scholarly journals Thermal Stresses in Gas Turbine Exhaust Duct Expansion Joints

1996 ◽  
Author(s):  
Michel D. Ninacs ◽  
Rodney P. Bell
Keyword(s):  
Gas Turbine ◽  
Thermal Stresses ◽  
Large Temperature ◽  
Thermal Gradients ◽  
Expansion Joints ◽  
Gas Leakage ◽  
Exhaust Duct ◽  
Gas Turbine Exhaust ◽  
Improved Design ◽  
Turbine Exhaust

This paper discusses the methods used to derive an improved design for gas turbine exhaust duct expansion joints. Typically these joints are subjected to very rapid increase in internal exhaust gas temperatures that result in large temperature differentials within the joint structures. The thermal gradients can cause stress levels in excess of yield and when the turbine is used intermittently, such as peaking power units would be, the net result is crack propagation and gas leakage.

Prediction of Pressure Rise in a Gas Turbine Exhaust Duct Under Flameout Scenarios While Operating On Hydrogen and Natural Gas Blends

2021 ◽  
Author(s):  
Orlando Ugarte ◽  
Suresh Menon ◽  
Wayne Rattigan ◽  
Paul Winstanley ◽  
Priyank Saxena ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Combustion Model ◽  
Computational Domain ◽  
Cfd Model ◽  
Exhaust Duct ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

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.

A Fluidic Technique for Measuring the Average Temperature in a Gas Turbine Exhaust Duct

1968 ◽  
Vol 90 (3) ◽  
pp. 265-270 ◽  
Author(s):  
C. G. Ringwall ◽  
L. R. Kelley
Keyword(s):  
Gas Turbine ◽  
Wave Velocity ◽  
Test Data ◽  
Output Pressure ◽  
Average Temperature ◽  
Phase Discrimination ◽  
Exhaust Duct ◽  
Average Wave ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

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.

Gas Turbine Exhaust Expansion Joints, Diverter and Damper Designs for the New Generation of Higher Temperature, High Efficiency Gas Turbines

1989 ◽  
Author(s):  
Lothar Bachmann ◽  
W. Fred Koch
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
Combined Cycle ◽  
Operating Conditions ◽  
High Mass ◽  
Expansion Joints ◽  
Gas Turbine Exhaust ◽  
New Generation ◽  
Turbine Exhaust

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.

Numerical and Experimental Study on the Suppression for the Infrared Signatures of a Marine Gas Turbine Exhaust System

2000 ◽  
Author(s):  
Shaorong Zhou ◽  
Zhaohui Du ◽  
Hanping Chen ◽  
Fangyuan Zhong
Keyword(s):  
Gas Turbine ◽  
Exhaust System ◽  
Scale Model ◽  
Ir Radiation ◽  
Exhaust Duct ◽  
Ir Signature ◽  
Gas Turbine Exhaust ◽  
Control Volumes ◽  
Cooling Air ◽  
Turbine Exhaust

The flow and thermal fields within the cooling air injection device which is widely used to suppress the infrared (IR) signatures of a marine gas turbine exhaust system were studied numerically and experimentally. A turbulence near-wall model based on the wall function method was adopted. The discretization equations were derived for the control volumes when conjugate heat transfer exists at their interfaces, with the radiation heat flux at the interfaces appearing as an additional source term. The solution method of entrained velocities at the entrance of secondary flow was introduced. The distributions of temperature and static pressure on the diffuser surface, and the temperature of gas at the outlet of the exhaust duct were simulated numerically. The numerical calculated results agreed well with corresponding scale model experimental data. Lastly, the measured IR radiation distributions by scale model experiments at different view angles and various engine power settings, with and without IR signature suppression (IRSS) devices were presented.

