Effects of non-equilibrium condensation on aerodynamics of the flow field in a steam turbine cascade

Esfe, Hamed Bagheri; Kermani, M.J.; Saffar‐Avval, Majid

doi:10.24200/sci.2017.4047

Cited by 3 publications

(2 citation statements)

References 28 publications

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“…But the losses value was overestimated due to the neglect of the wetness fraction. By the numerical investigation of Bagheri-Esfe [16] and Vatanmakan [17] for the condensing steam flow through turbine blades, it is shown that the entropy generation induced by non-equilibrium condensation can reduce the steam turbine efficiency and the large heat flux can reduce entropy generation.…”

Section: Introductionmentioning

confidence: 99%

Entropy generation and exergy destruction in condensing steam flow through turbine blade with surface roughness

Ding

Lakzian

et al. 2019

Energy Conversion and Management

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In the steam turbine, the wetness loss due to vapor condensation is one of the most crucial losses at low-pressure stage. This study focused on entropy generation and exergy destruction of condensing steam flow in turbine blade with the roughness. The governing equations including entropy transport equation combined with condensation model, transition SST model and roughness correlation were established and verified by experiments and theory. Flow field behaviors, such as wetness fraction, intermittency and turbulent viscosity distributions, controlled by the deviation angle were obtained to evaluate effects of back pressure ratio and surface roughness. The mass-averaged wetness fraction at outlet was also extracted considering the influence of uneven mass flux. Finally, each part of entropy generation derived from viscous, heat conduction, phase change and aerodynamic losses and exergy destruction ratio were analyzed.Research shows that roughness plays an important part in the intermittency and turbulent viscosity. The mass-averaged wetness fraction at outlet sharply drops with back pressure ratio but slightly decreases with the roughness. With the roughness rising * at stagnation condition mass generation rate, kgm -3 s -1 * 1

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Section: Introductionmentioning

confidence: 99%

Entropy generation and exergy destruction in condensing steam flow through turbine blade with surface roughness

Ding

Lakzian

et al. 2019

Energy Conversion and Management

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show abstract

“…Bagheri-Esfe et al. 31,32 studied the influence of nonequilibrium condensation on the efficiency and deflection angle of steam turbine stages under subsonic, transonic, and supersonic conditions, and compared and analyzed the aerodynamic characteristics of steam turbines in the NES and noncondensation models. Condensation had a great influence on the expansion and Mach number of the steam turbine under supersonic condition.…”

Section: Introductionmentioning

confidence: 99%

Condensation flow at the wet steam centrifugal turbine stage

Liu

Shi

et al. 2019

Proceedings of the Institution of Mechanical Engineers, Part A:

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This paper investigates spontaneous condensation of wet steam in a centrifugal turbine by means of three-dimensional computational fluid dynamics. The flow field and aerodynamic characteristics of the wet steam in the centrifugal turbine are compared and analyzed by using the equilibrium steam and nonequilibrium steam models, respectively, where the latter applies the classical droplet nucleation theory and neglects velocity slip between the liquid phase and the gaseous phase. The state parameters of wet steam are described here based on the IAPWS’97 formulation. It is concluded that under the design condition, the mass flow rate, wetness fraction, and flow angle of the wet steam centrifugal turbine in the nonequilibrium steam model all change compared with the equilibrium steam model, with values of 4.4%, 0.5%, and 10.57%, respectively. Then the performance variation of the wet steam centrifugal turbine is analyzed under different steam conditions and different outlet back-pressure conditions. The results show that the change law of the mass flow rate, shaft power, and wetness fraction in the centrifugal turbine are basically identical in both models, and the mass flow rate, shaft power, wheel efficiency, and entropy loss coefficient of the centrifugal turbine in the nonequilibrium steam model are all higher than those in the equilibrium steam model, whereas the outlet wetness fraction is lower than that in the equilibrium steam model.

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Multi-objective optimization of supercooled vapor suction for decreasing the nano-water droplets in the steam turbine blade

Hosseini

Lakzian

Nakisa

2023

International Communications in Heat and Mass Transfer

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Effects of non-equilibrium condensation on aerodynamics of the flow field in a steam turbine cascade

Cited by 3 publications

References 28 publications

Entropy generation and exergy destruction in condensing steam flow through turbine blade with surface roughness

Entropy generation and exergy destruction in condensing steam flow through turbine blade with surface roughness

Condensation flow at the wet steam centrifugal turbine stage

Multi-objective optimization of supercooled vapor suction for decreasing the nano-water droplets in the steam turbine blade

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