• 제목/요약/키워드: air pollution$CO_2$ use efficiency

검색결과 13건 처리시간 0.021초

난방용 보일러에서 NG-H2 혼소율에 따른 열 및 공해 성능의 검토 (A Study on the Thermal and Pollution Performances of the Heating Boilers with NG-H2 Mixture Ratio)

  • 서준선;김영직;박준규;이창언
    • 한국수소및신에너지학회논문집
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    • 제32권6호
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    • pp.573-584
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    • 2021
  • Hydrogen is evaluated as one of the new energy sources that can overcome the limitations and pollution problems of conventional fossil fuels. Although hydrogen is CO2-free, attention is required in NOx emission and flame stability in order to use hydrogen in existing gas fuel system. However, use of electric grids is an unrealistic strategy for decarbonization for residential and commercial heating. Instead, use of H2 that utilizes city gas grid is suggested as a reasonable alternative in terms of compatibility with existing systems, economic feasibility, and accessibility. In this study, the thermal efficiency and NOx performance of the boiler according to the H2 mixture ratio and vapor humidified ratio are reviewed for a humidified NG-H2 boiler that vapor humidity to combustion air. Mixed fuel with H2 (20%) is almost similar to NG in terms of efficiency, flame temperature, and pollution performance. Thus, it is expected to be directly compatible with the existing NG system. If the exhaust temperature of the H2 boiler is lowered to around 60℃ at a humidified ratio of 15-20%, the NOx emission concentration can be suppressed to about 5-10 ppm. The level of efficiency reaches 87% of the rated load efficiency, which is equivalent to the highest grade achievable.

Energy Efficiency and CO2 Emissions of the Transportation System of Kazakhstan: A Case of Almaty

  • Yessekina, Aiman;Urpekova, Amina
    • The Journal of Asian Finance, Economics and Business
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    • 제2권3호
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    • pp.41-46
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    • 2015
  • Energy saving in the transport sector in the framework of the annual growth of energy consumption, the degree of negative impact on the environment and the amount of harmful emissions are becoming increasingly important. The article considers the world tendencies of energy consumption in transportation sector and emphasizes its dependency from oil. Also article describes the dynamics of energy use and CO2 emissions from transport of city Almaty. In conclusion authors identify a number of problems in the transport sector, which hinder the implementation of energy efficiency measures and measures to reduce CO2 emissions.

은행나무의 잎끝마름병에 미치는 $SO_2$ 의 영향 (Effect of $SO_2$ on Leaf Tip Blight of Ginkgo biloba caused by Coniothyrium sp.)

  • 강연지;박소홍;이두형;배공형
    • 한국환경농학회지
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    • 제18권2호
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    • pp.179-184
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    • 1999
  • 대기오염과 병충해발생과의 관계를 규명하고자 은행나무에 $SO_2$ 가스를 처리한 후, 잎끝마름병균을 접종하여 식물의 생리·생화학적인 변화를 조사하였다. ${\mu}l/l$$SO_2$ 가스를 하루 8시간씩 7일간 은행나무에 처리한 결과 Chlorosis등의 가시피해는 나타나지 않았으나, 광합성이 대조구에 비해 40%가량 감소되고, $CO_2$ 이용효율과 수분이용효율이 감소되는 현상을 보였다. 가스처리 후 병원균을 상처접종시키고 42일 뒤 SI와 SFI의 발병도를 조사한 결과 SI가 SFI에 비해 3배 가량 빠르게 병이 진전되어 있었다. 병원균의 먹이가 되는 당의 함량은 대조구, SFI, SI간에 유의성을 보일 만큼의 차이는 보이지 않았으나, 광합성은 SI가 SFI에 비해 11%가량 저하되었다. 광합성이 저하되었음에도 불구하고 당의 함량이 유지되었으므로 탄소 고정관계를 알아본 결과 $CO_2$ 이용효율이 저하되지 않았음을 알 수 있었다. 이와 함께 수분이용효율이 SI에서 SFI에 비해 13.2% 증가되었다. 이상의 결과를 종합해 보면, 이온유출량 등으로 보아 $SO_2$ 가스처리로 인해 식물이 연약해져 병원균에 대한 저항력이 낮아졌고, 수분이용효율의 증가로 인해 탄소 고정이 활발하게 이루어짐으로써 당이 원활히 합성되는 한편 내부적인 변화로 인해 합성된 당의 전류가 억제되어 잎에 당이 축적되었기 때문에 SI의 발병도가 훨씬 높았던 것으로 생각된다.

