U.S. patent application number 13/995746 was filed with the patent office on 2013-10-31 for cleaning system for cleaning parabolic trough collector plants and cleaning method using said system.
This patent application is currently assigned to SENER, INGENIERIA Y SISTEMAS, S.A.. The applicant listed for this patent is Soledad Garrido Ortiz, Francesc Massabe Munoz, Carlos Javier Vicente Pena, Jose Ramon Villa Navarro. Invention is credited to Soledad Garrido Ortiz, Francesc Massabe Munoz, Carlos Javier Vicente Pena, Jose Ramon Villa Navarro.
Application Number | 20130284207 13/995746 |
Document ID | / |
Family ID | 45787155 |
Filed Date | 2013-10-31 |
United States Patent
Application |
20130284207 |
Kind Code |
A1 |
Vicente Pena; Carlos Javier ;
et al. |
October 31, 2013 |
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.
Inventors: |
Vicente Pena; Carlos Javier;
(Madrid, ES) ; Massabe Munoz; Francesc;
(Barcelona, ES) ; Villa Navarro; Jose Ramon;
(Madrid, ES) ; Garrido Ortiz; Soledad; (Madrid,
ES) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Vicente Pena; Carlos Javier
Massabe Munoz; Francesc
Villa Navarro; Jose Ramon
Garrido Ortiz; Soledad |
Madrid
Barcelona
Madrid
Madrid |
|
ES
ES
ES
ES |
|
|
Assignee: |
SENER, INGENIERIA Y SISTEMAS,
S.A.
Vizcaya
ES
|
Family ID: |
45787155 |
Appl. No.: |
13/995746 |
Filed: |
February 14, 2012 |
PCT Filed: |
February 14, 2012 |
PCT NO: |
PCT/EP2012/000745 |
371 Date: |
June 19, 2013 |
Current U.S.
Class: |
134/6 ;
15/103.5 |
Current CPC
Class: |
B08B 1/04 20130101; F24S
40/20 20180501; G05D 2201/0203 20130101; Y02B 10/20 20130101; Y02E
10/40 20130101; B25J 5/007 20130101; Y02E 10/45 20130101; B25J
9/0084 20130101; G05D 1/0238 20130101; G05D 1/027 20130101; B08B
1/00 20130101; F24S 50/00 20180501; B08B 3/024 20130101; F24S 23/74
20180501; B25J 11/0085 20130101; G05D 1/0278 20130101 |
Class at
Publication: |
134/6 ;
15/103.5 |
International
Class: |
F24J 2/46 20060101
F24J002/46 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 18, 2011 |
ES |
P201130389 |
Claims
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.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention belongs to the technical field of
mechanised cleaning systems for cleaning large surfaces,
specifically large reflective surfaces with a noticeable concave
curvature, and more specifically to the mechanised cleaning of
large parabolic trough collector plants.
BACKGROUND OF THE INVENTION
[0002] Many systems and methods for the mechanised cleaning of
large surfaces such as buildings, large windows, glass panels,
monuments, and specifically heliostats, trackers and photovoltaic
solar installations and large parabolic trough collector plants for
heating the fluids flowing inside the pipes fixed to said parabolic
trough collectors have emerged in the last few years. Articulated
arms which apply pressurised water or brushing devices applied by
articulated arms stand out among them. The more modern methods try
to be as automated as possible for the purpose of reducing labour
and human control to achieve the greatest efficiency possible, so
many of these systems incorporate robots for cleaning.
[0003] In terms of the particular case of parabolic trough
collector plants, these need a periodic maintenance for their
correct operation and for making the most out of the energy which
can be obtained from the same. One of the main maintenance
activities which directly influences the energy produced is the
reflectivity of the mirrors and the pipe making up the collector.
This reflectivity depends on several factors dirt build-up both on
the mirrors and on the tube through which the fluid flows being a
determining factor. To reduce the dirt and maintain an optimum
cleaning rate the periodic programming of cleaning activities is
necessary for maintaining the reflectivity of the mirrors in
optimum values and the absorbance of the tube and thus obtaining
the maximum performance of the plant.
[0004] The characteristics of these collector plants are such that
they make the cleaning the same a specific problem.
