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EN
The study aims to clarify the influence of pre-chamber (PC) configurations on the combustion process in the main chamber (MC) of medium-speed spark-ignition gas engines equipped with an active PC. A constant volume combustion chamber was prepared to simulate the chamber configurations of the gas engines. A high-speed shadowgraph was applied to visualize the torch flame development and the combustion process in the MC. Experiments were done by changing the charged gas in the MC, the number, and the diameter of the PC orifices. Combustion was most accelerated when the PC orifice configuration was set appropriately so that the adjacent torch flames would combine with each other. It was also found that the unburned mixture in the PC, which ejected prior to the torch flame, supported the penetration of the torch flame.
PL
Przedstawiono uwagi wynikające z obsługi spalinowych silników wykorzystywanych w przemyśle energetycznym jako stacjonarne agregaty prądotwórcze. Bazując na doświadczeniach z eksploatacji, przedstawiono przykłady diagnostyki właściwości oleju, pokazano jego zużywanie się oraz postępujące procesy starzenia. Zestawiono wybrane właściwości oleju mineralnego i syntetycznego oraz dokonano porównania olejów stosowanych w analizowanych silnikach gazowych.
EN
A review, with 19 refs., of oil properties diagnostics procedures and aging processes as well as technological and economic conditions regarding the properties of mineral and synthetic oils used in combustion gas engines applicable in the energy industry as stationary power generators.
EN
In this paper, the results of modeling of the burning process in the piston engines whose working process is realized on the basis of various conceptual approaches are presented: in diesel with direct injection of the fuel; in a gas engine with spark ignition; and in a two-fuel engine (in the gas-diesel), where the mixture of natural gas and air ignites with the help of the fuse dose of the diesel fuel. The models of burning based on the different in-principle approaches are analyzed and used. Verification of the models is performed by a comparison of the results of modeling with the experimental diagrams. The specific values of the empirical coefficients, used in modeling of the burning proces in the engines under study, are determined. The practical recommendations on the choice of the burning model depending on the working process conception are given.
EN
The biogas produced in municipal wastewater-treatment plants (WWTP) should be cleaned before it can be used as a fuel in internal combustion engines. Efficient running of such engines is possible only subject to using high quality biogas and lubricating oil. Otherwise, biogas impurities in course of complex chemical reactions may form deposits on various engine parts as well as seriously contaminate the lubricating oil. In this paper, mineral deposits containing high concentration of bismuth, silicon, sulphur, calcium and zinc are studied. Silicon deposits demonstrating strong friction properties are formed during combustion of volatile silica compounds. As these deposits build up, abrasion problems, ignition failure and even engine failure result. The bismuth containing deposits comes from bearings degradation, zinc and calcium were derived from the additives present in commercially available lubricating oil, while lead, aluminium, copper, nickel, iron and chromium were introduced by engine wear phenomena. The highest bismuth content was located at the engine cylinder heads and the lowest at the exhaust elements, whereas highest calcium content was registered on the pistons. Silicon containing deposits are highest in the exhaust and lowest at the engine head. Zinc deposits are highest at the piston.
PL
W artykule opisano doświadczenia związane z wieloletnią eksploatacją kogeneracyjnych agregatów prądotwórczych napędzanych silnikami gazowymi dla których jako paliwo wykorzystywany jest metan. Poruszono temat związany z pozyskaniem gazu z odmetanowania kopalń jako paliwa napędowego do silników gazowych. Zasygnalizowano problematykę związaną z poszukiwaniem rozwiązań badawczo-naukowych i ich zastosowania w przemyśle, w celu znalezienia rozwiązań zwiększających niezawodność parku maszynowego przy jednoczesnym utrzymaniu lub redukcji kosztów.
EN
There are described experiences connected with perennial exploitation of the cogenerational engine generators powered by gas engines which are fueled by methane in the article. There is covered a subject connected with sourcing the gas from demethanization of mines as an impulsive fuel for gas engines. There is signalized the issues connected with searching the experimental solutions and applying them in the industry to find the solutions increasing the reliability of the machinery park in the simultaneous maintenance or cost reduction.
