Long-life bearing solution at new Chinese nuclear power station

Long-life bearing solution at new Chinese nuclear power station Weir Pumps has recently supplied four vertical concrete volute circulating water pumps for the Qinshan phase Ill nuclear power station in China and SKF has created a bearing solution to accompany them that will last for years to come.

The pumps supply cooling water to condensers,

SKF and

which take exhaust steam from the main turbines.

relationship.

Each bespoke

components

unit has a 3.1 MW electric drive

motor, speed-reducing

gearbox, and intermediate

pumps

Weir

Pumps have

In fact,

a close working

many

of

on Weir’s Swallowglide

come

from

SKF. For

bearing

and Uniglide the

application,

meet a challenging

closely with Weir’s designers to produce the final

SKF to quickly deliver a suitable vertical bearing housing assembly between

personnel

Qinshan

bearing assembly and shafting system. In order to delivery schedule Weir asked

SKF’s technical

the

worked

engineered solution.

the drive motor and The Qinshan phase III nuclear power station is due

the pump.

to start commercial SKF’s lead-time for the project, from inception to

operation

in February 2003

with full capacity, and the second Heavy Water

delivery was a mere twelve weeks. In this short

Reactor, coming on-line in November 2003. Work

time, SKF successfully designed and supplied the

began on the project back on the 8th of June, in

bearings, housings, shafts and the interfaces. The

1998. It is part of a planned

completed

assemblies have since been fitted

in

nuclear

sector

in China.

expansion

of the

The authorities

are

place by the main site contractor.

currently constructing

three more Nuclear Power

The distance between the motor and the pump is

country’s

some 6.5m with the bearing assembly (750mm

2004. The installed capacity of the four new NPP’s

from flange-to-flange)

The

will total

was

current capacity.

Plants (NPP) with the aim of meeting 3% of the

space allowed

mounted

mid-way.

for the bearing arrangement

therefore

loosely that of a standard SKF SD split

plummer

block housing,

modified separation.

design

to

which

SKF the

design the most cost effective compromising capability immediately

the

sealing

needs from

this source by

6,60OMW, nearly three times China’s

was used in a

maximize

This allowed

electricity

the

solution and

bearing

flexibility

to

without

operational

of the unit. The assembly is located above an epicyclic reduction gearbox.

The SKF assembly includes a pair of SKFtaper roller bearings 32036X (180 mm bore), with a seal, nut and washer allowing

high operating speeds of up

to 990 rev/min. The housing consists of SG iron, which offers greater strength than conventional cast iron, coated with an epoxy polyamide

paint

finish, which is resistant under 100% humidity and site temperatures of -4’C to +4O”C. As a result of these features, the bearing life expectancy, which was originally specified to be 40,000 hours, has an anticipated lifetime in excess of 176,000 hours. All the components were inspected and assembled at SKF’s Service Centre in Luton UK, prior to being flown out to China.

www.worldpumps.com

Assembly of one of the four water pumps supplied, with SKF’s vertical bearing, for the Qinshan phase III nuclear power station in China.

WORLD PUMPS

September 2002 I19

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