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하이브리드 자동차의 EGR 밸브 오작동 시 엔진 성능에 미치는 영향 (A study on engine performance of EGR valve problem in Hybrid vehicles)

  • 송락현;조행묵
    • 에너지공학
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    • 제24권3호
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    • pp.34-39
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    • 2015
  • Recently, Air pollution is gradually increasing which are coming from the exhaust of the ICE vehicles in the world. ICE vehicle exhaust gas and $CO_2$ are widely suspected of contributing to the called greenhouse effect, fueling fears of global warming. Therefore, many countries are striving to decrease the vehicle exhaust gas and have developed a variety of policies as air pollution regulation plans. To comply with the regulations, automotive industry has developed hybrid vehicles, which have features of both ICE vehicles and electric vehicles. Hybrid car is eco-friendly and has lowered exhausting gases and improved fuel efficiency. This research has been written to show that break down cases with EGR valve in hybrid cars, steadily increasing in use, and to help with on-site maintenance.

풍력-태양전지에 의한 수소에너지 생산과 이용 모델 분석 (Model analysis for production and utilization of hydrogen energy from wind power and solar cell)

  • 이기문;박창권;정귀성;오병수
    • 한국수소및신에너지학회논문집
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    • 제12권4호
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    • pp.239-246
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    • 2001
  • Fossil fuel such as oil and natural gas has been used and will be no longer supplied enough to demand in the beginning of thisg century. The use of the fuel makes a lot of environmental pollution to threaten human being's health especially in big cities and produces a lot of $CO_{2}$ to make green house effect of the earth. It is the time to use clean fuel such as hydrogen to prevent the expected energy crisis and the pollution. A new engine such as fuel cell can be used instead of the conventional internal combustion engine with 2 to 3 times higher efficiency of the conventional engine. The fuel cell uses hydrogen and oxygen and produces electric energy and pure water, which is a calm engine without air pollution. In big cities the city buses and the taxies powered by hydrogen fuel cells are suggested to be operated for clean environment. The energy and cost analysis performed for hydrogen and electricity production from wind power and solar cell.

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수소 에너지 생산, 수송 및 이용에 대한 통합시스템 해석 (Analysis of the total system for production, transportation and utilization of hydrogen energy)

  • 오병수;서석진
    • 한국수소및신에너지학회논문집
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    • 제9권1호
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    • pp.38-45
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    • 1998
  • An energy crisis is expected in near future. Fossil fuel such as oil and natural gas has been used and will be no longer supplied enough to demand in the beginning of coming century. The use of the fuel makes a lot of environmental pollution to threaten human being's health especially in big cities and produces a lot of $CO_2$ to make green house effect of the earth. It is the time to use clean fuel such as hydrogen to prevent the expected energy crisis and the pollution. A new engine such as fuel cell can be used instead of the conventional internal combustion engine with 2 to 3 times higher efficiency of the conventional engine. The fuel cell uses hydrogen and oxygen and produces electric energy and pure water, which is a calm engine without air pollution. In big cities the city buses and the taxies powered by hydrogen fuel cells are suggested to be operated for clean environment. A model of the total energy system for production, transportation and utilization of hydrogen is calculated.

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디젤엔진의 운전인자 변화에 따른 엔진의 성능특성에 관한 연구 (A Study on Engine Performance Characteristics with Variation of Operating Condition in Diesel Engine)

  • 김기복
    • 한국산업융합학회 논문집
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    • 제23권4_2호
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    • pp.645-651
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    • 2020
  • In this study, It is necessary that we should study on more effective use about reciprocating engines because there are huge increase of air pollution. Diesel Engine is operated by injecting fuel directly to combustion chamber with high pressure. Diesel Engine has greater thermal efficiency and durability than Gasoline Engine. Also, Diesel Engine emitted low harmful exhaust witch caused by Gasoline Engine. There are many ways to improve of performance and decrease of harmful exhaust by controlling injection timing, changing amount of fuel and engine speed and so on. Especially, development and application of common rail direct injection Engine cause the increase of thermal efficiency by controlling a various of operating conditions. In this study we analyze characteristics of performance by changing a various of operating conditions.

