C02 refrigeration systems

[NMLS]

Hello all,

HFCs as a refrigerant can be used in simple refrigeration systems, i.e. system incorperating, compressor, oil seperator, condenser, control/expansion valve, evaporator, and accumulator. However, HFCs are being wend out of the automotive industry and carbon dioxide refrigerants are replacing them. C02 refrigerant, due to its thermodynamic properties, can achieve a C.O.P. compairable to HFC refrigerant C.O.P. only when used in a modified refrigeration system. Does any one have any insight as to what is incorperated in a modified system. Thank you for your time.

NMLS

 

[NickE]

What I know about CO2 systems:

1) the reed valves are different shapes.
2) the pressures are much much higher.

More could probably be found by googling the topic a few ways.

 

[patprimmer]

If the temperatures and pressures are significantly different, the seals and lubricants might be different.

Regards

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[Lou Scannon]

The best info available can probably be found searching recent publications at the sae.org website.

 

[dcasto]

I'd like to see that refrigeration cycle. I ran a typical cycle and I calculated 3.36 HP/ton of refrigeration with CO2. Butane uses 1.16 HP/ton. Freon 134a uses 1.34HP/ton.

The above is 40F vaporizer temp and 120 F condensor temp