Combustion Mode Switching Characteristics of a Medium-Duty Engine Operated in Compression Ignition/PCCI Combustion Modes

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Akhilendra Pratap Singh ◽  
Nikhil Bajpai ◽  
Avinash Kumar Agarwal
Keyword(s):  
Combustion Engine ◽  
Mode Switching ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Oxides Of Nitrogen ◽  
Combustion Mode ◽  
Engine Operation ◽  
Combustion Modes ◽  
Brake Mean Effective Pressure ◽  
Study Results

Premixed charge compression ignition (PCCI) combustion is a novel combustion concept, which reduces oxides of nitrogen (NOx) and particulate matter (PM) emissions simultaneously. However, PCCI combustion cannot be implemented in commercial engines due to its handicap in operating at high engine loads. This study is focused on the development of hybrid combustion engine in which engine can be operated in both combustion modes, namely, PCCI and compression ignition (CI). Up to medium loads, engine was operated in PCCI combustion and at higher loads, the engine control unit (ECU) automatically switched the engine operation to CI combustion mode. These combustion modes can be automatically switched by varying the fuel injection parameters and exhaust gas recirculation (EGR) by an open ECU. The experiments were carried out at constant engine speed (1500 rpm) and the load was varied from idling to full load (5.5 bar brake mean effective pressure (BMEP)). To investigate the emission and particulate characteristics during different combustion modes and mode switching, continuous sampling of the exhaust gas was done for a 300 s cycle, which was specifically designed for this study. Results showed that PCCI combustion resulted in significantly lower NOx and PM emissions compared to the CI combustion. Lower exhaust gas temperature (EGT) in the PCCI combustion mode resulted in slightly inferior engine performance. Slightly higher concentration of unregulated emission species such as sulfur dioxide (SO2) and formaldehyde (HCHO) in PCCI combustion mode was another important observation from this study. Lower concentration of aromatic compounds in PCCI combustion compared to CI combustion reflected relatively lower toxicity of the exhaust gas. Particulate number-size distribution showed that most particulates emitted in PCCI combustion mode were in the accumulation mode particle (AMP) size range, however, CI combustion emitted relatively smaller sized particles, which were more harmful to the human health. Overall, this study indicated that mode switching has significant potential for application of PCCI combustion mode in production grade engines for automotive sector, which would result in relatively cleaner engine exhaust compared to CI combustion mode engines.

Performance and emission characteristics of conventional diesel combustion/partially premixed charge compression ignition combustion mode switching of biodiesel-fueled engine

2019 ◽  
pp. 146808741986031
Author(s):  
Akhilendra Pratap Singh ◽  
Avinash Kumar Agarwal
Keyword(s):  
Aromatic Compounds ◽  
Electronic Control Unit ◽  
Mode Switching ◽  
Particulate Emissions ◽  
Exhaust Gas ◽  
Diesel Combustion ◽  
Compression Ignition ◽  
Combustion Mode ◽  
Performance And Emission ◽  
Combustion Modes

In this experimental study, a production grade engine was modified to operate in two combustion modes, namely conventional diesel combustion (CDC) and premixed charge compression ignition (PCCI) combustion, depending on the engine load. For mode switching, an open electronic control unit was programmed to operate the engine in PCCI combustion mode up to medium engine loads and then automatically switching it to CDC mode at higher engine loads, by varying the fuel injection parameters and the exhaust gas recirculation rate. For performance and emission characterization in the entire load range (idling-to-full load) of the test engine, a test cycle of 300 s was used, which included CDC mode, PCCI combustion mode, and transition between these two modes. Results showed that both mineral diesel and B20 (20% biodiesel blended with mineral diesel, v/v) fueled PCCI combustion resulted in significantly lower NOx and particulate emissions compared to baseline CDC. Relatively lower exhaust gas temperature in PCCI combustion mode led to slightly inferior engine performance and higher concentration of unregulated emission species such as SO2, HCHO, and so on. B20-fueled engine resulted in relatively lower unregulated emission species and particulates compared to the mineral diesel–fueled engine in both the combustion modes. In CDC mode, contributions of accumulation mode particles were significantly higher compared to nucleation mode particles. Relatively lower emission of aromatic compounds in PCCI combustion mode compared to CDC mode was another important finding of this study; however, B20-fueled engines resulted in slightly higher emissions of aromatic compounds.

