Browsing by Author "Pechout, Martin"

Now showing 1 - 11 of 11
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    Adaptation of Small Spark Ignition Engine to Alcohol Fuels
    (Technická Univerzita v Liberci, 2014-01-01) Pechout, Martin; Trnka, Miroslav; Novotný, Martin; Vojtíšek, Michal
    Most of the effort to decrease dependency on fossil fuels is taking place in vehicular applications. There are relatively few studies aimed to investigate possibilities and results of usage of alternative, mainly alcohol-based, fuels in small engines used for propulsion of small garden machinery. The aim of this paper is to investigate the effects of alcohol fuels, n-buthanol and E85, on the operation of small spark ignition engine without any modification and with simple carburetor modification. The test results of an unmodified engine show a remarkable mixture enleanment with increasing alcohol share accompanied by decrease in maximum torque, limitation of stable engine regimes, increased nitrogen oxides production and lowered production of carbon monoxide and hydrocarbons. Simple carburetor modification suppressed all the above mentioned negative impacts and thus allowed combustion of selected alcohol fuels.
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    Comparison of hydrogenated vegetable oil and biodiesel effects on combustion, unregulated and regulated gaseous pollutants and DPF regeneration procedure in a Euro6 car
    (Elsevier B.V., 2019-12-15) Pechout, Martin; Kotek, Martin; Jindra, Petr; Macoun, David; Hart, Jan; Vojtíšek-Lom, Michal
    The effects of traditional biodiesel (fatty acid methyl-esters, FAME) and a hydrotreated vegetable oil (HVO) were comprehensively investigated on a production Euro 6 diesel car, including fuel injection rate and timing, combustion analysis, emissions of regulated and unregulated pollutants, and regeneration of the diesel particle filter. The use of both biofuels is a part of the efforts to reduce emissions of greenhouse gases and health-relevant pollutants and to improve energy security and sustainability. HVO, albeit more expensive, offers benefits relative to FAME in terms of oxidation stability, injector fouling, energy content and cetane number. The car was fitted with an on-board instrumentation and subjected to a range of driving cycles on a chassis dynamometer. The fuel consumption calculated from instantaneous emissions data based on exhaust gas composition measured by an on-board FTIR and calculated exhaust flow matched directly measured fuel consumption within several percent on all fuels; differences in the consumption among the fuels correspond to different heating values. The combustion onset and maximum heat release rate were comparable for diesel and FAME but were advanced on HVO due to its higher cetane number, causing, at times, multiple distinct heat release peaks, suggesting that optimization of fuel injection timing for HVO might be beneficial. Emissions of methane and ammonia were negligible, of N2O were measurable and slightly lower for HVO than for other fuels, of formaldehyde were limited to cold engine accelerations and highest for FAME and negligible for HVO, of NO and NO2 were high on all fuels during all operating conditions except for the type approval test. The results confirm several relative advantages of HVO over RME, with penetration into engine lubricating oil during particle filter regeneration to be further investigated. The effects of HVO lubricity and other long-term effects were not evaluated here.
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    Internal Combustion Engines as the Main Source of Ultrafine Particles in Residential Neighborhoods: Field Measurements in the Czech Republic
    (MDPI, 2015-01-01) Štolcpartová, Jitka; Pechout, Martin; Dittrich, Luboš; Mazáč, Martin; Fenkl, Michael; Vrbová, Kristýna; Ondráček, Jakub; Vojtíšek-Lom, Michal
    Ultrafine particles (UFP, diameter < 100 nm) exposure has already been associated with adverse effects on human health. Spatial distribution of UFP is non-uniform; they concentrate in the vicinity of the source, e.g. traffic, because of their short lifespan. This work investigates spatial distribution of UFP in three areas in the Czech Republic with different traffic load: High traffic (Prague neighborhood—Sporilov), commuter road vicinity (Libeznice), and a small city with only local traffic (Celakovice). Size-resolved measurements of particles in the 5–500 nm range were taken with a particle classifier mounted, along with batteries, GPS and other accessories, on a handcart and pushed around the areas, making one-minute or longer stops at places of interest. Concentrations along main roads were elevated in comparison with places farther from the road; this pattern was observed in all sites, while particle number distributions both close and away from main roads had similar patterns. The absence of larger particles, the relative absence of higher concentrations of particles away from the main roads, and similar number distributions suggest that high particle number concentrations cannot be readily attributed to sources other than internal combustion engines in vehicles and mobile machinery (i.e., mowers and construction machines).
