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.

Combustion Noise Real-Time Evaluation and Processing for Combustion Control

2012 ◽  
Author(s):  
Fabrizio Ponti ◽  
Vittorio Ravaglioli ◽  
Davide Moro ◽  
Matteo De Cesare
Keyword(s):  
Diesel Engine ◽  
Closed Loop ◽  
Control Strategies ◽  
Combustion Process ◽  
Combustion Noise ◽  
Pollutant Emissions ◽  
Cylinder Pressure ◽  
Combustion Control ◽  
Engine Noise ◽  
Injection Parameters

Newly developed Diesel engine control strategies are mainly aimed at pollutant emissions reduction, due to the increasing request for engine-out emissions and fuel consumption reduction. In order to reduce engine-out emissions, the development of closed-loop combustion control algorithms has become crucial. Modern closed-loop combustion control strategies are characterized by two main aspects: the use of high EGR rates (the goal being to obtain highly premixed combustions) and the control of the center of combustion. In order to achieve the target center of combustion, conventional combustion control algorithms correct the measured value by varying Main injection timing. It is possible to obtain a further reduction in pollutant emissions through a proper variation of the injection parameters. Modern Diesel engine injection systems allow designing injection patterns with many degrees of freedom, due to the large number of tuneable injection parameters (such as start and duration of each injection). Each injection parameter’s variation causes variations in the whole combustion process and, consequently, in pollutant emissions production. Injection parameters variations have a strong influence on other quantities that are related to combustion process effectiveness, such as noise radiated by the engine. This work presents a methodology that allows real-time evaluating combustion noise on-board a vehicle. The radiated noise can be evaluated through a proper in-cylinder pressure signal processing. Even though in-cylinder pressure sensor on-board installation is still uncommon, it is believed that in-cylinder pressure measurements will be regularly available on-board thanks to the newly developed piezo-resistive sensors. In order to set-up the methodology, several experimental tests have been performed on a 1.3 liter Diesel engine mounted in a test cell. The engine was run, in each operating condition, both activating and deactivating pre-injections, since pre-injections omission usually produces a decrease in pollutant emissions production (especially in particulate matter) and a simultaneous increase in engine noise. The investigation of the correlation between combustion process and engine noise can be used to set up a closed-loop algorithm for optimal combustion control based on engine noise prediction.

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.

Diesel Engine Combustion Sensing Methodology Based on Vibration Analysis

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Ponti Fabrizio ◽  
Ravaglioli Vittorio ◽  
Cavina Nicolò ◽  
De Cesare Matteo
Keyword(s):  
Diesel Engine ◽  
Closed Loop ◽  
Combustion Process ◽  
Pressure Sensors ◽  
Thermal Conditions ◽  
Pollutant Emissions ◽  
Accurate Estimation ◽  
Cylinder Pressure ◽  
Combustion Control ◽  
Real Time Analysis

The increasing request for pollutant emissions reduction spawned a great deal of research in the field of combustion control and monitoring. As a matter of fact, newly developed low temperature combustion strategies for diesel engines allow obtaining a significant reduction both in particulate matter and NOx emissions, combining the use of high EGR rates with a proper injection strategy. Unfortunately, due to their nature, these innovative combustion strategies are very sensitive to in-cylinder thermal conditions. Therefore, in order to obtain a stable combustion, a closed-loop combustion control methodology is needed. Many works demonstrate that a closed-loop combustion control strategy can be based on real-time analysis of in-cylinder pressure trace that provides important information about the combustion process, such as start of combustion, center of combustion and torque delivered by each cylinder. Nevertheless, cylinder pressure sensors on-board installation is still uncommon, due to problems related to unsatisfactory measurement long term reliability and cost. This paper presents a newly developed approach that allows extracting information about combustion effectiveness through the analysis of engine vibrations. In particular, the developed methodology can be used to obtain an accurate estimation of the indicated quantities of interest combining the information provided by engine speed fluctuations measurement and by the signals coming from acceleration transducers mounted on the engine. This paper also reports the results obtained applying the whole methodology to a light-duty turbocharged common rail diesel engine.

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.

