80 research outputs found
Investigation of car engines emission control
Automobile exhaust gases significantly pollute the environment. Pollution decreases the modern electronic engine management system. Exhaust gas emissions due to correct the engine management system work Management system failures identify- the diagnostic aid. Automobile diagnostics is one of the main subjects in training cars service specialists in Vilnius College of Technologies and Design. The diagnostics subject consists of theoretical and practical training. Various types of engine management systems work and their faults are investigated in the laboratory. The main equipment consists of engine simulators. The development of using microprocessing technologies in automobile control requires more sophisticated diagnostics equipment. Most developing diagnostics equipment are systemic testers which take the information from the electronic control unit (ECU) about trouble codes' and display working parameters. However we can only see real sensors' signals by having direct contact. Students are measuring engine management signals in the laboratory by using an electricity signals input bloc. On the screen of the PC we can see the electronic management signals graphics image. The signals arc analyzed and that is how the faults are diagnosed. Experience of automobile electronic management signals research is necessary for the students in their practical work of automobile diagnosis
Research of Parameters of a Compression Ignition Engine Using Various Fuel Mixtures of Hydrotreated Vegetable Oil (HVO) and Fatty Acid Esters (FAE)
The present study is aimed at studying the energy and environmental performance at various engine loads (BMEP) with identical start of injection (SOI) for all fuel types. The combustion parameters for the fuel mixtures were analyzed using the AVL BOOST software (BURN subroutine). Five different blends were tested, consisting completely of renewable raw materials based on hydrotreated vegetable oil (HVO) and fatty acid methyl ester (FE100), and the properties of diesel fuel (D) were compared with respect to these blends. The mixtures were mixed in the following proportions: FE25 (FE25HVO75), FE50 (FE50HVO50), FE75 (FE75HVO25). In this study, diesel exhaust was found to produce higher NOx values compared to FE blends, with HVO being the lowest. Hydrocarbon and smoke emissions were also significantly lower for blends than for diesel. Possible explanations are the physical properties and fatty acid composition of fuel mixtures, affecting injection and further combustion. The results showed that blends containing more unsaturated fatty acids release more nitrogen oxides, thus having a lower thermal efficiency compared to HVO. No essential differences in CO emissions between D and HVO were observed. An increase in this indicator was observed at low loads for mixtures with ester. CO2 was reduced in emissions for HVO compared to the aforementioned blends and diesel. The results of the combustion analysis show that with a high content of unsaturated fatty acids, mixtures have a longer combustion time than diesel fuel.© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article
distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed
Efficient hydrotreated vegetable oil combustion under partially premixed conditions with heavy exhaust gas recirculation
This study performed a detailed analysis of combustion and emission characteristics of a single-cylinder compression ignition engine fuelled with diesel, hydrogenated vegetable oil (HVO) and their blend (50/50). Taking advantage of the high reactivity of HVO, the aim was to investigate how changes in fuel injection and exhaust gas recirculation (EGR) strategies can achieve partially premixed combustion with superior efficiency and ultra-low engine-out emissions. Without EGR, and with a multi-pulse injection strategy optimized for diesel, combustion timings were the same for all three investigated fuels. HVO exhibited higher tolerance to EGR in terms of combustion retarding, so it was possible to use high recirculation rates. This reduced nitrogen oxides, while maintaining high indicated efficiency. The pilot injection control allowed further extending the EGR dilution limit without incurring trade-offs with combustion efficiency and related carbon monoxide and unburned hydrocarbon emissions. Additionally, heavy EGR conditions supported reduction of soot for all three tested fuels. However, the best trade-off between soot and other emission compounds was observed for HVO. HVO also resulted in the lowest emissions of aldehydes and aromatics. In conclusion, on the given engine platform at a steady-state, mid-load operating point, HVO allowed for 43% indicated thermal efficiency with engine-out nitrogen oxides and carbon monoxide emissions near to Euro VI limits. This efficiency level was 1.5 percentage points above that for the optimized diesel operation.fi=vertaisarvioitu|en=peerReviewed
EFFICIENCY OF AN OFF-ROAD HEAVY-DUTY SERIES HYBRID DRIVE BASED ON A MODIFIED WORLD HARMONIZED TRANSIENT CYCLE
As electric drives slowly replace passenger cars and light special vehicles, electric drives in the heavy-duty road sector have started to emerge. As for off-road vehicles, there is some effort to reduce the amount of fossil fuel used. In this study, the series hybrid application for a heavy-duty tractor is investigated. Work conditions are described using modified worldwide transient vehicle cycle to evaluate the efficiency of an energy management system applied, as well as the overall vehicle performance and efficiency. As a result, in some test scenarios, smaller-than-expected energy outputs were identified and new ways to improve energy management were found
Betterment of ecological parameters of a diesel engine using Brown‘s gas
Hydrogen could become an important element, allowing us to accumulate and transfer energy in a clean way. Hydrogen can be used in cars as a fuel additive which increases the combustion efficiency of the fuel-air mixture. A small amount of hydrogen gas could also be produced in a car by decomposing water by means of electrolysis, using for this purpose the energy produced by the car's electric power generator. The hydrogen and oxygen (HHO) mixture obtained, which is also known as Brown's gaseous mixture, is supplied to the engine's intake manifold.