Stabilizing Excessive EGR With an Oxidation Catalyst on a Modern Diesel Engine

2002 ◽  
Author(s):  
Ming Zheng ◽  
David K. Irick ◽  
Jeffrey Hodgson
Keyword(s):  
Diesel Engine ◽  
Oxidation Catalyst ◽  
Stable Operation ◽  
Exhaust Gas ◽  
Oxides Of Nitrogen ◽  
Engine Operation ◽  
Turbocharged Diesel Engine ◽  
New Approach ◽  
Cyclic Variations ◽  
Gas Recirculation

For diesel engines (CIDI) the excessive use of exhaust gas recirculation (EGR) can reduce in-cylinder oxides of nitrogen (NOx) generation dramatically, but engine operation can also approach zones with high instabilities, usually accompanied with high cycle-to-cycle variations and deteriorated emissions of total hydrocarbon (THC), carbon monoxide (CO), and soot. A new approach has been proposed and tested to eliminate the influences of recycled combustibles on such instabilities, by applying an oxidation catalyst in the high-pressure EGR loop of a turbocharged diesel engine. The testing was directed to identifying the thresholds of stable operation at high rates of EGR without causing cycle-to-cycle variations associated with untreated recycled combustibles. The elimination of recycled combustibles using the oxidation catalyst showed significant influences on stabilizing the cyclic variations, so that the EGR applicable limits are effectively extended. The attainability of low NOx emissions with the catalytically oxidized EGR is also evaluated.

Multiple fuel injection strategy for premixed charge compression ignition combustion engine using biodiesel blends

2022 ◽  
pp. 146808742110667
Author(s):  
Akhilendra Pratap Singh ◽  
Ashutosh Jena ◽  
Avinash Kumar Agarwal
Keyword(s):  
Alternative Fuels ◽  
Fuel Injection ◽  
Engine Performance ◽  
Pilot Injection ◽  
Compression Ignition ◽  
Combustion Control ◽  
Combustion Mode ◽  
Biodiesel Blends ◽  
Injection Parameters ◽  
Study Results

In the last decade, advanced combustion techniques of the low-temperature combustion (LTC) family have attracted researchers because of their excellent emission characteristics; however, combustion control remains the main issue for the LTC modes. The objective of this study was to explore premixed charge compression ignition (PCCI) combustion mode using a double pilot injection (DPI; pilot-pilot-main) strategy to achieve superior combustion control and to tackle the soot-oxides of nitrogen (NOx) trade-off. Experiments were carried out in a single-cylinder research engine fueled with 20% v/v biodiesel blended with mineral diesel (B20) and 40% v/v biodiesel blended with mineral diesel (B40) vis-à-vis baseline mineral diesel. Engine speed and rate of fuel-mass injected were maintained constant at 1500 rpm and 0.6 kg/h mineral diesel equivalent, respectively. Pilot injection timings (at 45° and 35° before top dead center (bTDC)) and fuel quantities were fixed, while three fuel injection pressures (FIPs) and four different start of the main injection (SoMI) timings were investigated in this study. Results showed that multiple pilot injections resulted in a stable PCCI combustion mode, making it suitable for higher engine loads. For all test fuels, advancing SoMI timings led to relatively lesser knocking; however, engine performance characteristics degraded at advanced SoMI timings. B40 exhibited relatively superior engine performance among different test fuels at lower FIP; however, the difference in engine performance was insignificant at higher FIPs. Fuel injection parameters showed a significant effect on emissions, especially on the NOx and particulates. Advancing SoMI timing resulted in 20%–50% lower particulates emissions with a slight NOx increase; however, the differences in emissions at different SoMI timings reduced at higher FIPs. Somewhat higher particulates from biodiesel blends were a critical observation of this study, which was more dominant at advanced SoMI timings. Qualitative correlation between NOx-total particulate mass (TPM) was another critical analysis, which exhibited the relative importance of different fuel injection parameters for other alternative fuels. Overall, B20 at 700 bar FIP and 20° SoMI timing emerged as the most promising proposition with some penalty in CO emission.

