Protective box and offshore wind farm multiphysics full-link acquisition system

Abstract

Protective box, characterized in that it comprises: a box body comprising an outer housing and an inner frame arranged in this outer housing, wherein the outer housing has an opening on one side, wherein the inner frame is an annular structure consisting of several plates arranged in a row and is arranged at a distance from the inner wall of the outer housing, the opening on one side of the inner frame corresponding to the position of the opening of the outer housing; a door leaf rotatably connected to the outer housing and serving to open and close the opening; a sealing element arranged on the inside of the door leaf or on the open side of the inner frame and serving to form a seal with the corresponding contact surface when the door leaf is closed;as well as an elastic pressure structure arranged between the door leaf and the inner frame to generate a continuous elastic pressure force between at least one side edge of the door leaf and the corresponding side edge of the inner frame when the door leaf is closed, thereby increasing the sealing effect of the sealing element.

Description

TECHNICAL AREA The present invention relates to the technical field of offshore wind power, in particular a protective box and an offshore wind farm multiphysics full-link sensing system. STATE OF THE ART Operating conditions in offshore wind farms are extremely harsh. The turbines are exposed to high concentrations of salt spray, strong winds and waves, high humidity (5% to 95%, non-condensing), extreme temperatures (-40°C to 75°C), and continuous vibrations over the long term. As the hardware component of the unified data acquisition system, the operational reliability of the integrated acquisition terminals directly determines the continuity and accuracy of data acquisition. If the acquisition terminal fails due to insufficient water and humidity resistance, this leads to interruptions or inaccuracies in data acquisition. This not only disrupts the closed-loop control of the environment-structure response, impairs consistency correction in turbine load simulation, and reduces the accuracy of early fault warnings, but also increases the risk of unplanned outages and operating and maintenance costs.According to industry data, the operating and maintenance costs of wind turbines account for 25% to 30% of the electricity generation costs over the entire life cycle of a project; repairs due to equipment failures further increase this share. Therefore, the development of integrated data acquisition terminals with high water and humidity resistance, specifically designed for the unique conditions at sea, is a crucial prerequisite for the stable operation of a unified signal acquisition system and the support of intelligent management of offshore wind farms. The integrated data acquisition terminals and associated systems currently used in offshore wind energy generally exhibit problems adapting to the harsh conditions of deep and open sea with regard to their water and moisture resistance, and cannot meet the requirements for long-term stable operation: Firstly, most existing data acquisition terminals have a simple housing design that is not specifically designed to withstand wind and waves. Basic water resistance is achieved simply through an ordinary housing, without a special frame to protect against waves and rain.Under conditions of strong winds and high waves in deep and open seas, waves can strike the housing doors and joints directly, increasing stress on the sealing structure and allowing rainwater to penetrate through the gaps in the housing body, damaging internal circuits and sensors. Secondly, the sealing structures of existing devices are mostly based on a single sealing ring, failing to address the crucial requirement of moisture protection in the highly humid marine environment. Furthermore, they lack an elastic sealing mechanism to enhance resistance. Under the influence of long-term wind and wave vibrations, the sealing rings tend to age, deform, or become loose on the housing, leading to moisture ingress.In the humid marine environment, moisture accumulates on the surfaces of internal circuit boards and sensors even without apparent water ingress, leading to circuit corrosion and insulation deterioration. This can even cause inaccuracies in core components such as optical strain gauges and vibration accelerometers, increasing the data acquisition error rate and making it impossible to meet the accuracy requirements for millisecond-level time synchronization and high-frequency (50 Hz) shock data acquisition. Thirdly, the current design for water and moisture protection of the end devices does not adequately consider the specific operating and maintenance requirements of offshore installations.Although some devices may meet IP65 protection standards in the short term, sealing performance deteriorates rapidly after prolonged operation, necessitating frequent downtime for maintenance and replacement of sealing components. This not only increases operating and maintenance costs and labor, but also disrupts data collection and hinders the process of building a fault database based on the principle of simultaneous operation, data collection, and development. Furthermore, it impairs the iterative optimization of fault diagnostic models for the systems and makes it difficult to meet the requirements for long-term, cost-effective, and highly reliable operation and maintenance of offshore wind turbines in deep and open water. CONTENT OF THE PRESENT INVENTION The present invention provides a protective box and an offshore wind farm multiphysics full-link sensing system to solve the above-mentioned problems. In a first aspect, the present invention provides a protective box comprising the following: a box body comprising an outer housing and an inner frame arranged in this outer housing, wherein the outer housing has an opening on one side, the inner frame being an annular structure consisting of several plates arranged in a row and arranged at a distance from the inner wall of the outer housing, the opening on one side of the inner frame corresponding to the position of the