Influence of injection timing on performance, emission and combustion characteristics of a DI diesel engine running on waste plastic oil

Environmental concern and availability of petroleum fuels have caused interests in the search for alternate fuels for internal combustion engines. Waste plastics are indispensable materials in the modern world and application in the industrial field is continually increasing. In this context, waste plastics are currently receiving renewed interest. As an alternative, non-biodegradable, and renewable fuel, waste plastic oil is receiving increasing attention. The waste plastic oil was compared with the petroleum products and found that it can also be used as fuel in compression ignition engines. In the present work, the influence of injection timing on the performance, emission and combustion characteristics of a single cylinder, four stroke, direct injection diesel engine has been experimentally investigated using waste plastic oil as a fuel. Tests were performed at four injection timings (23°,20°,17° and 14° bTDC). When compared to the standard injection timing of 23° BTDC the retarded injection timing of 14° bTDC resulted in decreased oxides of nitrogen, carbon monoxide and unburned hydrocarbon while the brake thermal efficiency, carbon dioxide and smoke increased under all the test conditions.     

Effect of pilot fuel injection pressure and injection timing on combustion,performance and emission of hydrogen-biodiesel dual fuel engine

The present study highlights the influence of fuel injection pressure (FIP) and fuel injection timing (FIT) of Jatropha biodiesel as pilot fuel on the performance, combustion and emission of a hydrogen dual fuel engine. The hydrogen flow rates used in this study are 5lit/min, 7lit/min, and 9lit/min. The pilot fuel is injected at three FIPs (500, 1000, and 1500 bar) and at three FITs (5°, 11°, and 17?bTDC). The results showed an increase in brake thermal efficiency (B_th)from 25.02% for base diesel operation to 32.15% for hydrogen-biodiesel dual fuel operation with 9lit/min flow rate at a FIP of 1500 bar and a FITof17?bTDC. The cylinder pressure and heat release rate (HRR) are also found to be higher for higher FIPs. Advancement in FIT is found to promote superior HRR for hydrogen dual fuel operations. The unburned hydrocarbon (UHC) and soot emissions are found to reduce by 59.52% and 46.15%, respectively, for hydrogen dual fuel operation with 9lit/min flow rate at a FIP of 1500 bar and a FIT of 11?bTDC. However, it is also observed that the oxides of nitrogen (NO_X) emissions are increased by 20.61% with 9lit/min hydrogen flow rate at a FIP of 1500 bar and a FIT of 17?bTDC. Thus, this study has shown the potential of higher FIP and FIT in improving the performance, combustion and emission of a hydrogen dual fuel engine with Jatropha biodiesel as pilot fuel.     

Effect of metal based additive on performance emission and combustion characteristics of diesel engine fuelled with biodiesel

This study investigates the use of ferric chloride (FeCl₃) as a fuel borne catalyst (FBC) for waste cooking palm oil based biodiesel. The metal based additive was added to biodiesel at a dosage of 20 μmol/L. Experiments were conducted to study the effect of ferric chloride added to biodiesel on performance, emission and combustion characteristics of a direct injection diesel engine operated at a constant speed of 1500 rpm at different operating conditions. The results revealed that the FBC added biodiesel resulted in a decreased brake specific fuel consumption (BSFC) of 8.6% while the brake thermal efficiency increased by 6.3%. FBC added biodiesel showed lower nitric oxide (NO) emission and slightly higher carbon dioxide (CO₂) emission as compared to diesel. Carbon monoxide (CO), total hydrocarbon (THC) and smoke emission of FBC added biodiesel decreased by 52.6%, 26.6% and 6.9% respectively compared to biodiesel without FBC at an optimum operating condition of 280 bar injection pressure and 25.5^o bTDC injection timing. Higher cylinder gas pressure, heat release rate and shorter ignition delay period were observed with FBC added biodiesel at these conditions.     

