Load-bearing structure, power plant equipped with such a load-bearing structure, and method for adjusting such a load-bearing structure

Abstract

The invention relates to a supporting structure (3) comprising: - a support table (5) supported by at least four posts (17), each post (17) having, at its upper end, a connecting member (19) linking the support table (5) to the post (17), - at least four altimetric variation sensors configured to measure the relative altimetric variation of the support table (5), - a distance sensor configured to measure the distance between the upper end of a reference post (27) and the support table (5), and - an adjustment system configured to stabilize the deformation of the support table (5) based on measurements from the altimetric variation sensors (21) and the distance sensor (25). The invention also relates to a power plant (1) comprising such a supporting structure (3), as well as a method for adjusting such a supporting structure (3). Figure for the abstract: Fig. 1

Description

Title of the invention: Load-bearing structure, power plant equipped with such a load-bearing structure, and method for adjusting such a load-bearing structure technical field

[0001] The present application relates to a load-bearing structure, as well as a method for adjusting such a load-bearing structure. The invention also applies to a power plant comprising such a load-bearing structure, supporting in particular a rotating machine, such as a turbo-alternator unit. STATE OF THE ART

[0002] Typically, power plants, particularly nuclear or thermal power plants, include a turbo-alternator unit, which is a rotating machine that produces electricity from pressurized steam. Such a turbo-alternator unit thus consists of a steam turbine and an alternator.

[0003] Such a turbo-generator unit is supported by a support table, also called a unit table. This support table rests on columns typically made of reinforced concrete, and together they form a load-bearing structure. These columns are subject to non-uniform temperature variations, for example, due to the day-night cycle, particularly the sunrise and sunset cycle, and / or the start-up of auxiliary equipment nearby in the same enclosed space, also called the machine room. The different expansions of the columns cause deformation of the support table. Such deformation makes surveying and alignment operations for the turbo-generator unit particularly difficult, if not impossible. Indeed, the expansion of the columns due to temperature variations can be faster than the adjustment operations (topographic measurements, alignment).

[0004] Thus, for example, when adjusting the steam turbine, the relative positions between the shaft line and the bearings must be precisely adjusted to ensure proper operation of the steam turbine and the alternator. Any imperfections or errors in the alignment of the steam turbine can have significant consequences for the dynamic stability of the bearings and can therefore lead to operational difficulties or even significant damage to the bearings supporting the shaft line of the turbo-alternator unit.

[0005] In order to allow the adjustment of the turbo-alternator unit, the altimetric inspection of the steam turbine by NTHP (very high precision leveling) is carried out and The bearing adjustment operations are then carried out. However, these require the support table to remain stable over time. Due to the effects of diurnal cycles and / or the start-up of auxiliary equipment, such as pumps, thermal variations in the machine room cause significant expansion of the columns over relatively short time periods compared to the adjustment operations, because these are slender structures with low thermal inertia.

[0006] Due to non-uniform temperature changes in the machine room, some columns expand or contract more than others, for example by a few millimeters. These differential elevation changes affect the distribution of forces transmitted—directly or, more generally, indirectly, for example, by spring boxes—from the columns to the support table. Thus, the support table deforms over time, primarily vertically, while deformations along the plane of the support table are comparatively negligible.Such deformations result from altimetric variations at the poles, for example of several hundred micrometers, making topographic measurements and the adjustment of the turbo-alternator unit quite hazardous and imprecise, especially since the effects of thermal variations are faster than the measurement / adjustment / alignment operations.

[0007] Thus, difficulties arise during the alignment operations of the turbo-alternator unit, even though precautions are taken to limit temperature variations in the machine room. For this purpose, the machine room doors are closed several hours before the start of the surveying and alignment operations. Consequently, thermal loads are incurred, and the measures implemented to mitigate them are passive, such as, for example: closing the doors several hours before the intervention and not starting auxiliary equipment.

[0008] Surveying and alignment operations can be carried out at night, and the start-up of auxiliary equipment, which can cause local hot spots, is avoided. However, the problem of deformation of the support table persists. Thus, the quality of the surveying and the adjustment of the turbo-alternator unit depends on uncontrollable parameters such as sunlight, the effects of which are amplified when the machine room has a south-facing skylight, and is therefore particularly unpredictable.

[0009] The possible movements of the support table are vertical displacements along the Z axis, rotation around the X axis also called roll, rotation around the Y axis also called pitch, and deformation, for example of the hyperbolic paraboloid type or in "horse saddle" or of the torsion type.

