• Journal of Advanced Marine Engineering and Technology
• /
• 제22권2호
• /
• pp.248-256
• /
• 1998

The effects of fuel injection system on the performance in a V8-type diesel engine was stuided in this paper. Fuel injection system is important factor which influence the engine performance and exhaust emission bcasuse the properties in the injected fuel depend on the atomization characteristics. In this study using diesel engine of 17.7:1 compression ration the engine performance and exhaust emission are measured experimentally according to 1000, 1400, 2200rpm in the full-load conditions. The chosen parameters for the major system are such diameter shape of combustion chamber and intake system. The results are as follows: As the nozzle hole diameter and injection angle become smaller and as the injection timing gets advanced the fuel consumption and concentration of smoke are decreasing whereas concentration of $NO_{x}$ is increasing. Andconcentration of $NO_{x}$ is increasing in accordance with the increase of injection pipe diameter and nozzle protrusion. Also it is shown that re-entrant type combustion chamber is more effective than that of toroidal type in the improvement of $NO_{x}$ reduction.

• International Journal of Automotive Technology
• /
• 제3권1호
• /
• pp.1-8
• /
• 2002

There is Increasing world-wide interest in diesel particulate filters (DPF) because of their proven effectiveness in reducing exhaust smoke and particulate emissions. Fine particulates have been linked to human health . DPF use requires a means to secure the bum-out of the accumulated soot, a process called regeneration. If this is not achieved, the engine cannot continue to operate. A number of techniques are available, but most are complex, expensive or have a high electrical demand. The use of fuel additives to catalyse soot bum-out potentially solves the problem of securing regeneration reliably and at low cost. Work on organo-metallic fuel additives has shown that certain metals combine to glove exceptional regeneration performance. Best performance was achieved with a combination of iron and strontium based compounds. Tests were carried out un a bed engine and on road vehicles, which demonstrated effective and reliable regeneration from a tow dose fuel additive, using a single passive DPF. No control valves, flow diverters. heaters or other devices were employed to assist regeneration. Independent particle size measurements showed that there were no harmful side effects from the use of the iron-strontium fuel additive.

• 한국연초학회지
• /
• 제29권2호
• /
• pp.104-109
• /
• 2007

The amount of nitrate in the tobacco leaf has been shown to be correlated with the levels of alkaloids and nitrosamines. Also the nitrate content of the tobacco correlated closely with the smoke delivery of nitric oxide and tobacco-specific nitrosamines (TSNAs). These are related with the effect of the reconstituted tobacco leaf(Recon) using the tobacco stems. Adsorption process is gaining interest as one of the effective processes of advanced liquid treatment for liquid containing unnecessary materials. This study is focused on the evaluation of four anion exchangers, a cation exchanger and an activated carbon, as adsorbents for reduction of nitrate anion from Recon extract. In order to analyze the nitrate anion, the IC method used in this work was carried out with a Dionex ICS-2000 system. The effects of dosages of adsorbents and concentration of extract on the removal of nitrate anion were examined. Experimental results showed that for nitrate-anion exchanger, nitrate-cation exchanger and nitrate-activated carbon adsorption system, approximately 70 %, 10 %, and 4 % removal efficiencies were achieved at the Brix 10 and the 20 % addition. Although the activated carbon was little efficient for removal of nitrate ion, the removal of nicotine was very efficient at given conditions.

• 한국자동차공학회논문집
• /
• 제13권5호
• /
• pp.188-194
• /
• 2005

The direct injection diesel engine is one of the most efficient thermal engines. For this reason DI diesel engines are widely used for heavy-duty applications. But the world is faced with very serious problems related to the air pollution due to the exhaust emissions of diesel engine. So, that is air pollution related to exhaust gas resulted from explosive combustion should be improved. Exhaust Gas Recirculation(EGR) is a proven method to reduce NOx emissions. In this study, the experiments were performed at various engine loads while the EGR rates were set from $0\%$ to $30\%.$ The emissions trade-off and combustion of diesel engine are investigated. The brake specific fuel consumption rate is very slightly fluctuated with EGR in the range of experimental conditions. The ignition delay increased with increasing EGR rate. The maximum value of premixed combustion for the rate of heat release is increased with increasing EGR rate. NOx emissions are decreased with increasing EGR rate at high load and high speed. It was found that the exhaust emissions with the EGR system resulted in a very large reduction in oxides of nitrogen at the expense of higher smoke emissions.

