3
2. - 6
2.1. -
6
2.2. - 6
10
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1. " ".
2. - Ż
2.1. -
- . :
1) λ = 57 / ;
2) l = 2 ;
3) t′1= 100 ;
4) tʺ1 = 60 ;
5) d2 / d1 = 57 / 51 ;
6) t′2= 10 ;
7) tʺ2 = 35 ;
8) D2/D1 = 57/51;
9) Q = 95 .
2.2.
2.3.
2.4.
2.5.
2.6.
2.7.
2.8.
2.9. -
, :
t1 = 0,5(t′1+ tʺ1) = 0,5(100+60) = 80;
t2 = 0,5(t′2+ tʺ2) = 0,5(10+35) = 22,5;
. 2 (. 2) . 1.
t = 80 | t = 23 | ||
, /3 | ρ = 997,45 | ρ = 971,8 | |
, /(㷰) | = 4,180 | = 4,185 | |
, /(췰) | λ2 = 0,6047 | λ1 = 0,674 | |
, 2/ | ν2 = 0.985910-6 | ν1 = 0.36510-6 | |
Pr2 = 2,54 | Pr1 = 2,21 | ||
Q = G1cp1 (t′1+ tʺ1) = G2cp2 (t′2+ tʺ2) =;
ω1 =
ω2 =
Re1 =
Re > 104, , :
Nu1 = 0,021
,
t c1 ≈ 0,5(t1+ t2) =0,5(80+23) = 51,5
t 1 = 51,5, Pr =3,176.
|
|
Nu1 = 0,021308350,8
α1 = Nu1
Re2 =
d = D1- d2 =0.051-0.045 = 0.006 .
Re > 104, .
t c2 = t c1 = 56,5
Prc2 = Prc1 =3,176.
Nu2 =
α2 = Nu2
d 2/ d 1 < 2, ,
K=
δ = d 1- d 2/2 ; δ = 0,045 0,041/2 = 0,002 .
∆t 6 = t′ 1 + tʺ 2 = 95-55 = 40;
∆t = t′ 1 + tʺ 2 = 50-16 = 34;
t =
q = K ∆t = = 68257,7 /2.
F = =
n=
=
. 2 (. 2) Pr=3,495
=
. 2 (. 2) Pr=3,855
5 %, .
1) ..
( - 10- ., , . .
1973 . .: , 2004. 753 ., . ISBN 5-98535-004-5, dpi300, .)
2) .., ..
( . : , 2013. 68 .)