Control-Oriented Model of the Mean and Dispersion of Diesel Combustion Phasing With Ignition Assist

2021 ◽  
Author(s):  
Omar Ahmed ◽  
Robert Middleton ◽  
Anna Stefanopoulou ◽  
Kenneth Kim ◽  
Chol-Bum Kweon
Keyword(s):  
Diesel Engines ◽  
Controller Design ◽  
Thermal State ◽  
Operating Conditions ◽  
Injection Timing ◽  
Model Estimate ◽  
Combustion Behavior ◽  
Start Up ◽  
Crank Angle ◽  
Start Of Combustion

Abstract Diesel engines equipped with ignition assist devices such as glow plugs may improve combustion behavior at low temperatures and with low cetane fuels found in remote fields. The coordination of injection timing and the energy input of the ignition assist needs to continuously adjust to maintain the best combustion phasing at all conditions. However, most diesel engines do not use closed-loop combustion control and operate in a sub-optimal manner because the dispersion of combustion phasing, also known as cycle-to-cycle variability, requires careful feedback controller design. This work presents an initial investigation of a control-oriented model that captures the average and statistical influence of commercial glow plugs used for ignition assist beyond the start-up phase. Experiments were conducted at a single speed and load operating point as a proof of concept to obtain a model that quantifies the combustion phasing statistics and thus can guide feedback control design. The developed phenomenological model includes the engine’s thermal state because it impacts combustion behavior over the course of repeated experiments. The 3-term mean phasing model and 2-term standard deviation model estimate start of combustion within 0.6 and 0.2 crank angle degrees, respectively, and can be readily expanded to more operating conditions.

Determination of the Start and End of Combustion in a Direct Injection Diesel Engine Using the Apparent Heat Release Rate

2017 ◽  
Author(s):  
Joseph Gerard T. Reyes ◽  
Edwin N. Quiros
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Direct Injection ◽  
Injection Timing ◽  
Fuel Injector ◽  
Direct Injection Diesel Engine ◽  
Crank Angle ◽  
Start Of Combustion

The combustion duration in an internal combustion engine is the period bounded by the engine crank angles known as the start of combustion (SOC) and end of combustion (EOC), respectively. This period is essential in analysis of combustion for the such as the production of exhaust emissions. For compression-ignition engines, such as diesel engines, several approaches were developed in order to approximate the crank angle for the start of combustion. These approaches utilized the curves of measured in-cylinder pressures and determining by inspection the crank angle where the slope is steep following a minimum value, indicating that combustion has begun. These pressure data may also be utilized together with the corresponding cylinder volumes to generate the apparent heat release rate (AHRR), which shows the trend of heat transfer of the gases enclosed in the engine cylinder. The start of combustion is then determined at the point where the value of the AHRR is minimum and followed by a rapid increase in value, whereas the EOC is at the crank angle where the AHRR attains a flat slope prior to the exhaust stroke of the engine. To verify the location of the SOC, injection line pressures and fuel injection timing are also used. This method was applied in an engine test bench using a four-cylinder common-rail direct injection diesel engine with a pressure transducer installed in the first cylinder. Injector line pressures and fuel injector voltage signals per engine cycle were also recorded and plotted. By analyzing the trends of this curves in line with the generated AHRR curves, the SOC may be readily determined.

A New Predictive ID Model for Advanced High Speed Direct Injection Diesel Engines

2004 ◽  
Author(s):  
Lurun Zhong ◽  
Naeim A. Henein ◽  
Walter Bryzik
Keyword(s):  
Diesel Engines ◽  
High Speed ◽  
Direct Injection ◽  
Combustion Process ◽  
Operating Conditions ◽  
Injection System ◽  
Injection Timing ◽  
Common Rail Injection System ◽  
Common Rail Injection ◽  
Starting Conditions

Advance high speed direct injection diesel engines apply high injection pressures, exhaust gas recirculation (EGR), injection timing and swirl ratios to control the combustion process in order to meet the strict emission standards. All these parameters affect, in different ways, the ignition delay (ID) which has an impact on premixed, mixing controlled and diffusion controlled combustion fractions and the resulting engine-out emissions. In this study, the authors derive a new correlation to predict the ID under the different operating conditions in advanced diesel engines. The model results are validated by experimental data in a single-cylinder, direct injection diesel engine equipped with a common rail injection system at different speeds, loads, EGR ratios and swirl ratios. Also, the model is used to predict the performance of two other diesel engines under cold starting conditions.

