Port Injection Research Articles

Effect of natural gas direct injection (NGDI) on the performance and knock behavior of an SI engine

The unique properties of natural gas (NG), including high availability and lower cost compared with other fossil fuels, make it attractive in internal combustion engine (ICE) application. NG is composed mainly of methane and has greater knock resistance than gasoline, enabling higher compression ratios (CR). In contrast with the distinctive advantages, the NG fueled engines suffer from lower power and torque outputs. To address the subject, this study proposes an approach employing NG direct injection (NGDI) strategy (with higher volumetric efficiency unlike port injection), enabling a higher CR irrespective of knock limit. This work applies reactive computational fluid dynamics (CFD) to investigate spark ignited co-combustion of direct-injected NG with port-admitted gasoline. The results are validated against experimental data. In all simulated cases, the equivalence ratio (i.e., ∅ = 1) and the total input energy are kept constant. Engine performance is evaluated for three CRs (10.5, 11.5, and 12.5:1), five proportion of CNG (RCNG) and at part- and full-load conditions at an engine speed of 1500 rpm. Results indicated that while running RCNG = 100 % with a CR of 10.5:1, carbon monoxide (CO) and carbon dioxide (CO2) emissions were decreased by 29.3 % and 23.5 % respectively, compared to RCNG = 0 %. The corresponding emission reduction at CR = 11.5:1 was 27.1 % and 24 %; at CR = 12.5:1 they were 29.6 % and 23.5 % respectively. At each CR, the knock intensity at full load fell significantly as the percentage of NG increased. At a CR of 12.5:1, ringing intensity (RI) at full load decreased by 88.6 % when using RCNG = 100 %, instead of RCNG = 0 %. Under the same conditions, RCNG = 25 % cut RI by 56 %.

A comparative assessment of performance, combustion, and emissions of a gasoline port and direct injection camless engine

AbstractThe lower part‐load efficiency of the spark‐ignition (SI) engine is because of the higher pumping loss during the gas exchange process. In this study, the part‐load efficiency of a port fuel injection (PFI) and gasoline direct injection (GDI) camless engines were investigated. An in‐house developed electro‐pneumatic variable valve actuation (VVA) system controls the camless engine's intake valve events. The effect of un‐throttled operation with early intake valve closings (EIVC) on performance, combustion, and emissions was analyzed. The IVC timing for GDI camless engine was found to be lower (2°–7° crank angle) than the PFI camless engine for all operating conditions due to the in‐cylinder charge cooling. Hence, the pumping mean effective pressure (PMEP) for GDI camless engine was reduced, and brake specific fuel consumption (BSFC) was improved (maximum 2.1%) compared to the PFI camless engine. The THC and CO emissions were higher for GDI camless engine due to the relatively in‐homogeneous mixture formation, whereas the NOx emission was lower for all operating conditions.

The effects of variable excess air ratio and ignition timing on the performance and exhaust emissions in a direct injection Hydrogen-CNG fueled engine

This study investigates a direct injection (DI) engine fueled with compressed natural gas (CNG) enrichment with hydrogen blend (HCNG) in counter from the conversion of the port injection gasoline engine. The intention of the investigation was to examine the performance and exhaust gases from the effect of excess air ratio and timing angle changes in consequence of hydrogen increment to natural gas in comparison to gasoline engine performance and exhaust gases as a single fuel. The compression ratio was set at 14:1 with varying load at 3000 rpm, and the ignition timing was applied at −17, −19, −21, and −34°bTDC at WOT, and the amount of hydrogen enrichment to natural gas was applied at 10%, 20%, 30%, and 40%. The conditions on torque, power, heat release rate, brake specific fuel consumption, CO, and NOx were studied. Results showed that the power and torque increased by 8% with increasing the hydrogen content to 40% in fuel composition and advancing ignition timing and heat release rate as well as decreasing λ from 1.4 to 1.2 relative to the stoichiometric state. Also, the specific fuel consumption decreased by 18.5% in the optimal condition.

