• 대한기계학회논문집B
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• 제28권4호
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• pp.389-394
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• 2004

An experimental study on the NOx formation of LNG flame in fuel staged combustor has been studied. The design concept of multi fuel/air staged combustor is creation of two separate flame, a primary flame is a act as a pilot flame for the secondary combustion stage combustion zone, where most of fuel bums. Experiments were performed on a semi-industrial scale (thermal input 0.233 MW) in a laboratory furnace and Liquefied Natural Gas(LNG) was used as a primary and secondary fuels. This study included parametric study to identify the optimum operating conditions which are primary/secondary fuel ratio, and primary/secondary air ratio for reducing NOx emission with two types of nozzle. The test demonstrated that NOx emission can be reduced by >70% in accordance with operating conditions.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.161-166
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• 2001

An Experimental study on the NOx formation of LNG flame in fuel staged combustor has been studied. The design concept of multi fuel/air staged combustor is creation of two separate flame, a primary flame is act as a pilot flame for the secondary combustion stage combustion zone, where most of fuel burns. Experiments were performed on a semi-industrial scale (thermal input 0.233 MW) in a laboratory furnace and Liquefied Natural Gas(LNG) was used as primary and secondary fuels. The study included parametric study to identify the optimum operating conditions which are primary/secondary fuel ratio, and primary/secondary air ratio for reducing NOx emission with two types of nozzle. The test demonstrated that NOx emission can be reduced by >70% in accordance with operating conditions.

• 대한기계학회논문집B
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• 제28권11호
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• pp.1339-1347
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• 2004

Development of the low NOx heating boiler was strongly asked due to severe air pollution and the large number of boilers in korea. Compactness of the commercial boiler was also important because of low manufacturing cost and easy installation. In this study. newly developed compact low NOx burner, using turbulent gas diffusion combustion with multi-staged air supplies and multiple fuel nozzles, was investigated. Comparison study of the new burner was performed between experimental results and computational analysis. Commercial computational fluid dynamic(CFD) program named CFX-5.6 was used for numerical analysis of the low NOx burner inside the test combustor. Comparisons of experiment data and numerical result were performed under various equivalence ratio and fuel flow rate.

• 수산해양기술연구
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• 제51권4호
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• pp.545-552
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• 2015

The main object of this study is to investigate the collection characteristics of an electro-static multi-staged impaction system, experimentally. The experiment is carried out to analyze the characteristics of pressure drop and collection efficiency for the present system with the experimental parameters such as the inlet velocity, stage number, applied voltage and shape of discharge electrode, etc. In results, the pressure drop is shown below $148mmH_2O$ lower than that of the conventional bag filter at inlet velocity 3.46 m/s and 5 stage. For 5 stage, the collection efficiencies are to be 97.4, 99.0% with the applied voltage 0 kV at the inlet velocity 2.07, 3.46 m/s, while 98.4, 99.9% with 40 kV of a sharp edge discharge electrode. Additionally, the present system is to be considered as an effective compact system for a removal of particulate pollutants from marine diesel engines due to much higher collection efficiency and appropriate pressure drop.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2018년도 전력전자학술대회
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• pp.446-447
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• 2018

본 연구에서는 조선소 대형 블록 도장시설에서 배출되는 VOCs 가스처리를 위하여, 조선소 도장공정 및 배출가스 특성에 대한 분석 결과를 바탕으로, 이에 적합한 배출가스 저감장치를 구성하여 제안하였다. 본 연구에 제안된 저감장치는 펄스전원장치를 이용한 MSC(Multi Stage Corona)시스템 및 활성탄 흡착 시스템으로, 가스 처리능력이 우수하고, 종전 기술 RTO(Regenerative Thermal Oxidizer)에 비해 더 안전하고, 운전비용 면에서도 우수한 것으로 나타났다.

