• 제목/요약/키워드: fuel distribution

검색결과 1,400건 처리시간 0.029초

Effect of central hole on fuel temperature distribution

  • Yarmohammadi, Mehdi;Rahgoshay, Mohammad;Shirani, Amir Saied
    • Nuclear Engineering and Technology
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    • 제49권8호
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    • pp.1629-1635
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    • 2017
  • Reliable prediction of nuclear fuel rod behavior of nuclear power reactors constitutes a basic demand for steady-state calculations, design purposes, and fuel performance assessment. Perfect design of fuel rods as the first barrier against fission product release is very important. Simulation of fuel rod performance with a code or software is one of the fuel rod design steps. In this study, a software program called MARCODE is developed in MATLAB environment that can analyze the temperature distribution, gap conductance value, and fuel and clad displacement in both solid and annular fuel rods. With a comparison of the maximum fuel temperature, fuel average temperature, fuel surface temperature, and gap conductance in solid and annular fuel, the effects of a central hole on the fuel temperature distribution are investigated.

직분식 전기점화 엔진에서 PLIF기법에 의한 성층 혼합기의 분포특성 연구 (Study on the Fuel Vapor Distribution of the Stratified Charge in a DISI Engine by PLIF Technique)

  • 김성수
    • 동력기계공학회지
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    • 제12권6호
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    • pp.64-69
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    • 2008
  • The spatial fuel distribution of the stratified charge of a high pressure 6-hole injector was examined in a single cylinder optical direct injection spark ignition(DISI) engine. The effects of in-cylinder charge motion, and fuel injection pressure, and coolant temperature were investigated using a planar LIF(Laser Induced Fluorescence) technique. It was confirmed that the in-cylinder tumble flow played more effective role in the spatial fuel distribution of the stratified charge than the swirl flow during the compression stroke and the fuel distribution area increased due to the activation of the fuel vaporization by the increase of the coolant temperature. But, the increase of the fuel supplying pressure could not change the pattern of the fuel vapor distribution against the expectation.

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마이크로 가스 터빈용 연소기의 연료 노즐의 유량 분배에 관한 수치 해석적 연구 (Numerical Study on Flow Distribution of Fuel Nozzles for a Combustor in a Micro Gas Turbine)

  • 김태훈;도규형;한용식;김명배;최병일
    • 한국연소학회지
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    • 제19권4호
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    • pp.8-13
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    • 2014
  • Flow distribution of fuel nozzles for a combustor in a micro gas turbine is numerically investigated. The fuel supply system for the present study has 12 single nozzles with a diameter of several hundred micrometers. A uniform temperature distribution of a combustor outlet should be achieved for maximizing the lives of the turbine blades and nozzle guide vanes. For this, it is very important to uniformly supply fuel to a combustor. In order to investigate flow distributions of fuel nozzles, numerical models for fuel nozzles are made and solved by a commercial code, ANSYS FLUENT. An effect of a fuel nozzle diameter and fuel flow rates on flow distribution of fuel nozzles is numerically investigated. As a result, non-uniformity is increasing as a diameter of a single fuel nozzle increases. Finally, an appropriate diameter of a single fuel nozzle is suggested.

바이오디젤 구성성분 합성 및 연료특성 분석 (Synthesis of Biodiesel Components and Analysis of Their Fuel Characters)

  • 임영관;정충섭;한관욱;도진우
    • Tribology and Lubricants
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    • 제30권1호
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    • pp.52-58
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    • 2014
  • Because food crops serve as the raw materials for biodiesel, the increasing use of biodiesel as an alternative fuel can lead to adverse effects such as food price inflation and may contribute to global starvation. To solve these problems, efforts are being made to explore various nonedible raw materials for producing biodiesel. Different raw materials impart different fuel characteristics to biodiesel. In this study, we synthesized pure fatty acid methyl ester (FAME), which is a biodiesel component, and then analyzed its fuel properties. The fuel properties of pure FAME would be useful in producing biodiesel from various new raw materials.

