Pressure versus temperature (P-T), Pressure vs. volume(P-v), Temperature vs. volume(T-v),
Temperature vs. entropy, (T-s) Enthalpy vs. entropy(h-s), Pressure vs. enthalpy
The term saturation temperature designates the temperature at which
vaporization takes place.
For water at 99.6 C the saturation pressure is 0.1 M Pa, and for
water at 0.1 Mpa, the saturation temperature is 99.6 C.
If a substance exists as liquid at the saturation temperature and
pressure it is called saturated liquid.
If the temperature is of the liquid is lower than saturation
temperature at the existing pressure it is called sub-cooled liquid or
- When a substance exists as part
liquid and part vapor at the saturation temperature, its quality is defined as the ratio of the
mass of vapor to the total mass.
- If a substance exists as vapor
at the saturation temperature, it is called a saturated vapor.
- When the vapor is at a
temperature greater than the saturation temperature, it is said to exist as superheated vapor.
- At the critical point, the
saturated liquid and saturated vapor state are
- At supercritical pressures, the
substance is simply termed fluid rather than liquid or vapor.
- If the initial pressure at –200C
is 0.260 kPa, heat transfer results in increase of temperature to –100C. Ice passes directly
from the solid phase to vapor phase.
- At the triple point (0.6113
kPa) and a temperature of –200C, let heat transfer increase the
temperature until it reaches 0.010C. At this point, further heat
transfer may cause some ice to become vapor and some to become liquid. The
three phases may be present simultaneously in