1. ONE SOURCE ONE PURPOSE MANY SOLUTIONS Utility Users Group Meeting Orange Beach, AL August 4, 2015 GUIDELINES & TECHNIQUES FOR THE EFFECTIVE CONTROL OF CONDENSATE DISSOLVED OXYGEN (DO 2 ) IN STEAM SURFACE CONDENSERS Darren M. Nightingale Steam Surface Condensers: GUIDELINES & TECHNIQUES FOR THE EFFECTIVE CONTROL OF CONDENSATE DISSOLVED OXYGEN (DO 2 ) IN STEAM SURFACE CONDENSERS Prepared and Presented by Darren M. Nightingale Director of Engineering, TEi Condenser Division © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

2. Darren M. Nightingale Director of Engineering, Condenser Division Telephone: 323.838.1173 (Office) Telephone: 323.627.5527 (Cell) E-Mail: dnightingale@thermalengint.com THERMAL ENGINEERING INTERNATIONAL, INC. 10375 SLUSHER DRIVE Santa Fe Springs, CA 90670-3748 Introduction © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

3. GUIDELINES & TECHNIQUES FOR THE EFFECTIVE CONTROL OF CONDENSATE DISSOLVED OXYGEN IN STEAM SURFACE CONDENSERS: Low levels of dissolved oxygen in the condensate produced within steam surface condensers, is highly desirable and an increasingly important aspect related to the efficient operation of today’s power plants. The presence of high levels of dissolved oxygen within condensate can quickly contribute to accelerated corrosion & additional treatment requirements as well as increased maintenance and operational challenges. Under certain operating conditions, steam surface condensers can be expected to produce condensate with pre-defined, or guaranteed, levels of dissolved oxygen. However, these levels can only be achieved by a combination of following design guidelines and not exceeding operational limitations - this is not always the case. This 20min presentation includes the latest design guidelines, operational limitations and general considerations, as well as practical techniques, for minimizing dissolved oxygen levels for condensate produced within the condenser. Abstract - Overview © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

4. WHAT? WHAT?– Is Dissolved Oxygen? WHY? WHY? – Is DO 2 a Problem? WHERE? WHERE? – Does DO 2 Come From? HOW? HOW?– Should My Condenser Perform? WHEN? WHEN?– Does ‘High’ DO 2 Occur? HELP HELP!?– Can I Reduce my DO 2 ?! Presentation Agenda © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

5. WHAT? WHAT? – Is Dissolved Oxygen? Oxygen: Colorless, Odorless & Tasteless Gas. Occurs in its Free State as a Gas, O 2 Liquid only at -297.4°F. Oxygen in Air is 20.9% by Volume. Oxygen in Air is 23.1% by Mass. DO 2 in Air Saturated Make-up: 8,000 – 14,000 ppb O 2 © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

6. WHAT? WHAT? – Is Dissolved Oxygen? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

7. Power Plant System Diagram - FOSSIL Cooling TowerDeaerator LP Heaters Air Preheater Condenser Stack Flue gas desulfurization Electrostatic precipitator or Baghouse Steam Turbine Utility Boiler Air Superheater Reheater Economizer Fuel Firing System Generator Low NOx Burners SCR (DeNOx) Pulverizer Boiler Tubes HP Heaters WHY? WHY? – Is DO 2 a Problem? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

8. Nuclear / Coal Fired Typical Steam Power Plant Cycle WHY? WHY? – Is DO 2 a Problem? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

9. WHY? WHY? – Is DO 2 a Problem? HENRY’S LAW HENRY’S LAW Based on Henry's Law formulated by the English chemist William Henry states that at a given temperature, the solubility of a gas is directly proportional to the pressure of the gas directly above the liquid. LE CHATELIER’S PRINCIPLE LE CHATELIER’S PRINCIPLE Le Chatelier's principle states that a change in any of the factors determining equilibrium will cause the system to adjust to the changes in order to restore equilibrium. Le Chatelier's principle predicts that the solubility of a gas will increase as a system loses heat, and will decrease as a system gains heat. Steam Surface Condenser Steam Surface Condenser Needs to operate with maximum efficiency to remove as much Dissolved Oxygen as possible, however, this IS limited by Operational Parametrics! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

10. WHY? WHY? – Is DO 2 a Problem? CORROSION!! CORROSION!! pH Levels, pH Levels, Seal Faces, Seal Faces, Cavitation Pumps, etc. Cavitation Pumps, etc. 5ppb+ can induce pitting corrosion!! 5ppb+ can induce pitting corrosion!! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

