A compact offshore converter station installed by the floating installation method

Abstract

The present invention provides a compact offshore converter station installed by the float-over method, which includes an upper module and a jacket. Vertical channels are arranged at the four corners of the plane of the upper module. A horizontal traffic lane is provided at each of the south side, north side and the middle position of the upper module to form an I-shaped corridor layout. An integral bottom frame is arranged at the bottom of the upper module. The integral bottom frame serves as the beam of the main plant building, and the integral bottom frame serves as the structural conversion layer between the upper module and the jacket. The combination of the single-side auxiliary plant layout and the DC room mezzanine layout adopted in the present invention can effectively utilize the vertical space of the DC room, thereby simplifying the layout form of each floor traffic aisle from a "square" shape to an "I" shape. At the same time, the horizontal position deviation between the overall center of gravity and the geometric centroid of the structure is within an acceptable range, so that the lateral dimension of the plane of the upper module of the offshore converter station can be reduced by about 15 meters compared with the traditional double-side auxiliary plant.

Description

Technical Field

[0001] The present invention relates to an offshore converter station, in particular to a compact offshore converter station installed by the floating method, which is applicable to the field of offshore wind power generation. Background Art

[0002] Offshore wind power generation is a strategic emerging industry and has developed rapidly in recent years. However, at present, the offshore distance of offshore wind farms in China is generally within 30 km. Therefore, the electric energy output at the present stage is through AC submarine cables, and there is no case of applying DC output technology.

[0003] With the development of offshore wind power towards larger scales and farther distances, the economy of traditional AC power transmission methods is no longer applicable. Generally, when the offshore distance of an offshore wind farm exceeds 60 km, the DC power transmission method should be considered. For an offshore wind farm adopting DC power transmission, an offshore converter station needs to be built. The offshore converter station is the core device that collects the electric energy of the offshore wind farm through AC lines and then converts it into DC output.

[0004] China's onshore DC power transmission field has developed for many years, and several onshore converter stations have been built. For a conventional onshore converter station, generally according to the AC~DC process flow, functional modules such as converter transformers, high-voltage switches, arm reactors, converter valves, current-limiting reactors, and DC yard equipment are set. The converter transformers are generally arranged outdoors, and the rest of the equipment is set in a single-story factory building in a row. However, due to the differences in construction methods and the environments where offshore converter stations are located, there are significant differences in their layout schemes, structural forms, cooling methods, etc. compared with those onshore.

[0005] The existing technical solution of an offshore converter station (ZL 201910302415.7) is generally as follows: adopting a plant layout mode of one main and two auxiliary; the main plant arranges a valve hall (inside are components related to converter valves) and a DC room (inside are components related to arm reactors), and the large-span structures of the corresponding spaces adopt large solid-web beams; the bilateral symmetric auxiliary plants arrange auxiliary functional modules such as water supply and drainage, HVAC, and secondary electrics; the offshore installation adopts the high-position floating technology, and a temporary deck support frame (DSF) is set during the construction period to provide support in the center of the large-span main plant. This solution initially solves the problems of symmetric and compact layout of equipment and enables the functions of the offshore converter station to be realized. However, there are still some defects: First, due to the requirement of symmetry, auxiliary plants are set on both sides, resulting in a large plane size, low space utilization rate, and a large weight of the upper structure; Second, the large solid-web beam of the main plant has small stiffness, and the vertical deformation of the valve hall is large, which may affect the normal use performance of the converter valves; Third, the weight of the DSF can reach more than 3000 tons, but it is separated from the structure immediately after being installed in place and cannot play the role of a support structure during the long-term operation state, and the cost performance is low. In summary, it is necessary to improve the existing technical solution to further reduce the construction difficulty of the structure of the offshore converter station and enhance the project economy. Summary of the Invention

[0006] The technical problems to be solved by the present invention are as follows:

[0007] An offshore converter station is a super-large offshore engineering structure module, which not only needs to ensure the function realization of various electrical equipment, but also must take into account the construction feasibility and cost economy. Aiming at the deficiencies in the traditional technical solutions, the technical problems to be solved by the present invention include:

[0008] 1. The planar dimension and weight of the upper module of the offshore converter station are too large, resulting in insufficient space utilization.

