Numerical Simulation of Flow in Imported Steam Turbine Inlet Components with Equilibrated Holes in High Performance

2013 ◽  
Vol 712-715 ◽  
pp. 1263-1267
Author(s):  
Shan Tu ◽  
Shu Ming Wu ◽  
Qi Zhou ◽  
Hong Mei Zhang ◽  
Xiao Qing Zhu
Keyword(s):  
Flow Field ◽  
Steam Turbine ◽  
High Performance ◽  
Optimization Design ◽  
Great Influence ◽  
Control Valve ◽  
Stable Operation ◽  
Valve Seat ◽  
Valve Disc ◽  
Interior Flow

The main inlet component of steam turbine is control valve. The stable operation of the steam turbine control valve is vital for safe and stable operation of the steam turbine and safety production of the power plant. However, due to the complexity of the structure and unsteady characteristics of steam flow in the valve, there is not enough experimental method about the detailed flow characteristics of the area near control valve disc and the inside of the valve chamber up to now. This article is to focus on the simulation of the steam turbine control valve interior flow field which includes the valve pre-inlet channel in different conditions, then find the reasons which caused instability and pressure loss of the control valve by analyzing the flow field details, finally further optimization design. The profile matching of the valve disc and valve seat has a great influence on the interior flow field of control valve, so analysis of the high performance valve disc shape and divergence angle of valve seat is carried out, and the research conclusion is used for guide design and development of the control valve.

Digital Analysis of Hydraulic Cone Valve Turbulence Based on Fluent 3D Solver

2013 ◽  
Vol 385-386 ◽  
pp. 93-96
Author(s):  
Hong Ji ◽  
Wei Guo Zhu ◽  
Song Chen ◽  
Jing Zhao
Keyword(s):  
Flow Field ◽  
Great Influence ◽  
Internal Flow ◽  
Energy Utilization ◽  
Valve Seat ◽  
Taper Angle ◽  
Turbulent Characteristics ◽  
Hydraulic Hammer ◽  
Drive And Control ◽  
And Control

The hydraulic cone valve is an important basic component in Fluid drive and control technology. Characteristic of cone valve inner flow filed influences directly the valves performance. Especially when fluid flow in runner is turbulent, characteristics of flow field have great influence on the valves working performance.Main work of this paper is numerical calculation and simulation of cone valve inner runner flow field inside hydraulic hammer. First make a 3D modeling for cone valve using Pro/E, by fluent this paper analyses and discusses the distribution of hydraulic cone valve internal flow field including flow velocity field, pressure field and flow, etc when the cone valve core taper angle is 30°, the gap is 0.5 mm, and inlet velocity is different, analyses position and strength of the vortex, and finds out the main reason for energy consumption.The results of the study show that by the optimal design of the cone valve seat, the density degree of the flow and the size of the vortex is reduced, the energy loss is reduced, negative pressure zone also changes, the noise is reduced and the energy utilization is improved.

Numerical simulation of wet steam transonic condensation flow in the last stage of a steam turbine

2018 ◽  
Vol 28 (10) ◽  
pp. 2378-2403 ◽  
Author(s):  
Xu Han ◽  
Zhonghe Han ◽  
Wei Zeng ◽  
Peng Li ◽  
Jiangbo Qian
Keyword(s):  
Steam Turbine ◽  
Optimization Design ◽  
Great Influence ◽  
Parameter Distribution ◽  
Wet Steam ◽  
Saturation State ◽  
Content Type ◽  
Calculation Results ◽  
Last Stage ◽  
Condensation Flow

Purpose The purpose of this paper is to study the condensation flow of wet steam in the last stage of a steam turbine and to obtain the distribution of condensation parameters such as nucleation rate, Mach number and wetness. Design/methodology/approach Because of the sensitivity of the condensation parameter distribution, a double fluid numerical model and a realizable k-ε-kd turbulence model were applied in this study, and the numerical solution for the non-equilibrium condensation flow is provided. Findings The simulation results are consistent with the experimental results of the Bakhtar test. The calculation results indicate that the degree of departure from saturation has a significant impact on the wet steam transonic condensation flow. When the inlet steam deviates from the saturation state, shock wave interference and vortex mixing also have a great influence on the distribution of water droplets. Originality/value The research results can provide reference for steam turbine wetness losses evaluation and flow passage structure optimization design.

