scholarly journals Combustion and Emissions of Gasoline Compression Ignition Engine Fuelled with Gasoline-Biodiesel Blends

2021 ◽  
Author(s):  
Yanuandri Putrasari ◽  
Ocktaeck Lim

A gasoline compression ignition (GCI) engine was proposed to be the next generation internal combustion engine for gasoline. The effect of exhaust gas recirculation (EGR) and intake boosting on combustion and emissions of GCI engine fueled with gasoline-biodiesel blends by partially premixed compression ignition (PPCI) combustions are investigated in this study. Tests were conducted on a single-cylinder direct-injection CI engine, with 5% by volume proportion of biodiesel in gasoline fuel blends. Engine control parameters (EGR rate, intake boosting rate, and various injection strategies) were adjusted to investigate their influences on combustion and emissions of this GCI engine. It is found that changes in EGR rate, intake boosting pressure and injection strategies affect on ignition delay, maximum pressure rise rate and thermal efficiency which is closely tied to HC, CO, NOx and smoke emissions, respectively.

Author(s):  
Buyu Wang ◽  
Michael Pamminger ◽  
Thomas Wallner

Gasoline compression ignition (GCI) using a single gasoline-type fuel for port fuel and direct injection has been shown as a method to achieve low-temperature combustion with low engine-out NOx and soot emissions and high indicated thermal efficiency. However, key technical barriers to achieving low temperature combustion on multi-cylinder engines include the air handling system (limited amount of exhaust gas recirculation (EGR)) as well as mechanical engine limitations (e.g. peak pressure rise rate). In light of these limitations, high temperature combustion with reduced amounts of EGR appears more practical. Furthermore, for high temperature GCI, an effective aftertreatment system allows high thermal efficiency with low tailpipe-out emissions. In this work, experimental testing was conducted on a 12.4 L multi-cylinder heavy-duty diesel engine operating with high temperature GCI combustion using EEE gasoline. Engine testing was conducted at an engine speed of 1038 rpm and brake mean effective pressure (BMEP) of 14 bar. Port fuel and direct injection strategies were utilized to increase the premixed combustion fraction. The impact on engine performance and emissions with respect to varying the injection and intake operating parameters was quantified within this study. A combined effect of reducing heat transfer and increasing exhaust loss resulted in a flat trend of brake thermal efficiency (BTE) when retarding direct injection timing, while increased port fuel mass improved BTE due to advanced combustion phasing and reduced heat transfer loss. Overall, varying intake valve close timing, EGR, intake pressure and temperature with the current pressure rise rate and soot emissions constraint was not effective in improving BTE, as the benefit of low heat transfer loss was always offset by increased exhaust loss.


Author(s):  
Vittorio Manente ◽  
Bengt Johansson ◽  
Pert Tunestal

Exhaust gas recirculation (EGR) sweeps were performed on ethanol partially premixed combustion (PPC) to show different emission and efficiency trends as compared with diesel PPC. The sweeps showed that when the EGR rate is increased, the efficiency does not diminish, HC trace is flat, and CO is low even with 45% of EGR. NOx exponentially decreases by increasing EGR while soot levels are nearly zero throughout the sweep. The EGR sweeps underlined that at high EGR levels, the pressure rise rate is a concern. To overcome this problem and keep high efficiency and low emissions, a sweep in the timing of the pilot injection and pilot-main ratio was done at ∼16.5 bars gross IMEP. It was found that with a pilot-main ratio of 50:50, and by placing the pilot at −60 with 42% of EGR, NOx and soot are below EURO VI levels; the indicated efficiency is 47% and the maximum pressure rise rate is below 10 bar/CAD. Low load conditions were examined as well. It was found that by placing the start of injection at −35 top dead center, the efficiency is maximized, on the other hand, when the injection is at −25, the emissions are minimized, and the efficiency is only 1.64% lower than its optimum value. The idle test also showed that a certain amount of EGR is needed in order to minimize the pressure rise rate.


Author(s):  
Tongyang Gao ◽  
Shui Yu ◽  
Tie Li ◽  
Ming Zheng

Engine experiments were carried out to study the impact of multiple pilot injections of a diesel fuel on dual-fuel combustion with a premixed ethanol fuel, using compression ignition. Because of the contrasting volatility and the reactivity characteristics of the two fuels, the appropropriate scheduling of pilot diesel injections in a high-pressure direct-injection process is found to be effective for improving the clean and efficient combustion of ethanol which is premixed with air using a low-pressure port injection. The timing and duration of each of the multiple pilot injections were investigated, in conjunction with the use of exhaust gas recirculation and intake air boosting to accommodate the variations in the engine load. For correct fuel and air management, an early pilot injection of fuel acted effectively as the reactivity improver to the background ethanol, whereas a late pilot injection acted deterministically to initiate combustion. The experimental results further revealed a set of pilot injection strategies which resulted in an increased ethanol ratio, thereby reducing the emission reductions while retaining a moderate pressure rise rate during combustion.


