Lamtec LT 2 Assembly And Commissioning Manual page 38

4 Technical Description
4.12.2 Measurement of flue gas and intake air temperature and calculation of the efficiency of combustion
Type 6 57 R 0895K
NOTE:
Since three of the four analogue inputs are assigned in the LT 2 / KS1 DK, the
differential pressure sensor, which monitors the reference air, is removed and
replaced with a flow meter with limit value signal. This signal is fed to a digital input
and monitored as the warning "No reference air".
This frees up an analogue input for the intake air temperature.
See overleaf for electrical connection diagrams.
If the intake air temperature can be set as default beforehand, the above measure is
superfluous.
The calculation is based on the formula:
n = 100 ( q + q ) %
F Af Ag
q = loss of exhaust gas due to free heat
Af
q = loss of exhaust gas due to latent heat
Ag
q = ( t - t ) * [A / 21 – O
Af A L 2
The calculation of exhaust gas losses is based on the following mean fuel values:
Oil A = 0.68 B = 0.007
2
Gas A = 0.66
2
It is assumed that the combustion of CO and black smoke takes place freely. The
exhaust gas losses due to latent heat Ag are ignored.
Display:
Efficiency
Exhaust gas losses
Exhaust gas temperature
Intake air temperature
Other ranges on request
Measurement accuracy:
In the 6 57 R 0896 version, the intake air is fixed as default. The intake air
temperature is therefore not measured. This is only recommended if the intake air
temperature remains virtually constant the entire year round. The average intake air
temperature can be defined in parameter 1450.
For electrical connections, see the following two pages.
+ B]
2
B = 0.009
0...100%
0...100%
0...320°C (measuring card at analogue input 3)
0...320°C (measuring card at analogue input 2)
Temperature better than 2K
Efficiency/exhaust gas losses better than 0.2 %
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