Effects of the Air Volume in the Air Chamber on the Performance of Water Hammer Pump System

2011 ◽  
Vol 4 (2) ◽  
pp. 255-261 ◽  
Author(s):  
Sumio Saito ◽  
Masaaki Takahashi ◽  
Yoshimi Nagata
Keyword(s):  
Water Hammer ◽  
Pump System ◽  
Air Volume ◽  
Air Chamber

scholarly journals The Analysis for Energy Consumption of Marine Air Conditioning System Based on VAV and VWV

2018 ◽  
Vol 38 ◽  
pp. 04012
Author(s):  
Sai Feng Xu ◽  
Xing Lin Yang ◽  
Zou Ying Le
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Air Conditioning ◽  
Water Volume ◽  
Pump System ◽  
Air Conditioning System ◽  
Variable Air Volume ◽  
Air Volume ◽  
Marine Air ◽  
Variable Water

For ocean-going vessels sailing in different areas on the sea, the change of external environment factors will cause frequent changes in load, traditional ship air-conditioning system is usually designed with a fixed cooling capacity, this design method causes serious waste of resources. A new type of sea-based air conditioning system is proposed in this paper, which uses the sea-based source heat pump system, combined with variable air volume, variable water technology. The multifunctional cabins’ dynamic loads for a ship navigating in a typical Eurasian route were calculated based on Simulink. The model can predict changes in full voyage load. Based on the simulation model, the effects of variable air volume and variable water volume on the energy consumption of the air-conditioning system are analyzed. The results show that: When the VAV is coupled with the VWV, the energy saving rate is 23.2%. Therefore, the application of variable air volume and variable water technology to marine air conditioning systems can achieve economical and energy saving advantages.

Numerical Analysis of Pipeline Equipment Effect on Water Hammer Using Characteristic Method

2003 ◽  
Author(s):  
Mohammad R. Ansari ◽  
Abdolreza Davari
Keyword(s):  
Momentum Conservation ◽  
Water Hammer ◽  
Loss Coefficient ◽  
Maximum Pressure ◽  
Characteristic Method ◽  
Pump Impeller ◽  
Air Chamber ◽  
Large Pressure Gradient ◽  
Pipeline Equipment ◽  
The Moment

In this attempt effect of pipeline equipment behavior was considered on water hammer numerically. The effect includes opening / closing of the shut off valves, loss of coefficient of the outlet bypass pipe for the air chamber, elasticity of the pipeline and loss coefficient due to friction. In order to study the behavior, mass and momentum conservation equations were solved numerically using characteristic method during transient conditions. As a water hammer phenomena accompanies with large pressure gradient, so the pipeline equipment behavior and their effect were analyzed with respect to the maximum pressure occurrence. For a pipeline of 5000 m length, 1 m diameter, 1 m3/s discharge and 100 m height between upstream and downstream, the following result were concluded: 1-If the moment of inertia of the pump impeller increases by 400 percent, the maximum pressure occurred by the water hammer will decrease by 9 percent. 2-During on and off of the shut off valve, 80 percent of pressure increase due to water hammer was created during the last 15 percent of valve closure. 3-If pressure wave velocity increases by 75 percent, then the maximum pressure generated due to the water hammer will increase by 27 percent. 4-If the loss coefficient of the by pass line of the air chamber decreases by 90 percent, then the maximum pressure due to the water hammer will decrease by 20 percent. 5-If the pipeline Moody friction coefficient increases by 92 percent, the maximum pressure due to the water hammer will increase by 66 percent.

