scholarly journals Control of oxygen-to-carbon ratio and fuel utilization with regard to solid oxide fuel cell systems with anode-offgas recirculation: A review

2021 ◽  
Author(s):  
Felix Schaefer
Keyword(s):  
Control Strategies ◽  
Research Work ◽  
Future Research ◽  
Exhaust Gas ◽  
Fuel Utilization ◽  
Crucial Importance ◽  
Characteristic Parameters ◽  
System Configurations ◽  
Gas Recirculation ◽  
And Control

One of the possible SOFC system-configurations providing the highest potential of electrical DC-efficiency of up to 65% is a SOFC-system with anode exhaust gas recirculation (AEGR), where part of the depleted anode exhaust gas is recirculated and mixed with fresh natural gas upstream of the reformer. For safe and durable operation of a SOFC-system, the oxygen-to-carbon-ratio and the fuel utilization as characteristic parameters must not exceed stack- and reformer-specific thresholds. The determination and control of the characteristic parameters are therefore of crucial importance. However, this poses especially for SOFC-systems with AEGR due to enhanced system complexity a challenging task. In this paper, the authors present an overview on representative control strategies as well as different approaches to determine or diagnose characteristic parameters with emphasis on SOFC-systems with AEGR. Some conclusions are discussed based on the provided overview and outlines recommendations for future research work.

Study and Simulation on the Energy Efficiency Management Control Strategy of Ship Based on Clean Propulsion System

2015 ◽  
Author(s):  
Kai Wang ◽  
Xinping Yan ◽  
Yupeng Yuan
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Control Strategy ◽  
Control Strategies ◽  
Management Control ◽  
Propulsion System ◽  
Power Requirement ◽  
Doubly Fed ◽  
System Configurations ◽  
And Control

Nowadays, with the higher voice of ship energy saving and emission reduction, the research on energy efficiency management is particularly necessary. Energy efficiency management and control of ships is an effective way to improve the ship energy efficiency. In this paper, according to the new clean propulsion system configurations of 5000 tons of bulk carrier, the energy efficiency management control strategy of the clean propulsion system is designed based on the model of advanced brushless doubly-fed shaft generator, propulsion system using LNG/diesel dual fuel engine and energy consumption of the main engine for reducing energy consumption. The simulation model of the entire propulsion system and the designed control strategy were designed. The influence of the engine speed on the ship energy efficiency was analyzed, and the feasibility of the energy efficiency management control strategies was verified by simulation using Matlab/Simulink. The results show that the designed strategies can ensure the power requirement of the whole ship under different conditions and improve the ship energy efficiency and reduce CO2 emissions.

Small Scale Wind Generation System: Part II – A Novel Quasi-Z-Source Inverter and FRG-QZSI-Micro Grid Interface

2017 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
M. Ramkumar ◽  
K. N. Srinivas
Keyword(s):  
Control Strategies ◽  
Research Work ◽  
Open Loop ◽  
Small Scale ◽  
Loop Control ◽  
Power Injection ◽  
System Part ◽  
Micro Grid ◽  
Wind Generation System ◽  
And Control

<p>This paper proposes modelling, analysis and control of a small scale wind energy conversion system employing a direct driven Flux Reversal Generator (FRG) connected to the micro grid through a quasi-Z-source inverter (QZSI). This entire research is made up of two major parts viz., FRG and QZSI. In the part I report of this research work, the role of FRG has been thoroughly modelled and verified. In this part II, the modelling and analysis of QZSI for this purpose is presented. In addition, the modified space vector PWM (SVPWM) technique is proposed in this paper to satisfy the shoot-through characteristic of QZSI, which is a novel. The interface of FRG and QZSI to inject power in to micro grid has been finally presented. The simulation results are validated with the analytical results. Section I discusses the open loop control of QZSI. The mathematical modelling of QZSI for this purpose is given and analytically validated. This flowed by section II in which the proposed SVPWM is presented. The procedure to obtain triggering pulses using this proposed modulation technique is discussed. Section III presents closed loop control strategies for QZSI. Section IV presents the micro grid<br />inte face and power injection.</p>

scholarly journals Progress in Modeling and Control of Gas Turbine Power Generation Systems: A Survey

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2358 ◽  
Author(s):  
Omar Mohamed ◽  
Ashraf Khalil
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Control Strategies ◽  
Research Area ◽  
Future Research ◽  
Modeling And Control ◽  
Comprehensive Survey ◽  
And Control

This paper reviews the modeling techniques and control strategies applied to gas turbine power generation plants. Recent modeling philosophies are discussed and the state-of-the-art feasible strategies for control are shown. Research conducted in the field of modeling, simulation, and control of gas turbine power plants has led to notable advancements in gas turbines’ operation and energy efficiency. Tracking recent achievements and trends that have been made is essential for further development and future research. A comprehensive survey is presented here that covers the outdated attempts toward the up-to-date techniques with emphasis on different issues and turbines’ characteristics. Critical review of the various published methodologies is very useful in showing the importance of this research area in practical and technical terms. The different modeling approaches are classified and each category is individually investigated by reviewing a considerable number of research articles. Then, the main features of each category or approach is reported. The modern multi-variable control strategies that have been published for gas turbines are also reviewed. Moreover, future trends are proposed as recommendations for planned research.