Tests have been performed with 1.6 TD (SB) diesel engine. The automobile was tested on a chassis dynamometer running at a different speed. The engine was tested using fuel-air combustion mixture and fuel-air-HHO gas combustion mixture without additional adjustment of the fuel supply system. The test results have revealed that additional injection of HHO gas into combustion mixture resulted in up increase of fuel consumption, but the CO, the HC, the PM amount has decreased insignificantly. At few engine loads the amount of NOx decreased, however increasing the engine load resulted in a gradual increase.
Having analysed test results we came to a conclusion that additional supply of HHO gas into combustion mixture resulted in improvement of the combustion quality of fuel-air mixture and ecological performance of the engine. This is especially relevant for the automobiles which are not equipped with a supplementary exhaust gas toxicity decreasing system.
First published online: 11 Oct 201
INVESTIGATION OF COMBUSTION, PERFORMANCE AND EMISSION CHARACTERISTICS OF SPARK IGNITION ENGINE FUELLED WITH BUTHANOL – GASOLINE MIXTURE AND A HYDROGEN ENRICHED AIR
In this study, spark ignition engine fuelled with buthanol-gasoline mixture and a hydrogen-enriched air was investigated. Engine performance, emissions and combustion characteristics were investigated with different buthanol (10% and 20% by volume) gasoline mixtures and additionally supplied oxygen and hydrogen (HHO) gas mixture (3.6 l/min) in the sucked air. Hydrogen, which is in the HHO gas, improves gasoline and gasoline-buthanol mixture combustion, increases indicated pressure during combustion phase and decreases effective specific fuel consumption. Buthanol addition decreases the rate of heat release, the combustion temperature and pressure are lower which have an influence on lower nitrous oxide (NOx) emission in exhaust gases. Buthanol lowers hydrocarbon (HC) formation, but it increases carbon monoxide (CO) concentration and fuel consumption. Combustion process analysis was carried out using AVL BOOST software. Experimental research and combustion process numerical simulation showed that using balanced buthanol and hydrogen addition, optimal efficient and ecological parameters could be achieved when engine is working with optimal spark timing, as it would work on gasoline fuel
HHO (H2/O2) dujų panaudojimo vidaus degimo variklyje efektyvumo vertinimas
Straipsnyje apžvelgtos vandenilio, kaip vidaus degimo variklio (VDV) degalų, naudojimo galimybės ir perspektyvos. Apibendrinti įvairių tyrėjų gauti rezultatai tiriant VDV energetinius ir ekologinius rodiklius, į variklį papildomai tiekiant HHO dujas. Pateiktos eksperimentiniu būdu nustatytos energijos sąnaudos reikalingos HHO dujų gamybai elektrolizės būdu ir apskaičiuotas šių dujų panaudojimo vidaus degimo variklyje būvio ciklo energetinis efektyvumas. Įvertinus HHO dujose esančio vandenilio fizikines–chemines savybes ir šių dujų gamybos efektyvumą paaiškinta teigiama ir neigiama HHO dujų įtaka slėginio ir kibirkštinio uždegimo variklių rodikliams
Improvement of Efficiency of Operation of An Internal Combustion Engine by Using Brown’s Gas
Disertacijoje nagrinėjamas Brauno (vandenilio ir deguonies – HHO) dujų panaudojimo vidaus degimo varikliuose efektyvumas, dujas tiekiant į įsiurbiamą orą. Pagrindinis tyrimų objektas – vidaus degimo varikliai, veikiantys įprastiniais bei alternatyviaisiais degalais su papildomai tiekiamomis Brauno dujomis. Pagrindinis disertacijos tikslas – teoriškai pagrįsti ir eksperimentiškai ištirti Brauno dujų panaudojimo kibirkštinio ir slėginio uždegimo varikliuose racionalumą, įvertinant energetinius bei ekologinius rodiklius.