Effect of changing injection pressure on Mahua oil and biodiesel combustion with CeO2 nanoparticle blend on CI engine performance and emission characteristics

Alternative fuels have sparked a lot of interest as oil deposits have decreased and environmental concerns have grown. Biodiesel is an alternative fuel that is being researched as a possible replacement for fossil fuels. In the current investigation, the combustion performance, and emission characteristics of CI(Compression Ignition) engine were examined by changing the fuel injection pressure (180, 200, 220 and 240 bar). The biodiesel (B20) used in this analysis was obtained from Mahua oil at 20% v/v blended with neat diesel (20% Mahua Biodiesel + 80% Diesel). CeO₂(Cerium Oxide) nanoparticles were introduced to the B20 fuel at four distinct concentrations are 25, 50, 75, and 100 ppm. Performance characteristics such as BTE(Brake Thermal Efficiency) and BSFC(Brake Specific Fuel Consumption) were inferior to diesel, at 240 bar B20 with 25 ppm CeO₂ indicated 1.9% increased BTE and 3.8% reduced BSFC compared B20 and 6% lower EGT (Exhaust Gas Temperature) compared diesel. At 200 bar, fuel samples indicated slightly higher In-Cylinder pressure and lower HRR (Heat release rate) compared to diesel. At 200 bar FIP(Fuel Injection Pressure), HC(Hydro Carbon) and CO(Carbon Monoxide) emissions were reduced significantly compared to diesel. The largest reduction in smoke opacity and NOx(Nitrous Oxide) emissions were observed at 240 bar with 75 ppm dosage, but CO₂(Carbon Dioxide) emissions were higher at 220 bar.     

Performance, emission and combustion characteristics of biodiesel fuelled variable compression ratio engine

Experiments has been carried out to estimate the performance, emission and combustion characteristics of a single cylinder; four stroke variable compression ratio multi fuel engine fuelled with waste cooking oil methyl ester and its blends with standard diesel. Tests has been conducted using the fuel blends of 20%, 40%, 60% and 80% biodiesel with standard diesel, with an engine speed of 1500 rpm, fixed compression ratio 21 and at different loading conditions. The performance parameters elucidated includes brake thermal efficiency, specific fuel consumption, brake power, indicated mean effective pressure, mechanical efficiency and exhaust gas temperature. The exhaust gas emission is found to contain carbon monoxide, hydrocarbon, nitrogen oxides and carbon dioxide. The results of the experiment has been compared and analyzed with standard diesel and it confirms considerable improvement in the performance parameters as well as exhaust emissions. The blends when used as fuel results in the reduction of carbon monoxide, hydrocarbon, carbon dioxide at the expense of nitrogen oxides emissions. It has found that the combustion characteristics of waste cooking oil methyl ester and its diesel blends closely followed those of standard diesel.     

Evaluating combustion,performance and emission characteristics of diesel engine using karanja oil methyl ester biodiesel blends enriched with HHO gas

With a specific end goal to take care of the worldwide demand for energy, a broad research is done to create alternative and cost effective fuel. The fundamental goal of this examination is to investigate the combustion, performance and emission characteristics of diesel engine using biodiesel blends enriched with HHO gas. The biodiesel blends are gotten by blending KOME obtained from transesterification of karanja oil in various proportions with neat diesel. The HHO gas is produced by the electrolysis of water in the presence of sodium bicarbonate electrolyte. The constant flow of HHO gas accompanied with biodiesel guarantees lessened brake specific fuel consumption by 2.41% at no load and 17.53% at full load with increased the brake thermal efficiency by 2.61% at no load and 21.67% at full load contrasted with neat diesel operation. Noteworthy decline in unburned hydrocarbon, carbon monoxide, carbon-dioxide emissions and particulate matter with the exception of NO_x discharge is encountered. The addition of EGR controls this hike in NO_x with a slight decline in the performance characteristics. It is clear that the addition of HHO gas with biodiesel blends along with EGR in the test engine improved the overall characterization of engine.     

