Evaluation of heat required - thermodynamics, Mechanical Engineering

Evaluation of heat Required:

Heat which is required to generate steam is different from 'total heat' or enthalpy of steam. Heat required for generating steam means heat needed to produce steam from water the initial temperature of which is tºC (say) which is always more than 0ºC. Total heat or enthalpy of steam means heat needed to generate steam from water the initial temperature of which is 0°C. If initial temperature of water is 0°C, then of course heat needed to generate steam becomes equal to total heat or the enthalpy of steam.

970_Evaluation of heat Required.png

heat required to generate steam can be given by QDry=hf + hfg  - h' kJ/kg,

where h' = heat required to raise 1 kilogram water from 0°C to given initial temperature (say t°C) of water

= mst =1 × 4.2 × (t - 0) = 4.2t kJ [sp. heat of water = 4.2 kJ/kg K].

(b)  When steam is wet saturated, heat needed to generate steam can be given by

Qwet  = hf  + x.hfg - h' kJ/kg.

(c)  When steam is superheated, heat required can be given by

Qsup  =hf  + hfg + CP(tsup  - ts) - h' kJ/kg.

Posted Date: 10/15/2012 6:20:25 AM | Location : United States







Related Discussions:- Evaluation of heat required - thermodynamics, Assignment Help, Ask Question on Evaluation of heat required - thermodynamics, Get Answer, Expert's Help, Evaluation of heat required - thermodynamics Discussions

Write discussion on Evaluation of heat required - thermodynamics
Your posts are moderated
Related Questions
Change in entropy for reversible

MATERIALS WELDABILITY Electron beam welding has the ability to weld a variety of materials including dissimilar combinations. These can be split into general categories as to t

Q. What do you mean by Contractility? Heart being a muscular pump the ability to eject blood depends on the ability to contract. Another factor is the resistance in the vascula

Plate clutch pressure:  Check plate clutch pressure for any step using a straight edge.

Find out the recoil-velocity of the gun: As shell of mass 200 gm is fired at a velocity of 50 metres/second by a gun of mass 20 kg. Find out the recoil-velocity of the gun.

COMPARISON WITH CAM MECHANISMS WITH LINKAGES

give some best names

Construction of steam turbine : CONSTRUCTIO N DETAILS: 1 . Casing: It is made out of cast steel. The casing has rotor inside it. 2 .  Rotor: It carries blades o

is effective commucation an intergral aspect in the mechenical engineering field?

Airport Layout: The main components of an airport are: (a)        Runways (b)       Taxiways (c)        Apron (d)       Terminal area (i)        Terminal build