A 3D method to evaluate moisture losses in a low pressure steam turbine: Application to a last stage

Highlights• CFD-based shape optimization of a nozzle and a turbine blade regarding nucleating steam flow is performed.• Nucleation rate and droplet radius are the best suited objective functions for the optimization p rocess.• Maximum 34% reduction in entropy generation rate is reported for turbine cascade.• A maximum 10% reduction in Baumann factor and a maximum 2.1% increase in efficiency is achieved for a turbine cascade. Abstract:In this study CFD-based shape optimization of a 3D nozzle and a 2D turbine blade cascade is undertaken in the presence of non-equilibrium condensation within the considered flow channels.A two-fluid formulation is used for the simulation of unsteady, turbulent, supersonic and compressible flow of wet steam accounting for relevant phase interaction between nucleated liquid droplets and continuous vapor phase. An in-house CFD code is developed to solve the governing equations of the two phase flow and was validated against available experimental

show abstract

“…According to the condensation model adopted here (Eqs. [12][13][14][15][16][17][18], the phase change is represented by two mass sources:…”

Section: Non-equilibrium Condensation Modelmentioning

confidence: 99%

“…A 3D numerical simulation of wet steam flow through stationary and moving blades of a steam turbine was carried out by Yu et al [14]. The main motivation behind the study was the examination of the adverse effect of liquid droplet deposition (onto turbine blade) on the performance of the turbine.…”

Section: Introductionmentioning

confidence: 99%

CFD-based shape optimization of steam turbine blade cascade in transonic two phase flows

Abadi

Ahmadpour

Abadi

et al. 2017

Applied Thermal Engineering

View full text Add to dashboard Cite

show abstract

“…The results showed that the total wetness loss of the LP cylinder accounted for 3.65% of the total output power. Yu et al [23] simulated the condensate flow at the last stage of a 1000 MW fossil-fired steam turbine using an inhomogeneous multi-phase flow model. The results showed that the inlet droplet diameter had a significant effect on moisture loss.…”

Section: Introductionmentioning

confidence: 99%

Unsteady non-equilibrium condensation flow of 3-D wet steam stage of steam turbine with roughness using sliding mesh method

Ding

Sun

Lakzian

et al. 2022

International Journal of Thermal Sciences

View full text Add to dashboard Cite

“…Simultaneously, the Eulerian/Eulerian model is also used to simulate twophase flow (White, 2003 andGerber et al 2004). For the numerical investigation of flow mechanism in wet steam turbine stages, more researchers on the process of droplet growth as the non-equilibrium condensation flow of wet steam could reflect the change of the nucleation rate of the liquid phase, droplet number and the radius of the droplet (Yu et al 2015). However, when the steam flow is under the saturation line for the flow process of wet steam in the LSB, the condensation change of wet steam is in the Wilson points downstream (Wu et al 2007).…”

Section: Introductionmentioning

confidence: 99%

Effect of Wet Steam on Aerodynamic Performance of Low-Pressure Exhaust Passage with Last Stage Blade

Lin

Chang

Cao

et al. 2019

JAFM

View full text Add to dashboard Cite

The condensation of wet steam has important effects on the behavior of the flow field. To evaluate the aerodynamic performance of exhaust passage influenced by wet steam phase change condensation, a numerical investigation was conducted. Taking a 600 MW steam turbine as an example with consideration of the wet steam from the last stage blade and the steam exhaust of the BFPT (boiler feed water pump turbine), the governing equations of wet steam two-phase flow were adopted by the Eulerian-Eulerian approach. Results show that the wetness in the stator domain increases gradually while the wetness in the rotor domain varies little on the pressure surface and is in small increment on the suction surface. The velocity uniformity can be improved at condenser throat outlet as the mass flow or wetness increases. Moreover, the trend to improve the aerodynamic performance of exhaust passage benefits from the improvement of wetness at the last stage blade inlet. Conversely, with the increment of wetness at the BFPT inlet, the static pressure recovery coefficient reduces by 5.8% and the total pressure loss coefficient increases by 2.4%, resulting in a reduction of aerodynamic performance of exhaust passage.

show abstract

A 3D method to evaluate moisture losses in a low pressure steam turbine: Application to a last stage

Cited by 20 publications

References 26 publications

CFD-based shape optimization of steam turbine blade cascade in transonic two phase flows

CFD-based shape optimization of steam turbine blade cascade in transonic two phase flows

Unsteady non-equilibrium condensation flow of 3-D wet steam stage of steam turbine with roughness using sliding mesh method

Effect of Wet Steam on Aerodynamic Performance of Low-Pressure Exhaust Passage with Last Stage Blade

Contact Info

Product

Resources

About