Stability Prediction of the Nuclear Turbine Blades During Wet Steam Nonequilibrium Condensation Process

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Bing Guo ◽  
Weixiao Tang
Keyword(s):  
Turbine Blades ◽  
Condensation Process ◽  
Equivalent Stiffness ◽  
Wet Steam ◽  
Two Phase ◽  
Equivalent Damping ◽  
Novel Method ◽  
Phase Temperature ◽  
Nonequilibrium Condensation ◽  
The Stability

Stability of the nuclear turbine blades is difficult to be accurately predicted because the wet steam load (WSL) as well as its induced equivalent damping and stiffness during nonequilibrium condensation process (NECP) is hard to be directly calculated. Generally, in design, NECP is assumed as equilibrium condensation process (ECP), of which the two-phase temperature difference (PTD) between gaseous and liquid is ignored. In this paper, a novel method to calculate the WSL-induced equivalent damping and equivalent stiffness during NECP based on the combined microperturbation method (MPM) and computational fluid dynamics method (CFDM) was proposed. Once the WSL-induced equivalent damping and equivalent stiffness are determined, the stability of the blade-WSL system, of which the blade was modeled by a pretwisted airfoil cantilever beam, can then be predicted based on the Lyapunov's first method. Besides, to estimate the effects of PTD, comparisons between the WSL-induced equivalent damping and equivalent stiffness as well as the unstable area during NECP and ECP were presented. Results show that the WSL-induced equivalent damping and equivalent stiffness during NECP are more sensitive to the inlet boundary due to the irreversible heat transfer caused by PTD during NECP. Accordingly, the unstable area during NECP is about three times larger than during ECP.

scholarly journals A Novel Dehumidification Strategy to Reduce Liquid Fraction and Condensation Loss in Steam Turbines

Entropy ◽  
2021 ◽  
Vol 23 (9) ◽  
pp. 1225
Author(s):  
Yan Yang ◽  
Haoping Peng ◽  
Chuang Wen
Keyword(s):  
Two Phase Flow ◽  
Liquid Fraction ◽  
Turbine Blades ◽  
Suction Side ◽  
Phase Region ◽  
Condensation Process ◽  
Phase Flow ◽  
Steam Turbines ◽  
Two Phase ◽  
Nonequilibrium Condensation

Massive droplets can be generated to form two-phase flow in steam turbines, leading to erosion issues to the blades and reduces the reliability of the components. A condensing two-phase flow model was developed to assess the flow structure and loss considering the nonequilibrium condensation phenomenon due to the high expansion behaviour in the transonic flow in linear blade cascades. A novel dehumidification strategy was proposed by introducing turbulent disturbances on the suction side. The results show that the Wilson point of the nonequilibrium condensation process was delayed by increasing the inlet superheated level at the entrance of the blade cascade. With an increase in the inlet superheated level of 25 K, the liquid fraction and condensation loss significantly reduced by 79% and 73%, respectively. The newly designed turbine blades not only remarkably kept the liquid phase region away from the blade walls but also significantly reduced 28.1% averaged liquid fraction and 47.5% condensation loss compared to the original geometry. The results provide an insight to understand the formation and evaporation of the condensed droplets inside steam turbines.

The influence of the Stokes and Archimedes forces on the stability of a two-phase flow

2003 ◽  
Vol 3 ◽  
pp. 266-270
Author(s):  
B.H. Khudjuyerov ◽  
I.A. Chuliev
Keyword(s):  
Spectral Method ◽  
Stability Region ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Solid Phase ◽  
Stability Characteristic ◽  
Phase Flow ◽  
Two Phase ◽  
The Stability

The problem of the stability of a two-phase flow is considered. The solution of the stability equations is performed by the spectral method using polynomials of Chebyshev. A decrease in the stability region gas flow with the addition of particles of the solid phase. The analysis influence on the stability characteristic of Stokes and Archimedes forces.

Separation and purification of horseradish peroxidase from horseradish roots using a novel integrated method

2021 ◽  
Author(s):  
Wei Ji ◽  
Wenmei Ao ◽  
Mengqiu Sun ◽  
Chunlai Feng ◽  
Yun Wang
Keyword(s):  
Horseradish Peroxidase ◽  
Phase Extraction ◽  
Separation And Purification ◽  
Two Phase ◽  
Affinity Precipitation ◽  
Integrated Method ◽  
Novel Method ◽  
Temperature Controlled ◽  
Aqueous Two Phase Extraction

The aim of the present work was to develop a novel method integrating two-step aqueous two-phase extraction and temperature-controlled affinity precipitation for the separation and purification horseradish peroxidase (HRP) from...

