Offshore photovoltaic multi-loop submarine cable rear ditching construction system and construction method

Abstract

The invention provides an offshore photovoltaic multi-loop submarine cable rear ditching construction system and method, and relates to the technical field of offshore photovoltaic. According to the system, a trencher body is configured to execute layered multi-pass re-digging operation when the seabed condition is the colloid iron plate sand geology so that submarine cables can be buried to the preset depth of the seabed, the trencher body is provided with a multi-pump pressure spraying system, and the ground breaking strength of the trencher body is larger than or equal to 100 kPa; the supporting ship is configured to hoist the trencher main body to a preset position, and the trencher main body is positioned through the anchoring system; the integrated monitoring device is integrated on the trencher body and used for monitoring the position of the trencher body on the seabed and the working environment. And the linkage operation module is arranged at the land end and is configured to assist the trencher main body in segmented synchronous construction in the deep water area and the intertidal zone. The system solves the problem that rubber iron plate sand geological ground breaking is difficult when submarine cables are laid on the sea in a photovoltaic mode, multi-area synchronous burying operation can be achieved, the laying difficulty of the submarine cables is reduced, and the system is suitable for various submarine environments.

Description

Technical Field

[0001] The present disclosure relates to the field of offshore photovoltaic technology, and in particular to a multi-circuit submarine cable rear trenching construction system and a construction method for offshore photovoltaics. Background Art

[0002] Photovoltaic panels are devices that convert solar energy into electrical energy. They are widely used in the field of power generation due to their cleanliness and other characteristics. Since the power generation capacity of a single photovoltaic panel is limited, in order to meet the requirements of electricity use, multiple photovoltaic panels are usually required to generate electricity simultaneously. However, the layout of multiple photovoltaic panels requires a large space. The sea is suitable for the layout of photovoltaic power generation equipment because of its vast space and fewer obstructions.

[0003] After photovoltaic panels convert solar energy into electricity, they need to collect power lines to transmit the energy. The commonly used collection lines in photovoltaic systems are cables. The cables for offshore photovoltaics include land sections and seabed sections. Due to the complexity of the seabed environment and geology, the difficulty of laying submarine cables is much higher than that of laying land cables. At present, the laying of submarine cables for offshore photovoltaics on the seabed adopts the buried laying method. After the cables are dragged to the seabed by ships, they are buried in the seabed to protect the cables from external damage. However, this method is difficult to guarantee the laying quality of the cables on the seabed, especially for the special geology of the seabed, the cable is difficult to bury and the burial quality is poor.

[0004] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0005] In view of this, a multi-circuit submarine cable post-trenching construction system and construction method for offshore photovoltaics are provided. The construction system solves the problem that it is difficult to bury submarine cables in the colloidal iron plate sand geology of the seabed by performing post-trenching and multiple re-burying operations on the submarine cables, thereby reducing the difficulty of burying submarine cables. The system is suitable for a variety of seabed environments and can realize simultaneous burying operations in multiple areas, thereby improving the efficiency and quality of submarine cable burying and laying.

[0006] Other features and advantages of the present disclosure will become apparent from the following detailed description, or may be learned in part by the practice of the present disclosure.

[0007] According to one aspect of the present disclosure, a multi-circuit submarine cable rear trenching construction system for offshore photovoltaics is provided, the system comprising:

[0008] The trenching machine body is configured to perform layered multiple-pass digging operations when the seabed condition is colloidal iron plate sand geology, so that the submarine cable is buried to a preset depth on the seabed. The trenching machine body is equipped with a multi-pump pressure spraying system, and the soil breaking strength of the trenching machine body is ≥100kPa;

[0009] A support vessel, wherein the support vessel is configured to hoist the trencher body to a preset position, and the support vessel is positioned by an anchoring system;

[0010] An integrated monitoring device, integrated on the trenching machine body, comprising a front sonar device arranged at the front end of the trenching machine body and a rear sonar device arranged at the rear end of the trenching machine body, the integrated monitoring device being used to monitor the position of the trenching machine body on the seabed and the working environment;

[0011] The linkage operation module is arranged on the land side and is configured to assist the trenching machine body in synchronous construction in sections in the deep water area and the intertidal zone.

[0012] In an exemplary embodiment of the present disclosure, the trenching machine body includes a first trenching device for trenching in the deep water area and a second trenching device for trenching in the intertidal zone;

[0013] The first trenching device is traction-connected to the second trenching device, and the first trenching device is connected to the second trenching device through a pressure water pipeline;

[0014] The first trenching device is hoisted by the support vessel and positioned in the deep water area to perform layered multiple-pass trenching operations, and the second trenching device is hoisted by the linkage operation module and positioned in the intertidal zone to perform layered multiple-pass trenching operations. The first trenching device and the second trenching device operate continuously.

[0015] In an exemplary embodiment of the present disclosure, the linkage operation module includes a connected power device and a lifting device, the power device is used to move the second trenching device between the boundary of the deep water area and the land end; the lifting device lifts the second trenching device at the land end and positions it.

[0016] In an exemplary embodiment of the present disclosure, the support vessel further includes a traction assembly, wherein the traction assembly is connected between the first trenching device and the support vessel and is used for towing the first trenching device.

[0017] In an exemplary embodiment of the present disclosure, the ground-breaking strength of the first trenching device is greater than the ground-breaking strength of the second trenching device; the ground-breaking strength of the first trenching device is ≥120 kPa, and the ground-breaking strength of the second trenching device is ≥100 kPa.

[0018] In an exemplary embodiment of the present disclosure, the number of the submarine cable is at least 16, and the center distance between two adjacent submarine cables is not less than 1.2 times the maximum water depth of the area where the submarine cables are located, and the difference between the working area of ​​the trenching machine body and the submarine cable route is less than or equal to 3m.

