scholarly journals Reasonable Paths of Construction Ventilation for Large-Scale Underground Cavern Groups in Winter and Summer

2018 ◽  
Vol 10 (10) ◽  
pp. 3768 ◽  
Author(s):  
Jianchun Sun ◽  
Heng Zhang ◽  
Muyan Huang ◽  
Qianyang Chen ◽  
Shougen Chen
Keyword(s):  
Temperature Difference ◽  
Large Scale ◽  
Natural Ventilation ◽  
Three Dimensional ◽  
Axial Flow ◽  
Optimal Placement ◽  
Underground Cavern ◽  
Oil Storage ◽  
Co Concentration ◽  
Ventilation Scheme

Forced ventilation or newly built vertical shafts are mainly used to solve ventilation problems in large underground cavern groups. However, it is impossible to increase air supply due to the size restriction of the construction roadway, resulting in ventilation deterioration. Based on construction of the Jinzhou underground oil storage project, we proposed both a summer ventilation scheme and winter ventilation scheme, after upper layer excavation of the cavern is completed and connected with the shaft. A three-dimensional numerical model validated with field test data was performed to investigate air velocity and CO concentration. Fan position optimization and the influence of temperature difference on natural ventilation were discussed. The results show that CO concentration in the working area of the cavern can basically drop to a safe value of 30 mg/m3 in air inlet and exhaust schemes after 10 min of ventilation. Since there is inevitably a back-flow in the winter ventilation scheme, it is necessary to ensure that airflow is always moving towards the shaft. Optimal placement of the axial flow fan at the shaft bottom is on the central axis of the cavern, 5 m away from the shaft. The greater the temperature difference, the better the natural ventilation effect of the shaft. The natural ventilation effect of the shaft as an outlet in winter, is better than that of the shaft as an inlet in summer.

An Experimental Investigation of the Flow Through an Axial-Flow Pump

1995 ◽  
Vol 117 (3) ◽  
pp. 485-490 ◽  
Author(s):  
W. C. Zierke ◽  
W. A. Straka ◽  
P. D. Taylor
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Fast Response ◽  
Complex Flow ◽  
Penn State ◽  
Response Pressure ◽  
Axial Flow Pump ◽  
Scale Experiment ◽  
High Reynolds

The high Reynolds number pump (HIREP) facility at ARL Penn State has been used to perform a low-speed, large-scale experiment of the incompressible flow of water through a two-blade-row turbomachine. The objectives of this experiment were to provide a database for comparison with three-dimensional, turbulent flow computations, to evaluate engineering models, and to improve our physical understanding of many of the phenomena involved in this complex flow field. This summary paper briefly describes the experimental facility, as well as the experimental techniques—such as flow visualization, static-pressure measurements, laser Doppler velocimetry, and both slow- and fast-response pressure probes. Then, proceeding from the inlet to the exit of the pump, the paper presents highlights of experimental measurements and data analysis, giving examples of measured physical phenomena such as endwall boundary layers, separation regions, wakes, and secondary vortical structures. In conclusion, this paper provides a synopsis of a well-controlled, larger scope experiment that should prove helpful to those who wish to use the database.

Three-Dimensional Turbulent Flow in the Tip Region of an Axial Compressor Rotor Passage at a Near Stall Condition

2001 ◽  
Author(s):  
Hongwei Ma ◽  
Haokang Jiang
Keyword(s):  
Turbulent Flow ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Leading Edge ◽  
Rotating Stall ◽  
Suction Surface ◽  
Tip Leakage Vortex ◽  
Tip Leakage ◽  
Compressor Rotor

This paper presents an experimental study of the three-dimensional turbulent flow field in the tip region of an axial flow compressor rotor passage at a near stall condition. The investigation was conducted in a low-speed large-scale compressor using a 3-component Laser Doppler Velocimetry and a high frequency pressure transducer. The measurement results indicate that a tip leakage vortex is produced very close to the leading edge, and becomes the strongest at about 10% axial chord from the leading edge. Breakdown of the vortex periodically occurs at about 1/3 chord, causing very strong turbulence in the radial direction. Flow separation happens on the tip suction surface at about half chord, prompting the corner vortex migrating toward the pressure side. Tangential migration of the low-energy fluids results in substantial flow blockage and turbulence in the rear of a rotor passage. Unsteady interactions among the tip leakage vortex, the separated vortex and the corner flow should contribute to the inception of the rotating stall in a compressor.

