• 한국수소및신에너지학회논문집
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• 제31권4호
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• pp.380-386
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• 2020

This paper represents an analysis of the economic impact of firing natural gas/diesel and natural gas/by-product oil mixtures in diesel engine power plants. The objects of analysis is a power plant with electricity generation capacity (300 kW). Using performance data of original diesel engines, the fuel consumption characteristics of the duel fuel engines were simulated. Then, economic assessment was carried out using the performance data and the net present value method. A special focus was given to the evaluation of fuel cost saving when firing natural gas/diesel and natural gas/by-product oil mixtures instead of the pure diesel firing case. Analyses were performed by assuming fuel price changes in the market as well as by using current prices. The analysis results showed that co-firing of natural gas/diesel and natural gas/by-product oil would provide considerable fuel cost saving, leading to meaningful economic benefits.

• 방사성폐기물학회지
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• 제21권2호
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• pp.295-301
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• 2023

To broaden the utilization of nuclear energy, uranium as a fuel should be mined indispensably. Mining accounts for the largest portion of the cost of producing the uranium assembly. Therefore, this study analyzes the trends of uranium prices, which have a significant impacts on the mining cost. Uranium production contributing to the price fluctuations is explained in five periods from 1945 to the present. Moreover, the series of events affecting uranium prices from the 1970s until the present are verified. Among them, the most recent incidents considered in this study are the following: COVID-19 pandemic, Kazakhstan unrest, and Russia-Ukraine war. European countries have started to reconsider the transition to nuclear power to reduce their dependence on Russian oil and gas, which has contributed to the surge in uranium prices. Based on the results of this study, various international issues have been closely associated with the nuclear power industry and uranium, affecting the production of uranium and its price.

• 자원ㆍ환경경제연구
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• 제16권2호
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• pp.239-273
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• 2007

해외 판매 BC유의 국제벙커링과 수출의 경우에는 거의 유사한 품질에도 불구하고 서로 다른 가격으로 판매되고 있으며, 이 두 시장에서의 가격 차이는 2002년 이후에 크게 확대되는 모습을 보이고 있다. 실증 분석을 통하여 한국에서의 벙커링 가격과 수출 가격의 차이가 2002년 6월을 기점으로 구조적인 변화가 발생하였을 가능성이 있으며, 2002년 6월까지는 두 가격의 차이를 설명하지 못하였던 싱가포르에서의 벙커링과 연료유 가격 차이가 2002년 7월부터는 한국에서 두 가격의 차이를 설명하는 요인으로 나타나고 있음을 확인하였다. 또한, 미래 유가 상승을 기대하게 하는 전기 시차의 국제 원유가격의 상승률도 한국에서 벙커링과 수출 가격의 차이를 설명하는 요인임을 알 수 있었다. 이러한 추정 결과는 한국에서의 국제벙커링과 수출의 가격 차이가 가격차별에 의해서 설명될 가능성을 배제하지는 않는 결과이다.

• 한국연소학회지
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• 제20권2호
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• pp.40-45
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• 2015

This study is aimed to study combustion characteristics of low $NO_X$ burner using petroleum cokes as fuel. The petroleum coke, which is produced through the oil refining process, is an attractive fuel in terms of its high heating value and relatively low price. But petroleum coke is a challenging fuel because of its low volatile content, high sulfur and nitrogen content, which give rise to undesirable emission characteristics and low ignitability. The petroleum cokes burner is operated at fuel rich condition, and overfire air are supplied to achieve fuel lean condition. The low $NO_X$ burner is designed to control fuel and air mixing to achieve air staged combustion, in addition secondary and tertiary air are supplied through swirler. Air distribution ratio of triple staged air are optimized experimentally. The result showed that $NO_X$ concentration is lowest when overfire air is used, and the burner function at a fuel rich condition.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.103.1-103.1
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• 2010

Recently domestic wood pellet boilers are installed in rural and forestry houses. The fuel price per lower heating value of wood pellet is about 20 % lower than that of heating oil on July 2010. In spite of lower price of wood pellet, a few user of wood pellet boiler complain expensive fuel cost. One of this reason is inaccurate or improper air-fuel ratio setting of wood pellet boiler. O2 concentration of flue gas of domestic wood pellet boiler is about 9.7 % and there are few domestic wood pellet boiler which can control air-fuel ratio automatically. We tested a domestic wood pellet boiler in changing boiler thermal output and air-fuel ratio. The nominal boiler thermal output is 25 kW (21 500 kcal/h). We measured thermal efficiency and flue gas concentrations such as CO and NOx at each boiler thermal load with various air-fuel ratio. The results show that if air flow rate is the same as full load and part load, thermal efficiency of part load of 40 % drops about 7.7 %p compared to boiler full load case.

