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2.1.
Compressor
The compressor generates the needed pressure difference for evaporation and condensation between heat
sink and heat source in the refrigerant circuit. Vaporised refrigerant coming from the evaporator is drawn in
and compressed in the compressor to the condensing pressure.
The compressors used work on the basis of the scroll principle. Scroll compressors are maintenance-free,
quiet and have a very high degree of efficiency.
The flow temperature is controlled by switching on or off one or more compressors (see
8.7.5 Compressor
control
). Sequential changeover ensures that all compressors are loaded uniformly.
2.2.
Evaporator
The evaporator is a plate heat exchanger that transfer heat from the cold water to the refrigerant. In order
for the transfer of heat to take place, the refrigerant in the evaporator must have a lower temperature than
the cold water and changes its physical state upon heat absorption from liquid to gaseous.
If the cold water is polluted, deposits can accumulate on the transfer surfaces of the evaporator. This impairs
the transfer of heat to the refrigerant and has negative effects on the refrigerating capacity of the machine.
Therefore always make sure to use the prescribed water quality and do not make use of any other additives
than prescribed.
2.3.
Condenser
The condenser is a microchannel heat exchanger that transfers heat from the refrigerant to the ambient air.
In order for the transfer of heat to take place, the refrigerant in the condenser must have a higher temperature
than the drawn-in ambient air changes its physical state upon heat dissipation from gaseous to liquid.
Contaminated cooling air can cause deposits to accumulate on the condenser surface. This impairs the
transfer of the heat to the refrigerant. This restricts the operating limit of the machine and reduces the
refrigerating capacity of the machine. How to clean the condenser is described in
Chapter 9
Cleaning
. If you
operate your chiller in an environment contaminated with dust or oil vapours, make use of the optionally
available air filter mat
(see
9.1: Air filter mat
).
2.4.
Expansion valve
The expansion valve regulates the admission of liquid refrigerant to the evaporator and restricts the pressure
of the refrigerant before entering the evaporator. In this process, the refrigerant cools down to the evaporating
temperature.
The expansion valve used in the machine is regulated electronically. The electronic regulation ensures that
the evaporator is constantly optimally supplied with refrigerant. This improves the COP (coefficient of
performance) and reduces pressure fluctuations in the refrigeration circuit.
2.5.
Refrigerant
The refrigerant R410A circulates in the refrigeration circuit. It "transports" the heat from the evaporator the
condenser and continuously changes its physical state in doing so.
R410A is a fluorinated greenhouse gas consists of the zeotropic mixture 50% R32 and 50% R125 with
virtually negligible temperature glide. R410A has a very high volumetric cooling capacity and has no ozone
depletion potential (ODP=0). A corresponding safety data sheet can be requested from our KKT chillers
Service Team (
see: Contact details
).
2.6.
Oil
The compressor components subject to friction are lubricated by oil that is added to the refrigerant at the
factory. Polyolester-160SZ is used for this purpose. The oil is soluble in the refrigerant and distributes itself
with it throughout the entire refrigeration circuit. The total oil quantity of the specific unit can be taken from