Numerical Simulation and Analysis of Interior Flow Field in Control Valves under the Blocking Fault

2011 ◽  
Vol 317-319 ◽  
pp. 1452-1455 ◽  
Author(s):  
Yan Tao An ◽  
Yong Wang ◽  
Jun Gang Wang
Keyword(s):  
Flow Field ◽  
Field Model ◽  
Cfd Simulation ◽  
Control Valve ◽  
Internal Flow ◽  
Control Performance ◽  
Control Valves ◽  
Fluid State ◽  
Interior Flow ◽  
Valve Control

Establish interior flow field model of the control valves under the blocking fault, using the CFD simulation and analysis the internal flow field of the control valve under the blocking and the trouble-free. The research indicates that blocking changes the fluid state of motion, causes the vortex in the valve core, resulting energy loss and reduces valve control performance.

E101 Development of High Performance Steam Stop/Control Valve for Steam Turbine

2010 ◽  
Vol 2010.15 (0) ◽  
pp. 159-162
Author(s):  
Tsutomu OOISHI ◽  
Fumiio OOTOMO ◽  
Yasunori IWAI ◽  
Yoshiki NIIZEKI ◽  
Tomoo OOFUJI
Keyword(s):  
Steam Turbine ◽  
High Performance ◽  
Control Valve

Experimental investigation on the three-dimensional flow field from a meltblowing slot die

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 724-732
Author(s):  
Changchun Ji ◽  
Yudong Wang
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Great Influence ◽  
Distribution Characteristics ◽  
Air Velocity ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Airflow Distribution ◽  
Slot Die ◽  
Center Area

AbstractTo investigate the distribution characteristics of the three-dimensional flow field under the slot die, an online measurement of the airflow velocity was performed using a hot wire anemometer. The experimental results show that the air-slot end faces have a great influence on the airflow distribution in its vicinity. Compared with the air velocity in the center area, the velocity below the slot end face is much lower. The distribution characteristics of the three-dimensional flow field under the slot die would cause the fibers at different positions to bear inconsistent air force. The air velocity of the spinning centerline is higher than that around it, which is more conducive to fiber diameter attenuation. The violent fluctuation of the instantaneous velocity of the airflow could easily cause the meltblowing fiber to whip in the area close to the die.

scholarly journals Simultaneously controlling heat conduction and infrared absorption with a textured dielectric film to enhance the performance of thermopiles

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yunqian He ◽  
Yuelin Wang ◽  
Tie Li
Keyword(s):  
Heat Conduction ◽  
Infrared Absorption ◽  
High Performance ◽  
Performance Enhancement ◽  
Dielectric Film ◽  
Great Influence ◽  
Thermal Conductance ◽  
Molding Process ◽  
Absorption Properties

AbstractThe heat conduction and infrared absorption properties of the dielectric film have a great influence on the thermopile performance. Thinning the dielectric film, reducing its contact area with the silicon substrate, or adding high-absorptivity nanomaterials has been proven to be effective in improving thermopiles. However, these methods may result in a decrease in the structural mechanical strength and increases in the fabrication complexity and cost. In this work, a new performance-enhancement strategy for thermopiles by simultaneously controlling the heat conduction and infrared absorption with a TExtured DIelectric (TEDI) film is developed and presented. The TEDI film is formed in situ by a simple hard-molding process that is compatible with the fabrication of traditional thermopiles. Compared to the control FLat DIelectric (FLDI) film, the intrinsic thermal conductance of the TEDI film can be reduced by ~18–30%, while the infrared absorption can be increased by ~7–13%. Correspondingly, the responsivity and detectivity of the fabricated TEDI film-based thermopile can be significantly enhanced by ~38–64%. An optimized TEDI film-based thermopile has achieved a responsivity of 156.89 V·W−1 and a detectivity of 2.16 × 108 cm·Hz1/2·W−1, while the response time constant can remain <12 ms. These results exhibit the great potential of using this strategy to develop high-performance thermopiles and enhance other sensors with heat transfer and/or infrared absorption mechanisms.

