Dry type power supply and distribution device and method applied to shallow water underwater production system

Abstract

The invention relates to a dry-type power supply and distribution device and method applied to a shallow water underwater production system, the device comprises a lower structure foundation, a main deck and an upper top cover which are sequentially arranged from bottom to top, and the lower structure foundation is provided with a supporting structure frame and a guide sleeve; a submarine cable power distribution unit, an underwater dry-type power transformation cabin, an underwater dry-type power distribution cabin and an underwater dry-type control distribution cabin are arranged on the main deck. The lower end of the submarine cable power distribution unit, the lower end of the underwater dry-type power transformation cabin, the lower end of the underwater dry-type power distribution cabin and the lower end of the underwater dry-type control distribution cabin are all provided with guide columns matched with the guide sleeves. The dry-type transformer, the switch cabinet and the frequency converter equipment are arranged in the underwater dry-type electrical cabin, so that one path of high-voltage electricity from a long distance drives each underwater electric submersible pump after being subjected to underwater voltage transformation and frequency conversion, and the requirements of oil and gas field development in a shallow sea limited area are met.

Description

Technical Field

[0001] The present invention relates to a dry-type power supply and distribution device and method applied to a shallow underwater production system, belonging to the technical field of underwater oil and gas field engineering. Background Art

[0002] In restricted areas such as the navigation channels, sensitive areas, and military zones of the Bohai Sea, since it is impossible to erect offshore oil platforms, underwater production facilities are usually used to exploit oil and gas resources, which are then connected back to fixed platforms in surrounding oil and gas fields through mixed pipelines for further processing and external transmission.

[0003] Shallow-water subsea production systems rely on power from surrounding oil and gas platforms, typically within a 20km power supply distance. Platform-mounted inverters directly drive the subsea electric submersible pumps (ESPs) through a multi-core composite submarine cable. This direct-drive approach typically limits cable lengths to 25km. However, when cable lengths exceed 30km, the high cost of composite cables and the significant voltage drop across these long cables make it difficult to meet the full-cycle operating voltage requirements of the ESPs. Consequently, subsea power transformation and distribution are required for powering and controlling the ESPs in subsea production facilities powered by long-distance power. Summary of the Invention

[0004] In response to the above technical problems, the present invention provides a dry-type power supply and distribution device and method for shallow water underwater production systems. The power distribution device configures a dry-type transformer, switch cabinet, and frequency converter equipment in an underwater dry electrical compartment to realize underwater voltage and frequency conversion of high-voltage electricity from a long distance to drive each underwater submersible pump, thereby meeting the needs of oil and gas field development in shallow sea restricted areas.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A dry-type power supply and distribution device for shallow underwater production systems, comprising:

[0007] The lower structure foundation, main deck and upper cover are arranged in sequence from bottom to top. The lower structure foundation is provided with a supporting structure frame and a guide sleeve; the upper cover is provided with an equipment lifting port;

[0008] The main deck is provided with a submarine cable power distribution unit, an underwater dry substation, an underwater dry power distribution cabin and an underwater dry control distribution cabin. The lower ends of the submarine cable power distribution unit, the underwater dry substation, the underwater dry power distribution cabin and the underwater dry control distribution cabin are all provided with guide columns adapted to the guide sleeves.

[0009] The dry power supply and distribution device applied to shallow water underwater production systems, preferably, the submarine cable power distribution unit includes a structural frame, a submarine cable terminal, a cable pass-through and a wet electrical connector, and the top of the structural frame of the submarine cable power distribution unit is provided with a mounting lug and a sacrificial anode anti-corrosion block.

[0010] The dry-type power supply and distribution device applied to shallow underwater production systems, preferably, the underwater dry-type substation adopts an elliptical container structure, the metal shell of the container can withstand the external pressure of 100 meters of seawater, and a medium-voltage switchgear, a dry-type transformer and a primary heat exchanger are placed inside it. The outside of the underwater dry-type substation is provided with a wet-type electrical connector for underwater power flying wires, and the top of the underwater dry-type substation is provided with a mounting lug, a coolant circulation pump, a coolant circulation pipeline and a sacrificial anode anti-corrosion block.

