Use In Internal Combustion Engines Research Articles

Exploring Hydrogen-Enriched Fuels and the Promise of HCNG in Industrial Dual-Fuel Engines

This paper presents a theoretical analysis of the selected properties of HCNG fuel calculations and a literature review of the other fuels that allow the storage of ecologically produced hydrogen. Hydrogen has the most significant CO2 reduction potential of all known fuels. However, its transmission in pure form is still problematic, and its use as a component of fuels modified by it has now become an issue of interest for researchers. Many types of hydrogen-enriched fuels have been invented. However, this article will describe the reasons why HCNG may be the hydrogen-enriched fuel of the future and why internal combustion (IC) piston engines working on two types of fuel could be the future method of using it. CO2 emissions are currently a serious problem in protecting the Earth’s natural climate. However, secondarily, power grid stabilization with a large share of electricity production from renewable energy sources must be stabilized with very flexible sources—as flexible as multi-fuel IC engines. Their use is becoming an essential element of the electricity power systems of Western countries, and there is a chance to use fuels with zero or close to zero CO2 emissions, like e-fuels and HCNG. Dual-fuel engines have become an effective way of using these types of fuels efficiently; therefore, in this article, the parameters of hydrogen-enriched fuel selected in terms of relevance to the use of IC engines are considered. Inaccuracies found in the literature analysis are discussed, and the essential properties of HCNG and its advantages over other hydrogen-rich fuels are summarized in terms of its use in dual-fuel (DF) IC engines.

Lean ammonia-fueled engine operation enabled by hydrogen-assisted turbulent jet ignition

Anhydrous ammonia (NH3) use in internal combustion engines represents a zero-carbon energy solution that is fully sustainable if NH3 is generated renewably. An active hydrogen-fueled pre-chamber to induce turbulent jet ignition is investigated in this work as a means to enhance ignition energy and turbulent flame speed in an NH3 fueled engine. The strength of the turbulent jets, and thus their effectiveness in igniting the main-chamber and enhancing combustion, is highly dependent on pre-chamber equivalence ratio and hydrogen fraction. Local pre-chamber mixtures are varied in the present study by investigating a range of pre-mixed intake NH3-air equivalence ratios (ϕ = 0.5–1) under a consistent hydrogen direct injection strategy in the pre-chamber. Additionally, given the knock-resistance of NH3, multiple compression ratios were studied to investigate the impact on efficiency, emissions, and the combustion process. Results show a clear trade-off where leaner intake equivalence ratios enhance the reactivity of the pre-chamber (greater local hydrogen fraction and closer to stoichiometry) but reduce the reactivity of the main-chamber (lean and slow flame speed). Spark timing optimizes the trade-off under a fixed injection strategy; advancing spark provides more time for combustion to occur in the main-chamber but inhibits pre-chamber reactivity for a less energetic ignition of the main chamber. Optimal indicated thermal efficiency and minimum unburned NH3 and N2O emissions occur around 0.7–0.8 equivalence ratio for all compression ratios. Conversely, NOx is highest at these equivalence ratios but could theoretically be eliminated using selective catalytic reduction aftertreatment using the NH3 present in the exhaust.

Relationship between low-temperature oxidation activity and second-stage ignition delay: Experimental insights on n-pentanol / hydrogenated catalytic biodiesel blends

N-pentanol exhibits promising potential as a sustainable and eco-friendly biomass energy source. However, certain challenges such as ignition difficulty and unstable combustion exist. This study investigates the influence of low-temperature auto-ignition of n-pentanol/HCB (Hydrogenated Catalytic Biodiesel) blends on ignition and combustion characteristics and evaluates the correlation between low-temperature oxidation and second-stage ignition delay. Results show a linear positive correlation between the HCB content in n-pentanol and its low-temperature oxidation reactivity. The stronger the low-temperature oxidation activity of the blends, the shorter the second-stage ignition delay of blends. When the HCB content in blends is below 40 %, the low-temperature oxidation rate initially increases and then decreases. However, the low-temperature oxidation rate increases again when the HCB content exceeds 40 %. Moreover, the relationship between the initial CO2 generation rate and the HCB blending ratio follows an Exp exponential function under different critical compression ratios. Beyond 43.7 % HCB, an acceleration in the high-temperature combustion rate owing to an increase in the low-temperature oxidation rate again. In addition, the minimum ignition limit of n-pentanol/HCB blends was identified with 40 % HCB blends closely resembling diesel conditions and 50 % HCB blends showing a lower ignition limit, characterized by a critical temperature and pressure of 517.3 K and 8.66 bar, respectively. Furthermore, two distinct conditions for the minimum ignition boundary region of n-pentanol/HCB blends were defined, offering practical insights. In summary, a blend with a 50 % HCB ratio provides a promising solution for the low-temperature ignition and stable combustion of n-pentanol, addressing the challenges of simultaneous use in internal combustion engines.

