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4 - INSTALLATION
To ensure this, install pressure relief devices in the pipework and
service/check them regularly. Ensure that there are no shut-off
valves in the pipework between the heat pump connection and
the next pressure relief devices.
In addition to the mass flow to be dumped by the operator in an
emergency, the pressure relief device must additionally be able
to dump a mass flow corresponding to the required minimum
refrigerant blow-down capacity Qmd (see safety valve calculation
in section 10).
The heat pump must be operated only within the permissible
limits of use (see appendix). The system installer/operator must
ensure that the limits of use are maintained.
The temperature of the heat transfer medium at the evaporator
outlet must not fall below 4°C.
When selecting and sizing lines, observe the applicable general
and national standards, conditions and guidelines. The latest
applicable engineering standards must be taken into account and
observed.
We recommend hydraulic separation of the heat pump and heat
source. This separation can be achieved with a separate heating
circuit connected to a low loss header or buffer tank. On the source
side (evaporator), ensure sufficient buffer volume – at least 15
litres per kW of cooling capacity. A smaller buffer tank can only be
used in exceptional cases and at the user's own risk if the energy
supply and flow rate through the heat pump heat exchanger are
permanently constant.
The operating point (temperatures, flow rates) agreed in the
system datasheet must be ensured.
In any case, at least the minimum and maximum flow rate through
the evaporator as specified in the machine data (see appendix)
must be maintained during heat pump operation. The flow rate
must lie within the specified minimum and maximum values.
The parameters specified in the system datasheets (in particular
temperatures, temperature spreads, flow rate) must be met during
heat pump operation. Modified system parameters can result in
different heat pump outputs and/or temperatures.
If CARRIER is not notified of a specific operating point/specific
temperature spread in good time, the heat pump will normally be
sized with temperature differentials of 4–5 K between evaporator
inlet and outlet. In this case these values will have to be maintained
during heat pump operation.
As standard, the heat exchanger connections are Flange unions.
Ensure that these connections are not reversed. For the position
of these connections (inlets and outlets), see the dimensions sheet
in the appendix. The inlet and outlet are also labelled on the
evaporator. The connections must be tension-free and be made
with anti-vibration fittings.
When installing pipework, take care to avoid transmission of
structure-borne sound.
When sizing the source circulation pump, the internal pressure
differential of the heat pump evaporator must be taken into
account (in accordance with the operating point data).
10
Use only suitable media in the evaporator circuit. The limit values
specified in Table 1 must always be observed.
Ensure that no dirt or foreign bodies can enter the evaporator. We
strongly recommend that you install a filter, dirt separator, or at
least a filter strainer, upstream of the evaporator inlet.
Ensure that the filter is easily accessible and regularly cleaned. A
clogged strainer significantly impairs heat transfer and can cause
a safety shutdown. Install valves and thermometers in the flow
and return lines to allow continuous monitoring of the water/brine
flow rate and the heat pump operating state. At the lowest point
in the pipework, fit a drain pipe to allow the system to be drained.
Size the pipework according to the heat pump specification.
The flow velocity in the pipework should not exceed 1 m/s (noise/
pressure drop).
Regarding the temperature spread, please note the need for
source buffer tank charging: assuming that the source buffer tank
has been fully cooled to the required temperature, the heat pump
must then be stopped (via remote ON/OFF) until the buffer tank
has charged up again sufficiently or the system can operate at the
design temperature spread again. If, for example, the set
temperature is 10°C and the temperature spread between
evaporator inlet and evaporator outlet is 5 K, the heat pump should
run only when the temperature at the condenser inlet is 15°C or
more (see also section 6.2).
Before commissioning the heat pump, ensure that the evaporator
circuit contains no air or other gases and the system has reached
operating pressure.
CAUTION! The water or brine quality must be regularly
checked. Incrustations or acidic deposits could impair the
condition and function of the heat exchanger.
CAUTION! Impermissible media and substances they may
contain can destroy the components in the hydraulic circuit.
Excessively hard water/brine can result in deposits on the pipe
inner surfaces, which could impair the heat exchanger
performance.
The heat exchanger must not be exposed to dynamic or local
loads. Dynamic excess pressure and water hammer can damage
the heat exchanger.
Exceeding the highest permissible flow rate can cause erosion
and damage the evaporator.
After draining the evaporator water or brine circuit, always
thoroughly dry the evaporator tubes to prevent corrosion.
Pump cavitation and gas in the hydraulic circuit must be prevented.
During prolonged idle times, completely charge the heat exchanger
or fully drain and dry it.
WARNING! Never open the heat exchanger under pressure.
Risk of scalding.
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