[0011] The dry power supply and distribution device applied to shallow underwater production systems, preferably, the underwater dry power distribution cabin adopts an elliptical container structure, the metal shell of the container can withstand the external pressure of 100 meters of seawater, and a low-voltage switch cabinet and a primary heat exchanger are placed inside. The outside of the underwater dry power distribution cabin is provided with a wet electrical connector of the underwater power flying line, and the top of the underwater dry power distribution cabin is equipped with a mounting lug, a coolant circulation pump, a coolant circulation pipeline and a sacrificial anode anti-corrosion block.

[0012] The dry power supply and distribution device applied to shallow underwater production systems, preferably, the underwater dry control distribution cabin adopts an elliptical container structure, the metal shell of the container can withstand the external pressure of 100 meters of seawater, and an electric submersible pump inverter and a primary heat exchanger are placed inside. The outside of the underwater dry control distribution cabin is provided with a wet electrical connector of an underwater power flying line, and the top of the underwater dry control distribution cabin is provided with a mounting lug, a coolant circulation pump, a coolant circulation pipeline and a sacrificial anode anti-corrosion block.

[0013] The dry power supply and distribution device applied to shallow water underwater production systems preferably also includes a cooling system for the underwater dry electrical compartment. The cooling system inside the underwater dry electrical compartment is configured with a coolant circulation pipeline and a primary heat exchanger, and the cooling system on the top outside the underwater dry electrical compartment is provided with a coolant circulation pipeline and a coolant circulation pump.

[0014] The dry power supply and distribution device applied to shallow water underwater production systems is preferably provided with a heat exchange coil, an inlet fan and a supply fan inside the primary heat exchanger; the inlet end of the heat exchange coil is respectively connected to the inlet side of the coolant circulation pipeline inside the underwater dry substation, the underwater dry power distribution cabin and the underwater dry control distribution cabin; the outlet end of the heat exchange coil is respectively connected to the outlet side of the coolant circulation pipeline inside the underwater dry substation, the underwater dry power distribution cabin and the underwater dry control distribution cabin.

[0015] A second aspect of the present invention provides a power supply and distribution method for a dry power supply and distribution device applied to a shallow underwater production system, comprising the following steps:

[0016] The submarine cable first enters the submarine cable terminal of the submarine cable power distribution unit, where the outer sheath and armor of the submarine cable are removed, and the independent single-phase single-core cables of the submarine cable are drawn out and connected to one end of the cable crossing device, and the other end of the cable crossing device is connected to the wet electrical connector of the submarine cable power distribution unit;

[0017] One end of the electric flying wire is connected to the wet electrical connector of the submarine cable power distribution unit, and the other end is connected to the wet electrical connector of the underwater dry-type transformer cabin. The tail end of the wet electrical connector of the underwater dry-type transformer cabin is connected to the medium-voltage switchgear through a shipboard cable. The medium-voltage switchgear is connected to the dry-type transformer through a shipboard cable or a busbar bridge to complete the conversion of the medium-voltage electricity transmitted by the platform into the low-voltage electricity required by the underwater submersible pump frequency converter. The output end of the transformer is connected to the wet electrical connector through a shipboard cable and is connected to the underwater dry-type power distribution cabin through the electric flying wire;

[0018] One end of the wet electrical connector on the incoming line side of the underwater dry power distribution cabin is connected to the electric flying lead, and the other end is connected to the incoming line cabinet of the low-voltage switch cabinet. The cable laid in the outgoing line cabinet of the low-voltage switch cabinet is connected to the wet electrical connector on the outgoing line end of the underwater dry power distribution cabin. The other end of the wet electrical connector on the outgoing line end of the underwater dry power distribution cabin is connected to the electric flying lead of the underwater dry control distribution cabin.

