DEVICE FOR MEASURING FLUX REFLECTED BY A SOLAR FIELD EQUIPPED WITH A SYSTEM WITH VARIABLE CONFIGURATION RELATIVE TO PHOTODETECTORS OF SAID MEASURING DEVICE

Abstract

The flux measurement device (1), for the fluxes reflected by a solar array (101) of a solar power plant (100) towards a receiver (102) of the solar power plant and intended to be mounted at the receiver (102), comprises: - first photodetectors (2a, 2b, 2c, 2d) aligned along a corresponding alignment axis (a1), and - a system (3) configured to delimit, for each first photodetector (2a, 2b, 2c, 2d), in a given operating configuration of the measurement device (1), a monitored area of ​​the solar array (101), said system (3) being capable of varying between a first configuration with respect to the first photodetectors (2a, 2b, 2c, 2d) and a second configuration with respect to the first photodetectors (2a, 2b, 2c, 2d) such that the transition from the first configuration to the second configuration simultaneously modifies the monitored area. monitor each of the first photodetectors (2a, 2b, 2c, 2d).

Description

Scope of the invention

[0001] The invention relates to the field of solar power plants, and more particularly to measurement devices enabling the characterization of a solar field. State of the art

[0002] A solar power plant typically uses a solar field oriented towards the sun and configured to reflect sunlight towards a receiver, notably by concentrating it on that receiver.

[0003] For optimal operating efficiency, a solar power plant must be precisely configured to focus sunlight directly onto the receiver. A solar field can cover a large area, and even minor anomalies can lead to a loss of efficiency. Typical anomalies include a dirty reflector in the solar field or one that is incorrectly oriented towards the receiver.

[0004] This therefore results in a need for tools to ensure that the receiver's efficiency is maximized and / or to detect an anomaly in the solar field in order to correct it with a view to improving the efficiency of the solar power plant.

[0005] The state of the art offers various solutions to this need. In this regard, systems exist to ensure the correct orientation of a solar reflector; such systems are described in documents US4,013,885 and US2012 / 0132194. However, these systems only allow verification of the concentrator's orientation but do not measure its efficiency at the receiver.

[0006] Furthermore, systems exist for quantifying the solar rays reflected by reflectors towards a receiver. Document FR2972530 proposes a measurement device for determining the efficiency of an assembly comprising reflectors and a receiver.

[0007] US document 5,861,947 describes a focused beam measurement device using a single camera in combination with a movable mirror.

[0008] Document US2011 / 0180059 describes a concentrated beam measurement device using photovoltaic cells. A robot is configured to move along a receiver and has an arm which, when deployed, orients a line of photovoltaic cells towards a solar field. Object of the invention

[0009] The invention relates to a new measuring device, enabling in particular the easier detection of an anomaly.

[0010] We tend to satisfy this objective by means of a device for measuring fluxes reflected by a solar field of a solar power plant towards a receiver of the solar power plant and intended to be mounted at the receiver, said measuring device comprising: first photodetectors aligned along a corresponding alignment axis; and a system configured so as to delimit for each first photodetector, in a configuration of use of the measuring device, an area to be monitored of the solar field, said system being able to vary between a first configuration with respect to the first photodetectors and a second configuration with respect to the first photodetectors such that the change from the first configuration to the second configuration simultaneously modifies the area to be monitored of each of the first photodetectors.

[0011] The system includes a cover with mobility relative to the first photodetectors, said cover being configured so as to allow, for each position of the cover relative to the first photodetectors, on the one hand, to prevent a first part of the rays from the solar field from reaching the first photodetectors and, on the other hand, to allow the passage of a second part of the rays from the solar field towards the first photodetectors, and the mobility of the cover relative to the first photodetectors allows the passage from the first configuration to the second configuration.

[0012] According to one implementation, the cover comprises a plurality of blades pivotally mounted on a support of the measuring device incorporating the first photodetectors, the pivot axes of the blades being substantially orthogonal, in particular perpendicular, to the alignment axis of the first photodetectors, the pivot axes of said blades being substantially parallel to each other, the possible movement of the blades via the pivot axes corresponding to the mobility of the cover.

[0013] In particular, for each pair of adjacent first photodetectors, one blade from the plurality of blades is pivotally mounted between said first photodetectors of said pair, and the line of first photodetectors is framed by two blades from the plurality of blades.

[0014] Preferably, the blades of the plurality of blades are fixed together in motion, and in particular all remain parallel to each other regardless of the angle of pivot of said blades with respect to their respective pivot axes.

[0015] According to another embodiment, the cover includes a component, in particular a plate, having an elongated slit in a direction substantially orthogonal to the alignment axis of the first photodetectors, and regardless of the position of the slit with respect to said first photodetectors, the only rays from the solar field seen by said first photodetectors pass through this slit.

[0016] The measuring device may also include second photodetectors, the number of which is equal to that of the first photodetectors, the second photodetectors being aligned along an alignment axis parallel to the alignment axis of the first photodetectors, and said system not intercepting any of the rays from the solar field in the direction of said second photodetectors, alternatively the measuring device may include a single second photodetector, said system not intercepting any of the rays from the solar field in the direction of said second photodetector.

[0017] The device may include an analysis module connected to each of the first photodetectors and configured to process the data from the first photodetectors to establish a map of the solar flux reflected by the solar field towards the receiver.

[0018] According to one embodiment, the device may include a thermal flux gauge associated with one of the first photodetectors, in particular said one of the first photodetectors is aligned with the thermal flux gauge along an axis orthogonal, and in particular perpendicular, to the alignment axis of said first photodetectors.

[0019] The invention also relates to a solar power plant comprising a receiver and a solar field equipped with orientable reflectors to reflect solar rays towards the receiver, said solar power plant includes a measuring device as described arranged at the receiver.

[0020] Specifically, within the framework of this power plant, the reflectors are longitudinal reflectors, each longitudinal reflector being mounted for rotation about a pivot axis extending along its length, and the pivot axes of the longitudinal reflectors being substantially parallel to each other. Furthermore, the receiver is positioned at a distance from the solar field and has a longitudinal axis substantially parallel to the pivot axes of the reflectors. Next, the measuring device is arranged so that the alignment axis of the first photodetectors is substantially orthogonal to the longitudinal axis of the receiver. Finally, the measuring device is configured to move along the receiver.

[0021] The invention also relates to a method of using a measurement device of a solar power plant as described and this method includes a step of placing the measurement device at a plurality of main measurement positions relative to the receiver, and a measurement step implemented by the first photodetectors according to at least the first system configuration and the second system configuration, preferably said measurement step is implemented for each main measurement position.

[0022] The measurement device placement step may consist of moving the measurement device along the receiver so that in any main measurement position, the alignment axis of the photodetectors is substantially orthogonal to the longitudinal axis of the receiver.

[0023] According to one embodiment of the method, the latter is such that: the measuring device includes at least one second photodetector arranged so that the system does not intercept the rays from the solar field directed towards each second photodetector; the first photodetectors and each second photodetector are each formed by a photovoltaic cell; the measuring device includes a thermal flux gauge associated with a reference photodetector chosen from among the first photodetectors; and each measurement step consists of determining relative fluxes by each of the first photodetectors and for each configuration of the system at said corresponding main measuring position, a standard flux by each second photodetector at said corresponding main measuring position, and a reference flux by said thermal flux gauge at said corresponding main measuring position.Furthermore, the process then includes a step of using each determined standard flux, the determined relative fluxes and each determined reference flux to develop a map of the fluxes perceived by the receiver and coming from the solar field.

[0024] According to another implementation of the method, the latter is such that the measuring device comprises second photodetectors aligned along an axis substantially parallel to the alignment axis of the first photodetectors and arranged in such a way that the system does not intercept the rays from the solar field directed towards the second photodetectors, and the method comprises at least one set of steps implemented for each first photodetector, said set of steps comprising: placing said first photodetector at an acquisition position defined as the position occupied by said first photodetector in one of the principal measuring positions of the measuring device, and then determining from said first photodetector placed in said acquisition position relative fluxes from the solar field for at least the first and second configurations of the system;a placement of one of the second photodetectors associated with said first photodetector at said acquisition position, resulting in the measurement device occupying a secondary measurement position different from said one of the principal measurement positions, then a determination, from said one of the second photodetectors placed in the acquisition position, of a standard flux. Finally, in this other implementation, the method includes a step of using the determined standard fluxes and the determined relative fluxes to develop a map of the fluxes perceived by the receiver and originating from the solar field. In particular, the set of steps can be implemented in association with each principal measurement position.

[0025] According to an improvement of this alternative implementation, the first photodetectors are each formed by a photovoltaic cell. The measuring device includes a thermal flux gauge associated with a reference photodetector chosen from among the first photodetectors. The set of steps associated with said reference photodetector includes a step of placing the thermal flux gauge at the acquisition position, resulting in the measuring device occupying an additional measurement position different from one of the corresponding primary and secondary measurement positions. This is followed by a step of determining a reference flux from said thermal gauge. Finally, the utilization step further includes the use of each determined reference flux.