Multiple injection strategies with high water port injection rates for enhancing performance and emissions in a boosted SI engine

Water injection has been proven both to reduce emissions of nitrogen oxides and to improve fuel conversion efficiency via knock limit extension in turbocharged spark ignition (SI) engines. However, water injection still has several obstacles to maximize the benefits, such as an increase of particulate matter and unburned hydrocarbon emissions. In order to ameliorate the problems with a sufficient amount of water injection (water to fuel mass ratio > 0.5), this study adopted multiple fuel injection strategies, which inject fuel multiple times in a cycle. A boosted single-cylinder research engine equipped with a water port injector and a piezoelectric gasoline direct injector was utilized for this study over a range of water to fuel mass ratio (up to 1.0) and multiple fuel injection (single vs. triple) conditions. The results show that the drawbacks of water injection including combustion instability, unburned hydrocarbon, and particulate emissions were significantly improved with multiple fuel injections, and the relative thermal efficiency improvement and nitrogen oxide emission reduction were maximized up to 3.9% and 52.7%, respectively, with the combined injection strategy. In addition, the increased carbon monoxide emissions typical with multiple fuel injections were largely mitigated by the water injection strategy.

Comparison of ethanol/diesel fuel dual direct injection (DI2) strategy with reactivity controlled compression ignition (RCCI) in a diesel research engine

The dual direct injection (DI2) strategy is expected to cover the advantages of conventional diesel (CDI) mode while avoiding deficiencies of reactivity controlled compression ignition (RCCI) strategy such as high amount of incomplete combustion emissions and extremely high rate of pressure rise. Therefore, the present study focused on the comparison of combustion characteristics of these combustion modes in a diesel research engine, which was firstly operated under CDI mode at varying loadings and a constant speed of 2400 rpm to establish the reference data. Then, a low pressure port fuel injection (PFI) and high pressure gasoline direct injection (GDI) systems were activated to run on RCCI and DI2 modes, respectively, whereas test engine was already equipped with a common-rail direct injection (CRDI) system for conventional diesel fuel injection. Results showed that both direct and port injection methods increased the in-cylinder pressure (up to 9%) compared to conventional mode. In RCCI combustion, the rate of pressure rise increased more than direct injection and conventional mode. CDI exhibited higher thermal efficiency than RCCI and DI2 modes while both advanced modes were successful in reducing NOx and Smoke Opacity. However, significantly higher CO and unburned HC emissions were observed with both advanced modes in comparison to conventional one. Both CO and unburned HC emissions were reduced by direct injection of ethanol (DI2 strategy) at the rates of 16% and 35% compared with port injection method of RCCI strategy. This is an important finding of this study, which shows that the DI2 strategy has a potential to address a deficiency of RCCI and will bring it closer to its application to practical engines.

Study on Combustion and Emissions of a Combined Injection Spark Ignition Engine with Natural Gas Direct Injection Plus Ethanol Port Injection under Lean-Burn Conditions.

Conventional ethanol spark ignition (SI) engines have poor fuel atomization and mixture formation. The objective of this paper is to improve the combustion and emission performance of ethanol SI engines under lean-burn conditions through the dual-injection mode with ethanol port injection and compressed natural gas (CNG) direct injection (CDI+EPI). This paper studies the engine performance at 1500 rpm under five CNG direct injection ratios (CDIr) and five excess air ratios (λ). The results show that as the CDIr increases under lean-burn conditions, the following occurs: the minimum advance for best torque (MBT), the coefficient of variation (CoVIMEP), and CO and HC emissions decrease; the crankshaft rotation or time with cumulative heat release rate ranging from 10% to 90% (CA 10–90) and NOx emissions first decrease and then increase; and torque, peak in-cylinder pressure (Pmax), and the λ limit first increase and then decrease. The larger the CDIr is, the less influence λ has on the MBT. When CDIr = 15%, the CoVIMEP can be effectively reduced, the engine can still work stably in all lean-burn conditions, and the λ limit will reach the maximum value of 1.73, 19.31% higher than that of the original engine (CDIr = 0). When λ = 1.1, CO emissions decrease the most and HC emissions decrease the least. At this time, CO and HC emissions decrease by 1.56 vol % and 30 ppm, respectively, on average for every 0.1 decrease in λ. For CA 10–90, torque, and Pmax, λ = 1.1, 15% CDI, and 85% EPI is the optimal combination under lean-burn conditions. When CDIr ≥ 15%, NOx emissions are at an ideal level. Under lean-burn conditions, direct-injection CNG can form a good stratified natural gas/ethanol mixture in the cylinder, effectively improving the engine’s power and stability and reducing emissions. The λ = 1.1, 15% CDI, 85% EPI combination provides a cutting-edge and outstanding solution for a natural gas/ethanol combined injection SI engine.

