16 Heat Flow
Mk8 MM Manual Page | 279
16.5 Steam Flow Metering
16.5.1 Steam Flow Calculation
By the addition of one temperature detector it is possible to extrapolate steam flow from a boiler both as an
instantaneous value and a totalised amount over time. A full Steam Flow Metering package is available with
just the addition of one temperature sensor to the system, avoiding the cost of an expensive steam flow
meter and orifice plate that is typically accurate at the higher firing rates only.
Example 1: Steam Flow with Default Values
The fuel flow metering has been set in option 57 and commissioned for gas. The standing losses are set
default as 1% in expansion option 121. The total blowdown losses are set default as 1% in expansion option
122. The stack losses are set as default in the MM as 15% for oil and 19% for gaseous fuels.
Figure 16.4.1.i Fuel Flow
From fuel flow metering, in the screen above the burner is currently firing at 88% with a flow rate of
24.6MMBtu/hr. The net calorific value of the fuel into the wet side of the boiler can be determined by taking
away the losses from the flow rate:
= 1% ×
= 1% × 24,600,000
Therefore standing losses currently stand at 246,000 Btu/hr.
= 19% ×
= 19% × 24,600,000
Therefore stack losses are currently 4,674,000 Btu/hr.
To Next Page
Loading...
Need help?
General