[0026] According to another implementation, the process is such that the first photodetectors are each formed by a photovoltaic cell, and that the measuring device includes a thermal flux gauge associated with a reference photodetector chosen from among the first photodetectors.Therefore, the process includes, in association with each main measurement position, the following steps: a step of placing said first photodetectors at acquisition positions defined as the positions occupied by said first photodetectors in said main measurement position of the measuring device; a step of determining, for each of the first photodetectors placed in its acquisition position, relative fluxes for at least the first and second configurations of the system; a step of placing the thermal flux gauge at said acquisition position of the reference photodetector from which it results that the measuring device occupies a position distinct from said main measurement position, and a step of determining a reference flux from said thermal flux gauge placed at said acquisition position.In addition, the process includes a step of using determined reference fluxes and determined relative fluxes to develop a map of the fluxes perceived by the receiver and originating from the solar field.

[0027] According to yet another implementation of the method, the measuring device includes a second photodetector arranged so that the system does not intercept rays from the solar field directed towards the second photodetector, and the method includes at least one set of steps implemented for each main measuring position comprising: a placement of said first photodetectors at acquisition positions defined as the positions occupied by said first photodetectors in said main measuring position of the measuring device, then a determination from said first photodetectors placed in said acquisition positions of relative fluxes from the solar field for at least the first and second configurations of the system;a placement of the second photodetector in one of the acquisition positions, resulting in the measuring device occupying a secondary measurement position different from said primary measurement position, followed by a determination, from said second photodetector placed in the acquisition position, of a standard flux. In addition, the method includes a step of using the determined standard fluxes and the determined relative fluxes to develop a map of the fluxes perceived by the receiver and originating from the solar field. Description of the figures

[0028] The invention will be better understood upon reading the following description, given solely by way of non-limiting example and made with reference to the drawings in which: there figure 1 is a schematic illustration, viewed from a perspective perspective, of a particular embodiment of the invention, the figure 2 illustrative perspective view of another embodiment of the invention, the figure 3 is a top view of a linear Fresnel-type solar power plant, the figure 4 is a view according to AA of the figure 3 , THE figures 5 and 6 illustrate the viewing angles respectively for a first photodetector and for several first photodetectors used in the realization of the figure 1 , THE figures 7 And 8 illustrate the viewing angles respectively for a first photodetector and for several first photodetectors used in the realization of the figure 2 , there figure 9 illustrates an improvement in the method of execution of the figure 1 , there Figure 10 illustrates an improvement in the method of execution of the figure 2 , THE figures 11 to 13 illustrate different stages of a process of using the measuring device within a solar power plant.

[0029] In these figures, the same references are used to designate the same elements. Description of preferred embodiments of the invention

[0030] In the remainder of this description, the well-known characteristics and functions of a person skilled in the art are not described in detail.

[0031] On the figures 1 to 10 A coordinate system with perpendicular X, Y, and Z axes is shown. This system corresponds to the reference frame associated with a measurement device configuration within a solar power plant, in which the X and Y axes define a substantially horizontal plane and the X and Z axes—or Y and Z—define a substantially vertical plane. Preferably, the X axis is substantially parallel to the Earth's North-South axis. In this sense, the XYZ coordinate system allows the positioning of the represented elements to be determined. figures 1 to 10 within the solar power plant when it is operational.

[0032] In this description, "substantially parallel" means exactly parallel or parallel within a margin of error of approximately 10%, primarily due to the mounting clearances of components—for example, axes—that are parallel to each other. Similarly, "substantially vertical" means exactly vertical or vertical within a margin of error of approximately 10%, and "substantially horizontal" means exactly horizontal or horizontal within a margin of error of approximately 10%.

[0033] In this description, "orthogonal axes" refers to two axes in space parallel to imaginary lines intersecting at right angles. "Virtually orthogonal" means exactly orthogonal or orthogonal to within ±10%, for the same reasons described above. In a specific case, the elements may be virtually perpendicular to each other, that is, exactly perpendicular or perpendicular to within ±10%.

[0034] In this description, flux refers to a quantity, particularly of light, emitted by the sun and reflected by each reflector per unit of time. As will be described below, the flux can originate from a monitored area of ​​a solar field. The measuring device described below therefore allows for the measurement / determination of fluxes emanating from the solar field of a solar power plant in order to characterize said solar field or the fluxes perceived by a receiver at the solar power plant.

[0035] In this description, a pivot axis allows the rotation of an element associated with it around said pivot axis, in particular within a given permitted and advantageously controlled angular range.

[0036] THE figures 1 and 2Figure 1 illustrates a measuring device for the flux reflected by the solar array of the solar power plant towards the solar power plant receiver. This measuring device is designed to be mounted at the receiver; in other words, it is configured to withstand high temperatures due to the concentration of solar rays reflected by the solar array. Specifically, the measuring device is configured to withstand temperatures between -20°C and 80°C. The measuring device can move quickly, which means it does not have time to reach temperatures above 80°C. Therefore, when the measuring device is not taking a measurement, it is positioned in a "parked" position, out of the flux, meaning that the reflected rays are not directed towards it: it can then cool down.

[0037] The measuring device 1 is intended in particular to determine the contribution of each reflector in the solar field to the total flux distribution incident on the receiver, and also, where appropriate, to allow optimization of the orientation and therefore the aiming of the reflectors.

[0038] THE figures 3 and 4The diagram illustrates the measuring device 1 in an operational configuration, specifically within a solar power plant 100 comprising a solar array 101 equipped with a plurality of orientable reflectors 101a, 101b, 101c, 101d, 101e to reflect solar rays towards the receiver 102. The solar power plant 100 then includes the measuring device 1 positioned at the receiver 102. Preferably, this is a linear Fresnel solar power plant 100, for which the measuring device 1 is particularly well-suited. Such a linear Fresnel solar power plant comprises the solar array 101, composed of reflectors 101a, 101b, 101c, 101d, 101e forming longitudinal reflectors. The longitudinal reflectors 101a, 101b, 101c, 101d, 101e extend preferentially along the Earth's North-South axis so as to follow the sun's path S from East to West during the day.Each longitudinal reflector 101a, 101b, 101c, 101d, 101e is mounted to rotate about a pivot axis A ref1 , A ref2 , A ref3 , A ref4 , A ref5 , extending along its length (and therefore where appropriate substantially parallel to the North South axis), and the pivot axes A ref1 , A ref2 , A ref3 , A ref4 , A ref5 of the reflectors 101a, 101b, 101c, 101d, 101e are substantially parallel to each other. The pivot axes A ref1 , A ref2 , A ref3 , A ref4 , A ref5 are substantially parallel to the X axis. In addition, the receiver 102 of the solar power plant 100 is placed at a distance from the solar field 101, and has a longitudinal axis A Receiver oriented along the pivot axes of the reflectors 101a, 101b, 101c, 101d, 101e (on the . figure 3AReceiver and Aref3 coincide because they are parallel but superimposed at different heights along the Z-axis. In other words, the longitudinal axis AReceiver of the receiver is approximately parallel to the pivot axes Aref1, Aref2, Aref3, Aref4, Aref5 of reflectors 101a, 101b, 101c, 101d, 101e, and therefore approximately parallel to the X-axis. Although not shown, receiver 102 is conventionally held away from the solar field by a metal frame. The pivot axes of reflectors 101a, 101b, 101c, 101d, 101e define the focal line of said reflectors 101a, 101b, 101c, 101d, 101e. Each reflector 101a, 101b, 101c, 101d, 101e can be planar, but is generally concave in the transverse plane, that is, the plane perpendicular to the corresponding pivot axis of said reflector.For correct aiming, each reflector 101a, 101b, 101c, 101d, 101e is positioned such that its normal vector at the associated pivot axis is aligned with the bisector of the angle formed between the direction of the sun and the direction of the receiver 102 as seen by said reflector. Each reflector 101a, 101b, 101c, 101d, 101e may have a plurality of mirrors defining its reflective face. The reflectors 101a, 101b, 101c, 101d, 101e may be mechanically driven in rotation by a motor and a suitable mechanical system in order to track the sun throughout the day and reflect the incident solar flux onto the receiver 102 located above the solar field 101.

[0039] In this linear Fresnel solar power plant 100, the measurement device 1 described above is arranged so that an alignment axis A 1 of the first photodetectors of the measurement device 1 is substantially orthogonal to the longitudinal axis A Receiver of the receiver 102. By "at the level of the receiver 102", it is understood that the measurement device 1 can be mounted under the receiver 102 (preferably between the receiver and the solar field), or as close as possible to it, in the configuration of use.

[0040] The receiver 102 can be configured to receive the concentrated rays of the sun reflected by the solar field 100. More specifically, the receiver 102 allows for the storage of power, particularly in the form of heat. To this end, the receiver 102 can include an absorber, for example, consisting of at least one tube carrying a heat transfer fluid designed to recover the heat from the concentrated solar rays. This heat transferred to the heat transfer fluid can be stored latently or sensibly, either directly or via a secondary heat exchanger, converted into electricity, or more broadly used in any thermodynamic cycle—for example, refrigeration—or any industrial process—for example, a desalination unit.

[0041] A photodetector within the meaning of the present invention can be a pixel matrix, and preferably a photovoltaic cell.

