OM Custom Design Centrifugal Chiller

Extensive Capacity Range from 3,000-5,500 TR (10,550-19,350 kW)

With unsurpassed reliability and a chiller design that has been proven in thousands of installations worldwide, our YORK® OM Custom-Design Centrifugal Chiller features extraordinary capacity through advanced technology that is the end result of over 50 years of pioneering experience from Johnson Controls.

Cooling engineering marvels like the tallest buildings in the world (and even the U.S. Capitol complex) through custom chiller design, our water-cooled industrial chillers deliver all the flexibility and custom capabilities you need, no matter what.

• The World Leader – In large-scale cooling projects, OM chillers are used more than all other brands combined.
• Extraordinary Capacity – Available in sizes double the size of the largest packaged chiller, OM chillers minimize space and simplify operation.
• Unsurpassed Reliability – Industrial-grade construction enables OM chillers to operate 24/7 for decades.
• Exceptional Flexibility – Available in electric-, steam-, or gas-drive, for water- or air-cooled condensing, OM chillers can be used for water chilling, brine cooling, or ice building.

The following instructions outline the procedures to be followed for the operation of the YORK OM Titan™ retrofitted with OptiView Controls.
After the installation and during the Initial Start-Up, the Johnson Controls Start-Up Engineer will instruct the operators in the operation and necessary maintenance to be performed to maintain the YORK OM Titan™ retrofitted with OptiView Controls. This instruction should be thoroughly read by the operators to familiarize themselves with the operation of the unit.
It is important that those responsible for the installation, operation and maintenance of this system be provided with a copy of this manual so that they may thoroughly study its contents. This will help ensure successful operation of the system.
Standard Johnson Controls operating instructions are included in this manual. Where the specific instruction is different than the standard instructions, the specific instruction should be followed. On matters not covered by the specific instruction, the standard instruction may be used.
It is suggested that a factory-trained representative of Johnson Controls supervise any major service or maintenance operation. This is especially recommended should it be necessary to open the compressor or heat exchangers for any reason.

