Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Modeling and Control of EGR on Marine Two-Stroke Diesel Engines
Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, Faculty of Science & Engineering.ORCID iD: 0000-0002-1584-8165
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The international marine shipping industry is responsible for the transport of around 90% of the total world trade. Low-speed two-stroke diesel engines usually propel the largest trading ships. This engine type choice is mainly motivated by its high fuel efficiency and the capacity to burn cheap low-quality fuels. To reduce the marine freight impact on the environment, the International Maritime Organization (IMO) has introduced stricter limits on the engine pollutant emissions. One of these new restrictions, named Tier III, sets the maximum NOx emissions permitted. New emission reduction technologies have to be developed to fulfill the Tier III limits on two-stroke engines since adjusting the engine combustion alone is not sufficient. There are several promising technologies to achieve the required NOx reductions, Exhaust Gas Recirculation (EGR) is one of them.  For automotive applications, EGR is a mature technology, and many of the research findings can be used directly in marine applications. However, there are some differences in marine two-stroke engines, which require further development to apply and control EGR.

The number of available engines for testing EGR controllers on ships and test beds is low due to the recent introduction of EGR. Hence, engine simulation models are a good alternative for developing controllers, and many different engine loading scenarios can be simulated without the high costs of running real engine tests. The primary focus of this thesis is the development and validation of models for two-stroke marine engines with EGR. The modeling follows a Mean Value Engine Model (MVEM) approach, which has a low computational complexity and permits faster than real-time simulations suitable for controller testing. A parameterization process that deals with the low measurement data availability, compared to the available data on automotive engines, is also investigated and described. As a result, the proposed model is parameterized to two different two-stroke engines showing a good agreement with the measurements in both stationary and dynamic conditions.

Several engine components have been developed. One of these is a new analytic in-cylinder pressure model that captures the influence of the injection and exhaust valve timings without increasing the simulation time. A new compressor model that can extrapolate to low speeds and pressure ratios in a physically sound way is also described. This compressor model is a requirement to be able to simulate low engine loads. Moreover, a novel parameterization algorithm is shown to handle well the model nonlinearities and to obtain a good model agreement with a large number of tested compressor maps. Furthermore, the engine model is complemented with dynamic models for ship and propeller to be able to simulate transient sailing scenarios, where good EGR controller performance is crucial. The model is used to identify the low load area as the most challenging for the controller performance, due to the slower engine air path dynamics. Further low load simulations indicate that sensor bias can be problematic and lead to an undesired black smoke formation, while errors in the parameters of the controller flow estimators are not as critical. This result is valuable because for a newly built engine a proper sensor setup is more straightforward to verify than to get the right parameters for the flow estimators.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2018. , p. 200
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1904
Keywords [en]
Modeling for control, Ship Propulsion, Dynamic Simulation, Exhaust Gas Recirculation, Mean Value Engine Model, Parameterization, Compressor, Model Extrapolation
National Category
Control Engineering Vehicle Engineering
Identifiers
URN: urn:nbn:se:liu:diva-144596DOI: 10.3384/diss.diva-144596ISBN: 9789176853689 (print)OAI: oai:DiVA.org:liu-144596DiVA, id: diva2:1178537
Public defence
2018-03-23, Ada Lovelace, Ingång 27, B-huset, Campus Valla, Linköping, 10:15 (English)
Opponent
Supervisors
Funder
EU, Horizon 2020, 634135VINNOVA, LINK-SICAvailable from: 2018-01-30 Created: 2018-01-30 Last updated: 2018-05-15Bibliographically approved
List of papers
1. Parameterizing Compact and Extensible Compressor Models Using Orthogonal Distance Minimization
Open this publication in new window or tab >>Parameterizing Compact and Extensible Compressor Models Using Orthogonal Distance Minimization
2016 (English)In: Journal of engineering for gas turbines and power, ISSN 0742-4795, E-ISSN 1528-8919, Vol. 139, no 1, p. 012601-1-012601-10, article id GTP-15-1569Article in journal (Refereed) Published
Abstract [en]

A complete and compact control-oriented compressor model consisting of a mass flow submodel and an efficiency submodel is described. The final application of the model is a complete two-stroke mean value engine model (MVEM) which requires simulating the compressor operating at the low-flow and low-pressure ratio area. The model is based on previous research done for automotive-size compressors, and it is shown to be general enough to adapt well to the characteristics of the marine-size compressors. A physics-based efficiency model allows, together with the mass flow model, extrapolating to low-pressure ratios. The complexity of the model makes its parameterization a difficult task; hence, a method to efficiently estimate the 19 model parameters is proposed. The method computes analytic model gradients and uses them to minimize the orthogonal distances between the modeled speed lines (SpLs) and the measured points. The results of the parameter estimation are tested against nine different standard marine-size maps showing good agreement with the measured data. Furthermore, the results also show the importance of estimating the parameters of the mass flow and efficiency submodels at the same time to obtain an accurate model. The extrapolation capabilities to low-load regions are also tested using low-load measurements from an automotive-size compressor. It is shown that the model follows the measured efficiency trend down to low loads.