[0042] Within such a solar power plant 100, the measuring device 1 will preferably be configured to move along the receiver 102 along the Receiver axis A in a plurality of principal measurement positions. Specifically, for each principal measurement position, the alignment axis A1 of the first photodetectors remains substantially orthogonal to the Receiver axis A. In the frame of reference of the solar power plant 100, the measuring device 1 is moved beneath the receiver 102, that is, between the receiver 102 and the solar field 100, such that for each principal measurement position, the measuring device 1 is subjected to the rays (solar rays reflected by the solar field) normally perceived by the receiver 102 at said principal measurement position.Furthermore, the dimensions of the measuring device 1 are such that when it moves under the receiver 102, its impact on the efficiency of the solar power plant 100 is negligible.

[0043] To allow movement of the measuring device, the latter can be coupled to two longitudinal guides 103a, 103b and to a motor 104 ( figures 3 and 4 ) adapted to slide along these two longitudinal guides.

[0044] More generally, as illustrated in figures 1 and 2 The measuring device 1 comprises first photodetectors 2a, 2b, 2c, 2d aligned along the corresponding alignment axis A1. This alignment of the first photodetectors along axis A1 results in the first photodetectors 2a, 2b, 2c, 2d being arranged to form a line of first photodetectors 2a, 2b, 2c, 2d. On the figures 1 and 2These first four photodetectors 2a, 2b, 2c, 2d are not limited in number, as there may be more or fewer of them. The measuring device 1 also includes a system 3 configured to define, for each first photodetector 2a, 2b, 2c, 2d, in the operating configuration of the measuring device 1 (i.e., a configuration within the solar power plant where it is intended to measure the impact of a portion of the solar rays reflected by the solar array 101), a monitored area of ​​the solar array 101.This system 3 is capable of varying between a first configuration with respect to the first photodetectors 2a, 2b, 2c, 2d and a second configuration with respect to the first photodetectors 2a, 2b, 2c, 2d such that the change from the first configuration to the second configuration simultaneously changes the area to be monitored by each of the first photodetectors 2a, 2b, 2c, 2d.

[0045] The first and second configurations of System 3 have been described above. More specifically, System 3 can include other configurations. In particular, System 3 has a number of configurations such that the set of monitored areas allows, for a given primary measurement position, coverage of a portion of the solar field 100 extending between two lateral end reflectors arranged along the Y-axis. When all the primary measurement positions have been used by the measurement device 1, the entire solar field has been monitored, and it is therefore possible to map the fluxes emanating from the solar field in detail.

[0046] According to another formulation, system 3 can vary between a first configuration with respect to the first photodetectors 2a, 2b, 2c, 2d and a second configuration with respect to the first photodetectors such that the transition from the first configuration to the second configuration simultaneously modifies the viewing angle of all the first photodetectors 2a, 2b, 2c, 2d. Of course, when system 3 has more than two configurations and system 3 and the first photodetectors 2a, 2b, 2c, 2d share an axis of symmetry, some of the configurations could have equal viewing angles; nevertheless, preferably, at least the first and second configurations will always be present among these configurations such that the viewing angles all change simultaneously when transitioning from the first configuration to the second configuration and vice versa.

[0047] For a given configuration of system 3 with respect to the first photodetectors 2a, 2b, 2c, 2d, it is possible to determine, for each first photodetector 2a, 2b, 2c, 2d, a flux, specifically a relative flux, corresponding to the amount of light received by said first photodetector 2a, 2b, 2c, 2d and reflected by a corresponding area to be monitored. The determination of a flux by a photodetector can be performed by measuring an output signal from that photodetector. The flux is said to be relative because the measurement taken by the first photodetectors 2a, 2b, 2c, 2d is not necessarily solely a function of solar power; it can vary depending on the temperature of the first photodetector 2a, 2b, 2c, 2d and the received spectrum.In order to compare the relative fluxes determined from the first photodetectors 2a, 2b, 2c, 2d, the measuring device 1 may include an element 4 for maintaining the temperature of the first photodetectors 2a, 2b, 2c, 2d at a constant temperature, and / or an element 5 for determining the temperature of the first photodetectors 2a, 2b, 2c, 2d in order to adjust the interpretation of their signals so that each of the first photodetectors 2a, 2b, 2c, 2d over time can provide comparable relative flux values. On the... figures 1 and 2The support element 4 can be formed by a support 6 integrating the first photodetectors 2a, 2b, 2c, 2d and thus including a cooling system, and the element 5 enabling the temperature to be known can be a temperature probe integrated into the support 6. According to a variant not shown, an element 5 formed by a thermocouple is installed on each first photodetector 2a, 2b, 2c, 2d to allow the temperature of each first photodetector to be known in order to make a correct and comparable interpretation of all the fluxes, in particular relative fluxes from the first photodetectors.

[0048] In particular, in the operating configuration of measuring device 1, the rays incident on the first photodetectors 2a, 2b, 2c, 2d originate from / are reflected from the solar field 101. The rays referred to in this description and impacting the measuring device, in particular the first photodetectors or other components, are specifically solar rays reflected by the solar field. Thus, the rays seen by the first photodetectors 2a, 2b, 2c, 2d in the operating configuration are those directly reflected by the solar field 101 without the interposition of a third reflective element placed between the solar field 101 and the first photodetectors 2a, 2b, 2c, 2d and altering the path of said rays seen by the first photodetectors 2a, 2b, 2c, 2d.

[0049] As seen in figures 1 and 2Each of the first photodetectors 2a, 2b, 2c, 2d has a sensitive face designed to receive light rays. The sensitive faces are preferably arranged so that they are all included in the same plane, in particular so as to delimit a measurement plane.

[0050] More specifically, system 3 includes a cover 7 that is movable relative to the first photodetectors 2a, 2b, 2c, 2d. This cover 7 is configured so that, for each position of the cover 7 relative to the first photodetectors 2a, 2b, 2c, 2d, it allows, on the one hand, a portion of the rays from the solar array 101 of the solar power plant 100 to reach the first photodetectors 2a, 2b, 2c, 2d, and on the other hand, a portion of the rays from the solar array 101 of the solar power plant 100 to pass towards the first photodetectors 2a, 2b, 2c, 2d. The movable position of this cover 7 relative to the first photodetectors 2a, 2b, 2c, 2d enables switching between the first and second configurations.

[0051] According to an initial design of cache 7 illustrated in figure 1The latter comprises a plurality of blades 8a, 8b, 8c, 8d, 8e pivotally mounted on the support 6 of the measuring device 1, which incorporates the first photodetectors 2a, 2b, 2c, 2d. The pivot axes A2, A3, A4, A5, A6 of the blades 8a, 8b, 8c, 8d, 8e are substantially orthogonal, and in particular perpendicular, to the alignment axis A1 of the first photodetectors 2a, 2b, 2c, 2d. The pivot axes A2, A3, A4, A5, A6 of said blades 8a, 8b, 8c, 8d, 8e are substantially parallel to each other.

[0052] In particular, two adjacent first photodetectors are separated by a blade. Specifically, for each pair of adjacent first photodetectors, a blade from the plurality of blades is pivotally mounted between said first photodetectors of said pair, and the line of first photodetectors 2a, 2b, 2c, 2d, is framed by two blades 8a, 8e from the plurality of blades. As illustrated in the figure 1Here, "framed" means that the line of first photodetectors is arranged between two blades 8a, 8e of the plurality of blades. In this sense, each first photodetector 2b, 2c, located between the first photodetectors 2a, 2d at the end of the line, is adjacent to two other first photodetectors and is separated from these two other first photodetectors by two associated blades.

[0053] For an angular position of the blades 8a, 8b, 8c, 8d, 8e with respect to the first photodetectors 2a, 2b, 2c, 2d, only rays from the monitored areas of a part of the solar field associated with the main measurement position of the measuring device can reach the first photodetectors 2a, 2b, 2c, 2d.

[0054] Preferably, the cache 7 is configured so that all the blades 8a, 8b, 8c, 8d, 8e are fixed together in movement and in particular remain all parallel to each other regardless of the angle of pivot of said blades 8a, 8b, 8c, 8d, 8e with respect to their respective pivot axes.

[0055] The possible movement of blades 8a, 8b, 8c, 8d, 8e via pivot axes A2, A3, A4, A5, A6 corresponds to the mobility of the cover 7 described above. In other words, the mobility of the cover 7 relative to the first photodetectors is conferred here by the possibility of pivoting blades 8a, 8b, 8c, 8d relative to the support 6 incorporating the first photodetectors 2a, 2b, 2c, 2d.

[0056] A movement of one of the blades 8a, 8b, 8c, 8d, 8e preferentially causes each of the other blades to move. To achieve this, the measuring device 1 may include a motor 9 and a drive system 10 acting in synergy to allow the simultaneous movement of all the blades 8a, 8b, 8c, 8d, 8e of the plurality of blades. The motor 9 can be mounted on the support 6 and coupled to one of the blades – here, blade 8e – then blade 8e is connected to each of the other blades by a rod 10 which transmits the movement of blade 8e to the other blades 8a, 8b, 8c, 8d. This rod 10 is preferably located as close as possible to the support 6 to avoid shading the first photodetectors 2a, 2b, 2c, 2d.

