• 한국태양에너지학회 논문집
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• 제35권3호
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• pp.65-71
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• 2015

A solar thermal simulator is suitable for indoor experiments of solar receivers and reactors when solar insolation and weather conditions are not favorable. Moreover, due to the easy control of electric power input, the solar thermal simulator allows the adjustment of power input incident on solar receivers and reactors and thus the implementation of accurate experiments. We manufactured a solar simulator, which is comprised of three sets of a xenon lamp and an elliptical reflector. In order to serve as a test facility, optical characterization of the solar simulator via radiation heat flux measurement is a critical prerequisite. We applied the flux mapping method to measuring the heat flux distribution of the three lamps. We presented the measurement results in terms of the heat flux distribution, the peak heat flux, the power distribution, the maximum power, and the efficiency for electric power conversion into radiation power. Characterization results show that our solar simulator provides the peak heat flux of $3,019kW/m^2$, the maximum power of 16.9 kW, and the conversion efficiency of 45%, additionally with a 10% operation margin for output increase.

• 한국태양에너지학회 논문집
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• 제29권1호
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• pp.50-57
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• 2009

Heliostat in the tower type solar thermal power plant is a mirror system tracking the sun's movement to collect the solar energy and it is the most important subsystem determining the efficiency of solar thermal power plant. Thus a good performance of it, which is mostly the accurate sun tracking performance under the various hazardous operating condition, is required. Heliostat control system is a system to manage the heliostat sun tracking movement and other operations. It also communicates with the master controller through the heliostat filed control system to receive and send the informations required to operate the heliostat as a part of the solar thermal power plant. This study presents a heliostat control system designed and developed for the 1MW solar thermal power plant. We first define the functionality of heliostat control system. Then sun tracking controller as well as the sun tracking algorithm satisfying the required functionality have been developed. We tested the developed heliostat control system and it showed a good performance in regulation of heliostat motion and communication.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.161-164
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• 2008

For the development of solar thermal power tower plant from the early 80' to today, various kinds of receiver have been tested and evaluated. Most of 1st generation receiver used water/steam as a working fluid to operate steam turbine and now the first commercial solar power tower PS-10 also makes saturated steam. However, to increase thermal efficiency of storage system and to obtain practical use of solar energy, molten salt system have been used from THEMIS project in France at 1984. The Solar Tres plant of 17 MWe power generation will be constructed in Spain and have plan to operate 24 hours in summer. The air volumetric receiver system can be integrated with combined cycle of gas turbine and HRSG and also with steam turbine easily. Therefore, related researches to develop higher efficient solar power tower plant and to operate with stable are widely performed in the world.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.246-249
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• 2011

SolarPACES is an international cooperative network bringing together teams of national exports from around the world to focus on the development and marketing of concentrating solar power systems (also known as solar thermal power systems). It is one of a number of collaborative programs, called Implementing Agreements, managed under the umbrella of the International Energy Agency to help find solutions to worldwide energy problems. Technology development is at the core of the work of SolarPACES. Member countries work together on activities aimed at solving the wide range of technical problems associated with commercialization of concentrating solar technology, including large-scale system tests and the development of advanced technologies, components, instrumentation, and systems analysis techniques. In addition to technology development, market development and building of awareness of the potential of concentrating solar technologies are key elements of the SolarPACES program The Implementing Agreement specifies broad "Tasks," or thematic areas of work SolarPACES currently has three ongoing tasks, focusing on concentrating solar electric power systems (Task I), solar chemistry research (Task II), and solar technology and applications (Task III). An Operating Agent, nominated by the ExCo, is responsible for overseeing the work of each task Each task maintains a detailed program of work that defines all task activities, including their objectives, participants, plans, and budgets. In addition to technical reports of the activities and their participants, accomplishments and progress are summarized in the SolarPACES annual report. Many SolarPACES activities involve close cooperation among member countries (either through sharing of task activities or, occasionally, cost-sharing), although some cooperation is limited to sharing of information and results with other participants. In this paper, structure, works, and members of SolarPACES and Korean activies in the SolarPACES are introduced.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.320-323
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• 2011