Place, publisher, year, edition, pages
ASME Press, 2016
National Category
Applied Mechanics
Identifiers
urn:nbn:se:liu:diva-136199 (URN)10.1115/1.4034152 (DOI)000395511600016 ()
Note

Funding Agencies|European Union [634135]

Available from: 2017-04-03 Created: 2017-04-03 Last updated: 2018-09-26
2. Control-Oriented Compressor Model with Adiabatic Efficiency Extrapolation
Open this publication in new window or tab >>Control-Oriented Compressor Model with Adiabatic Efficiency Extrapolation
2017 (English)In: SAE International Journal of Engines, ISSN 1946-3936, E-ISSN 1946-3944, Vol. 10, no 4Article in journal (Refereed) Published
Abstract [en]

Downsizing and turbocharging with single or multiple stages has been one of the main solutions to decrease fuel consumption and harmful exhaust emissions, while keeping a sufficient power output. An accurate and reliable control-oriented compressor model can be very helpful during the development phase, as well as for engine calibration, control design, diagnostic purposes or observer design. A complete compressor model consisting of mass flow and efficiency models is developed and motivated. The proposed model is not only able to represent accurately the normal region measured in a compressor map but also it is capable to extrapolate to low compressor speeds. Moreover, the efficiency extrapolation is studied by analyzing the known problem with heat transfer from the hot turbine side, which introduces errors in the measurements done in standard gas stands. Since the parameterization of the model is an important and necessary step in the modeling, a tailored parameterization approach is presented based on Total Least Squares. A standard compressor map is the only data required to parameterize the model. The parameterization is tested with a database of more than 230 compressor maps showing that it can deal well with different compressor sizes and characteristics. Also, general initialization values for the model parameters are provided using the complete database parameterization results. The results show that the model accuracy is good and in general achieves relative errors below one percent. A comparison of the model accuracy for compressor maps with and without heat transfer influence is carried out, showing a similar model accuracy for both cases but better when no heat transfer is present. Furthermore, it is shown that the model is capable to predict the efficiency characteristics at low speed of two compressor maps, measured with near adiabatic conditions.

Place, publisher, year, edition, pages
United States: S A E Inc., 2017
National Category
Control Engineering Vehicle Engineering
Identifiers
urn:nbn:se:liu:diva-136799 (URN)10.4271/2017-01-1032 (DOI)
Funder
EU, Horizon 2020, 634135
Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2018-01-30Bibliographically approved
3. Modeling of a Large Marine Two-Stroke Diesel Engine with Cylinder Bypass Valve and EGR System
Open this publication in new window or tab >>Modeling of a Large Marine Two-Stroke Diesel Engine with Cylinder Bypass Valve and EGR System
2015 (English)In: 10th IFAC Conference on Manoeuvring and Control of Marine Craft MCMC 2015: Copenhagen, 24–26 August 2015 / [ed] Roberto Galeazzi and Mogens Blanke, IFAC Papers Online, 2015, Vol. 48, p. 273-278Conference paper, Published paper (Refereed)
Abstract [en]

A nonlinear mean value engine model (MVEM) of a two-stroke turbocharged marine diesel engine is developed, parameterized and validated against measurement data. The goal is to have a computationally fast and accurate engine model that captures the main dynamics and can be used in the development of control systems for the newly introduced EGR system. The tuning procedure used is explained, and the result is a six-state MVEM with seven control inputs that capture the main system dynamics.