[0057] The pivot axes A2, A3, A4, A5, A6 of the blades 8a, 8b, 8c, 8d, 8e are preferentially included in the measurement plane mentioned previously. This ensures, in particular, that the distance between a cell (a first photodetector) and a blade always remains the same.

[0058] Within the framework of the solar power plant 100 described previously, the measuring device 1 will be allowed to move along the receiver 102. In this respect, a given primary measurement position of the measuring device 1 relative to the receiver 102 defines the portion of the solar field to be monitored, and the blades, depending on their angular positions, allow for the monitoring of different areas within this portion of the solar field 101. This creates a fine segmentation of the solar field 101, enabling more precise localization of any potential problem. By performing an angular scan with the blades 8a, 8b, 8c, 8d, and 8e while acquiring signals from the first photodetectors 2a, 2b, 2c, and 2d, it is possible to determine fluxes, including relative fluxes, associated with all viewing angles across the entire width of the solar field 101.Next, it is possible to separate the part coming from each of the reflectors of the solar field 101 which ultimately corresponds to ranges of viewing angles depending on the overall geometry of the solar power plant 100.

[0059] In other words, it is understood that, particularly for each main measurement position of the measuring device 1 relative to the receiver 102, the blades 8a, 8b, 8c, 8d, 8e will allow the portion of the solar field 101 to be scanned in such a way that, for different positions of the blades 8a, 8b, 8c, 8d, 8e, the first photodetectors 2a, 2b, 2c, 2d will see rays emanating from different corresponding areas to be monitored within the portion of the solar field 100. By performing this angular scanning of the blades 8a, 8b, 8c, 8d, 8e by pivoting them around their respective axes of rotation, while acquiring the output signal – also called relative flux – from the first photodetectors 2a, 2b, 2c, 2d, the fluxes emanating from all viewing angles are then measured over a corresponding width from the receiver 102 to said position of main measure.

[0060] There figure 5This illustrates the behavior of one of the first photodetectors 2a associated with two blades 8a, 8b. A viewing angle α defines a zone Z1 of the solar field 101, and in particular of a reflector 101a of the solar field 101, from which the solar rays are reflected towards the first photodetector 2a. This viewing angle α is defined in particular by the size of the first photodetector 2a, the spacing between the blades 8a and 8b and the first photodetector 2a, the dimensions of the blades 8a, 8b and their angular positions. In particular, this viewing angle α lies in a plane passing through the alignment axis A1 described above and perpendicular to the measurement plane including the active faces of the first photodetectors 2a, 2b, 2c, 2d. figure 6 illustrates, for its part, the measurement device according to the figure 1It follows that each of the first photodetectors 2a, 2b, 2c, 2d, in association with the blades 8a, 8b, 8c, 8d, 8e, presents a viewing angle α, and that for a given angular position of all the blades, this viewing angle α is identical for all the first photodetectors 2a, 2b, 2c, 2d. The double arrows allow visualization of the zones Z1, Z2, Z3, and Z4 that the measuring device 1 can monitor for a given configuration of system 3 with respect to the first photodetectors 2a, 2b, 2c, 2d. It is then understood that changing the configuration of system 3 consists of modifying the angular position of the blades 8a, 8b, 8c, 8d, 8e, which results in a change in the areas to be monitored. For a given position of the blades 8a, 8b, 8c, 8d, 8e, the areas monitored by the first photodetectors 2a, 2b, 2c, 2d may partially overlap.Similarly, when changing the position of blades 8a, 8b, 8c, 8d, 8e, the new monitored areas may overlap the old monitored areas or not at all.

[0061] Furthermore, the dimensions of the blades 8a, 8b, 8c, 8d, 8e along their pivot axes A2, A3, A4, A5, A6 are such that, for each first photodetector 2a, 2b, 2c, 2d, all rays not originating from the corresponding area to be monitored, regardless of their longitudinal incidence, are shaded. In other words, the dimensions of the blades 8a, 8b, 8c, 8d, 8e, combined with their angular positions relative to the support 6, allow us to define, for each first photodetector 2a, 2b, 2c, 2d, the dimensions of an area to be monitored along the longitudinal axis of the reflectors of the solar field 101 and transversely to this longitudinal axis. Since the longitudinal incidence of the rays impacting the measuring device is not the same for all rays from the solar field, the longitudinal position of the monitored areas is not the same and evolves with the angular position of the blades.

[0062] Since the plates 8a, 8b, 8c, 8d, and 8e are positioned between the solar field 101 and the first photodetectors 2a, 2b, 2c, and 2d, it is preferable that they be as absorbent as possible to avoid any reflection of rays. To achieve this, these plates 8a, 8b, 8c, 8d, and 8e can be coated with black thermal paint or an absorbent layer.

[0063] The blades 8a, 8b, 8c, 8d mentioned previously also have the advantage of intercepting a large part of the solar power reflected by the solar field 101. In this sense, the first photodetectors 2a, 2b, 2c, 2d are subjected to only a small part of the flux incident on the receiver 102, and are therefore little thermally constrained.

[0064] According to a second achievement, notably illustrated in figure 2The cover 7 includes a component 11, specifically a plate, having a slit 12 elongated in a direction substantially orthogonal to the alignment axis A1 of the first photodetectors 2a, 2b, 2c, 2d. The slit 12 extends longitudinally along the axis A, which is substantially orthogonal to the axis A1. In particular, the only rays emanating from the solar field 101 and seen by each of the first photodetectors 2a, 2b, 2c, 2d, regardless of the configuration of the system 3 (and therefore the position of the slit 12) relative to the first photodetectors 2a, 2b, 2c, 2d, pass through this slit 12.In particular, the transition from the first to the second configuration of system 3 causes the slit 12 to move along the alignment axis A1 of the first photodetectors 2a, 2b, 2c, 2d, specifically such that, for any position of the slit 12 relative to the first photodetectors 2a, 2b, 2c, 2d, its elongation axis Aslit is substantially orthogonal to the alignment axis A1. The slit 12 is therefore preferentially straight so as to extend along its length along the elongation axis and has a constant width. The elongation of the slit 12 is oriented to take into account the longitudinal incidence of the rays reflected by the reflectors of the solar field 101, which follow the sun's path S throughout the day to reflect its rays towards the receiver 102.

[0065] There figure 7illustrates the behavior of one of the first photodetectors 2a associated with slit 12. Slit 12 defines a viewing angle α of the first photodetector 2a, allowing monitoring of an area Z1 of the solar field 101, or of a reflector 101a of the solar field 101. figure 8 illustrates, for its part, the measurement device according to the figure 2It follows that each of the first photodetectors 2a, 2b, 2c, 2d, in conjunction with the slit 12, has its own unique viewing angle, and that for a given position of the slit 12, the viewing angles of the different first photodetectors 2a, 2b, 2c, 2d may be at least partially different. The double arrows allow visualization of the zones Z1, Z2, Z3, and Z4 that the measuring device 1 can monitor for a given configuration of system 3 relative to the first photodetectors 2a, 2b, 2c, 2d. It is then understood that changing the configuration of system 3 involves modifying the position of the slit 12, which consequently changes the areas to be monitored. It is thus understood that the position of the slit relative to the first photodetectors is modified when the system configuration is changed.For a given position of the slit 12, the areas monitored by the first photodetectors 2a, 2b, 2c, 2d may partially overlap or not at all. Similarly, when the position of the slit 12 changes, the new monitored areas may or may not overlap the previously monitored areas. Thus, the position of the slit 12 and the orientation of its elongation allow us to determine, for each first photodetector 2a, 2b, 2c, 2d, in the operating configuration of the measuring device 1, from which area of ​​the solar field the incident rays originate. Furthermore, by moving this slit 12, it is possible to determine, for each first photodetector 2a, 2b, 2c, 2d, a total relative incident flux, a contribution from each direction, and therefore a contribution from each reflector.

[0066] The movement of the slot 12 can be achieved by moving the associated plate 11, for example by using suitable mechanical elements such as a motor 9 coupled to a rack 16 formed on a hood 17 carrying the plate 11.

[0067] Plate 11 can always be parallel to the measurement plane of the first photodetectors 2a, 2b, 2c, 2d.

[0068] Preferably, to limit heating of the measuring device 1, one face of the plate 11 in which the slot 12 is provided and intended to be oriented towards the solar field 101 in the configuration of use of the measuring device 1 is reflective of the rays from the solar field 101. For example, this face can be a mirror or be covered with a white thermal paint.

[0069] The use of the measuring device 1, and more specifically of one or the other of the first and second embodiments, allows for a more detailed mapping of the solar field 101. This mapping can then be used to locate a problem in a restricted area within the solar field 101 in order to resolve it quickly. In other words, generally speaking, the measuring device 1 can include an analysis module 13 connected to each of the first photodetectors 2a, 2b, 2c, 2d and configured to process the data from the first photodetectors 2a, 2b, 2c, 2d to create a map of the solar flux reflected by the solar field 101 towards the receiver 102. The analysis module 13 can also retrieve the temperature of each of the first photodetectors 2a, 2b, 2c, 2d to use these values ​​for mapping purposes.