The OM Titan Chiller operates under the following principles:
The fluid (to be cooled) flows through the tube side (inside the tubes) of the evaporator. Liquid refrigerant is located in the shell side of the evaporator, and is maintained at its saturation temperature by the compressor. The liquid refrigerant is at a lower temperature than the circulated fluid. Sensible heat flows from the fluid, through the evaporator tube walls to the refrigerant, thereby cooling the fluid. The heat transferred to the refrigerant causes it to boil.
In order to sustain this process, the refrigerant is held at the correct saturation temperature by drawing refrigerant vapor from the shell side of the evaporator. This is achieved through the use of the ‘M’ series multistage centrifugal compressor. The vapor drawn from the evaporator is compressed by the compressor to a sufficiently high pressure so that the superheated temperature of the discharge vapor is higher than that of the condenser water. The high pressure refrigerant is contacted to the condenser water (on the tube side of the condenser) and is condensed to a high pressure liquid. This liquid is flashed in one or two stages, cooling each time and returning back to the evaporator to complete the cycle. Flashing is the process by which the high pressure liquid is exposed to a lower pressure causing the refrigerant to boil, cooling the condensed refrigerant liquid. The vapor created in this process (flash gas) is drawn back into the compressor through the compressor side load (inter-stage) port or ports and the colder refrigerant liquid is used to provide cooling.
The M Series multistage compressor operates on the centrifugal principle. The compressor consists of two or more impellers which draw gas into the center (suction) and accelerates the vapor to high velocity (kinetic energy) at the discharge of the impeller. As the vapor exits the impeller, the velocity of the gas reduces as it passes through the diffuser (located around the circumference of the impeller), and the kinetic energy is transformed into potential (pressure) energy. This process is repeated for each impeller (compression stage). The compressor shaft is rotated by means of either, an electric motor (via a speed increasing gearbox), a direct drive steam turbine, a gas turbine (via a speed reducing gearbox) or a reciprocating gas engine (via a speed increasing gearbox).
O
M Subc ooling
D
escription and Operation
The OM Titan uses a two or more staged compressor with flash type intercooler. The liquid is flashed off at an intermediate pressure, to lower the enthalpy of the liquid refrigerant as it enters the evaporator, thus providing a greater refrigeration effect in the evaporator.
The OM Titan utilizes liquid subcooling in addition to the interstage cooling cycle for better efficiency. By passing liquid refrigerant over tubes in a subcooler section, the refrigerant temperature is lowered from the saturation temperature, to a subcooled temperature closer to the entering condenser water temperature. By lowering the refrigerant temperature ahead of the high stage expansion device, the amount of flash gas in the intercooler is lowered, thus reducing the gas flow through the second or possibly third stage impeller and therefore lowering overall horsepower.
The OM Titan chiller utilizes a subcooler bundle integral to the main condenser located in the bottom section of the condenser shell. As liquid refrigerant condenses in the main condenser, it drains to the bottom of the main condenser section. At the bottom, the refrigerant is channeled to the subcooler inlet area, located at the return water box end of the condenser (opposite from the water inlet nozzle). Refrigerant liquid enters the subcooler section from the sides and bottom (there is a plate blocking the top). Dual subcoolers are utilized in condensers with tube lengths 20 feet or longer.
The level of refrigerant in the subcooler is adjusted at full load to provide a liquid level an inch or two above the subcooler at the inlet area. This level needs to be sufficient at full load to prevent refrigerant gas from entering the subcooler. The refrigerant liquid flows axially down the shell length over the subcooler tubes, and exits out the bottom at the condenser water inlet end.
A pneumatic ball valve is mounted in the piping leaving the subcooler. This valve responds to the subcooler inlet level transmitter signal to maintain the refrigerant level above the subcooler tubes. A ball valve was selected for its ability to control over a wide range of chiller loads and “head” or differential pressure conditions. The valve is selected to fail open and opens on chiller shutdown, primarily to drain liquid from the subcooler section. This is a precaution against tube freezing, by ensuring that liquid refrigerant is not present in the subcooler during chiller pump down operations or if a major leak occurs.
O
M Intercooling
D
escription
There may be one or two stages of liquid intercooling furnished with the OM Titan chiller in the primary refrigeration circuit between the condenser and the evaporator. The intercooler performs several functions. The primary function is to flash the high pressure condensed refrigerant to an intermediate pressure corresponding to the M series multistage compressor’s inter-stage pressure. Flashing the high pressure liquid at the intermediate pressure reduces the horsepower required to compress the flash gas. This portion of the flash gas is only compressed from an intermediate pressure (inter-stage) to condensing pressure rather than from evaporator (low pressure) to condensing pressure. Secondary functions are the separation of the flash gas from the liquid refrigerant and providing a liquid seal between the high and low sides of the system.
The intercooler consists of a pressure vessel with internally mounted mesh eliminators, a float assembly, and baffles. The eliminators, located in the top of the vessel, separate droplets of liquid refrigerant from the flash gas before it flows to the compressor inter-stage port. A low pressure rectangular vane type float valve assembly maintains a liquid seal between the high and low side of the system. The pressure drop across the float valve causes the refrigerant to flash to an intermediate pressure lowering the refrigerant’s temperature to the corresponding temperature. A baffle is installed in the intermediate chamber over the float ball to minimize the effect of turbulence on the float ball and to aid in maintaining steady float operation.
Sight glasses and a hand operating device are provided to permit visual float valve inspection and manual float valve operation. A thermometer well, located near the float valve, is used for checking liquid temperatures. A manway with sight glasses allows for access to the float valve assembly and adjusting arm.
O
peration
Liquid refrigerant leaving the level control valve flashes to the intercooler pressure (and temperature). Upon entering the intercooler the liquid refrigerant separates from the flash gas. The flash gas returns to the compressor inter-stage port after passing through the mist eliminators. The liquid refrigerant, at intermediate pressure, flows to the float valve. The float valve will open, maintaining a liquid level in the intercooler, and allowing refrigerant flow to the evaporator. As the liquid refrigerant flows through the float valve it is exposed to evaporator pressure and flashes to the corresponding pressure and temperature.
If the OM Titan chiller is equipped with a second stage intercooler then the liquid leaving first stage intercooler is supplied to the second stage intercooler before allowing refrigerant to flow to the evaporator.
Maintenance and Service
Maintenance on intercooler consists primarily of keeping the float valve free to assure steady valve operation. Service consists of replacing an occasional float ball and arm assembly.
If the system capacity suddenly decreases as indicated by an increase in secondary refrigerant temperature, check float valve operation as follows:
If the low pressure float valve sticks in the open position, the liquid seal between the compressor intermediate pressure and evaporator pressure will be broken and gas at intermediate pressure, will flow directly into the evaporator. This will cause a reduction in capacity with possible increase in suction pressure and possible refrigerant carryover back to the compressor and increased current (amperage) readings.
If the float valve sticks, move the float up and down by means of the hand operation device. If this does not correct the condition it will be necessary to remove system refrigerant charge before removing the float through the manway opening to check the working parts and mechanisms. Inspect the float ball to be sure it is not collapsed or leaking. A collapsed or leaking ball (filled with refrigerant) will cause the valve to remain closed.

