Combustion Development Investigation in a Common Rail Multi-Jet Diesel Engine With Up to 4 Injections per Engine Cycle

2005 ◽  
Author(s):  
Fabrizio Ponti ◽  
Gabriele Serra ◽  
Carlo Siviero
Keyword(s):  
Degrees Of Freedom ◽  
Combustion Process ◽  
Experimental Tests ◽  
Point Of View ◽  
Injection System ◽  
Combustion Model ◽  
Jet Engines ◽  
Injection Parameters ◽  
Start Of Injection ◽  
Engine Cycle

Newly developed technologies for modern diesel engines allow designing injection patterns with many degrees of freedom. Multi-jet engines, for example, can perform up to 5 injections within the same engine cycle: Position and duration of each injection, together with rail pressure and EGR rate can be chosen in order to properly design the desired in-cylinder combustion process. This means that during the injection system setup process all the free parameters have to be set to the desired value. If all the injection parameters variations have to be investigated in order to properly set their values, a huge amount of experimental tests should be needed. From this point of view, in order to reduce the need for test bench experimental work, the development of a combustion model can be very useful, to help determining the best injection configuration, and therefore the desired combustion into the cylinder. Single zone combustion models seem to be suitable for this task, thanks to the quick response they can give, and the possibility of using them for control purposes. In the paper a model developed for injection patterns with up to 4 injections is used in order to describe the combustion behavior as a function of the injection parameters. A properly designed set of tests has been performed in order to identify the combustion model. The obtained results give information on the way the combustion parameters, for example the combustion delays (i.e. the time delays between each Start Of Injection SOI, and the corresponding Start Of Combustion SOC), or the amount of fuel burnt for each injection are modified as the combustion process proceeds into the cylinder or as the injection parameters change. The information obtained can be in the following used in order to design the desired injection pattern, using the identified model as a virtual experimental tests generator.

Real-Time Processing of Engine Acoustic Emission for Diesel Injectors Diagnostic and Recentering

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Fabrizio Ponti ◽  
Vittorio Ravaglioli ◽  
Matteo De Cesare
Keyword(s):  
Diesel Engine ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Control Strategies ◽  
Combustion Process ◽  
Experimental Tests ◽  
Pollutant Emissions ◽  
Injection System ◽  
Real Time Processing ◽  
Injection Parameters

Diesel engine control strategies use complex injection patterns which are designed to meet the increasing request for engine-out emissions and fuel consumption reduction. As a result of the large number of tuneable injection parameters in modern injection systems (such as start and duration of each injection), injection patterns can be designed with many degrees-of-freedom. Each variation of the injection parameters modifies the whole combustion process and, consequently, engine-out emissions. Aging of the injection system usually affects injection location within the cycle as well as the amount of injected fuel (compared to the target value), especially for small pre-injections. Since diesel combustion is very sensitive to injection pattern variations, aging of injectors strongly affects engine behavior, in terms of both efficiency and pollutant emissions production. Moreover, such variations greatly affect other quantities related to the effectiveness of the combustion process, such as noise radiated by the engine. This work analyses the effects of pre-injection variations on combustion, pollutant emissions, and noise radiated by the engine. In particular, several experimental tests were run on a 1.3 L common rail diesel engine varying the amount of fuel injected in pre-injections. Torque delivered by the engine and center of combustion (MFB50) were kept constant using a specifically designed closed-loop combustion controller. During the tests, noise radiated by the engine was measured by properly processing the signal coming from a microphone faced to the engine block. The investigation of the correlation between the combustion process and engine noise can be used to setup a closed-loop algorithm for detecting and recentering injectors' drifts over time.

Real-Time Processing of Engine Acoustic Emission for Diesel Injectors Diagnostic and Recentering

2017 ◽  
Author(s):  
F. Ponti ◽  
V. Ravaglioli ◽  
M. De Cesare
Keyword(s):  
Diesel Engine ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Control Strategies ◽  
Combustion Process ◽  
Experimental Tests ◽  
Pollutant Emissions ◽  
Injection System ◽  
Real Time Processing ◽  
Injection Parameters

Diesel engine control strategies use complex injection patterns which are designed to meet the increasing request for engine-out emissions and fuel consumption reduction. As a result of the large number of tuneable injection parameters in modern injection systems (such as start and duration of each injection), injection patterns can be designed with many degrees of freedom. Each variation of the injection parameters modifies the whole combustion process and, consequently, engine-out emissions. Aging of the injection system usually affects injection location within the cycle as well as the amount of injected fuel (compared to the target value), especially for small pre-injections. Since Diesel combustion is very sensitive to injection pattern variations, aging of injectors strongly affects engine behavior, both in terms of efficiency and pollutant emissions production. Moreover, such variations greatly affect other quantities related to the effectiveness of the combustion process, such as noise radiated by the engine. This work analyses the effects of pre-injection variations on combustion, pollutant emissions and noise radiated by the engine. In particular, several experimental tests were run on a 1.3L Common Rail Diesel engine varying the amount of fuel injected in pre-injections. Torque delivered by the engine and center of combustion (MFB50) were kept constant using a specifically designed closed-loop combustion controller. During the tests, noise radiated by the engine was measured by properly processing the signal coming from a microphone faced to the engine block. The investigation of the correlation between the combustion process and engine noise can be used to set up a closed-loop algorithm for detecting and recentering injectors’ drifts over time.

