FRANCIS TURBINE

Submitted To :Mr. PM Meena(Professor)Mechanical Engg. Dept. MBM Engg. College Jodhpur

Submitted By :Prashant Kumar SoniRajender SinghDeepak Kumar KakkadVinay Agarwal(BE Final Year)

FUNCTION OF TURBINE

Used for hydro electric power, i.e. cheapest source of power generation.

hydraulic energy mechanical energy electrical energy

power generating device

TYPES OF TURBINE

Pelton wheel turbine Francis turbine Kaplan turbine

Classification of turbines

Head and quantity of water availableHydraulic action of waterDirection of flow of water in the runnerSpecific speed of turbinesDisposition of the shaft of the runner

Francis turbine

Medium head(45m to 250m)Reaction(K.E.+P.E)mixed flow(radial + axial)medium specific speed(50 to 250) disposition of shaft of runner is vertical

Main Parts

Penstock-it is a large size conduit which conveys water from upstream to the dam/reservoir to the turbine runner

spiral casing- it constitutes a closed passage whose cross section area gradually decrease along flow direction area is maximum at inlet and nearly zero at exit

guide vanes-these vanes direct the water on the runner at an angle appropriate to the design, controlled by hand wheel or governor

Cont..

Governing mechanism-it changes the position of guide vanes to affect a variation in water flow rate, when the load condition on the turbine changes

Runner and runner blades-the driving force on the runner is both due to impulse and reaction effect(usually runner blades 16-24).

Draft tube-it is generally an expending tube which discharges the water, passing through the runner to the tail race.

Efficiencies Of Turbine

Hydraulic Efficiency - It is ratio of power developed by the runner of a turbine to the power supplied by the water at the inlet.

Mechanical Efficiency – It is ratio of power available at the shaft to power developed at the runner.

• Volumetric Efficiency - It is ratio of volume of the water actually striking the runner to the volume of water supplied to the turbine.

• Overall Efficiency - It is ratio of power available at the shaft of the turbine to the power supplied by the water at the inlet of the turbine.

Cont..

PARTS OF FRANCIS TURBINE

GOVERNING OF FRANCIS TURBINE

Advantage

It is most widely used turbine in world (70-80%).Effective use of water pressure as well as velocity.It is American standard turbine.Very good efficiency (80-94%).

Disadvantages

Cost is high.Due to it’s complex design and large no of moving parts, maintenance and repair is difficult and costly.

It is applicable to flow of medium head only.