EN
Article presents the results of long-term testing of prototype of 64 kVA biogas cogeneration set (CHP - Combined Heat and Power), build with support of financial means from the MCP R&D program 1 2 1. Between others, the impact of fueling with biogas from the sewage treatment plant on the engine oil has been investigated. Used oil analyses unveiled adverse presence of silicon compounds, i.e. siloxanes, permissible level of which (according to MAN standard) was exceeded several times. In order to reduce these compounds, prototype biogas filter based on activated carbon has been developed. Based on initial calculations, overall efficiency of this cogeneration set is circa 70%. For the consumer needs, the entire installation is enclosed in a compact soundproof canopy. Besides environmental merits, the cogeneration set shows also economical advantages. If operating continuously, the gen-set CHP would produce electrical and heat power in an amount that its purchasing cost would be returned after about 12 months, under condition of having biogas.
EN
Searching for further reduction of fuel consumption simultaneously with the reduction of toxic compounds emission new systems for lean-mixture combustion for SI engines are being discussed by many manufacturers. Within the European GasOn-Project (Gas Only Internal Combustion Engines) the two-stage combustion and Turbulent Jet Ignition concept for CNG-fuelled high speed engine has been proposed and thoroughly investigated where the reduction of gas consumption and increasing of engine efficiency together with the reduction of emission, especially CO2 was expected. In the investigated cases the lean-burn combustion process was conducted with selection of the most effective pre-combustion chamber. The experimental investigations have been performed on single-cylinder AVL5804 research engine, which has been modified to SI and CNG fuelling. For the analysis of the thermodynamic, operational and emission indexes very advanced equipment has been applied. Based on the measuring results achieved for different pre-chamber configurations the extended methodology of polioptimization by pre-chamber selection and the shape of main chamber in the piston crown for proposed combustion system has been described and discussed. The results of the three versions of the optimization methods have been comparatively summarized in conclusions.
EN
Liquefied natural gas (LNG) qualifies as sustainable and secure marine fuel that is reliable in supply. The international standards (IGF Code) and classification regulations have been aligned. First experiences in ship operations and design are now available. Initial reports from the practical ship operations show that the lack of knowledge and misjudgements of original equipment manufacturers (OEM’s), suppliers, consulting services and flag state authorities have led to operational restrictions or expensive retrofitting. The aim of this paper is to illustrate first experiences and operating instructions using this new and different marine fuel; derive recommendations for instructions for education and training programmes at maritime colleges, universities and business partners; present action recommendations for future operational concepts.
EN
The main task of a gas mixer is to mix the fuel (gas) with air in such a way that in the gas engine optimal combustion takes place. A high efficiency of the whole combustion process and low emissions are the decisive optimization parameters. An industrial gas engine operates mostly with a lean air-gas combustion mixture with an air excess coefficient ratio of → λ=1.6. Most often heat and power industrial gas engines operate with biogas. The biogas is produced by anaerobic digestion, where biodegradable materials in the absence of oxygen are fermented. That is why the biogas fuel consists mostly of methane → CH4 (up to 70 [%]), carbon dioxide → CO2 and traces of other contaminant gases. It is well known, that the performance of industrial gas engines strongly depends on the quality of air and fuel mixing and therefore homogeneity of the mixture. Improper air-gas mixture can lead to unstable operation of the entire gas engine and excessive emissions beyond the applicable environmental standards. Therefore, in this article numerical investigations were performed using the open source computational fluid dynamics software OpenFOAM to show the importance of mixture preparation for industrial heat and power gas engines by describing in detail the mixing behaviour in a Venturi gas mixer model.