[0070] On the figure 5A central zone Z1-1 is distinguished in which all rays directed towards the first photodetector 2a by the solar field 101 are not intercepted by the blades 8a, 8b. Furthermore, it is also understood from this figure 5 that the rays directed towards the first photodetector 2a and originating from the two zones Z1-2 and Z1-3 located on either side of the central zone Z1-1 are partially intercepted by the blades 8a, 8b. It therefore follows that, for a configuration of system 3, the rays actually measured by the first photodetector 2a do not correspond to all the rays actually reflected by the monitored zone towards the first photodetector 2a. This principle also applies to the second embodiment, as shown in the diagram. figure 7, where the zone Z1 includes the central zone Z1-1 and the two zones Z1-2 and Z1-3 located on either side of the central zone Z1-1, part of whose rays are intercepted by the slit 12. In this sense, it is deduced that there is a correction factor to be applied if we want to obtain the real values ​​of the contribution of a monitored zone of the solar field 101 to the luminous flux perceived by a first given photodetector, and therefore to the contribution of calories within the receiver 102.

[0071] Therefore, there is a problem related to the development or quantification of this correction factor to establish the difference between the flux, particularly the relative flux, actually perceived by one of the first photodetectors and the actual flux, particularly the relative flux, that it should have received. As illustrated in figures 9 And 10This correction factor can be determined using second photodetectors 14a, 14b, 14c, 14d of the measuring device 1, also called reference photodetectors, which do not exhibit the shading of system 3 that alters the perception of the first photodetectors 2a, 2b, 2c, 2d. In this case, these second photodetectors receive a flux potentially originating from all the solar field reflectors. To achieve this, the measuring device can include, for each first photodetector 2a, 2b, 2c, 2d, a second photodetector 14a, 14b, 14c, 14d located near the corresponding first photodetector 2a, 2b, 2c, 2d. In particular, the measuring device 1 comprises as many first photodetectors 2a, 2b, 2c, 2d as second photodetectors 14a, 14b, 14c, 14d, the second photodetectors 14a, 14b, 14c, 14d being aligned along an alignment axis A7 parallel to the alignment axis A1 of the first photodetectors 2a, 2b, 2c, 2d.Of course, it is understood that the amount of radiation received by the second photodetectors 14a, 14b, 14c, 14d along the alignment axis is not modified by system 3, regardless of the configuration of system 3, i.e., the position of the cover 7. Thus, system 3 does not intercept any of the rays emanating from the solar field 101 towards the second photodetectors. In other words, system 3 is configured so as not to intercept any of the rays emanating from the solar field towards the second photodetectors: system 3 does not shade the second photodetectors.The role of the second photodetectors 14a, 14b, 14c, 14d is to measure or determine the luminous fluxes, particularly relative fluxes, emanating from the solar field 101 without the perturbation induced by system 3. This is done to establish correction factors for the measurements taken by the first photodetectors 2a, 2b, 2c, 2d, especially for a given position of the cover and, in particular, in conjunction with a primary measurement position of the measuring device 1 relative to the receiver 102 in the operating configuration. This description describes the use of several second photodetectors, but it should be noted that a single second photodetector arranged so that system 3 does not intercept any of the rays emanating from the solar field towards said second photodetector may suffice. In this case, the correction factor calculated from the second photodetector can be the same for all the first photodetectors.To develop this correction factor using only one second photodetector, it is possible to compare the measurement from the second photodetector—which then sees the entire solar field—to the sum of the measurements from a first associated photodetector after scanning the entire solar field for a given measurement position. In fact, when using only one second photodetector, it is assumed that the proportion of rays intercepted by system 3, particularly the blades, is the same for each first photodetector. When using multiple second photodetectors, it is possible to obtain additional information and, in particular, to verify that the proportion of intercepted rays is the same for each of the first photodetectors. Furthermore, when using multiple second photodetectors, it is possible to provide a relative flux profile that directly corresponds to the entire solar field, which is complementary.Of course, the measuring device can also operate without a second photodetector(s).

[0072] We observe that in the usage configuration, the second photodetectors 14a, 14b, 14c, 14d are offset relative to the first detectors 2a, 2b, 2c, 2d along the axis of the receiver A Receiver.Thus, preferably, to evaluate the correction factor of each of the first photodetectors 2a, 2b, 2c, 2d for a given principal measurement position of the measuring device 1, when the measuring device 1 moves from its given principal measurement position to a new position relative to the receiver 102, its movement is at least temporarily stopped when the second photoreceptors 14a, 14b, 14c, 14d respectively reach positions previously occupied by the first photodetectors 2a, 2b, 2c, 2d in the given principal measurement position mentioned above so that said second photodetectors 14a, 14b, 14c, 14d can perceive fluxes similar to those previously reached by the first photodetectors 2a, 2b, 2c, 2d in order to determine the correction factors.

[0073] In particular, each second photodetector is aligned with a corresponding first photodetector along a substantially orthogonal axis, notably perpendicular to the alignment axis A1.

[0074] The use of the first photodetectors 2a, 2b, 2c, 2d, and where applicable the second photodetectors 14a, 14b, 14c, 14d, allows the mapping of the rays from the solar field using the relative fluxes corrected or not described previously. The second photodetectors can also be kept at temperature and each include a thermocouple to measure their temperature.

[0075] The second photodetectors can be connected to the analysis module 13 in such a way that their measurements are used by the analysis module 13 to correct the fluxes associated with the first photodetectors.

[0076] For consistent measurements, the first and second photodetectors are preferably identical.

[0077] In one implementation, the first and / or second photodetector(s) are photovoltaic cells, specifically triple junction cells capturing a spectrum extending, for example, from 300 nm to 1700 nm, and operating in particular at flux densities on the order of 1 MW / m². A thermocouple can be installed on each photovoltaic cell and measures its temperature. The temperature of the photovoltaic cells can be kept constant by an active cooling circuit so that the proportionality coefficient described below is the same for all photovoltaic cells. The response of the photovoltaic cells is characterized at the factory under a normalized AM1.5D spectrum, which corresponds to the light reaching Earth after passing through 1.5 times the thickness of the atmosphere, to confirm that their short-circuit current is identical. The dimensions of the photovoltaic cells are those of a one-centimeter square.Each photovoltaic cell is advantageously brazed onto a 3.5 cm x 3.5 cm copper plate. The benefit of using this type of photovoltaic cell lies in its price, which is significantly lower than that of a thermal flux gauge. However, the signal delivered is relative, as it depends on the spectrum and temperature. With this implementation, only a relative map can be determined initially using the relative fluxes.

[0078] To obtain an absolute map, it is possible to use the fact that the solar flux incident on this type of photovoltaic cell is proportional to the short-circuit current delivered by the cell. However, the proportionality coefficient depends on the received spectrum and the cell temperature. This implies that it is necessary to determine this proportionality coefficient beforehand by characterizing the cell's response with a known spectrum. Then, during measurement, the incident spectrum must be measured to determine the corresponding proportionality coefficient, which was determined beforehand. This is certainly feasible, but complex to implement. Therefore, to avoid these two steps, it is possible to use a thermal flux gauge to convert the relative response of the cells into kW / m², particularly for a given photovoltaic cell temperature.The use of the flux gauge within the framework of this measurement device can be done by applying the teachings of document FR2981737. More particularly, when the photovoltaic cells forming the first photodetectors 2a, 2b, 2c, 2d are positioned at a certain position relative to the receiver 102, the signal from all the photovoltaic cells forming the first photodetectors 2a, 2b, 2c, 2d is acquired while performing an angular scan of the blades or a scan via the slit 12 to obtain an overall flux profile (from the whole solar field) on a relative scale.The flux gauge, which uses a thermal effect, is positioned in line with a photovoltaic cell such that when the measuring device 1 is moved by a step corresponding to the distance between the flux gauge and the associated photovoltaic cell, the flux gauge detects the same flux previously detected by the associated photovoltaic cell during the acquisition of the overall flux profile. The flux gauge is arranged so as not to be shaded by system 3. Thus, a proportionality coefficient is easily obtained, which is the ratio of the flux gauge's response to the response of the associated photovoltaic cell. This coefficient can then be applied to the responses of all the associated photovoltaic cells for a corresponding principal measuring position in order to determine an associated absolute flux for the first photodetectors 2a, 2b, 2c, 2d.

[0079] The absolute flux allows, for example, to know the solar power received, for example in watts per square meter, by the measuring device 1 at each main measuring position and for each configuration of the system, so as to deduce the solar power received by the whole of the receiver 102 and to characterize the solar field, and more particularly each of the reflectors of the solar field 101.

[0080] THE figures 1, 2 , 9 And 10 illustrate precisely the measurement device comprising a thermal effect flux gauge 15 associated with one of the first photodetectors 2c, in particular aligned with the thermal effect flux gauge 15 along an axis A gauge orthogonal, and in particular perpendicular, to the alignment axis A1 of said first photodetectors 2a, 2b, 2c, 2d.

[0081] The thermal flux gauge is preferably a Gardon-type gauge. This type of gauge consists of a 2.5 cm diameter cylindrical copper block with a cooled, cooled surface, upon which rests a thin layer of Constantan material. When this layer is irradiated, the heat received is dissipated through the cylindrical copper section to a cooling water circuit. The incident flux is thus determined by measuring the temperature difference between the center of the irradiated surface and its periphery.

