Cleaning system for cleaning parabolic trough collector plants and cleaning method using said system

Abstract

The present invention relates to a cleaning system for cleaning parabolic trough collector plants made up of cleaning vehicles with moving means, cleaning means, and operating means thereof. The cleaning vehicles are autonomous and independent of one another, and have navigation means guiding and steering the cleaning vehicle in its movement along the plant. The navigation means are made up of a relative navigation system with an inertial unit and distance sensors which measure the distance of the cleaning vehicle to the parabolic trough collector, and an absolute navigation system with a GPS positioning sub-system. A control system integrates and controls the cleaning means, operating means, moving means and navigation means of the cleaning vehicles.

1 . A cleaning system for cleaning parabolic trough collector plants comprising a plurality of cleaning vehicles moving along the plant cleaning the parabolic trough collectors, each of these cleaning vehicles comprising
 a chassis, in which there are arranged   a moving means for the cleaning vehicle,   a cleaning means for cleaning the parabolic trough collectors, and   an operating means for operating the cleaning means, which position said cleaning means on the surface of the parabolic trough collectors to be cleaned, and move said cleaning means cleaning the collectors, wherein:   the cleaning vehicles are autonomous and independent of one another, additionally comprising in their chassis a navigation means for guiding and steering the cleaning vehicle in its movement along the parabolic trough collector plant, and which in turn comprise
 a relative navigation system, having
 an inertial unit, and 
 a plurality of distance sensors which measures the distance of the cleaning vehicle to the parabolic trough collector, 
 
 an absolute navigation system having a GPS positioning sub-system, 
   and the cleaning vehicles comprise a control system integrating and controlling the cleaning means, the operating means for operating said cleaning means, the moving means and the navigation means for moving the cleaning vehicles and cleaning the parabolic trough collectors.   
     
     
         2 . The cleaning system for cleaning parabolic trough collector plants according to  claim 1 , wherein:
 the operating means for operating the cleaning means comprise at least one robotic arm to which said cleaning means are fixed,   the cleaning means comprise at least one distance sensor which measures the distance of said cleaning means to the surface of the parabolic trough collector, and   once the cleaning means are positioned on the surface of the parabolic trough collector for cleaning, the at least one robotic arm moves them in a plane perpendicular to the parabolic trough collector and perpendicular to the direction of the cleaning vehicle, following the surface of said parabolic trough collector, while said cleaning vehicle is stopped.   
     
     
         3 . The cleaning system for cleaning parabolic trough collector plants according to  claim 1 , wherein the operating means for operating the cleaning means comprise
 a first robotic arm which brings the cleaning means closer to the surface of the upper part of the parabolic trough collector and moves them along the same, cleaning said upper part,   a second robotic arm which brings the cleaning means closer to the surface of the lower part of the parabolic trough collector and moves them along the same, cleaning said lower part.   
     
     
         4 . The cleaning system for cleaning parabolic trough collector plants according to  claim 2 , wherein the cleaning means comprise
 a straight and horizontal rotating roller, fixed to the end of the robotic arms, which rotates driven by an electric motor, and   a plurality of nozzles connected to a hydraulic system which spray pressurised water.   
     
     
         5 . The cleaning system for cleaning parabolic trough collector plants according to  claim 1 , wherein the cleaning vehicles comprise at least one additional nozzle fixed to the chassis connected to the hydraulic system which sprays pressurised water towards the pipe fixed to the collector through which the fluid to be heated by the collector flows, cleaning said pipe. 
     
     
         6 . The cleaning system for cleaning parabolic trough collector plants according to  claim 3 , wherein the first and second robotic arms are vertically misaligned. 
     
     
         7 . The cleaning system for cleaning parabolic trough collector plants according to  claim 1 , wherein the distance sensors are ultrasound sensors. 
     
     
         8 . The cleaning system for cleaning parabolic trough collector plants according to  claim 1 , wherein it comprises obstacle presence sensors arranged in a rear and a front part of the cleaning vehicles. 
     
     
         9 . The cleaning system for cleaning parabolic trough collector plants according to  claim 1 , wherein the absolute navigation system comprises a wireless communication system for communicating the cleaning vehicles with a fixed point of the plant. 
     
     
         10 . The cleaning system for cleaning parabolic trough collector plants according to  claim 1 , wherein the cleaning vehicles comprise a locating system for locating broken mirrors in the parabolic trough concentrator. 
     
     
         11 . The cleaning system for cleaning parabolic trough collector plants according to  claim 1 , wherein the cleaning vehicles comprise a locating system for locating leakages of the fluid flowing inside the pipe fixed to the parabolic trough collector. 
     
     
         12 . A cleaning method for cleaning parabolic trough collector plants using the cleaning system of  claim 1 , comprising:
 distributing the cleaning vehicles throughout the plant, positioning each of them at a first end of a parabolic trough collector,   positioning the cleaning vehicles parallel to the parabolic trough collector by means of their moving means and their navigation means, and then stopping said cleaning vehicles,   positioning the cleaning means on the surface of the first section of the parabolic trough collector to be cleaned by means of the operating means,   cleaning the first section of the parabolic trough collector by means of moving the cleaning means by the operating means in a plane perpendicular to the parabolic trough collector and perpendicular to the direction of the cleaning vehicle, following the surface of said parabolic trough collector while said cleaning vehicle is stopped,   separating the cleaning means from the surface of the first section of the cleaned parabolic trough collector,   moving the cleaning vehicles forward towards the next section of the parabolic trough collector by means of their moving means and their navigation means, and then stopping said cleaning vehicles for subsequently cleaning the next section of the collector,   separating the cleaning means from the surface of said last section of the cleaned parabolic trough collector, and autonomously moving the cleaning vehicles from the second end of the parabolic trough collector towards the first end of the next parabolic trough collector to be cleaned once the last section of the parabolic trough collector is cleaned.   
     
     
         13 . The cleaning method for cleaning parabolic trough collector plants according to  claim 12 , wherein in the step of cleaning the section of the parabolic trough collector the surface of the collector is sluiced by means of pressurised water sprayed by the nozzles of the cleaning means. 
     
     
         14 . The cleaning method for cleaning parabolic trough collector plants according to  claim 12 , wherein in the step of cleaning the section of the parabolic trough collector the following is performed
 sluicing the surface of the collector by means of pressurised water sprayed by the nozzles of the cleaning means, and   sluicing the surface of the collector by means of the straight and horizontal rotating roller driven by the operating means.   
     
     
         15 . The cleaning method for cleaning parabolic trough collector plants according to  claim 14 , wherein in the step of cleaning the section of the parabolic trough collector, after sluicing the surface of the collector by means of the rotating roller said surface of the collector is rinsed. 
     
     
         16 . The cleaning method for cleaning parabolic trough collector plants according to  claim 12 , wherein in the step of cleaning the section of the parabolic trough collector the pipe fixed to the parabolic trough collector is sluiced by means of pressurised water sprayed by the additional nozzles fixed to the chassis of the cleaning vehicles for cleaning said pipe. 
     
     
         17 . The cleaning method for cleaning parabolic trough collector plants according to  claim 12 , wherein in the step of moving the cleaning vehicles forward towards the next section of the parabolic trough collector, the pipe fixed to the parabolic trough collector is sluiced by means of pressurised water sprayed by the additional nozzles fixed to the chassis of the cleaning vehicles for cleaning said pipe.