Numerical Investigations on the Cooling Performance of the Internal Bypass Cooling System of the Ultra-Supercritical Steam Turbines Using CFD and Conjugate Heat Transfer Method

2013 ◽  
Author(s):  
Wenhao Huo ◽  
Jun Li ◽  
Jiandao Yang ◽  
Liqun Shi ◽  
Zhenping Feng
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Cooling System ◽  
Research Work ◽  
High Pressure Cylinder ◽  
Cooling Performance ◽  
Temperature Distributions ◽  
Pressure Cylinder ◽  
Steam Cooling ◽  
Transfer Method

The cooling effect of the internal bypass cooling system in high pressure cylinder of an ultra-supercritical steam turbine using the conjugation of the flow calculation and heat transfer method was numerically studied in this paper. Three-dimensional Reynolds-Averaged Navier-Stokes (RANS) solutions and k–ε turbulent model with scalable wall function were used to analyze the cooling performance based on the CFD software ANSYS-CFX. The details of the flow pattern of the fluid domains and temperature distributions of the solid domains in the system were illustrated. The temperature field of the high pressure cylinder was compared between the steam cooling case and the non-cooling case without consideration of the steam cooling of the internal bypass cooling system. The main conclusion that can be drawn out of this research work is that the high pressure inner casing and the large part of axial thrust balance piston can be effectively cooled by the internal bypass cooling system. In addition, the resulting temperature distributions of the inner casing are uniformed compared to the non-cooling case. The temperature of the outer casing of the high pressure cylinder increases a little compared to the non-cooling case.

High Pressure and Flow Rate Measurements on Peroxide Dosing Pumps Under Laboratory and Site Conditions

2006 ◽  
Author(s):  
Franz H. Trieb ◽  
Reinhard Karl ◽  
Rene Moderer
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Research Work ◽  
Maximum Pressure ◽  
Hydraulic Pressure ◽  
Site Conditions ◽  
High Pressure Cylinder ◽  
Injection Pump ◽  
Pressure Cylinder ◽  
High Pressure Level

The performance and reliability of peroxide dosing pumps are essential for every LDPE plant. The paper presents the results of measurement at an initiator injection pump under laboratory and site conditions. The recording was done with a flow meter and a high pressure transducer, both suitable for a maximum pressure of 400 MPa. It compares the results of hydraulic pressure inside the actuating cylinder at the intensifier with high pressure level and flow rate on the discharge connection of the pump. Direct measurement inside the high pressure cylinder and the possibilities to influence the fluctuations with a servo valve system round out the research work.

scholarly journals Experimental and Theoretical Research of a Hot Condition of High Pressure Cylinder of the T-100-130 Steam Turbine

2019 ◽  
Vol 62 (5) ◽  
pp. 459-468
Author(s):  
V. A. Kudinov ◽  
E. V. Kotova ◽  
O. Yu. Kurganova ◽  
V. K. Tkachev
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermal Conductivity ◽  
High Pressure ◽  
Steam Turbine ◽  
Temperature Difference ◽  
High Pressure Cylinder ◽  
Temperature State ◽  
Pressure Cylinder ◽  
Stationary Operation

The results of experimental and theoretical studies of the temperature state of the high- pressure cylinder (HPC) of the T-100-130 steam turbine for one of the start modes are presented. Taking into account the dependence of the coefficient of linear expansion on the temperature, the elongations of the individual sections of the casing under different temperatures and its total elongation after the turbine operation starts to correspond to the stationary operation mode have been found. The studies have shown that in the process of actuation the turbine there is a significant difference in temperature along the length of the HPC casing. In this case, the most intense heating occurs in the area from the second to the sixth section. The greatest temperature difference was observed in stationary operation at maximum temperature in the fifth section. Using the orthogonal method of L. V. Kantorovich, an approximate analytical solution of the thermal conductivity problem for a two-layer wall (turbine casing – thermal insulation) under inhomogeneous boundary conditions of the third kind is obtained. With the use of experimental data on the temperature state of the outer surface of the casing of the HPC by solving the inverse problem of thermal conductivity, the average heat transfer coefficients for the actuation period characterizing the intensity of heat transfer from steam to the casing have been found. On the basis of experimental data on the temperature change of any of the controlled parameters of the turbine over time, a theoretical method for predicting its change in a certain time range from the time of the its last measurement has been developed. The use of this method to predict the change in the temperature difference between the top and bottom of the HPC casing during the actuation showed that for a period of time equal to 3–5 minutes the forecast is fulfilled with high reliability.

