Empirical Study of Simultaneously Low NOx and Soot Combustion With Diesel and Ethanol Fuels in Diesel Engine

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Xiaoye Han ◽  
Kelvin Xie ◽  
Jimi Tjong ◽  
Ming Zheng
Keyword(s):  
Direct Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Injection Timing ◽  
Single Shot ◽  
Low Temperature Combustion ◽  
Load Range ◽  
Engine Load ◽  
Indicated Mean Effective Pressure ◽  
Soot Emissions

Diesel low temperature combustion (LTC) is capable of producing diesel-like efficiency while emitting ultra-low nitrogen oxides (NOx) and soot emissions. Previous work indicates that well-controlled single-shot injection with exhaust gas recirculation (EGR) is an operative way of achieving diesel LTC from low to mid engine loads. However, as the engine load is increased, demanding intake boost and injection pressure are necessary to suppress high soot emissions during the transition to LTC. The use of volatile fuels such as ethanol is deemed capable of promoting the cylinder charge homogeneity, which helps to overcome the high soot challenge and, thus, potentially expand the engine LTC load range. In this work, LTC investigations were carried out on a high compression ratio (18.2:1) engine. Engine tests were first conducted with diesel and LTC operation at 8 bar indicated mean effective pressure (IMEP) was enabled by sophisticated control of the injection pressure, injection timing, intake boost, and EGR application. The engine performance was characterized as the baseline, and the challenges were identified. Further tests were aimed to improve the engine performance against these baseline results. Experiments were, hence, conducted on the same engine with secondary ethanol port fuelling (PF). Single-shot diesel direct injection (DI) was applied close to top dead center (TDC) to ignite the ethanol and control the combustion phasing. The control sensitivity was studied through injection timing sweeps and EGR sweeps. Additional tests were performed to investigate the ethanol-to-diesel ratio effects on the mixture reactivity and the engine emissions. Engine load was also raised to 16.4 bar IMEP while keeping the simultaneously low NOx and soot emissions. Significant improvement of engine control and emissions was achieved by the DI+PF strategy.

Empirical Study of Simultaneously Low NOx and Soot Combustion With Diesel and Ethanol Fuels in Diesel Engine

2012 ◽  
Author(s):  
Xiaoye Han ◽  
Tongyang Gao ◽  
Usman Asad ◽  
Kelvin Xie ◽  
Ming Zheng
Keyword(s):  
Direct Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Injection Timing ◽  
Single Shot ◽  
Low Temperature Combustion ◽  
Load Range ◽  
Engine Load ◽  
Indicated Mean Effective Pressure ◽  
Soot Emissions

Diesel low temperature combustion (LTC) is capable of producing diesel-like efficiency while emitting ultra-low nitrogen oxides (NOx) and soot emissions. Previous work indicates that well controlled single-shot injection with exhaust gas recirculation (EGR) is an operative way of achieving diesel LTC from low to mid engine loads. However, as the engine load is increased, demanding intake boost and injection pressure are necessary to suppress high soot emissions during the transition to LTC. The use of volatile fuels such as ethanol are deemed capable of promoting the cylinder charge homogeneity, which helps to overcome the high soot challenge and thus potentially expand the engine LTC load range. In this work, LTC investigations have been carried out on a high compression ratio (18.2:1) engine. The engine was firstly fuelled with diesel, and LTC operation at 8 bar indicated mean effective pressure (IMEP) was enabled by sophisticated control of the injection pressure, injection timing, intake boost and EGR application. The engine performance was characterized as the baseline, and the challenges were identified. Further tests were aimed to improve the engine performance against these baseline results. Experiments were hence conducted on the same engine with secondary ethanol port injection (PI). Single-shot diesel direct injection (DI) was applied close to top dead center (TDC) to ignite the ethanol and control the combustion phasing. The control sensitivity has been studied through injection timing sweeps and EGR sweeps. Additional tests were performed to investigate the ethanol-to-diesel ratio effects on the mixture reactivity and the engine emissions. Engine load was also raised to 10 bar IMEP while keeping the simultaneously low NOx and soot emissions. Significant improvement of engine control and emissions was achieved by the DI+PI strategy.

