Analysis of the Flow in the Combustor—Transition Piece Considering the Variation in the Fuel Composition

Abstract

An analysis of the flow that depends on the fuel composition (natural gas) in the combustor–transition piece system, applying computational fluid dynamics, is presented. The study defines the velocity and temperature profiles at the exit of the transition piece and the hot streak along the system. The variation of the composition in the fuel depends of the amount of N2 contained in the fuel, and the hot track influences on the temperature distribution at the input of the first stage of vanes and blades of the gas turbine. The study takes place in a three-dimensional model in steady state using FLUENT® 6.3.26, applying the k-ε turbulence model and chemical equilibrium to the combustion process. The results show the influence of the transition piece geometry over the velocity and temperature profiles, principally, in the radial direction. The velocity profiles on the radial direction can be represented by six order polynomial and the temperature profile by third order polynomial. The temperature and velocity profiles keep a symmetry profile and they can be represented by six order polynomial at the circumferential direction. Knowing these profiles, it is possible to compute a more exact study of the heat transfer at vanes and blades of the first stage of the turbine to evaluate the performance and life of them. On the other hand, considering from 2% to 10% of N2 in the fuel composition, the maximum temperature is reduced in the combustion process and consequently the NOx emissions too.

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Computational Analysis of Cooling Effect with Different Flow Injection Angles On Double Chamber Model

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Local Heat Transfer Coefficient Measurements on an Engine-Representative Internal Cooling Passage

“…T HE continued drive to increase engine efficiency, to lower fuel consumption and environmental impact, has led to a rise in the turbine entry temperature. Raising this further is constrained by the high-pressure (HP) turbine blade and vane material temperatures, in which it has been speculated that a 10-15 K rise in component temperature may reduce blade life by half [1,2]. Improvements in the design of HP turbine blade internal cooling system, while maintaining component life, would allow for an increase in gas temperature and/or a reduction in coolant mass-flow rate; ultimately, both result in a reduction of specific fuel consumption.…”