• Title, Summary, Keyword: Exhaust gas temperature

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A Study on the Performance of an LPG (Liquefied Petroleum Gas) Engine Converted from a Compression Ignition Engine

  • Choi, Gyeung-Ho;Kim, Tae-Kwon;Cho, Ung-Lae;Chung, Yon-Jong;Caton, Jerald;Han, Sung-Bin
    • Journal of Energy Engineering
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    • v.16 no.1
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    • pp.1-6
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    • 2007
  • The purpose of this study was to investigate the reduction of exhaust gas temperature in a LPG engine that had been converted from a diesel engine. A conventional diesel engine was modified to a LPG (Liquefied Petroleum Gas) engine by replacing the diesel fuel injection pump with a LPG fuel system. The research was performed by measuring the exhaust gas temperature upon varying spark ignition timing, airfuel ratio, compression ratio, and different compositions of butane and propane. Engine power and exhaust temperature were not influenced by various butane/propane fuel compositions. Finally, among the parameters studied in this investigation, spark ignition timing is one of the most important in reducing exhaust gas temperature.

Thermal Caracteristics of the Automobile Exhaust gas based Heat exchanger with various Exhaust gas Temperature and Mass flow rate (자동차 배기가스 유량 및 온도 변화에 따른 열전발전용 열교환기 발열량 특성에 관한 연구)

  • Kim, Dae-Wan;Ekanayake, Gihan;Lee, Moo-Yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.15-20
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    • 2018
  • The objective of this study is to numerically investigate the thermal characteristics of an automobile exhaust-based heat exchanger for automotive thermoelectric power generation with various exhaust gas mass flow rates and temperatures. The heat exchanger for automotive thermoelectric power generation has a square-type pin installed inside, so the maximum amount of heat can be transferred to the thermoelectric element from the heat energy coming from the automobile exhaust gas. The exhaust gas mass flow rate changed from 0.01, to 0.02, to 0.03 kg/s, and the exhaust gas temperature changed from 400, to 450, to 500, to 550, to $600^{\circ}C$, respectively. A numerical simulation was conducted by using the commercial program ANSYS CFX v17.0. Consequently, the exhaust gas pressure difference between the inlet and the outlet of the heat exchanger is determined according to the flow rate of the exhaust gas. When the mass flow rate of the exhaust gas increased, the pressure difference between the inlet and the outlet of the heat exchanger increased, but the exhaust gas pressure difference between the inlet of the heat exchanger and the outlet did not vary with the exhaust gas temperature. Therefore, in order to obtain the maximum surface temperature from the heat exchanger, the exhaust gas mass flow rate should be lower, and the exhaust gas temperature should be higher.

Characteristics of Exhaust Gas Temperature and Harmful Emission During Cold Start Transient Operation in an SI Engine (가솔린엔진의 냉시동 천이구간에서 배출가스 온도 및 유해배출물 특성에 관한 연구)

  • Cho, Yong-Seok;Jeong, Dae-Chul;Park, Young-Joon;Kim, Duk-Sang
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.30 no.12
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    • pp.1181-1187
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    • 2006
  • Stringent regulations of exhaust emission from vehicles become a major issue in automotive industries. In SI engines, it is one of the crucial factor to reduce exhaust emissions during cold start in order to meet stringent regulations such as SULEV or EURO-4, because SI engines emit a large portion of total harmful exhaust compounds when they are cold. At early stages of cold start in gasoline engines, exhaust gas temperature plays a key role to improve three way catalyst by virtue of fast warmup. Therefore, this study focused on the increase of exhaust gas temperature under controls of engine operating parameters such as spark ignition timing, valve overlap by virtue of intake VVT and catalyst heating function. Furthermore, effects on harmful emission due to these parameters are also investigated. Experiments showed that retarded spark ignition timings and increased valve overlap may be helpful to increase exhaust gas temperature. It was also found that $NO_x$ was decreased with increased valve overlap. This study also showed that sudden changes in ISA and amount of fuel due to the deactivation of catalyst heating function cause temporal increase of harmful emissions.

