Figure 2. Data Mining Combustion Optimization (DACOMO) Screen. The DACOMO system monitors current process operating conditions and compares them to a process model constructed using data mining
techniques. It then recommends process setpoint changes to improve boiler efficiency.
small boiler-efficiency improvements that
are sustained will produce significant fuel
savings. Finding and monitoring process
relationships provides another set of eyes
on plant operations. When conditions
deviate from normal, investigation into
Source: University of Iowa College of Engineering Intelligent Systems Laboratory.
... a 1 percent change in combus-
tion efficiency rapidly pays for
improved knowledge-based
controls.
blowing or shutdown. Allowing the process
model to directly change control system
settings will enable UI to better quantify
how effective the system is at improving
efficiency. A human between the process
model and the control settings introduces
variation among individual operators, making it difficult to quantify the effectiveness
of recommendations when they must be
input manually.
Additional research is occurring at the
UI Intelligent Systems Laboratory to determine how the process would be expected
to operate outside the areas defined in
the historian. This research will predict
boiler performance with setpoint combinations that have not yet been tried, potentially discovering how the process can be
changed to achieve additional efficiency
gains. (Once DACOMO is fully operational
and its value has been proven, the UI plans
to develop the system for commercial use.)
It is difficult to exactly quantify the
cost savings that both the ODST and
DACOMO systems are producing. The UI
has seen instances, however, where early
alert information has enabled operators
to more quickly correct problems on a
scheduled basis, rather than reacting to
a machine failure (e.g., turbine generator
wiped bearings). The expense of additional fuel and purchased power resulting from a two-week unscheduled solid
fuel boiler or turbine generator outage
could easily pay for an early warning
system such as ODST. UI’s experience
with the DACOMO combustion efficiency
improvement system suggests that an
improvement in boiler efficiency of 1
percent to 3 percent may be possible, if
we were able to sustain the recommended process changes. As is the case at UI,
where each of our two boilers consumes
several million dollars of fuel per year, a
1 percent change in combustion efficiency
rapidly pays for improved knowledge-based controls.
The University of Iowa expects these
new control system technologies to have
positive benefits for our power plant. Even
these alerts helps operators and engineers
better understand the complex relationships that exist in their systems and equipment. In some cases these alerts reveal
conditions that, if left unchecked, would
lead to degraded machine conditions and
possibly machine trip or damage.
Looking beyond our experience with
this new technology at UI, we expect to
see these systems more widely deployed
as our rather conservative industry gains
acceptance of the power of computational
intelligence in process control.
Ferman Milster, PE, has been
with the University of Iowa facilities
management since 1991. As associate director of utilities and energy
management, his primary responsibility is overseeing operations at
the university’s power plant, a combined heat
and power facility. Prior to his work at UI, he
completed 20 years of active duty in the U.S.
Navy, where he specialized in ship and submarine
construction and maintenance. Milster is a past
board member of IDEA and a member of ASME.
He has undergraduate and graduate degrees in
mechanical engineering, is a registered professional engineer and does part-time consulting
in the district energy industry. He may be reached
at ferman-milster@uiowa.edu.
Paris in Detroit. IDEA was international even when it
was known as the National District Heating Association. This
photo from IDEA's archives was taken at the 42nd Annual
Conference held in Detroit, Mich., in 1951. Its caption reads: "E.E.
Dubry explains an operation to M.S. Legagneur of Paris, France."
Help IDEA celebrate 100 years June 28 thru July 1, 2009, in
Washington, D.C.
