scholarly journals The application of the cemented thickened/paste tailings backfill with large flow capacity in Chinese iron mines

2014 ◽  
Author(s):  
Aixiang Wu ◽  
Xiuxiu Miao ◽  
Hong-Jiang Wang ◽  
H Jiao ◽  
Youtuan Wang
Keyword(s):  
Flow Capacity ◽  
Large Flow

Investigation on the modeling and dynamic characteristics of a fast-response and large-flow water hydraulic proportional cartridge valve

2020 ◽  
Vol 234 (22) ◽  
pp. 4415-4432
Author(s):  
Mingxing Han ◽  
Yinshui Liu ◽  
Kan Zheng ◽  
Youchun Ding ◽  
Defa Wu
Keyword(s):  
Genetic Algorithm ◽  
Flow Rate ◽  
Dynamic Characteristics ◽  
Fast Response ◽  
Dynamics Simulation ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Flow Capacity ◽  
Water Hydraulic ◽  
Large Flow

In large-power and high-pressure hydraulic systems, the maximum instantaneous flow rate is often several thousand liters per minute. Normal proportional valves are often difficult to meet their requirements for large flow rate and fast response at the same time. And the leakage of hydraulic oil will seriously pollute the environment. Therefore, a novel water hydraulic proportional valve with fast response and high flow capacity is presented for the large transient power hydraulic system in this paper. The valve utilizes a two-stage structure with two 2/2-way water hydraulic proportional valves as the pilot stage and a cartridge poppet valve as the main stage to achieve fast-response and large-flow capacity simultaneously. A detailed and precise nonlinear mathematical model of the valve considering both structural parameters and flow force is developed. A comprehensive performance optimization has been carried out, which can be mainly divided into computational fluid dynamics simulation optimization based on reducing flow force and multi-objective optimization based on genetic algorithm. The effects of double U-grooves' parameters on the flow force (flow-induced loads) have been studied in detail by numerical simulation. Through the grooves geometry optimization, the maximum flow force can be reduced by 10%. Then, the influences of structure parameters on the performance of step response have been studied, and the optimal parameters of the valve have been obtained by multi-objective optimization based on genetic algorithm. The maximum overshoot has been reduced from 15% to 6% (about 60%) and the adjusting time has been reduced from 58 ms to 48 ms. The dynamic characteristics of the valve have been improved effectively. Finally, a test apparatus which has the ability to provide transient large flow is built. The accuracy of simulation model and optimization design method is verified by test results.

Optimal Construction of a Hydraulic Pump With Elliptic Rotated Piston by Kakeya-Besicovitch Application

2007 ◽  
Author(s):  
Petru Ungur ◽  
Petru A. Pop ◽  
Mircea Gordan ◽  
Nicodim Muresan
Keyword(s):  
Spindle Speed ◽  
Original Position ◽  
Hydraulic Motor ◽  
Hydraulic Pump ◽  
Constant Length ◽  
Variable Volume ◽  
Flow Capacity ◽  
Elliptical Section ◽  
Large Flow ◽  
Optimal Construction

The paper has presented an application of Kakeya-Besicovitch, third example about commutation of finite element beam endpoints inside of arbitrary small zone. This area is a hypocycloid with three cusped points at that inner tangent has a constant length independent by the point position of its inner tangent, which being rotated in clock-way it’s came back to its original position with its endpoints reversed. The application is a hydraulic pump compound by one rotated piston with elliptical section which is rolling in a fixed chamber with hypocycloid form and three cusped rounded tips after a curvature equal with major axe ellipse endpoints curvatures. The rolling motion is imposed by eccentric exterior source that acting inside of cylindrical pocket located in the center of elliptic piston, which divided the hypocycloid in three equal parts at 120° from each other. The pump could be working as a hydraulic motor which is endowed with rotating distributor that can feed each chamber with variable volume one by one due to moving the piston. The pump’s relevance is given by its efficiency, allowing a large flow capacity to a lower spindle speed, ensured a constant ratio spindle speed which working silence and a large stability.

