Oil Coolers - Daikin WDC Installation, Operation And Maintenance Manual

When the valve stem is not pushed forward or pulled back
completely, the valve is in "Mid Position," as shown in
CAUTION
Do not operate the system with the three-way valve stem in the Mid
Position.
Figure 8: Three-Way Valve, Mid Position

Oil Coolers

WARNING
This unit contains POE lubricants that must be handled carefully and the
proper protective equipment (gloves, eye protection, etc.) must be used
when handling POE lubricant. Failure to do so can result in personal injury.
POE must not come into contact with any surface or material that might
be harmed by POE, including certain polymers (e.g. PVC/CPVC and
polycarbonate piping).
Daikin Applied centrifugal chillers have a factory-mounted,
water-cooled oil cooler, temperature-controlled water regulating
valve and solenoid valve per compressor. All WDC units have
oil cooler connections located on the right hand tube sheet
under the evaporator Figure 9
10.
Field water piping to the inlet and outlet connections must be
installed according to good piping practices and include stop
valves to isolate the cooler for servicing. A cleanable filter (40
mesh maximum), and drain valve or plug must also be field-
installed. The water supply for the oil cooler should be from
the chilled water circuit or from a clean, independent source,
no warmer than 80°F (27°C), such as city water. When using
chilled water, it is important that the water pressure drop across
the evaporator is greater than the pressure drop across the oil
cooler or insufficient oil cooler flow will result. If the pressure
drop across the evaporator is less than the oil cooler, the oil
cooler must be piped across the chilled water pump, provided
that its pressure drop is sufficient. The water flow through the
oil cooler will be adjusted by the unit's regulating valve so that
the temperature of oil supplied to the compressor bearings
(leaving the oil cooler) is between 95°F and 105°F (35°C and
40°C).
IOM 1281-2 • CENTRIFUGAL WATER CHILLERS
Figure 8
or above the condenser Figure
Table 4: Oil Cooler Data
Hot Side
Compressor Size POE
Lube
079 - 087
Flow, gpm 9.9
Inlet Temp, °F 118.0
Outlet Temp, °F 100.0
Pressue Drop, psi -
100 - 126
Flow, gpm 15.8
Inlet Temp, °F 120.0
Outlet Temp, °F 100.0
Pressue Drop, psi -
Table 5: Cooling Water Connection Sizes
Model WDC 079-087
Conn Size 1 in.
Compressors using chilled water for oil cooling will often start
with warm "chilled water" in the system until the chilled water
loop temperature is pulled down. Data given above includes
that condition. As can be seen, with cooling water in the 45°F
to 65°F (7°C to 18°C) range, considerably less water will be
used, and the pressure drop will be greatly reduced.
When supplied with city water, the oil piping must discharge
through a trap into an open drain to prevent draining the cooler
by siphoning. The city water can also be used for cooling tower
makeup by discharging it into the tower sump from a point
above the highest possible water level.
NOTE: Particular attention must be paid to chillers with
variable chilled water flow through the evaporator.
The pressure drop available at low flow rates can be
insufficient to supply the oil cooler with enough water.
In this case an auxiliary booster pump can be used or
city water employed.
14
Installation
Cold Side Water Options to
achieve 100 °F Outlet Temp
11.9 2.9 2.0 1.54
80.0 65.0 55.0 45.0
87.3 94.5 98.3 101.4
4.3 0.3 0.14 0.09
21.9 5.1 3.5 2.7
80.0 65.0 55.0 45.0
87.0 95.0 99.0 102.3
3.78 0.23 0.11 0.07
WDC/WCC 100-126
1 1/2 in.
www.DaikinApplied.com