[0009] 2. The large-span solid web beam has a large weight and a small stiffness, and the floor of the equipment room deforms greatly, affecting the normal use of precision equipment.

[0010] 3. The DSF set during the construction period can only provide temporary effects in the pre-service state, and is separated from the structure during the long-term in-place state, and the input-output ratio of this part of the project quantity is relatively low.

[0011] Therefore, the present invention adopts the following technical solutions:

[0012] A compact offshore converter station installed by the floating installation method, characterized in that: the compact offshore converter station installed by the floating installation method includes an upper module and a jacket. Vertical channels are arranged at the four corners of the plane of the upper module. A horizontal traffic lane is arranged at the south side, north side and middle position of the upper module respectively to form an I-shaped corridor layout. An integral bottom frame is arranged at the bottom of the upper module. The integral bottom frame serves as the beam of the main plant building, and the integral bottom frame serves as the structural conversion layer between the upper module and the jacket.

[0013] While adopting the above technical solutions, the present invention can also adopt or combine the following technical solutions:

[0014] As a preferred technical solution of the present invention: a main plant and a secondary plant are respectively arranged on the east and west sides of the lower side of the upper module. Through-type valve halls are arranged on the north and south sides in the main plant. The secondary plant is divided into three layers. A seawater cooling system is arranged on the first layer, water tanks, a fire pump room and a seawater desalination system are arranged on the second layer, and a ventilation and air conditioning system is arranged on the third layer.

[0015] As a preferred technical solution of the present invention: a DC room is arranged above the valve hall, and a partition layer is arranged below the DC outgoing bushing in the DC room to arrange a secondary equipment room.

[0016] As a preferred technical solution of the present invention: the DC room adopts an unequal height layout.

[0017] As a preferred technical solution of the present invention: One side of the secondary equipment room is the cable layer, and on the other side of the secondary equipment room, there are a relay protection room, a communication machine room, and a battery room. At the same height outside the secondary equipment room, a bridge arm reactor body is provided in the DC room. On the side wall close to the bridge arm reactor body of the relay protection room, the communication machine room, and the battery room, a truss is provided. The height of the truss is the floor height of the relay protection room, the communication machine room, and the battery room. The upper and lower chord bars of the truss are the upper and lower layer beams of the relay protection room, the communication machine room, and the battery room.

[0018] As a preferred technical solution of the present invention: In the DC room, high-voltage insulation switches, coupling transformers, and power and control equipment are arranged at positions corresponding to the cable layer above the mezzanine.

[0019] As a preferred technical solution of the present invention: The integral bottom frame includes upper chord bars, lower chord bars, vertical struts, and diagonal struts. The outer vertical struts correspond to the column positions of the upper component, and the inner vertical struts correspond to the leg positions of the jacket.

[0020] As a preferred technical solution of the present invention: A pile leg docking buffer unit is arranged inside the lower end of the vertical strut.

[0021] As a preferred technical solution of the present invention: The jacket is of a split type or an integral type.

[0022] The present invention provides a compact offshore converter station installed by the floating method, which has the following beneficial effects:

[0023] 1. The combination of the single-side auxiliary workshop layout and the DC room mezzanine layout can effectively utilize the vertical space of the DC room, so that the layout form of each floor traffic aisle can be simplified from the "return" shape to the "I" shape, that is, the requirement for one longitudinal corridor is reduced, and at the same time, the horizontal position deviation between the overall center of gravity and the geometric centroid of the structure is within an acceptable range, so that the plane transverse dimension of the upper module of the offshore converter station can be reduced by about 15 meters compared with the traditional double-side auxiliary workshop, and the steel structure weight can also be significantly reduced accordingly.

[0024] 2. After adopting the integral bottom frame technology, the structural eccentricity problem caused by the single-side auxiliary workshop layout can be solved. The bottom frame can be used as the structural conversion layer between the upper module and the lower jacket, converting the asymmetric upper structure into a symmetric vertical rod layout, so that the symmetric vertical rods correspond to the symmetric jacket structure of the lower part, and the force transmission path is more reasonable.

