Transcript Slide 1
Maintaining the Flow ! Testing of Nuclear Feedpumps (and other important pumps) Feedwater System Reliability Improvement Meeting The subject today is feedwater pump testing ‘methodology’. Testing occurs initially in the shop following fabrication but eventually and repeatedly monitored under site conditions for many years. Bases for testing is to confirm degradation from design condition (COS), usually one point but could be over a range of conditions assuming: Stable and repeatable conditions process conditions. Equipment free of ‘defect’. Stable suction/NPSHA and speed conditions. Initial pump design, shop and plant test requirements are interconnected. January 23, 2012 FSRUG 2 Importance of Testing Important pumps need to be tested based upon plant reliability and plant safety criteria. Applies to CNP, HDP, SGFWP/RFWP and safety-related pumps. Less important for CWP. Less still for ‘miscellaneous’ pumps. Shop testing of all the pumps precede site acceptance testing. There are rarely ‘typical’ test results. ‘Full assembly’ testing of complete pumpset units at full speed at design process conditions. There are more deviations/errors in installed pump testing due to plant limitations.. January 23, 2012 FSRUG 3 ‘New Feedwater Pump Testing’ What is New? Hydraulic Institute Test Standard 14.6 – 2011. Larger Tolerance Bands (> 3% - 5%). Bilateral Tolerances (+/-). What Hasn’t Changed? Addressing levels of uncertainty vs. fluctuation. Shop vs. system requirements. Need to determine the onset and degree of degradation. Define the test point vs. COS and curve shape. Compare degradation vs. deviation. Connection between shop and site testing. January 23, 2012 FSRUG 4 Determining Baseline Conditions January 23, 2012 FSRUG 5 EPU - Feedpump Curves January 23, 2012 FSRUG 6 Comparison Of Test Locations January 23, 2012 FSRUG 7 Testing Deviations January 23, 2012 FSRUG 8 Identifying FIE January 23, 2012 FSRUG 9 Flow -Induced Errors Measurement of pump performance with installed pumps is often a difficult process. Affected by the location of flow measuring types. Line-size impact on velocity. Type and location of upstream and downstream fittings affecting turbulence. Site installed test equipment cannot duplicate the accuracy and duplication of shop test results. Baseline testing and data evaluation is vital. A newly-tested pump is typically more accurate that permanently installed instrumentation. Speed verification is vital (design of pump/motor @ shop speeds). January 23, 2012 FSRUG 10 Validating Performance Margins Monitor : Speeds on ASD (adjustable speed drive) pumps. Control valve positions (% open & ∆P) with constant speed pumps. Correcting and validating pump performance under shop conditions is always easier than at the site. When to address reduction of ‘wasted’ energy, shop vs. site. January 23, 2012 FSRUG 11 Testing Guidelines are Common for All Pumps Testing any pump for Nuclear Service should be based upon the same bases: Confirming mechanical assembly. Demonstrating hydraulic performance. Verifying condition following initial operation. The Shop Test Program is the last opportunity to: Confirm compliance to specification requirements. Permit changes prior to shipment and installation. Anticipate start-up and commissioning issues. Eliminate unknowns about the equipment before being exposed to installation and site conditions: OEM compliance. January 23, 2012 FSRUG 12 Test-Or-Not-To-Test Range of Testing: Accepting data from similar or earlier testing. Non-witnessed testing of job hardware. Witnessed testing of all job hardware. Costs of Testing: Based upon the ‘delay’ and ‘cost’ of not performing tests. Missing documentation for site use. Shop vs. Site Testing. Evaluation of Test data: Conducting adjustments. Pumps normally in operation at/near the COS are less likely to deviate or degrade. Test data is also likely repeatable. January 23, 2012 FSRUG 13 Site Testing of Existing Units Establishing priority of Test Parameters. Capacity Type and location of instrument. Correction factors. Developed Pressure (TDH) Type and location of instrument. Power Amps, kW. Speed Temperature Assuring fidelity/reproducibility. Uncertainty and fluctuations, shop vs. site. January 23, 2012 FSRUG 14 Pump & Process Allowances, Margins & Tolerances Allowance are the values added to pump capacity and TDH due to initial sizing uncertainty. Can be defined. Margins are the values added to pump capacity and TDH due to degradation. Can be defined. Tolerances are values of either capacity or TDH provided by industry standards due to degradation. Cannot be defined or guaranteed. Pumps can be made smaller, systems can’t be. January 23, 2012 FSRUG 15 Degradation of Pump Performance January 23, 2012 FSRUG 16 Testing Standards January 23, 2012 FSRUG 17 Project Test Criteria Define: Test Temperature. Test Speed. Time of Test. Scope of Equipment: Job vs. Shop Hardware. Instrumentation. Transient Requirements: Range of Upset Conditions. PTI: Acceptance Criteria. January 23, 2012 FSRUG 18 History of Hydraulic Institute Standards The Institute came into being in 1917. 1st Edition in 1921-Trade Standards in the Pump Industry. 3rd Edition in 1925- Standards of the Hydraulic Society. 7th Edition in 1937-Standards of the Hydraulic Institute. 9th Edition in 1951- Copyrighted. 10th Edition in 1964 13th Edition in 1975 14th Edition in 1983 HI 1.6/2.6 in 2000 HI 14.6 in 2011 January 23, 2012 FSRUG 19 Early HI Standards January 23, 2012 FSRUG 20 Previous Test Standards January 23, 2012 FSRUG 21 Current Tolerances - API January 23, 2012 FSRUG 22 Current Tolerances January 23, 2012 FSRUG 23 Current HI Tolerances January 23, 2012 FSRUG 24 Impact of New HI Shop Test Tolerances Design Engineering Defining minimum performance for pumps in nuclear service will require adherence to unilateral bases. Positive tolerances will affect driver required rating and discharge piping ratings. Shop Testing Acceptance criteria will require redefinition. Initial Site Baseline Testing Once the values are accepted, there should be no changes. Deviations Similar to present. January 23, 2012 FSRUG 25 Horizontal Pump Shop Test Setup January 23, 2012 FSRUG 26 Vertical Pump Shop Test Setup January 23, 2012 FSRUG 27 ‘Edge Engineering’ The issue of precision or accuracy should be addressed to aid in understanding the impact on pump, motor, piping and valve sizing, system efficiency and reliability. Avoid the tendency to ‘over-specify pumps’ and fluid systems. Avoid the tendency to design or specify at or near the MOP (minimum operating or design point). January 23, 2012 FSRUG 28