cascade systems -80

[cameron.e]

howzt guys this is my first time on your site as a registerd member and iam looking forward to being able to share my experiance with yous @ being able to gleam from your experiance.I am very intrested in cascade systems@ will really apreshiate it if one of yous could help me out on with some info on it as i only work on commercial refrigeration@ a\c

[lana]

Hi cameron,

In order to reach -80°C the first problem is the refrigerant. As you know the lower the temperature , the lower the pressure is. So we have to use a refrigerant which has high pressure at low temperatures. One of these refrigerant is R23.
Now another problem is the condensing pressure for R23, which will be too high at say 40°C condensing temperature. To decrease the condensing pressure we have to use another refrigeration cycle which would maintain the condensing pressure around say 5°C.
Therefore, we have two completely different cycles with two different refrigerants but with one heat exchanger in common. This heat exchanger is the evaporator for R22 and condenser for R23.
I attach a simple drawing for you.
Hope this helps a little.
Cheers