Deterministic Simulation of Surface Textures for the Piston Ring/Cylinder Liner System in a Free Piston Linear Engine

The use of synthesis gas (SYNGAS) from waste gasification has been pointed out as a key strategy to help the energy transition. However, SYNGAS’ low calorific power is considered a difficult obstacle to its technological use in internal combustion engines. To overcome this, a novel free-piston linear motor has been proposed to pave the way for the use of SYNGAS in the mobility sector. Surface texturing has vast potential to reduce friction losses in this system. This study utilizes a deterministic numerical model to investigate the mixed lubrication performance of a textured piston ring/cylinder liner conjunction in a free piston engine. The model considers the simultaneous solution of the lubrication and asperity contact problems at the roughness scale, including texturing features on the cylinder surface. The numerical model employs the Reynolds equation with mass-conserving cavitation to calculate the inter-asperity fluid pressure. The rough contact model utilizes the Hertz theory for elastic contact to calculate the contact pressure at each asperity between the piston liner surface and the admitted smooth and rigid ring surface. Surface texturing demonstrated remarkable effectiveness, particularly in the hydrodynamic lubrication regime, with a maximum friction reduction of 38.5% observed for an area coverage of 50%. This was accompanied by a notable shift in the transition from the boundary to the mixed lubrication regime. The textured surfaces exhibited consistent efficiency in reducing fluid pressure and shear stress as the coverage of the textured areas increased. The incorporation of dimples on these surfaces played a crucial role by augmenting the lubricant storage capacity while concurrently reducing the real shear and contact areas. This study offers valuable insights into the nuanced friction-reducing mechanisms of surface textures, illuminating their influence on the coefficient of friction and the formation of lubricant films across various lubrication regimes.

Utilisation of Ethyl Levulinate as Diesel Fuel Additive

The world is going through a radical phase of energy conversion, due to both environmental and socio-economic factors, which will lead to a progressive transition from fossil to renewable energy sources. As regards the light land transport sector (cars), the abandonment of propulsion systems based on the use of internal combustion engines (ICEs) in favour of electrification seems the preferred solution. On the contrary, for heavy land (trucks and trains), marine and air transport sectors the path to follow is not yet clear.A possible alternative to fossil fuels is certainly represented by bio-fuels, which should allow a drastic reduction of CO2 emissions and, to a lesser extent, of CO and particulate matter. The use of bio-fuels does not involve a drastic change in the systems of distribution and use of energy, as the existing infrastructures can remain unchanged. In particular, second generation bio-fuels (obtained from non-food matrices) are attracting more and more attention and, among these ones, oxygenated alcohols obtained from residual lignocellulosic biomasses appear extremely promising for the use in diesel engine.The present study analyses the utilisation of ethyl levulinate (EL), a versatile second generation bio-fuel that can be used in Diesel/gasoline engines. EL can be conveniently obtained from the sustainable one-pot acid-catalyzed conversion of waste lignocellulosic feedstocks, employing bioethanol as the solvent/reagent.EL has been tested in a small DI Diesel engine, blended up to 25% by volume with a commercial Diesel fuel, without significative changes in engine performance, moderately increasing NOx and HC emissions but significantly lowering soot and CO emissions by more than 50%.

