• Title/Summary/Keyword: Particulate flow

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Experiment study on hydrogen-rich gas generation using non-thermal plasma (저온 플라즈마를 이용한 과 수소가스 발생에 관한 실험적 연구)

  • Wang, Hui;Wei, Wei;Zheng, MengLei;Chae, Jae-Ou;Yu, Guang-Xun
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2918-2922
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    • 2007
  • This is a report of a feasibility study on the reduction of harmful substances such as particulate matters and nitric oxides emitted from diesel engines by using a plasma reforming system that can generate hydrogen-rich gas. In this paper, an exhaust reduction mechanism of the non-thermal plasma reaction was investigated to perform its efficiency and characteristics on producing hydrogen-rich gas. Firstly, we explain briefly the chemistry of hydrocarbon reforming. The experimental system is showed in the second part. Finally, we demonstrate the feasibility of producing hydrogen using non-thermal plasma. The experimental results are focused on the influence of the different operating parameters (air ratio, inlet flow rates, voltage) on the reformer efficiency and the composition of the produced gas.

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Flow Analysis of Yellow Dust Multi-Layer Mask for Maximization of Filtration Area (여과면적이 극대화된 황사용 주름마스크의 유동해석)

  • Jang, Sung-Cheol;Kim, Han-Joo
    • Journal of the Korean Society of Industry Convergence
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    • v.20 no.4
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    • pp.339-343
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    • 2017
  • Masks are a portable functional product for daily use. They can protect user health by filtering harmful fine particles in the air. In the past decade, there have been approximately 10 yellow dust incidences per year, amounting to a total duration of 20 days, and they continue to increase year after year. In addition, the frequency of yellow dust incidences in Korea has increased by more than four times compared to levels from the 1970s. Statistical reports indicate that annual damages caused by yellow dust amount to more than six trillion KRW. This study developed a zero-fog multi-layer mask with a collection efficiency and yellow dust and particulate matter filtration areas that are at least thrice as effective as existing masks. The new mask also reduces pressure drag by half.

Basic Performance Characteristics of HCCI (Homogeneous Charge Compression Ignition) Engine

  • Choi Gyeung Ho;Chung Yon Jong;Kim Ji Moon;Dibbler Robert W.;Han Sung Bin
    • Journal of Energy Engineering
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    • v.14 no.4 s.44
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    • pp.226-231
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    • 2005
  • Essentially combination of spark ignition and compression ignition engines, the HCCI engine exhibits low NOx and Particulate Matter (PM) emissions as well as high efficiency under part load. This paper is concerned with the Homogeneous Charge Compression Ignition (HCCI) engine as a new concept in engines and a power source for future automotive applications. In this research, a 4 cylinder diesel engine was converted into a HCCI engine, and propane was used as the fuel. The purpose of this research is to show the effects of fuel flow rate and the temperature of the intake manifold on the performance and exhaust of an HCCI engine.

Experimental and Finite Difference Method(FDM) Analysis on Collection Characteristics of Electrostatic Precipitator (전기집지기 집진특성 실험 및 유한차분해석에 관한 연구)

  • 김용진;홍원석;최헌오;함병훈;민춘식;유기선
    • Journal of Korean Society for Atmospheric Environment
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    • v.10 no.1
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    • pp.49-56
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    • 1994
  • Electrostatic Precipitators( EP ) are widely used in industry for controlling the emission of particulate pollutant Recently, a number of researches have been conducted to solve performance and reliability problems of EP, As a result of researches in the laboratory and of pilot scale, a technology of wide-pitch-spacing has been successfully applied to full scale units. It has been known that the wide-pitch-spacing can reduce the capital cost of newly installed precipitators, and the cost of rebuilding existing uints. In this paper, a systematic study was performed to develop a wide-pitch electrostatic precipitator. The study includes experimental and numerical work on the following : Particle collection characteristics for a bench-scale unit; gas flow characteristics( temperature and velocity distributions): other EP operating variables such as electric Power supply/control. The results are applied directly to design of wide-pitch-spacing EP and the developed numerical model was found to be a good argreement with the experimental results. The EHD simulation program is necessary to design the high efficiency EP.

