scholarly journals Research on the water hammer protection of the air vessel caused by underground pipe burst in long distance water supply system

2018 ◽  
Vol 246 ◽  
pp. 01066 ◽  
Author(s):  
Xingtao Wang ◽  
Jian Zhang ◽  
Xiaodong Yu ◽  
Lin Shi
Keyword(s):  
Water Supply ◽  
Check Valve ◽  
Water Hammer ◽  
Supply System ◽  
Water Supply System ◽  
Safe Operation ◽  
Long Distance ◽  
Underground Pipe ◽  
Pipe Burst ◽  
The Mathematical Model

The conventional air vessel installation is usually installed behind the check valve at the upstream end of the pipeline to effectively control the water hammer pressure due to pump trip. However, the water hammer pressure caused by underground pipe burst has been neglected. The water hammer protection of air vessel due to pipe burst in long distance water supply system was discussed in this paper. According to analysis of the process of the pipe burst, the mathematical model of underground pipe burst and air vessel were established. A new air vessel installation that was installed in the middle of the pipeline was proposed. The new air vessel installation was simulated by method of characteristics. Then it was compared with the conventional air vessel when the pump trip and the pipe burst occur respectively. The results show that both the conventional air vessel and the new air vessel can effectively protect the water hammer duo to the pump trip. Moreover, when pipe burst occurs, the conventional air vessel cannot achieve the safe operation of the long distance water supply system. However, under the same air vessel type parameters, the new air vessel installation can effectively protect the water hammer pressure.

Effect of multi-valve closure on superposed pressure in a tree-type long distance gravitational water supply system

2019 ◽  
Vol 68 (6) ◽  
pp. 420-430
Author(s):  
Xingtao Wang ◽  
Jian Zhang ◽  
Xiaodong Yu ◽  
Sheng Chen ◽  
Wenlong Zhao ◽  
...  
Keyword(s):  
Water Supply ◽  
Pressure Rise ◽  
Water Hammer ◽  
Supply System ◽  
Water Supply System ◽  
Maximum Pressure ◽  
Valve Closure ◽  
Long Distance ◽  
Maximum Water ◽  
Tree Type

Abstract Valves are installed at the end of each branch pipeline in a tree-type long distance gravitational water supply system to regulate flow. However, the sequential closing of all valves may cause a tremendous superposed pressure rise, even larger than the pressure rise under simultaneous valve closure. In this paper, the effects of sequential valve closure on the superposed maximum water hammer pressure rise in a pipeline were investigated. By using the wave superposition principle, a sequential valve closure formula leading to maximum water hammer was proposed and verified using numerical simulation based on a practical project. In addition, the superposed maximum pressure rises in the pipeline were compared under single, simultaneous and sequential valve closure, respectively. The results show that the sequential valve closure formula agrees well with the numerical results and the pressure rise in the pipeline under the sequential closing was the largest. Moreover, compared with the superposed maximum pressure rises at the main pipeline, the effect of sequential valve closure on superposed maximum pressure rise at the branch pipeline is more sensitive.

scholarly journals Development of the Energy Circuits of Development of Contour Regulation of the Supply of Hot Water for Buildings With Variable Flow

2021 ◽  
Vol 7 (1) ◽  
pp. 230-237
Author(s):  
J. Shan ◽  
J. Li ◽  
Z. Guo ◽  
A. Levtsev
Keyword(s):  
Water Supply ◽  
Check Valve ◽  
Supply System ◽  
Water Supply System ◽  
Hot Water ◽  
Actual Measurement ◽  
High Rise ◽  
Hot Water Supply ◽  
Hot Water Supply System ◽  
The Impact

The hot water supply system is one of the important components of the water supply and drainage system of high-rise civil buildings. With the development of the national economy and the improvement of people’s living standards, people’s requirements for popularizing hot water supply and improving hot water supply technology are becoming more and more urgent. In the process of hot water supply, the flow pressure of the pipeline is increased, and the purpose of hot water supply in high-rise buildings is achieved. The experiment analyzes the effect of the pressure ratio on the pipeline in front of the accumulator and the impact valve on the flow of coolant through the check valve. First, through the periodic opening and closing of the shock valve, the pressure continues to rise and fall, and the spring hose exhibits periodic pulsation. The effects of different pressure ratios on pipeline pressure and flow rate are studied, and the data of simulation calculation and actual measurement are analyzed through experiments. The research results have practical significance for improving the water supply efficiency of the hot water supply system of high-rise buildings.

scholarly journals A Case Study on Risk Assessment of Long Distance Water Supply System

