Forced cooling system suitable for submarine cable landing section

Abstract

The invention discloses a forced cooling system suitable for a submarine cable landing section, a submarine cable is laid through a protection pipe during landing, one end of the protection pipe is located on the land, and the other end of the protection pipe extends into the sea; a water taking pipe is arranged at the bottom of the well, the other end of the water taking pipe is located in the sea, a water taking head is upwards arranged at the end of the in-sea side of the water taking pipe, the height of the water taking head is higher than that of the water taking well, and water is taken through pressure difference. Cooling water is sucked in from the water taking well through the water diversion piece, and the cooling water is input from the land end of the cable protection pipe and discharged from the sea end of the cable protection pipe. The controller controls the start and stop of the water diversion member and the flow and flow velocity of cooling water according to the core temperature of the submarine cable. Seawater is used as a cooling medium to cool the landing section submarine cable, and the purposes of increasing the carrying capacity of the landing section of the submarine cable and reducing the sectional area of the submarine cable are achieved. Cooling water is collected by utilizing pressure difference, so that energy is saved; the cooling water can be discharged into the sea after cooling the submarine cable, the operation energy consumption is low, and no water resource is wasted.

Description

Technical Field

[0001] The invention relates to the technical field of submarine cables, and in particular to a forced cooling system suitable for a landing section of a submarine cable. Background Art

[0002] Submarine cables are divided into the land section, landing section and submarine section. The heat dissipation conditions of the landing section are far worse than those of the submarine section and the land section, resulting in the landing section allowing only 70% of the current carrying capacity of the low sea section and the land section. Limited by the current carrying capacity bottleneck of the landing section, submarine cables have been operating at a relatively low current carrying capacity level for a long time, resulting in a waste of resources. If the current carrying capacity of submarine cables is increased by simply increasing the cross-section of submarine cables, the project cost will be greatly increased.

[0003] Therefore, a forced cooling device for the landing section of a submarine cable is proposed to improve the heat dissipation conditions of the landing section of the submarine cable and achieve the purpose of increasing the current carrying capacity of the submarine cable. Summary of the invention

[0004] The purpose of the present invention is to provide a forced cooling system suitable for the landing section of a submarine cable in view of the above-mentioned deficiencies, so as to solve the problem in the prior art that the heat dissipation conditions of the landing section are far inferior to those of the submarine section and the onshore section.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A forced cooling system for an offshore cable, comprising:

[0007] The cable protection tube has a submarine cable running inside, one end of which is located in the submarine cable working well on the land side and the other end extends into the sea;

[0008] A water intake well, which is arranged on the land side and is used to store cooling water for use by the water guide member;

[0009] A water intake pipe, one end of which is connected to the bottom of the water intake well, and the other end of which extends into the sea. A water intake head is arranged upward at the end of the water intake pipe in the sea, which is exposed from the seabed. The elevation of the water intake head is higher than the elevation of the water intake well, so that the pressure difference can be used to transport seawater to the water intake well;

[0010] A water diversion member, used to draw cooling water from a water well, input the cooling water from one end of the cable protection tube, and discharge the cooling water from the other end of the cable protection tube;

[0011] The controller is connected with the submarine cable operation and maintenance management center and the water guide component signal, and controls the start and stop of the water guide component and the cooling water flow and flow rate according to the core temperature signal of the submarine cable obtained from the submarine cable operation and maintenance management center.

[0012] Furthermore, an electric valve is provided at the connection between the water intake well and the water intake pipe, and a water level sensor is also provided in the water intake well for detecting the water level;

[0013] The controller is connected to the electric valve and the water level sensor signal, and is used to control the opening and closing of the electric valve according to the water level.

[0014] Furthermore, a water inlet hole is provided at the side wall of the landward end of the cable protection tube, and the water guide member inputs cooling water into the cable protection tube through the water inlet hole;

[0015] When the submarine cable is led out from the onshore end of the protection tube, a first sealing wire clamp is set, which is used to seal the gap between one end of the cable protection tube and the submarine cable to prevent cooling water from flowing out from the end of the cable protection tube located on the onshore side.

[0016] Furthermore, a water outlet is provided at the end of the cable protection pipe on the sea side, and a one-way valve is provided on the water outlet, and the one-way valve is used to discharge waste water into the sea and can prevent silt from flowing back into the cable protection pipe;

[0017] When the submarine cable is led out from the end of the protection tube in the sea, a second sealing wire clamp is provided, which is used to seal the gap between the end of the cable protection tube extending into the sea and the submarine cable to prevent silt from entering the cable protection tube.

