Unsteady flow behavior of a steam turbine control valve in the choked condition: Field measurement, detached eddy simulation and acoustic modal analysis

Wang, Peng; Liu, Yingzheng

doi:10.1016/j.applthermaleng.2017.02.087

Cited by 35 publications

(6 citation statements)

References 15 publications

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“…Using DES to simulate the complex valve flow has been validated by Yonezawa et al, 15 where the frequencies of valve-induced pressure fluctuations were accurately captured and the rotating high-pressure region was confirmed to account for the flow-induced vibrations. Furthermore, according to Wang and Liu, 20 who conducted DESs on unsteady flow behavior in a full-scale steam turbine control valve under the cold-start warming-up condition of the steam turbine system, the frequencies of the fluctuating forces acting on the valve spindle determined by the DES agreed quite well with the field data measured in power plants. Similarly with the study by Wang and Liu, 20 the SST-based DES approach was also adopted in the present study.…”

Section: Numerical Setup Of the Steam Turbine Control Valvesupporting

confidence: 56%

“…Furthermore, according to Wang and Liu, 20 who conducted DESs on unsteady flow behavior in a full-scale steam turbine control valve under the cold-start warming-up condition of the steam turbine system, the frequencies of the fluctuating forces acting on the valve spindle determined by the DES agreed quite well with the field data measured in power plants. Similarly with the study by Wang and Liu, 20 the SST-based DES approach was also adopted in the present study. In the current study, the fluid domain of the control valve [Fig.…”

Section: Numerical Setup Of the Steam Turbine Control Valvesupporting

confidence: 56%

“…From DESs of the unsteady behaviors of wall-attached flow, in-phase and out-phase oscillations of the annular wall-attached jet were successfully identified by state-of-the-art proper orthogonal decomposition (POD). 20,21 However, comprehensively understanding the wall-detached flow is still insufficient, especially the dominant vortex structures and energetic pressure fluctuations, which contribute mostly to the highly unstable three-dimensional (3D) flows inside steam turbine control valves. 22,23 Continuing a previous study by Wang et al, 22 the present study focuses primarily on the unsteady behavior of wall-detached flow inside a bell-shaped steam turbine control valve.…”

Section: Introductionmentioning

confidence: 99%

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Unsteady behavior of wall-detached flow inside a steam turbine control valve

Wang

et al. 2019

Physics of Fluids

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Wall-detached flow inside an ultra-supercritical steam turbine control valve was comprehensively investigated with detached-eddy simulation, proper orthogonal decomposition (POD), and flow reconstruction. The dependency of the wall-detached flow on the control valve's opening ratio and pressure ratio was established first. Scattered wall-detached-flow, merged wall-detached-flow, and intersected wall-detached-flow were then identified by distinguishing the detachment scale of the wall-detached jet. Subsequently, flow analysis was conducted in terms of the statistical flow quantities, i.e., velocity fluctuation, turbulent kinetic energy, pressure loss, and pressure fluctuation. The statistical results demonstrated that the merged wall-detached-flow facilitated the most intensive velocity and pressure fluctuations inside the steam turbine control valve. The intersected wall-detached-flow encountered significant shock-wave reflections along the downstream pipe. By conducting POD analysis and flow reconstruction on the instantaneous flow snapshots, the dominant vortex structures and energetic pressure fluctuation modes were extracted to illustrate the wall-detached flow's unsteady behavior. The results showed that the instabilities of the scattered wall-detached-flow were primarily represented by the horizontal flapping motion of the wall-detached jet. However, for the merged wall-detached-flow, both the vertical out-phase oscillation and the horizontal flapping motion of the wall-detached jet intensified, yielding essential axial pressure fluctuation modes. As for the intersected wall-detached-flow, due to the complex wave reflections and propagations, essential regions with velocity discontinuities and diagonal crosslines with intensive pressure fluctuations formed inside the valve pipe. These findings are of great practical significance for the operation and optimization of steam turbine control valves in thermal power plants.

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Section: Numerical Setup Of the Steam Turbine Control Valvesupporting

confidence: 56%

Section: Numerical Setup Of the Steam Turbine Control Valvesupporting

confidence: 56%

Section: Introductionmentioning

confidence: 99%

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Unsteady behavior of wall-detached flow inside a steam turbine control valve

Wang

et al. 2019

Physics of Fluids

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“…These factors will seriously affect the efficiency and safety of the unit. Therefore, deeply understanding evaporation characteristics and efficient working area of MSHPTRV is essential for improving the performance [6].…”

Section: Introductionmentioning

confidence: 99%

Evaporation characteristics and efficient working area of multi-stage high pressure and temperature reducing valve

Cao

Dong

et al. 2022

THERM SCI

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A well understanding on the evaporation characteristics and efficient working area of MSHPTRV (multi-stage high pressure and temperature reducing valve) is important for improving the performance and safety of MSHPTRV. The water spraying and evaporation model are integrated into the flow model of MSHPTRV. Compared with the experimental data, the model can show the thermal process well. The flow characteristics and interaction between steam and droplets are presented. On this basis, the increase rate of entropy Sdis is adopted to analyze the thermodynamic loss and innovatively determine the efficient working area of MSHPTRV. The results show that the pressure reducing effect of the second orifice plate is prominent, which accounts for 41.6% of the total pressure drop. The "steam-water layer" is formed at the boundary of steam and water. At the inlet of second orifice plate, the maximum Sdis is 0.782, and the downstream of second orifice plate is the efficient working area of MSHPTRV. The length of evaporation section increases with the droplets diameter significantly.

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“…The control valve is mostly operated at a medium or large opening ratio with an optimized pressure drop. Peng et al [16] conducted a study to observe the flow behavior for a steam turbine control valve. Research has also been conducted by Shaoshih et al to analyze single turbine valve closure [17] and Ling et al [18] who develop an incipient fault diagnosis of the limit switch.…”

Section: Introductionmentioning

confidence: 99%

Automatic limit switch calibrator for control valve at steam turbine of a geothermal power plant

et al. 2021

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Measurement of fluid level in steam valves should require precise values. The instrument designed in this article is used to find out how precise the limit switch is used as an indicator control valve at certain points. The measurement technique will be implemented on a control valve on the geothermal power plant. This device is using the Arduino Due board as a data processor and modified the data signal of the vernier caliper to measure the valve opening. The TFT LCD layer is used to display the measurement and calibration results. The test results of this device indicate that this device has an accuracy level of more than 99%.

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Unsteady flow behavior of a steam turbine control valve in the choked condition: Field measurement, detached eddy simulation and acoustic modal analysis

Cited by 35 publications

References 15 publications

Unsteady behavior of wall-detached flow inside a steam turbine control valve

Unsteady behavior of wall-detached flow inside a steam turbine control valve

Evaporation characteristics and efficient working area of multi-stage high pressure and temperature reducing valve

Automatic limit switch calibrator for control valve at steam turbine of a geothermal power plant

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