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Refrigeration presentation

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Refrigeration presentation

  1. 1. Ammonia RefrigerationBy Matt G. & Hamish B.
  2. 2. AmmoniaDiscovered centuries ago, Ammonia’s uses areplentiful.Colourless, but omits a pungent odour hard toignore.Combined with specific materials in chemicalssuch as bleach to form a highly toxic ChlorineGas.
  3. 3. Ammonia inRefrigerationWith an Ozone Depletion Potential (ODP) of ZERO,Ammonia is a practical and efficient refrigerantprimarily used in commercial applications.Ammonia refrigeration systems usually workunder large tonnages.The following are some examples of someapplications one would find in a commerciallyoperated, Ammonia-based system:
  4. 4. Evaporative Condenser • Water is cooled by the evaporative cooling and rejects the heat into the atmosphere. • Condenses the high-pressure, high-temp. vapour by spraying water over the tubes. Fans pulls the ambient air over the coils to help assist in the condensing process. • The ‘evaporation’ comes from the heat being absorbed by the water being sprayed over the coils. The resulting vapour is released, disposing heat from the system. • As the water is evaporated it is replaced with a makeup system using a float.
  5. 5. Evaporative Condenser(Cont.) • In prevention of mineral deposits, as the water’s minerals build up during evaporation, the condensate needs to be able to escape the system and be replaced with fresh water. • Use wet-bulb temperature to drive the condensation process. • Approx. 3 gal/min of water is evaporated for every 100-tons of refrigerant.
  6. 6. MYCOM ReciprocatingCompressorModel: N6B6 Cylinder480 V; 125 HP; Single StageBelt DrivenWith a compression-ratio of 4.64:1Sweet.
  7. 7. Reciprocating Comp.(Cont.)• Gas tested @ 313 PSIG, 130 F (high side) and 185 PSIG, 96 F (low side).• Water tested at 470 PSIG (high side), and 470 PSIG (low side).• Running pressures – High side @ 151 PSIG. Low side @ 21 PSIG.• The Compressor is considered the heart of the refrigeration system. A compressor turns low-pressure, low-temperature vapour into high-pressure, high-temperature vapour, which is then sent out to the Condenser.• This compressor has water-cooled head gaskets to keep it from overheating.• In some systems (like ice rinks) the excess heat transfers to the coolant - such as ‘Glycol’ - to heat the surfaces underneath the ice.
  8. 8. Brine Chiller(Abbotsford Arena) Used to lower thetemperatures of Calcium Chloride to be used tofreeze the Ice for the hockey rink.Calcium Chloride is used because it has agreater heat-transfer-coefficient than Glycol.
  9. 9. Brine Chiller (Cont.)• ‘Shell-and-Coil’ are used when specific temperature ranges need to be maintained.• Abbotsford Arena’s Calcium Chloride was running at 27% by weight which becomes crystallized at -22 F, and has a PG of 1.25• The Brine is sent from, and circulated through by pumps.• The Brine is chilled by the evaporative refrigerant in the flooded evaporator containing the Brine Tubes.• Calcium chloride has a S.G. of 1.3. The PH levels should be above 7.• The Brine chiller has an electric heater which will heat the calcium chloride when it is in need of a quick defrost of the ice rink’s surface.
  10. 10. Ammonia. Not Bad.As there are plenty of logical uses for NH3(excluding its ingestion), there are many uses for itin the Refrigeration industry. Thanks for watching“This is horse-shit.” -Matt Matthews