Evaluation of Numerical Methods to Predict Temperature Distributions of an Experimentally Investigated Convection-Cooled Gas-Turbine Blade

2017 ◽  
Author(s):  
E. Findeisen ◽  
B. Woerz ◽  
M. Wieler ◽  
P. Jeschke ◽  
M. Rabs
Keyword(s):  
Heat Transfer ◽  
Numerical Methods ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Gas Turbines ◽  
Cooling System ◽  
Fe Model ◽  
Gas Turbine Blade ◽  
Transfer Coefficients ◽  
Temperature Distributions

This paper presents two different numerical methods to predict the thermal load of a convection-cooled gas-turbine blade under realistic operating temperature conditions. The subject of the investigation is a gas-turbine rotor blade equipped with an academic convection-cooling system and investigated at a cascade test-rig. It consists of three cooling channels, which are connected outside the blade, so allowing cooling air temperature measurements. Both methods use FE models to obtain the temperature distribution of the solid blade. The difference between these methods lies in the generation of the heat transfer coefficients along the cooling channel walls which serve as a boundary condition for the FE model. One method, referred to as the FEM1D method, uses empirical one-dimensional correlations known from the available literature. The other method, the FEM2D method, uses three-dimensional CFD simulations to obtain two-dimensional heat transfer coefficient distributions. The numerical results are compared to each other as well as to experimental data, so that the benefits and limitations of each method can be shown and validated. Overall, this paper provides an evaluation of the different methods which are used to predict temperature distributions in convection-cooled gas-turbines with regard to accuracy, numerical cost and the limitations of each method. The temperature profiles obtained in all methods generally show good agreement with the experiments. However, the more detailed methods produce more accurate results by causing higher numerical costs.

Clocking Effects of Inlet Non-Uniformities in a Fully Cooled High-Pressure Vane: A Conjugate Heat Transfer Analysis

2015 ◽  
Author(s):  
Duccio Griffini ◽  
Massimiliano Insinna ◽  
Simone Salvadori ◽  
Francesco Martelli
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Cooling System ◽  
Hot Spot ◽  
Three Dimensional ◽  
Leading Edge ◽  
Suction Side ◽  
Heat Transfer Analysis

A high-pressure vane equipped with a realistic film-cooling configuration has been studied. The vane is characterized by the presence of multiple rows of fan-shaped holes along pressure and suction side while the leading edge is protected by a showerhead system of cylindrical holes. Steady three-dimensional Reynolds-Averaged Navier-Stokes (RANS) simulations have been performed. A preliminary grid sensitivity analysis with uniform inlet flow has been used to quantify the effect of spatial discretization. Turbulence model has been assessed in comparison with available experimental data. The effects of the relative alignment between combustion chamber and high-pressure vanes are then investigated considering realistic inflow conditions in terms of hot spot and swirl. The inlet profiles used are derived from the EU-funded project TATEF2. Two different clocking positions are considered: the first one where hot spot and swirl core are aligned with passage and the second one where they are aligned with the leading edge. Comparisons between metal temperature distributions obtained from conjugate heat transfer simulations are performed evidencing the role of swirl in determining both the hot streak trajectory within the passage and the coolant redistribution. The leading edge aligned configuration is resulted to be the most problematic in terms of thermal load, leading to increased average and local vane temperature peaks on both suction side and pressure side with respect to the passage aligned case. A strong sensitivity of both injected coolant mass flow and heat removed by heat sink effect has also been highlighted for the showerhead cooling system.

Exploring Autofrettage Process to Improve the Fatigue Life on High-Pressure Cylinder

2013 ◽  
Vol 457-458 ◽  
pp. 518-521
Author(s):  
Feng Ling Yang ◽  
Shi Jin Zhang
Keyword(s):  
High Pressure ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Analysis ◽  
High Pressure Cylinder ◽  
Pressure Cylinder ◽  
Surface Variation ◽  
Life Improvement ◽  
Improve Fatigue Strength ◽  
Improve Fatigue

Autofrettage process is now widely used to improve fatigue strength of high pressure components. This paper focuses on the fatigue life improvement of the high-pressure cylinder treated by autofrettage process. In this process, a high pressure cylinder treated by autofrettage process has been simulated by using FEA software, and surface variation of the cylinder has been analyzed. To further understand this process, theoretical fatigue analysis has also been carried out.

