Wyniki wyszukiwania - BazTech

1

Simulation tests of a VCR engine as a propulsion unit in rail vehicles

Bajerlein Maciej, Urbański Patryk

Pojazdy Szynowe

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2020

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Nr 4

33--44

EN

The paper presents the possibility of using a VCR engine as a driving unit of a generating set in rail vehicles. Thermodynamic analyzes of the engine were also performed. For the purposes of the research, the piston path was generated in the dynamic simulation in Solidworks to study the processes occurring during the combustion process. This path was used to simulate the AVL Fire program for the same initial conditions. Different variants of the engine cam control with the same compression ratio were compared. The article analyzed the moment and the period of time that the piston remains in the Upper Dead Center (TDC).

PL

W ramach pracy przedstawiono możliwość zastosowania silnika VCR jako jednostki napędowej zespołu prądotwórczego w pojazdach szynowych. Dokonano również analiz termodynamicznych silnika. Na potrzeby badań wygenerowano drogę tłoka w symulacji dynamicznej w programie Solidworks do badania procesów zachodzących podczas procesu spalania. Droga ta została wykorzystana do przeprowadzenia symulacji w programie AVL Fire dla jednakowych warunków początkowych. Porównane zostały różne warianty wysterowania krzywki silnika przy jednakowym stopniu sprężania. W rozpatrywanym artykule analizowano moment oraz okres czasu jaki tłok pozostaje w Górnym Martwym Położeniu (GMP).

2

A High Performance Digital Time Interval Spectrometer: An Embedded, FPGA-Based System With Reduced Dead Time Behaviour

Arkani M.

Metrology and Measurement Systems

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2015

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Vol. 22, nr 4

601--619

EN

In this work, a fast 32-bit one-million-channel time interval spectrometer is proposed based on field programmable gate arrays (FPGAs). The time resolution is adjustable down to 3.33 ns (= T, the digitization/discretization period) based on a prototype system hardware. The system is capable to collect billions of time interval data arranged in one million timing channels. This huge number of channels makes it an ideal measuring tool for very short to very long time intervals of nuclear particle detection systems. The data are stored and updated in a built-in SRAM memory during the measuring process, and then transferred to the computer. Two time-to-digital converters (TDCs) working in parallel are implemented in the design to immune the system against loss of the first short time interval events (namely below 10 ns considering the tests performed on the prototype hardware platform of the system). Additionally, the theory of multiple count loss effect is investigated analytically. Using the Monte Carlo method, losses of counts up to 100 million events per second (Meps) are calculated and the effective system dead time is estimated by curve fitting of a non-extendable dead time model to the results (τNE = 2.26 ns). An important dead time effect on a measured random process is the distortion on the time spectrum; using the Monte Carlo method this effect is also studied. The uncertainty of the system is analysed experimentally. The standard deviation of the system is estimated as ± 36.6 × T (T= 3.33 ns) for a one-second time interval test signal (300 million Tin the time interval).

3

Project of an TDC signal distributor prototype with galvanic separation destined for studies of the beginning of selfignition using Langmuir probe

Rudnicki J., Piechowski L.

Journal of Polish CIMAC

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2014

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Vol. 9, no 2

173--183

EN

The knowledge of pistons' TDC is crucial while performing any kind of measurement beneficial to diagnostic inference of a diesel engine. The research of engines under exploitation often cause impartial difficulties with, eg. capability of probe installation. Therefore, it becomes crucial to minimalize those. The paper presents a description of a TDC impulse distributor - divider that provides signal delivery to more than one measurement system used during the research (here -cylinder indication system and Langmuir probe system). The necessity of galvanic separation of signals was justified and detailed, electronic schematic diagrams of two Solutions of TDC signals distributors were presented. Those are systems with two and four independent output. The distributor's system with two outputs was realized in practice as a prototype used during measurements performed on diesel engines. Alternative possibilities of manufacturing any kind of distributor, according to user's needs, were presented.

4

A novel method based solely on field programmable gate array (FPGA) units enabling measurement of time and charge of analog signals in positron emission tomography (PET)

Pałka M., Moskal P., Bednarski T., Białas P., Czerwiński E., Kapłon Ł., Kochanowski A., Korcyl G., Kowal J., Kowalski P., Kozik T., Krzemień W., Molenda M., Niedźwiecki S., Pawlik M., Raczyński L., Rudy Z., Salabura P., Gupta-Sharma N., Silarski M., Słomski A., Smyrski J., Strzelecki A., Wiślicki W., Zieliński M, Zoń N.

Bio-Algorithms and Med-Systems

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2014

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Vol. 10, no. 1

41--45

EN

This article presents an application of a novel technique for precise measurements of time and charge based solely on a field programmable gate array (FPGA) device for positron emission tomography (PET). The described approach simplifies electronic circuits, reduces the power consumption, lowers costs, merges front-end electronics with digital electronics, and also makes more compact final design. Furthermore, it allows to measure time when analog signals cross a reference voltage at different threshold levels with a very high precision of ~15 ps (rms) and thus enables sampling of signals in a voltage domain.

