PSI - Issue 36
S. Hryhorskyi et al. / Procedia Structural Integrity 36 (2022) 342–349 S. Hryhorskyi et al. / Structural Integrity Procedia 00 (2021) 000 – 000
346
5
0.367 0.764 0.918
36.0 − =
;
S
q
(14)
d
. .
o s
o
o
- on an inclined ground surface (angle of inclination to the horizon 0
2.5
):
(
) 0.205 0.727
0.257 1.075 −
(15)
. . 10.71 1 o s S
.
q
= +
d
3. Results The developed technique for detecting and calculating the parameters of leakage through a small hole was tested on a domestic oil pipeline with a nominal diameter of 700 mm and a length of 195 km. There are three OPS operating on the pipeline route, equipped with NM series centrifugal oil pumps. There are 12 control points along the pipeline, equipped with modern means of monitoring operating parameters (before and after linear dampers). Pressure sensors with an accuracy class of 0.075 and 0.1 are used. Information about the operating parameters of the oil pipeline is sent to the central control room with a frequency of 0.2 s. For a more accurate accounting of small oil leaks for the operating and energy parameters of the pipeline operation, it is necessary to take into account the profile of the route of individual sections of the pipeline between neighboring OPS, which is shown in Fig. 1. This figure also shows a graphical interpretation of the distribution of oil pressure along the length of the main oil pipeline. oil caused by depressurization of the second linear section of the oil pipeline. The performed multivariate calculations of the throughput and operating parameters of the investigated pipeline section using computer technologies made it possible to estimate the flow rate of oil through the hole by the dynamics of changes in oil pressure in characteristic sections (at the inlet and outlet of the OPS), in the case when depressurization occurred at a distance x (km) from the i-th stretch, and received the following analytical models: - oil pressure at the beginning of each run:
3
3
3 A x q − j out
2 +
3 B x q Р − + j
;
(16)
Р
=
out
out
out
, i j
, i j
і
i
1
1
j
j
=
=
- oil pressure at the inlet to intermediate OPS:
3
3
3 A x q − j inp
2 +
3 B x q Р − + j
;
(17)
Р
=
inp
inp
inp
, i j
, i j
і
і
1
1
j
j
=
=
- oil pressure at a distance x from the beginning of the i-th stretch:
3
3
3 A x q − j x
2 +
3 B x q Р − + j
;
(18)
Р
=
х
x
х
, i j
, i j
i
i
1
1
j
j
=
=
- equivalent diameter round hole:
2
4
4
3
3
j
j
−
−
B x
B x
−
l
l
q
, i j
, i j
1
1
j
j
=
=
(19)
;
d
=
+
+
l
4
4
4
i
3
3
3
j
j
j
2
2
−
−
−
A x
A x
A x
l
l
l
, i j
, i j
, i j
1
1
1
j
j
j
=
=
=
- the maximum possible loss of oil from infiltration into the soil:
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