[0005] Each collector longitudinally measures more than one hundred
meters and has a height of several meters. The collector is divided
into symmetrical upper and lower parts, depending on whether the
part is above or below its axis. The collectors can have different
sizes, but usually each of them can be formed from approximately
between several hundred and one thousand square meters of mirror
divided into facets. Each collector has hundreds of facets of
mirror with a separation therebetween and organised into rows and
columns both in the upper part of the collector and in the lower
part.
[0006] The shape of the collector is parabolic trough-like,
therefore the facets forming it are curved facets, with different
angle of curvature according to their arrangement in the collector.
In the focal point of the paraboloid a pipe through which a fluid
flows which rests on the collector is arranged by means of a
structure joining the support of the pipe with the paraboloid in
its axis. The cleaning system must therefore be such that the
cleaning tool used is capable of adapting to the curvature of the
mirrors such that the entire surface of the collector, both the
lower and upper parts can be cleaned, overcoming the tube and its
support structure, as well as the structure for supporting and
actuating the collector assembly.
[0007] In the collector cleaning operation, both the mirrors and
the pipe must be cleaned. The cleaning of the mirrors is very
delicate since they must be cleaned in an efficient manner but
without damaging them by wear or breakage, which involves a precise
control of the distance of the cleaning tool at all times with
respect to the mirror, as well as a careful selection of the
cleaning tool material if this is to be performed by contact. The
pipe is also very delicate since a breakage thereof would imply
serious problems for the plant, since it renders a complete loop of
collectors useless and needs the operation for emptying the fluid
and repairing said pipe. The arrangement of the pipe also involves
controlling the path and position of the cleaning tool and of the
arm supporting it to prevent impacts which cause damage to the
same.
[0008] The parabolic trough collector plants are organised in
hundreds of loops, each loop containing several collectors joined
linearly and in parallel forming a U. Therefore in each plant the
collectors are in the order of hundreds of linear kilometres, and
this is a particular characteristic of these plants since the
cleaning vehicle which is used to clean them must travel all these
kilometres while cleaning hundreds of thousands of square meters of
mirrors along the path, which must be done efficiently and quickly.
This implies that cleaning a complete plant requires a lot of time
and the plant must also be cleaned with a determined frequency for
maintaining the reflectivity of the mirrors, therefore if the
cleaning system is not capable of covering the entire path in a
determined time, more cleaning equipment is needed, implying a
greater cost.
[0009] The terrain of the plant which is uneven introduces another
additional characteristic typical of these plants. Said unevenness
must be absorbed by the cleaning system such that the movement of
the cleaning tool is not affected by the same, maintaining the
distance relative to the mirrors constant with respect to any
unevenness of the terrain. An impact with the mirrors or the pipe
causing damage therein is thus prevented. Likewise, in the rainy
season the terrain can become muddy and under these circumstances
the vehicle must avoid damaging the paths due to its weight as it
passes.
[0010] The frequency of cleaning is determined by several factors,
among them the quality of the cleaning system used. If the cleaning
system is not of high quality, the frequency of cleaning must be
increased, which results in a greater number of equipment necessary
for performing the cleaning and therefore a greater investment cost
thereon. If in contrast the cleaning is of quality, the frequency
of cleaning is lower, less equipment is needed and the investment
is lower. If the cleaning equipment needs human operation of any
type the costs of the plant increase due to the personnel cost
throughout the service life of the plant. Likewise heavy cleaning
equipment damage the terrain of the plant, making the investment on
machinery which repairs said terrain of the plant necessary or
preventing its use in rainy seasons.
[0011] In terms of the cleaning methods implemented for cleaning
large surfaces, automatic car wash services stand out where
rotating rollers and pressurised water clean the surfaces of the
cars for cleaning them. Documents GB1071366, U.S. Pat. No.
3,481,346 and US2004/0064908, for example, show inventions based on
moving the object to be cleaned and not on moving the cleaning
vehicle which will perform the cleaning as is the case in question.
Another type of cleaning devices are those which are intended for
cleaning tunnels, walls, panels, etc., such as those shown in
documents EP0668400, ES1034481 and EP0874086. All these systems
describe the cleaning of large surfaces by means of rollers and
pressurised water by means of tools which clean as the vehicle
moves and which have a structural shape adapted to the shape of the
surface to be cleaned.
