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

Author(s):  
Kuo Yang ◽  
Pingen Chen

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.

Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  

Currently the most promising solution for marine propulsion is the two-stroke low-speed diesel engine. Start of Injection (SOI) is of significant importance for these engines due to its effect on firing pressure and specific fuel consumption. Therefore these engines are usually equipped with Variable Injection Timing (VIT) systems for variation of SOI with load. Proper operation of these systems is essential for both safe engine operation and performance since they are also used to control peak firing pressure. However, it is rather difficult to evaluate the operation of VIT system and determine the required rack settings for a specific SOI angle without using experimental techniques, which are extremely expensive and time consuming. For this reason in the present work it is examined the use of on-board monitoring and diagnosis techniques to overcome this difficulty. The application is conducted on a commercial vessel equipped with a two-stroke engine from which cylinder pressure measurements were acquired. From the processing of measurements acquired at various operating conditions it is determined the relation between VIT rack position and start of injection angle. This is used to evaluate the VIT system condition and determine the required settings to achieve the desired SOI angle. After VIT system tuning, new measurements were acquired from the processing of which results were derived for various operating parameters, i.e. brake power, specific fuel consumption, heat release rate, start of combustion etc. From the comparative evaluation of results before and after VIT adjustment it is revealed an improvement of specific fuel consumption while firing pressure remains within limits. It is thus revealed that the proposed method has the potential to overcome the disadvantages of purely experimental trial and error methods and that its use can result to fuel saving with minimum effort and time. To evaluate the corresponding effect on NOx emissions, as required by Marpol Annex-VI regulation a theoretical investigation is conducted using a multi-zone combustion model. Shop-test and NOx-file data are used to evaluate its ability to predict engine performance and NOx emissions before conducting the investigation. Moreover, the results derived from the on-board cylinder pressure measurements, after VIT system tuning, are used to evaluate the model’s ability to predict the effect of SOI variation on engine performance. Then the simulation model is applied to estimate the impact of SOI advance on NOx emissions. As revealed NOx emissions remain within limits despite the SOI variation (increase).


Pomorstvo ◽  
2018 ◽  
Vol 32 (2) ◽  
pp. 228-238 ◽  
Author(s):  
Sergejus LebedevasPaulius ◽  
Paulius Rapalis ◽  
Rima Mickevicienė

In this study, we have investigated the efficiency of transport diesel engines CAT3512B-HD in transient braking and acceleration modes in 2M62M locomotives. A comparative analysis of the diesel engine performance has been performed at speeds of power increase and braking ranging from 4–5 kW/s to 17–18 kW/s. A decrease in the fuel economy occurred, and the main reason for it (compared with the steady-state operating condition at qcycl = idem) has been found to be the deterioration of the mechanical efficiency coefficient due to the loss of the additional equipment kinetic energy of the engine. The efficiency decreased by 3–3.5% under power increase operations and by 10–14% in the braking modes. The original methodology for the evaluation of the diesel engine parameters registered by the engine control units (ECU) in the engine operating conditions, mathematical modelling application AVL BOOST, and analytical summaries in artificial neural networks (ANNs) have been used. The errors in the obtained results have been 5–8% at a determination coefficient of 0.97–0.99.


Author(s):  
Shiyou Yang ◽  
Kangyao Deng ◽  
Yi Cui ◽  
Hongzhong Gu

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.


2021 ◽  
Author(s):  
Theofanis Chountalas ◽  
Maria Founti

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.


Author(s):  
Shiyou Yang ◽  
Kangyao Deng ◽  
Yi Cui ◽  
Hongzhong Gu

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.


2021 ◽  
Vol 264 ◽  
pp. 04021
Author(s):  
Sarvar Kadirov ◽  
Madamin Aripdjanov ◽  
Obidjon Ergashev ◽  
Ravshan Iskandarov

This article discusses the main history of the creation of high-speed short-stroke diesel engines and an assessment of the main factors that most significantly affect the working process of a diesel engine. When developing a new design of a high-speed diesel engine, it is necessary to pay special attention to the following factors: the intensity of the air charge, injection pressure parameters, the shape of the combustion chamber and the choice of the best option. Research carried out with a 7 x 0.15 mm nozzle in a wide range of speed changes (n = 1000 + 2800 min-1) shows that it is possible to find a position of the widened valve at which optimal results are obtained at medium and high rotational speeds, and on small - engine performance will deteriorate slightly.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Shiva Kumar ◽  
P. Srinivasa Pai ◽  
B. R. Shrinivasa Rao

Radial basis function neural networks (RBFNNs), which is a relatively new class of neural networks, have been investigated for their applicability for prediction of performance and emission characteristics of a diesel engine fuelled with waste cooking oil (WCO). The RBF networks were trained using the experimental data, where in load percentage, compression ratio, blend percentage, injection timing, and injection pressure were taken as the input parameters, and brake thermal efficiency (BTE), brake specific energy consumption (BSEC), exhaust gas temperature (), and engine emissions were used as the output parameters. The number of RBF centers was selected randomly. The network was initially trained using variable width values for the RBF units using a heuristic and then was trained by using fixed width values. Studies showed that RBFNN predicted results matched well with the experimental results over a wide range of operating conditions. Prediction accuracy for all the output parameters was above 90% in case of performance parameters and above 70% in case of emission parameters.


Author(s):  
H. Zimmermann ◽  
R. Gumucio ◽  
K. Katheder ◽  
A. Jula

Performance and aerodynamic aspects of ultra-high bypass ratio ducted engines have been investigated with an emphasis on nozzle aerodynamics. The interference with aircraft aerodynamics could not be covered. Numerical methods were used for aerodynamic investigations of geometrically different aft end configurations for bypass ratios between 12 and 18, this is the optimum range for long missions which will be important for future civil engine applications. Results are presented for a wide range of operating conditions and effects on engine performance are discussed. The limitations for higher bypass ratios than 12 to 18 do not come from nozzle aerodynamics but from installation effects. It is shown that using CFD and performance calculations an improved aerodynamic design can be achieved. Based on existing correlations, for thrust and mass-flow, or using aerodynamic tailoring by CFD and including performance investigations, it is possible to increase the thrust coefficient up to 1%.


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