• Title/Summary/Keyword: Be-NOx

Search Result 863, Processing Time 0.029 seconds

A Study on Numerical Analysis of Flow Uniformity According to Length and Degree Change of Mixed-Evaporator in 500 PS SCR Reactor (500 PS SCR 반응기 혼합증발관 길이와 각도 변화에 따른 유동균일도에 대한 수치해석적 연구)

  • Seong, Hongseok;Lee, Chungho;Suh, Jeongse
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.28 no.8
    • /
    • pp.337-342
    • /
    • 2016
  • A marine SCR System is emerging as an alternative to comply with NOx Tier III Emission standards, a restriction on greenhouse gas from vessels implemented by the International Maritime Organization. The system is greatly affected by the uniformity of the fluid flowing into the catalyst, so the performance of the catalyst of an SCR system needs to be guaranteed. This study conducted research on a mixed evaporator of an SCR system, which is one of the factors affecting the uniformity of the fluid. When the angle of the mixed evaporator is set to $90^{\circ}$, the fluid uniformity is at its highest at 83%, under the condition that the length of the mixed evaporator be 3.5 D. When the length was 3.5 D and less, the fluid uniformity had a tendency to improve relative to the case without a bent pipe. However, a longer mixed evaporator results in a more perfect liquidity development in the pipe with a liquidity distribution similar to the case where no curved pipe is formed in front of the catalyst. A lower angle for the mixed evaporator results in a lower flow uniformity, and a longer length of the mixed evaporator results in a lower difference in the flow uniformity caused by the angle. The flow uniformity can be improved by 6% with a mixed evaporator, which confirmed that all factors applied to an SCR system have a close relationship with the efficiency.

A study on the flow characteristics in a MILD combustion waste incinerator with the change of flue gas recirculation inlet location (MILD 연소 폐기물 소각로에서 배기가스 재순환 흡입구 위치에 따른 유동 특성 연구)

  • Ha, Ji Soo;Shim, Sung Hun;Jung, Eung Ho
    • Journal of Energy Engineering
    • /
    • v.23 no.3
    • /
    • pp.51-57
    • /
    • 2014
  • A MILD(Moderate and Intense Low oxygen Dilution) combustion, which is effective in the reduction of NOx, is considerably affected by the recirculation flow position of hot exhaust gas to the combustion furnace. A numerical analysis was accomplished to elucidate the flow characteristics in the MILD combustion incinerator for several cases with or without exhaust gas recirculation. It could be seen from the result of the present numerical study that the flow recirculation could be observed in the upper region over the vertical dividing wall for the case without exhaust gas recirculation. The optimal position of exhaust gas recirculation position was derived by the comparison of %RMS of x directional velocity for the cases with exhaust gas recirculation. The case with the exhaust gas recirculation position at the upper right of free board was the most effective with the smallest value of 57.4% RMS.

The Low $NO_{x}$ Characteristics of a Lean Premixed Gas Turbine Combustor (희박연소를 이용한 가스터빈 연소기의 저 $NO_{x}$ 특성)

  • Son, M.G.;Ahn, K.Y.;Kim, H.S.;Kim, Y.M.
    • Proceedings of the KSME Conference
    • /
    • 2001.06d
    • /
    • pp.66-70
    • /
    • 2001
  • The combustion characteristics have been investigated to develop the low $NO_{x}$ gas turbine combustor. The lean premixed combustion technology was applied to reduce the $NO_{x}$ emission. Also, the conventional combustor was designed and tested for the baseline of low $NO_{x}$ combustor performance. The test was conducted at the condition of high temperature and ambient pressure. The combustion air which has the temperature of 500K were supplied to the combustor through the air preheater. The temperature and emissions of $NO_{x}$ and CO were measured at the exit of combustor. The premixing chamber can be operated very lean condition of equivalence ratio around 0.35. The $NO_{x}$ was decreased with decreasing the equivalence ration. The CO was decreased with decreasing the equivalence ratio, but the CO was increased with decreasing the equivalence ratio below 0.45. But, at the very lean condition of equivalence ratio below 0.35 both NOx and CO were increased because of the flame unstability. The $NO_{x}$ was decreased slightly and CO was increased with increasing inlet air flowrate. This results can be used to determine the size of combustor. The low $NO_{x}$ combustor has lower values of $NO_{x}$ and CO compared with conventional one. Consequently the performance of combustor shows the possibility of the application to the gas turbine system.

