Research on modeling and control strategy of zero-carbon hybrid power system based on the ammonia-hydrogen engine

Abstract

In the context of carbon neutrality, high efficiency, low carbon, and zero environmental impact have become an essential development direction of internal combustion engines (ICEs). Hydrogen energy has the advantage of having a high calorific value. It also has zero carbon emissions and is considered one of the significant alternative fuels for ICEs. Moreover, ammonia has a high octane number and has an anti-knock effect, which facilitates the mitigation of knock in hydrogen ICEs and potentially mitigates the negative impact of knock on engine volume power. Scholars have carried out some explorations on ammonia-hydrogen ICEs (AHICE), which have been applied in marine power systems. It is anticipated that AHICE will become one of the most significant development directions in the field of vehicle power systems in the future. However, there are still some problems with using AHICEs in passenger cars. The proposed work presented a zero-carbon hybrid power system based on an AHICE. Specifically, the external characteristics curve and power output boundary were obtained by bench experiments of the ICE under wide open throttle (WOT) conditions and diverse engine speeds and λ. Indeed, a hybrid system model consisting of an AHICE and a power battery was built where the AHICE was used to respond to the demanded power and the power battery was used to provide additional power and store the electrical energy converted from braking. Incidentally, an engine control strategy was developed to expand the knock limit and power boundary by dynamically adjusting the ammonia-hydrogen volume ratio. Finally, a hybrid power system simulation model was established based on MATLAB/Simulink. The CLTC-P and WLTC simulation results demonstrated that the zero-carbon hybrid system which comprised AHICE and power battery can work in the high efficiency area. The AHICE demonstrates lower fuel consumption while satisfying power requirements. This work provides a promising route to zero-carbon hybrid technology for the passenger car industry facing the challenge of carbon neutrality.