Water hammer analysis when switching of parallel pumps based on contra-motion check valve

A suddenly pump stop in multi-pump parallel connection system could induce water hammer which may cause serious accidents. To prevent water hammer harm, comparing experiments was carried out to study the water hammer phenomenon in the lift closing check-valve adopted system and the shuttle check valve adopted system. The result indicates that, the shuttle check valve greatly cuts the peak-value produced by stop-pump water hammer impulsion, and reduces the probability of bringing a devastating water hammer accident.

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Water Hammer Characteristics for Parallel Pumps Water Supply Systems

Volume 3: Thermal Hydraulics; Instrumentation and Controls ◽

10.1115/icone16-48528 ◽

2008 ◽

Author(s):

Wenxi Tian ◽

Guanghui Su ◽

Suizheng Qiu ◽

Gaopeng Wang ◽

Qing Lu

Keyword(s):

Power Plant ◽

Nuclear Power Plant ◽

Water Supply ◽

High Speed ◽

Nuclear Power ◽

Optimization Design ◽

Check Valve ◽

Water Hammer ◽

Characteristic Line ◽

Water Supply Systems

The water hammer induced by abrupt velocity change of fluid flow is inevitable for nuclear power plant systems because of the sudden opening or closing of valves, the sudden startup or shutdown of the pumps and the rupture of pipes. The water hammer pressure wave can damage the pipes and cause the abnormal shutdown of Nuclear Power Plant (NPP). The object of this study is a Parallel Pumps Water Supply system (PPWS) adopted in a NPP. The PPWS is composed of two parallel mixed-flow pumps connected with a check valve separately, a container, a throttle flap and pipe lines. The Method of Characteristic line (MOC) was adopted to evaluate the water hammer behaviors of the PPWS during the alternate startup and shutoff conditions of two parallel pumps. A code was developed using Fortran language to compute the transient behaviors including he peak pressure, the flow velocity and the movement of the valve plate. The results indicate that the water hammer behaviors under low speed startup condition differ from that of high speed startup condition. The maximum pressure vibration amplitude is up to 5.0MPa occurring under high-high speed startup condition. The computation results are instructive for the optimization design of the PPWS so as to minimize the damage potential induced by water hammer.

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The Sensitivity of Counterweighted Swing Check Valve Performance to Counterweight Location

Aging Management and Component Analysis ◽

10.1115/pvp2003-2170 ◽

2003 ◽

Author(s):

L. I. Ezekoye

Keyword(s):

Flow Resistance ◽

Reverse Flow ◽

Check Valve ◽

Fast Response ◽

Water Hammer ◽

Flow Reversal ◽

Reverse Direction ◽

Valve Closure ◽

Forward Flow ◽

Opening And Closing

Check valves are used to minimize flow reversal. In general, the two primary design objectives of installing a check valve in a system include quick opening in forward flow and fast closure in reverse flow. The fast response requirements in both opening and closing directions are challenging. In the opening direction, the concern is to minimize forward flow resistance and, in the reverse direction, the objective is to minimize flow reversal and avoid water hammer. Check valve manufacturers have often used counterweights to permit quick opening or quick closing. The drawback of forward flow counterweight check valves is that in the flow reverse direction, the counterweights may retard valve closure. The location of the counterweight could further complicate the performance of the check valve. Misaligning the counterweight can also affect check valve performance. The use of quick closing counterweights present similar challenges. This paper examines the interaction of counterweight location and alignment on the performance of check valves.

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Optimization of the Location of Check Valve to Minimize the Water Hammer Effects in a Pipeline

Recent Advancements in Civil Engineering - Lecture Notes in Civil Engineering ◽

10.1007/978-981-16-4396-5_75 ◽

2021 ◽

pp. 879-889

Author(s):

P. D. Jiwane ◽

A. D. Vasudeo ◽

A. K. Singh

Keyword(s):

Check Valve ◽

Water Hammer

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

MATEC Web of Conferences ◽

10.1051/matecconf/201824601066 ◽

2018 ◽

Vol 246 ◽

pp. 01066 ◽

Cited By ~ 1

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.

