Performance analysis of the ammonia-enriched hydrogen-fueled Wankel rotary engine

Under the background of carbon neutral, hydrogen-fueled Wankel rotary engine (WRE) with high power density and compact layout has the potential to become a substitute for current fossil engines. Ammonia as a carbon-free renewable energy is considered alternative energy used in vehicles, however, its application on WRE is lacking. Therefore, the present work aims to investigate the performance of ammonia-enriched hydrogen-fueled WRE to analyze the feasibility of ammonia applied in hydrogen-fueled WRE. The main conclusions are as follows: Under test conditions, the maximum brake torque and thermal efficiency are obtained at about 30% and 40% volume fraction of ammonia in fuel, and compared with pure hydrogen conditions, achieving relative improvements of 21% and 29%, respectively. Slightly rich combustion is recommended to increase power and decrease NO emissions with an acceptable economic loss. In addition, ammonia enrichment can prevent the occurrence of abnormal combustion.