• 수산해양기술연구
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• 제52권3호
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• pp.248-256
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• 2016

The main purpose of this paper was to analyze the removal characteristics of gas/particulate phase pollutants for the present system. Experimentally, we performed to estimate the pressure drop and air pollution removal efficiency with physical variables such as stage number, tube velocity, tube diameter, water spray ($NH_4OH$), and so on. It was concluded that the pressure drop was shown below $111mmH_2O$ lower than that of the existing scrubber (centrifugal spray chamber, over 200 mmAq) at inlet velocity 3.46 m/s and 5 stage. The particular removal efficiency of this system was to be significantly higher at 99.8% in comparison with that of the existing scrubber for 5 stage, inlet velocity 3.46 m/s and $NH_4OH$ (aq) 300 mL/min. It was estimated that the removal efficiencies of $SO_2$ and $NO_2$ were 80% and 70% at system inlet velocity 2.07 m/s and $NH_4OH$ (aq) 300 mL/min respectively. Additionally, the present collection system was to be considered as an effective compact system for simultaneous removal of air pollutants (gas/particulate) due to much higher removal efficiency and appropriate pressure drop without a demister.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제29회 KOSCI SYMPOSIUM 논문집
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• pp.238-243
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• 2004

High temperature air blown gasification is new concept to utilize the waste heat from gasifier that is called the multi-staged enthalpy extraction technology. This process was developed to solve the economic problem due to air separation cost for the oxygen-blown as a gasifiying agent. In this study, we have performed the construction of pebble bed gasifier and operated it by controlling the pebble size and bed height. As a result, we can produce the syngas with the calorific value of 700kcal/$Nm^3$ at the condition of air temperature 650$^{\circ}C$.

• 대한기계학회논문집
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• 제17권7호
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• pp.1813-1822
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• 1993

An algorithm of fuzzy variable structrue control is proposed to design a closed loop fuel-injection system for the emission control of automotive gasoline engines. Fuzzy control is combined with sliding control at the switching boundary layer to improve the chattering of the stoichiometric air to fuel ratio. Multi-staged fuzzy rules are introduced to improve the adaptiveness of control system for the various operating conditions of engines, and a simplified technique of fuzzy inference is also adopted to improve the computational efficiency based on nonfuzzy micro-processors. The proposed method provides an effective way of engine controller design due to its hybrid structure satisfying the requirements of robustness and stability. The great potential of the fuzzy variable structure control is shown through a hardware-testing with an Intel 80C186 processor for controller and a typical engine-only model on an AD-100 computer.

• 한국연소학회지
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• 제14권4호
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• pp.25-32
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• 2009

In commercial combustion systems, heavy oil is one of main hydrocarbon fuel because of its economical efficiency. Regarding heavy oil combustion, due to increasing concerns over environmental pollutants such as carbon monoxide, unburned hydrocarbon and nitrogen oxides, development of low pollutant emission methods has become an imminent issue for practical application to numerous combustion devices. Also a great amount of effort has been tried to developed effective methods for practical using of biomass. It is also an important issue to reduce carbon tax. In this paper, an experimental study has been conducted to evaluate the effect of biomass reburning on NOx formation in a heavy oil flamed combustion furnace. Experiments were performed in flames stabilized by a multi-staged burner, which was mounted at the front of the furnace. Experimental tests were conducted using air-carried rice husk powder and LNG as the reburn fuel and heavy oil as the main fuel. The paper reports data on flue gas emissions and temperature distribution in the furnace for several kinds of experimental conditions. NOx concentration in the exhaust has decreased considerably due to effect of reburning. The maximum NOx reduction rate was 62% when the rice husk was used by reburn fuel, however it was 59% when the LNG was used by reburn fuel. The result shows the positive possibility of biomass reburning system for optimal NOx reduction.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.840-843
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• 2002

The dry pulverizing/Mixing device is used to deal with the spent fuels for the safe disposal. The separated pellets from hulls by a slitting device are put and oxidized from UO$_2$ solid pellet to U$_3$O$\_$8/ powder in the device. The device have been developed based on a voloxidation method which is one of several dry de-cladding methods. We have benchmarked dry de-cladding methods, analyzed applicability to the advanced spent fuel management process, integrated and compared several configuration, and finally derived detailed specifications proper to requirements for the device. Also, thermal characteristics of the device such as thermal stress and strain have been analyzed by the commercial software, 1-DEAS, and the reliability of the results have been verified by the KOLAS(Korea Laboratory Accreditation Scheme). The UO$_2$ solid pellets are put in the device which has a capacity of 20 kgHM per a batch, heated up about 600$^{\circ}C$ in the air environment. Then, the UO$_2$ solid pellets are oxidized into the U$_3$O$\_$8/ powder, and the powder is collected in a special vessel. The device has been designed and developed as fellows: the multi-staged fine hole meshes are used to reduce the size of the powder gradually, heat and air(oxygen) are supplied continuously to reduce the reaction time, and slight vibration effect are applied to collect powder cling to the device.