This large-capacity centrifugal
chiller meets your customer requirements, by design.
Carrier's 17DA Open Drive
Centrifugal Chiller is designed to address the most critical concerns
of large central plant operators and owners: Efficiency, Reliability
and Environmental Safety.
Unmatched Energy Efficiency
Energy-conscious central plant
and industrial customers can invest in the 17DA, knowing that
its efficiency is unmatched in the industry. Thanks to Carrier's
advanced compressor and heat exchanger technology, the 17DA chiller
is clearly the lowest energy consumer available. And its open
drive design lest you select the most economical power source
- and shift sources if desired - at any time during the unit's
long life.
Variable Inlet Guide Vanes
and a Diffuser Ring control the flow of gas through the 17DA's
single-stage, high efficiency shrouded impeller, producing optimum
performance across a wide range of operating conditions.
The variable inlet guide vanes
regulate the volume and direction of suction gas entering the
compressor. As the machine's capacity drops below 50%, the diffuser
ring gradually closes to maintain a high gas velocity through
the diffuser opening. This sequence maintains efficient and stable
operation down to 10% load, eliminating the possibility of compressor
surge and the need for inefficient hot gas bypass.
Optimal heat transfer is achieved
with a physical design that utilizes the latest tubing materials
and does not require energy-wasting eliminators. Another energy
saver, a Thermal Economizer in the condenser increases
refrigeration effect by lowering the condensed liquid temperature.
A Positive-Acting Liquid Level Control Valve Is used to
maintain refrigerant levels regardless of operating conditions.
Flexibility In A Packaged Design
The 17DA is actually hundreds
of centrifugal chillers in one. You can custom-design the unit
to meet your requirements by selecting the size and type of heat
exchanger, compressor, and prime mover. Selection of electric
motor, steam turbine or gas engine/turbine can also be optimized
for the best fuel economy now and in the future. Heat exchanger
flexibility combines efficiency and precise control to meet your
specific requirements. Various tube types, lengths and pass arrangements
can be optimized to suit virtually any flow and temperature rise
condition.
Using specialized software,
Carrier will assist you in making the most energy-efficient and
economical choices, and provide a detailed analysis of 17DA performance
under a full range of anticipated operating conditions.
Once your 17DA components
and options are specified, the compressor/prime mover assembly
is factory-built on a rigid, fabricated steel drive base which
is stress relieved to insure proper alignment. Speed increasers,
motors, steam turbines and gas engines and turbines are selected
to meet Carrier's strict engineering quality standards. Interconnecting
lubrication piping is also factory-mounted to provide and easy
to install package.
World-Class Reliability By Design
Years from now, the 17DA will
still operate just as economically as it did upon startup. By
concentrating on long-term reliability through preventive maintenance
design, Carrier has made uninterrupted quality performance and
low maintenance costs the hallmarks of this chiller, its highly
refined mechanical system has proven reliable in hundreds of applications
in both central plants and industrial process applications throughout
the world.
Journal Bearings.
These bearings are split sleeve, steel-backed and babbit-lined.
Steel provides the structural support needed to absorb high radial
loads, while the babbit lining protects the shaft from scoring
in case of a lubrication failure. The split-sleeve design allows
for inspection without removing the shaft.
Kingsbury-Type Thrust /
Counter-Thrust Bearings.
For superior handling of axial forces, eight floating pad automatically
align in a wedge formation to insure that load-carrying surfaces
are separated by a thick film of lubricant - even during accidental
reverse rotation - reducing wear and increasing bearing life.
A balancing piston further reduces thrust forces.
One-Piece bearing Chamber
Cover. To provide
quick access to all bearings and the carbon running seal, a simple,
four-bolt bearing cap design allows journal bearings to be removed
for inspection. The 17DA's drive coupling never has to be disturbed.
The Carrier 17DA Iso-Carbon
Seal System. This
system contains only three wearing parts and allows easy access
serving without removing the refrigerant and also prevents
refrigerant loss during shutdown.
