Marine centralized refrigeration system

Abstract

The application discloses a centralized refrigeration system on sea, which comprises a sea wind farm, a refrigeration station superconducting cable and an auxiliary power system, the sea wind farm comprises N rows of wind turbine units, N>=1, each row of wind turbine units comprises a plurality of wind driven generators arranged at intervals along a second direction; the refrigeration station is arranged in a middle area of the sea wind farm, at least two superconducting cables are arranged, and the at least two superconducting cables are sequentially connected with wind driven generators on both sides of the refrigeration station respectively, a cooling channel is arranged in the superconducting cable, an inlet end of the cooling channel is communicated with a liquid outlet, and an outlet end of the cooling channel is communicated with a liquid inlet. By arranging the refrigeration station in the middle area of the sea wind farm, installation between the superconducting cable and the wind driven generator can be facilitated, the distance between the refrigeration station and each wind driven generator is shortened, the length of the superconducting cable is shortened as much as possible, the loss of electric energy in the transmission process can be reduced, and the heat loss of the cooling medium can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of offshore wind power generation technology, and in particular to an offshore centralized refrigeration system. BACKGROUND

[0002] In recent years, offshore wind power has developed rapidly. By the end of 2021, the cumulative installed capacity of offshore wind power was 26.37 million kW. Compared with the cumulative installed capacity of onshore wind power (302 million kW), the development space of offshore wind power is huge, and it is a new main force of renewable energy generation in the future.

[0003] At present, superconducting cables are mainly used for power transmission. Compared with conventional power transmission cables, superconducting power transmission has the characteristics of large capacity, low loss, small size and light weight, and has become a large-scale power transmission technology with great potential.

[0004] Superconducting cables are usually cooled by closed liquid nitrogen forced flow circulation. The existing refrigeration methods are divided into two types, namely direct refrigeration of refrigerators and gas extraction and pressure reduction refrigeration. The refrigeration system of the refrigerator is stable and easy to maintain, but the equipment cost is high and the power consumption is high. The pressure reduction refrigeration structure is simple and easy to operate, but the liquid nitrogen consumption is large and the maintenance is difficult, and the liquid nitrogen needs to be supplemented. At present, the superconducting cable demonstration project mainly adopts the refrigerator refrigeration mode to ensure the 77K low-temperature environment of the superconducting cable. The refrigerators used for superconducting cables mainly include Stirling refrigerators, G-M refrigerators and inverse Brayton refrigerators. Safe, efficient and easy-to-maintain low-temperature refrigeration technology directly determines the long-distance efficient operation of superconducting cables, and is a key technology for promoting the industrial application of superconducting cable systems.

[0005] Compared with onshore environment, the situation of offshore wind farm is more complex, and the onshore offshore wind farm cannot be used as a reference for the construction of offshore wind farm. At present, there is a lack of research on the configuration of superconducting cable refrigeration system for the application scenario of offshore wind farm. The development process of offshore wind farm is limited by refrigeration technology, which is not conducive to the large-scale use of offshore wind farm. SUMMARY

[0006] The purpose of the embodiment of the present application is to provide an offshore centralized refrigeration system which can guide the configuration of the superconducting cable refrigeration system according to the specific layout of the offshore wind turbine, and improve the reliability of the superconducting cable refrigeration system.

[0007] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0008] An offshore centralized refrigeration system is provided, comprising:

[0009] The offshore wind farm comprises N rows of wind turbine units, N≥1, the N rows of wind turbine units are arranged at intervals along a first direction, each row of wind turbine units comprises a plurality of wind power generators arranged at intervals along a second direction, the first direction and the second direction form an angle;

[0010] The refrigeration station is arranged in a middle area of the offshore wind farm, and has a liquid outlet and a liquid inlet;

[0011] The superconducting cable is arranged at least in two, and the at least two superconducting cables are connected to the wind power generators on both sides of the refrigeration station in sequence, respectively. The superconducting cable is internally provided with a cooling channel, the inlet end of the cooling channel is communicated with the liquid outlet, the outlet end of the cooling channel is communicated with the liquid inlet, and the cooling medium flowing out of the refrigeration station sequentially cools all the wind power generators.