10
EN
The study concerns numerical tests of an internal combustion engine operating according to the over-expanded cycle carried out in the AVL Fire software. The research covered the modelling of a full working cycle of a conventional engine operating in accordance with the classic Otto cycle and an engine operating on the basis of an over-expanded cycle – the Atkinson cycle. As part of the work, three cases of Atkinson’s cycle were analysed, by closing the inlet valve before BDC (21º before BDC) and closing the valve after BDC (41º and 75º after BDC). As a result of modelling, space-time distributions of velocity, pressure and temperature in the cylinder of the modelled engine were obtained. Optimizations of the analysed cycles were carried out, finding the best ignition timing, at which it is possible to obtain the highest efficiency and the highest indicated mean effective pressure. The calculations showed that the engine operating according to the over-expanded cycle in order to obtain the best operating parameters requires earlier ignition timing compared to the conventional engine. In addition, in the engine operating according to the Atkinson cycle, there is a drop in the indicated mean effective pressure and an increase in the indicated thermal efficiency compared to the engine operating by the classical cycle.
EN
The running diagnostics of the combustion process in an internal combustion engine is essential for increasing its efficiency and to improving its performance indicators. The modern diagnostics of this process no longer concerns only measurements of fast-changing thermodynamic variables, but also measurements of other parameters allowing for its evaluation. The use of electrical or optical methods in diagnostics enables the evaluation of local process parameters, such as occurrence of the flame and its temperature distribution. Actually, there are some new methods under investigation which are proposed for this kind of diagnostic. This article focuses on demonstrating the potential for using an electric signal from the gas ionization to estimate the maximum combustion pressure in a cylinder of an SI engine. This is a comparative analysis of the gas ionization current signal in the cylinder and the fast-changing pressure at fixed operating points of a 4-stroke natural gas powered engine. The study was carried out on a one-cylinder 4-stroke SI engine equipped with a cylinder pressure recording system and monitoring of the cylinder ionization current using appropriate measuring systems. The influence of engine operating conditions on the ability to determine cylinder pressure based on the ionization current signal was analyzed. This impact assessment was analyzed statistically and a strong correlation was found between the analyzed signals. The obtained results point in the potential direction of development of this type of measuring system.
PL
Artykuł dotyczy endotermicznych pomp ciepła napędzanych silnikami zasilanymi gazem. Autor opisuje podstawowe założenia nowej normy europejskiej PN-EN 16905 i poddaje analizie podstawowe ograniczenia techniczne i ekonomiczne w zastosowaniu pomp ciepła napędzanych silnikami gazowymi. W pracy podano wybrane zastosowania omawianych pomp ciepła w różnych obszarach technicznych.
EN
The article is regarding endothermic heat pumps driven by gas engines. Author is describing the fundamental economic and technical barriers in applying of GEHPs. At the work are chosen applications of discussed pumps which are applied in various technical areas.
PL
Artykuł dotyczy endotermicznych pomp ciepła napędzanych silnikami zasilanymi gazem. Autor opisuje podstawowe założenia nowej normy europejskiej PN-EN 16905 i poddaje analizie podstawowe ograniczenia techniczne i ekonomiczne w zastosowaniu pomp ciepła napędzanych silnikami gazowymi. W pracy podano wybrane zastosowania omawianych pomp ciepła w różnych obszarach technicznych,
EN
The article is regarding endothermic heat pumps driven by gas engines. Author is describing the fundamental economic and technical barriers in applying of GEHPs. At the work are chosen applications of discussed pumps which are applied in various technical areas.
EN
The paper contains results of tests on the spark ignited (SI) engine modified to work as the engine with the overexpanded thermodynamic Miller cycle. Investigation was particularly focused on thermodynamic properties of the applied Miller cycle as well as combustion progress in the supercharged engine fuelled with various gaseous fuels as follows: coke gas, natural gas and hydrogen. Crucial conclusions deal with experimental investigation. The conclusions showed the following: IMEP was maintained at the same level with aid of supercharging, thermal indicated efficiency increased.