Diesel Engine Combustion Sensing Methodology Based on Vibration Analysis

2013 ◽  
Author(s):  
F. Ponti ◽  
V. Ravaglioli ◽  
N. Cavina ◽  
M. De Cesare
Keyword(s):  
Diesel Engine ◽  
Closed Loop ◽  
Combustion Process ◽  
Pressure Sensors ◽  
Thermal Conditions ◽  
Pollutant Emissions ◽  
Accurate Estimation ◽  
Cylinder Pressure ◽  
Combustion Control ◽  
Real Time Analysis

The increasing request for pollutant emissions reduction spawned a great deal of research in the field of combustion control and monitoring. As a matter of fact, newly developed low temperature combustion strategies for Diesel engines allow obtaining a significant reduction both in particulate matter and NOx emissions, combining the use of high EGR rates with a proper injection strategy. Unfortunately, due to their nature, these innovative combustion strategies are very sensitive to in-cylinder thermal conditions. Therefore, in order to obtain a stable combustion, a closed-loop combustion control methodology is needed. Many works demonstrate that a closed-loop combustion control strategy can be based on real-time analysis of in-cylinder pressure trace, that provides important information about the combustion process, such as start of combustion, center of combustion and torque delivered by each cylinder. Nevertheless, cylinder pressure sensors on-board installation is still uncommon, due to problems related to unsatisfactory measurement long term reliability and cost. This paper presents a newly developed approach that allows extracting information about combustion effectiveness through the analysis of engine vibrations. In particular, the developed methodology can be used to obtain an accurate estimation of the indicated quantities of interest combining the information provided by engine speed fluctuations measurement and by the signals coming from acceleration transducers mounted on the engine. This paper also reports the results obtained applying the whole methodology to a light-duty turbocharged Common Rail Diesel engine.

Effects of H2 Addition to CNG Blends on Cycle-to-Cycle and Cylinder-to-Cylinder Combustion Variation in an SI Engine

2012 ◽  
Author(s):  
Mirko Baratta ◽  
Stefano d’Ambrosio ◽  
Daniela Misul ◽  
Ezio Spessa
Keyword(s):  
Diagnostic Tool ◽  
Combustion Process ◽  
Experimental Tests ◽  
Test Point ◽  
Pollutant Emissions ◽  
Engine Operation ◽  
Pressure Transducers ◽  
Rate Analysis ◽  
Spark Plug ◽  
Wide Range

An experimental investigation and a burning-rate analysis have been performed on a production 1.4 liter CNG (compressed natural gas) engine fueled with methane-hydrogen blends. The engine features a pent-roof combustion chamber, four valves per cylinder and a centrally located spark plug. The experimental tests have been carried out in order to quantify the cycle-to-cycle and the cylinder-to-cylinder combustion variation. Therefore, the engine has been equipped with four dedicated piezoelectric pressure transducers placed on each cylinder and located by the spark plug. At each test point, in-cylinder pressure, fuel consumption, induced air mass flow rate, pressure and temperature at different locations on the engine intake and exhaust systems as well as ‘engine-out’ pollutant emissions have been measured. The signals correlated to the engine operation have been acquired by means of a National Instruments PXI-DAQ system and a home developed software. The acquired data have then been processed through a combustion diagnostic tool resulting from the integration of an original multizone thermodynamic model with a CAD procedure for the evaluation of the burned-gas front geometry. The diagnostic tool allows the burning velocities to be computed. The tests have been performed over a wide range of engine speeds, loads and relative air-fuel ratios (up to the lean operation). For stoichiometric operation, the addition of hydrogen to CNG has produced a bsfc reduction ranging between 2 to 7% and a bsTHC decrease up to the 40%. These benefits have appeared to be even higher for lean mixtures. Moreover, hydrogen has shown to significantly enhance the combustion process, thus leading to a sensibly lower cycle-to-cycle variability. As a matter of fact, hydrogen addition has generally resulted into extended operation up to RAFR = 1.8. Still, a discrepancy in the abovementioned conclusions was observed depending on the engine cylinder considered.

scholarly journals Some aspects of cycle variability at the Diesel engine fuelled with animal fats

2019 ◽  
Vol 112 ◽  
pp. 01014
Author(s):  
Adrian Nicolici ◽  
Constantin Pană ◽  
Niculae Negurescu ◽  
Alexandru Cernat ◽  
Cristian Nuţu
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Alternative Fuels ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Experimental Investigations ◽  
Maximum Pressure ◽  
Content Increase ◽  
Animal Fats ◽  
Viable Solution

