ASIM, Jan 27
Pratt & Whitney has unveiled its Hydrogen Steam-Injected, Intercooled Turbine Engine (HySIITE) concept, a novel hybrid engine designed to utilize hydrogen fuel for zero-carbon emissions. This concept combines the cryogenic properties of hydrogen with the thermodynamic benefits of steam injection, potentially achieving up to 35% lower energy use compared to current engines. A key advantage is the dramatic reduction in NOx emissions, potentially exceeding 99%, addressing a significant environmental concern associated with hydrogen combustion. The HySIITE project, funded by ARPA-E, focused on component and system design, including hydrogen combustion in a steam-air mix, evaporator design, and water production via condensation.
The HySIITE engine operates differently from conventional turbofans. Air is ingested into a small core at the rear, compressed, and mixed with injected steam before entering the combustor where hydrogen is ignited. The hot exhaust gas is then passed through an evaporator and condensers integrated into the bypass duct, cooling the exhaust and turning it into water. This water is then recycled back to the evaporator and converted into steam for injection into the compressor and combustor. This closed-loop system maximizes heat recovery and boosts efficiency.
Testing of the HySIITE concept has shown promising results, particularly in the combustibility of hydrogen with high steam-air ratios and the efficient production of water as a byproduct. The steam injection not only improves efficiency but also helps control NOx emissions and allows for intercooling within the compressor. Pratt & Whitney is continuing its hydrogen propulsion research through various initiatives, including collaborations with NASA and universities, exploring different aspects of hydrogen engine technology.
