Temat: combustion efficiency - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Multidimensional simulation of combustion and knock onset in gas engines
Autorzy:: Tatschl, R.
Priesching, P.
Schneider, J.
Powiązania:: https://bibliotekanauki.pl/articles/245656.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: gas engines
simulation
combustion
efficiency
knock onset
Opis:: Natural gas fuelled internal combustion engines enable efficient energy conversion with relatively low environmental impact. Depending on the specific application, the available fuel quality, and the emission regulations to be fulfilled, different types of gas-engine combustion systems are in use. The major performance and hence efficiency limiting factors in gas fuelled engines are related to the lower ignitability of natural gas at part load and the appearance of abnormal combustion (knock) at high load conditions. This article provides an overview of the multidimensional CFD simulation workflow for the investigation and assessment of flame propagation and knock onset characteristics in different types of natural gas fuelled internal combustion engines. The most common approaches for simulating flame propagation/combustion under engine conditions are presented together with selected models for describing the pre-flame reactions finally leading to knock onset in the unburned in-cylinder charge ahead of the flame. Based on selected application examples, the models’ performance and capabilities with respect to reflecting the essential characteristics of flame propagation and knock onset are presented.
Źródło:: Journal of KONES; 2018, 25, 2; 379-389
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 2.

Tytuł:: Total efficiency of adjustable compression ratio SI engine
Autorzy:: Sendyka, B.
Kula, K.
Kudzia, S.
Soczowka, J.
Powiązania:: https://bibliotekanauki.pl/articles/242772.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: SI engine
compression ratio
combustion engines
total efficiency
Opis:: The following paper includes adjustable ratio spark ignition engine's total efficiency analysis. Main modification of the engine is mounting of crankshaft on eccentric mechanism. Paper presents schemes of eccentric mechanism implemented in developed engine as well as adjustable compression ratio control system's block diagram. Propulsion from stepper motor is transmitted through self-locking worm gear. Value of compression ratio varies from 9.5 to 14. The main input signal for electronic control system is coming from knock-sensor mounted on the engine. If control system doesn't receive that signal it levels up compression ratio. As soon as signal appears ratio mentioned above is reduced by a value 0.05. During the investigation rotational speed of the engine was limited to nterval 1800-4000 [rpm] and throttle was partially closed. Relative increase of Suzuki engine's total efficiency presented in this paper surpasses 30 per cent. The outcome of investigation presents engine with variable compression ratio as a good prospect for the future. Constant adjustment of compression ratio with use of electronical control system allows significant improvement of total efficiency and consequently reducing fuel consumption.
Źródło:: Journal of KONES; 2007, 14, 4; 401-407
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 3.

Tytuł:: Opportunities of exhaust heat recovery and conversion to electricity
Autorzy:: Cienciała, M.
Kaźmierczak, A.
Krakowian, K.
Błasiński, T.
Powiązania:: https://bibliotekanauki.pl/articles/247492.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engine
heat recovery
simulation
efficiency
environmental protection
Opis:: The maximum efficiency of the conventional spark ignition engine is 33%, in the case of diesel engines is 42%. The conclusion is that the energy contained in the fuel and "released" in the combustion process is converted into mechanical work only in a small degree. The rest of the energy is unfortunately lost by heat, friction, or used to drive the engine accessories. It should also be noted that these values are peak efficiency, which is achieved only when the engine works in optimal parameters. At most used parameters engines reach efficiency on the level of 10% to 25%. In modern cars with a hybrid powertrain are solutions that can improve the efficiency of conventional internal combustion engines. It is worth to notice that there are few ways to improve the efficiency of a reciprocating engine. The main technological trends on which research is underway are knock ignition and heat recovery from the exhaust. More development seems to be the second solution, because it can be used to design new engines such as the replacement of the alternator on the generator of electricity from exhaust heat. Besides, it will be possible to adapt these systems to in-use units, which improve the energy balance of riding vehicles. In article, you will find information of literature analysis for exhaust heat recovery and conversion to electricity solutions, computerized exhaust modification with flow calculations, real modification, test bench creation, researches and scores, analysis.
Źródło:: Journal of KONES; 2013, 20, 4; 63-70
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 4.

