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A Tsolakis - One of the best experts on this subject based on the ideXlab platform.

  • improving Gasoline direct injection gdi engine efficiency and emissions with hydrogen from Exhaust Gas fuel reforming
    International Journal of Hydrogen Energy, 2014
    Co-Authors: Daniel Fennell, Jose Martin Herreros, A Tsolakis
    Abstract:

    Abstract Exhaust Gas fuel reforming has been identified as a thermochemical energy recovery technology with potential to improve Gasoline engine efficiency, and thereby reduce CO2 in addition to other Gaseous and particulate matter (PM) emissions. The principle relies on achieving energy recovery from the hot Exhaust stream by endothermic catalytic reforming of Gasoline and a fraction of the engine Exhaust Gas. The hydrogen-rich reformate has higher enthalpy than the Gasoline fed to the reformer and is recirculated to the intake manifold, i.e. reformed Exhaust Gas recirculation (REGR). The REGR system was simulated by supplying hydrogen and carbon monoxide (CO) into a conventional EGR system. The hydrogen and CO concentrations in the REGR stream were selected to be achievable in practice at typical Gasoline Exhaust temperatures. Emphasis was placed on comparing REGR to the baseline Gasoline engine, and also to conventional EGR. The results demonstrate the potential of REGR to simultaneously increase thermal efficiency, reduce Gaseous emissions and decrease PM formation.

  • application of Exhaust Gas fuel reforming in diesel and homogeneous charge compression ignition hcci engines fuelled with biofuels
    Energy, 2008
    Co-Authors: A Tsolakis, A Megaritis
    Abstract:

    This paper documents the application of Exhaust Gas fuel reforming of two alternative fuels, biodiesel and bioethanol, in internal combustion engines. The Exhaust Gas fuel reforming process is a method of on-board production of hydrogen-rich Gas by catalytic reaction of fuel and engine Exhaust Gas. The benefits of Exhaust Gas fuel reforming have been demonstrated by adding simulated reformed Gas to a diesel engine fuelled by a mixture of 50% ultra low sulphur diesel (ULSD) and 50% rapeseed methyl ester (RME) as well as to a homogeneous charge compression ignition (HCCI) engine fuelled by bioethanol. In the case of the biodiesel fuelled engine, a reduction of NOx emissions was achieved without considerable smoke increase. In the case of the bioethanol fuelled HCCI engine, the engine tolerance to Exhaust Gas recirculation (EGR) was extended and hence the typically high pressure rise rates of HCCI engines, associated with intense combustion noise, were reduced.

  • the influence of h2 and co on diesel engine combustion characteristics Exhaust Gas emissions and after treatment selective catalytic nox reduction
    International Journal of Hydrogen Energy, 2007
    Co-Authors: A Abujrai, A Tsolakis, A Megaritis
    Abstract:

    Abstract The requirement to significantly reduce NO x and particulate matter (PM) emissions while maintaining efficient combustion performance is one of the main drivers for internal combustion engine research. Modern diesel and premixed charge compression ignition (PCCI) engines have improved engine fuel economy and significantly reduced NO x and PM emissions achieved by advances in both combustion and Exhaust aftertreatment technologies. To date, it has been shown that vehicle emissions can be further improved by several catalytic systems including fuel reformers (i.e. partial oxidation, autothermal, and Exhaust Gas reforming) and aftertreatment systems, such as the selective catalytic reduction (SCR) of NO x under oxygen-rich conditions. Among the most promising on-board reforming technologies is the Exhaust-Gas reforming, which allows the fuel/air feed to the engine to be enriched with reformate containing H 2 and CO. This method is a combination of reforming and Exhaust-Gas recirculation (EGR) and referred to as REGR. This paper reports on experimental results obtained when 1 % Pt / Al 2 O 3 low temperature hydrocarbon-SCR catalyst was used to treat Exhaust Gas from a diesel engine operating with addition of simulated REGR (two different compositions). It has been shown that while REGR can directly improve engine performance and emissions by promoting the PCCI combustion mode, it can also benefit the performance of the SCR catalysts due to the presence of unburnt H 2 in the Exhaust Gas.