  • PDF

Effect of Fuel/Air Mixing Quality on Temperature Characteristics in a Lean Premixed Model Gas Turbine (희박 예혼합 모형 가스터빈 내에서 연료/공기 혼합정도가 온도 특성에 미치는 영향)

  • Lee Jong Ho;Chang Young June;Jeon Chung Hwan
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • v.y2005m4
    • /
    • pp.274-280
    • /
    • 2005
  • Experimental investigations were carried out in an atmospheric pressure, optically accessible and laboratory-scale dump combustor. The objective of this study is to obtain the phase-resolved gas temperatures at different phases of the oscillating pressure cycle during unstable combustion. To see the effect of incomplete fuel-air mixing on phase-resolved temperature characteristics, CARS temperature measurements were performed. Results including phase-resolved averaged temperature, normalized standard deviation and temperature probability distribution functions (PDFs) were provided in this paper. It could be found that the profile of mean temperature showed the in-phase relationship with pressure cycle. Temperature PDFs give an insight on the flame behavior as well as NOx emission characteristics. These results would be expected to play an important role in better understanding of driving mechanisms and thermo-acoustic interactions.

  • PDF

Genetically Optimized Self-Organizing Polynomial Neural Networks (진화론적 최적 자기구성 다항식 뉴럴 네트워크)

  • 박호성;박병준;장성환;오성권
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.53 no.1
    • /
    • pp.40-49
    • /
    • 2004
  • In this paper, we propose a new architecture of Genetic Algorithms(GAs)-based Self-Organizing Polynomial Neural Networks(SOPNN), discuss a comprehensive design methodology and carry out a series of numeric experiments. The conventional SOPNN is based on the extended Group Method of Data Handling(GMDH) method and utilized the polynomial order (viz. linear, quadratic, and modified quadratic) as well as the number of node inputs fixed (selected in advance by designer) at Polynomial Neurons (or nodes) located in each layer through a growth process of the network. Moreover it does not guarantee that the SOPNN generated through learning has the optimal network architecture. But the proposed GA-based SOPNN enable the architecture to be a structurally more optimized network, and to be much more flexible and preferable neural network than the conventional SOPNN. In order to generate the structurally optimized SOPNN, GA-based design procedure at each stage (layer) of SOPNN leads to the selection of preferred nodes (or PNs) with optimal parameters- such as the number of input variables, input variables, and the order of the polynomial-available within SOPNN. An aggregate performance index with a weighting factor is proposed in order to achieve a sound balance between approximation and generalization (predictive) abilities of the model. A detailed design procedure is discussed in detail. To evaluate the performance of the GA-based SOPNN, the model is experimented with using two time series data (gas furnace and NOx emission process data of gas turbine power plant). A comparative analysis shows that the proposed GA-based SOPNN is model with higher accuracy as well as more superb predictive capability than other intelligent models presented previously.

A Study on Synthetic Method and Material Characteristics of Magnesium Ammine Chloride as Ammonia Transport Materials for Solid SCR (Solid SCR용 암모니아 저장물질인 Magnesium Ammine Chloride의 합성방법 및 물질특성 연구)

  • Shin, Jong Kook;Yoon, Cheon Seog;Kim, Hongsuk
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.39 no.11
    • /
    • pp.843-851
    • /
    • 2015
  • Among various ammonium salts and metal ammine chlorides used as solid materials for the sources of ammonia with solid SCR for lean NOx reduction, magnesium ammine chloride was taken up for study in this paper because of its ease of handling and safety. Lab-scale synthetic method of magnesium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%). To understand material characteristics for lab-made magnesium ammine chloride, DA, IC, FT-IR, XRD and SDT analyses were performed using the published data available in literature. From the analytical results, the water content in the lab-made magnesium ammine chloride can be determined. A new test procedure for water removal was proposed, by which the adsorption rate of lab-made sample was found to be approximately 100%.

Characteristics of Low Temperature De-NOx Process with Non-thermal Plasma and NH3 Selective Catalytic Reduction (II) (저온 플라즈마 및 암모니아 선택적 환원공정을 활용한 저온 탈질공정의 특성(II))

  • Lee, Jae-Ok;Song, Young-Hoon
    • Applied Chemistry for Engineering
    • /
    • v.17 no.4
    • /
    • pp.414-419
    • /
    • 2006
  • Effects of water vapor, hydrocarbons, and CO, which are inevitably included in exhaust gases of combustion, on a combined $De-NO_{x}$ process of non-thermal plasma and $NH_{3}$ SCR (Selective Catalytic Reduction) have been investigated. Test results showed that fast SCR reaction enhanced $De-NO_{x}$ rate under the low temperature conditions, $150{\sim}200^{\circ}C$ The present test, however, showed that the role of the fast SCR reaction can be significantly suppressed by addition of hydrocarbons in a non-thermal plasma reactor. Detailed investigation verified that such suppressed role of the fast SCR reaction could be caused by the $NO_{2}/NO_{x}$ ratio modified by aldehydes produced from hydrocarbons in a non-thermal plasma reactor. In addition, the present study was confirmed that the effects of water vapor and CO were not noticeable compared with the hydrocarbon effects.