An Experimental Study on Variations of Exhaust Gas Temperature and Concentration with Synthetic Gas Combustion in Exhaust Manifold (배기관에서의 합성가스 연소에 따른 배기가스 온도 및 농도 변화에 관한 실험적 연구)

  • Cho, Yong-Seok;Lee, Seang-Wock;Yang, Seung-Il;Song, Chun-Sub;Park, Young-Joon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.4
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    • pp.56-62
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    • 2008
  • A synthetic gas reformed from hydrocarbon-based fuels consists of $H_2$, CO and $N_2$. Hydrogen contained in the synthetic gas is a very useful species in chemical processes, due to its wide flammability range and fast burning speed. The ESGI (Exhaust Synthetic Gas Injection) technology is developed to shorten the light-off time of three way catalysts through combustion of the synthetic gas in the exhaust manifold during the cold start period of SI engines. Before the ESGI technology is applied to the test engine, the authors set a test rig that consists of gas temperature and composition controllers, an exhaust pulse generator and an exhaust manifold with a visualization window, in order to optimize the point and conditions of injection of the synthetic gas. Through measuring burned gas temperatures and taking photographs of synthetic gas combustion at the outlet of the exhaust manifold, the authors tried to find the optimal injection point and conditions. Analysis of burned gas composition has been performed for various $O_2$ concentrations. As a result, when the synthetic gas is injected at the port outlet of the cylinder No. 4 and $O_2$ concentration exceeds 4%, combustion of the synthetic gas is strong and effective in the exhaust manifold.

An Experimental Study on Annulus Muffler of Automobile (자동차용 환상형 소음기에 관한 실험적 연구)

  • Kim, Byoung-Sam;Song, Kyu-Keun;Sim, Sang-Cherl;Cheong, Byeong-Kuk
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.217-222
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    • 2006
  • Internal combustion engine is the main source of environmental pollutants and therefore advanced technology is required to reduce harmful elements from the exhaust gases all over the world. Especially, when the exhaust gas is released front the automotive muffler, exhaust noise has many bad influence on the surrounding environment. In order to reduce the exhaust noise, it is necessary that automotive muffler must be designed for best exhaust efficiency. The sound insulation room was installed for the analysis of an acoustics characteristics of the noise from automotive muffler, in this study. Exhaust gas noise, noise distribution characteristics, pressure and temperature of exhaust gas were investigated with the change of annulus temperature of air cooled annulus automotive muffler and cooled annulus automotive muffler. The following results were obtained with this study. From the frequency analysis of automotive muffler, high noise distribution was observed in the range $100{\sim}2000Hz$. It means that the noise in this range has an dominate influence for the overall noise. Noise reduction of automotive muffler was affected by the temperature of annulus. It is caused the result that the high temperature and pressure of exhaust gas are changed lower by the drop of annulus temperature. The tendencies of noise, the temperature and pressure of exhaust gas are similar to the performance curve of engine. Exhaust gas pressure is determined by the r.p.m. of engine and affected by the cooling performance of automotive muffler.

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Effects of Engine Control Variables on Exhaust Gas Temperature and Stability during Cranking Operation of an SI Engine (가솔린기관의 시동시 기관 제어변수가 배기가스온도 및 시동성에 미치는 영향에 관한 실험적 연구)

  • Cho, Yong-Seok;An, Jae-Won;Park, Young-Joon;Kim, Duk-Sang;Lee, Seang-Wock
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.1
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    • pp.64-70
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    • 2007
  • Raising exhaust gas temperature during cold-start period is very crucial to improve emission performance of SI engines because it enhances the performance of catalyst in the early stage of engine start. In this study, control variables such as ignition timing, idle speed actuator(ISA) opening and fuel injection duration were extensively investigated to analyze variations in exhaust gas temperature and engine stability during cranking period. Experimental results showed that spark timing affected engine stability and exhaust gas temperature but the effects were small. On the other hand, shortened injection duration and increased ISA opening led to a significant increase in exhaust gas temperature. Under such conditions, increase in cranking time was also observed, showing that it becomes harder to start the engine. Based on these observations, a pseudo fuel-air ratio, defined as a ratio of fuel injection time to degree of ISA opening, was introduced to analyze the experimental results. In general, decrease in pseudo fuel-air ratio raised exhaust gas temperature with the cost of stable and fast cranking. On the contrary, an optimal range of the pseudo fuel-air ratio was found to be between 0.3 to 0.5 where higher exhaust gas temperatures can be obtained without sacrificing the engine stability.