Development of a Common Rail Diesel Engine Combustion Model for ROHR Real-Time Estimation

2011 ◽  
Author(s):  
Fabrizio Ponti ◽  
Vittorio Ravaglioli ◽  
Matteo De Cesare
Keyword(s):  
Diesel Engine ◽  
Real Time ◽  
Combustion Process ◽  
Time Estimation ◽  
Experimental Tests ◽  
Common Rail ◽  
Combustion Model ◽  
Combustion Control ◽  
Injection Parameters ◽  
Real Time Estimation

Combustion control is a crucial aspect in modern Diesel engines control strategies, mainly due to the requests to increase efficiency and maintain pollutant emissions within the values bounded by standard regulations. In order to perform an accurate combustion control, modern “closed loop” control algorithms require the evaluation of a large number of quantities that provide information about combustion process effectiveness. This work presents a methodology that allows real-time estimation of energy released, during the combustion process, in a Common Rail Multi-Jet Diesel engine. This procedure can be divided in two main steps. The first step consists in the development of a zero-dimensional combustion model based on the linear combination of a proper number of Wiebe functions. In this case, a zero-dimensional approach has been chosen, because it is accurate enough for this analysis and requires low computational efforts. Once the combustion model has been developed, it can be used to determine Rate of Heat Release (RoHR) and the angular position in which 50% of fuel burned within an engine cycle is reached (MFB50). The second section of this work describes the relationships existing between injection parameters (such as Start of Injection, injected fuel quantities, rail pressure...) and the Wiebe parameters identified in the first step of the procedure. The above mentioned relationships have been used to set up correlations that allow estimating Wiebe parameters, therefore ROHR and MFB50, starting from injection parameters. The results obtained in MFB50 estimation are particularly emphasized, because real-time knowledge of this quantity is necessary to feedback a control algorithm for optimal combustion positioning. This work is based on several experimental tests performed on a 2.2 liters Common Rail Multi-Jet Diesel engine. First, experimental tests have been carried out to identify the combustion model and the correlations existing between Wiebe parameters and injection parameters. Then, in order to determine the accuracy of the approach, the complete estimation methodology has been applied to the engine under study. This work describes a methodology for real-time estimation of several quantities that provide important information about combustion process effectiveness (useful, for example, in modern low temperature combustion control systems). No extra cost is needed, because the methodology requires no additional sensor.

scholarly journals Researches on Soot Filtration Process by Comparing Simulation and Experimental Tests

2021 ◽  
Vol 44 (4) ◽  
pp. 54-59
Author(s):  
Bogdan Manolin JURCHIȘ
Keyword(s):  
Particle Filter ◽  
Combustion Engine ◽  
Combustion Process ◽  
Engine Performance ◽  
Experimental Tests ◽  
Point Of View ◽  
Pollutant Emissions ◽  
Particulate Filter ◽  
The Creation ◽  
Two Stages

In this paper, the main objective of using numerical simulation was to highlight and analyse details that are very difficult to highlight through experimental tests. The development of the simulation model was also done for predictive purposes. In other words, after validation of the model, it can be used to estimate the filter load in other conditions than the experimental ones, respectively to evaluate how the particulate filter affects the operation of the internal combustion engine. In order to achieve the desired result, the creation of the model was done in two stages, the first stage was the creation of a model containing all the components of the engine, except the particle filter in order to identify the parameters of the combustion process and pollutant emissions - model validated on the basis of the indicated pressure curves, and the second stage was to complete the initial model with a particle filter and validate it from the point of view of the pressure drop, respectively of the engine performance, the aim was to obtain a trend, respectively values similar to the experimental ones.

