scholarly journals Theoretical and Experimental Studies of a Digital Flow Booster Operating at High Pressures and Flow Rates

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 211 ◽  
Author(s):  
Chenggang Yuan ◽  
Vinrea Lim Mao Lung ◽  
Andrew Plummer ◽  
Min Pan
Keyword(s):  
Energy Efficiency ◽  
High Pressure ◽  
Flow Rate ◽  
High Energy ◽  
Control Flow ◽  
Fluid Power ◽  
Analytical Models ◽  
Operating Pressure ◽  
Hydraulic Systems ◽  
Flow Rates

The switched inertance hydraulic converter (SIHC) is a new technology providing an alternative to conventional proportional or servo-valve-controlled systems in the area of fluid power. SIHCs can adjust or control flow and pressure by means of using digital control signals that do not rely on throttling the flow and dissipation of power, and provide hydraulic systems with high-energy efficiency, flexible control, and insensitivity to contamination. In this article, the analytical models of an SIHC in a three-port flow-booster configuration were used and validated at high operating pressure, with the low- and high-pressure supplies of 30 and 90 bar and a high delivery flow rate of 21 L/min. The system dynamics, flow responses, and power consumption were investigated and theoretically and experimentally validated. Results were compared to previous results achieved using low operating pressures, where low- and high-pressure supplies were 20 and 30 bar, and the delivery flow rate was 7 L/min. We concluded that the analytical models could effectively predict SIHC performance, and higher operating pressures and flow rates could result in system uncertainties that need to be understood well. As high operating pressure or flow rate is a common requirement in hydraulic systems, this constitutes an important contribution to the development of newly switched inertance hydraulic converters and the improvement of fluid-power energy efficiency.

Adaptive Control of a Piezoelectric Valve for Fluid-Borne Noise Reduction in a Hydraulic Buck Converter

2017 ◽  
Vol 139 (8) ◽  
Author(s):  
Min Pan
Keyword(s):  
High Speed ◽  
Fast Response ◽  
High Energy ◽  
Buck Converter ◽  
Control Flow ◽  
Operating Conditions ◽  
System Structure ◽  
Analytical Models ◽  
Hydraulic Systems ◽  
Switching Valve

The hydraulic buck converter (HBC) is a novel high-bandwidth and energy-efficient device which can adjust or control flow and pressure by a means that does not rely on throttling the flow and dissipation of power. However, the nature of a HBC can cause severe fluid-borne noise (FBN), which is the unsteady pressure or flow in the fluid-filled hydraulic circuit. This is due to the operation nature of a high-speed switching valve of the device. The FBN creates fluctuating forces on the pipes which lead to system structure-borne noise that develops air-borne noise reaching to 85 dB. Thus, there is a need for an effective method that does not impair the system performance and efficiency to reduce the FBN. This paper describes the first investigation of an active controller for FBN cancellation in a HBC based on in-series and by-pass structures. The dynamics and the noise problem of the HBC are investigated using the analytical models. A piezoelectrically actuated hydraulic valve with a fast response and high force is applied as the adaptive FBN attenuator. The performance and robustness of the designed noise controller were studied with different operating conditions of a HBC. Simulated and experimental results show that excellent noise cancellation (30 dB) was achieved. The proposed active attenuator is a very promising solution for FBN attenuation in modern digital hydraulic systems which promise high energy efficiency but suffer severe noise or vibration problems in practice.

Spray Outputs from a Variable-Rate Sprayer Manipulated with PWM Solenoid Valves

2018 ◽  
Vol 34 (3) ◽  
pp. 527-534
Author(s):  
Joao Eduardo Silva ◽  
Heping Zhu ◽  
João Paulo Arantes Rodrigues da Cunha
Keyword(s):  
Flow Rate ◽  
Duty Cycle ◽  
Pressure Fluctuations ◽  
Control Flow ◽  
Operating Pressure ◽  
Regression Equations ◽  
Variable Rate ◽  
Total Flow ◽  
Total Flow Rate ◽  
Flow Rates