  • Exhaust Gas assisted reforming of rapeseed methyl ester for reduced Exhaust emissions of ci engines
    Biomass & Bioenergy, 2004
    Co-Authors: A Tsolakis, A Megaritis
    Abstract:

    The nitrogen oxides (NOxx) emissions of compression ignition (CI) engines fueled with biodiesel are generally higher compared to conventional diesel fuelling. Previous research work in CI engines has shown that the partial replacement of hydrocarbon fuels by hydrogen combined with Exhaust Gas recirculation (EGR) can reduce NOxx and smoke emissions without significant changes to the engine efficiency. In the present study, the production of hydrogen-rich Gas by catalytic Exhaust Gas assisted fuel reforming of rapeseed methyl ester (RME) has been investigated experimentally as a way to provide the required hydrogen for the reduction of biodiesel emissions. For comparison, tests with ultra low sulphur diesel (ULSD) were also performed. The reforming experiments were carried out in a mini reactor supplied with Exhaust Gas from a single cylinder CI engine. In all cases, the reactor inlet temperature was kept at 290∘∘C which was chosen as a typical low Exhaust Gas temperature of diesel engines operating at part load. The engine operating condition (speed, load) was the same in all the tests and the reactor product Gas was examined as a function of the reactor fuel flow rate and the composition of fuel and engine Exhaust Gas. Up to 17% hydrogen content of the reformer product was achieved and the results indicated that the main reactions in the reformer were the exothermic complete oxidation of part of the fuel and the endothermic steam reforming reaction. Reforming of RME produced more hydrogen with higher fuel conversion efficiency compared to ULSD reforming.

  • application of Exhaust Gas fuel reforming in compression ignition engines fueled by diesel and biodiesel fuel mixtures
    Energy & Fuels, 2003
    Co-Authors: A Tsolakis, A Megaritis, Miroslaw L Wyszynski
    Abstract:

    In this study, the application of Exhaust Gas-assisted fuel reforming in compression ignition engines (CI) has been investigated. Experiments were conducted in a single-cylinder direct-injection (DI) diesel engine fueled by conventional diesel and also by a biodiesel mixture. First, the effects of Exhaust Gas recirculation (EGR) and addition of small amounts of hydrogen on the combustion and Exhaust emissions were explored. With the addition of hydrogen, the flow of the main fuel (diesel or biodiesel) was reduced to maintain constant indicated mean effective pressure (IMEP). Thus, in effect the tests involved fuel replacement by hydrogen rather than hydrogen addition. Second, the feasibility of producing hydrogen “on-board” by catalytic Exhaust Gas fuel reforming was examined by incorporating a laboratory reforming mini reactor in the engine Exhaust system. Prototype catalysts and different reaction conditions were examined. The results from the first part of the study showed that partial replacement of t...

A Megaritis - One of the best experts on this subject based on the ideXlab platform.

  • application of Exhaust Gas fuel reforming in diesel and homogeneous charge compression ignition hcci engines fuelled with biofuels
    Energy, 2008
    Co-Authors: A Tsolakis, A Megaritis
    Abstract:

    This paper documents the application of Exhaust Gas fuel reforming of two alternative fuels, biodiesel and bioethanol, in internal combustion engines. The Exhaust Gas fuel reforming process is a method of on-board production of hydrogen-rich Gas by catalytic reaction of fuel and engine Exhaust Gas. The benefits of Exhaust Gas fuel reforming have been demonstrated by adding simulated reformed Gas to a diesel engine fuelled by a mixture of 50% ultra low sulphur diesel (ULSD) and 50% rapeseed methyl ester (RME) as well as to a homogeneous charge compression ignition (HCCI) engine fuelled by bioethanol. In the case of the biodiesel fuelled engine, a reduction of NOx emissions was achieved without considerable smoke increase. In the case of the bioethanol fuelled HCCI engine, the engine tolerance to Exhaust Gas recirculation (EGR) was extended and hence the typically high pressure rise rates of HCCI engines, associated with intense combustion noise, were reduced.

