CLIVET WSH-XSC3, Инструкция по установке и эксплуатации

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9.2 NATURAL COOLING function
Enabling the Natural Cooling functions, the unit is able to independently manage a system for cold production using source water in the
event the temperature conditions of the fluid are favorable.
In this case, the source is managed as if it were the first unit available capacity step and can be used to cover the 100% of the cooling load
or also, in integration to the compressors, to cover a part of the cold demand by resetting or reducing the compressor power input.
The Natural Cooling installation should include the following additional components (not supplied by Clivet):
1) Natural Cooling water/water exchanger (SCNC in the main scheme): this exchanger shall be suitably dimensioned according to the fluid
temperature, user and source side, and according to the pressure drop of the remaining part of the installation and to the unit available
static pressure if pumps are not built-in.
2) Two 3-way on/off or equivalent valves (VNCS and VNCU in the main scheme): one on the source circuit and one on the user circuit. Also
these have to be suitably dimensioned according to the expected flow rates.
For the correct operation of the Natural Cooling function, the set point control must be set on supply (parameter 436 Tiporeg).
In the installation set up phase it will be necessary to remotely the probe on the source input water upstream of the switching valve source
side (VNCS).
The unit can be selected with or without hydronic assemblies user and source side: the system must be able to absorb/manage the flow
rate/head variations due to the heater change after the Natural Cooling exchanger insertion and exclusion.
The unit control provides an on/off signal to enable the Natural Cooling by switching the valves.
The Natural Cooling is enabled if the two following conditions are satisfied:
1) the entering water temperature, source side, must be lower than the cooling set point plus a delta defined by parameter 365 DeltaNC
(the value can be positive or negative) [Tws_in < (Set_c DeltaNC)]
2) the entering water temperature, user side, must be higher than the entering water temperature, source side, plus a delta defined by
parameter 366 IsteresiStopNC (the value can be only positive) [Tws_in < ( IsteresiStopNC)]
If one of these two conditions is not satisfied the Natural Cooling is disabled.
PDU Differential pressure switch, user side
PDS Differential pressure switch, source side
PRLU Installaton load pressure switch adjusted at 0.5 bar
SC Plate heat exchanger
VSU Safety valve adjusted at 6 bar (only if pumps or valves are present)
VSR Exhaust valve
BTIS Entering temperature probe, source side (to remotely) BTOS Leaving temperature probe, source side
BTIU Entering temperature probe, user side
BTOU Leaving temperature probe, user side
VNCS Natural Cooling valve, source side (provided by the Customer)
VNCU Natural Cooling valve, user side (provided by the Customer)
SCNC Natural Cooling exchanger (provided by the Customer)
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