The dry-cargo motorships of the Poltava class, designed for the transportation of general and refrigerated cargo, incorporate a refrigeration system based on direct evaporation for the cooling of extensive spaces. The Poltava, the first ship in this series, has a displacement of 15,630 tons and it contains five general cargo holds as well as one refrigerated hold with a useful space of 300 cubic meters which makes possible the transportation of 100-135 tons of perishable freight. The freon piping system in the refrigeration hold contains no distribution devices other than a header on the liquid side. The batteries measure 7 square meters in surface area each and are aligned in two groups of six batteries each. The VO-16 air coolers are of the finned type with a cooling surface of 16 square meters each. The batteries and air coolers are installed on the bulkheads of the hold. Each parallel line is provided with a TRV-7 automatic valve. The basic unit is designed to assure and maintain specified temperatures of plus 2 degrees C and -12 degrees C regardless of the outside temperature of the atmosphere. Operating trials showed that at plus 2 degrees C the evaporation temperature in some groups of heat exchangers was -24 degrees C and in others, plus 17 deg C; this discrepancy was traced to the difference in hydraulic drag between the parallel lines. This resulted in a nonuniform distribution of freon within each line, reducing by 30-40 percent the amount of freon in the system and causing the temperature of freon at the compressor outlet to rise to as high as 118 degrees C, thus reducing the overall reliability of the refrigerating system. Clearly the distributing header alone could not assure a uniform distribution of freon within the highly ramified piping system installed in the refrigeration hold, and hence special distributing devices are needed. Devices of this kind have already been developed by D. G. Zamkov at the TsNIIMF--(Central Scientific Research Institute of the Maritime Fleet) and currently they are undergoing tests with real heat transfer agents.

  • Corporate Authors:


    Leningrad,   USSR 
  • Authors:
    • Tretyukhin, A A
  • Publication Date: 1967

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Filing Info

  • Accession Number: 00015003
  • Record Type: Publication
  • Source Agency: Joint Publications Research Service
  • Files: TRIS
  • Created Date: May 7 1971 12:00AM