[0012] In terms of cleaning solar power plants of parabolic trough
collectors or solar panels, the method was similar to the usual
surface cleaning method, i.e., by using brushes and/or pressurised
water for cleaning the mirrors which are on the collectors, as
shown by documents ES1069495, WO2010/106195, ES2316317, ES2267393,
and WO2010/142837.
[0013] In the current cleaning systems for cleaning parabolic
trough collectors, the solution to the cleaning problem thereof has
been dealt with in different ways, the more common being using a
large and heavy vehicle which includes a tool that performs the
cleaning on said vehicle. This tool consists of a group of
pressurised water dispensers and can additionally incorporate
rotating rollers or brushes for cleaning the mirrors by contact, in
both cases the tool adopts the parabolic shape of the collector and
its size is determined by the height of said collector, which means
heavy tools, affecting the weight of the vehicle. The vehicle
usually moves in parallel to the collector while cleaning the same
in a longitudinal direction. Each vehicle is provided with one or
two tools, such that each cleans one half of the collector (the
upper or the lower part). Furthermore, these cleaning vehicles need
at least one operator to operate ft. These systems have a series of
problems, including the low cleaning quality, especially in the
cleaning systems for cleaning exclusively with pressurised water,
the frequency of cleaning must be increased and therefore the
investment on equipment and labour. Furthermore, since the
intervention of at least one operator is needed the costs per
cleaning operation increase. The heavy vehicles damage the terrain
of the plant, and the vehicles which longitudinally clean the
collector while moving forward are more susceptible to being
affected by the unevenness of the terrain and therefore are more
susceptible to damaging the collectors. Another problem is that the
cleaning tools which clean as the vehicle moves and which have the
shape of the collectors have to perform manoeuvres to overcome the
supports of the tube as well as the supports of the collectors
themselves and the joints between collectors.
[0014] A system which achieved an efficient cleaning of the
parabolic trough collectors preventing the drawbacks existing in
the systems of the state of the art above was therefore
desirable.
DESCRIPTION OF THE INVENTION
[0015] The present invention solves the problems existing in the
state of the art by means of a cleaning system for cleaning
parabolic trough collector plants, which is made up of a plurality
of cleaning vehicles moving along the plant cleaning the parabolic
trough collectors.
[0016] The cleaning vehicles used are small and light cleaning
vehicles for reducing their impact on the collector plants as much
as possible.
[0017] Each of these cleaning vehicles has a chassis in which there
are arranged moving means for moving the cleaning vehicle, cleaning
means for cleaning the parabolic trough collectors, and 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 them for cleaning the collectors.
[0018] The cleaning vehicles object of the present invention are
autonomous and independent of one another, i.e., they do not need
an operator to operate them during the cleaning process, which
reduces the operating costs. To that end they additionally have
navigation means in their chassis, guiding and steering the
cleaning vehicle in its movement along the parabolic trough
collector plant. These navigation means consist of a relative
navigation system and an absolute navigation system.
[0019] The relative navigation system is made up of an inertial
unit and a group of distance sensors, which measures the distance
of the cleaning vehicle to the parabolic trough collector.
[0020] The absolute navigation system has a GPS positioning
subsystem. The absolute navigation system can additionally
incorporate a wireless communication system for communicating the
cleaning vehicles with a determined point of the plant for
obtaining a greater precision in the positioning thereof. The
cleaning vehicles additionally have a control system integrating
and controlling the cleaning means, the operating means thereof and
the moving and navigation means of the vehicles for providing the
correct movement of the cleaning vehicles and an efficient cleaning
of the parabolic trough collectors at the same time.
[0021] The operating means for operating the cleaning means have
particularly at least one robotic arm to which said cleaning means
are fixed.
[0022] Furthermore, the cleaning means have at least one distance
sensor, which measures the distance of these cleaning means to the
surface of the parabolic trough collector.