[0018] Furthermore, the water diversion member comprises:

[0019] A water pump, wherein the water pump is provided with a water inlet pipe and a water outlet pipe, and is used to draw cooling water from a water well and input the cooling water from a water inlet hole in the cable protection tube;

[0020] The inlet end of the water inlet pipe of the water pump is connected with a filter screen for filtering mud and shellfish in the seawater;

[0021] The water intake pump is connected to the controller signal, and the flow rate and flow velocity of the cooling water are adjusted by the controller;

[0022] The energy supply component provides power for the water intake pump and is a permanent fixed power supply or a combination of a solar power generation device and a battery.

[0023] Furthermore, the cable protection pipe, water intake pipe and water guide parts are made of bidirectional stainless steel or other composite materials with corrosion properties.

[0024] The beneficial effects of the present invention are embodied in:

[0025] The present invention uses seawater as a cooling medium to cool the submarine cable at the landing section, thereby overcoming the problem that the heat dissipation condition of the landing section is far inferior to that of the submarine section and the onshore section under the prior art, and effectively increasing the transmission power of the submarine cable; the elevation of the water intake well is set to be lower than the elevation of the water intake head, and the cooling water is collected by using the pressure difference, which is beneficial to saving energy; the water outlet end of the cable protection pipe is set above the seabed, so that the cooling water can be discharged into the sea after the submarine cable is cooled, without causing pollution and waste of water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the overall structure of a forced cooling system suitable for a landing section of a submarine cable according to the present invention;

[0027] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0028] Figure 3 for Figure 1 Enlarged view of point B in the middle;

[0029] Figure 4 for Figure 1 Enlarged view of point C in the middle;

[0030] Figure 5 The effect of cooling water flow rate on the current carrying capacity of the landing section of the submarine cable.

[0031] In the figure:

[0032] 1. Submarine cables;

[0033] 2. Water well;

[0034] 3. Water intake pipe; 31. Water intake head;

[0035] 4. Submarine cable working well;

[0036] 5. Water diversion parts; 51. Water intake pump; 52. Water inlet pipe; 521. Filter; 53. Water outlet pipe; 54. Energy supply parts; 541. Fixed power supply; 542. Solar power generation device; 543. Battery;

[0037] 6. Cable protection tube; 61. Water inlet; 62. First plugging wire clamp; 63. Water outlet; 64. One-way valve; 65. Second plugging wire clamp;

[0038] 7. Controller;

[0039] 8. Electric valve;

[0040] 9. Water level sensor. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. In the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] Embodiment 1:

[0043] See also Figure 1-4 The present invention discloses a forced cooling system suitable for a landing section of a submarine cable 1, comprising:

[0044] A cable protection tube 6 is sleeved outside the submarine cable 1, one end of the cable protection tube 6 is located in the working well of the submarine cable 1 on the land side, and the other end extends into the sea;

[0045] A water intake well 2 is provided on the land side (i.e., the side of the land), and the bottom height of the water intake well 2 is lower than the height of the seabed, and is used to store cooling water;

[0046] A water intake pipe 3, one end of which is connected to the bottom of the water intake well 2, and the other end of which extends into the sea. A water intake head 31 is arranged upward at one end of the water intake pipe 3 located in the sea, and is exposed from the seabed. The elevation of the water intake head 31 is higher than that of the water intake well 2, so that the pressure difference can be used to transport seawater to the water intake well 2;

[0047] The water diversion member 5 is used to draw cooling water from the water intake well 2, input the cooling water from the land side of the cable protection pipe 6, and discharge the cooling water from the sea side of the cable protection pipe 6;

[0048] The controller 7 is connected with the signal of the submarine cable 1 operation and maintenance management center and the water guide component 5, and controls the start and stop of the water guide component 5 and the flow rate and velocity of cooling water according to the core temperature signal of the submarine cable 1 obtained from the submarine cable 1 operation and maintenance management center (the submarine cable 1 usually has a temperature-sensing optical fiber inside, and the submarine cable 1 operation and maintenance management center can measure the core temperature of the submarine cable 1 in real time).

[0049] In one embodiment, an electric valve 8 is provided at the connection between the water well 2 and the water intake pipe 3, and a water level sensor 9 is also provided in the water well 2 for detecting the water level;

[0050] The controller 7 is connected to the electric valve 8 and the water level sensor 9 for controlling the opening and closing of the electric valve 8 according to the water level. Since there is silt and shellfish in the seawater, the electric valve 8 can be closed to facilitate regular cleaning of the water well 2.

[0051] In one embodiment, a water inlet hole 61 is provided at the side wall of the upper end of the cable protection tube 6, and the water guide member 5 inputs cooling water into the cable protection tube 6 through the water inlet hole 61;

[0052] When the submarine cable 1 is led out from the onshore end of the protection tube, a first plugging clamp 62 is provided to seal the gap between the submarine cable 1 and the protection tube to prevent cooling water from flowing out from the onshore end of the protection tube.