피트(peat) 혼합담체를 이용한 저농도 질소산화물(NOx) 제거특성 (Removal Characteristics of Nitrogen Oxides (NOx) in Low Concentration using Peat-Mixed Media)

  • 강영현;김덕우;강선홍;권필주;김달우;황필기;심상보
    • 한국대기환경학회지
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    • 제26권3호
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    • pp.330-338
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    • 2010
  • In this study, removal characteristics of nitrogen oxides $(NO_x)$ from road transport by using peat as the packing media for biodegradation have been investigated in the long term. Physicochemical and biological treatment of peatmixed media eliminates any requirement to use chemical substances and also facilitates the biodegradable actions of microorganism. Safe biodegradation of pollutants, no need to apply additional microbes owing to their active growth, and no generation of secondary pollutants were found in this experiment. It was concluded that average removal efficiencies of nitric oxide (NO) and nitrogen dioxide $(NO_2)$ were 80% and 97% respectively with respect to the linear velocity 35~40 mm/s and 0.3 ppm ozone concentration in the long period operation. Inflow concentration of nitric oxide over 0.05 ppm was suitable when pretreated with ozone. Non-ozone stage was performed with linear velocity 20~100 mm/s and then the average removal efficiency of nitric oxide and nitrogen dioxide were 38% and 94% respectively. Other results showed that the apparent static pressure was raised with increases in applied water content and aerial velocity in mixed media during fan operation.

유동층 연소로에서 유.무연탄 혼합 연소법을 이용한 국내산 저질 무연탄의 활용에 관한 연구 (A Study on the Use of Low-Grade Domestic Anthracite by Anthracite - Bituminous Coal Blend Combustion in a Fluidized Bed Combustor)

  • 정종현;조상원
    • 한국환경과학회지
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    • 제6권3호
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    • pp.267-276
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    • 1997
  • It has been studded that combustion and the production of air pollution of anthracite - bituminous coal blend In a fluidized bed coal combustor, The objects of thIns study were to investigate mixing characteristics of the particles as well as the combustibility of the low grade domestic anthracite coal and Imported h19h calorific bltununous coal in the fluidized bed coal combustor. They were used as coal samples ; the domestic low grade anthracite coal with heating value of 2,010kca1/kg and the Imported high grade bituminous coal with beating value of 6,520kca1/kg. Also, the effects of air flow rate and anthracite fraction on the reaching time of steady state condition have been studied. The experimental results are presented as follows. The time of reaching to steady state was affected by the temperature variation. The steady state time was about 120 minute at 300sc1h which was the fastest. It has been found that $O^2$ and $CO^2$ concentration were reached steady state at about 100 minute. It has been found that $O^2$ concentration decreased and $CO^2$ concentration increased as the height of fluidlzed bed Increased. It was found that splash zone was mainly located from 25cm to 35cm above distributor. Also, as anthracite traction Increased, the mass of elutrlatlon particles Increased, and $CO^2$ concentration decreased. As gk flow rate Increased,$O^2$ concentration decreased and $CO^2$ concentration increased. Regardless of anthracite fraction and flow rate, the uncombustible weight percentage according to average diameter of elutriation particles were approldmately high In the case of One Particles. As anthracite traction and k now rate Increased, elutriation ratio Increased. As anthracite fraction was increased, exit combustible content over feeding combustible content was Increased. Regardless of anthracite fraction, size distribution of Ued material from discharge was almost constant. Over bed temperature 85$0^{\circ}C$ and excess air 20% , the difference of combution efficiencies were little. It is estimate that the combustion condition In anthracite-bituminous coal blend combustion is suitable at the velocity 0.3m/s, bed temperature 85$0^{\circ}C$, the excess air 20%.

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블랙카본 측정기용 초소형 사이클론 집진기 개발 (Development of a Miniature Aerosol Separator for a Black Carbon Measuring Instrument)

  • 안익현;임준형;이효영;육세진
    • 한국기계가공학회지
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    • 제19권12호
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    • pp.42-48
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    • 2020
  • Given the increasing interest in air pollution, several technologies to measure black carbon (BC) aerosol particles have been developed. As most BC aerosol particles are smaller than 1 ㎛, it is necessary to pre-separate the particles by size before a BC measuring instrument samples the aerosol particles. In this study, a miniature cyclone separator for portable BC measuring instruments was developed. A numerical approach was used to design the miniature cyclone separator with operating flow rates of 50, 100, or 150 mLPM, and then a prototype cyclone separator was manufactured for experimental validation. The numerical results of the cut-off size and pressure drop of the miniature cyclone separator agreed well with the experimental data. The cut-off sizes of the miniature cyclone separator were determined to be 2.9, 0.94, and 0.63 ㎛ for operating flow rates of 50, 100, and 150 mLPM, respectively. Thus, the miniature cyclone separator is suitable for use as a sampling inlet for the portable black carbon measuring instrument to sample BC aerosol or PM2.5 aerosol.