Bogdan CORBESCU


32-100 ELEMENTE DE CALCUL AL NECESARULUI DE AZOT PENTRU IZOLAREA CU DOP DE GHEAȚĂ A UNEI CONDUCTE ORIZONTALE DE DIAMETRU MARE

COMPUTATIONAL ELEMENTS FOR THE REQUIRED NITROGEN DURING THE ICE PLUG ISOLATION OF A HORIZONTAL HIGH DIAMETER PIPE-LINE
The technique of forming controlled ice plugs in pipe-line installations in order to isolate a section from the rest of the circuit is used for carrying out circuit maintenance or repair activities without shutting down the entire installation. Considering the results from a controlled test that has been carried out on a horizontal 300 mm nominal diameter pipe-line section, we elaborated a calculation model to reveal the quantity of required liquid nitrogen. It resulted consumption 50 % higher than the actual one. The difference comes from the approximations made for the ice plug dimensions in each stage of the process.
The paper then describes the convenience of visualizing the formation of ice plugs by studying the formation of the ice layers on the pipe inner wall.
Keywords: isolating a pipe-line section, visualizing the forming of ice layers
Cuvinte cheie: izolarea unui tronson de conductă, vizualizarea depunerii de gheaţă

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29-67 O ÎNCERCARE DE OBTURARE CU DOP DE GHEAŢĂ A UNUI TRONSON DE CONDUCTĂ ORIZONTALĂ (DN 300 mm) STRĂBĂTUT DE APĂ DEMINERALIZATĂ

A CONTROLLED ICE PLUG FORMING EXPERIMENT
CONDUCTED ON A HORIZONTAL PIPE SECTION (NPS 12)
WITH DEMINERALIZED WATER FLOWING THROUGH
In a hydraulic pipe-line installation, isolating a horizontal section
requires forming one or two ice plugs in a controlled process. This technique is
used for carrying out circuit maintenance or component replacements without
shutting down the entire installation. In both cases, the ice plug (or both ice
plugs) must be maintained until completing the repair activities. This paper
describes an experiment conducted on a horizontal NPS 12 horizontal pipe
section and its sequences, followed by the results and conclusions. The paper
is dedicated to specialists working in research and technological engineering.
Key words: cutting-off the flow, ice deposit, demineralised water,
hydraulic resistance
Cuvinte cheie: oprirea curgerii, depunere de gheaţă, apă
demineralizata, rezistenţa hidraulică

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29-46 OPTIMIZAREA FUNCȚIONĂRII UNEI PRIZE DE APĂ ECOLOGICE PRIN TESTAREA UNUI MODEL LA SCARĂ REDUSĂ

ECOLOGICAL WATER INTAKE OPTIMIZATION BY SMALL
SCALE MODELLING
The main objective of the paper is to demonstrate the efficiency of an
ecological water intake by optimizing its operation using experimental modelling
techniques. The tests have been performed on a dedicated small scale model
integrated in a specially design testing flume.
This paper presents the general considerations regarding the ecological
intakes for Mountain Rivers and focuses on identifying design methods suitable
for performance increasing. A simplified prototype installation was designed
starting from the patented sand-less ecological intake. Based on this design, a
1:10 small scale model was developed and installed in a dedicated stand. It
was possible to determine the water speed, the flow from the main channel and
the captured flow in different testing conditions, by using specific measuring
equipment and methods. The obtained results were transposed to the prototype
installation by applying Froude similarity criteria, proving to be useful to the
elaboration of the main design parameters for water intakes.
Keywords: water intakes, Mountain Rivers, experimental model, similarity
Cuvinte cheie: prize de apă, râuri de munte, model experimental,
similitudine

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28-48 OPORTUNITATEA VIZUALIZĂRII FORMĂRII CONTROLATE A DOPULUI DE GHEAŢĂ PE UN TRONSON DE CONDUCTĂ ORIZONTALĂ

THE CONVENIECE OF VISUALISING THE CONTROLLED FORMATION OF ICE PLUGS IN HORIZONTAL PIPE-LINE SECTION
The technique of forming controlled ice plugs in pipe-line installations in order to isolate a section from the rest of the circuit is used for carrying out circuit maintenance or repair activities without shutting down the entire installation. The geometrical characteristics of the ice plug can vary from one test to another, depending on the conditions under which the test is being carried out and the events that occur during this time. Studying this process requires visualizing the forming of ice layers inside the pipe.
This paper describes the convenience of visualizing the formation of ice plugs by studying the effect of the events and interventions that occur during controlled tests that have been carried out in horizontal pipe-line sections.
Key words: isolating a pipe-line section, visualizing the forming of ice layers
Cuvinte cheie: izolarea unui tronson de conductă, vizualizarea depunerii de gheaţă

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