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17 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Classification of hydroelectric power equipment |
● Generating equipment ● Auxiliary equipment i. Oil system ( Turbine oil, insulating oil) ii. Gas system ● Mechanical equipment- Crane ● Electrical equipment- Transformer |
G A M E |
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Basic types of Hydraulic turbine- Reaction Turbine |
● Reaction Turbine - Runner chamber is completely filled with water. - Driving energy is provided by the water partly in kinetic and partly in pressure form. - Runner surface is space warped surface - Water inlet pressure is greater than water outlet pressure. - Have draft tube Types: Francis, propeller & diagonal |
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Basic types of Hydraulic turbine- Impulse Turbine |
● Impulse Turbine - Runner chamber not completely filled with water. - Driving energy is provided by the water is only in kinetic energy form. - The water head is converted into velocity, producing kinetic energy - No pressure change during converting process. - Have no draft tube Types: Pelton Turbine |
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Francis Turbine(HL)-Mixed flow |
Characteristics - Same as Reaction Turbine Special - Inlet direction movement is radial and outlet direction movement is axial. - Mostly used by dam with high water head ranging from ( 30m-700m) - Have 14-19 blades. Kinds: i. High Specific Speed Runner ii. Medium Specific speed Runner iii. Low Specific speed Runner( The inlet diameter of the runner is greater than the discharge diameter) *Inlet diameter= Nominal diameter |
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Propeller Turbine(ZL)-Axial |
Characteristic - Have 3-8 blades. - Blades of Runner may be fixed/movable. - Both inlet and outlet flow directions are axial movement. Kinds: i. Fixed propeller ii. Movable(Kaplan) propeller |
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Fixed propeller type |
- Blades are fixed on hub. - The main scope of application is hydropower station with small change of water head. - The placement angle of the blade is always fixed in the optimal position of the design condition.
Advantage：：Design and installation simple , low construction cost.
Disadvantage：：Have low efficiency when there's changes in water head cannot be applied. |
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Movable (Kaplan) Turbine |
- Have adjustable blades - The blades are connected to the hub by a spherical flange - The blades can be rotated according to the changing conditions to maintain optimal placement angle. - It is commonly used in hydropower stations with frequent changes in water head.
Advantage：：Adjust the blade Angle according to the water head change to achieve the optimal operating condition. Disadvantage：：Design and installation are complex, High construction cost |
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Diagonal Turbine |
- A Reaction Turbine - Runner has conical hub - Angle between blade and main shaft is 30°~60°. |
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Pelton Turbine |
- An Impulse Turbine - Operate in high water, low discharge. - Runner are moved by water jet. - Tangential water flow direction. Kinds: Single-jet, Multi-jet |
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Turbine symbol |
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Turbine main shaft layout |
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Turbine spiral case type |
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Main parameters of turbine |
● Head of turbine (H) The difference in water specific energy between the beginning and the end of the turbine section 》 H= Hm-Hab, where; Gross water head(Hm)= Zupstream - Zdownstream Head Lost in intake and penstock(Hab)=Ha - Hb
● Discharge of turbine(Q) Water volume which lasted through turbine passage per unit time.
● Power output of turbine Nt = 9.8QHn, where n=effuciency
● Rotational speed The rotational speed of unit is the synchronous speed which is decided by number of pole pairs. f=（Pn）/60 |
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Turbine homologous |
Two or more turbine of different sizes, and are similar in design and construction . |
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Turbine constant |
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Purpose of turbine constant |
• To predict the characteristics of a full-size runner • To compare the characteristics of two or more turbine of the same type, design and construction. |
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Components of turbine |
1. Spiral case - To distribute uniformly the water around the stay ring, the wicket gates, and the runner. Types * Concrete: Volute angle(180°~270°), (H<40m), (ladder-shaped), Kaplan * Metal: Volute angle(180°~270°), (H>=40m),
2. Stay ring: (Single casing held together by stay vane). - Guide the flow into the wicket gate. - Carry the load from above and take force of internal water pressure. - It resists heavy loads imposed by the equipments of the power house
3. Wicket gate - Serve to start up and shut down the turbine. - Control its power output and its rotational speed.
4. Reaction turbine runner ** Propeller turbine runner ** Kaplan turbine
5. Draft tube - Allow the turbine to set above tailwater. - Guide the water smoothly to downstream.
6. Turbine cover: Prevents water in runner from getting to generator. |
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