11. LP Exhaust – Steam. LP Exhaust – Steam. LP Exhaust – Shaft Seals. LP Exhaust – Shaft Seals. Gland Seal Steam. Gland Seal Steam. Steam Bypass (CCGT). Steam Bypass (CCGT). > Desuperheater Entrained in Condensate. Entrained in Condensate. ‘Cold Water’ Make-Up. Especially if T MU < T Sat ‘Cold Water’ Make-Up. Especially if T MU < T Sat Air In-Leakage. Air In-Leakage. Shell Cracks. Shell Cracks. Gasket Leaks. Gasket Leaks. Etc., etc. Etc., etc. WHERE? WHERE? – Does DO 2 Come From? Problem? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

12. WHERE? WHERE? – Does DO 2 Come From? Problem? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

13. 7 ppb… 0.005 cc/l 14 ppb… 0.010 cc/l 21 ppb… 0.015 cc/l 42 ppb… 0.030 cc/l Most Condensers should not exceed 42ppb under practical operating conditions. [BWR-Nuke, 10-50ppb] Condensers can achieve as low as 7ppb and 14ppb given stable operation at the Design conditions (100% Duty!). Condensers do NOT perform well when they… …Operate at LOW LOAD Conditions! …Cycle or have Transient Operation! …Have to deal with High Quantities of Make-Up < T Sat !! HOW? HOW? – Should My Condenser Perform? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

14. KNOW THE ‘3/7 - 5/14’ RULE! To Maintain ≤ 7ppb ‘Cold’ Make-Up < T Sat. < 3% Steam Flow. To Maintain ≤ 14 ppb ‘Cold’ Make-Up < T Sat. < 5% Steam Flow. HEI > DO 2 Curves > Guarantees! Figures 3 & 5. 7ppb and 14ppb Curves. C.W. Inlet Temp., Duty & Back-Pressure. HOW? HOW? – Should My Condenser Perform? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

15. HEI: Standards for Steam Surface Condensers HEI (Heat Exchange Institute) Standards for Steam Surface Condensers –11 th Edition [Oct. 2012] –Addendum 1 [Aug. 2014] –Design Guidelines for DO 2 –Section 4.3 – O 2 Condensate –Sample Calculations –Venting Capacity –Performance Curves HEI = Guaranteed Performance!!! HOW? HOW? – Should My Condenser Perform? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

16. HEI Figure 3 Absolute Pressure Limit Curves for Oxygen Content Saturation Pressure versus C.W. Inlet Temperature Predicts Condensate Dissolved Oxygen Content at Curve A ≤ 7ppb Curve B ≤ 1 4ppb Superimpose Figure 3 on Condenser Performance Curves (versus Load)… HOW? HOW? – Should My Condenser Perform? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

17. HEI Figure 5 Absolute Pressure Limit Curves for Guarantees. Saturation Pressure versus C.W. Inlet Temperature. Predicts Cut-Off Point and Zero Load Performance. Curve A ≤ Cut-Off Curve B ≤ Zero Load Superimpose Figure 3 and Figure 5 onto Condenser Performance Curves – C.W. Inlet, Duty & Back- Pressure vs DO 2 Levels HOW? HOW? – Should My Condenser Perform? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

18. HEI Figure 5 Cut-Off to Zero Load must be reflected on Performance Curves to predict DO 2 Performance! NOTE: 5°F TTD is a Guarantee Limit!! HOW? HOW? – Should My Condenser Perform? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

19. PERFORMANCE CURVES  Back-Pressure (0.5-6.0 inHgA)  Heat Duty (0-120%)  Circ. Water Temps. (70-110°F)  Cleanliness Factor (85%) Curve A ≤ 7ppb Curve B ≤ 1 4ppb Performance Curves should be provided by all Condenser OEM’s for predicting your DO 2 performance!! HOW? HOW? – Should My Condenser Perform? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

20. Do Not Address Leaks! Do Not Address Leaks! i.e Fix Leaking Gaskets, etc. i.e Fix Leaking Gaskets, etc. Make-Up <T sat Make-Up <T sat 3%+ of W S >> 7ppb+ 3%+ of W S >> 7ppb+ 5%+ of W S >> 14ppb+ 5%+ of W S >> 14ppb+ Make-Up is in Poor Location Make-Up is in Poor Location Below Bundle! Below Bundle! NO Reheat!! NO Reheat!! Baffle/Elbow vs Spray Pipe Baffle/Elbow vs Spray Pipe Operational Parametrics Operational Parametrics LOW LOADS! LOW LOADS! Cycling / Transient Cycling / Transient Low C.W. Inlet (Winter) Low C.W. Inlet (Winter) WHEN? WHEN? – Does ‘High’ DO 2 Occur? © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

21. 1. Connection (Re)Design 1. Connection (Re)Design  Convert Baffles to Spray Pipes!  Revised Location to ABOVE Bundle, not side, or below  Install a properly designed Spray Pipe (Reheat) 2. Install a Hotwell Sparger 2. Install a Hotwell Sparger  High Make-Up (5%+ Q) &/or Low Make-Up Temp (<T Sat )  Operational Conditions (Low Load, Cycle, Low C.W. Temps) 3. Install a Vacuum Deaerator 3. Install a Vacuum Deaerator  High Make-Up (5%+ Q) &/or Low Make-Up Temp (<T Sat )  Achieve <5ppb HELP?! HELP?! – Can I Reduce My DO 2 ?! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