Development of a Spark Discharge PM Sensor for Measurement of Engine-Out Soot Emissions

2011 ◽  
Vol 133 (11) ◽  
Author(s):  
David P. Gardiner ◽  
Greg R. Pucher ◽  
William D. Allan ◽  
Marc LaViolette
Keyword(s):  
Mass Concentration ◽  
Control Strategies ◽  
Spark Discharge ◽  
Particulate Filter ◽  
Particulate Emissions ◽  
Exhaust Gas ◽  
Peak Voltage ◽  
Turbocharged Diesel Engine ◽  
Reference Measurements ◽  
Gas Recirculation

There is interest in measuring the engine-out particulate emissions from diesel engines in real time in order to optimize the engine control strategies such as exhaust gas recirculation (EGR) and monitor the loading of the particulate filter. This paper presents experimental results obtained using a measurement technique that produced a signal proportional to the peak voltage of a spark discharge that was exposed to the exhaust gas. The sensor was tested on a turbocharged diesel engine with exhaust soot levels from <0.1 FSN to >3.5 FSN, and compared with reference measurements of filter smoke number (FSN) from an AVL 415S smokemeter. The sensor signal showed a high correlation with the reference FSN measurements. Conversion of the FSN values to mass concentration values (using published techniques for the reference instrument) indicated that the output of the spark discharge soot sensor was nearly linear with mass concentration over a substantial portion of the measuring range. The sensor showed a response time of less than 2 s to step changes in FSN levels.

scholarly journals Influence of Exhaust Gas Recirculation, and Injection Timing on the Combustion, Performance and Emission Characteristics of a Cylinder Head Porous Medium Engine

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Chidambaram Kannan ◽  
Thulasi Vijayakumar
Keyword(s):  
Combustion Chamber ◽  
Cylinder Head ◽  
Research Work ◽  
Exhaust Gas Recirculation ◽  
Injection Timing ◽  
Emission Characteristics ◽  
Exhaust Gas ◽  
Performance And Emission ◽  
Homogeneous Combustion ◽  
Gas Recirculation

Homogeneous combustion has the potential of achieving both near-zero emissions and low specific fuel consumption. However, the accomplishment of homogeneous combustion depends on the air flow structure inside the combustion chamber, fuel injection conditions, and turbulence as well as ignition conditions. Various methods and procedures are being adopted to establish the homogeneous combustion inside the engine cylinder. In this research work, a highly porous ceramic structure was introduced into the combustion chamber (underside of the cylinder head). The influence of operating parameters such as exhaust gas recirculation (EGR) and injection timing on the combustion, performance, and emission characteristics of such developed engine was investigated in this research work.

scholarly journals Control-Oriented Modeling of Cycle-to-Cycle Combustion Variability at the Misfire Limit in SI Engines

2020 ◽  
Author(s):  
Bryan P. Maldonado ◽  
Brian C. Kaul
Keyword(s):  
Mathematical Formulation ◽  
Calibration Procedure ◽  
Model Parameters ◽  
Exhaust Gas ◽  
Cycle System ◽  
Si Engines ◽  
Engine Operating Condition ◽  
Gas Recirculation ◽  
And Control ◽  
Residual Air

Abstract A control-oriented model is presented that can capture the prior-cycle correlation of combustion cycles during conditions with high levels of exhaust gas recirculation (EGR). Combustion events are modeled in discrete time and the dynamic evolution is captured by the residual air, fuel, and inert gas trapped in the combustion chamber. The mathematical formulation of the model is presented together with the calibration procedure to emulate a particular engine operating condition. A cycle-to-cycle system identification methodology is described which allows regressing model parameters from experimental data. Simulations are presented and compared to real engine measurements to show the modeling potential for analysis and control of combustion events.

Characterization of temporal variations and feedback timescales of exhaust gas recirculation gas properties using high-speed diode laser absorption spectroscopy for next-cycle control of cyclic variability

2018 ◽  
Vol 20 (8-9) ◽  
pp. 945-952
Author(s):  
Gurneesh S Jatana ◽  
Brian C Kaul
Keyword(s):  
High Speed ◽  
Control Strategies ◽  
Direct Injection ◽  
Exhaust Gas Recirculation ◽  
Gasoline Direct Injection ◽  
Exhaust Gas ◽  
Recirculation Flow ◽  
Cyclic Variability ◽  
Laser Absorption ◽  
Gas Recirculation

Dilute combustion offers efficiency gains in boosted gasoline direct injection engines both through knock-limit extension and thermodynamic advantages (i.e. the effect of γ on cycle efficiency), but is limited by cyclic variability at high dilution levels. Past studies have shown that the cycle-to-cycle dynamics are a combination of deterministic and stochastic effects. The deterministic causes of cyclic variations, which arise from feedback due to exhaust gas recirculation, imply the possibility of using active control strategies for dilution limit extension. While internal exhaust gas recirculation will largely provide a next-cycle effect (short-timescale feedback), the feedback of external exhaust gas recirculation will have an effect after a delay of several cycles (long timescale). Therefore, control strategies aiming to improve engine stability at dilution limit may have to account for both short- and long-timescale feedback pathways. This study shows the results of a study examining the extent to which variations in exhaust gas recirculation composition are preserved along the exhaust gas recirculation flow path and thus the relative importance and information content of the long-timescale feedback pathway. To characterize the filtering or retention of cycle-resolved feedback information, high-speed (1–5 kHz) CO2 concentration measurements were performed simultaneously at three different locations along the low-pressure external exhaust gas recirculation loop of a four-cylinder General Motors gasoline direct injection engine using a multiplexed two-color diode laser absorption spectroscopy sensor system during steady-state and transient engine operation at various exhaust gas recirculation levels. It was determined that cycle-resolved feedback propagates through internal residual gases but is filtered out by the low-pressure exhaust gas recirculation flow system and do not reach the intake manifold. Intermediate variations driven by flow rate and compositional changes are also distinguished and identified.

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