A Ship Refrigerator Condenser Fails

A large naval supply ship operated multiple perishable food storage chambers chilled by a refrigeration system which used 3 sea water cooled condensers. The condensers were packed with 90/10 copper-nickel tubes. Within 6 weeks of leaving port after a refit and installation of the new sea water cooled condensers, the copper-nickel tubes pinholed and leaked sea water into the chiller system. The root cause was found to be inadequate conditioning of the 90/10 copper-nickel tubes, polluted sea water, silt deposition in the tubes during stagnant periods and turbulent flow during operations. It was recommended to install properly conditioned 90/10 copper-nickel tubes, control the water flow within properly set limits and dose polluted water to stop erosion-corrosion of the tubes.