MTV가 연소실내 연료분포 및 화염 안정성에 미치는 영향 연구 (Effects of MTV on fuel distribution and flame stability in a SI engine)

  • 김기성
    • 한국분무공학회지
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    • 제2권4호
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    • pp.36-46
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    • 1997
  • The present study investigated the effects of MTV(Manifold Throttle Valve) on the fuel distribution and the flame stability in a SI engine at cold, idling condition. For the quantitative measurement of fuel distribution with PLIF method, compensating techniques of various factors such as laser beam nonuniformity, background image and local OTF nonuniformity were developed. As a result, it was found that MTV had a positive effect on the air-fuel mixing and flame stability.

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주택용 연료전지 효율 향상을 위한 다중 스택 연료전지 시스템의 전력 분배 최적화 (Power Distribution Optimization of Multi-stack Fuel Cell Systems for Improving the Efficiency of Residential Fuel Cell)

  • 강태성;함성현;오환영;최윤영;김민진
    • 한국수소및신에너지학회논문집
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    • 제34권4호
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    • pp.358-368
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    • 2023
  • The fuel cell market is expected to grow rapidly. Therefore, it is necessary to scale up fuel cells for buildings, power generation, and ships. A multi-stack system can be an effective way to expand the capacity of a fuel cell. Multi-stack fuel cell systems are better than single-stack systems in terms of efficiency, reliability, durability and maintenance. In this research, we developed a residential fuel cell stack and system model that generates electricity using the fuel cell-photovoltaic hybrid system. The efficiency and hydrogen consumption of the fuel cell system were calculated according to the three proposed power distribution methods (equivalent, Daisy-chain, and optimal method). As a result, the optimal power distribution method increases the efficiency of the fuel cell system and reduces hydrogen consumption. The more frequently the multi-stack fuel cell system is exposed to lower power levels, the greater the effectiveness of the optimal power distribution method.

국내 차량 인증시험용 표준연료(경유) 도입 필요성 검토 연구 (A feasibility study on Introducing Reference Fuel(Diesel) for Testing Vehicles in South Korea)

  • 황인하;강형규;성상래;송호영;하종한;나병기
    • 한국응용과학기술학회지
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    • 제34권4호
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    • pp.974-985
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    • 2017
  • 2016년 기준 국내 자동차 등록대수는 약 2,200만대를 육박하고 있으나[1], 국내 자동차용 표준연료에 대한 기준은 부재한 상황이다. 자동차용 표준연료(Reference Fuel)는 차량의 연비와 배출가스를 인증하거나 새로운 자동차를 개발할 때 차량의 성능 등을 평가하기 위해 사용하는 연료를 의미한다. 현재 국내에는 차량의 배출가스, 성능, 연비시험 등을 위해 유통연료를 사용하고 있으며, 유통연료는 석유 및 석유대체연료사업법과 대기환경보전법 상의 품질기준을 만족하지만 각 제조사의 원료와 공정 등에 따라 연료의 물성 차이가 있어 차량 시험 시 편차가 발생할 수 있다. 본 연구에서는 국내 유통되는 자동차용 경유 품질모니터링 분석결과를 바탕으로 자동차용 경유의 시험용 표준연료 기준(안)을 설정하고, CRDI 방식의 차량에 적용하여 표준연료 기준(안)을 평가하였다.

