burner cycle time???

RoosterBoy

how many minutes would you conceder short cycle for a burner. how long should a burner fire for before it's considered short cycle
this is for a riello f3 burner with buderus g115 model 28
thanks

Brad White_2

Most any

boiler has to fire for at least two minutes roughly in order to stabilize combustion products (steady state production of CO2, CO, Nox and so forth). If you were to see a graph of the products during initial firing and especially from a cold start, you would see spikes of CO in particular and the other compounds as well. Flame -particularly in atmospheric gas) may change color during this period as an indication of less than complete combustion. When the flame settles to a steady color and state, that is a visual indicator.

At the point where all of these elements settle to steady state production and the flue passages are warmed up is the efficiency even close to design. From this condition subtract the yet-to-temperature fluid (water or steam) which will rapidly from this point rise to stable operation.

What I have described is at the stoichiometric (absolute combustion) level to illustrate what "work" is lost during short cycling. Anything less than two minutes is practically a waste, and once established (post two minutes) begins your benefit.
The specifics of your burner I will leave to others, but the general ideal is that the burner should be selected for 100% run time on a design day and cycling is expected naturally from there as outdoor temperatures rise, this you know.

RoosterBoy

Brad thanks very much for explaining this all to me i understand more now.

thanks alot