  • the influence of h2 and co on diesel engine combustion characteristics Exhaust Gas emissions and after treatment selective catalytic nox reduction
    International Journal of Hydrogen Energy, 2007
    Co-Authors: A Abujrai, A Tsolakis, A Megaritis
    Abstract:

    Abstract The requirement to significantly reduce NO x and particulate matter (PM) emissions while maintaining efficient combustion performance is one of the main drivers for internal combustion engine research. Modern diesel and premixed charge compression ignition (PCCI) engines have improved engine fuel economy and significantly reduced NO x and PM emissions achieved by advances in both combustion and Exhaust aftertreatment technologies. To date, it has been shown that vehicle emissions can be further improved by several catalytic systems including fuel reformers (i.e. partial oxidation, autothermal, and Exhaust Gas reforming) and aftertreatment systems, such as the selective catalytic reduction (SCR) of NO x under oxygen-rich conditions. Among the most promising on-board reforming technologies is the Exhaust-Gas reforming, which allows the fuel/air feed to the engine to be enriched with reformate containing H 2 and CO. This method is a combination of reforming and Exhaust-Gas recirculation (EGR) and referred to as REGR. This paper reports on experimental results obtained when 1 % Pt / Al 2 O 3 low temperature hydrocarbon-SCR catalyst was used to treat Exhaust Gas from a diesel engine operating with addition of simulated REGR (two different compositions). It has been shown that while REGR can directly improve engine performance and emissions by promoting the PCCI combustion mode, it can also benefit the performance of the SCR catalysts due to the presence of unburnt H 2 in the Exhaust Gas.

  • Exhaust Gas assisted reforming of rapeseed methyl ester for reduced Exhaust emissions of ci engines
    Biomass & Bioenergy, 2004
    Co-Authors: A Tsolakis, A Megaritis
    Abstract:

    The nitrogen oxides (NOxx) emissions of compression ignition (CI) engines fueled with biodiesel are generally higher compared to conventional diesel fuelling. Previous research work in CI engines has shown that the partial replacement of hydrocarbon fuels by hydrogen combined with Exhaust Gas recirculation (EGR) can reduce NOxx and smoke emissions without significant changes to the engine efficiency. In the present study, the production of hydrogen-rich Gas by catalytic Exhaust Gas assisted fuel reforming of rapeseed methyl ester (RME) has been investigated experimentally as a way to provide the required hydrogen for the reduction of biodiesel emissions. For comparison, tests with ultra low sulphur diesel (ULSD) were also performed. The reforming experiments were carried out in a mini reactor supplied with Exhaust Gas from a single cylinder CI engine. In all cases, the reactor inlet temperature was kept at 290∘∘C which was chosen as a typical low Exhaust Gas temperature of diesel engines operating at part load. The engine operating condition (speed, load) was the same in all the tests and the reactor product Gas was examined as a function of the reactor fuel flow rate and the composition of fuel and engine Exhaust Gas. Up to 17% hydrogen content of the reformer product was achieved and the results indicated that the main reactions in the reformer were the exothermic complete oxidation of part of the fuel and the endothermic steam reforming reaction. Reforming of RME produced more hydrogen with higher fuel conversion efficiency compared to ULSD reforming.

