Influences of hydrogen and various gas fuel addition to different liquid fuels on the performance characteristics of a spark ignition engine

Highlights

• Performance simulation is performed for different mixtures of gas-liquid fuels.

• Effects of different fuel mixtures on performance and NO are investigated.

• Performance and NO are noticeably affected by fuel kinds and ratios.

Abstract

This study reports the impacts of dual fuel mixtures on the theoretical performance characteristics of a spark ignition engine (SIE). The effects of addition of liquefied hydrogen, methane, butane, propane (additive fuels) into gasoline, iso-octane, benzene, toluene, hexane, ethanol and methanol fuels (primary fuels) on the variation of power, indicated mean effective pressure (IMEP), thermal efficiency, exergy efficiency, were examined by using a combustion model. The fuel additives were ranged from 10 to 50% by mass. The results exhibited that the ratios of hydrogen, methane, butane, propane noticeably affect the performance of the engine. The maximum increase ratio of power is 82.59% with 50% of toluene ratio and its maximum decrease ratio is 10.84% with 50% of methanol ratio in hydrogen mixtures. The maximum increase ratio of thermal efficiency and exergy efficiency are observed as 26.75% and 32.23% with the combustion of benzene-hydrogen mixtures. The maximum decrease ratio of thermal efficiency is 29.71% with the combustion of 50% of methanol ratio and it is 21.95% for the exergy efficieny with the combustion of 50% of ethanol ratio in hydrogen mixtures. The power, IMEP, thermal efficiency and exergy efficiency of primary fuels demonstrate different variation characteristics with respect to type and ratio of additive fuels.

