• Journal of Drive and Control
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• v.9 no.4
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• pp.52-57
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• 2012

In this study, in order to understand contents and ranges of design for the EGR Valve test system for improving quality and performance of EGR Valve, engine performance and exhaust gas characteristic of 3L-class diesel engine was analyzed. Experimental operation of engine performance test was performed with 50% engine load and 20% and 100% opening ratio of EGR Valve. From test of performance and exhaust gas characteristic of engine, torque output of engine and temperature and pressure of inlet and outlet of EGR Valve were measured. As a result, for design of EGR Valve test system, input fluid flow of EGR Valve must be set the same amount with exhaust gas flow that was below of engine speed of 2,500 rpm, and temperature of inlet of EGR Valve must be set under about $510^{\circ}C$. And the difference of temperature between inlet and outlet of EGR Valve must be over than about $200^{\circ}C$. Exhaust gas of inlet and outlet of EGR Valve were under 1 bar that was not considerable, and the difference of pressure between inlet and outlet of EGR Valve were under 1 bar that could not effect on mechanical operation of EGR Valve.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.4
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• pp.114-120
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• 2011

Fuel reforming technology for the fuel cell vehicles has been frequently applied to internal combustion engine for the reduction of engine out emissions. Since syngas which is reformed from fossil fuel has hydrogen as a major component, it has abilities to enhance the combustion characteristics with wide flammability and high speed flame propagation. In this paper, syngas was feed to a 2.0 liter SI engine with MPI to improve exhaust emissions under cold start and early state of idle condition. Syngas fraction is varied to 0%, 10%, 25%, with various ignition timings. Exhaust emission characteristics and the exhaust system temperature were measured to investigate the effects of syngas addition on cold start. Result showed that HC emission could be dramatically reduced due to the fact that syngas has $H_2$ and no HC as components. The amount of $NO_x$ emission was decreased with the increase of syngas fraction. Because the dilution effect of $N_2$ and the retard of ignition timing reduces the peak combustion temperature inside the cylinder. Exhaust gas temperature was lower than that of gasoline feeding condition. Retarded ignition timing, however, resulted in increased exhaust gas temperature approximated to gasoline condition. It is supposed that the usage of syngas in an SI engine is an effective solution to meet the future strict emission regulations.

• Journal of the Korean Institute of Gas
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• v.5 no.1
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• pp.7-14
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• 2001

In this work, the chemical composition of the exhaust gas from domestic gas boiler has been analysed in the point of thermodynamics and CO sensor has been characterized. We proposed that the combustion condition can be estimated by the exhaust gas composition, i.e., the excess air ratio and combustion temperature can be calculated simply by the measurement of the $O_{2}$ fraction and $H_{2}/CO$ in the exhaust gas. By analyse the on site situation domestic boiler, the excess air ratio is about $55\~110\%$. Therefore, the CO may be produced in domestic gas boiler by luminous(yellow) flames rapidly lose heat by radiation, turbulent flames may be partially quenched by the action of steep velocity gradients, and flames burning very close to a cold wall may be partial1y quenched by heat conductivity to the wall. The output voltage of CO sensor is lineally depend on the CO and $H_{2}$concentration. And the exhaust CO from boiler can be reduced by closed loop control with CO sensor

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.3
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• pp.39-47
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• 2003

UEGI (Unburned Exhaust Gas Ignition) is an alternative method for fast light-off of a catalyst. It ignites the unburned exhaust mixture using two glow plugs installed in the upstream of the close-coupled catalysts. In addition, a hydrocarbon adsorber was applied to the UEGI, for more effective reduction of HC emission. Engine bench tests show that the CCC reaches the light-off temperature laster than the baseline exhaust system and HC and CO emissions are reduced significantly during the cold start. From the vehicle test, it was observed that a few amount of HC emission was reduced even the catalysts were aged. It is expected to develop a solution kit applicable to a new vehicle or used one, to meet the emission regulation

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.2
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• pp.43-49
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• 2001

In order to satisfy the ULEV emissions regulation, fast light-off of a catalyst is essential for reduction of HC and CO emissions during the cold start. Cranking Exhaust Gas Ignition(CEGI) method developed in this study showed that the catalyst reaches the light-off temperature in a few seconds. The CEGI stops the ignition signal for a few seconds during the cranking period, so the unburned fuel-air mixture bypasses the combustion chamber and flows through the exhaust manifold. When the unburned mixture reaches two glow plugs installed upstream of the catalyst, it burns and releases the thermal energy to heat up the catalyst, In the FTP-75 vehicle tests, the CEGI showed that the exhaust emissions reduced by 47.7% for THC and by 88.6% for CO in the cold-transient phase of the test.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.4
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• pp.130-141
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• 1997

