Summer School on Energy Giacomo Ciamician Hydro Power ... ... ing. Nicola Fergnani 4 Electric power...

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Transcript of Summer School on Energy Giacomo Ciamician Hydro Power ... ... ing. Nicola Fergnani 4 Electric power...

  • Aula Magna – Rettorato

    Mercoledì 27 maggio 2015

    Hydro Power Plants

    Ing. Nicola Fergnani

    Summer School on Energy Giacomo Ciamician

  • ing. Nicola Fergnani

    2 Renewable energy & Hydropower

    Solar Energy

    Wind Energy

    Hydraulic

    Energy

    Fossil Fuels

    Tidal Energy Geothermal

    Energy

    Nuclear

    Energy

    Energy from

    sea currents

    Energy from

    waves

  • ing. Nicola Fergnani

    3

    The hydro power potential comes from the rain…

    ….then it’s an “energy condensate” of solar radiation

    Renewable energy & Hydropower

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    4

    Electric power generation from hydro potential is the most significant

    renewable source in the world in terms of energy production. In Italy

    13-16% of electrical power generation comes from hydro (average production

    of 45.7 TWh/year).

    Rapporto statistico GSE 2015

    Hydropower: statistics

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    5 Hydropower in the world

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    6

    Is it possible a further development of

    small hydro in developed countries?

    Small

    Hydro Revamp of

    existing plants

    In almost every European country there are only few possibilities or

    no possibilities for new big hydro plants:

    • most of the good location have already been exploited

    • environmental impact

    • opposition (NIMBY)

    Hydropower

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    7 Small Hydro: permitting procedures

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    8

    Power potential is evaluated as:

    • WATED HEAD (H)

    • AVAILABLE FLOW (Q)

    Hydro Power

    𝑃𝑖𝑑 𝑊 = ሶ𝑚 ∙ 𝑔 ∙ 𝐻

    = 𝜌 ∙ 𝑄 ∙ 𝑔 ∙ 𝐻

    𝐸𝑖𝑑 𝐽 = 𝑚 ∙ 𝑔 ∙ 𝐻

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    9 Classification

    I. - Weir integrated plant - Diversion Channel plants

    II. - Storage plants - Run-of-river plants

    III. - High head - Medium head - Low and very low head

    IV. - Pumped storage plants - Top power plants

  • ing. Nicola Fergnani

    10 I Classification

    Weir integrated plant

    A = B

    Powerhouse

    integrated in

    the weir

    A = intake point

    B = discharge point

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    11

    Q  Ecological

    Flow (DMV )

    Q = 100%

    Q = 100%

    Q = 100% - DMV

    I Classification

    Diversion channel plants A = intake point

    B = discharge point

    Ecological flow :

    Maintains the essential

    processes required to

    support healthy river

    ecosystems

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    12 I classification (weir-integrated)

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    13 I classification (weir-integrated)

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    14 I classification (diversion channel)

    Powerhouse cavern

    Intake weir

    Settling basin

    Surge tank

    (forebay tank)

    Tailrace tunnel

    Video

    https://www.youtube.c

    om/watch?v=S3MQJS

    DoTuw

    https://www.youtube.com/watch?v=S3MQJSDoTuw

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    15

    Water storage

     Storage plants

    • Pond plants [bacino]: filling rate 2~400h (storage

    capacity/average river flow rate)

    • Reservoir plants [serbatoio]: filling rate > 400h

     Run-of river plants: filling rate < 2h

    II classification

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    16

    Hydraulic head

    • High head (>100m) diversion channel needed (both storage or run-of-river)

    • Medium head (30 – 100 m) diversion channel needed (both storage or run-of-river)

    • Low head (2 - 30 m) both weir-integrated (very low head) or with diversion channel in most cases run-of-river

    III classification

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    17

    Energy storage capability

     Pumped-storage hydroelectricity (PSH) • Only pumped

    • Pumped + river

     Non-pumping plants

    IV classification PSH

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    18 IV classification PSH

