TheChief
21-05-2013, 06:51 PM
Gentlemen,
This is my first post and by all means I am no refrigeration expert. I am the Chief engineer on a 72m Superyacht. I have been advised that we may be relocating to the Gulf.
Now here is my problem. Sea water temperatures in the Gulf have been known to reach temperatures of 39 degrees C. We have onboard an indirect expansion chilled water air conditioning system. This comprises of three 176kW Bitzer CSH 75 61 - 60Y compressors. The refrigerant fluid is 134a. The condenser is sea water cooled. The system specifications state that the maximum permissible sea water temperature is 32 degrees. Normal operating pressures are around LP 2 Bar and HP 10 Bar. My concern is that with the higher sea water temperatures my machines will trip on high pressure. I have tried to find a table or calculation to work out the boiling temperature of 134a at 10bar but I have had no success.
Does anyone have any suggestions? Perhaps a gas change or is there a good and efficient way to regulate the HP?
Like I said I am no expert so all opinions and advice is much appreciated.
This is my first post and by all means I am no refrigeration expert. I am the Chief engineer on a 72m Superyacht. I have been advised that we may be relocating to the Gulf.
Now here is my problem. Sea water temperatures in the Gulf have been known to reach temperatures of 39 degrees C. We have onboard an indirect expansion chilled water air conditioning system. This comprises of three 176kW Bitzer CSH 75 61 - 60Y compressors. The refrigerant fluid is 134a. The condenser is sea water cooled. The system specifications state that the maximum permissible sea water temperature is 32 degrees. Normal operating pressures are around LP 2 Bar and HP 10 Bar. My concern is that with the higher sea water temperatures my machines will trip on high pressure. I have tried to find a table or calculation to work out the boiling temperature of 134a at 10bar but I have had no success.
Does anyone have any suggestions? Perhaps a gas change or is there a good and efficient way to regulate the HP?
Like I said I am no expert so all opinions and advice is much appreciated.