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EN
In the next few decades, the resources of oil will be depleted. From the other hand, growing market and usage of oils cause increase of oil price. Additionally, only some countries have oil deposits large enough to be independent from foreign suppliers. All these reasons show need for searching and development of new fuels, which can replace traditional ones produced from oil. One of the solutions for Diesel engines are bio-fuels produced from various vegetable oils like rapeseed, coconut or palm oil. Nowadays, the majority of new Diesel engines are equipped with Common Rail fuel injections system. It enables to achieve higher power of the engine, lower emissions and lower fuel consumption. This suggests that the Common rail system should be also utilized in Diesel engines supplied with bio-fuels, produced from various plants, as it was mentioned above. However, the bio-fuels have some properties much different from those of conventional Diesel fuel, for example they usually have significantly higher viscosity. In consequence, the fuel supply and fuel injection systems require some modifications. The paper presents results of the experimental test of Common Rail Diesel engine supplied with four fuels: standard Diesel fuel, rapeseed oil and two mixtures of these fuels: 70 percent of Diesel with 30 percent of rape seed oil and 50 percent of Diesel fuel with 50 percent of rape seed oil. For the research, a new test bench was built in Faculty of Production Engineering, Warsaw University of Life Sciences. The main element of the test bench is one cylinder, direct injection engine Farymann Diesel 18W. Originally, the engine was equipped with mechanical Bosh direct injection system, which was replaced with Common Rail system. The test bench enables measurements of various parameters: torque, pressure inside the cylinder, temperature of cooling water and exhaust gases, emissions etc. The tests of the modified engine were conducted with use of several types of piston and injector.
EN
The first research studies on utilization of gas detonation in production of coatings on steel substrate were conducted in the fifties of the last century. In the first half of the 20th century the first constructions of the detonation guns were presented and patented and the first results of the production of coatings were published. Nowadays, the method is widely utilized in aircraft industry. One of the main advantages of the detonation method is that it enables production of various kinds of coatings with use of a wide range of materials in form of fine particles: metals, alloys, carbides, oxides and others. The coatings obtained with usage of the detonation method have low porosity and high adhesion and cohesion. Potentially, the detonation method produces coatings with unique features, impossible to obtain by use of other methods. However, the quality of the coatings strongly depends on properties of the coatings material particles jet generated by the detonation gun and processes taking place inside the detonation gun barrel during acceleration of the particles by the flow behind the detonation wave. The main aim of the paper is to present the general description and basic features of the detonation method of production of coatings and an original, Polish design of the detonation gun utilized in the process. The paper also presents results obtained with the use of the detonation gun and some examples of applications of the method.
EN
The development of diagnostic methods suitable for the monitoring of practical flames is an important objective, which is receiving a growing attention and significant research efforts. This is motivated by the need to achieve a more precise description of the process and, ultimately, implement efficient and reliable control and optimization methods as a key step towards the development of more efficient, flexible, reliable and clean combustion systems. Many interesting attempts have been proposed, involving very different approaches in the use of various instruments and sensors. One of parameter difficult to control is distribution of reaction zone. Presently, such system which allows monitoring combustion process of industrial burners does not exist. Measurements of temperature or control of exist flame by using ionization probe provide only partial information about performance of combustion process. For that reason, new diagnostic methods should be developed. Many and interesting attempts have been proposed but one of interesting solution will be development of combustion process diagnostic methods by means of the Electrical Capacitance Tomography (ECT). Obtained results show that it will be a very good tool for research proposes, especially in development of a new combustion chamber operated at very high pressure, where installation of optical windows is very difficult and many time not possible.
