35
10.7 Example of FGR factor and FGR Maps Factor on the burner regulation.
We consider to set the AUX3 for FGR with the “
temp.contr.” Mode
The curve is as per the below table.
Point
1
2
3
4
Note
Load %
37,5 % 62,5 % 75 %
100 %
AUX3 FGR Curve
19,3 °
25,0 °
28,5 °
37,0 °
FGR temperature
72 °C
105 °C 121 °C 150 °C
The flue gas value increase from low to high flame.
The temperature is with burner in operative condition.
LMV52.400 will calculate a “Zero Curve” referred to flue gas 0°C temperature.
The “Zero Curve” is calculated in reference to the effect of the temperature on the smoke density.
If “FGR factor” is set at 100% LMV will not make any additional correction.
Point
1
2
3
4
Note
Pos. FGR con T = 0 °C
zero
curve
15 °C
18 °C
19,7 °C 23,8 °C
FGR Factor set on 100%
If “FGR factor” is set at lower value than 100% LMV will apply an additional correction to calculate the “Zero Curve”.
If “FGR factor” is 50%, the new “zero Curve” will be
Point
1
2
3
4
Note
Pos. FGR con T = 0 °C
zero
curve
7,6°
9,0°
9,8°
11,9°
FGR Factor set on 50%
The above example shows that – with the
zero curve
– a flue gas
recirculation (FGR) factor of 50% leads to a 50% reduction of the damper
positions.
If the temperature value of the smoke during the operation of the burner is higher than the temperature value during the commissioning, the AUX3
position will be bigger than the set values.
To avoid a wide opening of the FGR butterfly valve it could be necessary to limit the automatic correction LMV52.400.
This could be necessary if the AUX3 opening become bigger than 90°, if a flame instability happen, or the flue gas recirculation is too big…
To limit the correction due to a higher temperature value, it become necessary to set the parameter “FGR MaxPOS Factor”.
Point
1
2
3
4
Note
Pos. FGR
21,2°
27,5°
31,4°
40,7°
FGR MaxPOS Factor set on 10%
I valori sono il 10% in più rispetto ai corrispondenti settati inizialmente.
0
10
20
30
40
50
60
70
80
90
30
50
70
90
AUX3
FGR
Curve
on
commissioning
Zero
Curve
FGR
Factor
100%
Zero
Curve
FGR
Factor
50%
AUX3
FGR
Curve
FGR
MaxPOS
Factor
AUX3
Pos
ition
[°]
Burner load
[%]
The
LMV52.4…
performs
a
linear
interpolation
of
the
damper
positions
between
the
setting
values
and
the
zero
curve
,
depending
on
the
current
flue
gas
temperature.
When
the
flue
gas
temperatures
lie
above
the
setting
values,
the
calculated
damper
positions
are
higher
than
the
setting
values.
Summary of Contents for RX92R-FGR
Page 49: ...Siemens LMV5x Service Manual M12920CC rev 2 1 08 2017...
Page 56: ...8...
Page 60: ...12 2 2 LMV5x program structure...
Page 87: ...39...
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Page 96: ...Note Specifications and data subject to change Errors and omissions excepted...
Page 98: ...Annex1 Example for motor cable...
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Page 100: ...Annex 2 Example for sensor cable...
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Page 117: ...WB1 QF1 QF2...
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Page 122: ...WB1 SCHEDA LED QF1 QF2...
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