Carrier 30RB-210R - 12.2.3.3 Installation; 12.2.3.4 Operation

12.2.3.3 - Installation
The hydraulic supply for each desuperheater is delivered in
parallel.
The hydraulic connection on the desuperheater water inlet and
outlets must not generate any local mechanical stress on the
exchangers. If necessary, install exible couplings.
Fit water ow rate balancing and control valves at the exchanger
outlet.
Balancing and control of the ow rates may be performed by
reading the pressure drop in the exchangers.
The pressure drop on each of these must be identical to the total
water ow rate given by the selection programme.
To adjust the balancing valves before starting up the system, refer
to the pressure drop curves below.
It is possible to ne-tune the water ow rate settings for each
desuperheater when the unit is running at full load by trying to
obtain water outlet temperatures which are strictly identical for
each of the circuits.
Desuperheater (plate heat exchanger pressure drop curves)
1
10
100
0,11 10 100
1 2 3 4
5 6
Heat exchanger pressure drop (kPa)
Heat exchanger water ow rate (l/s)
1 Circuit with 1 compressor (165-550 KW units) 4 Circuit with 4 compressors (165-550 KW units)
2 Circuit with 2 compressors (165-550 KW units) 5 Circuit with 3 compressors (610-850 KW units)
3 Circuit with 3 compressors (165-550 KW units) 6 Circuit with 4 compressors (610-850 KW units)
12.2.3.4 - Operation
The desuperheater water circuit pump (see standard diagram –
item 20, in the section on "Installation and operation of the heat
recovery with desuperheater option") can be operated in
conjunction with:
- Start-up of the rst unit compressor: terminal 37/38
- Heating water requirement: output DO-01, terminal 491/492,
on the EMM board.
A dedicated ow switch (item 29) can also be installed to generate
an alarm if there is a problem with the pump (customer control
system).
The volume of the desuperheater circuit water loop must be as
low as possible to be able to rapidly increase the temperature
during warm-up.
The minimum desuperheater water inlet temperature is 30 °C.
This may require the use of a three-way valve (item 31), with its
controller and sensor controlling the minimum required water inlet
temperature.
It is essential for the desuperheater water loop to comprise a valve
and an expansion vessel which must be selected to take the
volume of the water loop and the maximum possible temperature
into account (120 °C), in the event that pump (item 20) stops
running.
12.2.3.5 - Operating limits
30RB/RBP 170-950 units
Desuperheater Minimum Maximum
Water inlet temperature at start-up °C 30
(1)
75
Water outlet temperature during operation °C 45 80
Water inlet temperature on shut-down °C 3 75
30RQ/RQP 165-520 units
Desuperheater Minimum Maximum
Water inlet temperature at start-up °C 30
(1)
60
Water outlet temperature during operation °C 45 80
Water inlet temperature on shut-down °C 3 60
Note: Do not exceed the maximum operating temperature.
(1) On start-up, the water inlet temperature must not be below 25 °C. On lower
temperature installations, a 3-way valve is required until the desuperheater water
outlet reaches 45 °C.
12 - OPTIONS
61