Research And Development Of Heliostats Dust-accumulation-degree Inspection Robot System In In-service Solar Power Tower Heliostat Field

In the Solar Power Tower(SPT),photothermal conversion efficiency is closely related to heliostat dust-accumulation-degree.In the heliostat field,the dust state of the mirror at different positions is closely related to the wind direction,wind speed and previous cleaning time.Due to the limited scope of mirror cleaning equipment and the lack of water resources in the plateau desert,it is necessary to give priority to cleaning higher dust-accumulation-degree mirrors to ensure photothermal conversion efficiency and reduce maintenance costs.Therefore,an inspection robot is required to obtain the state of the dust-accumulation-degree in the heliostat field and optimize the cleaning strategy.Because the heliostat field is large and the terrain is uneven,the mirror surface is large and the tilt angle is variable,and the measurement requirements of the dust-accumulation-degree instrument are different.In response to these special needs,the paper studied and developed a robot for dust-accumulationdegree inspection.The main research work and achievements are as follows:(1)Through literature reading,heliostat field visits and industry conferences,it was confirmed that the core of the on-demand cleaning strategy is to prioritize the areas to be cleaned according to the dust-accumulation-degree.Therefore,a special robot for detecting the dust-accumulation-degree of the heliostats was developed.After dimension evaluation,mechanical design,parameter accounting,program joint debugging.The robot can be equipped with a dust-accumulation-degree instrument,and can perform posture adjustment control for different mirror inclinations.It can also move stably along the specified path,and achieve the sampling inspection function of the mirror surface of the heliostat field.(2)The dust collecting characteristics of the heliostat surface were studied experimentally,and it was confirmed that the dust-accumulation-degree was negatively correlated with the mirror tilt.During the operation of the heliostat,the further away from the central heat-collecting tower,the greater the inclination of the mirror surface.Based on this,the paper divides the inspection area according to the wind direction and conducts inspections by sampling,comprehensively considers the dominant wind direction,heliostat position and other factors,and proposes a design scheme for the inspection path suitable for large-scale heliostat field.(3)For the change of the tilt angle of different heliostats,and different dustaccumulation-degree instruments have different adjustment requirements for detection distance and relative angle.By analyzing the posture control requirements of the dustaccumulation-degree instruments,a non-contact attitude measurement method was proposed.Then,a set of position measuring device and attitude adjustment mechanism was successfully developed,which can satisfy the control requirements for the detection distance and angle of the dust-accumulation-degree detecting device.(4)According to the requirements of robot inspection area and data transmission,the remote monitoring software of the heliostat field dust-accumulation-degree inspection robot was developed,which can achieve remote data collection,check inspection and dust-accumulation-degree data monitoring management.Through laboratory run verification and equipment acceptance evaluation,the inspection robot designed in this paper has the functions of autonomous navigation and positioning,detection device pose control,remote control,data acquisition and management.It has better application development and market prospects.