• 대한기계학회논문집
• /
• 제19권11호
• /
• pp.3054-3062
• /
• 1995

Recently, the improvement of fuel economy and the reduction of exhaust smoke and NOx have been successfully achieved by supplying diesel engines with emulsified diesel oil with water particles. In the present paper, the difference between the combustion of injected emulsified fuel and that of diesel oil spray is clarified by means of taking high-speed and color photographs of the flames in the engine cylinder. As the results, the two kinds of fuels show different combustion behavior each other in the growth of initial flame and in the termination of combustion process in the cylinder. Then, suitable combustion chamber design for the use of emulsified fuel is discussed on the basis of experimental data for various distribution of spray in different kinds of piston cavities. Some methods of clearing troubles caused by emulsified fuel injection are also discussed on the basis of performance tests with a remodeling test engine.

• 국제초고층학회논문집
• /
• 제7권4호
• /
• pp.265-285
• /
• 2018

This paper presents a state-of-the-art review on the design, research and education aspects of fire safety engineering (FSE) with a particular concern on high-rise buildings. FSE finds its root after Great Fire of Rome in 64 AD, followed by Great London Fire in 1666. The development of modern FSE is continuously driven by industry revolution, insurance community and government regulations. Now FSE has become a unique engineering discipline and is moving towards performance-based design since 1990s. The performance-based fire safety design (PBFSD) involves identification of fire safety goals, design objectives, establishment of performance criteria, and selection of proper solutions for fire safety. The determination of fire scenarios and design fires have now become major contents for PBFSD. To experience a rapid and positive evolution in design and research consistent with other engineering disciplines, it is important for fire safety engineering as a profession to set up a special educational system to deliver the next-generation fire safety engineers. High-rise buildings have their unique fire safety issues such as rapid fire and smoke spread, extended evacuation time, longer fire duration, mixed occupancies, etc., bringing more difficulties in ensuring life safety and protection of property and environment. A list of recommendations is proposed to improve the fire safety of high-rise buildings. In addition, some source information for specific knowledge and information on FSE is provided in Appendix.

• 수산해양기술연구
• /
• 제57권3호
• /
• pp.256-263
• /
• 2021

In this study, blending oils of diesel oil and butanol were used as fuel oil for diesel engine to measure combustion pressure, fuel consumption, air ratio and exhaust gas emission due to various operating conditions such as engine revolution and torque. Using these data, the results of analyzing the engine performance, combustion characteristics and exhaust emission characteristics such as NOx (nitrogen oxides), CO₂ (carbon dioxide), CO (carbon monoxide) and soot were as follows. The fuel conversion efficiency at each load was highest when driven in the engine revolution determined by a fixed pitch propeller law. Except 30% butanol blending oil, fuel conversion efficiency of the other fuel oils increased as the load increased. Compared to diesel oil, using 10% and 20% butanol blending oil as fuel oil was advantageous in terms of thermal efficiency, but it did not have a significant impact on the reduction of exhaust gas emissions. On the other hand, future research is needed on the results of the 20% butanol blending oil showing lower or similar levels of smoke concentration and carbon monoxide emission rate other than those types of diesel oil.

• 공업화학
• /
• 제28권1호
• /
• pp.112-117
• /
• 2017

이 연구에서는 피페라지노메틸-비스-포스폰산(PIPEABP), 메틸피페라지노메틸-비스-포스폰산(MPIPEABP), N,N-디메틸렌디아미노메틸-비스-포스폰산(MDEDAP) 그리고 비스-디메틸아미노메틸 포스핀산(DMDAP)의 화학 첨가제로 처리된 중질섬유판(MDF)의 연소가스 발생을 시험하였다. 15 wt%의 인-질소산류 첨가제 수용액으로 중질섬유판에 붓으로 3회 칠하여 실온에서 건조시킨 후, 콘칼로리미터(Conecalorimeter, ISO 5660-1, 2)를 이용하여 연소가스의 발생을 시험하였다. 그 결과, 인-질소산류 첨가제로 처리한 시험편의 최대연기발생률($SPR_{peak}$)은 무처리 시험편에 비교하여 18.5~41.5%로 낮게 나타내었다. 그러나 인-질소산류 첨가제로 처리한 시험편에 대한 최대일산화탄소 생성($CO_{peak}$), (6.7~24.2)%은 공시험편보다 높게 나타났다. 또한 최대이산화탄소 발생($CO_{2peak}$), (4.2~24.4)%은 공시험편보다 낮게 나타났다. 반면에 $O_2$의 최대결핍률은 사람에게 치명적일 수 있는 수준인 15%보다 훨씬 높으므로 그로 인한 위험성은 피할 수 있었다. 결론적으로 MDF에 인-질소산류로 처리한 시험편은 부분적으로 연소성이 억제되었다. 그러나 일산화탄소의 감소에는 부정적인 영향을 미쳤다.