[0010] Solutions have been considered such as insulating the poles, air conditioning in the machine room or locally at the poles. However, these solutions appear difficult to implement. Description of the invention

[0011] One objective of the present application is to remedy the aforementioned drawbacks by proposing a load-bearing structure that limits the influence of column expansion on the deformation of the support table, in order to achieve dimensional stability of the support table over time. Dimensional stability should be understood as geometric stability.

[0012] To this end, the invention proposes, according to a first aspect, a load-bearing structure, comprising: - a support table supported by at least four posts, each post having, at its upper end, a connecting element linking the support table to the post, - at least four altimetric variation sensors, each altimetric variation sensor being configured to measure the relative altimetric variation E of the support table, - a distance sensor configured to measure the distance between the top end of a reference post and the support table, the reference post being chosen from among the posts, and - an adjustment system configured to stabilize the deformation of the support table, the adjustment system comprising a set of actuators such that each post carries an actuator disposed between the post and the support table, the actuator being configured to change the distance between the post and the support table according to measurements from the altimetric variation sensors and the distance sensor.

[0013] Thus, the proposed solution does not seek to regulate the temperature but rather to compensate for the forces generated by the thermal expansion and contraction of the columns on the support table through the adjustment system. Consequently, the altimetric variations due to column expansion induced by non-uniform thermal loads in the machine room are compensated to prevent deformations of the support table that would hinder topographic measurements and alignment operations. The supporting structure compensates, via actuators, for the thermal expansion of the columns and thus stabilizes, limits, or prevents deformation of the support table, thereby ensuring its dimensional stability in the vertical direction. As a result, adjustment operations, such as topographic measurements and alignment, can be carried out without being disrupted over time by thermal variations.

[0014] The use of an active system thus makes it possible to limit the constraints during surveying and adjustment operations of the rotating machine, which is stationary during these operations, by guaranteeing the stability of the support table in the vertical direction (roll, pitch, and vertical deformations) over time. Furthermore, the device can also position and deform the table in order to reproduce precise and specified adjustment conditions, for example, those resulting from previous alignment / adjustment campaigns.

[0015] The elevation variations of the support slab at the posts are determined from measurements taken by both the elevation variation sensors and the distance sensor. In other words, the local elevation of the support slab at a post relative to the reference post is obtained by adding the distance value, the elevation variation value between the elevation variation sensor at the reference post, and the elevation variation sensor at the post in question. Each elevation variation sensor provides the relative elevation variation of the support slab at that sensor's location with respect to the other elevation variation sensors. The distance sensor allows the local elevation of the support slab to be determined relative to the top of a post, identified as a reference post.Thus, it is possible to maintain dimensional stability in the vertical direction of the support table while limiting the stroke of the actuators, because the expansion of the reference post is not compensated, the adjustment system thus only compensates for the deformations of the support table, without maintaining its absolute vertical position - also called global elevation - that is to say its vertical position relative to the base of the posts, i.e. relative to the floor or the foundation slab.

[0016] This therefore makes it easier to adjust an element supported by the support table, such as a rotating machine, in particular a turbo-alternator unit.

[0017] In the event of deformation of the support table, the altimetric variation observed by an altimetric variation sensor results in an altimetric variation at the observation point. For example, positioned equidistant from four posts, it will provide an average altimetric variation of the area between the four posts without being able to observe any deformations. Thus, to detect the deformation of the support table supported by at least four columns, a minimum of four altimetric variation sensors is required.

[0018] The load-bearing structure according to the invention is advantageously and optionally supplemented by the following features, taken alone or in any of their technically possible combinations:

[0019] - The supporting structure is configured to support a rotating machine. Thus, the Adjusting the rotating machine is made easier.

[0020] - Each altimetric variation sensor is positioned closer to a pole than the other altimetric variation sensors.

[0021] - Each altimetric variation sensor is configured to measure the altimetric variation time-based measurement of the support table at the level of the post it is closest to.

[0022] - Each altimetric variation sensor is configured to measure the altimetric variation The support table's timetric measurement is taken at a different point than those of the other altimetric variation sensors. This allows for optimal measurement of the support table's deformation.

[0023] - The altimetric variation sensors are arranged at different points on the table support units are configured to measure the altimetric variation of the support table at these different points. This allows for optimal measurement of the support table's deformation.

