Ferroli Oil Boiler

skippy5

Hi lads,
Was doing a service on a cast iron ferroli boiler fitted with an riello 40 g5 burner today.

max output - 64
min output - 44
Nozzle fitted 0.75 S 80deg
pump pressure 14 bar.(gas oil)

I know this set up dosnt quite give you the min output , but has being set up like this for 10 years or more.
My problem is I cant get the co2 % over 10.20.

02% - 7.2
c0 ppm - 118
C02%- 10.2
Ratio- 0.0012
pressure- 0.26
temp net- 122
temp flue- 151
eff gross%- 87.4
xs air%- 52.7

Maybe someone with a bit more experience than me could point me in the right direction to improving these readings.
Thanks

Dtp1979

skippy5 wrote: »

Hi lads,
Was doing a service on a cast iron ferroli boiler fitted with an riello 40 g5 burner today.

max output - 64
min output - 44
Nozzle fitted 0.75 S 80deg
pump pressure 14 bar.(gas oil)

I know this set up dosnt quite give you the min output , but has being set up like this for 10 years or more.
My problem is I cant get the co2 % over 10.20.

02% - 7.2
c0 ppm - 118
C02%- 10.2
Ratio- 0.0012
pressure- 0.26
temp net- 122
temp flue- 151
eff gross%- 87.4
xs air%- 52.7

Maybe someone with a bit more experience than me could point me in the right direction to improving these readings.
Thanks

Turn the air down till O2 is 5-6 percent

skippy5

Hi Dtp,
Tried this and it just sent the C0 way up and C02% down even more.

Wearb

skippy5 wrote: »

Hi Dtp,
Tried this and it just sent the C0 way up and C02% down even more.

How is your smoke test at those readings?

Wearb

Been giving this some more thought. You should have higher co2 readings with those 02 readings. I would check the integrity of your FGA sample. Is there a chance that there is air getting in after the combustion chamber and before your sample point.
Where are you taking the sample from?

I would also do a complete check of the flue way for even the slightest blockage.

Have you chosen correct fuel on your analyser?

jimf

are you sure this is the original burner/nozzle combination

seems grossly overaired as it is at 53% e air

this would explain the high co as well

it wouldn't surprise me if this is not the original burner

just try a .60/65 nozzle and see hot it effects things

sorry just read your post again ignore my comment re trying a smaller nozzle didn't see the output range half asleep

DGOBS

Oil pressure is too high swell, 12bar.

Which Ferroli is it, GN 1 or 2?

If boiler output range is 44-64kw, then your nozzle is also undersized (150k-220k BTU with a .75 nozzle??)

kscobie

I would change the nozzle, sometimes a brand new nozzle wont atomise the fuel properly

JamesM

I'm retired over a year now and it is amazing how quickly you forget things when you are not dealing with them every day :eek: But, I do remember that a G5 was almost impossible to get right with gas oil. It's meant to run on kerosene. The head that is usually fitted is just not suitable for gas oil.

DGOBS

Always was techy, very straight tube IMHO, but have run them on ClassD many times

skippy5

Hi Lads.
Thanks for all the replies.
Just to answer some of your question.
- sample taken 500mm above flue center (twin walled flue)
- the model is GN1 N 05
- flue ways are good and clean
- nozzle is small. I will change that
- had pump at 12 bar and the readings were worse
- heading back there on friday to try get my head around it

Wearb

skippy5 wrote: »

Hi Lads.
Thanks for all the replies.
Just to answer some of your question.
- sample taken 500mm above flue center (twin walled flue)
- the model is GN1 N 05
- flue ways are good and clean
- nozzle is small. I will change that
- had pump at 12 bar and the readings were worse
- heading back there on friday to try get my head around it

If you are sure that your flue sample is good and no air leaks, then see how you get on with a 1.0 or even a little larger nozzle at 12 bar. If still a problem then try 60 degree nozzle and see if that improves it. After that (as Jim suggested) it may be an incompatable burner or burner head. I have no idea what originally came with them.

scudo2

Play around with burner head adjustments and nozzles.
It will take time but you will add to your future knowledge.

agusta

1.00 US/gal at 12 bar will give you an output of 45kw approx. id be trying the 60 degree nozzle first

jimf

how u get on with this yesterday

skippy5

Hi Lads,
Only got back back to this on Friday as they ran out of fuel.
Sorry for delay.

- Changed nozzle for an 0 .85 60 deg solid at 12 bar
- Sealed up flue where air was getting in after chamber and before sample point.
- Results

- co 43
- co2% 11.20
- Ratio 0.0004
- O2% 5.80
- xs Air 38.50
- Flue temp 185
- Eff 86.0%

Thanks lads you were fairly on the ball.

Wearb

skippy5 wrote: »

Hi Lads,
Only got back back to this on Friday as they ran out of fuel.
Sorry for delay.

- Changed nozzle for an 0 .85 60 deg solid at 12 bar
- Sealed up flue where air was getting in after chamber and before sample point.
- Results

- co 43
- co2% 11.20
- Ratio 0.0004
- O2% 5.80
- xs Air 38.50
- Flue temp 185
- Eff 86.0%

Thanks lads you were fairly on the ball.

Not too bad at all. Were you tempted to try a 1.0 at near 10 bar?

DGOBS

10 bar would be a little low for Class D, may not get proper atomisation of fuel.

FGA flue temp a little on the low side, either boiler was not to temperature (FGA completed too early in cycle) or the boiler is under firing as the nozzle is too small

Wearb

DGOBS wrote: »

10 bar would be a little low for Class D, may not get proper atomisation of fuel.

FGA flue temp a little on the low side, either boiler was not to temperature (FGA completed too early in cycle) or the boiler is under firing as the nozzle is too small

Loops! Missed out on the gas oil bit. +1 on under fired. Don't want to turn it into a condensing boiler

skippy5

Would say 1 gal would have being ideal but I was getting better readings with the 0.85 gal.