c). 换热器出口至试验段入口：
t3 = 300C
p3 = 160bkg v3 = 0.0014166 m
V3 = = 1.528 m s
kgWv13 ρ3 = = 705.92 m3
v3 π4 2
d3 d3V3 5
Re3 = = 3.018 ×10
v3μ3 ?
0
3
μ3 = 89.36 ×10 Pa ? s
?6
热交换器 3?? ?=0.0? 10
? 1 + ?20000 ×f 3 = 0.0055+ 2.769× 1
6 10 ? ?? ?? 0.0015
1485 L V 3 ρ3 325 Pa ΔPf3 = f3 ? = 5927
2
?
试验段
d3 2
ΔPel3 = ρ3 g Δz3 = ?14530 Pa
ΔP 3 = 0
ρ3V3
ΔP 3 = 3K = 1483Pa
2
c
2
a
13:14:49 习题讲解 38
d). 试验段内：
t3 = 280.6C
ρ3 = 1
P3 =160b
mvkg3 3= 0.0013065
= 756.4 m V3 =
0
3 kg
μ3 = 97.37 ×10 Pa ? s
?6
= 1.409 m s 4
d3 3 5
Re3 = = 2.769 ×10
μ
v3
3
3?? ?
? ?=0.010
3 0.0055 ? 1+?20000×f4=+5554×10? ?? ??5 V 0.0015 ? ? 13 π143
v
2 3
.
d
L4 ρ4V
ΔPf4 = f4 = 14049Pa
d4 2
a
ΔPel4 = ρ4 g Δz4 = 747.332×9.8×1.2 = 8789Pa
? 1 1 ? W ΔPin = 0.72 ? 2 ?1751 ΔP 4 = G ( v1 ? v3 ) 2=Pa
2
4
热交换器 试验段 ? A4 A3 ? ρ
2
ΔPex = ?σex (1 ? σex ) G v = ?4446Pa
? = 13811Pa
13:14:49 习题讲解 39