Standby Generator used as Continues Generator 2

[Kevin8686]

Hello everyone ,

I am a new power plant operator and I need your consultation please,


What will happen to 5.7 MW / 4.16 KV / 60 HZ Standby generator used as Continues Generator.

It will be loaded with 1.5 MW Winter time,
And 2.5 MW Summer time.
For unlimited number of hours for the next 4 years.

What effects we will have on the generator ?
Will it run until next overhaul after 4 years ?

Please advice,
Kind regards.

 

[edison123]

5.7 MW generator running continuously 2.5 MW? No problem as long as it is electrically fit.

The question is about the prime mover. Is it Diesel engine? Steam turbine? Hydro turbine? Each have their own limitations under partial load.

Muthu

http://www.edison.co.in

 

[waross]

For diesel sets:
A standby set will have the rated capacity reduced to 10/11 or 90.9% of the standby rating..
It will be allowed to run at a 10% overload (the original standby rating) for one hour out of twelve hours, not to exceed 25 hours per year.
eg: A 165 KVA standby set will often have the same basic engine and the same generator end as a 150 KVA prime set.
In some instances only the nameplate will be changed.
But, the prime set may have enhanced or added accessories.
The prime set may have a larger oil sump on the same basic engine.
The prime set may have an added or enlarged oil cooler on the same basic engine.
The prime set may have larger oil filters on the same basic engine.
The prime set may have larger fuel filters on the same basic engine.
Loading:
With a 1.5 MW load on a 5.7 MW (26%) diesel engine there is a slight possibility of oil pumping or wet stacking.
If 1.5 is the maximum load and at times the load will be significantly less, the possibility of oil pumping out the exhaust may be much greater.
This is a characteristic of lightly loaded diesel engines and has nothing to do with prime/standby ratings.
With light loading, watch the oil consumption and check the exhaust for any raw lube oil being discharged.
Check also any low spots in the exhaust piping where oil may accumulate.
Oil may accumulate in low spots under light loading and then be expelled as burning blobs under heavy loading.
Overhauls:
We ran our set for 15,000 hours between minor overhauls (rings) and 30,000 hours between major overhauls.
We switched sets on-line and off-line as needed so the running sets were almost always well loaded.
With light loading you may be able to run more hours between ring jobs.
BEWARE
Wet stacking is not uncommon on new sets and after a ring job.
Combustion pressure is ported behind the piston rings to aid in sealing.
At light loads and lower combustion pressures new rings may not seal well.
I have cured serious wet stacking issues on new sets by load banking for several days to seat the new rings.

On the other hand, if your prime mover is not internal combustion, disregard this advice.
Others here may offer advice on light loading effects on other types of prime movers.

Bill
--------------------
"Why not the best?"
Jimmy Carter