[0053] In one embodiment, a water outlet 63 is provided at the side wall of the end of the cable protection tube 6 located in the sea, and a one-way valve 64 is provided on the water outlet 63. The one-way valve 64 is used to discharge the cooled waste water into the sea and prevent sludge from flowing back into the cable protection tube 6.

[0054] When the submarine cable 1 is led out from the underwater end of the cable protection tube 6 , a second sealing wire clamp 65 is provided to seal the gap between the submarine cable 1 and the cable protection tube 6 to prevent silt and gravel from flowing back and causing blockage of the cable protection tube 6 .

[0055] It should be pointed out that the first blocking wire clamp 62 and the second blocking wire clamp 65 are both common knowledge to technicians in the field of cable lines and are components that can be purchased on the market, so their specific structures are not described in detail here.

[0056] In one embodiment, the water guide member 5 comprises:

[0057] A water pump 51, wherein the water pump 51 is provided with a water inlet pipe 52 and a water outlet pipe 53, wherein the water inlet pipe 52 is connected to the water well 2, and the water outlet pipe 53 is connected to the water inlet hole 61 of the cable protection tube 6;

[0058] The inlet end of the water inlet pipe 52 is connected to a filter screen 521 for filtering mud and shellfish in the seawater;

[0059] The water intake pump 51 is electrically connected to the controller 7, and the flow rate and flow velocity of the cooling water are adjusted by the controller 7;

[0060] The energy supply component 54 provides power to the water intake pump 51 and is a combination of a fixed power supply 541 or a solar power generation device 542 and a battery 543 .

[0061] In this embodiment, since the submarine cable 1 is often installed in a remote place, there may be no permanent power supply nearby. However, there is abundant solar energy near the submarine cable 1. Therefore, the energy supply element 54 is set as a combination of a solar power generation device 542 (such as a photovoltaic panel) and a battery 543, which is conducive to energy conservation.

[0062] In one embodiment, the cable protection tube 6, the water intake pipe 3 and the water guide member 5 are made of bidirectional stainless steel or other composite materials with corrosion resistance. With this design, key parts will not be corroded by seawater. Preferably, other composite materials with corrosion resistance include Hastelloy, nickel-molybdenum alloy, copper-nickel alloy, etc.

[0063] In this embodiment, the water level sensor 9 detects the water level in the water well 2 in real time. When the water level in the water well 2 does not reach the preset range, the water guide 5 will not be started, so as to avoid mechanical damage and energy waste caused by the use of the water guide 5 under waterless conditions. When the water level sensor 9 detects that the water level in the water well 2 reaches the preset range and the temperature of the submarine cable 1 reaches the preset threshold, the controller 7 controls the water guide 5 to start working, inputs the cooling water in the water well 2 from the water inlet 61 of the cable protection tube 6, and discharges it from the water outlet 63 of the cable protection tube 6, thereby cooling the submarine cable 1. In this embodiment, when the temperature of the submarine cable core is lower than the allowable value, the cooling device does not work, thereby extending the service life of the device.

[0064] The present invention uses seawater as a cooling medium to cool the submarine cable 1 at the landing section, thereby overcoming the problem that the heat dissipation condition of the landing section is far inferior to that of the submarine section and the land section under the existing technical conditions, and effectively increasing the transmission power of the submarine cable 1; the elevation of the water intake well 2 is set to be lower than the elevation of the water intake head 31, and the cooling water is collected by using the pressure difference, which is conducive to saving energy; the water outlet end of the cable protection pipe 6 is set above the seabed, so that the cooling water can be discharged into the sea after the submarine cable 1 is cooled, and no water resource waste is caused.

[0065] Embodiment 2:

[0066] See also Figure 5 :

[0067] 220kV, three-core 3×630mm2 submarine cables have been widely used in offshore wind power transmission projects. The effectiveness of the present invention is verified by using this type of submarine cable. The boundary conditions of the landing section are as follows:

[0068] 220kV, three-core 3×630mm2 submarine cable, cable model HYJQF71-F-127 / 220-3×630, landing section soil thermal resistance coefficient 1.0C·m / W, maximum burial depth 35 meters, soil temperature 25℃, and the maximum allowable fiber core temperature of the submarine cable is 90℃.

[0069] The cable protection tube is made of stainless steel tube with an inner diameter of 800mm and a wall thickness of 12mm.

[0070] When the cooling system is not started, there is air between the submarine cable and the cable protection tube. Under this condition, the maximum current carrying capacity is 730A.

[0071] After starting the water pump to fill the cable protection tube with water, the heat dissipation conditions of the landing section of the submarine cable were greatly improved, and the maximum current carrying capacity was 790A.