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    19 IV classification PSH

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    20

    Energy stored in PHPS

    IV classification PSH

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    21

    Decreasing hydraulic

    head

    Hydraulic machines

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    22 Hydraulic machines

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    23

    The entire pressure drop of the turbine occurs

    in the nozzle, where pressure head is

    converted to velocity

    The turbine operates at atmospheric

    pressure

    Impulse turbines

    R=0

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    24

    High head: 60 - 1300 m

    Relatively small flows: 0.02 - 7 m3/s

    Video

    https://www.youtube.com/watch?v=3PoeMQeHePo

    Pelton turbine

    https://www.youtube.com/watch?v=3PoeMQeHePo

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    25

    Example of a 4 nozzles

    pelton turbine

     High specific power

     Very high efficiency (y>90%)

     High efficiency at partial loads (exclusion

    or flow reduction on the single nozzle)

     The stream should impact one blade per

    time

     Very fast run-away in case of

    grid/generator failure

    Pelton turbine

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    26 Pelton turbine

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    27

    50%

    55%

    60%

    65%

    70%

    75%

    80%

    85%

    90%

    95%

    0.0 0.2 0.4 0.6 0.8 1.0

    R e

    n d

    im e

    n to

    Portata / Portata nominale

    Pelton 1 getto

    Pelton 2 getti

    Pelton 4 getti

    Pelton turbine

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    28

    The pressure drop occurs partially on

    the stator and partially on the rotor

    The turbine is completely

    submerged in the flow

    A pressurized (or depressurized)

    discharge is possible

    Reaction turbines

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    29

    Reaction turbine suitable for low range heads and flows

    Flow range: 0.2-100 m3/s

    Head range: 20-500 m

    Francis turbine

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    30

    Video

    https://www.youtube.com/watch?v=pbliwh4-R2I

    Francis turbine

    https://www.youtube.com/watch?v=pbliwh4-R2I

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    31 Francis turbine

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    32

     Reaction turbine

     Up to very high flows per

    single turbine 2-100 m3/s

     Head: 2.5 – 40 m

     High efficiency at nominal

    flow-rate

     Expensive regulation devices

    required to achieve good

    partial load efficiency

     A well shaped diffuser is

    required

     Susceptible to cavitation

     Thin intake screen required

    Kaplan turbine

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    33

    Video

    Kaplan turbine

    https://youtu.be/0p03UTgpnDU

    https://youtu.be/0p03UTgpnDU

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    34

    Different possibilities for partial load regulation:

    A. Double regulation (stator + rotor)

    B. Single regulation (rotor)

    C. Single regulation (stator)

    D. No regulation (Propeller)

    Kaplan turbine

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    B. Single regulation (rotor)

    Kaplan turbine

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    Kaplan turbine

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    37

     Volumetric turbine

     Working range H = 1 – 6m

    Q < 7 m3/s

    Archimedes Screw turbine

    Video

    https://www.youtube.com/watch?v=bGViZ4p3Fuw

    https://www.youtube.com/watch?v=bGViZ4p3Fuw

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    38

    H

    Archimedes Screw turbine

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    39

    0

    10

    20

    30

    40

    50

    60

    70

    80

    90

    100

    0 0,2 0,4 0,6 0,8 1

    R e

    n d

    im e

    n to

    %

    Portata normalizzata Q/Qmax

    Archimedes Screw turbine

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    40

     Volumetric turbine

     Working range H = 1 – 6m

    Q < 7 m3/s

     Low speed – long lasting mechanics

     High efficiency at partial load

     Possible transit of debris

     Low cost and low maintenance

     Reduction of civil works

     Fish-Friendly Downstream

     Cost < Kaplan and VLH

     Limited flow and head range

     Efficiency < than Kaplan @ Qn

     Visual impact

    Archimedes Screw turbine

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    41 Archimedes Screw turbine