder rings, and the combustion chamber, as well as the subsystems and auxiliary mechanisms. These findings highlight the need for the development and application of new technologies and materials specifically designed for this type of hybrid engine.