Symposium on Welded Spiral Cases From the Manufacturer’s Viewpoint: A Five-Part Symposium

An important but unspectacular part of hydroelectric power developments is the steel spiral case that guides the water from the penstock into the hydraulic turbine. The increasing acceptance of welding and the use of high-strength steels in the construction of spiral cases have permitted and required the development of new construction methods. This report is a condensation of the five prepared statements by representatives of the U. S. and Canadian manufacturers presented at the 1957 Annual Meeting of The American Society of Mechanical Engineers.

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Development of Design Criteria for a High Pressure Vessel Construction Code

Journal of Pressure Vessel Technology ◽

10.1115/1.3264905 ◽

1987 ◽

Vol 109 (2) ◽

pp. 256-259 ◽

Cited By ~ 2

Author(s):

G. J. Mraz

Keyword(s):

High Pressure ◽

Pressure Vessel ◽

High Strength Steels ◽

High Strength ◽

Design Criteria ◽

Construction Methods ◽

Shrink Fitting ◽

Section Viii ◽

Pressure Stress ◽

Selection Of

Out of concern for public safety, most legal jurisdictions now require unfired pressure vessel construction to comply with the ASME Boiler and Pressure Vessel Code. Because the present two divisions of Section VIII of that Code are not well suited for high pressure design, a new division is needed [1]. The currently anticipated main design criteria of the proposed division are full plastic flow or full overstrain pressure, stress intensity in the bore, fatigue, and fracture mechanics. The rules are expected to allow better utilization of high strength steels already included in the present Section VIII. At the same time materials of even higher strength are introduced. The benefits of compressive prestress are recognized. Construction methods allowing it’s achievement, such as autofrettage, shrink fitting and wire winding are included. Reasons for selection of the criteria are given.

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Experimental and Numerical Simulations Predictions Comparison of Power and Efficiency in Hydraulic Turbine

Modelling and Simulation in Engineering ◽

10.1155/2011/146054 ◽

2011 ◽

Vol 2011 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Laura Castro ◽

Gustavo Urquiza ◽

Adam Adamkowski ◽

Marcelo Reggio

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Draft Tube ◽

Flow Simulation ◽

Numerical Data ◽

Hydroelectric Power Plant ◽

Hydraulic Turbine ◽

Hydroelectric Power ◽

Spiral Case

On-site power and mass flow rate measurements were conducted in a hydroelectric power plant (Mexico). Mass flow rate was obtained using Gibson's water hammer-based method. A numerical counterpart was carried out by using the commercial CFD software, and flow simulations were performed to principal components of a hydraulic turbine: runner and draft tube. Inlet boundary conditions for the runner were obtained from a previous simulation conducted in the spiral case. The computed results at the runner's outlet were used to conduct the subsequent draft tube simulation. The numerical results from the runner's flow simulation provided data to compute the torque and the turbine's power. Power-versus-efficiency curves were built, and very good agreement was found between experimental and numerical data.

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