Valorization of Agricultural Polyolefin Plastic Waste in the Kingdom of Morocco through Thermal Pyrolysis: Influence of Thermal Parameters on Pyrolytic Oil Yields

This article focuses on exploring the recycling of agricultural plastic waste mixtures through the route of thermal cracking. In an experimental setting within a pilot-scale batch reactor, the impact of temperatures and heating rates on the yields obtained in the pyrolysis process have been meticulously examined. The temperatures of the pyrolysis process were varied between 360°C and 480°C, while the heating rates underwent changes, including 10, 15, and 30°C/min. The response parameters were the liquid, solid, and gas fractions. This research indicates that moderate temperatures and slower heating rates, resulting in extended reaction times, promote the generation of liquid fuel from pyrolysis. We achieved an optimal liquid fuel yield of 79% at 380°C, employing a temperature ramp of 10°C/min. Characterization of pyrolysis fuel resulting from the pyrolysis process revealed an extensive variety of hydrocarbons, requiring prior fractionation for optimal use in internal combustion engines. This step led to the separation into three distinct fractions: a light fraction (analogous to gasoline), accounting for 22.62% of the total weight, a middle fraction (similar to diesel), weighing 53.67% of the weight, and a heavy fraction (comparable to heavy diesel), totaling 23.71% of the weight. The light fraction presents an octane rating in line with conventional gasoline values, while the middle fraction meets the required cetane criteria for diesel.

Numerical Prediction on In-Cylinder Mixture Formation and Combustion Characteristics for SIDI Engine Fueled with Hydrogen: Effect of Injection Angle and Equivalence Ratio

Although their ease of transport, storage, and use makes hydrocarbon fuels dominant in commercial energy systems, the emission of harmful gases, including greenhouse gases, is a fatal disadvantage. Despite ongoing research to improve thermal efficiency and reduce the emissions of internal combustion engines using conventional hydrocarbon fuels, achieving net-zero carbon requires decarbonizing fuels rather than reducing the use of internal combustion engines. Hence, transitioning away from hydrocarbon fuels and evolving internal combustion engines into clean engines using carbon-free fuels, such as hydrogen, is necessary. This study designs a 2.0 L research engine and numerically analyzes its combustion characteristics and spray behavior by varying the spray angle and equivalence ratio. When comparing the turbulence kinetic energy at a 45-degree spray angle with that at 30 degrees and 60 degrees, on average, there was a difference of approximately 37.54 m2/s2 and 26.21 m2/s2, respectively. However, misfires occur in the lean condition. Although hydrogen has a wide flammability range, poor mixture formation under lean conditions can result in misfires. The 60-degree spray angle resulted in the highest combustion temperatures and pressures for all equivalence ratio conditions, consequently leading to the highest emissions of nitrogen oxides. Specifically, at a lambda value of 2.5, the 60-degree spray angle emitted approximately 29 ppm, 0 ppm, and 161 ppm of nitrogen oxides for each respective spray angle.

The application and prospect of electrification in transportation

Human technology has developed very rapidly in just a few hundred years, especially in the development of transportation and travel methods. From the very beginning, the emergence of the steam engine, to the widespread use of internal combustion engines based on fossil fuel energy, and now the popularity of electric motors. This development process not only shows the rapid development of human science and technology, but also shows people's efforts in terms of fast, convenient, rapid and energy-saving transportation. Especially in the combination of electricity and people's transportation modes: from the very beginning of electric locomotives to electric vehicles with low prices and low maintenance costs, electricity is more and more widely used in traffic life. This study will focus on the production of electricity and the drawbacks in the process of electricity production, and the mainstream use of electricity in transportation. Finally, the future of transportation electrification is prospected and considered appropriately.

Combined mixture process design approach for flexible fuel maps development of ternary blends operated gasoline engine

