Wyniki wyszukiwania - BazTech

1

Fuel with a higher content of bio components in greenhouse effect aspects

Andrych-Zalewska Monika, Sitnik Lech, Sroka Zbigniew, Mihaylov Veselin

Combustion Engines

|

2023

|

R. 62, nr 1

36--42

EN

Transport is an energy-intensive sector of the economy and it is important where energy comes from and how it is used - now and in the future. The presented research results seem to encourage further work, despite the fact that the work had the character of basic research. The results were achieved in idealized conditions by the fact that the internal combustion engine was tested in static conditions on the test bench and the fuels contained components with strictly defined parameters. These conditions are different from everyday life. However, the obtained results seem to be valuable as they lead to conclusions regarding biofuels, and these conclusions are not directly formulated and published in the literature on the subject. The general conclusion from the research carried out is that the introduction of the so-called biofuels can contribute not to the reduction of CO2 emissions, but to its faster balancing in the environment. This balancing can be achieved but at the cost of increased fuel consumption. This increase in fuel consumption would probably not occur if the "bio" components in the fuel were synthetic hydrocarbons obtained from biomass. However, proving it requires wider studies, including LCA. Data for this LCA, especially about a fuel consumption, may be coming from long term operation of vehicles.

2

Electrochemical contactless machining - process characteristics, directions of development and practical applications

Ruszaj Adam

Journal of Engineering, Energy and Informatics

|

2021

|

No. 1

69--79

EN

Electrochemical machining was, is and will be widely applied in industry, because of its advantages: high metal removal, good surface layer quality without tool wear. The first applications took place in case of sinking, where detail shape is obtained as electrode-tool shape reproduction in a workpiece. The results of the process mainly depend on optimal electrolyte flow and are limited by temperature and hydrogen concentration increase. Because of these problems the pulse ECM process was worked out. In PECM process limitations of temperature and hydrogen concentration were overcome, accuracy increased, however metal removal rate was significantly decreased. The next way of overcoming process limitations was the advanced kinematic (milling) and simple cylindrical electrode tool shape introduction. Here the shape of a workpiece is obtained as a result of electrode-tool trajectory reproduction and problem of electrode-tool correction doesn’t exist. Practical applications of this way of ECM machining in case of macro details were rather limited to surface smoothing because o low metal removal rate. This way of machining is widely applied in case of micro-details (D< 1mm) manufacturing. Here ECM wire cutting operation have their applications. In the paper will be presented: general problems of ECM process modeling and technological process designing. Examples of ECM process practical applications will be also presented.

PL

Obróbka elektrochemiczna bezstykowa (ECM) jest i będzie coraz szerzej stosowana w przemyśle z uwagi na jej zalety, takie jak duża wydajność obróbki oraz brak zużycia narzędzia. Pierwsze zastosowania ECM obejmowały operacje drążenia, w których kształt przedmiotu obrabianego uzyskuje się jako odwzorowanie kształtu elektrody roboczej w materiale obrabianym. Wyniki procesu zależą głównie od optymalnych warunków przepływu elektrolitu i są ograniczone przez wzrost temperatury elektrolitu oraz koncentracji objętościowej wodoru. Aby zlikwidować te ograniczenia, opracowano proces impulsowej obróbki elektrochemicznej (PECM), w którym zlikwidowano ograniczenia wynikające z przyrostu temperatury i koncentracji objętościowej wodoru, niestety kosztem istotnego zmniejszenia wydajności obróbki. Drugim sposobem usunięcia ograniczeń procesu drążenia było wprowadzenie operacji frezowania i zastosowanie uniwersalnej cylindrycznej elektrody roboczej. Tutaj kształt przedmiotu otrzymuje się w wyniku odwzorowania trajektorii uniwersalnej elektrody roboczej, a ze względu na małe wymiary problem korekcji elektrody roboczej nie istnieje. Praktyczne zastosowania obróbki ECM uniwersalną elektrodą w przypadku obróbki makroelementów jest ograniczone ze względu na małą wydajność do operacji wygładzania. Ten sposób obróbki jest szeroko stosowany w obróbce mikroelementów (D< 1mm). Zastosowanie znalazły tutaj również operacje mikro-wycinania z zastosowaniem elektrody drutowej. W artykule omówione zostaną podstawowe problemy modelowania procesu ECM oraz projektowania procesu technologicznego. Przedstawione zostaną również przykłady zastosowań praktycznych.

