Research Progress and Challenges of Hydrogen-Ammonia Hybrid Fuel Engines
Shaokai Shen *
North China University of Water Resources and Electric Power, Zhengzhou, 450002, Henan, China.
Jintao Meng
North China University of Water Resources and Electric Power, Zhengzhou, 450002, Henan, China.
Jiaqi Wang
North China University of Water Resources and Electric Power, Zhengzhou, 450002, Henan, China.
Chunjian Zhou
North China University of Water Resources and Electric Power, Zhengzhou, 450002, Henan, China.
Yusen Zhao
North China University of Water Resources and Electric Power, Zhengzhou, 450002, Henan, China.
*Author to whom correspondence should be addressed.
Abstract
In this paper, we review the research status of hydrogen and ammonia engines, and discuss the potential of the two fuels as clean energy sources and their challenges. Hydrogen fuel has attracted attention due to its high energy density and zero-emission characteristics, but hydrogen fuel engines have problems such as increased nitrogen oxide emissions, tempering and early ignition. Ammonia fuel, as a carbon-free alternative fuel, has the advantage of being easy to store, but it is inferior to traditional fuels in combustion performance. This paper further analyzes the research progress of hydrogen/ammonia hybrid fuel engines, highlighting specific challenges such as optimizing the fuel mixture ratio, addressing safety concerns related to hydrogen's flammability and ammonia's toxicity, and overcoming technical difficulties in combustion control, points out the combustion support effect of hydrogen and the influence of ammonia on combustion rate, and discusses the advantages of hybrid fuel engines in emission control. Finally, this paper summarizes the current development trend of hydrogen/ammonia fuel engine technology and puts forward suggestions for future research directions.
Keywords: Hydrogen fuel engines, ammonia fuel engines, hydrogen/ammonia fuel blends, combustion characteristics, emission control, engine efficiency