4. WATER SYSTEM INSTALLATION
4.1 Basic requirements of connection of chilled
water pipes
CAUTION
●
After the unit is in place, chilled water pipes can be laid.
●
The relevant installation regulations should be abided with
when conducting connection of water pipes.
●
The pipelines should be free of any impurity, and all chilled
water pipes must conform to local rules and regulations of
pipeline engineering.
k. All low positions of the water system should be provided
with drainage ports, to drain water in the evaporator and the
system completely; and all high positions should be supplied
with discharge valves, to facilitate expelling air from the
pipeline. The discharge valves and drainage ports should
not be under heat preservation, to facilitate maintenance.
l. All possible water pipes in the system to be chilled should
be under heat preservation, including inlet pipes and flanges
of the heat exchanger.
m. The outdoor chilled water pipelines should be wrapped
with an auxiliary heating belt for heat preservation, and the
material of the auxiliary heat belt should be PE, EDPM, etc.,
with thickness of 20mm, to prevent the pipelines from
freezing and thus cracking under low temperature. The
power supply of the heating belt should be equipped with an
independent fuse.
n. When the ambient temperature is lower than 2
℃
, and the
unit will be not used for a long time, water inside the unit
should be drained. If the unit is not drained in winter, its
power supply should not be cut off, and the fan coils in the
water system must be provided with three-way valves, to
ensure smooth circulation of the water system when the
anti-freezing pump is started up in winter.
o. The common outlet pipelines of combined units should be
provided with mixing water temperature sensor.
WARNING
●
For the water pipeline network including filters and heat
exchangers, dreg or dirt may seriously damages the heat
exchangers and water pipes.
●
The installation persons or the users must ensure the
quality of chilled water, and de-icing salt mixtures and air
should be excluded from the water system, since they may
oxidize and corrode steel parts inside the heat exchanger.
7
I&O manual
●
Connection requirements of chilled water pipes
a. All chilled water pipelines should be thoroughly flushed, to
be free of any impurity, before the unit is operated. Any
impurity should not be flushed to or into the heat exchanger.
b. Water must enter the heat exchanger through the inlet;
otherwise the performance of the unit will decline.
c. The inlet pipe of the evaporator must be provided with a
target flow controller, to realize flow-break protection for the
unit. Both ends of the target flow controller must be supplied
with horizontal straight pipe sections whose diameter is 5
times that of the inlet pipe. The target flow controller must be
installed in strict accordance with “Installation & Regulation
Guide for Target Flow Controller” (Figure 4.3~4.4). The wires
of the target flow controller should be led to the electric
cabinet through shielded cable (see Electric Controlling
Schematic Diagram for details). The working pressure of the
target flow controller is 1.0MPa, and its interface is 1 inch in
diameter. After the pipelines are installed, the target flow
controller will be set properly according to the rated water
flow of the unit.
d. The pump installed in the water pipeline system should be
equipped with starter. The pump will directly press water into
the heat exchanger of the water system.
e. The pipes and their ports must be independently
supported but should not be supported on the unit.
f. The pipes and their ports of the heat exchanger should be
easy to disassemble for operation and cleaning, as well as
inspection of port pipes of the evaporator.
g. The evaporator should be provided with a filter with more
than 40 meshes per inch at site. The filter should be
installed near to the inlet port as much as possible, and be
under heat preservation.
h. The by-pass pipes and by-pass valves as shown in Fig.
4-1 must be mounted for the heat exchanger, to facilitate
cleaning of the outside system of water passage before the
unit is adjusted. During maintenance, the water passage of
the heat exchanger can be cut off without disturbing other
heat exchangers.
i. The flexible ports should be adopted between the interface
of the heat exchanger and on-site pipeline, to reduce
transfer of vibration to the building.
j. To facilitate maintenance, the inlet and outlet pipes should
be provided with thermometer or manometer. The unit is not
equipped with pressure and temperature instruments, so
they need to be purchased by the user.