[0019] One end of the wet electrical connector on the inlet side of the underwater dry control distribution cabin is connected to the electric flying wire from the underwater dry power distribution cabin, and the other end is connected to the inlet end of the submersible pump inverter. The submersible pump inverter realizes frequency conversion and voltage regulation of the underwater submersible pump through rectification and inversion links. One end of the wet electrical connector on the outlet side of the underwater dry control distribution cabin is connected to the outlet end of the submersible pump inverter, and the other end is connected to the electric flying wire. The other end of the electric flying wire is connected to the underwater submersible pump to supply power to the underwater submersible pump.

[0020] A third aspect of the present invention provides a cooling method for a dry-type power supply and distribution device used in a shallow underwater production system, comprising the following steps:

[0021] The underwater dry substation, underwater dry power distribution cabin and underwater dry control distribution cabin are provided with a coolant circulation pipeline, which is filled with coolant for cooling the electrical compartment and equipment. A coolant circulation pump is provided on the top of the electrical compartment, which pumps low-temperature coolant into the coolant circulation pipeline inside the electrical compartment. The inlet side of the coolant circulation pipeline is connected to the heat exchange coil in the primary heat exchanger on the one hand, and is also connected to the liquid cooling unit of the electric submersible pump inverter on the other hand. The high-temperature gas in the electrical compartment is sent into the primary heat exchanger through the inlet fan and is cooled by the heat exchanger. The low-temperature coolant in the heat exchange coil exchanges heat to become low-temperature gas, and the low-temperature gas is sent out by the blower fan to cool the electrical compartment. The low-temperature coolant in the heat exchange coil exchanges heat with the high-temperature gas to become high-temperature coolant, and after being combined with the high-temperature coolant flowing out of the electric submersible pump inverter, it is sent to the coolant circulation pipeline outside the electrical compartment. The external coolant circulation pipeline contacts low-temperature seawater, and the heat of the high-temperature coolant is absorbed by the seawater and turned into low-temperature coolant again, and then pumped into the electrical compartment through the coolant circulation pump to cool the compartment and the internal electrical equipment.

[0022] The present invention has the following advantages due to the adoption of the above technical solution:

[0023] 1. The underwater dry substation, underwater dry power distribution cabin, and underwater dry control distribution cabin of the present invention adopt an elliptical sealed container structure, which can isolate seawater outside the container shell. The interior of the electrical cabin is a pure dry environment, and electrical equipment used in conventional dry environments can be used. At the same time, the metal shell of the container can withstand the external pressure of 100 meters of seawater. The interior of the underwater electrical cabin is filled with inert gas, which can better protect the electrical equipment in the underwater electrical cabin from oxidation and corrosion and reduce the risk of internal fire.

[0024] 2. The present invention adopts a modular design. The lower ends of the submarine cable power distribution unit, underwater dry substation, underwater dry power distribution cabin, and underwater dry control distribution cabin are all provided with guide columns, which are inserted into the guide sleeves in the lower structure foundation to achieve precise positioning and installation fixation with the lower structure foundation. When any of the cabins needs to be repaired or upgraded, the equipment lifting port of the upper cover located directly above each electrical cabin can be opened, and the electrical cabin that needs to be recovered or replaced can be lifted by the construction vessel through the lifting lugs on its top.

