REFRIGERATION Refrigeration ................................................................................................................................................. 2 What it is ................................................................................................................................................... 2 Ductless problem................................................................................................................................... 4 Humidity problem ................................................................................................................................. 5 Temperature-range problem .................................................................................................................. 6 Heat-flow-rate problem ......................................................................................................................... 6 Noise problem ....................................................................................................................................... 7 What it is not ............................................................................................................................................. 7 What it is for ............................................................................................................................................. 7 History ....................................................................................................................................................... 8 How it is done ......................................................................................................................................... 10 Refrigeration efficiency definition ...................................................................................................... 11 Refrigeration capacity ......................................................................................................................... 12 Vapour compression refrigeration ...................................................................................................... 13 Absorption refrigeration ...................................................................................................................... 14 Gas expansion refrigeration ................................................................................................................ 17 Thermoelectric refrigeration ............................................................................................................... 18 Evaporative cooling ............................................................................................................................ 19 Desiccants ........................................................................................................................................... 20 Domestic refrigerators......................................................................................................................... 21 Portable and non-electric refrigerators ................................................................................................ 22 Magnetic refrigeration......................................................................................................................... 22 Air conditioning .................................................................................................................................. 23 Components ............................................................................................................................................ 24 Compressors ........................................................................................................................................ 24 Vaporisers and condensers .................................................................................................................. 26 Throttling devices ............................................................................................................................... 26 Piping .................................................................................................................................................. 27 Fans ..................................................................................................................................................... 27 Defrosting............................................................................................................................................ 27 Refrigerant fluids .................................................................................................................................... 29 Desired properties ............................................................................................................................... 29 Types ................................................................................................................................................... 29 Substitutive refrigerants ...................................................................................................................... 31 Second refrigerants: glycols, brines and binary ice ............................................................................ 33 Refrigerant-leakage detection ............................................................................................................. 33 Ice making ............................................................................................................................................... 33 Refrigeration 1 Ice cubes .............................................................................................................................................. 34 Flake ice (chip ice) .............................................................................................................................. 35 Crushed ice .......................................................................................................................................... 36 Fluid ice (or liquid ice, or slurry ice, or binary ice) ............................................................................ 36 Ice rinks ............................................................................................................................................... 36 Artificial snow..................................................................................................................................... 38 Ice chest................................................................................................................................................... 39 Cryogenics .................................................................................................................................................. 39 Applicatons ............................................................................................................................................. 40 Cryocooling ............................................................................................................................................. 41 Dry ice ..................................................................................................................................................... 43 Gas liquefaction ...................................................................................................................................... 43 Liquefied natural gas (LNG) ............................................................................................................... 45 Superconductivity ................................................................................................................................... 46 Superfluidity. Helium anomaly ............................................................................................................... 48 Cold effects on living matter ....................................................................................................................... 48 Hypothermia............................................................................................................................................ 48 Frostbite .................................................................................................................................................. 49 Food preservation by refrigeration .......................................................................................................... 50 Food preservation ................................................................................................................................ 50 Food-preservation by refrigeration ..................................................................................................... 51 Problematic of food-preservation by refrigeration .............................................................................. 53 The cold chain ..................................................................................................................................... 54 Cryosurgery and cryopreservation .......................................................................................................... 55 Cold effects on materials............................................................................................................................. 55 Heat pumps ................................................................................................................................................. 56 Type of problems .......................................................................................................................................