[0025] 3. Adopting the integral bottom frame technology can also strengthen the stiffness of the valve hall and reduce the deformation of the valve hall. The beam at the bottom of the valve hall, as the upper chord bar of the integral truss, can be reduced from the span of 30 - 40m in the traditional technology to the span of 10 - 20m, thus avoiding the setting of large-span solid web beams.

[0026] 4. By adopting the integral bottom frame technology, it can also replace the DSF in the traditional high-position floating support solution and produce additional beneficial effects. The integral bottom frame also ensures the effect of the installation height of the upper module, avoiding the one-time temporary investment in the steel consumption of 3000t - 4000t for the DSF. At the same time, by setting the LMU on the inner side of the lower end of the vertical rod, the more than ten-meter cantilever section that must be set between the upper module and the lower jacket in the traditional solution is avoided, so that there is no weak layer in the connection part, increasing the stiffness of the overall structure and reducing the relative shear deformation between the upper module and the lower jacket.

[0027] 5. Through the combined application of all the above technologies, compared with the traditional converter station, the total steel consumption (upper module + bottom frame + pile foundation) of the compact type can be reduced by more than 1000 tons. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the front view of the upper module and the split jacket of the present invention.

[0029] Figure 2 It is the first-floor plan layout of the upper module of the present invention.

[0030] Figure 3 It is the second-floor plan layout of the upper module of the present invention.

[0031] Figure 4 It is the third-floor plan layout of the upper module of the present invention.

[0032] Figure 5 It is the fourth-floor plan layout of the upper module of the present invention.

[0033] Figure 6 It is the fifth-floor plan layout of the upper module of the present invention.

[0034] Figure 7 It is the sixth-floor plan layout of the upper module of the present invention.

[0035] Figure 8 It is the front view of the upper module and the integral jacket of the present invention.

[0036] Figure 9 It is the side view of the jacket of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] To further illustrate the content, features and effects of the present invention, an embodiment is cited below and described in conjunction with the drawings as follows.

[0038] (1) As Figures 1-4As shown in the figure, the upper block of the offshore converter station is generally divided into two parts, the lower part of which is a main and a secondary plant. The north and south sides of the main plant are full-height valve halls 11; the secondary plant is divided into three floors, the first floor is equipped with a seawater cooling system 12, the second floor is equipped with a water tank 13, a fire pump room 14 and a seawater desalination system 15, and the third floor is equipped with a ventilation and air conditioning system 16.

[0039] (2) If Figures 5-7 As shown, a DC room 21 is arranged on the side above the valve hall opposite to the auxiliary plant. The DC room 21 is arranged at different heights, and a partition is arranged below the side close to the DC outlet bushing 22. The middle of the partition is connected to the cable room 23, and a passage for the DC outlet cable is reserved; the two sides are the relay room 24, the communication room 25 and the battery room 26. The relay room 24, the communication room 25 and the battery room 26 are provided with a truss structure on the wall of the side close to the bridge arm reactor body 27. The height of the truss is the floor height of the relay room 24, the communication room 25 and the battery room 26. The upper and lower chords of the truss are the upper and lower beams of the relay room 24, the communication room 25 and the battery room 26, and the truss support rods are round steel pipes. Above the cable room 23, a high-voltage insulating switch (GIS) 28, a connecting transformer 29 and matching power and control equipment 30 are arranged on the same floor as the DC outlet bushing 22.

[0040] (3) If Figures 2-7 As shown, vertical passages (staircases and elevators) 31 are arranged at the four corners of the upper block plane, and horizontal traffic passages 32-34 are arranged on the south side, the north side and the middle, thereby forming an "I"-shaped corridor layout.

[0041] The arrangement described in (1), (2) and (3) not only ensures the logical rationality of the relative positions of the functional modules used for AC to DC conversion and improves space utilization, but also allows the horizontal position of the center of gravity of the upper module to basically coincide with the geometric centroid, thereby preventing excessive eccentric loads from being generated on the lower conductor frame structure.