Influence of a Leaking Gap Downstream of the Injection Holes on Film Cooling Performance

1996 ◽  
Author(s):  
Y. Yu ◽  
M. K. Chyu
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Film Cooling ◽  
Cooling System ◽  
Convective Transport ◽  
Hole Injection ◽  
Thermochromic Liquid Crystal ◽  
Cooling Performance ◽  
Temperature Problem

This study investigated a practical but never exploited issue concerning the influence of flow leakage through a gap downstream on the film cooling performance with a row of discrete-hole injection. A heat transfer system as such can be categorized as either a three-temperature or a four-temperature problem, depending on the direction of leakage through the gap. To fully characterize a three-temperature based film-cooling system requires knowledge of both local film effectiveness and heat transfer coefficient. A second film effectiveness is necessary for characterizing a four-temperature problem. All these variables can be experimentally determined, based on the transient method of thermochromic liquid crystal imaging. Although the overall convective transport in the region is expected to be dependent on the blowing ratios of the coolants, the mass flow ratio of the two injectants, and the geometry, the current results indicated that the extent of flow injection or extraction through the gap has significant effects on the film effectiveness and less on the heat transfer coefficient which is primarily dominated by the geometric disturbance of gap presence.

Numerical Prediction of Cooling Performance Sensitivity of 1st Stage Nozzle Guide Vane Under Aerothermal Conditions

2019 ◽  
Author(s):  
Prasert Prapamonthon ◽  
Bo Yin ◽  
Guowei Yang ◽  
Mohan Zhang
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
High Pressure ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
High Pressure Turbine ◽  
Cooling Performance ◽  
Nozzle Guide Vane ◽  
Nozzle Guide

Abstract To obtain high power and thermal efficiency, the 1st stage nozzle guide vanes of a high-pressure turbine need to operate under serious circumstances from burned gas coming out of combustors. This leads to vane suffering from effects of high thermal load, high pressure and turbulence, including flow-separated transition. Therefore, it is necessary to improve vane cooling performance under complex flow and heat transfer phenomena caused by the integration of these effects. In fact, these effects on a high-pressure turbine vane are controlled by several factors such as turbine inlet temperature, pressure ratio, turbulence intensity and length scale, vane curvature and surface roughness. Furthermore, if the vane is cooled by film cooling, hole configuration and blowing ratio are important factors too. These factors can change the aerothermal conditions of the vane operation. The present work aims to numerically predict sensitivity of cooling performances of the 1st stage nozzle guide vane under aerodynamic and thermal variations caused by three parameters i.e. pressure ratio, coolant inlet temperature and height of vane surface roughness using Computational Fluid Dynamics (CFD) with Conjugate Heat Transfer (CHT) approach. Numerical results show that the coolant inlet temperature and the vane surface roughness parameters have significant effects on the vane temperature, thereby affecting the vane cooling performances significantly and sensitively.

scholarly journals Computational Evolving Technique for Casting Process of Alloys

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Amir M. Horr
Keyword(s):  
Heat Transfer ◽  
Continuous Casting ◽  
Numerical Simulations ◽  
Computational Models ◽  
Cooling System ◽  
Research Work ◽  
Industrial Process ◽  
Casting Process ◽  
Computational Time ◽  
Mechanical Coupling

The challenging task of bringing together the advanced computational models (with high accuracy) with reasonable computational time for the practical simulation of industrial process applications has promoted the introduction of innovative numerical methods in recent decades. The time and efforts associated with the accurate numerical simulations of manufacturing processes and the sophisticated multiphysical and multiscale nature of these processes have historically been challenging for mainstream industrial numerical tools. In particular, the numerical simulations of industrial continuous and semicontinuous casting processes for light metal alloys have broadly been reinvigorated to investigate the optimization of casting processes. The development of advanced numerical techniques (e.g., multiscale/physical, finite zoning, and evolving domain techniques) for industrial process simulations including the transient melt flow, heat transfer, and evolution of stress/strain and damage during continuous casting processes have endeavored many new opportunities. However, smarter and broader improvements are needed to capture the underlying physical/chemical phenomena including multiscale/physical transient fluid-thermal-mechanical coupling and dynamic heat-transfer changes during these processes. Within this framework, the cooling system including its fluid flow and its characteristic heat transfer has to be modelled. In the research work herein, numerical studies of a novel transient evolving technique including the thermal-mechanical phenomena and Heat Transfer Coefficient (HTC) estimation using empirical and reverse analyses are presented. The phase change modeling during casting process including liquid/solid interface and also the implementation of dynamic HTC curves are also considered. One of the main contributions of this paper is to show the applicability and reliability of the newly developed evolving numerical simulation approach for in-depth investigations of continuous casting processes.

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