Damping of Self-Excited Pressure Pulsations in Petrodiesel Pipeline

2014 ◽  
Vol 630 ◽  
pp. 375-382 ◽  
Author(s):  
Daniel Himr ◽  
Vladimir Haban
Keyword(s):  
Hydraulic System ◽  
Check Valve ◽  
Control Valve ◽  
Sampling Frequency ◽  
Pressure Pulsations ◽  
One Dimensional ◽  
Fuel Storage ◽  
Excited Oscillation ◽  
Subsequent Measurement ◽  
And Control

A pumping station in a fuel storage suffered from pressure pulsations in a petrodiesel pipeline. Check valves protecting the station against back flow made a big noise when disc hit a seat. Due to employees complaints we were asked to solve the problem, which could lead to serious mechanical problems. Pressure measurement in the pipeline showed great pulsations, which were caused by self-excited oscillation of control valves at the downstream end of pipeline. The operating measurement did not catch it because of too low sampling frequency. One dimensional numerical model of the whole hydraulic system was carried out. The model consisted of check valve, pipeline and control valve, which could oscillate, so it was possible to simulate the unsteady flow. When the model was validated, a vessel with nitrogen was added to attenuate pressure pulsations. According to the results of numerical simulation, the vessel was installed on the location. Subsequent measurement proved noticeably lower pulsations and almost no noise.

scholarly journals Static Characteristics of Pressure Control Valve

2017 ◽  
Vol 67 (1) ◽  
pp. 119-124
Author(s):  
Ondřej Vykoukal ◽  
Lumír Hružík ◽  
Adam Bureček
Keyword(s):  
Experimental Measurement ◽  
Hydraulic System ◽  
Check Valve ◽  
Control Valve ◽  
Pressure Control ◽  
Static Characteristics ◽  
Hydraulic Pump ◽  
Relief Valve ◽  
Pressure Control Valve

Abstract The article deals with the measurement of static characteristics of a pressure control valve. The pressure, at which the valve starts to leak oil, is adjusted by a spring. The measurement is performed on a hydraulic system that consists of tank, hydraulic pump, check valve, relief valve and pressure control valve which is measured. The results of this experimental measurement are Δp - Q characteristics of the pressure control valve for various pressure settings.

A Mathematical Model Including Mechanical Structure, Hydraulic and Control of LHDS

Robotica ◽  
2021 ◽  
pp. 1-16
Author(s):  
Guoliang Ma ◽  
Kaixian Ba ◽  
Zhiwu Han ◽  
Zhengguo Jin ◽  
Bin Yu ◽  
...  
Keyword(s):  
Simulation Model ◽  
Hydraulic System ◽  
Inverse Dynamics ◽  
Hydraulic Drive ◽  
Operation Time ◽  
Variable Load ◽  
Mechanical Structure ◽  
Load Characteristics ◽  
Common Problems ◽  
And Control

SUMMARY In this paper, mathematical models of kinematics, statics and inverse dynamics are derived firstly according to the mechanical structure of leg hydraulic drive system (LHDS). Then, all the above models are integrated with MATLAB/Simulink to build the LHDS simulation model, the model not only considers influence of leg dynamic characteristics on hydraulic system but also takes into account nonlinearity, variable load characteristics and other common problems brought by hydraulic system, and solves compatibility and operation time which brought by using multiple software simultaneously. The experimental results show the simulation model built in this paper can accurately express characteristics of the system.