scholarly journals Analysis of the Influence of Different Bionic Structures on the Noise Reduction Performance of the Centrifugal Pump

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 886
Author(s):  
Cui Dai ◽  
Chao Guo ◽  
Yiping Chen ◽  
Liang Dong ◽  
Houlin Liu
Keyword(s):  
Flow Field ◽  
Noise Reduction ◽  
Centrifugal Pump ◽  
Great Influence ◽  
Frequency Doubling ◽  
Sound Field ◽  
Internal Flow ◽  
Test System ◽  
Centrifugal Pumps ◽  
External Characteristics

The strong noise generated during the operation of the centrifugal pump harms the pump group and people. In order to decrease the noise of the centrifugal pump, a specific speed of 117.3 of the centrifugal pump is chosen as a research object. The bionic modification of centrifugal pump blades is carried out to explore the influence of different bionic structures on the noise reduction performance of centrifugal pumps. The internal flow field and internal sound field of bionic blades are studied by numerical calculation and test methods. The test is carried out on a closed pump test platform which includes external characteristics and a flow noise test system. The effects of two different bionic structures on the external characteristics, acoustic amplitude–frequency characteristics and flow field structure of a centrifugal pump, are analyzed. The results show that the pit structure has little influence on the external characteristic parameters, while the sawtooth structure has a relatively great influence. The noise reduction effect of the pit structure is aimed at the wide-band noise, while the sawtooth structure is aimed at the discrete noise of the blade-passing frequency (BPF) and its frequency doubling. The noise reduction ability of the sawtooth structure is not suitable for high-frequency bands.

Austenite Grain Evolution Mechanism of High Carbon Rail Based on Thermal Technology

2020 ◽  
Vol 837 ◽  
pp. 74-80
Author(s):  
Jun Yuan ◽  
Zhen Yu Han ◽  
Yong Deng ◽  
Da Wei Yang
Keyword(s):  
Grain Size ◽  
Tensile Strength ◽  
Rail Steel ◽  
Heating Temperature ◽  
Great Influence ◽  
Stable Operation ◽  
High Carbon ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Austenite Grains

In view of the special requirements of rails to ensure the safe and stable operation of Railways in China, the formation characteristics of austenite grains in high carbon rail are revealed through industrial exploration, the process of industrial rail heating and rolling is simulated, innovative experimental research methods such as different heating and heat treatment are carried out on the actual rails in the laboratory. Transfer characteristics of austenite grain size, microstructures and key properties of high carbon rail during the process are also revealed. The results show that the austenite grain size of industrial produced U75V rail is about 9.0 grade. When the holding temperature is increased from 800 C to 1300 C, the austenite grain size of high carbon rail steel decreases, the austenite grain are gradually coarsened, and the tensile strength increases slightly. The tensile strength is affected by the heating temperature. With the increase of heating temperature, the elongation and impact toughness of high carbon rail decrease. The heating temperature of high carbon rail combined with austenite grain size shows that the heating temperature has a great influence on austenite grain size, and has the most obvious influence on the toughness of high carbon rail.

Fine-control-valve of halide perovskite single crystal quality for high performance X-ray detection

2021 ◽  
Author(s):  
Weijun Li ◽  
Huayang Li ◽  
Jinmei Song ◽  
Chunjie Guo ◽  
Huimao Zhang ◽  
...  
Keyword(s):  
Single Crystal ◽  
High Performance ◽  
Control Valve ◽  
Crystal Quality ◽  
X Ray ◽  
Fine Control ◽  
Halide Perovskite
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