A Study on Biodiesel NOx Emission Control With the Reduced Chemical Kinetics Model

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Juncheng Li ◽  
Zhiyu Han ◽  
Cai Shen ◽  
Chia-fon Lee
Keyword(s):  
Chemical Kinetics ◽  
Combustion Process ◽  
Operating Conditions ◽  
Nox Emission ◽  
Kinetics Model ◽  
Combustion Model ◽  
Nox Emissions ◽  
Soot Emission ◽  
Start Of Injection ◽  
Combustion Processes

In this paper, the effects of the start of injection (SOI) timing and exhaust gas recirculation (EGR) rate on the nitrogen oxides (NOx) emissions of a biodiesel-powered diesel engine are studied with computational fluid dynamics (CFD) coupling with a chemical kinetics model. The KIVA code coupling with a CHEMKIN-II chemistry solver is applied to the simulation of the in-cylinder combustion process. A surrogate biodiesel mechanism consisting of two fuel components is employed as the combustion model of soybean biodiesel. The in-cylinder combustion processes of the cases with four injection timings and three EGR rates are simulated. The simulation results show that the calculated NOx emissions of the cases with default EGR rate are reduced by 20.3% and 32.9% when the injection timings are delayed by 2- and 4-deg crank angle, respectively. The calculated NOx emissions of the cases with 24.0% and 28.0% EGR are reduced by 38.4% and 62.8%, respectively, compared to that of the case with default SOI and 19.2% EGR. But higher EGR rate deteriorates the soot emission. When EGR rate is 28.0% and SOI is advanced by 2 deg, the NOx emission is reduced by 55.1% and soot emission is controlled as that of the case with 24% EGR and default SOI. The NOx emissions of biodiesel combustion can be effectively improved by SOI retardation or increasing EGR rate. Under the studied engine operating conditions, introducing more 4.8% EGR into the intake air with unchanged SOI is more effective for NOx emission controlling than that of 4-deg SOI retardation with default EGR rate.

A Comparative Study of Combustion Models for Spark Ignition Engines Based on Experimentation and CFD Simulation

2010 ◽  
Author(s):  
Raouf Mobasheri ◽  
M. Sadegh Shahrokhi-Dehkordi
Keyword(s):  
Comparative Study ◽  
Cfd Simulation ◽  
Combustion Process ◽  
Experimental Tests ◽  
Experimental Results ◽  
Nox Emission ◽  
Combustion Model ◽  
Spark Ignition Engines ◽  
Flamelet Model ◽  
Combustion Models

Computational fluid dynamics (CFD) is able to significantly reduce the number of experimental tests and measurements and lower the development time and costs. However some parameters which are needed for CFD calculation must be achieved experimentally. In this paper, a comparative study was carried out to clarify the effect of three different combustion models on the prediction capability of combustion process and NOx emission on a modified 4-cylinder MPFI SI engine. Validation of the combustion model has been performed through comparing simulation data with the experimental results and a satisfactory agreement between them has been achieved in terms of combustion parameters and NOx emission. The results show that, applying appropriate constants of each combustion model including Eddy break up model (Ebu), Probability density function (Pdf) and Coherent flamelet model (Cfm) causes the computational results to be in agreement with experimental results. Furthermore the results show that the nearest prediction in comparison with experimental results is by applying the Ebu model.

scholarly journals An Influence of Correction of the Ignition Advance Angle on the Combustion Process in SI Engine Fuelled by LPG with the Addition of DME

2019 ◽  
Vol 26 (4) ◽  
pp. 285-292
Author(s):  
Grzegorz Kubica ◽  
Paweł Marzec
Keyword(s):  
Full Range ◽  
Combustion Process ◽  
Experimental Tests ◽  
Point Of View ◽  
Si Engine ◽  
Fuel Component ◽  
Gaseous Fuels ◽  
Basic Engine ◽  
Positive Effect ◽  
Fuel Components

AbstractThe paper presents the results of tests of the SI engine fuelled by LPG with the addition of DME in the form of a mixture of gaseous fuels. Experimental tests were carried out on a chassis dynamometer in the full range of engine loads, at a fixed rotational speed: 2000, 2500 and 3000 rpm. The use of dimethyl ether (DME) as a fuel component makes it possible to exploit its important advantages. DME can be produced as a renewable fuel, which is important from the point of view of ecology. Another important fact is the presence of oxygen in this fuel, which has a positive effect on the engine volumetric efficiency. During the tests, the ignition timing was also adjusted due to the very good DME flammability. Two additional correction levels were applied, increasing the ignition advance by 3 and 6 CA degrees, compared to the factory settings of the driver. The analysis of the obtained results allowed determining the dependence of the basic engine parameters, in the function of the correction of ignition advance angle. In the summary, attention was also paid to the possibility of determining corrected maps of the ignition advance angle taking into account the variable proportions of fuel components.

