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Rochester Institute of Technology
RIT Scholar Works
Articles
1975
Predicting the properties of mixtures of R22 and
R12 part I - Thermodynamic properties
Satish Kandlikar
C. Bijlani
S. Sukhatme
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Kandlikar, Satish; Bijlani, C.; and Sukhatme, S., "Predicting the properties of mixtures of R22 and R12 part I - Thermodynamic
properties" (1975). American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE),Accessed from
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NO. 2343
I
I
PREDICTING THE PROPERTIES OF NIXTURES Of R22 AND R12
PART I - THERMODYNAMIb PROPER 1DES ,
1
,,
.
S. G. KANDLIKAR
C. A.131.1LANI
Student Member ASHRAM
Astatine Member
S. P. SUKMATME
-
I
Although the advantages of Using mixture refrigerants are well known, they have
not often been used. One reason for this is the nonavailability of reliable ,
and readily useable information on their thermodynamic and transport properties.
Even the properties of the azeotropic, mixture R501 (75 percent R22 and 25 per-'
cent R12 by weight) are not-yet well established.
The purpose of this study is to compile and complement previous work on
the R22/R12 system and to present in one place reasonably reliable predictive ,
methods and tabulated values for determining the properties of mixtures of R22'
and R12 of any concentration.
This study is divided into two parts: Part I deals with thermodynamic
properties and Part II with transport properties. Those thermodynamic proper-1
ties are as follows:
7 7
-
;
1. Equilibrium pressure and temperature
2. Equilibrium liquid and vapor phase compositions
3 . b e all y of saturated liquid
'4. Specific volume of saturated vapor
5. Enthalpy of saturated liquid
6. Enthalpy of saturated vapor
7. Specific heat of liquid at saturation
8. Specific heat of vapor at saturation
9. Entropy of saturated liquid
10. Entropy of saturated vapor.
--
PREVIOUS WORK
Bijlani (1 and 2) has developed procedures for the prediction of some thermoi dynamic properties of the system R22/R12, and Quraishi (3) has recommended an
equation of state for the azeotropic mixture R501. Experimental phase equilibrium data are reported by Loeffler (4), but the recent data by Kriebel (5) seems
to be more accurate since it was checked for thermodynamic consistency. The
heat of mixing and the latent heat of vaporization have been measured at-60.07F
i by Neilson and White (6).
DATA ON INDIVIDUAL REFRIGERANTS
To predict mixture properties, data on individual refrigerants are required.
These are taken from Ref. 5, 7,8 and 9. Whenever the data are available in the
form of equations, they are directly used. In the case of tabulated data, suitable equations are fitted over the desired temperature range.
Equation of State
Bijlani (1) has shown that the short Martin-Hou equation can represent the
P-V-T data with great accuracy. This equation with all its terms has the form:
S.G. Kandliker, C.A. Bijlani, and S.P. dukhatme, Department of Mechanical
'Engineering, Indian Institute of Technology, Powai, Bombay 400076
The values of the constants for A22 and R12 as obtained by Bijlani (1) are
as follows: Constant
R22
R12
--
A2
-5.108894E+0
-3.714446E+0
82
3.202996E-3
2.229788E-3
C2
-3.641094E+1
-2.819800E+1
A3
1.495317E-1
7.089601E-2
83
-1.243149E-4
-4.475688E-5
A4
-3.058400E-3
-7.375492E-4
84
3.200155E-6
5.622223E-7
C4
3.043126E-2
1.467384E-2
b
3.128E-3
3.458E-3
k
-4.2
-5.0
Saturated Liquid Density
The correlations for saturated liquid density are taken from Ref '7 for R22
and from Ref 8 for P12.
Saturated Liquid Enthalpy
The saturated liquid enthalpy values for R22 ri ot for P12 arc taken from Ref
9 and arts fitted by the least squares method es eleventh and eighth order polynomial functions respectively of (1 419.67) over the temperature range 360 to
660 R. The average absolute deviations are less than 0.03 percent for R22 and
0.01 percent for R12. Thus:
H = E 11(I).(T -419.67) 1=1
n = 11 for R22
(2)
n = 8 for 812
in which the constants H(I) become:
Constant
822
R12
H(1)
2.5284399E-1
2.1058947L-1
H(2)
1.8028825E-4
5.4887343E-5
H(3)
3.4259758E-7
1.5382998E-7
11(4) -3.5256820E-9
- 3.6692264E-10
8(5) -1.2304273E-10
- 3.3681939E-12
2.1294720E-12
1.3294897E-13
H(6)
8.0806707E-15
- 7.2100676E-16
H(8) -3.7145822E-16
1.3565186E-18
H(7)
H(9)
2.9867823E-18
H(10) -1.0118069E-20
H(11) 1.2818978E-23
.
