scholarly journals Test Program for High Efficiency Gas Turbine Exhaust Diffuser

2009 ◽  
Author(s):  
Thomas R. Norris
Author(s):  
Lothar Bachmann ◽  
W. Fred Koch

The purpose of this paper is to update the industry on the evolutionary steps that have been taken to address higher requirements imposed on the new generation combined cycle gas turbine exhaust ducting expansion joints, diverter and damper systems. Since the more challenging applications are in the larger systems, we shall concentrate on sizes from nine (9) square meters up to forty (40) square meters in ducting cross sections. (Reference: General Electric Frame 5 through Frame 9 sizes.) Severe problems encountered in gas turbine applications for the subject equipment are mostly traceable to stress buckling caused by differential expansion of components, improper insulation, unsuitable or incompatible mechanical design of features, components or materials, or poor workmanship. Conventional power plant expansion joints or dampers are designed for entirely different operating conditions and should not be applied in gas turbine applications. The sharp transients during gas turbine start-up as well as the very high temperature and high mass-flow operation conditions require specific designs for gas turbine application.


Author(s):  
Yuso Oki ◽  
Hiroyuki Hamada ◽  
Makoto Kobayashi ◽  
Isao Yuri ◽  
Saburo Hara

Coal is regarded as important fuel because of its stable supply and low price, but coal is blamed for its CO2 emission. Japanese utilities are making efforts to improve thermal efficiency and to expand biomass co-firing. On the other hand, CCS technologies are under development as a countermeasure for global warming and demonstration projects planned in several power stations are announced in world wide. As CO2 capture from power station requires huge in-house power, thermal efficiency is deteriorated. To make a breakthrough, NEDO started a project to develop the high-efficiency oxy-fuel IGCC system. This system recirculates gas turbine exhaust gas to both gasifier and gas turbine combustor. Recirculated exhaust gas is used both to feed pulverized coal to gasifier and to dilute syngas in gas turbine combustor. The target efficiency is 42% at HHV basis, equivalent to state of the art coal-fired power station. Various studies were done to confirm the concept of this system and to develop fundamental technologies necessary for the system since 2008 to 2014 as NEDO project. Based on the achievements, the project made another step since 2015 as a five-year joint NEDO project with MHI and MHPS. This paper introduces the latest status of this project executed by CRIEPI by referring several related papers.


Author(s):  
Norihiko Iki ◽  
Atsushi Tsutsumi ◽  
Yoshiaki Matsuzawa ◽  
Hirohide Furutani

IGCC achieve high efficiency energy conversion from coal to electricity. However its efficiency is below 50% [HHV]. To achieve higher efficiency, Advanced IGCC was planned by using exergy-recuperation concept. Advanced IGCC requires many breakthroughs in technology. Advanced IGCC achieve high efficiency by using the heat of reformed gas and the application of the autothermal reaction in the gasifier. Authors try parametric study of Advanced IGCC to figure out the desirable consists of Advanced IGCC. The performance of Advanced IGCC depends on coal, gasifier condition, configuration of components, etc. The heat value of the supplied coal is 667MW [HHV]. Foreign subbituminous coal is selected as standard fuel. The adiabatic efficiencies of the compressor, the gas turbine, steam turbine and condensing turbine at standard condition were defined so that the efficiency of IGCC with 1500 °C class gas turbine is 48% [HHV] with high performance gasifier. The efficiency of IGCC reaches to 52% [HHV] by applying autothermal reaction in the gasifier. This system requires the extra heat supply in order to hold the autothermal reaction condition in the gasifier. Therefore the net efficiency of this system is about 44% [HHV]. The net efficiency of the advanced IGCC is 48% [HHV]. On the other hand, 1700 °C class advanced IGCC can achieve 51% [HHV] net efficiency and its gas turbine exhaust high temperature heat to hold autothermal reaction condition. Increase of the adiabatic efficiencies of the compressor and the gas turbine enables the high efficiency of the advanced IGCC. If the adiabatic efficiency of compressor reaches to 87% and adiabatic efficiency of the gas turbine reaches to 92%, 1700 °C class advanced IGCC has the potential of over 60% [HHV].


1974 ◽  
Vol 96 (3) ◽  
pp. 181-184 ◽  
Author(s):  
J. R. Cummins

To investigate the sources of acoustic radiation from a gas turbine exhaust, a one-seventh scale model has been constructed. The model geometrically scales the flow path downstream of the rotating parts including support struts and turning vanes. A discussion and comparison of different kinds of aerodynamic and acoustic scaling techniques are given. The effect of the temperature ratio between model and prototype is found to be an important parameter in comparing acoustical data.


Author(s):  
Orlando Ugarte ◽  
Suresh Menon ◽  
Wayne Rattigan ◽  
Paul Winstanley ◽  
Priyank Saxena ◽  
...  

Abstract In recent years, there is a growing interest in blending hydrogen with natural gas fuels to produce low carbon electricity. It is important to evaluate the safety of gas turbine packages under these conditions, such as late-light off and flameout scenarios. However, the assessment of the safety risks by performing experiments in full-scale exhaust ducts is a very expensive and, potentially, risky endeavor. Computational simulations using a high fidelity CFD model provide a cost-effective way of assessing the safety risk. In this study, a computational model is implemented to perform three dimensional, compressible and unsteady simulations of reacting flows in a gas turbine exhaust duct. Computational results were validated against data obtained at the simulated conditions in a representative geometry. Due to the enormous size of the geometry, special attention was given to the discretization of the computational domain and the combustion model. Results show that CFD model predicts main features of the pressure rise driven by the combustion process. The peak pressures obtained computationally and experimentally differed in 20%. This difference increased up to 45% by reducing the preheated inflow conditions. The effects of rig geometry and flow conditions on the accuracy of the CFD model are discussed.


Author(s):  
W. V. Hambleton

This paper represents a study of the overall problems encountered in large gas turbine exhaust heat recovery systems. A number of specific installations are described, including systems recovering heat in other than the conventional form of steam generation.


1968 ◽  
Vol 90 (3) ◽  
pp. 265-270 ◽  
Author(s):  
C. G. Ringwall ◽  
L. R. Kelley

Circuit concepts and test data for a fluidic system to sense the average temperature in a gas turbine exhaust duct are presented. Phase discrimination techniques are used to sense the average wave velocity in a long tube and to produce an output pressure differential proportional to temperature error.


1974 ◽  
Author(s):  
Marv Weiss

A unique method for silencing heavy-duty gas turbines is described. The Switchback exhaust silencer which utilizes no conventional parallel baffles has at operating conditions measured attenuation values from 20 dB at 63 Hz to 45 dB at higher frequencies. Acoustic testing and analyses at both ambient and operating conditions are discussed.


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