22. 1. CONNECTION (RE)DESIGN Effective Effective for Improve Reheat Levels. Improve Deaeration. Avoid Baffles/Elbows. UseSpray Pipes Use Spray Pipes (proven). Re-Engineer Existing Baffles. Re-Route Internally (if Head!). Follow HEI & EPRI Guidelines. Locate above Bundle. not below, or at side Improve Distribution Improve Reheat! Use St/St Piping (longevity). $ Lowest Cost Option (Outage). $ Lowest Cost Option (Outage). HELP?! HELP?! – Can I Reduce My DO 2 ?! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

23. 1. CONNECTION (RE)DESIGN &/OR (RE)LOCATION HELP?! HELP?! – Can I Reduce My DO 2 ?! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

24. 1. CONNECTION (RE)DESIGN &/OR (RE)LOCATION HELP?! HELP?! – Can I Reduce My DO 2 ?! Spray Pipe above vs Baffle on side of Bundle!! Spray Pipe above vs Baffle on side of Bundle!! Increased Distribution Area & Volume. Improved the Contact/Residence Time. Reheating was vastly improved. Dissolved Oxygen liberated IN Bundle. Dissolved Oxygen removed from Bundle via Air Draw Off, Vent Duct & Vacuum Equipment Eliminated “Spikes” in DO 2 during Make-Up. Reduced DO2 by up to 21 ppb. © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

25. 2. INSTALL HOTWELL SPARGER VERY Effective VERY Effective for Raising Condensate Temperature. START-UP! Use for Cold Start-Up. Use of Hot Start-Up. Design for 30-60 mins. to T Sat. LOW (Transient) LOADS (Reheat). LOW C.W. Temperatures (Winter). Simple Control (On/Off). Popular in Combined Cycle Plants. And.…Base Loaded Fossil Units that now Cycle! Auxiliary Steam (typ. 50psiG @ 350°F & 1,200+ Btu/lb) When to Operate a Hotwell Sparger? V. IMPORTANT! $$ Medium Cost Option (Outage). $$ Medium Cost Option (Outage). HELP?! HELP?! – Can I Reduce My DO 2 ?! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

26. Typical Hotwell with Steam Sparger Piping to control dissolved Oxygen in condensate during Start-Up, Low Loads & Low C.W. Temperatures. 2. INSTALL HOTWELL SPARGER HELP?! HELP?! – Can I Reduce My DO 2 ?! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

27. HELP?! HELP?! – Can I Reduce My DO 2 ?! WHEN TO OPERATE A HOTWELL SPARGER? LOW LOADS! LOW LOADS! LOW DUTY! LOW DUTY! LOW C.W. INLET! LOW C.W. INLET! HIGH MAKE-UP! HIGH MAKE-UP! CYCLING! CYCLING! ONE BUNDLE OPERATION! ONE BUNDLE OPERATION! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

28. 3. INSTALL A VACUUM DEAERATOR HighlyEffective Highly Effective for Large Volume Make-Up. 5%+ of Steam flow Low Temp Make-Up. Make Up <T Sat Spray & Tray (proven). Robust (Range of Conditions). Uses Steam from Condenser. OR, Auxiliary Steam. Excellent for Cycling/Transient. Condenser Mounted ! Operates Continuously. $$$ Highest Cost Option (PROJECT) $$$ Highest Cost Option (PROJECT) HELP?! HELP?! – Can I Reduce My DO 2 ?! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

29. 3. INSTALL A VACUUM DEAERATOR HELP?! HELP?! – Can I Reduce My DO 2 ?! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

30. SUMMARY SUMMARY Know Your Condenser! Know Your Condenser! OEM Performance Curves; OEM Performance Curves; w/ HEI 7 & 14 ppb Curves. w/ HEI 7 & 14 ppb Curves. Address Air In Leakage. Address Air In Leakage. For ‘Cold Water’ Make-Up. Especially if T MU < T Sat For ‘Cold Water’ Make-Up. Especially if T MU < T Sat Make-Up Design (Spray Pipe) Make-Up Design (Spray Pipe) …and Location (above Tubes) …and Location (above Tubes) Use of Hotwell Sparger. Use of Hotwell Sparger. Vacuum Deaerator? Vacuum Deaerator? Always Monitor DO 2. Always Monitor DO 2. Address ‘High’ DO 2 !!! Address ‘High’ DO 2 !!! SUMMARY SUMMARY – Dealing with Condensate DO 2 © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

31. THANK YOU FOR YOUR TIME!! THANK YOU! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved

32. QUESTIONS? & ANSWERS! © 2015 Information contained herein is proprietary and confidential to Babcock Power Inc. All Rights Reserved