PL
W artykule przedstawione zostały wyniki stanowiskowych silnika o zapłonie iskrowym przystosowanym do pracy na zasadzie obiegu Millera. Badania skupiały się na właściwościach termodynamicznych wykorzystanego obiegu Millera jak również przebiegu spalania w doładowanym silniku zasilanym różnymi paliwami gazowym takimi jak: gaz koksowniczy, gaz ziemny, wodór. Główne wnioski uzyskane zostały w wyniku badań eksperymentalnych i wskazały wzrost odporności na spalanie stukowe przy wykorzystaniu obiegu Millera oraz podwyższenie sprawności indykowanej.
PL
Podczas eksploatacji węgla kamiennego wydziela się metan, którego część jest ujmowana systemem odmetanowania kopalni i w dużej części wykorzystywana do celów energetycznych. Pozostała, znaczna część wydzielającego się metanu jest odprowadzana systemem wentylacji kopalni na powierzchnię i ze względu na brak typowych technologii wykorzystania niskostężonego metanu (poniżej 0,75%) pozostaje niezagospodarowana. W Polsce następuje rozwój technologii wykorzystania metanu pokładów węgla dla celów energetycznych. W artykule przedstawiono możliwości jego wykorzystania do celów energetycznych oraz przykłady pracujących instalacji wykorzystujących metan pokładów węgla.
EN
In Poland follows the development of technologies for the use of methane captured in coal mines by methane drainage systems and from abandoned mines by opening from surface. Article presents the technologies to use drainage methane from mines in Poland by: injection of the pipeline with natural gas, use in boilers for solid and gas fuel, use in gas engines, producing heat and electricity mainly used in mining, gas liquefaction and transportation to customers, compression of gas from methane drainage station and transportation to customers. Also presented unique on a European scale technology of use ventilation air methane from mines for heat production. The use of coalbed methane is important for economic reasons (allows coal mine energy independence) and environmental (methane causes the greenhouse effect). In order to develop the technology to use coalbed methane following issues should be solved: intensification of mine methane drainage, increase investment in the full use of captured methane, utilization of ventilation air methane.
PL
W artykule przedstawiono stan zagrożenia metanowego w kopalniach Kompanii Węglowej S.A. Podano informacje dotyczące ujęcia metanu z odmetanowania górotworu oraz charakterystykę stacji odmetanowania kopalń KW S.A. Przedstawiono sposoby wykorzystania gazu ujętego systemami odmetanowania na powierzchnię.
EN
The absolute methane content in the mines of the Kompania Węglowa SA has been at a high level since 2003, despite a significant reduction in the level of coal production. In period of 2003-2013 in nine mines of Kompania Węglowa SA the methane drainage was used in order to secure the safe operation of mining plant. Investment activities were carried out systematically in order to develop methane drainage systems. It builds up more surface stations of methane drainage, as well as modernizes of existing facilities. Delivery of gas from drainage systems to the surface creates the possibility and even the necessity of its economic use. Commercial utilization of methane-gas from coal seams improves the economic effect of mines and is an argument that allows planning further investments associated with the capturing and utilisation of the gas. The heat and the electricity, which are produced on the basis of methane from methane drainage will reduce energy purchases. Additional benefits arise from the sale of heat for external entities. An additional effect of this activity is to protect the environment, associated with the reduction of greenhouse gas emissions and decrease consumption of fossil fuels.
PL
W pracy zamieszczono wyniki modelowania, w programie Kiva-3V, emisji tlenku azotu badawczego silnika S320ZI, zasilanego paliwem gazowym – metanem. Modelowanie przeprowadzono dla różnych wartości stałych szybkości reakcji kinetycznych tworzenia NO, przyjętych na podstawie wybranej literatury. W wyniku obliczeń uzyskano czasoprzestrzenne rozkłady koncentracji tlenku azotu w komorze spalania silnika badawczego oraz przebiegi zmian stężenia NO w funkcji kąta OWK.
EN
The numerical modelling results of nitric oxide emission of S320ZI research engine, powered by gas fuel – methane, using Kiva-3V software are presented in the paper. The modelling process was carried out for different values of kinetic reaction rate constants of NO formation. Reaction rate constants were adopted on the basis of selected literature. As a result of carried out calculations of nitric oxide concentration in combustion chamber of modelled engine and course of NO concentration variations in function of CA are obtained.