[0019] According to another aspect of the present disclosure, a trenching construction method for multiple-circuit submarine cables of offshore photovoltaics is provided, which is used in the above-mentioned construction system, and the method comprises:

[0020] S1. Using the support vessel to hoist the trenching machine body to the top of the submarine cable;

[0021] S2, using the multi-pump pressure jet system to generate a pressure water jet to suspend and blow sediments on the seabed surface to expose the submarine cable;

[0022] S3, hoisting the trenching machine body to a first position by means of the integrated monitoring device and the support vessel, wherein the first position is that the trenching machine body straddles the submarine cable, and the center line of the submarine cable is parallel to the center line of the trenching machine body;

[0023] S4. The trenching machine body performs multiple layers of repeated digging operations along the direction of the submarine cable route to bury the submarine cable to a preset depth on the seabed.

[0024] In an exemplary embodiment of the present disclosure, after step S3 and before step S4, the method further includes:

[0025] The trenching machine body performs preliminary excavation along a first direction to a first preset depth and a first preset length, wherein the first direction is a direction having a first preset angle with the center line of the submarine cable, and the first preset angle is greater than 0° and less than 90°;

[0026] Adjust the excavation direction of the trencher body to a second direction, and continue excavating until the excavation depth reaches a second preset depth and the excavation length reaches a second preset length, so as to form a preset slope below the submarine cable, so that part of the submarine cable fits on the surface of the preset slope, wherein the second direction is a direction having a second preset angle with the center line of the submarine cable, and the second preset angle is greater than the first preset angle.

[0027] In an exemplary embodiment of the present disclosure, the trenching machine body includes a first trenching device and a second trenching device connected to each other, and the method further includes:

[0028] Move the second trenching device to the vicinity of the first trenching device, and connect the second trenching device and the first trenching device through a pressure water pipeline;

[0029] Using the linkage operation module to tow the second trenching device to the intertidal zone area close to the land end;

[0030] The first trenching device performs multiple layered and repeated trenching operations on the submarine cable along the direction from the deep water area to the intertidal zone, and the second trenching device performs multiple layered and repeated trenching operations on the submarine cable along the direction from the intertidal zone to the deep water area until the operating area of ​​the first trenching device is connected with the operating area of ​​the second trenching device.

[0031] In an exemplary embodiment of the present disclosure, in step S1, the method includes:

[0032] Positioning the support vessel using an anchoring system, wherein the anchoring system includes at least four positioning anchors, and the distance between the anchor position of each positioning anchor and the adjacent submarine cable is not less than 100m;

[0033] Using the boom of the support vessel to hoist the trenching machine body offshore, and detecting the position of the submarine cable by the integrated monitoring device until the support vessel hoists the trenching machine body above the submarine cable;

[0034] The support vessel lowers the trenching machine body in a direction perpendicular to the sea level until the trenching machine body moves to just above the submarine cable.

[0035] The present disclosure provides a multi-circuit submarine cable post-trenching construction system for offshore photovoltaics. The system uses a trenching machine body to perform layered multiple-pass excavation operations when the seabed environment is colloidal iron plate sand geology, so that the submarine cable can be laid at a preset depth on the seabed, overcoming the influence of the seabed environment on the burial position and quality of the submarine cable; the system is assisted by a support ship to support and position the trenching machine body, and an integrated monitoring device is used to locate and monitor the position of the submarine cable by the trenching machine body, which can improve the accuracy of the laying position of the submarine cable on the seabed, avoid damage to adjacent submarine cables during the laying process, and thereby improve the laying quality of the submarine cable; in addition, the trenching machine body can also perform synchronous construction operations in deep water areas and intertidal zones at the same time, thereby improving the construction efficiency of submarine cable laying.

[0036] The present invention provides a method for digging trenches behind multiple submarine cables for offshore photovoltaics. By utilizing a trenching construction system behind multiple submarine cables for offshore photovoltaics, after an integrated monitoring device accurately positions a trenching machine body, the trenching machine body performs multiple layered and multiple-pass repeated digging operations. This method has high reliability and can improve the reliability and quality of submarine cable laying.

[0037] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0039] Figure 1 It is a structural schematic diagram of a multi-circuit submarine cable rear trenching construction system for offshore photovoltaics in an exemplary embodiment of the present disclosure.

[0040] Figure 2 It is a schematic diagram of the suspended blowing operation of the multi-pump pressure spraying system in the exemplary embodiment of the present disclosure.

[0041] Figure 3 It is a schematic diagram of a first position of a trenching machine body lifted by a support vessel in an exemplary embodiment of the present disclosure.

[0042] Figure 4 It is a schematic diagram of a second position of the trenching machine body being hoisted by a support vessel in an exemplary embodiment of the present disclosure.

[0043] Figure 5 It is a schematic diagram of a third position of the trenching machine body being hoisted by a support vessel in an exemplary embodiment of the present disclosure.

[0044] Figure 6 It is a schematic diagram of the position of the trenching machine body at a first preset angle during the deflection operation in the exemplary embodiment of the present disclosure.

[0045] Figure 7 It is a schematic diagram of the position of the trenching machine body at a second preset angle during the deflection operation in the exemplary embodiment of the present disclosure.

[0046] Figure 8 This is a schematic diagram of the position of the submarine cable after the trenching machine body is deflected in the exemplary embodiment of the present disclosure.

[0047] Fig. 9 It is a schematic diagram of the positional relationship between the support vessel and the anchor boat in an exemplary embodiment of the present disclosure.

[0048] Fig.10 It is a schematic diagram of the connection relationship between the traction device of the support vessel and the trencher body in the exemplary embodiment of the present disclosure.

[0049] Fig.11 It is a schematic diagram of the positional relationship between the trenching machine body and the submarine cable in an exemplary embodiment of the present disclosure.

[0050] Fig.12 The present invention is a flow chart of a method for trenching and constructing multiple submarine cables for offshore photovoltaics in an exemplary embodiment of the present invention.