[0012] As a preferred solution of the offshore centralized refrigeration system, each superconducting cable has two cooling channels, the two cooling channels are a first channel and a second channel, respectively, the lengths of the first channel and the second channel extend along the length direction of the superconducting cable, when N=1, the inlet end of the first channel is communicated with the liquid outlet, the outlet end of the first channel is communicated with the inlet end of the second channel, and the outlet end of the second channel is communicated with the liquid inlet.

[0013] As a preferred solution of the offshore centralized refrigeration system, each superconducting cable has two cooling channels, the two cooling channels are a first channel and a second channel, respectively, the lengths of the first channel and the second channel extend along the length direction of the superconducting cable, when N≥2, the inlet ends of the first channel and the second channel are communicated with the liquid outlet, and the outlet ends of the first channel and the second channel are communicated with the liquid inlet.

[0014] As a preferred solution of the offshore centralized refrigeration system, when N=2, the refrigeration station is arranged at the end of the two rows of wind turbine units, and the wind power generators located at the end away from the refrigeration station in the two rows of wind turbine units are communicated through the superconducting cable.

[0015] As a preferred solution of the offshore centralized refrigeration system, when N≥3, along the first direction, the wind turbine units located at the two edges of the offshore wind farm are edge wind turbine units, and the remaining wind turbine units are center wind turbine units, and the refrigeration station is arranged at the center of the center wind turbine units.

[0016] As a preferred solution of the offshore centralized refrigeration system, a flow meter is arranged on the superconducting cable, and the flow meter is used to detect the flow of the cooling medium in the cooling channel.

[0017] As a preferred solution of the offshore centralized refrigeration system, the outlet end and the inlet end of the superconducting cable are provided with the flow meters.

[0018] As a preferred solution of the offshore centralized refrigeration system, a pressure sensor is arranged on the superconducting cable, and the pressure sensor is used to detect the pressure of the cooling medium in the cooling channel.

[0019] As a preferred solution of the offshore centralized refrigeration system, the refrigeration station comprises a controller, a main refrigeration tank and a standby refrigeration tank, the controller is in communication with the main refrigeration tank and the standby refrigeration tank respectively, the liquid inlet and the liquid outlet of the main refrigeration tank are in communication with the cooling channel respectively, and the liquid inlet and the liquid outlet of the standby refrigeration tank are in communication with the cooling channel respectively.

[0020] As a preferred solution of the offshore centralized refrigeration system, the main refrigeration tank comprises a first pump body and a refrigeration machine connected with each other, the main refrigeration tank is refrigerated by a refrigerant refrigeration principle, and the standby refrigeration tank comprises a second pump body and a vacuum pump connected with each other, the standby refrigeration tank is refrigerated by a pressure reduction refrigeration principle.

[0021] As a preferred solution of the offshore centralized refrigeration system, a temperature sensor is arranged on the superconducting cable, and the temperature sensor is used to detect the temperature along the line of the superconducting cable.

[0022] As a preferred solution of the offshore centralized refrigeration system, an auxiliary power supply system is arranged, the auxiliary power supply system is electrically connected with the refrigeration station, the auxiliary power supply system is used to provide electric energy for the refrigeration station, the auxiliary power supply system comprises a power generation device and an auxiliary power supply power electronic conversion module, and the power generation device and the auxiliary power supply power electronic conversion module are electrically connected; and / or,

[0023] The auxiliary power supply system comprises a storage battery and the auxiliary power supply power electronic conversion module, and the storage battery and the auxiliary power supply power electronic conversion module are electrically connected.

[0024] The offshore centralized refrigeration system has the following beneficial effects: by arranging the refrigeration station in the middle of the offshore wind farm, the installation between the superconducting cable and the wind turbine can be facilitated, the distance between the refrigeration station and each wind turbine is shortened, so that the length of the superconducting cable is shortened as much as possible, the loss of electric energy in the transmission process can be reduced, and the heat loss of the cooling medium can also be reduced; the problems of excessively long superconducting cable, increased heat loss of the cooling medium in circulation, poor terminal refrigeration effect and the like caused by unreasonable arrangement of the refrigeration station can be avoided, the refrigeration efficiency can be improved, and the system configuration cost can be optimized. BRIEF DESCRIPTION OF DRAWINGS

[0025] The application will be further described in detail below with reference to the accompanying drawings and examples.

