Flow-Induced Acoustic Resonance in a Closed Side Branch Under a Low-Pressure Wet Steam Flow

2017 ◽  
Vol 139 (3) ◽  
pp. 031306 ◽  
Author(s):  
Yuta Uchiyama ◽  
Ryo Morita
Keyword(s):  
Acoustic Resonance ◽  
Low Pressure ◽  
Side Branch ◽  
Steam Flow ◽  
Wet Steam ◽  
Wet Steam Flow

Expansion of Multi-Purpose Steam Facility and Application to Acoustic Resonance in a Closed Side Branch Investigating Effects of Static Pressure Under Wet Steam Flow

2017 ◽  
Author(s):  
Yuta Uchiyama ◽  
Ryo Morita
Keyword(s):  
Power Plants ◽  
Static Pressure ◽  
Acoustic Resonance ◽  
Side Branch ◽  
Steam Flow ◽  
Structural Vibration ◽  
Test Facility ◽  
Wet Steam ◽  
Single Side ◽  
Wet Steam Flow

Flow-induced acoustic resonances in piping with closed side branches or T-junctions are one of the phenomena causing severe structural vibration and fatigue damage of the piping and components in many engineering applications such as power plants. Practical piping systems of power plants often have a steam flow, and moreover, the steam state can be not only dry steam but also wet steam. From our previous experiments under low-pressure dry and wet steam flows using a single side branch, higher acoustical damping was confirmed under wet steam than that under dry steam, which is considered to be caused by the existing liquid phase. Although the static pressure in practical steam piping is often higher than that in our previous experiments, the effects of the static pressure on acoustical damping under a wet steam flow have not been clarified. Thus, we constructed a new test facility that can be used to perform continuous flow test under dry and wet steam flows with higher pressures than our previous test facility. In this paper, we give an overview of the new steam test facility and some experimental results for the acoustic resonance in a single side branch under higher-pressure dry and wet steam flows than those in our previous studies, using the new facility to investigate and evaluate the effects of the static pressure.

Study on Effects of Spontaneous Condensation on Performance of Low Pressure Stages in a Steam Turbine

2006 ◽  
Author(s):  
Liang Li ◽  
Zhenping Feng ◽  
Guojun Li
Keyword(s):  
Steam Turbine ◽  
Stokes Equations ◽  
Low Pressure ◽  
Steam Flow ◽  
Vapor Flow ◽  
Wet Steam ◽  
Water Droplets ◽  
Flow Angle ◽  
Spontaneous Condensation ◽  
Wet Steam Flow

The formation of water droplets in low-pressure steam turbine seriously degrades the performance of the turbine. In order to simulate the wet steam flow with spontaneous condensation, an Eulerian/Eulerian model was developed, in which the Navier-Stokes equations for water vapor flow are coupled with two additional equations describing the formation and the distributions of water droplets. The classical condensation theory was used to model the condensation process. With this model, the three dimensional (3D) steady wet steam flow with spontaneous condensation in three low pressure (LP) stages of an industrial steam turbine was numerically investigated and the results were compared with those in superheated flow. The distribution of pressure, the enthalpy drop, the reaction degree, the outflow velocity and flow angle in each wet steam turbine stage obviously change due to the spontaneous condensation in wet steam flow, compare to those in the superheated flow. The re-distribution of flow parameters in condensing flow leads to that the turbine stages run at ‘off-design’ condition actually, which leads to additional efficiency losses besides the well-known non-equilibrium losses.

Modelling and Validation of Wet Steam Flow in a Low Pressure Steam Turbine

2011 ◽  
Author(s):  
Jo¨rg Starzmann ◽  
M. Schatz ◽  
M. V. Casey ◽  
J. F. Mayer ◽  
Frank Sieverding
Keyword(s):  
Steam Turbine ◽  
Droplet Size ◽  
Low Pressure ◽  
Numerical Results ◽  
Steam Flow ◽  
Droplet Growth ◽  
Wet Steam ◽  
Test Rig ◽  
Pressure Steam ◽  
Wet Steam Flow

Results of numerical investigations of the wet steam flow in a three stage low pressure steam turbine test rig are presented. The test rig is a scale model of a modern steam turbine design and provides flow measurements over a range of operating conditions which are used for detailed comparisons with the numerical results. For the numerical analysis a modern CFD code with user defined models for specific wet steam modelling is used. The effect of different theoretical models for nucleation and droplet growth are examined. It is shown that heterogeneous condensation is highly dependent on steam quality and, in this model turbine with high quality steam, a homogeneous theory appears to be the best choice. The homogeneous theory gives good agreement between the test rig traverse measurements and the numerical results. The differences in the droplet size distribution of the three stage turbine are shown for different loads and modelling assumptions. The different droplet growth models can influence the droplet size by a factor of two. An estimate of the influence of unsteady effects is made by means of an unsteady two-dimensional simulation. The unsteady modelling leads to a shift of nucleation into the next blade row. For the investigated three stage turbine the influence due to wake chopping on the condensation process is weak but to confirm this conclusion further investigations are needed in complete three dimensions and on turbines with more stages.

Experimental Investigation for Acoustic Resonance in Tandem Branches Under Each Dry and Wet Steam Flow

2015 ◽  
Author(s):  
Yuta Uchiyama ◽  
Ryo Morita
Keyword(s):  
Power Plants ◽  
High Cycle Fatigue ◽  
Acoustic Resonance ◽  
The United States ◽  
Steam Flow ◽  
Piping System ◽  
Wet Steam ◽  
Resonance Amplitude ◽  
Piping Systems ◽  
Wet Steam Flow

Flow-induced acoustic resonances of piping system containing closed side-branches are sometimes encountered in power plants. In the United States, the steam dryer in boiling water reactor had been damaged by high cycle fatigue due to acoustic-induced vibration under a power uprating condition. The steam piping systems of current power plants often have nearly saturated wet steam condition. The side-branches of current power plants vary in their configuration (single, tandem, and coaxial), number, and so on. Therefore, many types of flow-induced acoustic resonance at branch piping have been investigated by many researchers. However, most of previous studies were under air flow condition and there were few previous experiments under wet steam flow. In this study, some types of the acoustic resonance at branch piping are investigated by conducting experiments under each dry and wet steam conditions. As a result, it is clarified that influence of branch configurations (single or tandem) on resonance amplitude and frequency under steam flow. In addition, their differences between dry and wet steam are discussed.

Sign in / Sign up

Export Citation Format

Share Document