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Wyszukujesz frazę "valve control" wg kryterium: Temat


Tytuł:
Device for control the valvetrain and cylinder pressure of a spark-ignition engine
Autorzy:
Mamala, J.
Graba, M.
Bieniek, A.
Hennek, K.
Powiązania:
https://bibliotekanauki.pl/articles/241981.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engines
environmental protection
variable compression ratio
valve control
Opis:
This article describes the method of controlling an electric magnetic linear actuator that moves an inlet valve of an internal combustion engine. Thanks to the use of the electric control of the inlet valve of the internal combustion engine, it was possible to implement a variable effective compression ratio of the operating power unit, adapting it to the current needs and engine load. In this design, valvetrain was modified by introducing an autonomous intake valve operation with the use of a specially designed electromagnetic actuator. The introduction of this system necessitated an additional modification of the intake camshaft. The control was carried out with the use of a real-time controller with a built-in FPGA unit. The proposed design of a system with an electromagnetic actuator will allow obtaining an additional degree of freedom in the control unit. Particular attention should be paid to registered values or air pressure in the intake stroke for a closed or partially opened throttle, which generates significant pumping losses. The use of an electromagnetic actuator in the intake can help reduce said losses.
Źródło:
Journal of KONES; 2018, 25, 3; 339-346
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Study of the Effectiveness of a Combined Closure of the End Gate Pipeline Valve
Autorzy:
Herasymov, Henrikh H.
Gerasimov, Ievgenii G.
Ivanov, Sergiy Y.
Pinchuk, Oleg L.
Powiązania:
https://bibliotekanauki.pl/articles/241063.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN
Tematy:
valve closure modes
experimental installation
valve control device
results of experimental studies
Opis:
One of the ways to ensure a reliable operation of irrigation systems is to protect them from water hammer (hydraulic shock) damage that occurs when starting or stopping a pumping station. This can be achieved by creating conditions in which a water hammer will not occur in the pressure pipeline as a result of closing the end gate valve (EGV). The aim of the present study was to investigate processes occurring in the pipeline during a linear closure of the EGV, during a closure with one break point and during an intermittent closure, as well as to verify the effectiveness of a combined end gate valve closure of the pipeline. Based on experimental data and calculations, the article recommends a linear closure of the EGV with one break point.
Źródło:
Archives of Hydro-Engineering and Environmental Mechanics; 2019, 66, 1-2; 3-13
1231-3726
Pojawia się w:
Archives of Hydro-Engineering and Environmental Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The control of valve timing with magnetoelectric actuators
Autorzy:
Siczek, K.
Kuchar, M.
Powiązania:
https://bibliotekanauki.pl/articles/245603.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion engine
camless valve timing
valve timing control
magnetoelectric drive
Opis:
The new control algorithm for the valve timing in camless combustion engine is presented in the article. The magnetoelectric actuators have been used in the valve timing for analyzed popular combustion engine. Each titanium valve has been connected with the coil of actuator. Such coil can move in the magnetic field, generated in magnet circuit containing sintered Nd-Fe-B magnets, the core, pole shoes and air gaps. The movement of coil can occur when current flows in the coil winds and then electrodynamic force is generated. The nonlinear curves of generated electrodynamic force versus displacement of coil - valve assembly and vs. current in the coil have been computed using FEM method and presented in the article. The new mathematical model has been elaborated to calculate valve lift vs. coil lift for different coil currents and dynamic parameters of the coil. The values of current in coil should be controlled by the elaborated algorithm with the feedback. This algorithm has been based on tracing of position points of valve, during valve movement. The modelled course of valve lift vs. time has been first elaborated, for the needed rpm of engine. Next the first approximated current pulse train has been generated, the movement of the coil - valve assembly could be obtained. The calculated position of valve has been compared with the valve position from modelled course of valve lift vs. time. Basing on obtained difference of valve lift, the next current pulse train has been corrected in such a way, to obtain in any moment the closest position of valve to the one from modelled course. The obtained courses of valve lift vs. time for different modelled courses of valve lift vs. time and vs. rpm of engine have been presented in the article.
