• Journal of Advanced Marine Engineering and Technology
• /
• 제39권4호
• /
• pp.399-404
• /
• 2015

최근 국제 원유가의 폭등으로 선박의 연료비 부담이 상대적으로 가중되고 있으며, 또한 연료의 연소과정에서 발생하는 온실가스에 대한 국제적 규제 움직임도 가속되고 있다. 이에 따라 에너지 효율 개선을 위해서 선체의 설계변경, 마찰저항을 줄이기 위한 도료개발, 엔진의 열효율을 개선하기 위한 첨가제 개발, 연료를 절감하기 위하여 저속운전 등 다양한 방법들이 적용되고 있다. 따라서 최근 고유가 시대에 선박의 고속화와 대형화 및 에너지 절감형 선형의 개발이 필수요건이 되고 있다. 또한 선체 표면의 국부 영역에서 저항 값들의 정성 및 정량적인 변화와 보다 세밀한 분석은 불가피하다고 판단되어진다. 따라서 본 연구는 에너지 효율 개선을 위한 기초연구로서 현재 운항중인 선박의 선체에서 자생하는 해양생물로 인한 마찰저항을 확인하기 위하여 도크 전 후의 엔진성능을 분석하고 그 결과를 도크와 도크사이 2.5년의 데이터와 비교함으로서 주기관의 성능, 마찰저항과 부하변화 및 연료소비량과 선속에 미치는 연구 결과 등을 보고한다.

• Journal of Biosystems Engineering
• /
• 제7권1호
• /
• pp.53-61
• /
• 1982

As an attempt to reduce the consumption of petroleum resources and to improve the performance of a kerosene engine, a series of experiments was conducted using several kinds of ethanol-kerosene blends under the various compression ratios. The engine used in this study was a single-cylinder, four-cycle kerosene engine having a compression ratio of 4.5. To investigate the feasibility of ethanol-kerosene blends in the original engine, kerosene and blends of 5-percent, 10-percent, and 20-percent-ethanol, by volume, with kerosene were used. And to investigate the feasibility of improving the performance of the kerosene engine, a portion of the cylinder head was cut off to increase the compression ratio up to 5.0 by reducing the combustion chamber volume. Kerosene and blends of 30-percent and 40-percent-ethanol, by volume, with kerosene were used for the modified engine with an increased compression ratio. Variable speed tests at wide-open throttle were also conducted at five speed levels in the range of 1000 to 2200 rpm for each compression ratio and fuel type. Volumetric efficiency, engine torque, and brake specific fuel consumption were determined, and brake thermal efficiency based on the lower heating values of kerosene and ethanol was calculated. The results obtained in the study are summarized as follows: A. Test with the original engine: (1) No abnormal conditions were found when burning ethanol-kerosene blends in the original engine. (2) Volumetric efficiency increased with ethanol concentration in blends. When burning blends of 5-percent, 10-percent, and 20-percent ethanol, by volume, with kerosene, average volumetric efficiency increased 1.6 percent, 2.6 percent, and 4.1 percent respectively, than when burning kerosene. (3) Mean engine torque increased 5.2 percent for 5-percent-ethanol blend, 9.3 percent for 10-percent-ethanol blend, and 11.5 percent for 20-percent-ethanol blend than for kerosene. Increase in engine torque when using ethanol-kerosene blends was due to the improved combustion characteristics of ethanol as well as an increase in volumetric efficiency. (4) Up to ethanol concentration of 20 percent, mean brake specific fuel consumption was nearly constant inspite of the difference in heating value between ethanol and kerosene. (5) Brake thermal efficiency increased 0.3 percent for 5-percent-ethanol blend, 3.8 percent for 10-percent-ethanol blend, and 6.8 percent for 20-percent-ethanol blend than for kerosene. B. Test with the modified engine with an increased compression ratio: (1) When burning kerosene, mean volumetric efficiency, engine torque, and brake thermal efficiency were somewhat lower than for the original engine. (2) Engine torque increased 15.1 percent for 30-percent-ethanol blend and 18.4 percent for 40-percent-ethanol blend than for kerosene. (3) There was no significant difference in brake specific fuel consumption regardless of ethanol concentration in blends. (4) Brake thermal efficiency increased 15.0 percent for 30-percent-ethanol blend and 19. 5 percent for 40-percent-ethanol blend than for kerosene.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제18권1호
• /
• pp.66-71
• /
• 2018