Performance and Emission Characteristics in a Spark-Ignition LPG Engine with Exhaust Gas Recirculation (EGR 장착 스파크 점화 LPG 엔진의 성능 및 배기특성)

  • 조윤호;구준모;장진영;배충식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.1
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    • pp.24-31
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    • 2002
  • An experimental study was conducted to investigate the effects of EGR (Exhaust Gas Recirculation) variables on performance and emission characteristics in a 2-liter 4-cylinder spark-ignition LPG fuelled engine. The effects of EGR on the reduction of thermal loading at exhaust manifold were also investigated because the reduced gas temperature is desirable for the reliability of an engine in light of both thermal efficiency and material issue of exhaust manifold. The steady-state tests show that the brake thermal efficiency increased and the brake specific fuel consumption decreased with the increase of EGR rate in hot EGR and with the decrease of EGR temperature in case of cooled EGR, while the stable combustion was maintained. The increase of EGR rate or the decrease of EGR temperature results in the reduction of NOx emission even in the increase of HC emission. Furthermore, decreasing EGR temperature by $180^{\circ}C$ enabled the reduction of exhaust gas temperature by $15^{\circ}C$ in cooled EGR test at 1600rpm/370kPa BMEP operation, and consequently the reduction of thermal load at exhaust. The optimization strategy of EGR application is to be discussed by the investigation on the effect of geometrical characteristics of EGR-supplying pipe line.

Study on Shortening Light-Off Time of Three Way Catalyst and Reduction of Harmful Emissions with Exhaust Synthetic Gas Injection(ESGI) Technology during Cold Start of SI Engines (가솔린 기관의 냉간시동 조건에서 합성가스 배기분사 기술에 의한 촉매의 활성화 온도 도달시간 단축 및 유해배출물 저감에 관한 연구)

  • Cho, Yong-Seok;Lee, Seang-Wock;Won, Sang-Yeon;Song, Chun-Sub;Park, Young-Joon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.3
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    • pp.94-101
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    • 2008
  • Since regulations of exhaust emissions are continuously reinforced, studies to reduce harmful emissions during the cold start period of SI engines have been carried out very extensively worldwide. During the cold start period, raising the temperature of cold exhaust gas is a key strategy to minimize the light-off time of three way catalysts. In this study, a synthetic gas containing a large amount of hydrogen was injected into the exhaust manifold to raise the exhaust gas temperature and to reduce harmful emissions. The authors tried to evaluate changes in exhaust gas temperature and harmful emissions through controlling the engine operating parameters such as ignition timings and lambda values. Also the authors investigated both combustion stability and reduction of harmful emissions. Experimental results showed that combustion of the synthetic gas in the exhaust manifold is a very effective way for solving the problems of harmful emissions and light-off time. The results also showed that the strategy of retarded ignition timings and increased air/fuel ratios with ESGI is effective in raising exhaust gas temperature and reducing harmful emissions. Futhermore, the results showed that engine operating parameters ought to be controlled to lambda = 1.2 and ignition timing = $0{\sim}3^{\circ}$ conditions to reduce harmful emissions effectively under stable combustion conditions.

A Numerical Study on Flow around Exhaust Ducts of Flue Gas from Apartment Heating Boiler (공동주택 보일러 연소배기가스의 실내유입에 관한 수치적 연구)

  • 박외철;정락기
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.7
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    • pp.557-562
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    • 2003
  • Flue gas from apartment heating gas boiler is exhausted outside through an exhaust duct mounted horizontally in a vertical row on the wall. The flue gas includes nitrogen-oxides (NOx) and carbon monoxide. To investigate the possible entrainment of the flue gas into the apartments through the windows, a large eddy simulation (LES) based numerical method is utilized. Distribution of the velocity intensity and temperature around the exhaust ducts is presented for three numerical parameters: exhaust velocity, temperature of the flue gas, and exhaust duct length. The flow field visualized with particles inserted at the ends of the ducts is also presented. The results clearly show that the exhausted flue gas may flow into the apartments when the windows are open.

Funnel Design Guidance (Funnel 설계 권고안)

  • Jeong, Wang-Jo;Cho, Won-Ho;Kang, Dae-Youl;Kim, Seung-Hyuk
    • Special Issue of the Society of Naval Architects of Korea
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    • pp.59-64
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    • 2006
  • Most important factor to consider funnel performance is exhaust gas temperature and exhaust gas concentration Electric equipments on the wheelhouse top affected exhaust gas temperature. So, it is important that electric equipments keep away from high temperature. Though exhaust gas concentration is not a regulation and restraint, the exhaust 9as can cause serious problems for the on-board air quality and result in irreversible damage to the ship and people. So, we pocus on the exhaust gas concentration also. When judge whether a measured concentration is acceptable or not, criteria based on the LTEL (Long Term Exposure Limit). In this paper, we carried out the smoke simulation study. For this analysis, we used FLUENT which is commercial CFD (Computational Fluid Dynamics) code.

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