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
Solve the support reactions at A and D by using the force method. A is a fixed support; B and C are rigid joints; and D is a pin support. EI is constant for all members.

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Calculate the support reactions of beam: Q: Bending moment diagram (BMD) of the simple supported beam can be given as shown in figure given below. Calculate the support reac

Ease of Operation : For higher power transmissions, the operation of disengaging the clutch must not be tiresome to the driver.

why entropy always tends to increase?

Read two documents that will provide and answer the following questions: 1) You will note from reading the above referenced specifications that fewer valve types are recommended fo

How can I achieve a back and forth movement of carriage system. How can I reverse the motor to go back and forth.

wire-frame entities-representing ellipse and parabolas

(a) Oil, with density ρ= 900 kg/m 3 , and kinematic viscosity υ=0.00001m 2 /s, flows at the rate of 0.2m 3 /s through 500m of a cast iron pipe of diameter d=200mm. Using this infor

Types Of Polymerisation When some of bifunctional molecules connect in a chain structure, the reaction is termed as addition polymerisation.  However, these polymerizations do