Development of Fuel Conditioning System for 30 kW-class LFG Gasturbine Power Generation (30kW급 LFG 가스터빈 발전용 연료화 정제시스템 개발)

  • Hur, Kwang-Beom;Park, Jung-Keuk;Rhim, Sang-Gyu;Lee, Jung-Bin
    • New & Renewable Energy
    • /
    • v.6 no.1
    • /
    • pp.29-37
    • /
    • 2010
  • Biogas is a carbon neutral energy and consists of mostly methane and carbon dioxide, with smaller amounts of water vapor, and trace amounts of $H_2S$, Siloxane and other impurities. Hydrogen sulfide and Siloxane usually must be removed before the gas can be used for generation of electricity or heat. The goals of this project are to develope the Fuel conditioning system of Land Fill Gas for 30kW-Micro Gas Turbine co-generation system. The fuel conditioning system mainly consists of $H_2S$ removal system, Land Fill Gas compressor, Siloxane removal system and many filtering systems. The fuel requirement of 30kW MGT is at least 32% of $CH_4$, $H_2S$ (<30 ppm), Siloxane (<5ppb) and supply pressure (> 0.6 MPa) from LFG compressor. Main mechnical charateristics of Micro Gas Turbine system by using LFG have the specific performance; 1) high speed turbine speed (96,000 rpm) 2) very clean emmission NOx (<9 ppm) 3) high efficiency of energy conversion rate. This paper focuses on the development of design technology for LFG fuel conditioning system. The study also has the plan to replace the fuel of gas turbine and other distributed power systems. As the increase of Land Fill Gas (LFG), this system help to contribute to spread more New & Renewable Energy and the establishment of Renewable Portfolio Standards (RPS) for Korea.

Numerical Investigation of the Urea Melting and Heat Transfer Characteristics with Three Different Types of Coolant Heaters (냉각수 순환 방식 가열원 형상에 따른 요소수 해동 특성에 관한 수치적 연구)

  • Lee, Seung-Yeop;Kim, Man-Young;Lee, Chun-Hwan;Park, Yun-Beom
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.20 no.4
    • /
    • pp.125-132
    • /
    • 2012
  • Urea-SCR system, which converts nitrogen oxides to nitrogen and water in the presence of a reducing agent, usually AdBlue urea solution, is known as one of the powerful NOx reduction systems for mobile as well as stationary applications. For its consistent and reliable operation in mobile applications, such various problems as transient injection, ammonia slip, and freezing in cold weather have to be resolved. In this work, therefore, numerical study on three-dimensional unsteady heating problems were analyzed to understand the melting and heat transfer characteristics such as urea liquid volume fraction, temperature profiles and generated natural convection behavior in urea solution by using the commercial software Fluent 6.3. After validating by comparing numerical and experimental data with pure gallium melting phenomena, numerical experiment for urea melting is conducted with three different coolant heating models named CH1, 2, and 3, respectively. Finally, it can be found that the CH3 model, in which more coolant is concentrated on the lower part of the urea tank, has relatively better melting capability than others in terms of urea quantity of $1{\ell}$ for start-up schedule.

Environmentally Friendly Hybrid Power System for Cultivators

  • Kim, Sang Cheol;Hong, Young Ki;Kim, Gook Hwan
    • Journal of Biosystems Engineering
    • /
    • v.39 no.4
    • /
    • pp.274-282
    • /
    • 2014
  • Purpose: In this study, a hybrid power system was developed for agricultural machines with a 20-KW output capacity, and it was attached to a multi-purpose cultivator to improve the performance of the cultivator, which was evaluated using output tests. Methods: The hybrid system combined heterogeneous sources: an internal-combustion engine and an electric power motor. In addition, a power splitter was developed to simplify the power transmission structure. The cultivator using the hybrid system was designed to have increased fuel efficiency and output power and reduced exhaust gas emissions, while maintaining the functions of existing cultivators. Results: The fuel consumption for driving the cultivator in the hybrid engine vehicle (HEV) mode was 341 g/KWh, which was 36% less than the consumption in the engine (ENG) mode for the same load. The maximum power take off output of the hybrid power system was 12.7 KW, which was 38% more than the output of the internal-combustion engine. In the HEV mode, harmful exhaust gas emissions were reduced; i.e., CO emissions were reduced by 36~41% and NOx emissions were reduced by 27~51% compared to the corresponding emissions in the ENG mode. Conclusions: The hybrid power system improved the fuel efficiency and reduced exhaust gas emissions in agricultural machinery. Lower exhaust gas emissions of the hybrid system have considerable advantages in closed work environments such as crop production facilities; therefore, agricultural machinery with less exhaust gas emissions should be commercialized. However, the high manufacturing cost and complexity of the proposed system are challenges which need to be solved in the future.