Bryan Boilers Triple-Flex 150 ユーザーズマニュアル

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Date:  
8-4-2010 
 
Revision: 0 
 
Form:  
2396
 
or drop a stage if the run-limiting is providing too 
much heat (for example if a stage is running at a 
higher-than commanded rate due to anti-
condensation). 
 
By adjusting the parameters in an extreme way 
it is possible to define add-stage and drop-stage 
conditions that overlap or even cross over each 
other. Certainly it is incorrect to do this, and it 
would take a very deliberate and non-accidental 
act to accomplish it. But there are two points in 
this: 
LL master does not prevent it, and more 
important; 
it will not confuse the LL master because it is 
implemented as a state machine that is in only 
one state at a time; for example: 
• if its add-stage action has been triggered, it will 
remain in this condition until either a stage has 
been added, or 
• the criteria for its being in an add-stage 
condition is no longer met; only then will it take 
another look around to see what state it should 
go to next. 
 
Assumptions: 
 
Modulating stage 
The modulating stage is the 
Sola that is receiving varying firing rate requests 
to track the load. 
 
First stage 
This is the Sola that was turned on 
first, when no slave Solas were firing. 
 
Previous stage 
The Sola that was added to 
those stages that  are firing. Just prior to the 
adding of the Sola that is under discussion. 
 
Next stage 
The Sola that will or might be added 
as the next Sola to fire. 
 
Last stage 
The Sola that is firing and that was 
added the  most recently to the group of slaves 
that are firing.  Typically this is also the 
modulating stage, however as  the load 
decreases then the last-added stage will be at 
its minimum rate and the previous stage will be 
modulating. 
 
Lead boiler 
The Lead boiler is the Sola that is 
the first stage to fire among those stages which 
are in the equalize runtime (Lead/Lag) group. If 
a boiler is in the "Use first"  group it may fire 
before the Lead boiler fires. 
 
First boiler 
A Sola may be assigned to any of 
three groups: "Use First", "Equalize Runtime", or 
"Use Last". If one or more Solas are in the "Use 
First" category, then one of these (the one with 
the lowest sequence number) will always be the 
first boiler to fire. If there is no Sola in the "Use 
First" category and one or more are in the 
"Equalize Runtime" category, then the First 
boiler is also the Lead boiler. 
 
Add-stage method 
 
Add-stage detection timing 
 
Add-stage request 
An  Add-stage method 
implements the criteria for adding another stage. 
Criteria that may apply are the firing rate of a 
stage or stages vs. a threshold, the amount of 
operating point versus setpoint error seen by the 
master, the rate at which setpoint error is 
developing, and the rate at which a stage or 
stages are approaching their maximum or 
baseload firing rate. 
 
Typically these use Add-stage detection 
timing 
to determine how long these things have 
persisted. When all criteria have been met for a 
sufficient time, then an Add-stage request is 
active. 
 
Drop-stage method 
 
Drop-stage detection timing 
 
Drop-stage request 
A  Drop-stage method 
implements the criteria for dropping a stage. 
Criteria that may apply are the firing rate of a 
stage (or stages) vs. a threshold, the amount of 
operating point versus setpoint error seen by the 
master, the rate at which setpoint error is 
developing, and the rate at which a stage or 
stages are approaching their minimum firing 
rate. 
 
Typically these use Drop-stage detection 
timing 
to determine how long these things have 
persisted. When all criteria have been met for a 
sufficient time, then an Drop-stage request is 
active. 
 
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