Idea to stop wet stacking automatically

[robkiller]

I am working on an idea to see about a way to stop the problem of wet stacking automatically. I have a few questions before i post details. Lets start with an MEP003a but this will work with them all.

How much of a load the gen need to stop/prevent wet stacking and for how long?

How often does it need to have the above condition when running to prevent wet stacking?

I hope these questions make since. If not let me know i will try to ask it in a different way.

 

[davo727]

Do you have a plan to be able to vary the anti wet stacking load depending on what your amp draw is at that time or just going to use a timer to add in an additional fixed load at certain intervals? Using either a bank of heating elements and relays to cut them in or a braking device on the shaft?

 

[Speddmon]

Wet stacking is not generally an issue with air cooled diesels. Can it happen, Yes. But not often.

If you are wanting to prevent it, a fully loaded run for about an hour or so every 6 months to a year is fine. And that all depends on how much and how you run the generator in between. It may never need to be worked that hard to remove build up if you work it out when you are using it or if it is really hot outside during a normal run. The whole premise of running it loaded to prevent wet stacking is to make the engine build sufficient heat as to fully burn the fuel as it leaves the exhaust trane of the engine. Again, much more of a problem with liquid cooled diesels vs. air cooled as air cooled naturally run hotter.

 

[jamawieb]

Speddmon is correct, the Mep-002a and Mep-003a are not likely to wet stack since they are air cooled. Wet stacking usually only happens with the liquid cooled diesel's because they operate at a lower combustion temperature due to the cooling system.

 

[robkiller]

Do you have a plan to be able to vary the anti wet stacking load depending on what your amp draw is at that time or just going to use a timer to add in an additional fixed load at certain intervals? Using either a bank of heating elements and relays to cut them in or a braking device on the shaft?

"be able to vary the anti wet stacking load depending on what your amp draw is at that time"

This would be very simple but i went a bit further. I did not want to waste fuel by running the gen hard all the time when it may not be needed to prevent wet stacking.

It sounds like it may not be worth it for the MEP002/3 but would it be worth it for the water cooled units?
My plan was to program an Arduino or something similar to monitor the current from both lines coming from the generator. It would monitor the loads to help balance them and to help prevent wet stacking.

To prevent wet stacking it would monitor for the current and make sure that the generator had a load greater than the load needed to prevent wet stacking for the amount of time we determined it needs to prevent that wet stacking. If it needed to it would add loads to the unit using relays. Each relay can add 300 - 3000 kw depending on the setup. I was looking at a total of 3 relays for each leg.
It would trigger as many relays needed to meet the load demand of the generator to prevent wet stacking.

So example

Power is out for 24 hours we want the generator to run 80 percent load or 75 amps for at least an hour in a 8 hours period. During the day when everyone is up the power is over the required load for 1 hour as it is normally operating. So it would not need to add power to help it meet that need. However night comes and the generator is getting to that 8 hours and has only ran at 40 percent load. So it would add loads to make sure it gets over that 80 percent load for those 8 hours. After it meets the requirement it will take off the added loads again. If it is being loaded by the Arduino (or whatever device) to help meet the load need for that 8 hours. If all of the sudden someone kicked on a high output appliance. it would turn off relays to let the natural load from the house be used to meet that 80 percent load.

The relays would be simply on and off switches for outlets to run heaters or other power consuming devices. Or you could modify the relay setup to operate a load bank.

 

[m16ty]

Personally, I think the wet stacking issue is overrated. Can it happen, yes. Will it happen if you let the genset run with a light load for a couple of hours, no.

We've ran diesel farm tractors for several days with little load running a grain auger without ill effects.

Unless you're running your set for days on end without load, you should be ok.

What you posted will work fine but I think you are over thinking it. Just load it up about twice a day whenever it is convenient and don't worry so much about exact times.

If you are set on making it automatic, just get a water heater element in a tub of water and set it to come on with a timer.

 

[robkiller]

Personally, I think the wet stacking issue is overrated. Can it happen, yes. Will it happen if you let the genset run with a light load for a couple of hours, no.

We've ran diesel farm tractors for several days with little load running a grain auger without ill effects.

Unless you're running your set for days on end without load, you should be ok.

What you posted will work fine but I think you are over thinking it. Just load it up about twice a day whenever it is convenient and don't worry so much about exact times.

If you are set on making it automatic, just get a water heater element in a tub of water and set it to come on with a timer.

And this could be true thats why I am checking with you guys.

 

[steelandcanvas]

I can appreciate your engineering and thought process with trying to avoid the wet stacking issue, however I am in agreement with Ty and Tom. I have an 003A just for emergency back-up, and start it up maybe three times a year. I put the house and shop loads on it (about 85%), and run it for 45 minutes to an hour. On occasion, I'll drag it out to a display or Club rally, run it all day long with hardly any load (the MKT) and have had no issues with wet stacking.

 

[robkiller]

Thats good to know. If its not a problem then I wont worry about fixing it lol