scholarly journals Formation of Static Characteristics of a Diesel Engine

2020 ◽  
pp. 43-50
Author(s):  
A.G. Kuznetsov ◽  
S.V. Kharitonov
Keyword(s):  
Diesel Engine ◽  
Power Plants ◽  
Guide Vane ◽  
Fuel Efficiency ◽  
Maximum Pressure ◽  
Variable Geometry ◽  
Static Characteristics ◽  
Fuel Supply ◽  
Air Supply ◽  
Variable Geometry Turbine

The introduction of modern diesel fuel supply systems and the use of electronic components in control systems provide new possibilities for shaping engine characteristics targeted at specific energy consumers. Under these conditions, the type of engine characteristics is determined by the operation of the air supply system. This work examines the formation of static characteristics for a promising D500 diesel engine for train and ship power plants. Modeling of the diesel operation modes is carried out on computer models in the MATLAB/Simulink and Diesel-RK software packages. Variants of the full-load curves of the diesel engine are presented for different ways of turbocharger control: using a turbine of variable geometry and with sequential turbocharging. The fuel supply is limited according to the air-fuel ratio and the maximum pressure in the engine cylinders. For a variable geometry turbine, a matrix of the positions of the guide vane blades is obtained from the condition of optimizing diesel modes for fuel efficiency. Possibilities to obtain the efficiency characteristic that would provide the minimal fuel consumption for train and ship power plants are shown.

Lean and Straight Nozzle Vanes in a Variable Geometry Turbine: A Steady and Pulsating Flow Investigation

2008 ◽  
Author(s):  
Srithar Rajoo ◽  
R. F. Martinez-Botas
Keyword(s):  
Pressure Ratio ◽  
Velocity Ratio ◽  
Pulsating Flow ◽  
Maximum Pressure ◽  
Variable Geometry ◽  
Flow Investigation ◽  
Variable Geometry Turbine ◽  
The Difference ◽  
Vane Angle ◽  
Ratio Range

Variable Geometry Turbines (VGT) are widely used to improve engine-turbocharger matching and currently common in diesel engines. VGT has proven to provide air boost for wide engine speed range as well as reduce turbo-lag. This paper presents the design and experimental evaluation of a variable geometry mixed flow turbocharger turbine. The tests have been carried out with a permanent magnet eddy current dynamometer within a velocity ratio range of 0.47 to 1.09. The peak efficiency of the variable geometry turbine corresponds to vane angle settings between 60° and 65°, for both the lean and straight vanes in the region of 80%. The variable geometry turbine was tested under pulsating flow with straight and lean nozzle vanes for different vane angle settings, 40Hz and 60Hz flow. In general, the range of mass flow parameter is higher in the straight nozzle vanes with an average of 66.4% and 69.7% for 40Hz and 60Hz flow respectively. The straight nozzle vanes also shows increasing pressure ratio range compared to the lean nozzle vanes, which is more apparent in the maximum pressure ratio experienced by the turbine in an unsteady cycle. In overall, the cycle averaged efficiency in the straight vane configuration is marginally higher than the lean vane. Furthermore, the difference to the equivalent quasi-steady is better in the straight vane configuration compared to the lean vane.

scholarly journals Using Simulation for Development of The Systems of Automobile Gas Diesel Engine and its Operation Control

2018 ◽  
Vol 7 (2.28) ◽  
pp. 288 ◽  
Author(s):  
Mikhail G. Shatrov ◽  
Vladimir V. Sinyavski ◽  
Andrey Yu. Dunin ◽  
Ivan G. Shishlov ◽  
Andrey V. Vakulenko ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Fuel Efficiency ◽  
Fuel Supply ◽  
High Fuel Efficiency ◽  
Fuel Substitution ◽  
Basic Parameters ◽  
Cr System ◽  
And Control

The work was aimed at the development of gas supply, diesel fuel supply and electronic control systems for automobile gas diesel engines. Different ways of diesel engine conversion to operate on natural gas were analyzed. Gas diesel process with minimized ignition portion of diesel fuel injected by the CR system was selected. Electronic engine control and modular gas feed systems which can be used on high- and middle-speed gas diesel engines were developed. Diesel CR fuel supply system was developed in cooperation with the industrial partner. Simulation was used to obtain basic parameters and control methods of these systems. The base diesel engine was converted into gas diesel engine using the systems developed. Bench tests of the gas diesel engine demonstrated a high share of diesel fuel substitution with gas, high fuel efficiency and large decrease of NOх and СО2 emissions. 