SolarPACES is an international cooperative network bringing together teams of national experts from around the world to focus on the development and marketing of concentrating solar power systems (also known as solar thermal power systems). It is one of a number of collaborative programs, called Implementing Agreements, managed under the umbrella of the International Energy Agency to help find solutions to worldwide energy problems. Technology development is at the core of the work of Solar PACES. Member countries work together on activities aimed at solving the wide range of technical problems associated with commercialization of concentrating solar technology, including large-scale system tests and the development of advanced technologies, components, instrumentation, and systems analysis techniques. In addition to technology development, market development and building of awareness of the potential of concentrating solar technologies are key elements of the Solar PACES program. The Implementing Agreement specifies broad "Tasks," or thematic areas of work. SolarPACES currently has three ongoing tasks, focusing on concentrating solar electric power systems (Task I), solar chemistry research (Task II), and solar technology and applications (Task III). An Operating Agent, nominated by the ExCo, is responsible for overseeing the work of each task. Each task maintains a detailed program of work that defines all task activities, including their objectives, participants, plans, and budgets. In addition to technical reports of the activities and their participants, accomplishments and progress are summarized in the SolarPACES annual report. Many SolarPACES activities involve close cooperation among member countries (either through sharing of task activities or, occasionally, cost-sharing), although some cooperation is limited to sharing of information and results with other participants. In this paper, structure, works, and members of SolarPACES and Korean activies in the SolarPACES are introduced.

• 한국태양에너지학회 논문집
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• 제34권5호
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• pp.33-41
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• 2014

Heliostat field in a tower type solar thermal power plant is the sun tracking mirror system which affects the overall efficiency of solar thermal power plant most significantly while consumes a large amount of energy to operate it. Thus optimal operation of it is very crucial for maximizing the energy collection and, at the same time, for minimizing the operating cost. Heliostat field operational algorithm is the logics to control the heliostat field efficiently so as to optimize the heliostat field optical efficiency and to protect the system from damage as well as to reduce the energy consumption required to operate the field. This work presents the heliostat field operational algorithm developed for the heliostat field of 200kW solar thermal power plant built in Daegu, Korea. We first review the structure of heliostat field control system proposed in the previous work to provide the conceptual framework of how the algorithm developed in this work could be implemented. Then the methodologies to operate the heliostat field properly and efficiently, by defining and explaining the various operation modes, are discussed. A simulation, showing the heat flux distribution collected by the heliostat field at the receiver, is used to show the usefulness of proposed heliostat field operational algorithm.

• Advances in Energy Research
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• 제4권1호
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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.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.174-177
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• 2008

The proceeding of the $14^{th}$ biennial concentrating solar power SolarPACES symposium was closely reviewed and summarized to have an overview on up-to-date concentrated solar thermal technologies. A number of studies covering parabolic trough concentrating system, central receiver technology, solar fuels, dish and others were presented in the symposium which was held in Las Vegas, USA, from 4 to 7, 2008. Based on this overview a brief summary of technology trend and prospects were added in the paper.

• 한국태양에너지학회 논문집
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• 제31권3호
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• pp.80-88
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• 2011

Heliostat in the tower type solar thermal power plant is a sun tracking mirror system to reflect the solar energy to the receiver and the optical performance of it affects to the efficiency of whole power plant most significantly. Thus a solid understanding of heliostat's energy concentration characteristics is the most important step in designing of the heliostat field and the whole power plant. The work presented here is the analysis of energy concentration characteristics of heliostat used in 200kW solar thermal power plant, where the receiver located at 43m high in tower has $2{\times}2$m rectangular shape. The heliostat reflective surface is formed by 4 of $1{\times}1$m flat plate mirror facet and the mirror facet is mounted on the spherical frame. The direct normal incident radiation models in vernal equinox, summer solstice, autumnal equinox and winter solstice are first derived from the actually measured data. Then the intercept ratio, heat flux distribution and total energy collected at the receiver for the heliostats located in the various places of the heliostat field are investigated. Finally the effect of mirror facet installation error on the optical performance of the heliostat is analyzed.

• 한국태양에너지학회 논문집
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• 제31권2호
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• pp.53-62
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• 2011

Heliostat in the tower type solar thermal power plant is a sun tracking mirror system to reflect the solar energy to the receiver and the optical performance of it affects to the efficiency of whole power plant most significantly. Thus a proper design of structure of the heliostat reflective surface could be the most important step in the construction of such power plant. The work presented here is a design of structure of optical surface of heliostat, which will be used in 200kW solar thermal power plant. The receiver located at 43(m) high from ground in tower has $2{\times}2$(m) rectangular shape. We first developed the software tool to simulate the energy concentration characteristics of heliostat using the ray tracing technique. Then, the shape of heliostat reflective surface is designed with the consideration of heliostat's energy concentration characteristics, production cost and productivity. The designed heliostat's reflective surface has a structure formed by canting four of $1{\times}1$(m) rectangular flat plate mirror facet and the center of each mirror facet is located on the spherical surface, where the spherical surface is formulated by the mirror facet mounting frame.