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Wyszukujesz frazę "Atkinson cycle" wg kryterium: Temat


Wyświetlanie 1-7 z 7
Tytuł:
Effect of Volume Ratio of Heat Rejection Process on Performance of an Atkinson Cycle
Autorzy:
Ebrahimi, R.
Powiązania:
https://bibliotekanauki.pl/articles/1030546.pdf
Data publikacji:
2018-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
Atkinson cycle
heat rejection process
Opis:
The objective of this study is to analyze the effect of volume ratio of heat rejection process on the performance of dual cycle. Using finite-time thermodynamics, the relations between the volume ratio of heat rejection, the thermal efficiency, the power output, the heat transfer losses, the friction power and the compression ratio for an air standard Atkinson cycle have been derived. In the model, the nonlinear relation between the specific heats of working fluid and its temperature, the frictional loss and heat leakage loss are considered. The results show that the power output and the thermal efficiency first increase with the increase of volume ratio of heat rejection process and then start to decrease. The optimum value of the volume ratio of heat rejection which maximizes the power output is higher than that which maximizes the thermal efficiency, while the optimum value of the compression ratio which maximizes the power output is lower than that which maximizes the thermal efficiency. The results obtained in the present study provide guidance to the performance evaluation and improvement for practical internal combustion engines.
Źródło:
Acta Physica Polonica A; 2018, 133, 1; 201-205
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Increase of the total efficiency using the Atkinson cycle in the spark ignition engine
Autorzy:
Sendyka, B.
Sochan, A.
Powiązania:
https://bibliotekanauki.pl/articles/242315.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
variable valve timing
setting of valve timing
Atkinson cycle
Opis:
The paper presents the results of investigations performed on a combustion engine with Atkinson cycle included and application of variable valve timing. Investigations were carried out at constant rotational speed 2500 and 3500 RPM and at throttle opening 25% and 50%. Influence of the advance/delay angle of inlet valves closing on formation of exhaust gases toxic components such as: carbon monoxide, hydrocarbons and nitric oxides was presented. Basing on the obtained results difference of toxicity of exhaust gases before and after application of phase shifter and their concentration in places of total efficiency increments was demonstrated. Especially The Atkinson cycle comparing with conventional Otto cycle, characteristics of the electric motor applied in Toyota Prius generation, starting and work of engines (combustion engine and electric motor) during vehicle standstill, relation of specific fuel consumption in function of rotational speed for a Toyota Prius engine, generation II, in total efficiency of engines with Atkinson cycle and Mitsubishi GDI in function of rotational speed, relative increase in total efficiency as rotational speed function, influence of intake valves opening angle on concentration in exhaust gases: carbon monoxide, hydrocarbons and nitric oxides at diferrent throttle opening values are presented in the paper.
Źródło:
Journal of KONES; 2009, 16, 2; 407-411
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance Analysis of an Atkinson Cycle Engine under Effective Power and Effective Power Density Conditions
Autorzy:
Gonca, G.
Powiązania:
https://bibliotekanauki.pl/articles/1033412.pdf
Data publikacji:
2017-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
gasoline engine
Atkinson cycle
engine performance
power density
finite-time thermodynamics
Opis:
This study presents performance optimization of an Atkinson cycle engine using criteria named as effective power and effective power density conditions. The effects of design and operating parameters such as compression ratio, cycle pressure ratio, cycle temperature ratio, equivalence ratio, bore/stroke ratio, inlet temperature, inlet pressure, engine speed, friction coefficient, mean piston speed and stroke length, on the performance characteristics have been examined. Moreover, the energy losses have been determined as fuel energy and they have been classified as incomplete combustion losses, friction losses, heat transfer losses, and exhaust output losses. Realistic values of specific heats have been used depending on temperature of working fluid. The results of the study can be assessed as an engineering tool by the Atkinson cycle engine designers.
Źródło:
Acta Physica Polonica A; 2017, 132, 4; 1306-1313
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
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
Tytuł:
Study of Atkinson cycle in two-stroke diesel engine with opposed pistons
Autorzy:
Mitianiec, Władysław
Powiązania:
https://bibliotekanauki.pl/articles/133583.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
transport
two-stroke opposite piston engine
Atkinson cycle
scavenging
timing phases
silnik o tłokach przeciwbieżnych
obieg Atkinsona
wymiana ładunku
Opis:
The paper presents possibilities of change working parameters of two-stroke diesel engine with opposed pistons. Obtaining of higher engine efficiency is realized by applying of Atkinson cycle. Modification of scavenging process by changing pistons' position connecting with two crankshafts enables asymmetrical scavenge timing. Decreasing of shorter time of closing exhaust ports before compression process and longer expansion process give higher engine work and with high charging ratio increases engine power. These types of engines are recently recommended for power plant stations. The paper includes full analysis of engine work with scavenge and combustion processes for different timing phases based on geometry of the CI Leyland L60 engine by using of CFD modelling and own 0D model. Simulation tests indicate a high scavenge efficiency, good penetration of injected fuel and fast combustion process. The work contains figures of pressure, temperature traces and emission of main chemical species in exhaust gases with comparison of engine works for different timing phases. Atkinson cycle in two-cycle work of engine and full combustion process enables to achieve high total efficiency. The study is an input for realization of such processes in a future of power plant engines with different fuelling systems.
