• 제목/요약/키워드: DME(Dimethyl ether)

검색결과 157건 처리시간 0.023초

DME 연료의 증발, 점화 및 분무연소특성 해석 (Numerical Modeling for Vaporization, Auto-Ignition and Combustion Processes of Dimethyl Ether (DME) Fuel Sprays)

  • 유용욱;이정원;김용모
    • 한국연소학회지
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    • 제12권3호
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    • pp.33-39
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    • 2007
  • The present study is mainly motivated to investigate the vaporization, auto-ignition and combustion processes in high-pressure engine conditions. In order to realistically simulate the dimethyl ether (DME) spray dynamics and vaporization characteristics in high-pressure and high-temperature environment, the high-pressure vaporization model is utilized. The interaction between chemistry and turbulence is treated by employing the Representative Interaction Flamelet (RIF) model. The detailed chemistry of 336 elementary steps and 78 chemical species is used for the DME/air reaction. Numerical results indicate that the RIF approach, together with the high-pressure vaporization model, successfully predicts the essential feature of ignition and spray combustion processes.

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DME 연료의 점화 및 연소특성 해석 (Numerical Modeling for Auto-Ignition and Combustion Processes of Dimethyl Ether (DME) Fuel Sprays)

  • 이정원;류연숙;김용모
    • 한국분무공학회지
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    • 제10권4호
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    • pp.16-25
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    • 2005
  • The present study is mainly motivated to investigate the vaporization, auto-ignition and combustion processes in high-pressure engine conditions. In order to realistically simulate the dimethyl ether (DME) spray dynamics and vaporization characteristics in high-pressure and high-temperature environment, the high-pressure vaporization model is utilized. The interaction between chemistry and turbulence is treated by employing the Representative Interaction Flamelet(RIF) model. The detailed chemistry of 336 elementary steps and 78 chemical species is used for the DME/air reaction. Numerical results indicate that the RIF approach, together with the high-pressure vaporization model, successfully predicts the essential feature of ignition and spray combustion processes.

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COMBUSTION AND EMISSION CHARACTERISTICS OF A TURBOCHARGED DIESEL ENGINE FUELLED WITH DIMETHYL ETHER

  • Wu, J.;Huang, Z.;Qiao, X.;Lu, J.;Zhang, L.;Zhang, J.
    • International Journal of Automotive Technology
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    • 제7권6호
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    • pp.645-652
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    • 2006
  • This paper is concerned with an experimental study of a turbocharged diesel engine operating on dimethyl ether(DME). The combustion and emission characteristics of DME engine were investigated. The results showed that the maximum torque and power with DME could achieve a greater level compared to diesel operation, particularly at low speeds; the brake specific fuel consumption with DME was lower than the diesel at low and middle engine speeds. The injection delay of DME was longer than that of diesel. However, the maximum cylinder pressure, maximum pressure rise rate and combustion noises of DME engine were lower than those of diesel. The combustion velocity of DME was faster than that of diesel, resulting in a shorter combustion duration of DME. Compared with the diesel engine, $NO_x$ emissions of the DME engine were reduced by 41.6% on ESC data. The DME engine was smoke free at all operating points of the engine.

Dimethyl Ether와 디젤의 거시적 분무 특성 비교 (Comparison of Macroscopic Spray Characteristics of Dimethyl Ether with Diesel)

  • 유준;이주광;배충식
    • 한국자동차공학회논문집
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    • 제10권5호
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    • pp.73-80
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    • 2002
  • Dimethyl ether (DM) is one of the most attractive alternative fuel far compression ignition engine. Its main advantage in diesel engine application is high efficiency of diesel cycle with soot free combustion though conventional fuel injection system has to be modified due to the intrinsic properties of DME. Experimental study of DME and conventional diesel spray employing a common-rail type fuel injection system with a 5-holes sac type injector (hole diameter 0.168 ㎜/hole) was performed in a high pressure chamber pressurized with nitrogen gas. A CCD camera was employed to capture time series of spray images followed by spray cone angles and penetrations of DME were characterized and compared with those of diesel. Under atmospheric pressure condition, regardless of injection pressure, spray cone angles of the DME were wider than those of diesel and penetrations were shorter due to flash boiling effect. Tip of the DME spray was farmed in mushroom like shape at atmospheric chamber pressure but it was disappeared in higher chamber pressure. On the contrary, spray characteristics of the DME became similar to that of diesel under 3MPa of chamber pressure. Hole-to-hole variation of the DME spray was lower than that of diesel in both atmospheric and 3MPa chamber pressures. At 25MPa and 40MPa of DME injection pressures, regardless of chamber pressure, intermittent DME spray was observed. It was thought that vapor lock inside the injector was generated under the two injection pressures.

Catalytic Dehydration of Methanol to Dimethyl Ether (DME) over Solid-Acid Catalysts

  • Jun, Ki-Won;Lee, Hye-Soon;Rho, Hyun-Seog;Park, Sang-Eon
    • Bulletin of the Korean Chemical Society
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    • 제23권6호
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    • pp.803-807
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    • 2002
  • The conversion of dimethyl ether(DME) has been carried out over $\gamma-alumina$, silica-alumina, and modified $\gamma-aluminal$ catalysts. Especially, the water effect has been investigated on purpose to develop a suitable catalyst for one-step synthesis of DME from $CO_2$ hydrgenation, The $\gamma-Al_2O_3$ modified with 1 wt% silica is more active and less deactivated by water than unmodified one. $CO_2has$ no effect on catalytic dehydration of methanol to DME.

