Fuel Injection Parameters Research Articles

Effect of Fuel Injection Parameters on Engine Performance in A Conventional Single Cylinder Spark Ignition Engine

In this study, a 1D model was created using the Ricardo-Wave program for a single-cylinder, spark ignition, four-stroke, direct injection engine with a stroke volume of 398 cc. Air-fuel ratio (AFR), mixture temperature (MT), and start of injection (SOI) were used as fuel injection parameters. Using these parameters, 343 different cases were created. Brake power, thermal efficiency, and fuel consumption were used as engine performance parameters. By holding one injection parameter constant, a contour plot was created to examine the effect of the other two parameters on the engine performance parameter. According to the results, the effect of MT and SOI on brake power is 1%, the effect of AFR on brake power is 9.6%, the effect of MT and SOI on thermal efficiency is 1%, and the effect of AFR on thermal efficiency is 12.8%. The effect of MT and SOI on fuel consumption is 0.04%, the effect of AFR on fuel consumption is 22.9%, and the effect of AFR on brake specific fuel consumption is 22.9%. These results indicate that the most significant effect is provided by AFR, while MT and SOI also have a slight impact on engine performance.

Effect of pre-chamber fuel injection parameters and EGR on the combustion and emissions of a heavy-duty diesel engine

ABSTRACT This numerical simulation investigated the impact of pre-chamber fuel injection timing, injection angle, and exhaust gas recirculation (EGR) on combustion and emissions in a heavy-duty diesel engine using a pre-chamber combustion system. The results illustrate that the pre-chamber combustion system exhibits the potential to enhance the indicated thermal efficiency (ITE) of a diesel engine, while specific pre-chamber configurations can concurrently lower both NOx and soot emissions. The optimized cases show that the sustained turbulence generated by the pre-chamber enhances the redistribution of the unburned mixtures in the cylinder. The sustained turbulence leads to a broader range of gas mixtures near the equivalence ratio(Φ) of 1, resulting in complete combustion and lower NOx and soot emissions. In the optimized pre-chamber combustion system (with pre-chamber injection timing (PIT) at 0°CA ATDC and pre-chamber injection angle (PIA) at 54.5°), introducing 3% EGR results in a reduction of 11.61% in NOx emissions and 9.97% in soot emissions compared with the baseline engine.

Impact of fuel injection parameters associated with partially hydrogenated Ceiba pentandra biodiesel blend on CI engine characteristics

Multiple studies have shown that biodiesel blends significantly cut exhaust emissions. However, the most significant challenge was the rising emission of oxides of nitrogen (NOx). The authors' prior research showed that a Ceiba pentandra biodiesel blend (B20) with a higher IP of 260 bar and an advanced IT of 27° BTDC as an optimal Fuel injection parameter (FIP) resulted in superior combustion and reduced emissions except NOx. To further enhance engine performance, fuel reformulation strategies have been implemented together with FIP modification. This research intends to examine the impact of FIP combined with blending of partially hydrogenated biodiesel (HB) on engine characteristics. As a result of partial hydrogenation, the degree of unsaturation decreased by 60%, and the Cetane Number (CN) increased by 22%. Higher BTE (8%), TFC (3.4%), CP (13%), HRR (5%) and lower HC (12%), and CO (5.5%) emissions can be achieved when HB20 was combined with optimal FIP. Superior outcomes were seen with hydrogenated blend (HB20) than with normal B20, with a reduction in NOx emissions by 6.7% without significantly impacting the smoke emission trade-off. Thus, cutting-edge fuel reformulation approaches make way for eco-friendly engineering.

Parameter optimization for two-stroke direct-injection spark-ignition aviation kerosene engine

