28.01.2015 Views

Guidebook to Amani - MWUCE

Guidebook to Amani - MWUCE

Guidebook to Amani - MWUCE

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

FIELD TRIP TO AMANI IN TANGA<br />

A STUDY OF HYDRO-ELECTRIC POWER<br />

Suitable for Paper 1/2 (0460/1/2)<br />

Hydro- electric power is electricity produced by the power of falling water. Water from a<br />

reservoir or lake drops <strong>to</strong>wards the water turbine through a long pipe called a pens<strong>to</strong>ck.<br />

The water turbine changes the energy of movement (kinetic energy) in<strong>to</strong> energy in the<br />

form of mechanical power (mechanical energy).<br />

The distance the water falls before it strikes the water turbine is called the 'head'.<br />

There are three types of water turbine:<br />

. The Pel<strong>to</strong>n wheel-used with 'heads' of more than 300metres.<br />

. The Francis turbine-used with 'heads' of between 30 and 300metres.<br />

. The Kaplan turbine-used with 'heads' of less than 30metres.<br />

The movable gates called guide vanes or nozzles aim the falling water at the blades or<br />

buckets. The blades are pushed hence turning the wheel and the axle which is mounted<br />

vertically or horizontally. The axle is directly or indirectly connected <strong>to</strong> a machine, an<br />

electric genera<strong>to</strong>r or a dynamo.<br />

The Kaplan turbine<br />

41<br />

2006 © Laureate International School

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!