Evaluate total heat of steam - thermodynamics, Mechanical Engineering

Evaluate total heat of steam:

10 kg of wet saturated steam at 15 bar pressure is superheated to the temperature of 290°C at constant pressure. Find heat needed and the total heat of steam. The dryness fraction of steam is 0.85.

Sol.: From steam table, we get following data:

Absolute pressure (P)

bar

Saturation

temperature (t) ºC

Specific enthalpy kJ/kg

Water (hf)

Latent heat (hfg)

15

198.3

844.6

1947

Total heat of 10 kg wet saturated steam

=10 × 2499.55 = 24995.5 kJ                                                   .......ANS

Total heat of 1 kg superheated steam can be given by Hsup  = hf  + hfg  + Cp(tsup  - ts) kJ

= 844.6 + 1947 + 2.1 × (290 - 198.3) kJ

= 2984.17 kJ                                                                               .......ANS

Total heat of 10 kg superheated steam =10 × 2984.17 = 29841.7 kJ         .......ANS

= hf + hfg + Cp(tsup - ts) - (hf + xhfg)

= hfg  + Cp(tsup  - ts) - xhfg

=1947 + 2.1 x (290 - 198.3) - 0.85 x 1947 kJ = 484.62 kJ

Heat which is required to convert 10 kg wet saturated steam into 10 kg superheated steam

=10 × 484.62 = 4846.2 kJ                                                        .......ANS

Total heat of 1 kg wet saturated steam can be given by Hwet  = hf  + xhfg  kJ

= 844.6 + 0.85 × 1947 kJ = 2499.55 kJ

Heat which is required to convert 1 kg wet saturated steam into 1 kg superheated steam

= Hsup  - Hwet,

here Hsup = enthalpy of 1 kg superheated steam = hf + hfg + Cp(tsup - ts) kJ

Hwet = enthalpy of 1 kg wet saturated steam = hf  + xhfg  kJ

Heat which is required to convert 1 kg wet saturated steam into 1 kg superheated steam

Posted Date: 10/15/2012 7:24:01 AM | Location : United States







Related Discussions:- Evaluate total heat of steam - thermodynamics, Assignment Help, Ask Question on Evaluate total heat of steam - thermodynamics, Get Answer, Expert's Help, Evaluate total heat of steam - thermodynamics Discussions

Write discussion on Evaluate total heat of steam - thermodynamics
Your posts are moderated
Related Questions
Plate clutch warpage: Place plate clutch on surface plate and check for warpage. Ensure that0.20 mm feeler gauge does not slide freely.

explain different power plants..???

A tensile test on a specimen having an initial diameter of 13.11 mm and an initial gauge length of 200.0 mm, gave the following data:

Copper-Lead Alloys Copper-lead alloys, having a large percentage of lead have determined a considerable employ as bearing material lately. Straight, copper-lead alloys of such

Magnetic Susceptibility and Ferromagnetic Substances: Magnetic Susceptibility: The magnetic susceptibility (c) of a substance is defined  as the ratio of the intensity of magn

Efficiency Test on Sand Blasting:             After the study on sand blasting, the result was acceptable and the next step is planning to make order for new machine and searc

Sweep Representations  The simplest form of sweep is that produced by sweeping a two-dimensional area along an axis perpendicular to its plane. This form of sweep is most usefu


matle cutting