Miura BP-201STA, Operation Manual

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Document Control #: EN-MN-003-00
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2) Priority mode
Displays the mode with a priority during boiler MI control.
Supplementary Explanation
• Basic Priority Mode
MI control determines the minimum number of boilers to maintain the set maximum steam
output. If the load increases, the number of boilers performing combustion is increased
while securing the steam output capacity equivalent to the set steam output fluctuation
range. If the load decreases, the number of boilers performing combustion is reduced
according to the same operation as the operation for increasing the number of boilers
performing combustion when the load increases. Moreover, by setting the low fire hold
priority for low load to ON, a reduction control giving priority to switching the boilers in high
fire operation to low fire operation is performed. For details on setting the low fire hold
priority for low load, refer to the next page.
P
re
s
s
u
re
Fluctuation
range
Low
Boiler
priority
number
1 Low High High High High High High High
2 Low High High High High High
3 Low High High High
4 Low High
Fluctuation
range
Medium
Boiler
priority
number
1 Low Low High High High High High High
2 Low Low Low High High High High
3 Low Low Low High High
4 Low Low High
Fluctuation
range
Large
Boiler
priority
number
1 Low Low Low Low High High High High
2 Low Low Low Low High High High
3 Low Low Low Low High High
4 Low Low Low Low High
Figure 1: Increasing load
P
re
s
s
u
re
Fluctuation
range
Low
Boiler
priority
number
1 High High High High High High High Low
2 High High High High High Low
3 High High High Low
4 High Low
Fluctuation
range
Medium
Boiler
priority
number
1 High High High High High High Low Low
2 High High High High Low Low Low
3 High High Low Low Low
4 High Low Low
Fluctuation
range
Large
Boiler
priority
number
1 High High High High Low Low Low Low
2 High High High Low Low Low Low
3 High High Low Low Low Low
4 High Low Low Low Low
Figure 2: Decreasing load