[0024] - The number of altimetric variation sensors is equal to the number of poles. Thus, the deformation of the support table is measured optimally.

[0025] - Each altimetric variation sensor is positioned at the right angle to a post, The preferred placement is on the support table, under the support table, or within the thickness of the support table. This allows the adjustment system to achieve particularly precise adjustment at each post, since the measurement taken by each altimetric variation sensor is located locally at the same point as the actuator performing the adjustment for the post.

[0026] - The actuator is configured to change the distance between the post and the table of support based on measurements from altimetric variation sensors, the distance sensor and a preference setpoint defined by a user.

[0027] - The distance between the post and the support table is modified by the actuator by function of measurements from the altimetric variation sensors, the distance sensor and a preference setpoint defined by a user.

[0028] - Each altimetric variation sensor is a laser sensor or an HLS sensor (for Hydrostatic Leveling System). Such altimetric variation sensors allow for very precise measurement of altimetric variation, with a measurement accuracy on the order of a few micrometers.

[0029] - The altimetric variation sensors are hydrostatic leveling pots. Such altimetric variation sensors are particularly precise, with a measurement accuracy on the order of a micrometer (measurement noise less than a micrometer).

[0030] - The distance sensor is positioned at the right of the reference post.

[0031] - The supporting structure comprises at least ten posts, preferably sixteen posts.

[0032] - The support table is made of reinforced concrete or steel.

[0033] - The support table has a length between 30 meters and 100 meters, preferably equal to 60 meters.

[0034] - The support table has a width between 10 and 50 meters, of Preferably between 20 and 30 meters.

[0035] - The support table supports a rotating machine, preferably a turbo unit alternator. Thus, the adjustment operations of the rotating machine, and preferably of the turbo-alternator unit, are particularly improved.

[0036] - Each post is made of steel or reinforced concrete. Such a design is particularly very robust and allows to limit the number of posts, in particular because such posts are particularly resistant to compression, which is due to the large mass of the support table supported by the posts.

[0037] - Each post is made of steel. Indeed, external threats, such as earthquakes, Factors that may need to be considered during the design of the supporting structure. For example, the use of steel columns may be preferred; however, they exhibit greater sensitivity to thermal variations compared to reinforced concrete columns, particularly due to their lower thermal inertia, which amplifies deformations of the support table. This increased sensitivity reduces the altimetric stability of the support table, which, in the absence of a supporting structure conforming to the invention, could lead to significant difficulties during surveying and adjustment operations, especially the alignment of the rotating machine.

[0038] - Each pole has a height between 10 meters and 30 meters, of A height between 15 and 20 meters is preferred. This height is particularly suitable for allowing auxiliary equipment to be placed under the support table.

[0039] - The connecting member comprises an element whose rigidity is less than that of the support table and that of the post, preferably a spring-forming element. Thus, the vibrations resulting from the operation of the rotating machine, in particular the steam turbine of the turbo-alternator unit, are transmitted to the posts in a limited way, a fortiori to elements located near the supporting structure, such as neighboring civil engineering structures.

[0040] - The spring-forming element comprises at least one spring box interposed between The post and support table are preferably fitted with three to six spring boxes interposed between the post and the support table. These spring boxes allow the support table to be dynamically isolated from the posts and the rest of the civil engineering structure when the rotating machine, in particular the steam turbine of the turbo-alternator unit, is in operation.

[0041] - Each spring box comprises two metal plates between which are interposed a plurality of springs.

[0042] - The actuator assembly consists of hydraulic actuators, preferably hydraulic cylinders, more preferably double-acting hydraulic cylinders. The use of hydraulic force is particularly advantageous, each actuator being thus adapted to the transmission of significant forces aimed at locally modifying the altimetric position of the support table, which can have a mass on the order of a thousand tons.

[0043] - Each actuator is arranged between the upper end of a post and the table support and preferably comes into direct contact with the support table.

[0044] - Each actuator is arranged in a spring box interposed between the post and the support table. Thus, the actuation can be achieved in compression or tension, and this independently of the material composing the post and the material composing the support table.

[0045] - The adjustment system includes a control circuit, the control circuit controlling the set of actuators from measurements from the altimetric variation sensors, the distance sensor and a preferred setpoint defined by a user.