3

Simulation tests of selected gas flow parameters through combustion engine valves

Andrych-Zalewska Monika

Combustion Engines

|

2020

|

R. 59, nr 4

21--28

EN

The article presents the numerical analysis of a single-cylinder gasoline engine with indirect injection and spark ignition. The goal is to recognize and analyze gas flow through inlet and outlet valves and channels. These data were obtained from the simulation of a four-cycle engine cycle without combustion of the fuel-air mixture. The simulation was carried out in ANSYS, using a dedicated IC Engine module. After the simulation, the result was analyzed on the cross-sectional plane of both the valves and the combustion chamber. This method provided the necessary and concise representation of the flow characteristics. Five separate stages are presented – two describing the different displacement of the valve for each inlet and exhaust stroke and one representing the phenomenon of overlapping. The type of flow, its speed and tendency to create turbulence are described.

4

The profitability of disposing of vehicles fulfilling the older euro standards in terms of CO2 emission

Menes Maciej, Wiśniowski Piotr

Journal of KONES

|

2019

|

Vol. 26, No. 1

89--94

EN

The automotive market is developing very dynamically. In recent years, we can observe activities of automotive concerns in the production of new models of electric, hybrid and hydrogen vehicles, and conventional cars are supplied with increasingly economical and low-emission engines. There are also increasingly stringent standards related to exhaust emissions from the exhaust system. From September 1, 2018, passenger cars have to comply with the Euro 6d-Temp emission standard and be homologated according to the WLTP test procedure including the WLTC driving cycle and emission measurements in road traffic conditions. The exhaust components measured during the test, such as carbon oxides, nitrogen oxides or hydrocarbons, are toxic to living organisms. However, it seems that the most important issue in the long term may be the value of carbon dioxide emissions, the excess of which poses an ecological threat to the entire planet. The production of new vehicles equipped with modern complicated combustion engines, batteries, fuel cells and electronic devices is associated with a very high emission of this greenhouse gas The authors of the following article, based on their own research, sought to estimate the ecological profitability of replacing a used passenger car meeting the Euro-4 emissions standard for a new vehicle bearing in mind the value of carbon dioxide emissions during vehicle production. The analysis was to indicate how intensive the annual operation of the vehicle should be to make it profitable to recycle and replace it with a modern car with lower emissions considering the global sum of carbon dioxide emissions.

5

Analysis of the application of distributed propulsion to the AOS H2 motor glider

Kuźniar Michał, Orkisz Marek

Journal of KONES

|

2019

|

Vol. 26, No. 2

85--92

EN

The paper describes the selection of a distributed propulsion for the AOS H2 motor glider (selection of engines, their number, and propellers) and determination of its performance. This analysis is related to the research conducted on environment friendly and hybrid propulsions in various research centres. The main aim of the analyses conducted is to increase the performance of vehicles powered by electric motors. The batteries have a low density of energy, i.e. the ratio of mass to cumulated energy. Instead of a battery set, it is possible to apply a hybrid- electric system, where the combustion engine works as a generator or an electric-hydrogen generator, where the hydrogen cell supports a small set of batteries. One of such flying vehicles, fitting in this trend, is the AOS H2 motor glider built at the Rzeszow University of Technology in cooperation with other universities. It is a hybrid aircraft, equipped with a hydrogen cell, which together with a set of batteries is a source of electricity for the Emrax 268 electric motor. To increase the vehicle's performance (the range and flight duration), it is possible to use a distributed propulsion. This type of propulsion consists in placing many electric motors along the wingspan of the aircraft. Appropriate design of such a system (propeller diameters, engine power, number of engines) can improve the aerodynamic and performance parameters of the airframe. An analysis of the performance for the selected flight trajectory for this propulsion variant was conducted and compared to the performance of the AOS H2 motor glider equipped with traditional propulsion. The consumption of hydrogen was also determined for both systems. The results obtained were presented in the diagrams and discussed in the conclusions.

6

Vibration Diagnostics as an effective Tool for Testing Engines of Internal Combustion

Domotor F., Szabo J. Z.

