" ", .
1. .
2. ( ).
3. .
. 0.8 800 . , .
, , , , . , , . , , () . , . , . , , .
, ()
, (1)
- , /(2×4),
= × ;
- , /(2×4),
= 5.67;
e - ;
F - , 2;
1- , ;
- , .
(1) , /(2×4),
. (2)
, , ; . , .
() 1 2 , l, . : d = 0.025 .
, () () F. : (e = 0.97). 3, . , 4 5. , , . .
|
|
- 6 7.
, . , ( 1 2) .
, , ()
Q = Q + Q, (3)
Q = Q - Q. (4)
Q , . =0,97.
.
. (5)
, , , ..
,
Q = Q + . = (Q ) + eF[( /100)4 (T /100)4]. (6)
(6) (2),
. (7)
1. "I".
2. ( ).
3. .
4. , .
5. .
W, | W, | t1, C | t, | |
6. "0" .
1. , () Q = W, Q = W.
2. (2), F = pdl, d = 0.025, l = 0.42 .
3. (7).
4. t1, C
e = C / C0
5. (. ) e.
6. e
.
7. .
1. .
2. .
3. : , , , .
4. .
5. .
6. .
7. .
8. .
9. .
|
|
1. .. . .- . , 1982.
2. .., .., .. .- .: ,1981.
3. .., .. .- .: , 1977.
4. .. .- .: , 1980.
t, | e | |
225-572 | 0.039-0.057 | |
0.055 | ||
, 600 | 200-600 | 0.11-0.19 |
425-1020 | 0.144-0.377 | |
, | 0.242 | |
0.736 | ||
125-525 | 0.78-0.82 | |
925-1115 | 0.87-0.95 | |
770-1040 | 0.52-0.56 | |
940-1100 | 0.55-0.61 | |
, 600 | 200-600 | 0.80 |
0.82 | ||
, | 0.06 | |
, , | 0.20 | |
50-350 | 0.22 | |
, 600 | 200-600 | 0.61-0.59 |
, , | 80-115 | 0.018-0.023 |
, , | 0.072 | |
, 600 | 200-600 | 0.57-0.87 |
, | 0.906 | |
, | 0.875 | |
40-95 | 0.96-0.98 | |
, | 40-95 | 0.80-0.95 |
- | 0.821 | |
75-145 | 0.91 | |
, | 10-88 | 0.92-0.96 0.91 |
9
" ", () .
1. .
2. .
3. - , .
4. .
5. .
1. .
2. .
3. -. ; , .
4. .
5. , , .
6. : , .
7. , .
. . () -
Q = aFDt
F - , 2;
|
|
t = (t - to) - , ;
a - , /(2×).
a, , . , , , , .
, . , , . . , , , . , , . .
( ). .
(1)
(1)
Num = C (GrmPrm)n (2)
:
Num = a l0 / lm ;
Grm = b gl03Dt / nm2 ;
Prm = gm / am .
:
l0 - , ( l0 = d, l0 = h);
lm - /(×);
nm - , /;
b = 1/(tm+273) - , 1/;
Dt = tc t0 - , .
(1) (2) "m" , ()
tm = 0.5(tc + t0).
() 1, 2. , , 3 4 5. 6 7. , .
.
1. , "1".
2. , .
3. , .
4. .
|
|
1
U, B | I, | DE, | DT, | , K | |
1. , ,
Q = UI
U-, I- ,
2. ,
,
e = 0.5 - ;
=5.67- , /(2×4);
F = pdl - , , 2, d = 0.013;
l = 0.780 - , ;
- . ;
c - . ;
DT - . ;
D - - , .
3. ,
Q = Q - Q
4. , / (2×)
a = Q / (FDt)
5. .
6.
a = j(Dt)
7. (2).
.
,
tm = 0,5(tc + t0)
tm 2 lm, nm, am.
.
(GrmPrm) 3 n.