[0082] Gauge 15 can be linked to analysis module 13 which can use the data from said gauge to determine absolute flow values.

[0083] Of course, before determining the absolute flux associated with each of the first photodetectors 2a, 2b, 2c, 2d, the corresponding relative flux is preferably corrected with the correction factor. In this sense, a measuring device 1, according to a preferred mode, integrates the second photodetector(s) 14a, 14b, 14c, 14d and the thermal flux gauge 15.

[0084] According to a particular implementation, to perform measurements at a given primary measurement position, the measuring device moves to position itself at that primary measurement position. After an angular scan of the blades—or a scan of the slit 12—the flux profile corresponding to each reflector is deduced on a relative scale using the measurements from the first photodetectors 2a, 2b, 2c, 2d. The profiles obtained for each reflector are summed to obtain an overall profile. The measuring device can then move so that the second photodetectors 14a, 14b, 14c, 14d are positioned in the same positions as the first photodetectors 2a, 2b, 2c, 2d when the measuring device was in its primary measurement position, and the responses from the second photodetectors 14a, 14b, 14c, 14d are acquired. The same procedure is used for the thermal effect flux gauge 15.The relative value on the overall flux profile, corresponding to one of the first photodetectors in the same position as a second matching photodetector and associated with a corresponding position of the thermal flux gauge, can be compared to the measurement taken by said second photodetector to provide a proportionality coefficient between these two values. This proportionality coefficient can be applied to the overall flux profile and also to the flux profile from a single reflector. The relative signal is then converted to kW / m², notably by matching the measurement of the second photodetector with the thermal flux gauge.

[0085] It is understood from all that has been said above that the invention may also relate to a method of using the measuring device 1 within a solar power plant 100 as described previously.

[0086] More generally, as illustrated in figure 11The method of using the measuring device 1 as described in a solar power plant 100 as described may include a placement step E1 of the measuring device 1 at a plurality of main measuring positions relative to the receiver 102, and a measurement step E1-1 implemented by the first photodetectors 2a, 2b, 2c, 2d according to at least the first system configuration and the second system configuration 3. Of course, when system 3 is capable of adopting more than two configurations, the measurement step E1-1 is preferentially implemented for each of these configurations. In particular, the measurement step E1-1 is implemented for each main measuring position.According to one embodiment, the placement step E1 can be such that the movement of the measuring device is continuous with an acquisition speed and a movement speed allowing the measurements to be acquired where desired; in this case, the measurement step can be implemented a plurality of times during the movement of the measuring device, and each measurement step can be carried out from one or more close and successive main measurement positions.

[0087] Preferably, the placement step E1 of the measuring device 1 consists of moving the measuring device 1 along the receiver 102 such that in any main measuring position, the alignment axis A1 of the first photodetectors 2a, 2b, 2c, 2d is substantially orthogonal to the longitudinal axis A Receiver of the receiver 102.

[0088] In each measurement position, it follows that the first photodetectors 2a, 2b, 2c, 2d are each arranged in an acquisition position, this acquisition position is defined with respect to receiver 102.

[0089] As mentioned previously, the fluxes measured / determined by, or from, each of the first photodetectors 2a, 2b, 2c, 2d can be relative fluxes which can be corrected to take into account shading and / or which can be transformed by using a reference flux to determine absolute fluxes allowing for example to go back to a solar power perceived by the first photodetectors 2a, 2b, 2c, 2d and therefore the receiver 102.

[0090] In this sense, in the first case where we wish to take into account the shading caused by system 3, we find ourselves in the following situation: the measuring device 1 comprises second photodetectors 14a, 14b, 14c, 14d (in particular, as many second photodetectors as first photodetectors, as mentioned previously) aligned along an axis A7 substantially parallel to the alignment axis A1 of the first photodetectors 2a, 2b, 2c, 2d and arranged in such a way that system 3 does not intercept the rays coming from the solar field 101 and directed towards the second photodetectors 14a, 14b, 14c, 14d. In this first case, the method comprises at least one set of steps E100 (illustrated in figure 12) implemented for each first photodetector 2a, 2b, 2c, 2d, said set of steps E100 comprising: a placement E100-1 of said first photodetector 2a, 2b, 2c, 2d at an acquisition position defined as the position occupied by said first photodetector 2a, 2b, 2c, 2d in one of the main measurement positions of the measurement device 1, then a determination E100-2 from said first photodetector placed in said acquisition position of relative fluxes from the solar field 101 for at least the first and second configurations of the system 3 (this involves implementing a measurement step according to step E1-1 described above); and a placement E100-3 of one of the second photodetectors 14a, 14b, 14c, 14d associated with said first photodetector 2a, 2b, 2c, 2d at said acquisition position from which it follows that the measuring device 1 occupies a secondary measuring position different from said one of the main measuring positions,then an E100-4 determination from said one of the second photodetectors 14a, 14b, 14c, 14d placed in the acquisition position of a standard flux. Finally, the process includes a step E101 using the determined standard fluxes and the determined relative fluxes to create a map of the fluxes perceived by the receiver 102 and originating from the solar field 101. It is understood here that when a measurement / determination of a relative flux is performed by a first photodetector 2a, 2b, 2c, 2d at an acquisition position, a measurement is also performed by a second photodetector 14a, 14b, 14c, 14d at the same acquisition position to correct the relative fluxes determined by the first photodetector 2a, 2b, 2c, 2d corresponding to the first and second configurations, taking into account the shading induced by system 3. The, figure 12This shows that steps E100-1 and E100-2 are implemented before steps E100-3 and E100-4; this is just an example, as the reverse is also possible. During step E101, the determined relative fluxes are each preferably corrected using an associated standard flux. To perform this correction, for a first photodetector, the values ​​corresponding to the entire solar field for a given main measurement position must be summed. Once this correction is made, it is possible to return to fluxes corresponding to a particular reflector.

[0091] Preferably, in this first case, the set of steps E100 is implemented in association with each main measurement position. This allows the utilization step E101 to map the flows, particularly relative flows, perceived by the entire receiver 102 according to its length.

[0092] In an implementation of this first case, we will also seek to take into account the operating conditions of the solar power plant 100, in particular to determine absolute flux values. In this implementation, the situation is as follows: the first photodetectors 2a, 2b, 2c, 2d (and in particular the second photodetectors) are each formed by a photovoltaic cell such as described previously; the measuring device 1 includes a thermal flux gauge 15 (such as described previously) associated with a reference photodetector 2c chosen from among the first photodetectors.Here, the set of steps E100 associated with the reference photodetector 2c includes a placement step E100-5 of the thermal flux gauge 15 at the acquisition position, resulting in the measuring device 1 occupying an additional measurement position different from the corresponding primary and secondary measurement positions. This is followed by a determination step E100-6 of a reference flux from the thermal flux gauge 15. Finally, the utilization step E101 further includes the use of each determined reference flux. The use of each determined reference flux allows, in particular, the calculation of a perceived solar power for each acquisition position of each first photodetector associated with a primary measurement position, and this for each configuration of the system 3 at the corresponding primary measurement position.It is then possible to associate, through the different configurations of the system, which solar power comes from which monitored area of ​​the solar field.

[0093] In a second case, it is possible to neglect the rays intercepted by system 3 and originating from the areas to be monitored. In this sense, the second photodetectors 14a, 14b, 14c, 14d are not necessary, and the situation can be as follows: the first photodetectors 2a, 2b, 2c, 2d are each formed by a photovoltaic cell, notably as described previously; the measuring device 1 comprises a thermal flux gauge 15 (notably as described previously) associated with a reference photodetector 2c chosen from among the first photodetectors. In this second case, the process comprises, in association with each main measuring position, the following steps ( figure 13): a placement step E1000 of said first photodetectors 2a, 2b, 2c, 2d at acquisition positions defined as the positions occupied by said first photodetectors 2a, 2b, 2c, 2d in said main measurement position of the measurement device 1; a determination step E1001, for each of the first photodetectors 2a, 2b, 2c, 2d placed in its acquisition position, of relative fluxes for at least the first and second configurations of the system 3 (this consisting in particular of the implementation of a measurement step E1-1); a step of placing E1002 the thermal flux gauge 15 at said acquisition position of the reference photodetector 2c, from which it results that the measuring device 1 occupies a position distinct from said main measuring position, and a step of determining a reference flux from said thermal flux gauge 15 placed at said acquisition position.In this second case, the process includes a step E1004 using determined reference fluxes and determined relative fluxes to create a map of the fluxes perceived by the receiver and originating from the solar field on an absolute scale. The use of each reference flux makes it possible, in particular, to calculate the perceived solar power for each acquisition position of each first photodetector 2a, 2b, 2c, 2d, and this for each configuration of system 3. It is then possible, using the different configurations of system 3, to associate which solar power originates from which monitored area of ​​the solar field 101.

