Документ 2021554

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678.029.43
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-15
+30 ° ).
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-
-
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-15
+30 ° .
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1)
;
2)
-
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3)
-
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-
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:
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(
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-
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i
T
t
i
1
r
r r
T
r
i
i
z
T
,
z
(1)
0 t
tm ; 0 r
r2 ; 0
z l,
–
;r–
-
;t –
-
; l –
. 1.
; tm –
; r, z –
,
i=1
; i=2 –
.
:
T r , z, 0
t1
t2 t3
(2)
T0 .
t4
:
. 1.
T r ,0, t
(3)
T
(
,
-
)
T
z
:
(4)
0.
z 0
U
63
, 2006,
,
-
,
.
,
:
T r ,l ,t
(5)
T0 .
r=0
a)
:
lim
r
0
2
T
r
r
0.
(6)
:
T
r
1
T r2 , z , t
T0 ,
(7)
r r2
a
.
,
-
[1].
b)
.
:
1
T r1
T
r
T
r
2
r r1 0
0, z, t
T r1
(8)
r r1 0
0, z , t .
(9)
(1)-(9)
[2].
: r1=0,103; r2=0,110; l=0,1 ; l1=0,4; l2=0,03 /(
3
r1=950; r2=1,2
; 1=2500; 2=1000
/(
).
);
c)
,
Termo
Tracer
TH7102WV.
=20°
170, 190, 210° .
-
0
.2
,
.
d)
. 2.
(2)
t = 300
64
(1)
t
): a) t =0; b) t=35 c; c) t = 165 c; d)
3,
1
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-
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-
t.
.
,
-
,
(3)
t
(4).
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-
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.
.
-30° .
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,
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,
[3].
,
.3
-
4
= -30 °
0
tp,
(10).
.
.
-
,
,
,
=20
0
a)
=210°
«
’’.
(r,z,t).
t=tk, k=1,2,...N.
-
,
.
20
,
(
. 1).
t1
20
t2
,
.
-
40
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,
(r,z,t),
-
,
10
.
»
tk,
,
.
-
,
b)
:
M
p
J t
2
T ri , z j , t k
T ri , z j , t k
,
i 1 j 1
ri , z j –
.
j
-
zj ,
Z
,
.z j
Z,
.
,
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,
,
-
U
65
, 2006,
c)
3,
1
d)
. 3.
:
– 0 = 20° ;
– 0 = -30° ; tp –
tp=100 c; b) tk=80 c; tp=160 c; c) tk=100 c; tp=200 c; d) tk=150 c; tp=280 c
.1
,
tk; a) tk=50 c;
,
-
.
,
1.
2.
1977. 656 .
3.
.
.
.
.:
.
:
.,
.
.:
, 1971. 560 .
. .:
,
/
.
, 1988. 312 .
,
.
N.P. Starostin, O.A. Ammosova
Welding Conditions for Polyethylene Pipes at Low Temperatures Based on Heat Process
Modeling
The paper shows the analysis of a non-stationary temperature field in the process of polyethylene pipe welding at different ambient
temperatures. The researchers assume that the maximum joint strength is provided when the heating and connecting of welded elements are
up at such temperature distribution which can be reached with the welding design mode (at an ambient temperature from -15 C to +30 C).
Calculations educed the duration of operations at low ambient temperatures which are not stated in the normative documents.
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