Tytuł:: Effective compression ratio of combustion engine as a way of increasing efficiency
Autorzy:: Drabik, D.
Mamala, J.
Powiązania:: https://bibliotekanauki.pl/articles/245128.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: engine
internal combustion engine
efficiency
air pollution
compression ratio
Opis:: The article describes the processes that take place in an engine. The main terms connected with the compression ratio are explained. Moreover, the relationship between the compression ratio and the engine efficiency is discussed. This paper is a repetition of issues connected with functioning of the engine. In this article, variables that influence the chart are described, along with some examples of the way to increase engine efficiency. This article focuses on selected methods of improving efficiency of internal combustion engines. In order to fully understand processes taking place in the combustion chamber, it is necessary to create theoretical charts of thermal cycles and, then, to compare them with actual charts obtained as a result of measurements. The structure of contemporary engines is influenced by various factors, for example preservation of natural environment or limited fuel resources. These factors are crucial for mechanical engineering and engine design. Therefore, energy consumption and environmental impact of engines are taken into consideration when researching new ways and methods of enhancing engine efficiency. One of the main aims of the researchers and engineers is to reduce the emission of carbon dioxide (CO2), carbon monoxide (CO), hydrocarbons (HC) and oxides of nitrogen (NOx) in exhaust fumes. Improved engine efficiency, lowered fuel consumption and reduced emission of toxic substances are the main advantages of internal combustion engines characterized by variable compression ratio.
Źródło:: Journal of KONES; 2016, 23, 3; 93-99
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 5.

Tytuł:: Experimental investigations of various modes of charging on HCCI engine
Autorzy:: Prasad, A. Renuka
Bhandari, Rakesh
Jagadish, Donepudi
Powiązania:: https://bibliotekanauki.pl/articles/245191.pdf
Data publikacji:: 2019
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: HCCI technology
homogeneous mixture
thermal efficiency
combustion rate
emissions
Opis:: Homogeneous Charged Compression Ignition technology is most favourable or suitable for Internal Combustion engines for reducing the exhaust emissions and enhances the Thermal efficiency, improve the fuel consumption, and increase the rate of combustion. This article represents the various charging methods on HCCI technology engine; it improves the engine performance and determines the emission characteristics of HCCI technology engine. The homogeneous mixture prepared with different methods. In –cylinder internal homogeneous mixture preparation method applied in this present work. It reduces the exhaust emissions released from the combustion chamber. However, oxides of nitrogen and soot emissions are significantly reduce, because combustion starts at lower temperatures and various points in combustion chamber. The HCCI technology generates small amount of exhaust emissions and it improves the performance of the engine. In addition, performance and released emissions depends on the quality and quantity of homogeneous mixture.
Źródło:: Journal of KONES; 2019, 26, 1; 119-126
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 6.

Tytuł:: Determination of thermal efficiency of the spark ignition systems
Autorzy:: Sendyka, B.
Mitianiec, W.
Noga, M.
Wachulec, W.
Powiązania:: https://bibliotekanauki.pl/articles/246099.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion process
ignition system
thermal efficiency
spark plug
CNG
Opis:: The paper presents results of measurements performed to determine thermal efficiency of spark ignition systems. Because of small pressure change after sparking process smali volume chamber has been proposed for measurements. A direct measurement method of pressure increment determination has been chosen. In this method one pressure chamber is used. The caloric chamber isfilledwith nitrogen, which is a neutral gas. It is preferable medium than air because it is one-component gas and it has a precisely-known value of a specific gas constant. The value of speciflc gas constant is reąuested to calculate a value of discharge energy given to the gas. In the chosen method pressure increment in the chamber during spark discharge is measured. The pressure increment in the chamber during ignition is strictly related to the energy of spark discharge. The energy balance calculations determined values of heat los s es for two types of electrodes (normal and "thin") anddifferent initial pressure (p=0 bar and p=25 bar). The maximal value of the thermal efficiency was observedfor the higher value of pressure in chamber and thin electrodes of spark ping. It was also stated, that the higher thermal efficiency for" thin " spark ping electrodes is a result of reduced heat transfer. The paper presents results of the tests carried out in the caloric chamber of 4. l cm3 filled with nitrogen at ambient temperature using PCB transducer direct measurement method. Results of the measurements done using differential pressure transducer for the same parameters like in thefirst measurement method were similar.
Źródło:: Journal of KONES; 2010, 17, 1; 365-371
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 7.

