Split Injection Strategies for Biodiesel-Fueled Premixed Charge Compression Ignition Combustion Engine—Part II: Particulate Studies

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Akhilendra Pratap Singh ◽  
Avinash Kumar Agarwal
Keyword(s):  
Fuel Injection ◽  
Combustion Engine ◽  
Chemical Characterization ◽  
Injection Pressure ◽  
Morphological Characterization ◽  
Pilot Injection ◽  
Compression Ignition ◽  
Main Injection ◽  
Fuel Injection Pressure ◽  
Injection Strategies

Abstract In this study, experiments were performed in a single-cylinder research engine to investigate the particulate matter (PM) characteristics of the engine operated in premixed charge compression ignition (PCCI) mode combustion vis-a-vis baseline compression ignition (CI) mode combustion using three test fuels, namely, B20 (20% v/v biodiesel blended with mineral diesel), B40 (40% v/v/ biodiesel blended with mineral diesel), and baseline mineral diesel. The experiments were carried out at constant fuel injection pressure (FIP) (700 bar), constant engine speed (1500 rpm), and constant fuel energy input (0.7 kg/h diesel equivalent). PM characteristics of PCCI mode combustion were evaluated using two different fuel injection strategies, namely, single pilot injection (SPI) (35 deg before top dead center (bTDC)) and double pilot injection (DPI) (35 deg and 45 deg bTDC) at four different start of main injection (SoMI) timings. Results showed that both PCCI mode combustion strategies emitted significantly lower PM compared to baseline CI mode combustion strategy. However, the blending of biodiesel resulted in relatively higher PM emissions from both CI and PCCI combustion modes. Chemical characterization of PM showed that PCCI mode combustion emitted relatively lower trace metals compared to baseline CI mode combustion, which reduced further for B20. For detailed investigations of particulate structure, morphological characterization was done using transmission electron microscopy (TEM), which showed that PM emitted by B20-fueled PCCI mode combustion posed potentially lower health risk compared to baseline mineral diesel-fueled CI mode combustion.

Split Injection Strategies for Biodiesel-Fueled Premixed Charge Compression Ignition Combustion Engine—Part I: Combustion, Performance, and Emission Studies

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Akhilendra Pratap Singh ◽  
Avinash Kumar Agarwal
Keyword(s):  
Fuel Injection ◽  
Combustion Engine ◽  
Injection Pressure ◽  
Pilot Injection ◽  
Compression Ignition ◽  
Load Range ◽  
Performance And Emission ◽  
Combustion Performance ◽  
Combustion Modes ◽  
Injection Strategies

Abstract In this study, a single-cylinder research engine was used to investigate the comparative combustion, performance, and emissions characteristics of the engine in a premixed charge compression ignition (PCCI) mode combustion vis-a-vis baseline compression ignition (CI) mode combustion using three test fuels, namely, B20 (20% v/v biodiesel blended with mineral diesel), B40 (40% v/v biodiesel blended with mineral diesel), and mineral diesel. For both combustion modes, experiments were performed at constant fuel injection pressure (FIP, 700 bar), engine speed (1500 rpm), and fuel energy input (0.7 kg/h diesel equivalent). PCCI mode combustion experiments were performed at four different start of main injection (SoMI) timings using two different pilot fuel injection strategies, namely, single pilot injection (SPI, 35 deg before top dead center (bTDC)) and double pilot injection (DPI, 35 deg, and 45 deg bTDC). Results showed that advancing SoMI timing for both CI and PCCI combustion modes resulted in knocking; however, the DPI strategy resulted in relatively lesser knocking compared with the SPI strategy. The performance of PCCI mode combustion was relatively inferior compared with baseline CI mode combustion; however, biodiesel blends slightly improved the performance of PCCI mode combustion. Overall, this study shows that the PCCI mode combustion operating load range can be improved by using the DPI strategy.

