On 26/09/2012 22:42, tony sayer wrote:
In article , SteveW steve@walker-
family.me.uk scribeth thus
On 26/09/2012 13:51, tony sayer wrote:
In article , Andy Champ
scribeth thus
On 24/09/2012 20:25, tony sayer wrote:
So then its dissipating under full throttle 300/400 kW?, Surely not?..

At full throttle it's probably a bit more efficient. So 200/300kW.

Surprising isn't it!

Andy

Yes very. I was standing near a 25 kW load bank for a generator test and
that was bloody hot and throwing out a -Lot- of heat.

A piddling little one The 30MW loadbank that we used to test 24MW
generators used baths of chemically dosed water and adjustable insertion
electrodes, with the water being pumped in, continually overflowing and
being pumped through fanned coolers and back in. The column of steam
generated was impressive; the glow of the arcing electrodes gave a very
good impression of a fire at the base - the neighbouring houses called
the fire brigade more than once! The noise of the generator's RB-211,
its cooling fans, ventilation fans and the lubrication system's gear
pumps had to be heard to be believed - taking measurements within inches
of the casing of the RB-211 was somewhat warm (there was no external
casing, just the bare engine) and rather noisy.

SteveW


Impressive!..

A friend of mine was studying engineering at Imperial college some time
ago now and he related to a time where they were at a Jet test facility
and had a lot of respect for the bloke from Rolls Royce who was doing
some "fine tuning" right next to the engine under what seemed take off
power!....

Just how much power does a 211 make and what's the efficiency like?..

I don't know the efficiency, although you could work it out - I'm fairly
sure that at 24MW we were burning about 120 litres a minute of red
diesel. The system was not optimised for that though, as it was intended
for a North Sea oil-rig and to start on diesel, then switch to natural
gas as the platform began producing.

I also don't know what the RB-211 is actually capable of, as the setup
was of an industrial RB-211 exhausting into a Dresser-Rand gas turbine
running at 3600 rpm and driving a Brush ac generator to produce 11kV,
3-phase, 60 Hz. I don't know whether the RB-211 or the turbine was the
limiting factor or even if either was being fully utilised.

There was a further 1.2MW diesel driven (Black Start) unit to provide
electrical and hydraulic power to start the main units. That was started
by a three shot hydraulic/Nitrogen bladder accumulator setup. If all
three shots failed, then they could be pumped back up by hand!

The units were for Shell Gannet.

SteveW