Design and Performance of a Controlled Turbocharging System on Marine Diesel Engines

2006 ◽  
Author(s):  
Ioannis Vlaskos ◽  
Ennio Codan ◽  
Nikolaos Alexandrakis ◽  
George Papalambrou ◽  
Marios Ioannou ◽  
...  
Keyword(s):  
Steady State ◽  
Engine Performance ◽  
Operating Conditions ◽  
Electric Actuator ◽  
Engine Simulation ◽  
Engine Control System ◽  
Turbocharging System ◽  
Compressor Impeller ◽  
Marine Diesel ◽  
And Performance

The paper describes the design process for a controlled pulse turbocharging system (CPT) on a 5 cylinder 4-stroke marine engine and highlights the potential for improved engine performance as well as reduced smoke emissions under steady state and transient operating conditions, as offered by the following technologies: • controlled pulse turbocharging, • high pressure air injection onto the compressor impeller as well as into the air receiver, and • an electronic engine control system, including a hydraulic powered electric actuator. Calibrated engine simulation computer models based on the results of tests performed on the engine in its baseline configuration were used to design the CPT components. Various engine tests with CPT under steady state and transient operating conditions show the engine optimization process and how the above-mentioned technologies benefit engine behavior in both generator and propeller law operation.

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 CFD Study of Nozzle Configurations for Ultra High Bypass Engines

1993 ◽  
Author(s):  
H. Zimmermann ◽  
R. Gumucio ◽  
K. Katheder ◽  
A. Jula
Keyword(s):  
Engine Performance ◽  
Operating Conditions ◽  
Aerodynamic Design ◽  
Thrust Coefficient ◽  
Optimum Range ◽  
Installation Effects ◽  
Wide Range ◽  
And Performance ◽  
Aircraft Aerodynamics ◽  
Bypass Ratio

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%.

Modeling and performance analysis of diesel engine considering the heating effect of blow-by on cylinder intake gas

2021 ◽  
pp. 146808742110692
Author(s):  
Zhenyu Shen ◽  
Yanjun Li ◽  
Nan Xu ◽  
Baozhi Sun ◽  
Yunpeng Fu ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Engine Performance ◽  
Marine Diesel Engine ◽  
Heating Effect ◽  
Shipping Industry ◽  
Low Speed ◽  
Proposed Model ◽  
International Regulations ◽  
Marine Diesel ◽  
And Performance

Recently, the stringent international regulations on ship energy efficiency and NOx emissions from ocean-going ships make energy conservation and emission reduction be the theme of the shipping industry. Due to its fuel economy and reliability, most large commercial vessels are propelled by a low-speed two-stroke marine diesel engine, which consumes most of the fuel in the ship. In the present work, a zero-dimensional model is developed, which considers the blow-by, exhaust gas bypass, gas exchange, turbocharger, and heat transfer. Meanwhile, the model is improved by considering the heating effect of the blow-by gas on the intake gas. The proposed model is applied to a MAN B&W low-speed two-stroke marine diesel engine and validated with the engine shop test data. The simulation results are in good agreement with the experimental results. The accuracy of the model is greatly improved after considering the heating effect of blow-by gas. The model accuracy of most parameters has been improved from within 5% to within 2%, by considering the heating effect of blow-by gas. Finally, the influence of blow-by area change on engine performance is analyzed with considering and without considering the heating effect of blow-by.

Operation and Control of a Supercritical CO2 Compressor

2021 ◽  
Author(s):  
Joshua D. Neveu ◽  
Stefan D. Cich ◽  
J. Jeffrey Moore ◽  
Jason Mortzheim
Keyword(s):  
Steady State ◽  
Critical Point ◽  
Operating Conditions ◽  
State Control ◽  
Power Cycle ◽  
Low Head ◽  
And Performance ◽  
Steady State Control ◽  
And Control ◽  
Thermal Sources

