Measurement of turbine pressures at TVA`s Norris Hydro Project

Book · Sun Dec 31 04:00:00 EST 1995

OSTI ID:220138

Hopping, P; Mobley, M; Pearson, H ^[1]

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1. TVA Engineering Lab., Norris, TN (United States)

The two 50-mW units at the Tennessee Valley Authority`s (TVA`s) Norris Hydro Project are to be upgraded with new Francis runners by the end of 1996. To increase the level of dissolved oxygen (DO) in the turbine discharges, the new turbines will include several alternatives for aerating the flow. For unit 2, the first to be upgraded, aeration outlets will be located at four sites - the discharge edge of the runner buckets, the base of the runner hub, the runner crown, and the wall of the draft tube cone. For each site, the amount of air drawn through the outlets will depend on the local pressure at the outlets and the headloss characteristics of the air supply passageways. Estimates for the pressure are available by two methods - numerical solutions of the governing equations of continuity and momentum, and measurements in the physical model of the turbine. Ideally, pressures obtained by each method should compare favorably. In analyzing the aeration alternatives for Norris, however, comparisons were found to be poor for the discharge edge of the runner buckets. To address these and other concerns, prototype pressure measurements were made in the existing units, both on the runner and in the draft tube cone. The results found that pressures measured on the discharge edge of the runner buckets agree better with the numerical computations, whereas those measured in the draft tube cone agree better with the physical model. The measurements allow the pressure coefficient to be determined for baffles located on the turbine hub and the wall of the draft tube cone. The headloss characteristics of the air supply passageway for the turbine hub is determined based on measured airflows. To provide additional data for estimating runner pressures and designing aeration outlets, similar measurements are planned for the new turbines.

• OSTI ID: 220138
• Report Number(s): CONF-9507190--
• Country of Publication: United States
• Language: English

Related Subjects

13 HYDRO ENERGY
AERATION
CLINCH RIVER
EXPERIMENTAL DATA
HYDRAULIC TURBINES
MEDIUM-HEAD HYDROELECTRIC POWER PLANTS
MODIFICATIONS
PRESSURE MEASUREMENT
TENNESSEE VALLEY AUTHORITY
TESTING