The Evolution Required in Standard Cars for the Use of New EGR-VGT Control Strategies

2005 ◽  
Author(s):  
J. F. Arnold ◽  
N. Langlois ◽  
H. Chafouk
Keyword(s):  
Diesel Engine ◽  
Control Strategies ◽  
Low Cost ◽  
Intake Manifold ◽  
Variable Geometry ◽  
Emission Norm ◽  
Variable Geometry Turbine ◽  
The Cost ◽  
Intake Manifold Pressure ◽  
New Strategies

This paper is a study into the possibility of using new control strategies in a standard car. The air system of a diesel engine equipped with a variable geometry turbine and an EGR system (EGR valve and throttle) is considered. New strategies, like GPC or H∞ permit an improvement of the control of both the fresh air flow and the intake manifold pressure. These strategies are not used today in standard car due to the mismatch of both the instrumentation of the ECU’s calculation power. The cost of proposed technology to meet the next emission norm are presented. Some low cost solutions are presented to permit an improvement of the engine control.

Nonlinear Control of a Turbocharged Diesel Engine for Powertrain Control Applications

2000 ◽  
Author(s):  
Jonas Fredriksson ◽  
Bo Egardt
Keyword(s):  
Diesel Engine ◽  
Combustion Efficiency ◽  
Torque Control ◽  
Variable Geometry ◽  
Nonlinear Controller ◽  
Turbocharged Diesel Engine ◽  
Control Applications ◽  
Engine Torque ◽  
Powertrain Control ◽  
Variable Geometry Turbine

Abstract This paper concerns the problem of controlling a diesel engine with a variable geometry turbine (VGT). The idea presented is to use the variable geometry of the turbine for controlling the amount of inlet air and the objective is to combine air-to-fuel ratio control with engine speed or engine torque control. The nonlinear controller is designed using so called backstepping. The control strategy seems to have a great potential, since the combustion efficiency can be kept high while reducing the turbo-lag and the emission level. The control algorithms can be extended to handle powertrain control applications. The application studied here is control of driveline oscillations.

scholarly journals Experimental Study on the Effects of Air Supply Control on Combustion and Emissions Performance at Medium and Low Load for a Dual-Fuel Diesel Engine

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2944 ◽  
Author(s):  
Yu-Hui Peng ◽  
Yu-Peng Huang ◽  
Jia-You Tang ◽  
Qi-Feng Huang ◽  
Yi-Ran Huang
Keyword(s):  
Diesel Engine ◽  
Fuel Efficiency ◽  
Specific Energy Consumption ◽  
Fuel Mixture ◽  
Dual Fuel ◽  
Compression Ignition Engines ◽  
Excess Air ◽  
Air Supply ◽  
Low Load ◽  
Load Conditions

Lowering the amount of excess air is believed to increase the density of the air-fuel mixture and help improve the combustion rate for compression ignition engines. This paper proposes an approach of adding a throttle body at the intake pipe to control the excess air ratio with reduction of air supply to achieve a better balance between the power, emissions and fuel efficiency at medium and low load of a natural gas dual-fuel diesel engine converted from a conventional diesel engine. Various experiments in both pure diesel and dual-fuel mode under intermediate engine speed are performed with the proposed critical method of excess air ratio control. The experimental results reveal that better excess air ratio is very beneficial for the power output and brake specific energy consumption in dual-fuel combustion under medium and low load conditions. Moreover, the substitution rate can reach as high as 40% under low load conditions with throttle control.

scholarly journals Transient response of a large two-stroke marine diesel engine coupled to a selective catalytic reduction exhaust aftertreatment system

2019 ◽  
Author(s):  
Μιχαήλ Φωτεινός
Keyword(s):  
Diesel Engine ◽  
Selective Catalytic Reduction ◽  
Transient Response ◽  
Catalytic Reduction ◽  
Exhaust Aftertreatment ◽  
Marine Diesel Engine ◽  
Variable Geometry ◽  
Aftertreatment System ◽  
Marine Diesel ◽  
Variable Geometry Turbine