[0051] The reference numerals are described as follows:

[0052] 10. Trenching machine body; 11. Multi-pump pressure spraying system; 101. First trenching device; 102. Second trenching device; 20. Support vessel; 21. Anchoring system; 22. Towing assembly; 40. Linkage operation module; 41. Power unit; 42. Hoisting device; 50. Anchor boat; 60. Submarine cable; 601. First preset angle; 602. Second preset angle. DETAILED DESCRIPTION

[0053] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale.

[0054] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0055] The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may exist in addition to the listed elements / components / etc.; the terms "first", "second" and "third" etc. are used merely as labels and are not intended to limit the quantity of their objects.

[0056] In related technologies, an offshore photovoltaic system is a system that converts solar energy into electrical energy. Its core component is a photovoltaic module. The electrical energy converted by the photovoltaic module is usually transmitted to the land user end through cables. Submarine cables are the main way to ensure the transmission of electrical energy generated by offshore power generation systems. The laying status of submarine cables determines the reliability of subsequent electrical energy transmission in offshore power generation systems.

[0057] Cables between offshore photovoltaics and land usually go through three laying stages: land cable, submarine cable, and land cable. Among them, the laying of submarine cables is the process of laying cables on the seabed. Due to the complex seabed environment, the complex geological features of the seabed, and complex environmental factors such as waves, the laying quality of submarine cables is difficult to guarantee, and the requirements for construction equipment and construction are also extremely strict. At present, commonly used submarine cable laying methods include towing laying, burying laying, and jet laying, but these methods are difficult to meet the changeable geological conditions of the seabed, especially for colloidal iron sand geology. The devices used in the above methods are difficult to excavate this geology, and it is difficult to meet the requirements for submarine cable laying for offshore photovoltaics. The laying quality of submarine cables is even more difficult to guarantee.

[0058] Based on this, the embodiment of the present disclosure provides a multi-circuit submarine cable trenching construction system for offshore photovoltaics, such as Figure 1 As shown, combined Figures 2 to 11 The system includes: a trencher body 10, a support vessel 20, an integrated monitoring device and a linkage operation module 40.

[0059] Among them, the trencher body 10 is configured to perform layered multi-pass excavation operations when the seabed conditions are colloidal iron plate sand geology, so that the submarine cable 60 is buried to a preset depth on the seabed. The trencher body 10 is equipped with a multi-pump pressure spraying system 11, and the soil breaking strength of the trencher body 10 is ≥100kPa; the support ship 20 is configured to hoist the trencher body 10 to a preset position, and the support ship 20 is positioned by an anchoring system 21; the integrated monitoring device is integrated on the trencher body 10, including a front sonar device arranged at the front end of the trencher body 10 and a rear sonar device arranged at the rear end of the trencher body 10, and the integrated monitoring device is used to monitor the position of the trencher body 10 on the seabed and the working environment; the linkage operation module 40 is arranged on the land end, and is configured to assist the trencher body 10 in the synchronous construction of sections in the deep water area and the intertidal zone.

[0060] The present disclosure provides a multi-circuit submarine cable post-trenching construction system for offshore photovoltaics. The system uses a trenching machine body 10 to perform layered multiple-pass excavation operations when the seabed environment is colloidal iron plate sand geology, so that the submarine cable 60 can be laid at a preset depth on the seabed, overcoming the influence of the seabed environment on the burial position and quality of the submarine cable 60; the system is assisted by a support ship 20 to support and position the trenching machine body 10, and an integrated monitoring device is used to locate and monitor the position of the submarine cable 60 by the trenching machine body 10, which can improve the accuracy of the laying position of the submarine cable 60 on the seabed, avoid damage to adjacent submarine cables 60 during the laying process, and thereby improve the laying quality of the submarine cable 60; in addition, the trenching machine body 10 can also perform synchronous construction operations in deep water areas and intertidal zones at the same time, thereby improving the construction efficiency of laying the submarine cable 60.

[0061] In the present disclosure, the colloidal iron plate sand geology is mainly composed of cementing materials, iron minerals and sand particles, and has the physical properties of high hardness, high density and low porosity. This geological structure usually appears in sedimentary environments, such as rivers, lakes, oceans, etc. In these environments, sand particles, cementing materials and iron minerals are deposited together, and after a long period of compaction and cementation, hard rock formations are formed.

[0062] The multi-circuit submarine cable for offshore photovoltaic provided by the present disclosure is laid between offshore photovoltaic and the land end (coastline). The submarine cable 60 mainly refers to a section of the cable located on the seabed between the photovoltaic components in the offshore photovoltaic system and the land power transmission end. The photovoltaic components are usually located above the sea level. After the photovoltaic components are led out of the land cable, the land cable is converted and connected with one end of the submarine cable 60. Then the submarine cable 60 extends from the seabed to the land end. The other end of the submarine cable 60 is converted and connected with the cable at the land end, thereby forming an offshore photovoltaic cable system to meet the transmission of electricity at sea and on land. It should be noted that the offshore photovoltaic system disclosed in the present disclosure includes the above-mentioned cable system, and the conversion connection between the submarine cable 60 and the land cable is not described in detail here.

[0063] Furthermore, in order to meet the power generation needs of offshore photovoltaics, the number of submarine cables 60 for offshore photovoltaics is at least 16, and multiple submarine cables 60 are laid side by side at intervals, and the center distance between two adjacent submarine cables 60 is not less than 1.2 times the maximum water depth of the area where the submarine cables 60 are located, so as to avoid interference between adjacent submarine cables 60 and meet the power generation needs of offshore photovoltaics. In addition, for the area where multiple submarine cables 60 are laid in parallel, the distance from the edge of the area to the outermost submarine cable 60 is at least 10m, so as to ensure that sufficient submarine cable 60 laying space is provided for offshore photovoltaics, and no waste of space and materials is caused. For example, in an area where the water depth is not greater than 8.5 m, the center distance between adjacent submarine cables 60 can be 1.2 times the maximum water depth, that is, the center distance between adjacent submarine cables 60 is 1.2×8.5 m=10.2 m. To facilitate the determination of the distance, the center distance can be an integer of 11 m. However, it should be noted that in order to ensure sufficient distance, when rounding the center distance between adjacent submarine cables 60, it is necessary to round up. The above embodiment is only for illustrative purposes, and the specific numerical values ​​given therein do not specifically limit the parameters such as the center distance between the submarine cable 60 and adjacent submarine cables 60 disclosed in the present invention.