Effects of hydrogen injection strategy on the hydrogen mixture distribution and combustion of a gasoline/hydrogen SI engine under lean burn condition

Hydrogen is a carbon free energy carrier with high diffusivity and reactivity, it has been proved to be a kind of suitable blending fuel of spark ignition (SI) engine to achieve better efficiency and emissions. Hydrogen injection strategy affects the engine performance obviously. To optimize the combustion and emissions, a comparative study on the effects of the hydrogen injection strategy on the hydrogen mixture distribution, combustion and emission was investigated at a SI engine with gasoline intake port injection and four hydrogen injection strategies, hydrogen direct injection (HDI) with stratified hydrogen mixture distribution (SHMD), hydrogen intake port injection with premixed hydrogen mixture distribution (PHMD), split hydrogen direct injection (SHDI) with partially premixed hydrogen mixture distribution (PPHMD) and no hydrogen addition. Results showed that different hydrogen injection strategy formed different kinds of hydrogen mixture distribution (HMD). The ignition and combustion rate played an important role on engine efficiency. Since the SHDI could use two hydrogen injection to organize the HMD, the ignition and combustion rate with the PPHMD was the fastest. With the PPHMD, the brake thermal efficiency of the engine was the highest and the emissions were slight more than that with the PHMD. PHMD achieve the optimum emission performance by its homogeneous hydrogen. The engine combustion and emission performance can be optimized by adjusting the hydrogen injection strategy.

Combustion control of DME HCCI using charge dilution and spark assistance.

To realize the potential of DME for clean combustion, fueling control is essential. In this research, the challenges, advantages, and applicability of high-pressure direct injection and low-pressure port injection are reviewed and evaluated, especially in relevance to HCCI combustion. In this study, emphasis is given to the applicable ranges of low-pressure fuel delivery in relevance to load, air-fuel ratio, and inert gas dilution, for realizing HCCI combustion. The strategy of high-pressure direct injection is advantageous for combustion phasing control, but the fuel handling is challenging because of the high vapor pressure of DME fuel. The strategy of port fuel injection is prone to early combustion and, consequently, tends to produce excessive pressure rise rates in the combustion chamber. This challenge is escalated at higher engine loads, making homogenous charge compression ignition difficult to achieve. In this paper, the load extension of DME-fueled HCCI combustion was explored. First, the impact of dilution on the combustion characteristics of DME HCCI was studied under lean and CO2 diluted conditions. Under the present empirical setups, results show that the lean-burn strategy has limited capability of combustion phasing control, especially when the engine load is above 5 bar IMEP. The CO2 dilution strategy can significantly retard the combustion phasing until the fulfillment of combustion becomes unstable. It was found that spark assistance is advantageous for combustion control. With an effective application of excess air, intake CO2 dilution and spark assistance, an engine load of 8 bar IMEP was reached with appropriate combustion phasing, with ultra-low NOx emissions.

