EGR System Research Articles

Process Analysis of Selective Exhaust Gas Recirculation for CO2 Capture in Natural Gas Combined Cycle Power Plants Using Amines

Postcombustion CO2 capture from natural gas combined cycle (NGCC) power plants is challenging due to the large flow of flue gas with low CO2 content (∼3–4 vol %) that needs to be processed in the capture stage. A number of alternatives have been proposed to solve this issue and reduce the costs of the associated CO2 capture plant. This work focuses on the selective exhaust gas recirculation (S-EGR) configuration, which uses a membrane to selectively recirculate CO2 back to the inlet of the compressor of the turbine, thereby greatly increasing the CO2 content of the flue gas sent to the capture system. For this purpose, a parallel S-EGR NGCC system (53% S-EGR ratio) coupled to an amine capture plant (ACP) using monoethanolamine (MEA) 30 wt % was simulated using gCCS (gPROMS). It was benchmarked against an unabated NGCC system, a conventional NGCC coupled with an ACP (NGCC + carbon capture and storage (CCS)), and an EGR NGCC power plant (39% EGR ratio) using amine scrubbing as the downstream capture technology. The results obtained indicate that the net power efficiency of the parallel S-EGR system can be up to 49.3% depending on the specific consumption of the auxiliary S-EGR systems, compared to the 49.0% and 49.8% values obtained for the NGCC + CCS and EGR systems, respectively. A preliminary economic study was also carried out to quantify the potential of the parallel S-EGR configuration. This high-level analysis shows that the cost of electricity (COE) for the parallel S-EGR system varies from 82.1 to 90.0 $/MWhe for the scenarios considered, with the cost of CO2 avoided (COA) being in the range of 79.7–105.1 $/ton CO2. The results obtained indicate that there are potential advantages of the parallel S-EGR system in comparison to the NGCC + CCS configuration in some scenarios. However, further benefits with respect to the EGR configuration will depend on future advancements and cost reductions achieved on membrane-based systems.

Analysis of the potential of a new automotive two-stroke gasoline engine able to operate in spark ignition and controlled autoignition combustion modes

The need to reduce the emissions coming from automobiles encourages the attempts to study different engine configurations and new combustion strategies. In this case, a two stroke engine able to operate in Controlled AutoIgnition (CAI) and Spark Ignition (SI) combustion modes is studied, with the purpose of getting lower NOx and CO2 emissions than with other currently employed solutions. The engine configuration retained for the research is a uniflow scavenging configuration with intake ports in the cylinder liner and exhaust valves in the cylinder head. These valves are controlled by a Variable Valve Timing (VVT) system. The scavenging is guaranteed by an external blower driven by the crankshaft. Finally, the fuel supply is performed by a direct injection (DI) air-assisted fuel injection system.Through this paper the adjusting parameters to control the engine operation, as well as their influence on the CAI and SI combustion modes have been studied, providing the most relevant information and knowledge for controlling and optimizing the engine performance. Once these controlling parameters were studied, an EGR system was introduced in order to analyze the effect of this other parameter over the combustion process, as well as to determine the potential benefits of introducing such a system in this type of engines.

Gain-scheduled EGR control algorithm for light-duty diesel engines with static-gain parameter modeling

This paper presents a model-based gain scheduling algorithm of a PI-based EGR controller for light-duty diesel engines. In order to capture nonlinear characteristic of the EGR system, we have proposed a new scheduling variable to illustrate the static-gain of the plant model as a linear function. The proposed scheduling variable is composed of the air-tofuel ratio of the exhaust gas and the pressure ratio between the exhaust and intake manifolds. Using the scheduling variable, a static-gain model achieved 0.94 of the R-squared value with 810 of steady-state measurements which include key engine operating conditions. Based on the model of the static-gain parameter, the gains of the PI controller are decided by Skogestad internal model control (SIMC) tuning rule in real-time. Through various scenarios of engine experiments, the proposed gain scheduling algorithm represented that the PI gains were successfully adapted according to the changes of the engine operating conditions.