Production Engineering Archives

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2017

|

Vol. 16

3--6

EN

There are several methods of automotive diagnostics used in services to detect a large variety of faults and damages of various parts of engines of internal combustion. Undoubtedly, they are effective, but they are simply unable to find all types of mechanical faults occurring during the operation. This is the reason why authors of this paper tried to use a special tool, which has been proven for years for detecting faults of rolling element bearing in rotating machinery. During their research, the authors tried to find valuable results by measuring vibration of various parts of engines. Three items were tested, a Diesel engine and two Otto motors. A large number of measurements have been taken at various speed, at different points, in different directions, with different parameter setup, etc. However, there was one setup which has been applied to all three engines. It is the measurement setup of vibration velocity, in the frequency range of 2 Hz-300 Hz. Valuable consequences have been found regarding the clogging of the air filters and the exhaust systems. As a conclusion the authors expressed their opinion, that, apart from the traditional diagnostic methods used in services, vibration measurements can also be useful, especially for detecting faults of rolling element bearings.

7

Effect of different biofuels on common rail injector flow rate

Rybak A., Hunicz J., Krzaczek P., Golimowski W., Marcinkowski D.

Combustion Engines

|

2017

|

R. 56, nr 4

39--43

EN

In this study dynamic flow rates of a common rail injector using diesel fuel and different biofuels were determined. As biofuels, fatty acid methyl esters originating from canola, poultry, cattle and used cooking oil were tested. The tested fuels exhibited different physical properties e.g. density and viscosity. Measurements of the injector delivery rates were performed on a test stand designed for determination of injectors and injection pumps characteristics. Each fuel was tested at temperatures between 30 and 60°C, under injection pressure in the range of 30–180 MPa and injection time in the range of 200–1600 microseconds. The results showed differences in injector flow rates depending on used fuel, however different fuel properties affected amount of fuel injected especially at short injection durations.

8

Hydrogen as fuel in operation of internal combustion engines

Kruczyński S., Ślęzak M., Gis W.

Journal of KONES

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2016

|

Vol. 23, No. 4

237--244

EN

Hydrogen internal combustion engines (HICE) are presently the subject of numerous R&D projects. For hydrogen fuelling mainly, spark-ignition engines are adapted but it is also possible to adjust self-ignition engines. Self-ignition engines may be fuelled only with dual-fuels and usually demonstrate an oversized level of compression ratio requiring reduction because of engine knocking, whereas spark-ignition engines – on the contrary feature an undersized level of compression ratio that needs to be increased to ensure an effective combustion process. Hydrogen may be used also for gasoline dual-fuel engines. Hydrogen utilization as diesel engine fuel should be considered depending on the type of diesel cycle: 1.The use of hydrogen alone or as an addition to gasoline or LPG and methane in spark-ignition engines; 2.The use of hydrogen as an addition to diesel oil in self-ignition engines. In the paper are presented the review of the literature on the use only of hydrogen as a fuel or only of the additionof hydrogen to hydrocarbon fuels in engines with spark ignition and diesel. Have been studied combustion process, generation of heat and power, and efficiency of the engine. Have been evaluated opportunities to reduce harmful emissions. Have been evaluated possibilities of using hydrogen as a fuel for both type of engines. In the paper are presented the review use hydrogen as a fuel for vehicles with fuel cells too.

9

Feeding the engines of fleet vehicles with bioxdiesel fuel and heavy alcohols

Struś M., Poprawski W., Rewolte M., Kardasz P.

Journal of KONES

|

2016

|

Vol. 23, No. 4

495--503

EN

This paper presents results of the research on the efficiency of the Diesel engines of the fleet vehicles fed with the new type of second-generation biofuel BIOXDIESEL at non-stationary and stationary conditions and natural operation on roads. The BIOXDIESEL fuel used for the laboratory testing of physical and chemical properties, engine tests and natural road operation, which is a blend of fatty acid ethyl esters (FAEE) obtained from the waste vegetable and animal fats, bioethanol and Diesel fuel. For the testing, several different types of vehicles have been used: passenger vehicles, small parcel delivery vans, agriculture machines and heavy trucks used for long distance international transport. The results of the vehicles engines testing in non-stationary conditions, results of measurement engines performance on vehicle test bed and results of natural road operation on roads of the vehicles used for testing indicate quasi-identical efficiency of the engines, which were fueled with BIOXDIESEL fuel and standard Diesel. The paper also presents results of initial research, which indicates the direction of future research, which is related to increase the calorific value of the biofuels, which may be obtained by replacement of used bioethanol with the heavier alcohols of renewable resources. Physical and chemical properties of the heavier alcohols indicate the possibility to use them as an additive to the biofuels. The paper presents also results of initial engine tests with a blend of the fuel with different heavier alcohols.