Alternate means of harnessing energy are currently being researched. However, not all demographics are in a position to switch over to these alternatives while complying with the change in existing infrastructure. The present study aspires to evaluate the effectiveness of ternary fuel blends in existing automotive engines to offer a more flexible mode of operation without demanding any modifications to the existing spark-ignition (SI) engine. It focuses on the compatibility between biofuels and pure gasoline as a flexi-fuel alternative in internal combustion engines (ICE) for improved combustion characteristics. Butanol and Lemon Peel Oil (LPO) are highly competitive renewable biofuels for use in internal combustion engines due to their many advantages. Empirical research is conducted on studying mixtures at different engine speeds and blend concentrations. Accordingly, a combined mixture process design model is developed by virtue of the Design of Experiments (DOEs). ANOVA or analysis of variance method is employed, in addition, to determine the influence of input parameters on output parameters. From the results, it is observed that utilizing pure gasoline or a blend with 90% gasoline produced the least amount of peak cylinder pressure (Pmax) alongside minimum levels of mean gas temperature (MGT), and cumulative heat release rate (CHRR). This indicated a lower efficiency of fuel combustion when using higher proportions of gasoline in the blend. Additionally, engine speed is found to have a significant influence over all the performance parameters where it exhibited an inverse relationship which showed that higher engine speed produced inferior results and vice versa. The desirability matrix yields the most optimal blend, displaying a substantial desirability score of 0.683 running on 50% gasoline, 20% n-butanol, and 30% LPO, at 1523.485 rpm. A comparison between the results of Pmax, CHRR, and MGT between pure gasoline and the optimal blend yields a performance enhancement of 16%, 0.5%, and 6.4%, respectively. Overall, from the research, both butanol and LPO meet the ascribed expectations and are observed to significantly enhance the different combustion parameters. These results can thus be further extrapolated to ascertain the partial replacement of straight gasoline in real-life scenarios with butanol and LPO.

SWOT analysis of electric transport and V2G implementation for power system sustainable development in the terms of Ukraine

An analysis was carried out to examine the prospects for the integration of smart charging technologies, such as Vehicle-to-Grid (V2G), into the power system in Ukraine. The country is experiencing a growing concern regarding greenhouse gas emissions. The transport sector in Ukraine is one of the most energy-intensive sectors of the economy and contributes significantly to environmental degradation. The use of internal combustion engines in transport also increases the country’s dependence on imported fuel due to the high demand for petroleum products. The integration of electric transport and smart charging technologies, particularly V2G, is seen as a critical solution with immense potential to mitigate climate change. V2G technology is becoming increasingly relevant as the world transitions towards a more sustainable energy future. V2G refers to the bi-directional flow of energy between electric vehicles (EVs) and the grid. With V2G, EVs can not only consume energy from the grid but also supply energy back to the grid during peak demand periods, helping to stabilize the grid and increase its resilience. Therefore, it is imperative to develop a stable policy to promote these technologies and compare the features of the policy of integrating electric vehicles and the energy system in Ukraine. A qualitative strategic planning methodology, Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis, was used to evaluate the diverse measures and initiatives related to electric transport development and infrastructure while integrating them into the power system. This analysis identified problems associated with the impact of EV charging on the power system, such as the inability to provide increased energy needs or limiting the EV charging infrastructure load. However, a high percentage of renewable energy sources, increased social awareness of climate change, and reduced prices of electric vehicles could provide the necessary opportunities for developing electric transport in Ukraine.

Catalysts for Air Pollution Control: Present and Future

Due to the continuous increase in both industrial activities and in the use of internal combustion engines, the quality of atmospheric air has progressively deteriorated, both in urban conglomerates and globally [...]

Tribological behavior of steel-based composite coatings produced by cold spray

This study investigates the microstructure, the mechanical properties, the topography and the tribological behavior of a composite coating obtained by cold spray, as a potential candidate for its use in internal combustion engines in the automotive sector. The coating consists of a 410 L matrix and M2 tool steel reinforcements. For comparison, a single component 410 L cold sprayed coating and a wire arc coating, used in some of today's car engines, are also studied. Post-spraying, the coatings underwent specific surface finishing. Their microstructure and topographies were observed. A lubricated reciprocating sliding test was performed, resulting in an exceptionally low friction coefficient and negligible wear, even in harsh conditions for the composite coating. The analyses revealed that the surface finish creates protuberances due to the presence of hard M2 particles, activating a series of mechanisms bringing to the stabilization of a tribofilm. This can be considered responsible for the exceptional tribological properties observed. This study proposes the application of surface textures with protuberances, in particular, their use in lubricated contacts in presence of fully formulated oils, and how cold spray is a suitable process to easily produce them.

