Daikin Clima-Flex IOM CLIM Series, Инструкция по установке, эксплуатации и обслуживанию

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WATER FLOW LIMITATIONS
Constant evaporator flow
Maximum flow rate and pressure drop are based on a 6°F
temperature drop. Flow rates above the maximum values will
result in unacceptable pressure drops and may cause excessive
erosion, which could lead to failure.
The minimum flow rate and pressure drop are based on a full
load evaporator temperature drop of 16°F. Evaporator flow rates
below the minimum values can result in laminar flow leading to
low pressure alarms, fouling and poor temperature control.
VARIABLE EVAPORATOR FLOW
Reducing the evaporator flow rate in proportion to the load can
reduce the energy consumption of the system. The rate of flow
change should be a maximum of 10 percent of the flow per minute.
For example, if the maximum design flow rate is 200 gpm and is to
be reduced to a flow rate of 140 gpm, the flow change is 60 gpm.
Ten percent of 200 gpm equals a change of 20 gpm per minute,
or a minimum of three minutes to go from the maximum flow to
the desired flow.
If the flow rate falls below the minimum allowable, large reductions
in heat transfer can occur. If the flow rate exceeds the maximum,
excessive pressure drop and tube erosion can occur.
System water considerations
Reducing the evaporator flow rate in proportion to the load can
reduce the energy consumption of the system. The rate of flow
change should be a maximum of 10 percent of the flow per minute.
For example, if the maximum design flow rate is 200 gpm and is to
be reduced to a flow rate of 140 gpm, the flow change is 60 gpm.
Ten percent of 200 gpm equals a change of 20 gpm per minute,
or a minimum of three minutes to go from the maximum flow to
the desired flow.
If the flow rate falls below the minimum allowable, large
reductions in heat transfer can occur. If the flow rate exceeds the
maximum, excessive pressure drop and tube erosion can occur.
Figure 9. Factory installed strainer
Installation and Application Information
EVAPORATOR FREEZE PROTECTION
Evaporator freezing can be a problem in the application of air-
cooled water chillers in sub-zero temperature areas. To protect
against freezing, the evaporator comes with insulation and an
electric heater. Although the evaporator is equipped with freeze
protection, it does not protect the water piping external to the unit
or the evaporator itself if there is a power failure or the heater
burns out, or if the chiller cannot control the chilled water pumps.
Use one of the following recommendations for additional freeze
protection:
!
CAUTION
!
Improper use of detergents, chemicals and additives in the
cooling system water can adversely affect the performance
of the chiller and potentially result in repair costs not covered
under warranty. Any decision to use these products is at
the discretion of the owner/occupant/operator/user, and the
owner/occupant/operator/user assumes full responsibility for
any damage that may occur due to their use.
1. If the unit will not operate during the winter, drain the evapora-
tor and cold water lines and flush them with glycol.
2. Add a glycol solution to the chilled water system. Breakage
protection should be approximately 10°F below the minimum
design ambient temperature.
3. Insulate exposed piping.
4. Add thermostatically controlled heat by wrapping lines with
heat tape.
5. When glycol is added to the water system for freeze protec-
tion, the refrigerant suction pressure will be lower, the cooling
performance will be lower and the water side pressure drop
will be higher.
COLD WATER PUMP
It is important that the chilled water pumps are connected to
and controlled by the chiller microprocessor. The controller will
activate the pump whenever at least one chiller circuit is enabled
for operation, whether there is a call for cooling or not. This helps
ensure proper start-up sequencing of the unit. The pump will
also turn on when the water temperature is below the freeze set
point for longer than the specified time to help prevent evaporator
freeze-up. Connection points are shown in the field wiring diagram
beginning on page 25.
Water systems should be cleaned and flushed prior to chiller
installation. Water testing and treatment should be verified during
initial chiller installation/commissioning and should be maintained
on an ongoing basis by water treatment professionals.
!
CAUTION
!
Adding glycol or draining the system is the recommended
method of freeze protection. If the chiller does not have
the ability to control the pumps and the water system is not
drained or does not have adequate glycol at subfreezing
temperatures, catastrophic evaporator failure can occur.