Purpose: Performance recovered from SCR through cleaning was studied, measuring differential pressure, NOx reduction efficiency, fuel consumption and engine power before and after cleaning. Ideal cleaning intervals are proposed based on SCR mileage and differential pressure. SCR endurance and reliability improvements through cleaning were studied through physicochemical testing of SCR durability at 43,000km 50,000km, and 110,000km respectively. Methods: Engine power, fuel consumption and exhaust gas were measured using engine full load tests and ND-13 MODE by installing the SCR before cleaned at total engine mileages of 400,000 km, 300,000km and 200,000km. The same tests were performed after cleaning the SCR catalytic converter. Endurance and reliability of the SCR cleaning was studied through the same test by SCR catalyst after each 43,000km 50,000km, 110,000km, durability test on SCR cleaning. Conclusion: We confirmed the low-performance of the SCR due to clogging is restored by SCR cleaning technology. The NOx reduction efficiency was restored to 82%, 86% and 88% from 69%, 72% and 79%. As well as the NOx reduction efficiency, it was confirmed that the engine power, fuel consumption and back pressure was restored to fresh SCR levels. As a result of the durability and reliability achieved through SCR cleaning, we confined the appearance and reduction efficiency through visual inspection and ND-13 MODE are similar to new SCR catalysts. Finally, it was judged that there was no change in performance even when driving the SCR without cleaning throughout the 100,000 km mileage warranty.

• Journal of Advanced Marine Engineering and Technology
• /
• 제28권3호
• /
• pp.516-521
• /
• 2004

In this paper, the effects of ethanol blended gasoline on emissions and their catalytic conversion efficiencies characteristics were investigated in gasoline engine with an electronic fuel injection. The results showed that the increase of ethanol concentration in the blended fuels brought the reduction of THC and $CO_2$ emissions from the gasoline engine. THC emissions were drastically reduced up to thirty percent. And brake specific fuel consumption was increased. but brake specific energy consumption was similar level. However. unburned ethanol and acetaldehyde emissions increased. The conversion efficiency of Pt/Rh based three-way catalysts and the effect of ethanol on CO and NOx emissions were investigated by the change of engine speed. load and air/fuel ratio. Furthermore, the ethanol blended fuel results in the reduction effect of THC. CO and NOx emissions at idle speed.

• 유통과학연구
• /
• 제18권9호
• /
• pp.67-75
• /
• 2020

Purpose: The purpose of this study is to enhance sales promotion efficiency for using solid refuse fuel facilities. Renewable energy technology using Solid Refuse Fuel (SRF) is an economic efficiency technology that recovers waste by burning various wastes. A survey on the pollutants discharged from the solid fuels facilities was investigated so that the SRF facilities could be expanded, distributed and reflected in the policy. Research design, data, and methodology: In this study, 9 business sites using SRF and Bio-SRF as main raw materials were investigated for 2 years. The characteristics of target business sites such as the type of fuel used, combustion method, combustion temperature, daily fuel consumption and environmental prevention facilities were studied. Results: The average pollution & ammonia concentration of Bio-SRF facilities was found to be 88.15% higher than that of SRF facilities. But the average acetaldehyde concentration of SRF facilities was found to be 88.15% higher than that of Bio-SRF facilities. Conclusions: The main issue is how much electric power generation using combustible materials affects air pollution. The waste recycling law provides the standard value according to the fuel property, but there is a considerable gap with the mixed fuel. Therefore, for efficient utilization of facilities using solid fuel products, additional research is needed to improve the distribution structure of exhaust pollutants is needed.

• 자원ㆍ환경경제연구
• /
• 제10권1호
• /
• pp.45-64
• /
• 2001

This paper estimates the gasoline price elasticities of demand for automobile fuel efficiency in Korea to examine indirectly whether the government policy of raising fuel prices is effective in inducing less consumption of fuel, relying on a hedonic technique developed by Atkinson and Halvorsen (1984). One of the advantages of this technique is that the data for a single year, without involving variation in the price of gasoline, is sufficient in implementing this study. Moreover. this technique enables us to circumvent the multicollinearity problem, which had reduced reliability of the results in previous hedonic studies. The estimated elasticities of dam and for fuel efficiency with respect to the price of gasoline, on average, is 0.42.