[0025] 3. The present invention arranges coolant circulation pipelines outside and on the top of the underwater dry substation, underwater dry power distribution cabin, and underwater dry control distribution cabin, making full use of natural low-temperature seawater to cool the cabins and internal electrical equipment of the underwater dry substation, underwater dry power distribution cabin, and underwater dry control distribution cabin. The high-temperature coolant coming out of the cabin is converted into low-temperature coolant after heat exchange with seawater. The coolant is made to flow in the circulation pipeline by a coolant circulation pump arranged on the top, and the low-temperature coolant is then pumped into the coolant circulation pipeline inside the underwater dry substation, underwater dry power distribution cabin, and underwater dry control distribution cabin. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an elevation view of an underwater dry power supply and distribution cabin provided in one embodiment of the present invention;

[0027] Figure 2 A plan view of the main deck of the underwater dry power supply and distribution cabin provided for this embodiment of the present invention;

[0028] Figure 3 A diagram of the top cover of the underwater dry power supply and distribution cabin provided in this embodiment of the present invention;

[0029] Figure 4 A connection diagram of the underwater dry power supply and distribution cabin provided in this embodiment of the present invention;

[0030] Figure 5 An internal diagram of a submarine cable power distribution unit provided in this embodiment of the present invention;

[0031] Figure 6 This is a diagram of the interior of the underwater dry-type substation provided by this embodiment of the present invention;

[0032] Figure 7 An internal diagram of the underwater dry power distribution cabin provided by this embodiment of the present invention;

[0033] Figure 8 An internal diagram of the underwater dry control distribution cabin provided by this embodiment of the present invention;

[0034] Figure 9 A diagram of the cooling system for the underwater dry power distribution cabin provided in this embodiment of the present invention;

[0035] The reference numerals in the figures are as follows:

[0036] 1-Substructure foundation; 2-Main deck; 3-Submarine cable power distribution unit; 4-Underwater dry-type transformer compartment; 5-Underwater dry-type power distribution compartment; 6-Underwater dry-type control distribution compartment; 7-Upper cover; 8-Submersible pump; 9-Submarine cable terminal; 10-Cable pass-through; 11-Wet-type electrical connector; 12-Sacrificial anode anti-corrosion block; 13-Guide column; 14-Medium-voltage switchgear; 15-Dry-type transformer; 16-Primary heat exchanger; 17-Coolant circulation pump; 18-Coolant circulation pipeline; 19-Low-voltage switchgear; 20-Submersible pump inverter; 21-Inlet fan; 22-Supply fan; 23-Heat exchange coil. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by ordinary persons in this field based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] Unless otherwise defined, the technical or scientific terms used in the present invention shall have the usual meanings understood by persons of ordinary skill in the field to which the present invention belongs. The words "first", "second", "third", "fourth" and similar terms used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

[0039] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside," "outside," "inner side," "outer side," "lower," "upper," etc. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.

[0040] Shallow-water subsea production systems rely on power from surrounding oil and gas platforms, typically within a 20km power supply distance. Platform-mounted inverters directly drive the subsea electric submersible pumps (ESPs) through a multi-core composite submarine cable. This direct-drive approach typically limits cable lengths to 25km. However, when cable lengths exceed 30km, the high cost of composite cables and the significant voltage drop across these long cables make it difficult to meet the full-cycle operating voltage requirements of the ESPs. Consequently, subsea power transformation and distribution are required for powering and controlling the ESPs in subsea production facilities powered by long-distance power.

[0041] Based on the above technical problems, the present invention provides a dry-type power supply and distribution device for shallow water underwater production systems. By configuring dry-type transformers, switch cabinets, and frequency converter equipment in the underwater dry electrical compartment, it can realize the underwater transformation and frequency conversion of high-voltage electricity from a long distance to drive each underwater submersible pump, thereby meeting the needs of oil and gas field development in shallow sea restricted areas.

[0042] like Figure 1 、 2 As shown in Figures 3 and 3, the dry-type power supply and distribution device for shallow underwater production systems involved in the present invention comprises: a lower structure foundation 1, a main deck 2 and an upper top cover 7 arranged in sequence from bottom to top, and a supporting structure frame and a guide sleeve are provided on the lower structure foundation 1; a submarine cable power distribution unit 3, an underwater dry-type substation 4, an underwater dry-type power distribution cabin 5 and an underwater dry-type control distribution cabin 6 are provided on the main deck 2, and the lower ends of the submarine cable power distribution unit 3, the underwater dry-type substation 4, the underwater dry-type power distribution cabin 5 and the underwater dry-type control distribution cabin 6 are all provided with guide columns 13 adapted to the guide sleeve.

