ENGINEERING TRIPOS PART IB - 2012/2013

PAPER 8 - ELECTIVE (2)

Mechanical Design for renewable Energy

Leader: Dr. H.E.M Hunt

Timing: Weeks 1-4 Easter term

Structure: 14 lectures + 2 examples classes, 4 lectures/week

AIMS

The aims of the course are to:

• Describe technologies for renewable energy, and their principal advantages and disadvantages.
• Analyse the aerodynamics and structural loading of wind turbine blades, the choice of materials, and the effect of scale.
• Analyse the mechanical and electrical aspects of wind turbine machinery.
• Use streamlined life cycle analysis to estimate the energy payback periods for wind turbines of different sizes, and to compare wind energy with alternative renewable energy systems.

OBJECTIVES

As specific objectives, by the end of the course students should be able to:

Life cycle analysis of renewable energy systems

• Summarise the technical, social, environmental and economic challenges of various renewable energy systems.
• Perform approximate life cycle analyses to estimate energy payback periods for different systems.

Wind Turbine Aerodynamics

• Analyse the aerodynamic loads on a wind turbine blade.
• Calculate the energy capture potential of a wind turbine.

Structural design and material selection for wind turbines

• Follow an appropriate methodology for preliminary design of wind turbine blades.
• Make a realistic fatigue lifetime prediction for blade structures.
• Select materials and perform structural optimisation for towers and turbine blades.

Mechanics of wind turbines

• Analyse epicyclic and parallel gearboxes as applied to wind turbine generators.
• Undertake a simple modal analysis of a wind turbine.
• Outline principle sources of noise generation in wind turbines.

Electrical power generation in wind turbines

• Understand how the generator rating is chosen and the implication for turbine/generator control,annual energy production and system payback period.
• Know the main electrical technologies that are used and their advantages and disadvantages, with reference to the implications for the need for a gearbox, fixed vs variable speed operation and power electronic convertors for interfacing to the 3-phase grid.
• Understand how the induction motor theory taught in the Lent Term may be extended to induction generators.

SYLLABUS

1. Overview of renewable energy systems (1L, Dr DD Symons)

1.1 Renewable energy technologies: wind, hydro, solar, tidal; development status in UK, EU, worldwide. (2) Chap. 5

2. Life cycle analysis of renewable energy systems (1L, Dr MPF Sutcliffe )

2.1 Product life cycles: material production, manufacture & installation, use and maintenance, disposal and recycling.

2.2 Estimates of embodied energy in wind turbine systems and payback period; recycling potential for end of product life.

2.3 Comparison with other renewable energy systems

3. Fundamentals of wind turbine design (1L, Dr DD Symons)

3.1 Fundamental fluid mechanics limits to energy generating potential, including derivation of Betz limit, influence of size and height, estimates of wind loading, capacity factor.

4. Wind turbine loading (3L, Dr. D.D. Symons)

4.1 Aerofoil aerodynamics

4.2 Blade element momentum theory

4.3 Centrifugal loading

4.4 Self weight loading

5. Structural design and material selection for wind turbines (3L, , Dr MPF Sutcliffe)

5.1 Scaling effects


5.2 Material performance indices


5.3 Shape optimization


5.4 Composite blades

Examples Class 1

6. Mechanics of wind turbines (2L, Dr DD Symons /Dr MPF Sutcliffe)

6.1 Gearbox design: epicyclic and parallel drives, velocity ratios and tooth force calculations

6.2 Vibration modelling and modal analysis.

6.3 Noise and vibration.

7.1 Electrical challenges of generating electricity from wind energy- contrast with conventional fossil fuel generation met in the Lent Term

7.2 Generator rating in terms of volume and rotational speed.

7.3 Need for gearbox - the electrical perspective.

7.4 Choice of generator rating by considering output electrical power vs wind speed, annual energy production, payback period.

7.5 Generator technologies and their advantages and disadvantages
(i) Implications for gearbox.
(ii) Implications for fixed or variable speed operation.
(iii) Implications for power electronic convertors and interfacing to the 3-phase grid.

7.6 Extension of induction motor theory met in the Lent Term to induction generators.

7.7 Simple output power and reactive power calculations.

7.8 Slip energy recovery and variable speed operation.

Examples Class 2

8. Guest lecture (1L,Mike Watling,Evance Wind)

Small-scale wind energy or Large-scale wind energy





REFERENCES


Please see the Booklist for Part IB Courses for references for this module.

EXAMPLES PAPERS

1.Global warming and carbon footprints. Life cycle analysis. Wind power fundamentals. Wind turbine aerodynamics and loading.

2. Manufacturing. Materials. Fatigue. Mechanics. Electrical Power

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Last updated: May 2012

teaching-office@eng.cam.ac.uk