Characterization of Partially Premixed Combustion With Ethanol: EGR Sweeps, Low and Maximum Loads

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Vittorio Manente ◽  
Bengt Johansson ◽  
Pert Tunestal
Keyword(s):  
High Efficiency ◽  
Pressure Rise ◽  
Premixed Combustion ◽  
Maximum Pressure ◽  
Pressure Rise Rate ◽  
Start Of Injection ◽  
Partially Premixed Combustion ◽  
Rise Rate ◽  
Partially Premixed ◽  
Gas Recirculation

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.

Characterization of Partially Premixed Combustion With Ethanol: EGR Sweeps, Low and Maximum Loads

2009 ◽  
Author(s):  
Vittorio Manente ◽  
Bengt Johansson ◽  
Pert Tunestal
Keyword(s):  
High Efficiency ◽  
Pressure Rise ◽  
Premixed Combustion ◽  
Maximum Pressure ◽  
Pressure Rise Rate ◽  
Partially Premixed Combustion ◽  
Rise Rate ◽  
Low Load ◽  
Partially Premixed

EGR sweeps were performed on Ethanol Partially Premixed Combustion, PPC, to show different emission and efficiency trends as compared to Diesel PPC. The sweeps showed that increasing the EGR rate 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 timing of the pilot injection and pilot-main ratio was done at ∼16.5 bar 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 SOI at −35 TDC 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.

Investigation on the Impact of Fuel Properties on Partially Premixed Combustion Characteristics in a Light Duty Diesel Engine

2012 ◽  
Author(s):  
Hadeel Solaka ◽  
Martin Tunér ◽  
Bengt Johansson
Keyword(s):  
Pressure Rise ◽  
Combustion Characteristics ◽  
Premixed Combustion ◽  
Unburned Hydrocarbon ◽  
Light Duty ◽  
Start Of Injection ◽  
Partially Premixed Combustion ◽  
Rise Rate ◽  
Partially Premixed ◽  
The Impact

The impact of fuel composition on the emission performance and combustion characteristics for partially premixed combustion (PPC) were examined for four fuels in the gasoline boiling range together with Swedish diesel MK1. Experiments were carried out at 8 bar IMEPg and 1500 rpm with 53±1% EGR and λ = 1.5. This relation gave inlet mole fractions of approximately 5% CO2 and 13% O2. The combustion phasing was adjusted by means of start of injection (SOI), for all fuels, over the range with stable combustion and acceptable pressure rise rate combined with maintained λ, EGR ratio, inlet pressure, and load. The operating range was limited by combustion instability for the high RON fuels, while MK1 and the low RON fuels could be operated over the whole MBT plateau. The largest difference in engine-out emissions between the fuels was the filtered smoke number (FSN), as the gasoline fuels produced a much lower FSN value than MK1. Higher RON value gave higher levels of carbon monoxide (CO) and unburned hydrocarbon (HC) for the gasoline fuels, while MK1 had the lowest levels of these emissions.

Fuel Stratification and Partially Premixed Combustion With Neat N-Butanol in a Compression Ignition Engine

2017 ◽  
Author(s):  
Shouvik Dev ◽  
Tongyang Gao ◽  
Xiao Yu ◽  
Mark Ives ◽  
Ming Zheng
Keyword(s):  
Direct Injection ◽  
Pressure Rise ◽  
Premixed Combustion ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Engine Load ◽  
Fuel Stratification ◽  
Partially Premixed Combustion ◽  
Rise Rate ◽  
Partially Premixed

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.

Performance of Dual Fuel Engine Running on Jojoba Oil as Pilot Fuel and CNG or LPG

2007 ◽  
Author(s):  
Mohamed Y. E. Selim ◽  
M. S. Radwan ◽  
H. E. Saleh
Keyword(s):  
Methyl Ester ◽  
Natural Gas ◽  
Pressure Rise ◽  
Combustion Noise ◽  
Dual Fuel ◽  
Maximum Pressure ◽  
Injection Timing ◽  
Pressure Rise Rate ◽  
Rise Rate ◽  
Pilot Fuel

The use of Jojoba Methyl Ester as a pilot fuel was investigated for almost the first time as a way to improve the performance of dual fuel engine running on natural gas or LPG at part load. The dual fuel engine used was Ricardo E6 variable compression diesel engine and it used either compressed natural gas (CNG) or liquefied petroleum gas (LPG) as the main fuel and Jojoba Methyl Ester as a pilot fuel. Diesel fuel was used as a reference fuel for the dual fuel engine results. During the experimental tests, the following have been measured: engine efficiency in terms of specific fuel consumption, brake power output, combustion noise in terms of maximum pressure rise rate and maximum pressure, exhaust emissions in terms of carbon monoxide and hydrocarbons, knocking limits in terms of maximum torque at onset of knocking, and cyclic data of 100 engine cycle in terms of maximum pressure and its pressure rise rate. The tests examined the following engine parameters: gaseous fuel type, engine speed and load, pilot fuel injection timing, pilot fuel mass and compression ratio. Results showed that using the Jojoba fuel with its improved properties has improved the dual fuel engine performance, reduced the combustion noise, extended knocking limits and reduced the cyclic variability of the combustion.