[0094] The first and second cases described above are optimized in that the corrections for relative fluxes and / or the use of reference fluxes are performed for each acquisition position by successively placing the appropriate sensors in each of these acquisition positions. According to a less precise but faster implementation, it is possible to consider that the second photodetector(s) 14a, 14b, 14c, 14d and the thermal flux gauge 15 are sufficiently close to the corresponding first photodetectors 2a, 2b, 2c, 2d to detect essentially the same solar power.In this case, the situation may be as follows: the measuring device 1 includes at least one second photodetector (when the measuring device includes second photodetectors 14a, 14b, 14c, 14d, they are aligned along an axis A7 substantially parallel to the axis A1 of alignment of the first photodetectors 2a, 2b, 2c, 2d) and arranged in such a way that the system 3 does not intercept the rays from the solar field 101 and directed towards each second photodetector 14a, 14b, 14C, 14d; and / or the first photodetectors 2a, 2b, 2c, 2d (and in particular each second photodetector) are each formed by a photovoltaic cell in particular as described previously; the measuring device 1 includes a thermal effect flux gauge 15 (in particular as described above) associated with a reference photodetector 2c chosen from among the first photodetectors.In this implementation, each measurement step E1-1 consists of determining relative fluxes by each of the first photodetectors 2a, 2b, 2c, 2d and, for each configuration of system 3 at the corresponding main measurement position, a standard flux by each second photodetector 14a, 14b, 14c, 14d at the corresponding main measurement position, and, where applicable, a reference flux by the thermal flux gauge 15 at the corresponding main measurement position. Finally, the method includes a step of using each determined standard flux, the determined relative fluxes, and / or each determined reference flux to develop a map of the fluxes perceived by the receiver 102 and originating from the solar field 101. This map allows, where applicable, the representation of the relative fluxes, the corrected relative fluxes, and / or the absolute fluxes perceived by the receiver 102.

[0095] According to one embodiment, the operating method allows a profile to be established for each reflector using information from measuring device 1. In some cases, one or more monitored areas may be formed at the level of two adjacent reflectors, and it is not possible to separate the contribution of each reflector; such monitored areas are called uncertainty zones. Since these uncertainty zones are theoretically predeterminable, measurements made by the first detectors and associated with these uncertainty zones are disregarded. The relative profile of each reflector can be obtained by summing the relative fluxes corresponding to the monitored areas comprising exclusively that reflector. The overall relative profile of the solar field is obtained by summing all the relative profiles of the reflectors in the solar field.This overall profile is therefore altered to some extent because it contains certain areas multiple times, other areas (the uncertainty zones) are suppressed, and the system can generate a shading effect that attenuates the measurements. For this last point, comparison with the second, unshaded photodetectors allows for correction of the relative flux.

[0096] In this process, flux determinations from the first and second photodetectors are performed while they are maintained at a reference temperature. Where applicable, the described operating steps take this reference temperature into account. Alternatively, the temperatures of the first and second photodetectors are measured and used in the operating step to generate the corresponding map.

[0097] The implementations of the method described above and using the second photodetectors can also be implemented using a single second photodetector, a calibration flux measurement of which can be used to correct all the relative fluxes determined for a given principal measurement position. In this sense, the measurement device 1 may include a second photodetector (in particular, a single second photodetector) arranged such that the system 3 does not intercept the rays emanating from the solar field 101 and directed towards the second photodetector, and the method then comprises at least one set of steps implemented for each principal measurement position, including: placing said first photodetectors at acquisition positions defined as the positions occupied by said first photodetectors in said principal measurement position of the measurement device,then a determination from said first photodetectors 2a, 2b, 2c, 2d placed in said acquisition positions of relative fluxes from the solar field 101 for at least the first and second configurations of system 3; a placement of the second photodetector in one of the acquisition positions from which it results that the measuring device 1 occupies a secondary measurement position different from said primary measurement position, then a determination from said second photodetector placed in the acquisition position of a standard flux; and the method includes a step of using the determined standard fluxes and the determined relative fluxes to develop a map of the fluxes perceived by the receiver 102 and emanating from the solar field 101. According to an improvement, the first photodetectors 2a, 2b, 2c,2d are each formed by a photovoltaic cell (including, in particular, said second photodetector) and the measuring device 1 comprises a thermal flux gauge 15 associated with a reference photodetector 2c chosen from among the first photodetectors 2a, 2b, 2c, 2d. In this case, the set of steps also includes a step of placing the thermal flux gauge at said acquisition position of the reference photodetector, from which it follows that the measuring device occupies a position distinct from said main measurement position, and a step of determining a reference flux from said thermal flux gauge placed at said acquisition position. The use step may then further include the use of each reference flux to develop a map of the fluxes perceived by the receiver and emanating from the solar field.

[0098] Preferably, within the context of the solar power plant or process, for each main measurement position of the measuring device, each system configuration chosen from at least the first and second configurations is such that the first photodetectors 2a, 2b, 2c, 2c only detect rays from the solar field originating from a single reflector. In other words, for a given configuration of system 3, the monitored areas all belong to a single reflector. This facilitates post-measurement processing to determine the relative and / or absolute fluxes emanating from a particular reflector.

[0099] From the foregoing, it is clear that the distribution of the flux incident on receiver 102 and originating from each reflector can be determined, notably through measurements, thus enabling the detection of any drifts in the solar tracking of each reflector individually. This measurement device can therefore support an existing solar tracking system. Alternatively, and more advantageously, the control of a reflector's motor drive can be based solely on data from measurement device 1, thereby eliminating the need for conventional methods of solar tracking the reflector that rely on calculating the sun's position. The orientation of each reflector can be adjusted to maximize the interception factor, which is the ratio of the energy intercepted by the absorber to the energy reflected by the solar field.

[0100] Furthermore, analyzing the shape and distribution of the determined fluxes allows for the identification of defects on the reflectors (broken mirrors, shape defects, dust) and the identification of areas of the solar field shaded by clouds. It is also possible to deduce the total flux distribution incident on receiver 102 by summing the contributions from each reflector.

[0101] Finally, by knowing the shape and distribution of the flux incident at receiver 102 from each reflector, as well as its location relative to the absorber, aiming strategies can be effectively implemented to uniformize the flux incident at the absorber. This prevents the formation of hot spots at the absorber, minimizes differential expansion between the absorber tubes in the case of a multi-tube absorber, and thereby limits the degradation of a selective layer of the absorber and potentially of the heat transfer fluid.This selective coating can be a paint or a vacuum-deposited coating applied to the absorber tubes. Their function is to increase absorption and reduce infrared emission from the absorber, thus improving the thermal exchange efficiency between the radiation incident on the receiver and the heat transfer fluid. A limitation of measurement device 1, when using photovoltaic cells and a thermal flux gauge, lies in the fact that the thermal flux gauge and the triple-junction cells are not the same size, which distorts the correlation between the two responses. Indeed, since the flux is not constant across the surface of the cells and the gauge, the average measured flux density depends on their surface areas. This limitation is resolved by positioning the cells and gauge in an area where the flux varies linearly.Thus, the average incident flux density on each of the two sensors remains the same and the correspondence remains valid.

[0102] In the case of using a thermal flux gauge, the first photodetectors, and where applicable the second photodetector(s), are preferably photovoltaic cells.

[0103] In particular, it is understood from what has been said in this description that when we measure / determine a flux, whether it is a relative flux, a standard flux, a reference flux, or other, it is a flux coming from the solar field.

Claims

1. Device (1) for measuring fluxes reflected by a solar field (101) of a solar power plant (100) in the direction of a receiver (102) of the solar power plant and intended to be mounted at the level of the receiver (102), said measuring device (1) comprising: • first photodetectors (2a, 2b, 2c, 2d) aligned along a corresponding axis of alignment (A1), and • a system (3) configured so as to delineate for each first photodetector (2a, 2b, 2c, 2d), in a configuration of use of the measuring device (1), a zone to be monitored of the solar field (101), said system (3) being able to vary between a first configuration relative to the first photodetectors (2a, 2b, 2c, 2d) and a second configuration relative to the first photodetectors (2a, 2b, 2c, 2d) so that the passage from the first configuration to the second configuration simultaneously modifies the zone to be monitored of each of the first photodetectors (2a, 2b, 2c, 2d), characterized in that the system (3) comprises a shield (7) having a mobility relative to the first photodetectors (2a, 2b, 2c, 2d), said shield (7) being configured so as to make it possible for each position of the shield (7) relative to the first photodetectors (2a, 2b, 2c, 2d), on the one hand, to prevent a first portion of the rays issuing from the solar field (101) to reach the first photodetectors (2a, 2b, 2c, 2d) and, on the other hand, to allow the passage of a second portion of the rays issuing from the solar field (101) in the direction of the first photodetectors (2a, 2b, 2c, 2d), and in that the mobility of the shield (7) relative to the first photodetectors (2a, 2b, 2c, 2d) allows the passage from the first configuration to the second configuration.

2. Device according to Claim 1, characterized in that the shield (7) comprises a plurality of blades (8a, 8b, 8c, 8d, 8e) pivotably mounted on a support (6) of the measuring device (1) integrating the first photodetectors (2a, 2b, 2c, 2d), the axes of pivoting (A2, A3, A4, A5, A6) of the blades being substantially orthogonal, notably perpendicular, to the axis of alignment (A1) of the first photodetectors (2a, 2b, 2c, 2d), the axes of pivoting (A2, A3, A4, A5, A6) of said blades (8a, 8b, 8c, 8d, 8e) being substantially parallel to one another, the possible movement of the blades (8a, 8b, 8c, 8d, 8e) via the axes of pivoting (A2, A3, A4, A5, A6) corresponding to the mobility of the shield (7).

