The possibility of using methane-hydrogen fuel in converted gas turbine engines for power plants

Given that the topic of using methane-hydrogen mixtures as fuel for gas turbine engines used as part of power plants has been actively developed recently, it is necessary to have engineering methods for calculating the fuel system and the combustion chamber of engines operating on such fuel. In this article, we propose a method that allows to perform such calculations. For the calculation, a gas turbine unit (GTU) NK-16ST based on a converted aircraft engine is taken. The calculation according to this method is made in three stages. At the first stage, the composition is selected and the thermophysical characteristics of the gas in question are determined. At the second stage, the fuel system is calculated, the consumption characteristics of the engine fuel system and the combustion chamber system are built. A comparison of the consumption characteristics built for natural gas and methane-hydrogen mixture is made. This analysis allows us to develop recommendations for optimizing the design of fuel supply equipment and fuel nozzles, in terms of changing the volume of internal channels. At the third stage, the combustion chamber is calculated and recommendations are made about the need to change the front-end device or redistribute air along the length of the flame tube. The burning heat stress parameter is used to estimate the sufficiency of the available volume of the flame tube for operation on a methane-hydrogen mixture and to determine the average gas temperature in the combustion zone of the combustion chamber. According to the result of the work performed the possibility of operating the NK-16ST gas turbine unit on a methane-hydrogen mixture was confirmed. It is also concluded that for the supply of large volumes of methane-hydrogen mixture, in comparison with natural gas, it is necessary to increase the size of pipelines, metering units, control units and fuel nozzles.