INTRODUCTION
YORK Titan™ Multistage Industrial Chillers offer a complete
combination of features for total owner satisfaction
– for district energy, central plant and similar demanding
industrial chiller applications up to a capacity of 5,200 tons
(18,300 kWR) using HFC-134a refrigerant.
MATCHED COMPONENTS MAXIMIZE EFFICIENCY
Actual chiller efficiency cannot be determined by analyzing
the theoretical efficiency of any one chiller component. It
requires a specific combination of heat exchangers [evaporator,
condenser, flash economizer (intercooler)], compressor,
gear and motor performance to achieve the lowest system
kW/Ton (kW/kWR). Titan chiller technology matches chiller
system components to provide maximum chiller efficiency
under actual – not just theoretical operating conditions.
APPLICATION FLEXIBILITY
Titan chillers can be applied in many ways and with many
modifications to suit any application. These chillers are
designed with such drivers as induction or synchronous
electric motors, condensing and/or exhausting steam turbines,
gas or diesel engines or gas turbines. They can be
applied to a broad range of brine cooling requirements; for
heat recovery or heat pumps; and for river or sea water,
closed-water-circuit (radiator) or air-cooled condensing.
OPEN DRIVE DESIGN
Hermetic-motor burnout can cause catastrophic damage
to the internal components of a chiller. The entire chiller
must be cleaned thoroughly, and the refrigerant replaced.
The Titan centrifugal chillers eliminate this risk by utilizing
open-drive motors, engines and turbines. Refrigerant
never comes in contact with the motor, preventing contamination
of the rest of the chiller.
PRECISE CHILLED WATER TEMPERATURE SETTING
TO 0.1°F (0.05°C)
A chiller is designed to produce chilled water at a given
temperature. In the past, the setting of this crucial temperature
involved laborious trial-and-error adjustments,
often accurate to only ±1°F (0.5°C). And a setting of
1°F (0.5°C) below design can increase chiller energy
consumption by as much as 3%, wasting thousands of
kilowatt-hours per year.
The Titan Control Center eliminates this energy waste.
Now you have the capability of setting chilled water temperature
to a resolution of 0.1°F (0.05°C) – right at your
fingertips. Energy savings through chiller control has never
been easier – or more accurate.
HIGH-EFFICIENCY HEAT EXCHANGERS
Titan chiller heat exchangers offer the latest technology
in heat-transfer-surface design to give you maximum efficiency
and compact design. Water-side and refrigerant-side
design enhancements minimize both energy consumption
and tube fouling.
CHOICE OF ENERGY SAVERS
Titan chillers are also available as an option with “Free
Cooling” (cooling without the use of the unit’s compressor),
operating at up to 60% design load. This modification
is used during those periods of the year when the
available condenser water temperature is lower than the
required chilled water temperature. This mode of operation
offered by Johnson Controls has almost doubled the
capacity compared to competitive free cooling modes,
and can save thousands of dollars in operating costs by
eliminating the need to operate the compressor during
these conditions.
Heat recovery, another energy saver, is available for the
reclamation of heat from condenser water. A modified
split-bundle shell and tube condenser is used for this
application.
For those places of the world where water is scarce, the
Titan Chiller can be applied with an air-cooled condenser,
thereby eliminating the need for water in the condensing
portion of the air-conditioning cycle. Contact your local
Johnson Controls Sales Engineer for additional information.
INDUSTRIAL APPLICATIONS
The Titan chiller can also be selected and manufactured
to meet many industrial applications, such as chemical
and petrochemical processes, brine cooling, mine
applications, etc. The uses are practically unlimited.
Contact your local Johnson Controls Sales Engineer for
additional information.
EQUIPMENT SELECTION OPTIMIZED
The Titan Chiller operates economically throughout
the
year and over the life of the equipment because of its
highly flexible design. Each unit is optimized to suit each
unique job requirement utilizing Johnson Controls’ experience
with every type of application.
Titan Chillers are selected to suit each individual job application,
physical area size, and location requirements.
A
full range of optimized components have been designed
to meet every possible selection requirement through use
of the Titan Chiller Computer Selection/Rating Program.
All are equipped and rated in accordance with the requirements
of ARI Standard 550 (latest revision).
LOWER POWER DEMAND AND OPERATING COSTS
The Titan Chiller is engineered to operate efficiently with
the reduced entering condenser water temperatures
usually
available during most of the operating year. Power
consumption falls as condenser water temperature
drops,