[0046] - The adjustment system includes a user interface, which is connected to the The control circuit is configured to allow a user to define the deformation of the support table. Thus, the user can choose to stabilize the support table's deformation according to a predefined or desired model. This could, for example, be the table's deformation as observed in a previous calibration campaign.

[0047] - Alternatively or in addition to the characteristic according to which the The supporting structure is such that each altimetric variation sensor is configured to measure the relative altimetric variation of the support slab. For each column, the supporting structure includes an altimetric variation sensor configured to measure the altimetric variation of the column's upper end. Thus, the altimetric variations of the columns are known precisely from the measurements taken by each altimetric variation sensor.

[0048] According to a second aspect, the invention proposes a power plant comprising a load-bearing structure conforming to the first aspect.

[0049] The power plant according to the invention is advantageously and optionally supplemented by the following features, taken alone or in any of their technically possible combinations:

[0050] - The power plant is a nuclear power plant.

[0051] - The power plant is a thermal power plant.

[0052] According to a third aspect, the invention proposes a method for adjusting a structure carrier conforming to the first aspect, which comprises the following steps: - measure the relative altimetric variation by each altimetric variation sensor, - measure the distance using the distance sensor, - for each post, determine a local elevation value of the support table relative to the top end of the reference post as a function of the measurement of the relative elevation change made by the elevation change sensor closest to the post and the measurement of the distance made by the distance sensor, and determine an error resulting from a comparison of the local elevation value to a setpoint value called the setpoint, - For each post, based on the setpoint value, control the actuator mounted on the post in such a way as to minimize the error value relative to each altimetric variation sensor. In other words, the actuator mounted on the post is controlled until the support table undergoes an altimetric variation that minimizes the error, so that the altimetric position of the table tends towards the setpoint.

[0053] Thus, the adjustment of the supporting structure is carried out in a simple manner.

[0054] The adjustment method according to the invention is advantageously and optionally supplemented by the following features, taken alone or in any of their technically possible combinations:

[0055] - The adjustment method further comprises the following alternative or complementary step commentary on the aforementioned steps consisting of measuring the relative altimetric variation by each altimetric variation sensor, and measuring the distance by the distance sensor, For each post, determine a local altimetric value of the support table relative to the top end of the reference post as a function of the measurement of the relative altimetric variation made by the altimetric variation sensor closest to the post and the measurement of the distance made by the distance sensor, and determine an error resulting from a comparison of the local altimetric value to a setpoint value called the setpoint: - for each post, measure the altimetric variation of the top end of the post using the altimetric variation sensor, estimate a local altimetric value of the support table relative to the top end of the post as a function of all altimetric variation measurements, a model of the supporting structure, and determine an error value resulting from a comparison of the local altimetric value to a setpoint value.

[0056] - The setpoint value is predefined, preferably equal to an altimetric value obtained previously based on a prior measurement of the alti- variation metric and a previous measurement of the distance. Thus, it is possible to maintain the support table in the same configuration as during the previous measurement, which allows adjustment operations to be carried out without further deformation of the support table occurring, or in such a way that further deformation of the support table is imposed in order to recover a previous adjustment configuration.

[0057] - The adjustment process further comprises the following steps: - enter a correction instruction using the user interface, the correction instruction being a function of at least one value from the support table chosen from among a deformation value, a roll value, a pitch value and an altimetric displacement value preferably relative to the reference post, - depending on the correction instruction and for each post, calculate a control value for the actuator carried by the post.

[0058] - The setpoint value is greater than a predetermined minimum value, and in less than a predetermined maximum value. Thus, the setpoint value cannot exceed the technical constraints of the actuator, particularly in terms of stroke and force.

[0059] - The adjustment process steps are carried out when the rotating machine is at the stop. DESCRIPTION OF THE FIGURES

[0060] Other features, objectives and advantages of the invention will become apparent from the detailed description below, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings, given by way of non-limiting examples and on which:

[0061] Fig. 1 is a schematic front view of a power plant comprising a load-bearing structure according to an embodiment;

[0062] Fig. 2 is a schematic view from below of a support table forming part of the load-bearing structure shown in Fig. 1;

[0063] The [Fig.3] is a schematic and partial view of a detail of the load-bearing structure according to an embodiment;

[0064] The [Fig.4] is a schematic front and partial view of the load-bearing structure according to one embodiment;

[0065] The [Fig.5] is a schematic and partial view of a detail of the load-bearing structure according to an embodiment variant;

[0066] Fig. 6 schematically represents the steps of a process for adjusting the load-bearing structure according to an embodiment;

[0067] Figure 7 schematically represents the steps of a process for adjusting the load-bearing structure conforming to a variant of the design.