Influence of injection timing on performance,combustion and emission characteristics of a diesel engine running on hydrogen-diethyl ether,n-butanol and biodiesel blends

In the present research, 5% hydrogen was added to 95%diesel fuel, diethyl ether (DEE), n-butanol (nB), and spirulina microalgae in this investigation (SMA). The fuels were then tested using a numerical tool and the Diesel RK-Model programme in a single cylinder CI engine. The results showed that the 5%H95%DEE blend consistently showed the highest level of specific fuel consumption (SFC) with increasing trend as the injection timings was advanced. In terms of brake thermal efficiency (BTE), all blends experienced decreasing trend except for 5%H95%nB. The addition of 5% hydrogen into 95% n-butanol gave relatively stable level of BTE for the entire injection timings. Furthermore, all blends witnessed relatively the same exhaust gas temperature (EGT) trend with only minor changes. Not much significance was observed from the most retarded to the most advanced injection timing. In terms of peak in-cylinder pressure, all the investigated blends saw increasing trend with the advancing injection timing. However, they experienced slight reduction at the most advanced fuel injection timing (FIT). Except for 5%H95%SMA, all blends show the highest peak in-cylinder pressure at 26.5 deg. before TDC. With regards to the ignition delay (ID), 5%H95%nB always gave the longest ID except at the 29.5 deg. before TDC, while the 5%H95%DEE consistently showed the shortest ID with nearly the same value for all Its at around 1.8–3.1 deg. Regarding the emissions, the use of n-butanol (5%H95%nB) consistently produced the lowest CO₂, smoke, NO_X, and particulate matter (PM) emissions throughout the entire injection timings.     

Effects of oxyhydrogen on the CI engine fueled with the biodiesel blends: A performance,combustion and emission characteristics study

The main purpose of this study is to analyse the effects of oxy hydrogen (HHO) along with the Moringa oleifera biodiesel blend on engine performance, combustion and emission characteristics. HHO gases were generated using the typical electrolysis process using the potassium hydroxide solution. The experiments were performed under various engine loads of 25%, 50%, 75%, and 100% in a constant speed engine. Biodiesel from the M. oleifera was prepared by the transesterification process. Further, the procured biodiesel blends mixed with neat diesel at the concentration of 20% (B20) and 40% (B40). In addition to above, the HHO gas flow rate to the engine chamber maintained at the flow rate of 0.5 L^-1. The use of the 20% and 40% blends with HHO reported less BTE compared to the neat diesel. However, B20 reported marginal rise in the BTE due to the addition of the HHO gas. On the other hand, addition of HHO gas to the blends significantly dropped the brake specific fuel consumption. With regard to the emissions, addition of the biodiesel blends reduced the concentration of the CO, HC, and CO₂. Nevertheless, no reduction reported in the formation of the NO. However, adding the HHO to the biodiesel reduced the average NOx by 6%, which is a substantial effect. Overall, HHO enriching biodiesel blends are the potential replacement for the existing fossil fuels for its superior fuel properties compared to the conventional diesel.     

Effects of second hydrogen direct injection proportion and injection timing on combustion and emission characteristics of hydrogen/n-butanol combined injection engine

Hydrogen and n-butanol are superior alternative fuels for SI engines, which show high potential in improving the combustion and emission characteristics of internal combustion engines. However, both still have disadvantages when applied individually. N-butanol fuel has poor evaporative atomization properties and high latent heat of vaporization. Burning n-butanol fuel alone can lead to incomplete combustion and lower temperature in the cylinder. Hydrogen is not easily stored and transported, and the engine is prone to backfire or detonation only using hydrogen. Therefore, this paper investigates the effects of hydrogen direct injection strategies on the combustion and emission characteristics of n-butanol/hydrogen dual-fuel engines based on n-butanol port injection/split hydrogen direct injection mode and the synergistic optimization of their characteristics. The energy of hydrogen is 20% of the total energy of the fuel in the cylinder. The experimental results show that a balance between dynamics and emission characteristics can be found using split hydrogen direct injection. Compared with the second hydrogen injection proportion (IP2) = 0, the split hydrogen direct injection can promote the formation of a stable flame kernel, shorten the flame development period and rapid combustion period, and reduce the cyclic variation. When the IP2 is 25%, 50% and 75%, the engine torque increases by 0.14%, 1.50% and 3.00% and the maximum in-cylinder pressure increases by 1.9%, 2.3% and 0.6% respectively. Compared with IP2 = 100%, HC emissions are reduced by 7.8%, 15.4% and 24.7% and NOx emissions are reduced by 16.4%, 13.8% and 7.9% respectively, when the IP2 is 25%, 50% and 75%. As second hydrogen injection timing (IT2) is advanced, CA0-10 and CA10-90 show a decreasing and then increasing trend. The maximum in-cylinder pressure rises and falls, and the engine torque gradually decreases. The CO emissions show a trend of decreasing and remaining constant. However, the trends of HC emissions and NOx emissions with IT2 are not consistent at different IP2. Considering the engine's dynamics and emission characteristics, the first hydrogen injection proportion (IP1) = 25% plus first hydrogen injection timing (IT1) = 240°CA BTDC combined with IP2 = 75% plus IT2 = 105°CA BTDC is the superior split hydrogen direct injection strategy.     