[0023] Thus, as a result of the distance sensors, the cleaning
means can be brought precisely and safely closer to the surface of
the parabolic trough collector without damaging it. Once
positioned, for performing the cleaning tasks, the robotic arm
moves the cleaning 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. in other words, the vehicle
does not move forward and actuates its cleaning means at the same
time, as occurs in the systems of the state of the art, but first
moves forward, then stops, and then positions the cleaning means
and actuates them. When it finishes, it removes the cleaning means
and moves again.
[0024] Since the movement is in the plane perpendicular to the
collector, the supports of the tube fixed thereto are not obstacles
for cleaning the collector since they only come into contact with
the bristles or hair of the cleaning means and not with any rigid
element of the cleaning vehicle, not having to modify the
trajectory of the tool in these sections.
[0025] The operating means for operating the cleaning means are
preferably made up of two robotic arms. A first robotic arm brings
the cleaning means closer to the surface of the upper part of the
parabolic trough collector and moves them along this surface
cleaning this upper part. A second robotic arm brings the cleaning
means closer to the surface of the lower part of the parabolic
trough collector and moves them along this surface cleaning this
lower part.
[0026] In terms of the cleaning means, these are particularly made
up of a straight and horizontal rotating roller fixed to the end of
the robotic arms, which rotates driven by an electric motor, and of
a plurality of nozzles connected to a hydraulic system which spray
pressurised water. The function of the hydraulic system is to
transport the water from the water tank to the nozzles, and is made
up of pumps, flow valves, check valves, flow regulating valves, the
nozzles and the pipes for its transportation.
[0027] Therefore, in this case, the cleaning means do not adopt the
parabolic trough shape of the collector as occurs in the systems
existing in the state of the art, but it will be a straight tool
which will clean the collector from bottom to top or from top to
bottom, the trajectory of the robotic arm, not the tool, is that
which is adapted to the shape of the collector. It allows optimally
sizing the cleaning means, since their length will not thus be
conditioned by the height of the collector, and the sizes of these
cleaning means may be smaller so the cleaning vehicle may also be
smaller and lighter.
[0028] According to the particular embodiments of the invention,
the cleaning vehicles of the cleaning system can have a locating
system for locating broken mirrors in the parabolic trough
concentrator as well as a locating system for locating leakages of
the fluid flowing inside the pipe fixed to the parabolic trough
collector.
[0029] An efficient high safety cleaning of the parabolic trough
collectors is achieved with this system, since neither the
collectors nor the pipes fixed thereto are damaged by accidental
impacts from the cleaning means (such as the rollers) or from the
operating means (such as the robotic arms), as occurs in other
methods existing in the state of the art. Furthermore, since the
vehicles are autonomous and independent of one another, the
presence of operators for driving them or for the cleaning itself
is not necessary, a considerable cost saving being achieved.
[0030] Another object of the present invention is a cleaning method
for cleaning parabolic trough collector plants which uses the
cleaning system described above and which is made up of the
following steps:
[0031] First, the cleaning vehicles are distributed along the
entire plant, positioning each of them at a first end of a
parabolic trough collector.
[0032] Next the cleaning vehicles are positioned in parallel to the
parabolic trough collector by means of their moving means and their
navigation means, and the vehicles are stopped.
[0033] Once the cleaning vehicles are stopped, the operating means
position the cleaning means on the surface of the first section of
the parabolic trough collector to be cleaned, and these clean the
first section of the parabolic trough collector by means of moving
the cleaning means driven by the operating means in a plane
perpendicular to the parabolic trough collector and perpendicular
to the direction of the cleaning vehicle. Thus, the means follow
the surface of the parabolic trough collector, while the cleaning
vehicle is stopped. In other words, in this method the vehicle
first moves forward, then stops, and then positions the cleaning
means and actuates them. When it finishes, it removes the cleaning
means and moves again.
[0034] The cleaning means are then separated from the surface of
the first section of the already cleaned parabolic trough
collector, and once these are separated the cleaning vehicles move
forward towards the next section of the parabolic trough collector
by means of their moving means and their navigation means.
Subsequently, the cleaning vehicle stops again to again clean the
next section, the different sections of the collector are thus
successively cleaned.
[0035] Once the last section of the parabolic trough collector is
cleaned, the cleaning means are separated from the surface of this
last cleaned section, and the cleaning vehicles autonomously move
to the next parabolic trough collector to be cleaned, the entire
process being repeated again.