Saturated Liquid Specific Heat
;
In a similar manner, the satUrated liquid specific heat values at constant
preSsure for R22 and for R12 are taken from Ref 9 and are fitted by the least
squares method as a fourth order polynomial function of absolute temperature
over the range of 360 to 660 R. The calculated values agree with the original'
values to•the last-digit. Thus:
'
C
Pi
5
E
11.
C(1) p(' -1)
in which the constants C(i) become:
R22
Constant
R12
2.7861431E+0
'2.2021156E+0
C(2) -2.2971282E-2
-1.8404225E-2
C(1)
C(3)
7.7565845E-5 .
C(4) -1.1608676E-7
C(5)
6.5654243E-41 6.2756385E-5
-9.4173491E-8
5.2904772S-11
Ids ai ras H at Ca acit
The correlations for the ideal gas heat capacity at constant volume are
8 for R12.
taken from Ref 7 for R22 and from Ref
EVALUATION OF MIXTURE PROPERTIES
Equation of State
The Martin Hoe Equation (1q (1)) is also used to represent the P -V -T
relationship for mixtures. The constants of this equation are obtained by
suitably combining the constants for individual refrigerants. The combining
rules, suggested by Dijlani (1) and later modified by Quraishi (3) to agree with
the azeotropic mixtures R502 and R503, are believed to be valid for the binary
system R22/R12 and are used. These combining rules are
Constant A2:
.
(A2)m
•
1 , 2 -0.1X1 X (4a)
x1(A2)1 /2 + x (A )-2/2
2
2 2
Constant 132 :
(B2)
,
x (B2)1
m' 1( 13 2)1 + 2
.
Constant C2:
(4b)
Equilibrium Pressure and Temperature
.
Mixtures of refrigerants boil through a range of temperature at a given
pressure. Similarly the bubble point and dew point pressures for a given
temperature and concentration are different. These are obtained from the respective bubble point and de* point curves. For pure refrigerants, these two
curves can be represented by a single equation.
Vapor pressure data of pure refrigerants is well represented by Antoine's
`Equition:
lb(P) = A +
(5)
Bijlani (2) has used the same equation for representing the bubble point curve
for the system R22/R12 with the help of Loeffler's data The same procedure
will be followed, and the equilibrium data of pressure, temperature and concentration given by Kriebel in the temperature range 380 to 600 R will be used
to obtain the bubble point and dew point curves in the form of Eq (5).
Bubble Point Curves
ln (Pts)
A
BBL +
BB2
B
(6)
in (PD) '2 0" T-CD
(7)
Dew Point Curvet
DD2
the constants BB1, BB2, DD1, and DD2 are considered to be polynomial functions
of concentration:
6
BB1 =
E Bl(I) Y ( I -1)
(8a)
I=1
BB2 A
6
Iii
I =1
y(/-1) .
DD1
6
E Dl(I) YV(I -1 )
I=1
DD2
6t D2(I) YV (I-1)
/A1
(8b)
(9a)
(9b)
The constants CB and CD take values between 25 and 50 for pure refrigerants.
So, for mixtures over the entire range of concentration, this value is varied in
steps of unity, and the 24 constants in Eq (8) and (9) are evaluated by the .
least squares method. Then values of presaures calculated from &I - (6) and (7)
are compared with the original data and those values of CB and CD, which give
best agreement with the data over the entire range, are selected.
It was found that for the value CB - CD = 35, the average absolute deviations from the original data were minimum (0.421 percent for D.P. curve and
,0.527 percent for D.P. curve), With these values of CB and CD, the other con'stants are found to have the following Values:
B1(1) = 1.22095352E+1
D1(1) = 1.22097208E+1
81(2) = -1.22882463E+0 D1(2) = -5.28703810E-1
B1(3) = 6,21189084E+0'
D1(3) = ,6.90830461E+0
• - B1(4) = -1.01467610E+1,
:
-
-
D1(4) = -1.99669780E+1--
B1(5) = 6.91461772E+0
Dl(5) = 2.19836792E+1
B1(6) = -1.36151186E+0 D1(6) = -8:00690212E+0
82(1) = -3.84123014E+3 D2(1) = -3.84131226E+3
B 2 ( 2 ) = 1.11635983E+3
D2(2) = 4.45378468E+2
82(3) = -3.46853800E+3 ' 02(3) - -3.17706719E+3,
82(4) = 5.18083844E+3
D2(4) = 1.01448365E+4
82(5) = -3.46692800E+3 D2(5) = -1.17573616E+4
B2(6) = 6.79394878E+2
D2(6) = 4,38535765E+3
and
•
•
A
Equilibrium Vapor Phase Con:Position
The equilibrium vapor phase composition can he calculated by methods based
on thermodynamic considerations (e.g, Barker's (11) Method). HOwever, the procedure is usually quite cumbersome, and because Kriebel's experimental results
are available, a very simple method is deVeloped here.