Cylinder-Specific Combustion Phasing Modeling for a Multiple-Cylinder Diesel Engine

2018 ◽  
Author(s):  
Wenbo Sui ◽  
Carrie M. Hall
Keyword(s):  
Prediction Model ◽  
Diesel Engines ◽  
Measurement Errors ◽  
Equivalence Ratio ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Integral Model ◽  
Low Carbon ◽  
Crank Angle ◽  
The Impact

An optimal combustion phasing leads to a high combustion efficiency and low carbon emissions in diesel engines. With the increasing complexity of diesel engines, model-based control of combustion phasing is becoming indispensable, but precise prediction of combustion phasing is required for such strategies. Since cylinder-to-cylinder variations in combustion can be more significant with advanced combustion techniques, this work focuses on developing a control-oriented combustion phasing model that can be leveraged to provide cylinder-specific estimates. The pressure and temperature of the intake gas reaching each cylinder are predicted by a semi-empirical model and the coefficients of this intake pressure and temperature model are varied from cylinder-to-cylinder. A knock integral model is leveraged to estimate the SOC (start of combustion) and the burn duration is predicted as a function of EGR fraction, equivalence ratio of fuel and residual gas fraction in a burn duration model. After that, a Wiebe function is utilized to estimate CA50 (crank angle at 50% mass of fuel has burned). This cylinder-specific combustion phasing prediction model is calibrated and validated across a variety of operating conditions. A large range of EGR fraction and fuel equivalence ratio were tested in these simulations including EGR levels from 0 to 50%, and equivalence ratios from 0.5 to 0.9. The results show that the combustion phasing prediction model can estimate CA50 with an uncertainty of ±0.5 crank angle degree in all six cylinders. The impact of measurement errors on the accuracy of the prediction model is also discussed in this paper.

Control-Oriented Model Development and Experimental Validation for a Modern Diesel Engine

2020 ◽  
Author(s):  
Kuo Yang ◽  
Pingen Chen
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Model Development ◽  
Engine Performance ◽  
Operating Conditions ◽  
Least Square ◽  
Injection Timing ◽  
Model Based ◽  
Wide Range ◽  
Mean Square Errors

Abstract Modern Diesel engines have become highly complex multi-input multi-output systems. Controls of modern Diesel engines to meet various requirements such as high fuel efficiency and low NOx and particulate matter (PM) emissions, remain a great challenge for automotive control community. While model-based controls have demonstrated significant potentials in achieving high Diesel engine performance. Complete and high-fidelity control-oriented Diesel engine models are much needed as the foundations of model-based control system development. In this study, a semi-physical, mean-value control-oriented model of a turbocharged Diesel engine equipped with high-pressure exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT) is developed and experimentally validated. The static calibration of Diesel engine model is achieved with the least-square optimization methodology using the experimental test data from a physical Diesel engine platform. The normalized root mean square errors (NRMSEs) of the calibration results are in the range of 0.1095 to 0.2582. The cross-validation results demonstrated that the model was capable of accurately capturing the engine torque output and NOx emissions with the control inputs of EGR, VGT and Start of Injection timing (SOI) in wide-range operating conditions.

Comparison of Crankangle Based Ignition Timing Methods on an HCCI Engine

2010 ◽  
Author(s):  
Ahmad Ghazimirsaied ◽  
Mahdi Shahbakhti ◽  
Charles Robert Koch
Keyword(s):  
Heat Release ◽  
Operating Conditions ◽  
Main Stage ◽  
Cyclic Variation ◽  
Ignition Timing ◽  
Crank Angle ◽  
Pressure Trace ◽  
Engine Operating Condition ◽  
Start Of Combustion ◽  
Third Derivative

Autoignition timing of a mixture in Homogeneous Charge Compression Ignition (HCCI) is very dependant and sensitive to the engine operating condition. To characterize combustion timing, different crank angle dependant methods are used but these methods can exhibit inaccurate results at some operating conditions. In this paper, a criterion that divides the engine operating condition into two regions, low and high cyclic variations (unstable operation) is defined. Then, different crankangle based methods for determining the start of combustion inside the cylinder for each of the two regions are compared. The start and duration of combustion are compared for wide range of operating conditions and the relative merits of each method discussed. The methods for characterizing the start of combustion are: CA50 based on the total heat release; the start of combustion from the third derivative of the pressure trace with respect to crank angle; the start of combustion from the third derivative of the pressure trace with respect to crank angle with two limits; CA10 based on total heat release; CA10 based on peak of main stage of combustion. The last method is introduced in this paper and has advantages in terms of accuracy of ignition timing detection and correlation with the start of combustion particularly for high cyclic variation engine operation. A new criterion, defined as the ratio between peak of main stage and the sum of peak of main stage and cool flame stage of heat release, is introduced to more accurately identify the operating region of the engine. This criterion is used to understand the performance of each of those crank angle based methods. The performance of each of those methods is investigated for both the low cyclic variation and the high cyclic variation (unstable) region of the engine.