Optimization of operating parameters of an off-road automotive diesel engine running at highway drive conditions using Response Surface Methodology

2020 ◽  
pp. 1-48 ◽  
Author(s):  
Vinod Babu Marri ◽  
K. Madhu Murthy ◽  
G. Amba Prasad Rao
Keyword(s):  
Response Surface Methodology ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Operating Parameters ◽  
Injection Timing ◽  
Boost Pressure ◽  
Pilot Injection ◽  
Injection Quantity ◽  
Main Injection ◽  
Fuel Injection Pressure

Abstract The typical tradeoff between the two major emissions from compression ignition (CI) engines, smoke and oxides of nitrogen, is the unresolved challenge to the researchers. Techniques like engine downsizing, lowering intake oxygen concentration, multiple injections, use of retarded injection timings and higher injection pressures, etc. are widely employed for the alleviation of these harmful emissions. The influence of variation of fuel injection pressure (FIP), boost pressure, pilot injection timing (PIT), pilot injection quantity (PIQ) and main injection timing (MIT) are experimentally investigated in the present work. Mahindra mHawk four-cylinder diesel engine with provisions of a variable-geometry turbocharger (VGT), exhaust gas recirculation (EGR), and common-rail direct injection (CRDi) is chosen for the experimentation. Test runs are conducted at 1750 rpm and 80.3 N.m (4.6 bar bmep) corresponding to highway drive conditions, using 10 % EGR. Response surface methodology is employed for the design of experiments and to analyze the experimental data. Multi-objective response optimization is carried out to optimize engine-operating parameters that give desired performance and engine-out emissions. Confirmatory tests are conducted at design conditions to validate the results predicted by the model. This study reveals that the optimum performance and emission characteristics could be obtained using 120 kPa boost pressure; 61.1 MPa fuel injection pressure; 11.5 % pilot injection quantity with pilot injection at 332 °CA and main injection at 359 °CA.

Effect of Fuel Injection Pressure and Premixed Ratio on Mineral Diesel-Methanol Fueled Reactivity Controlled Compression Ignition Mode Combustion Engine

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Akhilendra Pratap Singh ◽  
Nikhil Sharma ◽  
Dev Prakash Satsangi ◽  
Avinash Kumar Agarwal
Keyword(s):  
Fuel Injection ◽  
Combustion Engine ◽  
Engine Performance ◽  
Injection Pressure ◽  
High Reactivity ◽  
Compression Ignition ◽  
Oxides Of Nitrogen ◽  
Reactivity Controlled Compression Ignition ◽  
Hc Emissions ◽  
Fuel Injection Pressure

Abstract Reactivity controlled compression ignition (RCCI) mode combustion has attracted significant attention because of its superior engine performance and significantly lower emissions of oxides of nitrogen (NOx) and particulate matter (PM) compared with conventional compression ignition (CI) mode combustion engines. In this experimental study, effects of fuel injection pressure (FIP) of high reactivity fuel (HRF) and premixed ratio of low reactivity fuel (LRF) were evaluated on a diesel-methanol fueled RCCI mode combustion engine. Experiments were performed in a single cylinder research engine at a constant engine speed (1500 rpm) and constant engine load (3 bar BMEP) using three different FIPs (500, 750, and 1000 bar) of mineral diesel and four different premixed ratios (rp = 0, 0.25, 0.50, and 0.75) of methanol. Results showed that RCCI mode resulted in more stable combustion compared with baseline CI mode combustion. Increasing FIP resulted in relatively higher knocking, but it reduced with increasing premixed ratio. Relatively higher brake thermal efficiency (BTE) of RCCI mode combustion compared with baseline CI mode combustion is an important finding of this study. BTE increased with increasing FIP of mineral diesel and increasing premixed ratio of methanol. Relatively dominant effect of increasing FIP on BTE at higher premixed ratios of methanol was also an important finding of this study. RCCI mode combustion resulted in higher carbon monoxide (CO) and hydrocarbon (HC) emissions, but lower PM and NOx emissions compared with baseline CI mode combustion. Increasing FIP of HRF at lower premixed ratios reduced the number concentration of particles; however, effect of FIP became less dominant at higher premixed ratios. Relatively higher number emissions of nanoparticles at higher FIPs were observed. Statistical and qualitative correlations exhibited the importance of suitable FIP at different premixed ratios of LRF on emission characteristics of RCCI mode combustion engine.