The type of two-stroke spark-ignition(SI) engine is still the main power sources of small and medium unmanned aerial vehicles. A transition from gasoline to aviation kerosene or light diesel fuel and from carburetor or port-injection equipment to direct-injection(DI) equipment is prevailing. However, the performance of two-stroke DI-SI engine fueled with aviation kerosene is not very good under medium and high loads. Therefore, using the two-stroke DI-SI kerosene engine modified from port-injection SI gasoline engine as the research subject, the effects of different parameters on engine combustion and performance were studied and parameter optimization was also carried out at high loads. Based on the optimal fuel injection parameters, the influences of ignition time, compression ratio, scavenging/exhaust port area and scavenging/exhaust phase on the operating characteristics of two-stroke engine were analyzed. It was indicated that ignition timing, compression ratio and scavenging/exhaust phase have obvious impacts on engine performance, while the scavenging port area shows little impact on engine performance. An optimization calculation with genetic algorithm was made by determining the optimal values of six parameters such as compression ratio, ignition time, scavenging port area, exhaust port area, scavenging phase and exhaust phase. After optimization, the power(P) of the engine was increased by 7.6 % and the thermal efficiency(η) was enhanced by 3.2 % without knock. The results will lay a foundation for further design and research of two-stroke aviation RP-3 SI-DI engine.

Laboratory Tests of Electrical Parameters of the Start-Up Process of Single-Cylinder Diesel Engines

Despite continuous work on new power systems for vehicles, machines, and devices, the combustion engine is still the dominant system. The operation of the combustion engine is initiated during the starting process using starting devices. The most common starting system used is the electric starter. The starting process of an internal combustion engine depends on the following factors: the technical condition of the starting system, technical condition of the engine, battery charge level, lubricating properties, engine standstill time, engine and ambient temperature, type of fuel, etc. This article presents the results of laboratory tests of the electrical parameters of the starting process of a single-cylinder compression–ignition engine with variable fuel injection parameters and ambient temperature conditions. It was confirmed that for the increased fuel dose FD2, higher values of the measured electrical parameters (Imax, Pmax, and Pmed) were obtained compared to the series of tests with the nominal fuel dose. Knowledge of the values of the electrical parameters of the starting process is important not only for the user (vehicle driver, agricultural machinery operator, etc.), but above all for designers of modern starting systems for combustion engines and service personnel. The obtained results of testing the electrical parameters of the combustion engine during start-up may be helpful in designing new drive systems supported by a compression–ignition combustion engine.

Study to Establish the Relationship Between Fuel Injection Parameters and Exhaust Emission Content of Fishing Vessels’ Diesel Engines to Diagnose the Technical State

Fuel injection parameters of diesel engines are essential. It directly affects the process of forming the combustion mixture, fuel combustion, and emission formation. The fuel injection pressure with the pressure at the end of the compression stroke in the engine cylinder at the time of fuel injection is worth noting. If the above parameters are reduced compared to the technical requirements, the combustion process is incomplete, and soot emissions increase. On that basis, the article studies the relationship between fuel injection parameters and exhaust emissions by simulation and experimental methods, through which it is possible to recognize emission results for the diagnosis technical state of the fuel injection system and the group that encloses the engine’s combustion chamber. Research results on the 6CHE Yanmar diesel engines of the fishing vessels at zero load conditions show that. When soot emissions increase by more than 20%, the fuel injection pressure is reduced compared with technical requirements. The fuel injection system and the group that encloses the combustion chamber need to be maintained on time to prevent damage incidents that may occur and to ensure the safety of people and fishing vessels when operating at sea for a long time.

Impact of fuel injection parameters and hydrogen enrichment on CI engine characteristics fueeled with Ceiba pentandra biodiesel

ABSTRACT Alternative fuel resources are currently gaining popularity as a potential solution to the challenges caused by a shortage of petroleum fuels and the associated increase in environmental pollution. Hydrogen (H2) as an alternative fuel source is getting a lot of attention. The motivation of this research was to examine how the fuel injection parameters (FIP) and H2 enrichment influence CI engine features when blended with Ceiba pentandra biodiesel. Based on the findings of prior research work, a 20% biodiesel blend (B20) and optimal FIP of 260 bar and 27° BTDC were selected for this trial, along with 10 lpm of H2 enrichment. As compared to diesel at standard FIP, the synergistic action of B20 with H2 enrichment and optimum FIP achieved the goal of improving performance and combustion, leading to increased brake thermal efficiency (10%), cylinder pressure (5%), and heat release rate (7.4%) while reducing brake-specific fuel consumption (9%) and emitting lesser emissions of hydrocarbon (16%), carbon monoxide (12%), and smoke (18%) emissions than diesel, except Nitrogen oxides. Therefore, combining these two strategies of optimum FIP and H2 enrichment with novel Ceiba pentandra biodiesel blend opens the door to a healthier ecosystem with superior combustion and lesser emission.

