Application of Hydrogen–Oxygen Steam Generators for Secondary Flash Steam Superheating at Geothermal Power Plants

Abstract

One of the promising areas of applying hydrogen technologies in power engineering is to increase the capacity utilization factor and efficiency of turbine units by means of hydrogen–oxygen steam generators for superheating the working medium under the conditions in which the surplus electricity generated at power plants during the periods of daily and seasonal reduction in electric power consumption can be used for generating hydrogen. The use of steam superheating systems on the basis of hydrogen–oxygen steam generators at geothermal power plants is especially important in view of a low energy potential of geothermal heat carrier serving as the initial heat source. The article presents the results from computational studies of the technical advisability and technical-economic efficiency of implementing systems for increasing the secondary flash steam energy potential by using a hydrogen–oxygen steam generator and a binary power unit at a direct-cycle geothermal power plant operating on steam hydrotherms. The results from computational studies into the power characteristics of a combined binary cycle geothermal power plant with secondary flash steam superheating depending on the expansion pressure variations and the hydrogen–oxygen steam generator capacity are considered. It has been determined that the use of a 12-MW hydrogen–oxygen steam generator for superheating secondary flash steam results in that the steam wetness downstream of the steam turbine last stage decreases from 14 to 7%. Calculation results have shown that the topping of a direct-cycle geothermal power plant with a system for increasing the energy potential of secondary flash steam on the basis of a hydrogen–oxygen steam generator and a binary power plant makes it possible to increase the geothermal power plant capacity by almost 25% and its efficiency by 3.0–3.5%. Based on the feasibility study results, investors can select the optimal composition and characteristics of equipment in implementing a system for increasing the energy potential of secondary flash steam using a hydrogen–oxygen steam generator and a binary power unit at a direct-cycle geothermal power plant.