Effect of hydrogen enrichment on performance,combustion, and emission of a methanol fueled SI engine

The study of potentially high rated alternative fuel (Methanol) for the IC engines is an exciting topic in the recent research advancement. However, the study of combination of methanol and hydrogen is considered to address both economic and environmental needs. Hydrogen with best combustion characteristics will compensate for the drawbacks of methanol as a fuel. In the present investigation hydrogen enrichment to methanol has shown a significant enhancement in performance and combustion; the overall emission has reduced substantially. The experiments for a different set of trials, including hydrogen enrichment ranging between 5% and 20% with 2.5% increment, the engine is operated with wide-open throttle (WOT) condition for different speeds. The increase in enrichment of hydrogen has shown a rise in BTE, BP, and a reduced BSEC value. The percentage increase in BTE is between 20 and 30%, and an increase in hydrogen beyond 12.5% would affect the volumetric efficiency, and thus performance declines after that. The exhaust emissions have a huge impact on hydrogen enrichment; CO, HC, and CO₂ emission are reduced by 30–40%; however, an increase in cylinder temperature due to rapid combustion slightly increases the NO_x emission. Thus hydrogen enriched methanol operating at higher compression ratio can improve the overall engine characteristics significantly.     

Effect of injection parameters on the combustion and emission characteristics in a common-rail direct injection diesel engine fueled with waste cooking oil biodiesel

The objective of this paper was to study the effects of the injection pressure and injection timing on the combustion and emission characteristics in a single-cylinder common-rail direct injection (CRDI) diesel engine fueled with waste cooking oil (WCO) biodiesel and commercial diesel fuel. The fuel property including fatty acid composition for the biodiesel were measured and compared with those of the conventional diesel fuel. The engine tests were conducted at two injection pressures (80 and 160 MPa) and different injection timings from −25 to 0 crank angle degree (CAD) after top dead center (aTDC) under two different engine loads. The results showed that the indicated specific fuel consumption (ISFC) with respect to the injection timings of the biodiesel was higher than that of the diesel fuel under all experimental conditions. The peak cylinder pressure and the peak heat release rate of the biodiesel were slightly lower, while the ignition delay was slightly longer under all operating conditions. In terms of emissions, the biodiesel had benefits in reduction of smoke, carbon monoxide (CO), hydrocarbon (HC) emissions especially with high fuel injection pressure. The nitrogen oxide (NO_x) emissions of the biodiesel were relatively higher than those of the diesel under all experimental conditions.     

Experimental investigations on combustion, performance and emissions characteristics of neat karanji biodiesel and its methanol blend in a diesel engine