Darbe sprendžiami keli pagrindiniai uždaviniai: ištirti Brauno dujų gamybos įrenginio veikimo energetinį efektyvumą, nustatyti Brauno dujų koncentracijos degiajame mišinyje įtaką kibirkštinio ir slėginio uždegimo variklių darbo proceso rodikliams bei deginių taršai, nustatyti Brauno dujų įtaką degalų užsiliepsnojimui slėginio uždegimo variklyje.
Disertaciją sudaro įvadas, trys skyriai, rezultatų apibendrinimas, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai ir šeši priedai.
Įvadiniame skyriuje aptariama tiriamoji problema, darbo aktualumas, aprašomas tyrimų objektas, formuluojamas darbo tikslas bei uždaviniai, pateikiama tyrimų metodika, darbo mokslinis naujumas, darbo rezultatų praktinė reikšmė, ginamieji teiginiai. Įvado pabaigoje pristatomos disertacijos tema autoriaus paskelbtos publikacijos ir pranešimai konferencijose bei disertacijos struktūra.
Pirmasis skyrius skirtas literatūros apžvalgai. Jame apžvelgta vandenilio vartojimą skatinantys veiksniai, vandenilio ir Brauno dujų naudojimo vidaus degimo varikliuose tyrimų metodika ir rezultatai. Formuluojamos skyriaus išvados ir tikslinami disertacijos uždaviniai. Antrajame skyriuje pateikiama Brauno dujų panaudojimo vidaus degimo varikliuose tyrimo metodika. Trečiajame skyriuje pateikti Brauno dujų panaudojimo kibirkštinio ir slėginio uždegimo varikliuose eksperimentinių tyrimų ir skaitinio modeliavimo rezultatai.
Disertacijos tema paskelbta 14 mokslinių straipsnių: šeši – tarptautinėse duomenų bazėse esančiuose mokslo leidiniuose, du iš jų – „ISI Web of Science“ duomenų bazėje, aštuoni – kituose recenzuojamuose mokslo leidiniuose. Disertacijos tema perskaityta trylika pranešimų Lietuvos bei kitų šalių konferencijose
The Effect of Intake Valve Timing on Spark-Ignition Engine Performances Fueled by Natural Gas at Low Power
To reduce the greenhouse effect, it is important to reduce not only carbon dioxide but also methane emissions. Methane gas can be not only a fossil fuel (natural gas) but also a renewable energy source when it is extracted from biomass. After biogas has been purified, its properties become closer to those of natural gas or methane. Natural gas is an alternative energy source that can be used for spark-ignition engines, but its physicochemical properties are different from those of gasoline, and the spark-ignition engine control parameters need to be adjusted. This article presents the results of a study that considers a spark-ignition engine operating at different speeds (2000 rpm, 2500 rpm, and 3000 rpm) and the regulation of the timing of intake valve closure when the throttle is partially open (15%), allowing the engine to maintain the stoichiometric air–fuel mixture and constant spark timing. Studies have shown a reduction in engine break torque when petrol was replaced by natural gas, but break thermal efficiency has increased and specific emissions of pollutants (NOx, HC, CO2 (g/kWh)) have decreased. The analysis of the combustion process by the AVL BOOST program revealed different results when the engine ran on gasoline as opposed to when it ran on natural gas when the timing of intake valve closure changed. The volumetric efficiency of the engine and the speed of the combustion process, which are significant for engine performance due to the different properties of gasoline and natural gas fuels, can be partially offset by adjusting the spark timing and timing of intake valve closure. The effect of intake valve timing on engine fueled by natural gas more noticeable at lower engine speeds when the engine load is low
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