5

Acquisition of diagnostic information from the indicator diagrams of marine engines using the electronic indicators

Polanowski S., Pawletko R.

Journal of KONES

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2011

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Vol. 18, No. 3

359-366

EN

The paper analyzes the factors influencing the quantity and quality of diagnostic information obtained by engine indication with electronic indicators and pressures analyzers. Amount of information obtained virtually unchanged since the advent of the first construction pressure analyzers produced by Autronica and ABB Company. In many cases, the value of the maximum combustion and compression pressures, can be measured using these devices with sufficient accuracy and reliability, is if ignition occurs after piston TDC. Determination of the mean indicated pressure, compression ratio and heat release characteristics required to develop a method of TDC determination on the indicator diagrams, generate reliable angular axes in real time and pressure sensors of sufficient accuracy. It should be noted that in the latest solution of ABB system, a correction of thermodynamic loss angle and combustion pressure sensors of high accuracy were introduced. For marine diesel engines diagnosis, the pressure sensor measuring sustainability is important because of the ability to create trends of specific diagnostic parameters, which may constitute an additional, important source of diagnostic information. The paper presents an overview of currently available pressure sensors that can be used during marine engines indication. Most important issues related to the pressure measurement on indicator valves were characterized. An assessment of the gas channels and the quality of the angular axis impact for the parameters of indicator graphs was done.

6

Analysis of application of chosen methods for tdc determination in marine diesel engines

Łutowicz M.

Journal of KONES

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2009

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Vol. 16, No. 4

301-306

EN

In the operating marine diesel engines the indication diagnostics tests are usually performed through a 0.5-1.0 me ter long indication channel which delays and disfigures the pressure signal being measured. the delay depends on the engine 's speed and load. the pressure sensor itself together with an amplifler is an additional source of delay and disfigurements, so the registered pressure curve is displaced even if theTDC piston's position hadbeen estimated with the highest accuracy. when the over exploited engine is being tested the angle of delay can achieve several degrees and differ for each cylinder. in that case cylinders' load is unequal and torsional vibrations occur in the engine operation. in case when some simplifying assumptions have been adopted the part of diagnostic information is lost what could lead to a false diagnosis. in the paper the attention is focused on the mistakes which could be made in the marine diesel engine diagnostics when different TDC assessment methods are used. TDC corrections with compression pressure analysis are possible only in case when crankshaft angle position is precise. in case of measurement with constant frequency such corrections are possible only when the engine is good balanced.

7

Scalony licznik czasu o rozdzielczości 50 ps w reprogramowalnym układzie FPGA

Szplet R., Jachna Z., Kalisz J.

Elektronika : konstrukcje, technologie, zastosowania

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2006

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Vol. 47, nr 9

41-45

PL

Opisano budowę, zasadę działania oraz wyniki badań scalonego licznika czasu o rozdzielczości 50 ps i niepewności pomiarowej poniżej 60 ps. Do pomiaru odcinka czasu użyto metodę interpolacji dwustopniowej. W pierwszym stopniu interpolacji wykorzystano zegar wielofazowy, a w drugim cyfrowe linie opóźniające. Licznik czasu został wykonany w reprogramowalnym układzie FPGA (Field Programmable Gate Array). Artykuł zawiera również opis oprogramowania diagnostycznego umożliwiającego kalibrację licznika, wykonywanie pomiarów oraz gromadzenie, przetwarzanie i zobrazowanie wyników pomiarów.

EN

This paper describes the design, operation and test results of an integrated time counter with a 50 ps resolution and the standard measurement uncertainty below 60 ps. The time interval is measured with the use of the two-stage interpolation method. A multiphase clock and digital delay lines are used in the first and second stages of interpolation, respectively. Time counter is implemented in a single reprogrammable FPGA (Field Programmable Gate Array) device. Additionally, we describe the control/diagnostic software that allows calibration of the counter, measurement control as well as, processing and displaying of measurement data.

8

Badanie procesu sprężania dla potrzeb diagnostyki okrętowych tłokowych silników spalinowych

Korczewski Z., Łutowicz M.

Zeszyty Naukowe / Akademia Morska w Szczecinie

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2004

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nr 1 (73)

355-367

PL

Omówiono sposób aproksymacji funkcją wykładniczą wyników badania procesu sprężania czynnika roboczego w cylindrach okrętowego tłokowego silnika spalinowego Sulzer 6AL20/24, wyposażonego w czujnik ciśnienia umieszczony w głowicy. Daje to możliwość wyznaczenia położenia GMP, ciśnienia początkowego i ciśnienia sprężania wtedy, gdy zapłon następuje przed GMP.

EN

The paper discusses a method of an approximation of the results of the compression process examined on 6AL20/24 Sulzer engine cylinders. The approximation has been carried out by means of an exponential function. The method allows to determine the TDC position, initial pressure as well as compression pressure when the ignition comes before TDC.