Investigation of injection parameters coupled with fuel reactivity on combustion and emissions in dual direct-injection GCI engine

Fuel injection parameters and fuel reactivity significantly affect engine performance, combustion, and emissions. The dual direct-injection strategy could compensate for the insufficient heat release rate to improve the gasoline compression ignition (GCI) mode with medium injection pressure for high loads. This research aims to couple injection parameters and fuel reactivity to optimize the combustion, emissions, and engine performance of the dual direct-injection GCI mode at high loads. The effect of research octane number (RON) of gasoline, injection timing, and injection pressure of dual injection system on combustion and emissions was investigated. Results show that the optimized dual direct-injection GCI mode can simultaneously achieve high thermal efficiency, low emissions, and low maximum pressure rise rate (MPRR) at high loads with the maximum indicated mean effective pressure (IMEP) of about 16 bar with indicated thermal efficiency (ITE) of 48.5%. Delaying the injection timing of injector-1 reduced the peak pressure (Ppeak), MPRR, and NOx emissions. Ppeak, CO, NOx, and indicated specific fuel consumption (ISFC) decreased compared to the dual-injector simultaneous injection case when the injection timing of injector-2 was retarded to between 5 and 10°CA ATDC. Increasing the injection pressure of injector-2 reduced CO, THC, ISFC, and particulate emissions. Lower RON gasoline obtains higher ITE while higher RON gasoline obtains lower particulate emissions.

Macroscopic and microscopic spray characterisation of Low-Octane blends for gasoline compression ignition engines

Gasoline compression ignition is an advanced combustion technology that controls harmful emissions from low-octane fuels used in compression ignition engines. Fuel’s physical properties and injection strategy influence the fuel–air mixture formation and combustion. High volatile fuel and fuel injection pressure improve the spray atomisation and fuel–air mixture formation. Gasoline-diesel blends are widely investigated for gasoline compression ignition engine applications. This study investigated microscopic and macroscopic spray characteristics of 70 % v/v gasoline and 30 % v/v diesel blend (G70), 80 % v/v gasoline and 20 % v/v diesel blend (G80), and baseline diesel injected at different fuel injection pressures. Parameters such as liquid fuel spray penetration length, spray cone angle, and droplet size and velocity distributions were assessed. The results of these parameters help determine the effect of the fuel injection parameters on combustion. It was found that though the liquid spray penetration length was not significantly different for the three test fuels, G70 exhibited a slightly lower liquid spray penetration length than the other two test fuels. Increasing the diesel fraction in the test blend reduced the spray cone angle and improved the axial dispersion of the fuel spray. The spray droplet diameter reduced with increasing gasoline fraction in the test blend and the fuel injection pressure. Sauter mean diameter decreased by up to 20 % for G80 than baseline diesel and up to 36 % with an increased fuel injection pressure from 300 to 700 bar. This study addressed a significant research gap in the spray characteristics of gasoline-diesel blends and provided a benchmark for simulation based model validation.

Multipurpose optimization of fuel injection parameters for diesel engine using response surface methodology

The hike in fuel prices and rapid depletion of fuel reserves have compelled scientists to focus on energy conservation, environmental protection, engine performance improvement, and cost saving. The prime objective of the study is to compare the empirical results with response surface methodology (RSM) optimized results in order to check the accuracy of model designed by RSM. Therefore, the current study examines the effect of fuel injection parameters (nozzle opening pressure and protrusion) on diesel engine performance and exhaust emissions. RSM technique was applied to predict engine performance and exhaust emission parameters along with their optimization. The brake thermal efficiency (BTE) was incremented by 1.23 % for protrusion from 1.5 to 2.5 mm under 240 bar nozzle opening pressure (NOP). BTE was increased by 0.94 and 4.51 % for 1.5 and 2.5 mm protrusion respectively. CO emission was decremented by 4.47 and 11.31 % for 1.5 and 2.5 mm protrusion respectively when the NOP changed from 230 to 240 bar. RSM model optimized input conditions 240 bar pressure, 2.5 mm protrusion, and 1935.67 engine rpm. The engine was again tested on RSM-optimized conditions and the highest absolute percentage error (APE) of 4.42 % was obtained for NOx emission, while the lowest APE of 2.89 % was obtained for BSFC.

