• Title/Summary/Keyword: NOx Level

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Effects of Each Characteristics on NOx Emission Values for Marine 4-Stroke Diesel Engine (선박용 디젤기관(4-Stroke)의 특정인자가 질소산화물에 미치는 영향 고찰)

  • Lee, J.W.;Kwon, O.S.;Kim, J.T.;Lee, B.W.
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2005.06a
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    • pp.74-80
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    • 2005
  • It becomes necessary for engine manufactures to verify whether lots of engines on test bed during shop test are in compliance with NOx Technical Code for marine diesel engines more efficiently on the basis of engine group test concept which contains parent engine and member engines since all the engines are not needed to take NOx measurement. In addition, it becomes more obliged to consider parameters which affect NOx emission level and describe these parameters in NOx technical file as engine information and settings to define engine operation range with tolerance to make sure the engines are still in compliance with NOx emission limit on board after shop test. During preparation of engine group test for 4-stroke marine diesel engines, we evaluated NOx emission value under different engine operating conditions and found that there are certain parameters, for example, Charge air temperature and Max. cylinder pressure which have influence on NOx emission level. The NOx emission shall be satisfied with NOx technical code by means of controlling such parameters.

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INFLUENCE OF OPERATION PATTERNS OF LIGHT-DUTY FREIGHT VEHICLES ON NOx POLLUTION AT LOCAL ROADSIDES

  • Saito, A.;Ueki, S.;Takada, Y.
    • International Journal of Automotive Technology
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    • v.7 no.3
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    • pp.269-276
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    • 2006
  • Running tests on roads were conducted to clarify the influences of road infrastructure, traffic condition and vehicle's emission level to the amount of emission at local roadsides, and to reveal the operation patterns which can reduce the emission peaks. NOx emission peaks of two light duty freight diesel vehicles which have different emission levels were evaluated by using an on-board measurement system. Tests were carried out with various payload conditions and road conditions. As a result many NOx emission peaks were observed when the vehicles were starting or accelerating at intersections. The test vehicle which has higher emission level caused higher frequency and level of NOx emission peaks. Shifting up at lower engine speed in combination with lower acceleration brought out not only reduction of NOx emission peaks level but also of $CO_2$ mass emission.

Combustion characteristics of coaxial diffusion flame with preheated air temperature and dilution level (예열공기온도와 희석비율에 따른 동축 확산 화염의 연소 특성)

  • Kim, Jin-Sik;Kwark, Ji-Hyun;Jeon, Chung-Hwan;Chang, Young-June
    • 한국연소학회:학술대회논문집
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    • 2001.11a
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    • pp.51-56
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    • 2001
  • An experiment using preheated air in the coaxial diffusion flame burner was carried out in order to decrease NOx emission and improve the thermal efficiency. Preheated air combustion generally produces high NOx emissions but it was known very well to reduce NOx emission by diluting the combustion air with inert gas in preheated air combustion. In our study, $N_2$ gas was used for diluent and propane was utilized for fuel. We set the combustion air temperature on 300K, 500K, 700K, 900K and dilution level from 21% to 10% in terms of oxygen concentration. NOx emission increased along increment of combustion air temperature and decreased along increment of dilution level(lowering of oxygen concentration in combustion air). Flame-off limit with dilution level enhanced, flame length became longer and the location of maximum flame temperature became lower with increasing of combustion air temperature.

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A Study on the Method of NOx Reduction and NOx Measurement for the Diesel Engines (디젤기관의 NOx 저감방법 및 NOx 측정에 관한 연구)

  • 남정길;김준효;최주열
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2002.05a
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    • pp.193-199
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    • 2002
  • According to the NOx level requirement of annex Vl to IMO(International Maritime Organization) MARPOL 73/78, this regulation shall apply to each diesel engine with a power output of more than 130 ㎾ which is installed on a ship constructed and undergoes a major conversion on or after 1 January 2000. It is inevitable to adopt IMO standard for marine engines. Therefore, most of diesel engines which are being currently built should be tested and surveyed in accordance with the NOx technical code. In this study, various technics of NOx reduction methods were investigated for the diesel engines and the methods of NOx measuring were introduced by the new and simplified field detecting equipment. These results can be utilized for the basic design and developement of diesel engine for NOx reduction.

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Development of High Efficiency and Low Pollutant Cogeneration Hybrid System (고효율 저공해 열병합발전 하이브리드 시스템 개발)

  • Choi, Jae-Joon;Kim, Hyouck-Ju;Chung, Dae-Hun;Park, Hwa-Choon
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.1031-1035
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    • 2008
  • The importance of the more efficient cogeneration system is emphasized. Also the more clean energy is needed at recent energy system. The cogeneration system using Lean burn engine is more preferred to the system using Rich burn engine because of the electrical efficiency. Although the cogeneration system using Lean burn engine is economically preferred, because of the NOx emission level, the system using Rich burn engine with 3-way catalyst can only be used in Korea. The NOx regulation level is 50ppm at oxygen level 13%. The cogeneration hybrid system is consist of Lean burn gas engine, afterburner, boiler, economizer, DeNOx catalyst, combustion catalyst, absorption chiller, cooling tower and grid connection system. The system was accurately evaluated and the result is following ; 90% total efficiency, below 10ppm NOx, 50ppm CO, 25ppm UHC. The cogeneration hybrid system can meet the NOx level and exhaust gas regulation. It can achieve the clean combustion gas and efficient cogeneration system.

