Temat: thermodynamic - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Integrated approach of environmental issues in industrial complex treated as complicated operated machine
Autorzy:: Kamiński, A.
Powiązania:: https://bibliotekanauki.pl/articles/246034.pdf
Data publikacji:: 2015
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: integrated environmental approach
thermodynamic machine
Opis:: Refining, petrochemical and energy industry are examples of influence on all environment components. Uncontrolled imposing new stricter burdens and legal requirements may cause the lack of expected results in reducing their impact on the environment. Moreover, effects may be counterproductive. Simultaneously, companies have to balance between legislative challenges, social expectations and technical possibilities, paying special attention on Corporate Social Responsibility (CSR), sustainability and biodiversity. During the Fifth Refinery Forum in Brussels, representatives of the European Commission admitted that legislation laid down within the European Union in the years 2000-2012 lowered the competitiveness of European refining industry. This status is proven by the analysis of refining industry prepared by The Directorate-General for Internal Market, Industry, Entrepreneurship and SMEs, and Joint Research Centre [1]. Weakening demand for fuels, lack of opportunities for increasing the capacity of European refineries (permanent shutdowns) and shale revolution cause a number of challenges including environmental. Therefore, it is necessary to take into account all factors mentioned above, and an integrated approach to environmental and climate protection in the face of changing legal regulations becomes crucial. This article proposes a new integrated, model approach to all issues connected with environmental protection in refining, petrochemical and energy complexes. In simple words, such complexes require maintenance shutdowns, repairs, overhauls. In addition, in the process various forms of energy is used and converted, so we can talk about the “exploitation of high thermodynamic machine”.
Źródło:: Journal of KONES; 2015, 22, 2; 110-114
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Thermal analysis of car air cooler
Autorzy:: Trzebiński, D.
Szczygieł, I.
Powiązania:: https://bibliotekanauki.pl/articles/242031.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: car air conditioning
refrigerant
thermal comfort
thermodynamic cycle
Opis:: People more and more time spend in vehicles (cars, trains, planes, buses or subway). This is the reason why the thermal comfort has more and more paid attention. In one hand people try to make comfort (in each situation) whatever they are at home, office or in car. In the other hand the thermal conditions in the cabin of vehicles directly influences on the driver's and passengers safety. The investigations presented in this paper are the part of larger project, which assumes complex modelling of thermal state of car interior. First part assumes creation of CFD model of car interior. Second part is thermodynamic modelling of air cooling unit in order to estimate the influence of basic cabin parameters on the A/C unit COP, power consumption of the unit and fuel consumption of the vehicle. In the paper thermodynamic analysis of car air cooler is presented. Typical refrigerator cycles are studied: one with uncontrolled orifice and non controlled compressor, second with thermostatic controlled expansion valve and externally controlled compressor. The influence of refrigerant charge and the inlet air temperature on the coefficient of performance, exergy efficiency, heat flux and temperature in evaporator and compressor net power were investigated. The impact of improper refrigerant charge on the performance of A/C systems was also checked.
Źródło:: Journal of KONES; 2011, 18, 2; 439-446
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Investigation into the effect of bore/stroke ratio on a single cylinder two stroke opposed piston engin
Autorzy:: Alqahtani, A. M.
Wyszynski, M. L.
Mazuro, P.
Powiązania:: https://bibliotekanauki.pl/articles/245226.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: opposed-piston
two-stroke
AVL Boost
thermodynamic modelling
Opis:: Opposed-piston (OP) engine’s promising fuel efficiency has attracted the interest of automotive industry in the recent years. The opposed-piston two-stroke (OP2S) engine technology heightens this fuel efficiency benefit and offers advances in structure, power density and thermal efficiency whilst sustaining its lower cost and weight. Today thermodynamic modelling remains an indispensable and cost effective route in the development and optimisation of internal combustion engines (ICEs). To achieve this goal, the OP2S engine is simulated and validated against experimental results in AVL Boost™, which is hailed as one of the most reliable and advanced engine simulation tools. Detailed analyses of the piston dynamics, heat release, scavenging and heat transfers are highlighted in discrete sections of this paper. Having compared distinct heat release models, the Wiebe 2-Zone model emerged efficacious in replicating the heat release characteristics of the PAMAR™ engine. In comparing the numerical and experimental results, the simulation revealed minimal differences in peak pressure, peak temperature and maximum pressure raise rate, under ±2.5% differences for indicated power, IMEP, indicated thermal efficiency (ITE) and ISFC. Subsequently, confidence taken from the validated numerical model is then deployed to investigate the effect of stroke-to-bore (S/B) ratio on OP2S performance. Three combinations of S/B ratios (0.5, 1.25, and 1.69) with identical swept volume are analysed in this study. Utilisation of the validated model ensured the standardisation of intake, exhaust and the combustion systems in order to isolate the effects of S/B ratio. Results indicate that heat losses decrease with increasing S/B ratio because of the reduced surface area-to-volume in the cylinder. Consequently, an improvement in ITE and mechanical efficiency is observed with reduced ISFC for higher S/B ratios. A tendency of upsurge in combustion efficiency is also evident for higher S/B ratio due to reduced heat transfer near minimum volume of the combustion chamber.
