Hi everyone,
I'm a new member and thought I would share a few pictures of a 2-stage cascade refrigeration system I designed and build with two other co-workers. It uses twin 6-cylinder Copeland discus compressors. I am using hydrocarbon blends (80% Propene, 20% Ethane in 1st stage, 67% Ethane, 33% Ethene in 2nd stage). The unit has all large plate HX's (biggest ones are 21 meter2 area). There is a water-cooled condenser on the 1st stage with water-cooled pre-condenser on 2nd stage. A 30-ton cooling tower with pump circulates about 80-gpm of water flow. Note also the large suction accumulators, 4 gas cylinder "fade-out" vessels and the twin oil separators in series on the cold circuit. I also am using electronic (stepper motor controled) expansion valves on both refrigeration circuits.
This refrigeration system has 54 kW (yes 54,000 Watts) of cooling at evaporator temperature of -70C. It is part of a gas separation process that requires methanol to be cooled (about a 16 gpm flow) from -30C to -60C. Under full load each compressor consumes 115 Amps of 208 VAC 3-phase power.
Kevin Hotton
Bookmarks