Numerical Investigations on the Aerodynamic Performance of Turbine Stage and Rotordynamic Characteristics of Stator Seal With Consideration of Supplementary Steam

2015 ◽  
Author(s):  
Zhigang Li ◽  
Jun Li ◽  
Shizhu Wang ◽  
Dawei Ji ◽  
Gaohui Xiao ◽  
...  
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Labyrinth Seal ◽  
Aerodynamic Performance ◽  
High Pressure Cylinder ◽  
Turbine Stage ◽  
Boundary Flow ◽  
Rotordynamic Coefficients ◽  
Pressure Cylinder ◽  
Stator Blade

The supplementary steam structure is used in the high pressure cylinder to increase the power output of steam turbine through increase the mass flow rate. In this work, the supplementary steam structure installed between the fifth and sixth stage of the high pressure cylinder of steam turbine is taken as the research object. The flow field and aerodynamic performance of the fifth and sixth stage was numerically investigated at different supplement steam rates using the three-dimensional Reynolds-Averaged Navier-Stokes (RANS) and k–ε turbulent model solutions. The inlet/outlet boundary flow conditions of the stator labyrinth seal of the sixth stage was determined based on the steady computations at three different supplementary steam rates. The unsteady flow field and rotordynamic coefficients of the stator labyrinth seal were calculated using the multi-frequency elliptical whirling orbit model and dynamic grid technique based on the unsteady RANS solutions. The numerical results show that the supplementary steam jet impacts on the hub regions of the stator blade of the sixth stage and results in the vortex flow. This flow behavior leads to the non-uniform inlet aerodynamic parameters at the entrance of the stator blade of the sixth stage. The aerodynamic performance decreases with the increase of the supplementary steam rates. The supplementary steam jet changes the inlet preswirl and boundary flow condition of the stator labyrinth seal of the sixth stage. The fluid excitation rotordynamic coefficients of the stator labyrinth seal would change due to the variation of the boundary flow condition. The detailed flow pattern of the turbine stage and variation of the rotordynamic coefficients of the stator labyrinth seal at different supplementary steam rates were also illustrated and discussed.

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.

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.

Comparison of Steady and Unsteady Coupled Heat-Transfer Simulations of a High-Pressure Turbine Blade

2015 ◽  
Author(s):  
Markus Schmidt ◽  
Christoph Starke
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Steady State ◽  
Flow Field ◽  
Film Cooling ◽  
Strong Increase ◽  
Pressure Side ◽  
Turbine Stage ◽  
High Pressure Turbine ◽  
Time Resolved

This article presents results for the coupled simulation of a high-pressure turbine stage in consideration of unsteady hot gas flows. A semi-unsteady coupling process was developed to solve the conjugate heat transfer problem for turbine components of gas turbines. Time-resolved CFD simulations are coupled to a finite element solver for the steady state heat conduction inside of the blade material. A simplified turbine stage geometry is investigated in this paper to describe the influence of the unsteady flow field onto the time-averaged heat transfer. Comparisons of the time-resolved results to steady state results indicate the importance of a coupled simulation and the consideration of the time-dependent flow-field. Different film-cooling configurations for the turbine NGV are considered, resulting in different temperature and pressure deficits in the vane wake. Their contribution to non-linear effects causing the time-averaged heat load to differ from a steady result is discussed to further highlight the necessity of unsteady design methods for future turbine developments. A strong increase in the pressure side heat transfer coefficients for unsteady simulations is observed in all results. For higher film-cooling mass flows in the upstream row, the preferential migration of hot fluid towards the pressure side of a turbine blade is amplified as well, which leads to a strong increase in material temperature at the pressure side and also in the blade tip region.

Investigation of the Flow Field in a High-Pressure Turbine Stage for Two Stator-Rotor Axial Gaps—Part II: Unsteady Flow Field

2006 ◽  
Vol 129 (3) ◽  
pp. 580-590 ◽  
Author(s):  
P. Gaetani ◽  
G. Persico ◽  
V. Dossena ◽  
C. Osnaghi
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Unsteady Flow ◽  
Outer Part ◽  
Secondary Flows ◽  
Pressure Probe ◽  
Turbine Stage ◽  
Mean Flow ◽  
Tip Leakage Flow ◽  
Flow Measurements

An extensive experimental analysis was carried out at Politecnico di Milano on the subject of unsteady flow in high pressure (HP) turbine stages. In this paper, the unsteady flow measured downstream of a modern HP turbine stage is discussed. Traverses in two planes downstream of the rotor are considered, and, in one of them, the effects of two very different axial gaps are investigated: the maximum axial gap, equal to one stator axial chord, is chosen to “switch off” the rotor inlet unsteadiness, while the nominal gap, equal to 1/3 of the stator axial chord, is representative of actual engines. The experiments were performed by means of a fast-response pressure probe, allowing for two-dimensional phase-resolved flow measurements in a bandwidth of 80kHz. The main properties of the probe and the data processing are described. The core of the paper is the analysis of the unsteady rotor aerodynamics; for this purpose, instantaneous snapshots of the rotor flow in the relative frame are used. The rotor mean flow and its interaction with the stator wakes and vortices are also described. In the outer part of the channel, only the rotor cascade effects can be observed, with a dominant role played by the tip leakage flow and by the rotor tip passage vortex. In the hub region, where the secondary flows downstream of the stator are stronger, the persistence of stator vortices is slightly visible in the maximum stator-rotor axial gap configuration, whereas in the minimum stator-rotor axial gap configuration their interaction with the rotor vortices dominates the flow field. A good agreement with the wakes and vortices transport models has been achieved. A discussion of the interaction process is reported giving particular emphasis to the effects of the different cascade axial gaps. Some final considerations on the effects of the different axial gap over the stage performances are reported.

scholarly journals Specific Features of the Replacement of the Available Flow Path by the Optimal Flow Path when Upgrading the Steam Turbine High-Pressure Cylinder

2021 ◽  
pp. 5-11
Author(s):  
Riza Sherfedinov ◽  
Oleksandr Usatyi ◽  
Olena Avdieieva ◽  
Mykhailo Daludin ◽  
Illia Yenin
Keyword(s):  
High Pressure ◽  
Turbine Unit ◽  
Optimization Problem ◽  
Flow Path ◽  
Feed Water ◽  
High Pressure Cylinder ◽  
Efficient Operation ◽  
Thermal Circuit ◽  
Optimal Flow ◽  
Pressure Cylinder

This scientific paper gives the main research data obtained during the solution of the search problem to define optimal parameter values for the thermal circuit of the К-540-23.5 turbine unit that would provide the most efficient operation both for the optimal version of the high pressure cylinder (HPC) as part of the turbine unit and the turbine unit on the whole. The effect of the distribution of heat differences in the stages of the optimal flow part of the high pressure cylinder used by the К-540-23.5 turbine on the integral quality factors of the turbine unit has been assessed. The calculation studies of the thermal circuit of the turbine unit with the optimal flow section of the high-pressure cylinder showed that the temperature of the underheated feed water in the high pressure heater (HPH) arranged near the steam generator has the most critical effect on the power and economical efficiency of the high pressure cylinder and entire turbine unit. The two-criterion Pareto problem for the upgrading of the turbine unit was formulated and solved to define optimal underheating temperature values. Consideration was given to the two variants of the solution of the optimization problem for the feed water underheating temperature in the high pressure heater. Comparison and analysis of the two variants of solution for the two-criterion optimization problem showed the identity of the obtained data and it confirms the correctness of the problem formulation and the algorithms used for its solution.

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