[0068] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION

[0069] Fig. 1 represents a power plant 1 comprising a supporting structure 3. The power plant 1 is advantageously a nuclear power plant or a thermal power plant.

[0070] The supporting structure 3 includes a support table 5. Advantageously, thanks to the support table 5, the supporting structure 3 is configured to support a rotating machine 7.

[0071] The support table 5 is advantageously made of reinforced concrete or steel.

[0072] The support table 5 has a length between 30 meters and 100 meters, preferably equal to 60 meters. The length is shown along the X axis on [Fig.1].

[0073] Thus, the X axis is a longitudinal axis, the Y axis is a transverse axis orthogonal to the X axis, and the Z axis is a vertical axis orthogonal to the X axis and the Y axis.

[0074] As shown in [Fig.2], the support table 5 may include longitudinal support beams 9 and transverse support beams 11.

[0075] The support table 5 has a width between 10 and 50 meters, preferably between 20 and 30 meters. The width is shown along the Y axis in [Fig.2].

[0076] The support table 5 supports a rotating machine 7, preferably a turbo-alternator unit. Such a turbo-alternator unit advantageously comprises a steam turbine 13 and an alternator 15.

[0077] The support table 5 is supported by at least four posts 17. Advantageously, the supporting structure 3 comprises at least ten posts 17, preferably sixteen posts 17.

[0078] Each post 17 is made of reinforced concrete or steel.

[0079] Each post 17 has a height between 10 meters and 30 meters, preferably a height between 15 meters and 20 meters.

[0080] Each post 17 carries, at its upper end - more precisely taken along the Z axis, which is a vertical axis as shown in [Fig.1] -, a connecting member 19 linking the support table 5 to the post 17.

[0081] The supporting structure 3 also includes at least four altimetric variation sensors 21.

[0082] Advantageously, as shown in [Fig.2], the number of altimetric variation sensors 21 is equal to the number of poles 17.

[0083] Preferably, each altimetric variation sensor 21 is configured to measure the relative altimetric variation of the support table 5.

[0084] Advantageously, each altimetric variation sensor 21 is configured to measure the relative altimetric variation of the support table 5 with respect to the other altimetric variation sensors 21.

[0085] Advantageously, each altimetric variation sensor 21 is arranged closer to a post 17 than the other altimetric variation sensors 21. Preferably, each altimetric variation sensor 21 is configured to measure the altimetric variation of the support table 5 at the post 17 of which it is closest.

[0086] Advantageously, each altimetric variation sensor 21 is configured to measure the altimetric variation of the support table 5 at a point different from those of the other altimetric variation sensors 21. Preferably, the altimetric variation sensors 21 are arranged at different points of the support table 5 and are configured to measure the altimetric variation of the support table 5 at these different points.

[0087] Advantageously, as shown schematically in [Fig.2] and [Fig.3], each altimetric variation sensor 21 is positioned opposite a post 17, preferably arranged on the support table 5, under the support table 5, or in the thickness of the support table 5.

[0088] Preferably, each altimetric variation sensor 21 is an HLS sensor, for Hydrostatic Leveling System. Advantageously, the altimetric variation sensors 21 are hydrostatic leveling pots. In this case, as shown in [Fig. 2], the altimetric variation sensors 21 are preferably connected to each other by a hydrostatic leveling network 23. Advantageously, such a hydrostatic leveling network 23 consists of a free-surface air / water pipe, in other words, a pipe containing air and water in which the interface between the air and the water is free. The altimetric variations are in fact relative altimetric variations between the different altimetric variation sensors 21.Local altimetric variations, i.e. between the support table 5 and each upper end of the post 17 closest to the altimetric variation sensor 21 considered, and global altimetric variations, i.e. between the support table 5 and the ground or floor supporting each post 17, are not observed by the altimetric variation sensors 21.

[0089] The supporting structure 3 also includes a distance sensor 25. Advantageously, the distance sensor 25 is configured to measure the distance between the upper end of a reference post 27 and the support table 5. The reference post 27 is chosen from among the posts 17.

[0090] Advantageously, as schematically represented in [Fig. 3], the distance sensor 25 is positioned directly opposite the reference post 27. Conversely, a post 17 not forming the reference post 27 is identical to the schematic representation of [Fig.3], except that it does not include a distance sensor positioned at the right of post 17.