Numerical investigation of hydrogen enriched natural gas effects on different characteristics of a SI engine with modified injection mechanism from port to direct injection

This research investigates two main stages of conversion of port fuel-injected engine to direct-injection. The firs one is the modification of Injection mechanism of CNG direct-injection engine. The second stage is the investigation of Hydrogen effects as an alternative gaseous additive on CNG. The Results were measured at different injection pressures (15, 20, and 25 bar) and various hydrogen enrichment as additive fuel to CNG. At the first stage, results show that compared to the Gasoline port injection system, a CNG direct-injection engine can decrease CO2 emission up to 59.5% and increase NOx emission up to 56.9%. In the second stage, when Hydrogen being used in the fuel mixture, and an increase in the injection pressure (from 15 to 25 bar) in the DI engine along with 30%HCNG applies, the amounts of engine power and torque enhanced about 5.92% and 6.55%, respectively. Also, fuel conversion efficiency increased by up to 6.87% with 25 bar of injection pressure compared to conventional system. Emission reduction up to 32.5% for CO observed in case of using 40%HCNG relative to pure CNG. NOx emission had a reverse correlation with Hydrogen concentration, it increased about 22.5% while using 40% of Hydrogen in volumetric blend HCNG.

Operating parameters optimization for lower emissions in diesel engine with PCCI-DI mode using Taguchi and grey relational analysis

Searching for ultra-low emission engines particularly for automotive applications is still ongoing. Even though LTC combustion mode results a prominent advantages in terms of reducing both NOx and PM and also lowering the consumption of fuel, it mainly faces with the challenge of excess emissions of HC and CO. This study aimed to optimize the operating control factors for low emissions in PCCI-DI engine under LTC mode. Parameters include injection timing, EGR level, dieseline ratio and engine load. Computation of analyzing the grey relation with hybrid of Taguchi was applied. In designing of experiments and conducting tests Taguchi's L9 matrix was applied. Air-blast of methanol intake port supply and dieseline application instead of diesel was implemented aiming emission reductions. Optimum combinations were found using GRA and ANOVA. Following the optimization work; advanced injection timing of 25o before TDC, 25% EGR, dieseline 90:10 in % and load 75 % (A2B1C3D3) was found optimal combination level for the proposed aim of emission reductions. Key findings of the results following the experiment conducted using this optimal combination includes; reduction of 68.02% NOx and 62.37% in smoke comparing with the base-line conventional diesel combustion mode. Rankings and ANOVA indicated another findings that injection timing being most influential with a contribution of 69.35% followed by load, dieseline ratio and EGR level respectively. This study confirmed dieseline direct injection with methanol port injection is capable of reducing emissions and better NOx with HC and CO trade-offs in PCCI-DI engines.

Numerical investigation of the combined effect of injection angle and injection pressure in a gasoline direct injection rotary engine

This study aims to explore the combined effect of injection angle and injection pressure in a gasoline direct injection rotary engine through numerical simulation. Simulation results show that with the increase of injection angle, the fuel impinging position changes from the rotor recess to the middle cylinder block. At the same injection angle, the fuel enrichment area turns to the front of the combustion chamber with the increase of injection pressure. The lower injection angle is helpful to obtain a more uniform fuel distribution. Especially, with increase of injection pressure, the in-cylinder inhomogeneity index presents a downward trend. Under different injection pressures, the flame propagation period of the 0° injection angle is the most stable. The stable flame development and propagation processes make it easy to obtain higher indicated thermal efficiency. The highest indicated thermal efficiency is obtained at 0° injection angle and 15 MPa injection pressure, which is up to 24.99%. Moreover, compared with the fuel intake port injection, part of direct injection strategies help to get higher in-cylinder peak pressure. The higher in-cylinder temperature promotes the formation of NOx, but the organization of the in-cylinder fuel distribution can effectively reduce CO and Soot emissions.

Experimental investigations of methanol fumigation via port fuel injection in preheated intake air in a single cylinder dual-fuel diesel engine

