Burner back pressure

[SJB060685]

Can someone explain to me how a higher burner back pressure in millibar affects thermal output? I’m training on oil and read a lot of manuals. Riello for example state the firing rates for various burner models and what can be achieved in output terms in relation to burner back pressure, ie a 26kw output can be achieved with a relatively high back pressure but say a 60kw requires a much lower back pressure. I have spent hours googling and have yet to find a definitive scientific answer.

 

[Tea-Break]

I feel if it’s a definitive answer you require, why not
pose the question directly to one of the burner manufacturers.
You could contact EOGB who I’m sure would be happy to help. Alternatively one of the numerous boiler manufacturers will be able to assist.
As I should assume it is based on the design of the combustion chamber, secondary heat exchanger and flue etc.

 

[MikeJhn]

I think it's about pump pressure vs Nozzle size and Bernoulli's theorem.

 

[SJB060685]

Hi guys.

Thanks for replying. I understand how combustion chamber design and size can affect back pressure, as well as flue conditions and pump pressure and nozzle size etc etc. I have emailed EOGB technical department to see if they can give me a definitive answer.

Thanks again