Hydraulic and Environmental Performance of Aerating Turbines

Transcription

1 Hydraulic and Environmental Performance of Aerating Turbines Presented by Patrick A. March Principal Consultant, Hydro Performance Processes Inc. EPRI/DOE Conference on Environmentally-Enhanced Hydropower Turbines May 19-20, 2011 Washington Court Hotel, Washington, DC 1

2 Overview of Presentation Brief History of Aerating Turbines Description of need for DO improvements Turbine venting and hub baffles Auto-venting (i.e., self-aerating) turbines Hydraulic and Environmental Performance Measurement difficulties Performance under aerating and non-aerating conditions Environmental Optimization of Aerating Turbines Recommendations 2

3 Need for Improved DO in Reservoir Releases 3

4 Streamlined Hub Baffles (Norris, Pre-AVT) flow flow trailing edge of turbine bucket bar stock (typ) vacuum breaker opening Flat Plate Baffle section of schedule 40 pipe vacuum breaker opening Streamlined Baffle 4

5 Prototype AVT, TVA s Norris Plant, December

6 Sectional View of Aerating Francis Turbine 6

7 Hydraulic and Environmental Performance 7

8 Measurement Difficulties 8

9 Typical Effects of Aeration on Efficiency Decrease in in Turbine Efficiency (%) (%) Aeration Influence on Turbine Efficiency (Q wopt 1.0) w /Q wopt = 0.8) 1.2) Distributed Aeration Distributed Aeration Central Aeration Central Aeration Distributed Aeration Peripheral Aeration Peripheral Aeration Central Aeration Linear Extrapolation (Central Aeration) Linear Extrapolation (Central Aeration) Peripheral Aeration Linear Extrapolation (Distributed Aeration) Linear Extrapolation (Distributed Aeration) Linear Extrapolation (Peripheral Aeration) Linear Extrapolation (Peripheral Aeration) Linear Extrapolation (Peripheral Aeration) Case Study (Central Aeration) Linear Extrapolation (Distributed Aeration) Case Study (Central Aeration) Case Study (Distributed Aeration) Case Study (Distributed Aeration) Case Study (Distributed Aeration) Case Study (Peripheral Aeration) Case Study (Peripheral Aeration) Case Study (Peripheral Aeration) Qa/Qw (%) Qa/Qw (%) 9

10 Example: Challenges for Optimization 1.10 Net Head Efficiency Test Results (Central and Distributed Aeration) Net Head = 95 ft 2002 Upgraded Unit, Central Aeration Off Upgraded Unit, Central Aeration On (Qa/Qw = 2.7% to 4.4%) Original Unit, Central Aeration Off Original Unit, Central Aeration On (Qa/Qw = 0% to 3.1%) Normalized Net Head Turbine Efficiency Upgraded Unit, Distributed Aeration Off 2008 Upgraded Unit, Distributed Aeration On (Qa/Qw = 5.0% to 7.4%) Turbine Output (MW) 10

11 TDG Effects on Unit Order and Efficiency Optimized Plant Efficiency (%) for Specified Unit Order Overall Plant Efficiency Curves (Gross Head = 95 ft) Typical Summer Winter Ops (AC,AH,VH) (AH,VH,AC) Optimized Summer Winter Ops (VH,AC,AH) Power (MW) 11

12 Scheduling for Efficient Operation Actual vs Optimized Energy Aerating Operation July2010-Energy Head Optimized Plant Efficiency (%) Power (MW) 75 12

13 Recommendations for the Hydro Industry Turbine manufacturers, agencies, and utilities should provide access to existing hydraulic and environmental performance information for aerating turbines. Industry should establish a national database of hydraulic and environmental performance data for aerating turbines: Funded by DOE, USACE, or EPRI, or other appropriate sponsor(s) Maintained by a national laboratory with related experience, such as Oak Ridge National Laboratory. Additional performance information should be solicited for the small minimum flow turbine installations with DO enhancement. ASME PTC-18 s efforts to develop a comprehensive test code for aerating turbines should be financially supported by the hydropower industry. 13

14 Recommendations for Additional Research Conduct long term monitoring and data analyses for aerating turbines to provide performance results over a wide range of conditions Improve aeration scaling relationships between physical models and prototypes Improve models for predicting gas transfer and resulting DO and TDG levels Improve models for predicting draft tube effects on turbine efficiency under aerating and non-aerating conditions Develop and demonstrate cost-effective DO enhancement options for Kaplan and bulb turbine units Develop and improve environmental optimization tools Develop cost-effective methods to measure DO in reservoir releases 14