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    Nástavba stacionárního motoru pro odběr výkonu
    (2007-01-01) Pechout, Martin
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    Nástavba stacionárního motoru pro odběr výkonu.
    (Technická Univerzita v Liberci, 2007-01-01) Pechout, Martin; Kaniok, Jozef
    Bachelor thesis deals with engineering design of the power take-off adjunct unit for engine used as stationary power source. This adjunct unit contains the single dry friction disk clutch with lock system. The power take-off systems with description are introduced on the beginning of the work. As a next the engine output, the designed clutch mechanism and the lock system is described and basic strength calculation is elaborated. The thesis besides deals with additional pneumatic control system. The power take-off adjunct unit design documentation is the final result of the project and it is included as supplement.
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    Regulated and Non-Regulated Emissions from Euro 6 Diesel, Gasoline and CNG Vehicles under Real-World Driving Conditions
    (MDPI, 2020-02-01) Suarez-Bertoa, Ricardo; Pechout, Martin; Vojtíšek, Michal; Astorga, Covadonga
    The transport sector is one of the main sources air pollutants. Different exhaust after-treatment systems have been implemented over the years to control the emissions of criteria pollutants. However, while reducing the emissions of the target compounds these systems can lead to the emissions of other pollutants and/or greenhouse gases such as NH3 or N2O. Following the implementation of the Real Driving Emissions (RDE) test procedure in the EU, vehicles have been equipped with more complex after-treatment configurations. The impact that these technologies may have on the emissions of non-regulated pollutants during real-world driving have not been evaluated until now. In the current study we present the on-road emissions of a series of non-regulated pollutants, including NH3, N2O, CH4 and HCHO, measured with a portable FTIR from a series of Euro 6d, Euro 6c and Euro 6d-TEMP, gasoline diesel and compressed natural gas (CNG) vehicles during real-world testing. The obtained results show that it is possible to measure N2O, NH3, CH4 and HCHO during on-road operation. The results also highlight the importance of the measurement of the emissions of these pollutants during real-world driving, as the emissions of NH3 (a particulate matter precursor) and those of N2O and CH4 (green-house gases) can be high from some vehicle technologies. NH3 emissions were up to 49 mg/km for gasoline passenger cars, up to 69 mg/km for the CNG light-commercial vehicle and up to 17 mg/km a diesel passenger car equipped with a selective catalytic reduction system (SCR). On the other hand, N2O and CH4 emissions accounted for up to 9.8 g CO2 eqv/km for a diesel passenger car equipped with a combination of diesel oxidation catalysts (DOC), lean NOx traps (LNT), SCR and possibly an ammonia slip catalyst ASC.
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    The genotoxicity of organic extracts from particulate truck emissions produced at various engine operating modes using diesel or biodiesel (B100) fuel: A pilot study
    (ELSEVIER, RADARWEG 29, 1043 NX AMSTERDAM, NETHERLANDS, 2019-10-01) Novotná, Božena; Sikorová, Jitka; Milcová, Alena; Pechout, Martin; Dittrich, Luboš; Vojtíšek-Lom, Michal; Rossner, Pavel; Brzičová, Táňa; Topinka, Jan
    An analysis of the toxic effects of emissions should reflect real traffic conditions. The exhaust emissions of particulate matter from diesel engines strongly depend on their operating conditions, with low-speed, low-load "urban creep" conditions, common for truck traffic in heavily congested urban areas, being one of the worst. We aimed to detect the genotoxicity of organic extracts from particulate matter in the exhaust of the diesel engine Zetor 1505 running on diesel and biodiesel (B100) fuels at characteristic modes of extended "urban creep", typical for transit truck traffic in Prague, comparing the first 5 min of idling with extended (20-80 min) idling, full load after idle, "stabilized" full load, and 30% load. The diluted exhaust was sampled with high volume samplers on glass fiber fluorocarbon coated filters. The filters were extracted with dichloromethane and DNA damage was analyzed in A549 cells using comet assay, with the inclusion of formamidopyrimidine DNA glycosylase (FPG) and endonuclease III (ENDOIII) to recognize oxidized DNA bases. The cells were exposed to extractable organic matter (EOM) for 4 and 24 h at non-cytotoxic dose corresponding to 0.001 m(3) of undiluted exhaust gas per ml cell media. At the 4 h exposure interval, all samples from B100 and diesel emissions induced DNA damage. EOM from the extended idle engine mode exerted the strongest genotoxic effect for both fuels. Twenty hours later, the cells exposed to diesel EOM exhibited a further increase of DNA strand breaks compared to the preceding interval. In contrast, DNA damage seemed to be fully repaired in cells treated with EOM derived from biodiesel B100. The preliminary results suggest that (i) diesel emissions are more genotoxic than the emissions from B100, (ii) biodiesel induced DNA lesions are repaired within 24 h.
