• Journal of the Korean Solar Energy Society
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• v.34 no.3
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• pp.21-29
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• 2014

Heliostat field control algorithm is the logics to operate the heliostat field of tower type solar thermal power plant and it could include various methodologies of how to control the heliostat field so as to optimize the energy collection efficiency as well as to reduce the system operating cost. This work, as the first part of the consecutive works, presents heliostat aiming mint allocation scheme which will be used in the heliostat field control algorithm for 200kW solar thermal power plant built in Daegu, Korea. We first discuss the structure of heliostat field control system required for the implementation of aiming scheme developed in this work. Then the methodologies to allocate the heliostat aiming points on the receiver are discussed. The simulated results show that the heliostat aiming point allocation scheme proposed in this work reduces the magnitude of peak heat flux on the receiver more than 40% from the case of which all the heliostats in the field aim at the center of receiver simultaneously. Also it shows that, when the proposed scheme is used, the degradation of heliostat field optical efficiency is relatively small from the maximal optical efficiency the heliostat field could have.

• Journal of the Korean Solar Energy Society
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• v.34 no.5
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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.