Load Testing of GTGs at offshore

[NickParker]

Could you provide guidance on how to conduct load testing for the GTGs at offshore? Since we lack load banks offshore, it appears that we'll need to perform the testing using real process loads. For onshore testing, we utilize load banks managed by a load bank controller, with loading increments of 25%, 50%, 75%, and 100%.

 

[waross]

Have you considered a liquid rheostat?
Basically a conductive liquid and conductive electrodes.
For offshore testing you are surrounded by conductive liquid.
Can you source a lot of scrap iron?
I have more than once load banked a generator with plastic barrels of salt water and discarded leaf springs from a truck as electrodes.
I have heard of a dumpster filled with water and a forklift used to lower electrodes used for larger generators.
You may control the current by the amount of your electrodes submerged.
You can figure out the details.
Tips:
Do this on the lee side so that any Brown's gas produced is dissipated away from the rig.
No swimming around the electrodes.
Lift the neutral ground during the test to avoid the hull acting as an electrode.
You may need to turn off any electrolytic protection during the test.
Due diligence, you may consider inspecting any zincs before and after the test.
Alternately, look for a lot of plastic barrels or a dumpster bin.
The barrel or bin solution has the advantage that you may add salt to increase the conductivity of the liquid.


--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[waross]

You will boil off a lot of water. Plan on topping up the water every hour or three.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[FacEngrPE]

Liquid rheostats are available from several OEM's and can be specified as load banks.

https://patents.google.com/patent/US4039854A/en

The hardware is identical to a liquid resistance starter.

https://www.pthglobal.com.au/what-is-a-liquid-resistance-starter

Caution - keep the water flow rate high enough that the water never boils in the electrode tank. That tends to cause flashovers at the insulators supporting the electrodes, particularly with medium voltage units.

Caution - If the tank is metal it will become a part of the circuit. Either bonding must be used to limit step voltage to something reasonable, or appropriate engineering measures must be used to prevent people from approaching the energized tank.

 

[wayne440]

FWIW, most load banks are transportable.

 

[LittleInch]

well what are your loads off shore?

How many of them are not motors?
Can you start a motor with more than one GTG then isolate it to only one to get your approx loads?
Any resistance loads are preferable, but the how is down to you to figure out what you can turn on. You may need to open the breakers on the switchboards to isolate loads to one generator.

It can be done, but you need the SLD and current measurement.

But why not sail a load bank out on a barge and connect it?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.