The Schematic of Kaplan Turbine-Turbomecines-Lecture Slides, Slides of Turbomachinery

Download The Schematic of Kaplan Turbine-Turbomecines-Lecture Slides and more Slides Turbomachinery in PDF only on Docsity!

The Schematic of Kaplan Turbine

Major Parts of A Kaplan Turbine

Design of Guide Wheel

D

go

N

gH

k

D

ug

go

k

ug

1.3 to 2.25 :

Higher values for high

specific speeds

Number of guide vanes : 8 to 24 : Higher number of vanesfor large diameter of guide wheel.

Outlines of Kaplan Runner

Whirl Chamber

Guide Vanes

a

b

The space between guide wheel outlet and kaplan runner isknown as Whirl Chamber. a=0.13 D

runner

& b=0.16 to 0.2 D

runner

.

The Kaplan Runner

Inside the Hub

Adaptation Mechanism inside the Hub

Runner diameter section

The runner diameter De can be calculated by thefollowing equation:

N

H

N

D

s

runner

4 3

H

Q

N

N

s

Blade Characteristics for Micro Hydel Plants

Blade Characteristics for Micro Hydel Plants

Hydraulic Energy Diagram

H

s

H

total

H

ri

H

re

H

m

CAVITATION

Cavitation occurs especially at spots where the pressure is low.

In the case of a Kaplan turbine, the inlet of the runner is quitesusceptible to it.

At parts with a high water flow velocity cavitation might alsoarise.

The major design criteria for blades is : Avoid Cavitation.

First it decreases the efficiency and causes crackling noises.

The main problem is the wear or rather the damage of theturbine’s parts such as the blades.

Cavitation does not just destroy the parts, chemical properties arealso lost.

DESIGN OF THE BLADE

Two different views of a blade

Hydrodynamics of Kaplan Blade