Mechanism for cleaning solar collector surfaces

• US 10,111,563 B2
• Filed: 01/18/2013
• Issued: 10/30/2018
• Est. Priority Date: 01/18/2013
• Status: Active Grant

• Current Assignee: NovaSource Power Opco, Inc.
• Original Assignee: Sunpower Corporation (Totalenergies Se)
• Inventors: Grossman, Marc, Jeanty, Cedric
• Primary Examiner(s): Markoff, Alexander
• Application Number:
  US13/745,722
• Publication Number:
  US 20140202492A1
• Time in Patent Office: 2,111 Days
• CPC Class Codes: A47L 11/38 Machines, specially adapted for cleaning walls, ceilings, roofs, or the like
• CPC Class Codes: A47L 7/0004 Suction cleaners adapted to take up liquids, e.g. wet or dry vacuum cleaners floor-scrubbing machines taking-up dirty liquid by suction A47L11/30
• CPC Class Codes: B08B 1/12 Brushes
• CPC Class Codes: B08B 3/026 Cleaning by making use of hand-held spray guns; Fluid preparations therefor
• CPC Class Codes: F24S 40/20 Cleaning; Removing snow
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02E 10/52 PV systems with concentrators

Abstract

A system and method for cleaning a collector surface of a solar collector. The system includes a first liquid-dispensing unit configured to deliver a first spray of liquid to the collector surface. The system also includes a brush element having a longitudinal side oriented along a first direction and disposed adjacent to the first liquid-dispensing unit. A first squeegee element is oriented along the first direction and adjacent to the brush element. The first squeegee element, the brush element, and the first liquid-dispensing unit define a first cleaning area. A second squeegee element is oriented along the first direction and separated from the first squeegee element by a gap to define a second cleaning area. The system also includes a second liquid-dispensing unit configured to deliver a second spray of liquid to the second cleaning area located between the first and second squeegees.

Claims

1. A robotic cleaning device configured to clean a row of inclined solar collectors, the robotic cleaning device configured to traverse across the row of inclined solar collectors, each of the inclined solar collectors having a collector surface, and to cross gaps between adjacent solar collectors in the row, the robotic cleaning device comprising:

a first cleaning module configured to be swept along a portion of a collector surface of a solar collector, the first cleaning module comprising;

a first liquid dispenser mounted on a leading edge of the first cleaning module and configured to deliver a first spray of cleaning liquid to the portion of the collector surface, and

a brush element having a longitudinal side oriented along a first direction that is perpendicular to a direction in which the first cleaning module is swept, the brush element being disposed adjacent to the first liquid dispenser; and

a second cleaning module configured to be swept at a constant interval behind the first cleaning module, the second cleaning module comprising;

a first squeegee element oriented along the first direction and mounted at a leading edge of the second cleaning module, a first cleaning area being defined as an area between the first liquid dispenser of the first cleaning module and the first squeegee element of the second cleaning module;

a second squeegee element oriented along the first direction and mounted on a trailing edge of the second cleaning module to form a second cleaning area between the first and second squeegee elements; and

a second liquid dispenser mounted between the first and second squeegee elements and configured to deliver a second spray of liquid to the portion of the collector surface within the second cleaning area;

a frame having a front end and a back end, the back end being configured to be disposed at a top of the row of inclined solar collectors and including a guide mechanism to prevent the robotic cleaning device from sliding from the row of inclined solar collectors;

a front continuous track mechanism disposed at the front end of the frame, the front continuous track mechanism comprising a first rolling support, the front continuous track mechanism extending along a length of the frame in the first direction; and

a rear continuous track mechanism disposed at the back end of the frame, the rear continuous track mechanism comprising a second rolling support, the rear continuous mechanism extending along the length of the frame in the first direction;

wherein, via the first and second rolling supports, the front and rear continuous track mechanisms are configured to;

convey the first and second cleaning modules in a sweep direction along top surfaces of the row of inclined solar collectors, and

convey the first and second cleaning modules across gaps between adjacent solar collectors in the row of inclined solar collectors,

wherein the first liquid dispenser is configured to deliver the first spray within the first cleaning area and the second liquid dispenser is configured to deliver the second spray within the second cleaning area as the first and second cleaning modules are swept across collector surfaces of solar collectors in the row of inclined solar collectors, and

wherein the robotic cleaning device further includes;

a front sensor disposed at the front end of the frame, the front sensor being configured to produce a front sensor response signal in response to detecting the gap between adjacent solar collectors of a row of solar collectors as the first and second cleaning modules are swept across collector surfaces of the row of solar collectors;

a rear sensor disposed at the back end of the frame, the rear sensor being configured to produce a rear sensor response signal in response to detecting the gap between the adjacent solar collectors of the row of solar collectors as the first and second cleaning modules are swept across the collector surfaces of the row of solar collectors in use; and

a phase-locked loop control circuit configured to;

compare relative timings of the first sensor response signal and the rear sensor response signal, and

adjust the relative speed of the first and rear continuous track mechanisms based on the comparison of the relative timings of the front sensor response signal and the rear sensor response signal.

2. The robotic cleaning device of claim 1, wherein the brush element is a rotating brush element having bristles radially extending from a central rod.

3. The robotic cleaning device of claim 2, wherein the bristles of the brush element are arranged in a helical pattern, and the brush element is configured to auger cleaning liquid toward an upper end of the row of inclined solar collectors when the brush element is rotated.

4. The robotic cleaning device of claim 1, wherein the frame comprises:

one or more lateral beams arranged from the front to back end of the frame, wherein the one or more lateral beams are configured to mechanically joint the front and rear continuous track mechanisms.

5. The robotic cleaning device of claim 4, wherein the one or more lateral beams are formed from a hollow tubular structure, and the one or more lateral beams are at least partially filled with the cleaning liquid.

6. The robotic cleaning device of claim 1, wherein the phase-locked-loop control circuit is configured to increase a speed of either of the front and rear continuous track mechanisms in response to an increase in the timing difference between the front sensor response signal and the rear sensor response signal.

7. The robotic cleaning device of claim 1, wherein the phase-locked-loop control circuit is configured to decrease a speed of either of the front and rear continuous track mechanisms in response to an increase in the timing difference between the front sensor response signal and the rear sensor response signal.