Abstract Among the list of advanced technologies required to support the energy industry’s novel Supercritical Carbon Dioxide (sCO2) power cycle is the need for a robust and responsive control system. Recent testing has been performed on a 2.5 MWe sCO2 compressor operating near the critical temperature (31C) and critical pressure (73.8 bar), developed with funding from the US DOE Apollo program and industry partners. While sCO2 compression has been performed before, operating near the critical point has many key benefits for power generation with its low head requirements and smaller physical footprint. However, with these benefits come unique challenges, namely controlling this system to steady-state operating conditions. Operating just above the critical point (35°C [95°F] and 8.5 MPa [1,233 psi]) there can be large and rapid swings in density produced by subtle changes in temperature, leading to increased difficulty in maintaining adequate control of the compressor system. This means that proper functionality of the entire compressor system, and its usefulness to a closed loop recompression Brayton power cycle, is largely dependent on variables such as thermal sources, precision and response time of the instrumentation, proper heat soaking, and strategic filling and venting sequences. While other papers have discussed the science behind and performance of sCO2 compressors, this paper will discuss the challenges associated with steady-state control of the compressor at or near operating conditions, how the fill process was executed for optimal startup, and changes that occurred while idling during trip events.

Military Engine Response to Compressor Inlet Stratified Pressure Distortion by an Integrated CFD Analysis

2006 ◽  
Author(s):  
Leonardo Melloni ◽  
Petros Kotsiopoulos ◽  
Anthony Jackson ◽  
Vassilios Pachidis ◽  
Pericles Pilidis
Keyword(s):  
Engine Performance ◽  
Low Pressure ◽  
Operating Conditions ◽  
High Fidelity ◽  
Inlet Flow ◽  
Performance Simulation ◽  
Simulation Strategy ◽  
Compressor Inlet ◽  
And Performance ◽  
Pressure Compressor

Especially in aircraft applications, the inlet flow is quite often non uniform resulting in severe changes in compressor performance and hence, engine performance. The magnitude of this phenomenon can be amplified in military engines due to the complex shape of intake ducts and the extreme flight conditions. The usual approach to engine performance simulation is based on non-dimensional maps for compressors and turbines and assumes uniform flow characteristics throughout the engine. In the context of the whole engine performance, component-level, complex physical processes, such as compressor inlet flow distortion, can not be captured and analyzed. This work adopts a simulation strategy that allows the performance characteristics of an engine component, resolved from a detailed, high-fidelity analysis, to be transferred to an engine system analysis carried out at a lower level of fidelity. The methodology described in this paper utilizes an object-oriented, zero-dimensional gas turbine modeling and performance simulation system and a high-fidelity, three-dimensional, computational fluid dynamics (CFD), low-pressure compressor model. The CFD model is based on the overall geometry and performance of the low-pressure compressor of a modern, two-spool, low by-pass ratio (LBR) military turbofan engine and is subjected to both clean and distorted inlet flows. The analysis involves the generation of two characteristic maps for the first stage of the LP compressor from CFD simulations that account for a range of operating conditions and power settings with a uniform and a distorted inlet flow. The same simulation strategy could be adopted for other engine components such as the intake or the high-pressure compressor and for different magnitudes and types of distortion (i.e. radial, circumferential). By integrating the CFD-generated maps, into the 0-D engine analysis system, this paper presents a relative comparison between the ‘uniform-inlet’ engine performance (baseline compressor stage map) and the engine performance obtained after using the map accounting for a typical extent of stratified inlet distortion. The analysis carried out by this study, demonstrates relative changes in the simulated engine performance larger than 1%.