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    Vysokotlaké střikování biopaliv se systémem Common Rail
    (Technická Univerzita v Liberci, 2011-01-01) Pechout, Martin; Scholz, Celestýn
    The subject of the thesis is the creation of a simplified one-dimensional computational model of a Common Rail diesel engine fuel injection system, calibrated with experimental data obtained during operation on diesel fuel. Additionally a simulation of behavior of plant-based biofuel was conducted and results compared to diesel fuel operation.
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    Zážehové motory při provozu na biobutanolová paliva
    (Technická Univerzita v Liberci, 2016-01-01) Pechout, Martin; Laurin, Josef
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    Zážehové motory při provozu na biobutanolová paliva
    (Technická Univerzita v Liberci, 2017-4-27) Pechout, Martin; ; Laurin Josef, doc. Ing. CSc. Skolitel : 55347; Stuchlík Martin, Ing. Konzultant : 60189; Novák Pavel, Ing. Konzultant2 : 65843
    Práce se zaobírá možnostmi použití paliv obsahujících butanol, jakožto alkoholu vyrobitelného z obnovitelných zdrojů, v současných zážehových motorech.Z teoretické rozvahy vyplývá, že vlastnosti obou uvažovaných izomerů (n-butanolu a iso butanolu) jsou v mnohém výhodnější oproti etanolu, kdy vyniká například nižší nutný nárůst doby vstřiku (přibližně 21%) pro butanol nežli prakticky dvojnásobný pro etanol.Spalování butanolu bylo zkoumáno na motoru s otevřeným řízením za několika vybraných provozních režimů a na vozidlovém motoru se standardní řídicí jednotkou při ustálených režimech, pokrývajících většinu provozní oblasti motoru. U vozidlového motoru byla také sledována míra zachování výchozí bohatosti směsi a u obou pak průběh hoření, teploty a složení výfukových plynů. Výsledkem je doporučené mírné snížení předstihu zážehu za nízkých zatížení, zejména pro n-butanol. Dále bylo u obou motorů konstatováno snižování teplot výfukových plynů s rostoucí náhradou benzinu butanolem. Rovněž třísložkový katalytický reaktor vykazoval schopnost korektní funkce bez ohledu na podíl butanolu v palivu. Zároveň se však v nemalé míře projevila vysoká teplota varu butanolu, deformující destilační křivku, a vedoucí k výraznému zhoršení startovatelnosti studeného motoru. U zkoušeného vozidlového motoru se projevila již od středních podílů butanolu.Jízdní zkoušky za reálných podmínek při provozu prohřátého motoru ukazují úspěšnost adaptace řídicí jednotky motoru pro jednotlivé podíly butanolu včetně vysokých. Část vozidel byla schopna za reálného provozu s prohřátým motorem akceptovat bez jakýchkoliv úprav poloviční, a v některých případech i vyšší, podíl butanolu za cenu problematické startovatelnosti. V případě přímého vstřiku paliva byla testována pouze nižší koncentrace, avšak bez zaznamenatelných potíží. V případech úspěšné adaptace převládaly emise plynných znečišťujících látek srovnatelné s provozem na benzin. Navíc výsledky ukazují výrazný pokles produkce pevných částic při přímém vstřiku paliva do válce. Dále jsou v teoretické rovině porovnána opatření pro zachování startovatelnosti motoru, která byla zjištěna jako problematická při přídavku butanolu.Z experimentů na malých motorech vyplývá možnost zachovat nezměněnou bohatost směsi jednoduchou úpravou karburátoru, srovnatelné či nižší produkce sledovaných plynných znečišťujících látek a výrazný pokles emitovaných pevných částic. Daní za toto je zhoršená startovatelnost studeného motoru při vysokých koncentracích butanolu a několikanásobný nárůst množství vypouštěných aldehydů, je-li místo benzinu spalován butanol.Celkově lze pro oba izomery butanolu očekávat obdobný potenciál pro úspěšné nahrazení benzinu v řádu nízkých až vysokých desítek procent v závislosti na míře úprav motorů.