The increased focus on alternative fuels research in the recent years are mainly driven by escalating crude oil prices, stringent emission norms and the concern on clean environment. The processed form of vegetable oil (biodiesel) has emerged as a potential substitute for diesel fuel on account of its renewable source and lesser emissions. The experimental work reported here has been carried out on a turbocharged, direct injection, multi-cylinder truck diesel engine fitted with mechanical distributor type fuel injection pump using biodiesel-methanol blend and neat karanji oil derived biodiesel under constant speed and varying load conditions without altering injection timings. The results of the experimental investigation indicate that the ignition delay for biodiesel-methanol blend is slightly higher as compared to neat biodiesel and the maximum increase is limited to 1 deg. CA. The maximum rate of pressure rise follow a trend of the ignition delay variations at these operating conditions. However, the peak cylinder pressure and peak energy release rate decreases for biodiesel-methanol blend. In general, a delayed start of combustion and lower combustion duration are observed for biodiesel-methanol blend compared to neat biodiesel fuel. A maximum thermal efficiency increase of 4.2% due to 10% methanol addition in the biodiesel is seen at 80% load and 16.67 s⁻¹ engine speed. The unburnt hydrocarbon and carbon monoxide emissions are slightly higher for the methanol blend compared to neat biodiesel at low load conditions whereas at higher load conditions unburnt hydrocarbon emissions are comparable for the two fuels and carbon monoxide emissions decrease significantly for the methanol blend. A significant reduction in nitric oxide and smoke emissions are observed with the biodiesel-methanol blend investigated.     

Comparative performance analysis of diesel engine fuelled with hydrogen enriched edible and non-edible biodiesel

In the present study, a comparative analysis of enrichment of hydrogen alongside diesel fuel and two different sources of biodiesel namely rice bran oil is an edible oil, and karanja oil being non-edible is tested. Hydrogen at a fixed flow rate of 7 lpm is inducted through the intake manifold. A total of six fuel samples are considered: diesel (D), hydrogen-enriched diesel (D + H₂), hydrogen-enriched 10, and 20% rice bran biodiesel blend (RB10 + H₂ and RB20 + H₂), and hydrogen-enriched 10 and 20% karanja biodiesel blend (KB10 + H₂ and KB20 + H₂). Results indicate that enrichment of hydrogen improves combustion and results in 2.5% and 1.6% increase in the brake thermal efficiency of diesel fuel and rice bran biodiesel, respectively. For karanja biodiesel the increment is negligible. Fuel consumption of the D + H? is 6.35% lower and for RB10 + H? and KB10 + H? it is decreased by 2.9% and 1.3%, respectively. The Presence of hydrogen shows the 4–38% lower CO emissions and 6–14% lower UHC emission due to better combustion. The blends RB10 + H? and KB10 + H? produce up to 6–13% higher NOx emission and that for the blends RB20 + H? and KB20 + H? it goes up to 25%. Overall rice bran oil is found to provide better performance than karanja biodiesel.     

A review of the effects of catalyst and additive on biodiesel production, performance, combustion and emission characteristics

This article is a literature review of the effect of different catalysts and additives on biodiesel production, performance, combustion and emission characteristics. This study is based on the reports of about 60 scientists who published their findings between 1998 and 2010. It was reported that base catalyst produced more biodiesel compared to acid type catalysts. There was not much variation in engine performance with the use of catalyst. Combustion characteristics were improved with the use of additives. It was found that ignition delay was reduced and premixed combustion duration was increased with the addition of catalyst. HC emission and PM emission were reduced with the use of catalysts.     

Effect of fuel injection timing of hydrogen rich syngas augmented with methane in direct-injection spark-ignition engine

The product of gasification of solid biomass, also called syngas is believed to be good fuel for internal combustion engines in the move from the carbon based fuel to zero emission fuels. The only problem is its lower calorific value which is placed at one third of that of compressed natural gas (CNG). There are latest efforts to enhance the hydrogen rich syngas by augmenting it with methane so that the calorific value can be improved. This paper presents experimental results of the effect of the start of fuel injection timing (SOI) on the combustion characteristics, performance and emissions of a direct-injection spark-ignition engine fueled with a 20% methane augmented hydrogen rich syngas of molar ratio of 50% H₂ and 50% CO composition. The engine was operated at fully open throttle and the start of fuel injection (SOI) was varied at 90, 120 and 180° before top dead center (BTDC). The experiment was conducted at lean mixture conditions in the low and medium engine speed ranges (1500–2400 RPM). The spark advance was set to the minimum advance for a maximum brake torque in all the test parameters. The methane augmented hydrogen rich syngas was observed to perform well over wide range of operation with SOI = 180°CA BTDC. However, SOI = 120°CA BTDC performed well at lower speeds recording improved performance and emissions. Limitation of operable load was observed for both SOI = 120°CA BTDC and 90°CA BTDC due to an insufficient time for complete injection of fuel at lower relative air–fuel ratio (λ) with higher speeds.     

