3 Commissioning Procedure
Mk8 MM Manual Page | 89
3.5 Fuel Flow Metering
If fuel flow metering has been enabled in option 57, the message ‘No Fuel Flow Data’ will display on the
Home screen once the burner has been commissioned. Fuel flow metering is used to rate the size or burner
and calculate the firing rate.
If fuel flow metering is not commissioned and sequencing is optioned, then MM will assume a default burner
rating which is based on the fractional fuel valve angle.
The fuel flow is commissioned from the low fire point up to the high fire point. The low fire point will set the
burner rating in MW if metric of MMBTu/hr if imperial.
On the Mk8 MM, fuel flow metering can be taken as the values entered in the fuel flow commissioning
screen from the fuel flow meter or through a 4-20mA signal input on terminals EX- and EX+.
3.5.1 Commissioning Fuel Flow Through MM
If a fuel flow meter is not available and only arbitrary values are going to be used, it is important to make
sure a good range of values are is entered (e.g. 1 to 10) with equal spaces between the values. Not doing
this could lead to problems when using IBS and the flame graphic.
When using arbitrary values it is good practice to use the following calculation to determine the heat value for
each of the 10 points.
=
9
For example: Burner Rating: 5.4MW; Turndown Ratio: 5:1.
5.4 (
5.4
5
)
9
= 0.48
Giving the range (5.40, 4.92, 4.44, 3.96, 3.48, 3.00, 2.52, 2.04, 1.56, 1.08), with 1.08MW as the low fire point
and 5.4MW as the high fire burner rating point derived using an estimated burner turndown value.
Fuel flow metering serves to totalise the amount of fuel being used at each position. If any changes are
made to the curve through Single Point Change, then fuel flow will need to be re-commissioned.
Enable Fuel flow commissioning by setting option 57. Fuel flow commissioning is done in Run mode while
the burner is firing.
On the Home Screen, press to access the System Configuration screen.
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