[0091] As shown in [Fig. 3], the connecting member 19 comprises an element whose rigidity is less than that of the support table 5 and that of the post 17, preferably a spring element. Advantageously, the spring element comprises at least one spring box 29 interposed between the post 17 and the support table 5, preferably between three and six spring boxes 29 interposed between the post 17 and the support table 5.

[0092] Advantageously, each spring box 29 comprises two metal plates 31, 33, between which are interposed a plurality of springs 29.

[0093] As shown in [Fig.4], the supporting structure 3 also includes an adjustment system 37. The adjustment system 37 is configured to stabilize the deformation of the support table 5.

[0094] The adjustment system 37 comprises a set of actuators 39. Advantageously, the set of actuators 39 consists of hydraulic actuators, preferably hydraulic cylinders, more preferably double-acting hydraulic cylinders. Thus, an actuator 39 may comprise a single hydraulic actuator, preferably a hydraulic cylinder, more preferably a double-acting hydraulic cylinder. Alternatively, an actuator 39 may comprise a plurality of hydraulic actuators, preferably hydraulic cylinders, more preferably double-acting hydraulic cylinders.

[0095] Advantageously, each post 17 carries an actuator 39 disposed between the post 17 and the support table 5, as schematically represented in [Fig. 4], in which only three posts 17—one of which is the reference post 27—are shown, for the sake of simplification. The actuator 39 is configured to change the distance between the post 17 and the support table 5. Preferably, the distance between the post 17 and the support table 5 is changed by the actuator 39 based on measurements from the altimetric variation sensors 21 and the distance sensor 25.

[0096] Preferably, the actuator 39 is configured to modify the distance between the post 17 and the support table 5 based on measurements from the altimetric variation sensors 21, the distance sensor 25, and a user-defined preference setpoint. Thus, the distance between the post 17 and the support table 5 is modified by the actuator 39 based on measurements from the altimetric variation sensors 21, the distance sensor 25, and a user-defined preference setpoint.

[0097] Advantageously, each actuator 39 is arranged between the upper end of a post 17 and the support table 5. Preferably, each actuator 39 is arranged in a spring box 29 interposed between the post 17 and the support table 5, as shown schematically for example in [Fig.3]. Alternatively, according to a variant not shown, each actuator 39 comes into direct contact with the support table 5.

[0098] Advantageously, the adjustment system 37 includes a control circuit 41, as schematically represented in [Fig. 4]. The control circuit 41 controls the set of actuators 39 based on measurements from the altimetric variation sensors 21 and the distance sensor 25, and based on a preferred setpoint defined by a user.

[0099] Advantageously, a default setpoint conforms to the state of the supporting structure 3 when the control circuit 41 is put into service.

[0100] For example, when each actuator 39 is a hydraulic cylinder, preferably a double-acting hydraulic cylinder, the control circuit 41 controls a pump 43 and a distribution element 45, which supply each actuator 39 with hydraulic fluid, and this independently, on the basis of a control value C specific to each actuator 39. Each actuator 39 can thus locally modify the altimetric position of the support table 5, which makes it possible in particular to stabilize the deformation of the support table 5 when the posts 17 expand in a differentiated manner.

[0101] Advantageously, the adjustment system 37 includes a user interface 47, which is connected to the control circuit 41 and is configured to allow a user to control the deformation of the support table 5.

[0102] Preferably, user interface 47 is configured to allow the user to enter: - a deformation value; thus, a deformation of the support table 5 can be chosen and stabilized by entering for each altimetric variation sensor 21 a deformation value, representative of a specific relative altimetry to be reached; if one seeks to keep the support table 5 flat, in other words without deformation, a zero value is entered or entered by default; a non-zero deformation value allows the support table to be deformed and placed in the conditions of adjustment desired by the user; in other words, the user enters a desired deformation (for example a zero deformation over time), then this deformation is used to calculate a setpoint value R which is used to calculate a control value C for the control of the actuator 39 at the level of each post 17; - a roll value, namely a rotation of the support table 5 around the X axis, preferably by entering an angle between -0.05° and 0.05°; the roll value being zero by default; - a pitch value, namely a rotation of the support table 5 around the Y axis, preferably by entering an angle between -0.05° and 0.05°; the pitch value being zero by default; - an altimetric displacement value, namely a displacement of the support table 5 along the Z axis relative to the upper end of the reference post, preferably by entering an altimetric displacement value between -2 millimeters and 2 millimeters; the altimetric displacement value being zero by default.