10

Analysis of chosen fuels influence on turboprop engine work performance

Jakubowski R.

Journal of KONES

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2016

|

Vol. 23, No. 2

163--170

EN

The analysis of work parameters of a turboprop engine fuelled by various fuels was done in the paper. The turboprop engine model was presented in the beginning. The main feature of this model is description of the flow in the engine as semi-perfect gas model. By the way, the change of fumes chemical composition influence the gas properties as heat constant and isentropic index are determined. Next energy balance of a compressor and turbine was analysed and turbine pressure drop was evaluated. Finally, engine output power was determined. It was done for selected fuels, which could be applied in the aero engines. The results of analyse were presented in the tables and charts and discussed. Summary of the test results with the results for contemporary applied fuel allows drawing the conclusions about the turboprop engine performance change by various fuel application. Main of them refers to the point that higher combustion heat value of fuel and higher heat constant of fumes cause better engine work conditions By this way the hydrogen seems to be perspective fuel of future, because its combustion heat value is three times JET A-1 and by this way it is possible the engine fuel consumption will be lower.

11

The effects of dust extraction on multi-cyclone and non-woven fabric panel filter performance in the air filters used in special vehicles

Dziubak T.

Eksploatacja i Niezawodność

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2016

|

Vol. 18, no. 3

348--357

EN

Common impurities found in the inlet air to the internal combustion engine of motor vehicles are characterized. Dust concentrations in the air were analysed for different operating conditions of a motor vehicle. It is shown that the most common and the most harmful air impurity for the technical machinery is a mineral dust from roads. The benefits of using the inertial filter (multicyclone) as a first stage of air filtration, including extended engine life are presented. The methods of dust extraction from a dust collector of the air filter multi-cyclone are shown. The necessity of regular ejection dust extraction from the multi-cyclone dust collector is shown. A dust extraction rate m0 is defined and its effects on the cyclone separation efficiency and flow resistance are shown. The test method and the test conditions for a two-stage filter in multi-cyclone - non-woven fabric filter element configuration are developed. The characteristics of the separation efficiency and flow resistance of the cyclone and the non-woven fabric filter were determined as a function of dust mass supplied with the inlet air to the two-stage filter for three different extraction rates and without dust extraction from the multi-cyclone dust collector. The separation efficiency and flow resistance were determined for a multi-cyclone and a non-woven fabric filter without dust extraction from the multi-cyclone dust collector and with or without periodical maintenance. The benefits of periodical cleaning of the dust collector were shown.

PL

Scharakteryzowano zanieczyszczenia powietrza wlotowego silnika spalinowego pojazdu mechanicznego. Przeanalizowano wartości stężenia pyłu w powietrzu dla różnych warunków eksploatacji pojazdów. Przedstawiono korzyści w postaci wydłużenia czasu eksploatacji silnika wynikające ze stosowania filtru bezwładnościowego (multicyklonu), jako pierwszego stopnia filtracji powietrza. Pokazano metody usuwania pyłu z osadnika multicyklonu filtru powietrza. Wykazano konieczność bieżącego, poprzez ejekcyjne odsysanie, usuwania pyłu z osadnika multicyklonu. Zdefiniowano stopnień odsysania pyłu m0 oraz wykazano jego wpływ na skuteczność filtracji i opory przepływu cyklonów. Opracowano metodykę i warunki badań filtru dwustopniowego pracującego w układzie: multicyklon-włókninowy wkład filtracyjny. Wyznaczono charakterystyki skuteczności filtracji i oporów przepływu multicyklonu oraz włókniny filtracyjnej w zależności od masy pyłu dostarczonej wraz z powietrzem wlotowym do filtru dwustopniowego dla trzech wartości stopnia odsysania m0 = 5%, m0 = 10%, m0 = 20% oraz bez odsysania pyłu z osadnika multicyklonu. Wyznaczono charakterystyki skuteczności filtracji i oporów przepływu multicyklonu oraz włókniny filtracyjnej bez odsysania pyłu z osadnika multicyklonu i z okresowym obsługiwaniem oraz bez obsługiwania. Wykazano konieczność okresowego czyszczenia osadnika pyłu.

