Homework 2 Due Monday February 8, 2008
1.
Complete the following table for H2O. (C&B)
|
T
(°C) |
P
(kPa) |
h
(kJ/kg) |
X
|
Phase
description |
|
|
200 |
|
0.7 |
|
|
140 |
|
1800 |
|
|
|
|
950 |
|
0.0 |
|
|
80 |
500 |
|
-- |
|
|
|
800 |
3161.7 |
-- |
|
2.
Complete the following table for H2O. (C&B)
|
T
(°C) |
P
(kPa) |
u
(kJ/kg) |
Phase
description |
|
|
400 |
1450 |
|
|
220 |
|
|
saturated
vapor |
|
190 |
2500 |
|
|
|
|
4000 |
3040 |
|
3.
Complete the following table for refrigerant-134a. (C&B)
|
T
(°C) |
P
(kPa) |
v
(m3/kg) |
Phase
description |
|
-8 |
320 |
|
|
|
30 |
|
0.015 |
|
|
|
180 |
|
saturated
vapor |
|
80 |
600 |
|
|
4.
Solve the following problems from S. R. Turns, "Thermodynamics: Concepts
and Applications."
2.81
2.89 Dh @ 272 kJ/kg
2.92 A: X @ 0.83
2.96 m @ 0.095 kg
2.99 mf @ 2.07 kg
5.
For a saturated mixture of liquid and vapor, hav represents the
average enthalpy per unit mass. Starting
with the total enthalpy defined as:
H = Hf + Hg
and H = mth,
Derive
the relation:
hav = hf + xhfg, in which x represents the “quality” of the mixture and hfg = hg – hf.
"(C&A)"
indicates a problem taken from Y. A. çengel
and M. A. Boles, "Thermodynamics – An Engineering Approach," fifth
edition.