Momentum exchange impact damper design methodology for object-wall-collision problems

2017 ◽  
Vol 24 (14) ◽  
pp. 3206-3218
Author(s):  
Yohei Kushida ◽  
Hiroaki Umehara ◽  
Susumu Hara ◽  
Keisuke Yamada
Keyword(s):  
Optimal Design ◽  
Design Methodology ◽  
Design Parameters ◽  
Momentum Exchange ◽  
Impact Damper ◽  
One Dimensional ◽  
Practical Design ◽  
Wall Collision ◽  
Damper Design ◽  
And Control

Momentum exchange impact dampers (MEIDs) were proposed to control the shock responses of mechanical structures. They were applied to reduce floor shock vibrations and control lunar/planetary exploration spacecraft landings. MEIDs are required to control an object’s velocity and displacement, especially for applications involving spacecraft landing. Previous studies verified numerous MEID performances through various types of simulations and experiments. However, previous studies discussing the optimal design methodology for MEIDs are limited. This study explicitly derived the optimal design parameters of MEIDs, which control the controlled object’s displacement and velocity to zero in one-dimensional motion. In addition, the study derived sub-optimal design parameters to control the controlled object’s velocity within a reasonable approximation to derive a practical design methodology for MEIDs. The derived sub-optimal design methodology could also be applied to MEIDs in two-dimensional motion. Furthermore, simulations conducted in the study verified the performances of MEIDs with optimal/sub-optimal design parameters.

The Study of Temperature Control Hydraulic Sensor

2012 ◽  
Vol 468-471 ◽  
pp. 1266-1269
Author(s):  
Yan Jun Zhang ◽  
Zi Ming Kou ◽  
Gui Jun Gao ◽  
Jun Zhang
Keyword(s):  
Temperature Control ◽  
Hydraulic System ◽  
Control Valve ◽  
Elastic Force ◽  
Working Environment ◽  
Hydraulic Circuit ◽  
New Type ◽  
Spool Valve ◽  
Special Working

Abstract. To improve the automation degree in special working environment which contains explosive gas. We develop a new type of temperature control hydraulic sensor basically on theory and lots of experiments. As the temperature reaches about 85°C，the motion part of the inductor will stretch to a certain length, and then it will push the adjusting rod. Simultaneously，the adjusting rod will overcome the elastic force of the spring and compel the spool valve to deform, and finally the control valve port will be open, it allows the control oil of the hydraulic system to pass. At last it reaches our destination that we can make the control of hydraulic circuit be realized.

Soft Switching Approach to Reducing Transition Losses in an On/Off Hydraulic Valve

2009 ◽  
Author(s):  
Michael B. Rannow ◽  
Perry Y. Li
Keyword(s):  
Hydraulic System ◽  
Check Valve ◽  
Fluid Flows ◽  
Soft Switching ◽  
Total System ◽  
System Efficiency ◽  
Hydraulic Systems ◽  
Controlled Systems ◽  
Flow Through ◽  
Hydraulic Valve

A method for significantly reducing the losses associated with an on/off controlled hydraulic system is proposed. There has been a growing interest in the use of on/off valves to control hydraulic systems as a means of improving system efficiency. While on/off valves are efficient when they are fully open or fully closed, a significant amount of energy can be lost in throttling as the valve transitions between the two states. A soft switching approach is proposed as a method of eliminating the majority of these transition losses. The operating principle of soft switching is that fluid can temporarily flow through a check valve or into a small chamber while valve orifices are partially closed. The fluid can then flow out of the chamber once the valve has fully transitioned. Thus, fluid flows through the valve only when it is in its most efficient fully open state. A model of the system is derived and simulated, with results indicating that the soft switching approach can reduce transition and compressibility losses by 79%, and total system losses by 66%. Design equations are also derived. The soft switching approach has the potential to improve the efficiency of on/off controlled systems and is particularly important as switching frequencies are increased. The soft switching approach will also facilitate the use of slower on/off valves for effective on/off control; in simulation, a valve with soft switching matched the efficiency an on/off valve that was 5 times faster.

