Biodyzelino ir vandenilio bendro degimo proceso slėginio uždegimo variklyje tyrimas

Increasing environmental pollution, concerns about oil price, traffic related health effects and depletion of fossil fuel resources are forcing humanity to limit the consumption or to look for new forms of energy. The cleanest power suitable for the road trans-port would be the electric energy produced of the clean sources such as solar, hydro, wind power and stored in batteries or extracted from hydrogen using fuel cell technology. However, the limitted range of driven distance are the obstacle for today battery electric cars. The lack of hydrogen fuelling stations, high price of hydrogen and expensive materials, limits the outbreake of the fuel cell technology. According to experts, hybrid systems including both electric and internal combustion engines consuming the renewable fuels would be the main power plant of vehicles decreasing the exhaust emissions of the internal combustion engine remains the important research subject for the time beeing. This dissertation work presents the study of performance, efficiency and ecological indicators of the co-combustion process of hydrogen with various renewable biomass based biofuels and their blends in the compression ignition engine. Experimental investigation and numerical simulation methods were applied in order to have a complex understanding of biodiesel fuels and influence of hydrogen on the engine work cycle. Introductory chapter presents the formulation of the problem, object and importance of the thesis, aim and the tasks of the work. The scientific novelty, theoretical and practical value of results obtained during experiments, and the list of published scientific publications by the author are presented. The scientific literature according to the theme of the thesis overviewed in the first chapter. The composition of biomass based biofuels with transestherification and hydrotreatening processes, heating values of the fuel and other features were reviewed according to other scientist’s works. The influence of the main parameters on CI engine efficiency and emission parameters were discussed. The second chapter represents the set-up of engines used at experiment, its methodology, calculations of heating values of the fuel mixtures used in experiment, calculations of hydrogen energy share according to the biodiesel flow rate, calculation of mass fraction burned, theoretical analysis of the rate of heat release, numerical simulation of performed experiments are discussed. The results of experiments obtained during tests of biodiesel and hydrogen fuel mixtures, numerical analysis and simulation of mentioned fuel mixtures presented in the third chapter. Research of various hydrogen energy share revealed that, higher engine efficiency and lower exhaust gas emissions in CI engine can be achieved. 11 scientific papers focused on the subject of the doctoral thesis have been published: 2 – in publications of the Clarivate Analytics Web of Science database with citation index; 1 – in Conference Proceedings publications of the Clarivate Analytics Web of Science database; 5 – in publications of other international database; 3 – in publications of other reviewable scientific publications.Dissertatio

Experimental investigations of hydrogen effects on performance and emissions of renewable diesel fueled RCCI

The article presents the study of hydrogen effects on performance, combustion and emissions characteristics of renewable diesel fueled single cylinder CI engine with common rail injection system in RCCI mode. The renewable diesel fuels as the HRF are the HVO and it blend with petrol diesel further named PRO Diesel, investigated in this study. The purpose of this investigation was to examine the influence of the LRF – hydrogen addition to the HRF on combustion phases, engine performance, efficiency, and exhaust emissions. HES was changed within the range from 0 to 35%. Hydrogen injected through PFI during intake stroke to the combustion chamber, where it created homogeneous mixture with air. The HRF was directly injected into combustion chamber using electronic controlled unit. Tests were performed at both fixed and optimal injection timings at low, medium and nominal engine load. After analysis of the engine bench results, it was observed that lean hydrogen – HRF mixture does not support the flame propagation and efficient combustion. While at the rich fuel mixture and with increasing hydrogen fraction, the combustion intensity concentrate at the beginning of the combustion process and shortened the ignition delay phase. Decrease of CO, CO2 and smoke opacity was observed with increase of hydrogen amounts to the engine. However, increase of the NO concentration in the engine exhaust gases was observed. Article in Lithuanian. Vandenilio įtaka energiniams ir emisijos rodikliams alternatyviu dyzelinu veikiančiame RCCI variklyje – eksperimentinis tyrimas Santrauka Straipsnyje pateiktas tyrimas apie vandenilio įtaką vieno cilindro slėginio uždegimo variklio energiniams parametrams ir deginių sudėčiai, kuriame alternatyvūs dyzeliniai degalai įpurškiami akumuliatorine įpurškimo sistema „Common rail“, varikliui veikiant RCCI režimu. Šiame tyrime buvo naudojami aukšto cetaninio skaičiaus alternatyvus dyzelinis degalas HVO ir jo mišinys su dyzelinu, toliau vadinamu PRO Diesel. Šio tyrimo tikslas – išbandyti žemo cetaninio skaičiaus degalo – vandenilio – įtaką aukšto cetaninio skaičiaus alternatyvaus dyzelinio degalo HVO degimo fazėms, variklio veikimo efektyvumui ir deginių kiekiui. Vandenilio energtinė dalis mišinyje buvo keičiama nuo 0 iki 35 %. Vandenilis buvo tiekiamas įsiurbimo fazės metu, įsiurbimo kanalu į degimo kamerą, kurioje jis, susimaišęs su oru, sudaro homogeninį mišinį. Aukšto cetaninio skaičiaus degalas HVO buvo tiesiogiai įpurškiamas į degimo kamerą, įpurškimo momentą ir trukmę valdant elektroniniu būdu. Bandymai buvo atliekami nekeičiant įpurškimo kampo ir nustačius optimalų įpurškimo kampą, esant žemai, vidutinei ir nominaliajai variklio apkrovai. Išnagrinėjus bandymo rezultatus buvo pastebėta, kad, degant liesam vandenilio-HVO mišiniui, liepsna plinta lėtai ir mišinys dega neveiksmingai. Esant riebiam degalų mišiniui ir didinant vandenilio energijos dalį, degimo intensyvumas koncentruojasi degimo proceso pradžioje ir sutrumpėja uždegimo gaišties trukmė. Buvo pastebėta, kad CO, CO2 ir kietųjų dalelių sumažėjo didinant vandenilio kiekį, tačiau padidėjo NO koncentracija variklio išmetamosiose dujose. Reikšminiai žodžiai: vandenilis, RCCI, HVO, NExBTL, PRO Diesel, MFB, degimo procesas, deginių emisija, detonacija