Charts for water hammer in pipelines with air chambers

1977 ◽  
Vol 4 (3) ◽  
pp. 293-313 ◽  
Author(s):  
Eugen Ruus
Keyword(s):  
Water Column ◽  
Pipe Wall ◽  
Water Hammer ◽  
Wall Friction ◽  
Low Resistance ◽  
Discharge Line ◽  
Air Chamber ◽  
Basic Parameters ◽  
Computer Studies

Upsurges and downsurges are calculated and plotted for a simple pump discharge line provided with an air chamber. Basic parameters such as pipeline constant, air chamber parameter, pipe wall friction, and orifice resistance are used. The results of this paper can be used to determine the necessary volume of the air chamber. Computer studies indicate that the assumption of the rigid water column and the concentration of pipe friction at the pump end of the pipeline yields reasonably good results at the pump end; however, because of these assumptions, large errors in estimation of both upsurges and downsurges occur at the midpoint and particularly at the quarter point of the pipeline. Pipe friction has a substantially different effect on surges than that of the orifice resistance; these two effects should therefore be considered separately. A differential orifice is recommended and considered; this orifice should have a low resistance to flow out of the chamber.

scholarly journals Reducing the Effects of Water Hammer Phenomenon in Pipelines by Changing the Closing Rate of Line Break Valve (LBV)

2021 ◽  
Author(s):  
Mohammad Reza Boroomand ◽  
◽  
Nasim Safar Razavizadeh ◽  
Ahmad Eshghi ◽  
◽  
...  
Keyword(s):  
Transmission Line ◽  
Initial Conditions ◽  
Saline Water ◽  
Flow Analysis ◽  
Flow Simulation ◽  
Environmental Hazards ◽  
Water Hammer ◽  
Air Chamber ◽  
Water Transmission ◽  
Closing Rate

Line break valves in pipelines are using to prevent environmental hazards caused by the entry of the fluid into the surrounding. The operation of these valves leads to sudden changes in pressure and velocity, resulting in the occurrence of the water hammer phenomenon. The water hammer pressure will cause serious problems such as the destruction of pipelines and transmission line equipment and tools. Due to the salinity of water, when a fracture occurs, the amount of water that enters the surrounding is environmentally essential, so the use of several LBVs is vital. This paper investigated a water transmission line with a total length of 337 km that transfers saline water from Khoor Moosa to Azadegan plain. This study discussed the closing of the valve at different rates and the solution to reduce its destructive effects. WaterGEMS V8i software and Hammer V8i software are respectively using to perform a steady flow simulation and damping flow analysis for this phenomenon. The results obtained from the steady-state flow simulation is the initial conditions in the damping flow calculations. Then, by reducing the closing rate of the valve in 6 different scenarios, the volume of air chambers decreased. Finally, the results led to creating a linear relationship between the valve closing rate and the capacity of the air chamber. The optimal model for this rate depends on reducing the construction cost as well as the environmental hazards caused by discharged water.

scholarly journals POTENSI TEKANAN WATER HAMMER PADA PIPA PVC 1,5 IN SEBAGAI DRIVE PIPE UNTUK POMPA HIDRAM

2020 ◽  
Vol 6 (2) ◽  
pp. 536-540
Author(s):  
Rusmana ◽  
Salsabila Risti Runisa ◽  
Rima Melati
Keyword(s):  
Water Hammer ◽  
Drive Pipe ◽  
Air Chamber

Pada penelitian ini dibuat simulasi sistem pompa hidram yang mencakup instalasi pengujian water hammer dengan tambahan drive pipe berbahan PVC dan Galvanis. Pipa uji lerdiri dari pipa galvanis diameter 1 in sepaniang 25 meter dan disambung dengan pipa galvanis diameter 1,5 in sepanjang 12,25 meter. Pipa uji yang ke 2 adalah pipa galvanis diameter 1 in disambung dengan pipa PVC diameter 1,5 in sepanjang 12,25 meter. Simulasi ini bertujuan untuk melihat fenomena potensi tekanan water hammer pada kedua pipa uji tersebut. Sumber air dialirkan dengan menggunakan pompa ke pipa uji sebagai drive pipe lalu aliran tersebut dihentikan oleh penutupan katup solenoid yang diatur oleh ATMEGA 16 controller. Tekanan yang dihasilkan akibat penutapan katup inilah yang disebut tekanan water hammer yang kemudian disimpan di air chamber. Jika katup delivery dibuka maka air mengalir melalui delirery pipe. Semakin tinggi tekanan water hammer, maka semakin tinggi kemampuan untuk menaikan air. Pemilihan material untuk bahan drive pipe akan berpengaruh pada tekanan yang dihasilkan. Penggunaan pipa PVC pada debit 202,75 ml/s menghasilkan tekanan sebesar 1 bar. Sedangkan, pipa galvanis pada debit 185,12 ml/s menghasilkan tekanan sebesar 4,7 bar.