Οι μεγάλοι δίχρονοι ναυτικοί κινητήρες diesel χρησιμοποιούνται ως μέσο πρόωσης στην πλειονότητα των ποντοπόρων ναυτικών εφαρμογών. Με στόχο τη μείωση του περιβαλλοντικού αποτυπώματος του θαλάσσιου τομέα, ο Διεθνής Ναυτιλιακός Οργανισμός έχει θεσπίσει κανονισμούς που θέτουν αυστηρά όρια στις εκπεμπόμενες εκπομπές οξειδιών του αζώτου (ΝΟx) από ναυτικούς κινητήρες, γνωστούς και ως κανονισμούς ΙΜΟ Tier III. Η Επιλεκτική Καταλυτική Αναγωγή (Selective Catalytic Reduction, SCR) είναι μια τεχνολογία μετεπεξεργασίας καυσαερίων που επιτρέπει την συμμόρφωση με τα νέα πρότυπα εκπομπών NOx. Λόγω της απαίτησης υψηλών θερμοκρασιών για ομαλή λειτουργία του συστήματος SCR, σε ναυτικές εφαρμογές 2-Χ κινητήρων, το SCR τοποθετείται ανάντη του στροβίλου, δηλαδή μεταξύ του κινητήρα και του υπερπληρωτή (στην πλευρά υψηλής πίεσης του στροβίλου). Αυτό έχει ως αποτέλεσμα την διατάραξη της σύζευξης του κινητήρα και του υπερπληρωτή εισάγοντας προκλήσεις στην μεταβατική λειτουργία του κινητήρα. Λόγω της μεγάλης θερμικής αδράνειας του συστήματος SCR, ο υπερπληρωτής αποκρίνεται σε μία μεταβολή φορτίου του κινητήρα με μία σημαντική χρονική καθυστέρηση, η οποία σε χαμηλό φορτίο του κινητήρα μπορεί να οδηγήσει το σύστημα σε θερμική αστάθεια. Ερευνητές έχουν υπογραμμίσει την ευαισθησία του συστήματος και έχουν προτείνει περίπλοκες και κοστοβόρες λύσεις για να διασφαλίσουν την εύρωστη λειτουργία του, όπως το σύστημα στροβίλου μεταβλητής γεωμετρίας (Variable Geometry Turbine, VTG).Η διατριβή αυτή διερευνά τη μεταβατική απόκριση μεγάλου δίχρονου ναυτικού κινητήρα diesel, χωρίς μεταβλητότητα υπερπληρωτή, συνδεδεμένου με σύστημα απορρύπανσης καυσαερίων SCR. Σκοπός της εργασίας είναι η διερεύνηση της επίδρασης του συστήματος SCR υψηλής πίεσης στην μεταβατική απόκριση του κινητήρα με έμφαση στη λειτουργία σε χαμηλό φορτίο κινητήρα. Λόγω του υψηλού κόστους που εμπεριέχεται στα πειράματα με μεγάλους δίχρονους κινητήρες, η έρευνα διεξήχθη μέσω μοντελοποίησης και προσομοίωσης. Αναπτύχθηκαν μοντέλα μηδενικής διάστασης (zero dimensional models) για την προσομοίωση του κινητήρα πρόωσης και του συστήματος SCR. Το μοντέλο του κινητήρα αναπτύχθηκε χρησιμοποιώντας τον κώδικα προσομοίωσης κινητήρων του Εργαστηρίου Ναυτικής Μηχανολογίας MOTHER και επιβεβαιώθηκε με χρήση διαθέσιμων μετρήσεων από τις δοκιμές αγοράς του κινητήρα (shop trials). Επιπλέον, αναπτύχθηκε ένα μοντέλο για το σύστημα SCR ώστε να ληφθεί υπόψη η θερμοκρασιακή δυναμική του συστήματος. Το μοντέλο SCR επιβεβαιώθηκε μέσω σύγκρισης των αποτελεσμάτων του, με διαθέσιμες μετρήσεις από μία κλίνη δοκιμών ναυτικού κινητήρα με σύστημα SCR. Σε μεταβατικές καταστάσεις φόρτισης, το φορτίο που πρέπει να υπερνικήσει ο κινητήρας, δηλαδή η ροπή της έλικας, δεν είναι γνωστό εκ των προτέρων αλλά είναι προιόν περίπλοκων αλληλεπιδράσεων μεταξύ του κινητήρα, της έλικας και της γάστρας του πλοίου. Προκειμένου να επιτευχθή ακριβής πρόβλεψη του φορτίου του κινητήρα κατά τη διάρκεια των μεταβατικών φαινομένων, μοντέλα για την έλικα και τη γάστρα του πλοίου αναπτύχθηκαν και ενσωματώθηκαν στα μοντέλα γάστρας και έλικας. Το συζευγμένο μοντέλο του συστήματος πρόωσης επικυρώθηκε υπό συνθήκες μεταβατικής φόρτισης χρησιμοποιώντας διαθέσιμα μετρημένα δεδομένα επί πλοίου.Το συνολικό σύστημα προσομοιώθηκε υπό μεταβατική φόρτιση υπό καλές και δυσμενείς καιρικές συνθήκες. Τα αποτελέσματα έδειξαν ότι η μεταβατική απόκριση του κινητήρα επηρεάζεται πράγματι από την παρουσία του συστήματος SCR και το αποτέλεσμα είναι πιο έντονο στην περιοχή χαμηλότερου φορτίου κινητήρα. Ωστόσο, η θερμική αστάθεια του συστήματος μπορεί να αποφευχθεί και το σύστημα είναι σε θέση να λειτουργεί ακόμη και κατά τη λειτουργία σε πολύ χαμηλό φορτίο.