The progressive diminution of the oil reserves all over the world highlights the necessity of using alternative fuels derived from durable renewable resource. The use of the alternative fuels represents a viable solution to reduce the pollutant emissions and to replace fossil fuels. Thus, a viable solution is the use of the animal fats in mixture with the diesel fuel at the diesel engines. A D2156 MTN8 diesel engine was firstly fuelled with diesel fuel and then with different blends of diesel fuel-animal fats (5% and 10% animal fats content). In the paper are presented some results of the experimental investigations of engine fuelled with preheated animal fats. The raw animal fats effects on the combustion process and on the pollutant emissions at different engine loads and 1450 rev/min engine speed are showed. The engine cycle variability increases at the animal fats content increase. The cycle variability for maximum pressure, maximum pressure angle and indicated mean effective pressure is analysed. The cycle variability coefficients values don’t exceed the recommended values of the standard diesel engine.

Needle Displacement Visualization With Simultaneous Measurement of Injection Rate for CR Diesel Injector: A Novel Experimental Technique

2019 ◽  
Author(s):  
Giancarlo Chiatti ◽  
Ornella Chiavola ◽  
Fulvio Palmieri
Keyword(s):  
Experimental Technique ◽  
Optical Sensors ◽  
Digital Imaging ◽  
Measurement Techniques ◽  
Combustion Process ◽  
Injection Rate ◽  
The Other ◽  
Pollutant Emissions ◽  
Injection System ◽  
Injection Strategy

Abstract The control of combustion is a key topic for diesel engine development in terms of performance and pollutant emissions. The combustion process is piloted through the proper injection strategy, which depends on the features of the injection system. Mechanical-hydraulic models of high-pressure injection systems often support the accurate tuning of the injection strategy. The higher is the accuracy in the modeling of the electro-injector behavior, the deeper is the role of the simulation. Under such a viewpoint, the validation of the models is undoubtedly fundamental. One of the most crucial information characterizing the injector relies on the measurement of the needle displacement. Needle displacement affects rate, timing and quantity of injected fuel; it also influences the flow features within the nozzle, which are then reflected by the primary atomization process. Needle is considered hardly-accessible due to the injector architecture itself, making difficult the measurement of displacement. Nevertheless, the problem has been handled in different ways and three measurement techniques have been proposed. On one side, there is the measurement based on eddy-current transducers; on the other side, there are two alternative procedures, based on the use of optical sensors. However, in all cases, the needle is traced indirectly, since the position of the control plunger of the needle is observed. The current contribution presents a novel experimental technique for the measurement of needle displacement. The method is based on the direct visualization of the needle, allowing for the detailed definition of its law of motion through digital imaging, when the injector is characterized on a test-rig under transient conditions. The paper describes the details of the diagnostic scheme, the experimental facility and the digital imaging set-up. The main features and the capabilities of the method are discussed, in comparison with the other available techniques.

The Effects of Injection Parameters on the Performance of Common Rail Light Duty Engine Fueled with Palm Oil Biodiesel

2013 ◽  
Vol 465-466 ◽  
pp. 322-326 ◽  
Author(s):  
M. Adlan Abdullah ◽  
Farid Nasir Ani ◽  
Masjuki Hassan
Keyword(s):  
Diesel Engine ◽  
Palm Oil ◽  
Fuel Economy ◽  
Fuel Injection ◽  
Control Strategies ◽  
Engine Performance ◽  
Common Rail ◽  
Injection Timing ◽  
Injection Duration ◽  
Injection Parameters

It is in the interest of proponents of biodiesel to increase the utilization of the renewable fuel. The similarities of the methyl ester properties to diesel fuel and its miscibility proved to be an attractive advantage. It is however generally accepted that there are some performance and emissions deficit when a diesel engine is operated with biodiesel. There are research efforts to improve the diesel engine design to optimize the combustion with biodiesel. Since the common rail engines operates on flexible injection strategies, there exist an opportunity to improve engine performance and offset the fuel economy deficit by means of optimizing the engine control strategies. This approach may prove to be more practical and easily implemented. This study investigated the effects of the fuel injection parameters - rail pressure, injection duration and injection timing - on a common rail passenger car engine in terms of the fuel economy. Palm oil based biodiesel up to 30% blend in diesel was used in this study. The end of injection, (EOI), was found to be the most important parameter for affecting fuel consumption and thermal efficiency.

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