• Current Photovoltaic Research
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• v.7 no.4
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• pp.121-124
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• 2019

In this research, the concept of a salt farm parallel solar power system, which produce salt and electricity at the same site, is proposed for the first time in the world. The concept is that large waterproof plates made by interconnected solar modules are installed at the bottom of the salt farm. The pilot system was successfully installed at a sea shore, and verified its feasibility as a solar power plant. For deeper understanding, simulations for power prediction of the system were carried out and compared with the field test results. The power generation of the salt farm parallel system is comparable to conventional solar power plants. The cooling effect by sea water contributes more to the increase in the crystalline silicon photovoltaic module performance than the absorption loss due to sea water by maintaining certain height above the module.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.162.1-162.1
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• 2010

Cavitation phenomenon has long been a difficult problem that regarded as negative event to fluid machines or industrial facilities. In the latest, however, some engineers became to understand the power of cavitation and use it to cleaning wall after developing cavitation nozzle. In this paper, we introduce new concept for power-generation system using cavitation jet flow maid by nozzle and impulse turbine in vacuum condition. The vacuum needed to make cavitation is generated naturally by Torricelli's vacuum, 10.23m effective head drop without additional power. We analyzed water's boiling and the steam's mean free path according to vacuum purity levels for nozzles and turbine blades. The nozzles make water accelerate in the neck and boil in expansion section of the nozzles. The shape of the impulse turbine is designed for absorption of the molecule's kinetic energy of the steam.

• Journal of KSNVE
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• v.7 no.4
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• pp.621-629
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• 1997

For computer aided design and costruction of low noisy power plants, indoor and outdoor noise prediction program has been developed. The program utilizes the predefined data of noise sources and building materials and has the faculty to estimate the source level using the empirical formula in case of the measured data not being available. In the noise prediction, the mutual noise propagation between indoor and outdoor sites are considered. The outdoor noise source in the calculation of geometric divergence effects is modelled as the omni-directional finite line or planar source according to the source geometry and the receiving points. Outdoor noise prediction is carried out to consider the diffraction effect due to plant structures as well as the attenuation effect due to atmospheric absorption and soft ground. The results of indoor and outdoor noise prediction for a recently constructed diesel engine power plant show good agreement with the measured.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.6-12
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• 2012

We present the optical models and calculation results of thin-film organic solar cells (OSCs) at oblique incidence of light, using the transfer matrix method. The simple expression for the optical power dissipation is derived at oblique incidence for s- and p-polarized light. The spatial distribution of the electric field intensity, the optical power density, and the optical power dissipation are calculated in both s- and p-polarized light with respect to the incidence angle. We identify how the light absorption efficiency for p-polarized light becomes relatively larger than that for s-polarized light as the incidence angle increases.

• Korean Journal of Optics and Photonics
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• v.4 no.3
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• pp.289-293
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• 1993

A Nd:YLF laser pumped by a CW GaAlAs laser diode(LD) at 792 nm has been designed and fabricated. The output power was investigated as a function of LD spectrum and pump power. A folded laser resonator was desinged to compensate for the astigmatism produced at the Brewster surface of Nd:YLF rod. We obtained output power of CW 1.1 Watt when the pumping power was 2.8 Watt and the output wavelength of LD was temperature tuned to the peak absorption line of Nd:YLF. The overall efficiency was 39 % and slope efficiency was 41 %.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.705-711
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• 2005

In DC traction substation with 12-pulse diode rectifiers, the DC line voltage tends to rise above noload voltage because it can't absorb the regenerative power caused by electric brakes of train. To solve this problem, an IGBT regenerative inverter should be installed and recycles the surplus regenerative power by delivering it. to the supply grid. In this paper, the DC traction substation equipped with a IGBT regenerative inverter is studied using computer simulation. Matlab/simulink is used to simulate the operation of regenerative inverter which injects the regenerative power into the supply grid and stabilizes the DC line voltage. It is confirmed that the high quality regenerative power is delivered to the supply grid thorough computer simulation.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.279-281
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• 2005

In DC traction substation with 12-pulse diode rectifiers, the DC line voltage tends to rise above noload voltage because it can't absorb the regenerative power caused by electric brakes of train. To solve this problem, an IGBT regenerative inverter should be installed and thus recycles the surplus regenerative power by delivering it to the supply grid. In this paper, the DC traction substation equipped with a IGBT regenerative inverter is studied using computer simulation. Matlab/simulink is used to simulate the operation of regenerative inverter which injects the regenerative power into the supply grid and stabilizes the DC line voltage. It is confirmed that the high quality regenerative power is delivered to the supply grid thorough computer simulation.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.10
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• pp.917-924
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• 2012

Noise power of large machineries, such as textile looms, winders, and twisting machines, is often measured in a reverberant space because they cannot be installed and operated in an anechoic chamber due to their size, weight, and operating conditions. Factors affecting the measurement error of an in-situ noise power measurement include the nonuniform reverberation time and the direction of sound intensity vector which is usually regarded as normal to the measurement surface. In this study errors due to these factors are estimated with the aid of numerical simulation based on the ray-tracing technique. The averaging of reverberation times measured at several points on the measurement surface is suggested to reduce the errors from nonuniform absorption. Also the direction cosine of each surface element is taken into account, which as a whole is represented as a solid angle of the measurement surface.

• Nuclear Engineering and Technology
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• v.34 no.1
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• pp.9-21
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• 2002

Recently each domestic NPP has achieved zero release in liquid effluent activity. However, when looking back past experiences in world nuclear power operation, it is thought that another maximum activity reduction in the released liquid effluent just prior to falling it into environment, if possible, will bring a good effect in PA viewpoint. As the intent of applying the safety concept of diversity to conducting the above activity reduction measure, a scheme passing that effluent through the Deposition Bed just before discharging it into ocean environment was divised. Both Zeolite and ＂the mixed ＂Anthracite-sand＂ were derived as the main activity adsorption medium used in the Deposition Bed, and the schematic drawings of this Bed were presented.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.6
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• pp.714-720
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• 2003

Due to the electric power shortage in summer season and regulation of freon refrigerant, the application of gas absorption refrigeration and hot water systems are considerably increasing trend. But, this system consists of condenser, heat exchanger, supply pipe and radiator etc. which are easily corroded by acidity and dissolved oxygen and gases. In result, this system occurs scale attachment and corrosion damage like pitting and crevice corrosion. In this study, electrochemical polarization test of heat exchanger tubing material (copper, aluminium brass, 30% cupronickel(30% Cu-Ni)) was carried out in 60% lithium bromide solution at $95^{\circ}C$. As a result of polarization test, corrosion behavior by impressed potential and local corrosion. such as galvanic corrosion, pitting corrosion behavior, of tubing materials was investigated. The main results obtained are as follows: (1) The effect of pitting and crevice corrosion control of 30% cupronickel in 60% LiBr solution at $95^{\circ}C$ is very excellent. (2) Dissimilar metal corrosion of 30% cupronickel coupling to aluminium bronze is the most sensitive. (3) Current density behavior of tube materials by impressed potential is high in order of copper > aluminium brass > 30% cupronickel.