• 한국컴퓨터정보학회논문지
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• 제26권10호
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• pp.179-184
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• 2021

본 논문에서는 딥러닝 기반의 순환신경망을 이용하여 선박 연료유 예측을 시도하였다. 해운업에서는 선박 운항비에서 연료유가 차지하는 비중이 가장 크고 가격 변동성도 크기 때문에, 해운 기업은 합리적이고 과학저인 방법으로 연료유를 예측하여 시장경쟁력을 확보할 수 있다. 본 논문에서는 순환신경망 모델 3가지(RNN, LSTM, GRU)를 이용하여 싱가폴의 HSFO 380CST 벙커유 가격을 단기 예측하였다. 예측결과, 첫째, 선박 연료유 단기적 예측을 위해서는 장기 메모리를 사용하는 LSTM, GRU보다는 일반적인 RNN 모델의 성능이 우수한 것으로 분석되어, 장기적 정보의 예측 기여가 낮은 것으로 분석되었다. 둘째, 계량경제학 모델을 사용한 선행연구와 비교하여 순환신경망 모델의 예측성능이 우수한 것으로 분석되어 연료유가의 비선형적 특성을 고려한 순환신경망 모델을 통한 예측 연구의 필요성을 확인하였다. 연구의 결과는 선박 연료유의 단기 예측을 통하여 해운기업의 선박 연료유 수급 결정과 같은 의사결정에 도움이 될 수 있을 것으로 기대된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전력기술부문
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• pp.409-411
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• 2008

전문기관들의 장기 유가전망치를 바탕으로 타 발전용 연료의 장기가격 예측 가능성을 엿보기 위해, 유가와 타 발전용 연료간 상관관계를 분석해 본 결과 유가와 LNG가격은 상당한 유의성을 가지고 있는 것으로 나타난 반면, 타 전원과는 유의성이 미약한 것으로 나타났다. 따라서 엑셀 회귀분석을 통해 도출된 유가와 LNG 가격간의 상관식을 이용하여 LNG장기가격을 전망하는 것은 가능하다고 판단되나 결과치를 활용하기 위해서는 보다 정밀한 검증이 요구된다.

• Journal of Biosystems Engineering
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• 제38권4호
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• pp.306-311
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• 2013

Purpose: With the ever-rising energy prices, thermal energy heavily consuming facilities of the agricultural sector such as commercialized greenhouses and large-scale Rice Processing Complexes (RPCs) need to cut down their energy cost if they must run profitable businesses continually. One possible way to reduce their energy cost is to utilize combustible agricultural by-products or low-price oil instead of light oil as the fuel for their boiler systems. This study aims to analyze the heavy oil combustion characteristics of a newly developed hot water boiler system that can use both rice husk and heavy oil as its fuel convertibly. Methods: Heavy oil combustion experiments were conducted in this study employing four fuel feed rates (7.6, 8.5, 9.5, 11.4 $l/h$) at a combustion furnace vacuum pressure of 500 Pa and with four combustion furnace vacuum pressures (375, 500, 625, 750 Pa) at fuel feed rates of 9.5 and 11.4 $l/h$. Temperatures at five locations inside the combustion furnace and 20 additional locations throughout the whole hot water boiler system were measured to ascertain the combustion characteristics of the heavy oil. From the temperature measurement data, the thermal efficiency of the system was calculated. Flue gas smoke density and concentrations of air-polluting components in the flue gas were also measured by a gas analyzer. Results: As the fuel feed rate or combustion furnace vacuum pressure increased, the average temperature in the combustion furnace decreased but the thermal efficiency of the system showed no distinctive change. On the other hand, the thermal efficiency of the system was inversely proportionally to the vacuum level in the furnace. For all experimental conditions, the thermal efficiency remained in the range of 80.1-89.6%. The CO concentration in the flue gas was negligibly low. The NO and $SO_2$ concentration as well as the smoke density met the legal requirements. Conclusions: Considering the combustion temperature characteristics, thermal efficiency, and flue gas composition, the optimal combustion condition of the system seemed to be either the fuel feed rate of 9.5 $l/h$ with a combustion furnace vacuum pressure of 375 Pa or a fuel feed rate of 11.4 $l/h$ with a furnace vacuum pressure between 500 Pa and 625 Pa.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.782-783
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• 2007

Exhaustion of fossil fuel resources and high oil price, and furthermore environmental crisis due to emission of carbon dioxide from fossil fuel are serious problems in these days. In order to overcome these problems it is necessary to find and utilize the every energy saving measures and to make maximum utilization of renewable energy resources. The objective of this paper is to develop an instrument to verify the feasibility of Co-Generation System application in an Apartment Complex.

• 한국CDE학회논문집
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• 제17권2호
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• pp.71-78
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• 2012

Recently, the ratio of fuel cost to the operational cost of a ship is increasing according to the increase of the international oil price. Thus, many studies are being made to reduce the cost; for example, a method for acquiring the sea state information, a method for estimating fuel consumption, a method for determining the ship's optimal route, and so on. However, these studies were not incorporated together and being independently made in different fields. In this study, by improving and incorporating such studies, a method for determining a ship economic route based on the acquisition of the sea state and estimation of fuel consumption was proposed. To evaluate the applicability of the proposed method, it was applied to an optimal routing problem of the ocean area including many islands. The result shows that the proposed method can yield the economic route minimizing fuel consumption.