Wyniki wyszukiwania - Biblioteka Nauki

1

Researches of model plazma reactor for purify diesel exhaust gas of particulates

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Zawadzki A. , Irzycki A. , Kalina P. , Snopkiewicz K.

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tom Vol. 13, No. 3

437-441

EN

The device being investigated generates the low-temperature corona discharge in the stream of exhaust gas, causing the positive charging of particulates. The charged particulates are coming in electrostatic field to agglomeration and acceleration and next mechanically separated from the fumes. The reactor is powered by 10 – 15 kV DC voltage. This work is a continuation of the previously reconnaissance research conducted in Institute of Aviation which showed, that principle problem to be resolved was the deposit of soot between high-voltage electrodes and their insolating housing which caused a current leakage and in effect gradual drop of supply voltage resulting the restriction of reactor’s effective work time. However the 40% effectiveness of exhaust gas purifying of particulates was the result, which encouraged the authors to continuation of research work. As opposed to earlier “flat” structure, the mentioned one is made as an axial symmetrical. The device is placed immediately behind the exhaust manifold and works in high temperature area. Several variants of basic reactor’s structures were investigated. Subsequent research work will comprise modifications of discharge zone and electrostatic field geometry as well improving efficiency of mechanical particulates separator.

PL

Badane urządzenie wytwarza w strumieniu spalin niskotemperaturowe wylądowania koronowe powodujące jedno-imienne dodatnie naładowanie cząstek starych. Obdarzone ładunkiem cząstki stale ulegają aglomeracji i akceleracji w polu elektrostatycznym, a następnie są mechanicznie oddzielane od strumienia spalin. Urządzenie jest zasilane prądem stałym o roboczym napięciu 10-15 kV. Prace stanowią kontynuację badań rozpoznawczych prowadzonych w Instytucie Lotnictwa, w wyniku których okazało się, że zasadniczym problemem do rozwiązania było osadzanie się sadzy między elektrodami wysokiego napięcia a ich izolacyjną obudową powodujące przepływ prądu, a w efekcie stopniowy spadek napięcia zasilania skutkujący ograniczeniem czasu efektywnej pracy urządzenia. Jednakże uzyskanie ok. 40% skuteczności oczyszczania spalin z cząstek stałych uznano za efekt zachęcający do dalszych badań. W odróżnieniu od uprzednio badanego modelu płaskiego obecne modelowe urządzenie wykonano w układzie osiowo-symetrycznym. Urządzenie usytuowane za kolektorem wylotowym silnika pracuje w strefie spalin o wysokiej temperaturze. Przebadano v kilku wariantach wyjściowe modelowe urządzenie będące podstawą dalszych modyfikacji, które obejmować będą zarówno kształtowanie strefy wyładowań koronowych i odchylającego pola elektrostatycznego, jak i doskonalenie mechanicznego separatora cząstek

2

Impact of low-temperature corona discharges on gaseous pollutants level in diesel engine's exhaust gas

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Irzycki A. , Kalina P. , Snopkiewicz K.

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tom Vol. 17, No. 2

145-152

EN

This publication presents the results of research on level changes of gaseous pollutants contained in the exhaust gas in the consequence of applying of equipment taking advantage of low-temperature corona discharges. Not only influence of different plasma reactor configurations on the emission of toxins have been evaluated, but also on the main parameters of the engine under test and exhaust gas cleaning efficiency as well. The device supplied by DC voltage of 10-15 kV the operating value generated a low-temperature corona discharge in the especially formed electrostatic field. The devices were located behind the exhaust manifold of Diesel engine then operated in the high temperature zone of exhaust. The survey was realized in parallel with on-going research program at Institute of Aviation which has related to purification of Diesel engine's exhaust gas from particulates. The test results of emission of toxins obtained using the flat-arrangement and the axial-symmetric reactor systems were compared and discussed. The multi-variant designs of axial-symmetric device allowed the purposeful formation of favourable shape and intensity of electrostatic field and values of current, which induced the corona discharge. This activity has created better research capabilities for different geometric configurations of the reactors, namely linear and angular location and size of deflecting electrodes, structure of blade assembly generating a corona discharge, matching of proper distance between deflecting electrodes and blades.