opening of the outer housing; a door leaf rotatably connected to the outer housing and serving to open and close the opening; a sealing element arranged on the inside of the door leaf or on the open side of the inner frame and serving to form a seal with the corresponding contact surface when the door leaf is closed;as well as an elastic pressure structure arranged between the door leaf and the inner frame to generate a continuous elastic pressure force between at least one side edge of the door leaf and the corresponding side edge of the inner frame when the door leaf is closed, thereby increasing the sealing effect of the sealing element. In an optional embodiment, the elastic pressure structure comprises a hinge arranged between the door leaf and the box body, the hinge comprising a pivot shaft and a first connecting element and a second connecting element, which are elastically deformable; wherein one end of the first connecting element is fixed to the box body, while the other end is rotatably connected to the pivot shaft; wherein one end of the second connecting element is fixed to the door leaf 3, while the other end is rotatably connected to the pivot shaft; wherein, when the door leaf is closed, the first connecting element and the second connecting element deform elastically, thereby generating a sustained tensile force between the door leaf and the box body, which causes a hinged side edge of the door leaf to fit tightly against the inner frame. In an optional embodiment, both the first connecting element and the second connecting element have a bend, whereby when the door leaf is closed, the first connecting element and the second connecting element deform elastically at the bending points. In an optional embodiment, the elastic pressure structure comprises a rotary lock arranged on one side of the door leaf and a corresponding first locking groove arranged on the inner frame; wherein the locking tongue of the rotary lock can be rotated and engaged in the first locking groove, the contour of the locking tongue being designed such that, during engagement, it gradually presses the door leaf against the inner frame, thereby ensuring that the edge of the door leaf on that side fits snugly against the inner frame. In an optional embodiment, the elastic clamping structure comprises elastic retaining blocks arranged at the upper and lower edges of the door leaf, and second locking grooves arranged accordingly on the upper and lower plates of the inner frame; wherein the elastic retaining blocks have an arcuate structure projecting towards the inner frame and a projection, wherein, when the door leaf is closed, the arcuate structure and the projection slide over the edges of the inner frame and finally allow the projection to engage in the second locking groove, the elastic retaining blocks being in an elastically deformed state and thus pressing the upper and / or lower edges of the door leaf firmly against the inner frame. In an optional embodiment, helical toothed lip seals are arranged on the inner walls of the upper and lower plates of the outer housing near the opening, which elastically come into contact with the top and bottom of the door leaf when the door leaf is closed in order to scrape off liquid residues. In an optional embodiment, sealing strips are further arranged on the inner walls of the upper plate and the lower plate of the outer housing on the inside of the helical toothed lip seal; wherein a frame-shaped elevation is provided on the inner edge of the door leaf, the upper and lower edges of which form an elastic sealing fit with the sealing strips when the door leaf is closed. In an optional embodiment, the sealing strip and the helical toothed lip seal have a gap at their two horizontal ends to the side walls of the outer casing, creating drainage channels between the upper and lower ends of the door leaf and the inner walls of the outer casing, which are connected to the space between the inner frame and the outer casing. In an optional embodiment, the inner frame is rigidly connected to the inner wall of the outer housing via the collection tray, which is formed such that the central area of ​​the plate body of the inner frame extends outwards; wherein support columns for attaching detection terminals are provided on the top, rear and side plates of the outer housing. In a second aspect, the present invention further provides an offshore wind farm multiphysics full-link acquisition system comprising: a protective box mentioned above; an integrated acquisition terminal arranged in the protective box; and multiple environmental and structural response signal acquisition devices arranged on the rotor blades of the wind turbine, in the cabin, on the tower, on the foundation, and in the surrounding waters; wherein the multiple environmental and structural response signal acquisition devices transmit the acquired heterogeneous data from various sources via wired or wireless connections to the integrated acquisition terminal, which protocol-converts and time-synchronizes the data and then transmits it to the central control server. BRIEF DESCRIPTION OF THE DRAWING To better illustrate the specific embodiments of the present invention or the prior art technical solutions, the drawings necessary for describing the specific embodiments or the prior art are briefly presented below. It is self-evident that the drawings described below represent some embodiments of the present invention; for a person skilled in the art, it is possible to develop further embodiments from these drawings without any creative effort. Fig. 1 shows a schematic diagram of the overall structure of a protective box in an embodiment of the present invention; Fig. 2 shows a partially enlarged diagram according to Fig. 1; Fig. 3 shows a partially enlarged view of point B according to Fig. 1; Fig.Figure 4 shows a schematic diagram of the overall structure of a protective box in an embodiment of the present invention in a different direction; Figure 5 shows a schematic diagram of the structure of a helical toothed lip seal in a protective box in an embodiment of the present invention; Figure 6 shows a schematic diagram of the deformation of a first connecting element