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consists of a single cylinder 3000-r.p.m. primary turbine of 16,000
kW and a two cylinder 1500-r.p.m. condensing turbine of 84,000 kW;
the first machine operates with steam at 1350 p.s.i.g. 950°F and
exhausts at 600 p.s.i.g. to the second unit without reheating. With
this plant the station achieved a thermal efficiency of 31-5 per cent
in the best week of 1946. A duplicate set is on order.
The
second high pressure plant was put into operation at Willesden in
the following year. It has a three cylinder single-axis turbine
of 32,000 kW, running at 3000 r.p.m. and operating with initial
steam conditions of 1300 p.s.i.g. 950°F.
Two
60,000-kW 3000-r.p.m. three cylinder turbines for Littlebrook, Kent,
are designed for 1235 p.s.i.g. 825°F with reheating to 825°F
between the high and intermediate pressure cylinders, and six 45,000-kW
3000-r.p.m. two cylinder machines for the new Cliff Quay station,
Ipswich, are for 600 p.s.i.g. 825°F. All these have low pressure
cylinders of the double flow type with a multi-exhaust in each flow.
As well as all the turbo-generator sets for Cliff Quay, the Company
has supplied the 132-kV and 33-kV switchgear at this station.
Four
25,000-kW pass-out sets for district heating service were shipped
to Russia after the war. Two of them were two cylinder 3000-r.p.m.
machines, designed for inlet conditions of 398 p.s.i.g. 750°F
and for passing out 300,000 Ib of steam an hour at pressures from
85 to 114 p.s.i.g.
The
supervisory equipment developed by the Company to show any shaft
eccentricity arising from unbalanced rotor heating and differential
expansion of rotor and stator when starting and stopping has become
a standard product known as Turbovisory gear and is now provided
on most large turbines.
The
latest figure (1948) for the best thermal efficiency of the main
steam stations in this country, omitting reheat stations, was 26-76
per cent; this compares with a maximum of 16.9 per cent in 1922.
In no less than twenty of these twenty-seven years the top figure
for thermal efficiency was obtained by stations wholly or mainly
equipped with Metropolitan-Vickers generating plant.
There
is every chance of bettering this achievement. Not only has M-V
supplied one in four of the existing generating sets in Great Britain,
but forty-one turbogenerator sets of 30,000 to 60,000 kW capacity
have been put in hand for new stations and extensions since the
war. The total capacity of these orders adds up to more than two
million kilowatts.
For
overseas power stations generating sets of 20,000 kW or more, aggregating
over three-quarters of a million kilowatts in capacity, are now
on order. Of the many stations completely equipped by the Company,
Klip in the Transvaal has created a remarkable record for reliability
with twelve 33,000-kW units; figures published in 1947 showed that
for the
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