Coping with Varying Evaporating Temperatures on Trans Crit CO2 Systems

[Kwaker]

I have a scenario whereby I have multiple evaporators operating on the same CO2 condensing unit with widely varying evaporating temperatures.

I don't know of anyone that offers an EPR valve suitable for high pressures so wonder how I can control the evaporating temperatures in the highest evaporating systems.

F&V evaporator is at +2°C with the lowest evap temp fixture at -7°C. I can't have the F&V at -7 because the Delta T to the Room (+8°C) is too wide and could dry product.

I could separate the F&V evaps onto their own condensing units but I need to keep the number of condensing units to a minimum for economic and space reasons.

Any help/advice would be very much appreciated.

[Brian_UK]

I'm not an expert on CO² but would a plate heat exchanger providing a secondary cooling fluid circuit for the higher temperature circuit be feasible?

[seanf]

Could a ICM valve be used as a EPR? Is it for a pack or a cubo2 type of unit?

[RANGER1]

As Sean mensions, Danfoss will be able to sort you out.

http://files.danfoss.com/TechnicalInfo/Dila/01/DKRCEPAR1A102_The%20Food%20Retail%20CO2%20application%20handbook_DILA.pdf

[Glenn Moore]

You can use either a combination of a Danfoss ICS valve with a CVP (HP) pressure pilot valve as a simple back pressure control valve , or an ICM valve with an ICAD motor plus an electronic controller such as an EKC 361 with a PT1000 temperature sensor for remote control applications . Did this on many supermarket CO2 systems in the UK