NOTE: A continuous emmissions monitoring system
(CEMS) is required by the Clean Air Act Amendment
(CAAA) of 1990 if the fuel utilized is oil or coal
and the heat input is 10 million BTU/HR or greater.
A CEMS may also be required by state or local laws.
If a CEMS is necessary the designer should review
the CAAA and the relevant state or local law early
in the project to allow time to incorporate the
requires CEMS specifications and to determine which
flue gas emmissions will be included in the required
reports.
**************************************************************************
An automatic control system shall be installed for each boiler in
accordance with the manufacturer's recommendations. All locally indicating
instrumentation and controls shall be provided and installed complete, as
required to suit equipment furnished and as shown. All remote
instrumentation, controls, and their connection points will also be
provided and installed as indicated. If the controls are manufactured by a
manufacturer other than the boiler manufacturer, installation of the
controls shall be in accordance with the control manufacturer's
instructions. Automatic controllers shall be located on the control room
panel as specified. Equipment shall operate either pneumatically,
electrically, or electronically. Pneumatic control systems shall conform
to ASME B19.3. Air filter regulator sets shall be installed at each
control valve and transmitter in the system. Master air filter regulator
set on the control panel shall be of the dual type where one side can be
cleaned and repaired while the other is in operation. Exterior control air
piping and devices shall be protected from freezing by use of a
regenerative desiccant dryer. Each system shall be provided with a
selector switch or other means to permit manual control of the firing rate
when required. Electrical control devices shall be rated at 120 volts and
shall be connected as specified in Section 16402 INTERIOR DISTRIBUTION
SYSTEM. Operating and limit controls shall be wired to interrupt the
ungrounded circuit conductor. [Steam and energy generating equipment shall
include instrumentation and sufficient metering for accountability
interface with a future Energy Monitoring and Control System (EMCS).] If
pneumatic controls are provided, duplex air compressors with a drier
between the compressors and tank shall be provided. Air compressor units
shall be sized to run not more than 60 percent of the time when all
controls are in service.
2.9.1
Positioning Type
Positioning type control equipment shall be capable of maintaining boiler
steam pressure within plus or minus 2 percent of the set pressure over the
complete range of boiler operation. Set point controllers may be used for
on/off functions only. Combustion efficiency shall be maintained without
appreciable manual adjustment. System shall be capable of maintaining the
specified pressure provided that the load does not exceed a 15 percent per
minute change in capacity at any one time. Master transmitter shall be
connected to the main steam header where the steam pressure is to be
controlled. The signal transmitted from this point to the master
controller shall be a function of steam pressure. On multiple boiler
installations, a means shall be provided to base load on individual boilers
while on automatic, and each boiler unit shall be individually controlled.
Provision shall be made on the control system for adding on other boilers
to the system with only minor wiring or piping changes on the panel. Each
automatic controller shall have a manual-to-automatic station and indicator
SECTION 15846A
Page 47
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