Alternatives to HCFCs in the Refrigeration and Air Conditioning Sector 69 S ection 02 2.8.1 Results obtained for the refrfrigeraration circuit operarating at medium temperaraturure Nr . crt E quipment Curr ent - R 22 Proposed – R 404A Result after retrofit 1 Evaporators – refrigerating rooms R ollerTo = -8oCDT = 8oCQo = 2,17KW R ollerTo = -8oCDT = 8oCQo = 2,26KW Q o R 404A= +4% 2 Evaporators – refrigeration cabinets Asim Roller DHN 602LTo = -7oCDT = 8oCQo = 4,50KW To = -7oCDT = 8oCQo = 4,68KW Q o R 404A= +4% 3 G roup of compressors 4 x Copeland Discus, D3DCDC4 – 1000 each To = - 12oCTc = + 45oCT subcooling = 3oCQo = 18KW/bucPel = 7,16KW/bucCOP = 2,51 4 x Copeland Discus, D3DCDC4 – 1000 each To = - 12oCTc = + 45oCT subcooling = 3oCQo = 19,1KW/bucPel = 8,0KW/bucCOP = 2,39 Q o grup R 404A = +6%Pel grup R 404A = +12% 4 Condensers 1 buc - 2 x 3 fansAsim Guntner GVVGVVGVV 050.1C / 2 x 3 LWLWE Tc = + 45oCText = + 35oC 1 buc - 2 x 3 fansAsim Guntner GVVGVVGVV 050.1C / 2 x 3 LWLWE Tc = + 45oCText = + 35oC Q c R 404A = -2% 5 R equired refrigeration power / circuit Qo required circuit = 65,42KW Qo required circuit = 65,42KW Q o required circuit /Qo grup R 404A = 65,42/76,4 = 86% 6 R equired condensing power / circuit Qc required circuit = 86%x 1.02 x 108,4KW = 95KW S afety factor (R 404A) = 100,6 / 95KW = 1.059% (+6%) C onclusions for the medium temperarature stage: Existing equipment parts are, from a mechanical point of view, completely functional with the R-404A refrigerant, provided that the technician follows the proper cleaning procedures, oil changes, filters, settings on the mechanical safety and control elements. The air cooled condenser may be used in the installation, with R-404A, up to temperatures of the external air (coil inlet) at most equal to +36oC, and only in case all fans are functional, and the surface of the coil is maintained under normal cleaning conditions.