For any given liquid mole fraction Of R22 and any given temperature, the
bubble point pressure is calculated from Eq (6). Using this pressure as the
dew point pressure and with the given temperature, the equilibrium vapor phase
;composition is obtained from Eq (7). This calculation is done by the Newton'Raphson Iterative Technique_ and presents no difficulties determining liquid
:mole fractions up to 0.1 of R22. Above this value (particularly at low temper-,
atures), two problems arise as illustrated in Fig. 1. Firstly, corresponding
to a given pressUre and temperature, there are apparently two vapor phase
compositions (points B and C). Secondly, the equilibrium vapor phase composi'tion often lies close to the minimum of the T,- YV curve, thus making the
Newton-Raphson Technique unsuitable. The first difficulty is resolved by
recognizing that the equilibrium vapor Phase composition and the given liquid.
,mole fraction must lie on the same side of the minimum value. Thus 'at these
compositions, the corresponding slölies of the T Y and T- YV cures should
have the same sign. In order to overcome the second difficulty, a search
:technique is used instead of the Newton-Raphson Technique. The temperature is
; calculated froM Eq (7) by varying the concentration in steps of 0.0005. The
'concentration yielding a temperature which agrees within 0.005 F of the given
'value is taken to be the eqUilibrium vapor phase comPosition.
I Density of Saturated Liquid Mixture
!
.
,
..,
.
The volume of mixing fOi* the binary liquid system R22/R12 as measured by
Loeffler (4) is very small, and neglecting it does not introduce an error
!.greater than 1.5 percent. Rlso the effect of small changes in pressure on
liquid density is negligibld. Thus, the saturated 3,ieni4 refriferent volume* I
at the system temPerature are additive, and the density of the saturated
liquid mixture is given by,
Specific Volume-of Saturated Vapor Mixture
Eq (1) is used to find the volume of the:saturated vapor. The. NeWt0P .Raphson ;terative:Zechnique.4.0 OMEaoyekfOr_this,purpose,„ .
Enthalpy of Saturated Liquid Mixture
The enthalpy of the liquid mixture is given by:
(where: H m i x is the enthalpy of mixing.
The enthalpy of mixing has been CalCulated by Bijlani (2) by step integrating Margule's Equation and adusting the constants to fit the data of
'Neilson and White (6). These equations are as follows:
I Enthalpy of Saturated Vapor Mixture
The variation of enthalpy of vapor with pressure and temperature is given
bvs
Substituting:
Substituting for P and fiksiv from Eq (1) and integrating Eq (20) between a
reference temperature and zero pressure to any given temperature T, pramsura P
'and voLume Vs
where: AEI, 8E1 ... are the conLtants in the individual refrigerant ideal gas
heat capacity correlations.
,
XX depends on the reference state. /n the present case, the enthalpy of
saturated pure liquid refrigerant at -40 F is taken to be zero. To reduce any
errors in the Eq (23), the enthalpy values are corrected at -60.07 F to agree
with the latent heat of vaporization data of Neilson and White (6). Thus:
where AL are the latent heat values in Dtuilb mole of Neilson and White. These
values are fitted by the least squares method as a fifth order polynomial
function of the mole fraction of R22.
Thugs
The constants A(I) become:
A(1) - 5.8298967E+3
A(2) 1.1 -3.8326504E+2
A(3) m -6.9372150E+2
A(4) • -5 1693059E+2
A(5)
.
9.9005677E+2
A(6) .., 5.0924091E+2
Specific Heat of Liquid Mixture at Saturation
Neglecting the effect of small changes in pressure and the variation of
lA temperature and pressure, the specific heat of
!the liquid mixture at saturation is given by: •
.heat
of Mixing with changes
'Specific Heat of Vapor Mixture at Saturation
•
Differentiating the expression for the enthalpy of saturated vapor mixture,
Eq (23), with respect to temperature at constant pressure, determines the
'specific heat at constant pressure of the, vapor mixture at saturation. Thus:
.