Primary alcohols are emerging as promising alternative fuels for diesel engines. Dual-fuel engine operation with port injection (fumigation) of methanol has emerged as a novel concept for simultaneous reduction of particulate matter (PM) and oxides of nitrogen (NOx). This experimental study investigates the effect of intake air preheating on methanol-fumigated agricultural diesel engines. Methanol premixing ratio was kept constant at 50% (M50) for all test conditions. The experiments were performed at a constant speed of 1500 rpm at two intake temperatures of 40 °C and 80 °C, and engine load was varied from 1.25 to 5 bar brake mean effective pressure (BMEP). It was observed that intake air heating influenced the engine’s combustion, performance, and emission characteristics. Higher intake air temperature (M50, 80 °C) resulted in higher peak in-cylinder pressure and brake thermal efficiency (BTE) than the low-temperature case (M50, 40 °C). Higher intake air temperature compensated for the cooling effect due to evaporation of methanol caused by a shorter combustion duration, leading to more efficient energy conversion. Higher hydrocarbons (HC) and carbon monoxide (CO) emissions were observed in addition to lower nitric oxide (NO) emission for M50 vis-a-vis baseline diesel at all loads. The study concluded that intake air temperature significantly affects methanol-diesel dual-fuel engine characteristics and will be an important parameter requiring optimisation before large-scale methanol implementation in agriculture and transport sectors.

Study on the ignitability of a high-pressure direct-injected methane jet using a scavenged pre-chamber under a wide range of conditions

Natural gas is a promising alternative fuel for internal combustion engines, it allows for a reduction of engine-out emissions without impairing high engine efficiencies. Although this approach is already utilized from small to large engine classes, it is almost exclusively based on the combustion of a premixed homogeneous charge. For ignition, small engines use standard spark plugs or pre-chambers, while large and lean-operated engines use pre-chambers and pilot injections. Direct high-pressure gas injection is a more recent, alternative way to operate gas engines which offers benefits compared to premixed operation such as high combustion pressures, leaner operation, easier quantity regulation, and higher compression ratios, among others. However, in contrast to diesel injection, the compression temperatures are too low for the auto-ignition of the gas jets. Therefore, an additional ignition system is required, usually a pilot injection system is used. In this study, the usability and performance of a scavenged pre-chamber used for the ignition a high-pressure gas jet has been investigated in an optically accessible test-rig that is able to operate at engine-like conditions. Results show that the turbulent hot jet generated by the pre-chamber was able to ignite the high-pressure gas jet under a wide range of operating conditions. Moreover, it also appears to be a promising ignition strategy for very early direct injection during the compression stroke as well as for port injection. The good performance is attributed to the intense mixing of the main gas jet with the hot jet exiting the pre-chamber.

Experimental investigation of water injection and spark timing effects on combustion and emissions of a hybrid hydrogen-gasoline engine

This paper aimed to study the effects of water injection and spark timing on performance of a hybrid hydrogen-gasoline engine. For this aim, a modified four-cylinder turbocharged gasoline direct injection (GDI) engine equipped with hydrogen port injection and port water injection system was developed. In this study, the engine speed was maintained at 1300 rpm and the throttle opening of 30% with an excess air/fuel ratio of 1. The hydrogen energy percentage of 15%, water fuel mass ratio of 0.2 and 0.4 was added into the intake port. When the hydrogen energy percentage was changed, the gasoline fraction was also adjusted to keep the mixture at the stoichiometric. For all tested conditions, the spark timing was varied from 1 to 42°CA before top dead center (BTDC) with a fixed interval of 2°CA. Experimental results showed that maximum brake torque (MBT) spark timing varied when water and/or hydrogen is added. With hydrogen addition, the worsened combustion caused by water injection can be improved. Also, the variation of IMEP and COVIMEP versus spark timing became more insensitive with hydrogen addition. With water injection, the high NO emission caused by hydrogen addition can be largely reduced, however with side effect of higher HC and CO emissions.

Experimental Investigation on Impact of EGR Configuration on Exhaust Emissions in Optimized PCCI-DI Diesel Engine

The main objective of this work is to analyse the impact of different EGR configurations (no EGR, cold EGR, and hot EGR) on exhaust emissions of PCCI-DI engine. Methanol port injection, dieseline direct injection, advanced injection timing, and different EGR rates were adapted and optimized on the baseline engine. A hybrid algorithm of grey relational analysis with the Taguchi method was implemented for optimization. Results were compared among the PCCI-DI combustion strategy with the baseline using cold EGR, hot EGR, and no EGR configurations. Both cold and hot EGR configurations resulted in lower emission of NOx plus smoke at different loads. At low loads, hot EGR showed promising results of lower HC and CO than the cold EGR with a difference of 18.33% and 33.3%, respectively. NOx and smoke reductions simultaneously and better trade-offs were obtained using cold EGR configuration.