[0064] The following will describe in detail the various parts of the multi-circuit submarine cable trenching construction system for offshore photovoltaic power generation provided by the embodiment of the present disclosure in conjunction with the accompanying drawings:

[0065] In the embodiments provided in the present disclosure, Figures 1 to 8 As shown, the system includes a trenching machine body 10, which is configured to perform layered multi-pass digging operations when the seabed condition is colloidal iron plate sand geology, so as to bury the submarine cable 60 to a preset depth on the seabed.

[0066] Among them, layered operation refers to dividing the preset depth of the seabed into multiple depths of different lengths, and the multiple depths are progressive in sequence, and the trenching machine body 10 operates at a seabed depth each time to form progressive excavation. Multiple-pass operation can refer to repeated excavation for excavation operations within a layer; it can also refer to multiple-pass excavation operations after one excavation within a layer. Through layered and multiple-pass excavation operations, hard, sticky and other seabed strata can be broken one by one to reach the burial depth of the submarine cable 60.

[0067] The difference between the operating area of ​​the trenching machine body 10 and the route of the submarine cable 60 is less than or equal to 3m, so as to avoid the trenching machine body 10 causing damage to the adjacent laid submarine cable 60 during operation. The submarine cable route refers to the laying path of the submarine cable 60 on the seabed, which is a continuous path and covers the area from offshore photovoltaic to the land end. Different submarine cables 60 have different submarine cable routes. For example, the submarine cable route can be determined or adjusted according to the specific structural parameters of the submarine cable 60. Further, in order to ensure the operating area of ​​the trenching machine body 10 and avoid the influence of the trenching machine body 10 on the laid submarine cable 60, the difference between the operating area of ​​the trenching machine body 10 and the submarine cable route can be ±1.3m. The operating area of ​​the trenching machine body 10 is much smaller than the center distance of the adjacent submarine cables 60, which ensures the reliability of the laying of the submarine cable 60.

[0068] like Figure 2 As shown, the trenching machine body 10 is equipped with a multi-pump pressure spraying system 11, which can perform suspended blowing operations on the submarine cable 60 before burying, and also expose the specific position of the submarine cable 60, which is convenient for the subsequent burying of the submarine cable 60. In addition, this spraying system can also be used to crush hard materials such as rocks during the excavation operation, and assist in removing impurities such as excavated mud or gravel to ensure the laying environment of the submarine cable 60. The spraying system includes multiple pumps, nozzles, control components and auxiliary components, wherein the pump can be a high-pressure water pump, and multiple high-pressure water pumps are connected in parallel or in series to increase the pressure and flow of the spraying system. The nozzle is connected to the pump to concentrate the high-pressure water flow generated by the high-pressure water pump on the target area, which is the submarine cable laying area. The specific structure of the nozzle can be selected and adaptively adjusted according to the actual use requirements and flushing requirements of the spraying system. The control component can adjust the working state of multiple pumps to improve the working efficiency of the pump. The auxiliary components can be pipes and connectors, etc., and the connection between the pump, the nozzle, and the control component is realized through the auxiliary components to ensure the smooth transmission of the high-pressure water flow. Of course, the jet flushing system may also include other unlisted components or assemblies to meet the requirements of laying the submarine cable 60 .

[0069] In order to ensure that the trenching machine body 10 can dig different seabed geology, the ground breaking strength of the trenching machine body 10 is ≥ 100kPa, for example, it can be 100kPa, 120kPa, 140kPa, 160kPa, 180kPa, 200kPa, etc. The ground breaking strength of the trenching machine body 10 can be determined according to the actual seabed depth, main geological conditions and other factors. In addition, considering the power and volume of the trenching machine body 10, the trenching machine body 10 with greater power tends to have a larger volume. Therefore, the ground breaking strength of the trenching machine body 10 should not be too small to avoid failing to achieve the stratum breaking effect, but the ground breaking strength should not be too large to avoid wasting the power of the trenching machine body 10 and avoid being unsuitable for the laying spacing of adjacent submarine cables 60 due to its excessive volume.

[0070] In some embodiments, since the submarine cable 60 is laid in different water depth environments, the trenching machine body 10 includes a first trenching device 101 for trenching in deep water areas and a second trenching device 102 for trenching in intertidal zones.

[0071] Among them, the deep water area refers to the area between the offshore photovoltaic and the land end, close to the offshore photovoltaic, in which the water depth is at least 5m. In the present disclosure, the deep water area can be an area with a water depth of 6m to 8m. Of course, the water depth of the deep water area can also be changed according to the subsequent development of offshore photovoltaics. For example, after the offshore photovoltaic can be laid in the ocean farther from the coastline, the division of the deep water area can be adaptively adjusted according to the layout distance of the offshore photovoltaic, and the construction system provided by the present disclosure can also be adaptively adjusted to meet the submarine cable laying requirements of offshore photovoltaics.

[0072] The intertidal zone (shallow water area) refers to the area between the offshore photovoltaic and the land end, close to the land end (coastline), in which the water depth is less than or equal to 5m. In the present disclosure, the intertidal zone can be an area with a water depth of 0m to 3m. Of course, the water depth of the intertidal zone can also be changed according to the subsequent development of offshore photovoltaics. For example, after offshore photovoltaics can be laid in the ocean farther from the coastline, the division of the intertidal zone can be adaptively adjusted according to the layout distance of offshore photovoltaics, and the construction system provided by the present disclosure can also be adaptively adjusted to meet the submarine cable laying requirements of offshore photovoltaics.

[0073] Among them, since the first trenching device 101 operates in deep water areas, the geological environment it faces is more complex. In order to meet the needs of submarine cable laying in deep water areas, the ground breaking strength of the first trenching device 101 is ≥120kPa. For example, the ground breaking strength of the first trenching device 101 can be 120kPa, 140kPa, 160kPa, 180kPa or 200kPa, etc.