연료품질 및 연비계산 방법 변화에 따른 연비특성 분석 (Analysis of fuel economy characteristics depending on the fuel quality and calculation method changed)

  • 이민호;임완규;임재혁;김기호
    • 동력기계공학회지
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    • 제20권4호
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    • pp.52-62
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    • 2016
  • Nowadays, emissions of a vehicle are been getting by testing on a chassis dynamometer and a test modes. Also, fuel efficiency is calculated by carbon-balance method that is applying the emissions(CO, THC and $CO_2$) to the fuel calculation formular. In Korea, before 2014, the formular did not include the fuel factors (density, net heat value and carbon weight fraction), but the constants were based on the fuel properties of 2000s. So, this formular did not consider a characteristic of test fuel property that was changed when progressing fuel efficiency test. The characteristics of test fuel property which was distributed in domestic have a difference of quality depending on production regions and oil-refining facilities. Because the fuel properties are variable value during refineries, crude oils and blending contents of a bio-fuel, vehicle fuel is changed for each test. Therefore, the fuel qualities need to apply for a fuel economy test. In this paper, changing patterns of a fuel properties were reviewed during history of fuel standards. Also, the appropriateness of the methods was discussed by calculating and comparing fuel economies with the fuel factors and the constants.

디젤차량 연비시험에 있어 시험온도 및 냉각팬 조건이 미치는 영향분석에 관한 연구 (A Study on the Influence of Test Temperature & Cooling Fan Condition on the Fuel Test of Diesel Vehicle)

  • 김현진;김성우;임재혁;노경하;이정천;김기호;오상기
    • 동력기계공학회지
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    • 제21권6호
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    • pp.46-55
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    • 2017
  • Due to the arise of natural disasters caused by global warming, consumers have more interest in the fuel efficiency of their vehicles, and fuel efficiency became an important factor in comparing vehicles. In this market situation, methods to measure fuel efficiency has become one of the main interests of vehicle related organizations and laboratories, and the current method to measure fuel efficiency is to follow the notification established by the ministry of trade, industry and energy, ministry of environment, and the ministry of land, infrastructure and transport. In this study, we analyze the influence of vehicle fuel efficiency according to test temperature and cooling fan condition which have the possibility to cause difference in fuel efficiency. The analysis results of the influence of the fuel efficiency according to the test temperature, the difference of the fuel efficiency of the test temperature ($21{\sim}29^{\circ}C$) within the allowable range of the notification showed a maximum difference of 2.9%. Therefore, it is necessary to consider the introduction of a test method that permits only the temperature change based on the reference point as the allowable range even in the test within the allowable range. The analysis of the influence of the fuel efficiency according to the cooling method showed no significant effect, and it seems reasonable to maintain the test method of the current notification.

수분오염에 따른 경유의 연료적 특성 (The Fuel Characteristics of Diesel by Water Contamination)

  • 임영관;원기요;강병석;박소휘;박장민;강대혁
    • Tribology and Lubricants
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    • 제36권6호
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    • pp.385-390
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    • 2020
  • It rains heavily, such as long rain and typhoons, during a typical rainy season in Korea. In this season, several fuel contamination accidents by water and vehicular problems caused by water contaminated fuel occur. Many research groups have studied the effects of water contaminated fuel on vehicles and environment. However the characteristics of water contaminated fuel have not been studied. In this study, we prepared diesel samples with a constant ratio of water (0~30 volume %) using an emulsifier. Then, we analyzed these diesel samples for their representative fuel properties. In the analytical results, diesel with 30% water showed an increase in fuel properties such as density (823→883 kg/㎥), kinematic viscosity (2.601→6.345 ㎟/s), flash point (47→56℃), pour point (-22→2℃), CFPP (cold filter plugging point) (-17→20℃) and copper corrosion number (1a→2a). The low temperature characteristics, such as low pour point and CFPP, blocks the fuel filter in the cold season. In addition, water contaminated diesel decreases lubricity (190→410 ㎛) under high frequency reciprocating rig (HFRR) and derived cetane number (54.81→34.25). The low lubricity of fuel causes vehicle problem such as pump and injector damage owing to severe friction. In addition, the low cetane diesel fuel increases exhaust gases such as NOx and particulate matters (PM) owing to incomplete combustion. This study can be used to identify the problems caused by water contamination to vehicle and fuel facilities.