Źródło:
Journal of KONES; 2009, 16, 3; 357-365
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Binary valves in analog control
Autorzy:
Mielewczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/242392.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
control
digital signal
actuator
control valve
transducer
positioner
Opis:
Continuous control systems are built with standard transducer measured signal, the controller and actuator. The actuator is responsible for the direct setting of the size of the control object. The actuator is connected to the control valve and the actuator position change signal into the flow rate of the working medium. Since the operating element is required the linear characteristics in the standard signal range to work. The other hand, the control valve provides flow characteristics linear or equal percentage. This flow control principle is used in various control systems. The actuator of the control valve is always equipped with a positioner, which corrects errors in the position of the valve relative to the input signal. The presented design of the control valve is an analogue system. Using the technique of converting multiple digital signal causes, the system is susceptible to damage. Remove the intermediate elements can improve the quality control and safety system. Such benefits give a design of the operating element based on direct digital processing unit and control program. The examples of control present article.
Źródło:
Journal of KONES; 2017, 24, 2; 141-146
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flow analysis of hydraulic poppet control valve by means of computional fluid dynamics
Autorzy:
Łazowski, J.
Krasucki, J.
Powiązania:
https://bibliotekanauki.pl/articles/248062.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
poppet control valve
computational fluid dynamics (CFD)
flow characteristics
Opis:
The poppet control valve is one of the most widespread hydraulic components. The paper purpose is the evaluation of flow characteristics of poppet valve by means of a complete numerical analysis. The aim of this analysis is to evaluate the valve fluid dynamic performance, exploiting computational fluid dynamics (CFD) techniques, in order to give the reliable indications needed to define the valve design criteria and avoid expensive experimental tests. The numerical analysis was performed by using the commercial code of CFD, and the numerical results show the complete flow field inside the valve. Axisymmetric as well as three-dimensional valve model was considered and the simulation results also are verified with experimental results. The results have confirmed the good accuracy of the simplified CFD analysis based on 2D axisymmetric valve model being more efficient than full 3D approach and show this method as very useful to forecast flow characteristics of poppet control valves. Hydraulic control poppet valve, distribution of the velocity in layers of the fluid, computational grid in the modelled geometry, pressure distribution for axisymmetric and three-dimensional mode for different flow rate, fluid velocity distribution in valve metering section for axisymmetric and three-dimensional model for different flow rates, the example of streamlines, the comparison of flow characteristics are contained in the publication.
Źródło:
Journal of KONES; 2012, 19, 1; 251-259
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aproksymacja charakterystyki przesterowania rozdzielacza suwakowego w diagnostyce stanu jego uszkodzenia
Approximation of directional spool valve control characteristic in fault diagnosis
Autorzy:
Jędrzykiewicz, Z.
Podsiadło, A.
Stojek, J.
Powiązania:
https://bibliotekanauki.pl/articles/156738.pdf
Data publikacji:
2006
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
aproksymacja
charakterystyka przesterowania rozdzielacza suwakowego
rozdzielacz suwakowy
uszkodzenia rozdzielacza suwakowego
approximation
directional spool valve control characteristic
fault diagnosis
Opis:
W artykule wykonano analizę możliwości wykorzystania aproksymacji modelem transmitancyjnym charakterystyki przesterowania rozdzielacza hydraulicznego, którą użyto do identyfikacji zaistniałego typu uszkodzenia tłoczka rozdzielacza. Wykonano zestaw tłoczków z zamodelowanymi uszkodzeniami, w które następnie wyposażono badany rozdzielacz. Opisano budowę stanowiska laboratoryjnego oraz przebieg badań. Wykorzystując pakiet Matlab\Simulink wyznaczono parametry modeli transmitancyjnych. Całość zakończono wnioskami.
The article discusses possibility of use transfer function as approximation of spool valve control characteristic in fault diagnosis. In order to carry out experiments typical damage of hydraulic spool valve were prepared. The laboratory station and the method of research were talk over. By use Matlab\Simulink program the transfer function models were determined. Finally the results and conclusions were presented.
