• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.163-166
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• 2010

Numerical analysis is conducted to design the high temperature heat exchanger of Stirling engine by using the commercial CFD solver FLUENT. The fin-tube type of heat exchanger numerical calculation is conducted by changing the shape, number and material of fin shape of working fluid channel, etc in three-dimensional combustion field. Adjusted one-way constant velocity is used as the representative velocity of oscillating flow. The optimum design of heat exchanger considering the heat trasfer capability is suggested by using the calculation results.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.252-257
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• 2010

The availability of the thermal energy has been deeply recognized recently to encourage the cascade usage of thermal energy from combustion. Within the frame work, a 1 kW class Stirling engine based cogeneration system has been proposed for a unit of a distributed energy system. The capacity has been designed to be adequate for the domestic usage, which requires high compactness as well as low emission and noised. To develop a highly efficient system with satisfying these requirements, a premixed slot flame burner has been proposed and a series of numerical simulation has been performed to establish a design tool for the combustion chamber. The thermal radiation model has been found to highly affect the computational results and a proper resolution to analyze the heat transfer characteristics of the high temperature heat exchanger. Finally, the combustion characteristics of the premixed flame with the metal fiber type burner has been studied.

• 대한기계학회논문집
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• 제18권7호
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• pp.1751-1758
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• 1994

A new set of governing equations is derived for the dynamic analysis of the Free-Piston Stirling Engines(EPSE). Equations from the ideal adiabatic model for the thermodynamic analysis of the working fluid are incoporated with the equations of motion for the moving masses of the system, resulting in a set of nonlinear differential equations. The coupled set of equations are numerically integrated with proper intial conditions to obtain a steady state response of the engine. The proposed method is compared with the conventional method of analyzing EPSE based mainly on the ideal isothermal model. The results clearly shows the limitationsl of the conventional methods and the relative advantages of the method proposed in the present study.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.177-183
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• 2008

For 10 kW-class Stirling engine using scroll expander and scroll compressor, considerations on thermal expansion of the fixed and orbiting scroll members of the scroll expander due to high gas temperature at the expander inlet has resulted in adopting of the keys between the fixed scroll and main frame for the fixed scroll side and spring type insertion between the orbiting scroll base plate and supporting holders for orbiting scroll side. Dynamic analysis on the fixed and orbiting scroll members and the shafts of the scroll expander showed that using of these devices for complying thermal expansion caused large variations of the forces acting on the fixed scroll keys and on the power transmitting shafts and also on the shaft bearings.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2001년도 춘계학술대회 논문집
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• pp.122-128
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• 2001

The simulation analyses of a dish solar power system with stirling engine in this study are applied to system performance prediction if four different test sites; Seoul, Pusan and Cheju in Korea, and Naha in Japan. The effects of difference of concentrator type such as monolithic and stretched-membrane construction on system efficiency are also evaluated. The total amount of generated power for a year depends on the site. However the total maximum system efficiency in every site is approximately 16% and there isnt striking difference. It is also found that the maximum collector efficiency of stretched-membrane concentrator is about 3∼15% lower than that of the monolithic type.

• Journal of Biosystems Engineering
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• 제17권4호
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• pp.305-313
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• 1992

Stirling 기관(機關)의 피스톤 Seal부분에서의 마찰저항(摩擦抵抗)을 감소(減少)시킴과 동시 에 작동가스의 누설량(漏泄量)을 감소(減少)시켜서 기관출력(機關出力)을 증대(增大)시킬 목적(目的)으로 재질(材質) 및 밀봉(密封) 형식(形式)이 서로 다른 Piston ring식 밀봉기구(密封機構)와 금속(金屬) Bellows를 이용한 밀봉기구(密封機構)를 시작(試作)해서 마찰저항(摩擦抵抗)과 작동가스의 누설량(漏泄量)을 조사(調査)하고, 이들 밀봉기구(密封機構)를 실험(實驗) 기관(機關)에 장착(裝着)해서 운전시험(運轉試驗)을 통해 각 밀봉기구(密封機構)의 성능(性能)을 검토(檢討)하였다. 그 결과(結果) Bellows를 Power piston의 Actuator로 시작(試作)한 밀봉기구(密封機構)가 다른 Piston-ring식(式) 밀봉기구(密封機構)에 비(比)해, 피스톤링과 실린더벽 사이의 마찰저항(摩擦抵抗) 및 작동(作動)가스의 누설량(漏泄量)이 현저하게 감소(減少)하였으며, D-type은 B-type에 비해 도시출력(圖示出力)은 약 1.6배, 축출력(軸出力)은 약 1.2배로 증가(增加)하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.794-799
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• 2001

