Thermodynamic properties of R22 REPORT THERMODYNAMIC PROPERTY TABLES OF REFRIGERANT R22 Submitted to DR. T.P. ASHOK BABU Professor, Department of Mechanical Engineering National Institute of Technology, Karnataka Surathkal. Submitted by, Nagendra 10TH09F 1 st Sem, M.Tech Thermal Engineering Department of Mechanical Engineering ( M.Tech) Page 1
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Thermodynamic properties of R22
REPORT
THERMODYNAMIC PROPERTY TABLES OF REFRIGERANT R22
Submitted to
DR. T.P. ASHOK BABUProfessor,
Department of Mechanical EngineeringNational Institute of Technology, Karnataka
Surathkal.
Submitted by,
Nagendra 10TH09F
1st Sem, M.Tech
Thermal Engineering
Department of Mechanical Engineering ( M.Tech) Page 1
Thermodynamic properties of R22
ABSTRACT:
The report consists of the development of thermodynamic properties of refrigerant 22.
The equations for the development of the refrigerant properties are taken from the technical
paper and ASHRAE data hand book. Critical temperature and critical pressure are taken from
the ASHRAE data hand book. Manual calculations are done and the program is developed
using Microsoft Excel. The enthalpy of saturated liquid at 00c is taken from the ASHRAE
data hand book and is taken as the reference. The graphs of (Psat v/s Vg), (Psat v/s hg),
(Psat v/s Tsat), (Psat v/s Sg) are plotted using Microsoft excel. The graphs for the calculated
values is then compared with the graphs taken from the ASHRAE data hand book.
Department of Mechanical Engineering ( M.Tech) Page 2
Department of Mechanical Engineering ( M.Tech) Page 3
Thermodynamic properties of R22
1. INTRODUCTION
A refrigerant is a substance used in a heat cycle usually including, for enhanced
efficiency, a reversible phase change from a gas to a liquid. Traditionally, fluorocarbons,
especially chlorofluorocarbons were used as refrigerants, but they are being phased out
because of their ozone depletion effects. Other common refrigerants used in various
applications are ammonia sulphur dioxide, and non-halogenated hydrocarbons such as
methane.
There are different types of refrigerants namely
In-Organic Refrigerants Designation
a)Water (H20) R 718
b) Ammonia (NH 3) R717
c) Carbon Dioxide ( CO₂) R744
d) Nitrous Oxide (N2O) R764
.Organic Refrigerants
a) Monofluoro-Tetrachloro Methane(CFCl3¿ R11
b) Difluoro-Dichloro Methane (CF₂Cl₂) R12
c) Difluoro-Monochloro Methane (CHF₂Cl) R22
Refrigerant22(CHClF₂) is commonly used in reciprocating compressors in window
type air conditioners and large units such as package units and central air conditioning
plants.It is also used for low temperature refrigeration applications, cold storages,food
freezing and storage etc, with reciprocating and often with centrifugal compressors in very
large capacity air conditioning plant
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Thermodynamic properties of R22
2. GENERAL PROPERTIES OF REFRIGERANT 22
From ASHRAE table the following data was obtained
TABLE 1: General properties of Refrigerant 22.
Designation R22
Chemical name Difluro-Monochloro Methane
Chemcial formula CHCLF2
Molecular Weight 86.48 Kg/mole
Normal Boiling point -40.8 0C
Critical Temparature 369.14 K
Critical Pressure 4990 Kpa
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Thermodynamic properties of R22
3. NOTATIONS
Psat Saturation pressure
Tsat Saturation temperature
ρ density
vf specific volume of liquid
vg specific volume of vapour
Cf specific heat of liquid
Cpo constant pressure specific heat at zero pressure
Cvo constant volume specific heat at zero pressure
R gas constant
Ru Universal gas constant (8314.3 J/kmol K)
Pc Critical pressure
Tc Critical Temperature
H enthalpy
U internal energy
S entropy
ω accentric factor
T r reduced temperature
M Molecular weight
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Thermodynamic properties of R22
4. EXPERIMENTAL DATA / CORRELATIONS REQUIRED TO ESTABLISH
THERMODYNAMIC PROPERTIES OF REFRIGERANTS
The following minimum experimental data / correlations are required to establish the Thermodynamic properties of Refrigerants.
Psat versus Tsat or Tsat versus Psat. P-v-T data or equation of state for gaseous phase. Liquid density ρ or specific volume vf. Liquid specific heat Cf. Zero-pressure constant pressure specific heat Cpo or constant volume specific
heat Cvo (=Cpo – R) of the gaseous phase.
P-H diagram
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