A study of ammonia-hydrogen-electricity cogeneration coupled to a very high-temperature heat source

•A novel ammonia-hydrogen-electricity cogeneration system was proposed.•The hydrogen-electricity cogeneration systems with a VHTR were reviewed.•The energy of high-temperature oxygen was used for ammonia production.•The total efficiency was improved by coupling the ammonia production. Nuclear hydrogen production is recognized as a promising way of achieving large-scale hydrogen production. However, the high product temperature increases the cost of conventional high-pressure or liquid hydrogen storage and transportation. Ammonia shows considerable promise as a hydrogen carrier. However, vast heat is required in the ammonia production process. Therefore, this paper proposes a model of ammonia production by nuclear heat. The relatively higher grade thermal energy from the reactor is applied for hydrogen production, and the lower is for electricity generation. High-temperature oxygen, a by-product, provides heat for the Haber-Bosch process, converting hydrogen into ammonia and achieving reasonable cascade utilization of energy. The results show that the thermal efficiency production reaches 67.8%. The total energy efficiency increases by 7.5% after introducing ammonia production.