Development Prospective of EGR System Applied on Gasoline Engine—A Review

Development Prospective of EGR System Applied on Gasoline Engine—A Review

Study of Performance and Emission Analysis of Dual Biodiesel Fuelled on LHR Diesel Engine Supported by EGR System

Study of Performance and Emission Analysis of Dual Biodiesel Fuelled on LHR Diesel Engine Supported by EGR System

LPL EGR 시스템용 압출 튜브 구조의 알루미늄 EGR 쿨러 성능 설계

LPL EGR 시스템용 압출 튜브 구조의 알루미늄 EGR 쿨러 성능 설계

Model based burnt gas fraction controller design of diesel engine with VGT/Dual loop EGR system

-Recently, regulation of NOx and PM emission in diesel engines has become stricter and the EGR system has been expanded into a dual loop EGR system to increase EGR rate as well as to utilize exhaust gas strategically. In terms of engine combustion characteristics, burnt gas fraction is becoming an important factor of solving the NOx and PM emission reduction problem more efficiently but conventional controller focused only pressure and air flow rate targets. Unlike the previous studies, this paper describes a model based burnt gas fraction control structure for a diesel engine with a dual loop EGR and a turbocharger. Feedforward control inputs based on burnt gas fraction states aids in the precise control of diesel engines, especially in transient states by considering coupled behavior within the system. For the controller validation, a control oriented reduced order model of a diesel engine air management system is established to simplify the control input computation and its stability is proved by analysing the internal dynamics stability. Then, a sliding mode controller is designed and controller robustness at certain operating points is validated using an HiLS bench.

Experimental verification of optimized NOX reduction strategies in a decrepit Euro-3 diesel engine retrofitted with a cooled EGR system

Vehicle-produced NOx is among emissions that deteriorate human health and the environment. To regulate the NOx emissions from transport, especially from diesel-powered vehicles, various standards have been established globally, and regulations are becoming more stringent across the world. Considerable NOx from diesel vehicles are due to the compression ignition characteristics of engines. Accordingly, to meet the national and global standards, manifold advanced aftertreatment technologies, such as EGR, SCR and LNT, have been developed and widely adopted since introduction of the Euro-4 standards in 2006. In Korea, current allowable NOx standards have been greatly reinforced to one fourth of the permissible level in 2004 and one sixth in 2000. However, the percentage of diesel vehicles in Korea more than 10 years old, manufactured prior to Euro-4, is still significant, accounting for 29% of passenger vehicles, 32% of buses, and 45% of trucks in total registration. Against this backdrop, tremendous efforts are required to improve air quality, especially in metropolitan areas. Of all technical options currently available, installing a cooler to typical EGR systems is considered as a more efficient way for superannuated diesel vehicles to meet the Euro-4 than installing a SCR or LNT in terms of technical acceptability and costeffectiveness. In this study, NOx characteristics of a decrepit Euro-3 diesel engine are thoroughly analyzed before and after the installation of the EGR coolers with different cooling capacities. By applying real time control of EGR rate and exhaust backpressure in calibration procedures, optimized NOx reduction strategies are established.

Hybrid EGR and turbocharging systems control for low NOX and fuel consumption in an automotive diesel engine

An experimental investigation was made on a downsized Euro 5 turbocharged diesel engine managing high/low pressure EGR systems and the variable nozzle turbine, aiming at major reductions in NOX emissions while enhancing fuel consumption in comparison with reference configuration. Three part load engine operating conditions were chosen at low and medium speed levels, applying different strategies to a number of control variables (relative air–fuel ratio, VNT opening degree/intake pressure, valves position in low pressure EGR circuit), thus exploring the whole range of high/low pressure EGR proportion. In suitable operating modes of tested conditions, NOX emissions were reduced up to 58–66%. Brake specific fuel consumption decreased around 5–9.5% at low speed/load, 1.7–3.3% in the intermediate condition while no advantages were achieved in the third working point. The activation of low pressure loop confirmed to be beneficial for turbocharger performance, rising its rotational speed thus granting for a better transient response, while increase in soot emissions ranged in a wide interval. For each condition, optimal operating modes were identified, with the relevant EGR proportion. A prevailing contribution from the long route circuit was generally requested, up to the exclusion of short route loop at higher level of speed and load.

