scholarly journals Energy Management of Low-Pressure Systems Utilizing Pump-Unloading Valve and Accumulator

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4423 ◽  
Author(s):  
Patrick Stump ◽  
Nathan Keller ◽  
Andrea Vacca
Keyword(s):  
Power Loss ◽  
Low Pressure ◽  
Hydraulic Control ◽  
Hydraulic Systems ◽  
Minimal Impact ◽  
Cooling Flow ◽  
Duty Cycles ◽  
Hydraulic Equipment ◽  
Variable Displacement ◽  
Continuous Power

In the context of improving energy efficiency and fuel consumption of mobile hydraulic equipment, it is important to analyze all the sources of power loss occurring within the hydraulic systems. While plenty of analyses have been performed on the working implements and the main transmission systems, very little attention has been paid to low-pressure (LP) systems until recently. LP systems are required on closed-circuit hydraulic systems to replenish losses, provide cooling flow, and maintain a pilot pressure necessary to operate hydraulic control valves and variable displacement units. It is shown that these circuits, which are often thought to have minimal impact on power consumption, actually cause significant, continuous power loss. A new method of power savings in these circuits is investigated through management of charge pump flow by application of an accumulator-sense pump-unloading (ASPU) valve. This work further proposes the combination of a split LP architecture with an ASPU valve. Three systems are simulated using Simcenter Amesim® and MATLAB/Simulink®. Using realistic duty cycles and unit loss models on a circuit for mobile off-road hydraulic equipment, it is shown that a standard LP system can consume about 5 kW of power. Power savings of up to 65% over a standard LP system are demonstrated by the proposed architecture.

scholarly journals A Flexible Adjustment and Control System for Hydraulic Machines

10.14311/1576 ◽  
2012 ◽  
Vol 52 (4) ◽  
Author(s):  
Daniel Banyai ◽  
Lucian Marcu
Keyword(s):  
Control System ◽  
Numerical Simulations ◽  
Dynamic Behavior ◽  
Hydraulic Control ◽  
Hydraulic Systems ◽  
Hydraulic Machines ◽  
Variable Displacement ◽  
And Control ◽  
Flow Power ◽  
Hydraulic Control System

Due to the advantages of hydraulic systems with variable displacement, it was necessary to design a control system that can adjust the pressure, flow, power or a combination of these features, that can be easily integrated into the pump body without changing its mechanical construction. The objective of this work was to study the dynamic behavior of this electro-hydraulic control system. To achieve these objectives, first the adjusting system was analyzed by numerical simulations, and then a stand was constructed for testing the performance of these adjustable pumps. It was shown that this control system is superior to existing systems.

A New Approach to Sizing Low Pressure Systems

2017 ◽  
Author(s):  
Nathan Keller ◽  
Monika Ivantysynova
Keyword(s):  
Hydraulic System ◽  
Low Pressure ◽  
Hydraulic Systems ◽  
Pressure System ◽  
Hydraulic Unit ◽  
Duty Cycles ◽  
Low Pressure System ◽  
Hydrostatic Transmissions ◽  
Cylinder Flow ◽  
Low Pressure Systems

Closed-circuit hydraulic systems, like hydrostatic transmissions and Displacement Controlled (DC) architecture systems, require an integrated low-pressure system. These low-pressure systems provide several important functions to the hydraulic system. They prevent cavitation, provide cooling flow through the cooler, replenish the hydraulic system with cool oil, assist in the oil filtration process, provide pressure to the hydraulic unit control systems and, in the case of DC systems with differential cylinders, balance the unequal cylinder flow. Traditionally, the sizing of low-pressure systems is accomplished using a static sizing approach. In this approach, a constant efficiency of the hydraulic units is assumed, and the system is operating at a maximum power condition. The result is often an oversized charge pump and accumulator, if one is present. A dynamic sizing method has been developed using MATLAB/Simulink® with high fidelity empirical loss models for hydraulic displacement machines. Using realistic duty cycles for hydraulic systems and measured data, the low-pressure system can be accurately sized. Dynamically sizing low-pressure systems reduce parasitic losses on the prime mover because of smaller pump sizes, thus freeing power to be used elsewhere. Another concept presented in this work is the possibility of isolating the hydraulic unit control pressure supply and the low-pressure system. Realistic examples have been simulated to demonstrate the power savings of dynamically sizing low-pressure systems.

