Combustion gas and NO emission characteristics of hazardous waste mixture particles in a fixed bed

Ling Tao,Guangbo Zhao,Rui Sun 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.3

Experiments with fixed-bed incinerators were carried out to model the combustion characteristics and gas emission characteristics of hazardous waste mixture particles in a grate furnace. The results indicate that combustion can be divided into three stages: ignition, main combustion and combustion completion stage. According to the various concentrations of O_2, CO-2 and CO, the main combustion stage can be subdivided into pyrolysis gas combustion and char combustion. Primary air rate, moisture and particle size have significant effects on concentrations of combustion gases and NO. Bed height has no effect on CO-2 concentrations but does have an effect on other combustion gases and NO emissions.

실물형 연소기의 형상에 따른 연소특성속도 비교

김종규(Jonggyu Kim),한영민(Yeoung-Min Han),안규복(Kyubok Ahn),김문기(Munki Kim),서성현(Seonghyeon Seo),최환석(Hwan-Seok Choi) 한국추진공학회 2008 한국추진공학회 학술대회논문집 Vol.2008 No.5

30톤급 액체로켓엔진 실물형 연소기의 형상에 따른 연소특성속도에 대한 연구를 수행하였다. 본 연구에서 연소기의 형상은 연소기 헤드와 분리가 가능한 내열재 및 채널 냉각형 연소실(ε=3.2), 그리고 일체형인 팽창비가 각각 3.5와 12인 재생냉각형 연소기이다. 연소압력은 약 53~60 bar 그리고 추진제 유량은 약 89 kg/s이고, 적용된 분사기는 리세스수가 1.0인 동축 와류형이다. 설계점 연소시험에서 팽창비가 12인 일체형 재생냉각 방식의 연소기가 가장 큰 연소특성속도를 보였는데 이는 추진제인 케로신이 분무되기 전 챔버 냉각으로 인한 온도 상승에 따른 엔탈피의 증가 및 연소압력의 증가에 기인한 것이다. Effects of chamber configuration on combustion characteristic velocity of full-scale combustion chamber for 30-tonf-class liquid rocket engine were studied. The configurations of combustion chamber are ablative and channel cooling chamber (ε=3.2) which have detachable mixing head, and single body regenerative cooling chamber which has nozzle expansion ratio of 3.5 and 12, respectively. The combustion chambers have chamber pressure of 53~60 bar and propellant mass flow rate of 89 kg/s, and the injectors of all combustion chamber have recess number 1.0 and double-swirl characteristics. The hot firing test results at design point show that the combustion characteristic velocity of the regenerative cooling chamber which has nozzle expansion ratio of 12 is higher than that of other combustion chambers. The reasons for the above result are the increases of combustion pressure and enthalpy of kerosene which is heated due to cooling of the chamber wall before injection into the combustion field.

저온 탄화한 바이오매스와 석탄 그리고 혼합물의 연소특성 평가

박상우 한국폐기물자원순환학회 2013 한국폐기물자원순환학회지 Vol.30 No.6

The following are the results from an evaluation of the combustion characteristics of biomass processed with lowtemperature carbonization and coal, and those of a blend of both. Differential thermo-gravimetric (DTG) analysis has revealed that the number of curves was reduced as a result of carbonization and that the fuel quality was improved due to the increase of initial temperature (IT). It was also confirmed that the carbonized samples consisting only of the biomass required less combustion time (tq), while samples blended with coal burned longer than the weighted average value. The combustion time of a blended sample was shorter at an carbonization temperature of 400oC than at 300oC, and the combustion stability was achieved due to a narrow range of change in the combustion characteristics. The reaction rate constant (k) of the samples blended with coal was found to be smaller for all blend ratios, when compared with that of the unblended samples (raw, carbonized biomass). The combustion reaction models that were applicable for the devolatilization-combustion zone were diffusion (D1, D3) and Reaction order (O3) models; diffusion (D1-D4) model was primarily employed in the char combustion zone. In summary, low-temperature carbonization contributed to minimizing the change in the combustion characteristics of the biomass/coal blend.

강제 맥동류를 이용한 연소특성 연구

양영준(Young-Joon Yang) 한국기계가공학회 2012 한국기계가공학회지 Vol.11 No.5

The combustion characteristics using forced pulsating flow were experimentally investigated with confined premixed flames stabilized by a reward-facing step. The intermittent combustion has many merits, for instance, such as high load combustion, high heat transfer, low emission gas, compared with those of continuous combustion. For these purposes, data processing of binary image was conducted to reveal the differences between intermittent and continuous combustion. As the results, it was possible to calculate the reaction zone using OH-emission band and, therefore, showed that forced pulsating flow was useful in combustion technology.

