Function block inputs

[fn] Siegert's constants

This parameter specifies where the function block obtains the constants which are required for the calculation.

If a fuel is specified as source, the values from the standard configuration are used.

The function block performs the calculation if the selected fuel is used in single operation.

0	Individual values
1	Fuel 1
2	Fuel 2
3	Fuel 3

[O2,dry] Dry oxygen content [Vol.-%]

Analog channel

[ϑL] Combustion air temperatur [°C]

Analog channel

[ϑA] Exhaust gas: Temperature [°C]

Analog channel

[qK1] Boiler: Fixed losses

Fixed value

Surface loss (e.g. 2%).

[qK2] Boiler: Variable losses

Analog channel

[A] A according to Siegert

Fixed value

Fuel	Constant
Light oil	0.68
Heavy fuel oil	0.69
Natural gas L	0.66
Natural gas H	0.66

[B] B according to Siegert

Fixed value

Fuel	Constant
Light oil	0.007
Heavy fuel oil	0.007
Natural gas L	0.009
Natural gas H	0.009

[En] External release

Digital channel

Function block outputs

[qA] Exhaust gas: Losses [%]

qA = (A / (21-O2,tr) + B) x (ϑA - ϑL)

[ηF] Efficiency: Firing [%]

ηF = 100% - qA

[ηK] Efficiency: Boiler [%]

ηK = 100% - qA - qK1 - qK2