and a second connecting element. Reference symbol list 1 Outer housing 2 Inner frame 21 First locking groove 22 Second locking groove 3 Door leaf 4 Sealing element hinge 51 Pivot shaft 52 First connecting element 53 Second connecting element 6 Rotary lock 61 Locking shaft 62 Locking tongue 7 Elastic retaining block 71 Arc-shaped structure 72 Projection 8 Helical toothed lip seal 9 Sealing strip 10 Collection tray 11 Support column DETAILED DESCRIPTION To further clarify the objectives, technical solutions, and advantages of the embodiments of the present invention, the technical solutions of the embodiments of the present invention are described below with reference to the drawings included therein. It is understood that the described embodiments represent only a portion of the embodiments of the present invention and do not encompass all embodiments. All further embodiments that a person skilled in the art in this field can derive from the embodiments described in the present invention without any inventive effort fall within the scope of protection of the present invention. Operating conditions in offshore wind farms are extremely harsh. The turbines are exposed to high concentrations of salt spray, strong winds and waves, high humidity (5% to 95%, non-condensing), extreme temperatures (-40°C to 75°C), and continuous vibrations over the long term. As the hardware component of the unified data acquisition system, the operational reliability of the integrated acquisition terminals directly determines the continuity and accuracy of data acquisition. If the acquisition terminal fails due to insufficient water and humidity resistance, this leads to interruptions or inaccuracies in data acquisition. This not only disrupts the closed-loop control of the environment-structure response, impairs consistency correction in turbine load simulation, and reduces the accuracy of early fault warnings, but also increases the risk of unplanned outages and operating and maintenance costs.According to industry data, the operating and maintenance costs of wind turbines account for 25% to 30% of the electricity generation costs over the entire life cycle of a project; repairs due to equipment failures further increase this share. Therefore, the development of integrated data acquisition terminals with high water and humidity resistance, specifically designed for the unique conditions at sea, is a crucial prerequisite for the stable operation of a unified signal acquisition system and the support of intelligent management of offshore wind farms. The integrated data acquisition terminals and associated systems currently used in offshore wind energy generally exhibit problems adapting to the harsh conditions of deep and open sea with regard to their water and moisture resistance, and cannot meet the requirements for long-term stable operation: Firstly, most existing data acquisition terminals have a simple housing design that is not specifically designed to withstand wind and waves. Basic water resistance is achieved simply through an ordinary housing, without a special frame to protect against waves and rain.Under conditions of strong winds and high waves in deep and open seas, waves can strike the housing doors and joints directly, increasing stress on the sealing structure and allowing rainwater to penetrate through the gaps in the housing body, damaging internal circuits and sensors. Secondly, the sealing structures of existing devices are mostly based on a single sealing ring, failing to address the crucial requirement of moisture protection in the highly humid marine environment. Furthermore, they lack an elastic sealing mechanism to enhance resistance. Under the influence of long-term wind and wave vibrations, the sealing rings tend to age, deform, or become loose on the housing, leading to moisture ingress.In the humid marine environment, moisture accumulates on the surfaces of internal circuit boards and sensors even without apparent water ingress, leading to circuit corrosion and insulation deterioration. This can even cause inaccuracies in core components such as optical strain gauges and vibration accelerometers, increasing the data acquisition error rate and making it impossible to meet the accuracy requirements for millisecond-level time synchronization and high-frequency (50 Hz) shock data acquisition. Thirdly, the current design for water and moisture protection of the end devices does not adequately consider the specific operating and maintenance requirements of offshore installations.Although some devices may meet IP65 protection standards in the short term, sealing performance deteriorates rapidly after prolonged operation, necessitating frequent downtime for maintenance and replacement of sealing components. This not only increases operating and maintenance costs and labor, but also disrupts data collection and hinders the process of building a fault database based on the principle of simultaneous operation, data collection, and development. Furthermore, it impairs the iterative optimization of fault diagnostic models for the systems and makes it difficult to meet the requirements for long-term, cost-effective, and highly reliable operation and maintenance of offshore wind turbines in deep and open water. In connection with Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6, the exemplary embodiments of the present invention are explained in more detail below. In one aspect, an embodiment of the present invention provides a protective box comprising a box body, a door leaf 3, a sealing element 4, and an elastic pressure structure, wherein the box body comprises an outer housing 1 and an inner frame 2 arranged in this outer housing 1, wherein the outer housing 1 has an opening on one side, wherein the inner frame 2 is an annular structure consisting of several plates arranged in a row and is arranged at a distance from the inner wall of the outer housing 1, wherein the opening on one side of the inner frame 2 corresponds to the position of the opening of the outer housing 1; wherein the door leaf 3 is rotatably connected to the outer housing 1 and serves to open and close the opening;wherein the sealing element 4 is arranged on the inside of the door