[0043] Further, if Figure 5 As shown, the submarine cable power distribution unit 3 includes a structural frame, a submarine cable terminal 9, a cable pass-through 10 and a wet electrical connector 11. The top of the structural frame of the submarine cable power distribution unit 3 is provided with a mounting lug and a sacrificial anode anti-corrosion block 12.

[0044] Furthermore, in some preferred embodiments of the present invention, Figure 6 As shown, a medium-voltage switchgear 14, a dry-type transformer 15 and a primary heat exchanger 16 are placed inside the underwater dry-type substation cabin 4. The underwater dry-type substation cabin 4 adopts an elliptical container structure. The metal shell of the container can withstand the external pressure of 100 meters of seawater. A wet electrical connector 11 of the underwater power flying line is provided on the outside. The top of the underwater dry-type substation cabin 4 is equipped with a mounting lug, a coolant circulation pump 17, a coolant circulation pipeline 18 and a sacrificial anode anti-corrosion block 12.

[0045] Furthermore, in some preferred embodiments of the present invention, Figure 7As shown, the underwater dry power distribution cabin 5 adopts an elliptical container structure. The metal shell of the container can withstand the external pressure of 100 meters of sea water. A low-voltage switchgear 19 and a primary heat exchanger 16 are placed inside. The underwater dry power distribution cabin 5 is provided with a wet electrical connector 11 of the underwater power flying line on the outside. The top of the underwater dry power distribution cabin 5 is equipped with a mounting lug, a coolant circulation pump 17, a coolant circulation pipeline 18 and a sacrificial anode anti-corrosion block 12.

[0046] Furthermore, in some preferred embodiments of the present invention, Figure 8 As shown, the underwater dry control distribution cabin 6 adopts an elliptical container structure. The metal shell of the container can withstand the external pressure of 100 meters of seawater. An electric submersible pump inverter 20 and a primary heat exchanger 16 are placed inside. A wet electrical connector 11 of an underwater power electric flying line is provided on the outside of the underwater dry control distribution cabin 6. The top of the underwater dry control distribution cabin 6 is equipped with a mounting lug, a coolant circulation pump 17, a coolant circulation pipeline 18 and a sacrificial anode anti-corrosion block 12.

[0047] Further, if Figure 9 As shown, the dry power supply and distribution device of the present invention also includes a cooling system for the underwater dry electrical compartment. The cooling system inside the underwater dry electrical compartment is equipped with a coolant circulation pipeline 18 and a primary heat exchanger 16, and the cooling system on the top outside the underwater dry electrical compartment is provided with a coolant circulation pipeline 18 and a coolant circulation pump 17.

[0048] A second aspect of the present invention provides a power supply and distribution method for a dry power supply and distribution device applied to a shallow underwater production system, comprising the following steps:

[0049] The submarine cable first enters the submarine cable terminal 9 of the submarine cable power distribution unit 3. At the submarine cable terminal 9, the outer sheath and armor of the submarine cable are removed, and the independent single-phase single-core cables of the submarine cable are drawn out and connected to one end of the cable crossing device 10. The other end of the cable crossing device 10 is connected to the wet electrical connector 11 of the submarine cable power distribution unit 3.

[0050] One end of the electric flying wire is connected to the wet electrical connector 11 of the submarine cable power distribution unit 3, and the other end is connected to the wet electrical connector 11 of the underwater dry-type transformer cabin 4. The tail end of the wet electrical connector 11 of the underwater dry-type transformer cabin 4 is connected to the medium-voltage switch cabinet 14 through a shipboard cable. The medium-voltage switch cabinet 14 is connected to the dry-type transformer 15 through a shipboard cable or a bus bridge, completing the conversion of the medium-voltage electricity transmitted from the platform into the low-voltage electricity required by the underwater submersible pump inverter 20. The output end of the transformer is connected to the wet electrical connector 11 through a shipboard cable and is connected to the underwater dry-type power distribution cabin 5 through the electric flying wire.