3

Some problems resulting from powering of turbine engines by liquified petroleum gas (LPG)

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Balicki W. , Kalina P. , Snopkiewicz K. , Irzycki A.

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tom Vol. 20, No. 4

17--22

EN

There has been observed for several years a number of attempts to introduce for everyday use small power units which utilize turbine engine as propulsion unit (the U.S., Japan, and Europe). Efficiency increase of such devices is achieved by improving of turbine engine design as well as utilizing of exhaust gas thermal energy to heat the compressed air supplied to combustion chamber and, for example to heat usable water. Significant orientation of turbine engine improvements lead to the modernization of combustion processes by applying of gaseous fuels (such as compressed natural gas) or implementation of high-temperature catalytic combustion. The purpose of these changes reduction of hydrocarbons, carbon monoxide and nitrogen oxides emissions. In Propulsion Department of Aviation Institute a scientific project has been realized, in which the object of study was aircraft turbine engine powered by a liquid propane-butane mixture. The paper presents some results of engine tests carried out, especially concerning feeding system, special fuel system applied LPG pumping systems with the use of sliding-vane pump and by means of pressure reservoir and combustion process of LPG atomized with the use of original GTD-350 vortex injector, adapted for aviation kerosene Jet-A.

4

Comparison the piston air engine performance with aviation gasoline (Avgas) or the E-85 ecological fuel supply

100%

Balicki W. , Irzycki A. , Snopkiewicz K.

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tom Vol. 17, No. 3

25-32

EN

The fuel presently used for feeding of aircraft piston engines (petrol including TEL) is characterized by "strong unfriendliness" for environment. Many research centres have been going on fuels investigation, which could substitute Avgas utilized in aviation. This is why are there no being in force for Europe standards defining the allowable emission of pollutions in exhaust gases of aircraft piston engines (equivalent to EURO - standards introduced for traction engines). The mixtures of gas o line and alcohols are tested as "alternative" aircraft fuels for spark ignition engines, and in case of Diesel engines - evenjet kerosene. During the research works on test bed carried out at Institute of Aviation the performance offour-stroke aircraft carburettor piston engine supplied by "classical" aircraft petrol and the E - 85 fuel (mixture of petrol and ethanol) were compared. Except for measuring the functional parameters of engine (rotational speed, torque, specific fuel consumption, pressures and temperatures) the emissions of gaseous pollutants incorporated in exhaust gas were measured and analyzed. The range of modifications of engine supply system - necessary to introduce in case of changing of fuel type within the tested engine -was worked up. There are foreseen comparative test of fuelling the engine with mixtures of petrol and alcohols in different proportions in the next phase of research works.

5

Testing of initiation of rotating detonation process in hydrogen - air mixtures

100%

Balicki W. , Irzycki A. , Łukasik B. , Snopkiewicz K.

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tom Vol. 19, No. 2

25-34

EN

The paper presents results of some research work done in the project, which aims to apply of an innovative combustion chamber to the turbine engine. Expected benefits of using of a new chamber in which classical deflagration type combustion process would be replaced with a detonation combustion type, arise from greater efficiency of FickettJacobs cycle, which corresponds to rotating detonation combustion, in comparison to "classical" Brayton cycle, characteristic of deflagration combustion. The presented task concerned fundamental research carried out on test bench designed and built at the Institute of Aviation in Warsaw. To initiate the detonation combustion in the fuel-air mixtures the ignition device of appropriately high energy is necessary. The released energy should be directed to the area where the mixture has proper constitution - preferably close to stoichiometric one. Four different ignition manners were examined in the course of research: electrical ignition system adapted from turbine engine (semiconductor spark plug), powder charge ignition (handgun cartridges), detonation primer ignition using pentryt, and high voltage discharge (plasma jet). The appearance of detonation type combustion was identified on the basis of combustion gas pressure run, measured using piezoelectric sensors at a frequency of 1 MHz.

6

Measurements of pressure in front of shock wave : assessment of methodology influence on the measurement results on the basis of experiments with the shock tube

88%

Perkowski W. , Irzycki A. , Kawalec M. , Łukasik B. , Snopkiewicz K.

