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TVP Manual (full) March 2007 CE rev 03.doc
4.30 Principle of operation
For the user and installer the TVP maybe considered as a classical refrigeration system where
gas is compressed and cooled to induce condensation to a liquid. The liquefied gas is then
passed through a metering device (orifice) causing a pressure drop and subsequent
evaporation within a closed volume (cryo-coil) producing a cooling effect. The system differs
from a conventional system in that it has several different gases and a complex array of heat
exchange surfaces are used to achieve the cryogenic temperature required.
The TVP uses the auto-cascade principle, which achieves low temperatures in a single
compressive step. This is different from many other low temperature refrigeration systems,
which achieve low temperatures by linking together two or more compressive refrigeration
steps to form a classical cascade system. Further background information on auto-cascade
systems can be obtained from Telemark.
1. Compressor
2. Condenser
3. Evaporator
Diagram 21 Simple refrigeration cycle
1
2
3
H
2
O