Development of the Hydrogen Fueled Internal Combustion Engine for Off-road Applications

In recent years, the reduction of greenhouse gases has emerged as a global challenge, prompting various sectors worldwide to undertake initiatives aimed at achieving carbon neutrality by eliminating overall greenhouse gas emissions. Within the energy sector, hydrogen produced through the electrolysis of water using renewable energy has garnered attention as a promising energy solution. This is due to its suitability for the storage and transport of renewable energy, as well as its low greenhouse gas emissions during combustion. In the automotive market, fuel cell vehicles that convert hydrogen into electrical energy to power motors have already been introduced alongside hybrid and electric vehicles. Conversely, in the off-road market, there are various applications, including construction and agricultural machinery, which often face difficulties in charging due to off-grid usage and limited opportunities for regenerative braking. These issues prevent the full utilization of the advantages offered by electric motors. Consequently, there is an increasing demand not only for options related to batteries and fuel cells but also for a diverse range of power sources tailored to specific applications. Based on these circumstances, we are developing a hydrogen fueled internal combustion engine (HICE) for off-road applications that generates power directly through hydrogen combustion. This HICE is designed to be compatible with currently mass-produced diesel engines used in various off-road applications, facilitating its installation into these applications. Furthermore, to facilitate practical demonstrations within Japan, a port fuel injection system operating within a low-pressure range has been adopted. This design choice enhances ease of handling while ensuring compliance with Japan's stringent regulations regarding high-pressure gases. This paper presents the development approach for the HICE, focusing on compatibility with industrial diesel engines, regulatory considerations, and the unique challenges and solutions identified during the installation of the engine into off-load application.