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RGover
20-07-2008, 10:33 AM
Hi has any one come across transcritical systems working on Co2, I know that Linde have a number of systems installed ove europe?:cool:

iced
20-07-2008, 06:44 PM
Star Refrigeration are punting a small one, athough I believe they dont have any tried and tested in the field

NoNickName
20-07-2008, 09:49 PM
Yes, I have. Linde, Knudsen Koling, Ahlsell.... questions?

750 Valve
21-07-2008, 01:06 PM
There is one installed in a supermarket in Adelaide Australia

RGover
21-07-2008, 01:15 PM
Hi all thanks for replys, I was after some information with regards the Transcritical side of things, i beli:confused:eve there are no condensers on this type of system?

NoNickName
21-07-2008, 02:11 PM
What was called condenser in a subcritical or normal cycle, here is called "gas cooler".

GXMPLX
21-07-2008, 02:14 PM
You donīt condense in a transcritical system so you donīt have a "condenser" but you do have a heat exchanger that does the same function: reject heat of compression+heat absorbed.

RGover
21-07-2008, 03:22 PM
How does the gas cooler work? how do you get liquid?how do you maintian liquid pressure?
:confused:

NoNickName
21-07-2008, 03:59 PM
the gas cooler does what it says: it cools the gas, but being supercritical, it doesn't condense, so you don't get liquid.

After the gas cooler, a special regulation valve is installed, which lowers the pressure (it's a throttling device, like a TXV, but unlike a TXV it doesn't throttle liquid). As the pressure lowers, the gas approaches the critical pressure and transforms into liquid.

The difference between a normal cycle and a transcritical one, is that in the latter liquid forms after the throttling device, while in the former cycle liquid is present already before of it.

RGover
21-07-2008, 04:05 PM
Thanks all is becoming clear.