3. Device according to the preceding claim, characterized in that for each pair of adjacent first photodetectors, a blade of the plurality of blades is pivotably mounted between said first photodetectors of said pair, and in that the line of first photodetectors (2a, 2b, 2c, 2d) is framed by two blades (8a, 8e) of the plurality of blades (8a, 8b, 8c, 8d, 8e), the blades (8a, 8b, 8c, 8d, 8e) of the plurality of blades preferably being constrained to move together, and notably all remaining parallel to one another whatever the angle of pivoting of said blades (8a, 8b, 8c, 8d, 8e) relative to their respective axes of pivoting (A2, A3, A4, A5, A6) may be.

4. Device according to Claim 1, characterized in that the shield (7) comprises a member (11), notably a plate, having a slot (12) elongated in a direction substantially orthogonal to the axis of alignment (A1) of the first photodetectors (2a, 2b, 2c, 2d), and in that whatever the position of the slot (12) relative to said first photodetectors (2a, 2b, 2c, 2d) may be, the only rays issuing from the solar field (101) and seen by said first photodetectors (2a, 2b, 2c, 2d) pass through this slot (12).

5. Device according to any one of the preceding claims, characterized in that it comprises: • second photodetectors (14a, 14b, 14c, 14d) the number of which is equal to that of the first photodetectors (2a, 2b, 2c, 2d), the second photodetectors (14a, 14b, 14c, 14d) being aligned along an axis of alignment (A7) parallel to the axis of alignment (A1) of the first photodetectors (2a, 2b, 2c, 2d), and said system (3) intercepting none of the rays issuing from the solar field (101) in the direction of said second photodetectors (14a, 14b, 14c, 14d), or • only one second photodetector, said system (3) intercepting none of the rays issuing from the solar field (101) in the direction of said second photodetector (14a, 14b, 14c, 14d).

6. Device according to any one of the preceding claims, characterized in that it comprises an analysis module (13) connected to each of the first photodetectors (2a, 2b, 2c, 2d) and configured so as to process the data issuing from the first photodetectors (2a, 2b, 2c, 2d) to establish a map of the solar flux reflected by the solar field (101) in the direction of the receiver (102).

7. Device according to any one of the preceding claims, characterized in that it comprises a thermal effect flux gauge (15) associated with one of the first photodetectors (2c), notably said one of the first photodetectors (2c) is aligned with the thermal effect flux gauge (15) along an axis orthogonal, and notably perpendicular, to the axis of alignment (A1) of said first photodetectors (2a, 2b, 2c, 2d).

8. Solar power plant (100) comprising a receiver (102) and a solar field (101) provided with reflectors (101a, 101b, 101c, 101d, 101e) adjustable to reflect the solar rays in the direction of the receiver (102), characterized in that it comprises a measuring device (1) according to any one of the preceding claims disposed at the level of the receiver (102).

9. Method of using the measuring device (1) of a solar power plant (100) according to Claim 8, characterized in that it comprises a step of placement (E1) of the measuring device (1) at a plurality of principal measuring positions relative to the receiver (102), and in that it comprises a measuring step (E1-1) implemented by the first photodetectors (2a, 2b, 2c, 2d) in at least the first configuration of the system (3) and the second configuration of the system (3), preferably said measuring step is implemented for each principal measuring position, the step of placement (E1) of the measuring device (1) preferably consisting in moving the measuring device (1) along the receiver (102) so that in any principal measuring position, the axis of alignment (A1) of the photodetectors (2a, 2b, 2c, 2d) is substantially orthogonal to the longitudinal axis of the receiver (102).

10. Method according to Claim 9, characterized in that: • the measuring device (1) comprises at least one second photodetector arranged such that the system (3) does not intercept the rays issuing from the solar field (101) and oriented toward each second photodetector, • the first photodetectors (2a, 2b, 2c, 2d) and each second photodetector are each formed by a photovoltaic cell, • the measuring device (1) comprises a thermal effect flux gauge (15) associated with a reference photodetector chosen among the first photodetectors (2a, 2b, 2c, 2d), and in that each measuring step (E1-1) consists in determining relative fluxes by each of the first photodetectors (2a, 2b, 2c, 2d) and for each configuration of the system (3) at said corresponding principal measuring position, a calibration flux by each second photodetector at said corresponding principal measuring position, and a reference flux by said thermal effect flux gauge (15) at said corresponding principal measuring position, and in that the method comprises a step of utilization of each calibration flux determined, the relative fluxes determined and each reference flux determined to generate a map of the fluxes perceived by the receiver (102) and issuing from the solar field (101).

11. Method according to Claim 9, characterized in that the measuring device (1) comprises second photodetectors (14a 14b, 14c, 14d) aligned along an axis (A7) substantially parallel to the axis of alignment (A1) of the first photodetectors (2a, 2b, 2c, 2d) and arranged such that the system (3) does not intercept the rays issuing from the solar field (101) and oriented toward the second photodetectors (14a 14b, 14c, 14d), and in that the method comprises at least one set of steps (E100) implemented for each first photodetector (2a, 2b, 2c, 2d), said set of steps (E100) comprising: • a placement (E100-1) of said first photodetector (2a, 2b, 2c, 2d) at an acquisition position defined as the position occupied by said first photodetector (2a, 2b, 2c, 2d) in one of the principal measuring positions of the measuring device (1), then a determination (E100-2) from said first photodetector (2a, 2b, 2c, 2d) placed in said acquisition position of relative fluxes issuing from the solar field (101) for at least the first and second configurations of the system (3), • a placement (E100-3) of one of the second photodetectors (14a 14b, 14c, 14d) associated with said first photodetector (2a, 2b, 2c, 2d) at said acquisition position which results in the measuring device (1) occupying a secondary measuring position different from said one of the principal measuring positions, then a determination (E100-4) from said one of the second photodetectors (14a 14b, 14c, 14d) placed in the acquisition position of a calibration flux, and in that the method comprises a step of utilization (E101) of the calibration fluxes determined and the relative fluxes determined to generate a map of the fluxes perceived by the receiver (102) and issuing from the solar field (101), the set of steps (E101) preferably being implemented in association with each principal measuring position.

12. Method according to Claim 11, characterized in that: • the first photodetectors (2a, 2b, 2c, 2d) are each formed by a photovoltaic cell, • the measuring device (1) comprises a thermal effect flux gauge (15) associated with a reference photodetector (2c) chosen among the first photodetectors (2a, 2b, 2c, 2d), • the set of steps (E100) associated with said reference photodetector (2c) comprises a step of placement (E100-5) of the thermal effect flux gauge (15) at said acquisition position which results in the measuring device (1) occupying an additional measuring position different from said corresponding one of the principal measuring positions and from said corresponding secondary measuring position, then a step of determination (E100-6) from said thermal gauge of a reference flux, and in that the utilization step (E101) further comprises the use of each reference flux determined.

13. Method according to Claim 9, characterized in that: • the first photodetectors (2a, 2b, 2c, 2d) are each formed by a photovoltaic cell, • the measuring device (1) comprises a thermal effect flux gauge (15) associated with a reference photodetector (2c) chosen among the first photodetectors (2a, 2b, 2c, 2d), and in that the method comprises, in association with each principal measuring position, the following steps: • a step of placement (E1000) of said first photodetectors (2a, 2b, 2c, 2d) at acquisition positions defined as the positions occupied by said first photodetectors (2a, 2b, 2c, 2d) in said principal measuring position of the measuring device (1), • a step of determination (E1001), for each of the first photodetectors (2a, 2b, 2c, 2d) placed in its acquisition position, of relative fluxes for at least the first and second configurations of the system (3), • a step of placement (E1002) of the thermal effect flux gauge (15) at said acquisition position of the reference photodetector (2c) which results in the measuring device (1) occupying a position distinct from said principal measuring position, and a step of determination of a reference flux from said thermal effect flux gauge (15) placed at said acquisition position, and in that the method comprises a step of utilization (E1004) of the reference fluxes determined and the relative fluxes determined to generate a map of the fluxes perceived by the receiver and issuing from the solar field.

14. Method according to Claim 9, characterized in that the measuring device (1) comprises a second photodetector arranged such that the system (3) does not intercept the rays issuing from the solar field (101) and oriented toward the second photodetector, and in that the method comprises at least one set of steps implemented for each principal measuring position comprising: • a placement of said first photodetectors (2a, 2b, 2c, 2d) at acquisition positions defined as the positions occupied by said first photodetectors (2a, 2b, 2c, 2d) in said principal measuring position of the measuring device (1), then a determination (E100-2) from said first photodetectors (2a, 2b, 2c, 2d) placed in said acquisition positions of relative fluxes issuing from the solar field (101) for at least the first and second configurations of the system (3), • a placement of the second photodetector in one of the acquisition positions which results in the measuring device (1) occupying a secondary measuring position different from said principal measuring position, then a determination from said second photodetector placed in the acquisition position of a calibration flux, and in that the method comprises a step of utilization of the calibration fluxes determined and the relative fluxes determined to generate a map of the fluxes perceived by the receiver (102) and issuing from the solar field (101).