Fuel Injection Strategy for Utilization of Mineral Diesel-Methanol Blend in a Common Rail Direct Injection Engine

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Akhilendra Pratap Singh ◽  
Nikhil Sharma ◽  
Vikram Kumar ◽  
Dev Prakash Satsangi ◽  
Avinash Kumar Agarwal
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Injection Pressure ◽  
Pilot Injection ◽  
Oxides Of Nitrogen ◽  
Gas Temperature ◽  
Injection Strategy ◽  
Main Injection ◽  
Pilot Fuel ◽  
Fuel Injection Pressure

Abstract Methanol fueled internal combustion (IC) engines have attracted significant attention due to their contributions in reducing environmental pollution and fossil fuel consumption. In this study, a single-cylinder research engine was operated on MD10 (10% (v/v) methanol blended with mineral diesel) and baseline mineral diesel to explore an optimized fuel injection strategy for efficient combustion and reduced emissions. The experiments were conducted at constant engine speed (1500 rpm) and load (3 kW) using two different fuel injection strategies, namely, single pilot injection (SPI) and double pilot injection (DPI) strategy. For each pilot fuel injection strategy, the start of main injection (SoMI) timing was varied from −3 to 6° crank angle (CA) before top dead center (bTDC). To examine the effect of fuel injection pressure (FIP), experiments were performed at three different FIPs (500, 750, and 1000 bars). Results showed that the MD10 fueled engine resulted in superior combustion compared with baseline mineral diesel, which was further improved by DPI at higher FIPs. The use of DPI strategy was found to be more effective at higher FIPs, resulting in higher brake thermal efficiency (BTE), lower exhaust gas temperature (EGT), and reduced oxides of nitrogen (NOx) emissions compared with SPI strategy. Detailed investigations showed that the addition of methanol in mineral diesel reduced particulates, especially the accumulation mode particles (AMP). Different statistical analysis and qualitative correlations between fuel injection parameters showed that higher FIP and advanced SoMI timings were suitable for particulate reduction from the MD10 fueled engine.

Experimental investigation of dwell time characteristics in high-pressure double-solenoid-valve fuel injection system

2019 ◽  
Vol 233 (13) ◽  
pp. 3281-3292
Author(s):  
Dan Xu ◽  
Qing Yang ◽  
Xiaodong An ◽  
Baigang Sun ◽  
Dongwei Wu ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Injection Pressure ◽  
Solenoid Valve ◽  
Injection System ◽  
Fuel Injection System ◽  
Pilot Injection ◽  
Main Injection ◽  
Injection Interval ◽  
The Difference ◽  
Variation Rule

The double-solenoid-valve fuel injection system consists of an electronic unit pump and an electronic injector. It can realize the separate control of fuel supply and injection and has the advantages of adjusting pressure by cycle and flexible controlling of the injection rate. The interval angle between the pilot and main injection directly affects the action degree and the characteristics of two adjacent injections, affecting engine performance. This work realizes multiple injection processes on the test platform of a high-pressure double-solenoid-valve fuel injection system, with maximum injection pressure reaching 200 MPa. In this study, the interval between driven current signal of pilot injection termination and that of main injection initiation is defined as the signal interval (DT1), whereas the interval between pilot injection termination and main injection initiation is defined as the injection interval (DT2). The differences between the signal and the injection intervals are calculated, and the variation rule of the difference with respect to the signal interval is analyzed. Results show that the variation rule of the difference with the signal interval first decreases, then increases, and finally decreases. The variation rule of the delay angle from the start of needle movement to the start of fuel injection is found to be the root cause of this rule. The influence of the injection pressure on needle deformation and fuel flow rate of the nozzle results in the variation rule. In addition, the influence of the cam speed, temperature, and pipe length on the difference between the signal and injection interval is determined. This research provides guidance for an optimal control strategy of the fuel injection process.

scholarly journals Effect of port injection pressure on mixture quality in Homogeneous charges compression ignition (HCCI) engine

2021 ◽  
Vol 9 (2) ◽  
pp. 37-41
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Injection Pressure ◽  
The Other ◽  
Emission Characteristics ◽  
Compression Ignition ◽  
Fuel Injector ◽  
Compression Ignition Engine ◽  
Hcci Engine ◽  
Fuel Injection Pressure