Methanol (M85) Port Fuel-Injected Spark Ignition Motorcycle Engine Development—Part 1: Combustion Optimization for Efficiency Improvement and Emission Reduction

<div>Limited fossil fuel resources and carbonaceous greenhouse gas emissions are two major problems the world faces today. Alternative fuels can effectively power internal combustion engines to address these issues. Methanol can be an alternative to conventional fuels, particularly to displace gasoline in spark ignition engines. The physicochemical properties of methanol are significantly different than baseline gasoline and fuel mixture-aim lambda; hence methanol-fueled engines require modifications in the fuel injection parameters. This study optimized the fuel injection quantity, spark timing, and air–fuel ratio for M85 (85% v/v methanol + 15% v/v gasoline) fueling of a port fuel-injected single-cylinder 500 cc motorcycle test engine. Comparative engine performance, combustion, and emissions analyses were performed for M85 and baseline gasoline. M85-fueled engine exhibited improved combustion characteristics such as higher peak in-cylinder pressure, heat release rate, and cumulative heat release due to higher flame speed and the effect of fuel oxygen. The brake thermal efficiency increased by up to 23% at lower loads and 8% at higher loads for M85 fueling. Carbon monoxide was reduced by 11.4–94% and 46.1–94.4% for M85 w.r.t. baseline gasoline at 2500 and 3500 rpm, respectively, at varying engine loads. Hydrocarbon emissions showed mixed trends for M85 w.r.t. baseline gasoline. Nitric oxide emissions were 4–90.2% higher for M85 w.r.t. baseline gasoline at 2500 rpm, at varying engine loads; however, mixed trends were observed at 1500 and 3500 rpm. Carbon monoxide, hydrocarbons, and nitric oxide emissions were 4.6, 38.9, and 84.3% lower for M85 than baseline gasoline during idling. Overall the M85-fueled motorcycle engine emitted fewer harmful pollutants, indicating its superior environmental sustainability, except for slightly higher NO emission.</div>

Coupling effect of shaft torsional vibration and advanced injection angle on medium-speed diesel engine block vibration

Engine body vibration is an important safety concern for diesel engines as it can lead to severe engine damages and even catastrophic failures. Traditional methods for excitation computation assume that the rotational speed and the cylinder pressure remain stable under each working cycle, which makes it impossible to precisely predict vibration peaks at certain frequencies. But in practice, the existence of shafting torsional vibration will lead to the fluctuation of rotational speed and cylinder pressure. To predict engine block vibration more accurately, this paper proposes a novel method considering the instantaneous variations in rotational speed and cylinder pressure. It is implemented by two steps. Firstly, an innovative model considering the coupling effect between shaft torsional vibration and advanced injection angle is proposed, it particularly explains how the cylinder pressure and instantaneous rotational speed vary due to the coupling effects. Secondly, the excitation forces that cause block vibration are analyzed and their computational formulas are improved. This method also considers the offset of excitation loading position caused by torsional vibration. The coupling model is experimentally verified and the excitations are loaded into a finite element model of the diesel engine for vibration response prediction. The results reveal that the coupled model can predict vibration peaks at sideband frequencies and thus makes the frequency spectrum much richer than that of the traditional method. Furthermore, it shows that the acceleration results obtained by the coupled model have better prediction accuracy than those obtained from traditional methods, with the deviation percentage reducing from 6.31% and 8.41% to 0.64% and 0.32% in the X and Z direction. It indicates that the coupled model is more reliable in predicting the vibration response of the engine block. Finally, the effect of advanced injection angle on engine block vibration is investigated and the optimal value of the advanced injection angle is determined to be 29 CA, which makes the engine block vibration reduced by 3.60%, 2.72%, and 3.16% in the X, Y, and Z direction comparing to the original advanced injection angle. Overall, this study presents an improved approach for predicting engine block vibrations and offers valuable insights for the design of shafting structures and fuel injection parameters in marine diesel engines.