Źródło:
Pomiary Automatyka Kontrola; 2006, R. 52, nr 2, 2; 12-14
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of losses and energy efficiency of hydrostatic drives with hydraulic cylinder
Autorzy:
Skorek, G.
Powiązania:
https://bibliotekanauki.pl/articles/260205.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
energy losses
energy efficiency
hydrostatic system
control structures
proportional directional control valve
cylinder
Opis:
Energy efficiency of hydrostatic transmissions, and especially efficiencies of drives with motor speed controlled by throttle, as well as efficiency of hydraulic servomechanisms can in fact be higher than the efficiency values most frequently given by the respective literature in this field. With the progress achieved in recent years in the development of hydraulic systems it is becoming necessary to develop methods for precise energy efficiency calculation of such systems. It is difficult to imagine that more and more, better and better machines and control elements could be used without the possibility of a mathematical tool at our disposal to enable an accurate analysis and assessment of behavior of the system in which such machines and control elements have been applied. The paper discusses energy savings using mathematical model of losses in elements, the energy efficiency of the system. There are possibilities to reduce energy losses in proportional control systems (in the pump, in the throttle control unit, especially in the cylinder), and thus to improve the energy efficiency of the throttling manifold. The considerations allow for comparison of the loss power resulting from the applied hydraulic control structure of the hydraulic cylinder and the power consumed by the pump from the electric motor that drives it, the power necessary to provide pump-driven hydraulic cylinder. The article shows the impact on the output (useful) power consumed in the considered systems, and the impact on the power consumed of the loss power in the individual elements. The paper presents also formulas of loss power, formulas of energy efficiency connected with investigated hydrostatic drives, two schematic diagrams of hydraulic systems, their principle of operation and problems of studying losses in elements and energy efficiency characteristics of systems consisting of a feed assembly, control set and cylinder. It also includes a subject matter connected with an energy loss power of hydrostatic systems with hydraulic cylinder controlled by proportional directional control valve. Diagrams of loss power of two hydraulic systems worked at the same parameters of speed and load of a cylinder, which were different due to structure and ability of energy saving, were presented and compared.
Źródło:
Polish Maritime Research; 2018, 4; 114-129
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving the effective efficiency of a spark ignition engine through the use of a fully independent valve control system
Autorzy:
Żmudka, Zbigniew
Postrzednik, Stefan
Powiązania:
https://bibliotekanauki.pl/articles/2097609.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
SI engine
theoretical cycle
charge exchange
engine efficiency
independent valve control
silnik ZI
cykl teoretyczny
wymiana ładunku
sprawność silnika
niezależne sterowanie zaworami
Opis:
The article presents theoretical research of the proposed system of fully independent valve control (FIVC) of the SI engine. The analysis included controlling the movement of the intake valves, which results in adjusting the mass of the fresh charge to the current engine load, as well as the movement of the exhaust valves, where the main aim is to keep the rest of the exhaust gas in the cylinder, i.e. implementation of internal EGR. The open theoretical Seiliger-Sabathe cycle with the classic throttle regulation of load is the reference cycle for assessment of benefits and study of the effectiveness of obtaining work as a result of application of the FIVC system. A comparative analysis of the effectiveness of application of the proposed system was carried out based on the selected quantities: fuel dose, cycle work, relative work of charge exchange and cycle efficiency. The use of the FIVC to regulate the SI engine load makes it possible to eliminate the throttle and thus reduce the charge exchange work, especially in the partial load range. And this then leads to an increase in internal and effective work, which in turn results in an increase in the effective energy efficiency of an engine operation.
Źródło:
Combustion Engines; 2021, 60, 4; 30--35
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Realization of the Atkinson-Miller cycle in spark-ignition engine by means of the fully variable inlet valve control system
Autorzy:
Żmudka, Z.
Postrzednik, S.
Przybyła, G.