IMO NOx Tier III対応 低圧EGRシステム

IMO NOx Tier III対応 低圧EGRシステム

EGR Systems Employment to Reduce the Fuel Consumption of a Downsized Turbocharged Engine at High-load Operations

In this work, a promising technique, consisting in an introduction of the external low pressure cooled EGR system, is analyzed by means of a 1D numerical approach with reference to a downsized spark-ignition turbocharged engine. The effects of various EGR amounts are investigated in terms of fuel consumption at full load operations. The proposed results highlight that EGR allows for increasing the knock safety margin. Fuel economy improvements however depend on the overall engine recalibration, consisting in proper settings of the A/F ratio and spark advance, compatible with knock occurrence. The numerical recalibration also accounts for additional limitations on the turbocharger speed, boost level, and turbine inlet temperature. The maximum BSFC improvement by the proposed solution is 5.9%.

A Review on an Opportunity to Reduce Exhaust Emission from Diesel Engine Using Exhaust Gas Recirculation

Internal combustion engines, plays an important role in the transportation sector and also in individual transport. Also it is a major source of manmade emissions. Presently there are many technologies are developed which are used to reduce the fuel consumption and exhaust emission from a diesel engine. In a CI engine fuel consumptions is reduced to a considerable amount, but the emission of NOx (Nitrogen Oxide) is a critical issue. This paper tries to present a review about the impact of EGR system on the exhaust emission of a CI engine. This is one of the methods which reduce the nitrogen oxide emissions of a diesel engine to a considerable level. In EGR – Exhaust Gas Recirculation method, a part of the exhaust gases is recirculated into the combustion chamber. Due to complete combustion of unburned fuel particles, there is a reduction in peak combustion temperature which in turn reduces the formation of NOX. By controlling the amount of available oxygen, which makes possibilities of reduction in the flame temperature in the combustion chamber, EGR system is effectively reduce the NOx emission from an engine.

Assessment of pollutants emission and aftertreatment efficiency in a GTDi engine including cooled LP-EGR system under different steady-state operating conditions

Nowadays, EGR systems are being incorporated in the research focused on spark-ignition direct-injection engines as a solution to the problems presented by them; i.e. knock risk and high combustion temperature which produces high NOx emission. Since the major part of the investigations are centered on engine performance or engine simulation aside pollutants emission and aftertreatment evaluation, this paper focuses on these topics: gaseous and particle emission analysis and aftertreatment efficiency evaluation when cooled LP-EGR system is applied to a GTDi engine.This work has been performed in a 4-cylinder, turbocharged, direct-injection gasoline engine with 2.0 L displacement. The equipment used in this study are TSI-EEPS for particle measurement and HORIBA MEXA 1230-PM for soot measurement being HORIBA MEXA 7100-DEGR with a heated line selector the system employed for regulated gaseous emission measurement and aftertreatment evaluation. A reduction around 50% of NOx with an increase of HC and CO emissions was found in medium-load operating points. At full-load conditions, the suppression of fuel enrichment including EGR leads in a drastically reduction in CO maintaining similar HC and NOx emissions. Furthermore, PN and soot emissions also decrease as EGR is included and spark timing advanced in all the tested conditions.

초희박 LPG 직접분사식 엔진에서 질소산화물 저감을 위한 배기재순환 적용성 평가

Abstract - In order to keep the competitiveness of LPG fuel for transportation fuel, the difference in fuel consumption with gasoline and cost for an aftertreatment system should be reduced with continuous development of technology for LPG engine. In the present study, spray-guided type direct injection combustion system, whose configuration is composed of direct injector in the vicinity of spark plug, was employed to realize stable lean combustion. A certain level of nitrogen oxides(NO x ) emits due to a locally rich mixture regions in the stratified mixture. With the application of EGR system for the reduction of NO x , 15% of NO x reduction was achieved whereas fuel consumption and hydrocarbon emission increased. By the application of EGR, the combustion speed reduced especially appeared at initial flame development period and peak heat release rates and increasing rates for heat release rate decreased as EGR rate increased due to the dilution effect of intake air.Key words : LPG engine, Lean combustion, Spray-guided type direct injection system, Exhaust gas recirculationKIGAS Vol. 19, No. 4, pp 22~28, 2015 http://dx.doi.org/10.7842/kigas. 2015.19.4.22(Journal of the Korean Institute of Gas)

