Large 2-stage cascade

[Kevin Hotton]

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

[Buckeye]

Good Grief that is a monster !!!
Love it man !

[NKrader]

what the hell are you cooling with that?

the core of the earth?


EDIT: 115amps @220... holy hell.. thats more than my house is wired for... total..

[Charles Wirth]

Welcome to XS

Does it blend? Nice cascade.

[dinos22]

EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEK but cant it hold a load with a 7GHz Gulftown with 2volts (j/k)

[lesstutrey]

i am turned on. seriously. there's nothing wrong with me!

[dejanbinladen]

holy :S

[Dualist]

That's amazing work dude.!

[[XC] gomeler]

You've already answered a lot of my questions in your first post. Curious, was this build to chill that methanol for 24/7/365 or is this just an experiment? I like using those cylinders as your expansion tanks

[Kevin Hotton]

Hi all,

The unit is trailer mounted and is a pilot-plant sized system. It will receive CO2/H2 gas from a methane/steam reformer (also trailer mounted). The ultimate use is CO2 ground injection for tertiary oil recovery. So yes the unit is designed for 24/7 operation (for a few days to demonstrate process). When we run it now we blend nitrogen and carbon-dioxide and the separator/cascade refrigeration system separates the gases back to one stream CO2 one stream N2 and vents them to the atmosphere. We can empty a 55,000 scf nitrogen tube trailer (semi truck size) and 4-tons of CO2 in about 6-hours!!! I am currently working on a system to liquefy the CO2.

Also the blend of Propene/Ethane and Ethane/Ethene are zeotropic and introduces temperature "glide" into the condensation and evaporation HX's. However this is a benifit thermodynamically in our application.

Glad you all enjoyed the photo's.
Kevin Hotton

[[XC] gomeler]

Was wondering why it looked like it had brake lights. So, if I understand correctly this entire system will process methane, consume water, and yield hydrogen and CO2. I imagine you guys save off the hydrogen and another system will process the CO2 to inject it in to the well to increase productivity on older wells? You mention that this is a pilot plant, will this scale up to a massive installation at a well or are you looking at just trucking things around this sized to inject CO2 into various wells as a service?

I ask all this as I remember seeing a post about a guy who worked in the oil industry where they were injecting liquid nitrogen in to the wells for I believe this same reason. I could be mistaken, it might have been carbon dioxide.

[Kevin Hotton]

No gometer,

It is TWO trailers. This is just the gas-separator-unit. The other trailer is the reformer-unit. You are correct that in some instances N2 is injected in oil wells. This has been done "big time" at Mexico's huge Cantarell oil field in the Gulf of Mexico. I think so much has been injected that once the field is fully depleted that they will allow the pressurized N2 to return to the surface and drive generators making electricity for "years"!

Kevin

[mytekcontrols]

Very impressive indeed!

So while I'm striving to build ever smaller AutoC's, you and your team are building some of the biggest stuff I've ever seen.

[Marvin]

that is insane