Tytuł:: Model and experimental research of the pressure cooling system for the internal combustion engine
Autorzy:: Krakowski, R.
Powiązania:: https://bibliotekanauki.pl/articles/244930.pdf
Data publikacji:: 2014
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engines
cooling system
energy balance
engine efficiency
environmental protection
Opis:: In this paper, the existing methods to reduce the heat discharged by the engine were characterized and the efficiency of combustion piston engine was analysed, where it was shown the need and the potential for reducing the heat dissipated directly or indirectly to the surrounding atmosphere. The model of the engine cooling system for high coolant temperature developed through AMESim software was presented in this paper. The model of the cooling system was made based on test stand solution designed and built using original components and units diesel engine 4CT90. The simulation researches results of temperature course and pressure course were shown. In this paper was demonstrated that it is possible to maintain the assumed constant pressure of 0.3 MPa in the system and obtain it at the elevated liquid temperature leading to an increase in overall engine efficiency. These researches were carried out also on the experimental model stand, which confirmed the results obtained in simulation researches. Then 4CT90 engine test stand was described, where speed characteristics as a function of torque, power and specific fuel consumption and load characteristics as a function of the fractions of hydrocarbons, carbon monoxide and carbon dioxide, as well as specific and hourly fuel consumption were performed. Comparison of parameters and efficiency assessment of engine interacts with a traditional and pressure cooling system. The efficiency of the engine with the pressure and a traditional cooling system was evaluated.
Źródło:: Journal of KONES; 2014, 21, 4; 289-296
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 8.

Tytuł:: The description of the total efficiency of 2SZ-FE engine with the variable valve timing
Autorzy:: Sendyka, B.
Sochan, A.
Noga, M.
Rodak, Ł.
Powiązania:: https://bibliotekanauki.pl/articles/243046.pdf
Data publikacji:: 2007
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: silnik spalinowy
obieg Atkinsona
spalanie
sprawność ogólna
silnik
combustion engine
Atkinson cycle
combustion
total efficiency
engine
Opis:: In this paper there were conducted tests of the combustion engine with the Atkinson cycle and with applying variable valve timing. There was described the 2SZ-FE engine characteristics and assigned the total efficiency before and after application of the phase shifter. Secondly, there was determined the thermal efficiency of the single engine work cycles and also engine 's total efficiency by using the optoelectronic pressure sensor and mathematical programme. After that, it was available to present the range of the variable valve timing. Atkinson system, phases of 2SZ-FE engine timing gear, the total efficiency distribution during 75 % of throttle opening and when inlet valves are open, the total efficiency increase during 75 % of throttle opening, the total efficiency distribution during 50 % of throttle opening and when suction valves are open, the total efficiency increase during 50 % of throttle opening, the total efficiency distribution during 25 % of throttle opening and when inlet valves are opened, the total efficiency increase during 25 % of throttle opening, the total efficiency distribution with application of phases shifter are presented in the paper.
Źródło:: Journal of KONES; 2007, 14, 2; 401-407
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 9.

Tytuł:: Simple tank-to-wheels analysis tool for future vehicle powertrains
Autorzy:: Vavra, J.
Macek, J.
Takats, M.
Cerovsky, Z.
Powiązania:: https://bibliotekanauki.pl/articles/243520.pdf
Data publikacji:: 2008
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: vehicle powertrain efficiency
internal combustion engine
fuel cells
simulation
driving cycle
Opis:: The future powertrains have to be properly assessed in early stages of vehicle design using simple and fast but reliable tools. The aim of the paper is to develop a simulation tool suitable for any of current transient cycles for finding of upper limits of tank-to-wheel efficiencies of recent or future vehicle powertrains in different concepts of vehicles to assess their potential, to find gaps between the state-of-the-art and to find ways to bridge them. The simulation philosophy and procedure may be described in the following steps. The testing cycle power demands on vehicle movement are analyzed and the optimum operation efficiency of a primary mover (engine, fuel cell, electric motor) is assigned to them. Dynamic torques at powertrain are accounted for. Speed, speed slip (driving machine/wheels) and load dependencies of transmission efficiency are simulated by simple models. In the case of a hybrid solution, charging and discharging efficiencies of energy accumulators and additional losses (e.g., in converters and inverters) are considered. The clear modular structure of the simulation tool enables the researcher to amend new features of powertrain components. The links to more detailed simulation tools are prepared. The simulation tool is described by regression and algebraic models (based on the results of higher level simulation tools) in a way giving immediate response during sensitivity analysis. The examples of tool calibration for different powertrains and results comparing powertrain potential are presented for lower medium class passenger car. The current simulation tool creates a useful link between detailed and accurate but CPU time demanding 1-D tools, based on partial differential equations, and rules-of-thumb, used sometimes for initial potential assessments. Moreover, the described tool does not require detailed data on the powertrain during early stage of design but it shows its potential for further development.
Źródło:: Journal of KONES; 2008, 15, 3; 525-534
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 10.