Abstract. Pressure fluctuations from air-assisted orchard sprayers can cause nozzles to discharge inaccurate flow rates during variable-rate spray applications. Variations in total flow rate discharged from 40 nozzles, each coupled with a pulse-width-modulated (PWM) solenoid valve, were determined for a variable-rate air-assisted sprayer. Variables for the total flow rate measurements were number of active nozzles ranging from 1 to 40 and PWM duty cycle ranging from 10% to 100%. Experiments were conducted under conditions with and without operating pressure adjustments. Under the no-pressure-adjustment condition, the operating pressure in the spray line was not adjusted for compensation when either the number of active nozzles or PWM duty cycle was changed. Under the pressure-adjustment condition, the operating pressure was adjusted to retain at 242 kPa. The total flow rate increased as duty cycle and/or number of active nozzles increased under both pressure conditions. However, the operating pressure in the spray line dropped considerably as either the number of active nozzles or duty cycle increased under the no-pressure-adjustment condition, resulting in significant lower total flow rates compared to the pressure-adjustment condition. The differences in total flow rates between the two pressure conditions increased as duty cycle and number of active nozzles increased. To improve future intelligent sprayer accuracy, two-variable regression equations were established to predict and control total flow rates with different duty cycles and numbers of active nozzles operated simultaneously. Keywords: Flow control, Flow rate, Hydraulic nozzle, Pesticide, Precision sprayer.

Analysis of Static Characteristics of Pressure Seal in Actual High Pressure Pump

2011 ◽  
Author(s):  
Isao Hagiya ◽  
Katsutoshi Kobayashi ◽  
Yoshimasa Chiba ◽  
Tetsuya Yoshida ◽  
Akira Arai
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
High Speed ◽  
Control Volume ◽  
Leakage Flow ◽  
High Pressure Pump ◽  
Flow Rates ◽  
Leakage Flow Rate ◽  
Rotor Dynamic ◽  
Pressure Seal

We predicted the leakage flow rates of a pressure seal in an actual high-pressure multistage pump. Since the pressure of the actual pump is higher than that of a model pump, accurate prediction of leakage flow rate and rotor dynamic forces for an actual pump is more difficult than that for a model pump. A non-contacting seal is used as a pressure seal to suppress leakage flow for high-pressure multistage pumps. When such pumps are operated at high speed, the fluid force acting on an eccentric rotor may cause vibration instability. For vibration stability analysis, we need to estimate static and dynamic characteristics of the pressure seals, i.e., leakage flow rate and rotor dynamic coefficients. We calculated the characteristics of the pressure seal based on Iwatsubo group’s method. The pressure seal we developed has labyrinth geometry consisting of grooves with different sizes. This method numerically calculates the characteristics of the grooved seal by using a three-control-volume model and a perturbation method. We compared the calculated and measured leakage flow rates. We found that the calculated results quantitatively agreed with the measured one in the actual pump and the characteristics of pressure and velocity for the seal with non-uniform-sized grooves were clarified.

Characteristics Analysis of Pneumatic Booster Valve With Energy Recovery

2016 ◽  
Author(s):  
Fan Yang ◽  
Kotaro Tadano ◽  
Gangyan Li ◽  
Toshiharu Kagawa
Keyword(s):  
Energy Efficiency ◽  
Energy Saving ◽  
Flow Rate ◽  
Pressure Fluctuation ◽  
Energy Recovery ◽  
High Energy ◽  
State Equation ◽  
Conservation Equation ◽  
Local Pressure ◽  
Supply Pressure

Pneumatic booster valve is widely used in local pressure boost circuit for energy saving, a new booster valve with energy recovery (short for BVER) was proposed in this paper in order to further improve the energy efficiency. Firstly, the principle of BVER was introduced by comparing with the traditional booster. Based on flow-rate characteristics equation, gas state equation, energy conservation equation, etc., the mathematics model of BVER was established, and the flow-rate characteristics, boost ratio, pressure in tank and energy efficiency were systematically analyzed by simulation. Lastly, the model was verified by experiments. This study shows that: firstly, the pressure decreased sharply with the flow-rate’s increasing, and the pressure in tank is much lower than in BVER. Secondly, the boost ratio was affected by supply pressure, regulator coefficient and the diameter of recovery chamber. Thirdly, the pressure fluctuation in tank decreases with the tank volume increasing, and the pressure fluctuation is less than 1% when tank volume is larger than 10L. Lastly, the energy efficiency will increase 5∼10 percent with the boost ratio increases 15∼25 percent under different supply pressure. This study proves that BVER has better performance than VBA for its high boost ratio and high energy efficiency, and it provides a reference for booster valve’s design and energy saving.