A study on the impact of fuel injection parameters and boost pressure on combustion characteristics in a diesel engine using alcohol/diesel blends

Engine researchers focused on alcohol fuels since the invention of diesel engines in the 1900s, and the rise in petrochemical costs in the 1970s triggered this concern. This study investigates the impacts of the injection start timing, pilot injection application, and boost air pressure increase, on combustion and exhaust emissions in a common rail diesel engine fueled with ethanol/butan-2-ol/diesel blends. The lowest combustion noise was obtained in the pilot injection application as 83.8 dB in E15B3. The results indicated that the peak point of cylinder gas pressure rose by more than 5 % in the application of pilot fuel injection and advanced injection timing, compared to conventional engine operating conditions. However, maximum CO2 and NOx were seen in the pilot injection application using FBDF as 5.7 % and 670 ppm, respectively. As alcohol rate increases in fuel blends, the average 1.3 °CA in the ignition delay period was increased, while the total combustion period was shortened more than 6 °CA. This result shows that the combustion reactions of alcohol/diesel fuels occur faster than pure diesel. However, the variation in the ignition delay and total combustion periods of the test fuels considerably reduced with pilot fuel injection application. These results indicates that pilot fuel injection may be applied very controlled according to changing engine conditions. It was calculated in statistical analysis that except for the coefficient variation of the maximum pressure increase rate, the other coefficient variation values were relatively stable and below 3 %. In addition, it was determined that the results of the finite element analysis are proportional to the pressure values obtained experimentally.

Influence of fuel injection parameters at low-load conditions in a partially premixed combustion (PPC) based heavy-duty optical engine

The study examined the effects of second injection timings and fuel injection pressures (FIPs) in a double-injection based partially premixed combustion (PPC) using a single-cylinder heavy-duty optical diesel engine equipped with two different configurations, namely all-metal and optical. The thermodynamic analysis of energy balance, exhaust emissions, and particulates characterization was conducted in an all-metal engine configuration. For the same base engine architecture, high-speed natural combustion luminosity, cool-flame, and electronically excited hydroxyl (OH*) chemiluminescence, and planar laser-induced fluorescence (PLIF) imaging of formaldehyde (HCHO-PLIF) were applied in the optical configuration. Additionally, 1D modeling using GT-Power was utilized to examine the distribution of heat transfer losses through the individual cylinder boundaries. The experiments were conducted at low-load conditions at a fixed fuel mean effective pressure (MEPfuel) using a primary reference fuel with a volumetric mixture of 50% n-heptane and 50% iso-octane (PRF50). The results demonstrated that for a fixed first injection, the second injection timing of −6°CA aTDC is the most favorable condition due to increased gross indicated efficiency, reduced exhaust losses, decreased uHC/CO/soot emissions with a slight compromise on heat losses and NOx emissions. Among the tested FIPs of 1200, 1500, and 1800 bar, 1500 bar showed higher efficiency, and overall lower energy losses and exhaust emissions. At higher FIPs, the overall flame development process revealed reduced luminous intensity with dispersed signals formed downstream of the nozzle due to increased premixed combustion. For 1800 bar FIP, both cool-flame and HCHO signals showed an increased rate of reaction zones close to the bowl-wall region from where the OH radicals developed. Not only the initial low- to high-temperature reaction transition was faster for 1800 bar FIP but the signal decay of HCHO signals by OH radicals was also rapid in the late cycle. These findings explained the root cause of increased heat transfer losses and higher uHC/CO emissions at 1800 bar FIP.

A parametric study to improve first firing cycle emissions of a gasoline direct injection engine during cold start