The Effect of Bandwidth of Semiactive Dampers on Vehicle Ride

1993 ◽  
Vol 115 (3) ◽  
pp. 571-575 ◽  
Author(s):  
J. Lieh
Keyword(s):  
Fourier Transform ◽  
Significant Influence ◽  
Switching Time ◽  
Control Valve ◽  
Mean Square ◽  
Active Suspensions ◽  
Car Model ◽  
Frequency Responses ◽  
And Control ◽  
Valve Switching

A passenger car model with a full car body and four wheel-axle assemblies is used to investigate the influence of semiactive suspensions on ride performance. Mean square values are evaluated for various damping levels and control valve switching times. Due to severe nonlinearities, frequency responses are not obtained directly. They are reconstructed from Fast Fourier Transform (FFT) using a Hanning window. The results are compared with those from LQR active suspensions and pure on-off dampers. The effect of control valve switching time (bandwidth) is studied and shows a significant influence on the vehicle ride, suspension travels, and tire deflections.

scholarly journals Simulation of dynamics of hydraulic system with proportional control valve

2016 ◽  
Vol 114 ◽  
pp. 02008 ◽  
Author(s):  
Adam Bureček ◽  
Lumír Hružík ◽  
Martin Vašina
Keyword(s):  
Hydraulic System ◽  
Control Valve ◽  
Proportional Control

scholarly journals Discovering the two faces of religious charismatic action – traditional and modern: a model

1999 ◽  
Vol 17 (1) ◽  
pp. 273-304
Author(s):  
Jane Williams-Hogan
Keyword(s):  
Structural Characteristics ◽  
Modern Society ◽  
Natural World ◽  
One Dimensional ◽  
New Religions ◽  
The World ◽  
The Gift ◽  
Rational Calculation ◽  
Traditional Societies ◽  
And Control

In this paper, the author examines the issue of charisma and prophecy in secularized societies. In traditional society the charismatic personality or the prophet brought a universalizing and rationalizing message which simultaneously expanded and penetrated the sphere of external order in the world, giving people the ability to manipulate and control the natural world. The disenchanted world is the end product of this process, when no more mysterious forces come into play, and when one can in principle master all things through rational calculation. The gift of rationality almost randomly bestowed in the ancient world becomes, for Weber, the rightful inheritance of the modern individual. Clarity brought by charisma in a dark and foreboding world loses its brilliance and its ability to beckon when the world is filled with light. In investigating charisma in only traditional societies, Weber saw charisma as one dimensional, solely as the force of rationality. So envisioned, charisma dissipates in the very act of realizing itself through the transformation of the world. Given Weber's analysis, therefore, one would not expect to find genuinely new religions emerging within our transformed and rational modern society. In the examination of the founding something that is best identified by the sociological term charisma, though obviously in modern guise, is clearly evident. This points to the possibility that charisma is not static but has the dynamic capacity to be responsive to the structural characteristics of the society in which it operates.

Feedback Servo Pump Station Overflow Innovative Energy-Saving Design

2011 ◽  
Vol 341-342 ◽  
pp. 452-455
Author(s):  
Liang Yuan Shen ◽  
Hong Guang Wang ◽  
Rui Jun Zhang ◽  
Peng Peng Liu
Keyword(s):  
Energy Saving ◽  
Hydraulic System ◽  
Adaptive Functioning ◽  
Supply Voltage ◽  
Load Condition ◽  
Control Valve ◽  
Work Requirements ◽  
Pump Station ◽  
Short Time ◽  
Large Flow

The usual hydraulic pump station pumps the general use of quantitative supply voltage level or constant pressure, using the corresponding control valve speed to adapt to work requirements, when the hydraulic system is intermittent or low-load condition, a large number of high-pressure oil through regulator overflow Back to the tank overflow valve, causing a great deal of energy consumption, when the hydraulic system requires a large flow of oil, it will result in a short time for the fluid system for liquid inadequate and under-voltage phenomenon. To solve this problem, we propose to improve the program, and conducted the analysis and comparison of several options to determine the source of energy-saving adaptive overall scheme of oil, its reasonable design, implementation of the automatic adaptive functioning, energy loss Small, the effect is significant.

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