• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
• /
• pp.24-26
• /
• 1994

This paper describes a numerical model for the short-term operation strategy of the cogeneration systems. Especially this paper considered various auxiliary equipments used for the effective operation of cogeneration system. Minimum daily operation costs of topping cycle are calculated by using LP. Simulation results of some cases are analyzed and compared each other. Through these simulations the validity of the proposed model considered various auxiliary equipments is verified.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
• /
• pp.117-119
• /
• 1995

For an effective application of the cogeneration system for commercial and industrial buildings, we need to develop a relevant model to determine the long-term based optimal sizing of the cogeneration system considering electrical and thermal load demands, buy and sell contracts with electric utility and the annual production cost. In assessing the optimal sizing of cogeneration, we have to consider both economic parameters and their capacity expansion for the increased electrical and thermals demand in the future. In this paper, we propose a mathematical model for the optimal sizing of cogeneration systems considering annual production costs and other economic parameter such as, lifetime of the equipment, time value of the capital, etc. In the case study, we thoroughly examine the effects of the economic parameters and determine the optimal size of the sample system. In addition, we calculate the payback period of the cogeneration investment.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
• /
• pp.128-130
• /
• 1995

This paper presents the optimal operation scheduling on cogeneration systems connected with auxiliary equipment by using the possibility fuzzy theory. The probability fuzzy theory is a method to obtain the possibility of the solution from the fuzzification of coefficients. Simulation is carried out to obtain the boundary of heat production in each time interval. Simulation results shows effectively the flexible operation boundary to establish operation scheduling.

• 에너지공학
• /
• 제6권1호
• /
• pp.11-18
• /
• 1997

본 논문은 에너지 효율이 높은 열병합발전시스템을 대상으로 유전알고리즘을 적용하여 단기운전계획을 수립하였다. 특히 열병합발전시스템의 효율은 약 70%이지만 효율이 일정하지 않을 뿐만 아니라 비선형적인 특징을 가지므로 실제 산업체의 열병합발전소의 데이터를 기초로 하여 적합한 가변효율방정식을 구하였다. 또한 본 논문에서 적용된 유전알고리즘은 계산시간의 감소와 높은 정밀도를 가진 실변수 유전알고리즘으로 시뮬레이션 하였다. 그 결과로 가변효율을 가진 열병합발전시스템의 단기운전계획이 유전알고리즘을 적용하여 적절하게 운전계획이 수립되고 있음을 나타내었으며 각종 보조설비가 유연성 있게 협력하며 필요시마다 효율적으로 운전되고 있음을 확인하였다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2001년도 춘계학술대회논문집D
• /
• pp.726-731
• /
• 2001

A thermal design software is developed for the heat recovery steam generator(HRSG) of combined cogeneration systems. The heat transfer is calculated by using the element method to account for the varying thermal properties across the heat transfer elements. The circulation balance is computed for the evaporator to accurately estimate the steam generation rate and to check the proper circulation of the boiler water through the tubes. The software developed can be used to simulate HRSG systems with various combinations of auxiliary burner, wall superheater, superheater, reheater, evaporator, and economizer. Systems with several different combinations of the system components are successfully tested. And it is concluded that the developed software can be used for the design of heat recovery steam generators with various combinations of heat transfer components.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 춘계학술대회 논문집 전력기술부문
• /
• pp.183-186
• /
• 2001

This paper describes the optimal operation scheduling of total cogeneration system which is interconnected with combined heat power plant of utility and district heat devices. The numerical modeling about the cogeneration system and the auxiliary thermal energy devices are established and simulation is carried out by LINDO program in order to minimize the operation cost under the national viewpoint. The results reveal that the established numerical modeling and the operation strategy can be effectively applied to the total cogeneration systems to reduce the energy cost.

• 대한기계학회논문집B
• /
• 제25권4호
• /
• pp.451-460
• /
• 2001

An analysis program for the thermal performance prediction of steam turbine cogeneration systems with multi-extraction, reheat and regeneration has been developed on the basis of the thermodynamic heat balance method. Heat balance analyses were performed for a commercial cogeneration power plant using the program. Its appropriateness was verified by comparing its heat balance results with those of other commercial programs and those provided by the original system designer. Further parametric analyses were carried out and performance improvement measures in designing the plant were suggested.

• 대한전기학회논문지:전력기술부문A
• /
• 제49권6호
• /
• pp.280-288
• /
• 2000

Recently, there has been growing interest in utilizing cogeneration(COGN) systems with a high-energy efficiency due to the increasing energy consumption and the lacking of energy resource. But an insertion of COGN system to existing power distribution system can cause several problems such as voltage variations, harmonics, protective coordination, increasing fault current etc, because of reverse power of COGN, especially in protective coordination. A study on a proper coordination with existing one is being required. The existing power distribution system is operated with radial type by one source and protection system is composed based on unidirectional power source. But an Insertion of COGN system to power distribution system change existing unidirectional power source system to bidirectional power source. Therefore, investigation to cover whole field of power distribution system must be accomplished such as changing of protection devices rating by increasing fault current, reevaluation of protective coordination. In this paper, simulation using PSCAD/EMTDC was accomplished to analyze effect of COGIN on distribution fault current. Also, the existing protection system of 22.9[kV] power distribution system and customers protection system to protect of COGIN was analyzed and the study on protective coordination between of two protection system accomplished.

• Nuclear Engineering and Technology
• /
• 제39권1호
• /
• pp.9-20
• /
• 2007

Design study on the Gas Turbine High Temperature Reactor 300-Cogeneration (GTHTR300C) aiming at producing both electricity by a gas turbine and hydrogen by a thermochemical water splitting method (IS process method) has been conducted. It is expected to be one of the most attractive systems to provide hydrogen for fuel cell vehicles after 2030. The GTHTR300C employs a block type Very High Temperature Reactor (VHTR) with thermal power of 600MW and outlet coolant temperature of $950^{\circ}C$. The intermediate heat exchanger (IHX) and the gas turbine are arranged in series in the primary circuit. The IHX transfers the heat of 170MW to the secondary system used for hydrogen production. The balance of the reactor thermal power is used for electricity generation. The GTHTR300C is designed based on the existing technologies of the High Temperature Engineering Test Reactor (HTTR) and helium turbine power conversion and on the technologies whose development have been well under way for IS hydrogen production process so as to minimize cost and risk of deployment. This paper describes the original design features focusing on the plant layout and plant cycle of the GTHTR300C together with present development status of the GTHTR300, IHX, etc. Also, the advantage of the GTHTR300C is presented.

• 조명전기설비학회논문지
• /
• 제16권5호
• /
• pp.75-82
• /
• 2002

본 논문에서는 열병합발전설비의 최적운용계획을 위한 새로운 수리적 모델을 제안하였다. 본 논문에서 제안한 알고리즘은 에너지생산량에 따른 비용의 비선형적인 문제를 구간별로 선형화된 함수를 이용하여 혼합정수 계획법으로 모델링하였다. 제안한 수리적 모델은 종래 제시되었던 열병합발전설비의 최적운용을 위한 모델링 기법에서 해결하지 못했던 한계사항을 극복한 것으로서, 더욱 현실에 근접한 최적운용을 위한 모델이 되었다. 또한 본 연구에서는 시뮬레이션을 통해 다양한 사례에 대한 열병합발전설비의 최적 운용계획을 제시함으로서 수리적 모델의 유용성을 입증하였다.