The four basic parts of the
system are a Stationary Contact Sleeve, a Rotating Contact
Ring, a free-floating Iso-Carbon Ring that rotates
between the two and Self-Contained Shutdown Seal. A Spring
Retainer maintains accurately controlled, fixed pressure between
all these parts. These components isolate the refrigerant circuit
from the bearing chamber, enabling bearings to be inspected and
serviced without removing refrigerant from the machine. Additionally,
all contact surfaces are finished optically flat to within one
light band (11.6 millionths of an inch).
The system is continually
bathed with oil to form the refrigerant seal. The oil and refrigerant
gas that mix at the Iso-Carbon Ring flow to a separate chamber
where the gas is separated by heat and returned to the suction
side of the compressor. The oil returns to the atmospheric reservoir.
At least five gallons of fully-recoverable oil flow through the
Carrier Iso-Carbon Seal System every 24 hours of operation.
The Iso-Carbon Seal System
automatically continues its sealing function even during shutdown
when the compressor is still pressurized with refrigerant. After
the machine stops, the normally higher oil pressure at the Counter-Thrust
Bearing is reduced below refrigerant gas pressure. The now
higher gas pressure forces a shoulder on the compressor shaft
against a stationary Shutdown Seal to complete and maintain
a positive seal.
At start-up, this action is
reversed
the main oil pump increases oil pressure to the
counter-thrust bearing until it is higher than the refrigeration
pressure. This exerts force against the counter-thrust bearing
and the shaft is moved toward the inlet end of the compressor
to release the shutdown seal.
For increased operating reliability,
the 17DA features two fail-safe switches. The Shutdown Seal
Movement Switch prevents the compressor form starting until
normal operating oil pressure is applied to the counter-thrust
bearing. The movement of the shaft to the thrust position releases
the shutdown seal. The Shaft Movement Switch shuts down
the machine if there is any shaft movement beyond a precalibrated
limit.
The Atmospheric Lubrication System. This extremely efficient lubrication system is the only one of its kind in the industry. Its design performs two specific functions:
Unlike other refrigeration
compressor lubrication systems, minimal refrigerant is absorbed
in the oil, eliminating both oil foaming at start-up and the need
for an oil heater in the reservoir. Furthermore, the Oil Reservoir
and shaft bearing chamber are vented to the atmosphere.
The Iso-Carbon Seal is the
only place where oil and refrigerant come in contact. Oil is
pumped through the seal chamber preventing refrigerant from leaking
past the seal. This oil flows to the Separation Tank where
it is heated. Any absorbed refrigerant is boiled off and returned
to the compressor suction side. The pure oil is then automatically
returned to the oil reservoir. The system has an oil pressure
switch that will shut down the compressor should the oil pressure
drop below optimum operating conditions.
The significant advantage
of Carrier's Atmospheric Lubrication System is that it allows
for inspection and servicing of all bearings and seal parts without
the costly and time-consuming process of removing refrigerant
from the machine.
ASME - Certified Heat Exchangers.
17DA heat exchangers
fully conform to ASME code and are independently inspected throughout
fabrication and testing. Carrier's standard design features include
marine-style water boxes for tube cleaning, double-grooved tube
sheets for superior tube mechanical bonding and closely spaced
intermediate supports to eliminate tube vibration during operation.
The entire chiller is ISO-9001 certified in design and fabrication.
Factory Pre-Assembled Pumpout
Unit. For transferring
refrigerant and distilling refrigerant charge, an optional pumpout
unit is available. It features a 7.5 H.P. compressor mounted
on a refrigerant storage tank and is suited for single or multiple
chiller installations. The fully assembled, pre-wired unit includes
refrigerant valves, piping, sight glass and compressor relief
valves.
Proven Controls Technology
Custom-Designed Controls.
Carrier meets your precise control requirements with microprocessor-based
control solutions ranging from stand-alone modules to fully integrated
control systems that communicate with your existing or future
central plant facilities.
Installation time is kept
to a minimum since each panel is pre-wired and pre-piped to terminals
and bulkheads, then leak and continuity tested. All instruments
settings are factory-adjusted to their approximate operating points.
Environmental Safety
Non-Ozone Depleting Refrigerant. While the 17DA's efficiency and reliability go a long way towards creating peace of mind, its non-ozone depleting refrigerant, HFC-134a, completes the picture. HFC-134a contains no chlorine and faces no regulatory phaseout, ensuring the environmentally safe operation of this chiller for many years to come.