2014 ◽  
Vol 70 ◽  
pp. 1762-1771 ◽  
Author(s):  
J. Zhang ◽  
J. Gao ◽  
M. Diao ◽  
W. Wu ◽  
T. Wang ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Water Supply ◽  
Supply System ◽  
Water Supply System ◽  
Long Distance

Design of water supply system from rivers using artificial intelligence to model water hammer

2018 ◽  
Vol 26 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Amirhossein Salimi ◽  
Hojat Karami ◽  
Saeed Farzin ◽  
Mohammadreza Hassanvand ◽  
Armin Azad ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Water Supply ◽  
Water Hammer ◽  
Supply System ◽  
Water Supply System ◽  
Model Water

Chlorine dioxide disinfection by-products in the Nová Bystrica-Čadca-Žilina long distance water supply system

2006 ◽  
Vol 6 (2) ◽  
pp. 209-214
Author(s):  
J. Kriš ◽  
K. Munka ◽  
E. Büchlerová ◽  
M. Karácsonyová ◽  
L. Gajdoš
Keyword(s):  
Water Supply ◽  
Chlorine Dioxide ◽  
Distribution System ◽  
Supply System ◽  
Water Supply System ◽  
Water Disinfection ◽  
Long Distance ◽  
Residual Concentration ◽  
Chlorine Dioxide Disinfection ◽  
By Products

In a process of water disinfection it is necessary to distinguish between primary disinfection focused on removal or inactivation of microbiological contaminants from raw water, and secondary disinfection focused on maintenance of residual concentration of the disinfector in distribution system. Current practice related to disinfection follows two approaches. The paper presents results from a stage task solution “Research of physical-chemical changes in water quality during its distribution” at the Nová Bystrica-Čadca-Žilina long distance water supply system (LDWSS) focused on the presence of disinfection by-products by using chlorine dioxide.

scholarly journals Formula for determining the size of the air tank in the long-distance water supply system

2020 ◽  
Author(s):  
Xuyun Chen ◽  
Jian Zhang ◽  
Nan Li ◽  
Xiaodong Yu ◽  
Sheng Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Water Supply ◽  
Theoretical Calculation ◽  
Selection Process ◽  
Supply System ◽  
Water Supply System ◽  
Operating Parameters ◽  
Long Distance ◽  
Calculation Results ◽  
Simulation Results

Abstract In the long-distance water supply system, the air tank can effectively protect the water hammer when the pump stops, and the shape parameters of the air tank determine the protective effect. Based on the theory of rigid water body and harmonic vibration, this paper derived the calculation formulas for the surge and bottom pressure changing process of the air tank in the system with and without friction and impedance and put forward the theoretical method to estimate the air tank volume and established the relationship between the operating parameters and the volume. Combined with the actual water supply project, under different working conditions, the theoretical calculation results and numerical simulation results were compared and analyzed. The results showed that the theoretical calculation results of the system with friction and impedance had a better fitting performance than the numerical simulation results, and the operating parameters of the air tank derived after considering the influence of friction and impedance were accurate. This method can simplify the selection process of air tank body parameters. At the same time, the shape optimization of the air tank considering friction and impedance can be improved by 40–50% compared with the results of ignoring friction and impedance.

scholarly journals Water hammer protective performance of a spherical air vessel caused by a pump trip

2019 ◽  
Vol 19 (6) ◽  
pp. 1862-1869 ◽  
Author(s):  
Lin Shi ◽  
Jian Zhang ◽  
Xiaodong Yu ◽  
Sheng Chen
Keyword(s):  
Water Supply ◽  
Method Of Characteristics ◽  
Water Hammer ◽  
Supply System ◽  
Long Distance ◽  
Effective Measure ◽  
Gas Volume ◽  
Protective Performance ◽  
Force Characteristics ◽  
Control Water

Abstract The use of air vessels is an effective measure to control water hammer in a long-distance water supply system. The traditional shape of such vessels is cylindrical. In this paper, an innovative spherical air vessel is proposed to improve the force characteristics of the tank. A mathematical model of the spherical air vessel was established using the method of characteristics. A comparison was performed of water-hammer protection performance between the spherical air vessel and the cylindrical air vessel based on a practical water supply project. Furthermore, a sensitivity analysis on the parameters of the spherical air vessel was performed. The results showed that the spherical air vessels had better protective performance compared with the cylindrical air vessels. Under the same protection requirements, the spherical air vessel can reduce the total volume and surface area by more than 10%. In addition, for a fixed volume of the spherical air vessel, the protective effect improves with the increase of the initial gas volume. Increasing the connecting pipe diameter of the air vessel is beneficial for low-pressure protection, whereas it is adverse to high-pressure protection; in contrast, altering the installation elevation has little effect on water-hammer protection.

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