Pumped Hydropower Storage - Evan

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University of Technology Sydney 48670 Engineering Design Pumped Hydropower Storage PRESENTATION UTS:ENG 30th May 2006 Design Team Members • Richard Gallagher (c) – Mechanical Engineering • Felipe Thomas – Mechanical Engineering • Evan Beaver – Mechanical Engineering, – Environmental Science • Adrian Fernandes – Mechanical and Mechatronic Engineering – Engineering Innovation • (Tom) Ka Lun Wong – Mechanical Engineering • (Billy) Ping Yung Chan – Mechanical Engineering Design Process • Needs Analysis • Limitations/Restrictions/Assumptions • Criteria Evaluation • Calculations and Sketches • Concept Evaluation • Concept Selection • Functional Specification Needs Analysis • Stakeholders – Engineering Design Students – Academic Staff – Australian Government – Australian Power Industry – Developing Nations Power Suppliers Problem Statement • The Australian Government is in need of efficient and sustainable technology solutions and are interested in renewable energy industries. • The benchmark pump/turbine energy storage system is located at Bendeela near the south coast of New South Wales • We are required to design and build a pump/turbine system that exceeds the current benchmark. Objectives • To design and build an efficient gravitational potential storage device for use in hydroelectric schemes. • During low-demand periods water is pumped up-hill storing potential energy • In higher demand times, the reservoir is tapped, and the potential recovered to generate electricity. Bendeela Pumping and Power Station (Benchmark) • Flow rate 5.7 m³/s • Head 607 m • Pipe Ø 3.68 m 3.1 m • Reversible Mixed Flow Pump/Turbine • 88.8% Efficiency Scaled Test Rig (Incomplete) Criteria for Evaluation • Efficiency! • Ease of Manufacture • Cost • Simplicity • Size and Weight • Speed Functional Requirements • Flow Rate (7.76L/s Max.) • Power Efficiency (Benchmark Min 88.8%) • Speed (1500 RPM Max.) • Size (Impeller Ø 120mm Max.) • Cost (Within student budget range ie: very low) • Simplicity (Less parts, less can go wrong) • Safety (All moving parts must be made safe) • Maintenance (None, One-test Prototype) Concurrent Engineering • Life Cycle Analysis • Team Based Design • Multiple Concept Generation and Evaluation • Design and Manufacture considered in parallel • Emphasis on Communication Concept Generation • All team members had an attempt at sketching 3 concepts keeping in mind the limitations, requirements and the needs of the stakeholders. Concept Analysis • Analysis was conducted on the 4 most practical pump/turbine combinations. – Bucket Elevator/Pelton Wheel – Centrifugal Pump/Pelton Wheel – Archimedes Screw/Francis Turbine – Axial Flow Pump/Turbine – Mixed Flow Pump/Turbine Morphological Diagram Function Concept 5 Concept 1 Concept 2 Concept 3 Concept 4 Decomposition (Benchmark) Conversion of Archimedes Mechanical Screw Energy Bucket Centrifugal Axial Flow Mixed Flow into Fluid Pump/ Elevator Pump Pump Pump Kinetic Inclined Energy Plane Conversion of Fluid PVC Pipe Soup Spoon Kinetic Energy Francis Axial Flow Mixed Flow Into Pelton Pelton Turbine Turbine Turbine Mechanical Wheel Wheel Energy Weighted Pugh Table Design A1- A1- A2- A2- A3- A4- Bendeela % Criteria B1 B2 B1 B2 B3 B4 (A5-B5) Efficiency 35 - - - + - - Datum 25 - + - - - - Datum Manufacture Cost 20 + + + + - + Datum Simplicity 12.5 - - + - S + Datum Weight, Size 5 - - S S - + Datum Speed 2.5 - - - S - - Datum Σ 100 -60 -10 -35 +42.5 -17.5 -20 0 Selected Concept Centrifugal Pump / Pelton Wheel Selected Concept Soup Spoon Pelton Wheel • Design Calculations For BEST Results – Ns = 0.164 (Pelton Range, 0.03 – 0.3) – Ds = 19 from Cordier Diagram – D = 220 mm – Jet Velocity = 5.5 m/s – RPM = 500 Max Pelton Wheel Construction Pelton Wheel Construction Pelton Wheel Construction Selected Concept Pelton Wheel Pelton Wheel Testing Actual Test Results • Water Flow Rate = 0.27 L/s • Test 1 – 310 RPM, 1.6 W generated • Test 2 – 248 RPM, 1.05 W generated • Test 3 – 230 RPM, 1.2 W generated • Turbine Efficiency = 43.2% Pump Construction Initial Planning • Being a student project brings limitations • Must be low-cost • Easy to manufacture • 1 hour run time • From readily available parts • Form follows function Pump Construction Inspiration • Other pumps: rubber vanes lead to very high internal friction Pump Construction Inspiration • No concept of ‘critical surfaces’ in centrifugal pump • Warman pump demonstrated in class clarified ideas Pump Construction Critical Design Parameters • Essentially a circular plane with perpendicular/radial drive-faces • Faces curve back from centre, to create pressure in volute • Volute increases in size so that pressure is directed down the pipe • Sealing, clearance and friction would be the limiting factors Pump Construction Material Selection - Housing • A CD spindle case meets all the criteria • Strong plastic (vinyl, HD polystyrene, polycarbonate) • CD’s fit snugly inside, solving tolerance problems Pump Construction Impeller • CDs formed the impeller base and top • Sections of PVC pipe (100mm ID) cut for blades • Pipe section gives gentle curve in the blade • Liberal amounts of glue Pump Construction Volute • Gluing onto the polystyrene case was very difficult • So was sealing around the edge • The volute was then internally ported Pump Construction Inlet • A nylon tank fitting was chosen for inlet • This was glued to the top of the case, and again ported to match Pump Construction Testing • The pump performed well in testing • Using 228W the pump ran at 0.773L/s • Static head of 1.97m • 6.5% efficiency, excluding electrical/mechanical losses in motor Pump Construction Post Mortem - Deficiencies • Sealing around the volute – this was obviously a high stress point and requires more attention in future Pump Construction Post Mortem - Deficiencies • Sealing around the shaft – This was extremely difficult to fix, and the hope was that the spinning blades would discourage flow out Pump Construction Post Mortem - Deficiencies • Internal friction – there were no bearings used, the idea being to utilise the internal pressure to support moving surfaces. Test Results – Shortcoming • Leakage of Pump • Torque from motor too strong • Optimum Nozzle Diameter needs more prototype testing with the turbine. Improvements and Suggestions • Silicon used for pump – Silicon more suitable for plastics • Possible Pelton wheel Impeller materials – Wood – Harder Materials than Polystyrene – Heavier materials for more torque and inertia • Polystyrene Box for Pelton Wheel – Use Perspex for splashguard and to stick to bearings and see the turbine operate Improvements and Suggestions • Sealing and internal friction could be fixed with a sealed bearing, shown below • Volute sealing and strength could be improved with more glue and ribs/gussets to spread stress away from the join Learning outcomes • Design Stages – Identify needs (meet customer expectations) – Preliminary design (concepts generated, draft calculations) – Detailed design (detailed calculations) – Manufacturing (low cost, easy and efficient methoding) – Testing (re-iterative design, testing and modifications) – Present to customer (measure customer fulfillment) • Budget control and material choice – Cheap – Environmentally friendly – Strong and Durable – Light Learning outcomes (cont’d) • Good time management • Team design decision – Morphological diagram and Pugh table • Value on Engineering Design – Efficiency more than money • Ability to show evidences to convince others