• 신재생에너지
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• 제4권3호
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• pp.23-35
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• 2008

In the present study, performances of fuel cell driven compound source hybrid heat pump system applied to a large community building are simulated. Among several renewable energy sources, ground, river, sea, and waste water sources are chosen as available alternative energies. The performance and energy cost are varied with the hybrid heat pump sources. The system design and operation process appropriate for the surrounding circumstance guarantee the high benefit of the heat pump system applied to a large community building. Th system is driven by fuel cell system instead of the late-night electricity due to the advantages of the low energy cost and waste heat with high temperature.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.940-945
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• 2009

Energy planning for hybrid energy system is important to increase the flexibility in the urban community and national energy systems. Expected maximum loads, load profiles and yearly energy demands are important input parameters to plan for the technical and environmental optimal energy system for a planning area. The method for energy demand prediction has been based on artificial neural networks(ANN). The advantage of ANN with respect to the other method is their ability of modeling a multivariable problem given by the complex relationships between the variables. This method can produce 10% of errors hourly load profile from individual building to urban community. As the results of this paper, energy demand prediction system has been developed based on simulink.

• 한국가스학회지
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• 제14권6호
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• pp.27-30
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• 2010

본 논문은 LNG 냉열에너지를 이용한 지역집단 냉방에너지 시스템을 공급하기 위한 시스템 공정설계에 관한 연구이다. 새로이 개발한 LNG 냉방시스템은 여러 개의 열교환기, LNG 저장탱크, 열매체 저장탱크, 여러 개의 냉열에너지 저장탱크, 가스냉방기, 압축기, 정압기, 저온 및 고온에너지 공급배관 등으로 구성되도록 설계하였다. 또한, 가스냉방기는 여름철에 도시가스 소모량에 의해 충분하지 못한 LNG 냉열에너지를 안정적으로 공급하기 위해 설치되었다. 냉방에너지 공급시스템은 공기라는 열매체와 200kcal/kg의 냉열에너지를 가진 LNG 사이의 열교환 작용에 의해 냉방에너지를 공급하는 효율성과 안전성을 함께 갖추고 있다. 또한, LNG 냉열에너지를 이용한 지역집단 냉방에너지 공급시스템은 공기중으로 CO2나 프레온 가스를 방출하기 않는다는 장점을 간고 있다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2002년도 추계 학술발표회 논문집
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• pp.45-51
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• 2002

CES(Community Energy System)란 구역형의 소규모 지역냉난방시스템으로 세계에서 일본이 가장 발달된바, 일본의 도입 실태분석이 향후 국내 CES 도입에 중요한 자료가 될 것으로 판단되므로 일본에서의 소규모 지역냉난방시스템 도입사례에 대한 조사분석한 내용을 소개하고자 한다. 일본에서의 지역열공급사업의 개념은 1개소 또는 수개소의 열공급플랜트로부터 복수의 건물에 지역배관을 통하여 냉수ㆍ증기ㆍ온수 등을 보내어 냉난방ㆍ급탕을 행하는 것이다.(중략)

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.634-637
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• 2008

Ground source heat pumps are clean, energy-efficient and environment-friendly systems cooling and heating. Although the initial cost of ground source heat pump system is higher than that of air source heat pump, it is now widely accepted as an economical system since the installation cost can be returned within an short period of time due to its high efficiency. In the present study, performances of ground source compound hybrid heat pump system applied to a large community building are simulated. The system design and operation process appropriate for the surrounding circumstance guarantee the high benefit of the heat pump system applied to a large community building. If among several renewable energy sources, ground, river, sea, waste water source are chosen as available alternative energies are combined, COP of the system can be increased largely and hybrid heat pump system can reduced the fuel cost.

• 조명전기설비학회논문지
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• 제24권1호
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• pp.85-90
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• 2010

본 논문은 기존 분산전원 신뢰도에 관한 연구를 기반으로, 여러 구역전기사업자로 인해 분산전원의 소유권과 수용가에 대한 전력공급 책임이 분리된 배전계통에 적용할 수 있는 신뢰도 해석기법을 제안한다. 구역전기사업자는 자신의 수용가에게 양질의 전력서비스를 제공할 의무가 있으므로, 계통사고시 자신의 분산전원 비상전력을 자신의 수용가에게 우선적으로 공급하는 비상대책을 선호한다. 기존 신뢰도 해석기법에서는 하나의 운영주체가 모든 전력원과 전력망을 관리하기 때문에, 여러 구역전기사업자가 존재하는 계통운영 상황에서 분산전원의 소유권을 별도로 고려하지 않는 해석결과는 실제 신뢰도 지수와 차이를 보일 수 있다. 본 논문의 사레연구에서는 RBTS 2번 모선에 2개의 구역전기사업자가 존재하는 경우를 모의하였으며, 기존 기법과 제안된 기법의 신뢰도 지수 결과를 비교하여 제안된 기법의 유효성을 증명하였다.

