In a combine cycle power plant (gas turbines, heat recovery steam generator and high steam pressure and low steam pressure turbines) there are two methane gas turbines. Each is about two stories high. The gas turbines are designed to take advantage of the inflow air to keep the turbine blades well below the flame temperature.
In 2016, GE manufactured a combined cycle power plant with an efficiency of 62.22%. This went straight into the Guinness World Records as the most efficient at that time. What makes combined cycle power plants so efficient? (araner.com)
When considering the future of LENR one would be wise to consider this benchmark.