[0051] One end of the incoming wet electrical connector 11 of the underwater dry power distribution cabin 5 is connected to the electric flying lead, and the other end is connected to the incoming cabinet of the low-voltage switch cabinet 19. The outgoing cabinet of the low-voltage switch cabinet 19 lays a cable that is connected to the outgoing wet electrical connector 11 of the underwater dry power distribution cabin 5. The other end of the outgoing wet electrical connector 11 of the underwater dry power distribution cabin 5 is connected to the electric flying lead of the underwater dry control distribution cabin 6.

[0052] One end of the wet electrical connector 11 on the incoming side of the underwater dry control distribution cabin 6 is connected to the electric flying wire from the underwater dry power distribution cabin 5, and the other end is connected to the incoming end of the electric submersible pump inverter 20. The electric submersible pump inverter 20 realizes frequency conversion and voltage regulation of the underwater electric submersible pump through rectification and inversion links. One end of the wet electrical connector 11 on the outgoing side of the underwater dry control distribution cabin 6 is connected to the outgoing end of the electric submersible pump inverter 20, and the other end is connected to the electric flying wire. The other end of the electric flying wire is connected to the underwater submersible pump to supply power to the underwater submersible pump.

[0053] like Figure 9 As shown, the underwater dry-type substation compartment 4, underwater dry-type power distribution compartment 5, and underwater dry-type control distribution compartment 6 are equipped with a coolant circulation pipeline 18 filled with coolant for cooling the electrical compartment and equipment. A coolant circulation pump 17 is installed on the top of the electrical compartment, pumping low-temperature coolant into the coolant circulation pipeline 18 within the underwater dry-type electrical compartment. The inlet side of the coolant circulation pipeline 18 within the underwater dry-type electrical compartment is connected to the heat exchange coil 23 within the primary heat exchanger 16 and to the liquid cooling unit of the electric submersible pump inverter 20. High-temperature gas from the underwater dry-type electrical compartment is fed into the primary heat exchanger 16 via an inlet fan 21. It exchanges heat with the low-temperature coolant in the heat exchange coil 23, converting it into low-temperature gas. The low-temperature gas is then discharged via a supply fan 22 to cool the compartment. The low-temperature coolant in the heat exchange coil 23 of the primary heat exchanger 16 exchanges heat with the high-temperature gas, turning it into high-temperature coolant. This coolant is then combined with the high-temperature coolant flowing out of the submersible pump inverter 20 and fed into the coolant circulation line 18 outside the underwater dry electrical compartment. This external coolant circulation line 18 comes into contact with low-temperature seawater, where the heat from the high-temperature coolant is absorbed by the seawater and turned back into low-temperature coolant. This coolant is then pumped back into the underwater dry electrical compartment by the coolant circulation pump 17, cooling the compartment and the electrical equipment within.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A dry power supply and distribution device used in shallow water underwater production systems, characterized in that: include: A lower structure foundation (1), a main deck (2) and an upper cover (7) are arranged in sequence from bottom to top, wherein the lower structure foundation (1) is provided with a supporting structure frame and a guide sleeve; and the upper cover (7) is provided with an equipment hoisting port; The main deck (2) is provided with a submarine cable power distribution unit (3), an underwater dry-type transformer cabin (4), an underwater dry-type power distribution cabin (5) and an underwater dry-type control distribution cabin (6); the lower ends of the submarine cable power distribution unit (3), the underwater dry-type transformer cabin (4), the underwater dry-type power distribution cabin (5) and the underwater dry-type control distribution cabin (6) are all provided with guide columns (13) adapted to the guide sleeves.

