A Piezoelectric Actuator-Based Direct-Drive Valve for Fast Motion Control at High Operating Temperatures

This paper experimentally investigates the control performances of a piezostack actuator direct-drive valve (PADDV) operating at high temperatures. In this study, the PADDV system is designed based on special specifications featuring a high operating temperature (150 °C) and wide control bandwidth (200 Hz). After manufacturing the PADDV with design limitations such as size and maximum input voltage to the piezostack actuator, the displacement of a spool located inside the valve system, which is directly related to the flow rate, is controlled at several different temperatures and motion frequencies. In order to undertake this, the PADDV system is installed inside a heat chamber equipped with air vessels and pneumatic–hydraulic cylinders. The piezoelectric actuator is partially insulated using an aerogel to prevent permanent damage due to high temperatures above 120 °C, which is higher than the Curie temperature. To control the valve system, a PID (proportional–integral–derivative) controller is realized in which control gains are properly tuned using fuzzy logic according to the change of temperature and frequency. It is shown from the experimental results that the proposed PADDV with thermal insulation can provide the target dynamic motion of 200 Hz at 150 °C by implementing the fuzzy-based PID controller.

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Control performances of a piezoactuator direct drive valve system at high temperatures with thermal insulation

Smart Materials and Structures ◽

10.1088/0964-1726/25/9/097003 ◽

2016 ◽

Vol 25 (9) ◽

pp. 097003 ◽

Cited By ~ 4

Author(s):

Yung-Min Han ◽

Chulhee Han ◽

Wan Ho Kim ◽

Ho Yong Seong ◽

Seung-Bok Choi

Keyword(s):

High Temperatures ◽

Thermal Insulation ◽

Direct Drive ◽

Valve System

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A new type of a direct-drive valve system driven by a piezostack actuator and sliding spool

Smart Materials and Structures ◽

10.1088/0964-1726/23/7/075002 ◽

2014 ◽

Vol 23 (7) ◽

pp. 075002 ◽

Cited By ~ 16

Author(s):

Juncheol Jeon ◽

Chulhee Han ◽

Young-Min Han ◽

Seung-Bok Choi

Keyword(s):

Direct Drive ◽

Valve System ◽

New Type ◽

Piezostack Actuator

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Design and modeling of new suspension system using direct drive servo-valve system actuated by piezostack actuator

10.1117/12.2218507 ◽

2016 ◽

Author(s):

Chulhee Han ◽

Wan Ho Kim ◽

Seung-Bok Choi

Keyword(s):

Suspension System ◽

Direct Drive ◽

Servo Valve ◽

Valve System ◽

Piezostack Actuator

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3B13 Control of the Direct Drive Valve System Actuated by Piezostack Actuator(The 12th International Conference on Motion and Vibration Control)

The Proceedings of the Symposium on the Motion and Vibration Control ◽

10.1299/jsmemovic.2014.12._3b13-1_ ◽

2014 ◽

Vol 2014.12 (0) ◽

pp. _3B13-1_-_3B13-9_

Author(s):

Juncheol Jeon ◽

Chulhee Han ◽

Seung-Bok Choi

Keyword(s):

Vibration Control ◽

Direct Drive ◽

International Conference ◽

Valve System ◽

Piezostack Actuator

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Influence of Heat on Seed Germination of Cistus Laurifolius and Cistus Ladanifer

International Journal of Wildland Fire ◽

10.1071/wf9920015 ◽

1992 ◽

Vol 2 (1) ◽

pp. 15 ◽

Cited By ~ 47

Author(s):

L Valbuena ◽

R Tarrega ◽

E Luis

Keyword(s):

Seed Germination ◽

High Temperatures ◽

Exposure Time ◽

Germination Rate ◽

Heat Exposure ◽

Cistus Ladanifer ◽

Different Temperatures ◽

Petri Dishes ◽

Germinated Seeds

The influence of high temperatures on germination of Cistus laurifolius and Cistus ladanifer seeds was analyzed. Seeds were subjected to different temperatures for different times, afterwards they were sowed in plastic petri dishes and monitored for germinated seeds over two months.The germination rate observed in Cistus ldanifer was greater than in Cistus laurifolius. In both species, heat increased germination percentages. For Cistus laurifolius higher temperatures or longer exposure times were needed. Germination percentages of Cistus ladanifer were lower when heat exposure time was 15 minutes.It must be emphasized that germination occurred when seeds were not treated, while seeds exposed to 150�C for 5 minutes or more did not germinate.

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Linear and non-linear analysis on two-dimensional steel frame under different temperatures

Journal of Structural Fire Engineering ◽

10.1108/jsfe-12-2017-0047 ◽

2019 ◽

Vol 10 (1) ◽

pp. 48-55

Author(s):

Parthasarathi N. ◽

Satyanarayanan K.S. ◽

Prakash M. ◽

Thamilarasu V.

Keyword(s):

High Temperatures ◽

Progressive Collapse ◽

Transient State ◽

Steel Frame ◽

Frame Structure ◽

Two Dimensional ◽

Content Type ◽

Frame Building ◽

Different Temperatures ◽

Steel Frame Structure

Purpose Progressive collapse because of high temperatures arising from an explosion, vehicle impact or fire is an important issue for structural failure in high-rise buildings. Design/methodology/approach The present study, using ABAQUS software for the analysis, investigated the progressive collapse of a two-dimensional, three-bay, four-storey steel frame structure from high-temperature stresses. Findings After structure reaches the temperature results like displacement, stress axial load and shear force are discussed. Research limitations/implications Different temperatures were applied to the columns at different heights of a structure framed with various materials. Progressive collapse load combinations were also applied as per general service administration guidelines. Originality/value This study covered both steady-state and transient-state conditions of a multistorey-frame building subjected to a rise in temperature in the corner columns and intermediate columns. The columns in the framed structure were subjected to high temperatures at different heights, and the resulting displacements, stresses and axial loads were obtained, analysed and discussed.

