• Journal of Power Electronics
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• v.2 no.1
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• pp.11-18
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• 2002

The development of the solar and the wind energy is necessary since the future alternative energies that have no pollution and no limitation are restricted. Currently MW Class power generation system has been developed, but it still has a few faults with the weather condition. In order to solve these existing problems, combined generation system of photovoltaic and wind power was suggested. It combines wind power energy and solar energy to have the supporting effect from each other. However, since even combined generation system cannot always generate stable output with everchanging weather condition, power storage apparatus that uses elastic energy of spiral spring to combined generation system was also added for the present study.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.360-363
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• 2012

A solar air heating has low efficiency compared with the solar water heating because the heat capacity of the air is small. The heat received by solar collector plate is not fully transferred to the air and then a part of them became the losses to the environment through conduction and convection process. This research is focusing on a design of better combined multi-purposed system suggested by us and aims to secure the more efficient solar energy utilization by combining the hot water and air heating system. The result in this paper has shown that the proposed design has better thermal performance than that of the common design. Furthermore, it was found that the performance of the combined air - water heating system increases the efficiency from 30% to 35%-40%.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.16 no.4
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• pp.392-405
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• 1987

A study of appling solar assisted heat pump heating system to Korean climatic charac-teritics has been undertaken through computer simulation using TRNSYS (A Transient System Simulation Program). It is insufficient for heating system composed of each of solar and heat pump system to supply heat met with heating load. So SAHP (Solar Assisted Heat Pump) heating systems which combined solar system with heat pump system are analized using the standard weather data of Korea. And SAHP heating systems are categorized into the series system in which the solar storage is used as the source for the heat pump, the parallel system in which ambient air is used as the source for the heat pump, and the dual source system in which the storage or ambient is used as the source depending on which source yields the lowest work input. These combined system are better than each of solar and heat pump heating system in view of thermal performance, and parallel system is most effective among these combined systems.

• Advances in Energy Research
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• v.4 no.1
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• pp.29-45
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• 2016

There has been a growing interest in the recent time for the development of solar power tower plants, which are mainly used for utility scale power generation. Combined heat and power (CHP) is an efficient and clean approach to generate electric power and useful thermal energy from a single heat source. The waste heat from the topping Brayton cycle is utilized in the bottoming HRSG cycle for driving steam turbine and also to produce process steam so that efficiency of the cycle is increased. A thermal storage system is likely to add greater reliability to such plants, providing power even during non-peak sunshine hours. This paper presents a conceptual configuration of a solar power tower combined heat and power plant with a topping air Brayton cycle. A simple downstream Rankine cycle with a heat recovery steam generator (HRSG) and a process heater have been considered for integration with the solar Brayton cycle. The conventional GT combustion chamber is replaced with a solar receiver. The combined cycle has been analyzed using energy as well as exergy methods for a range of pressure ratio across the GT block. From the thermodynamic analysis, it is found that such an integrated system would give a maximum total power (2.37 MW) at a much lower pressure ratio (5) with an overall efficiency exceeding 27%. The solar receiver and heliostats are the main components responsible for exergy destruction. However, exergetic performance of the components is found to improve at higher pressure ratio of the GT block.

• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.11-17
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• 2012

In this study, a simulation program was developed with heat transfer model in the thermal storage tank for a solar collector and burner combined heating and hot water supply system. Analysis was conducted with variation of operating condition and schedule to analyze performance of a hot water supply and panel heating system with a solar collector and burner combined thermal storage tank. The simulation program is divided two sections. One part is calculation of temperature variation of water which flows through the panel in the floor for heating of the residential house during 24 hours, and the other part is heat transfer calculation for the reaction time to get desired water temperature in the thermal storage tank. As results, light oil consumption and system performance during operation period were analyzed with variation of climate condition and with or without solar collector. Most of the case, oil could be saved about from 24 to 41% with installing the solar collector. The performance of the system is more dependent on radiation time of the solar collector rather than the intensity of the solar radiation which was adopted for the climate analysis.