Technical Note: Investigation on emission characteristics of a compression ignition engine with oxygenated fuels and exhaust gas recirculation

2000 ◽  
Vol 214 (5) ◽  
pp. 503-508 ◽  
Author(s):  
H. W. Wang ◽  
Z. H. Huang ◽  
L. B. Zhou ◽  
D. M. Jiang ◽  
Z. L. Yang
Keyword(s):  
Linear Relationship ◽  
Reduction Rate ◽  
Exhaust Gas Recirculation ◽  
Emission Characteristics ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Mass Percentage ◽  
Compression Ignition Engine ◽  
Brake Mean Effective Pressure ◽  
Gas Recirculation

Investigations of emission characteristics were carried out on a compression ignition, dimethyl ether engine (DME) with exhaust gas recirculation (EGR) and on a diesel engine with a dimethyl carbonate (DMC) additive. The experimental results show that the DME engine with EGR can simultaneously reduce smoke and NOx emissions. The NOx can be reduced by about 20 per cent for every 10 per cent of EGR introduction, while smoke remains at zero. The diesel equivalent brake specific fuel consumption (b.s.f.c.) shows a slight decrease when DMC is added, while the effective thermal efficiency shows a slight improvement. It is found that the smoke reduction rate and smoke show a linear relationship with DMC percentage or oxygen mass percentage in the diesel fuel. For the specific brake mean effective pressure (b.m.e.p.), smoke will be reduced by 20 per cent for every 10 per cent DMC added and by 40 per cent when the oxygen mass percentage in the fuel reaches 10 per cent. The CO decreases when DMC is added, while NOx shows an increase. This difference is pronounced at a high b.m.e.p. For the specific b.m.e.p., CO and NOx show a linear relationship with DMC mass percentage in the fuel; CO will be reduced by 20 per cent while NOx will be increased by 20 per cent for every 10 per cent DMC added.

A Study of Combustion Inefficiency in Diesel LTC and Gasoline-Diesel RCCI via Detailed Emission Measurement

2014 ◽  
Author(s):  
Shouvik Dev ◽  
Prasad Divekar ◽  
Kelvin Xie ◽  
Xiaoye Han ◽  
Xiang Chen ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Combustion Process ◽  
Speciation Analysis ◽  
Ratio Test ◽  
Emission Measurement ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Engine Operation ◽  
Incomplete Combustion ◽  
Production Of Hydrogen

Reduction of engine-out NOx emissions to ultra-low levels is facilitated by enabling low temperature combustion (LTC) strategies. However, there is a significant energy penalty in terms of combustion efficiency as evidenced by the accompanying high levels of hydrocarbon (HC), carbon monoxide (CO), and hydrogen emissions. In this work, the net fuel energy lost as a result of incomplete combustion in two different LTC regimes is studied. The first LTC strategy, partially premixed compression ignition (PPCI), is investigated using a single, high pressure, in-cylinder injection of diesel fuel along with the application of exhaust gas recirculation (EGR). The second strategy includes dual-fuel application – reactivity controlled compression ignition (RCCI) of port injected gasoline and direct injected diesel. Moderate to high levels of EGR are necessary during engine operation in either of the two LTC pathways. A detailed analysis of the incomplete combustion products was conducted while the engine was operated in the aforementioned LTC modes. Speciation analysis of hydrocarbons was performed by sampling the exhaust gas in an FTIR. The total HC and the CO emissions were simultaneously measured using an FID and an NDIR, respectively. The production of hydrogen during the combustion process was also evaluated using a mass spectrometer. Engine tests were conducted at a baseline load level of 10 bar IMEP in the PPCI and RCCI modes. Load extension tests, up to 17 bar IMEP, were then conducted in the RCCI mode by increasing the gasoline-to-diesel fuel ratio. Test results indicated that CO, H2, and light HC made up for most of the combustion in-efficiency in the PPCI mode while heavier HC and aromatics were significantly higher in the RCCI mode.