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Oxidation of Soot Particles with O Radicals Generated in a AC Streamer Corona Discharge (AC 스트리머 코로나 방전으로 생성된 O 라디칼과 매연 입자의 산화반응)

  • Kim, Pil-Seung;Lee, Kyo-Seung;Hwang, Jung-Ho
    • Journal of the Korean Society of Combustion
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    • v.8 no.1
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    • pp.9-16
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    • 2003
  • Carbon soot emission from combustion processes, especially from diesel engines, is a subject of growing concern since soot is known to seriously affect human health. Efforts have been made to oxidize soot particles utilizing Non-Thermal Plasma(NTP) techniques. When oxygen is carried into a plasma device, electrons generated by the plasma dissociate the oxygen, resulting in the formation of oxygen atoms. These highly activated atoms, called O radicals, are known as strong oxidizing agent. This paper presents concentration variations of CO and $CO_2$ at the exit of the plasma device, resulting from the soot oxidation by O radicals, with variations of inlet oxygen concentration, gas temperature, and gas flow rate. Based on the data, Arrehenious rate constants of reactions between C(s)+O and C(s)+O+O were proposed.

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EXPERIMENTAL STUDY ON HOMOGENEOUS CHARGE COMPRESSION IGNITION ENGINE OPERATION WITH EXHAUST GAS RECIRCULATION

  • Choi, G.H.;Han, S.B.;Dibble, R.W.
    • International Journal of Automotive Technology
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    • v.5 no.3
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    • pp.195-200
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    • 2004
  • This paper is concerned with the Homogeneous Charge Compression Ignition (HCCI) engine as a new concept in engines and a power source for future automotive applications. Essentially a combination of spark ignition and compression ignition engines, the HCCI engine exhibits low NOx and Particulate Matter (PM) emissions as well as high efficiency under part load. The objective of this research is to determine the effects of Exhaust Gas Recirculation (EGR) rate on the combustion processes of HCCI. For this purpose, a 4-cylinder, compression ignition engine was converted into a HCCI engine, and a heating device was installed to raise the temperature of the intake air and also to make it more consistent. In addition, a pressure sensor was inserted into each of the cylinders to investigate the differences in characteristics among the cylinders.

Fouling Analyses of Heat Exchangers for PSR (주기적안전성평가를 위한 원전 열교환기 Fouling 평가)

  • Hwang, K.M.;Jin, T.E.;Han, S.G.;Kim, B.S.
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1467-1472
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    • 2003
  • Fouling of heat exchangers is generated by water-borne deposits, commonly known as foulants including particulate matter from the air, migrated corrosion produces; silt, clays, and sand suspended in water; organic contaminants; and boron based deposits in plants. This fouling is known to interfere with normal flow characteristics and reduce thermal efficiencies of heat exchangers. This paper focuses on fouling analyses for six heat exchangers of two primary systems in two nuclear power plants; the regenerative heat exchangers of the chemical and volume control system and the component cooling water heat exchangers of the component cooling water system. To analyze the fouling for heat exchangers, fouling factor was introduced based on the ASME O&M codes and TEMA standards. Based on the results of the fouling analyses, the present thermal performances and fouling levels for the six heat exchangers were predicted.

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Riser Design Approach for Particle-Circulation-Type Heat Exchangers (입자 순환식 열교환기의 상승관 설계방법)

  • Jun Yong-Du
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.311-312
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    • 2002
  • In this paper a systematic design approach to determine the optimum size (height) of circulating fluidized bed heat exchanger for exhaust gas heat recovery is prososed. Unlike the convensional heat exchangers where the length of the heat exchanger section is not very much emphasized, the vertical length of heat exchanger tube in the case of fluidized bed heat exchangers is important because this length determines the time interval during which particles reside and transfer heat in the heat exchanger section. For particles initial conditions are nearly stationary, accelerating particles motion should be considered rather than simply assuming fully developed condition. A way to estimate optimum tube length at different fluid velocity and particle sizes is suggested based on the required conditioning time for heat transfer from the flue gas to solid particles.

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Multi-Step Reheating Process of Metal Matrix Composites for Thixoforming (Thixoforming을 위한 금속 복합재료의 다단 재가열 공정)

  • 허재찬;강충길
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.180-183
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    • 1997
  • The forming process of metal matrix composites by the die casting and squeeze casting process are limited in size and dimension in term of final parts without machining. The thixoforming process for metal matrix composites has numerous advantages compared to die casting, squeeze casting and compocasting. The characteristics of thixoforming process can decrease the liquid segregation because of he improvement in fluidity in a globular microstructure state and utilizes flow without air entrapment. Therefore, in order to obtain the sound parts of metal matrix composites by using thixoforming process which as co-existing solidus-liquidus pahse, it si very important to obtain reheating condition. However, for he thixoforming process, the billet with the desired volume fraction must be heated to obtain a uniform temperature distribution over the entire cross-sectional areas. To obtain the reheating conditions of composites, the particulate reinforced metal matrix composites for thixoforming were fabricated by combined stirring process which is simultaneously performed with electro-magnetic stirring process which is simultaneously performed with electro-magnetic stirring and mechanical stirring process.

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