Design of ultrasonic transducer for leakage detection on PVC water pipeline
Nowadays most of the water pipelines for domestic and commercial areas are made from polyvinyl chloride (PVC). It has advantages such as lighter weight, higher flexibility to comply with ground quake and tremble, higher resistibility to corrosion as a result of climate and temperature changing, a...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2014
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/64385/1/FK%202014%20145IR.pdf |
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| Summary: | Nowadays most of the water pipelines for domestic and commercial areas are made
from polyvinyl chloride (PVC). It has advantages such as lighter weight, higher
flexibility to comply with ground quake and tremble, higher resistibility to corrosion
as a result of climate and temperature changing, along with lower production and
installation cost. However, it has less resistibility to endure pressures either from
inside or outside the pipeline. Since these pipelines are not for valuable liquids such
as petroleum, there is no particular monitoring system available for them yet. In
many cases, leakage occurs for months or even years and they cannot be detected
unless the leakage effect becomes significant. According to a study 10% of US water
pipelines had water loss which estimated to cost around $4.3 billion per year. Almost
the same percent of loss or even more is existing in European counties. Therefore
having a simple and affordable monitoring system is necessary for natural resources
conservation.
The conventional pipelines monitoring systems are commonly used to monitor long
distance metallic petroleum pipelines and they are not reliable for monitoring the
short distance PVC pipelines. This thesis discussed a non-invasive ultrasonic PVC
pipelines monitoring system with modified V-topology. The proposed technique uses
a pair of 40 KHz ultrasonic transducers with designed interface circuitries for
emitting and receiving the signal. The designed interface circuits improved the
emitted and received signal along with reduces of power consumption. The analysis
carried includes signal fitness recognition and normalized cross-correlation that
compared the transmitted and received signal. The developed system consumed
2.5W which can be supply from USB port. The proposed technique is for leak
detection with power consumption around 2.5 watts, which can be supplied from
universal serial bus or any available battery with more than 0.5 mA current injection.
In wireless communication system is transmitting results of pipe monitoring in conjunction with temperature and humidity to the center. This information is
available in installed on board LCD and designed webpage through online access. In comparison with available techniques, this ultrasonic monitoring is non-invasive
to pipeline as there is no contact or involvement with it. Proposed method is designed
to monitor physical condition of PVC pipelines and differentiate pipe with leakage
from a healthy pipeline by use of air-coupled transducers. The system’s operation has
been tested on a general size PVC pipeline with 60 mm diameter for different size of
orifices from 3 mm to 6 mm. As a result of experimental tests, system was able to
detect orifices as small as 4.5 mm and greater accurately. System applied on pipeline
with and without water and results proved that the pipe with very low pressure has
very close trend to pipe without water. Occurrence of leakage in pipeline decreases
the strength of received signal and increase of orifice tends to weakening it further.
Operation tested for different location angles from 20 to 70 degrees and 60 degree
was chosen as relatively high signal strength with recognition accuracy of 94.924%
and covering area on pipeline near to 90 cm. Along with leak recognition, this
research revealed that the smaller angle contributes to longer transducers distance
and less accuracy. Then by increase of central frequency angles, accuracy of
recognition reduced as well. |
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