HYDROGEN-OXYGEN STEAM GENERATOR FOR A CLOSED HYDROGEN COMBUSTION CYCLE

Abstract

The paper analyzes the problems of combustion hydrogen in an oxygen medium for produce high-temperature steam that can be used to produce electricity at various power plants. For example, at the nuclear power plants, the use of a H2-O2 steam generator as part of a hydrogen energy complex makes it possible to increase its power and efficiency in the operational mode due to steam-hydrogen overheating of the main working fluid of a steam-turbine plant. In addition, the use of the hydrogen energy complex makes it possible to adapt the nuclear power plants to variable electric load schedules in conditions of increasing the share of nuclear power plants and to develop environmentally friendly technologies for the production of electricity. The paper considers a new solution of the problem of effective and safe use of hydrogen energy at NPPs with a hydrogen energy complex.Technical solutions for the combustion of hydrogen in the oxygen medium using direct injection of cooling water or steam in the combustion products have a significant drawback – the effect of “quenching” when injecting water or water vapor which leads to a decrease in the efficiency of recombination during cooling of combustion products that is expressed in an increase fraction of non-condensable gases. In this case, the supply of such a mixture to the steam cycle is unsafe, because this can lead to a dangerous increase in the concentration of unburned hydrogen in the flowing part of the steam turbine plant. In order to solve this problem, the authors have proposed a closed hydrogen cycle and a hydrogen vapor overheating system based on it, and carried out a study of a closed hydrogen combustion system which completely eliminates hydrogen from entering the working fluid of the steam cycle and ensures its complete oxidation due to some excess of circulating oxygen.The paper considers two types of hydrogen-oxygen combustion chambers for the system of safe generating of superheated steam using hydrogen in nuclear power plant cycle by using a closed system for burning hydrogen in an oxygen medium. As a result of mathematical modeling of combustion processes and heat and mass transfer, we have determined the required parameters of a hydrogen-oxygen steam generator taking into account the temperature regime of its operation, and a power range of hydrogen-oxygen steam generators with the proposed combustion chamber design.