Development of HIDEC Adaptive Engine Control Systems

1987 ◽  
Vol 109 (2) ◽  
pp. 146-151
Author(s):  
R. J. Landy ◽  
W. A. Yonke ◽  
J. F. Stewart
Keyword(s):  
Integrated Control ◽  
Engine Performance ◽  
Control Mode ◽  
Engine Control ◽  
Engine Model ◽  
Engine Control System ◽  
Fuel Flow ◽  
Expected Performance ◽  
Propulsion Control ◽  
And Performance

The NASA Ames/Dryden Flight Research Facility is sponsoring a flight research program designated Highly Integrated Digital Electronic Control (HIDEC), whose purpose is to develop integrated flight-propulsion control modes and evaluate their benefits in flight on NASA F-15 test aircraft. The Adaptive Engine Control System (ADECS I) is one phase of the HIDEC program. ADECS I involves uptrimming the P&W Engine Model Derivative (EMD) PW1128 engines to operate at higher engine pressure ratios (EPR) and produce more thrust. In a follow-on phase, called ADECS II, a constant thrust mode will be developed which will significantly reduce turbine operating temperatures and improve thrust specific fuel consumption. A performance seeking control mode is scheduled to be developed. This mode features an onboard model of the engine that will be updated to reflect actual engine performance, accounting for deterioration and manufacturing differences. The onboard engine model, together with inlet and nozzle models, are used to determine optimum control settings for the engine, inlet, and nozzle that will maximize thrust at power settings of intermediate and above and minimize fuel flow at cruise. The HIDEC program phases are described in this paper with particular emphasis on the ADECS I system and its expected performance benefits. The ADECS II and performance seeking control concepts and the plans for implementing these modes in a flight demonstration test aircraft are also described. The potential payoffs for these HIDEC modes as well as other integrated control modes are also discussed.

scholarly journals A Steady-State Equivalent Circuit of TSCAOI Configured Induction Generator for Renewable Energy Conversion Systems

2021 ◽  
Vol 6 (1) ◽  
pp. 20-30
Author(s):  
Zhijia Wang ◽  
Keyword(s):  
Renewable Energy ◽  
Steady State ◽  
Energy Conversion ◽  
Equivalent Circuit ◽  
Equivalent Circuit Model ◽  
Operating Conditions ◽  
Voltage Unbalance ◽  
Energy Conversion Systems ◽  
State Behaviour ◽  
And Performance

3-phase cage induction machines, operated in two series-connected and one-isolated (TSCAOI) winding configuration, have been proposed to generate standalone single-phase electricity at variable speeds for renewable energy conversion systems. However, the steady-state behaviour and performance of this particular generator are not yet to be theoretically investigated. This paper therefore presents the first theoretical investigation based on the steady-state equivalent circuit model for standalone TSCAOI configured generators. Moreover, this paper is the first to adopt the winding function approach to derive a dynamic mathematical model for TSCAOI configured generators. This approach not only eliminates the cumbersome mathematical manipulation required in all previous papers related to TSCAOI configured generators but also provides a visual insight into the resulting winding distribution of the machine. In order to investigate the load and excitation characteristics pertinently, the dynamic model is transformed into two different equivalent circuit models by appropriate selected transformation matrix. Using these two models, this paper identified the impacts of system parameters on the load and excitation characteristics, as well as on the level of voltage unbalance. Experimental results of a prototype generator under various operating conditions are presented, together with simulated results, to demonstrate the accuracy of the proposed investigations.

Study on Mixed Pulse Converter (MIXPC) Turbocharging System and Its Application in Marine Diesel Engines

2010 ◽  
Vol 54 (01) ◽  
pp. 68-77
Author(s):  
Yi Cui ◽  
Hongzhong Gu ◽  
Kangyao Deng ◽  
Shiyou Yang
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Thermal Load ◽  
Fuel Efficiency ◽  
Operating Conditions ◽  
Tvd Scheme ◽  
Boost Pressure ◽  
Turbocharging System ◽  
Marine Diesel ◽  
Pulse Converter

In order to improve fuel efficiency and power density, the boost pressure of diesel engine is increasing continuously. The increase in boost level leads to some problems, such as lack of air under part load operating conditions, response delay during transient processes, and high mechanical and thermal load. In order to meet the high boost level demand, a new type of turbocharging system—mixed pulse converter (MIXPC) turbo-charging system for multicylinder diesel engines (from 4 to 20 cylinders) has been invented. A turbocharged diesel engine simulation model, based on one-dimensional finite volume method (FVM) and total variation diminishing (TVD) scheme, has been developed and used to design and analyze the MIXPC turbocharging system. The applications of MIXPC system in in-line 8- and 4-cylinder and V-type 16-cylinder medium-speed marine diesel engines have been studied by calculation and experiments. The results show that the invented MIXPC system has superior engine fuel efficiency and thermal load compared with original turbocharging systems.