Introduction

In the literature, many studies were performed on the SI engine fuelled with different fuel blends to show their economical and ecological influences and to increase thermal efficiency and decrease emission formations. Du et al. [1] conducted an empirical study on emission outputs and economy of the fuels of a compression ignition engine run on diesel-gasoline mixtures. Rodríguez-Antón et al. [2] surveyed the impacts of the ethyl-tert-butyl-ether and ethanol on physical specifications of gasoline fuel. Sun et al. [3] carried out a theoretical examination by using detailed chemical kinetic model to reveal the exergetic losses of a spark ignition engine run with fuel composed of toluene, iso-octane, 2-pentene, n-heptane. Elfasakhany [4] examined the influences of binary-ternary mixtures of gasoline-methanol-ethanol on the emission output and performance properties of SIEs. Kukkadapu et al. [5] determined ignition delay times of blends of toluene, iso-octane and n-heptane fuels. Cai and Pitsch [6] proposed a novel combustion mechanism for iso-octane blends with n-heptane. Wang et al. [7] examined the emission outputs and combustion specifications of 3 fuels which have low octane like naphtha, blends of gasoline-diesel and gasoline-n-heptane. Ahmed et al. [8] developed a novel numerical method to formulate gasoline surrogates. Wu et al. [9] proposed a simulation to examine the impact of mechanism of spray combustion for diesel blends with gasoline. Dryer [10] proposed theoretical models for chemical kinetics and emission specifications of different fuel types such as aromatics and olefins. Fu et al. [11] presented a new model to enhance the performance properties of an engine run on liquefied methane depending on the variation of compression ratio. It was reported that torque enhanced and BSFC inclined by optimizing the engine conditions. Aleiferis et al. [12] examined the specifications of combustion and flame propagation of different fuels in an SIE. Sileghem et al. [13] determined the velocity of laminar burning for heptane, toluene, gasoline and isooctane at variable temperature and equivalence ratio. Mansfield et al. [14] performed various empirical and theoretical works to investigate the ignition specifications of iso-octane blends. Baloo et al. [15] analyzed flame instabilities of the methane mixtures with isooctane. Javed et al. [16] defined the oxidation specifications of various isooctane-heptane-gasoline blends based on detailed kinetic mechanism and empirical tests. Járvás et al. [17] proposed a new model for droplet evaporation of gasoline-ethanol mixtures by using CFD modelling. Wang et al. [18] empirically conducted a work to examine the effects of high compression ratios on the knock suppression and thermal efficiency for an SIE operated with alcohol blends with gasoline. Chen and Zhang [19] investigated the impact of thermo-fluid specifications on the spray properties of a new gasoline injector with various fuel types including ethanol, n-pentane, iso-octane and gasoline. Pereira et al. [20] reported a novel and easy strategy for the simultaneous description of methanol and ethanol in fuel blends. Avila et al. [21] developed a high-performance liquid chromatography method refractive-index detection to quantify ethanol ratio in gasoline fuel. Chen et al. [22] studied five gasoline-ethanol mixtured fuels such as Haltermann CARB LEV III E10 gasoline and 7%, 14%, 23% 36% ethanol by vol. Xu et al. [23] analyzed the combustion strategy of diesel-gasoline mixtures in a dual-fuel engine. The experimental results demonstrated that specific fuel consumption, soot and NOx minimized with the increasing of gasoline. Stähelin et al. [24] used coconut shell based activated carbon as adsorbent for removal of toluene and benzene from synthetic automotive gasoline. Singh et al. [25] reported that an engine fuelled with natural gas yields lower CO₂ compared to an engine fuelled with other liquid fuels. Lemaire et al. [26] analyzed the emission and performance of an SIE fuelled with mixtures of gasoline with 5 different fuel kinds such as methyl propionate, ethyl alcohol, butanone, butyl alcohol and butanal under homogeneous injection condition in proportions of 10, 20 and 40 vol%. Song et al. [27] proposed a modifying mechanism containing 103 species and 201 reactions for simulating ignition delay times with pressure and temperature of a supercritical gasoline. Chen et al. [28] examined formation of the spray mixture of gasoline-ethanol mixtures in a constant volume vessel (direct injection SI engine). Silva et al. [29] analyzed the influences of ethanol ratio on the research octane number (RON) of a four-component gasoline surrogate composed of n-heptane, toluene, iso-octane and iso-butylene. Wang et al. [30] examined the impacts of octane sensitivity and chemical structure of methanol on engine knocking suppression and converted to an effective octane index parameter to determine the anti-knocking specifications of a gasoline-type fuel. Shi et al. [31] conducted empirical and simulation studies to analyze the impacts of injection angle and hydrogen concentration on the combustion of a Wankel engine fuelled with gasoline as main fuel. Lim et al. [32] examined the effects of mixture of gasoline with oxygenated fuels like ethanol, ethyl and methyl tertiary-butyl ether on the pollutant emission outputs of gasoline vehicles. They reported that HC and CO emissions diminished with increasing percentage of additive fuels. Badra et al. [33] measured the octane numbers (ON) of ethanol mixtures with five surrogates of gasoline fuel such as hexene, n-pentane, cyclopentane, trimethylbenzene and iso-pentane. Al-Esawi et al. [34] examined the evaporation and combustion properties gasoline-ethanol blends. Vallinayagam et al. [35] analyzed the emissions and performance characteristics of terpineol-gasoline blends used in an SI engine. They compared the results of terpineol-gasoline blends and pure gasoline fuel. Sakthivel et al. [36] compared combustion, performance and emission formation characteristics of pure gasoline and ethanol-gasoline blends. HC and CO diminished, however, NOx raised with the increasing ratio of ethanol in the blends. Ji et al. [37] investigated the performance of an SI engine fuelled with gasoline-hydrogen mixtures. Qian et al. [38] carried out a series of works on direct injection of gasoline surrogates and port injection of ethanol by using an SIE operated on dual fuels. Sarathy et al. [39] presented a comprehensive review study to better understand combustion characteristics, physical and chemical kinetic specifications of gasoline and its surrogates like iso-butane, n-butane, n-pentane, 2,2-dimethylpropane, 2-methylbutane, n-hexane, n-heptane, heptane isomers, 2-methylhexane, n-octane, benzene, toluene, xylene, ethylbenzene, cyclopentane, cyclohexane, methylcyclohexane, ethylcyclohexane, di-isobutylene. Akansu et al. [40] examined engine performance, combustion and emissions of an SI engine operated on hydrogen-ethanol-gasoline mixtures. Su et al. [41] empirically investigated combustion specifications of a rotary engine operated on gasoline-hydrogen dual-fuel under different operating conditions. Yilmaz and Tastan [42] examined the influences of hydrogen addition into an SI engine operated with gasoline-methanol mixtures on the cylinder pressure, brake thermal efficiency, brake specific fuel consumption and pollutant emissions. Yang and Ji [43] studied on the performance of rotary engines operated on hydrogen-gasoline and hydrogen-butanol at 1 of equivalence ratio. The results indicated that hydrogen addition provided performance improvement for both gasoline and butanol fuelled engines. Acar and Dincer [44] investigated the energetic and exergetic performances of an integrated multigeneration system consisting of electrolyzer, thermal power plant; and methanol production reactor which produces methanol and hydrogen. They reported that the proposed multigeneration system has 68% of energy and 47% of exergy efficiencies. Ozturk and Dincer [45] proposed a new integrated system composed of geothermal-based power and hydrogen production and mixing of hydrogen with natural gas in Denizli, Turkey. It was reported that the system has 46.8% of energy efficiency and 77.9% of exergy efficiency. Ozturk and Dincer [46] developed a natural gas and hydrogen mixing system and they applied this system to a residential area. The results indicated that carbon emissions decreased with increasing hydrogen ratio in the mixture. The maximum energy and exergy efficiencies have been found as 67.3% and 53.2%. Manigandan et al. [47] examined the impacts of TiO₂ and hydrogen addition into a gasoline engine at the different ignition pressure, ignition timing and exhaust gas recirculation (EGR) ratios. Ilhak et al. [48] presented an experimental study to investigate performance and emissions characteristics of an SIE fuelled with acetylene/gasoline mixtures.

In the literature, there are not any in-depth studies investigating the impacts of the addition of liquefied hydrogen, methane, butane, propane into liquid toluene, isooctane, hexane, gasoline, benzene, ethanol and methanol altogether on the power, mean effective pressure, thermal efficiency and exergy efficiency of an SIE at one of the equivalence ratio (stoichiometric condition). Thus, this work has a remarkable originality for contributing to the research field.