Tytuł:: The experimental assessment of air supply system modification on inlet air filtration efficiency and military vehicle engine effectiveness improvement
Autorzy:: Dziubak, T.
Trawiński, G.
Powiązania:: https://bibliotekanauki.pl/articles/243953.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: combustion engines
air filters
filtration efficiency
flow drag
filter absorbency
effective parameters of the engine
mechanical efficiency
Opis:: Specific features of air inlet system of BWP-1 vehicle UTD-20 engine are shown. The tests results of filtration efficiency and air flow drag for BWP-1 vehicle air filter standard version are presented. The necessity of UTD-20 engine air supplying system constructional changes are proved. The inlet air filtration system for BWP-1 engine with the porous filter was proposed and performed. The characteristics of the air purification efficiency (fi=f(mp) and flow drag Delta p- f(mp) Delta p= f(Omega c) for designed air filter were determined. Absorbency of filter for air nominal stream of engine BWP-1 was specified. The designed and executed partition air filter was subjected to comparative tests on an engine test bench. The influence of modernized air filter and fuel dose increase on engine effective parameters were determined. The tests covered comparison of effective parameters (determined for maximum load) of a UTD-20 engine equipped with a standard air filter (variant 1), a modernized air filter (variant 2) and additionally, for the modernized air filter, with injection pump with fuel dose increased (variant 3). There were determined the influence the proposed changes on indicated and effective torque during engine free acceleration and its mechanical efficiency as well.
Źródło:: Journal of KONES; 2010, 17, 3; 79-86
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 11.

Tytuł:: Comparison of combustion of gasoline and methanol in the si engine dual fuelled
Autorzy:: Stelmasiak, Zdzisław
Powiązania:: https://bibliotekanauki.pl/articles/242301.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: methyl alcohol
gasoline
spark ignition engine
combustion parameters
thermal efficiency
dual fuelling
Opis:: In the paper are presented comparative tests of combustion of gasoline and combustion of methanol in spark ignition engine of the Fiat 1100 MPI type. The engine was equipped with a prototype suction manifold with duplex injectors on each cylinder. Implemented system enabled dual fuel operation of the engine with any fraction of the alcohol. Engine performance and start-up capabilities were the same like in case of the operation on gasoline only. Type and parameters of the fuel supply can be changed in any time during operation of the engine. The study dealt with comparison of a selected parameters used to assessment of combustion of the fuels: pressure of the working medium p, rate of pressure rise dp/d, heat release rate dQ/d, temperature of the working medium, and combustion angle. The investigations pointed at considerable differences in run of combustion of the gasoline and combustion of the methanol, as autonomous fuels. Moreover, addition of methanol to gasoline results in considerable differences in combustion process, comparing to combustion of gasoline mixtures. The combustion goes on more dynamically, especially during initial phase of the process, while total time of the combustion is shorter. Effects of these changes are: higher maximal pressures, faster rates of pressure growth and heat release. Extent of change of combustion parameters depends on methanol fraction in total dose of the fuel supplied to the engine. Addition of the methanol effects in growth of general efficiency of the engine, which increases together with growth of methanol fraction and engine load. Absolute growth of the efficiency amounted to 2-5%, while relative growth amounted to 6-16%. Such significant growth of the efficiency should lead to reduction of energy consumption during engine operation.
Źródło:: Journal of KONES; 2013, 20, 1; 317-328
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 12.

