Refrigeracion Y Aire Acondicionado
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Publicado: 3 de diciembre de 2012
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CHAPTER 20
THERMOPHYSICAL PROPERTIES OF REFRIGERANTS
T
HIS chapter presents data for the thermodynamic and transport
properties of refrigerants, arranged for the occasional user. The
refrigerants have a thermodynamic property chart on pressureenthalpy coordinates with an abbreviated set of tabular data for the
saturated liquid and vapor on the facingpage. In addition, tabular
data in the superheated vapor region are given for R-134a to assist
students working on compression cycle examples.
For each cryogenic fluid, a second table of properties is provided
for the vapor at a pressure of one standard atmosphere; these data
are needed when such gases are used in heat transfer or purge gas
applications. For zeotropic blends, including R-729(air), tables are
incremented in pressure, with properties given for the liquid on the
bubble line and vapor on the dew line. This arrangement is used
because pressure is more commonly measured in the field while
servicing equipment; it also highlights the difference between the
bubble and dew-point temperatures (the “temperature glide” experienced with blends).
Most of the CFC refrigerantshave been deleted. Tables for R-11,
R-13, R-113, R-114, R-141b, R-142b, R-500, R-502, R-503, and
R-720 (neon) may be found in the 1997 ASHRAE Handbook—
Fundamentals. R-12 has been retained to assist in making comparisons. Revised formulations have been used for many of the refrigerants; these conform to international standards, where applicable.
Thermodynamic properties of R-12, R-22, R-32,R-123, R-125, R134a, R-143a, R-152a, R-717 (ammonia), and R-744 (carbon dioxide) and refrigerant blends R-404A, R-407C, R-410A, and R-507
conform to ISO/DIS Draft Standard 17584, Refrigerant Properties.
Reference states used for most of the refrigerants correspond to the
international convention of 200 kJ/kg for enthalpy and 1 kJ/(kg·K)
for entropy, both for saturated liquid at 0°C. Exceptionsare water and
fluids with very low critical temperatures (e.g., ethylene, cryogens).
These data are intended to help engineers make preliminary
comparisons among unfamiliar fluids. For greater detail and a
wider range of data, see the sources in the References.
Refrigerant
Refrigerant
Page
Halocarbon Refrigerants
Page
R-718 (water/steam) . . . . . . . . . . . . . . . . . . .. . . . . . . . . 20.36
Methane Series
R-744 (carbon dioxide) . . . . . . . . . . . . . . . . . . . . . . . . . . 20.38
R-12 (dichlorodifluoromethane). . . . . . . . . . . . . . . . . . .
20.2
R-22 (chlorodifluoromethane) . . . . . . . . . . . . . . . . . . . .
20.4
R-23 (trifluoromethane) . . . . . . . . . . . . . . . . . . . . . . . . .
20.6
R-32 (difluoromethane) . .. . . . . . . . . . . . . . . . . . . . . . .
20.8
Ethane Series
Hydrocarbon Refrigerants
R-50 (methane) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.40
R-170 (ethane). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.42
R-290 (propane) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.44
R-123(2,2-dichloro-1,1,1-trifluoroethane) . . . . . . . . . . 20.10
R-600 (n-butane) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.46
R-124 (2-chloro-1,1,1,2-tetrafluoroethane) . . . . . . . . . . 20.12
R-600a (isobutane) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.48
R-125 (pentafluoroethane) . . . . . . . . . . . . . . . . . . . . . . . 20.14
R-1150 (ethylene) . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . 20.50
R-134a (1,1,1,2-tetrafluoroethane) . . . . . . . . . . . . . . . . . 20.16
R-1270 (propylene) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.52
R-143a (1,1,1-trifluoroethane) . . . . . . . . . . . . . . . . . . . . 20.20
R-152a (1,1-difluoroethane) . . . . . . . . . . . . . . . . . . . . . . 20.22
Propane Series
Cryogenic...
CHAPTER 20
THERMOPHYSICAL PROPERTIES OF REFRIGERANTS
T
HIS chapter presents data for the thermodynamic and transport
properties of refrigerants, arranged for the occasional user. The
refrigerants have a thermodynamic property chart on pressureenthalpy coordinates with an abbreviated set of tabular data for the
saturated liquid and vapor on the facingpage. In addition, tabular
data in the superheated vapor region are given for R-134a to assist
students working on compression cycle examples.
For each cryogenic fluid, a second table of properties is provided
for the vapor at a pressure of one standard atmosphere; these data
are needed when such gases are used in heat transfer or purge gas
applications. For zeotropic blends, including R-729(air), tables are
incremented in pressure, with properties given for the liquid on the
bubble line and vapor on the dew line. This arrangement is used
because pressure is more commonly measured in the field while
servicing equipment; it also highlights the difference between the
bubble and dew-point temperatures (the “temperature glide” experienced with blends).
Most of the CFC refrigerantshave been deleted. Tables for R-11,
R-13, R-113, R-114, R-141b, R-142b, R-500, R-502, R-503, and
R-720 (neon) may be found in the 1997 ASHRAE Handbook—
Fundamentals. R-12 has been retained to assist in making comparisons. Revised formulations have been used for many of the refrigerants; these conform to international standards, where applicable.
Thermodynamic properties of R-12, R-22, R-32,R-123, R-125, R134a, R-143a, R-152a, R-717 (ammonia), and R-744 (carbon dioxide) and refrigerant blends R-404A, R-407C, R-410A, and R-507
conform to ISO/DIS Draft Standard 17584, Refrigerant Properties.
Reference states used for most of the refrigerants correspond to the
international convention of 200 kJ/kg for enthalpy and 1 kJ/(kg·K)
for entropy, both for saturated liquid at 0°C. Exceptionsare water and
fluids with very low critical temperatures (e.g., ethylene, cryogens).
These data are intended to help engineers make preliminary
comparisons among unfamiliar fluids. For greater detail and a
wider range of data, see the sources in the References.
Refrigerant
Refrigerant
Page
Halocarbon Refrigerants
Page
R-718 (water/steam) . . . . . . . . . . . . . . . . . . .. . . . . . . . . 20.36
Methane Series
R-744 (carbon dioxide) . . . . . . . . . . . . . . . . . . . . . . . . . . 20.38
R-12 (dichlorodifluoromethane). . . . . . . . . . . . . . . . . . .
20.2
R-22 (chlorodifluoromethane) . . . . . . . . . . . . . . . . . . . .
20.4
R-23 (trifluoromethane) . . . . . . . . . . . . . . . . . . . . . . . . .
20.6
R-32 (difluoromethane) . .. . . . . . . . . . . . . . . . . . . . . . .
20.8
Ethane Series
Hydrocarbon Refrigerants
R-50 (methane) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.40
R-170 (ethane). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.42
R-290 (propane) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.44
R-123(2,2-dichloro-1,1,1-trifluoroethane) . . . . . . . . . . 20.10
R-600 (n-butane) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.46
R-124 (2-chloro-1,1,1,2-tetrafluoroethane) . . . . . . . . . . 20.12
R-600a (isobutane) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.48
R-125 (pentafluoroethane) . . . . . . . . . . . . . . . . . . . . . . . 20.14
R-1150 (ethylene) . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . 20.50
R-134a (1,1,1,2-tetrafluoroethane) . . . . . . . . . . . . . . . . . 20.16
R-1270 (propylene) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.52
R-143a (1,1,1-trifluoroethane) . . . . . . . . . . . . . . . . . . . . 20.20
R-152a (1,1-difluoroethane) . . . . . . . . . . . . . . . . . . . . . . 20.22
Propane Series
Cryogenic...
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