Dilution Effects on Partially-Premixed Combustion of an Ultra-Low Sulphur Diesel Fuel Under Low-Load Operation

2012 ◽  
Author(s):  
Cosmin E. Dumitrescu ◽  
W. Stuart Neill ◽  
Hongsheng Guo ◽  
Wallace L. Chippior
Keyword(s):  
Oxygen Concentration ◽  
Diesel Fuel ◽  
Fuel Injection ◽  
Premixed Combustion ◽  
Start Of Injection ◽  
Partially Premixed Combustion ◽  
Partially Premixed ◽  
Heavy Duty Diesel ◽  
Hc Emissions ◽  
Dilution Effects

Dilution of partially-premixed combustion (PPC) using different combinations of excess air (λ>1) and exhaust gas recirculation (EGR) was investigated in a single-cylinder, heavy-duty diesel engine equipped with common-rail fuel injection. The experiments were limited to a single fuel injection event using ultra-low sulphur diesel fuel at a low engine load (∼3 bar BMEP) and engine speeds of 900 and 1350 rpm. The start of injection was varied to optimize the combustion performance and emissions. The experimental results show that increasing air dilution at constant EGR reduced BSFC slightly. CO and HC emissions decreased significantly due to the increased oxygen concentration, but NOx and soot emissions increased. For a given level of charge dilution, there was an optimal EGR rate to minimize BSFC. NOx emissions decreased significantly as the proportion of dilution by EGR was increased, but CO and HC emissions increased due to the reduced in-cylinder temperature and oxygen concentration, which increased the combustion duration.

Combustion parameter evaluation of diesel engine via vibration acceleration signal

2021 ◽  
pp. 146808742110308
Author(s):  
Pan Zhang ◽  
Wenzhi Gao ◽  
Yong Li ◽  
Zhaoyi Wei
Keyword(s):  
Peak Pressure ◽  
Pressure Rise ◽  
Peak Position ◽  
Maximum Pressure ◽  
Cylinder Pressure ◽  
Combustion Control ◽  
Pressure Rise Rate ◽  
Acceleration Signal ◽  
Rise Rate ◽  
Start Of Combustion

Efficient combustion control has increasingly become a quality requirement for automobile manufacturers because of its impact on pollutant and greenhouse gas emissions. In view of this, the management system development of modern internal combustion engines is mainly aimed at combustion control. The real-time detection of in-cylinder pressure characteristic parameters has a considerable significance on the closed-loop combustion control of the internal combustion engine. This paper presents a detection method in which the start of combustion, peak pressure, maximum pressure rise rate, and phase of maximum pressure rise rate are identified through vibration acceleration signal. In order to analyze the relationship between vibration and in-cylinder pressure signal, experimental data are acquired in a diesel engine by implementing various injection strategies and engine operating conditions (speed and load). The results show that the start of combustion can be detected by analyzing its relationship with the peak position of the filtered vibration signal, and the phase of the maximum pressure rise rate can be identified by examining its relationship with the zero-cross position that is adjacent to the right of the peak position. Moreover, the filtered vibration signals are also truncated in the same length and utilized as inputs for algorithms to detect the peak pressure and the maximum pressure rise rate. The algorithms are mainly performed on data compression (or feature extraction) and target regression. Major algorithms, such as one-dimensional convolutional neural network, compression sensing, wavelet decomposition, multilayer perceptron, and support vector machine, are tested. Various experimental results verify that for the test engine the phase detection accuracy of the start of combustion and maximum pressure rise rate is less than 1.7°CA for a 95% prediction interval width. For the detection of the peak pressure and maximum pressure rise rate, the normalized error threshold is set as 0.05, then the accuracies can be not less than 95%.

Potential of Fuel Stratification for Reducing Pressure Rise Rate in HCCI Engines Fueled With DME/n-Butane

2011 ◽  
Author(s):  
Ocktaeck Lim ◽  
Narankhuu Jamsran ◽  
Soojin Jeong ◽  
Youngduck Pyo ◽  
Kyuyeol Park
Keyword(s):  
Chemical Reaction ◽  
Pressure Rise ◽  
Reaction Model ◽  
Maximum Pressure ◽  
Mixture Ratio ◽  
Pressure Rise Rate ◽  
Fuel Stratification ◽  
Auto Ignition ◽  
Rise Rate ◽  
Hcci Engines

We investigated the efficacy of fuel stratification in a pre-mixture of di-methyl ether (DME) and n-Butane, which have different auto-ignition characteristics, for reducing the pressure rise rate (PRR) of homogeneous charge compression ignition (HCCI) engines. A new chemical reaction model was created by mixing DME and n-Butane and compared to existing chemical reaction models to verify the effects. The rate of maximum pressure rise depends on mixture ratio. When DME was charged with stratification and n-butane was charged with homogeneity, the maximum PRR was the lowest. The calculations were performed using the SENKIN application of CHEMKIN-II.

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