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Influence of Drying in Hyptis pectinata Essential Oil

Journal of Agricultural Science ◽

10.5539/jas.v10n4p96 ◽

2018 ◽

Vol 10 (4) ◽

pp. 96

Author(s):

Núbia Angélica de Ávila Branquinho ◽

Fabiano Guimarães Silva ◽

Osvaldo Resende ◽

Luiz Cláudio Almeida Barbosa ◽

Daniel Emanuel Cabral de Oliveira ◽

...

Keyword(s):

Essential Oil ◽

Anhydrous Sodium Sulfate ◽

Fixed Bed ◽

Chemical Characterization ◽

Automated System ◽

Caryophyllene Oxide ◽

System A ◽

Different Temperatures ◽

Drying Conditions

The present study assessed the effects of drying at different temperatures (35, 45 and 55 °C) and air velocities (1 and 2 m s-1) on the content and chemical characteristics of Hyptis pectinata essential oil. Drying was conducted in a fixed-bed dryer, and the temperatures and air velocities were controlled and recorded by an automated system. A 350±0.12 g quantity of fresh leaves was used for each of the four repetitions in each dryer. From the material obtained after drying, 60 g of each repetition was used to extract essential oil by the hydrodistillation method. Dichloromethane was used as the solvent, and anhydrous sodium sulfate was used as the desiccating agent. Gas chromatography in the forms of GC-MS and GC-FID were used for the chemical characterization of the essential oil compounds. Decreasing drying times and decreasing concentrations of essential oils were observed with increasing temperatures. A GC-MS analysis of the essential oil from H. pectinata leaves led to the identification of 19 compounds. A sesquiterpene called caryophyllene oxide was the most abundant compound under all drying conditions, with the highest concentration at a temperature of 55 °C, ranging from approximately 42 to 53%.

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Comparative study of a small size wind generation system efficiency for battery charging

Serbian Journal of Electrical Engineering ◽

10.2298/sjee120707003m ◽

2013 ◽

Vol 10 (2) ◽

pp. 261-274 ◽

Cited By ~ 1

Author(s):

Messaoud Mayouf ◽

Rachid Abdessemed

Keyword(s):

Control Strategies ◽

Power Converter ◽

Maximum Power ◽

Wind Generation ◽

Direct Drive ◽

Generation System ◽

Battery Charging ◽

Pulse Width Modulated ◽

System A ◽

Wind Generation System

This paper presents an energetic comparison between two control strategies of a small size wind generation system for battery charging. The output voltage of the direct drive PMSG is connected to the battery through a switch mode rectifier. A DC-DC boost converter is used to regulate the battery bank current in order to achieve maximum power from the wind. A maximum powertracking algorithm calculates the current command that corresponds to maximum power output of the turbine. The DC-DC converter uses this current to calculate the duty cycle witch is necessary to control the pulse width modulated (PWM) active switching device (IGPT). The system overview and modeling are presented including characteristics of wind turbine, generator, batteries, power converter, control system, and supervisory system. A simulation of the system is performed using MATLAB/SIMULINK.

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Effects of High Temperatures on the Physical and Mechanical Properties of Carbonated Ordinary Concrete

Advances in Materials Science and Engineering ◽

10.1155/2019/5753232 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10 ◽

Cited By ~ 4

Author(s):

Qifang Xie ◽

Lipeng Zhang ◽

Shenghua Yin ◽

Baozhuang Zhang ◽

Yaopeng Wu

Keyword(s):

Mechanical Properties ◽

Weight Loss ◽

Elastic Modulus ◽

High Temperatures ◽

Elevated Temperatures ◽

Physical And Mechanical Properties ◽

Surface Characteristics ◽

Time Service ◽

Different Temperatures ◽

Cooling Methods

Fires are always known for seriously deteriorating concrete in structures, especially for those with certain carbonation due to long-time service. In this paper, 75 prism specimens were prepared and divided into four groups (three carbonated groups and one uncarbonated group). Specimens were tested under different temperatures (20, 300, 400, 500, 600, and 700°C), exposure times (3, 4, and 6 hours), and cooling methods (water and natural cooling). Surface characteristics, weight loss rate, and residual mechanical properties (strength, initial elastic modulus, peak, and ultimate compressive strains) of carbonated concrete specimens after elevated temperatures were investigated and compared with that of the uncarbonated ones. Results show that the weight loss rates of the carbonated concrete specimens are slightly lower than that of the uncarbonated ones and that the cracks are increased with raising of temperatures. Surface colors of carbonated concrete are significantly changed, but they are not sensitive to cooling methods. Surface cracks can be evidently observed on carbonated specimens when temperature reaches 400°C. Residual compressive strength and initial elastic modulus of carbonated concrete after natural cooling are generally larger than those cooled by water. The peak and ultimate compressive strains of both carbonated and uncarbonated concrete specimens increase after heating, but the values of the latter are greater than that of the former. Finally, the constitutive equation to predict the compressive behaviors of carbonated concrete after high temperatures was established and validated by tests.

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