EN
The paper presents the results of an investigation of gas engines used in the Polish system of natural gas transmission. The investigation concerned both four-stroke and two-stroke engines. The engines were fed with two kinds of gas fuel - low-calorific natural gas containing 54.5 % of methane, and with high-methane (up to 95 %) natural gas. Combustion in both types of engines with different methods of mixture supply into the cylinder was analysed for different parameters. The paper also presents numerical computations of basic physical values characterizing combustion of gas fuels in engines. The computations were made with Cantera numerical code based on the mechanism of elementary reactions occurring while burning methane GRI 3.0 for various molar fractions of methane in the gas fuel.
PL
W artykule przedstawiono rezultaty badań silników gazowych wykorzystywanych w polskim systemie przesyłowym gazu ziemnego. Badania te wykonano na silnikach cztero- i dwusuwowych. Jednostki te były zasilane dwoma rodzajami paliw gazowych: niskokalorycznym gazem ziemnym o zawartości metanu wynoszącej 54,5 % oraz wysokometanowym gazem ziemnym zawierającym do 95 % metanu. Analizie poddano proces spalania w wyżej wymienionych silnikach dla różnych parametrów eksploatacyjnych oraz różnych metod doprowadzenia mieszanki do cylindra. Przedstawiono również obliczenia numeryczne podstawowych wielkości fizycznych charakteryzujących proces spalania paliw gazowych w silnikach. Obliczenia przeprowadzono przy użyciu kodu numerycznego Cantera, bazującego na mechanizmie reakcji elementarnych zachodzących przy spalaniu metanu GRI 3.0 dla różnych udziałów molowych metanu w gazie paliwowym.
19
Content available remote Bezodpadowa metoda oczyszczania gazu ze zgazowania biomasy
PL
Opracowano dwa warianty innowacyjnego sposobu oczyszczania gazu ze zgazowania odpadów drzewnych. Dla każdego z wariantów opracowano schemat technologiczny wytwarzania 150Nm3/h gazu oczyszczonego, spełniającego wymagania dla zasilania dwupaliwowego silnika gazowego.
EN
Two variants of an innovative method for the purification of gas from gasification of wood waste has been elaborated. For each of these variants flowsheet for producing of 150Nm3/h purified gas that meets the power requirements for dual fuel gas engine have been developed.
20
Content available Gaz koksowniczy paliwem do silnika gazowego
PL
Gaz koksowniczy otrzymywany w koksowniach podczas produkcji koksu zawiera w swoim składzie ponad 50% wodoru, ok. 25% metanu, ok. 6% tlenku węgla oraz ok. 2% wyższych węglowodorów i posiada wartość opałowa na poziomie 18 MJ/m3. W zależności od wielkości produkcji zakładu koksowniczego dostępny jest w ilościach od 5 – 100 tys. m3/h. Wykorzystanie go jako paliwa do silnika gazowego, z uwagi na zawarte w nim zanieczyszczenia, głównie naftalenu i smoły jest utrudnione. Opracowana została oryginalna, bezodpadowa metoda dodatkowego doczyszczania gazu koksowniczego z naftalenu i smół na drodze wymywania olejem napędowym, który utylizowany jest jako dawka zapłonowa w silniku dwupaliwowym. Rozwiązanie zostało zgłoszone do ochrony patentowej.
EN
Coke oven gas acquired during production of coke is composed of 50% hydrogen, about 25% methane, about 6% carbon monoxide and around 2% of higher hydrocarbons and has a lower heating value about of 18 MJ/m3. Depending upon the scale of production of coke plant it is available in quantities from 5-100 thousand m3/h. Application as a fuel for gas engine, due to contaminants in its composition, mainly naphthalene and tars is difficult. An original, waste free, method was developed for additional cleaning of coke gas from naphthalene and tars on the basis of scrubbing with diesel oil, which is utilized further as an ignition injection in dual fuel engine. This solution has been applied for a patent protection.
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