Switchmode Hydraulic Power Supply Theory

2005 ◽  
Author(s):  
Jianwei Cao ◽  
Linyi Gu ◽  
Feng Wang ◽  
Minxiu Qiu
Keyword(s):  
Flow Rate ◽  
Dynamic Characteristics ◽  
Power Supply ◽  
Power Loss ◽  
High Speed ◽  
Hydraulic Pressure ◽  
Hydraulic Systems ◽  
Hydraulic Pump ◽  
Hydraulic Power ◽  
Supply Pressure

Switchmode hydraulic power supply is a new kind of energy-saving pressure converting system, which is originally proposed by the authors. It is mainly applied in multiple-actuator hydraulic systems, and installed between hydraulic pump and actuators (one switchmode hydraulic power supply for one actuator). It can provide pressure or flow rate that is adapted to the consumption of each actuator in the system by boosting or bucking the pressure, with low power loss, and conveniently, through high-speed switch valves, just like a hydraulic pressure transformer. There are two basic types of switchmode hydraulic power supply: pressure boost and pressure buck. Their structures and working principles are introduced. The dynamic characteristics of two typical types of switchmode hydraulic power supply, the pressure boost type and the pressure buck type, were analyzed through simulations and experiments. The performances were evaluated, and improvements on the efficiency of switchmode hydraulic power supply were proposed.

Real Power Loss Reduction by Billfish and Red Mullet Optimization Algorithms

2021 ◽  
Author(s):  
Lenin Kanagasabai
Keyword(s):  
Power Loss ◽  
Voltage Stability ◽  
Reactive Power ◽  
Smart Cities ◽  
Fitness Function ◽  
Loss Reduction ◽  
Real Power ◽  
Red Mullet ◽  
Power Loss Reduction ◽  
Continuous Power

In this paper Billfish Optimization Algorithm (BOA) and Red Mullet Optimization (RMO) Algorithm has been designed for voltage stability enhancement and power loss reduction. Electrical Power is one among vital need in the society and also it plays lead role in formation of smart cities. Continuous power supply is essential and mainly quality of the power should be maintained in good mode. In this work real power loss reduction is key objective. Natural hunting actions of Billfish over pilchards are utilized to model the algorithm. Candidate solutions in the projected algorithm are Billfish and population in the exploration space is arbitrarily engendered. Movement of Billfish is high, it will attack the pilchards vigorously and it can’t escape from the attack done by the group of Billfish. Then in this paper Red Mullet Optimization (RMO) Algorithm is proposed to solve optimal reactive power problem. Projected RMO algorithm modeled based on the behavior and characteristics of red mullet. As a group they hunt for the prey and in each group there will be chaser and blocker. When the prey approaches any one of the blocker red mullet then automatically it will turn as new chaser. So roles will interchangeable and very much flexible. At any time chaser will become blocker and any of the blocker will become a chaser with respect to prey position and conditions. Then in that particular area when all the preys are hunted completed then red mullet group will change the area. So there will be flexibility and changing the role quickly with respect to prey position. Alike to that with reference to the fitness function the particle will be chosen as chaser. By means of considering L (voltage stability) - index BOA, and RMO algorithms verified in IEEE 30- bus system. Then without L-index BOA and RMO algorithms is appraised in 30 bus test systems. Both BOA and RMO algorithms condensed the power loss proficiently with improvement in voltage stability and minimization of voltage deviation.

scholarly journals Application of low-temperature low-pressure hydrogen plasma: treatment of artificially prepared corrosion layers

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Petra Fojtíková ◽  
Lucie Řádková ◽  
Drahomíra Janová ◽  
František Krčma
Keyword(s):  
Low Temperature ◽  
Chemical Reduction ◽  
Hydrogen Plasma ◽  
Optical Emission ◽  
Low Pressure ◽  
Oh Radicals ◽  
Plasma Chemical ◽  
Duty Cycles ◽  
Fundamental Research ◽  
Pressure Hydrogen

AbstractThe aim of this work is the application of low-temperature low-pressure hydrogen plasma on artificially prepared corrosion layers, so called plasma chemical reduction. It is necessary to use samples with artificially prepared corrosion layers because it is impossible to use the real artifacts for fundamental research. The bronze was chosen as a sample material. Formation of corrosion layers on the bronze samples was carried out in concentrated hydrochloric acid vapors with the addition of sand. The radio-frequency hydrogen plasma was generated in the flowing regime at a pressure of 160 Pa. Different values of supplied power were chosen as well as different discharge modes: continuous or pulsed mode with varied duty cycles. By the combination of supplied power and mode factors, we selected two values of effective power. The process of plasma chemical reduction was monitored by optical emission spectroscopy (OES) and simultaneously, the sample temperature was measured. Rotational temperatures were calculated from OH radicals spectra. Changes in the structure and elemental composition were determined using scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX).