수소 에너지 밀도가 높은 디메틸에테르(DME) 제조 촉매에 관한 연구 (A Study on the Catalyst for the Synthesis of DME with Hydrogen Energy Density)

  • 장은미;백영순;오영삼
    • 한국수소및신에너지학회논문집
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    • 제19권5호
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    • pp.445-452
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    • 2008
  • DME(Dimethyl ether) Dimethyl Ether (DME) is a new clean fuel and an environmental-benign energy resource. In comparison with other fuels, DME rapidly decomposes into carbon dioxide ($CO_2$) and water in the atmosphere without forming ozone. It can be manufactured from various energy sources including natural gas, coal, biomass and spent plastics. In addition to its environmentally friendly properties, DME is considered as one of the most promising candidates for the substitute of LPG and diesel fuel. In this work, we will be studied to find optimized condition for the catalyst of DME energy manufacture from hydrogen and carbon oxide and its chemical and physical characteristics.

순수 DME의 직접분사식 디젤기관의 성능 및 배기가스 특성 (Engine Performance and Exhaust Emissions Characteristics of DI Diesel Engine Operated with Neat Dimethyl Ether)

  • 표영덕;이영재;김강출;김문헌
    • 대한기계학회논문집B
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    • 제27권5호
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    • pp.589-595
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    • 2003
  • DME(Dimethyl ether) is an oxygenated fuel with a octane number higher than that of diesel oil. It meets the ULEV emission regulation and reduces the smoke to almost zero when used in a diesel engine. In the present study, engine performance and exhaust emissions were investigated with a conventional DI diesel engine which has a jerk type injection pump. Test results showed that the power with DME were almost same as that of pure diesel oil, and the brake thermal efficiency increased a little. Also, smoke index from DME engine showed nearly zero level, but NO$_{x}$ was increased compare to diesel oil.

디메틸에테르 연료를 사용하는 3.3리터 디젤기관의 배기성능 개선 (Improvement of Emission Performance in a 3.3 Liter DI Diesel Engine by Using Dimethyl Ether Fuel)

  • 표영덕;이영재;김문헌
    • 한국자동차공학회논문집
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    • 제15권4호
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    • pp.178-185
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    • 2007
  • A study is improvement of power and emission in a inline-pump Dr diesel engine by using Dimethyl ether Fuel. Dimethyl ether (DME) is an oxygenated fuel with a cetane number higher than that of diesel oil. It meets the ULEV emission regulation and reduces the smoke to almost zero when used in a diesel engine. But NOx emission is almost same and CO, THC emissions are lower than that of diesel engine. The emissions aren't satisfied the stronger emission regulation in the further. Generally DOC (Diesel Oxidation Catalyst) is used to reduce CO & THC emissions and EGR (Exhaust Gas Recirculation) system is used to reduce NOx emission. Test results showed that the torque and the power with DME were almost same as those of pure diesel oil, but the brake thermal efficiency increased a little. also the BSEC (Brake Specific Energy Consumption) with DME was similar that of diesel. The test results showed that the DOC was the vary effective method to reduce the CO emission in case of Dimethyl Ether Fuel in diesel engine. But, THC emission is showed a little reduction rates. Also EGR system was the very effective method to reduce the NOx emission in case of Dimethyl Ether Fuel in diesel engine.

SAPO-34 촉매상에서 디메틸에테르로부터 경질올레핀 제조 및 물의 첨가 효과 (Effect of Water Addition on the Conversion of Dimethyl Ether to Light Olefins over SAPO-34)

  • 백승찬;이윤조;전기원
    • Korean Chemical Engineering Research
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    • 제44권4호
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    • pp.345-349
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    • 2006
  • SAPO-34 촉매상에서 DME(dimethyl ether) 또는 메탄올로부터 경질 올레핀(에틸렌, 프로필렌, 부텐)을 제조하는 반응을 수행하여, 각각의 올레핀들과 CO, $CO_2$와 같은 부 생성물의 수율을 반응온도와 시간의 흐름에 따라 비교해서 관찰하였다. DME 전환반응은 메탄올 전환반응과 비교하여 볼 때 촉매의 비활성화가 급격히 진행되었다. 물을 첨가할 경우, 올레핀의 수율을 증가와 함께 코크 생성에 의한 촉매의 비활성화가 감소하여 촉매의 수명이 길어짐을 확인하였다.

DME 예혼합 압축착화 엔진에서 다단분사를 통한 연료 성층화 (Fuel stratification by multiple injection in DME HCCI engine combustion)

  • 윤현숙;배충식
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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    • pp.311-312
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    • 2012
  • Homogeneous charge compression ignition combustion with multiple-injection strategy using dimethyl-ether was investigated in a single cylinder direct-injection compression-ignition engine. The combustion performance and exhaust emissions were tested by varying the post injection conditions. The experiments were carried out under low load and low speed conditions. By the late post injection near the top dead center, the combustion phase was retarded and lengthened, and the fuel conversion efficiencies improved without the drawbacks of exhaust emissions increment.

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