[0042] (4) If Figure 1 As shown, an integral bottom frame 41 is arranged at the bottom of the upper block. The integral bottom frame 41 is composed of an upper chord 42, a lower chord 43, a vertical support rod 44, and an oblique support rod 45: the integral bottom frame 41 is the beam at the bottom of the valve hall; the upper chord 42, the lower chord 43, and the vertical support rod 44 are circular steel pipes; the outer vertical support rod 44 corresponds to the position of the upper structure column, the inner vertical support rod 44 corresponds to the position of the conductor frame 51 leg, and a pile leg docking buffer unit (LMU) is arranged on the inner side of the lower end of the vertical support rod 44; the oblique support rod 45 is used to transfer the load of the upper and lower parts, and transfer the upper structure load to the conductor frame; the node position formed by the oblique support rod 45 and the lower chord rod 43 on the inner side of the conductor frame 51 corresponds to the position of the slideway support during loading and transportation, and corresponds to the situation of two slideways in this embodiment; the lower chord rod 43 is connected to the hull deck.

[0043] (5) As Figure 1 , 8 shown in Figures 51 to 9, the jacket can adopt the split form of 51 in Figure 1 or the integral form of 52 in Figure 8 , depending on different limiting conditions such as the water depth where the structure is located and the draft of the floating installation vessel. When an integral jacket structure is adopted, one side of the jacket is connected to the upper module with a row of LMU, and each row of LMU forms a single-piece jacket. To ensure the stability of the single-piece jacket and better bear the horizontal force, a row of auxiliary piles is arranged on the outside of the single-piece jacket. Two single-piece jackets are connected into a whole with a temporary support frame and installed as a whole. After the jacket is installed and the pile driving is completed, the intermediate temporary support frame is removed to form a notch for the floating-in method of the ship.

[0044] The above embodiments are only a relatively optimal technical solution of the present invention. Those skilled in the art should understand that without departing from the principle and essence of the present invention, the technical solutions or parameters in the embodiments can be modified or replaced, and all should be covered within the protection scope of the present invention.

Claims

1. A compact offshore converter station installed by the floating method, characterized in that: The compact offshore converter station installed by the floating method includes an upper module and a jacket. Vertical channels are arranged at the four corners of the plane of the upper module. A horizontal traffic lane is provided at each of the south side, north side and middle position of the upper module to form an I-shaped corridor layout. An integral bottom frame is arranged at the bottom of the upper module, and the integral bottom frame serves as the beam of the main workshop and the structural conversion layer between the upper module and the jacket. The integral bottom frame includes upper chord bars, lower chord bars, vertical struts and diagonal struts. The outer vertical struts correspond to the column positions of the upper assembly, and the inner vertical struts correspond to the leg positions of the jacket. A pile leg docking buffer unit is arranged inside the lower end of the vertical strut. One main workshop and one auxiliary workshop are respectively arranged on the east and west sides of the lower side of the upper module. Valve halls with full height are arranged on the south and north sides of the main workshop. The auxiliary workshop is divided into three layers. A seawater cooling system is arranged on the first layer, water tanks, a fire pump room and a seawater desalination system are arranged on the second layer, and a ventilation and air conditioning system is arranged on the third layer. A DC room is arranged above the valve hall, and a mezzanine is arranged below the DC room near the DC outgoing bushing to arrange the secondary equipment room. The DC room adopts an unequal height layout.

2. The compact offshore converter station installed by the floating method according to claim 1, characterized in that: One side of the secondary equipment room is a cable layer. On the other side of the secondary equipment room, there are a relay protection room, a communication machine room and a battery room. A bridge arm reactor body is arranged at the same height outside the secondary equipment room in the DC room. A truss is arranged on the wall of the relay protection room, communication machine room and battery room near the bridge arm reactor body. The height of the truss is the storey height of the relay protection room, communication machine room and battery room. The upper and lower chord bars of the truss are the upper and lower storey beams of the relay protection room, communication machine room and battery room.

3. The compact offshore converter station installed by the floating method according to claim 2, characterized in that: High-voltage insulating switches, coupling transformers and power and control equipment are arranged in the DC room at the position corresponding to the cable layer above the mezzanine.

4. The compact offshore converter station installed by the floating method according to claim 1, wherein: The jacket is of a split type or an integral type.

Images