[0074] Since the second trenching device 102 operates in the intertidal zone, in order to meet the laying requirements of the submarine cable 60 in the intertidal zone and balance the relationship between the power and volume of the second trenching device 102, the ground-breaking strength of the second trenching device 102 is ≥100 kPa. For example, the ground-breaking strength of the first trenching device 101 can be 100 kPa, 120 kPa, 140 kPa, 160 kPa, 180 kPa, etc. In addition, the ground-breaking strength of the second trenching device 102 can be less than the ground-breaking strength of the first trenching device 101, so as to meet the traction effect of the first trenching device 101 on the second trenching device 102.

[0075] In order to make the first trenching device 101 and the second trenching device 102 assist each other in operation, the first trenching device 101 is connected to the second trenching device 102 by traction, for example, the first trenching device 101 is connected to the second trenching device 102 by traction through a traction wire rope. The first trenching device 101 and the second trenching device 102 are connected through a pressure water pipeline. When the second trenching device 102 is operating, the first trenching device 101 can provide a water source for the second trenching device 102, and the water source has a certain pressure, which can ensure the construction operation requirements of the second trenching device 102 for the water source pressure.

[0076] In the embodiments provided in the present disclosure, Figure 1 As shown, combined Figures 3 to 5 The system includes a support vessel 20 , which is configured to hoist the trenching machine body 10 to a preset position, and the support vessel 20 is positioned by an anchoring system 21 .

[0077] The trenching machine body 10 needs to be supported by the support ship 20 for construction work. Before the construction work, the trenching machine body 10 can be placed on the support ship 20, and the trenching machine body 10 is transported to the area near the starting point of the operation by the support ship 20, and then the trenching machine body 10 is hoisted to the starting point of the construction by the hoisting equipment of the support ship 20 itself, that is, the support ship 20 is guaranteed to hoist the trenching machine body 10 near the submarine cable 60. For example, the first trenching device 101 is used for laying submarine cables 60 in deep sea areas. The laying location of the submarine cable 60 is often far away from the land end. In order to facilitate the transportation of the first trenching device 101, the first trenching device 101 is usually transported by the support ship 20. In addition, the support ship 20 can also provide support and positioning for the trenching machine body 10, so as to avoid the trenching machine body 10 deviating from the route during the construction work due to the influence of marine environmental factors, which affects the laying quality of the submarine cable 60.

[0078] like Fig. 9As shown, when the support vessel 20 transports the trencher body 10 , an anchor boat 50 can be used to assist the support vessel 20 in moving along the route of the cable 60 , thereby ensuring the balance of the support vessel 20 and improving the transportation stability of the trencher body 10 by the support vessel 20 .

[0079] Furthermore, the support vessel 20 is provided with an anchoring system 21, which may include 4 positioning anchors and 2 side anchors to improve the stability of the support vessel 20. In the present disclosure, in order to avoid interference between the anchoring system 21 and the submarine cable 60, the distance between the anchor position of each anchor of the anchoring system 21 and the adjacent submarine cable 60 is usually not less than 100m, so as to avoid damage to the submarine cable 60 during positioning.

[0080] like Fig.10 As shown, the support vessel 20 further includes a traction assembly 22, which is connected between the first trenching device 101 and the support vessel 20. The traction assembly 22 is used to tow the first trenching device 101. For example, the traction assembly 22 may be a steel wire rope group or a cable wind rope group. By connecting the traction assembly 22 to the hull of the support vessel 20 to pull the first trenching device 101, the stability of the first trenching device 101 during the laying of the submarine cable 60 can be maintained. Furthermore, since the stability of the first trenching device 101 indirectly affects the stability of the second trenching device 102, when the traction assembly 22 ensures the stability of the first trenching device 101, the stability of the second trenching device 102 is indirectly improved.

[0081] In the embodiment provided by the present disclosure, the system includes an integrated monitoring device (not shown in the figure), which is integrated on the trenching machine body 10. The integrated monitoring device includes a front sonar device arranged at the front end of the trenching machine body 10 and a rear sonar device arranged at the rear end of the trenching machine body 10. The integrated monitoring device is used to monitor the position of the trenching machine body 10 on the seabed and the working environment.

[0082] Among them, the front sonar device and the rear sonar device can be composed of one or more of dual-frequency multi-beam sonar, dual-frequency multi-beam sonar, dual-frequency imaging sonar, trenching depth sensor, equipment attitude sensor, and water depth sensor.

[0083] After the support vessel 20 hoists the first trenching device 101, the operation starting point of the first trenching device 101 needs to be accurately determined. The first trenching device 101 needs to be configured directly above the submarine cable 60, and the first trenching device 101 can start operation only when the center lines of the two are parallel to each other. Therefore, the relative position relationship between the first trenching device 101 and the submarine cable 60 can be determined by an integrated monitoring device to ensure the laying requirements of the first trenching device 101.

[0084] In addition, the integrated monitoring device can also monitor the position of the trencher body 10 on the seabed and the working environment. For example, the laying status and laying depth of the submarine cable 60 can be monitored through sonar equipment, and the trenching profile data and surrounding obstacle identification information of the trencher body 10 as well as parameters such as the inclination angle, water depth and travel speed of the trencher body 10 can be monitored. The above parameters can be presented in the form of images, making the working status of the trencher body 10 more intuitive and specific, providing a reference for adjusting the construction operation of the trencher body 10.

[0085] It should be noted that the front sonar device and the rear sonar device are not limited to monitoring the front and rear ends of the trencher body 10, but the combination of the front sonar device and the rear sonar can cover the circumferential position of the trencher body 10 and can extend to a certain sea area so as to obtain real-time operation information of the trencher body 10.

[0086] In the embodiments provided in the present disclosure, Figure 1 As shown, the system includes a linkage operation module 40, which is arranged at the land end. The linkage operation module 40 is configured to assist the trenching machine body 10 in synchronous construction in sections in the deep water area and the intertidal zone.

