Old spec Tutorial 1 Problem 9 (ENGR5003) - Revisica

Old spec Tutorial 1 Problem 9TutorialOld spec ENGR2172:215 min

ENGR217 (old spec) Thermo L6 Tutorial 1, Problem 9 official answers

A rigid tank of volume 1.5 $\mathrm{m^3}$ contains 2 kg of wet steam at 75 C.

Formulas you may need

Wet steam: $v = (1 - x)v_f + xv_g$ , $u = (1 - x)u_f + xu_g$ (on the formula sheet)
First law, closed rigid system: $Q = \Delta U = m(u_2 - u_1)$ (on the formula sheet)
Linear interpolation in the saturation tables (learn this, Lecture 9)

(a)
What is the dryness fraction?
x =-
(b)
If the water is heated slowly until it is completely vaporised (becomes dry steam), determine the temperature and pressure at this point.
T =C
p =kPa
(c)
How much heat is required for the heating process?
Q =kJ
(d)
Sketch the process on a T-v diagram, with respect to the saturation lines.

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