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Analisis Variasi Beban dan Bentuk Disk Katup Limbah Terhadap Efek Water Hammer

Journal of Mechanical Engineering, Science, and Innovation ◽

10.31284/j.jmesi.2021.v1i1.1759 ◽

2021 ◽

Vol 1 (1) ◽

Author(s):

Gilang Satrio Bawono ◽

Dwi Khusna ◽

Zain Lillahulhaq ◽

Naili Saidatin

Keyword(s):

Check Valve ◽

Water Hammer ◽

Relief Valve

Katup merupakan peralatan mekanik statis yang bertujuan untuk mengontrol aliran dan tekanan dalam suatu sistem perpipaan. Pemilihan jenis katup, bentuk desain dan jenis material memiliki peran yang sangat penting dalam kinerja dan kehandalan sistem. Pompa hidram bekerja dengan memanfaatkan proses palu air. Terjadinya palu air akan mengakibatkan sebagian air menuju ke tabung udara dan sebagian lagi akan mengalami aliran balik pada pipa penggerak. Pencegahan water hammer bisa dengan cara pemasangan check valve, relief valve, menambah waktu pembukaan dan penutupan valve. Oleh karena iu pada penelitian ini akan digunakan variasi beban dan bentuk katub limbah terhadap efek water hammer Penelitian ini menggunakan variasi katup limbah champfer,normal dan fillet. Hasil penelitian menunjukan bentuk disk champfer dengan berat beban 200 gram memliliki kecepatan aliran tertinggi yaitu 0,72752 m/s dengan nilai Reynold 18479,21. Sedangan variasi bentuk disk fillet memili nilai kecepatan terrendah dengan nilai 0.48276 m/s dengan nilai reynold 12262,29.

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CFD Numerical Simulation of Water Hammer in a Vortex Diode

Volume 8: Computational Fluid Dynamics (CFD); Nuclear Education and Public Acceptance ◽

10.1115/icone26-81790 ◽

2018 ◽

Cited By ~ 1

Author(s):

Junrong Wang ◽

Zhiguo Wei ◽

Jinlan Gou ◽

Qi Xiao ◽

Shaodan Li ◽

...

Keyword(s):

Pressure Fluctuation ◽

3D Model ◽

Transient Flow ◽

Flow Characteristics ◽

Check Valve ◽

Water Hammer ◽

Nuclear Industry ◽

Pipeline System ◽

1D Model ◽

Inlet Conditions

In the pipeline system of nuclear industry, shock wave pressure in a pipe will be caused by the fast closing check valve after the pumping stops. This phenomenon is known as water hammer, which brings hidden danger to the security and reliability of the pipeline system. Specially, water hammer may cause serious damage on the pipeline system by the valve misoperation, by the valve malfunction, or by other unexpected events. A vortex diode is used as a highly reliable check-valve in nuclear applications, where it mainly benefits from the intrinsic properties of no moving parts and no leakage. In this paper, we proposed a novel method based on a vortex diode to protect water hammer. In the traditional analysis, a simple one-dimensional (1D) model is often used to simulate the water hammer. However, it is difficult to get the transient flow characteristics in a vortex diode using a 1D model. Thus, a three-dimensional (3D) model using computational fluid dynamics (CFD) is proposed to analyze water hammer in a pipeline system with a vortex diode. The 3D model was firstly verified by comparing the numerical results of CFD with experimental results of a water hammer test. Based on the 3D model, the water hammer was simulated at different inlet conditions in a pipeline system with a vertex diode. In order to investigate the vortex diode used as a leaky check-valve, the inlet pressure was decreased by the corresponding value of pump head to simulate the pump stop after the quasi-steady state was achieved in the vortex diode. It is found that the pressure fluctuation of water hammer is comparable to the pump value, which is not varying with initial velocity in the pipeline system. Thus, we have proved that a vortex diode in the pipeline system acts significantly in suppressing pressure fluctuation of water hammer. This study presents a CFD-based numerical method for water hammer and could be useful in protecting water hammer in nuclear industry.

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