[0026] Figure 1 Schematic diagram of the centralized refrigeration system on the sea for an embodiment of the application (arrows indicate the direction of cooling medium flow).

[0027] Figure 2 Schematic diagram of the centralized refrigeration system on the sea for another embodiment of the application (arrows indicate the direction of cooling medium flow).

[0028] Figure 3 Schematic diagram of the centralized refrigeration system on the sea for another embodiment of the application (arrows indicate the direction of cooling medium flow).

[0029] Figure 4 Schematic diagram of the centralized refrigeration system on the sea for another embodiment of the application (arrows indicate the direction of cooling medium flow).

[0030] Figure 5 Schematic diagram of the centralized refrigeration system on the sea for another embodiment of the application (arrows indicate the direction of cooling medium flow).

[0031] Figure 6 Schematic diagram of the cross section of the cooling channel for an embodiment of the application.

[0032] Figure 7 Schematic diagram of the cooling channel for an embodiment of the application (counterflow refrigeration mode; arrows indicate the direction of cooling medium flow).

[0033] Figure 8 Schematic diagram of the cooling channel for an embodiment of the application (counterflow refrigeration mode; arrows indicate the direction of cooling medium flow).

[0034] Figure 9 Schematic diagram of the connection of the distributed refrigeration machine and the cooling channel for an embodiment of the application (counterflow refrigeration mode; arrows indicate the direction of cooling medium flow).

[0035] Figure 10 Schematic diagram of the connection of the distributed refrigeration machine and the cooling channel for an embodiment of the application (counterflow refrigeration mode; arrows indicate the direction of cooling medium flow).

[0036] Figure 11 Schematic diagram of the auxiliary power supply system for the standby power supply of the refrigeration station for an embodiment of the application

[0037] Figure 12 Schematic diagram of the auxiliary power supply system for the standby power supply of the refrigeration station for an embodiment of the application

[0038] 1, pressure sensor; 2, wind turbine; 201, wind generator; 3, superconducting cable; 301, first channel; 302, second channel; 4, valve; 5, flow meter; 6, refrigeration station; 61, main refrigeration box; 611, refrigeration machine; 612, first pump body; 62, standby refrigeration box; 621, vacuum pump; 622, second pump body; 63, control module; 64, sensing module; 65, liquid outlet; 66, liquid inlet; 7, distributed refrigeration machine; 701, distributed refrigeration machine cryogenic components; 8, auxiliary power system; 801, wave power generation equipment; 802, solar power generation equipment; 803, battery; 804, auxiliary power power electronic conversion module; 805, auxiliary power input switch; 9, refrigeration station main power system; 901, main power switch; 902, main power power electronic conversion module. DETAILED DESCRIPTION

[0039] In order to make the technical problems solved by the present application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the embodiments of the present application will be further described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0040] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0041] As Figures 1 to 8As shown, the offshore centralized refrigeration system provided by the present application comprises an offshore wind farm, a refrigeration station 6 and superconducting cables 3. The offshore wind farm comprises N rows of wind turbine units 2, wherein N≥1, the N rows of wind turbine units 2 are arranged at intervals along a first direction, each row of wind turbine units 2 comprises a plurality of wind power generators 201 arranged at intervals along a second direction, and the first direction and the second direction form an angle. The refrigeration station 6 is arranged in a middle region of the offshore wind farm, and has a liquid outlet 65 and a liquid inlet 66. At least two superconducting cables 3 are arranged, and the at least two superconducting cables 3 are sequentially connected to the wind power generators 201 on both sides of the refrigeration station 6. The superconducting cable 3 is internally provided with a cooling channel, the inlet end of the cooling channel is in communication with the liquid outlet 65, and the outlet end of the cooling channel is in communication with the liquid inlet 66. The cooling medium discharged from the refrigeration station 6 sequentially cools and cools all the wind power generators 201. By arranging the refrigeration station 6 in the middle region of the offshore wind farm, the installation between the superconducting cable 3 and the wind power generator 201 can be facilitated, the distance between the refrigeration station 6 and each wind power generator 201 can be shortened, and thus the length of the superconducting cable 3 can be shortened as much as possible. This not only can reduce the loss of electric energy in the transmission process, but also can reduce the heat loss of the cooling medium. The present embodiment can avoid problems such as excessively long superconducting cables 3, increased heat loss of the cooling medium in circulation, poor terminal refrigeration effect and the like caused by unreasonable arrangement of the refrigeration station 6, and is conducive to improving the refrigeration efficiency and optimizing the system configuration cost.

