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Mass flow rate is defined by the limit [3] [4] ˙ = =, i.e., the flow of mass through a surface per time .. The overdot on ˙ is Newton's notation for a time derivative.Since mass is a scalar quantity, the mass flow rate (the time derivative of mass) is also a scalar quantity.
Worldwide production of R-22 in 2008 was about 800 Gg per year, up from about 450 Gg per year in 1998, with most production in developing countries. [2] R-22 use is being phased out in developing countries, where it is largely used for air conditioning applications. R-22 is prepared from chloroform: HCCl 3 + 2 HF → HCF 2 Cl + 2 HCl
Chlorodifluoromethane (R-22 or HCFC-22), a type of Freon. [9] [10] Dichlorodifluoromethane (R-12 or CFC-12), the most commonly used Freon brand refrigerant prior to its ban in many countries in 1996 and total ban in 2010. 1,1,1,2-Tetrafluoroethane (R-134a or HFC-134a), one of the main replacements for the formerly widespread R-12.
Refrigerant concentration limit / immediately dangerous to life or health in parts per million (volume per volume) and grams per cubic meter Molecular mass in atomic mass units Normal boiling points for pure substances, bubble and dew points for zeotropic blends, or normal boiling point and azeotropic temperature for the azeotropic blends, at ...
From 1930 to 1935, they developed dichlorodifluoromethane (CCl 2 F 2 or R12), trichlorofluoromethane (CCl 3 F or R11), chlorodifluoromethane (CHClF 2 or R22), trichlorotrifluoroethane (CCl 2 FCClF 2 or R113), and dichlorotetrafluoroethane (CClF 2 CClF 2 or R114), through Kinetic Chemicals which was a joint venture between DuPont and General Motors.
R-410A is a refrigerant fluid used in air conditioning and heat pump applications. It is a zeotropic but near-azeotropic mixture of difluoromethane (CH 2 F 2, called R-32) and pentafluoroethane (CHF 2 CF 3, called R-125). R-410A is sold under the trademarked names AZ-20, EcoFluor R410, Forane 410A, Genetron R410A, Puron, and Suva 410A.
R-407C is a mixture of hydrofluorocarbons used as a refrigerant. It is a zeotropic blend of difluoromethane (R-32), pentafluoroethane (R-125), and 1,1,1,2-tetrafluoroethane (R-134a). Difluoromethane serves to provide the heat capacity, pentafluoroethane decreases flammability, tetrafluoroethane reduces pressure. [ 1 ]
A representative pressure–volume diagram for a refrigeration cycle. Vapour-compression refrigeration or vapor-compression refrigeration system (VCRS), [1] in which the refrigerant undergoes phase changes, is one of the many refrigeration cycles and is the most widely used method for air conditioning of buildings and automobiles.