Born to Freeze

  There are several applications where the condensing temperature needs to reach extremely high values and “traditional” refrigerants are outside of the application envelope of any kind of compressor technology. In the past R114 used to be the preferred choice for this kind of systems, nowadays several replacements with lower GWP values are under evaluation. R245fa seems to be one of the most promising gas to replace the “old” R114. R245fa (GWP 1030) is a non-flammable refrigerant used for ORC cycle for power generation and suitable also as refrigerant for chillers with large centrifugal compressor. Having a critical temperature of 154°C, this gas seems to be a reasonable choice for high ambient temperature applications. One possible configuration to exceed 100°C condensing temperature could be a cascade system with R134a in the MT stage and R245fa in the HT stage .  Thanks to the robust design and reliability of DORIN compressor s, this configuration has been tes...

      CO 2 comes as the natural choice as refrigerant for various applications, from the food retail applications to the industrial refrigeration .  This trend is confirmed worldwide, and Africa follows rapidly the latest trends in refrigeration. The leading country for installations in Africa is so far South Africa both in subcritical and in transcritical installation where, thanks to the excellent design of HC Heat-Exchangers and the Dorin CD range, CO2 is able to perform efficiently even at high ambient temperature. HC Heat-Exchangers chooses Dorin compressors to cover the retail supermarket business helping the transition to natural refrigerants while improving the efficiency of the system compared to the equivalent old HFC system. Giving 116kW MT @ -10°C and 48kW LT @ -35°C HC Kronos is installed in several domestic supermarkets, granting excellent performance in terms of COP and reliability of the system. The system is design with CD transcritical 4...

    The installation of air-cooled condensing unit , although simple, requires some precautions. The condensing unit requires correct positioning for a good ventilation which avoids the recirculation of air which can cause condensation problems. Furthermore, the correct sizing of the liquid and suction pipes is important for the proper functioning of the system. It is important to avoid the backflow of lubricant and liquid refrigerant to the compressor when the condensing unit stops.   It is necessary to provide suitable siphons at the base of each vertical section with an upward direction of the flow; if the discharge line is of high vertical development which connects the compressor to the remote condenser, that is installed at a higher altitude, it must be equipped with an adequate number of siphons. Even the suction line, the pipe that connects the evaporator to the compressor suction, must meet certain requirements such as: • favor the return of oil to th...