Place, publisher, year, edition, pages
IFAC Papers Online, 2015
Keywords
Engine modeling, diesel engines, parametrization, validation, nonlinear systems
National Category
Control Engineering Vehicle Engineering
Identifiers
urn:nbn:se:liu:diva-136802 (URN)10.1016/j.ifacol.2015.10.292 (DOI)2-s2.0-84992491352 (Scopus ID)
Conference
10th IFAC Conference on Manoeuvring and Control of Marine Craft
Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2018-02-05Bibliographically approved
4. A Model of a Marine Two-Stroke Diesel Engine with EGR for Low Load Simulation
Open this publication in new window or tab >>A Model of a Marine Two-Stroke Diesel Engine with EGR for Low Load Simulation
2016 (English)In: 9th EUROSIM Congress, 2016Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

A mean value engine model of a two-stroke ma-rine diesel engine with EGR that is capable of simulatingduring low load operation is developed. In order to beable to perform low load simulations, a compressor modelcapable of low speed extrapolation is also investigated andparameterized for two different compressors. Moreover, aparameterization procedure to get good parameters for bothstationary and dynamic simulations is described and applied.The model is validated for two engine layouts of the same testengine but with different turbocharger units. The simulationresults show a good agreement with the different measuredsignals, including the oxygen content in the scavengingmanifold.

Keywords
Modeling, Parameterization, Simulations, Exhaust gas recirculation, Combustion engines
National Category
Vehicle Engineering Control Engineering
Identifiers
urn:nbn:se:liu:diva-136804 (URN)
Conference
9th EUROSIM Congress on Modelling and Simulation. 12 - 16 September 2016 in Oulu, Finland.
Funder
EU, Horizon 2020, 634135
Available from: 2017-04-26 Created: 2017-04-26 Last updated: 2018-02-22Bibliographically approved
5. Control-oriented modeling of two-stroke diesel engines with exhaust gas recirculation for marine applications
Open this publication in new window or tab >>Control-oriented modeling of two-stroke diesel engines with exhaust gas recirculation for marine applications
2018 (English)In: Journal of Engineering for the Maritime Environment (Part M), ISSN 1475-0902, E-ISSN 2041-3084Article in journal (Refereed) Epub ahead of print
Abstract [en]

Large marine two-stroke diesel engines are widely used as propulsion systems for shipping worldwide and are facing stricter NOx emission limits. Exhaust gas recirculation is introduced to these engines to reduce the produced combustion NOx to the allowed levels. Since the current number of engines built with exhaust gas recirculation is low and engine testing is very expensive, a powerful alternative for developing exhaust gas recirculation controllers for such engines is to use control-oriented simulation models. Unfortunately, the same reasons that motivate the use of simulation models also hinder the capacity to obtain sufficient measurement data at different operating points for developing the models. A mean value engine model of a large two-stroke diesel with exhaust gas recirculation that can be simulated faster than real time is presented and validated. An analytic model for the cylinder pressure that captures the effects of changes in the fuel control inputs is also developed and validated with cylinder pressure measurements. A parameterization procedure that deals with the low number of measurement data available is proposed. After the parameterization, the model is shown to capture the stationary operation of the real engine well. The transient prediction capability of the model is also considered satisfactory which is important if the model is to be used for exhaust gas recirculation controller development during transients. Furthermore, the experience gathered while developing the model about essential signals to be measured is summarized, which can be very helpful for future applications of the model. Finally, models for the ship propeller and resistance are also investigated, showing good agreement with the measured ship sailing signals during maneuvers. These models give a complete vessel model and make it possible to simulate various maneuvering scenarios, giving different loading profiles that can be used to investigate the performance of exhaust gas recirculation and other controllers during transients.

Place, publisher, year, edition, pages
Sage Publications, 2018
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:liu:diva-147828 (URN)10.1177/1475090218768992 (DOI)
Conference
Proceedings of the Institution of Mechanical Engineers
Available from: 2018-05-15 Created: 2018-05-15 Last updated: 2018-05-21

Open Access in DiVA

Modeling and Control of EGR on Marine Two-Stroke Diesel Engines(4146 kB)281 downloads
File information
File name FULLTEXT01.pdfFile size 4146 kBChecksum SHA-512
9f8ae0a9018dcf78a1da2a985994d26a77f50c4d1894a4de8823d0961c19fea3857dc8e34f1d5fd2d0a0e11f893f8236281ca996a26ddde81e762c23f71b3f21
Type fulltextMimetype application/pdf
omslag(132 kB)20 downloads
File information
File name COVER01.pdfFile size 132 kBChecksum SHA-512
84478dd1dc5e998e57f728bb6943ec2e5d5a76d7e60f9ad9b7b9eda294717d52156a402c21cd88c0db77bf225a6da3c5742536ddf976942b47858ccdeb7eb8a5
Type coverMimetype application/pdf

Other links

Publisher's full text

Search in DiVA

By author/editor
Llamas, Xavier
By organisation
Vehicular SystemsFaculty of Science & Engineering
Control EngineeringVehicle Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 281 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

doi
isbn
urn-nbn

Altmetric score

doi
isbn
urn-nbn
Total: 1413 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf