Abstract
During water filling a long-slope pipeline, air pocket is very likely to be entrapped at peak point. In order to track air movement and predict air removal conditions, a mathematical model of air pocket evolution, including its formation, compression, and entrainment, is proposed in this paper. The simulation results were compared with the engineering field data and the two are basically consistent. Furthermore, the two most important factors which play a great role in the removal of air pocket, i.e., the terrain category and the inlet flow rate, are analyzed in detail. It is concluded that the removal conditions reach three outcomes: air pocket compressed and partly removed, compressed and completely removed, and compressed without any removal. In this paper, the terrain which leads to the last outcome is called the “Dangerous Terrain.” And for the “Dangerous Terrain,” it is of great importance that the inlet flow rate should be strictly confined within a certain level. While for the other two categories of terrains, an increased flow rate is in any respect beneficial to the removal of air pocket.
Highlights
Air pocket is very likely to be entrapped at high points during water filling a long-slope pipe. e entrapped air, if cannot be removed properly and timely, may cause a series of probable damages, such as water column separation, pipeline transport efficiency reduction, power consumption increase, etc. [1,2,3]
By giving a comprehensive consideration of air pocket formation, compression, and entrainment, a mathematical method of air pocket evolution during water filling a longslope pipeline is proposed in this paper
E most important factors that affect the removal of air pocket are the terrain category and the inlet flow rate
Summary
Air pocket is very likely to be entrapped at high points during water filling a long-slope pipe. e entrapped air, if cannot be removed properly and timely, may cause a series of probable damages, such as water column separation, pipeline transport efficiency reduction, power consumption increase, etc. [1,2,3]. Air pocket is very likely to be entrapped at high points during water filling a long-slope pipe. It should be noted that most of the current research is still based on horizontal or near-horizontal pipes or individual downward-sloping pipes, rather than pipelines laid along mountainous areas with continuous long-slope and typical V-shaped pipes For the latter, air-water flow will be much more complex. Many considerable works on air entrapment have been carried out to date, due to the weak understanding of the air–water interaction mechanism in the long-slope pipeline, the flow characteristics associated with air pocket formation, compression, and entrainment have been rarely studied. Erefore, based on a comprehensive consideration of formation, compression, and entrainment of air pocket, a mathematical model of air pocket evolution is proposed in this paper to track air movement and predict air removal conditions in long-slope pipelines. Based on all the above, the model is considered to have a significant meaning in laying the theoretical and scientific basis on the optimal design and safe operation for water filling pipelines with long slopes
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