[0087] Among them, the first trenching device 101 is hoisted and positioned in the deep water area by the support ship 20 to perform layered multiple-pass digging operations, and the second trenching device 102 is hoisted and positioned in the intertidal zone by the linkage operation module 40 to perform layered multiple-pass digging operations. The first trenching device 101 and the second trenching device 102 operate continuously and synchronously.

[0088] The linkage operation module 40 includes a connected power device 41 and a hoisting device 42. The power device 41 is used to move the second trenching device 102 between the boundary of the deep water area and the land end; the hoisting device 42 hoists the second trenching device 102 at the land end and positions it.

[0089] Before the laying of the submarine cable 60 begins, the second trenching device 102 needs to be towed and connected with the first trenching device 101. Since the first trenching device 101 is in a deep water area, the second trenching device 102 needs to be transported to the area near the first trenching device 101 to complete the towing connection between the two. In some embodiments, the power device 41 may include a winch arranged at the land end. After the second trenching device 102 is connected to the first trenching device 101, the second trenching device 102 is moved to a position close to the coastline by the winch. Of course, the power device 41 may also include equipment such as a transport boat, and the second trenching device 102 may also be moved to the area near the first trenching device 101 by the power device 41. In some embodiments, the hoisting device 42 may be a crane arranged at the land end, and the second trenching device 102 may be hoisted at the starting point of the laying of the submarine cable 60 by the crane.

[0090] The linkage operation module 40 provided in the present invention can ensure that the trenching machine body 10 composed of the first trenching device 101 and the second trenching device 102 can simultaneously carry out the laying operation of the submarine cable 60 in different sea areas, and the operations of the two maintain synchronous continuity, thereby completing the synchronous and continuous laying of the submarine cable 60 in the deep sea area and the intertidal zone, thereby improving the efficiency and quality of the laying of the submarine cable 60.

[0091] The present disclosure provides a multi-circuit submarine cable post-trenching construction system for offshore photovoltaics. The system uses a trenching machine body 10 to perform layered multiple-pass excavation operations when the seabed environment is colloidal iron plate sand geology, so that the submarine cable 60 can be laid at a preset depth on the seabed, overcoming the influence of the seabed environment on the burial position and quality of the submarine cable 60; the system is assisted by a support ship 20 to support and position the trenching machine body 10, and an integrated monitoring device is used to locate and monitor the position of the submarine cable 60 by the trenching machine body 10, which can improve the accuracy of the laying position of the submarine cable 60 on the seabed, avoid damage to adjacent submarine cables 60 during the laying process, and thereby improve the laying quality of the submarine cable 60; in addition, the trenching machine body 10 can also perform synchronous construction operations in deep water areas and intertidal zones at the same time, thereby improving the construction efficiency of laying the submarine cable 60.

[0092] The disclosed embodiment provides a trenching construction method for multiple-circuit submarine cables of offshore photovoltaic power generation, which is applicable to the construction system provided by any of the above embodiments, such as Fig.12 As shown, combined Figures 1 to 11 The method includes: steps S1 to S4.

[0093] In step S1, the trenching machine body 10 is hoisted above the submarine cable 60 by using the support vessel 20;

[0094] Step S2, using the multi-pump pressure jet system 11 to generate a pressure water jet to suspend and blow sediments on the seabed surface to expose the submarine cable 60;

[0095] Step S3, hoisting the trencher body 10 to a first position by using the integrated monitoring device and the support vessel 20, wherein the first position is that the trencher body 10 straddles the submarine cable 60, and the center line of the submarine cable 60 is parallel to the center line of the trencher body 10;

[0096] Step S4: the trenching machine body 10 performs multiple layers of repeated digging operations along the route direction of the submarine cable 60 to bury the submarine cable 60 to a preset depth on the seabed.

[0097] The present invention provides a method for trenching multiple submarine cables for offshore photovoltaics. By utilizing a trenching construction system for multiple submarine cables for offshore photovoltaics, after an integrated monitoring device accurately positions a trenching machine body 10, the trenching machine body 10 performs multiple layered and multiple-pass repeated trenching operations. This method has high reliability and can improve the reliability and quality of the laying of the submarine cable 60.

[0098] The following will describe in detail the various steps of the multi-circuit submarine cable trenching construction method for offshore photovoltaics provided by the embodiment of the present disclosure in conjunction with the accompanying drawings:

[0099] In the embodiments provided in the present disclosure, Figure 3 , Figure 4 and Figure 5 As shown, in step S1 , the trenching machine body 10 is hoisted above the submarine cable 60 by using the support vessel 20 .

[0100] In some embodiments, step S1 includes: steps S11 to S13.

[0101] Among them, step S11, as Fig.11 As shown, the support vessel 20 is positioned using an anchoring system 21, the anchoring system 21 includes at least four positioning anchors, and the distance between the anchor position of each positioning anchor and the adjacent submarine cable 60 is not less than 100m;

[0102] Step S12: Figure 4 As shown, the trenching machine body 10 is hoisted offshore by using the boom of the support vessel 20, and the position of the submarine cable 60 is detected by a monitoring device until the support vessel 20 hoists the trenching machine body 10 above the submarine cable 60;

[0103] Step S13: Figure 5 As shown, the support vessel 20 lowers the trenching machine body 10 in a direction perpendicular to the sea level until the trenching machine body 10 moves to just above the submarine cable 60 .

[0104] The trenching machine body 10 moves to the position directly above the submarine cable 60, which means that the center line of the trenching machine body 10 is parallel to the center line of the submarine cable 60, that is, the trenching machine body 10 straddles the submarine cable 60. The trenching machine body 10 can refer to the first trenching device 101 and the second trenching device 102 straddling the submarine cable 60, respectively, and the above conditions are met.