12

Directions in vehicle efficiency and emissions

Johnson T. V., Joshi A.

Combustion Engines

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2016

|

R. 55, nr 3

3--8

EN

This paper provides a general review of light-duty (LD) and heavy-duty (HD) regulations, engine technology, and key emission control strategies. The US is placing a stronger emphasis on laboratory emissions, and the LD regulations are about an order of magnitude tighter than Euro 6, but Europe is focusing on real-world reductions. The California HD low-NOx regulation is advancing and may be proposed in 2017/18 for implementation in 2023+. The second phase of US HD greenhouse gas regulations propose another 25-30% tightening beyond Phase 1, beginning in 2021. LD and HD engine technology continues showing marked improvements in engine efficiency. LD gasoline concepts are closing the gap with diesel. HD engines are demonstrating more than 50% BTE using methods that can reasonably be commercialized. LD and HD diesel NOx technology trends are also summarized. NOx storage catalysts and SCR combinations are the lead approach to meeting the LD regulations. Numerous advanced NOx technologies are being evaluated and some promise for meeting the California HD low NOx targets. Oxidation catalysts are improved for both diesel and methane oxidation applications. Gasoline particulate filters (GPF) are the lead approach to reducing particles from gasoline direct injection (GDI) engines. They reduce PAH emissions, and catalyzed versions can be designed for low back pressure. Regeneration largely occurs during hot decelerations.

13

Budowa zdalnie sterowanego robota

Pierepienko Aleksandra

Zeszyty Naukowe WSEI. Seria Transport i Informatyka

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2015

|

T. 5, nr 1

41--48

PL

W niniejszym referacie przedstawię budowę zdalnie sterowanego robota, przygotowanego w projekcie stażowym. Jego główną jednostką będzie Raspberry Pi 2. Robot sterowany będzie kontrolerem do konsoli XBOX 360. Do programowania wykorzystano system Raspbian oraz język Python2, z biblioteką pygame.

EN

Construction of remote-controlled robot will be presented in this paper. It has been prepared as practice project. Raspberry Pi2 has been used as main controlling unit. This robot is controlled with XBOX 360 console. Raspbian system and Python2, with pygame library have been used for software development.

14

Selected aspects of use dimethyl ether (DME) in compression ignition engines

Wojs M. K., Orliński P.

Zeszyty Naukowe Instytutu Pojazdów / Politechnika Warszawska

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2015

|

z. 1/101

103--108

EN

The article presents some aspects of combustion dimethyl ether in compression ignition engines along with the required alterations fuel supply system. It also draws attention to the physicochemical properties of DME as a fuel, particularly its low lubricity which requires the use of additives in order to prevent seizing elements of the fuel pump.

PL

Artykuł przedstawia wybrane aspekty spalania eteru dimetylowego w silniku o zapłonie samoczynnym wraz z wymaganymi przeróbkami układu paliwowego. Zwraca też uwagę na właściwości fizykochemiczne DME jako paliwa, szczególności jego niską smarność co wymaga zastosowania dodatków w celu uniknięcia zatarcia elementów pompy paliwowej.

15

Silniki tarczowe z magnesami trwałymi

Glinka T., Wolnik T.

Śląskie Wiadomości Elektryczne

|

2015

|

Nr 4 (121)

18--22

PL

Przedmiotem artykułu są dwa rodzaje silników tarczowych: w jednym uzwojenie twornika jest umieszczone na rdzeniu ferromagnetycznym (jak na rys. 1), w drugim twornik jest bezrdzeniowy z uzwojeniem dwuwarstwowym (jak na rys.4). Uzależniono moment elektromagnetyczny silnika od liczby par biegunów p i stosunku średnicy wewnętrznej d do średnicy zewnętrznej D, (d/D),jak na rysunku 3. Wykorzystując tę zależność obliczono moc znamionową silnika jako funkcję wymiarów twornika. Wyniki przedstawiono w tabeli I. Korzystając z tych relacji obliczono wymiary twornika silnika o parametrach znamionowych: 3 kW, 180 V, 2000 ob./min. Przedstawiona metoda obliczenia wymiarów silnika stanowi pierwszy etap projektowania. Drugi etap projektowania silnika obejmuje optymalizację jego obwodu elektromagnetycznego np. poprzez obliczenia metodą elementów skończonych.