  • application of Exhaust Gas fuel reforming in compression ignition engines fueled by diesel and biodiesel fuel mixtures
    Energy & Fuels, 2003
    Co-Authors: A Tsolakis, A Megaritis, Miroslaw L Wyszynski
    Abstract:

    In this study, the application of Exhaust Gas-assisted fuel reforming in compression ignition engines (CI) has been investigated. Experiments were conducted in a single-cylinder direct-injection (DI) diesel engine fueled by conventional diesel and also by a biodiesel mixture. First, the effects of Exhaust Gas recirculation (EGR) and addition of small amounts of hydrogen on the combustion and Exhaust emissions were explored. With the addition of hydrogen, the flow of the main fuel (diesel or biodiesel) was reduced to maintain constant indicated mean effective pressure (IMEP). Thus, in effect the tests involved fuel replacement by hydrogen rather than hydrogen addition. Second, the feasibility of producing hydrogen “on-board” by catalytic Exhaust Gas fuel reforming was examined by incorporating a laboratory reforming mini reactor in the engine Exhaust system. Prototype catalysts and different reaction conditions were examined. The results from the first part of the study showed that partial replacement of t...

Jianqin Fu - One of the best experts on this subject based on the ideXlab platform.

  • Experimental investigation on the influences of Exhaust Gas recirculation coupling with intake tumble on Gasoline engine economy and emission performance
    Energy Conversion and Management, 2016
    Co-Authors: Jianqin Fu, Guohui Zhu, Yan Xia, Jingping Liu, Feng Zhou, Shuqian Wang
    Abstract:

    To improve the economy and emission performance of Gasoline engine under part load, the approach of Exhaust Gas recirculation coupling with intake tumble was investigated by bench testing. Based on a naturally aspirated Gasoline engine, the sweeping test of Exhaust Gas recirculation rate was conducted in two intake modes (with/without intake tumble), and the parameters related to engine heat-work conversion process and emission performance were measured. Through comparing and analyzing the measured data, the effects of Exhaust Gas recirculation coupling with intake tumble on Gasoline engine economy and emission performance were revealed. The results show that pumping loss decreases gradually while in-cylinder residual Gas fraction increases linearly with the Exhaust Gas recirculation rate increasing; the high-pressure cycle efficiency ascends with Exhaust Gas recirculation rate increasing due to the decrease of heat transfer loss and Exhaust Gas energy loss. Thus, the improvement of indicated thermal efficiency is the superposition of double benefits of low-pressure cycle and high-pressure cycle. At 1600 r/min and 2.94 bar, the indicated thermal efficiency can be increased by 4.29%. With the increase of Exhaust Gas recirculation rate, nitrogen oxide emissions almost fall linearly, but hydrocarbon and carbonic oxide emissions have no obvious change in the effective range of Exhaust Gas recirculation rate. The biggest advantage of intake tumble is that it can extend the effective range of Exhaust Gas recirculation rate. As a result, the potential of energy conservation and emission reduction of Exhaust Gas recirculation is largely improved.

  • comparison and analysis of engine Exhaust Gas energy recovery potential through various bottom cycles
    Applied Thermal Engineering, 2013
    Co-Authors: Jianqin Fu, L J Wang, Zhengxin Xu, Banglin Deng
    Abstract:

    Abstract In this paper, aimed to recover engine Exhaust Gas energy and improve engine thermal efficiency, various means of bottom cycles for engine Exhaust Gas energy recovery are proposed, and those include direct recovery means through Exhaust Gas expansion, such as secondary expansion, and indirect recovery means through heat transfer, such as Rankine steam cycle, Brayton air cycle, etc. The performances and characteristics of each bottom cycle are studied by cycle processes calculation and then the energy recovery potentials are compared. The results show that direct recovery bottom cycle through secondary expansion demonstrates little, if any, positive potential for a Gasoline engine, and it only suits to diesel engine at full load with high boost pressure. The improvement range also differs with engine speeds and energy recovery potential is low. However, indirect recovery bottom cycles have larger applied range and higher Exhaust Gas energy recovery potential compared to direct recovery means. In all indirect recovery bottom cycles discussed, the maximum energy recovery potentials reduce in the sequence of over-heated Rankine steam cycle, standard Rankine steam cycle, Brayton air cycle with regeneration and standard Brayton air cycle.

Banglin Deng - One of the best experts on this subject based on the ideXlab platform.

