42/23-55 EN Rev. 1
SCC-C Sample Gas Cooler Operator’s Manual
25
Description
Principle
The SCC-C sample gas cooler contains 1 or 2 heat exchangers in which the
sample gas is cooled down to 3 °C.
Refrigerant Circuit
(see Fig. 8)
Depending on the operating conditions, the refrigerant compressor
1
compresses
the vaporous refrigerant from suction pressure of around 100 kPa (= 1.0 bar) to
800–1700 kPa (= 8–17 bar).
In the downstream air-cooled refrigerant condenser
2
the vaporous refrigerant is
condensed by means of cooling. The liquid refrigerant flows through the
refrigerant drier
3
to the capillary pipe
4
.
In the capillary tube
4
the pressure of the liquid refrigerant is reduced from its
condensation pressure 800–1700 kPa (= 8–17 bar) to a lower pressure
(evaporation pressure) 100 kPa (= 1.0 bar), and the refrigerant passes into the
evaporator
6
.
In the heat exchanger
5
, which is inset in a hole in the cooling block
7
, energy is
extracted from the sample gas; the sample gas is cooled, and the energy is fed
into the vaporous refrigerant at an evaporation pressure of 100 kPa (= 1.0 bar,
approx. –10 °C). The vaporous refrigerant is sucked in once more by the
refrigerant compressor
1
.
In order to keep the sample gas outlet temperature (dew point) constant, the
refrigerant mass flow is regulated by the temperature-controlled valve
8
in the
bypass of the refrigerant compressor
1
in accordance with the output required.
The valve is open when no cooling is required.
Fig. 8
Refrigerant Circuit
°C
2
3
4
5
6
7
1
8
9
1
Refrigerant
Compressor
2
Refrigerant
Condenser
3
Refrigerant
Drier
4
Capillary
Tube
5
Heat
Exchanger
6
Evaporator
7
Cooling
Block
8
Valve
9
Temperature
Controller
Continued on next page