EN

Two types of disc motors are investigated in the paper: with salient poles, where armature core is made of ferromagnetic steel, as shown in Fig. I, with coreless armature and two layer winding, as shown in Fig.4. Dependence of rotating torque on number of pole pairs p and ratio of inner diameter d to outer diameter D (P=d/D) has been determined for salient-pole motors (Fig.3). Basing on these characteristics, the motor's rated power has : been calculated depending on motor's dimensions. The results are set out in Table I. In case of coreless armature motor the basic dependencies between motor dimensions and electromechanical parameters have been given. Using these relations, armature dimensions have been calculated for 3 kW, 180 V, 2000rpm motor. The described methodology of calculating armature magnetic circuit dimension and winding data constitutes first design phase j of disc motor. During second design phase the motor should be optimised and its magnetic circuit calculated e.g. by some field method.

16

Zagrożenia przy stosowaniu silnikowych paliw alternatywnych

Woliński M.

Logistyka

|

2015

|

nr 5

1651--1654, CD1

PL

W artykule przedstawiono zagrożenia pożarowo – wybuchowe, zagrożenia dla zdrowia ludzi oraz zagrożenia dla środowiska związane ze stosowaniem alternatywnych paliw silnikowych. Porównano te zagrożenia ze stwarzanymi przez „tradycyjne” paliwa.

EN

Paper presents fire and explosion hazards, hazards for human health, as well as environmental hazards connected with application of alternative engine fuels. Discussed hazards were compared with these which are characteristic for “traditional” engine fuels.

17

Wpływ obciążeń eksploatacyjnych na strukturę mobilnej platformy pływającej

Trzaska M., Barnat W., Kiczko A.

Logistyka

|

2015

|

nr 5

1573--1580, CD1

PL

W pracy przedstawiono wyniki badań eksperymentalnych mobilnej platformy pływającej, podczas których badano poziom naprężeń w łożu silnika obciążonego w warunkach eksploatacyjnych. Testy zostały przygotowane i przeprowadzone przez Wojskową Akademię Techniczną i PIMOT. Do pomiaru odkształceń konstrukcji wykorzystano czujniki tensometryczne wraz z mostkiem pomiarowym ESAM CF. W wyniku przeprowadzonych testów z różnym obciążeniem stwierdzono, że poziom odkształceń oraz naprężeń zredukowanych w łożu silnika nie osiąga poziomu naprężeń plastycznych dla stali.

EN

In an article presents results obtained during experimental investigation of mobile floating platform. During tests was measured the level of strains in engine mount in operational conditions. The tests were performed by Military University of Technology and Automotive Industry Institute. To measure strains of construction used strain gauges with ESAM Traveller CF Signal Conditioner Amplifier System with CF-Card data Storage. The results obtained during trials shows the level of strains and stress in engine mount did not exceed the level of yield stress for material.

18

Environmental emissions and efficiency of a direct injection diesel engine fueled with various fatty acid methyl esters

Sairam K., Gopinath A., Velraj R.

Environment Protection Engineering

|

2015

|

Vol. 41, nr 1

125--135

EN

Environmental emissions and efficiency of a direct injection diesel engine fueled with fatty acid methyl esters (FAMEs) have been experimentally investigated and compared with petro-diesel. Rubber seed oil methyl ester, cotton seed oil methyl ester, neem oil methyl ester, and mahua oil methyl ester were used as fuels. The brake specific fuel consumption, brake thermal efficiency, and exhaust gas temperature, nitrogen oxides, carbon monoxide, hydrocarbons, and smoke emissions were investigated. Mahua oil methyl ester exhibits higher brake thermal efficiency compared to other FAMEs. The NOx was found to be higher, while CO, HC, and smoke emissions of rubber seed oil methyl ester were lower than the other fuels at all loads.

19

Operating properties of non-woven fabric panel filters for internal combustion engine inlet air in single and two-stage filtration systems

Dziubak T., Szwedkowicz S.

