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Basic requirements
The chilled water pipelines may be connected as per relevant procedure when the unit is installed in
place. Such pipelines shall be free from any foreign matter, and must conform to local piping regulations
and rules.
1.
Before unit operation, thoroughly flush all chilled water pipelines to ensure that they are free from
any foreign matter. Note: Do not flush any foreign matter into the evaporator.
2.
Water must flow into the heat exchanger via the inlet. The opposite water direction through the heat
exchanger may degrade the unit performance, and give rise to fault in flow switch.
3.
The water pump installed in the water pipeline system is equipped with a starter, and directly pumps
water into the heat exchanger of the water system.
4.
Tubing and connectors must not be mounted on the unit but independently supported.
5.
The nozzles and connectors of the heat exchanger shall be easily disassembled for operation,
cleaning and inspection over the evaporator nozzle.
6.
The evaporator is provided with a 40-mesh filter, which must be installed at the water inlet of the unit
and insulated (see the above diagram).
7.
The heat exchanger ports and the site pipelines shall be flexibly connected to reduce vibration
transmitted to buildings.
8.
To facilitate troubleshooting, a thermometer or pressure gauge shall be installed on the water inlet
and outlet pipelines. Pressure or temperature instrument are not provided with the unit and are at
users' own expenses.
9.
Drain ports shall be arranged at all low points of the water system to ensure that water in the
evaporator and the system is completely discharged; exhaust valves shall be arranged at all high
points to vent air in the pipelines. The exhaust valves and drain ports are not insulated for easy
troubleshooting.
10. All water pipelines in the system exposed to frost shall be thermally insulated.
11. Outdoor chilled water pipelines shall be covered with an auxiliary heating tape and insulated with 20
mm thick thermal insulation material, so as to avoid frozen or ruptured pipelines due to low
temperature. The power supply of the heating tape shall be equipped with a separate fuse.
12. Where the ambient temperature is below 0℃, or the unit is to idle for a long time, please discharge
water from the unit through the water outlet pipeline connected with the plate heat exchanger of the
unit. If no water discharge is required for the unit in winter, do not cut off the power supply. The fan
coil in the water system must be provided with a 3-way valve to ensure that the water system is
smoothly circulated after the winterizing water pump is started.
The bypass pipes and stop valves of water inlet and outlet pipelines shown in the above diagram must be installed to
facilitate cleaning of other systems outside of the water pipeline prior to the unit commissioning. During maintenance, the
water pipelines of the heat exchanger may be cut off without interference to other heat exchangers.
3.5 Air conditioning piping system design
The air conditioning piping system should have sufficient conveying capacity. For exam ple, in the
central air conditioning system, the water system is used to ensure that the circulating water volume of
each air conditioning unit or fan coil air conditioner reaches the designed flow to ensure the normal
operation of the unit;
Reasonable layout of pipelines: The layout of pipelines should be the same as possible. Although the
initial investment is slightly increased, it is easy to maintain the hydraulic stability of the loop. If an
external system is used, the pressure between the branches must be paid attention to in the design.
Balance problem
When determining the pipe diameter of the system, it should ensure that the design flow can be
transmitted, and the resistance loss and water flow noise are small to obtain economical and reasonable
effects. As we all know, the large diameter of the pipe is more investment, but the flow resistance is
small, the power consumption of the circulating water pump is small, and the freight is used low.
Therefore, a pipe diameter that can minimize the sum of investment and operating costs should be
determined. At the same time, in the design to eliminate the problem of large flow and small temperature
difference, this is the economic principle of pipeline design;
In the design, strict hydraulic calculations must be carried out to ensure that the water balance
requirements are met between the various loops, so that the air conditioning water system has good
hydraulic and thermal conditions in actual operation;
The air conditioning piping system must meet the adjustment requirements for the central air
CAUTION
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