Źródło:: Journal of KONES; 2016, 23, 2; 9-16
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Failure of gas turbine cone burner by carburization
Autorzy:: Ardy, H.
Putra, S.
Hardianto, T.
Powiązania:: https://bibliotekanauki.pl/articles/247322.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: gas turbine
cone burner
Hastelloy-X
carburization
microstructure
carbide
thermodynamic simulation
Opis:: Gas turbine for a power plant has 72 pieces of cone burner in its combustion chamber. High-speed diesel oil (HSD) is use as fuel to produce 130 MW of power at 3,000 rpm. The maximum temperature at the turbine inlet is estimated about 1087 centigrade and at the outlet is between 400-540oC. Sixty percent of the cone burner failed repetitively at one side of the tip-end after 6,000 hours of service. The refurbished cone burner has to be replaced by a new one after 18,000 of service-hours. The cone burner material is cast Hastelloy-X (nickel based alloys). Metallurgical analyses by microstructural observation using optical and scanning electron microscopes, and energy dispersive spectroscope have been performed to observe the change in burner microstructure. Thermodynamics analysis has been performed to obtain temperature distribution around the failed section. Two failed cone burners have been examined; cone burner that has not been repaired, and that has been repaired twice. Thermodynamics analysis result shown that the temperature around the failed section is between 897 to 1087 centigrade. Microstructure of the good part, far from the failed section, consists of cast structure of austenite matrix and fine carbide particles. Severe carbide precipitation and growth was observed on the failed section even the nominal carbon content in material is only 0.10 percent (max.). Severe carbide precipitation occurred because of carbon ingress from the environment (carburization) which combines with carbide forming elements in material (chromium, molybdenum, and tungsten). As a result, the corrosion and oxidation resistance of material decreased significantly after long time exposure at high temperature that led to oxidation, thinning, and failure of the cone burner tip. Failure only localized on one side of the tip-edge, therefore refurbishment by welding and coating can be performed to extend the life cycle of cone burner. The current examination results shows that the replacement cycle is not only limited to 18,000 hours but can also be extended to 48,000 hours.
Źródło:: Journal of KONES; 2012, 19, 2; 9-16
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Possibility of the charge exchange work diminishing of an internal combustion engine in part load
Autorzy:: Postrzednik, S.
Żmudka, Z.
Powiązania:: https://bibliotekanauki.pl/articles/247156.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: engine efficiency
charge exchange work
engine load
valve actuating
thermodynamic cycle
Opis:: Internal combustion engines, used for driving of different cars, occur not only at the full load, but mostly at the part load. The relative load exchange work at the full (nominal) engine load is significant low. At the part load of the IC engine his energy efficiency r)e is significantly lower than in the optimal (nominal field) range of the performance parameters. One of the numerous reasons of this effect is regular growing of the relative load exchange work of the IC engine. The load exchange work of IC engine essentially determines the effective engine efficiency. It is directly connected with the quantitative regulation method common used in the IC engines. From the thermodynamic point of view - the main reason of this effect is the throttling process (causing exergy losses) occurring in the inlet and outlet channels. The known proposals for solving of this problem are based on applying of the fully electronic control of the motion of inlet, outlet valves and new reference cycles. The independent actuating (steerage) procedures of the ICE inlet valves should assure the adequate mass of the fresh charge, while procedures of the outlet valves are focused on the optimal exhaust gas recirculation rate, according to the engine load. The idea presented in the paper leads to diminishing the charge exchange work of the IC engines. The mentioned above problem can be solved using presented in the paper a new concept of the reference cycle (called as eco-cycle) of IC engine.
Źródło:: Journal of KONES; 2011, 18, 4; 377-387
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Preliminary analysis of thermodynamic cycle of turbofan engine fuelled by hydrogen
Autorzy:: Marszalek, N.
Powiązania:: https://bibliotekanauki.pl/articles/247482.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: liquid hydrogen
turbofan engine
turbine cooling
engine thermodynamic cycle
engine performance
Opis:: Presented article is focus on analysis of the effect of hydrogen fuel on turbofan engine performance. Selected properties of hydrogen and possibility of introduction in civil aviation were discussed. Hydrogen implementation as aviation fuel offers obvious advantages such as low emission of combustion product, higher payload, lower fuel consumption, general availability but also poses great technical challenges. The most important aspect is to ensure engine operational safety at very high level. Hydrogen implementation would eliminate the aviation dependence of exhausting sources of fossil fuels especially of crude oil. The thermodynamic model of turbofan engine was implemented in MATLAB environment. Accepted assumptions have been discussed. Turbine cooling process has been included in the numerical model. Working fluid was modelled as semi-perfect gas. Analysis was carried out for take-off and design point conditions. Engine performances were compared for two kinds of applied fuels: liquid hydrogen and commonly used in turbine engines kerosene. Combustion heat of hydrogen is about three time higher than in comparison with conventional turbine engine fuel, what exert significant influence on engine performance. The results of engine thermodynamic cycle analysis indicate the increase in specific thrust and significant reduction of specific fuel consumption. The results are presented in tabular form and on the graphs. Obtained results have been discussed and the direction of further research was indicated.