The purpose of this study is to investigate the effect of fuelinjection pressure onhomogeneous charge formation and performanceand emission characteristics of Homogeneous charge compression ignition engine. The fuel injection pressure isone of the primary parameter for improvingthe homogeneity of the mixture and governing the power output and emission characteristics of HCCI engine. In this investigation, diesel fuelwasinjected at different injection pressuresas 2bar, 3bar, 4bar and 5bar respectively throughbyport fuel injector. The experimental investigationsshow that increasing the fuel injection pressure will promote the fuel to penetrate with air and creates well pre mixedair/fuel charge.The result shows, the specific fuel consumption (SFC) of HCCI engine isslightlyhigherthan the SFC of conventional diesel engine.The HCCI engine with 3bar injection pressure operated engine has lower SFC values compared to other injection pressure operated HCCI engine.The brake thermal efficiency of HCCI engine, operated with 3barinjection pressure has maximum BTE values over the other injection pressure operated engine.From theresult, it is observed that HCCI engine has lower smoke density values compared to conventional diesel engine andfurther reducedby increasing the fuel injection pressure. The 3bar injection pressure operated HCCI engine has emitted lower smoke densitycompared to other injection pressure operated HCCI engine. The 3bar injection pressureoperated HCCIengine hasemittedmaximum oxides of nitrogen (NOx) emissions than the other injection pressure operated HCCI engine. Other exhaust emissions of carbon monoxide (CO) and hydrocarbon (HC)emissions are increased when compared toconvention diesel engine

Simultaneous Schlieren–PLIF Studies for Ignition and Soot Luminosity Visualization With Close-Coupled High-Pressure Double Injections of n-Dodecane

2017 ◽  
Vol 139 (1) ◽  
Author(s):  
Ahmed Abdul Moiz ◽  
Khanh D. Cung ◽  
Seong-Young Lee
Keyword(s):  
Ignition Delay ◽  
Dwell Time ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Constant Density ◽  
Ambient Temperatures ◽  
Soot Precursors ◽  
Planar Laser ◽  
Main Injection ◽  
Fuel Injection Pressure

Studies are performed in a constant volume preburn type combustion vessel over a range of ambient temperatures (750 K, 800 K, and 900 K) at constant density (22.8 kg/m3) with 15% O2 by volume in the ambient at 1200 bar (n-dodecane) fuel injection pressure. The influence of the pilot (first) spray flame on the ignition and combustion characteristics of the main (second) injection is investigated while varying injection pressure, dwell time, and injection strategy. Simultaneous schlieren (with soot luminosity imaging) and 355 nm planar laser-induced fluorescence (PLIF) imaging for formaldehyde (CH2O) and polycyclic aromatic hydrocarbons (PAH) visualization was performed. At both 900 K and 800 K ambient, main injection exhibits a reduction in ignition delay (ID) by a factor of 2 over their respective pilots. For the ambient temperature condition of 750 K, reducing injection pressure from 1500 bar to 1200 bar causes a significant increase in ignition delay (by ∼0.8 ms), which was attributed to the influence of injection pressure on spray-mixing and early development of cool flame. Also, at 750 K ambient condition, multiple injection schedule having two 0.5 ms injections separated by a 0.5 ms dwell was found to have a shorter ignition delay than a single 0.5 ms injection. Studies carried at an 800 K ambient show that by increasing the dwell time, main interaction with pilot reactive intermediates can be controlled to avoid an early rich ignition of the main spray and to reduce soot precursors.

A Study on the Performance and Emissions Characteristics of a DI Compression Ignition Engine Operated With LPG and DTBP Blending Fuels

2011 ◽  
Author(s):  
Hoin Kang ◽  
Jerald A. Caton ◽  
Seangwock Lee ◽  
Seokhwan Lee ◽  
Seungmook Oh
Keyword(s):  
Combustion Chamber ◽  
Fuel Injection ◽  
Ambient Pressure ◽  
Injection Pressure ◽  
Chamber Pressure ◽  
Injection Timing ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Bench Tests ◽  
Fuel Injection Pressure