Nanostructured Al2O3/graphene additive in bio-based lubricant: A novel approach to improve engine performance

Personal and industrial use of internal combustion engines (ICEs) is projected to continue until 2050 and beyond. Yet demands to reduce global dependence on petrochemicals and fossil fuel-derived lubricants are increasing and environmentally necessary. New strategies for maintaining and enhancing ICE performance by reducing friction, wear, fuel consumption, and exhaust emissions will reduce the depletion of mineral and fossil fuel reserves and environmental pollution. This paper reports the tribological enhancement of nano-bio lubricants formulated using 2D nanocomposites of Al2O3/graphene as novel additives in coconut oil, whose performance as a lubricant compares favorably with the mineral-based engine oil 15W40. Structural, compositional, and morphological characterization of the Al2O3/graphene nanocomposite revealed an ultra-fine particle size (< 10 nm) with spherical/laminar morphology and a rich sp2 domain, exhibiting a consistent colloidal stability when formulated as nanofluid. Through the use of various characterization techniques, including friction and wear analysis we gained valuable insight into the tribological mechanism. Our optimization of this 2D tribological system using coconut oil formulation resulted significant reductions in the coefficient of friction (28 %), specific fuel consumption (8 %), and exhaust pollutant emissions (CO, SO2, and NOx). This work demonstrates the benefits of using nano-bio lubricant formulated using coconut oil and 2D-based hybrids as base stock and additives, delivering solutions to global challenges such as improving fuel consumption while reducing environmental pollution; solutions that can be transferred to other areas where lubricants are a necessity.

Evaluation and extension of ignition delay correlations for dual-fuel operation with hydrogen or methanol in a medium speed single cylinder engine

Hydrogen (H2) and methanol (MeOH) are promising fuels for sustainable transport, owing to their ideal properties for use in internal combustion engines: CO2 neutral (when produced renewably), ultralow emissions, and high efficiencies. The dual-fuel (DF) technology where diesel is used as a pilot to ignite port fuel injected H2 or MeOH is of particular interest for retrofitting existing diesel engines (DE). Although some experimental work has been conducted on high-speed DE, there has been limited numerical investigation in this area. Therefore this work focuses on medium speed large bore engines and on the ignition delay (ID) timing of the diesel pilot, a crucial parameter to well predict numerically as it denotes the start of heat release. Experiments were carried out using H2 and MeOH in DF on the same single cylinder engine. The measured IDs are reported and visualize the difference of the effect of both fuels. Next, diesel ID correlations are evaluated on their predictive capabilities in DF. They fail however to predict the increasing ID from the inhibition effect of MeOH. Therefore, new ID correlations were developed for DF with H2 and MeOH, emphasizing the importance of additional terms such as the methanol equivalence ratio to describe this inhibition effect. Finally, the new correlations were compared with correlations for DF with natural gas to explore similarities and differences.

The Effect of Avgas Fuel Injection Pressure on Injection Temperature

The use of internal combustion engines has become common in transportation, especially in aviation, one of which is the Cessna training aircraft with a piston engine. The effect of fuel injection pressure on injection temperature has been a focus of many studies because it has the potential to improve combustion efficiency. Increasing the fuel injection pressure in avgas causes an increase in injection temperature and also enhances temperature stability during injection.

Recent Progress on Combustion Characteristics of Ammonia-Based Fuel Blends and Their Potential in Internal Combustion Engines

Review Recent Progress on Combustion Characteristics of Ammonia-Based Fuel Blends and Their Potential in Internal Combustion Engines Denghao Zhu , and Bo Shu * Department of Physical Chemistry, Physikalisch-Technische Bundesanstalt, Bundesallee 100, DE-38116 Braunschweig, Germany * Correspondence: bo.shu@ptb.de Received: 21 November 2022 Accepted: 22 December 2022 Published: 18 January 2023 Abstract: Ammonia has recently attracted numerous attentions from researchers and policy makers as promising energy and hydrogen carrier for mitigating the carbon footprints in the energy sector. The mature infrastructure for the production, storage, and transportation of ammonia allows a quick role of ammonia in energy systems. By applying green hydrogen and renewable energies, green ammonia can be produced, which makes ammonia even more attractive. Prior to the commercial use of ammonia for large-scale energy systems, e.g., internal combustion engines and stationary gas turbines, a fundamental understanding of the ignition and combustion behaviors of ammonia is essential. In the past decades, a lot of studies on ammonia combustion have been published. Those studies covered broad topics including experimental and numerical investigations which were either fundamental or practical oriented. To continuously follow state-of-the-art and to provide a brief overview of the most recent research on ammonia combustion so that others can easily identify the most relevant work, this review summarizes the recent progress on combustion characteristics of ammonia and ammonia fuel blends as well as their potential use in internal combustion engines. Combining the advantages and drawbacks identified in both fundamental and practical studies, a clearer road map for ammonia application is given.

