MICRO HYDROELECTRIC POWER PLANT WITH CHAIN TURBINE

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MICRO HYDROELECTRIC POWER PLANT WITH CHAIN
TURBINE

• Nguyen Minh Duy

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Content

• Overview about hydroelectric power plant
• Analysis chain turbine
• Governor using for chain turbine
• Work in the future

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Hydropower to Electric Power
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Hydropower to Electric Power
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How Hydropower Works

• Water from the reservoir flows due to gravity to
  drive the turbine.
• Turbine is connected to a generator.
• Power generated is transmitted over power lines.

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How Hydropower Works (2)

• A water turbine that cover the energy of flowing
  or falling water into mechanical energy that
  drives a generator, which generates electrical
  power. This is a heart of hydropower power plant.
• A control mechanism to provide stable electrical
  power. It is called governor.
• Electrical transmission line to deliver the power
  to its destination.

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Vietnam Hydroelectric Potential
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Vietnam Hydroelectric Potential (2)

• Vietnam, the nation yearly average of rainfall is
  about 1,861mm.
• There are more than 2,200 big-to-small rivers and
  streams. So Vietnam is rich hydropower resource.
• Vietnam is agricultural country (agriculture
  20.1). This is a goal to invest SHP.

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Sizes of Hydropower Plants

• Pico hydroelectric plant
• Up to 10kW, remote areas away from the grid
• Micro hydroelectric plant
• Capacity 10kW to 300kW, usually provided power
  for small community or rural industry in remote
  areas away from the grid
• Small hydroelectric plant
• Capacity 300kW to 1MW
• Mini hydroelectric plant
• Capacity above 1MW
• Medium hydroelectric plant
• 15 - 100 MW usually feeding a grid
• Large hydroelectric plant
• More than 100 MW feeding into a large electricity
  grid

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Micro Hydropower Systems

• Many creeks and rivers are permanent, they never
  dry up, and these are the most suitable for
  micro-hydro power production
• Micro hydro turbine could be a waterwheel
• Newer turbines Pelton wheel (most common)
• Others Turgo, Crossflow and various axial flow
  turbines

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Turbine Classified
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Impulse Turbines

• Uses the velocity of the water to move the runner
  and discharges to atmospheric pressure.
• The water stream hits each bucket on the runner.
• High head, low flow applications.
• Types Pelton turbine, Turgo turbine

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Pelton Turbine
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Turgo Turbine
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Reaction Turbines

• Combined action of pressure and moving water.
• Runner placed directly in the water stream
  flowing over the blades rather than striking each
  individually.
• Lower head and higher flows than compared with
  the impulse turbines.

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Francis Turbine
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Kaplan Turbine
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Turbine Selection Chart
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Chain Turbine

• It is a gravity machine
• It is built up of two parallel chain systems
  joint together at the chains with a series of
  buckets.
• The flow rater entering the buckets is
  controlled by the water valve through a motor to
  open or close the valve.
• Buckets fill full of water go down to bring to
  rotary sprocket system.

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Analysis of the Chain Turbine

• With flow rate is 1m3/s, and the head is 20m.
• Assume H119m, H21m, the diameter of the
  sprocket is 1m.

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Analysis of the Chain Turbine (2)

• The gross power output
• Apply the principle of work and energy with the
  bucket of chain turbine
• The maximum speed of bucket
• The angular velocity the sprocket would be
• The rotational speed of the sprocket would be

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Analysis of the Chain Turbine (3)

• Number of buckets in chain turbine

Number of buckets The volume of a bucket (m3)
8 0.50
10 0.40
12 0.36
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Analysis of the Chain Turbine (4)

• The power output is
• The power out of the turbine shaft
• The efficiency of the chain turbine is given by

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Analysis of the Chain Turbine (5)

• Rotational velocity of sprocket depends on the
  distance of between two shafts of turbine H1.
• Rotational velocity of turbine shaft is slow, so
  it cannot directly connect with generator. It
  need a power transmission
• Efficiency of chain turbine is low.

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Advantages of Chain Turbine

• It is run-of-river power plant.
• Do not worry about the turbidity of water.
• There is no danger of cavitations.
• It is simple to construct, repaired and
  maintenance.

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Disadvantages of Chain Turbine

• The slow rotation of chain turbine leads to high
  speed ratios when connect to generator at 600 rpm
  1500 rpm.
• This chain turbine operation is very noise.
• Structure of turbine is very big

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Governor

• To maintain the generator at a constant 50Hz
  frequency, it is necessary to maintain the
  generator shaft at a constant rotational speed.
• In the independent hydroelectric power plant,
  the rotational speed of the micro hydro power
  generator can be change when loads are added or
  subtracted from the electrical system.

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Governor (2)

• The system frequency can be maintained constant
  by eliminating the mismatch between generator and
  load.
• Governor is to receipt the frequency signal from
  the output of generator.
• And it is compared with standard frequency
  signal.
• From these results, governor output signal is
  coming-out to control the valve of water at the
  entrance to the turbine.

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Transfer Function Block Diagram of Hydro Plant

• power system gain constant (Hz/p.u)
• nominal starting time of water in penstock (s)
• integral gain constant for servo system
• proportional gain controller constant for servo
  motor

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Governor Transfer Function

• Chain Turbine transfer function
• water starting time at full load
• So transfer function of chain turbine is

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Generator Transfer Function

• Assume nominal load
• Frequency 50Hz
• The latter load assumption yields
• So, the system gain constant and time constant
  are given by
• The transfer function of generator

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Transient responses of system for step changes in
load, showing deviations in system frequency
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Transient responses of system for step changes in
load, (1.5kW) for different integral gain value,
showing deviations in system frequency (1)
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Transient responses of system for step changes in
load, (1.5kW) for different integral gain value,
showing deviations in system frequency (2)
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Transient responses of system for step changes in
load, (1.5kW) for different integral gain value,
showing deviations in system frequency (1)
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Transient responses of system for step changes in
load, (1.5kW) for different integral gain value,
showing deviations in system frequency (2)
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Governor Discussion

• It is more flexible than classical governor.
• This governor effectively eliminate the frequency
  deviations due to load disturbances for different
  nominal loadings of the system
• It is importance as the saved water can be used
  for irrigation.

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Work in the Future

• In China, YiuHwa Engineering Company is building
  a hydroelectric power plant with chain turbine to
  experiment and research with capacity 200kW.
• This plant has two turbines and built with head
  20m and flow rate 1.03m3/sec

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THANK YOU