[0042] Each superconducting cable 3 has two cooling channels, which are a first channel 301 and a second channel 302, and the lengths of the first channel 301 and the second channel 302 extend along the length direction of the superconducting cable 3.

[0043] Referring to Figure 1 and Figure 7The offshore wind farm only has a single row of wind turbine units 2, i.e., N=1. In this case, a counter-current cooling method is used to cool the wind turbine generators 201 within the offshore wind farm. The counter-current cooling method involves connecting the inlet end of the first channel 301 to the outlet 65, the outlet end of the first channel 301 to the inlet end of the second channel 302, and the outlet end of the second channel 302 to the inlet 66. The first channel 301 and the second channel 302 within the superconducting cable 3 are connected. The cooling medium in the second channel 302 flows in the opposite direction. The cooling medium flows in from the inlet of the first channel 301 and out from the outlet of the superconducting cable 3, achieving a circulating flow of the cooling medium between the superconducting cable 3 and the cooling station 6. In this embodiment, the superconducting cable 3 is arranged in a straight line along the second direction. When the cooling medium flows into the first channel 301, it can perform a first cooling effect on the wind turbine 201. When the cooling medium flows into the second channel 302, it can perform a second cooling effect on the wind turbine 201. By using counter-current cooling to cool the wind turbine 201 in an offshore wind farm with only a single row of wind turbine units 2, the length of the superconducting cable 3 can be reduced, thereby reducing power loss. Since the number of wind turbines 201 is small, the temperature difference of the cooling medium in the first channel 301 and the second channel 302 is small and does not affect the cooling effect on the wind turbine 201.

[0044] Reference Figures 2 to 4 , Figure 8 When an offshore wind farm has two or more rows of wind turbines 2 (N≥2), a co-current cooling method is used to cool the wind turbines 201 within the offshore wind farm. This co-current cooling method involves connecting the inlet ends of the first channel 301 and the second channel 302 of the superconducting cable 3 to the outlet 65, and connecting the outlet ends of the first channel 301 and the second channel 302 to the inlet 66. The cooling medium flows in the same direction within the first channel 301 and the second channel 302, and the first channel 301 and the second channel 302 are not connected. By using the co-current cooling method to cool two or more rows of wind turbines 201 in the offshore wind farm, compared to the counter-current cooling method, the co-current cooling method can shorten the flow path of the cooling medium within the superconducting cable 3, accelerate the circulation speed of the cooling medium, and improve the cooling effect of the cooling medium on the wind turbines 201. In this embodiment, the cross-section of the first channel 301 is annular, and the second channel 302 is located within the annular area of ​​the first channel 301.

[0045] Reference Figure 2, the offshore wind farm is provided with two rows of wind turbine generators 2, i.e. N = 2, the refrigeration station 6 is arranged at the end of the two rows of wind turbine generators 2, and the wind power generators 201 located at the end away from the refrigeration station 6 in the two rows of wind turbine generators 2 are connected through the superconducting cable 3. In this embodiment, along the first direction, the refrigeration station 6 is located in the middle region of the offshore wind farm, and along the second direction, the refrigeration station 6 is located at the end of the wind turbine generators 2.