Preliminary Investigation of Direct Injection Neat n-Butanol in a Diesel Engine

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Tadanori Yanai ◽  
Xiaoye Han ◽  
Graham T. Reader ◽  
Ming Zheng ◽  
Jimi Tjong
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Preliminary Investigation ◽  
Pressure Rise ◽  
Engine Performance ◽  
Injection Pressure ◽  
Injection Timing ◽  
Boost Pressure ◽  
Indicated Mean Effective Pressure ◽  
Rise Rate

The characteristics of combustion, emissions, and thermal efficiency of a diesel engine with direct injection (DI) neat n-butanol were investigated. The engine ran at a load of 6.5–8.0 bar indicated mean effective pressure (IMEP) at 1500 rpm engine speed and the injection pressure was controlled to 900 bar. The intake boost pressure, injection timing, and EGR rate were adjusted to investigate the engine performance. The tests demonstrated that neat n-butanol had the potential to achieve ultralow emissions. However, challenges related to reducing the pressure rise rate and improving the ignition controllability were identified.

RCCI of Synthetic Kerosene With PFI of N-Butanol-Combustion and Emissions Characteristics

2015 ◽  
Author(s):  
Valentin Soloiu ◽  
Martin Muiños ◽  
Tyler Naes ◽  
Spencer Harp ◽  
Marcis Jansons
Keyword(s):  
Thermal Efficiency ◽  
Fuel Injection ◽  
Direct Injection ◽  
Cetane Number ◽  
Engine Performance ◽  
Reactivity Controlled Compression Ignition ◽  
Ultra Low Sulfur Diesel ◽  
Indicated Mean Effective Pressure ◽  
Soot Emissions ◽  
Low Sulfur

In this study, the combustion and emissions characteristics of Reactivity Controlled Compression Ignition (RCCI) obtained by direct injection (DI) of S8 and port fuel injection (PFI) of n-butanol were compared with RCCI of ultra-low sulfur diesel #2 (ULSD#2) and PFI of n-butanol at 6 bar indicated mean effective pressure (IMEP) and 1500 rpm. S8 is a synthetic paraffinic kerosene (C6–C18) developed by Syntroleum and is derived from natural gas. S8 is a Fischer-Tropsch fuel that contains a low aromatic percentage (0.5 vol. %) and has a cetane number of 63 versus 47 of ULSD#2. Baselines of DI conventional diesel combustion (CDC), with 100% ULSD#2 and also DI of S8 were conducted. For both RCCI cases, the mass ratio of DI to PFI was set at 1:1. The ignition delay for the ULSD#2 baseline was found to be 10.9 CAD (1.21 ms) and for S8 was shorter at 10.1 CAD (1.12 ms). In RCCI, the premixed charge combustion has been split into two regions of high temperature heat release, an early one BTDC from ignition of ULSD#2 or S8, and a second stage, ATDC from n-butanol combustion. RCCI with n-butanol increased the NOx because the n-butanol contains 21% oxygen, while S8 alone produced 30% less NOx emissions when compared to the ULSD#2 baseline. The RCCI reduced soot by 80–90% (more efficient for S8). However, S8 alone showed a considerable increase in soot emissions compared with ULSD#2. The indicated thermal efficiency was the highest for the ULSD#2 and S8 baseline at 44%. The RCCI strategies showed a decrease in indicated thermal efficiency at 40% ULSD#2-RCCI and 42% and for S8-RCCI, respectively. S8 as a single fuel proved to be a very capable alternative to ULSD#2 in terms of combustion performance nevertheless, exhibited higher soot emissions that have been mitigated with the RCCI strategy without penalty in engine performance.

Distribution of Two-Stage Direct Injection CNG-Air Mixture near Lean Limit Using CFD

2013 ◽  
Vol 465-466 ◽  
pp. 448-452
Author(s):  
Mas Fawzi ◽  
Bukhari Manshoor ◽  
Yoshiyuki Kidoguchi ◽  
Yuzuru Nada
Keyword(s):  
Fuel Injection ◽  
Direct Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Gas Jet ◽  
Exhaust Emission ◽  
Injection Technique ◽  
Injection Timing ◽  
Two Stage ◽  
Lean Burn

Previous work shows that gas-jet ignition with two-stage injection technique is effective to extend lean combustible ranges of CNG engines. In this report, the robustness of the gas-jet ignition with two-stage injection method was investigated purposely to improve the performance of a lean burn direct injection CNG engine. The experiment was conducted using an engine at speed of 900 rpm, fuel-injection-pressure of 3MPa, equivalence ratio at 0.8, and ignition timing at top dead center. The effect of first injection timing on the test engine performance and exhaust emission was analyzed. First injection timings near the gas-jet ignition produced unstable combustion with occurrence of misfires except at a timing which produced distinctively good combustion with low HC and CO emissions. Computational fluid dynamics was used to provide hindsight of the fuel-air mixture distribution that might be the cause of misfires occurrence at certain injection timings.