RME CO-combustion with hydrogen in compression ignition engine: performance, efficiency and emissions / Slėginio uždegimo variklio energinių, efektyvumo ir deginių emisijos rodiklių tyrimas naudojant rapsų metilesterį ir vandenilį

The article presents the test results of the single cylinder CI engine with common rail injection system operating on biofuel – Rapeseed Methyl Ester with addition supply of hydrogen. The purpose of this investigation was to examine the influence of the hydrogen addition to the biofuel on combustion phases, engine performance, efficiency, and exhaust emissions. HES was changed within the range from 0 to 44%. Hydrogen was injected into the intake manifold, where it created homogeneous mixture with air. Tests were performed at both fixed and optimal injection timings at low, medium and nominal engine load. After analysis of the engine bench tests and simulation with AVL BOOST software, it was observed that lean hydrogen – RME mixture does not support the flame propagation and efficient combustion. While at the rich fuel mixture and with increasing hydrogen fraction, the combustion intensity concentrate at the beginning of the combustion process and shortened the ignition delay phase. AVL BOOST simulation performed within the wide range of HES (16–80%) revealed that combustion intensity moves to the beginning of combustion with increase of HES. Decrease of CO, CO2 and smoke opacity was observed with increase of hydrogen amounts to the engine. However, increase of the NO concentration in the engine exhaust gases was observed. Santrauka Straipsnyje pateikti tyrimo rezultatai, gauti atlikus bandymą vieno cilindro slėginio uždegimo variklyje su biodegalais – rapsų metilesterį (RME) ir vandenilį. Biodegalai įpurškiami akumuliatorine įpurškimo sistema „Common rail“. Šio tyrimo tikslas – ištirti, kaip vandenilis veikia biodegalų degimą, variklio veikimą, jo efektyvumą ir deginių susidarymą. Vandenilio energinė dalis degimo mišinyje buvo keičiama nuo 0 iki 44 %. Vandenilis buvo tiekiamas įsiurbimo fazės metu įsiurbimo kanalu į degimo kamerą, kurioje jis, susimaišęs su oru, sudaro homogeninį mišinį. Bandymai buvo atliekami nekeičiant įpurškimo kampo, nustačius optimalų įpurškimo kampą esant žemai, vidutinei ir nominaliai variklio apkrovai. Išnagrinėjus variklio bandymų rezultatus ir sumodeliavu AVL BOOST programa, buvo pastebėta, kad, esant liesam vandenilio ir RME mišiniui, liepsnos plitimas yra lėtas, mišinys dega neveiksmingai. Tačiau riebus degalų mišinys ir padidinta vandenilio energijos dalis užtikrina degimo intensyvumą degimo proceso pradžioje ir sutrumpina uždegimo gaišties trukmę. AVL BOOST modeliavimas, atliktas plačiu vandenilio energijos dalies diapazonu (16–80 %), patvirtino teiginį, kad degimas tampa intensyvesnis degimo pradžioje dėl padidinto vandenilio kiekio. Didinant vandenilio kiekį, buvo pastebėta, kad išmetamosiose dujose sumažėjo CO, CO2 ir kietųjų dalelių, tačiau padidėjo NO koncentracija. Reikšminiai žodžiai: vandenilis, RME, dyzelinas, slėginio uždegimo variklis, degimo procesas, deginių emisija, detonacija