Hydraulic-feedback proportional valve design for construction machinery

2015 ◽  
Vol 229 (17) ◽  
pp. 3162-3178 ◽  
Author(s):  
Wei Liu ◽  
Jianhua Wei ◽  
Jinhui Fang ◽  
Shizhen Li
Keyword(s):  
Control Valve ◽  
Response Speed ◽  
Optimal Parameters ◽  
Valve Design ◽  
Proportional Valve ◽  
Construction Machinery ◽  
Flow Capacity ◽  
Locus Method ◽  
Increasing Demand ◽  
Large Flow

Due to the increasing demand for large-tonnage construction machinery, the manufacturers call for a reliable and inexpensive proportional control valve with large flow capacity. In this work, a novel throttle poppet valve based on hydraulic-feedback principle has been studied comprehensively and optimized to meet the requirements of the construction machinery. A detailed and precise mathematical model has been developed and validated through experiments. According to the model, basic status of the valve under different working conditions has been analyzed, and the impacts of the parameters on the performances of response speed and the pressure stiffness have been studied through the root locus method. To find the optimal parameters suitable for construction machinery, an optimization based on non-dominated sorting genetic algorithm II was carried out, and the performances have been significantly improved. Finally, by adopting the analysis on the parameters and the optimization results, guidelines for designing the hydraulic-feedback proportional valve in various sizes are presented.

Research on the performance of electro-hydraulic proportional flow valve controlled by active pilot pump

2016 ◽  
Vol 231 (4) ◽  
pp. 720-731 ◽  
Author(s):  
Yunxiao Hao ◽  
Long Quan ◽  
Jiahai Huang
Keyword(s):  
Pressure Differential ◽  
Small Displacement ◽  
Flow Pulsation ◽  
Pump Speed ◽  
Pump Flow ◽  
Flow Capacity ◽  
Flow Through ◽  
Large Flow ◽  
Proportional Flow ◽  
Flow Valve

The cartridge flow valves, used in heavy machine and equipment, have the advantages of low leakage, large flow capacity, simple structure, and ease of modulation. However, in order to reduce the influence of load variety on the flow through valve, a pressure differential compensator or a cartridge type flow sensor should be added to the proportional throttle valve. These methods have disadvantages of reducing the flow capacity of valve and increasing the throttling loss. To overcome these disadvantages, a low energy consumption, high controllable electro-hydraulic proportional flow valve which consists of a hydraulic transistor (Valvistor) and a small displacement hydraulic pump driven by a servo motor is proposed firstly in the world. As the pump flow is basically proportional to the pump speed and little influenced by load variety, the flow through main valve is proportional to pilot pump speed. In the research, it’s known that feedback throttle slot pre-opening will cause the decrease of the main valve flow as pressure drop increases. So, small orifices are used instead of the pre-opening of feedback throttle slot to reduce the influence of load variety on the flow through valve. Furthermore, a method of pressure differential changing with pilot pump rotational speed calibration is introduced to further mitigate the influence of pressure difference. In this paper, the mathematical dynamic model of the valve is also established and the stability criterion of valve is derived. The influence of valve parameters and the flow pulsation of pilot pump on valve flow performance is analyzed and simulated. In view of the pilot pump flow pulsation frequency being much higher than the valve natural frequency, the research shows that the influence of flow pulsation of pilot pump on valve flow performance is very little. The research work provides a new method for the large flow electro-hydraulic proportional control system.

WELL TESTING HORIZONTALGAS-CONDENSATE WELLS

2017 ◽  
pp. 56-61
Author(s):  
M. L. Karnaukhov ◽  
O. N. Pavelyeva
Keyword(s):  
Comparative Analysis ◽  
Skin Effect ◽  
Horizontal Wells ◽  
Gas Condensate ◽  
Low Permeability ◽  
Well Testing ◽  
Flow Capacity ◽  
Formation Zone ◽  
Horizontal Wellbore

The well testing of gas-condensate horizontal wells are discussed in the article and the comparative analysis of borehole flow capacity, depending on the mode of it’s operation is presented. Extra attention is focused on the issue of timely identification of the reasons for the reduction of fluid withdrawal from the reservoir. The presence of high skin effect is proved, which confirms the existence of low-permeability of bottomhole formation zone related to condensation in the immediate area of the horizontal wellbore.

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