Entropy of Saturated Liquid Mixture
The entropy of the saturated liquid mixture is computed from the entropy
of the saturated vapor mixture and the enthalpy of vaporization. Thus at a
given pressure:
,where: Tav is the average of the dew point and bubble point temperatures,
;Entropy of Saturated Vapor Mixture
The change in entropy is given by:
YY depends on the reference state chosen. In this case also, the entropy
of the saturated pure liquid refrigerant at -40 F is taken to be zero. However,
for-the azeotropic mixture R501, the reference state for enthalpy and entropy is
shifted to zero for saturated liquid mixture at -40 F.
DATA EVALUATION
With the help of methods developed above, the thermodynamic properties for mixtures of R22 and R12 are calculated in the temperature range of -100 to +200 F.
A computer program (Ref 10) is developed for this purpose.
FPS units are employed throeghout, since all the thermodynamic properties
for pure refrigerants are available in these units.
Tables 1-6 contains thermodynamic properties at concentrations of 0, 0.2, 0.4•
-
0.6, 0.8, and'1.0 in the temperature range of -50 to +100 F in steps of 10 deg P.
The concentrations of 0 and 1, corresponding to the pure refrigerants, are given
so that interpolation can be readily done for any concentration. The same
thermodynamic properties are given ih Table 7 for the azeotropic mixture R501..
More detailed tabulations over a larger range of temperature are given in
Ref 10.
It can be observed that the tabulated values for pure refrigerants R22 and
R12 differ slightly from those given in Ref 9. This is because Kriebel's vapor
pressure data is used in the entire range of concentration and because the modified equation of state is used for pure refrigerants.
Accuracy of Prediction
The equilibrium pressure and temperature relationship is accurate to within
1 percent. Saturated liquid density and specific heat values arc expected to be
accurate within + 1 percent. Saturated vapor specific volume, enthalpy, specific
heat and entropy; and saturated liquid entropy are all believed to be accurate
within + 3 percent at temperatures well below critical. However, near critical
temperatures, larger deviations are possible.
NOMENCLATURE
C
specific heat at constant . pressure, Btu/lbm F
C vspecific heat at constant volume, Btu/lb m F
H
specific enthalpY, Btu/lbm
P
pressure, lbein2
R
gas constant -
S
specific entropy, Btu/lb mF
T
Temperature, R
V
specific volume, ft3/ib m
W
molecular weight, lb m/lbm mole
X
liquid weight fraction of R22
XV
vapor weight fraction of R22
ly
TV
liquid mole fraction of R22
vapor Imola fraction of-R22
-
Superscripts
*
ideal gas state
Subscripts
1
1
R22
2
R12
c
critical
fg
difference between vapor and liquid
I,
liquid
m
mixture
✓
vapor'
-
Greek symbols
density , lnm/fti
activity Coefficient
REFERENCES
"Pressure-Volume-Temperature Relationships of Binary
1. C.A. Bijlani,
Mixtures of Refrigerants", Proceedings, 13th Int. Cong. of Refrigeration,
Washington, 1971
•
"Thermodynamic Properties and Refrigeration Characteristics
2. C.A. Bijlani,
of Binary Mixtures of Freon 12 and Freon 22", Doctoral thesis, Indian Institute
of Technology, Bombay, 1967
3. R.A. Quraishi, "Predicting the Pressure-Volume-Temperature Behaviour of
Binary Mixtures of Fluorocarbon!, M.Tech. Dissertation, Indian Institute of
Technology, Bombay, 1972
4. H.J. Loeffler,
"Some Properties of the Binary System rreon -12 -Freon -22
and of Ternary System Freon -12 -Freon -22 -Napthetic Mineral-Oil", Annexe, I.I.R.
143, 1969-61
"Phase EquilibriUS Between Liquid and Vapor in the Binary
5. M. Kriebel,
1System of Difluoromonochloromsthane -DiflUorodichloromethane", Doctoral
Dissertation, D83, Berlin, 1966
6. E.F. Neilson, and D. White, "Heat of Vaporization and Solution of a Binary
Mixture of Fluorocarbons", J. Phys. Chem. 63, 1363-5, 1959
Thermodynamic Properties of Freon-22, E.I. Du Pont De Nemours and Co. (Inc),
Wilmington, Delaware
8. Thermodynamic Properties of Freon-12 E.I. Du Pont de Nemours and Co. (Inc.), `
Wilmington, Delaware
9. ASHRAE HANDBOOK OF FUNDAMENTALS, 1972
10. S.G. Kandlikar, and S.P. Sukhatme "TherModynamic and Transport Properties of
R22/R12 Mixtures", Report, Thermal Sciences Group, Mach. Engg. Dept. Indian
Institute of Technology, Bombay, 1974
11. J.A. Barker, "Determination of Activity Coefficients from Total-Pressure
Measurements", Australian J. Chem., 6, 2 7-10, 1953
ACKNOWLEDGEMENT
These computations were performed on the CDC-3600 Computer system of the Tata
institute of rundaMental Research, Bombay.