LPG (Liquefied Petroleum Gas) has been widely used as an alternative fuel for gasoline and diesel vehicles in light of clean fuel and diversity of energy resources. But conventional LPG vehicles using carburetors or MPI fuel injection systems can’t satisfy the emissions regulations and CO2 targets of the future. Therefore, it is essential to develop LPG engines of spark ignition or compression ignition type such that LPG fuel is directly injected into the combustion chamber under high pressure. A compression ignition engine using LPG is the ideal engine with many advantages of fuel economy, heat efficiency and low CO2, even though it is difficult to develop due to the unique properties of LPG. This paper reports on numerical and experimental studies related to LPG fuel for a compression ignition engine. The numerical analysis is conducted to study the combustion chamber shape with CATIA and to analyze the spray and fluid behaviors with FLUENT for diesel and LPG (n-butane 100%) fuels. In one experimental study, a constant volume chamber is used to observe the spray formation for the chamber pressure 0 to 3MPa and to analyze the flame process, P-V diagram, heat release rate and emissions through the combustion of LPG fuel with the cetane additive DTBP (Di-tert-butyl peroxide) 5 to 15 wt% at 25MPa of fuel injection pressure. In engine bench tests, experiments were performed to find the optimum injection timing, lambda, COV and emissions for the LPG fuel with the cetane additive DTBP 5 to 15 wt% at 25MPa fuel injection pressure and 1500 rpm. The penetration distance of LPG (n-butane 100%) was shorter than that of diesel fuel and LPG was sensitive to the chamber pressure. The ignition delay was in inverse proportion to the ambient pressure linearly. In the engine bench tests, the optimum injection timing of the test engine to the LPG fuel with DTBP 15 wt% was about BTDC 12° CA at all loads and 1500 rpm. An increasing of DTBP blending ratio caused the promotion of flame and fast burn and this lead to reduce HC and CO emissions, on the other hand, to increase NOx and CO2 emissions.

scholarly journals Effect of Premixed Fuel Preparation for Partially Premixed Combustion With a Low Octane Gasoline on a Light-Duty Multicylinder Compression Ignition Engine

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Adam B. Dempsey ◽  
Scott Curran ◽  
Robert Wagner ◽  
William Cannella
Keyword(s):  
High Pressure ◽  
Thermal Efficiency ◽  
Fuel Injection ◽  
Premixed Combustion ◽  
Injection System ◽  
Injection Timing ◽  
Pilot Injection ◽  
Compression Ignition ◽  
Partially Premixed Combustion ◽  
Injection Strategies

Gasoline compression ignition (GCI) concepts with the majority of the fuel being introduced early in the cycle are known as partially premixed combustion (PPC). Previous research on single- and multicylinder engines has shown that PPC has the potential for high thermal efficiency with low NOx and soot emissions. A variety of fuel injection strategies have been proposed in the literature. These injection strategies aim to create a partially stratified charge to simultaneously reduce NOx and soot emissions while maintaining some level of control over the combustion process through the fuel delivery system. The impact of the direct injection (DI) strategy to create a premixed charge of fuel and air has not previously been explored, and its impact on engine efficiency and emissions is not well understood. This paper explores the effect of sweeping the direct injected pilot timing from −91 deg to −324 deg ATDC, which is just after the exhaust valve closes (EVCs) for the engine used in this study. During the sweep, the pilot injection consistently contained 65% of the total fuel (based on command duration ratio), and the main injection timing was adjusted slightly to maintain combustion phasing near top dead center. A modern four cylinder, 1.9 l diesel engine with a variable geometry turbocharger (VGT), high pressure common rail injection system, wide included angle injectors, and variable swirl actuations was used in this study. The pistons were modified to an open bowl configuration suitable for highly premixed combustion modes. The stock diesel injection system was unmodified, and the gasoline fuel was doped with a lubricity additive to protect the high pressure fuel pump and the injectors. The study was conducted at a fixed speed/load condition of 2000 rpm and 4.0 bar brake mean effective pressure (BMEP). The pilot injection timing sweep was conducted at different intake manifold pressures, swirl levels, and fuel injection pressures. The gasoline used in this study has relatively high fuel reactivity with a research octane number of 68. The results of this experimental campaign indicate that the highest brake thermal efficiency (BTE) and lowest emissions are achieved simultaneously with the earliest pilot injection timings (i.e., during the intake stroke).

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