Influence of biodiesel on engine combustion and emission characteristics

This paper discusses the influence of biodiesel on the engine combustion characteristics. The considered fuel is neat biodiesel from rapeseed oil. The considered engine is a bus diesel engine with injection M system. The engine characteristics are obtained by experiments and numerical simulation. The results obtained with biodiesel are compared to those obtained with mineral diesel under various operating regimes. In this way, the influences of biodiesel usage on the injection pressure, injection timing, ignition delay, in-cylinder gas pressure and temperature, heat release rate, exhaust gas temperatures, harmful emissions, specific fuel consumption, and on engine power are analyzed. Furthermore, the relationships among fuel properties, injection and combustion characteristics, harmful emissions, and other engine performance are determined. Special attention is given to possible explanations of higher NO_x emission in spite of lower in-cylinder gas temperature.     

Numerical simulation of biodiesel fuel combustion and emission characteristics in a direct injection diesel engine

The effect of the physical and chemical properties of biodiesel fuels on the combustion process and pollutants formation in Direct Injection (DI) engine are investigated numerically by using multi-dimensional Computational Fluid Dynamics (CFD) simulation. In the current study, methyl butanoate (MB) and n-heptane are used as the surrogates for the biodiesel fuel and the conventional diesel fuel. Detailed kinetic chemical mechanisms for MB and n-heptane are implemented to simulate the combustion process. It is shown that the differences in the chemical properties between the biodiesel fuel and the diesel fuel affect the whole combustion process more significantly than the differences in the physical properties. While the variations of both the chemical and the physical properties between the biodiesel and diesel fuel influence the soot formation at the equivalent level, the variations in the chemical properties play a crucial role in the NO_x emissions formation.     

Effect of mixture strength and injection timing on combustion characteristics of a direct injection hydrogen-fueled engine

An experimental investigation was performed to characterize the hydrogen combustion in a spark-ignition direct-injection engine. It was focused on the effects of mixture strength and injection timing on the characteristics of hydrogen combustion. For this purpose, the practical tests were carried out on an experimental test rig. It is originally designed for optimization of the direct-injection natural-gas engine. The experimental test-rig results comprised the traces for the in-cylinder pressure, mass fraction burned, and heat release rate under the different operation conditions. The results obtained show that the richer mixture condition produced higher pressure trends at all tested points. Besides that, it exhibited a faster rate of increase in combustion rate due to the increase of flame speed. However, the combustion characteristics deteriorated due to the lack of mixture stratification with earlier injection timing. It is concluded that direct-injection timing is essential to achieve better combustion performance. Moreover, retarding the spark ignition timing is also crucial to avoid abnormal combustion in the case of a richer mixture and early start on injection.     

A study of spray strategies on improvement of engine performance and emissions reduction characteristics in a DME fueled diesel engine

This paper investigated the impact of injection angle and advance injection timing on combustion, emission, and performance characteristics in a dimethyl ether (DME) fueled compression ignition engine through experimentation on spray behaviors and the use of numerical methods. To achieve this aim, a visualization system and two injectors with different injection angles were used to analyze spray characteristics. The combustion, emission, and performance characteristics were analyzed by numerical methods using a detailed chemical kinetic DME oxidation model. Each of five injection angles and timings were selected to examine the effect of injection angle and timing. It was revealed that the injected spray with narrow injection angles was impinged on the bottom wall after the SOI of BTDC 60°, and most of the fuel spray and evaporation with the wide injection angles had a distribution at the crevice region when the injection timing was advanced. In addition, NO_x emissions at the SOI of BTDC 20° and TDC had higher values, and the soot emission quantities were extremely small. The narrow injection angles had good performance at the advanced injection timing, and the injection timing over a range of BTDC 40-20° showed superiority in performance characteristics.