[0105] In some specific embodiments, moving the trencher body 10 by the support vessel 20 may include: lifting the trencher by the support vessel 20, lowering the trencher body 10 to a height of 0.5 m above the top of the submarine cable 60, adjusting the boom of the support vessel 20 to move left and right, and finding the specific position of the submarine cable 60; finding the center line of the submarine cable 60 by the integrated monitoring device on the trencher body 10, and adjusting the center line of the trencher body 10 to be directly above the submarine cable 60; and lowering the trencher body 10 to the seabed again to ensure that the trencher straddles the submarine cable 60.

[0106] The above steps S11 to S13 are suitable for respectively determining the positional relationship between the first trenching device 101 and the second trenching device 102 and the submarine cable 60. Of course, when the trenching machine body 10 includes multiple trenching devices, each trenching device can determine its relative positional relationship with the submarine cable 60 by the above method.

[0107] The trenching machine body 10 includes a first trenching device 101 and a second trenching device 102, and the method further includes: moving the second trenching device 102 to the vicinity of the first trenching device 101, and connecting the second trenching device 102 and the first trenching device 101 through a pressure water pipeline; using the linkage operation module 40 to pull the second trenching device 102 to the intertidal zone near the land end; the first trenching device 101 performs multiple layers and multiple times of repeated trenching operations on the submarine cable 60 along the direction from the deep water area to the intertidal zone, and the second trenching device 102 performs multiple layers and multiple times of repeated trenching operations on the submarine cable 60 along the direction from the intertidal zone to the deep water area, until the operation area of ​​the first trenching device 101 is connected to the operation area of ​​the second trenching device 102. The specific connection relationship and operation method of the first trenching device 101 and the second trenching device 102 are as shown in the embodiment of the above system, and will not be repeated here.

[0108] The first trenching device 101 and the second trenching device 102 provided in the present invention synchronously and continuously lay the submarine cable 60, which can shorten the laying time of the submarine cable 60 and improve the laying efficiency. In addition, different devices are used to lay the submarine cable 60 according to different areas, which can improve the adaptability of the trenching machine body 10 to various seabed environments, realize adapting to local conditions, and thus improve the laying quality of the submarine cable 60.

[0109] In the embodiments provided in the present disclosure, Figure 2As shown, in step S2, the sediment on the seabed surface is suspended and blown by the multi-pump pressure jet system 11 to expose the submarine cable 60. Before the submarine cable 60 is buried, the submarine cable 60 will be buried under the seabed due to the natural silting of the seabed. Therefore, before the trenching machine body 10 is in place, the multi-pump pressure jet system 11 is required to perform a suspension blowing operation to expose the specific position of the cable so that the trenching machine body 10 can determine the position.

[0110] In the embodiments provided in the present disclosure, Figure 5 As shown, in step S3, the trencher body 10 is hoisted to the first position by integrating the monitoring device and using the support vessel 20. The first position is that the trencher body 10 straddles the submarine cable 60, and the center line of the submarine cable 60 is parallel to the center line of the trencher body 10. The specific implementation process of this step is shown in the embodiment of the system and will not be repeated here. The determination of the position of the trencher body 10 in step S3 is also suitable for the determination of the position of the first trenching device 101 in the deep water area and the position of the second trenching device 102 in the intertidal zone.

[0111] After step S3, Figure 6 , Figure 7 and Figure 8 As shown, the method also includes: the trencher body 10 performs preliminary excavation along a first direction to a first preset depth and a first preset length; the excavation direction of the trencher body 10 is adjusted to a second direction, and the excavation is continued until the excavation depth reaches a second preset depth and the excavation length reaches a second preset length, so as to form a preset slope below the submarine cable 60, so that part of the submarine cable 60 fits on the surface of the preset slope.

[0112] The above method can be used to make the seabed inclined before and / or after the trenching machine body 10 starts working. The inclined operation can ensure that the submarine cable 60 is not damaged by stress during the burial process, thereby further improving the reliability of the burial of the submarine cable 60.

[0113] The first direction is a direction having a first preset angle 601 with the center line of the submarine cable 60, and the first preset angle 601 is greater than 0° and less than 90°; the second direction is a direction having a second preset angle 602 with the center line of the submarine cable 60, and the second preset angle 602 is greater than the first preset angle 601. For example, the first preset angle 601 may be 25°, and the second preset angle 602 may be 45°. Of course, the above process includes but is not limited to two excavations, and may also be divided into three, four or even more times of deflection operations to meet the laying requirements of the submarine cable 60.

[0114] In the embodiment provided by the present disclosure, in step S4, the trenching machine body 10 performs multiple layers of multiple digging operations along the cable route direction to bury the submarine cable 60 to a preset depth on the seabed. Specifically, the first trenching device 101 can perform multiple layers of multiple digging operations in the deep water area, and the second trenching device 102 can perform multiple layers of multiple digging operations in the intertidal zone. The first trenching device 101 and the second trenching device 102 can operate synchronously and continuously to improve the laying efficiency and quality of the submarine cable 60.

[0115] In some specific embodiments, the trenching machine body 10 times of layered and multi-pass digging operations can be divided into three layers and three times of digging operations. For example, the first operation can break the hard sand layer on the seabed surface, and the operation depth can be 0.5m to 0.8m; the second operation can expand the trench width to 1.2 times the diameter of the submarine cable 60, the trench width can be 11m, and the operation depth is extended by 1.2m to 1.5m on the basis of the first operation; the third operation completes the final burial depth and liquefies the backfill soil through the multi-pump pressure spraying system 11 and covers the submarine cable 60. Of course, the number of operations of the trenching machine body 10 can be adaptively adjusted according to actual operation requirements. For example, the number of layers and times of construction operations can be four, five, six or even more times to adapt to different submarine geological conditions and improve the versatility and applicability of the construction method.

[0116] The present invention provides a method for trenching multiple submarine cables for offshore photovoltaics. By utilizing a trenching construction system for multiple submarine cables for offshore photovoltaics, after an integrated monitoring device accurately positions a trenching machine body 10, the trenching machine body 10 performs multiple layered and multiple-pass repeated trenching operations. This method has high reliability and can improve the reliability and quality of the laying of the submarine cable 60.