[0036] According to a particular embodiment of the method, 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.
[0037] According to an alternative embodiment, in the step of
cleaning, the surface of the collector is sluiced by means of
pressurised water sprayed by the nozzles of the cleaning means, and
the surface of the collector is also sluiced by means of the
straight and horizontal rotating roller driven by the operating
means. Furthermore, a rinsing is preferably performed after
sluicing with the roller.
[0038] A high quality high safety cleaning of the parabolic trough
collectors is performed by means of this method, since neither the
collectors nor the pipes fixed thereto are damaged by accidental
impacts from the cleaning means or from the operating means as can
occur in other methods existing in the state of the art.
Furthermore, since the cleaning method is performed by vehicles
which are autonomous and independent of one another, the presence
of operators for driving them or for the cleaning itself is not
necessary, a considerable cost saving being achieved.
DESCRIPTION OF THE DRAWINGS
[0039] To facilitate the understanding of the invention an
embodiment of the invention will be described below with an
illustrative and non-limiting character referring to a set of
drawings.
[0040] FIG. 1 schematically shows a side view of a collector and
the pipe with the fluid to be heated fixed thereto.
[0041] FIG. 2 is an elevational view of the collector and the pipe
of the above figure.
[0042] FIG. 3 is a schematic view of a loop of four collectors of a
parabolic trough collector plant.
[0043] FIG. 4 schematically shows a cleaning vehicle of the
cleaning system object of the present invention in the position for
cleaning the collector and the pipe of FIGS. 1 and 2.
[0044] FIG. 5 is a schematic plan depiction of the cleaning vehicle
in the position for cleaning the collector and the pipe.
[0045] These drawings refer to a group of elements which are:
[0046] 1. parabolic trough collectors [0047] 2. upper part of the
collector [0048] 3. lower part of the collector [0049] 4. pipe
through which the fluid to be heated by the collector flows [0050]
5. cleaning vehicles [0051] 6. chassis of the cleaning vehicle
[0052] 7. moving means of the vehicle [0053] 8. robotic arm [0054]
9. nozzles [0055] 10. rotating roller of the cleaning means [0056]
11. GPS positioning system [0057] 12. distance sensors [0058] 13.
first end of the parabolic trough collector [0059] 14. second end
of the parabolic trough collector [0060] 15. support of the pipe
through which the fluid to be heated flows [0061] 16. support of
the collector
DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
[0062] The object of the present invention is a cleaning system for
cleaning parabolic trough collector plants, which is made up of a
group of cleaning vehicles 5 moving along the plant cleaning the
parabolic trough collectors 1.
[0063] As can be observed in FIGS. 4 and 5, each of these cleaning
vehicles 5 is in turn made up of a chassis 6, in which there are
arranged moving means 7 of the cleaning vehicle 5, cleaning means
for cleaning the parabolic trough collectors 1, and operating means
for operating the cleaning means which position said cleaning means
on the surface of the parabolic trough collectors 1 to be cleaned,
and move them, thus cleaning the collectors 1.
[0064] The chassis 6 is a small and light platform and has the
elements necessary for performing the movement for translating and
steering the cleaning vehicle 5. It will particularly have rear
wheel drive and optionally front wheel drive, and front wheel
turning or steering. The systems for actuating both the drive and
the direction will be controlled by electric systems, even though
the final actuation is of another type, i.e., mechanical,
hydraulic, etc. Even though the drive is hydraulic, for example,
the instructions are transmitted to valves and pumps by means of an
electric system.
[0065] The cleaning vehicles 5 are autonomous and independent of
one another, therefore they have navigation means 11,12, in their
chassis 6 guiding and steering the cleaning vehicle 5 in its
movement along the parabolic trough collector plant 1. These
navigation means 11,12 are in turn made up of a relative navigation
system and an absolute navigation system.
[0066] The relative navigation system has an inertial unit (made up
of gyroscopes, accelerometers, encoders and odometers), and a group
of distance sensors 12 which measures the distance of the cleaning
vehicle 5 to the parabolic trough collector 1. These distance
sensors are preferably ultrasound sensors.