Experimental investigation on combustion behaviour, performance and emission of fusel oil-gasoline blends using turbocharged SI engine

Because of rising energy demand and pollution concerns in the transportation and industrial sectors, alternative fuel development is critical. The fusel oil, which is a by-product of ethanol distillation molasses, is receiving a lot of interest. The combustion characteristics, performance, and emissions of a 1.8L turbocharged four-cylinder, port injection, spark-ignition engine will be used to compare fusel oil blends with gasoline in this study. The experiment was carried out at a constant engine speed of 2000 rpm with a throttle load of 10-40%. Four samples with various ratios of gasoline combined with fusel oil were tested (100% gasoline, 10%, 20%, and 30% are referred to as F0, F10, F20, and F30 respectively). As a result, compared to gasoline, fusel oil blends increase Brake Specific Fuel Consumption (BSFC) by 5-22%. In comparison to gasoline, the combustion behaviour of in-cylinder pressure, Rate of Heat Release (ROHR), Rate Of Pressure Rise (ROPR), and Mass Fraction Burn (MFB) shows an early 2-3 Degree Crank Angle (CAD). Due to differences in attributes and oxygen content, the Brake Thermal Efficiency (BTE) of combustion utilising fusel oil blends suffers a modest drop of 13-16%. When compared to gasoline, fusel oil blends emit 3-4% less hydrocarbon (HC), 7.5-24.5% less carbon monoxide (CO), and 18-36% less nitrogen oxide (NOx). To summarise, fusel oil blends without water extraction blended with gasoline have a substantial impact on turbocharger engine functioning.

Experimental study on combustion and emission of an SI engine with natural gas/ethanol combined injection

Pure ethanol spark ignition (SI) engines have poor fuel atomization and mixture formation at lower load. The objective of this study is to improve the performance of ethanol SI engines through dual-injection mode with ethanol port injection plus compressed nature gas direct injection (EPI + CDI). In this paper, the performance engine at different compressed nature gas direct injection ratio (CDIr) and DIT was studied at the speed of 1500rmp. The results show that, with the increase of CDIr or the delay of direct injection timing (DIT), torque, Pmax and NOx first increases and then decreases; CA 10–90, CoVIMEP, CO and particle number (PN) first decreases and then increases; HC keeps decreasing. When CDIr = 5%, DIT = 150°CA BTDC, CA 10–90 reaches the lowest value, which is about 6.21% lower than the original engine. Besides, under this operation condition, CoVIMEP decreases to 1.13%, which is about 18.72% lower than the original engine. It is worth noting that the higher torque and Pmax at this time indicate the better combustion in the cylinder, but NOx does not increase significantly. In addition, total particle number (TPN) also reaches the minimum at this time. When CDIr = 5%, 10%, 15% and 20%, HC is reduced by 11.42%, 13.53%, 20.05% and 23.26% on average. When CDIr ≤ 10%, the overall CO is lower than the original engine. In summary, EPI + CDI can not only effectively improve combustion, but also reduce emissions. The cooperation of 5%CDIr + 95%EPI + 150°CA BTDC DIT can form an effective stratified mixture in the cylinder, providing stable and promising performance. And it is the best direct injection strategy for CDI + EPI dual-fuel combined injection SI engine.