The simulation analyses of a solar power system with monolithic concentrator by using a stirling engine are carried out to predict the system performance in four test sites. The site has different intensities and distributions of direct solar radiation respectively. Seoul, Pusan and Cheju in Korea, and Naha in Japan are selected as test sites. To accomplish the same demand of a 25 kW output that the power level of a system has, it needs to take the matching of collector/receiver with engine/generator systems. In such a case, also, the size of the collector is sometimes adjusted. In this study, the diameter of the collector is decided by using the solar radiation of design point, which is defined as the sum of average and standard deviation $\sigma$ of maximum direct solar radiation distribution for a day during a year in the respective test site. It is found that the average power output during the system operating time in the case of slope error ${\sigma}_s=2.5$ is within the range of 9 to 13 kW.

• 설비공학논문집
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• 제21권2호
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• pp.94-102
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• 2009

Conceptual design of scroll expander and scroll compressor for 10kW-class Stirling engine utilizing solar energy as heat source has been carried out to estimate the applicability of scroll mechanism for Stirling cycle. CO2 was chosen as working fluid, since it has lower expansion index and higher density among probably usable gases. Gas temperature at the expander inlet was set at $700^{\circ}C$, and that at the compressor inlet was at $40^{\circ}C$. System efficiency reached maximum at the pressure ratio of about 2.5, and the peak efficiency increased with increasing high side pressure. Due to safety concern, the pressure condition of 6 MPa/2.5 MPa was chosen as design condition. Orbiting scroll members for the expander and compressor were designed to have double-sided structure in order to reduce the overall scroll size and to cancel out the axial gas forces acting on the orbiting scroll base plate. By parametric study on the scroll profile, smaller possible size for the scroll members was obtained. With the shaft speed of 3600rpm, the shaft output of the designed scroll expander was calculated to be 45.4kW, while input power for the scroll compressor was 34.5kW, yielding 10.9kW for the output power of the Stirling engine. System efficiency was estimated to be about 7.3%, and overall efficiencies of the scroll expander and compressor were around 84.1% and 88.3%, respectively.

• Journal of Biosystems Engineering
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• 제30권4호
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• pp.195-201
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• 2005

The output of Stirling engine is influenced by the regenerator effectiveness. The regenerator effectiveness is influenced by heat transfer and flow friction loss of the regenerator matrix. In this paper, in order to provide a basic data for the design of regenerator matrix, characteristics of heat transfer and flow friction loss were investigated by a packed method of matrix in the oscillating flow as the same condition of operation in a Stirling engine. As matrices, several kinds of combined wire screen meshes were used. The results are summarized as follows; The packed meshes with high mesh no. in the side of heater part of regenerator showed effective than the packed meshes with low mesh no. in the side of cooler part of regenerator. The temperature difference and pressure drop of the regenerator were not made by the specific surface area of wire screen meshes but by the minimum free-flow area to the total frontal area. Among the No. 150 single screen meshes, 200-60 combined meshes, the 200-150-100 combined meshes showed the highest in effectiveness.

• 한국태양에너지학회 논문집
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• 제30권6호
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• pp.118-124
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• 2010

In order to develop commercial model of 10kW dish-Stirling solar thermal power system, modification for the exiting facility was taken for a year as a Leading Project in KIER. During the project, solar tracking system, control and monitoring system and high durability reflector were developed and long term operation were performed. The solar tracking system was tested for four months to investigate the degree of precision and adapted to the control system for an actual operation from October in 2009. The sun tracking accuracy of ${\pm}4$ mrad using modified control system was obtained and the system operated successfully during the experimental period. The monitoring system displays engine pressure, electric generation amounts, generator RPM, receiver temperatures, and etc. from Stirling engine and weather data of Direct Normal Irradiation, Horizontal Global Insolation, wind speed & direction, and atmosphere temperature from weather station. According to the operating results in a clear sky day, electric power of 6,890 W was generated at the DNI value of 850 W/$m^2$ and the averaged solar-to-electricity efficiency during a whole day reached to 18.99%. From the overall operating results, linear power generation trend could be observed with increasing DNI value. The solar-to-electricity efficiency achieved to 19% around the DNI value of 700 W/$m^2$ and increased to 20% when the DNI value goes up to 900 W/$m^2$.