[0067] Furthermore, for facilitating the navigation of the cleaning
vehicle 5, it can have obstacle presence sensors arranged in the
rear and front part
[0068] In addition, the absolute navigation system has a GPS
positioning sub-system 11, which will consist of a GPS antenna and
receiver.
[0069] Additionally, according to a particular embodiment this
absolute navigation system comprises a wireless communication
system for communicating the cleaning vehicles 5 with a determined
fixed point of the plant, such as for example a radio receiver in
each vehicle and a fixed system with radio emitter in the plant, or
any wireless system. This additional communication will provide a
greater precision in positioning the vehicle.
[0070] Furthermore, the cleaning vehicles 5 have a control system
integrating and controlling the cleaning means and the operating
means for operating them, and the moving means 7 and the navigation
means 11,12 for moving the cleaning vehicles 5 and an efficient
cleaning of the parabolic trough collectors 1.
[0071] The cleaning vehicles 5 can optionally be provided with a
communication system with remote operators for remote control
thereof.
[0072] The operating means for operating the cleaning means of the
present invention particularly have a robotic arm 8 to which the
cleaning means are fixed.
[0073] In this embodiment the cleaning means have at least one
distance sensor 12, which measures the distance of said cleaning
means to the surface of the parabolic trough collector 1. After the
cleaning means are positioned on the surface of the parabolic
trough collector 1 for cleaning said collector 1, the robotic arm 8
moves the cleaning means in a plane perpendicular to the parabolic
trough collector 1 and perpendicular to the movement direction of
the cleaning vehicle 5. The cleaning is thus performed, the
cleaning means following the surface of the parabolic trough
collector 1, while the cleaning vehicle 5 is stopped. To obtain
this movement, the robotic arms 8 have at least two degrees of
freedom, and will consist of two metal structures the joints of
which have motors or electric servomotors with their reduction
gears.
[0074] FIGS. 4 and 5 show a preferred embodiment of the cleaning
system for cleaning collector plants based on robotic arms 8
providing the cleaning means with the movement described above. In
this preferred embodiment the cleaning means are made up of two
robotic arms 8. A first robotic arm 8 brings the cleaning means
closer to the surface of the upper part 2 of the parabolic trough
collector 1, and moves them along the same cleaning said upper part
2. A second robotic arm 8 brings the cleaning means closer to the
surface of the lower part 3 of the parabolic trough collector 1,
and moves them along the same cleaning said lower part 3.
[0075] In terms of the cleaning means, according to a preferred
embodiment of the invention shown in FIGS. 4 and 5, the cleaning
means are made up of a straight and horizontal rotating roller 10
fixed to the end of the robotic arms 8, which rotates driven by an
electric motor, and of a group of nozzles 9, which are connected to
a hydraulic system and which spray pressurised water for cleaning
the collector 1. The pressurised water will be sprayed by the
nozzles 9 before the roller 10 passes along the surface to be
cleaned and optionally once the roller has passed for rinsing the
surface.
[0076] The cleaning vehicles 5 preferably have at least one
additional nozzle 9 fixed to the chassis 6 and connected to the
hydraulic system which sprays pressurised water towards the pipe 4
fixed to the collector 1 through which the fluid to be heated by
said collector flows for cleaning this pipe 4.
[0077] As can be observed in FIG. 5, according to a preferred
embodiment of the operating means, the first and second robotic
arms 8 are vertically misaligned to prevent dirtying the one which
is on top of the other and wetting the one which is underneath in
the cleaning operation.
[0078] According to the preferred embodiments of the present
invention, the cleaning vehicles 5 can have, performed by means of
sensors, a locating system for locating broken mirrors in the
parabolic trough concentrator 1, and also a locating system for
locating leakages of the fluid flowing inside the pipe 4 fixed to
the parabolic trough collector 1.
[0079] Another object of the present invention is a cleaning method
for cleaning parabolic trough collector plants which uses the
cleaning system described above.
[0080] In this cleaning method, the first step consists of
distributing the cleaning vehicles 5 along the entire plant,
positioning each of them at a first end 13 of a parabolic trough
collector 1 to be cleaned. This distribution can be done
autonomously by the cleaning vehicles 5 or in an assisted
manner.
