Systems with multi-circuit condensers and/or evaporators

In these systems, each compressor should have its own refrigerating circuit – the pipes of the different circuits then run through the evaporator and/or condenser in parallel, if necessary. Each circuit receives its own expansion and solenoid valve and can be adapted to the respective load conditions with appropriate control. Among other things, the mutual influence due to the thermal connection in the heat exchangers must be taken into account.

During the shutdown times of individual circuits, the risk of liquid refrigerant being displaced into the evaporator increases in these systems (no temperature and pressure equalisation possible). In such cases, a check valve downstream of the oil separator and a standstill bypass (Standstill bypass for oil separator) should be used. In the case of compound connection, the compressors should be controlled with automatic sequency change.

In critical cases, additional suction accumulators on the suction side or a pump down system may be necessary (Pump down system).

The same applies to individual units where temperature and pressure equalisation cannot occur during longer standstills.