Źródło:
Combustion Engines; 2019, 58, 3; 121-128
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Late intake valve closing as a way of the throttleless control of SI engine load
Autorzy:
Żmudka, Z.
Postrzednik, S.
Przybyła, G.
Powiązania:
https://bibliotekanauki.pl/articles/247952.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
spark-ignition engine
variable valve actuation
late intake valve closing
open Atkinson-Miller cycle
charge exchange process
cycle efficiency
Opis:
The paper tackles the problems connected with the charge exchange in internal combustion engines. The theoretical analysis of the charge exchange process in the SI engine has been presented. The realization of the charge exchange process is connected with the necessity of overcoming the flow resistances, then with the necessity of doing a work, so-called the charge exchange work. The flow resistance caused by throttling valve is especially high at the partial load running of an engine. A system with independent, late intake valve closing has been analysed. The use of the analysed system to governing of an engine load will enable to eliminate a throttling valve from inlet system and reduce the charge exchange work, especially within the range of partial load. The decrease of the charge exchange work leads to an increase of the internal and effective works, which results in an increase of the effective efficiency of the spark ignition engine. The open, theoretical Atkinson-Miller cycle has been assumed as a model of processes proceeding in the engine with variable intake valve actuation. The system has been analysed individually and comparatively with open Seiliger-Sabathe cycle, which is theoretical cycle for the classic throttle governing of engine load. Benefits resulting from application of the system with late intake valve closing have been assessed on the basis of the selected parameters: a fuel dose, a cycle work, relative charge exchange work and cycle efficiency.
Źródło:
Journal of KONES; 2012, 19, 1; 491-499
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carnotization of the power cycle of internal combustion reciprocating engine
Karnotyzacja obiegu tłokowego silnika spalinowego
Autorzy:
Mendera, K. Z.
Powiązania:
https://bibliotekanauki.pl/articles/244333.pdf
Data publikacji:
2007
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
obieg teoretyczny
obieg z przedłużoną ekspansją
obieg Atkinsona
obieg Millera
wczesne zamknięcie zaworu dolotowego
późne zamknięcie zaworu dolotowego
Air Standard Cycle
Extended expansion cycle
Miller cycle
Atkinson cycle
Early Intake Valve Closure
Late Intake Valve Closure
Opis:
There are two ways to increase the thermodynamic efficiency of the engine cycle known as the carnotization of the power cycle. The first is to ensure the highest possible maximum parameters and the second is to allow the working medium to expand further than in the standard cycle. This is known generally as the over-expansion or extended expansion cycle. This paper presents theoretical and numerical investigations into the effect of extended expansion on the thermal efficiency and mean effective pressure. The performance of an air standard Atkinson cycle was considered and compared to that of the Sabathe cycle. The Miller version of extended expansion air standard cycle was analysed for both naturally aspirated and supercharged engine. Additionally, the numerical simulation of supercharged engine was also carried out. In both cases, two inlet valve closing strategies were evaluated (Early Intake Valve Closure-EIVC and Late Intake Valve Closure - LIVC). From the present investigation it is concluded that the extended expansion concept is an effective way of the carnotization of the power cycle of internal combustion reciprocating engine. The main conclusion resultanting from presented paper deals controls of closing angle of inlet valve which is to be an effective way of influence on the course of temperature changes of the working charge and what should be useful for the level emission decreasing of nitrous oxides.
Karnotyzacja obiegu silnika spalinowego tj. poszukiwanie sposobu podwyższenia jego sprawności może dotyczyć zarówno źródła górnego (sposobu doprowadzania ciepła) jak i dolnej przemiany odprowadzania ciepła Karnotyzacja źródła dolnego to wszelkie próby zmierzające do przedłużenia ekspansji czynnika roboczego. W pracy przedstawiono teoretyczną i numeryczną analizę wpływu przedłużenia ekspansji na sprawność i ciśnienie średnie obiegu silnikowego. Przeprowadzono analizę teoretyczną obiegu Atkinsona, a jej wyniki porównano z klasycznym obiegiem Sabathe. Dokonano także analizy obiegu Millera zarówno dla silnika niedoładowanego jak i doładowanego oraz zrealizowano badania symulacyjne obiegu doładowanego silnika z przedłużoną ekspansją. W obu przypadkach analizę przeprowadzono zarówno dla wczesne zamknięcie zaworu dolotowego jak i późnego zamknięcie zaworu dolotowego. Przeprowadzone badania usprawiedliwiają tezę, iż koncepcja przedłużonej ekspansji może być skutecznym sposobem karnotyzacji obiegu tłokowego silnika spalinowego. Główny wniosek wynikający z prezentowanego artykułu dotyczy sterowania kątem zamknięcia zaworu dolotowego, może być efektywnym sposobem oddziaływania na przebieg zmian temperatury czynnika roboczego i co powinno być przydatne dla ograniczania poziomu emisji tlenków azotu.
Źródło:
Journal of KONES; 2007, 14, 4; 257-264
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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