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DIESEL ENGINE NOx REDUCTION BY SNCR UNDER SIMULATED FLOW REACTOR CONDITIONS

  • Nam, Chang-Mo;Kwon, Gi-Hong;Mok, Young-Sun
    • Environmental Engineering Research
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    • v.11 no.3
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    • pp.149-155
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    • 2006
  • NOx reduction experiments were conducted by direct injection of urea into a diesel fueled, combustion-driven flow reactor which simulated a single engine cylinder ($966cm^3$). NOx reduction tests were carried out over a wide range of air/fuel ratios (A/F=20-40) using an initial NOx level of 530ppm, and for normalized stoichiometric ratios of reductant to NOx (NSR) of 1.5 to 4.0. The results show that effective NOx reduction with urea occurred over an injection temperature range of 1100 to 1350K. NOx reduction increased with increasing NSR values, and about a 40%-60% reduction of NOx was achieved with NSR=1.5-4.0. Most of the NOx reduction occurred within the cylinder and head section (residence time <40msec), since temperatures in the exhaust pipe were too low for additional NOx reduction. Relatively low NOx reduction is believed to be due to the existence of higher levels of CO and unburned hydrocarbons (UHC)inside the cylinder, and large temperature drops along the reactor. Injection of secondary combustible additives (diesel fuel/$C_2H_6$) into the exhaust pipe promoted further substantial NOx reduction (5%-30%) without shifting the temperature windows. Diesel fuel was found to enhance NOx reduction more than $C_2H_6$, and finally practical implications are further discussed.

Experimental Investigation on DeNOx Performance according to the Urea-SCR System Control at Various Operating Conditions for Diesel Engines (디젤엔진의 운전조건 변화 및 Urea-SCR 시스템 제어에 따른 DeNOx 성능에 대한 실험적 연구)

  • Han, Jung-Won;Gong, Ho-Jeong;Hwang, In-Goo;Myung, Cha-Lee;Park, Sim-Soo
    • Transactions of the Korean Society of Automotive Engineers
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    • v.18 no.6
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    • pp.76-83
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    • 2010
  • Recently, as the current and future emission regulations go stringent, the research of NOx reduction has become a subject of increasing interest and attention in diesel engine. Selective Catalytic Reduction (SCR) is one of the effective technology to reduce NOx emission from diesel engine. Especially, Urea-SCR that uses urea as a reductant is becoming increasingly popular as a cost effective way of reducing NOx emissions from heavy duty vehicles. In this research, we designed urea injector and DCU (Dosing Control Unit) specially developed for controlling the Urea-SCR process onboard vehicles. As passenger and commercial diesel engine experiment, we grasped characteristics of NOx emission and SCR catalyst temperature level in advance. As a result, highest NOx emission level was shown in condition of low engine speed and high load. On the other hand, SCR catalyst temperature was highest at high engine speed and load. On the basis of these result, we conducted the NOx reduction test at steady engine operating conditions using the urea injector and DCU. It was shown that 74% NOx conversion efficiency on the average and 97% NOx conversion efficiency was obtained at high SCR catalyst temperature.

Combustion Characteristics and Application of Cyclon Combustor

  • Chae, J.O.;Xu, F.Z.;Yu, J.;Moon, S.I.;Kim, K.Y.
    • 한국연소학회:학술대회논문집
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    • 2001.06a
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    • pp.82-89
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    • 2001
  • This paper concerns lean gas cyclone combustion system adopting distributed inlets with different velocity to promote ignition and burnout properties. Detailed temperature measurements have been achieved under different operating conditions and flue gas compositions and NOx have been measured. Experimental results show that cyclone combustor provided increasing combustion stability and reduction NOx emission level to negligible level.

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A Study on Low-NOx Combustion in an Oil Burner for an Industrial Boiler (산업 보일러용 오일버너에서의 저 NOx 연소 연구)

  • Shin, Myung-Chul;Kim, Se-Won;Park, Ju-Won;Bang, Byeong-Ryeol;Yang, Won;Go, Young-Gun
    • Journal of the Korean Society of Combustion
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    • v.14 no.1
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    • pp.19-24
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    • 2009
  • A novel low NOx oil burner of 0.7 MW (for a 1 ton steam/hr industrial boiler) was designed and tested to investigate the combustion characteristics through in-flame measurement and flue gas analysis. Flame shape was observed by CCD camera and $CH^*/{C_2}^*$ radical distribution in the flame were observed, along with measurement of flue gas composition such as NOx and CO, for various heat inputs, excess airs and pressure of the fuel spary nozzles. The flame showed the two-zone structure: fuel-rich and fuel-lean zone, which was very favorable for the low-NOx combustion, and the NOx emission for haevy oil combustion was significantly reduced to < 150 ppm at 4 % $O_2$, compared with the NOx level of a conventional heavy oil burner.

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NOx Reduction in the $10MW_{e}$ Power Boiler by Combustion Improvement (연소개선에 의한 $10MW_{e}$급 발전용 보일러의 NOx 저감)

  • Kim, Tai-Hyeung;Kim, Sung-Chul;Ahn, Kook-Young;Hong, Sung-Sun
    • 한국연소학회:학술대회논문집
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    • 2000.05a
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    • pp.26-34
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    • 2000
  • Geometry change of burner nozzle has influence on fuel atomizing and combustion characteristics. NOx reduction technologies can be divided into two method; Before combustion method(NOx treatment of fuel) and After combustion method(NOx treatment of flue gas). In this study, experiments are carried out using difference nozzle and combustion condition change to reduce NOx in heavy oil fired thermal utility boiler. These methods have advantage like easy application and low installation cost. By this method NOx can be reduced by 18% and maintain CO emission level.

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