CHARACTERIZATION OF PERODUA MYVI K3-VE I4 ENGINE PERFORMANCE USING EXHAUST GAS RECIRCULATION (EGR)

Internal combustion engines are the main power source for automobile vehicles. As current emission regulations becomes more stringent, more fuel efficient and less polluting engines are becoming the focus of car manufacturers. This paper presents the study of improving the performance of K3-VE I4 internal combustion engine that is used in the Perodua Myvi for the Perodua Eco-Challenge 2013. The strategy was to use an EGR system to reduce Brake Specific Fuel Consumption (BSFC) while maintaining or increasing the engine power. The effects of different location of EGR on the engine performance were tested on a chassis dynamometer. The sensitivity of the engine performance and gas emission were studied since EGR implementation plays a major role in influencing NOx emission. The performance parameter such as engine power and BSFC were then analysed. The result shows that a significant increase of power can be achieved and a reduction of around 56% was obtained on the BSFC. While the best NOx reduction was around 93%. These improvements are obtained at low RPM that corresponds to Perodua Eco-Challenge’s objective.

Optimisation of Boosting Stage and LP EGR System through Pre-swirl Throttle

Optimisation of Boosting Stage and LP EGR System through Pre-swirl Throttle

SECFR 시스템의 차량적용을 위한 분무균일도향상에 관한 연구

Abstract Lower recirculated gas temperature at EGR system reduces NOx and PM emissions. However, EGR Cooler can bepolluted by PM generated from recirculated EGR gas, and it reduces cooling efficiency and the amount of EGR gassimultaneously. The SECFR(Steam EGR Cooler Fouling Remover) system which uses the evaporated washer fluidsteam caused by high temperature of EGR gas was manufactured for removing fouling generated on the cooler surface.Since an injection pressure of wind shield washer fluid in the vehicle is approximately 0.5 bar, it is not enough toatomize the injected washer fluid. Thus, it is necessary to apply a method to atomize the washer fluid. In this study,the impinging plate was used to promote the atomization of spray washer fluid for the purpose of apply SECFR sys-tem to vehicles and measured the DAR(Droplet Area Ratio) and DUI(Droplet Uniformity Index) through the sprayvisualization. 기호설명 EGR : 배기가스재순환NOx : 질소산화물PM : 입자상 물질HC : 미연 탄화수소CO : 일산화탄소DUI : 액적균일도DAR: 액적분포면적율

Fuel Economy Improvement and Knock Tendency Reduction of a Downsized Turbocharged Engine at Full Load Operations through a Low-Pressure EGR System

Fuel Economy Improvement and Knock Tendency Reduction of a Downsized Turbocharged Engine at Full Load Operations through a Low-Pressure EGR System

디젤 엔진의 연비 향상을 위한 저압 배기재순환 시스템의 적용에 관한 연구

디젤 엔진에서 저압 배기재순환 시스템의 적용을 통한 질소산화물 저감과 연비 향상에 관한 효과를 확인하였다. 엔진의 정상 상태 및 과도 상태에서 시험이 진행되었으며, 차량상사를 통한 NEDC 모드 테스트를 위하여 별도의 제어로직도 개발되었다. 정상 상태의 시험결과에서 저압 배기재순환 시스템은 고압 배기재순환 시스템에 비하여 질소산화물 저감 및 연비 향상에 유리함을 확인하였고, NEDC 모드 테스트 결과로부터 배출가스의 증가없이 연비를 향상시킬 수 있는 것으로 나타났다. LP(low pressure)-EGR system was investigated to evaluate its potential on fuel economy improvement and NOx emission reduction in a diesel engine. A diesel engine was tested for the evaluation of LP-EGR system at both of steady-state and transient test. For a transient test, control logic for LP-EGR valve operation was developed and a NEDC mode test was conducted by using a vehicle status simulation test. The steady-state results showed that LP-EGR system can reduce more NOx emission or fuel consumption comparing to the conventional HP(high pressure)-EGR. From the NEDC mode test, this LP-EGR system showed a possibility to improve fuel economy without a penalty of emissions.

Modeling of a Large Marine Two-Stroke Diesel Engine with Cylinder Bypass Valve and EGR System

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.