scholarly journals THE CONCEPT OF COMBUSTION PROCESS ORGANISATION IN A BOXER TWO-STROKE DIESEL ENGINE AT A HIGH LEVEL OF BOOSTING

2021 ◽  
pp. 45-51
Author(s):  
I.V. Parsadanov ◽  
A.G. Lal
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Fuel Efficiency ◽  
Combustion Process ◽  
Mixing Efficiency ◽  
Diesel Generator ◽  
Piston Group ◽  
Air Supply ◽  
Cylinder Piston ◽  
High Level

Based on the analysis and synthesis of previously performed theoretical and practical studies, the paper proposes a concept of combustion process organization in a boxer two-stroke diesel engine at a high level of boosting. Such diesel engines are produced in Ukraine and are widely used in land, sea and rail transport, as diesel generator plants. The implementation of this concept will ensure the reduction of the thermal stress of the cylinder piston group for these diesel engines, while improving fuel efficiency. The features of the organization of the working process in a boxer two-stroke diesel engine are briefly considered. The contribution of Ukrainian, Russian and American scientists to the development and improvement of their mixing efficiency is noted. Following the purpose of the research, which determines the choice of directions for the development and implementation of technical solutions for the simultaneous reduction of fuel consumption and thermal tension of the cylinder-piston group when forcing a boxer two-stroke diesel engine, it is proposed to use the amount of released heat as a criterion for evaluating the quality of combustion. Based on the results of earlier studies, conceptual foundations for increasing the efficiency of the combustion process of a highly boosted boxer two-stroke diesel engine have been developed, which are directly related to the air supply, fuel supply, the rationale for choosing the shape of the combustion chamber are determined by the amount of heat released during combustion and the nature of its change in the crankshaft rotation angle.

Mild Hybridization via Electrification of the Air System: Electrically Assisted and Variable Geometry Turbocharging Impact on an Off-Road Diesel Engine

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
Nicola Terdich ◽  
Ricardo F. Martinez-Botas ◽  
Alessandro Romagnoli ◽  
Apostolos Pesiridis
Keyword(s):  
Energy Efficiency ◽  
Diesel Engine ◽  
Transient Response ◽  
Engine Speed ◽  
Variable Geometry ◽  
Flow Capacity ◽  
Electrically Assisted ◽  
Air System ◽  
Variable Geometry Turbine ◽  
Reduction Of Co2

Electric turbocharger assistance consists in incorporating an electric motor/generator within the turbocharger bearing housing to form a mild hybrid system without altering other mechanical parts of the engine. This makes it an ideal and economical short-to-medium-term solution for the reduction of CO2 emissions. The scope of the paper is to assess the improvements in engine energy efficiency and transient response correlated to the hybridization of the air system. To achieve this, an electrically assisted turbocharger with a variable geometry turbine has been compared to a similar, not hybridized system over step changes of engine load. The variable geometry turbine has been controlled to provide different levels of initial boost, including one optimized for efficiency, and to change its flow capacity during the transient. The engine modeled is a 7-liter, 6-cylinder diesel engine with a power output of over 200 kW and a sub-10-kW turbocharger electric assistance power. To improve the accuracy of the model, the turbocharger turbine has been experimentally characterized by means of a unique testing facility available at Imperial College and the data has been extrapolated by means of a turbine meanline model. Optimization of the engine boost to minimize pumping losses has shown a reduction in brake-specific fuel consumption up to 4.2%. By applying electric turbocharger assistance, it has been possible to recover the loss in engine transient response of the efficiency-optimized system, as it causes a reduction in engine speed drop of 71%–86% and of 79%–94% in engine speed recovery time. When electric assistance is present in the turbocharger, actuating the turbine vanes to assist transient response has not produced the desired result but only a decrement in energy efficiency. If the variable geometry turbine is opened during transients, an improvement in specific energy efficiency with negligible decrement in engine transient performances has been achieved.

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