A Study on an Automatically Variable Intake Exhaust Injection Timing Turbocharging System for Diesel Engines

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Shiyou Yang ◽  
Kangyao Deng ◽  
Yi Cui ◽  
Hongzhong Gu
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
High Speed ◽  
Control Mechanism ◽  
Operating Conditions ◽  
Combustion Model ◽  
Injection Timing ◽  
Low Speed ◽  
Turbocharging System ◽  
High Torque

A new turbocharging system, named automatically variable intake exhaust injection timing (AVIEIT), is proposed. Its main purpose is to improve the performance of low-speed high torque operating conditions and improve the economy of high-speed operating conditions for high-speed supercharged intercooled diesel engines. The principle of the AVIEIT turbocharging system is presented. A control mechanism for the proposed AVIEIT system used for a truck diesel engine is introduced. An engine simulation code has been developed. In this code, a zero-dimensional in-cylinder combustion model, a one-dimensional finite volume method-total variation diminishing model for unsteady gas flow in the intake and exhaust manifolds, and a turbocharger model are used. The developed code is used to simulate the performances of diesel engines using the AVIEIT system. Simulations of a military use diesel engine “12V150” and a truck diesel engine “D6114” using the AVIEIT system have been performed. Simulation results show that the in-cylinder charge air amount of the diesel engine with the AVIEIT system is increased at low-speed high torque operating conditions, and the fuel economy is improved at high-speed operating conditions. In order to test the idea of the AVIEIT system, an experiment on a truck diesel engine D6114 equipped with an AVIEIT control mechanism has been finished. The experiment results show that the AVIEIT system can improve the economy of high-speed operating conditions. Both the simulation and experiment results suggest that the AVIEIT system has the potential to replace the waste-gate and variable geometry turbocharger turbocharging systems.

Effect of Low-Sulfur Fuel on Auxiliary Engine Combustion and Performance

2021 ◽  
Author(s):  
Theofanis Chountalas ◽  
Maria Founti
Keyword(s):  
Combustion Rate ◽  
Diesel Engines ◽  
Engine Performance ◽  
Operating Conditions ◽  
Injection System ◽  
Combustion Mechanism ◽  
Injection Timing ◽  
Cylinder Pressure ◽  
Marine Diesel ◽  
And Performance

According to the current legislation, since 01/01/2020 it is necessary to operate marine diesel engines in a wide range of areas using MGO (Marine Gas Oil). Currently, most marine diesel engines operate on HSFO (High Sulfur Fuel Oil). In the present work the effect of MGO and HSFO on the combustion mechanism and performance of Marine Diesel Auxiliary Engines is investigated. This can be accomplished via comparative evaluation of operational parameters and net combustion rate at various engine operating conditions. In this work, performance evaluation is based on the processing of measured engine cylinder pressure data acquired at sea using both fuel types. The measured cylinder pressure traces are analyzed to determine the net combustion rate, ignition delay, dynamic start of fuel injection timing, injection-combustion quality and combustion duration. Final analysis confirmed that there is considerable impact of the fuel type on engine performance and the combustion mechanism. Due to the high rotational speed of auxiliary engines, alterations in engine operation and especially the different dynamic response of the injection system between the two fuel types, led to measurably deviating engine performance, akin to different engine tuning. Severity of fuel effect was found dependent on engine type and especially condition.

scholarly journals Evaluation of a Semiempirical, Zero-Dimensional, Multizone Model to Predict Nitric Oxide Emissions in DI Diesel Engines’ Combustion Chamber

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Nicholas S. Savva ◽  
Dimitrios T. Hountalas
Keyword(s):  
Nitric Oxide ◽  
Diesel Engines ◽  
Fuel Injection ◽  
Operating Conditions ◽  
Injection Timing ◽  
Boost Pressure ◽  
Cylinder Pressure ◽  
No Formation ◽  
Calculation Step ◽  
Multizone Model