2. The dry power supply and distribution device for shallow underwater production system according to claim 1 is characterized in that: The submarine cable power distribution unit (3) comprises a structural frame, a submarine cable terminal (9), a cable pass-through (10) and a wet electrical connector (11); a mounting lug and a sacrificial anode anti-corrosion block (12) are provided on the top of the structural frame of the submarine cable power distribution unit (3).

3. The dry type power supply and distribution device for shallow water underwater production system according to claim 1 is characterized in that: The underwater dry-type transformer cabin (4) adopts an elliptical container structure, the metal shell of the container can withstand the external pressure of 100 meters of sea water, and a medium-voltage switch cabinet (14), a dry-type transformer (15) and a primary heat exchanger (16) are placed inside. The underwater dry-type transformer cabin (4) is provided with a wet-type electrical connector (11) of an underwater power electric flying line on the outside, and the top of the underwater dry-type transformer cabin (4) is provided with a mounting lug, a coolant circulation pump (17), a coolant circulation pipeline (18) and a sacrificial anode anti-corrosion block (12).

4. The dry type power supply and distribution device for shallow water underwater production system according to claim 1 is characterized in that: The underwater dry power distribution cabin (5) adopts an elliptical container structure. The metal shell of the container can withstand the external pressure of 100 meters of seawater. A low-voltage switch cabinet (19) and a primary heat exchanger (16) are placed inside. The underwater dry power distribution cabin (5) is provided with a wet electrical connector (11) of an underwater power flying line on the outside. The top of the underwater dry power distribution cabin (5) is equipped with a mounting lug, a coolant circulation pump (17), a coolant circulation pipeline (18) and a sacrificial anode anti-corrosion block (12).

5. The dry type power supply and distribution device for shallow underwater production system according to claim 1 is characterized in that: The underwater dry control distribution cabin (6) adopts an elliptical container structure. The metal shell of the container can withstand the external pressure of 100 meters of seawater. An electric submersible pump frequency converter (20) and a primary heat exchanger (16) are placed inside. A wet electrical connector (11) of an underwater power electric flying line is provided on the outside of the underwater dry control distribution cabin (6). The top of the underwater dry control distribution cabin (6) is equipped with a mounting lug, a coolant circulation pump (17), a coolant circulation pipeline (18) and a sacrificial anode anti-corrosion block (12).

6. The dry type power supply and distribution device for shallow underwater production system according to claim 1 is characterized in that: The invention also includes a cooling system for the underwater dry electrical cabin, wherein the cooling system inside the underwater dry electrical cabin is equipped with a coolant circulation pipeline (18) and a primary heat exchanger (16), and the cooling system outside the top of the underwater dry electrical cabin is provided with a coolant circulation pipeline (18) and a coolant circulation pump (17).

7. The dry power supply and distribution device for shallow underwater production system according to any one of claims 3 to 6, characterized in that: The primary heat exchanger (16) is provided with a heat exchange coil (23), an inlet fan (21) and a supply fan (22); the inlet end of the heat exchange coil (23) is respectively connected to the inlet side of the coolant circulation pipeline (18) inside the underwater dry-type transformer cabin (4), the underwater dry-type power distribution cabin (5) and the underwater dry-type control distribution cabin (6); the outlet end of the heat exchange coil (23) is respectively connected to the outlet side of the coolant circulation pipeline (18) inside the underwater dry-type transformer cabin (4), the underwater dry-type power distribution cabin (5) and the underwater dry-type control distribution cabin (6).

