Level Control Of The Evaporator - GEA RedGenium Operating Instruction

Description
3.2.5

Level control of the evaporator

The liquid refrigerant is injected into the evaporator via an electronic expansion
valve.
Control is effected by calculating the mass flow of refrigerant in relation to the
pressure loss across the expansion valve and its characteristics.
In addition, the fluid level of ammonia is evaluated in an oblique pipe after the
condenser. If the level decreases, the lower sensor sends a signal to the valve to
reduce the opening position. If, on the other end, the maximum level sensor indi-
cates a level that is too high, the expansion valve opens further.
54
Notice
The following points must be checked before commissioning to ensure cor-
rect functioning of the injection control.
► Checking the settings: have compressor frame size and type of expan-
sion valve been properly selected; are pressure transmitters correctly
scaled?
► Checking the fill level indicators: are the sensors installed and wired?
► Checking the information for filling: is the system filled according to the
specifications for refrigerant and oil? (No condensable gases, e.g. air, may
be in the piping to ensure proper functioning of the injection control.)
L_151511_2
19.12.2019