Siemens LMV5 Series Basic Documentation page 257

Siemens Building Technologies
HVAC Products
18.7 Auxiliary functions
18.7.1 Warning when flue gas temperature is too high
If a flue gas temperature sensor is connected and activated, a warning is delivered in
case the adjusted flue gas temperature is exceeded. Excessive flue gas temperatures
are an indicator of increased boiler losses ⇒ boiler should be cleaned. The warning
threshold for gas- and oil-firing can be set separately.
Parameter:
MaxTempFlueGas Gas
Parameter:
MaxTempFlueGas Oil
18.7.2 Combustion efficiency
If an O sensor, a combustion air and flue gas temperature sensor is connected and
2
activated, the combustion efficiency will be calculated and displayed.
Parameter:
Combustion air temperature sensor (NoSensor, Pt1000,
LG-Ni1000)
Parameter:
Flue gas temperature sensor (NoSensor, Pt1000, LG-Ni1000)
To ensure that the calculation will be made correctly, the fuel parameters must be
selected and set in accordance with the type of fuel burnt.
Also refer to subsection 18.10.2, Parameterization .
The calculation is made according to the following formula (1. BimSchV = 1. Bundes-
Imissionsschutzverordnung = First Federal Imission Protection Decree):
Flue gas volume ratio:
O2 value dry:
Flue gas losses:
Efficiency:
Basic Documentation LMV51...
18 Addendum 4: LMV52... with O2 trim control and O2 module
V_afNmin
AVft =
V_atrNmin
•
AVft O2GehaltLu
=
O2_tr
O2GehaltLu
O2Wert _ feucht
⎛
A2
= ⎜ ⎜
qa
−
⎝
O 2 GehaltLuft
η
= −
100 % qa
F
ft
ft
+ −
AVft 1
⎞
(
ϑ
+ • ⎟ ⎟ −
B
Abgas
⎠
O 2 _ tr
)
ϑ
Zuluft
257/278
CC1P7550en
01.10.2003