Development of Robust Microvavles for Compact Robust Pumps/Hydraulic Actuators

2007 ◽  
Vol 121-123 ◽  
pp. 1207-1210
Author(s):  
B. Li ◽  
Q. Chen
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Pressure Support ◽  
Test Results ◽  
Valve Design ◽  
Standard Process ◽  
Flow Rates ◽  
Forward Flow ◽  
Large Flow

In situ UV-LIGA assembled robust micro check valves with large flow rates (>10 ml/s, displacement related), high-pressure support ability (>10 MPa) and high operational frequencies (>10 kHz) made of nano-structured nickel were presented in this paper. The microvalve consists of an array of 80 single micro valves to achieve the required flow rates. Test results show that the forward flow rate is about 19 ml/s under pressure of 90Psi. The backward flow rate is negligible. The reliability of the valve is ensured by the valve design and nanostructured nickel realized. The tested tensile strength of a nano structured nickel is about 1GPa. The strength of SU-8 is 50MPa, which is more than 50% higher that fabricated with a standard process.

PREDICTION OF CONDENSATE FLOW RATES IN LARGE DIAMETER HIGH PRESSURE WET GAS PIPELINES

1978 ◽  
Vol 18 (1) ◽  
pp. 171 ◽  
Author(s):  
R. S. Cunliffe
Keyword(s):  
High Pressure ◽  
Residence Time ◽  
Flow Rate ◽  
Large Diameter ◽  
Operating Pressure ◽  
Gas Pipelines ◽  
Liquid Holdup ◽  
Wet Gas ◽  
Exploration And Production ◽  
Demand Changes

Esso Australia Ltd. operates two offshore gas platforms for Esso Exploration and Production Australia Inc. and Hematite Petroleum Pty. Ltd. in the Gippsland Basin. Gas and condensate from the Marlin platform flow to the gas plant near Sale, Victoria through a 67 mile, 20 inch pipeline. Gas and condensate from the Barracouta platform flow to the plant through a 30 mile, 18 inch pipeline. Average flowing pressure is 1300 psig. Condensate: gas ratios are 65 bbl/MMscf for Marlin and 15 bbl/MMscf for Barracouta.As these platforms are the only source of supply for the city of Melbourne, gas rates are changed to match gas demand. Changes in gas rate are accompanied by changes in condensate flow. From consideration of liquid holdup and liquid residence time, a method of predicting the condensate flow rate resulting from gas rate change was developed.A controlled run was made to test the prediction. After holding the Marlin gas rate steady at 150 MMscfd for 50 hours to reach equilibrium holdup conditions, the rate was increased to 250 MMscfd and held at this rate for 26 hours to reach equilibrium conditions again. The condensate flow rate out of the pipeline was monitored continually.The Marlin pipeline test demonstrated that changes in condensate flow rate resulting from changes in gas rate in high pressure wet gas pipelines can be predicted within 15 per cent of actual rates using liquid holdup and liquid residence time as input data. In the absence of holdup data from pipeline pigging, Eaton's correlation will provide good values for holdup for wet gas pipelines with operating pressure up to 1500 psig and which traverse relatively flat topography.This work has application in the sizing of liquid surge capacity required to receive condensate from high pressure wet gas pipelines. In many cases, investment in slug catcher facilities can be greatly reduced without risk of overfilling with liquid.

