In-situ calibration of feedwater flow nozzles
- ENCOR-AMERICA, Inc., Mountain View, CA (United States); and others
Feedwater flow is often the most difficult power-plant parameter to measure reliably. Over the life of a power plant, the feedwater nozzle can accumulate deposits, erode, or suffer other damage that can render the original nozzle calibration inaccurate. Recalibration of installed feedwater flow nozzles is expensive and time consuming. Traditionally, the nozzle is cut out of the thick wall feedwater piping and send to a laboratory for recalibration--an especially difficult, expensive, and time-consuming task in high-pressure lines. ENCOR-AMERICA, Inc. has developed an accurate and cost-effective method of in-situ calibration of feedwater nozzles by measuring (concurrently) feedwater flow and differential pressure across the nozzle at various flow rates. During the tests, feedwater flow is determined indirectly. Extraction steam to the highest pressure feedwater heater is measured by use of a high-accuracy turbine flowmeter. This meter is calibrated in an independent laboratory with a primary or secondary device traceable to the National Institute of Standards and Technology (NIST). The feedwater flow is then calculated by performing a heat balance around the feedwater heater. This paper discusses test theory and instrumentation. Also presented are test results of an in-situ feedwater nozzle calibration test performed at Montana Power Company`s Colstrip Unit 2 Power Plant.
- Research Organization:
- Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Encor-America, Inc., Mountain View, CA (United States)
- OSTI ID:
- 114963
- Report Number(s):
- EPRI-TR-104241-V4; CONF-940540-VOL.4; TRN: 95:007224-0002
- Resource Relation:
- Conference: 1994 Electric Power Research Institute (EPRI) heat-rate improvement conference, Baltimore, MD (United States), 3-5 May 1994; Other Information: PBD: Jun 1995; Related Information: Is Part Of 1994 EPRI heat-rate improvement conference. Final report, Volume 4; PB: 400 p.
- Country of Publication:
- United States
- Language:
- English
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