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tom Vol. 20, No. 4

333--340

EN

The experiments, described in the article, are related to research of a rotating detonation that has been conducted in the Institute of Aviation in Warsaw since 2009, under the OPIE project: “Turbine engine with detonation combustion chamber”. Measurements of the shock wave parameters, are among the most difficult in the art. This is due to high speed of the wave transition, and above all, a very small thickness of the shock wave. For the purposes of the mentioned project, a methodology for measuring pressure on the rotating detonation wave was developed. It included the type of sensors, their location and their protection from heat and flames. In order to determine the capabilities, limitations and accuracy of the method that was used, a series of experiments were planned and carried out. They enabled the assessment of the impact, on the measurement of pressure in the shock wave, of the following factors: the location of the sensor (frontal and lateral) relative to the shock wave front, protrusion or retraction of the sensor in its housing, the covering of the sensor with a protective layer (such as a high temperature silicon). This paper presents the results of the experiments that were carried out with use of a small shock tube of a simple design. The high-pressure part of the tube (so-called “driver”) was charged with the compressed nitrogen gas. The membrane was designed to be torn by pressure and pressure magnitude of the shock wave were measured by a “twin pair” of the Kistler 603B type piezoelectric sensors, one of which was always the reference sensor.

7

Study on kerosene atomization process under a high speed air stream

88%

Perkowski W. , Irzycki A. , Snopkiewicz K. , Grudzień Ł. , Kawalec M.

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tom Vol. 18, No. 4

341-347

EN

For the needs of fuel-injection system development for the experimental detonation combustion chamber with a rotating detonation (PoiG - Project: "Turbine engine with detonation combustion chamber") a series of experiments with injection of kerosene under a high speed air stream was performed at the Institute of Aviation. The proper preparation of combustible mixture is very important for the initiation and sustenance of a rotating detonation. The task in case of kerosene-air mixture is far more difficult than for mixtures of hydrogen-air or kerosene-oxygen. A simple stream injector has been tested as a base system, and the kerosene was injected perpendicular to the air stream vector directly from the plane wall of the constant cross-section channel. The process of injection and atomization of kerosene was observed in the special transparent visualization chamber, enabling the spray observation of two mutually perpendicular directions. In subsequent experiments air pressure, air temperature and air flow velocity as well as and injection pressure of kerosene were varied. The tested process was photographed and, in case of chosen experiments, filmed using a high-speed digital camera. The surveys were aimed at identifying and assessing of following parameters of fuel atomization process: the range of the fuel stream and filling grade of research channel with aerosol, aerosol homogeneity and the size of forming it droplets, the possible presence of fuel streams flowing down the walls of channel. The resulting photos allowed for more comprehensive, but only a qualitative assess of the spraying process, while the filmed small regions of visualization chamber allowed the counting down and dimensioning of droplets. This paper presents a test facility and measuring techniques applied during the research activity and selected results of carried out tests.

8

GTD-350 engine powered by LPG : research work

88%

Kalina P. , Niedziałek B. , Gryglewski W. , Irzycki A. , Snopkiewicz K.

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2013

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tom Vol. 20, No. 3

209--214

EN

The paper presents results of comparative tests of exhaust gases toxicity of GTD-350 turboshaft engine powered by Liquefied Petroleum Gas (LPG) and conventional JET-A1 fuel. Structure of GTD-350 engine’s test bed was discussed. Because of explosion danger of LPG vapour the test stand was arranged in the open air. Paper comprises specification of LPG supply system, gas injector’s construction and visualization of LPG injection. The supply system was based on the newly constructed pressurized injectors. Required LPG operating pressure was obtained by pressurizing LPG tank using nitrogen and LPG-flow was controlled using needle valve. A series of photographs presents shape of fuel streams for new injector supplied by JET-A1 and LPG. Photos of flame torches for multi-hole and conical type injectors fuelled by LPG are inserted as well. A comparative study of carbon monoxide, nitrogen oxides, hydrocarbons and carbon dioxide as well as oxygen concentration for GTD-350 equipped with new injectors fuelled by LPG and standard supplied by Jet-A1 was carried out. The study comprised turbocharger speed range between 40 and 80% of NTS. The exhaust gas temperature comparison for above-mentioned configuration is presented as well. All data shown in presented figures are mean of 6 measurements. All completed tests were carried out for standard GTD-350 engine combustion chamber.