Influence of RBD Palm Olein on Hydraulic Pump Performance

2014 ◽  
Vol 931-932 ◽  
pp. 403-407
Author(s):  
Weerapong Chanbua ◽  
Unnat Pinsopon
Keyword(s):  
Energy Efficiency ◽  
Flow Rate ◽  
Hydraulic System ◽  
Palm Olein ◽  
Potential Candidate ◽  
Hydraulic Systems ◽  
Hydraulic Pump ◽  
Hydraulic Oil ◽  
Rbd Palm Olein ◽  
Accredited Laboratory

At the present time, researchers try to find alternative fluids for being used as lubricants or hydraulic fluids that are biodegradable and environmental friendly. In this study, Refined-Bleached-Deodorized (RBD) palm olein was investigated whether it is such a potential candidate. RBD palm olein could be easily acquired since it is of the type used as cooking oil. The physical properties of both conventional hydraulic oil and RBD palm olein were tested and compared by an accredited laboratory. The performance of the hydraulic systems when using both fluids as working mediums were also tested and compared. The experimental results show that temperature significantly affected the performance of the hydraulic system when using conventional hydraulic oil, whereas the performance of the hydraulic system when using RBD palm olein barely changed with temperatures. At the temperatures below 60 °C, the RBD palm olein yielded less flow rate and less energy efficiency. However, for the temperatures above 60 °C, the RBD palm olein yielded slightly more flow rate and slightly more energy efficiency. It can be confirmed from this study that RBD palm olein can be used as an alternative hydraulic fluid.

scholarly journals MODELING OF GAS-DYNAMIC PROCESSES IN THE ELEMENTS OF IMPULSE EJECTOR

2021 ◽  
pp. 66-72
Author(s):  
G. O. Voropaiev ◽  
Ia. V. Zagumennyi ◽  
N. V. Rozumnyuk
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Dynamic Processes ◽  
Stable Operation ◽  
Operating Pressure ◽  
Gas Generator ◽  
Gas Dynamic ◽  
Ejector Nozzle

The paper presents the numerical results on gas-dynamic processes in various elements of the impulse ejector, including pre-chamber, supersonic nozzle and mixing chamber, to determine optimal geometric parameters providing the given flow rate characteristics. At an extra-high pressure of the ejecting gas (>100 bar) it is impossible to create a nozzle design with continuously changing cross-sectional area and limited nozzle length. So, it is necessary to place a pre-chamber between the gas generator and the ejector nozzle for throttling full gas pressure. In order to optimize the pre-chamber parameters in the ejector with discrete holes of the gas generator and the operating pressure in the range of 400÷1000 bar, a series of calculations were performed to determine the pre-chamber parameters, ensuring stable operation of the supersonic annular nozzle at the high pressure of 35÷45 bar and the flow rate of 0.5÷0.6 kg/s. 3D numerical simulation of the gas flow into the pre-chamber through the gas generator holes shows the degree of the flow pattern non-uniformity in the pre-chamber at the ejector nozzle inlet is quite low. This justifies the numerical simulation of gas flow in the ejector in axisymmetric formulation and allows restricting the number of the gas generator holes without inducing significant non-uniformity in the azimuthal direction.

scholarly journals An ex Situ Underground Coal Gasification Experiment with a Siderite Interlayer. Course of the Process, Production Gas, Temperatures and Energy Efficiency

2020 ◽  
Author(s):  
Marian Wiatowski ◽  
Krzysztof Kapusta ◽  
Jacek Nowak ◽  
Marcin Szyja ◽  
Wioleta Basa
Keyword(s):  
Energy Efficiency ◽  
High Temperature ◽  
Flow Rate ◽  
Coal Gasification ◽  
High Energy ◽  
Ex Situ ◽  
Hard Coal ◽  
Underground Coal Gasification ◽  
Gasification Process ◽  
Process Gas

Abstract A 72-hour ex situ hard coal gasification test in one large block of coal was carried out. The gasifying agent was oxygen with a constant flow rate of 4.5 Nm3/h. The surroundings of coal were simulated with wet sand with 11% moisture content. A 2-cm interlayer of siderite was placed in the horizontal cut of the coal block. As a result of this process, gas with an average flow rate of 12.46 Nm3/h was produced. No direct influence of siderite on the gasification process was observed; however, measurements of CO2 content in the siderite interlayer before and after the process allowed to determine the location of high-temperature zones in the reactor. The greatest influence on the efficiency of the gasification process was exerted by water contained in wet sand. At the high temperature that prevailed in the reactor, this water evaporated and reacted with the incandescent coal, producing hydrogen and carbon monoxide. This reaction contributed to the relatively high calorific value of the resulting process gas, averaging 9.41 MJ/kmol, and to the high energy efficiency of the whole gasification process, which amounted to approximately 70%.

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