Powiązania:
https://bibliotekanauki.pl/articles/240220.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spark-ignition engine
variable inlet valve control
open theoretical cycle
charge exchange process
silnik o zapłonie iskrowym
zawór
otwarty obieg teoretyczny
wymiana ładunku
Opis:
The theoretical analysis of the charge exchange process in a spark ignition engine has been presented. This process has significant impact on the effectiveness of engine operation because it is related to the necessity of overcoming the flow resistance, followed by the necessity of doing a work, so-called the charge exchange work. The flow resistance caused by the throttling valve is especially high during the part load operation. The open Atkinson-Miller cycle has been assumed as a model of processes taking place in the engine. Using fully variable inlet valve timing the A-M cycle can be realized according to two systems: system with late inlet valve closing and system with early inlet valve closing. The systems have been analysed individually and comparatively with the open Seiliger-Sabathe cycle which is a theoretical cycle for the classical throttle governing of the engine load. Benefits resulting from application of the systems with independent inlet valve control have been assessed on the basis of the selected parameters: fuel dose, cycle work, charge exchange work and a cycle efficiency. The use of the analysed systems to governing of the SI engine load will enable to eliminate a throttling valve from the system inlet and reduce the charge exchange work, especially within the range of part load operation.
Źródło:
Archives of Thermodynamics; 2014, 35, 3; 191-205
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stanowisko do wyznaczania charakterystyk statycznych i dynamicznych zaworów proporcjonalnych
Test stand for estimation of static and dynamic characteristic of proportional hydraulic valves
Autorzy:
Kudźma, Z.
Stosiak, M.
Herok, S.
Powiązania:
https://bibliotekanauki.pl/articles/276099.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
rozdzielacz proporcjonalny
sterowanie proporcjonalne
charakterystyki
przekładnia hydrostatyczna
badania
proportional directional control valve
proportional control
characteristics
hydrostatic transmission
research
Opis:
W artykule przedstawiono stanowisko do wyznaczania charakterystyk statycznych i dynamicznych zaworów sterowanych w technice proporcjonalnej. Opisano układ sterujący rozdzielaczem proporcjonalnym i wielokanałowy tor sterująco-pomiarowy ze specjalistycznym oprogramowaniem umożliwiającym generowanie dowolnego w czasie przebiegu sygnału sterującego oraz na akwizycję danych pomiarowych. Przedstawiono przykładowe wyniki wyznaczania charakterystyk proporcjonalnego rozdzielacza regulacyjnego najnowszej generacji. Zamieszczono przykład zastosowania uzyskanych wyników pomiarowych do uściślenia modelu matematycznego sterowania rozruchem przekładni hydrostatycznej pod kątem minimalizacji hałasu.
In the paper a test stand for determination of static and dynamic proportional valves characteristic was presented. A multichannel test stand was developed and presented in the paper. Moreover control system of proportional directional control valve and multichannel slotted line with special software for generation several control signals were presented too. Moreover some experimental tests results were presented for high-response proportional directional control valve. An example of application obtained results for mathematical model refinement of control of hydrostatic transmission start with minimum noise criterion was presented.
Źródło:
Pomiary Automatyka Robotyka; 2014, 18, 3; 112-119
1427-9126
Pojawia się w:
Pomiary Automatyka Robotyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza numeryczna zaworu kulowego - charakterystyka przepływowa i kawitacyjna
Numerical analysis of ball valve - flow and cavitation characteristics
Autorzy:
Mocek, P.
Powiązania:
https://bibliotekanauki.pl/articles/156497.pdf
Data publikacji:
2011
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
charakterystyki zaworów
obliczeniowa mechanika płynów
kawitacja
control ball valve
cavitation
computational fluid mechanics
Opis:
W artykule zaprezentowano rezultaty obliczeń numeryczną mechaniką płynów (CFD) charakterystyki zaworu kulowego. Porównano rezultaty obliczeń metodami równań domykających k- oraz z wykorzystaniem symulacji wielkich wirów LES. Przeprowadzono również analizę numeryczną problemu kawitacji w zaworze kulowym. Uzyskane charakterystyki pokrywają się z danymi eksperymentalnymi. Obliczenia numeryczne CFD mogą mieć zastosowanie w optymalizacji kształtek profilowych oraz redukcji zużycia erozyjnego elementów zaworu.