• 해양환경안전학회지
• /
• 제18권1호
• /
• pp.41-47
• /
• 2012

최근 국제 원유가의 폭등으로 선박의 연료비 부담이 상대적으로 가중되고 있으며, 또한 연료의 연소과정에서 발생하는 온실가스에 대한 국제적 규제 움직임도 가속되고 있다. 이와 같은 상황에서, 온실가스의 배출을 최소화하면서 연료소모량을 줄이기 위해 많은 선사들이 감속운항을 취하고 있으며, 선박용 엔진 개발 분야에서는 엔진의 연료 효율성 개선 문제와 대체에너지 사용 분야에 주력하고 있다. 따라서, 본 연구에서는 실제 해상에서의 선속대비 연료소모량을 계측하고, 건조과정에서 실시된 육상 엔진실험 자료와 2007~2009년까지의 AB-LOG를 분석하여, 특정 외력조건에서의 대상선박에 대한 연료소모량을 고려한 최적의 속력을 14~15노트, 주기관의 RPM을 140~150 RPM으로 제안하였다.

• 한국항공운항학회지
• /
• 제31권2호
• /
• pp.81-88
• /
• 2023

SHM (Structural Health Monitoring) technique for monitoring aircraft structural health and damage, EHM (Engine Health Monitoring) for monitoring aircraft engine performance, and APM (Application Performance Management) is used for each function. APMS (Airplane Performance Monitoring System) is a program that comprehensively applies these techniques to identify the difference between the performance manual provided by the manufacturer and the actual fuel mileage of the aircraft and reflect it in the flight plan. The main purpose of using APMS is to understand the performance of each aircraft, to plan and execute flights in an optimal way, and consequently to reduce fuel consumption. First, it is to check the fuel efficiency trend of each aircraft, check the correlation between the maintenance work performed and the fuel mileage, find the cause of the fuel mileage increase/decrease, and take appropriate measures in response. Second, it is to find the cause of fuel mileage degradation in detail by checking the trends by engine performance and fuselage drag effect. Third, the APMS is to be used in making maintenance work decisions. Through APMS, aircraft with below average fuel mileage are identified, the cause of fuel mileage degradation is identified, and appropriate corrective actions are determined. Fourth, APMS data is used to analyze the economic analysis of equipment installation investment. The cost can be easily calculated as the equipment installation cost, but the benefit is fuel efficiency improvement, and the only way to check this is the manufacturer's theory. Therefore, verifying the effect after installation and verifying the economic analysis is to secure the appropriateness of the investment. Through this, proper investment in fuel efficiency improvement equipment will be made, and fuel efficiency will be improved.

• 한국정밀공학회지
• /
• 제22권6호
• /
• pp.192-198
• /
• 2005

Recently, Automobile manufacturers regarding stability, economic environmental-friendly problems by the development of automobile. This reason is increasingly strict environmental regulations to lower fuel consumption and reduce emission. Designing more efficient and low emission control exhaust system results in more efficient Performance, reduced back Pressure and higher convert efficiency. Also to reduce the noise and the vibration of the automobile. According to develop variable type muffler, dual muffler and active intelligence exhaust system unit. Improvement in engine performance and fuel consumption rate, higher conversion efficiency demand information of pressure fraction and heat characteristics. To be able to determine these factor fur we experiment on each case of exhaust system unit. In this study, how back pressure is distributed in flow-through in exhaust system and how to design exhaust system flexibleness, efficiency, lower back pressure and optimal performance. This study furnish basic data for engineers, technicians.

• Design & Manufacturing
• /
• 제16권2호
• /
• pp.20-25
• /
• 2022

In line with the rapid economic growth of many countries, fossil fuel energy sources are also rapidly depleting. Therefore, the price is also rising rapidly, so it is necessary to develop new and renewable energy sources such as hydropower, geothermal power, nuclear power, wind power and solar energy to replace fossil fuel energy in the future. In this study, development of rotating concentrator module system, development of rotating module control control system, development of lamp and charge control controller, configuration and prototype production of rotating concentrating solar LED street light system, efficiency of rotating concentrating solar LED street light, and power production. The research was conducted in the order of evaluation of comprehensive performance tests such as consumption and consumption. As a result, the developed high-efficiency rotation-concentrating hybrid solar LED street light module system has a 50% higher light-gathering efficiency than existing products by tracing sunlight by self-developing a rotation-collecting module on existing solar LED street lamps according to the characteristics of Korea's topography. and the power generation was improved by more than 40%.