[0103] Alternatively or in addition to the feature in which the support structure 3 is such that each altimetric variation sensor 21 is configured to measure the altimetric variation of the support table 5, the support structure 3 includes, for each post 17, an altimetric variation sensor 21 configured to measure the altimetric variation of the upper end of the post 17, as shown in [Fig. 5]. Optionally, the support structure 3 does not include a distance sensor 25.

[0104] Fig. 6 represents the main steps of a process for adjusting a load-bearing structure 3 as defined above.

[0105] Such an adjustment method comprises the following steps: - P100 measure the relative altimetric variation V by each altimetric variation sensor 21, - PI 10 measures the distance D using the distance sensor 25, - for each post 17, P120 determine a local altimetric value A of the support table 5 at the post 17 relative to the upper end of the reference post 27 as a function of the measurement of the relative altimetric variation V made by the altimetric variation sensor 21 closest to the post 17 and the measurement of the distance D made by the distance sensor 25, and P130 determine an error value E resulting from a comparison of the local altimetric value A to a setpoint value R, the setpoint value R being preferably a setpoint defined by a user and able to be corrected according to the constraints imposed on the control of the actuators 39,

[0106] - for each post 17, from the error value E, P140 command the actuator 39 carried by the post 17, so as to minimize the error value E relative to each altimetric variation sensor 21.

[0107] Advantageously, step P140 is carried out by the adjustment system 37, preferably by the control circuit 41.

[0108] Advantageously, the adjustment process steps are carried out when the rotating machine 7 is stopped.

[0109] Advantageously, the adjustment process steps can be carried out in real time, or repeated at a predefined frequency, in order to achieve servo control of the The support table 5 moves to the action point. Feedback loops are thus created, for example of the PI type for "proportional-integral". Thus, at each time step, each actuator 39 at each post 17 has a specific control value C applied.

[0110] Advantageously, the control circuit 41 is configured to perform steps P120, P130, and P140 of the adjustment process. Preferably, step P140 is performed by the control circuit 41, which thus selectively controls each actuator 39 by means of the pump 43 and the distribution element 45.

[0111] Advantageously, the adjustment method is such that the setpoint value R is predefined, preferably equal to a local altimetric value A obtained previously as a function of a prior measurement of the relative altimetric variation V and a prior measurement of the distance D.

[0112] Advantageously and as shown in [Fig.7], the adjustment method is such that the control value C is greater than a predetermined minimum value Cmin, and less than a predetermined maximum value Cmax.

[0113] Advantageously, Cmax is between 0.6 and 2 millimeters, preferably between 0.6 and 1.2 millimeters. For example, when each actuator 39 can only be used in one direction, a constraint is imposed forcing the actuators 39 to work only in compression. Alternatively, for example when the actuator 39 can work in tension / compression, Cmin is between -2 millimeters and 2 millimeters, preferably between -1.2 millimeters and 1.2 millimeters.

[0114] The predetermined minimum value Cmin and the predetermined maximum value Cmax may depend on a maximum force applicable by the actuator 39 and / or a maximum control value C not to be exceeded.

[0115] Advantageously, the adjustment method is such that it further comprises the following steps: - P150 enter a CC correction command using the user interface 47, the CC correction command being a function of at least one value from the support table 5 chosen from a deformation value, a roll value, a pitch value and an altimetric displacement value preferably relative to the reference post 25, and optionally the predetermined minimum value Cmin and the predetermined maximum value Cmax, - depending on the correction instruction CC and for each post 17, P160 calculate a control value C for the actuator 39 carried by the post 17.

[0116] Advantageously, the control circuit 41 is configured to perform step P160 of the adjustment process, preferably in real time.

[0117] Optionally, the adjustment process further includes the following step shown in [Fig.7], an alternative or complement to steps P100, P10 and P120 mentioned above: - for each post 17, P170 measure the altimetric variation VA of the top end of the post 17 using the altimetric variation sensor 21, P180 estimate a local altimetric value A of the support table 5 relative to the top end of the post 17 as a function of the set of altimetric variation measurements VA, of a model of the supporting structure 3, and P130 determine an error value E resulting from a comparison of the local altimetric value A to a setpoint value R.