Tytuł:: Hydrogen-diesel co-combustion anomalies in a CI engine
Anomalie przebiegu spalania wodoru z olejem napędowym w silniku wysokoprężnym
Autorzy:: Grab-Rogaliński, K.
Szwaja, S.
Powiązania:: https://bibliotekanauki.pl/articles/244062.pdf
Data publikacji:: 2008
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: wodór
silnik z zapłonem samoczynnym
spalanie stukowe
sprawność indykowana
hydrogen
compression ignition engine
combustion knock
indicated efficiency
Opis:: W artykule przedstawiono eksperymentalne wyniki z indykowania silnika wysokoprężnego z wtryskiem bezpośrednim oleju napędowego, w którym wodór współspalano z olejem napędowym. Wodór do silnika był doprowadzany przez urządzenie wtryskowe zamontowane na kolektorze dolotowym. Następnie poddano analizie przebiegi ciśnień podczas współspalania wodoru, którego udział energetyczny w całkowitej dawce paliwa wahał się od zera do kilkunastu procent. Pomiary przeprowadzono dla mieszanek ubogich. Analiza numeryczna danych eksperymentalnych pozwoliła uzyskać odpowiedzi na następujące zagadnienia: prędkość spalania, przebieg wydzielania ciepła i spalanie stukowe. Przy niesprzyjających warunkach wodór jako paliwo silnikowe ma skłonności do generowania tzw. „stuku" począwszy już od chwili jego zapłonu w komorze spalania silnika. Takim niesprzyjającym warunkiem w silniku wysokoprężnym jest wysoki stopień sprężania. Z drugiej strony efekt spalania stukowego można złagodzić spalając mieszankę palną przy dużym nadmiarze powietrza, co zostało zaobserwowane w silniku z zapłonem iskrowym zasilanym wodorem. Ponadto, współspalanie wodoru z olejem napędowym w silniku wysokoprężnym powinno przynieść korzyści w postaci zwiększenia sprawności indykowanej silnika, ze względu na przyśpieszenie procesu spalania oraz niższą emisję cząstek stałych PM ze względu na lepsze ujednorodnienie mieszanki palnej. Uzyskane przez autorów rezultaty skłaniają do kontynuacji badań w zakresie wykorzystania wodoru jako paliwa, nie tylko dla silnika z zapłonem iskrowym, ale również dla silnika z zapłonem samoczynnym, w którym zapłon inicjowany byłby pilotową dawką oleju napędowego.
Hydrogen as an engine fuel has tendency to generate knock, which starts from ignition in a combustion chamber under unfavorable conditions. In the CI engine such the unfavorable condition is high compression ratio (CR). Anyway, knock effect should be reduced. Burning lean air-fuel mixture is the effective method to achieve combustion without knock. Furthermore, burning diesel with hydrogen should increase the engine indicated efficiency due to increase of a combustion speed, which can be expressed by the mass fraction burnt (MFB). Hydrogen addition should also reduce the PM emission in the exhaust. The experimental results of indicating a compression ignition (CI) direct injection engine, in which hydrogen with diesel was co-combusted, are presented in the paper. Hydrogen was delivered to the engine cylinder by an injector mounted on an intake manifold. Hydrogen was injected at amount in the range of 0 to few percent of its energy share in relation to the entire energy of both diesel and hydrogen doses. Investigation was performed for lean air-hydrogen-diesel combustible mixture. The experimental data analysis makes it possible to find several correlations as follows: mass fraction burnt (MFB), coefficient of variation of indicated mean effective pressure (COVpi) and combustion knock intensity with the hydrogen energy share. The results of investigation obtained by authors induce to continue research on hydrogen as fuel not only for the SI engine but also for the CI engine, where hydrogen would assist diesel or it would be considered as basic fuel ignited by a diesel pilot.
Źródło:: Journal of KONES; 2008, 15, 2; 109-116
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 13.