톱밥과 여과 탈수 폐오일슬러지의 고형연료 연소특성

이주용,배성근,서정윤 한국폐기물자원순환학회 2014 한국폐기물자원순환학회지 Vol.31 No.8

Waste oil sludge was generated from waste oil purification process, oil bunker, or the ocean plant. Although it has high calorific values, it should be treated as a designated waste. During the recycling process of construction and demolition wastes or the trimming process of woods, a lot of sawdust is produced. In this study, the feasibility of BOF (biomass and waste oil sludge Fuel) as a source of renewable energy was estimated. To estimate combustion characteristics, a lab scale batch type combustion reactor was used and temperature fluctuation and the flue gas composition were measured for various experimental conditions. The results could be summarized as follows: the maximum CO2 concentration in the flue gas was increased with increasing waste oil sludge content in BOF. SO2 concentration in the flue gas was showed a tendency such as the highest CO2 concentration in the flue gas. With increasing waste oil sludge content in BOF, the combustion time was rather shorter although the increase of the CO2 concentration in the flue gas was delayed. Because the carbon conversion rate showed small difference with increasing the mixing ratio of waste oil sludge in BOF, BOF with the mixing ratio of waste oil sludge of 40% was effective for combustion. With decreasing the air/fuel ratio and the mixing ratio of waste oil sludge in BOF, activation energy and frequency factor were increased. The optimal air/fuel ratio for the combustion of BOF was 1.5.

분사조건에 따른 커먼레일 디젤엔진에서 바이오디젤의 연소특성

윤승현(Seung Hyun Yoon),김명윤(Myung Yoon Kim),황진우(Jin Woo Whang),전학식(Hak Sik Jeon),이창식(Chang Sik Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The characteristics of combustion and emission of biodiesel fuel were investigated in a single cylinder DI diesel engine equipped with a common rail injection system. In order to compare the emissions of oxygenated fuel with the diesel fuel, tested fuels were neat diesel and biodiesel obtained from soybean oil. Experimental results show that the peak injection rate is reduced when the engine is fueled with biodiesel at 100㎫ injection pressure. The peak combustion pressure and heat release of biodiesel was lower than that of diesel at an injection pressure of 100㎫ because of lower heating value. However, NOx emission of biodiesel combustion was decreased compared with diesel combustion. The ignition delay of biodiesel was reduced due to a higher cetane number of the biodiesel fuel. HC and CO emissions are decreased at a high injection pressure. Cooled-EGR increased the ignition delay and decreased maximum combustion pressure and the NOx emission was rapidly decreased with 30, 45% of EGR rate.

톱밥과 여과 폐중유슬러지의 고형연료 연소 특성

이주용,서정윤 한국폐기물자원순환학회 2015 한국폐기물자원순환학회지 Vol.32 No.1

Waste heavy oil sludge is considered oil waste that can be utilized as a renewable energy source. Although it has high calorific values, it should be treated as a designated waste. During the recycling process of construction and demolition wastes or the trimming process of woods, a lot of sawdust is produced. In this study, the feasibility of BOF (biomass and waste heavy oil sludge fuel) as a source of renewable energy was estimated. To investigate its combustion characteristics, a lab scale batch type combustion reactor was used, and temperature fluctuation and the flue gas composition were measured for various experimental conditions. The results could be summarized as follows: The solid fuel pellets manufactured from waste heavy oil sludge and sawdust had C 50.21 ~ 54.77%, H 10.25 ~ 12.66%, O 25.84 ~ 34.83%, N 1.01 ~ 1.04%, S 1.03 ~ 1.07%. Their lower heating values ranged from 4,780 kg/kcal to 5,530 kg/kcal. The density of the solid fuel pellets was increased from 0.63 g/cm3 to 0.85 g/cm3 with increasing the mixing ratio of waste heavy oil sludge. The maximum CO2 concentration in the flue gas was increased with increasing waste heavy oil sludge content in BOF. SO2 concentration in the flue gas was showed a tendency such as the highest CO2 concentration in the flue gas. With increasing waste heavy oil sludge content in BOF, the combustion time became rather shorter although the increase of the CO2 concentration in the flue gas was delayed. Because the carbon conversion rate showed small difference with increasing the mixing ratio of waste heavy oil sludge in BOF, BOF with the mixing ratio of waste heavy oil sludge of 30% was effective for combustion. With increasing the mixing ratio of waste heavy oil sludge in BOF, activation energy and the amount of total CO emissions were increased, while activation energy was decreased with increasing the air/fuel ratio. Therefore, the optimal air/fuel ratio for the combustion of BOF was 1.5.