Źródło:: Journal of KONES; 2018, 25, 3; 347-354
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Optimization of heat release rate equation for spark ignition engine
Optymalizacja równania szybkości wydzielania ciepła w tłokowym silniku spalinowym o zapłonie iskrowym
Autorzy:: Mendera, K. Z.
Smereka, M.
Powiązania:: https://bibliotekanauki.pl/articles/949479.pdf
Data publikacji:: 2008
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: silnik spalinowy
właściwości termodynamiczne
analiza szybkości wydzielania ciepła
internal combustion engine
thermodynamic properties
heat release analysis
Opis:: Ciśnienie w cylindrze jest efektem procesu spalania, zmian objętości komory spalania (ruch tłoka), zmian chemicznej kompozycji czynnika (właściwości termodynamiczne), wymiany ciepła oraz przepływów masy czynnika (efekt szczelinowy i przedmuchy). Do analizy termodynamicznej niezbędna jest znajomość ciśnienia w komorze spalania oraz ilościowy wpływ wszystkich wymienionych czynników. Ciśnienie w cylindrze stanowi cenną informację o procesie spalania i należy się spodziewać, że użycie czujników ciśnienia w silnikach seryjnych byłoby interesujące pod względem możliwości sterowania silnikiem. Obecne prace, dla silników z zapłonem iskrowym, rozwijają się w kierunku stosowania analizy wydzielania ciepła na podstawie danych ciśnienia z komory spalania. Analiza udziału części spalonej (MFB) może być używana do określania właściwości termodynamicznych czynnika w cylindrze dla przejścia od ładunku niespalonego do spalonego. Artykuł prezentuje model wydzielania ciepła, oparty na I Zasadzie Termodynamiki, dla silnika z zapłonem iskrowym, bazujący na ciśnieniu w cylindrze, z wykorzystaniem zmiennych właściwości czynnika roboczego. Oceniono wpływ poszczególnych członów równania na otrzymywaną całkowitą ilość ciepła wydzielonego.
Cylinder pressure built by combustion process is affected by the changes in the volume of combustion chamber (due to piston travel) and chemical composition (and hence thermodynamic properties), heat transfer and gas flows. To examine (and further to develop the combustion process), it is necessary to relate each term to measured in-cylinder pressure changes and then combine them to quantify the combustion effects. The cylinder pressure can give valuable information about the combustion process and it is expected that it will also be interesting to use pressure sensor in production engine. The present work develops and applies heat release rate (HRR) analysis for SI engine pressure data. Mass fraction burned (MFB) is used to interpolate the in-cylinder gas properties for the burned and unburned charge. This paper presents heat release model, based on in-cylinder pressure data from spark ignition engine, which uses instantaneous properties of working fluid to calculate cumulative heat release characteristics. Heat release rate equation, based on First Law of Thermodynamic was applied to a control volume and its fundamental parts were discussed and their influence evaluated separately. Based on this sensitivity analysis, the optimal formulation of HRR equation for SI engine was proposed and tested
Źródło:: Journal of KONES; 2008, 15, 3; 335-346
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Multi-parametric and multi-objective thermodynamic optimization of a spark-ignition range extender ICE
Autorzy:: Toman, R.
Brankov, I.
Powiązania:: https://bibliotekanauki.pl/articles/243112.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: Range Extender
hybrid electric vehicle
battery electric vehicle
internal combustion engine
spark ignition
thermodynamic optimization
genetic algorithm
Opis:: The current legislation pushes for the increasing level of vehicle powertrain electrification. A series hybrid electric vehicle powertrain with a small Range Extender (REx) unit – comprised of an internal combustion engine and an electric generator – has the technical potential to overcome the main limitations of a pure battery electric vehicle: driving range, heating, and air-conditioning demands. A typical REx ICE operates only in one or few steady-states operating points, leading to different initial priorities for its design. These design priorities, compared to the conventional ICE, are mainly NVH, package, weight, and overall concept functional simplicity – hence the costeffectiveness. The design approach of the OEMs is usually rather conservative: parting from an already-existing ICE or components and adapting it for the REx application. The fuel efficiency potential of a one-point operation of the REx ICE is therefore not fully exploited. This article presents a multi-parametric and multi-objective optimization study of a REx ICE. The studied ICE concept uses a well-known and proven technology with a favourable production and development costs: it is a two-cylinder, natural aspirated, port injected, four-stroke SI engine. The goal of our study is to find its thermodynamic optimum and fuel efficiency potential for different feasible brake power outputs. Our optimization tool-chain combines a parametric GT-Suite ICE simulation model and modeFRONTIER optimization software with various optimization strategies, such as genetic algorithms, gradient based methods or various hybrid methods. The optimization results show a great fuel efficiency improvement potential by applying this multi-parametric and multi-objective method, converging to interesting short-stroke designs with Miller valve timings.
Źródło:: Journal of KONES; 2018, 25, 3; 459-466
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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