PL
W artykule zobrazowano struktury w strefie połączenia powłoki detonacyjnej WC/Co 88 12 na podłożu stali S215 oraz powłoki WC/Co 83 17 na podłożu stali C45, uformowane przy detonacyjnym spalaniu mieszaniny gazów propan-butan z tlenem i z proszków o granulacji 25÷56 .m. Badania struktury przeprowadzono za pomocą mikroskopu świetlnego i mikroskopu elektronowego skaningowego wyposażonego w spektrometr rentgenowski z dyspersją energii do analizy liniowej i punktowej. W powłokach bogatszych w kobalt stwierdzono większą niejednorodność i pasmowość w rozmieszczeniu materiału powłokowego, przy czym cząstki WC ulegały ok. 10-krotnemu rozdrobnieniu. Istotne zmiany nastąpiły w strefie pośredniej w podłożach. Rozmieszczenie i morfologia płytek cementytu i osnowy ferrytycznej w kilkumikronowej warstwie podłoża wskazuje, że ulegają one podczas natryskiwania jeszcze silniejszemu niż WC odkształceniu, zwłaszcza w miejscach, gdzie przy formowaniu powłoki nastąpiły zawirowania.
EN
In the paper structures of connection of detonation coatings of WC/Co 88 12 on steel S215 base and detonation coatings of WC/Co 83 17 on steel C45 base are presented. The coatings were produced by means of propane-butane- oxygen mixture detonation. Diameter of coatings materials particles were in the range of 25 to 56 .m. Analysis of structures was conducted by use light and scanning electron microscope equipped with line and point analysis EDS spectrometer. In the coatings with higher Co concentration higher non-homo- geneity with concurrent high (ten times) WC/Co pulverization was found. Sig- nificant changes of structure were found in an intermediate zone in the steel base. Distribution and morphology of cementite plates and ferrite fabric in the base layer indicate that they undergo higher, than WC/Co, deformation during production of coatings. The deformation is very visible in places with strong turbulizations.
EN
Hydrogen is regarded as a potential future fuel for various kinds of vehicles: fuel cell cars, trucks, buses etc. Storing and transportation issues are the crucial safety problems concerned with utilization ofhydrogen. Because of its very łów density hydrogen needs to be stored under very high pressure, in range of 35 division sign 70 MPa, and this create hazard of sudden discharge of hydrogen leading to ignition and severe accident. The aim of the presented research is an experimental investigation of hydrogen ignition as a result of a compression and heating of air by shock wave generated by the discharge of the hydrogen. Mixing of the air heated up by the shock wave and expanding hydrogen can produce combustible mixture of sufficiently high temperature and can lead to ignition. The critical conditions for ignition depend mainly on hydrogen discharge pressure, geometrical configuration, parameters of the ambient air, obstacles, etc. Experimental research -was conducted on a facility specially constructed in Combustion Laboratory, the Institute of Heat Engineering, Warsaw University of Technology. The facility consists from the pressure tank and high pressure hydrogen installation. To allow visualization the observation section is equipped with high quality optical windows. Schlieren visualization system and high speed digital camera was used to register high pressure hydrogen outflow and potential ignition. The high speed digital camera was used to take Schlieren or direct pictures of the process. Additionally, the experiment is registered with use of conventional digital camera. Experiments were conducted for different discharge pressure of hydrogen and outflow to "open space " as well to specially prepared obstacles. Critical condition for which ignition occurs were evaluated for both cases. The high speed Schlieren and direct pictures taken during the experiments are presented in the paper. The influence of presence of obstacles on the feasibility of hydrogen ignition during outflow from high pressure installation is discussed and analyzed.