Comparative study on combustion and emissions of SI engine with gasoline port injection plus acetone-butanol-ethanol (ABE), isopropanol-butanol-ethanol (IBE) or butanol direct injection

Vehicles powered by internal combustion engine are now facing stringent regulatory requirements, so it is urgent to improve engine thermal efficiency and reduce harmful emissions. Alcohols have attracted wide attention because of their renewability and cleaner emissions, and the bio-butanol is most similar to gasoline and has been widely investigated in spark ignition (SI) engine. However, the high energy consumption of separation and purification during fermentation process leads to the high price of bio-butanol. ABE and IBE are the intermediates for the preparation of butanol by different fermentation methods, and using ABE and IBE directly in SI engine will greatly reduce the cost. Combined injection is the most suitable injection approach for dual-fuel engine because the engine can flexibly control the dual-fuel injection ratio and parameters. Therefore, the combustion and emissions of gasoline/ABE, gasoline/IBE and gasoline/butanol were experimentally compared based on gasoline port injection plus alcohol direct injection mode. The results show that gasoline/IBE is better than gasoline/ABE and gasoline/butanol in power performance and brake thermal efficiency (BTE). And when the direct injection ratio (DIr) is low, the gaseous emissions of gasoline/ABE are superior, while emissions of gasoline/butanol are superior at high DIr. In addition, the particle number (PN) of gasoline/ABE is always the lowest among the three modes, and the particle basically show unimodal distribution. Overall, as direct injection fuel in dual-fuel combined injection engine, ABE and IBE have more advantages than butanol in terms of combustion and emissions performance as well as cost.

Investigation of Performance and Emission Characteristics of Diesel-Ethanol PCCI Engine

Using numerical analysis and the ANSYS Forte 19.2 package, this study investigates the performance, combustion, and emission characteristics of dual-fuel operation using ethanol as a partial substitute for diesel in a direct injection compression ignition engine. The study discovered that adding ethanol to diesel engines reduces peak cylinder pressure and temperature due to its evaporative cooling qualities, with a maximum error of only 2.5%, exhibiting remarkable alignment between simulation and experimental data. The experiment was conducted on a modified single cylinder direct injection CI engine with an ethanol port injector controlled purely by Arduino software. The tests were carried out with different Ethanol substitutions at varied engine loads (0, 20%, 40%, 60%, 80%, and 100%). The study looked at the performance and emissions of a DI CI engine with ethanol substitutes of 10%, 20%, and 30%, with E10 outperforming and E30 outperforming, but caution is urged due to increased energy degradation. E10 and E20 ethanol replacements dramatically cut CO, HC, and NO emissions in diesel engines, improving environmental performance with modest changes.

Influences of hydrogen addition from different dual‐fuel modes on engine behaviors

AbstractCompression ignition (CI) engines have good performance but more exhaust emissions. Dual fuel (DF) engines have better performance and lower emissions compared to CI mode. Also, the scarcity of fossil fuels made the researchers to find alternative fuels to power CI engines. Therefore, the present work aims to use hydrogen (H2) and honne oil biodiesel (BHO) to investigate the performance of CI engines in DF mode. Also, it aims to compare the performance of CI engines in various DF modes, namely induction, manifold injection, and port injection. First, the CI engine was fuelled completely by diesel fuel and BHO. The data were gathered when the engine ran at a constant engine speed of 1500 rpm and at 80% load. Second, the CI engine was operated in various DF modes and data were generated. CI engine operation in DF mode was smooth with biodiesel and H2. The brake thermal efficiency (BTE) of 32% and 31.1% was reported with diesel and biodiesel, respectively, for manifold injection due to low energy content and high viscosity of biodiesel. These values were higher than CI mode and other DF modes. Fuel substitution percentage for DF manifold injection was 60% and 57% with diesel and biodiesel, respectively. Smoke, hydrocarbon (HC), and carbon monoxide (CO) emissions were lower than conventional mode, but a reverse trend was observed for oxides of nitrogen (NOx) emissions. Heat release rate (HRR) and peak pressure (PP) were higher than conventional mode due to the fast combustion rate of hydrogen. The shortest ignition delay (ID) period was noticed for traditional diesel fuel, but it was longer for BHO biodiesel due to its higher viscosity and lower cetane number. On the contrary, the presence of hydrogen led to an increment in the combustion duration (CD) owing to the scarcity of oxygen in CD. Consequently, the paper clearly showed that the injection way of hydrogen plays a respectable role in the engine characteristics.