Help with Oxigen tuning

[joukeder]

The best result I have now is presented here:
http://www.beara.org/stg4.jpg
Main changes are:
I keep the burner grate much cleaner by brushing it twice a week (Do other people need to do that?)
I have set the I factor in PID to 10 in stead of 100
I have set Oxygen regulation to 25 from 100.
What do you think?

I am still perturbed by the fact that my 24Kw boiler does not come to over 17 KW. It takes more then one hour to get the temp up to 50 degr C.
How do I see that the Biocomfort boiler is 24KW?
My other boiler that is 16KW looks exactly the same.....

Regards
Jouke

[tn]

The best result I have now is presented here:
http://www.beara.org/stg4.jpg
Main changes are:
I keep the burner grate much cleaner by brushing it twice a week (Do other people need to do that?)
I have set the I factor in PID to 10 in stead of 100
I have set Oxygen regulation to 25 from 100.
What do you think?

I am still perturbed by the fact that my 24Kw boiler does not come to over 17 KW. It takes more then one hour to get the temp up to 50 degr C.
How do I see that the Biocomfort boiler is 24KW?
My other boiler that is 16KW looks exactly the same.....

Regards
Jouke

hi Joukeder

Yes, I think it loooks quite good now.
I have tryed to notice my own oxygen level for a while with automatig oxygen control switched on.
I can see that when i have much crushed pellets in my auger pipe, it deviates a lot more than when I have a clean Auger pipe.
And I think that is your main problem too, because the deviation in auger feed is very variable, when you have a lot of crushed pellets in the pipe, and it's a bigger problem with high angle on the pipe.
It's quite easy to here when the pellets is falling down into the burner, that the amount deviates, and if the oxygen control try'es to compensate for this, it actually does the oxygen changes problem bigger. By limiting the regulation to 25, you obtaine to adjust slower, and thereby only adjust for more staing changes and not for the iregular changes from the auger, so thats good.
What I do to limit the problem is to add some food-oil to the bottom of the pipe from time to time.
very little can do the trick to bind the crushed pellets, so they are feeded instead of staying in the pipe. Only 1 liter per 1-2 month can do it. feeded with very small amount per time.
her are a link to an example of such a device http://www.woodville.dk/index.php?entry ... 011-190819

About the effekt of your burner, The burner itself is the same for 16 and 24 KW, only the settings deviate. And then the Auger is bigger.
The High blower settings is an indication of the KW. It's almost the same value as the maximum effekt. Ie is 'it about 24 your burner/auger is for 24 KW. And about 16 it's a 16 KW burner.
And I think that an Auger for 24 KW is more unstable than a 16 KW because it's bigger so that extends your oxygen problem too.

[joukeder]

Hi Torben,
That explanation was very helpful.
I have now experimented with the max blower setting and indeed I can now reach full 24KW power when I set it to 25. The oxygen control then takes the max pellets to 31, not far from what you calculated to be correct.
This makes a good improvement on the time it needs to reach desired temperature.
I think the conclusion must be that when driving the unit with Oxygen control, one must reduce some of the default settings for Oxygen gain and PID, keep the burning grate clean and one can adjust the power settings of the boiler with the max airflow from the blower.

I now brush the burning grate twice a week. Is that what other people do too?

Regards
Jouke

[tn]

Hi Torben,
That explanation was very helpful.
I have now experimented with the max blower setting and indeed I can now reach full 24KW power when I set it to 25. The oxygen control then takes the max pellets to 31, not far from what you calculated to be correct.
This makes a good improvement on the time it needs to reach desired temperature.
I think the conclusion must be that when driving the unit with Oxygen control, one must reduce some of the default settings for Oxygen gain and PID, keep the burning grate clean and one can adjust the power settings of the boiler with the max airflow from the blower.

I now brush the burning grate twice a week. Is that what other people do too?

Regards
Jouke

Hi Jouke

nice to hear that it seems to be working quite good now.

About the cleaning of the burner grate. I do it my self once a week, and then there are some leight weight ashes in the front of the grate and some more fixed at the inner position.
I think that the leightweight ashes is no problem because that will be blown away if it fill up.
The more fixed ash blocks for the air in the buttom, so that should be limited.
But you can try to play with cleaning blower, cleaning interval and cleaning time to limit it.
Also it's importent with a good burning process air/pellets ratio so that your ash is gray, not white and not black.
In your case with automatic oxygen control, you will ofcause have to change the oxygen target in order to change the ratio.