Water hammer in the pump-rising pipeline system with an air chamber

2014 ◽  
Vol 26 (6) ◽  
pp. 960-964 ◽  
Author(s):  
Sang-Gyun Kim ◽  
Kye-Bock Lee ◽  
Kyung-Yup Kim
Keyword(s):  
Water Hammer ◽  
Pipeline System ◽  
Air Chamber

1616 Effect of water hammer on blood pump system

2007 ◽  
Vol 2007.2 (0) ◽  
pp. 243-244
Author(s):  
Ryo YAMANO ◽  
Kohhei TANAKA ◽  
Young-Joon KIM ◽  
Youichi NAKAMURA ◽  
Hiroshi TSUKAMOTO ◽  
...  
Keyword(s):  
Water Hammer ◽  
Blood Pump ◽  
Pump System ◽  
Effect Of Water

scholarly journals Rationing the Pressurized Air-Vessel Volume for Water Hammer Protection in Water Pipe Systems

2018 ◽  
Vol 6 (2) ◽  
Author(s):  
Ahmed El-Dabaa ◽  
Osama Khorais
Keyword(s):  
Water Hammer ◽  
Safety System ◽  
Piping System ◽  
Equivalent Resistance ◽  
Initial State ◽  
Efficient Operation ◽  
System Protection ◽  
Transient Problems ◽  
Air Volume ◽  
Pump Station

Air vessel is one of the efficient devices for controlling and protecting the piping system against transient problems as water hammer phenomenon. Old studies illustrated the air vessel importance and its working methodology. In order to maximize the performance and minimize the hazardous problems of such system, protection devices (such as air vessel) cost is one of the considerations in the design process. Therefore, its characteristics are highly important for efficient operation with less expensive safety system. This research paper presents a numerical modelling work to investigate the effect of the Air Vessel parameters, such as (1) dimensions (diameter, D, height, H), (2) the connection equivalent resistance, hlc, between the vessel and the main pipeline and (3) initial state parameter (initial air volume, Vai). Those parameters affects the vessel total volume (Vt) and operation as well as the safety system. A pump station is simulated as a case study using Wanda model. The results showed that the specifications change in vessel height, H, connection equivalent resistance, hlc, with main pipe and initial air volume, Vai, have a great impact on the system protection against transient problems when using the air vessel.

scholarly journals Pengaruh Diameter Lubang Snifter-Valve Terhadap Peningkatan Tekanan Dalam Tabung Udara Pompa Hydram

2019 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Made Sucipta ◽  
Made Suarda ◽  
I Nengah Suweden
Keyword(s):  
Water Hammer ◽  
The Body ◽  
Orifice Diameter ◽  
Drive Pipe ◽  
Pump Operation ◽  
Air Volume ◽  
Supply Problem ◽  
Maximum Work ◽  
Electrical Supply ◽  
Increased Pressure

