关键词: 氨, 化学回热, 微燃机, 热力性能

Abstract: This article constructs an ammonia-fueled micro gas turbine cycle based on chemical recuperation, using energy and exergy analysis methods to evaluate its thermodynamic performance, analyze the reasons for efficiency improvement, and study the impact of key parameters. The study shows that within the parameter range of combustion chamber outlet temperatures of 750—1050℃ and pressure ratios of 3—8, the efficiency of the ammonia-fueled chemical recuperation micro gas turbine cycle can reach 28.8%—41.7%, which is about 1.87—5.61 percentage points higher than that of a methane-fueled micro gas turbine recuperation cycle. The combination of microturbine with chemical recuperation significantly improves efficiency and specific work; the ammonia thermal chemical recuperation system can recover 36%—43% of the exhaust exergy, with the chemical recuperation reactor accounting for more than one-half of this recovery. The exergy recovery by the chemical recuperator is the fundamental reason for the increased cycle efficiency; the micro gas turbine exhaust can increase the molar ratio of H2 in the ammonia decomposition gas to more than 35%, with a maximum of 68%, effectively improving the fuel combustion characteristics; for every 10℃ increase in the chemical recuperation reaction equilibrium temperature difference, the cycle efficiency decreases by about 0.2 percentage points, thus efficient ammonia decomposition in the thermal chemical recuperation reactor is crucial.

Key words: Ammonia, Chemical-recuperated, Microturbine, Thermodynamic performance