The Reliability Research on Water-Sealed Conditions of Underground Water-Sealed Oil Storage Caverns in Guangdong Huizhou, China

2012 ◽  
Vol 170-173 ◽  
pp. 1318-1324 ◽  
Author(s):  
Bin Zhang ◽  
Bo Yang ◽  
Yu Xin Jie ◽  
Xiang Yang Kang ◽  
Li Qing Li
Keyword(s):  
Large Scale ◽  
High Reliability ◽  
Three Dimensional ◽  
Underground Water ◽  
Evaluation Index System ◽  
Fuzzy Analytical Hierarchy Process ◽  
Oil Storage ◽  
Before And After ◽  
Hierarchy Process

Reliability of water-sealed conditions is crucial to the safety of water-sealed oil-storage. With a case study of underground water-sealed oil storage cavern in Huizhou, a reliability evaluation index system of water-sealed conditions is estabilished based on the main factors influencing water-sealed conditions. Also, a zonal evaluation of water-sealed conditions of the cave rock mass ranging from 0m to -70m is made by Fuzzy Analytical Hierarchy Process. Moreover, a three-dimensional numerical seepage model is established to study the seepage laws of the groundwater before and after the cavern excavation, and the water inflow during excavation and operation can be forecasted too. The results prove that the cavern site is suitable for the construction of large-scale underground oil storage caverns for its good water-sealed conditions and high reliability.

Unsteady Three-Dimensional Turbine Aerodynamics

1983 ◽  
Vol 105 (2) ◽  
pp. 322-331 ◽  
Author(s):  
H. D. Joslyn ◽  
R. P. Dring ◽  
O. P. Sharma
Keyword(s):  
Total Pressure ◽  
Velocity Vector ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
High Response ◽  
Phase Lock ◽  
Reduced Data ◽  
Made In ◽  
Periodic Changes

High response aerodynamic measurements were made in a large-scale, axial, flow turbine model to study the unsteadiness and three dimensionality of the flow. High response velocity vector and total pressure data were acquired. A comparison was made of the results of phase lock averaging both raw and reduced data (voltages and velocities). The velocity vector measurements showed that there were strong radial flows present as well as significant periodic changes in the flow field due to relative rotor and vane positions. Random, periodic, and total unsteadiness levels were computed from the instantaneous and phase-lock-averaged velocity data. Time-averaged data were compared with an inviscid two-dimensional calculation. A comparison was also made of time-averaged total pressure measurements obtained from high-response and low-response (steady-state) probes.

scholarly journals Optimization Scheme for Construction Ventilation in Large-Scale Underground Oil Storage Caverns

2018 ◽  
Vol 8 (10) ◽  
pp. 1952 ◽  
Author(s):  
Heng Zhang ◽  
Jianchun Sun ◽  
Fang Lin ◽  
Shougen Chen ◽  
Jiasong Yang
Keyword(s):  
Turbulence Model ◽  
Large Scale ◽  
Axial Flow ◽  
Navier Stokes ◽  
Ventilation Mode ◽  
Air Velocity ◽  
Gas Dispersion ◽  
Air Inlet ◽  
Oil Storage ◽  
Heavy Trucks

The ventilation effect has a direct influence on the efficiency and security of the construction of an underground cavern group. Traditional forced ventilation schemes may be ineffective and result in resource wastage. Based on the construction ventilation of the Jinzhou underground oil storage project, an axial flow gallery ventilation mode using shafts as the fresh air inlet was proposed. A 3D steady RANS (Reynolds Averaged Navier-Stokes) approach with the RNG (Renormalization-group) k-ε turbulence model was used to study airflow behavior and hazardous gas dispersion when different ventilation schemes were employed. Field test values of the air velocity and CO concentration in the main cavern and construction roadway were also adopted to validate the RNG k-ε turbulence model. The results showed that the axial flow gallery ventilation mode can ensure that the direction of air flow is the same as that of heavy trucks, fresh air is always near the excavation face, and the disturbance of the construction process is greatly reduced. The scheme is suitable for large-scale caverns with a ventilation distance less than 2 km, and an intermediate construction shaft is not needed. When the ventilation distance exceeds 2 km, it is possible to use jet fans to assist the axial flow gallery ventilation mode or to completely adopt jet-flow gallery ventilation.

A Trace Gas Technique to Study Mixing in a Turbine Stage

1988 ◽  
Vol 110 (1) ◽  
pp. 38-43 ◽  
Author(s):  
H. D. Joslyn ◽  
R. P. Dring
Keyword(s):  
Temperature Profile ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Surface Flow ◽  
Trace Gas ◽  
Inlet Temperature ◽  
Turbine Stage ◽  
Radial Temperature ◽  
Gas Concentration

An experimental technique to study mixing in a turbine stage is demonstrated. An axisymmetric, radial temperature profile at the inlet to the first stator of a large-scale, low-speed, single-stage, axial flow turbine model is simulated with a radial trace gas concentration distribution. Mixing or redistribution of the inlet profile by three-dimensional aerodynamic mechanisms (other than temperature-driven mechanisms) is determined from trace gas concentration measurements made in both the stationary and rotating frames of reference at various locations through the turbine. The trace gas concentration contours generated are consistent with flow pitch angle measurements made downstream of the first stator and with surface flow visualization on the rotor airfoil and the hub endwall. It is demonstrated that this trace gas technique is well suited to quantify many aspects of the redistribution and diffusion of an inlet temperature profile as it is convected through a turbine stage.