[0081] Next the cleaning vehicles 5 are arranged parallel to the
parabolic trough collector 1 using their moving means 7 and their
navigation means 11,12, and they are then stopped.
[0082] Once the cleaning vehicles are stopped, the operating means
position the cleaning means on the surface of the first section of
the parabolic trough collector 1 to be cleaned, and the first
section of the parabolic trough collector 1 is cleaned by means of
moving the cleaning means by the operating means. The movement
caused by the operating means is in a plane perpendicular to the
parabolic trough collector 1 and perpendicular to the direction of
the cleaning vehicle 5, travelling the parabolic surface of the
collector 1 from top to bottom or of bottom to top. The cleaning
means thus follow the surface of the parabolic trough collector 1,
as long as said cleaning vehicle 5 is stopped.
[0083] When the cleaning of the section has ended, the operating
means separate the cleaning means from the surface of the first
section of the parabolic trough collector 1, and the cleaning
vehicles 5 move forward towards the next section of the parabolic
trough collector 1 by means of their moving means 7 and their
navigation means 11,12.
[0084] The movement is performed maintaining the fixed distance to
the collector 1 by means of the distance sensors 12. When the
cleaning vehicle 5 has to move along the collector 1, but the
distance sensors 12 can not detect it, either due to the breakage
or the gaps between collectors 1, the movement will be performed
assisted by the inertial unit. The movement will also be supervised
by the absolute navigation system to know for sure when the end of
the collectors 1 has been reached and to calibrate the relative
positions.
[0085] Next the cleaning vehicle 5 is again stopped for
subsequently cleaning the next section of the collector 1.
[0086] Once the last section of the parabolic trough collector 1 is
cleaned, the operating means separate the cleaning means from the
surface of said last section of the parabolic trough collector 1,
and the cleaning vehicle 5 autonomously moves from the second end
14 of the parabolic trough collector 1 towards the first end 13 of
the next parabolic trough collector 1 to be cleaned.
[0087] The step of cleaning the section of the parabolic trough
collector 1 can particularly consist of sluicing the surface of the
collector 1 by means of pressurised water sprayed by the nozzles 9
of the cleaning means.
[0088] Alternatively, and preferably, the step of cleaning consists
of sluicing the surface of the collector 1 by means of pressurised
water sprayed by the nozzles 9 of the cleaning means, and also
sluicing the surface of the collector 1 by means of the straight
and horizontal rotating roller 10 driven by the operating means
which cleans the surface which has previously been sluiced by the
water. Additionally, according to a preferred embodiment of the
invention, after sluicing by means of the rotating roller 10 a
subsequent rinsing of the surface is performed.
[0089] While the sluicing is performed by means of the rotating
roller 10, the nozzles 9, orientated towards the next section of
collector 1, will perform a sluicing by spraying water towards this
section which will be sluiced by the roller 10 in the next forward
movement of the cleaning vehicle 5.
[0090] Furthermore, this step of cleaning can include sluicing the
pipe 4 fixed to the parabolic trough collector 1 by means of
pressurised water which is sprayed by the additional nozzles 9
fixed to the chassis 6 of the cleaning vehicles 5 for cleaning said
pipe 4.
[0091] Preferably, in the step of moving the cleaning vehicles 5
forward towards the next section of the parabolic trough collector
1, the pipe 4 fixed to the parabolic trough collector 1 is sluiced
by means of pressurised water sprayed by the additional nozzles 9
fixed to the chassis 6 of the cleaning vehicles 5 for cleaning said
pipe 4. The pipe 4 is thus cleaned while the cleaning vehicle 5
moves. This does not affect the safety of the mirrors of the
parabolic trough collector 1 because although the sluicing is being
performed while the cleaning vehicle 5 moves, there is no risk of
the rollers 10 or the robotic arms 8 impacting the parabolic trough
collector 1 since these are withdrawn and separated from it, and
furthermore, the imperfections that could exist in the terrain are
not transmitted to the cleaning means.
[0092] Once the invention has been clearly described, it must be
stated that the particular embodiments described above are
susceptible to detail modifications as long as they do not alter
the fundamental principal and the essence of the invention.
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