Prediction of Pressure Rise in a Gas Turbine Exhaust Duct Under Flameout Scenarios While Operating on Hydrogen and Natural Gas Blends

2021 ◽  
Author(s):  
Orlando Ugarte ◽  
Suresh Menon ◽  
Wayne Rattigan ◽  
Paul Winstanley ◽  
Priyank Saxena ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Combustion Model ◽  
Computational Domain ◽  
Cfd Model ◽  
Exhaust Duct ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

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.

scholarly journals Establishing the Longitudinal Temperature Distribution for Fully Developed Turbulent Flow in a Gas Turbine Exhaust Duct

1970 ◽  
Author(s):  
P. J. Torpey ◽  
R. M. Welch
Keyword(s):  
Temperature Distribution ◽  
Gas Turbine ◽  
Accurate Determination ◽  
Exhaust System ◽  
Longitudinal Temperature ◽  
Exhaust Duct ◽  
Fully Developed Turbulent Flow ◽  
Gas Turbine Exhaust ◽  
Heat Flow Model ◽  
Turbine Exhaust

The ability to predict the longitudinal temperature distribution along a gas turbine exhaust duct facilitates the selection of the proper duct material and the appropriate paint or other external coating. It also allows accurate determination of thermal expansion over the entire length. A first-order differential equation is derived from a one-dimensional heat flow model for the exhaust system. A digital computer program employing this model is also presented. The computer solution, in addition to eliminating tedious manual computation, extends the analysis capability by accounting for changes in temperature and flow-dependent variables along the duct length. Measured gas and duct wall temperatures for a 1.5-kw gas turbine exhaust system are compared with values predicted by the analysis. Good agreement is noted throughout that portion of the system in which fully developed flow exists.

A Transcritical CO2 Rankine Cycle With LNG Cold Energy Utilization and Liquefaction of CO2 in Gas Turbine Emission

2008 ◽  
Author(s):  
Meibin Huang ◽  
Wensheng Lin ◽  
Hongming He ◽  
Anzhong Gu
Keyword(s):  
Gas Turbine ◽  
Rankine Cycle ◽  
Energy Utilization ◽  
Working Fluid ◽  
Large Temperature ◽  
Specific Work ◽  
Environment Friendly ◽  
Cold Energy ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

A novel transcritical Rankine cycle is presented in this paper. This cycle adopts CO2 as its working fluid, with exhaust from a gas turbine as its heat source and LNG as its cold sink. With CO2 working transcritically, large temperature difference for the Rankine cycle is realized. Moreover, the CO2 in the gas turbine exhaust is further cooled and liquefied by LNG after transferring heat to the Rankine cycle. In this way, not only the cold energy is utilized, but also a large part of the CO2 from burning of the vaporized LNG is recovered. In this paper, the system performance of this transcritical cycle is calculated. The influences of the highest cycle temperature and pressure to system specific work, exergy efficiency and liquefied CO2 mass flow rate are analyzed. The exergy loss in each of the heat exchangers is also discussed. It turns out that this kind of CO2 cycle is energy-conservative and environment-friendly.

A Transcritical CO2 Rankine Cycle With LNG Cold Energy Utilization and Liquefaction of CO2 in Gas Turbine Exhaust

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Wensheng Lin ◽  
Meibin Huang ◽  
Hongming He ◽  
Anzhong Gu
Keyword(s):  
Gas Turbine ◽  
Rankine Cycle ◽  
Energy Utilization ◽  
Working Fluid ◽  
Large Temperature ◽  
Specific Work ◽  
Environment Friendly ◽  
Cold Energy ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

A novel transcritical Rankine cycle is presented in this paper. This cycle adopts CO2 as its working fluid with exhaust from a gas turbine as its heat source and liquefied natural gas (LNG) as its cold sink. With CO2 working transcritically, large temperature difference for the Rankine cycle is realized. Moreover, the CO2 in the gas turbine exhaust is further cooled and liquefied by LNG after transferring heat to the Rankine cycle. In this way, not only is the cold energy utilized but also a large part of the CO2 is recovered from burning of the vaporized LNG. In this paper, the system performance of this transcritical cycle is calculated. The influences of the highest cycle temperature and pressure to system specific work, exergy efficiency, and liquefied CO2 mass flow rate are analyzed. The exergy loss in each of the heat exchangers is also discussed. It turns out that this kind of CO2 cycle is energy-conservative and environment-friendly.

