Search results
Results from the WOW.Com Content Network
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 ...
This is a collection of temperature conversion formulas and comparisons among eight different temperature scales, several of which have long been obsolete.. Temperatures on scales that either do not share a numeric zero or are nonlinearly related cannot correctly be mathematically equated (related using the symbol =), and thus temperatures on different scales are more correctly described as ...
Thermodynamic data is usually presented as a table or chart of function values for one mole of a substance (or in the case of the steam tables, one kg). A thermodynamic datafile is a set of equation parameters from which the numerical data values can be calculated. Tables and datafiles are usually presented at a standard pressure of 1 bar or 1 ...
A refrigerant needs to have: a boiling point that is somewhat below the target temperature (although boiling point can be adjusted by adjusting the pressure appropriately), a high heat of vaporization, a moderate density in liquid form, a relatively high density in gaseous form (which can also be adjusted by setting pressure appropriately), and ...
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. Opteon halogenated olefins now replacing Freons in many applications.
Thanks to the low GWP value, it fulfils the requirements of EU regulation 517/2014 on refrigerants for new systems even without the certificate of exemption otherwise necessary. Systems using the refrigerant R-469A up to 3.6 kg filling quantity are exempt from the Leak test in accordance with EU regulation 517/2014.
Unlike CFCs used as refrigerants, trifluoroethane has no chlorine atoms and therefore is not ozone-depleting. Its high chemical stability and infra-red absorbency make it a potent greenhouse gas with a lifetime of about 50 years and a global warming potential of 4300, which are at the high end compared to many other commonly used HFC refrigerants.
A frigorific mixture may be used to obtain a liquid medium that has a reproducible temperature below ambient temperature. Such mixtures were used to calibrate thermometers. In chemistry a cooling bath may be used to control the temperature of a strongly exothermic reaction. A frigorific mixture may be used as an alternative to mechanical ...