Num ,
Num = al0 / lm
a, /(2×)
2
tm, | l ´102, /(×) | ´106, 2/ | n ´ 106, 2/ |
2.51 | 20.0 | 14.16 | |
2.59 | 21.4 | 15.06 | |
2.67 | 22.9 | 16.00 | |
2.76 | 24.3 | 16.90 | |
2.83 | 25.7 | 17.95 | |
2.90 | 27.2 | 18.97 | |
2.96 | 28.6 | 20.02 | |
3.05 | 30.2 | 21.09 | |
3.13 | 31.9 | 22.10 | |
3.21 | 33.6 | 23.13 |
3
(Grm Prm) | n | |
1´10-3 ¸5´102 | 1.18 | 0.125 |
5´102 ¸ 2´107 | 0.54 | 0.25 |
2´107 ¸ 1´1013 | 0.135 | 0.33 |
1. a a , %
.
2. .
1. . ., .. .- .: ,1977.
2. .. . .- .:,1982.
3. . . .- .:1980.
4. .., .., .. .- .: ,1981.
10
" ", .
1. ( ) (- ).
2. .
3. , .
4. .
5. .
.
Q, , -
Q = aFDt,
a - , /(2×0);
F , , 2;
Dt = tc t , 0.
a, .. , . , , , , .
|
|
. , , , - .
, , . .
( ). :
R = 1´10 ¸ 1´105
Nu = 0.5Re0.5Pr0.38(Pr0 / Prc)0.25. (1)
Re = 1´103 ¸2´105
Nu = 0.25Re0.6Pr0.38(Pr0 / Prc)0.25. (2)
:
Nu = alo / lm ;
Re = wlo / nm ;
r = nm / m .
:
lo , ( lo = d, lo = h);
lm , /(2×0);
w , /;
nm , 2/;
m , 2/.
. "m" , t, 0, tm = 0.5(tc + t0).
(1) (2) : :
Num = 0.43Rem0.5 (3)
Num = 0.216Rem0.6. (4)
, 1 (), 2 . 3 4 5. 6 7 8 9 10. 11 12. .
.
1. , "1".
2. 3, .
3. 7, ~ 2 /.
4. 12, . 1.
5. .
1
W, / | U, B | I, | DE, | T, | DT, | a, /(2×) | Re | Nu | |
1. Q, ,
Q = UI,
U , ;
I , .
2. Q, ,
Q = eC0F[(Tc/100)4 (To/100)4],
e = 0.5 ;
C0 = 5.67 , /(2×4);
F = pdl , 2;
d = 0.013 , l = 0.3 ;
T0 , ;
Tc = To + DT , ;
DT = 1,48D , ;
DE - , .
3. Q, ,
Q = Q Q.
4.
a, /(2×),
a = Q/(FD).
5. .
6.
a = j(D).
7. (3) (4).
.
, 0
tm = 0,5(t + t0).
tm . 2 lm, nm.
2
t, 0 | ||||||||||
l×102, /(×) | 2.51 | 2.59 | 2.67 | 2.76 | 2.83 | 2.90 | 2.96 | 3.05 | 3.13 | 3.21 |
n×106, 2/ | 14.6 | 15.06 | 16.00 | 16.90 | 17.95 | 18.97 | 20.02 | 21.09 | 22.10 | 23.13 |
.
, , a, /(2×)
a = Num×lm /d.
8. (%) a a
D = (a - a)100/a .
9. .
1. .
2. .
3. -, . : , .
4. .
5. .
6. , , .
7. : , .
8. , .
1. .., .. .- .: , 1977.
2. .. .- .: , 1980.
3. .. . .- .: , 1982.
4. .., .., .. .- .: , 1987.
"", "- ",
" ", "",
" "
270100, 270300, 270400, 270500, 270900, 271100,
170600, 170500, 071900, 320700, 210200
,
,
,
,
..
..
020449 31.10.97. . 2001.
60´84/16. .
. . . . . 4. .- . . 3.8.
300 . . . .
()
:
394017 , . , 19