TABLE 1 THERMODYNAMIC PROPERTIES OF BINARY MfXTURE R22-R12
Mole fraction of R22 = 0.0 (pure R12)
Volume
Temperature Pressure gu ft0,
F
psia
Vapor
-10
7.08
9.24
11.90
15.14
19.03
5.0189
3.9191
3.0981
2.4767
2-.0004.
-50
-43
-33
-23
.
Density
113/cu ft
Liquid
95.62
94.66
93.69
92.70 .
91.69
Enthalpy*
Btle40,
EiquitrVapor
Li4indvapor
-2.101
0.000
2.112
4.235
6.371
71.809
72.945
74.078
75.206
76.326
0.210
0.212
0.213
0.215
0.216
0.128
0.130
0.133
0.135
0.138
-0.00507
0.00000
0.00496
0.00982
0.01459
0,17534
0.17382
77.436
78.534
79.617
80.684
81.731
0.218
0.219
0.221
0.222
0.224
0.140
0.143
0.146
0.149
0.152
0
23.67
10
20
30
40
29.15
35.56
43.00
51.57
1.6311
1.3415
1.1121
0.9288
0.7806
90.66
89.61
.68.51
87.43
86.33 8.520
10..684.
12.863
15.059
- 17.273
50
6370
61.38 .
72.54
85.14
99.30
115.13
0.6605
0.5618
0.4803
0.4126
0.3558
85.14
83.95
82.72
81.45
80.15
19.508
21.766
24.050
26.364
28.712
82.757
83.757
84.729
85.670
65.575
0.226 0.156
0.228 0.159
0.230 0.163
0.233 0.167
0:237 0.172
132.73
0.3080
78.79
31.100
87.441
0.241
80
90
100
Equilibrium
Entropy*
VapOr
Btuflb R
Liquid Vapor Composition**
Specific heat
BV3ilb F
0.177
.
0.17245
0 .0
0.0
.
0.0
0.17124
0.0
0.17016
0.0
0.01927
0.02367
0.02841
0.03287
0.03728'
0.16920
0.16834
0.16757
0.16689
0.18628'
0.0
0.0
0.0
0.0
0.0
0.04163
0.04594
0.05022
0.05446
0.05869
0.16573
0.16523
0.16476
0.16436
0.16396
0.0
0.0
0.0
0.0
0.0
0.06291
0.16358
0.0
*Based on 0 for the saturated pure liquid refrigerant at -40F
**Expressed in mole fraction of R22
Note: The above values for pure refrigerants differ slightly from those given in Ref (9)
because of the following reasons: (i) The vapor pressure data of Kriebel is used
(ii) A modified equation of state is used, (iii) Some property values in Ref (9)
are fitted by the least square method as functions of temperature.
Temperature
Pressure
•sia
volume
•
Vapor
F
Density
Enthalpy*
lb cu ft Bt lb
Liquid
Liquid Vapor
Specific heat
Btu lb F
iqui• Vapor
Equilibrium
Entropy*
Vapor Bim lb R
'qui. Vapor Composition**
-50
-40
-30
-20
'-10
9.13
11.82
15.10
19.06
23.79
7.92
10.32
13.27
16.85
21.15
4.7498
3,7147
2.9406
2.3538
1.9034
94.55
93.59 i
92.61
91.61
90.59
-0.977
1.177
3.345
5.529
7.729
75.782
76.917
78.046
79.167
80.277
0.218
0.219
0.221
0.223
0.224
0.130
0.132
0.135
0.137
0.140
-0.00362
0.00165
0.00681
0.01187
0.01685
0.18616;
0.18441
0.18283
0.18141
0.18012
0.388
0.383
0.378
0.373
0.368
0
10
20
29.39
35.95
43.58
26.27
32,30
39.35
1.5536
1.2790
1.0613
89.55
88.49_
87.41
9.946
12.180
14.432
81.375
82.488
83.523
0.226
0.227
0.229
0.143
0.146
0.149
0.02173
0.02655
0.03128
0.17896
0.177'91
0.17696
0.363
0.358
0.353
30
40
52.39
62.47*
47.52
56.93
0.8870
0.7463
,86.29
85.15
16.705
18.998
84.568
85.590
0.231
0.233
0.1527
0.156
0.03596 0.17609
0.04057 0.17530
0.3418
0.343
.