  • comparison and analysis of engine Exhaust Gas energy recovery potential through various bottom cycles
    Applied Thermal Engineering, 2013
    Co-Authors: Jianqin Fu, L J Wang, Zhengxin Xu, Banglin Deng
    Abstract:

    Abstract In this paper, aimed to recover engine Exhaust Gas energy and improve engine thermal efficiency, various means of bottom cycles for engine Exhaust Gas energy recovery are proposed, and those include direct recovery means through Exhaust Gas expansion, such as secondary expansion, and indirect recovery means through heat transfer, such as Rankine steam cycle, Brayton air cycle, etc. The performances and characteristics of each bottom cycle are studied by cycle processes calculation and then the energy recovery potentials are compared. The results show that direct recovery bottom cycle through secondary expansion demonstrates little, if any, positive potential for a Gasoline engine, and it only suits to diesel engine at full load with high boost pressure. The improvement range also differs with engine speeds and energy recovery potential is low. However, indirect recovery bottom cycles have larger applied range and higher Exhaust Gas energy recovery potential compared to direct recovery means. In all indirect recovery bottom cycles discussed, the maximum energy recovery potentials reduce in the sequence of over-heated Rankine steam cycle, standard Rankine steam cycle, Brayton air cycle with regeneration and standard Brayton air cycle.

  • an open steam power cycle used for ic engine Exhaust Gas energy recovery
    Energy, 2012
    Co-Authors: Jingping Liu, Chengqin Ren, Linjun Wang, Banglin Deng
    Abstract:

    Abstract In order to improve IC engine energy utilization efficiency, an open steam power cycle used for IC engine Exhaust Gas energy recovery is proposed. The bottom cycle concept is designed on a four-cylinder naturally aspirated IC engine: with three cylinders taken as ignition cylinder, the last one is used for steam expansion cylinder; IC engine Exhaust pipe is coupled with a Rankine steam cycle system which uses the high temperature Exhaust Gas to generate steam; then, the steam is injected into steam expansion cylinder and expands in the cylinder. In this way, the Otto cycle (or diesel cycle) of traditional IC engine and the steam expansion cycle (open Rankine cycle) are coupled on IC engine. On this basis, the energy recovery potential of this bottom cycle is studied by cycle processes calculation and parameters analysis. The research results show that the recovery efficiency of Exhaust Gas energy is mainly limited by Exhaust Gas temperature. The maximum bottom cycle power can reach 19.2 kW and IC engine thermal efficiency can be improved by 6.3% at 6000 r/min. All those can prove this novel bottom cycle concept has larger potential for energy saving and emission reduction on IC engine.

Jonathan Chauvin - One of the best experts on this subject based on the ideXlab platform.

  • Control of a turbocharged Diesel engine fitted with high pressure and low pressure Exhaust Gas recirculation systems
    Proceedings of the 48h IEEE Conference on Decision and Control CDC held jointly with 2009 28th Chinese Control Conference, 2009
    Co-Authors: Olivier Grondin, Philippe Moulin, Jonathan Chauvin
    Abstract:

    Exhaust Gas recirculation is an effective way for reducing nitric oxides emissions in Diesel engine achieving low temperature combustion (LTC). Two strategies can be applied to recirculate burnt Gas in a turbocharged Diesel engine using the high pressure loop or the low pressure loop. This paper describes a generic model based control structure for Diesel engines with dual-loop Exhaust Gas recirculation (EGR) and variable geometry turbocharger. An observer is designed to estimate the Exhaust Gas flow coming from the high pressure loop or from the low pressure loop. These estimates are used for the intake burnt Gas fraction control. This approach avoids direct measurement or implementation of additional sensors. In addition, a generic model based control based on motion planning is adapted to the low pressure EGR system. The main advantage of the approach is that turbocharger and Exhaust Gas recirculation systems controllers have a limited number of calibration parameters. The observer and controller results are presented and validated on a LTC-Diesel engine with a dual-loop EGR system.