Question

Chemical/Mechanical Engineering Thermodynamics:
Steam is heated from 40ºC, 7.35 kPa to 10 MPa and 475ºC. Determine average temperature of heat supply in ºC.

I am just out of clue here. Any help will be appreciated.

Answer 1

The average temperature? That's weird. I could see them wanting to know the heat applied perhaps, but temperature? Also this problem is missing a lot of critical details. Is it flowing steam or is it a fixed quantity of steam in a closed container? Are the container boundaries fixed or is it like some sort of piston device? Hmmmn is that the entire question?

As an aside: To heat it to 475 degC, without the application of work, you would need the heat supply to be at minimum that hot. In fact ideally if you don't want a heat exchanger to be too large you would want there to be a minimum temperature difference (Driving force) all along the heat exchanger.