scholarly journals Pressure Loss Modeling of Non-Symmetric Gas Turbine Exhaust Ducts Using CFD

2009 ◽  
Author(s):  
Steven Farber ◽  
Wahid Ghaly
Keyword(s):  
Gas Turbine ◽  
Pressure Loss ◽  
Total Pressure ◽  
Three Dimensional ◽  
Total Pressure Loss ◽  
Combustion Gases ◽  
Exhaust Duct ◽  
Duct Geometry ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

In typical gas turbine applications, combustion gases that are discharged from the turbine are exhausted into the atmosphere in a direction that is sometimes different from that of the inlet. In such cases, the design of efficient exhaust ducts is a challenging task particularly when the exhaust gases are also swirling. A parametric Computational Fluid Dynamics (CFD) based study was carried out on non-symmetric gas turbine exhaust ducts where the effects of geometry and inlet aerodynamic conditions were examined. These exhaust ducts comprise an annular inlet, a flow splitter, an annular to rectangular transition region, and an exhaust stub. The duct geometry, which is a three-dimensional complex one, is approximated with a six-parameter model (four geometric and two aerodynamic), which was coupled with a design of experiment method to generate a relatively small number of exhaust ducts. The flow in these ducts was simulated using CFD for different values of inlet swirl and aerodynamic blockage and the numerical results were reviewed so as to assess the effects of the geometric and aerodynamic parameters on the total pressure loss in the exhaust duct. These flow simulations were used as a data base to generate a total pressure loss model that designers can use as a tool to build more efficient non-symmetric gas turbine exhaust ducts.

Novel Gas Turbine Exhaust Temperature Measurement System

2013 ◽  
Author(s):  
Upul DeSilva ◽  
Richard H. Bunce ◽  
Heiko Claussen
Keyword(s):  
Temperature Measurement ◽  
Gas Turbine ◽  
Speed Of Sound ◽  
Gas Temperature ◽  
Turbine Engine ◽  
Process Gas ◽  
Exhaust Duct ◽  
Topographical Mapping ◽  
Gas Turbine Exhaust ◽  
Turbine Exhaust

Siemens Energy, Inc. has been investigating the potential of a new approach to measuring the process gas temperature leaving the turbine of their heavy industrial gas turbine engines using an acoustic pyrometer system. This system measures the bulk temperature crossing a plane behinds the last row of turbine blades and is a non-intrusive measurement. It has the potential to replace the current intrusive multiple point measurement sensor arrays for both engine control and performance evaluation. The acoustic pyrometer is a device that measures the transit time of an acoustic pulse across the exhaust duct of the engine. An estimate of the temperature of the process fluid can be made from the transit time. Multiple passes may be made at various radial positions to improve the measurement. The gas turbine exhaust is a challenging environment for acoustic temperature measurement where there can be significant temperature stratification and high velocity. Previous applications of acoustic pyrometers to measure process gas temperature in power plants have been confined to applications such as boilers where rapid temperature changes are not expected and fluid velocity patterns are well known. The present study describes the results of acoustic pyrometer testing in an operating gas turbine engine under load using an active acoustic pyrometer system containing eight sets of transmitters and receivers, all external to the turbine exhaust flow path. This active method technology is based on the temperature dependence of the isentropic speed of sound from the simple ideal gas assumptions. Sound transmitters and receivers are mounted around the exhaust duct to measure the speed of sound. Very sophisticated topographical mapping techniques have been developed to extract temperature distribution from using any where from 2 to 8 sensors with up to 24 paths and 400 points. Cross correlation of sensor results to obtain topographical mapping of gas isotherms in a plane in full engine field tests have been conducted to prove the feasible of this technology on a gas turbine engine. The initial installation of the active acoustic pyrometer system in an engine exhaust was accomplished in 2009. All the tests indicate that the steady state measurements of the acoustic pyrometer system fall within 10C of the measured exhaust thermocouple data. An additional installation on a different model engine was subsequently made and data have been gathered and analyzed. Results of these tests are presented and future evaluation options discussed.

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