50
60
70
80
90
73.95
86.94
101.53
117.85
136.00
67.68
79.89
93.67
109.14
126.41
0.6317
0.5376
0.4599
0.3951
0.3409
83.98
82.77
81.53
80.25
78.92
21.316
23.660
26.034
28.440
30.882
86.587
87.555
88.491
89.392
90.252
0.235
0.237
0.240
0.243
0.247
0.159
0.163
0.168
0.172
0.177
0.04514 0.17457
0.04966 0.17389
0.05414 0.17326
0.05860 0.17267
0.06303 0.17210
0.338
0.333
0.320
0.323
0.319
100
156.09
145.60
0.2952
77.54
33.366
91.069
0.252
0.183
0.06746
0.314
0.17154
Temperature
IP
•
Pressure
•sia
:.
Density
Volume
Enthalpy*
t lb lb cu ft' Btu lb
Vapor
144111•LIquid Vapor
Specific heat
Btu- ib F
iqul•Vapor
EntrOpy*
Equilibrium
Btu lb R
Vapor
Lqul• Vapor Composition**
-5 0
-40
-30
-20
-10
10.49
13.56
17.30
21.82
27.20
9.23
11.99
15.38
19.49
24.41
4.3270
3.3910
2.6894
2.1564
1.7464
93.38
92.41
91.42
90.41
89.38'
-0.312
1.935
4.202
6.488
8.796
80.534
81.661
82.77?
83.882
84.972
0.226
0.228
0.230
0.231
0.233
0.132
0.134
0.137
0.140
0.143
-0.00200
0.00349
0.00587
0.01417
0.0193?
0
10
20
30
33.56
41.00
49.65
30.25
37.12
45.13
1.4274
1.1765.
0.9772
88.34
87.26
86.1?
11.125
13.476
15.849
86.045
87.098
88.128
0.235
0.237
0.239
0.146
0.149
0.153
69.63
54.42.
71.64 - 65.06
0.8174
85.04
18.246
80.133
0.241
0.6881
83.89
20.670
90.109
40
50
60
70
80
90
84.01
98.67
115.14
133.53
153,97
77.22
91.00
106.53
123.94
143.35
0.5827
0.4961
0.4244
0.3647
0.3145
82.71
81.49
80.23
78.93
.77.58
23.122
25.605
28.121
30.673
33.265
. 91.053
100
176.58
164.87
- 0.2722
76.15
35.902
95,161
91.962
92.832
93.658
94.436
.
0.19766
0.19566 •
0.19384,
0.19218
0.19067
0.546
0.544
0.541
0.5390.537
0.02450
0.02955
0.03453
0.18928
0.18801
0.18683
0.534
0.532
0.530
0.156
0403945
0.18574
0.528
0.243
0.160
0.04431
0.18473
0.525 -
0.245
0.248
0.251
0.255
0.259
0.165
0.169
0.174
0.180
0.186
0.04913 0.18378
0.05390 0.18289
0.05864 0.18203
0.06335 -0.18121
0.06805 0.18041
0.523
0.521
0.518
0.516
0.514
0.264
0.193
0.072•2
0.511
0.17961
A
Temperature
F
• .
Density
PreeeUre
Volume
-sia
t lb lb cu f
0* Vapor
iquid
•
..........-------........
