Steam Tables: Oil fired boiler questions

AI Thread Summary
The discussion focuses on resolving issues related to calculations for an oil-fired boiler problem in a mechanical science exam. The original poster expresses confusion after completing parts a and b of the exam, particularly regarding the pressure used in their calculations. It is noted that the boiler operates at 1050 kPa, which is equivalent to 10.5 bar, contradicting the 1.5 bar used in their answers. Participants suggest double-checking the calculations and using the correct steam properties based on the specified pressure. The poster acknowledges the mistake and plans to correct their figures and provide a clearer image for further assistance.
BenC1994
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Homework Statement


This is from a practice mechanical science exam for HNC engineering.

See attachment for the question sheet off a practice exam. I have no idea how to do this after the a and b parts and my answers for which are below the question (underlined), any suggestions or solutions would be greatly appreciated.

Homework Equations


Q = M*c*(Temperature Difference)
I think...

The Attempt at a Solution

 

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BenC1994 said:

Homework Statement


This is from a practice mechanical science exam for HNC engineering.

See attachment for the question sheet off a practice exam. I have no idea how to do this after the a and b parts and my answers for which are below the question (underlined), any suggestions or solutions would be greatly appreciated.

Homework Equations


Q = M*c*(Temperature Difference)
I think...

The Attempt at a Solution


You should double check your calculations for parts a) and b).

According to the problem statement, the boiler operates at a pressure of 1050 kPa. {At least, that's what I can read from the tiny image attached.}

Your solution for part a) says that the properties of saturated steam are for at pressure of 1.5 bar.

Your solution for part b) appears to be using the enthalpy of superheated steam at a pressure of 1.5 bar.

What's the definition of a bar?
 
SteamKing said:
You should double check your calculations for parts a) and b).

According to the problem statement, the boiler operates at a pressure of 1050 kPa. {At least, that's what I can read from the tiny image attached.}

Your solution for part a) says that the properties of saturated steam are for at pressure of 1.5 bar.

Your solution for part b) appears to be using the enthalpy of superheated steam at a pressure of 1.5 bar.

What's the definition of a bar?
Ah I see my mistake with the answer now, 1050kpa would be 10.5 bar not 1.5 Bar

1.5 bar is 1.5x10^5 pa or n/m^2

Will correct mistake, input correct figures for h and include a better image...
 

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