IMR® 2800
40
IMR Environmental Equipment, Inc.
4 CALCULATIONS
The
IMR 2800
calculates most parameters that are important for the measurement of a
combustion process:
- Heat losses
- Excess Air
- Carbon dioxide CO2
- mg/m3, mg/m3 (Ref.O2)
- NOx (NO+NO2)
4.1 EXCESS AIR
In reality it is not possible to achieve a perfect combustion using the theoretically required
amount of air. Therefore excess air is needed.
The ratio of the volume of air to the volume of air theoretically required is excess air.
Lambda
O meas
20 9
20 9
2
. / (
.
.)
The excess air value must be kept low, as it needs to be heated resulting in a decrease of the
flame temperature and an increase of the flue gas temperature, thereby deteriorating the
efficiency.
4.2 CARBON DIOXIDE CO2
The CO2 percentage in flue gases depends upon the amount of carbon contained in the fuel. In
order to achieve an optimum combustion a small CO value and a maximum CO2 value must
be set (ideally the entire carbon is converted into CO2).
CO
CO
O meas
2
20 9
20 9
2
2
max
. ((
.
.) /
. )
CO2max =
max. CO2 of the fuel
The flue gas CO content that results from incomplete combustion is to be kept as small as
possible because of its toxicity. In addition this CO content takes up latent heat, which results
in higher flue gas losses.
