New Turbocharged Hydrogen Engine Tested in the US

Specialists from the Southwest Research Institute (SwRI) in the US have developed and tested an innovative internal combustion engine that uses hydrogen instead of conventional gasoline or diesel fuel. According to ixbt.com, the unit is primarily designed for medium-duty commercial vehicles and is expected to represent an important step toward environmentally friendly technologies. This was reported by Ixbt.com reports .

Unlike vehicles with the fuel cells that are common today, this engine does not convert hydrogen into electricity. Instead, hydrogen burns directly inside the cylinders, driving the pistons. In essence, it is a classic internal combustion engine, but with hydrogen used instead of gasoline as the fuel. Like conventional gasoline engines, it is equipped with a spark-ignition system.

Hydrogen engine retains diesel characteristics

The engineers sought to give the new power unit a key characteristic of diesel engines: high torque at low engine speeds. This performance is considered essential for commercial vehicles. SwRI specialists initially tested the technology in an experimental single-cylinder engine, studying hydrogen combustion characteristics and various injection strategies before transferring the solutions to a full-size multi-cylinder engine.

During development, the specialists had to solve a number of complex problems, including pre-ignition, uneven combustion, and coordinated operation of all systems. The engine was equipped with a turbocharger to deliver the required power at low engine speeds. The turbocharger increased the amount of air entering the cylinders, making it possible to burn more hydrogen and boost torque.

Technical innovations and environmental aspects

Because hydrogen burns much faster than gasoline, the engineers significantly modified the intake system. Since the geometry of a conventional gasoline engine was unsuitable, SwRI developed special intake ports and enlarged valves. These components ensure sufficient airflow and help form the fuel-air mixture more efficiently. Dedicated software monitors engine operation in real time.

Because hydrogen is highly flammable, one of the most difficult tasks was preventing it from igniting spontaneously under the influence of hot components or residual gases before the spark plug fired. Such events can cause uneven engine operation, power loss, and even engine failure. Therefore, a substantial portion of the testing focused on preventing these malfunctions.

From an environmental perspective, hydrogen contains no carbon, so its combustion produces virtually no direct CO₂ emissions and water becomes the main reaction product. However, it cannot be considered completely environmentally friendly because high temperatures can cause nitrogen and oxygen in the air to form nitrogen oxides (NOx). Precise process control and an emissions-treatment system are therefore required.

According to SwRI, the technology's main advantage is that it can preserve existing automotive infrastructure. Manufacturers will not have to completely abandon conventional engines, transmissions, equipment, and service procedures to switch to battery-electric powertrains or fuel cells.