Modelling and Assessment of Compressor Faults on Marine Gas Turbines

2012 ◽  
Author(s):  
I. Roumeliotis ◽  
N. Aretakis ◽  
K. Mathioudakis ◽  
E. A. Yfantis
Keyword(s):  
Gas Turbines ◽  
Engine Performance ◽  
Performance Model ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Maximum Speed ◽  
Performance Modelling ◽  
Engine Operation ◽  
Marine Propulsion ◽  
And Performance

Any prime mover exhibits the effects of wear and tear over time, especially when operating in a hostile environment. Marine gas turbines operation in the hostile marine environment results in the degradation of their performance characteristics. A method for predicting the effects of common compressor degradation mechanisms on the engine operation and performance by exploiting the “zooming” feature of current performance modelling techniques is presented. Specifically a 0D engine performance model is coupled with a higher fidelity compressor model which is based on the “stage stacking” method. In this way the compressor faults can be simulated in a physical meaningful way and the overall engine performance and off design operation of a faulty engine can be predicted. The method is applied to the case of a twin shaft engine, a configuration that is commonly used for marine propulsion. In the case of marine propulsion the operating profile includes a large portion of off-design operation, thus in order to assess the engine’s faults effects, the engine operation should be examined with respect to the marine vessel’s operation. For this reason, the engine performance model is coupled to a marine vessel’s mission model that evaluates the prime mover’s operating conditions. In this way the effect of a faulty engine on vessels’ mission parameters like overall fuel consumption, maximum speed, pollutant emissions and mission duration can be quantified.

Assessment of Turbocharger Turbine Unsteady Flow Modelling Methodology on Engine Performance

2014 ◽  
Author(s):  
Ammar Mustafa ◽  
Ricardo F. Martinez-Botas ◽  
Apostolos Pesiridis ◽  
Meng Soon Chiong ◽  
Srithar Rajoo
Keyword(s):  
Steady State ◽  
Engine Performance ◽  
Simulation Software ◽  
Turbine Wheel ◽  
Engine Simulation ◽  
Entry Model ◽  
Modelling Methodology ◽  
Modelling Techniques ◽  
Turbine Design ◽  
Steady State Performance

Although it is well known that the flow entering a turbine of a turbocharger engine is highly unsteady, engine manufacturers prefer to use turbine performance predictions that are based on steady-state performance maps, which inherently lead to inaccuracies in the turbine’s behavior and mismatches between turbocharger turbines and engines. The reason for this preference is due to the turbocharger turbine design software that are generally available to engine manufacturers being based on and compatible with steady-state performance maps and this fact led researchers to investigate how the inaccuracies of this steady-state treatment of the turbine can be alleviated. To this effect, this paper investigates how modelling techniques on Ricardo Wave, a 1D gas dynamics engine simulation software, gives rise to more accurate turbine swallowing curve predictions using steady-state maps. In particular, the turbine being investigated is that of Szymko [1], which is a twin nozzleless mixed-flow turbine that is being powered by a 10 litre, 6 cylinder 4 stroke diesel engine with an operating range from 800–2000 RPM for which 800, 1200 and 1600 engine RPM relate to 40, 60 and 80Hz exhaust gas pulse frequencies at the turbine. The main investigation in this paper is to demonstrate the capability of the engine simulation software to deal with unsteady flows and specifically to show the significant effect of accounting for the volute design in the single turbine wheel entry model. The data obtained in this investigation were compared with those of Szymko [1], which offered a validated set of data to compare against.

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