leaf 3 or on the open side of the inner frame 2 and serves to form a seal with the corresponding contact surface when the door leaf 3 is closed; wherein the elastic pressure structure is arranged on the door leaf 3 and the inner frame 2 in order to generate a continuous elastic pressure force between at least one side edge of the door leaf 3 and the corresponding side edge of the inner frame 2 when the door leaf 3 is closed, thereby increasing the sealing effect of the sealing element 4. The box body forms the main frame and mounting base of the protective enclosure. It comprises an outer housing 1 and an inner frame 2 located inside the outer housing 1. The outer housing 1 is typically made of corrosion-resistant metal (such as stainless steel or an aluminum alloy) and, as a whole, has the shape of a box with a rectangular opening on one side, thus providing the equipment inside with initial physical protection as well as a basic form that protects it from wind and waves. The inner frame 2 is a rectangular, ring-shaped housing structure formed from several (e.g., four) panels arranged in a row. This inner frame 2 is located inside the outer housing 1, with a certain distance maintained between the individual panels and the corresponding inner side walls of the outer housing 1. This distance creates a collection tray 10. The opening on one side of the inner frame 2 (i.e., its front opening) is precisely aligned with the front opening of the outer housing 1 and, together with it, forms an access point for the installation and maintenance of the equipment. The door leaf 3 is pivotally connected to the opening side of the outer housing 1 via a hinge joint and serves to open and close this opening to facilitate the installation, commissioning or maintenance of the recording terminals inside the box. To ensure tightness, a sealing element 4 is provided in the present embodiment. In a preferred embodiment, the sealing element 4 is an annular sealing mat that is fixedly installed on the inner surface of the door leaf 3, its position corresponding to the front opening edge of the inner frame 2. When the door leaf 3 is closed, this sealing mat lies tightly against the open end face of the inner frame 2, thus creating a primary static sealing barrier between the two. The decisive improvement of the present embodiment lies in the elastic pressure structure. This structure is not a conventional door lock or simple latch, but is arranged separately and serves specifically to actively and continuously exert an elastic pressure force on the door leaf 3 in the direction of the inner frame 2 after the door leaf 3 has been closed. Due to the construction described above, the protective housing in the present embodiment not only forms a collection tray 10 for wave dissipation through its two-layer structure consisting of the outer housing 1 and the inner frame 2, but also actively ensures a continuous, evenly distributed sealing pressure after the door leaf 3 is closed, thanks to its independent elastic pressure structure. This design guarantees that the sealing mat remains in close contact with the inner frame 2 under all operating conditions (especially in the event of slight deformation of the structure due to long-term wind and wave vibrations), thereby significantly improving the reliability and durability of the seal.This allows the protective housing to achieve a moisture protection rating, effectively preventing the ingress of moisture in environments with high humidity and salt spray, and ensuring the long-term, stable operation of the internal data acquisition terminals under harsh marine conditions. This solves the technical problems mentioned in the prior art, namely the susceptibility to seal failure in existing devices, as well as failures and data inaccuracies caused by moisture ingress. In one embodiment, the elastic pressure structure comprises a hinge 5 arranged between the door leaf 3 and the box body; wherein the hinge 5 comprises a pivot shaft 51 as well as a first connecting element 52 and a second connecting element 53, which are elastically deformable; wherein one end of the first connecting element 52 is attached to the box body, while the other end is rotatably connected to the pivot shaft 51; one end of the second connecting element 53 is attached to the door leaf 3, while the other end is rotatably connected to the pivot shaft 51; when the door leaf 3 is closed, the first connecting element 52 and the second connecting element 53 deform elastically, creating a continuous tensile force between the door leaf 3 and the box body, which causes a side edge of the door leaf 3 fitted with the hinge 5 to lie tightly against the inner frame 2. The first connecting element 52 is an elastically deformable component, essentially L-shaped, consisting of a first bending plate and a second bending plate connected perpendicular to each other. The first bending plate is fixedly attached to the box body by means of connecting elements (e.g., screws or welding). The second bending plate is bent towards the outside of the outer housing 1, with its end rotatably connected to the rotating shaft 51. In a preferred embodiment, the end of the second bending plate is wound around or placed on the rotating shaft 51. The second connecting element 53 is also an elastically deformable component, essentially L-shaped, and consists of a third and a fourth bending plate connected perpendicular to each other. The third bending plate is fixed to the inner surface of the door leaf 3. The fourth bending plate is bent towards the surface of the door leaf 3, its end also rotatably connected to the same rotating shaft 51, for example by winding it onto the rotating shaft 51, and the fourth bending plate is arranged on the rotating shaft 51 next to the second bending plate of the first connecting element 52. As shown in Fig. 6, when the door leaf 3 is closed, the position of the pivot shaft 51 and a side of the first connecting element 52 and the second connecting element 53 connected to the pivot shaft 51 changes, thereby increasing the bending angle of the second connecting element 53 and exerting an inward tensile force on the door leaf 3 to achieve a continuous and stable preload