Enthalpy*
Btu/lb
Liquid Vapor
Specific heat
Btu lb P
lqui. Vapor
11.45
14.80
18.89
23.8129.68
10.95
14.16
18.08
22.80
28.44
3.8838
3.0564
2.4334
1.9581
1.5911
92.08
91.10
90.10
89.08e
88.05
-0.230
2.128
4.512
6.921
9.357
0
10
20
30
40
36.61
44.73
54.16
65.03
77.46
35.11
42.93
52.01
62.4874.47
1.3044
1.0782
0.8978
0.7528
0.6351
86.99
85.91
84.80
83.67
82.50
91.205
11.819
14.308 • 92.222
93.211
16.825
94.168
19.370
21.947
95.091
50
60
70
80
90
91.60
107.57
125.51
145.55
167.81
88.11
103.53
120.85
140.21
161.73
0.5389
0.4596
0.3937
0.3387
0.2925
81.31
80.07
78.80
77.48
76.12
24.558
27.205
29.890
32.615
35.384
95.977
96.820
97.617
98.363
99.052
0.257
0.260
0.264
0.268
0.273
100
192.44
185.55
0.2533
74.69
38.203
99.679
0.278
-50
-40
-30
-20
-10
85.803
86.916
88.016
89.099
90.163
Entropy*
EquilibriuM
Btu b R
Vapor
Liqui Vapor Composition**
0.236
0.238
0.240
0.241
0.243
0.135
0.137
0.140
0.143
0.146
-0.00112e
0.00463
0.01029
0.01585
0.02134
0.20976
0.20752•
0.20546
0.20357
0.20183
0.245
0.247
0.250
0.252'
0.150
0.153
0.157
0.162
0.02674
0.03208
0.03735
0.04255
0.20021
0.19872
0.19732
0.19601
0.672
0.672
0.673
-0.673
0.28g
0.166
0.04771
0.19478-
0.673
0.171
0.176
0.182
0.189
0.196
0.05282
0.05789
0.06292
0.06793
0.07292
0.19361
0.19249
0.19142
0.19037
0.18933
0.674
0.674
0.674
0.674
0.675
0.204
0.07789
0.18830
0.675
1
0.671
0..671
9.6711
0.672;
0.672:
Pressure
Temperature
nsia
F
B
-
DP
Density
Volume
Enthalpy*
cu ft/lb lb/cu ft Btu/lb
vapor .
Liquid
Liquid vapor
Specific heat
Btu/lb F
Liquid Vapor
Equilibrium-.
Entropy*
Vapor
Btu/lb R
L,quid Vapor Coilpositiun**
3.8081
2.9973
2.3866
1.9206
1.5606
90.63
89.64
88.63
87,61
86.56
.4).692
1.56?
4.056
6.578
9.131
91.633
92.740
93.833
94.905
95.953-
0.247
0.249
0.251
0.253
0.137
0.140
0.143
0.146
0.150
-0.00227
0.00372
0.00961
0.01543
0.02117
0.22360
0.22100
0.21860
0.21638
0.21431
0.807
0.812
0.816
1.819
0.821
38.32
46.84
56.73
68.13
81.18
1.2793
1.0573
0.8803
0.7379
0.6223
85.49
84.40
83.29
82.14
80.9?
11.717
14.335
16.985
19.669
22.390
96.975
97.96?
98.925
99.846
100.727
0.257
0.260
0..262
0.265
0.267
0.153
0.157
0.162
0.166
0.171
0.02683
0.03243
0,03797
0.04344
0.04887
0.21239
0.21059
0.20889
0.20729,
0.20576
0.822
0.823
0.824
0.825 '
0.826
96.65
113.58
132.60
153.86
177.59
96,02
112.79
131.63
152.68
79.76
78.51
77.22
75.89
25.150
27.982
30.796
33.686
101.563
102.350
103.083
103.757
0.271
0.274
0.278
0.283
0.177
0.183
0.189
0.197
0.05426
0.05961
0.06492
0.07021
0.20430
0.20290
0.20153
0.20019
0.825
0.827
0.827
0.827
176.37
0.5278
0.4499
0.3852
0.3311
0.2857
74.50
36.622, 104.364
0.288
0.205
0.07546
0.1906
0.82?
203.6?
201.95
0.2472
73.05
39.612
104.899
0.295
0.215
0.08074
0.19753
0.828
-50
-40
-30
-20
-10
11.98
15.50
19.83
24.98
31.16
11.97
15.48
19.75
24.91
31.06
0
10
20
30
40
38.48
47.05
57.02
68,51
81.6?
53
60
70
80
90
100
-
TABLE 6 THERMODYNAMIC PROPERTIES OP BINARY MIXTURE R22-R12
Mole fraction of R22 1.0 (pure R22)
Temperature
F
Pressure
s ip
Volume
Density
Vapor
Liquid
_
-50
-40
-30
- 11.66
15.18
19.50
4.2302
3.3080
2.6178
89.00
-20
-10
24.74
2.0943
31.02
0
10
20
Enthalpy*
L qui
Vapor
0.140
-0.142
0.145
0.149.
