integrated solutions group - fsrugfsrug.org/presentations 2012/flowserve - feed system...
TRANSCRIPT
© Flowserve Corporation (2009)
Integrated Solutions Group Feed System Analysis
© Flowserve Corporation (2009)
Integrated Solutions Group
• Roger DeBlois - Manager, Assessment Engineering • Watson Tomlinson – Pump Improvement Engineer • Rich Holbert – Senior Nuclear Sales Engineer
2
© Flowserve Corporation (2009)
Goals and Objectives • Describe some Feed System Analysis techniques and
methods including data collection • Highlight difference between Component Testing and
System Analysis • Discuss some potential obstacles to Feed System
Analysis • Describe a couple of case studies
© Flowserve Corporation (2009)
Feed System Assessment Goals
• A comprehensive assessment of pumping system using advanced data collection tools and methods coupled with sophisticated modeling techniques
• Increase availability and reliability of key rotating machinery • Identify opportunities to reduce energy usage of major systems
and critical equipment • Diagnose the root cause of an underperforming system and
premature or recurring equipment failures • Develop solutions for chronically problematic equipment using
life cycle cost (LCC) projections
4
© Flowserve Corporation (2009)
System Analysis vs. Component Test • Multiple components verses single piece • Operational trending verses performance snapshot • Transient capture verses single point
Parts • Root Cause Analysis • System Cause and Effect • Identification of equipment deficiency • Process efficiency optimization • O&M Cost Avoidance
Methodology
© Flowserve Corporation (2009)
Analysis
3960*GPM Head SpecificGravity
BHPη × ×=
© Flowserve Corporation (2009)
Efficiency Calculations, Turbine Driven BFP
To perform this calculation, OEM and test data must be at the same flow. It is assumed that
test and OEM BHP are the same.
© Flowserve Corporation (2009)
Hydraulic Network Analysis • Process fluids/fittings library
• Head loss curves
• Areas of excessive pressure loss
• Control logic evaluation
• NPSH margins
• Validate with field testing
• Run “what if” analysis
• Confirm designs ≠ capital
© Flowserve Corporation (2009)
© Flowserve Corporation (2009)
Case Study
Problem • Coal-fired Fossil Power Plant, 650 MW • Unknown performance of Boiler Feed and Condensate Pumps • Historically un-reliable feed pump • Suspected Boiler Feed Pump operating out on its curve beyond BEP.
© Flowserve Corporation (2009)
Actions • Installed Wireless instrumentation and logged data for several weeks • Inspected used/spare condensate rotor • Rebowl existing condenstate pumps to APKD design with material upgrade
© Flowserve Corporation (2009)
Monitoring Points (IPS Instrumentation) • Boiler Feed Pump Discharge Pressure, Flow. • Boiler Feed Pump Reheat Spray Flow, Pressure • Boiler Feed Pump Recirculation Flow, Balance Line
Leakoff Flow • Boiler Feed Pump Speed (Tachometer) • Condensate Pumps Suction Flow • Condensate Pumps Suction, Discharge Pressure • Condensate Pump Power
© Flowserve Corporation (2009)
Power
© Flowserve Corporation (2009)
Monitoring Points (DCS) • Hotwell Level • Condenser Vacuum • Heater Inlet and Outlet Temperatures • Deaerator Level, Pressure, Temperature (Saturation) • In-kind BFP parameters and Condensate Pump parameters
© Flowserve Corporation (2009)
Condensate Pump Performance
© Flowserve Corporation (2009)
Condensate Pump Impellers
• Condensate pump was disassembled for inspection
• Significant erosion was found on each of the series stages (2 -7).
• Operation back on curve
© Flowserve Corporation (2009)
Condensate Pump Impellers • The damage was almost identical on each stage, and the
example shown is the 4th stage impeller. • Damage to the impeller indicates excessive flow through the
balance holes resulted in erosion around balance holes as well as damage to the vane tips. The excessive recirculation through the balance holes is also a significant contributor to the reduction in pump performance.
• 1st stage impeller showed some cavitation damage on suction side of vanes. Also, visual signs of recirculation due to operation at low flows.
© Flowserve Corporation (2009)
© Flowserve Corporation (2009)
Boiler Feed Pump
© Flowserve Corporation (2009)
Boiler Feed Pump Performance
© Flowserve Corporation (2009)
DCS vs. IPS
© Flowserve Corporation (2009)
Plant Flow Monitoring Potential Issues • Temperature compensation. Flow meters such as a pitot
arrangement require temperature compensation. • Calibration • Flow orifice wear • Location of installed flow instrumentation in plant system
(straight runs, fully developed flow regime, etc.) • Temporary instrumentation setup and operator experience
© Flowserve Corporation (2009)
Case Study
Site Information •Generating station produces power and steam for large oil sands refinery. •The unit utilizes:
•(3) De-aeration Units •(5) Flowserve 6x8x11 DVMX 5-stage Boiler Feed Pumps •(8) Boilers
Reason for Assessment •Determine the current conditions of service? • Reduce the total cost of ownership by:
•Increasing the mean time between failure. •Reducing the number of operating pumps to 4 from 5 at full load.
•Determine the flow distribution from De-aeration Units. •Evaluate the flow through the recirculation lines.
© Flowserve Corporation (2009)
Actions •Installed pressure transducers, flow meters and laser tachometers. •Monitored plant parameters for one week. •Performed operational performance tests on Boiler Feed Pumps and associated recirculation lines. •Monitored vibration at various operational conditions.
© Flowserve Corporation (2009)
Higher flow target vs. Current Capability
0100200300400500600700800900
1000110012001300140015001600170018001900200021002200230024002500
31G-10A 31G-10B 31G-10C 31G-10D 31G-10E
Flow
(G
PM
)
Required Flow at 9459 GPM Total Flow
Required Discharge Flow Maximum Discharge Flow (GPM)
Current Max output
© Flowserve Corporation (2009)
Analysis / Conclusions •Created pump curves and plots of several system parameters.
•Performed Net Positive Suction Head analysis. •Performed recirculation line flow analysis including minimum continuous stable flow and onset of recirculation calculations. •Performed a flow distribution analysis on the De-aerator
discharges and created a hydraulic model to help determine the cause of inconsistent flow distributions.
•Verified installed instrumentation readings. •Performed a detailed vibration analysis including harmonic
resonance analysis. •Performed a total feed water flow distribution analysis.
•Made hydraulic re-rate recommendations for all (5) Boiler Feed Pumps to achieve desired goals.
© Flowserve Corporation (2009)