force. By applying the design shown in the present embodiment, the tight seal of the door leaf 3 on the hinge side no longer relies solely on the contact pressure of the door lock, but a continuous and stable preload force is achieved through the elastic deformation of the hinge 5 itself. This effectively solves the problem that, with conventional hinges, the hinge side easily becomes a weak point in the seal due to the lack of active contact force. In particular, it compensates for gaps that develop after prolonged use due to vibrations and deformation, thus ensuring the long-term reliability and durability of the seal on this side of the protective housing. This is a crucial link in the chain for achieving the goal of comprehensive moisture protection. In one embodiment, both the first connecting element 52 and the second connecting element 53 have a bend; when the door leaf 3 is closed, the first connecting element 52 and the second connecting element 53 deform elastically at the bending points. In one embodiment, the elastic pressure structure comprises a rotary lock 6 arranged on one side of the door leaf 3 and a corresponding first locking groove 21 arranged on the inner frame 2; the locking tongue 62 of the rotary lock 6 can be rotated and engaged in the first locking groove 21, the contour of the locking tongue 62 being designed such that, during engagement, it gradually presses the door leaf 3 against the inner frame 2, causing the edge of the door leaf 3 on this side to fit snugly against the inner frame 2. The rotary lock 6 extends through the entire thickness of the door leaf 3. One end of the rotary lock located on the outside of the door leaf 3 is provided with a keyhole into which a special key can be inserted to turn it. One end of the rotary lock located on the inside of the door leaf 3 is connected to the locking tongue 62. The locking tongue 62 is fixedly connected to the inner end of the locking shaft 61 and can rotate together with the locking shaft 61. As shown in Fig. 4, the cross-section of the locking tongue 62 (i.e., the cross-section perpendicular to its axis of rotation 51) is specifically designed to have an arcuate projecting structure on a side facing the door leaf 3. The first locking groove 21 is formed on the inner wall of a corresponding side plate of the inner frame 2 and represents a recess or notch adapted to the shape of the locking tongue 62. When the operator closes the door leaf 3, they insert the key into the keyhole and turn it, which rotates the locking shaft 61 together with the locking tongue 62. In the initial phase of the rotation, the edge of one side of the locking tongue 62, which has the arcuate protrusion, first slides into the entrance of the first detent groove 21. As the locking tongue 62 continues to rotate, the apex of the arcuate protrusion also gradually penetrates the first detent groove 21. During this locking process, the interaction of the arc-shaped profile of the locking tongue 62 with the solid wall surfaces of the first locking groove 21 creates a geometric "wedge effect". Specifically, the contact point between the surface of the arc-shaped protrusion and the side wall of the first locking groove 21 shifts continuously towards the door leaf 3 as the rotation progresses. This causes the locking tongue 62 (together with the attached door leaf 3) to be gradually pressed against the side plate of the inner frame 2, perpendicular to the plane of the door leaf 3. This process is similar to a cam mechanism that converts the rotational movement into a linear compression movement. When the locking tongue 62 rotates into its final locking position (e.g., by 90 degrees), the contact force described above reaches its maximum value and is maintained. Thus, in the present embodiment, the rotary lock 6 not only fulfills the function of a mechanical lock, but also actively generates a sustained force during the locking process that presses the door leaf 3 against the inner frame 2. This design ensures that the door leaf 3 fits extremely tightly against the inner frame 2 on the side of the lock, which significantly enhances the sealing effect on this side and effectively prevents gaps that could arise due to vibrations or manufacturing tolerances, thereby preventing the ingress of moisture at this point. In one embodiment, the elastic clamping structure comprises elastic retaining blocks 7 arranged at the upper and lower edges of the door leaf 3 (not shown on the top of the door leaf 3 in Fig. 1), and second locking grooves 22 arranged accordingly on the upper and lower plates of the inner frame 2. The elastic retaining blocks 7 have an arcuate structure 71 projecting towards the inner frame 2 and a projection 72. When the door leaf 3 is closed, the arcuate structure 71 and the projection 72 slide over the edges of the inner frame 2, and the projection 72 finally engages in the second locking groove 22. The elastic retaining blocks 7 are then in an elastically deformed state, thus pressing the upper and / or lower edges of the door leaf 3 firmly against the inner frame 2. The elastic retaining block 7 is preferably made of an engineering plastic (such as POM or reinforced nylon) or spring steel, which exhibits good elastic and fatigue-resistant properties. Its main body is attached to the inside of the door leaf 3 via connecting elements (e.g., snap-fit ​​grooves or screws), with the middle and lower part of the elastic retaining block 7 forming a free end. The free end of the elastic retaining block 7 has an arc-shaped structure 71 and a projection 72, the underside of the arc-shaped structure 71 (i.e., the side facing the box body) being formed as a smooth arc-shaped structure 71 projecting downwards (in the case of an upper retaining block) or upwards (in the case of a lower retaining block). The projection 72 is located on the arc-shaped structure 71, more precisely on a side facing the door leaf 3 itself, and has a local projection 72. The second locking groove 22 is formed on the inside of the upper and lower plates of the inner frame 2. In particular, a recessed space can be provided in the middle of the upper and lower plates of the inner frame 2, wherein the second locking groove 22 is located