Work on the reduction of particulate matter(PM) from a diesel vehicl has led to a new trp system and a control method to control the combustion rate of the PM filtrated in the trap, which was named as 'Active Exhaust Feeding Regeneration(AEFR) System' by its operation mechanism. Ceramic cordierite filter is a major component of the trap and susceptible to thermal shock. Therefore the system should be designed to reduce the peak temperature and temperature gradients in the trap ; these have been considered to be the main factors causing thermal shock of the filter during the regeneration. It uses the engine's exhaust gas partially for the regeneration of the ceramic filter. It controlled bypass flow rate of the engine's exhaust gas precisely to control the temperature of the gas entrained into the filter. Gas temperatures were measured inside filter, and the oxygen concentration at the outlet of the filter was also monitored during the regeneration to analyze the combustion process of the PM. The temperature distributions and temperature gradients in the filter during the regeneration varied widely according to the regeneration control schemes. Finally, this system shows relatively low peak temperature and temperature gradients in the filter during its regeneration. It is considered that this system uses a mew method to control the combustion rate of the PM, which is different from the methods used in the previous studies.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.802-806
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• 2004

For the protection of the local air quality and the global atmosphere, the emissions of trace species including nitric oxides (NO and NO$_2$) from gas turbines are regulated by local governments and by the International Civil Aviation Organization. In-situ measurements of such species are needed not only for the development of advanced low-emission combustion concepts but also for providing emissions data required for the sound assessment of the effects of the emissions on environment. We have been developing a laser absorption system that has a capability of simultaneous determination of NO and NO$_2$concentrations in the exhaust jets from aero gas turbines. A diode laser operating near 1.8 micrometer is used for the detection of NO while a separated visible tunable diode laser operating near 676 nanometers is used for NO$_2$. The sensitivities at elevated temperature conditions were determined for simulated gas mixtures heated up to 500K in a heated cell of a straight 0.5 m optical path. Sensitivity limits estimated as were 30 ppmv-m and 3.7 ppmv-m for NO and NO$_2$, respectively, at a typical exhaust gas temperature of 800K. Experiments using the simulated exhaust flows have proven that $CO_2$ and $H_2O$ vapor - both major combustion products - do not show any interference in the NO or NO$_2$ measurements. The measurement system has been applied to the NO/NO$_2$ measurements in NO and NO$_2$ doped real combustion gas jets issuing from a rectangular nozzle having 0.4 m optical path. The lower detection limits of the system were considerably decreased by using a multipass optical cell. A pair of off-axis parabola mirrors successfully suppressed the beam steering in the combustion gas jets by centralizing the fluctuating beam in sensor area of the detectors.

• Journal of Internet of Things and Convergence
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• v.8 no.1
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• pp.23-29
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• 2022

The product to be developed in this study is a heat recovery device which generates steam or hot water at high temperature and high pressure by heating water using exhaust gas from diesel engine, gas engine, gas turbine, etc. as an exhaust gas boiler off heat boiler(EGB) type for ship and power generation. The steam vapor or the created warm water is used as the power source required for the steerage heating and hot water facility or the HFO heating of the ship, and the turbine drive. The principle of waste heat boilers serves to heat water as high temperature exhaust gas with heat pass through the tube of the boiler. The heated water is a structure that is sent to a cabin or turbine device in the form of steam. In this study, the objective of this study is to maximize the efficiency by increasing the heat transfer surface by replacing the tube which is the heat transfer part of EGB with the plate tube.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.3
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• pp.243-248
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• 2013

Internal combustion engines typically expel 30%-40% of the energy supplied by fuel to the environment through their exhaust system. Therefore, further significant improvements in the thermal efficiency of IC engines are possible by recovering the waste heat from the engine exhaust gas. With this fact in mind, a numerical simulation was carried out to investigate the potential of using thermoelectric generation with an internal combustion engine for waste heat recovery. Physical parameters such as the exhaust temperature and mass flow rate were evaluated in the exhaust system, and the optimum location for inserting a thermoelectric generator (TEG) into the system was determined. The TEG will be located in the exhaust system and will use the energy flow between the warmer exhaust gas and the external environment. The optimum position of the temperature distribution and the TEG performance were predicted through numerical analysis. The experimental results obtained showed that the power output significantly increases with the temperature difference between the cold and hot sides of the TEG.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.151-152
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• 2012

Collectors connected to diesel engine exhaust pipe for application of PM reduction facilities which was used to reduce PM from the exhaust gas produced from ship, Filtration performance of PM was tested. In this system, it was confirmed that the bag house can remove over 90 percent of PM from a lot of high temperature and high pressure gases produced in diesel engine. The results obtained from performance test show the potential possibility for commercialization of ceramic filter collectors which is applied to reduction facilities of flue gas produced from a diesel engine on the ship.