Pompa hydram telah banyak diaplikasikan terutama di daerah pedesaan atau perbukitan dimana ketersediaan suplai energy listrik menjadi kendala. Pompa hydram adalah pompa mekanis yang memanfaatkan peningkatan tekanan (water hammer) yang terjadi akibat mekanisme penutupan katup limbah secara tiba-tiba. Untuk itu pada badan pompa hydram dipasang tabung udara untuk mengurangi denyutan aliran air hasil pemompaan. Dalam kurun waktu tertentu operasi pompa hydram, jumlah udara yang ada dalam tabung udara akan terus berkurang. Untuk menggantikan volume udara dalam tabung udara tersebut maka pompa hydram dilengkapi dengan katup penghirup udara (snifter-valve). Namun dalam implementasinya, katup ini hanya berupa lubang berdiameter 1 ÷ 2 mm pada jarak sekitar 2 cm di bawah katup tekan pada badan pompa hydram. Namun sampai saat ini belum ada acuan diameter lubang snifter-valve tersebut. Oleh sebab itu, pada penelitian ini diinvestigasi besarnya peningkatan tekanan yang terjadi dalam tabung udara pompa hydram. Pada penelitian ini pompa hydram dilengkapi dengan katup hirup dengan variasi diameter lubangnya yaitu 0,5, 1,0, 1,5, 2,0 dan 2,5 mm. Hasil penelitian menunjukkan bahwa pada model pompa hydram dengan pipa penggerak berdiameter 1¼ inchi yang diuji, peningkatan tekanan yang terjadi dalam tabung udara berkisar antara 0,4 sampai dengan 0,5 bar. Snifter-valve dengan lubang berdiameter 1,5 mm menghasilkan peningkatan tekanan water hammer tertinggi dalam tabung udara sehingga memberikan kerja tertinggi yang terjadi dalam pompa hydram. Hydraulic ram pumps have been implemented and installed mainly in hilly or remote area where they are facing public electrical supply problem. Hydraulic ram pumps are mechanical pumps that utilize the increased water hammer due to the sudden shutdown mechanism of the waste valve. Therefore, the hydraulic ram pump is equipped with air vessel to reduce the pulsation of the pumping water flow. Within a certain period of hydraulic ram pump operation, the amount of air present in the air vessel will continue to decrease. In order to replace the air volume in the air vessel, the hydraulic ram pump is equipped with a snifter-valve. However, in its implementation, this valve is only a hole with a diameter of 1 ÷ 2 mm at a distance of about 2 cm below the delivery valve on the body of the hydraulic ram pump. However, there has not been any reference for determining the diameter of the snifter-valve hole yet. Therefore, in this study, works carried out for investigating the magnitude of the increased pressure that occurs in the air vessel of hydram pump. In this study, a hydraulic ram pump equipped with a snifter-valve with various orifice diameters of 0.5, 1.0, 1.5, 2.0 and 2.5 mm. The results show that for the hydraulic ram pump model with 1¼ inch diameter of the drive pipe that tested, the incrising pressure in the air vessel is about 0.4 up to 0.5 bar. The snifter-valve with 1.5 mm orifice diameter generates the highest incrising pressure of water hammer pressure in the air vessel, therefore, it gives the maximum work in the hydraulic ram pump.

Design & Calculation of Air Chamber of Air Cushion Belt Conveyor

2013 ◽  
Vol 473 ◽  
pp. 3-6
Author(s):  
Bang Ying Peng ◽  
Jian Hua Yan ◽  
Shu Cao
Keyword(s):  
Influence Factors ◽  
Practical Experience ◽  
Structure Design ◽  
Air Pressure ◽  
Design Calculation ◽  
Belt Conveyor ◽  
Air Volume ◽  
Air Chamber ◽  
Air Cushion ◽  
Opening Method

The article mainly provides an overview of air cushion belt conveyor, and describes design of air chamber, as an important part of the air cushion belt conveyor. The article introduces reasonable structure design of the air chamber from aspect of practical experience. In addition, the article researches air pressure design and calculation of air chamber, design and calculation of air volume of the air chamber, as well as power determination and design calculation on fan. The article designs and calculates per opening area of the air chamber as well as opening method of the chute depending on air pressure and air volume, and simultaneously analyzes formation influence factors and features of air pad in the chute. And finally, the article proposes reference conclusion and suggestions on the basis of research on the design of the air chamber.

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