The water hammer protection and corrosion protection technology of long distance and large elevation difference pressure gravity flow water conveyance pipe

2013 ◽  
pp. 413-416
Keyword(s):  
Corrosion Protection ◽  
Water Hammer ◽  
Gravity Flow ◽  
Long Distance ◽  
Protection Technology ◽  
Water Conveyance ◽  
Elevation Difference

Polyline Closure Law Design and Realization in Long-Distance Water-Supply Project

2010 ◽  
Author(s):  
Jian Zhang ◽  
Xiaodong Yu ◽  
Jianfeng An ◽  
Arash Hazrati
Keyword(s):  
Water Supply ◽  
Theoretical Basis ◽  
Temporal Distribution ◽  
Break Point ◽  
Water Hammer ◽  
Long Distance ◽  
Closure Time ◽  
Water Conveyance ◽  
Flow Inertia ◽  
Application Scope

Long-distance water-supply project is an effective way to solve the uneven spatial and temporal distribution of water resources, but the safety of water conveyance system is threatened seriously by water-hammer. Based on the research of the characteristic of water-hammer with pipe friction considered, the formula of indirect water-hammer is deduced and the application scope of the formula is also discussed, which is the theoretical basis for the design of polyline closure law. To the defects that valve closure time is long and response of accident is slow in the long-distance water-supply project, polyline closure law is designed with consideration of valve overflowing property, which greatly reduces the closure time and water-hammer. At the same time, the flow inertia is large in long-distance water-supply project and break point of polyline closure law is hard to fix. In order to improve the reliability of the mechanical operating system, locking device is installed, which make the polyline closure law carry out successfully and provide a new idea for water hammer protection in long-distance water-supply project.

Analysis on Air Valve Placement in Long-Distance Water Conveyance Pipeline System

2012 ◽  
Vol 610-613 ◽  
pp. 2513-2518
Author(s):  
Shi Feng Huang ◽  
Feng Wang ◽  
Hui Xu ◽  
Xiao Xian Wei
Keyword(s):  
Water Hammer ◽  
Pipeline System ◽  
Key Factors ◽  
Long Distance ◽  
Protection Measures ◽  
Pressure Pipeline ◽  
Pipeline Project ◽  
Water Conveyance ◽  
Air Valve ◽  
Exhaust Valves

Water hammer is one of the key factors that can cause accidents by the burst of pressure pipeline. Important features and related reasons of accidents caused by water hammer in long-distance water conveyance pipeline system were introduced, and protection measures were presented. An long-distant raw water conveyance pipeline project was taken as an example to study on the influence of protective effect by different placement schemes of air valves based on hydraulic transient simulation and analysis. Results shows that largest number of air valves does not reach the best and unreasonable placement of air valves might be the cause of an accident. It is critical to select the proper location of air valves, it is necessary to pay more attention on local hump in the front of pipeline near the pump and put exhaust valves instead of inlet valves at the back of pipeline (except some higher hump location).

Discussion on the Harm and Protection of Water Hammer of Cavities Collapsing during Long Distance Water Transfer Project

2013 ◽  
Vol 777 ◽  
pp. 407-411
Author(s):  
Li Zhao ◽  
Yu Dong Lu
Keyword(s):  
Water Hammer ◽  
Water Transfer ◽  
Constant Speed ◽  
Long Distance ◽  
Hydraulic Impact ◽  
Tube Explosion ◽  
Valve Effect ◽  
Air Valve ◽  
Pipeline Pressure

In long distance water transfer project, the pipeline pressure caused by the change of hydraulic impact on pipeline is the most dangerous, which cavities hammer boost up to the general water several times, the tube explosion phenomenon is most caused by water hammer of cavities collapsing. After long-term practice, two-way surge tower and constant speed buffer air valve effect remarkable on water hammer of cavities collapsing.

Multiobjective optimization of a tubular pump to improve the applicable operating head and hydraulic performance

2020 ◽  
pp. 095440622094711
Author(s):  
Wenlong Zhao ◽  
Jian Zhang ◽  
Xiaodong Yu ◽  
Daqing Zhou ◽  
Melih Calamak
Keyword(s):  
High Efficiency ◽  
Guide Vane ◽  
Optimization Method ◽  
Critical Parameters ◽  
Long Distance ◽  
Blade Thickness ◽  
Weighted Matrix ◽  
Wide Range ◽  
Shaft Power ◽  
Water Conveyance

Tubular pumps are widely used in irrigation and water conveyance projects. However, the operating head of most of these pumps is low, and only a few studies have focused on the design of an efficient tubular pump with a head more than 5 m, which is common in long-distance water supply projects. This work aims to improve the operating head and efficiency of tubular pumps while maintaining a low shaft power. The multi-objective orthogonal optimization method was used to determine the critical parameters of the tubular pump, i.e., blade number, airfoil, blade thickness and guide vane distance, and nine design schemes were selected. Next, by using computational fluid dynamics (CFD), a 3D model of the tubular pumps under different schemes was established, and the results were compared. Subsequently, the range method and weighted matrix method were utilized to find the optimized scheme. In addition, an experimental investigation was performed to verify the simulation and the performance of the designed tubular pump. The results indicated that the optimized scheme improved the operating head to 6.9 m with higher efficiency of 84.2% and a lower shaft power of 27.7 kW. The modeling results were in agreement with the experimental measurements, and the designed tubular pump had a wide range of high-efficiency zones.

Hydraulic capacity of ancient water conveyance systems to Ephesus

2014 ◽  
Vol 14 (6) ◽  
pp. 1010-1017 ◽  
Author(s):  
Ünal Öziş ◽  
Ayhan Atalay ◽  
Yalçın Özdemir
Keyword(s):  
Long Distance ◽  
Clay Pipes ◽  
Inverted Siphon ◽  
Saint John ◽  
Water Conveyance ◽  
Ancient Times

Ephesus was supplied by several long-distance water conveyance systems in ancient times. The 8 km long Şirince water conveyance system consists of baked clay pipes, and had a hydraulic capacity of around 10 l/s. The 7 km long Derbentdere water conveyance system consists also of baked clay pipes; and its hydraulic capacity was around 20 l/s. The 36 km long Değirmendere water conveyance system is a masonry conduit; its hydraulic capacity was around 200 l/s. The 42 km long Kayapınar water conveyance was also a masonry conduit; its hydraulic capacity was around 100 l/s. The Şirince system was extended over to the Ayasuluk hill and Saint John basilica in the 6th century ad by the 650 m long Selcuk aqueduct, serving as the venter of an inverted siphon.

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