Impact of Pyrolysis Oil Addition to Ethanol on Combustion in the Internal Combustion Spark Ignition Engine

Thermal processing (torrefaction, pyrolysis, and gasification), as a technology can provide environmentally friendly use of plastic waste. However, it faces a problem with respect to its by-products. Pyrolysis oil obtained using this technology is seen as a substance that is extremely harmful for living creatures and that needs to be neutralized. Due to its relatively high calorific value, it can be considered as a potential fuel for internal combustion spark-ignition engines. In order make the combustion process effective, pyrolysis oil is blended with ethanol, which is commonly used as a fuel for flexible fuel cars. This article presents results from combustion tests conducted on a single-cylinder research engine at full load working at 600 rpm at a compression ratio of 9.5:1, and an equivalence ratio of 1. The analysis showed improvements in combustion and engine performance. It was found that, due to the higher calorific value of the blend, the engine possessed a higher indicated mean effective pressure. It was also found that optimal spark timing for this ethanol-pyrolysis oil blend was improved at a crank angle of 2–3° at 600 rpm. In summary, ethanol-pyrolysis oil blends at a volumetric ratio of 3:1 (25% pyrolysis oil) can successfully substitute ethanol in spark-ignition engines, particularly for vehicles with flexible fuel type

In-cylinder combustion analysis of a SI engine fuelled with hydrogen enriched compressed natural gas (HCNG): engine performance, efficiency and emissions

The main objective of this study was to investigate the effect of hydrogen addition on spark ignition (SI) engine’s performance, thermal efficiency, and emission using variable composition hydrogen/CNG mixtures. The hydrogen was used in amounts of 0%, 20%, 40% by volume fraction at each engine speed and load. Experimental analysis was performed at engine speed of 1200 rpm, load of 120 Nm corresponding BMEP = 0.24 MPa, spark timing 26 CAD BTDC, and at engine speed of 2000 rpm, load of 350 Nm corresponding BMEP = 0.71 MPa, spark timing 22 CAD BTDC. The investigation results show that increasing amounts of hydrogen volume fraction contribute to shorten ignition delay time and decrease of the combustion duration, that also affect main combustion phase. The combustion duration analysis of mass fraction burned (MFB) was presented in the article. Decrease of CO2 in the exhaust gases was observed with increase of hydrogen amounts to the engine. However, nitrogen oxides (NOX) were found to increase with hydrogen addition if spark timing was not optimized according to hydrogen’s higher burning speed

Evaluating combustion, performance and emission characteristics of CI engine operating on diesel fuel enriched with HHO gas

Research of efficient and ecological parameters was carried out with compression ignition (CI) engine using diesel fuel and additionally supplied hydrogen and oxygen (HHO) gas mixture. HHO gas is produced by electrolysis when the water was dissociating. At constant engine‘s brake torque and with increasing HHO gas volumetric concentration in taken air up to 0.2%, engine efficient indicators varies marginally, however, with bigger HHO concentration these parameters becomes worse. HHO increases smokiness, but it decreases NOx concentration in exhaust gas. Numerical analysis of combustion process using AVL BOOST software lets to conclude that hydrogen, which is found in HHO gas, ignites faster than diesel fuel and air mixture. Hydrogen combustion before TDC makes a negative work and it changes diesel fuel combustion process – diesel ignition delay phase becomes shorter, kinetic (premixed) combustion phase intensity gets smaller

Combustion of RME – diesel and NExBTL – diesel blends with hydrogen in the compression ignition engine

The article presents the test results of the single cylinder compression ignition engine with common rail injection system operating on biofuels and conventional diesel blends with hydrogen. Two types of liquid fuels were tested: blend of the 7% Rapeseed Methyl Ester (RME) with conventional diesel fuel and Neste Pro Diesel – blend of the 15% Hydrotreated Vegetable Oil (HVO), produced by Neste Oil Corporation with conventional diesel fuel. The purpose of this investigation was to examine the influence of the hydrogen addition to biofuels and diesel blends on combustion phases, autoignition delay, engine performance efficiency and exhaust emissions. Hydrogen fraction was changed within the range from 0 to 43% by energy. Hydrogen was injected into the intake manifold, where it created homogeneous mixture with air. Tests were performed at both fixed and optimal injection timings at low, medium, and nominal engine load. After analysis of the engine bench tests and simulation with AVL BOOST software, it was observed that increasing hydrogen fraction shortened the fuel ignition delay phase and it affected the main combustion phase. Moreover, decrease of carbon monoxide (CO), carbon dioxide (CO2) and smoke opacity was observed with increase of hydrogen amounts to the engine. However, increase of the nitrogen oxide (NOx) concentration in the engine exhaust gases was observed