• 농촌지도와개발
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• 제11권2호
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• pp.251-265
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• 2004

The agricultural sector's economic structure in Korea is regarded to encounter major barriers on the way toward revitalizing its economic prosperity. Among many, the energy-related problem is one of prime nuclei embedded in the country's agricultural sector. The ought-to-come structural changes in the country's agricultural energy system hinge upon the central government's policy direction as well as efforts of local governments and local farming community members. The indirect aids via 'cross subsidy' of electricity tariff rate and 'tax-exempt price' of oil fuels are two notable causes of the unsustainable energy consumption pattern in the country's agricultural sector. As measures, demand-side management(DSM) and energy-efficiency promotions are regarded to be the most attractive methods for energy conservation and economic productivity as well. Development of renewable energy sources are also receiving a great deal of attention for the long-term alternatives to the country's existing oil-based agricultural production mode. This study examines the contributive potential of DSM approaches and renewables-based technologies. With the critical evaluation on the concurrent adversities of the country's agricultural energy system, various sources of renewable energy-solar power, wind power, biomass, etc.-are examined for the purpose of technological and economical viability. As sufficient potentials of renewable energy sources are being estimated, both the system production cost and the installation cost for the county's rural areas are expected to lower in the long term. DSM options are also evaluated to be fruitful even in the short term. Both the public and civil arenas must galvanise each side's effort in order to promote these policy options and community potentials.

• 한국태양에너지학회 논문집
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• 제29권3호
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• pp.37-44
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• 2009

The field-surveyed and measured energy consumption data is processed to develop building energy demand models for heating, hot water, cooling, and electricity. The load models are systematically organized as a database and hourly loads for a span of year (8760 hours) are generated by the program. Rased on those models a Microsoft Access application program is developed to calculate energy demands for a Community Energy System (CES) composed of 17 types of buildings. User-friendly interfaces are provided to assist non-expert end users and necessary tools to link the calculation results to subsequent coagulations such as operation simulation or economic assessment.

• Journal of Electrical Engineering and Technology
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• 제5권4호
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• pp.530-537
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• 2010

By development of renewable energy and more efficient facilities in an increasingly deregulated electricity market, the operation cost of distributed generation (DG) is becoming more competitive. International environmental regulations of the leaking carbon become effective to reinforce global efforts for a low-carbon paradigm. Through increased DG, operators of DG are able to supply electric power to customers who are connected directly to DG as well as loads that are connected to entire network. In this situation, a community energy system (CES) with DGs is a new participant in the energy market. DG's purchase price from the market is different from the DG's sales price to the market due to transmission service charges and other costs. Therefore, CES who owns DGs has to control the produced electric power per hourly period in order to maximize profit. Considering the international environment regulations, CE will be an important element to decide the marginal cost of generators as well as the classified fuel unit cost and unit's efficiency. This paper introduces the optimal operation of CES's DG connected to the distribution network considering CE. The purpose of optimization is to maximize the profit of CES. A Particle Swarm Optimization (PSO) will be used to solve this complicated problem. The optimal operation of DG represented in this paper would guide CES and system operators in determining the decision making criteria.

• 설비공학논문집
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• 제21권6호
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• pp.355-366
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• 2009

In the present study, fuel cell driven ground source heat pump system is applied to a large community building and performance of the heat pump system is computationally analyzed. Conduction heat transfer between brine pipe and ground is analyzed by TEACH code to predict the performance of heat pump system. Predicted COP of the heat pump system and the energy cost were compared with variation of the location of the objective building the water saturation rate of soil and the driven powers of heat pump system. Significant reduction of energy cost can be accomplished by employing the fuel cell driven heat pump system in comparison with the late-night electricity driven system. It is due to the low electricity production cost of fuel cell system and the application of recovered waste heat generated during electricity production process to the heating of large community building.