New ammonia refrigeration plant

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New ammonia refrigeration plant

  1. 1. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 Franc Kosi, P.E. The Society for Air-Conditioning, Heating and Refrigeration (KGH) Belgrade, Serbia CASE STUDY: A NEW REFRIGERATION PLANT BASED ON AMMONIA WITH SECONDARY FLUIDS LOOPS 1
  2. 2. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 DESCRIPTION OF ASSIGNMENT To design refrigeration system for an meat industry factory , capacity of about 7.000 chicken per hour (or 105.000 a day). The product are frozen meat pieces, boiled and dried sausages and ham product. The total refrigerated area (two levels) is approximately of 21.250 m2; it comprises 49 cold rooms and production spaces, a quick freezing tunnel, four freezing plate heat exchagers and tunnel for precooling of chicken meat before processing. 2
  3. 3. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 SITE INFORMATION The factory is situated about 60 km to the south from Belgrade. The design ouside dry and wet bulb air temperature are +35°C and +24°C, respectively. 3
  4. 4. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 THE SYSTEM: The refrigeration system includes central refrigeration unit based on ammonia, and seven sub-systems with water solution of propylene-glycol as a secondary refrigerant. All of the ammonia evaporators: liquid overfeed, circulation numbers 3 to 6 high system efficiency and reduced operating expenses; the evaporator surface is used efficiently and the compressors are protected; central unit (CP, PV, CP) are located in the machinery room; thus, they are under operator surveillance or computer monitoring. 4
  5. 5. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 AMMONIA AS A REFRIGERANT Ammonia has greatest application as a refrigerant in industrial settings, primarily in the food processing and food distribution sectors (also in the petrochemical and even pharmaceutical sectors). Ammonia has superior thermodynamic properties and ammonia refrigeration systems are more efficient (3-10%) than most traditional and newer refrigerants in a wide range of evaporating and condensing temperatures (+10 to –45° C); Generally speaking, ammonia refrigeration systems cost 10-20% less to install than systems using alternative industrial refrigerants. zero ODP, zero GWP, low TEWI; no cumulative effects on the environment; very limited (a few days) atmospheric lifetime (it is considered to be “biodegradable.”) self-alarming pungent odor! even the slightest traces of ammonia in the air can be easy detected. 5
  6. 6. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011FLAMMABILITY of AMMONIAAmmonia is difficult to ignite and exhibits a narrow range of flammability (it isflammable only at high concentrations and under extremely limited conditions).Because ammonia will not sustain a flame on its own, ignition of ammonia vaporrequires an uninterrupted external flame source.Ammonias burning velocity, at a maximum of 8 cm/s, is substantially lower than otherflammable refrigerants, and is not high enough to create an explosion. For thesereasons, ammonia explosions are rare.Properly designed ammonia refrigeration systems that are well ventilated and free ofopen flames or ignition sources mitigate against potential explosion. 6
  7. 7. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 WHY PROPYLEN GLYCOL (as a secondary fluid)? Cost of maintaining: low; Bio degradability in water: good, fluid is completely water soluble; Toxicity: medium (based on mono propylene glycol and corrosion inhibitors); Flash point: 420° C; Operational temperature: –30°to 50° C; Fluid is suitable for mixed metal systems; Thermophysical properties: poor! 7
  8. 8. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 REFRIGERATION LOAD Evaporator Temperature of Refrigeration Nr. Refrigerant Temperature of the Consumer Secondary Fluid Capacity Primary System / / °C °C kW / freezing tunnel, plate 1. ammonia -42 - 682.0 heat exchangers 2. ammonia -33 - 204.2 frozen food storage 3. ammonia -10 - 847.0 technology equipment cooling chambers (25) 4. propylene-glycol, 40% -16 -12/-8 1361.8 at -5 to +0°C cooling chambers (24) 5. propylene-glycol, 25% -10 -5/-1 1496.2 at +2 to +8°C 6. propylene-glycol, 25% -10 +7/12 451.7 air handling units propylene-glycol, 25% - -12/-8 7. “ice water” (tertiary -16 34.3 technology equipment +0.5/+5.5 refrigerant ) 8
  9. 9. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 9
  10. 10. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 10
  11. 11. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 SCREW COMPRESSOR UNITS Installed Working Swept volume Refrigeration Nr. Swept volume electric condititons (calculated) capacity power / tO/ tC, °C m3/h m3/h kW kW CP-1 2300,0 379,3 132 -42/-10 4157 CP-2 2300,0 379,3 132 CP-3 -33/-10 786 846,5 231,2 55 CP-4 1486,0 830,3 315 -16/+35 2391 CP-5 1126,1 613,6 250 CP-6 2311,6 1481,8 450 CP-7 -10/+35 6697 2311,6 1481,8 450 CP-8 2311,6 1481,8 450 Total: 2.234 11
  12. 12. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 TABLE T-4. EVAPORATIVE CONDENSERS Working condititons Number of Make-up Installed electric Nr. Capacity condensers Water Flow power TDB/TWB / kW / m3/h kW 1. +35/+24 1.500 5 2.62x5=13.1 5x42.0=210 2. +35/+24 2.000 1 3.6 51.0 Total: 9.500 / 16.9 261.0 12
  13. 13. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 PRESSURE VESSELS Temperature of Volume of Mass of Nr. Type of Vessel Dimensions Ammonia Amonia Amonia - °C mm m3 kg Low-Pressure Suction 1. -42 Φ1300x5000 1.66 1.150 Accumulator Low-Pressure Suction 2. -33 Φ800x2600 0.33 225 Accumulator High-Pressure Suction 3. -16 Φ1200x4000 1.15 605 Accumulator High-Pressure Suction 4. -10 Φ1200x3250 0.92 600 Accumulator High-Pressure Suction 5. Accumulator/Intercooler and -10 Φ1400x5000 1.95 1260 Subcooler High-Pressure Suction 6. -10 Φ800x2500 0.32 205 Accumulator 7. Thermosiphon Accumulator +35 0.2604x20.000 0.53 310 8. High-Pressure Receiver +35 Φ1000x3500 1.37 805 Total: 5.160 13
  14. 14. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 BENEFITS: The amount of ammonia used in the system is relatively high. One of the reason is two- stage compression. However, ammonia system components are located just close to the compressor room; thus there is not ammonia in the production and storage units; The refrigeration system inludes the subsystem for using the waste heat (i.e. heat extracted through compressor oil cooling); heat of cooling is used for sanitary water heating; The working fluid is an 40% water solution of propylene-glycol; The total heat power of heating is as 802.9 kW ; Energy efficiency of the refrigeration plant could be additionaly increassed by using a certain part of condenastion heat for water heating purposses. 14
  15. 15. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 Ammonia refrigeration safety features address minimizing the refrigerant charge, suitable ventilation, ammonia absorbing systems, restricting the use of ammonia in public locations, and promoting indirect cooling systems With regulations properly tailored to ammonia refrigeration systems, the application of ammonia refrigeration systems will probably become more widespread. 15
  16. 16. ROUNDTABLE ON CLIMATE & OZONE-FRIENDLY TECHNOLOGIES Belgrade, May 10, 2011 THANK YOU! 16

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