thus lowering operating costs. The Titan unit’s ability to
operate down to approximately 55°F (13°C) entering
condenser water temperature reduces power usage tremendously
as shown in the curve, Fig. 1.
Steam turbine or gas engine drive capability adds further
incremental energy savings as a result of the turbine/gas
engine governor being able to automatically adjust compressor
speed in response to required head to optimize
unit performance, in conjunction with pre-rotation vane
position.
PARTLOAD OPERATION
The ability of large tonnage chillers to operate at partload
conditions is most important to economical operation.
Titan chillers are equipped with effective fully automatic
partload capacity controls. Automatic control of the hot-gas
by-pass in conjunction with the compressor’s prerotation
vanes (and speed control with steam turbine or gas engine
drive) coordinates their operation with the system head
requirements (entering condenser water temperature) to
minimize operating costs. The Johnson Controls multistage
compressor with pre-rotation vanes is especially
efficient in partload performance in the 50% to 100% capacity
range which is most crucial to large tonnage units.
Automatic safe control down to 10% partload conditions
is incorporated in the overall unit/control system.
PARTLOAD PERFORMANCE
The versatility of the Johnson Controls TMaster Computerized
Selection
Program for Titan Chiller(s) allows
in-depth studies for partload evaluations where energy is
of major concern. Typical partload performance is graphically
shown in Fig. 1, Curve 1, depicting the reduction of
compressor shaft horsepower (i.e. energy) as the required
load is reduced, and the condenser water temperature
falls. If a constant design water temperature is required
(typically 85°F, 29°C), then Curve 2 is typical.
VARIABLE SPEED
The PLC incorporates Johnson Controls’ patented algorithm
for variable speed control, assuring stable operation
while affording the maximum efficiency at any operating
condition within the application envelope. This feature
can be used for variable frequency drive (VFD) control on
electrically powered chillers as well as governor control on
turbine- and gas-engine-driven chillers.
The Johnson Controls method of variable speed control is
superior to others. It incorporates the actual compressor
operating limits, and determines the best combination of
speed and inlet vane position, based on the process requirements
and operating parameters. In this way, surge
is eliminated, the process set point is always respected,
and stable, efficient operation is assured.
STANDARD CHILLERS
Titan Chillers are offered in a broad range of sizes and
component details to meet unique customer requirements.
Chillers in a series of standard pre-selected increments
up to 5,200 tons (18,300 kWR) can be used to achieve
significant savings in first cost and delivery time. Contact
your Johnson Controls Sales Representative for performance,
dimensions, and details.