Unsteady Three-Dimensional Turbine Aerodynamics

1982 ◽  
Author(s):  
H. D. Joslyn ◽  
R. P. Dring ◽  
O. P. Sharma
Keyword(s):  
Total Pressure ◽  
Velocity Vector ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
High Response ◽  
Phase Lock ◽  
Reduced Data ◽  
Made In ◽  
Periodic Changes

High response aerodynamic measurements were made in a large scale, axial, flow turbine model to study the unsteadiness and three dimensionality of the flow. High response velocity vector and total pressure data were acquired. A comparison was made of the results of phase lock, averaging both raw and reduced data (voltages and velocities). The velocity vector measurements showed that there were strong radial flows present as well as significant periodic changes in the flow field due to relative rotor and vane positions. Random, periodic, and total unsteadiness levels were computed from the instantaneous and phase lock averaged velocity data. Time averaged data were compared with an inviscid two-dimensional calculation. A comparison was also made of time averaged total pressure measurements obtained from high response and low response (steady-state) probes.

Measurement and Calculation of Turbine Cascade Endwall Pressure and Shear Stress

2005 ◽  
Vol 128 (2) ◽  
pp. 232-239 ◽  
Author(s):  
Brian M. Holley ◽  
Sandor Becz ◽  
Lee S. Langston
Keyword(s):  
Shear Stress ◽  
Skin Friction ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Predictive Ability ◽  
Wall Friction ◽  
Friction Coefficients ◽  
Local Skin ◽  
Aerodynamic Loss

The complex three-dimensional fluid flow on the endwall in an axial flow turbine blade or vane passage has been extensively investigated and reported on in turbomachinery literature. The aerodynamic loss producing mechanisms associated with the endwall flow are still not fully understood or quantitatively predictable. To better quantify wall friction contributions to endwall aerodynamic loss, low Mach number wind tunnel measurement of skin friction coefficients have been made on one endwall of a large scale cascade of high pressure turbine airfoils, at engine operating Reynolds numbers. Concurrently, predictive calculations of the endwall flow shear stress have been made using a computational fluid dynamics (CFD) code. Use of the oil film interferometry skin friction technique is described and applied to the endwall, to measure local skin friction coefficients and shear stress directions on the endwall. These are correlated with previously reported measured local endwall pressure gradients. The experimental results are discussed and compared to the CFD calculations, to answer questions concerning endwall aerodynamic loss predictive ability.

scholarly journals Negative Incidence Flow Over a Turbine Rotor Blade

1983 ◽  
Author(s):  
H. David Joslyn ◽  
Robert P. Dring
Keyword(s):  
Gas Turbines ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Turbine Rotor ◽  
Surface Flow ◽  
Separated Flows ◽  
Turbine Rotor Blade ◽  
Pressure Surface ◽  
Pressure Distributions

The operation of variable cycle gas turbines at negative incidence can result in highly three dimensional separated flows on the turbine rotor pressure surface. These flows can impact both performance and durability. The present program was conducted to experimentally study the behavior of surface flow on a large scale axial flow turbine rotor with incidence varying up to and including negative incidence separation. Fullspan pressure distributions and surface flow visualization were acquired over a range of incidence. The data indicate that at large negative incidence, pressure surface separation occurred and extended to 60 percent chord at midspan. These separated flows were simulated at midspan by applying potential flow theory to match the measured pressure distributions.

Measurement and Calculation of Turbine Cascade Endwall Pressure and Shear Stress

2005 ◽  
Author(s):  
Brian M. Holley ◽  
Sandor Becz ◽  
Lee S. Langston
Keyword(s):  
Shear Stress ◽  
Skin Friction ◽  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Predictive Ability ◽  
Wall Friction ◽  
Friction Coefficients ◽  
Local Skin ◽  
Aerodynamic Loss

The complex three-dimensional fluid flow on the endwall in an axial flow turbine blade or vane passage has been extensively investigated and reported on in turbomachinery literature. The aerodynamic loss producing mechanisms associated with the endwall flow are still not fully understood or quantitatively predictable. To better quantify wall friction contributions to endwall aerodynamic loss, low Mach number wind tunnel measurement of skin friction coefficients have been made on one endwall of a large scale cascade of high pressure turbine airfoils, at engine operating Reynolds numbers. Concurrently, predictive calculations of the endwall flow shear stress have been made using a computational fluid dynamics (CFD) code. Use of the oil film interferometry skin friction technique is described and applied to the endwall, to measure local skin friction coefficients and shear stress directions on the endwall. These are correlated with previously reported measured local endwall pressure gradients. The experimental results are discussed and compared to the CFD calculations, to answer questions concerning endwall aerodynamic loss predictive ability.

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