on the vertical side wall on a side of the recessed space facing the door leaf 3 and its shape is adapted to the projection 72. When the operator pushes the door leaf 3 to close, the free ends of the elastic retaining blocks 7, located on the top and bottom of the door leaf 3, come into contact with the top or bottom edge of the inner frame 2. First, the edge of the arcuate structure 71 on the underside of the elastic retaining block 7 makes contact. As the door leaf 3 continues to rotate into the closing position, the arcuate structure 71 slides along the edge of the inner frame 2 and is compressed, forcing the free ends of the elastic retaining blocks 7 into an upward elastic bend. As the door leaf 3 approaches complete closure, the projection 72 on the elastic retaining blocks 7 moves into the position corresponding to the second locking groove 22. At this point, the projection 72 is in a "raised" state due to the previous compression of the arched structure 71. Once the door leaf 3 reaches the closed position and the projection 72 is aligned with the second locking groove 22, the elastic potential energy stored in the elastic retaining block 7 begins to discharge, its free end moves downwards back to its initial position, and the projection 72 then engages in the second locking groove 22. At this point, the rear side of the projection 72 (the side facing away from the door leaf 3) engages in the locking surface of the second locking groove 22 (the groove bottom surface facing away from the door leaf 3, i.e., surface a in Fig. 4). In this final state, the middle to lower part of the elastic retaining block 7 is still in a somewhat elastically deformed state, and its projection 72 is also compressed in the locking groove. This continuous elastic restoring force is transmitted via the fixed end of the elastic retaining block 7 to the door leaf 3 and continuously and firmly presses the upper and lower edges of the door leaf 3 against the upper and lower plates of the inner frame 2, so that they rest against them. The mechanism of the elastic retaining block 7 in the present embodiment, through the mechanical process of "sliding - compressing - snapping - locking" at the upper and lower edges of the door leaf 3, creates a connection similar to a "bolt," but with a sustained elastic preload. It not only provides reliable mechanical locking, but—more importantly—its elastic properties effectively absorb and compensate for gaps caused by temperature fluctuations, structural vibrations, or slight deformations. This ensures the long-term stability and uniformity of the sealing pressure between the upper and lower edges of the door leaf 3 and the inner frame 2, which is a crucial link in the comprehensive moisture-resistant sealing system of the protective box. In one embodiment, helically toothed lip seals 8 are arranged on the inner walls of the upper plate and the lower plate of the outer housing 1 near the opening, which come into elastic contact with the upper and lower surfaces of the door leaf 3 when the door leaf 3 is closed in order to scrape off liquid residues. The helical lip seal 8 is typically made of rubber or silicone, which is characterized by high elasticity and excellent weather and corrosion resistance. Its main body is designed as an elongated structure and is attached to the inner surface of the upper and lower plates of the outer casing 1 via a bracket. Its essential feature is that the free ends are shaped as flexible lip edges with an angled inclination. The inclination direction of these lip edges is uniform and always points towards the outside of the outer casing 1 (i.e., towards the opening). When the operator closes the door leaf 3, the upper and lower edges of the door leaf 3 first come into contact with the flexible lip edges of the helical toothed lip seal 8 at the corresponding points when entering the opening and slide relative to each other. Due to the angled design of the lip edges and their flexibility, this sliding contact creates a wiping and a dissipating effect. Wiping action: Similar to a windshield wiper, the lip edges of the helically toothed lip seal 8 can effectively wipe off water droplets, salt water droplets or other liquid contaminants adhering to the top and bottom of the door leaf 3 from the surface of the door leaf 3. Drainage effect: The scraped liquid is drained under the guidance of the lip edges along the direction of inclination (i.e. outwards), thus preventing liquid from accumulating at the entrance of the gap between the door leaf 3 and the outer casing 1, and, most importantly, preventing it from flowing along the surface of the door leaf 3 into the critical sealing area inside (i.e., to the junction between the sealing mat of the door leaf 3 and the inner frame 2). In this embodiment, the arrangement of the helical-toothed lip seal 8 removes the majority of any liquid water that may have entered the door leaf 3 during the final phase of its closing process. This design not only directly improves the protective capacity of the protective housing against splashing water and temporary immersion, but, more importantly, reduces the operating pressure on the main sealing surface and the risk of permeability by minimizing the amount of water that the main sealing element 4 (sealing mat) has to handle. This indirectly improves the reliability and durability of the entire sealing system. This is of great importance for achieving a long-term, stable moisture barrier in marine environments with high salt spray and high humidity. In one embodiment, sealing strips are further arranged on the inner walls of the upper plate and the lower plate of the outer housing 1 on the inside of the helically toothed lip seal 8; a frame-shaped projection is provided on the inner edge of the door leaf 3, the upper and lower edges of which form an elastic sealing fit with the sealing strips 9 when the door leaf 3 is closed. The sealing strips 9 preferably consist of an age-resistant, highly elastic rubber or silicone material, their cross-section being designed in various shapes to meet the requirements for assembly and sealing. In a preferred embodiment, the sealing strip 9 has an L-shaped cross-section. The L-shaped