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.

scholarly journals Study on Combustion and Emission Characteristics of Marine Diesel Oil and Water-In-Oil Emulsified Marine Diesel Oil

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1830 ◽  
Author(s):  
Moonchan Kim ◽  
Jungmo Oh ◽  
Changhee Lee
Keyword(s):  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Direct Injection ◽  
Internal Combustion ◽  
Diesel Oil ◽  
Combustion Efficiency ◽  
Compression Ignition ◽  
Compression Ignition Engines ◽  
Brake Mean Effective Pressure ◽  
Marine Diesel

Compression ignition engines used as marine engines are the most efficient internal combustion engines. They are well-established products, and millions are already on the market. Water-in-MDO (marine diesel oil) emulsions are the best alternative fuel for compression ignition engines and can be utilised with the existing setup of 2.0 L automotive common rail direct injection (CRDI) engines. They have benefits for the simultaneous reduction of both NOx and smoke (black carbon). Furthermore, they have a significant impact on the improvement of combustion efficiency. Micro-explosions are the most important phenomenon of water-in-diesel emulsions inside an internal combustion engine chamber. They affect both the emission reduction and combustion efficiency improvements directly and indirectly in accordance with the brake mean effective pressure (BMEP) and rpm. Owing to the influence of micro-emulsions on the combustion and emissions of water-in-diesel emulsion fuel, the reduction ratios of NOx and smoke in a used engine are approximately 30% and 80%, respectively. The effect of the operating parameters on micro-emulsions is presented.

An Experimental Investigation of the Exhaust Emissions From Spark-Assisted Homogeneous Charge Compression Ignition in a Single-Cylinder Research Engine

2009 ◽  
Author(s):  
P. E. Keros ◽  
B. T. Zigler ◽  
J. T. Wiswall ◽  
S. M. Walton ◽  
M. S. Wooldridge
Keyword(s):  
Homogeneous Charge Compression Ignition ◽  
Exhaust Emissions ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Engine Operation ◽  
Single Cylinder ◽  
Spark Timing ◽  
Homogeneous Charge

The present study investigates the potential impact of spark-assisted (SA) homogeneous charge compression ignition (HCCI) on pollutant exhaust gas emissions from an internal combustion engine. A single-cylinder research engine was used to compare the exhaust emissions of the engine when operated in HCCI, SA-HCCI and conventional spark ignited modes of operation. The study builds on previous results demonstrating the effects of the spark plasma kernel on the ignition process [1, 2]. Specifically, this study investigates the NOx, CO, and HC emissions from an optical engine fueled with indolene in HCCI and SA-HCCI modes at fuel lean conditions. Fuel/air equivalence ratios ranged from φ = 0.3–0.6. Time-averaged emissions were measured using an exhaust gas analyzer. In-cylinder pressure data were also acquired. The results show NOx emissions follow the trends of peak in-cylinder pressure implying that thermal NOx mechanisms dominate both the HCCI and SA-HCCI modes of engine operation. For SA-HCCI, spark timing could be used to change ignition phasing, and consequently change the in-cylinder peak pressure and resulting NOx emissions. Comparing HCCI and SA-HCCI emissions at nominally similar conditions (specifically, comparable indicated mean effective pressures and equivalence ratios) yielded similar NOx emissions. These data show that SA-HCCI may not have a NOx penalty when the spark timing is carefully applied.

Operating Parameters of Catalysts With Catalytic Converter for Compression Ignition Engine

2005 ◽  
Author(s):  
P. V. Walke ◽  
N. V. Deshpande ◽  
L. P. Daddamwar
Keyword(s):  
Diesel Engine ◽  
Catalytic Converter ◽  
Circulation System ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Oxides Of Nitrogen ◽  
Test Rig ◽  
Compression Ignition Engine ◽  
Perforated Plates ◽  
Secondary Air

Testing of catalytic converter with exhaust gas re-circulation system for diesel engine to reduce pollute gases is chosen for present work. The emphasis is given on hydrocarbon (HC), carbon monoxide (CO) and oxides of nitrogen. The catalytic converter was developed with variations of catalyst plates. Perforated plates of copper and combination of copper oxide and cerium oxide (CeO2 +CuO) were used as the catalyst. Copper spacer was used in between plates to vary the distance. Secondary air was injected into the converter to aid oxidization of HC and CO. Experimental study was carried out on computerized kirloskar single cylinder four stroke (10 B.H.P, 7.4 KW) diesel engine test rig with an eddy current dynamometer. The converter was tested with various combination with exhaust gas re-circulation (EGR) system. There are some improvements in the reduction and conversion efficiency of HC & CO. Exhaust gas re-circulation has proved to be effective in reducing NOx.

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