Investigation on the combustion noise of a pilot-ignited direct-injection natural-gas engine

2016 ◽  
Vol 230 (14) ◽  
pp. 1942-1957 ◽  
Author(s):  
Menghan Li ◽  
Qiang Zhang ◽  
Guoxiang Li
Keyword(s):  
Natural Gas ◽  
Direct Injection ◽  
Injection Pressure ◽  
Pressure Level ◽  
Combustion Noise ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Engine Load ◽  
Gas Engine ◽  
Natural Gas Engine

In this paper, the effects of the injection timing, the injection pressure and the engine load on the combustion noise of a pilot-ignited direct-injection natural-gas engine were explored by analysing the separate components of the in-cylinder pressure. The results suggested that retarding the injection timing and reducing the injection pressure are effective ways of controlling the combustion noise. This can be attributed to the promoted burning rate at advanced injection timings and to the increased injection pressure. However, the effect of the engine load seems to be less obvious, although the resonance pressure level appears to increase with increasing engine load; the estimated combustion noise shows a decreasing tendency.

Analysis of the Combustion Process in a EURO III Heavy-Duty Direct Injection Diesel Engine

2002 ◽  
Vol 124 (3) ◽  
pp. 636-644 ◽  
Author(s):  
J. M. Desantes ◽  
J. V. Pastor ◽  
J. Arre`gle ◽  
S. A. Molina
Keyword(s):  
High Speed ◽  
Direct Injection ◽  
Combustion Process ◽  
Engine Performance ◽  
Injection Pressure ◽  
Pollutant Emissions ◽  
Injection Timing ◽  
Engine Operation ◽  
Operation Conditions ◽  
Representative Points

To fulfill the commitments of future pollutant regulations, current development of direct injection (DI) Diesel engines requires to improve knowledge on the injection/combustion process and the effect of the injection parameters and engine operation conditions upon the spray and flame characteristics and how they affect engine performance and pollutant emissions. In order to improve comprehension of the phenomena inherent to Diesel combustion, a deep experimental study has been performed in a single-cylinder engine with the main characteristics of a six-cylinder engine passing the EURO III legislation. Some representative points of the 13-mode engine test cycle have been considered modifying the nominal values of injection pressure, injection load, intake pressure, engine speed, and injection timing. The study combines performance and emissions experimental measurements together with heat release law (HRL) analysis and high-speed visualization. Controlling parameters for BSFC, NOx, and soot emissions are identified in the last part of the paper.

Injection Timing Variation and its Influence on the Performance and Combustion Characteristics on a Direct Injection CI Engine

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
V. Hariram ◽  
S. Seralathan ◽  
M. Rajasekaran ◽  
G. John
Keyword(s):  
Direct Injection ◽  
Pressure Rise ◽  
Engine Performance ◽  
Injection Pressure ◽  
Injection Timing ◽  
Gas Temperature ◽  
Optimum Parameters ◽  
Rate Of Heat Release ◽  
Ci Engine ◽  
And Performance

The present experimental investigation aims at improving the combustion and performance parameters by varying the injection timing. A 3.5 kW single cylinder stationary CI engine equipped with eddy current dynamometer is used in this investigation. The static injection timing is varied using spill method by an advancement and retirement of 2 CAD with respect to standard injection timing of 23 BTDC. On comparison with the standard injection timing, the brake thermal efficiency, cylinder pressure, rate of heat release, mean gas temperature and rate of pressure rise are found to increase along with a significant decrease in brake specific fuel consumption for an advanced injection timing of 21 BTDC. Negative improvement is observed with respect to retarded injection timing of 25 BTDC. Optimum parameters for enhanced engine performance is found to be 21 BTDC injection timing with a 200 bar injection pressure at rated speed.

scholarly journals Experimental investigation on performance and emission characteristics of diesel - Jatropha methyl ester blends fueled diesel engine at optimum engine operating parameters

2010 ◽  
Vol 7 (2) ◽  
pp. 399-406 ◽  
Author(s):  
M. Venkatraman ◽  
G. Devaradjane
Keyword(s):  
Diesel Engine ◽  
Methyl Ester ◽  
Compression Ratio ◽  
Direct Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Injection Timing ◽  
Performance And Emission ◽  
Performance And Emissions ◽  
Blended Fuel