longitudinal plate is firmly installed on the inner surface of the upper and lower plates of the outer housing 1 by adhesive bonding or mechanical fastening, while the transverse plate extends horizontally inwards (towards the center of the housing body). Accordingly, a continuous, frame-shaped projection is machined or attached to the inner edge of the door leaf 3 (i.e., on the side where the sealing mat is attached). This frame-shaped projection surrounds the top, bottom, and side edges of the inner perimeter of the door leaf 3, and its cross-section may be substantially rectangular or trapezoidal. When the door leaf 3 is closed and finally locked, the frame-shaped projection on the inside of the door leaf 3 moves into the position corresponding to the sealing strip 9. At this point, the upper and lower edges of the frame-shaped projection come into contact with the ends or the top of the L-shaped transverse plate of the sealing strip 9 at the corresponding points. Since the door leaf 3 is continuously pressed firmly by the elastic pressure structure, the hard edge of the frame-shaped elevation exerts a vertical pressure on the flexible sealing strip 9, causing elastic deformation at the contact points of the sealing strip 9 and thus forming a tight, elastic sealing fit between the two. This second seal, consisting of the sealing strip 9 and the frame-shaped protrusion, forms a synergistic protective system together with the outer helical-toothed lip seal 8. The primary function of the helical-toothed lip seal 8 is to scrape off large quantities of liquid water and prevent its ingress; the inner sealing strip 9, on the other hand, is responsible for permanently preventing any small amounts of moisture that might penetrate the first line of defense in the form of water vapor, mist, or through capillary action, and also for blocking any liquids that might penetrate through gaps between the top and bottom of the door leaf 3 and the outer casing 1. This double-seal design significantly improves the reliability of the entire sealing barrier of the protective enclosure under sustained harsh operating conditions and provides a higher degree of protection for the equipment inside. In one embodiment, the sealing strip 9 and the helically toothed lip seal 8 have a distance at their two horizontal ends from the side walls of the outer housing 1, thereby creating drainage channels between the upper and lower ends of the door leaf 3 and the inner walls of the outer housing 1, which are connected to the space between the inner frame 2 and the outer housing 1. In extreme cases where a small amount of seawater or condensation penetrates through the outermost gap between the door leaf 3 and the outer casing 1, most of this liquid is initially retained and wiped away by the helical lip seal 8. Even if an extremely small amount of liquid penetrates further inwards, it is effectively stopped by the second sealing line, which consists of the inner sealing strip 9 and the frame-shaped protrusion. Crucially, however, any amount of liquid that has not yet evaporated in time and may accumulate in the complex cavity enclosed by the outer casing 1, the inner frame 2, the sealing strip 9, and the door leaf 3 now has a clear drainage pathway. Under the influence of gravity, the liquid can flow unhindered through the drainage channels 113 located at both ends into the larger collection tray 10 between the inner frame 2 and the casing 1.This collection tray 10 is designed to direct the liquid to the bottom of the box body, where it is either drained from the box through the one-way valve outlet at the bottom or by natural evaporation. In one embodiment, the inner frame 2 is firmly connected to the inner wall of the outer housing 1 via the collection tray 10, which is designed such that the central area of ​​the plate body of the inner frame extends outwards; wherein support columns 11 for attaching detection terminals are provided on the top, back and side plates of the outer housing 1. In another aspect, an embodiment of the present invention further provides an offshore wind farm multiphysics full-link acquisition system comprising: a protective box of the above; an integrated acquisition terminal arranged in the protective box; and multiple environmental and structural response signal acquisition devices arranged on the rotor blades of the wind turbine, in the cabin, on the tower, on the foundation, and in the surrounding waters; wherein the multiple environmental and structural response signal acquisition devices transmit the acquired heterogeneous data from various sources via wired or wireless links to the integrated acquisition terminal, which protocol-converts and time-synchronizes the data and then transmits it to the central control server. In the present embodiment, the integrated data acquisition terminal, which acts as a data node, is protected by a special protective housing with exceptional environmental adaptability. This directly solves the problem of conventional data acquisition systems, where the high failure rate of the terminals in environments with salt spray, high humidity, and vibrations leads to interruptions and distortions of the data connection, which in turn impairs the effectiveness of the entire acquisition system. The present invention ensures that data acquisition, aggregation, and transmission are always robust and reliable, even under extremely harsh external conditions.This allows full-link data to be continuously, completely and accurately captured, providing an indispensable basis in the form of high-quality data for calibrating the digital twin model of the wind turbine, updating the load spectrum, and iteratively optimizing intelligent operating and maintenance algorithms, ultimately helping to reduce operating and maintenance costs and risks throughout the entire life cycle of offshore wind farms in the deep sea. Although the embodiments of the invention have been described with reference to the accompanying drawings, a person skilled in the art may make various modifications and variants without departing from the spirit and scope of the invention; such modifications and variants all fall within the scope defined by the accompanying claims.