[0072] The water pump flow rate has a great influence on the heat dissipation conditions and current carrying capacity of the submarine cable. When the water flow rate is not considered, the current carrying capacity of the submarine cable is increased from 730A to 790A, an increase of 8.2%. Considering a small water flow rate, for example: when the water flow rate is 0.001m / s, the current carrying capacity of the submarine cable can be increased by 11.74%; when the water flow rate increases to 1m / s, the current carrying capacity of the submarine cable can be increased by 12.84%. At this time, the cooling device proposed by the present invention has an obvious saturation trend in improving the current carrying capacity of the submarine cable.

[0073] In addition to the flow rate, the cooling water temperature has a great influence on the increase in the current carrying capacity of the submarine cable. Considering that the present invention uses seawater as cooling water, the seawater temperature is determined by the natural ambient temperature and cannot be adjusted in this invention, the effect of the cooling water temperature on the increase in the current carrying capacity is not analyzed in this embodiment.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0075] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0076] In addition, the meaning of "and / or" appearing in the full text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0077] In addition, "plurality" means two or more.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A forced cooling system suitable for the landing section of a submarine cable, characterized in that: include: A cable protection tube (6) is sleeved outside the submarine cable (1), one end of the cable protection tube (6) is located in the submarine cable working well (4) on the land side, and the other end extends into the sea; A water well (2), located on the land side, for storing cooling water; A water intake pipe (3), one end of which is connected to the bottom of the water intake well (2), and the other end of which extends into the sea. A water intake head (31) is arranged upwardly at the end of the water intake pipe in the sea to expose the seabed. The elevation of the water intake head (31) is higher than the elevation of the water intake well (2), and the seawater is transported to the water intake well (2) by using the pressure difference. A water diversion member (5) is used to draw cooling water from the water intake well (2), input the cooling water from the land side of the cable protection pipe (6), and discharge the cooling water from the sea side of the cable protection pipe (6); The controller (7) is connected to the submarine cable operation and maintenance management center and the water guide component (5) by signal, and controls the start and stop of the water guide component (5) and the flow rate and velocity of cooling water according to the core temperature signal of the submarine cable (1) obtained from the submarine cable operation and maintenance management center.

2. The forced cooling system for the landing section of a submarine cable according to claim 1 is characterized in that: An electric valve (8) is provided at the connection between the water intake well (2) and the water intake pipe (3), and a water level sensor (9) is also provided in the water intake well (2) for detecting the water level; The controller (7) is signal-connected to the electric valve (8) and the water level sensor (9) and is used to control the opening and closing of the electric valve (8) according to the water level.

3. The forced cooling system applicable to the landing section of a submarine cable according to claim 1 or 2, characterized in that: A water inlet hole (61) is provided at the side wall of the landward end of the cable protection tube (6), and the water guide member (5) inputs cooling water into the cable protection tube (6) through the water inlet hole (61); When the submarine cable (1) is led out from the onshore end of the protection tube (6), a first plugging clamp (62) is provided to seal the gap between the submarine cable (1) and the protection tube (6) to prevent cooling water from flowing out from the onshore end of the protection tube (6).

4. The forced cooling system applicable to the landing section of a submarine cable according to claim 1 or 2, characterized in that: A water outlet hole (63) is provided on the side wall of the end portion of the cable protection tube (6) in the sea, and a one-way valve (64) is provided on the water outlet hole (63). The one-way valve (64) is used to discharge the cooled waste water into the sea and can prevent sludge from flowing back into the cable protection tube (6); When the submarine cable (1) is led out from the underwater end of the cable protection tube (6), a second plugging wire clamp (65) is provided to seal the gap between the submarine cable (1) and the cable protection tube (6) to prevent silt and gravel from flowing back and causing blockage of the cable protection tube (6).

5. The forced cooling system for the landing section of a submarine cable according to claim 3 is characterized in that: The water guide member (5) comprises: A water intake pump (51), the water intake pump being provided with a water inlet pipe (52) and a water outlet pipe (53), the water inlet pipe (52) being connected to the water intake well (2), and the water outlet pipe (53) being connected to the water inlet hole (61) of the cable protection pipe (6); The inlet end of the water inlet pipe (52) is connected to a filter screen (521) for filtering mud and shellfish in the seawater; The water intake pump (51) and the controller (7) are electrically connected, and the flow rate and flow velocity of the cooling water are adjusted by the controller (7); The energy supply component (54) provides power to the water intake pump (51) and is a combination of a fixed power supply (541) or a solar power generation device (542) and a storage battery (543).

6. The forced cooling system applicable to the landing section of a submarine cable according to claim 1 or 2, characterized in that: The cable protection tube (6), the water intake pipe (3) and the water guide member (5) are made of bidirectional stainless steel or other composite materials with corrosion resistance.

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