The Ultrahigh Efficiency Gas Turbine Engine With Stator Internal Combustion

Abstract

The current article introduces a physics-based revolutionary technology that enables energy efficiency and environmental compatibility goals of future generation aircraft and power generation gas turbines (GTs). An ultrahigh efficiency GT technology (UHEGT) is developed, where the combustion process is no longer contained in isolation between the compressor and turbine, rather distributed in three stages and integrated within the first three high pressure (HP) turbine stator rows. The proposed distributed combustion results in high thermal efficiencies, which cannot be achieved by conventional GT engines. Particular fundamental issues of aerothermodynamic design, combustion, and heat transfer are addressed in this study along with comprehensive computational fluid dynamics (CFD) simulations. The aerothermodynamic study shows that the UHEGT-concept improves the thermal efficiency of GTs 5–7% above the current most advanced high efficiency GT engines, such as Alstom GT24. Multiple configurations are designed and simulated numerically to achieve the optimum configuration for UHEGT. CFD simulations include combustion process in conjunction with a rotating turbine row. Temperature and velocity distributions are investigated as well as power generation, pressure losses, and NOx emissions. Results show that the configuration in which fuel is injected into the domain through cylindrical tubes provides the best combustion process and the most uniform temperature distribution at the rotor inlet.

Combined numerical and experimental investigations of heat transfer of a highly loaded low-pressure turbine blade under periodic inlet flow condition

“…Although in the current conventional engines the temperature level is not considerably high to cause thermal damages and require extensive heat transfer studies, authors decided to perform such analysis for a number of reasons. With the new and novel stateof-the-art engine design, 2,3 rotor blades, even at lowpressure section of the engine, are exposed to relatively high temperature. Also, the current everincreasing trend in turbine inlet temperature will eventually require LPTs to withstand high temperatures too.…”

The ultra-high efficiency gas turbine engine, UHEGT, part I: Design and numerical analysis of the multistage system

“…Moreover, modern aircrafts are increasingly demanding engines with higher thrust output, smaller size, and lower weight. The Ultra-High Efficiency Gas Turbine (UHEGT), introduced in our previous studies, [1][2][3][4] could help the gas turbine industry to achieve those goals much faster. UHEGT enables reheat process in gas turbines by implementing sequential combustion into multiple stator rows.…”

“…The first stage of a multistage UHEGT was simulated via CFD in our previous study. 1 Different combustor configurations were tested and the optimum was introduced. Some of the important factors in designing the UHEGT and the corresponding background research are discussed herein.…”

“…Further details of this calculation can be found in. 1 Figure 1. Technology change from (a) conventional GT to (b) more advanced GT24/26 and (c) the most advanced engine with UHEGT technology.…”

“…The corresponding TS diagram for each engine is shown on the right; from. 1 The advantages of the reheat process in gas turbines are discussed in multiple studies by Alstom researchers. 5,9,10 In a reheat combustion system, high peak flame temperatures which could lead to exponential increase in NOx are avoided.…”