Steam tables are defined as the thermodynamic data that contain the properties of water or steam. ... Property tables list the properties from saturated water to steam

1. Properties of
Pure
Substances
Presented By:
Ankit Kumar Singhal
Assistant Professor
Mech. Engg. Deptt.

2. Pure Substance
A substance that has a constant chemical composition
throughout its mass is called a pure substance. It is one
component system. It may exist in one or more phases.
e.g. Water, Air
Phases of a Pure Substances:
Solid
Liquid
Gas or Vapour

3. 4’
4’’1’’ 2’’ 3’’
1’ 2’ 3’
2 3 4 5 61
Phase Diagram
P
v
5’ 6’
5’’ 6’’
Solid
Solid starts melting
Solid changes into liquid
Liquid starts vapourizing
Liquid changes into vapour

4. 6’’’5’’’4’’’
3’’’2’’’
6’’5’’4’’
3’’2’’
6’5’4’
3’
6
2’
54
32
S
L
L + V
V
Saturated
Solid Line
Saturated
Liquid Line
Saturated
Vapor Line
p
v
Triple Point
Line
S V
Critical Point
Sublimation
Phase Diagram

6. Phase Diagram
4’
1’
2’ 3’
2 3
4 5
6
1
5’
6’4’’
1’’
2’’ 3’’
5’’
6’’
T
S

7. 4’’
2’’ 3’’
5’’
4’
2’ 3’
5’
2 3
4 5
S
L
L + V
V
Triple Point Line
S V
Critical Point
Phase Diagram
T
S

8. Property Tables
Saturated Liquid and Saturated Vapour State:
f = properties of saturated liquid
g = properties of saturated vapour
vf = Specific volume of saturated liquid
vg = Specific volume of saturated vapour
vfg = Difference between vf and vg

9. Property Tables
Saturated Liquid –Vapour Mixture:
Dryness Fraction ; 𝑥 =
𝑚𝑎𝑠𝑠 𝑜𝑓 𝑑𝑟𝑦 𝑣𝑎𝑝𝑜𝑢𝑟
𝑚𝑎𝑠𝑠 𝑜𝑓 𝑑𝑟𝑦 𝑣𝑎𝑝𝑜𝑢𝑟+𝑚𝑎𝑠𝑠 𝑜𝑓 𝑙𝑖𝑞𝑢𝑖𝑑
𝑢 = 1 − 𝑥 𝑢 𝑓 + 𝑥𝑢 𝑔 𝑢 = 𝑢 𝑓 + 𝑥𝑢 𝑓𝑔
ℎ = 1 − 𝑥 ℎ 𝑓 + 𝑥ℎ 𝑔h = ℎ 𝑓 + 𝑥ℎ 𝑓𝑔
s = 1 − 𝑥 𝑠𝑓 + 𝑥𝑠 𝑔 𝑢 = 𝑠𝑓 + 𝑥𝑠𝑓𝑔

10. Property Tables
Superheated Vapour:
Compare to saturated vapour, superheated vapour is characterized by
Higher temperature (T>Tsat, at a given pressure)

11. 11
o Critical point - the temperature and pressure above which there
is no distinction between the liquid and vapor phases.
o Triple point - the temperature and pressure at which all three
phases can exist in equilibrium.
o Sublimation - change of phase from solid to vapor.
o Vaporization - change of phase from liquid to vapor.
o Condensation - change of phase from vapor to liquid.
o Fusion or melting - change of phase from solid to liquid.
Important Definition

12. 12
o Saturation is defined as a condition in which a mixture
of vapor and liquid can exist together at a given
temperature and pressure.
o Saturation pressure is the pressure at which the liquid
and vapor phases are in equilibrium at a given
temperature
For a pure substance there is a definite relationship
between saturation pressure and saturation temperature. The
higher the pressure, the higher the saturation temperature

13. 13
o Latent heat: The amount of energy absorbed or
released during a phase-change process.
o Latent heat of fusion: The amount of energy absorbed
during melting. It is equivalent to the amount of energy
released during freezing.
o Latent heat of vaporization: The amount of energy
absorbed during vaporization and it is equivalent to the
energy released during condensation.
 At 1 atm pressure, the latent heat of fusion of water
is 333.7 kJ/kg and the latent heat of vaporization is
2256.5 kJ/kg.

14. 14
o When a substance exists as part liquid and part vapor at
saturation conditions, its quality (x) is defined as the
ratio of the mass of the vapor to the total mass of both
vapor and liquid.
o The quality is zero for the saturated liquid and one for
the saturated vapor (0 ≤ x ≤ 1)
o For example, if the mass of vapor is 0.2 g and the mass
of the liquid is 0.8 g, then the quality is 0.2 or 20%.
x
mass
mass
m
m m
saturated vapor
total
g
f g
 


15. 15
Example 1.1
Determine the saturated pressure, specific volume, internal energy
and enthalpy for saturated vapor at 45oC and 50oC.

16. Example 1.2
Determine the saturated pressure, specific volume, internal energy
and enthalpy for saturated water vapor at 47⁰ C .

17. 17
Solution:
 Extract data from steam table
T Psat v u h
45 9.5953 15.251 2436.1 2582.4
47 Psat v u h
50 12.352 12.026 2442.7 2591.3
Interpolation Scheme for Psat
 Interpolation for Psat
@47
9.5953 47 45
12.352 9.5953 50 45
10.698
sat
sat
P
P kPa
 

 

 Do the same principal to
others!!!!