A parametric study was carried out for the first firing cycle of a 4-cylinder, 2.0-liter, turbocharged gasoline direct injection (GDI) engine. The primary goal was to see how changes in the fuel injection parameters would affect the GDI engine combustion and emissions for the first four combustion events that constitute the first firing cycle. Experimental studies were carried out with a custom-designed powertrain control system to measure the HC emissions and pressure development for the first firing cycle. The quantitative experimental results were accompanied by simulations of the detailed temporal and spatial fuel concentration profiles using Converge CFD engine simulation software. An alternative calculation method was used to calculate the average combustion equivalence ratio for each of the four cylinders. This method showed that the majority of the cold start HC emissions during the first firing cycle was unburned gasoline and its possible decomposition products, which did not contribute significantly to the combustion and heat release. For the same amount of fuel injected into a cylinder, increased fuel rail pressure resulted in better evaporation and combustion, while slightly increasing the HC emissions during the cold start process. A multiple injection strategy was studied that split the fuel delivery between the intake stroke and the compression stroke with either one or two injections in each of those strokes (two or four injections total). The quadruple injection strategy led to better first cycle combustion, with higher engine IMEP and lower HC emissions. This resulted from a richer fuel mixture in the region near the spark plug due to better fuel evaporation and a better spatial fuel distribution. While increasing fuel rail pressure with either injection strategy failed to significantly lower the HC emissions given the same amount of injected fuel mass, higher rail pressure with the quadruple injection strategy resulted in higher IMEP for the same amount of injected fuel; this may provide the possibility to reduce the total fuel injection mass which may have benefits for both fuel consumption and emissions.

Optimization of a low heat rejection engine run on oxy‑hydrogen gas with a biodiesel-diesel blend

This experimental investigation examines the combined effects of varying compression ratio (CR) and fuel injection parameters such as fuel injection pressure (FIP) and start of injection (SOI) / injection timing on the performance of a dual-fuel low heat rejection (LHR) engine run on oxy‐hydrogen (HHO) gas with Jatropha biodiesel-diesel blend (JME20) as pilot fuel. The CR is varied from 16.5 to 18.5 in intervals of one, FIP is varied from 220 to 240 bar in intervals of 20 bar,and the SOI is varied from 24.5° to 27.5°CA bTDC in intervals of 1.5°CA. The performance, emission, and combustion characteristics of the dual-fueled LHR engine are studied, based on which the engine operating conditions are optimized. The results reveal that operating the LHR engine with 18.5 CR, 240 bar FIP, and 26°CA bTDC SOI using HHO in dual fuel operation mode with JME20 injected fuel gives better brake thermal efficiency (BTE) (6.6% higher than diesel) and combustion characteristics along with lower carbon monoxide (CO), hydrocarbon (HC), and smoke emissions. In contrast, a slight penalty in nitric oxide (NO) emissions is noticed irrespective of the engine operating conditions.

Thermodynamic analysis on coupling characteristic of Twin-VGT and fuel injection parameters at variable altitudes

ABSTRACT The decrease of inlet charge and mismatch of air and fuel are main reasons for the decrease of engine performance at variable altitudes. Understanding coupling mechanism between two-stage turbocharging and fuel injection system is key to maximize its potential for engine power recovery at variable altitudes. This paper focused on the coupling characteristic of twin variable geometry turbocharging (Twin-VGT) and fuel injection parameters on key parameters of gas path, in-cylinder combustion, and energy flow of the diesel engine at variable altitudes. Firstly, a thermodynamic cycle model of a Twin-VGT diesel engine aiming at variable altitudes was established and validated by experimental data. Furthermore, the coupling mechanism of high-pressure variable geometry turbocharging (HVGT) and low-pressure variable geometry turbocharging (LVGT) vanes on exhaust available energy (EAE), global expansion ratio (GER) and its distribution, global boost ratio (GBR) and its distribution, isentropic efficiency of the Twin-VGT, combustion process, and energy flow of the engine were studied at different altitudes. Enthalpy drop ratio is regulated by HVGT and LVGT and the isentropic efficiency of two-stage turbine reaches to maximum when openings of HVGT and LVGT at 0.35 and 0.75, respectively, at the altitude of 5500 m. Finally, this paper investigated the coupling characteristic of turbocharging and fuel injection parameters on combustion process and engine performance, which provides the theoretical basis for collaborative controlling of the Twin-VGT and fuel injection parameters at variable altitudes. Brake thermal efficiency (BTE) is affected by exhaust temperature which is mainly controlled by HVGT openings and injection advance angle (IAA) at variable altitudes, and BTE reaches to maximum when openings of HVGT at 0.4 and IAA at −5.5°CA under fixed engine load at the altitude of 5500 m.