On the performance of a cascade of turbine rotor tip section blading in wet steam Part 3: Wake traverses

1997 ◽  
Vol 211 (8) ◽  
pp. 639-648 ◽  
Author(s):  
F Bakhtar ◽  
H Mashmoushy ◽  
O C Jadayel
Keyword(s):  
Liquid Phase ◽  
Two Phase Flow ◽  
Turbine Rotor ◽  
Phase Flow ◽  
Wet Steam ◽  
Flow Conditions ◽  
Two Phase ◽  
Blow Down ◽  
The Third ◽  
Phase Mixture

During the course of expansion of steam in turbines the fluid first supercools and then nucleates to become a two-phase mixture. The liquid phase consists of a large number of extremely small droplets which are difficult to generate except by nucleation. To reproduce turbine two-phase flow conditions requires a supply of supercooled vapour which can be achieved under blow-down conditions by the equipment employed. This paper is the third of a set describing an investigation into the performance of a cascade of rotor tip section profiles in wet steam and presents the results of the wake traverses.

scholarly journals Variation principle in calculating the flow of a two-phase mixture in the pipes of the cooling systems in high-rise buildings

2018 ◽  
Vol 33 ◽  
pp. 02063 ◽  
Author(s):  
Andrey Aksenov ◽  
Anna Malysheva
Keyword(s):  
Channel Cross Section ◽  
Variation Principle ◽  
Two Phase ◽  
Liquid Phases ◽  
Rate Of Increase ◽  
Annular Layer ◽  
Gas Liquid Flow ◽  
The Stability ◽  
Air Conditioning Systems ◽  
Physical Laws

The analytical solution of one of the urgent problems of modern hydromechanics and heat engineering about the distribution of gas and liquid phases along the channel cross-section, the thickness of the annular layer and their connection with the mass content of the gas phase in the gas-liquid flow is given in the paper.The analytical method is based on the fundamental laws of theoretical mechanics and thermophysics on the minimum of energy dissipation and the minimum rate of increase in the system entropy, which determine the stability of stationary states and processes. Obtained dependencies disclose the physical laws of the motion of two-phase media and can be used in hydraulic calculations during the design and operation of refrigeration and air conditioning systems.

scholarly journals Schéma SRNHS Analyse et Application d'un schéma aux volumes finis dédié aux systèmes non homogènes

2006 ◽  
Vol Volume 5, Special Issue TAM... ◽  
Author(s):  
Slah SAHMIM ◽  
Fayssal Benkhaldoun
Keyword(s):  
Shallow Water ◽  
Scalar Case ◽  
Finite Volume Scheme ◽  
Two Phase ◽  
Homogeneous Systems ◽  
Selfsimilar Solution ◽  
International Audience ◽  
The Stability ◽  
New Formulation ◽  
Water Problems

International audience This article is devoted to the analysis, and improvement of a finite volume scheme proposed recently for a class of non homogeneous systems. We consider those for which the corressponding Riemann problem admits a selfsimilar solution. Some important examples of such problems are Shallow Water problems with irregular topography and two phase flows. The stability analysis of the considered scheme, in the homogeneous scalar case, leads to a new formulation which has a naturel extension to non homogeneous systems. Comparative numerical experiments for Shallow Water equations with sourec term, and a two phase problem (Ransom faucet) are presented to validate the scheme. Cet article concerne l'analyse et l'application, d'un schéma proposé récemment por une classe de systèmes non homogènes. Nous considérons ceux pour lesquels le problème de Riemann correpondant admet une solution autosimilaire. Deux exemples importants de tels problèmes sont l'écoulement d'eau peu profonde au-dessus d'un fond non plat et les problèmes diphasiques. l'analyse de stabilité du schéma, dans le cas scalaire homogène, amène à une nouvelle écriture qui a une extension naturelle pour le cas non homogène. Des expériences numériques comparatives pour des équations de saint-Venant avec topographie variable, et un problème diphasique (Robinet de Ransom) sont présentés pour évaluer l'efficacité du schéma.

scholarly journals Stability of the barium-benzo-15-crown-5 complex in nitrobenzene saturated with water

2006 ◽  
Vol 71 (11) ◽  
pp. 1147-1151 ◽  
Author(s):  
E. Makrlík ◽  
P. Vaňura
Keyword(s):  
Stability Constant ◽  
Aqueous Phase ◽  
Extraction Constant ◽  
Two Phase ◽  
Nitrobenzene Phase ◽  
Activity Measurements ◽  
System L ◽  
Exchange Extraction ◽  
Phase Water ◽  
The Stability

From extraction experiments and ?-activity measurements, the exchange extraction constant corresponding to the equilibrium Ba2+(aq) + SrL2 2+(nb) _ BaL 2 2+(nb) + Sr2+(aq) occurring in the two-phase water-nitrobenzene system (L = benzo-15-crown-5; aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K ex (Ba2+, SrL22+) = 0.3 ? 0.1. Furthermore, the stability constant of the benzo-15-crown-5-barium complex in nitrobenzene saturated with water was calculated for the temperature of 25 ?C: log ?nb (BaL2 2+) = 13.3?0.1.

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