• Journal of the Korean Solar Energy Society
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• v.33 no.5
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• pp.95-104
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• 2013

This study set out to devise an optimized system to take into account life cycle cost(LCC) and ton of carbon dioxide($TCO_2$) by applying the weighted coefficient method(WCM) to "public-purpose" facility buildings according to the mandatory 5% and 11% of new renewable energy in total construction costs and anticipated energy consumption, respectively, based on the changes of the public obligation system. (1) System installation capacity is applied within the same new renewable energy facility investment according to the mandatory 5% of new renewable energy in total construction costs. Both LCC and $TCO_2$ recorded in the descending order of geothermal, solar, and photovoltaic energy. The geothermal energy systems tended to exhibit an excellent performance with the increasing installation capacity percentage. (2) Optimal systems include the geothermal energy(100%) system in the category of single systems, the solar energy(12%)+geothermal energy(88%) system in the category of 2-combined systems, and the photovoltaic energy(12%)+solar energy(12%)+geothermal energy(76%) system and the photovoltaic energy(12%)+solar energy(25%)+geothermal energy(63%) system in the category of 3-combined systems. (3) LCC was the highest in the descending order of photovoltaic, geothermal and solar energy due to the influences of each energy source's correction coefficient according to the mandatory 11% of new renewable energy in anticipated energy consumption. The greater installation capacity percentage photovoltaic energy had, the more excellent tendency was observed. $TCO_2$ recorded in the descending order of geothermal, photovoltaic and solar energy with the decreasing installation capacity of photovoltaic energy. The greater installation capacity percentage a geothermal energy system had, the more excellent tendency it demonstrated. (4) Optimal systems include the geothermal energy(100%) system in the category of single systems, the photovoltaic energy(62%)+geothermal energy(38%) system in the category of 2-combined systems, and the photovoltaic energy(50%)+solar energy(12%)+geothermal energy(38%) system and the photovoltaic energy(12%)+solar energy(12%)+geothermal energy(76%) system in the category of 3-combined systems.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.51 no.4
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• pp.169-174
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• 2002

The developments of the solar and the wind power energy are neccessary since the future alternative energies that have no pollution and no limitation are restricted. Currently power generation system of existing problems, combined generation system of photovoltaic(400W) and wind power generation system(400W) was suggested. It combines wind power and solar energy to have the supporting effect from each other. However, weather condition, power compensation device that uses elastic energy of spiral spring to combined generation system was also added for the present study. In an experiment, when output of system gets lower than 12V(charging voltage), power was continuously supplied to load through the inverter by charging energy obtained from generating rotary energy of spiral spring operates in small scale generator.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.12B no.1
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• pp.24-30
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• 2002

The developments of the solar and the wind power energy are necessary since the future alternative, energies that have no pollution and no limitation are restricted. Currently power generation system of MW scale has been developed, but it still has a flew faults with the weather condition. In order to solve these existing problem combined generation system of photovoltaic(400W) and wind power generation system(400W) was suggested. It combines wind power and solar energy to have the supporting effect from each other. However, since even combined generation system cannot always generate stable output with ever-changing weather condition, power storage apparatus that uses elastic energy of spiral spring to combined generation system was also added far the present study. In an experiment, when output of combined generation system gets lower than 12V(charging voltage), power was continuously supplied to load through the inverter by charging energy obtained from generating rotary energy of spiral spring operates in small scale generator.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1136_1138
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• 2009

This paper gives a basic Energy performance data of micro gas turbine and Renewable Energy(BIPV and Solar Collector System) installed in Hospital Building. The efficiency of solar collector and BIPV system was 30%, 10% individually, and lower than micro gas turbines. Micro gas turbines are small gas turbines that burn gaseous and liquid fuels to produce a high-energy exhaust gas and to generate the electrical power. Recently the size range for micro gas turbines is form 30 to 500kW and power-only generation or in combined heat and power(CHP) systems. If micro gas turbine was operated only for electric energy, the efficiency was about 30%, but for combined heat and power, the efficiency was about 90%. Finally, installed in large hospital, Micro gas turbine system was operated to CHP mode, was high-efficiency system than Solar collector and BIPV system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.439-444
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• 2009

This paper gives a basic Energy performance data of micro gas turbine and Renewable Energy(BIPV and Solar Collector System) installed in Hospital Building. The efficiency of. solar collector and BIPV system was 30%, 10% individually, and lower than micro gas turbines. Micro gas turbines are small gas turbines that bum gaseous and liquid fuels to produce a high-energy exhaust gas and to generate the electrical power. Recently the size range for micro gas turbines is form 30 to 500kW and power-only generation or in combined heat and power(CHP) systems. If micro gas turbine was operated only for electric energy, the efficiency was about 30%, but for combined heat and power, the efficiency was about 90%. Finally, installed in large hospital, Micro gas turbine system was operated to CHP mode, was high-efficiency system than Solar collector and BIPV system.