• 한국화재소방학회논문지
• /
• 제15권1호
• /
• pp.23-33
• /
• 2001

지하공동구는 최근 통신의 발달로 인해 국가 중추기능으로서의 주요 역할을 하는 시설로, 사고시 신속한 대처가 힘들고 케이블 연소시 발생하는 유독가스에 의한 검은 연기로 공동구 내에 진입하여 소화화기가 힘들다. 따라서, 화재발생시 막대한 재산피해 및 통신의 두절 등 국가의 중추신경이 마비됨은 물론 시민 불편사항을 초래시켰다. 본 논문은 지금까지 발생되어온 공동구 화제를 바탕으로 실제 공동구 모형을 제작하여 화재를 재현함으로서, 과학적으로 화재의 성상을 분석하고 지하공동구 내에 소방설비를 갖춘 후에 일정온도에서 각각의 소방설비들이 제대로 작동하는지를 검증하는데 그 목적이 있다. 화재실험은 지하 공동구 내에 정온식 감지선형 감지기, 방화문, 연결살수설비 및 환기설비를 설치하고 송.배전케이블은 일정구간 내화도료로 도장하며 난방관은 내화피복된 상태에서 실험하였다. 그 결과 최고 온도가 $932^{\circ}c$로 측정되었고 일정온도에서 정온식 감지선형 감지기가 작동하여 화재위치를 정확히 수신반에 나타내었다. 그리고 송.배전케이블은 일정구간 내화도료로 도장한 것은 내화성능이 없는 것으로 나타났고, 내화피복된 난방관은 약 30분 정도의 내화 성능이 있는 것으로 나타났다. 컴퓨터 화재 시뮬레이션은 실제 화재 시험시의 화재하중을 입력하여 실시한 결과 최고 온도가 $943^{\circ}c$로 실제 화재시의 최고 온도인 $932^{\circ}c$와 거의 일치하였다. 따라서 공동구 화재하중만으로 화재 시뮬레이션을 실시하여 화재의 성상에 대한 예측이 가능한 것으로 판단되며 시뮬레이션으로 얻는 열방출량, 연기층의 높이, 산소, 일산화탄소, 이산화탄소의 농도 등의 결과 값들을 실제 화재 실험시의 값으로 적용시킬 수 있는 것으로 판단된다. 0.05ppb보다 높은 수준으로 예측되어 유럽의 허용기준치를 초과하는 것으로 나타났다.확보를 위한 위생관리 업무 향상을 위해서는 본 연구에서 가장 취약한 부분으로 드러난 시설 및 기기들을 우선 보완해야 할 것으로 사료된다.ons. Specific growth rate of dechlorinators showed little difference between the slurry and the low-moisture sediments; however, growth yield was high in the sediments of reduced moisture content. The reduction of sediment moisture decreased the dechlorination rate and extent of PCBs but did not inhibit the growth of PCB dechlorinators.1.4mg, 여학생이 159.3mg이었다. 이상의 결과로 보아 에너지, 단백질, 칼슘, 비타민 A 등 대부분의 영양소 섭취량이 권장량에 미치지 못하여 성장기에 있는 아동들의 영양소 섭취 상태에 문제가 있음을 시사해 주었다. 5. 조사 대상자의 식습관과 영양소 섭취량의 상관관관계는 식사 시간의 규칙성은 단백질, 식이성 섬유소, 비타민 A 및 티아민섭취량과 양의 상관을 나트륨섭취량과는 음의 상관관계가 있었다. 음식의 간(염도)은 인과 콜레스테롤 섭취와 음의 상관관계를 나타냈다. 들깨가루나 들기름 사용 여부는 열량, 탄수화물 및 인의 섭취량과 음의 상관을, 지방, 철분, 리보플라빈 및 나이아신섭취량과는 양의 상관관계를 나타냈었다. 결식여부는 지방, 철분 및 나이아신섭취량과는 양의 상관관계를, 열량, 탄수화물, 인 나트륨, 및 콜레스테롤섭취량과는 음의 상관을 보였다. 외식이

• 한국가스학회지
• /
• 제16권6호
• /
• pp.107-114
• /
• 2012

화재감지 시스템은 화재발생 시 위험 감지 및 전파를 위해 사용되고 있는데, 현재 사용 중인 대부분의 화재감지 시스템은 실보와 비화재보의 가능성으로부터 오동작이 빈번하게 발생한다. 본 연구에서는 화재감지의 신뢰성 개선을 위해 열 감지기, 연기 감지기 및 일산화탄소 농도 감지기의 3가지 독립정보를 통합적으로 이용하여 화재를 감지하는 알고리즘을 제안하고, LabVIEW를 이용하여 test bed를 구축하여 검증하였다. 즉, NIST의 Fire Research Division에서 제공하는 상황별 센서 측정 데이터를 이용하여 시뮬레이션을 진행하였으며, 실보와 비화재보의 가능성을 저감시키는 것을 확인할 수 있었다.