In the present study, a semiempirical, zero-dimensional multizone model, developed by the authors, is implemented on two automotive diesel engines, a heavy-duty truck engine and a light-duty passenger car engine with pilot fuel injection, for various operating conditions including variation of power/speed, EGR rate, fuel injection timing, fuel injection pressure, and boost pressure, to verify its capability for Nitric Oxide (NO) emission prediction. The model utilizes cylinder’s basic geometry and engine operating data and measured cylinder pressure to estimate the apparent combustion rate which is then discretized into burning zones according to the calculation step used. The requisite unburnt charge for the combustion in the zones is calculated using the zone equivalence ratio provided from a new empirical formula involving parameters derived from the processing of the measured cylinder pressure and typical engine operating parameters. For the calculation of NO formation, the extended Zeldovich mechanism is used. From this approach, the model is able to provide the evolution of NO formation inside each burned zone and, cumulatively, the cylinder’s NO formation history. As proven from the investigation conducted herein, the proposed model adequately predicts NO emissions and NO trends when the engine settings vary, with low computational cost. These encourage its use for engine control optimization regarding NOxabatement and real-time/model-based NOxcontrol applications.

A Study on an Automatically Variable Intake Exhaust Injection Timing Turbo-Charging System for Diesel Engines

2009 ◽  
Author(s):  
Shiyou Yang ◽  
Kangyao Deng ◽  
Yi Cui ◽  
Hongzhong Gu
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
High Speed ◽  
Control Mechanism ◽  
Operating Conditions ◽  
Combustion Model ◽  
Injection Timing ◽  
Low Speed ◽  
Charging System ◽  
High Torque

A new turbo-charging system, named AVIEIT (automatically variable intake exhaust injection timing), is proposed. Its main purpose is to improve the performance of low speed high torque operating conditions and improve the economy of high speed operating conditions for high-speed supercharged inter-cooled diesel engines. The principle of the AVIEIT turbo-charging system is presented. A control mechanism for the proposed AVIEIT system used for a truck diesel engine is introduced. An engine simulation code has been developed. In this code, zero-dimensional in-cylinder combustion model, one-dimensional FVM-TVD (finite volume method-total variation diminishing) model for unsteady gas flow in the intake and exhaust manifold, and turbocharger model are used. The developed code is used to simulate the performances of diesel engines using the AVIEIT system. Simulations of a military use diesel engine “12V150” and a truck diesel engine “D6114” using the AVIEIT system have been performed. Simulation results show that the in-cylinder charge air amount of the diesel engine with the AVIEIT system is increased at low speed high torque operating conditions, and the fuel economy is improved at high speed operating conditions. In order to test the idea of the AVIEIT system, an experiment on a truck diesel engine “D6114” equipped with an AVIEIT control mechanism has been finished. The experiment results show that the AVIEIT system can improve economy of high speed operating conditions. Both the simulation and experiment results suggest that the AVIEIT system has the potential to replace the Waste-Gate and VGT turbo-charging systems.

Detailed analytical model of a single-cylinder diesel engine in the crank angle domain

2001 ◽  
Vol 215 (11) ◽  
pp. 1197-1216 ◽  
Author(s):  
Y. H. Zweiri ◽  
J. F. Whidborne ◽  
L. D. Seneviratne
Keyword(s):  
Diesel Engines ◽  
Engine Speed ◽  
Friction Model ◽  
Operating Conditions ◽  
Thermodynamic Control ◽  
Single Cylinder ◽  
Crank Angle ◽  
Non Linear ◽  
Control Volumes ◽  
Good Agreement

A detailed analytical non-linear dynamic model for single-cylinder diesel engines is developed. The model describes the dynamic behaviour between fuelling and engine speed and includes models of the non-linear engine and dynamometer dynamics, the instantaneous friction terms and the engine thermodynamics. The model operates in the crank angle domain. The dynamometer model enables the study of the engine behaviour under loading. The instantaneous friction model takes into consideration the viscosity variations with temperature. Inertia variations with piston pin offset are presented. In-cycle calculations are performed at each crank angle, and the correct crank angles of ignition, speed variations, fuel supply and air as well as fuel burning rate are predicted. The model treats the cylinder strokes and the manifolds as thermodynamic control volumes by using the filling and emptying method. The model is validated using experimentally measured cylinder pressure and engine instantaneous speeds, under transient operating conditions, and gives good agreement. The model can be used as an engine simulator to aid diesel engines control system design and fault diagnostics.

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