Tytuł:: Hydrogen-diesel co-combustion anomalies in a CI engine
Anomalie przebiegu spalania wodoru z olejem napędowym w silniku wysokoprężnym
Autorzy:: Grab-Rogaliński, K.
Szwaja, S.
Powiązania:: https://bibliotekanauki.pl/articles/247558.pdf
Data publikacji:: 2008
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: wodór
silnik z zapłonem samoczynnym
sprawność indykowana
spalanie stukowe
hydrogen
compression ignition engine
combustion knock
indicated efficiency
Opis:: W artykule przedstawiono eksperymentalne wyniki z indykowania silnika wysokoprężnego z wtryskiem bezpośrednim oleju napędowego, w którym wodór współspalano z olejem napędowym. Wodór do silnika był doprowadzany przez urządzenie wtryskowe zamontowane na kolektorze dolotowym. Następnie poddano analizie przebiegi ciśnień podczas współspalania wodoru, którego udział energetyczny w całkowitej dawce paliwa wahał się od zera do kilkunastu procent. Pomiary przeprowadzono dla mieszanek ubogich. Analiza numeryczna danych eksperymentalnych pozwoliła uzyskać odpowiedzi na następujące zagadnienia: prędkość spalania, przebieg wydzielania ciepła i spalanie stukowe. Przy niesprzyjających warunkach wodór jako paliwo silnikowe ma skłonności do generowania tzw. "stuku" począwszy już od chwili jego zapłonu w komorze spalania silnika. Takim niesprzyjającym warunkiem w silniku wysokoprężnym jest wysoki stopień sprężania. Z drugiej strony efekt spalania stukowego można złagodzić spalając mieszankę palną przy dużym nadmiarze powietrza, co zostało zaobserwowane w silniku z zapłonem iskrowym zasilanym wodorem. Ponadto, współspalanie wodoru z olejem napędowym w silniku wysokoprężnym powinno przynieść korzyści w postaci zwiększenia sprawności indykowanej silnika, ze względu na przyśpieszenie procesu spalania oraz niższą emisję cząstek stałych PM ze względu na lepsze ujednorodnienie mieszanki palnej. Uzyskane przez autorów rezultaty skłaniają do kontynuacji badań w zakresie wykorzystania wodoru jako paliwa, nie tylko dla silnika z zapłonem iskrowym, ale również dla silnika z zapłonem samoczynnym, w którym zapłon inicjowany byłby pilotową dawką oleju napędowego.
Hydrogen as an engine fuel has tendency to generate knock, which starts from ignition in a combustion chamber under unfavourable conditions. In the CI engine such the unfavourable condition is high compression ratio (CR). Anyway, knock effect should be reduced. Burning lean air-fuel mixture is the effective method to achieve combustion without knock. Furthermore, burning diesel with hydrogen should increase the engine indicated efficiency due to increase of a combustion speed, which can be expressed by the mass fraction burnt (MFB). Hydrogen addition should also reduce the PM emission in the exhaust. The experimental results of indicating a compression ignition (CI) direct injection engine, in which hydrogen with diesel was co-combusted, are presented in the paper. Hydrogen was delivered to the engine cylinder by an injector mounted on an intake manifold. Hydrogen was injected at amount in the range of 0 to few percent of its energy share in relation to the entire energy of both diesel and hydrogen doses. Investigation was performed for lean air-hydrogen-diesel combustible mixture. The experimental data analysis makes it possible to find several correlations as follows: mass fraction burnt (MFB), coefficient of variation of indicated mean effective pressure (COVpi) and combustion knock intensity with the hydrogen energy share. The results of investigation obtained by authors induce to continue research on hydrogen as fuel not only for the SI engine but also for the CI engine, where hydrogen would assist diesel or it would be considered as basic fuel ignited by a diesel pilot.
Źródło:: Journal of KONES; 2008, 15, 3; 163-170
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 14.