8. A power supply and distribution method for a dry power supply and distribution device used in a shallow underwater production system, characterized in that: The steps include: The submarine cable first enters the submarine cable terminal (9) of the submarine cable power distribution unit (3), the outer sheath and armor of the submarine cable are removed at the submarine cable terminal (9), and the independent single-phase single-core cables of the submarine cable are drawn out and connected to one end of the cable crossing device (10), and the other end of the cable crossing device (10) is connected to the wet electrical connector (11) of the submarine cable power distribution unit (3); One end of the electric flying wire is connected to the wet electric connector (11) of the submarine cable power distribution unit (3), and the other end is connected to the wet electric connector (11) of the underwater dry-type transformer cabin (4). The tail end of the wet electric connector (11) of the underwater dry-type transformer cabin (4) is connected to the medium-voltage switch cabinet (14) through a ship cable. The medium-voltage switch cabinet (14) is connected to the dry-type transformer (15) through a ship cable or a bus bridge, completing the conversion of the medium-voltage electricity transmitted by the platform into the low-voltage electricity required by the underwater submersible pump frequency converter (20). The output end of the transformer is connected to the wet electric connector (11) through a ship cable and is connected to the underwater dry-type power distribution cabin (5) through the electric flying wire. One end of the wet electric connector (11) on the incoming line side of the underwater dry power distribution cabin (5) is connected to an electric flying lead, and the other end is connected to an incoming line cabinet of a low-voltage switch cabinet (19); a cable is laid in the outgoing line cabinet of the low-voltage switch cabinet (19) and connected to the wet electric connector (11) on the outgoing line side of the underwater dry power distribution cabin (5); and the other end of the wet electric connector (11) on the outgoing line side of the underwater dry power distribution cabin (5) is connected to an electric flying lead of an underwater dry control distribution cabin (6); One end of the wet electrical connector (11) on the inlet side of the underwater dry control distribution cabin (6) is connected to the electric flying wire from the underwater dry power distribution cabin (5), and the other end is connected to the inlet end of the submersible pump frequency converter (20). The submersible pump frequency converter (20) realizes frequency conversion and voltage regulation of the underwater submersible pump through rectification and inversion links. One end of the wet electrical connector (11) on the outlet side of the underwater dry control distribution cabin (6) is connected to the outlet end of the submersible pump frequency converter (20), and the other end is connected to the electric flying wire. The other end of the electric flying wire is connected to the underwater submersible pump to supply power to the underwater submersible pump.

9. A cooling method for a dry power supply and distribution device used in a shallow underwater production system, characterized in that: The steps include: The underwater dry substation cabin (4), the underwater dry power distribution cabin (5) and the underwater dry control distribution cabin (6) are provided with a cooling liquid circulation pipeline (18), wherein the cooling liquid circulation pipeline (18) is filled with cooling liquid for cooling the electrical cabin and equipment. A cooling liquid circulation pump (17) is provided on the top of the electrical cabin, wherein the cooling liquid circulation pump (17) pumps low-temperature cooling liquid into the cooling liquid circulation pipeline (18) inside the electrical cabin. The inlet side of the cooling liquid circulation pipeline (18) is connected to the heat exchange coil (23) in the primary heat exchanger (16) on the one hand, and is also connected to the liquid cooling unit of the submersible pump inverter (20) on the other hand. The high-temperature gas in the electrical cabin is sent into the cooling liquid circulation pipeline (18) through the inlet fan (21). The primary heat exchanger (16) exchanges heat with the low-temperature coolant in the heat exchange coil (23) to become low-temperature gas, and the low-temperature gas is sent to the electrical compartment through the blower fan (22) to cool the electrical compartment. The low-temperature coolant in the heat exchange coil (23) exchanges heat with the high-temperature gas to become high-temperature coolant, and after being combined with the high-temperature coolant flowing out of the submersible pump inverter (20), it is sent to the coolant circulation pipeline (18) outside the electrical compartment. The external coolant circulation pipeline (18) contacts with low-temperature seawater. The heat of the high-temperature coolant is absorbed by the seawater and then becomes low-temperature coolant again. It is then pumped into the electrical compartment through the coolant circulation pump (17) to cool the compartment and the internal electrical equipment.

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