Siemens LMV5 Quick Start Manual page 70
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Also See for LMV5:
- Technical instructions (374 pages) ,
- Basic documentation (278 pages) ,
- Manual (39 pages)
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Fuel-Air Ratio Curves (Combustion Curves) continued.
The 'Load' is the label used to designate the fuel input (firing rate) of the burner at any point. The
'Load' number should be set based upon a fuel meter. If a fuel meter is unavailable, burner head
pressures could be used to approximate fuel flow into the burner. A 10 to 1 turndown burner should
have Point 1 set to 10% load, and Point (up to 15) set to 100% load. A spreadsheet is available to
automatically calculate the numbers seen below for any given burner.
Figure 4-1.11 Example of Typical Combustion Curves
16 MM Btu/hr Gas Burner, 10 to 1 Turndown, FGR, Gas 1000 BTU /SCFH
Point
1
2
3
4
5
6
7
8
9
10
11
12
After a curve is set up, points can be added and subtracted to any location in the curve. The load
that is selected for the additional point determines where it will be inserted. When the point is
inserted, it will 'bump' the other point numbers over 1 number. For example if Point 5 is defined as
43% load, and Point 6 is defined as 51% load, and an additional point is added at 48% load, Point
5 will remain 43% load and Point 6 will now be 48% load. Point 7 will be 51 % load.
If points are deleted from an existing curve, the reverse of what was previously explained happens.
Although not recommended, a curve could consist of two points. One point at low fire and one
point at high fire. The LMV5 would simply draw a line between the two points and that would be
the combustion 'curve'.
Typically at least 10 points are defined from low to high fire, and each point is set at optimum
combustion. If O2 trim is being used, at least 10 points must be set for proper O2 trim functionality.
LMV5 QSG Rev 4
Gas SCFH
Load %
1600
10
2909
18
4218
26
5527
35
6836
43
8145
51
9455
59
10764
67
12073
75
13382
84
14691
92
16000
100
Sec 4
.
Gas Deg
Air Deg
7
10
11
15
14
18
17
25
22
29
27
36
33
44
40
52
48
63
56
72
65
79
73
85
Pg 14
www.scccombustion.com
Aux 1 Deg
30
37
40
41
45
48
45
40
35
31
27
20
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