2019 ◽  
Vol 69 (4) ◽  
pp. 25-32
Author(s):  
Chríbik Andrej ◽  
Polóni Marián ◽  
Minárik Matej

AbstractThe paper deals with the influence of selected component of synthesis gas on internal parameters of combustion engine that is planned to be used in micro-cogeneration unit. The aim is to better understand the mechanism of combustion of carbon monoxide mixed with methane and as a follow-up to optimize the operation of the Lombardini LGW 702 engine on change of fuel composition. Generally, an increasing proportion of carbon monoxide in methane mixture leads to a decrease in engine performance (mean indicated pressure) and the hourly fuel consumption in each of the operating modes of the engine increases. With growing proportion of CO in mixture with CH4, the maximum pressure in the cylinder increases together with pressure rise rate up to approximately 10 % vol. of CH4. With further increasing proportion of CH4, there is a significant decrease of the before-mentioned engine parameters. The optimum ignition angle for pure methane, or carbon monoxide, does not change significantly and it is about 27° CA BTDC.


2016 ◽  
Vol 18 (8) ◽  
pp. 847-857 ◽  
Author(s):  
Mayura H Halbe ◽  
David J Fain ◽  
Gregory M Shaver ◽  
Lyle Kocher ◽  
David Koeberlein

Premixed charge compression ignition (PCCI) is a promising combustion strategy for reducing in-cylinder NOx and particulate matter formation in diesel engines without incurring fuel penalty. However, one of the challenges in PCCI implementation is that the process does not allow direct control of the combustion timing. The crank angle of 50% heat release, known as the CA50, is generally a reasonable proxy for the quality of combustion in terms of maximum pressure rise rate, combustion noise, and fuel conversion efficiency. This paper outlines the development, and validation, of a real-time capable estimation strategy for diesel-fueled PCCI CA50 using production-viable measurements that do not include in-cylinder pressure. The CA50 estimation strategy considers both stages of diesel-fueled PCCI combustion—low-temperature heat release and high-temperature heat release, which contributes most to the cumulative heat released during combustion. The strategy is validated using a PCCI CA50 dataset generated with a wide range of positions of a variable geometry turbocharge, exhaust gas recirculation fractions, and intake valve closing timings. The model estimates CA50 within ±2 CAD for 65 out of 80 data points and exhibits an error standard deviation of 2.55 CAD.


2021 ◽  
pp. 146808742098457
Author(s):  
Yoshimitsu Kobashi ◽  
Tu Dan Dan Da ◽  
Ryuya Inagaki ◽  
Gen Shibata ◽  
Hideyuki Ogawa

Ozone (O3) was introduced into the intake air to control the ignition in a gasoline compression ignition (GCI) engine. An early fuel injection at −68 °CA ATDC was adopted to mix the fuel with the reactive O-radicals decomposed from the O3, before the reduction of the O-radicals due to their recombination would take place. The second injection was implemented near top dead center to optimize the profile of the heat release rate. The engine experiments were performed around the indicated mean effective pressure (IMEP) of 0.67 MPa with a primary reference fuel, octane number 90 (PRF90), maintaining the 15% intake oxygen concentration with the EGR. The quantity of the first injection, the second injection timing as well as the ozone concentration were changed as experimental parameters. The results showed that the GCI operation with the ozone addition makes it possible to reduce the maximum pressure rise rate while attaining high thermal efficiency, compared to that without the ozone. Appropriate combinations of the ozone concentration and the first injection quantity achieve low smoke and NOx emissions. Further, the ozone-assisted GCI operation was compared with conventional diesel operation. The results showed that the indicated thermal efficiency of the ozone-assisted GCI combustion is slightly lower than that of the conventional diesel combustion, but that GCI assisted with ozone is highly advantageous to the smoke and NOx emissions.


Author(s):  
Yan Chang ◽  
Brandon Mendrea ◽  
Jeff Sterniak ◽  
Stanislav V. Bohac

Spark Assisted Compression Ignition (SACI) offers more practical combustion phasing control and a softer pressure rise rate than Homogeneous Charge Compression Ignition (HCCI) combustion, and improved thermal efficiency and lower NOx emissions than Spark Ignition (SI) combustion. Any practical engine, including one that uses SACI in part of its operating range, must be robust to changes in ambient conditions. This study investigates the effects of ambient temperature and humidity on stoichiometric SACI engine performance, combustion and emissions. It is shown that at the medium speed and load SACI test point selected for this study, increasing ambient air temperature from 20°C to 41°C advances combustion phasing, increases maximum pressure rise rate, causes a larger fraction of the charge to be consumed by auto-ignition (and a smaller fraction by flame propagation), increases NOx, and increases Brake Specific Fuel Consumption (BSFC). Increasing ambient humidity from 32% to 60% retards combustion phasing, reduces maximum pressure rise rate, causes a larger fraction of the charge to be consumed by auto-ignition and a smaller fraction by flame propagation, increases Coefficient of Variation of IMEP (COV) of IMEP, reduces NOx, and increases BSFC. These results show that successful implementation of SACI combustion in real-world driving requires a control strategy that compensates for changes in ambient temperature and humidity.