scholarly journals Modern Modeling of Water Hammer

2017 ◽  
Vol 24 (3) ◽  
pp. 68-77 ◽  
Author(s):  
Kamil Urbanowicz
Keyword(s):  
Side Effects ◽  
Adverse Effects ◽  
Water Hammer ◽  
Hydraulic Systems ◽  
Weighting Functions ◽  
Transient Flows ◽  
Hydraulic Equipment ◽  
Pressure Changes ◽  
The Impact ◽  
Reduced Pressures

Abstract Hydraulic equipment on board ships is common. It assists in the work of: steering gear, pitch propellers, watertight doors, cargo hatch covers, cargo and mooring winches, deck cranes, stern ramps etc. The damage caused by transient flows (which include among others water hammer) are often impossible to repair at sea. Hence, it is very important to estimate the correct pressure runs and associated side effects during their design. The presented study compares the results of research on the impact of a simplified way of modeling the hydraulic resistance and simplified effective weighting functions build of two and three-terms on the estimated results of the pressure changes. As it turns out, simple effective two-terms weighting functions are able to accurately model the analyzed transients. The implementation of the presented method will soon allow current automatic protection of hydraulic systems of the adverse effects associated with frequent elevated and reduced pressures.

scholarly journals Design of PI Controllers for Hydraulic Control Systems

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
LJubiša Dubonjić ◽  
Novak Nedić ◽  
Vojislav Filipović ◽  
Dragan Pršić
Keyword(s):  
Control Systems ◽  
Transmission Lines ◽  
Relative Stability ◽  
High Order ◽  
Hydraulic Control ◽  
Hydraulic Systems ◽  
Algebraic Equations ◽  
Nyquist Criterion ◽  
Pi Controllers ◽  
Nonlinear Algebraic Equations

The paper proposes a procedure for design of PI controllers for hydraulic systems with long transmission lines which are described by models of high order. Design is based on the combination of the IE criterion and engineering specifications (settling time and relative stability) as well as on the application ofD-decomposition. In comparison with some known results, the method is of graphical character, and it is very simple (solving nonlinear algebraic equations is eliminated). The paper presents the algorithm of software procedure for design of the controller. The method is compared with other methods at the level of simulation, and its superiority is shown. By applying the Nyquist criterion, it is shown that the method possesses robustness in relation to non modelled dynamics.

The Kinematic and Dynamic Analysis of Hydraulic Control System Based on the Lagrangian Force Method

2018 ◽  
Vol 15 (05) ◽  
pp. 1850041
Author(s):  
Thi-Na Ta ◽  
Cao-Sang Tran ◽  
Yunn-Lin Hwang
Keyword(s):  
Control System ◽  
Dynamic Analysis ◽  
Hydraulic System ◽  
Lagrange Equation ◽  
Control Parameters ◽  
Hydraulic Control ◽  
Hydraulic Systems ◽  
Dynamical Parameters ◽  
Characteristic Effect ◽  
Hydraulic Control System

In this paper, the hydraulic control system design and dynamic analysis are considered in superior calculation efficiency based on Lagrangian method and fundamental laws for getting control algorithms to investigate about hydraulic system how to control hydraulic system and take hydraulic controller to the optimization. The systems built in dynamical parameters are associated hydraulic control system achieved with control parameters. And then, an interface is achieved. The relations between control parameters are obtained. The numerical tools are going to determine all kinematic parameters of bodies such as displacement, velocities, accelerations as well as reaction forces are responded. The AMESim and RecurDyn are used such Computer Aided Engineering (CAE) techniques to solve the numerical examples in this paper. Those examples will imply that the equation of motion based on Euler–Lagrange equation and characteristic effect of force is executable. Through results, we could achieve control improvement at different hydraulic systems.

The Research of Oil Pressure Fluctuation Influence to Rolling Mill Control Precision

2013 ◽  
Vol 330 ◽  
pp. 624-628
Author(s):  
Chun Ming Chen ◽  
Ya Jun Liu ◽  
Yun Xia Zhang ◽  
Dan Xia Guo
Keyword(s):  
Pressure Fluctuations ◽  
System Control ◽  
Hydraulic Control ◽  
Control Precision ◽  
Pressure Variable ◽  
Displacement Pump ◽  
Practical Engineering ◽  
Variable Displacement ◽  
Oil Source ◽  
And Control

Oil source made up of constant pressure variable displacement pump, accumulator, and pipeline is widely used to provide stable pressure for electro-hydraulic control system in practical engineering. Based on the experiment, the relationship between initial charging pressure & volume of the accumulator at inlet of the servo valve and control precision is analyzed in detail, and coupling rules between the load variation and the pressure fluctuations of oil-source are obtained, the rules can give reference for selecting initial charging pressure & volume of the accumulator according to the requirement of system control precision, which can further improve control precision and product quality by optimizing equipment parameters.

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