Yes you are correct. There is a cylinder-piston assembly and a motor connected to piston inside the compressor. The lower part of compressor is filled with cooling oil while upper part has gas. The gas is pushed out through cylinder to the heat exchanger for cooling.
You can read more about compressors by searching pages on Google.
You have a point, for effencient using of variable RPM compressors, you need valved evaporator. (simular using in cars AC)
standard fridge have capillair-pipe (sp?) to make constant flowing fluids to evapoator near without sensitivity of pressure on both side, and if compressors RPM going down - is high risk capillair-pipe going dry and transporting gas without cooling effect. Capillair-pipe working as 'constant current source' for cooling liquid and capillairs-pipe length and compessors capacity is very close coupled together...
Ie. cooling systems with compressors is very unliniar and not easy to manage with linear working PID-system...
You have a point, for effencient using of variable RPM compressors, you need valved evaporator. (simular using in cars AC)
standard fridge have capillair-pipe (sp?) to make constant flowing fluids to evapoator near without sensitivity of pressure on both side, and if compressors RPM going down - is high risk capillair-pipe going dry and transporting gas without cooling effect. Capillair-pipe working as 'constant current source' for cooling liquid and capillairs-pipe length and compessors capacity is very close coupled together...
Ie. cooling systems with compressors is very unliniar and not easy to manage with linear working PID-system...
Does anyone know how long can the refrigerator compressor run?
additionly, in the compressor data sheet, i can not find any information about compressor runtime.
So, how to determine the compressor runtime in this case?
Can somebody tell me where can i download some literature where it is explained the technology of working refrigeration system with example: 3 compressors, one is with frequency inverter, other direct with contactor, 6fans, PLC, 2 pressure sensors 4-20mA(LP and HP), temperature sensors(room and outside), etc.
It is for freezing meat for example.
There is one controller Eliwell EWCM9100 witch we would like to replace.
PLS if somebody can send me the link or by email the litterature explaining the ligic and control theory so we could write the program in PLC?
Any help is hugely appreciated!
Best Regards
Stanislas