In the paper there are presented the results of numerical calculations of the ball valve characteristics with use of the computational fluid dynamics. The calculations were carried out with use of the hypothesis of turbulent flows, the k- and simulations of large vor-texes (DS LES). The flow patterns in and downstream the ball valves with respect to different valve openings are visualized using the computational fluid mechanics Fluent commercial code. The CFD procedure was validated on the basis of the experimental data obtained by other authors. The valve applied in industry is shown in Fig. 1. The numerical grids were prepared in the Gambit preprocessor. Fig. 2 presents the view of the numerical grid for valve in the sample 10, 30, 75o angle closure for the valve whose main dimensions are given in Fig. 3. The calculation results are local physical flow fields inside the valve. For example, the velocity vector fields in the valve crossection are shown in Fig. 4. The CFD calculation results were used for calculating the valve characteristics. They are presented in Fig 5a. The figure shows the measured and calculated values of the flow resistance factor and cavity index compared with the measurement results obtained by other authors. Fig. 5b shows the comparison of the data from literature [13] with the results of numerical calculations using different turbulence models. In that figure there is presented the modelling of the single phase and two phase gas-liquid mixture. The obtained characteristics coincide with the experimental data which allows using that method for optimising the profile shapes when applying the numerical iterative correction. The calculation results for two-phase flows are shown in Fig. 6. In that picture there are presented the cavitation zones for which the volumetric concentration of water vapour is greater than 10%. The results of theoretical predictions were found to be in general agreement with those obtained from calculations within the acceptable level of accuracy.
Źródło:
Pomiary Automatyka Kontrola; 2011, R. 57, nr 1, 1; 97-100
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza efektywności niezależnego sterowania zaworami wylotowymi jako sposobu realizacji wewnętrznej recyrkulacji spalin
Analysis of effectiveness of independent exhaust valve control as a method of an internal EGR realization
Autorzy:
Żmudka, Z.
Postrzednik, S.
Przybyła, G.
Powiązania:
https://bibliotekanauki.pl/articles/132866.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
silnik spalinowy
otwarty obieg teoretyczny
wymiana ładunku
niezależne sterowanie zaworami wylotowymi
wewnętrzna recyrkulacja spalin
internal combustion engine
open theoretical cycle
charge exchange
independent exhaust valve control
internal exhaust gas recirculation
Opis:
Przeprowadzono analizę systemu z niezależnym, wcześniejszym zamknięciem zaworu wylotowego, który umożliwia realizację wewnętrznej recyrkulacji spalin oraz wyeliminowanie przepustnicy w silniku ZI. Odniesieniem dla oceny korzyści oraz badania efektywności pozyskiwania pracy, w wyniku zastosowania tego systemu sterowania, jest otwarty obieg teoretyczny Seiligera-Sabathe’a z powszechnie stosowaną klasyczną regulacją dławieniową obciążenia. Analizę porównawczą efektywności zastosowania zaproponowanego systemu przeprowadzono opierając się na wybranych wielkościach: dawce paliwa, pracy obiegu, względnej pracy wymiany ładunku oraz sprawności obiegu. Najlepsze efekty w zakresie zmniejszenia dawki paliwa i zwiększenia sprawności obiegu dla analizowanego systemu, w porównaniu do systemu z regulacją dławieniową, uzyskuje się w obszarze średniego obciążenia silnika.
A system with independent, early exhaust valve closing has been analysed. The analysed system enables realization of an internal EGR and elimination of a throttling valve from inlet system of a spark ignition engine. The open, theoretical cycle has been assumed as a model of processes proceeding in an engine. The system has been analysed individually and comparatively with open Seiliger-Sabathe cycle. Benefits resulting from application of the system with early exhaust valve closing have been assessed on the basis of the selected parameters: a fuel dose, a cycle work, a relative charge exchange work and a cycle efficiency. The best results within decrease of fuel consumption and increase of cycle efficiency are obtained for mean engine load.
Źródło:
Combustion Engines; 2013, 52, 3; 338-345
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of dynamic parameters of the selected components within digitally controlled hydraulic system
Autorzy:
Kamiński, M.
Szlagowski, J.
Dąbrowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/950156.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
mobile hydraulics
proportional directional control valve
hydraulic cylinder control
electro-hydraulic pilot valve
hydraulic system modelling
hydraulika mobilna
sterowanie siłownikiem hydraulicznym
elektrohydrauliczny zawór pilotowy
modelowanie układu hydraulicznego
Opis:
Dynamic parameters characterizing proportional hydraulic components are essential factors affecting the performance of the construction machinery automatic control system. Knowledge of these parameters is inevitable in modelling the automatically controlled hydraulic power systems as well as designing and analysing the control algorithms. This article presents a methodology of assessing the dynamic parameters of selected components being part of digitally controlled hydraulic power system. The analysed system comprised a typical for mobile hydraulics applications PVG32 proportional directional control valve (DCV) and a variable displacement piston pump. The control system utilised an MC088 PLC controller with specifically prepared and configured software. The measuring system was based on CANbus, which, combined with the PLC used, allowed for flexible configuration of the sensor variables and logging both analogue and digital signals. Among others, the DCV characteristics, the response to step and sinusoidal inputs and DCV hysteresis were examined. The goal was to gather the data required for system modelling and to assess the importance and influence of the investigated parameters onto the model being created.
Źródło:
Journal of KONES; 2018, 25, 1; 205-214
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical model of the hydraulic valve timing system
Autorzy:
Mitianiec, W.
Bac, J.
Powiązania:
https://bibliotekanauki.pl/articles/242296.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
transport
combustion engines
valve timing
hydraulic control
Opis:
The paper presents a conception and mathematical model of the hydraulic valve timing system. It describes the complex physical phenomena that occur between system components and the hydraulic liquid. Basing on postulates and initial conditions model, one was simulated the movement of elements system resulting from the flow of pressured liquid. The model was simulated in Matlab/Simulink program for different geometrical parameters of the hydraulic system and electric control parameters in order to obtain required lift and timing of valves in YARIS SI 1.3 l engine. The paper presents structure of Simulink model and results of calculation in Simulink. One represented the influence of various parameters and dimensions system on the character of valve lift. The relationship between the diameter of the rod and the liquid significantly affects the valve time-area parameter. The feeding liquid pressure in the system and the re-steering time have the biggest influence on course of valve lift. After preliminary tests the guidelines for the hydraulic valve timing system have been developed. The determined simulation results in Simulink were used to calculate of the device work in the engine computer model created in GT-Power program. The proposed solution was compared with the cam valve timing systems. On the basis of the simulations tests show a big superiority of the hydraulic valve timing system at higher rotational speeds.
Źródło:
Journal of KONES; 2011, 18, 2; 311-321
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modern actuator
Autorzy:
Mielewczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/242423.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
main engine
control
controller
actuator
regulating valve
transducer
Opis:
The main engine of the ship is a complex technical object, which provides propulsion of the screw and ensures the safety of a ship at sea. It consists of a number of control systems such as lube oil temperature control, temperature control of the cooling water, fuel viscosity control or adjustable speed control of the main engine. Each of the main propulsion control system affects the safety of the ship. Continuous automation systems are built with standard transducer of measured quantity, the controller and actuator. The actuator is responsible for the direct setting of the size of the control object. The actuator is connected to the control valve and the actuator position change translates into a change in the flow rate of the working medium. Thus, the operating element is required to operate in the linear characteristics of the standard signal range. From the other hand, the control valve provides flow characteristics linear or of equal percentage. This control principle of medium flow is used in various control systems. The actuator of the control valve is always equipped with a positioner, which corrects errors in the position of the valve relative to the input signal. The presented design of the motorized valve is an analog system. Using the technique of converting multiple digital signal causes the system complexity and predisposition to damage. Eliminating the intermediate elements can improve the quality control and system safety. Then it is beneficial to have a design of the operating element based on the direct digital processing unit. The aim of paper has been to present design of the valve actuator, which completely abandons the digital-to-analogue convertor. The new design should increase the level of security of the system and quality control. The design layout is presented in the article. The new actuator is on-off valves, which control, directly from the digital bits, the form of the output signal. The control signal may use the control algorithms to be used or developed individually to the actuator design.
Źródło:
Journal of KONES; 2014, 21, 2; 221-226
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł

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