COMPRESSOR – INDUSTRIAL TYPE – 2 OR
3-STAGE
CASING – Rigid, close grain, high grade cast iron – horizontally
split to provide access to rotor assembly – top
vertical flanged suction and discharge connections –
flanged interstage gas connection for flash economizer
(intercooler) – design allows major wearing parts (journal
and thrust bearings, shaft seal, and main oil pump) to
be inspected or replaced without removing upper half of
casing. Compressor casing designed and constructed
in accordance with Design Working Pressures (DWP)
detailed in Table 1 on page 10.
ROTOR – Fabricated (furnace-brazed) aluminum alloy
impellers, shrouded type with backward curved blades,
dynamically balanced, and overspeed tested; designed
and constructed to resist corrosion, erosion and pitting,
and maintain initial balance and performance characteristics
– hot rolled heat treated alloy steel main shaft designed
to result in operation well below first critical speed,
without vibration – rotor assembly dynamically balanced
– balance piston on last stage impeller to minimize axial
thrust load on thrust bearing.
BEARINGS – Precision machined aluminum alloy single
piece tapered bore type journal bearings; aluminum alloy
tilting pad type thrust bearing; aluminum alloy reverse
thrust bearing. Bearings are accessible without removing
the top half of casing.
LUBRICATION SYSTEM – Completely factory packaged,
assembled and piped with oil sump reservoir as integral
part of compressor. The sump is vented to compressor
suction pressure.
• A main oil pump mounted directly on rotor shaft assures
forced feed lubrication to all bearings and seals
at all times, even under power failure coastdown
conditions.
• An external auxiliary oil pump (CAOP) assures pressure
lubrication prior to start-up during normal shutdown
and at any time main oil pump does not maintain
required pressure. The CAOP is a cast iron gear type
pump, close coupled to a TEFC motor available for
200 thru 600 volts – 3 phase – 60/50 Hertz service:
2 HP (1.5 kW) for M__26 and M__38, and 3 HP (2.2
kW) for M__55 compressors.
• Dual Oil Filters with 15-micron replaceable pleated
paper elements, and change-over valve permitting
filter element replacement during unit operation.
• Oil cooler, external water cooled cleanable shell and
copper tube type – for entering water temperatures
up to 90°F (32°C) at .0005 Ft2 °F hr/Btu(.000088m2
°C/W) fouling factor.
• Thermostatic oil temperature control valve bypasses
the oil cooler to maintain desired oil cooler leaving oil
temperature.
• Oil heater(s), 1000 watt, 115 volt – 1 phase –60/50
Hertz thermostatically controlled immersion type – 1
heater for M__26, and 2 heaters for M__38 and M__55
compressor – to maintain 150°F (66°C) sump oil
temperature during shutdown to minimize refrigerant
accumulation in oil.
• Weld pad type oil level sight glass.
• Hard wired safety switches for High Thrust Bearing
Oil Discharge Temperature and Low Oil (differential)
Pressure.
• 100 ohm RTD with 4-20mA temperature transmitters
(3) for: Refrigerant Discharge Gas; Thrust Oil Discharge;
Shaft End Bearing Oil Outlet.
• Thermometers (dual scale °F/°C) industrial bimetallic
element 5” (127 mm) dial adjustable angle type with
stainless steel case, and 3/4” (19 mm) NPT S.Stl.
Thermowells (5) for: Supply Bearing Oil; Thrust Bearing
Discharge Oil; Oil Reservoir (sump); Shaft End
Bearing Outlet; and Oil After Oil Cooler.
• Pressure gauges – Industrial 4-1/2” (114 mm) dial solid
front phenolic case with brass socket and phosphor
bronze bourdon tube, with dual English (psi) and metric
(kPa) scale (5) for: Supply Bearing Oil After Filter; Oil
Before Filter; Thrust Bearing Discharge Oil; Balance
Piston; Oil Sump.
• Pressure taps for connection to Pressure Transmitters
adjacent to above gauges.
• Automatic Sump Vent Valve to slowly equalize sump
pressure to suction on start-up. Consists of ball-valve
with pneumatic operator (80 PSIG / 55.5 kPa air required)
with actuating air solenoid valve, filter, restrictor
valve and gauges.
• Oil charging valve and oil drain valves
All electrical components for NEMA-1 application.
SHAFT SEAL – Rotating cast iron runner – stationary
precision spring-loaded carbon ring, – small face area,
low rubbing speed. The shaft seal is pressure lubricated
in operation and oil flooded at all times by means of an
upper gravity feed reservoir in the sump housing. The shaft
seal is accessible without removing top half of casing.
CAPACITY REDUCTION – The bronze airfoil-shaped
prerotation vanes (PRV) are radially arranged in the
inlet to the first stage impeller. They regulate the volume
of refrigerant suction gas handled by the compressor
to provide highly efficient partload operation; and
in conjunction with automatic hot-gas bypass provide