커먼레일 디젤엔진에서 대두유의 연소특성

윤승현(Seung Hyun Yoon),김명윤(Myung Yoon Kim),권상일(Sang Il Kwon),전학식(Hak Sik Jeon),이창식(Chang Sik Lee) 한국자동차공학회 2006 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

In this work, a single cylinder DI diesel engine equipped with common-rail injection system was used to investigate the effect of biodiesel on the combustion and emission characteristics. In order to compare the emissions of oxygenated fuel with the diesel fuel, tested fuels were neat diesel and biodiesel obtained from soybean oil. Experimental results show that the peak injection rate is reduced when the engine is fueled with biodiesel. The peak combustion pressure of biodiesel was higher than that of neat diesel at an injection pressure of 100㎫. The ignition delay of biodiesel was reduced due to a higher cetane number of the biodiesel. HC and CO emissions are decreased at a high injection pressure and IMEP, thermal efficiency are also increased. However, NOx, emission of biodiesel combustion was increased compared with diesel combustion. Cooled-EGR increased the ignition delay and decreased maximum combustion pressure and the NOx, emission was rapidly decreased with 30% of EGR rate.

5kW 급 MCFC 발전시스템 촉매연소기의 유동 및 연소 특성에 대한 수치적 연구

김종민(Chongmin Kim),이연화(Younwha Lee),김만영(Man Young Kim),김형곤(Hyung gon Kim),홍동진(Dongjin Hong),조주형(Ju Hyeong Cho),김한석(Han-Seok Kim),안국영(Kook Young Ahn) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

MCFC (molten carbonate fuel cell) power generation system is prime candidate for the utilization of fossil based fuels to generate ultra clean power with a high efficiency. In the MCFC power plant system, a combustor performs a role to supply high temperature mixture gases for cathode and heat for reformer by using the stack off-gas of the anode which includes a high concentration of H₂O and CO₂. Since a combustor needs to be operated in a very lean condition and to avoid excessive local heating, catalytic combustor is usually used. The catalytic combustion is accomplished by the catalytic chemical reaction between fuel and oxidizer at catalyst surface, different from conventional combustion. In this study, a mathematical model for the prediction of internal flow and catalytic combustion characteristics in the catalytic combustor adopted in the MCFC power plant system is suggested by using the numerical methods. The numerical simulation models are then implemented into the commercial CFD code. After verifying result by comparing with the experimental data and calibrated kinetic parameters of catalytic combustion reaction, a numerical simulation is performed to investigate the variation of flow and combustion characteristics by changing such various parameters as inlet configuration and inlet temperature. The result show that the catalytic combustion can be effectively improved for most of the case by using the perforated plate and subsequent stable catalytic combustion is expected.

Experimental Investigations on Spray Characteristics of Potential Fuels for Advance Low Temperature Combustion Engines

( Saurabh Kumar Gupta ),( M. Murugesa Pandian ),( Anand Krishnasamy ) 한국액체미립화학회 2017 한국액체미립화학회 학술강연회 논문집 Vol.2017 No.-

Advanced low temperature combustion (LTC) strategies including Premixed Charge Compression Ignition (PCCI), Reactivity Controlled Compression Ignition (RCCI), Stratified Charge Compression Ignition (SCCI) and High Efficiency Clean Combustion (HECC) are proposed to simultaneously reduce oxides of nitrogen (NOx) and particulate matter (PM) emissions to near zero levels along with higher thermal efficiencies. However, precise control of ignition timings is difficult to achieve in these LTC strategies as it is primarily controlled by the molecular composition of fuel by altering physical and chemical delay period and creating reactivity stratification. Fuel spray characteristics plays a vital role in varying the rate of fuel-air mixing and physical delay period. The potential fuels for advanced LTC modes include fuels with optimal reactivity and better volatility. The effects of physical properties and its impact on spray behavior of potential fuels for LTC are sparsely available. The present work intends to study the effects of changes in properties and injection pressures on the macroscopic spray behavior of potential fuels for advanced LTC engines. The experiments are carried out in a constant volume spray chamber with different potential fuels for advanced combustion engines, viz. Diesel with 10%,20% and 30% gasoline (DG10, DG20 and DG30) and Diesel with 10%,20% and 30% kerosene (DK10, DK20 and DK30). The fuel injection pressures and the injection strategies have been chosen as representative of direct injection diesel engine working conditions. The spray characteristics such as spray tip penetration distance, spray cone angle are obtained by using a high resolution spray visualization system for the different fuel blends. The obtained results show that the changes in physical properties of the fuel blends affect the macroscopic fuel spray behavior. Further, as compared to that of conventional diesel, all the fuel blends show a significant difference in the macroscopic spray characteristics.