Dynamic individual-cylinder analysis of a Gasoline Direct Injection engine emissions for cold crank-start at elevated cranking speed conditions of a Hybrid Electric Vehicle

The cold crank-start phase significantly contributes to the engine-out total emissions during the US Federal Test Procedure (FTP). A Gasoline Direct Injection (GDI) engine dynamics and emissions are investigated during the first three engine cycles of the cold crank-start in Hybrid Electric Vehicle (HEV) elevated cranking speed at 20 °C. To this end, the impact of the operating strategy on the individual-cylinder engine-out emissions is analyzed quantitatively. For this purpose, a new dynamic method was developed to translate the engine-out emissions concentration measured at the exhaust manifold outlet to mass per cycle per cylinder. The HEV elevated cranking speed provides valve timing control, throttling, and increased fuel injection pressure from the first firings. This study concentrates on analyzing the cranking speed, spark timing, valve timing, and fuel injection strategy and parameters effect on engine-out emissions. Design of Experiment (DOE) method is used to create a two-step multi-level fractional-factorial test plan with a minimum number of test points to evaluate the significant parameters affecting engine-out emissions during cold crank-start. Out of the first step DOE analysis, the optimal cranking speed, spark timing, and valve timing, which results in the lowest unburnt HydroCarbon (HC) and NOx emissions, are distinguished. Then, fixing the first step parameters at their optimal values, the second step is accomplished with the fuel injection parameters sweep. The split injection parameters, including the Start of the first Injection (SOI), End of the second injection (EOI), and split ratio (SR), in addition to the first cycle additive fuel factor, are investigated. Results show that the high cranking speed with stabilized low Manifold Absolute Pressure (MAP), highly-retarded spark timing, high valve overlap, late intake first injection, 30 CAD bTDC firing EOI, and low first cycle fuel factor reduces the HC emissions 94%.

Experimental investigations on the effect of fuel injection parameters on diesel engine fuelled with biodiesel blend in diesel with hydrogen enrichment

Fuel injection pressure and injection timing are two extensive injection parameters that affect engine performance, combustion, and emissions. This study aims to improve the performance, combustion, and emissions characteristics of a diesel engine by using karanja biodiesel with a flow rate of 10 L per minute (lpm) of enriched hydrogen. In addition, the research mainly focused on the use of biodiesel with hydrogen as an alternative to diesel fuel, which is in rapidly declining demand. The experiments were carried out at a constant speed of 1500 rpm on a single-cylinder, four-stroke, direct injection diesel engine. The experiments are carried out with variable fuel injection pressure of 220, 240, and 260 bar, and injection timings of 21, 23, and 25 °CA before top dead center (bTDC). Results show that karanja biodiesel with enriched hydrogen (KB20H10) increases BTE by 4% than diesel fuel at 240 bar injection pressure and 23° CA bTDC injection timing. For blend KB20H10, the emissions of UHC, CO, and smoke opacity are 33%, 16%, and 28.7% lower than for diesel. On the other hand NOx emissions, rises by 10.3%. The optimal injection parameters for blend KB20H10 were found to be 240 bar injection pressure and 23 °CA bTDC injection timing based on the significant improvement in performance, combustion, and reduction in exhaust emissions.

Study on interactive effects of CRDi engine operating parameters through RSM based multi-objective optimization technique for biofuel application

The current research focuses on the optimization of D+LPO (20% waste-based lemon peel oil and 80% diesel) fueled Common Rail Direct Injection (CRDi) engine fuel injection parameters for the optimum performance and emission characteristics. The foremost influential fuel injection parameters such as Injection Pressure (IP), Dwell Time (DT), Pilot Mass (PM) and Pilot Timing (PT) are considered to enhance the performance and decrease the emissions. Engine output responses like Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC), Hydrocarbons (HC), Carbon monoxide (CO), nitrogen oxides (NOx) and smoke emissions are modeled by using Response Surface Methodology (RSM). Analysis of Variance (ANOVA) disclosed that all the developed models are statistically significant with an R2 value of 0.9735 for BTE, 0.9719 for BSFC, 0.8517 for CO, 0.956 for HC, 0.9282 for NOx and 0.927 for smoke. Multi-objective optimization is performed using the desirability function approach to minimize the BSFC, HC, CO, NOx and smoke with maximum BTE. The D+LPO blend at IP 700 bar, PM 20%, PT 27°bTDC and 12° DT was predicted to be an optimum operating condition for this particular engine. Confirmatory tests were used to validate the predicted combination, and the prediction error was determined to be less than 5%.