A Phenomenological Combustion Model for Common Rail Multi-Jet Diesel Engine

2004 ◽  
Author(s):  
Fabrizio Ponti ◽  
Gabriele Serra ◽  
Carlo Siviero
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Angular Position ◽  
Combustion Process ◽  
Common Rail ◽  
Proper Function ◽  
Combustion Model ◽  
Number Of Injections ◽  
Engine Cycle ◽  
The Way

The simplest way to describe the combustion process into the cylinder of an internal combustion engine and the associated heat release is to estimate at each crankshaft angular position the mass fraction of fuel burned using a proper function. There is a number of functions recorded in the literature that have been used for this purpose, the most relevant being likely the so-called Wiebe function. These functions have been developed both for spark ignition and diesel engines. The development of modern Common Rail injection systems makes the application of this kind of methodology particularly challenging. The trend seems to indicate, in fact, that in the near future Diesel engine injection systems will perform up to five injections per engine cycle. Therefore the way energy is released into the cylinder could become very complex to be described and the simple approaches developed up to now could be not sufficient anymore. This paper deals with the development of a single zone combustion model able to correctly describe the heat release rate for a common rail multi-jet diesel engine employing up to 4 injections per engine cycle. The model has been developed step-by-step from the simplest case of a single injection to the more complex one with 4 injections. It has been identified and validated using experimental data obtained employing from 1 to 4 different injections. Premixed and diffusive combustions have been taken into account, both modelled as “Wiebe functions”. Particular identification problems (such as modelling error with multiple injection or identification robustness procedure) are approached on the basis of real data. The main result is that increasing the number of injections actuated (and then the combustion phases) predictive properties of the model are still acceptable, and identification procedure is robust if initial values of unknown parameters are properly set. The obtained results allowed observing for example the way the combustion delays (i.e the time delays between each Start of Injection and the corresponding Start of Combustion) are modified as the number of injections increases, as well as other important combustion characteristics.

scholarly journals Investigation into the effect of different fuels on ignition delay of M-type diesel combustion process

2008 ◽  
Vol 12 (1) ◽  
pp. 103-114 ◽  
Author(s):  
Dzevad Bibic ◽  
Ivan Filipovic ◽  
Ales Hribernik ◽  
Boran Pikula
Keyword(s):  
Diesel Engine ◽  
Ignition Delay ◽  
Fuel Injection ◽  
Direct Injection ◽  
Combustion Process ◽  
Injection System ◽  
Biodiesel Fuel ◽  
Injection Timing ◽  
Injection Angle ◽  
Start Of Injection

An ignition delay is a very complex process which depends on a great number of parameters. In practice, definition of the ignition delay is based on the use of correlation expressions. However, the correlation expressions have very often limited application field. This paper presents a new correlation which has been developed during the research project on the direct injection M-type diesel engine using both the diesel and biodiesel fuel, as well as different values of a static injection timing. A dynamic start of injection, as well as the ignition delay, is defined in two ways. The first approach is based on measurement of a needle lift, while the second is based on measurement of a fuel pressure before the injector. The latter approach requires calculation of pressure signals delay through the fuel injection system and the variation of a static advance injection angle changing. The start of a combustion and the end of the ignition delay is defined on the basis of measurements of an in-cylinder pressure and its point of separation from a skip-fire pressure trace. The developed correlation gives better prediction of the ignition delay definition for the M-type direct injection diesel engine in the case of diesel and biodiesel fuel use when compared with the classic expression by the other authors available in the literature.

scholarly journals Combustion Optimization for Coal Fired Power Plant Boilers Based on Improved Distributed ELM and Distributed PSO

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1036 ◽  
Author(s):  
Xinying Xu ◽  
Qi Chen ◽  
Mifeng Ren ◽  
Lan Cheng ◽  
Jun Xie
Keyword(s):  
Power Plant ◽  
Combustion Process ◽  
Optimization Method ◽  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Combustion Model ◽  
Nox Emissions ◽  
Coupling Characteristics ◽  
Learning Machine ◽  
Combustion Optimization

Increasing the combustion efficiency of power plant boilers and reducing pollutant emissions are important for energy conservation and environmental protection. The power plant boiler combustion process is a complex multi-input/multi-output system, with a high degree of nonlinearity and strong coupling characteristics. It is necessary to optimize the boiler combustion model by means of artificial intelligence methods. However, the traditional intelligent algorithms cannot deal effectively with the massive and high dimensional power station data. In this paper, a distributed combustion optimization method for boilers is proposed. The MapReduce programming framework is used to parallelize the proposed algorithm model and improve its ability to deal with big data. An improved distributed extreme learning machine is used to establish the combustion system model aiming at boiler combustion efficiency and NOx emission. The distributed particle swarm optimization algorithm based on MapReduce is used to optimize the input parameters of boiler combustion model, and weighted coefficient method is used to solve the multi-objective optimization problem (boiler combustion efficiency and NOx emissions). According to the experimental analysis, the results show that the method can optimize the boiler combustion efficiency and NOx emissions by combining different weight coefficients as needed.

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