Tytuł:: Investigation on the improoving of ICE energy conversion efficiency at different engine load
Badania nad poprawą efektywność konwersji energii silnika spalinowego przy jego różnych obciążeniach
Autorzy:: Postrzednik, S.
Żmudka, Z.
Powiązania:: https://bibliotekanauki.pl/articles/245399.pdf
Data publikacji:: 2009
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: silniki spalinowe
efektywność pracy
stopnie doskonałości
kryteria eksploatacji
combustion engines
engine efficiency
engine excellence
operation criteria
load exchange work
Opis:: Effective work of internal combustion engines, which are used as the driving source ofcars, occurs not only at the fuli load, but mostly at the part load, when the energy efficiency eta e is significant lower than in the optimal (nominal field) range of the performance parameters. One of the numerous reasons of this state is regular growing of the relative load exchange work of the IC engine. Using the worked out theoretical formulas it has been calculated that the relative load exchange work can achieve value up to 40% at the part load (e.g. idle run) of the IC engine, whereby in red systems the engine speed influences the results too. As consequence of the growing of the relative load eichange work is the significant drop of the engine efficiency; from ca. 45% down to ca. 25%. The solutions of this problem are based on the fully independent control of the motion of inlet and outlet valves, whereby the optimal internal recirculation ratio of flue gases should be taken into account. Thanks to the introduction of proposed solutions the energy efficiency of the all system can usually considerably eiceeds the energy efficiency of itself combustion engine, dealt individually, though will appear the necessity of carrying of necessary investment-issues.
W pracy przedstawiono podstawowe ujęcie zagadnienia konwersji energii w układzie silnika spalinowego, co jest związane z racjonalną eksploatacją silnika spalinowego, szczególnie przy obciążeniach różnych (niższych) od nominalnych. W polu pracy każdego silnika spalinowego występuje podobszar jego optymalnej eksploatacji (najwyższa efektywna sprawność energetyczna ni e, najniższe jednostkowe zużycie paliwa be). Często się zdarza, że silnik spalinowy pracuje pod obciążeniem częściowym, a wtedy jego efektywna sprawność energetyczna r/e jest znacznie niższa, aniżeli w obszarze nominalnym. Wyrazem tego jest także obniżenie wartości stopienia doskonałości wewnętrznej eta oraz doskonałości mechanicznej eta,m silnika spalinowego. Jedną z głównych przyczyn tego stanu rzeczy, jest względny wzrost pracy wymiany ładunku. Przeprowadzone obliczenia wykazały, że względna (w stosunku do osiąganej pracy całego obiegu) praca wymiany ładunku może dochodzić do 40% (np. na biegu jałowym). W celu ograniczenia tych strat, proponuje się różne rozwiązania, np. elektroniczne, niezależne sterowanie ruchem zaworów dolotowych i wylotowych, lepszą organizację samego obiegu termodynamicznego. Dzięki wprowadzeniu proponowanych rozwiązań sprawność energetyczna całego układu może zwykle znacznie przewyższyć sprawność energetyczną samego silnika spalinowego, traktowanego indywidualnie, aczkolwiek wystąpi konieczność poniesienia niezbędnych nakładów inwestycyjnych.
Źródło:: Journal of KONES; 2009, 16, 4; 375-384
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Skocz do pozycji: 15.

Tytuł:: Various designs of the two-stroke engine heads with the valve flushed system
Autorzy:: Łoza, Ł.
Kaźmierczak, A.
Borkowska, J.
Skorupa, P.
Krakowian, K.
Cienciała, M.
Powiązania:: https://bibliotekanauki.pl/articles/242546.pdf
Data publikacji:: 2015
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: engine
two-stroke
internal combustion
valve flushed system
piston-controlled cam
high petrol consumption
oil in the petrol
toxic by-products
loud noise
uneven running
low efficiency
Opis:: The two-stroke engines have never acquired the popularity of the four-stroke engines due to their inherent performance limitations. The tasks of many engineering teams were to find the basic causes, which resulted in the inferior performance of these engines. Today’s task is to build a two-stroke engine whose performance could match that of a four-stroke engine in areas of common use. The most typical performance problems of a two-stroke engine are high petrol consumption caused by low efficiency, toxic by-products of combustion being emitted into the atmosphere (caused by oil present in the petrol), and uneven and loud engine noise. The greatest challenge is to achieve a good chamber purge during one stroke in which the fresh fuel mixture flows through the piston-controlled inlet port while at the same time the fumes are being exhausted through the outlet port. This in contrast with the four-stroke engines where the intake and exhaust are each done with two separate strokes. From the energy point of view, the two-stroke engine is not efficient because a certain amount of fresh fuel is being wasted in the exhaust fumes. We propose to replace the piston-controlled cam with the valve-flushed system, which will cause the combustion process to become more efficient. The purpose of this paper is to present various designs of the engine heads and analyse their performance. The goal of this proposal is to choose the best combination of these engine heads in order to achieve the optimum overall engine performance.
Źródło:: Journal of KONES; 2015, 22, 4; 187-190
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

Artykuł

Zmień widok

na półce

Informacja

Wyszukujesz frazę "combustion efficiency" wg kryterium: Temat

Źródło danych

Dostawca treści

Kolekcja

Rok wydania

Wydawca

Temat

Autor

Typ dokumentu

Język