CFD Review  
Serving the CFD Community with News, Articles, and Discussion
 
CFD Review

User Preferences
Site Sponsorship
Headline Feeds
Mobile Edition
Privacy Policy
Terms of Service
twitter

Submit a CFD Story

Site Sponsors
Siemens PLM Software
Pointwise: Reliable CFD meshing
Software Cradle

Tell a Friend
Help this site to grow by sending a friend an invitation to visit this site.

CFD News by Email
Did you know that you can get today's CFD Review headlines mailed to your inbox? Just log in and select Email Headlines Each Night on your User Preferences page.

 
CFD Helps in Ensuring Safe Power Plant
Posted Tue April 15, 2003 @03:50PM
Print version Email story Tweet story
Application By R. Buettner, R. Walterskötter and H. Schmidt,
Framatome ANP GmbH TGT1, Germany

The safety aspects of gas turbine power plant have become a major concern around the world, and many local safety authorities now require the analysis of leakage in the gas supply of turbines as a part of the approval to operate plants. Safety is our specialty at the Technical Centre of Framatome ANP GmbH. Capitalizing on our extensive expertise in power plant technology, we offer a multi-disciplinary approach to consulting with, among others, competence in material technologies and thermal fluid dynamics.

Over the years, we have gained comprehensive experience in the safety aspects of gas turbine power, with the analysis of many different plants and designs. In a recent project, we looked at reducing hazards due to hypothetical leakages in the fuel gas system of a turbine. The turbine was located in an acoustic enclosure which employed forced-convection ventilation to diffuse any gas leakage to below a specified concentration level. The specified level is defined as "under control" by the local Health & Safety department. If this condition is fulfilled, the risk of an explosion causing significant damage or injury can be considered as controlled.


Sponsor CFD Review

We needed to determine that, should a leak occur in the fuel system, gas would be detected before it reached the specified concentrations. We decided to use CFX-5 for the analysis, its automatic mesh generation capability speeding up the meshing work enormously. We accurately represented most of the components inside the enclosure, with additional grid refinement in the vicinity of the gas leakage. Some smaller details were simplified, for example, the silencer and the perforated plate at the roof duct were modeled as regions with resistance coefficients, and the front gas turbine pillars were modeled as thin surfaces. We set the gas leak to be a methane jet with an initial speed of nearly Mach one. For turbulence modeling, we used the standard k-e model with logarithmic wall functions and buoyancy forces to account for the heat transfer between the turbine surfaces and the flow.

These CFD calculations showed that the volume of the methane cloud at the critical concentration was smaller than the stipulated maximum value. However, they also made clear that geometric constraints around the leakage site were leading to stagnation and poor mixing, and that higher methane concentrations, though still below the critical value, could be expected in these regions. Improvements to the efficiency of the ventilation were then studied, and based on these results we could optimize the positions of the methane detectors, leading to a plant that exceeds the Health & Safety requirements.

cfd model
CFD model of the gas turbine acoustic enclosure.

low methane cloud
Simulated cloud with low methane concentration.

methane jet leak
Simulated methane jet leaking from the fuel entry system.

secondary flow patterns
Secondary flow patterns in a cross section, shaded by methane concentration (bottom view), showing the regions where the gas is entrained.

[ Post Comment ]

GAMBIT 2.1 to Include Native CATIA V4 Translation | CFD Applications in the Chemical and Process Industries  >

 

 
CFD Review Login
User name:

Password:

Create an Account

Related Links
  • CFX
  • CFX-5
  • Framatome ANP GmbH
  • More on Application
  • Also by nwyman
  • This discussion has been archived. No new comments can be posted.

    FORTUNE PROVIDES QUESTIONS FOR THE GREAT ANSWERS: #19 A: To be or not to be. Q: What is the square root of 4b^2? All content except comments
    ©2017, Viable Computing.

    [ home | submit story | search | polls | faq | preferences | privacy | terms of service | rss  ]