steam formation
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Transcript of steam formation
Vishwakarma govt engg
EME: Steam formation
Prepared by :• Name: soni kunjan r.• Branch: mechanical• Enroll: 140170119058• Sem:
Steam formation
Consider a cylinder fitted with a piston which can move freely upward and downward in it. consider 1 kg of water at C under the piston. A weight w is placed over the piston so that it exert constant pressure p on water. Now if heat supplied to water, a rise in temp will be noticed and this will continue till boiling point is reached .
The temperature at which the water boil , depends on the pressure acting on it
When the boiling point of water is reached , there will be slight increase in volume of water shown in fig. below slide.
Cylinder with w Wight .
Steam formation graph
IMPORTANT TERMS RELATING STEAM FORMATION
Sensible heat of water (hf ): It is defined as the quantity of heat absorbed by 1 kg of water when it is heated from 0°C (freezing point) to boiling point. It is also called total heat (or enthalpy) of water or liquid heat invariably.
Latent heat or hidden heat (hfg): It is the amount of heat required to convert water at a given temperature and pressure into steam at the same temperature and pressure. It is expressed by the symbol hfg
Total heat or enthalpy of wet steam (h):It is defined as the quantity of heat required to convert 1 kg of water at 0°C into wet steam at constant pressure. It is the sum of total heat of water and the latent heat and this sum is also called enthalpy.
Total heat or enthalpy of wet steam (h):It is defined as the quantity of heat required to convert 1 kg of water at 0°C into wet steam at constant pressure. It is the sum of total heat of water and the latent heat and this sum is also called enthalpy.
Superheated steam: When steam is heated after it has become dry and saturated, it is called superheated steam and the process of heating is called superheating. Superheating is always carried out at constant pressure. The additional amount of heat supplied to the steam during superheating is called as ‘Heat of superheat’
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