In the present investigation, tests were carried out to determine engine performance, combustion and emissions of a naturally aspirated direct injection diesel engine fueled with diesel and Jatropha Methyl ester and their blends (JME10, JME20 and JME30). Comparison of performance and emission was done for different values of compression ratio, injection pressure and injection timing to find best possible combination for operating engine with JME. It is found that the combined compression ratio of 19:1, injection pressure of 240 bar and injection timing of 27?bTDC increases the BTHE and reduces BSFC while having lower emissions.From the investigation, it is concluded that the both performance and emissions can considerably improved for Methyl ester of jatropha oil blended fuel JME20 compared to diesel.

scholarly journals Influence of Ultra Injection Pressure with Dynamic Injection Timing on CRDI Engine Performance Using Simarouba Biodiesel Blends

2018 ◽  
Vol 15 (4) ◽  
pp. 5748-5759
Author(s):  
Srinath Pai ◽  
Abdul Sharief ◽  
Shiva Kumar
Keyword(s):  
Diesel Engine ◽  
High Speed ◽  
Direct Injection ◽  
Engine Performance ◽  
Injection Pressure ◽  
Injection Timing ◽  
Brake Thermal Efficiency ◽  
High Speed Diesel ◽  
Performance And Emissions ◽  
Smoke Opacity

A single cylinder diesel engine upgraded to operate Common Rail Direct Injection (CRDI) system and employed in this investigation. Tests were conducted on this engine using High-Speed diesel (HSD) and Simarouba biodiesel (SOME) blends to determine the influence of Injection Pressure (IP) and Injection Timing (IT) on the performance and emissions. Four unique IP of 400 bar to 1000 bar, in steps of 200 bar and four differing ITs of 10°, 13°, 15° and 18° before Top Dead Center (bTDC) combinations were attempted for the 25% to full load. Compression Ratio (CR) of 16.5 and Engine speed of 1500 RPM was kept constant during all trails. Critical performance parameter like Brake Thermal Efficiency (BTE) and Brake Specific Fuel Consumption (BSFC) were analyzed, primary emission parameters of the diesel engine The NOx and Smoke opacity were recorded. Finally, the outcomes of each combination were discussed.

An Investigation of Multi-Injection Strategies for a Dual-Fuel Pilot Diesel Ignition Engine at Low Load

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Amin Yousefi ◽  
Madjid Birouk
Keyword(s):  
Single Injection ◽  
Fluid Dynamic ◽  
Engine Performance ◽  
Dual Fuel ◽  
Injection Timing ◽  
Double Injection ◽  
Indicated Mean Effective Pressure ◽  
Soot Emissions ◽  
Injection Pulse ◽  
Injection Strategies

A multidimensional computational fluid dynamic (CFD) model was developed in order to explore the combined effect of injection timing and fuels quantity ratio of different injection strategies on the combustion performance and emissions characteristics of a dual-fuel indirect injection (IDI) engine with a pilot diesel ignition. The total mass of pilot diesel and premixed natural gas equivalence ratio were kept constant while various injection strategies (single, double, and triple) were investigated at 25% engine load and speed of 800 rpm. Results revealed that the released heat of triple injection pulse during the expansion stroke is the same or higher than that of single and double injection pulses at specified injection timings. It affects positively the engine performance. The highest indicated mean effective pressure (IMEP) can be achieved using single injection pulse at all first injection timings. It is observed that double and triple injection pulses possess comparable indicated thermal efficiency (ITE) and IMEP to those of single injection at specified injection timings. The highest ITE is found 47.5% at first injection timing of −16 deg after top dead center (ATDC) for both single and double injection pulses. Nitrogen oxides (NOx) mole fraction generally increases when retarding the injection timing. By applying double and triple injection pulses, NOx emissions decrease, on average, by 9% and 14% compared to that of the single injection pulse. Using double and triple injection pulses, soot emissions increase, on average, by 10% and 32%, respectively, compared to single injection pulse. However, at specified injection timings, the effect of all injection pulses on soot emissions is negligible at relative advanced first injection timing. Carbon monoxide (CO) emissions decrease slightly for all injection strategies when the injection timing varies from −20 deg ATDC to −12 deg ATDC. In this range, dual-fuel operation with triple injection pulse produces the lowest CO emissions. By using triple injection pulse at suitable injection timings, CO emissions decrease by around 7.4% compared to single injection pulse. However, by applying double and triple injection pulses, unburned methane increases, on average, by 16% and 52%, respectively, compared with that of single injection pulse. However, at injection timings of −12 deg ATDC and −8 deg ATDC, triple and double injection pulses produce comparable level of unburned methane to that of single injection pulse.

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