U.S. Boiler Company K2WT-080B, Инструкция по установке, эксплуатации и обслуживанию

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XII. Operation
(continued)
8. DHW Two boiler Start
When the Indirect Water Heater (IWH) parameter is
set to “Primary Piped” and the DHW Two Boiler Start
parameter is set to “Enabled” two boilers are started
without delay in response to a DHW call for heat.
This feature allows rapid recovery of large IWH’s and
multiple IWH’s.
9. Optimized Boiler Modulation
Boiler firing rate is managed to increase smoothly
as boilers are started. For example, when a second
boiler is started the initial firing rate is 100%/2 or 50%,
when the third boiler is started the firing rate starts at
200%/3 or 66%. After the initial start, the Sequence
Master develops a unison firing rate demand based on
it’s setpoint and sensed header temperature.
10. Innovative Condensing Boiler Control
During low loads, the Sequence Master limits firing rates
to a “Base Load Common Rate” to ensure modulating
condensing boiler peak operating efficiency. Lower
firing rates boost efficiency by helping increase the
amount of flue gas water vapor condensation. The
Control maintains a “Base Load Common Rate” until
the last lag boiler is started. At this point, the “Base
Load Common Rate” is released to allow boilers to
modulated as required to meet heat load.
11. Advanced Boiler Sequencing
After there is a Call For Heat input, both header water
temperature and boiler firing rate percent are used to start
and stop the networked boilers. The control starts and
stops boilers when the water temperature is outside the
user selected “Diff Above” and “Diff Below” settings.
Also, in order to minimize temperature deviations, the
control adjusts the number of boilers running based
on the firing rate. This combination allows the boilers
to anticipate slow load changes before they disrupt
water temperature yet still respond quickly to sudden
load changes. These special sequencer features help
reduce energy wasting system temperature swings and
the resulting unnecessary boiler cycling.
12. Stop All Boilers
All boilers are stopped without delay if the Call for
Heat input is removed or if the header temperature is
higher than 195°F (90.6°C) (field adjustable).