[0117] It should be noted that, although the steps of the multi-circuit submarine cable trenching construction system for offshore photovoltaics in the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps, etc.

[0118] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A multi-circuit submarine cable trenching construction system for offshore photovoltaics, characterized in that: include: The trenching machine body is configured to perform layered multiple-pass digging operations when the seabed condition is colloidal iron plate sand geology, so that the submarine cable is buried to a preset depth on the seabed. The trenching machine body is equipped with a multi-pump pressure spraying system, and the soil breaking strength of the trenching machine body is ≥100kPa; A support vessel, wherein the support vessel is configured to hoist the trencher body to a preset position, and the support vessel is positioned by an anchoring system; An integrated monitoring device, integrated on the trenching machine body, comprising a front sonar device arranged at the front end of the trenching machine body and a rear sonar device arranged at the rear end of the trenching machine body, the integrated monitoring device being used to monitor the position of the trenching machine body on the seabed and the working environment; The linkage operation module is arranged on the land side and is configured to assist the trenching machine body in synchronous construction in sections in the deep water area and the intertidal zone.

2. The multi-circuit submarine cable trenching construction system for offshore photovoltaics according to claim 1 is characterized in that: The trenching machine body includes a first trenching device for trenching in the deep water area and a second trenching device for trenching in the intertidal zone; The first trenching device is traction-connected to the second trenching device, and the first trenching device is connected to the second trenching device through a pressure water pipeline; The first trenching device is hoisted by the support vessel and positioned in the deep water area to perform layered multiple-pass trenching operations, and the second trenching device is hoisted by the linkage operation module and positioned in the intertidal zone to perform layered multiple-pass trenching operations. The first trenching device and the second trenching device operate continuously.

3. The multi-circuit submarine cable trenching construction system for offshore photovoltaics according to claim 2 is characterized in that: The linkage operation module includes a connected power device and a lifting device, wherein the power device is used to move the second trenching device between the boundary of the deep water area and the land end; the lifting device lifts the second trenching device at the land end and positions it.

4. The multi-circuit submarine cable trenching construction system for offshore photovoltaics according to claim 2 is characterized in that: The support vessel further includes a traction assembly, which is connected between the first trenching device and the support vessel and is used for towing the first trenching device.

5. The multi-circuit submarine cable rear trenching construction system for offshore photovoltaics according to any one of claims 2 to 4, characterized in that: The ground-breaking strength of the first trenching device is greater than the ground-breaking strength of the second trenching device; the ground-breaking strength of the first trenching device is ≥120 kPa, and the ground-breaking strength of the second trenching device is ≥100 kPa.

6. The multi-circuit submarine cable rear trenching construction system for offshore photovoltaics according to any one of claims 1 to 4, characterized in that: The submarine cable has at least 16 loops, and the center distance between two adjacent loops of the submarine cable is not less than 1.2 times the maximum water depth of the area where the submarine cable is located. The difference between the operating area of ​​the trenching machine body and the submarine cable route is less than or equal to 3m.

7. A trenching construction method for multiple-circuit submarine cables for offshore photovoltaics, used in the construction system according to any one of claims 1 to 6, characterized in that: include: S1. Using the support vessel to hoist the trenching machine body to the top of the submarine cable; S2, using the multi-pump pressure jet system to generate a pressure water jet to suspend and blow sediments on the seabed surface to expose the submarine cable; S3, hoisting the trenching machine body to a first position by means of the integrated monitoring device and the support vessel, wherein the first position is that the trenching machine body straddles the submarine cable, and the center line of the submarine cable is parallel to the center line of the trenching machine body; S4. The trenching machine body performs multiple layers of repeated digging operations along the direction of the submarine cable route to bury the submarine cable to a preset depth on the seabed.

8. The method for constructing multiple-circuit submarine cables for offshore photovoltaic power generation according to claim 7, characterized in that: After step S3 and before step S4, the method further includes: The trenching machine body performs preliminary excavation along a first direction to a first preset depth and a first preset length, wherein the first direction is a direction having a first preset angle with the center line of the submarine cable, and the first preset angle is greater than 0° and less than 90°; Adjust the excavation direction of the trencher body to a second direction, and continue excavating until the excavation depth reaches a second preset depth and the excavation length reaches a second preset length, so as to form a preset slope below the submarine cable, so that part of the submarine cable fits on the surface of the preset slope, wherein the second direction is a direction having a second preset angle with the center line of the submarine cable, and the second preset angle is greater than the first preset angle.

9. The method for constructing multiple-circuit submarine cables for offshore photovoltaic power generation according to claim 7, characterized in that: The trenching machine body includes a first trenching device and a second trenching device connected to each other, and the method further includes: Move the second trenching device to the vicinity of the first trenching device, and connect the second trenching device and the first trenching device through a pressure water pipeline; Using the linkage operation module to tow the second trenching device to the intertidal zone area close to the land end; The first trenching device performs multiple layered and repeated trenching operations on the submarine cable along the direction from the deep water area to the intertidal zone, and the second trenching device performs multiple layered and repeated trenching operations on the submarine cable along the direction from the intertidal zone to the deep water area until the operating area of ​​the first trenching device is connected with the operating area of ​​the second trenching device.

10. The method for constructing multiple-circuit submarine cables for offshore photovoltaic power generation according to any one of claims 7 to 9, characterized in that: In step S1, the method comprises: Positioning the support vessel using an anchoring system, wherein the anchoring system includes at least four positioning anchors, and the distance between the anchor position of each positioning anchor and the adjacent submarine cable is not less than 100m; Using the boom of the support vessel to hoist the trenching machine body offshore, and detecting the position of the submarine cable by the integrated monitoring device until the support vessel hoists the trenching machine body above the submarine cable; The support vessel lowers the trenching machine body in a direction perpendicular to the sea level until the trenching machine body moves to just above the submarine cable.

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