Author(s):  
Shouvik Dev ◽  
Tongyang Gao ◽  
Xiao Yu ◽  
Mark Ives ◽  
Ming Zheng

Homogeneous Charge Compression Ignition (HCCI) has been considered as an ideal combustion mode for compression ignition engines due to its superb thermal efficiency and low emissions of nitrogen oxides (NOx) and particulate matter (PM). However, a challenge that limits practical applications of HCCI is the lack of control over the combustion rate, which either deteriorates thermal efficiency at low engine load, or produces excessive pressure rise rate and combustion noise at high engine load. Fuel stratification and partially premixed combustion (PPC) have considerably improved the control over the heat release profile with modulations of the ratio between premixed fuel and directly injected fuel, as well as injection timing for ignition initiation. It leverages the advantages of both conventional direct injection compression ignition and HCCI. Compared with those of HCCI, the ignition ability and combustion efficiency of PPC are significantly enhanced at low engine load, and the low emissions of NOx and PM are maintained with lower pressure rise rate. In this study, neat n-butanol is employed to generate the fuel stratification and partially premixed combustion in a single cylinder compression ignition engine. A fuel such as n-butanol can provide additional benefits of even lower emissions, and can potentially lead to a reduced carbon footprint and improved energy security if produced appropriately from biomass sources. Intake port fuel injection (PFI) of neat n-butanol is used for the delivery of the premixed fuel, while the direct injection (DI) of neat n-butanol is applied to generate the fuel stratification. Effects of PFI-DI fuel ratio, DI timing, and intake pressure, on the combustion, are studied in detail. Different conditions are identified at which clean and efficient combustion can be achieved at a baseline load of 6 bar IMEP. An extended load of 14 bar IMEP is demonstrated using stratified combustion with combustion phasing control.


Author(s):  
Yan Chang ◽  
Brandon Mendrea ◽  
Jeff Sterniak ◽  
Stanislav V. Bohac

Spark-assisted compression ignition (SACI) offers more practical combustion phasing control and a lower pressure rise rate than homogeneous charge compression ignition (HCCI) combustion and improved thermal efficiency and lower NOx emissions than spark ignition (SI) combustion. Any practical passenger car engine, including one that uses SACI in part of its operating range, must be robust to changes in ambient conditions. This study investigates the effects of ambient temperature and humidity on stoichiometric SACI combustion and emissions. It is shown that at the medium speed and load SACI test point selected for this study, increasing ambient air temperature from 20 °C to 41 °C advances combustion phasing, increases maximum pressure rise rate, causes a larger fraction of the charge to be consumed by auto-ignition (and a smaller fraction by flame propagation), and increases NOx. Increasing ambient humidity from 32% to 60% retards combustion phasing, reduces maximum pressure rise rate, increases coefficient of variation (COV) of indicated mean effective pressure (IMEP), reduces NOx, and increases brake-specific fuel consumption (BSFC). These results show that successful implementation of SACI combustion in real-world driving requires a control strategy that compensates for changes in ambient temperature and humidity.


2021 ◽  
pp. 146808742098819
Author(s):  
Wang Yang ◽  
Cheng Yong

As a non-intrusive method for engine working condition detection, the engine surface vibration contains rich information about the combustion process and has great potential for the closed-loop control of engines. However, the measured engine surface vibration signals are usually induced by combustion as well as non-combustion excitations and are difficult to be utilized directly. To evaluate some combustion parameters from engine surface vibration, the tests were carried out on a single-cylinder diesel engine and a new method called Fourier Decomposition Method (FDM) was used to extract combustion induced vibration. Simulated and test results verified the ability of the FDM for engine vibration analysis. Based on the extracted vibration signals, the methods for identifying start of combustion, location of maximum pressure rise rate, and location of peak pressure were proposed. The cycle-by-cycle analysis of the results show that the parameters identified based on vibration and in-cylinder pressure have the similar trends, and it suggests that the proposed FDM-based methods can be used for extracting combustion induced vibrations and identifying the combustion parameters.


Sign in / Sign up

Export Citation Format

Share Document