EN
The European Union directive obliges to the usage of 6% bio-fuels approx in the year of 2010. Diesel fuel can be superseded by rapeseed oil esters with the properties similar to mineral fuel. However, the production of aliphatic oils esters is expensive and requires large expenditure of capital. Considering the costs of the rapeseed oil esters production, the tests were undertaken in many countries for the application as fuel to the non-stressed diesel engines, a raw rapeseed oil with the omission of esterification process. The application of the rapeseed oil as fuel has also this advantage, that it can be produced on the own needs in property farms and processing plants. Moreover remainder on the expression of oil in the shape of oilcakes, can be utilized as the animal feed or as energy source. The tests of the rapeseed oil application to the tractors engines of the agricultural and structural machines, were already performed in the 30's in Germany, Italy and Belgium. Also in United States, research was performed for utilization of palm oil and fish fat to fuel application. The rapeseed oil properties differ from the diesel fuel. The possibility exists of certain improvement of vegetable fuel attributes through the oil additives. The one of the possibilities for the improvement of the rapeseed oil properties as fuel are the gasoline admixtures. Such additions influence on the fuel - air mixture creation process course and combustion. The vaporize temperature of the rapeseed fuels is much higher then the diesel fuel vaporize temperature, that has essential influence on the creation of fuel-air mixture process and combustion. For the purpose of lowering of these temperatures to the rapeseed oil the U95 gasoline was added. The research of the combustion process for the mixtures of rapeseed oil with gasoline and rate of heat release during the combustion analysis was performed.
PL
Dyrektywa Unii Europejskiej zobowiązuje do stosowania w roku 2010 ok. 6% biopaliw. Olej napędowy może być zastąpiony estrami oleju rzepakowego o zbliżonych właściwościach do paliwa mineralnego. Produkcja estrów olejów tłuszczowych jest jednak kosztowna i wymaga dużych nakładów inwestycyjnych. Ze względu na koszty produkcji estrów oleju rzepakowego, w wielu krajach podjęto próby stosowania jako paliwa do niewysilonych silników Diesla, surowego oleju rzepakowego z pominięciem estryfikacji. Zastosowanie oleju rzepakowego jako paliwa ma również tę zaletę, że może być produkowane na potrzeby własne w gospodarstwach rolnych i zakładach przetwórczych. Ponadto pozostałości po tłoczeniu oleju w postaci makuchów, mogą być wykorzystywane do celów hodowlanych bądź energetycznych. Próby stosowania oleju rzepakowego do silników ciągników maszyn rolniczych i budowlanych, prowadzono już w latach trzydziestych w Niemczech, Włoszech i Belgii. Również w Stanach Zjednoczonych, prowadzono badania wykorzystania do celów paliwowych oleju palmowego i tłuszczów rybnych. Olej rzepakowy różni się swoimi właściwościami od oleju napędowego. Istnieją możliwości poprawy pewnych cech paliwa roślinnego przez dodatki. Jedną z możliwości poprawy właściwości oleju rzepakowego jako paliwa są domieszki benzyny. Dodatki takie wpływają na przebieg procesu tworzenia mieszaniny paliwowo-powietrznej oraz spalanie. Temperatura odparowania paliw rzepakowych jest znacznie wyższa od temperatur oleju napędowego, co ma istotny wpływ na proces tworzenia mieszaniny paliwowo-powietrznej i spalanie. W celu obniżenia tych temperatur do oleju rzepakowego dodano benzyny U95. Przeprowadzono badania procesu spalania mieszanin oleju rzepakowego z benzyną i dokonano analizy wywiązywania ciepła w czasie spalania.
7
Content available remote Research on gas oil and rape oil methyl esters sprayed in constant volume chamber
EN
Research of gas oil and rape oil methyl esters spraying in a constant volume chamber at differential injection pressure and counterpressure are presented.
PL
Przedstawiono wyniki badań procesu rozpylania oleju napędowego i estrów metylowych oleju rzepakowego w komorze o stałej objętości przy różnych ciśnieniach wtrysku i przeciwciśnieniu w komorze.
EN
One of the methods of dust explosions mitigation is the use of venting systems, the task of which is to diminish the pressure rise. Nevertheless, the systems posses some inherent drawbacks. One of them is the presence of rarefaction wave, which propagates back and may interact with dust layers, which are present inside the facility. The objective of the study is to simulate the process of dust lifting caused by rarefaction waves and show how it may lead to the formation of combustible dust-air cloud.
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