Eksploatacja i Niezawodność

|

2015

|

Vol. 17, no. 4

519--527

EN

The parameters of basic filter media used in inlet air systems of internal combustion engines of motor vehicles are presented. Performance properties of the air filters defining their basic parameters are discussed. The effects of single and two-stage filtration systems on performance, including filter medium dust capacity are presented. The methods and conditions for testing non-woven fabric filters in single and two-stage filtration systems were developed. Filter separation efficiency and flow resistance characteristic curves for non-woven fabric filters as a function of dust capacity were determined. Dust capacity of tested non-woven fabrics was determined for allowable flow resistance values. The effects of fractional composition of dust downstream of the inertial filter on reduction of dust capacity of non-woven fabrics in two-stage filtration systems were shown.The advantages including improvement in service life and reduction of wear of engine components due to use of inertial filter as the first filtration stage are presented.

PL

Przedstawiono parametry podstawowych materiałów filtracyjnych powietrza wlotowego silników pojazdów mechanicznych. Omówiono właściwości eksploatacyjne filtru powietrza i określające je podstawowe parametry. Przedstawiono wpływ warunków filtracji jednostopniowej i dwustopniowejna właściwości eksploatacyjne, a w tym na chłonność materiału filtracyjnego.Opracowano metodykę i warunki badań włóknin filtracyjnych pracujących w warunkach filtracji jednostopniowej i dwustopniowej. Wyznaczono charakterystyki skuteczności filtracji i oporów przepływu włóknin filtracyjnych w zależności od współczynnika chłonności pyłu. Dla dopuszczalnej wartości oporu przepływu wyznaczonowartości współczynnika chłonności pyłu badanych włóknin. Wykazano wpływ składu frakcyjnego pyłu za filtrem bezwładnościowym na zmniejszenie wartości współczynnika chłonności pyłu włóknin pracujących w warunkach filtracji dwustopniowej. Przedstawiono korzyści w postaci wydłużenia czasu eksploatacji i minimalizacji zużycia elementów silnika wynikające z stosowania filtru bezwładnościowego, jako pierwszego stopnia filtracji powietrza.

20

Straty i sprawność energetyczna silników i układów napędowych

Paszota Z.

Napędy i Sterowanie

|

2013

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R. 15, nr 5

82--90

PL

Straty i sprawność energetyczna każdego silnika napędowego muszą być przedstawiane jako funkcje wielkości fizycznych niezależnych od występujących w silniku strat. Takimi wielkościami są prędkość i obciążenie wymagane przez napędzana silnikiem maszynę lub urządzenie, zmieniające się w polu pracy napędu. Prędkość i obciążenie silnika decydują o chwilowej mocy użytecznej silnika oraz w zróżnicowany sposób o występujących w silniku odmianach i wielkościach strat. Tymczasem straty i sprawność energetyczna hydrostatycznych silników i układów napędowych oceniane są przez badaczy i producentów jako funkcje parametrów, które same zależą od strat. Podstawową przyczyną takiej sytuacji jest tradycyjne, szeroko rozpowszechnione i jednocześnie mylne spojrzenie na przebieg mocy w silnikach i w układach napędowych reprezentowane wykresem Sankeya spadku mocy zgodnego z kierunkiem przepływu mocy. Konieczne jest zastąpienie wykresu Sakeya proponowanym wykresem wzrostu mocy w silniku i w układzie napędowym przeciwnego do kierunku przepływu mocy. Proponowane spojrzenie na straty i sprawność energetyczną powinno być zastosowane w rozważaniu wszystkich odmian silników i układów napędowych. Celem artykułu jest pokazanie problemów wynikających z powyższych postulatów na przykładzie pracy silnika wyporowego pracującego w hydrostatycznym układzie napędowym. Aby umożliwić obiektywną ocenę zachowania energetycznego różnych odmian i wielkości silników i układów napędowych, należy opisywać oraz porównywać straty i sprawność energetyczną jako zależne od współczynnika prędkości i współczynnika obciążenia silnika zmieniających się w polu pracy układu napędowego. Przedstawione propozycje otwierają nową perspektywę nieuniknionych badań silników i układów napędowych, umożliwiająca obiektywne porównywanie sprawności energetycznej różnych odmian silników i układów.