A review on performance and emission characteristics of a diesel engine fueled with gaseous &amp; liquid fuels

There is a growing need for alternative fuels because of growing concerns about the environmental harm caused by the usage of fossil fuels. In an effort to reduce energy use, a number of research have been conducted. It is widely accepted that biofuels derived from biomass are a viable alternative to petroleum-based fuels. Biogas, a biomass-derived fuel, is suitable for use in internal combustion engines due to its superior air mixing ability and clean burning qualities. In comparison to other secondary fuels, biogas is less costly and emits fewer pollutants because of anaerobic digestion of a variety of organic materials like kitchen trash, agricultural waste, municipal solid waste and so on, being the process through which it is produced. As part of this investigation, biogas usage is reviewed in case of dual fuel engines. Diesel & biogas dual fuel diesel engines have been proven to emit less hydrocarbons (HC), smoke and particulate matter than conventional diesel engines. A complete literature study is conducted for establishing emission, combustion & performance characteristics for biogas combustion for CI engines.

"IMPROVING THE DEVELOPMENT OF A PISTON RING BASED ON SOLID LUBRICANT"

"In the article, in relation to the similar conditions of use of internal combustion engines with a crank mechanism and the main indicators of a piston seal having the same design parameters (in particular, cylinder diameter, piston stroke), a comparative assessment of the indicators characterizing their duty cycle and indicator parameters of each of the engines is made (in particular, by the magnitude of the indicator tangential and circumferential force, torque and indicator power). The authors carried out work on the use of sealing in the form of rings with a contact surface based on a solid antifriction material – graphite. It is concluded that, in relation to similar conditions of use, the indicator torques formed during the working cycle of these machines are not equal in magnitude. The indicator torque of the crank mechanism of the engine exceeds the corresponding torque of the internal combustion engine. This conclusion also applies to the ratio of the indicator capacities of the considered thermal machines. Keywords: Internal combustion engine, crank mechanism, working fluid, piston, piston ring, grease."

Various control methods of permanent magnet synchronous motor drives in electric vehicle: a technical review

Day by day use of internal combustion engines (ICE) compared to electric vehicles (EV) is deteriorating because mainly of pollution and their less fuel availability. In the present scenario, an electric vehicle plays a major role in place of an ICE vehicle. So that performance of EV can be improved by proper selection of electric motor. Initially, EV prefers induction motors for traction purposes, but complexity in controlling induction motor, permanent magnet synchronous motor (PMSM) presently used in EV by most of the electric vehicle manufacturers due to its advantages. This paper reviews on various control methods for PMSM used in EV. Various control methods are being used for EV applications. Initially, conventional direct torque control (DTC) technique being used in controlling electric motors but it has a drawback of high torque and flux ripples. Hence, intelligent controllers are predominantly using in controlling PMSM drives.

Optimal carbon-electricity trade-offs through the virtual power plant concept

To ameliorate the increased challenges relating to renewable energy sources set by European Union targets for the 2020, 2030 and 2050 paradigms, in this work a carbon-electricity model is proposed by making use of a virtual power plant mechanism. The radical configuration is arranged for the islanded power system of Cyprus, by making use of internal combustion engines, steam generators and domestic wind, photovoltaic and biomass units. Using an algorithm relied on mixed-integer linear programming, clean resources integration can be enhanced in a cost-effective manner in terms of total production and emission cost. Based on actual data with respect to load demand and power generation, the proposed concept offers optimal carbon-electricity trade-offs in the presence of storage. Specifically, the annual amount of carbon-dioxide emissions decreases by almost 74,000tn increasing the renewables share from 25.73 to 64.33% at the virtual power plant level. The released emissions are completely eliminated by making use of hydrogen derived by renewable hydrogen pathways in 100% renewable systems. The incomes of the assessed scenarios towards 2050 paradigm of de-carbonization are 81.360 M€ and 112.148 M€ for the respective life-cycle analysis without and with regenerative fuel-cell storage facility. As for future directions to research, a more comprehensive carbon-trading system is indicated to consolidate other Greenhouse gas emissions, including carbon oxide (CO), methane (CH4), nitrogen dioxide (NO2) and sulfur dioxide (SO2).