Question

Explain briefly the following terms: a) Superheated steam b) Saturated steam c) Dryness fraction d) Sensible Heat e) Latent Heat f) Dry steam g) Wet Steam.

Answer 1

a) Superheated steam: At every pressure , there is a saturation temperature or boiling point. At saturation temperature, phase change will occur and constant temperature and pressure. If when all the vapor get converted into saturated vapor and heating is still continue then the temperature of saturated vapor increases at constant temperature. So the steam at by pressure presents at higher temperature than saturation temperature is known as Superheated steam.

b) Saturated Steam : At every pressure , there is a saturation temperature or boiling point. At saturation temperature, phase change will occur and constant temperature and pressure. The vapor present, when all liquid converted to vapor at saturation conditons is known as saturated steam.

c) Dryness Fraction: It is the fraction of vapor present in the mixture of saturated liquid -vapor mixture (in equillibruim) at saturation conditions. It is denoted by 'x'.

d) Sensible heat: The heat which cause the change in temperature of the matter or fluid is known as sensible heat.

e) Latent Heat: The heat which causes phase change at saturation e.g from liquid to vapor is known as latent heat.

f) Dry steam: The saturated steam is also known as dry steam. It does not contain any saturated liquid.

g) Wet steam: The mixture of saturated liquid and saturated vapour.