Claims

Protective box, characterized in that it comprises: a box body comprising an outer housing and an inner frame arranged in this outer housing, the outer housing having an opening on one side, the inner frame being an annular structure consisting of several plates arranged in a row and arranged at a distance from the inner wall of the outer housing, the opening on one side of the inner frame corresponding to the position of the opening of the outer housing; a door leaf rotatably connected to the outer housing and serving to open and close the opening; a sealing element arranged on the inside of the door leaf or on the open side of the inner frame and serving to form a seal with the corresponding contact surface when the door leaf is closed;as well as an elastic pressure structure arranged between the door leaf and the inner frame to generate a continuous elastic pressure force between at least one side edge of the door leaf and the corresponding side edge of the inner frame when the door leaf is closed, thereby increasing the sealing effect of the sealing element. Protective box according to claim 1, characterized in that the elastic pressure structure comprises a hinge arranged between the door leaf and the box body, the hinge comprising a pivot shaft and a first connecting element and a second connecting element, which are elastically deformable; wherein one end of the first connecting element is attached to the box body, while the other end is rotatably connected to the pivot shaft; wherein one end of the second connecting element is attached to the door leaf 3, while the other end is rotatably connected to the pivot shaft; wherein, when the door leaf is closed, the first connecting element and the second connecting element deform elastically, thereby generating a sustained tensile force between the door leaf and the box body, which causes a hinged side edge of the door leaf to lie tightly against the inner frame. Protective box according to claim 2, characterized in that both the first connecting element and the second connecting element have a bend, wherein when the door leaf is closed the first connecting element and the second connecting element deform elastically at the bending points. Protective box according to claim 1, characterized in that the elastic pressure structure comprises a rotary lock arranged on one side of the door leaf and a corresponding first locking groove arranged on the inner frame; wherein the locking tongue of the rotary lock can be rotated and engaged in the first locking groove, wherein the contour of the locking tongue is designed such that, during engagement, it gradually presses the door leaf against the inner frame, thereby ensuring that the edge of the door leaf on this side lies tightly against the inner frame. Protective box according to claim 1, characterized in that the elastic pressure structure comprises elastic retaining blocks arranged at the upper and lower edges of the door leaf, and second locking grooves arranged accordingly on the upper and lower plates of the inner frame; wherein the elastic retaining blocks have an arcuate structure projecting towards the inner frame and a projection, wherein, when the door leaf is closed, the arcuate structure and the projection slide over the edges of the inner frame and finally allow the projection to engage in the second locking groove, wherein the elastic retaining blocks are in an elastically deformed state and thus press the upper and / or lower edges of the door leaf firmly against the inner frame. Protective box according to one of claims 1 to 5, characterized in that helically toothed lip seals are arranged on the inner walls of the upper plate and the lower plate of the outer housing near the opening, which come into elastic contact with the upper and lower surfaces of the door leaf when the door leaf is closed in order to scrape off liquid residues. Protective box according to claim 6, characterized in that sealing strips are further arranged on the inner walls of the upper plate and the lower plate of the outer housing on the inside of the helically toothed lip seal; wherein a frame-shaped elevation is provided on the inner edge of the door leaf, the upper and lower edges of which form an elastic sealing fit with the sealing strips when the door leaf is closed. Protective box according to claim 7, characterized in that the sealing strip and the helically toothed lip seal have a distance at their two horizontal ends to the side walls of the outer housing, whereby drainage channels are formed between the upper and lower ends of the door leaf and the inner walls of the outer housing, which are connected to the space between the inner frame and the outer housing. Protective box according to claim 1, characterized in that the inner frame is firmly connected to the inner wall of the outer housing via the collection tray, which is formed such that the central area of ​​the plate body of the inner frame extends outwards; wherein support columns for attaching detection terminals are provided on the top, rear and side plates of the outer housing. Offshore wind farm multiphysics full-link acquisition system, characterized in that it comprises: a protective box according to any one of claims 1 to 9; an integrated acquisition terminal arranged in the protective box; and multiple acquisition devices for environmental and structural response signals arranged on the rotor blades of the wind turbine, in the cabin, on the tower, on the foundation and in the surrounding waters; wherein the multiple acquisition devices for environmental and structural response signals send the acquired heterogeneous data from various sources via wired or wireless connections to the integrated acquisition terminal, which protocol-converts and time-synchronizes the data and then transmits it to the central control server.

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