[0118] Advantageously, the control circuit 41 is configured to perform step P180 of the adjustment process.

[0119] Optionally, the supporting structure 3 does not include a distance sensor 25.

[0120] The embodiment variants can be combined with each other according to any com technically possible combination.

Claims

Demands

1. A load-bearing structure (3), characterized in that it comprises: - a support table (5) supported by at least four posts (17), each post (17) having, at its upper end, a connecting member (19) linking the support table (5) to the post (17), - at least four altimetric variation sensors (21), each altimetric variation sensor (21) being configured to measure the relative altimetric variation V of the support table (5), - a distance sensor (25) configured to measure the distance between the upper end of a reference post (27) and the support table (5), the reference post (27) being selected from among the posts (17), and - an adjustment system (37) configured to control the deformation of the support table (5), the adjustment system (37) comprising a set of actuators (39) such that each post (17) has an actuator (39) disposed between the post (17) and the support table (5),the actuator (39) being configured to modify the distance between the post (17) and the support table (5) according to measurements from the altimetric variation sensors (21) and the distance sensor (25).

2. Supporting structure (3) according to claim 1, wherein each altimetric variation sensor (21) is arranged closer to a post (17) than the other altimetric variation sensors (21).

3. Supporting structure (3) according to claim 2, wherein each altimetric variation sensor (21) is positioned at the right of a post (17), preferably disposed on the support table (5), under the support table (5), or in the thickness of the support table (5).

4. Supporting structure (3) according to any one of claims 1 to 3, wherein the distance sensor (25) is positioned at the right of the reference post (27).

5. Load-bearing structure (3) according to any one of claims 1 to 4, wherein the actuator assembly (39) is composed of hydraulic actuators, preferably hydraulic cylinders, more preferably double-acting hydraulic cylinders.

6. Load-bearing structure (3) according to any one of claims 1 to 5, wherein the support table (5) supports a rotating machine (7), preferably a turbo-alternator unit.

7. Load-bearing structure (3) according to any one of claims 1 to 6, in which each post (17) is made of reinforced concrete or steel.

8. Load-bearing structure (3) according to any one of claims 1 to 7, wherein each post (17) has a height of between 10 meters and 30 meters, preferably a height of between 15 meters and 20 meters.

9. Load-bearing structure (3) according to any one of claims 1 to 8, wherein the connecting member (19) comprises a spring-forming element.

10. Load-bearing structure (3) according to claim 9, wherein the spring-forming element comprises at least one spring box (29) interposed between the post (17) and the support table (5), preferably between three and six spring boxes (29) interposed between the post (17) and the support table (5).

11. Load-bearing structure (3) according to any one of claims 1 to 10, wherein the adjustment system (37) comprises a control circuit (41), the control circuit (41) controlling the set of actuators (39) from measurements of the altimetric variation sensors (21), the distance sensor (25) and a user-defined preference setpoint.

12. Supporting structure (3) according to any one of claims 1 to 11, wherein each altimetric variation sensor (21) is an HLS sensor.

13. Power plant (1) comprising a supporting structure (3) according to any one of claims 1 to 12, preferably the power plant (1) being a nuclear power plant or a thermal power plant.

14. A method for adjusting a load-bearing structure (3) according to any one of claims 1 to 12, comprising the following steps: - P100 measuring the relative elevation change V by each elevation change sensor (21), - P10 measuring the distance D by the distance sensor (25), - for each post (17), P120 determining a local elevation value A of the support table (5) at the post (17) relative to the top of the reference post (27) as a function of the measurement of the relative elevation change V made by the elevation change sensor (21) closest to the post (17) and the measurement of the distance D made by the distance sensor (25), and P130 determining an error value E resulting from a comparison of the value local altimetric A to a setpoint value R, - for each post (17), from the error value E, P140 control the actuator (39) carried by the post (17), so as to minimize the error value E relative to each altimetric variation sensor (21).

15. A method for adjusting according to claim 14, which further comprises the following steps: - P150 enter a CC correction command using the user interface (47), the CC correction command being a function of at least one value from the support table (5) chosen from a deformation value, a roll value, a pitch value and an altimetric displacement value preferably relative to the reference post (25), and optionally the predetermined minimum value Cmin and the predetermined maximum value Cmax, - depending on the correction setpoint CC and for each post (17), P160 calculate a setpoint value R for the actuator (39) carried by the post (17).

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