# Another nasty question, RE: superheated wet steam?

1. Aug 5, 2007

### nickbone59

1. The problem statement, all variables and given/known data
A gas fired superheater takes wet steam at a pressure of 40 bar and a dryness fraction of 0.95 and heats it isobarically such that it leaves at 380c. Assuming no losses occur, sketch the process on a ts diagram and determine;

i)the rise in specific entropy through the superheater
ii)the necessary rate of heat transfer to the steam, neglecting kinetic and potential energy changes, if the steam flowrate is 1.2 Kg/s
iii)the volumetric flow rate of gas in m^3/hr needed to fire the super heater, if combustion is 100% efficient and the gas has a calorific value (LCV) of 17,500 kJ/m^3
iv)the annual cost of firing the superheater if the combustion efficiency is now 85% and the gas costs 2.1p/m^3

2. Relevant equations
Don't know where to start or what equations to use???

3. The attempt at a solution
Haven't got a clue, searched the internet for similar examples or relevant equation, nothing in my notes either or in the books i have from the library!