0.152
-0.00605
0.00000
0.00598
0.01189
0.01774
0.24142
0.23827
0.23535
0.23263
0.23008
1.000
1.000
1,000
0.156
0.160
0.165
0.169
0.175
0.02353
0.02926
0.03493
0.04055
0.04614
0.22769
0.22544
0.22330
0.22127
0.21933
1.000
.1.000
1.000
107.956
0 271
0.274
0.276
0.279
0.283
108.760
109.506
110.189
110.800
111.333
'0.181
0.286
0.187
0.290
0.295, 0.194
0.202
0.300
0.212
0.307
0.05169
0.057210.06271
0.06818
0.21746
0.21564
0.21387
0.21212
1,030
27.173
30.121
33.117
36.164
1.000
1.07
1.000
0.07364
0.21039
1.000
39.267
111.778
0.314
0.07909
0.20665
1.000
86.99
98.870
99.996
1C1.101
1.6923
85.96
84.90
5.131
7.753
102.183
103.236
38.50
47.30
57.57
1.3799
1.1346
0.9400
83.82
82.72
81.60
10.411
13.105
15.836
134.259
105.246
106.194
30
40
69.48
83.17
0.7842
0.6583
80.44
79.25
18.606
107.099
21.417
50
98.81
'0.5558
78.03
24.272
60
70
80
90
116.55,
136.57
159.03
184.08
0.4717
0.4021
0.3442
0.2956
76.77
75.47
74.12
72.71
100
211.90
0.2546
71.23
aqua
Entropy*
EquilibriuM
Btu/lb R
Vapor
Liquid Vapor Composition**
0.260
0.262
0.264
0.266
0.269
-2.511
0.000
2.547
88.01
Specific heat
Btu _lb F
Vapor
0.222
*Based on 0 for the saturated pUre liquid refrigerant at -40F
**Expressed in mole fraction of R22
Note: The above values for pure refrigerants differ slightly from those given in Ref (9)
because of the following reasons: (i) The vapor pressure data of Kriebel is used
(ii) A modified equation of state is used, (iii) Some property values in Ref (9)
are fitted by the least square method as functions of temperature.
1.000
1.000
1.000
.1.000
Temperature
F
Pressure
m 'a
•
Volumeft b
Vapor
Density
Enthalpy*
lb cu ft' B
lb
Liquid
Liquid Vapor
Specific heat
Btu lb F
iqui• Vapor .
-
EquilibriuM
Entropy*
Btu lb R
Vapor
iglu. apor Composition**
-50
-40
-30
-20
-10
11.99
15.51
19.81
25.00
31.19
11.98
15.49
19.77
24.94
31.10
3.8156
3.002E
2.3907
1.9236
1.5628
90.57
89.58
88.5?
87.55
86.50
-2.462
0.000
2.493
5.018
7.575
90.339'
91.460
92.542
93.615
94.663
0.248
0.250
0.251
0.254
0.256
0
10
20
30
40
38.52
47.11
57.09
68.60
81.78
38.38
46.91
56.82
68.25
81.34
1.2810
1 0586
0.0612
0.7386
0.6229
85.44
84.34
83.23
82.08
80.91
10.165
12.787
15.441.
18.130
20.855
95.684
96.675
98.553
99.433
0.258
0.154
0.260
0.158
0.262_
0.162.
0.265
0.166
0.268 '0.171
0.02313 0.20925
0.02874 0.20743
0.03428 0.20572
G.03977. 0.20410
0.04520 0.20257
0.829
0.830
0.8311
0.832
0.832
50
60
70
80
90
96.78
113.74
132.80
154.11
177.80.
96.21
113.02
131.91
'153.02
176.48
0.5282
0.4502
0.3854
0.3313
0.2858
79.70
78.45
77.16
75.82
74.43
23.620
26.427
29.277
32.172
35.114
100.268
101.053
101.784
102.454
103.059
0.271
0.275
0.279
0.284
0.289
0.177
0.183'
0.190
0.197
0.206 •
0.05060 0.20109
0.05596 0.19967
0.06128 0.19829
0.06658 '0.19694
0.07186 0.19560
0.832
0.833
0.833
0.833
0.83Z
100
204.02
202.43
0.2472 • 72.98
38,109
103.590
0.295
0.215
0.07713
0.834
0.137
0.140
0.143
0.146
0.150
-0.00600
0.00000
0.00589
0.01171
0.01746
-
"
0.22054
0.21792
0.21551
0.21327
0.21119
0.19426
0.813
0.819 '
0.823
0.826
0.828
MOLE FRACTION OF R 22 -
Fig. 1 Temperature concentration diagram for binary system R22/R12