The invention provides a closed-
loop control method for a point focusing
solar furnace, which comprises the following steps of: placing a CCD (
Charge Coupled Device) camera at a main
optical axis of a reflecting surface of a secondary condenser, and controlling the
CCD camera by a computer to collect
light spot images which are converged and reflected to a heat absorber by the secondary condenser; the horizontal direction deviation
delta X and the vertical direction deviation
delta Y of the
light spot center position O'and the center position O of the heat absorber are calculated through
image processing, and the computer sends the
light spot deviation to the
heliostat local controller to control the
heliostat to adjust the light spot center position O 'to return to the center position O of the heat absorber; and when the deviation of the light spot in the horizontal direction and the deviation of the light spot in the vertical direction are smaller than a set threshold value, the light spot deviation correction process is finished, and closed-
loop control is completed. Normal work of the
solar furnace is not affected, tracking errors of the
solar furnace can be automatically detected and corrected, the tracking precision of the solar furnace can be remarkably improved compared with open-
loop control, and the solar furnace closed-loop control method is real-time and efficient.