[0046] When N ≥ 3, along the first direction, the wind turbine generators 2 located at the two ends of the offshore wind farm are edge wind turbine generators, and the remaining wind turbine generators 2 are central wind turbine generators, and the refrigeration station 3 is arranged at the central position of the central wind turbine generators. Referring to Figure 3 , the offshore wind farm is provided with three rows of wind turbine generators 2, and then the refrigeration station 6 is arranged at the center of the wind turbine generators 2 located in the middle. Referring to Figure 4 , the offshore wind farm is provided with five rows of wind turbine generators 2, and the refrigeration station 6 is also located at the center of the wind turbine generators 2 in the middle. When N ≥ 3, whether along the first direction or along the second direction, the refrigeration station 6 is located in the middle of the offshore wind farm, i.e. the refrigeration station 6 is arranged at the central position of the offshore wind farm; in this embodiment, the number of wind power generators 201 in the offshore wind farm is large, and arranging the refrigeration station 6 at the central position of the offshore wind farm can shorten the distance between the refrigeration station 6 and each wind power generator 201, thereby shortening the length of the superconducting cable 3 and reducing the cost.

[0047] Referring to Figure 3 and Figure 4 , according to the specific positions of the wind power generators 201, the superconducting cable 3 can be used to sequentially connect each wind power generator 201, and the length of the superconducting cable 3 can be shortened as much as possible.

[0048] In this embodiment, the valve 4 is arranged between the refrigeration station 6 and the cooling channel of the superconducting cable 3. By arranging the valve 4, the flow of the cooling medium in the cooling channel can be controlled, and the cooling operation of the wind power generator 201 can be adjusted according to the actual situation.

[0049] Further, the flow meter 5 is arranged on the superconducting cable 3, and the flow meter 5 is used to detect the flow of the cooling medium in the cooling channel. By arranging the flow meter 5, the flow of the cooling medium in the superconducting cable 3 can be judged, and in cooperation with the valve 4, the flow of the cooling medium can be adjusted according to the actual needs.

[0050] Preferably, the outlet end and the inlet end of the superconducting cable 3 are both provided with the flow meter 5. It can be understood that the offshore wind farm occupies a large area, and the length of the superconducting cable 3 is long. By arranging the flow meter 5 at the outlet end and the inlet end of the superconducting cable 3, the flow of the cooling medium in the superconducting cable 3 can be judged by comparing the flow at the outlet end and the inlet end, for example, whether a blockage occurs in the cooling channel, thereby improving the safety of the operation.

[0051] Further, the superconducting cable 3 is provided with a pressure sensor 1 for detecting the pressure of the cooling medium in the cooling channel. By providing the pressure sensor 1, the pressure in the cooling channel can be detected in real time, and the pressure difference between the inside and outside can be detected. In combination with the flow meter 5 and the valve 4, the flow of the cooling medium can be adjusted by the valve 4 to ensure that the pressure inside and outside the cooling channel is within a safe range, thereby ensuring the safety of the operation. In this embodiment, the pressure sensor 1 is provided in multiple, and the multiple pressure sensors 1 are arranged along the length direction of the cooling channel. In this way, the number of detection points can be increased, and the detection accuracy can be improved.

[0052] The provision of the pressure sensor 1 and the flow meter 5 can remotely monitor the refrigeration operation of the refrigeration station 6 on the wind turbine 201, i.e., in a centralized monitoring and control manner. This can facilitate management.

[0053] Specifically, the refrigeration station 6 includes a controller, a main refrigeration tank 61 and a backup refrigeration tank 62. The controller is in communication with the main refrigeration tank 61 and the backup refrigeration tank 62, respectively. The inlet 66 and the outlet 65 of the main refrigeration tank 61 are in communication with the cooling channel, respectively. The inlet 66 and the outlet 65 of the backup refrigeration tank 62 are in communication with the cooling channel, respectively. By providing the controller, the main refrigeration tank 61 and the backup refrigeration tank 62, under normal circumstances, the main refrigeration tank 61 can be used alone to refrigerate the cooling medium. When the main refrigeration tank 61 fails or needs to be repaired, the backup refrigeration tank 62 can be started to refrigerate and cool the cooling medium, so that the refrigeration station 6 can maintain normal operation and improve the reliability of the refrigeration operation of the refrigeration station 6. Preferably, the main refrigeration tank 61 and the backup refrigeration tank 62 use different refrigeration principles to refrigerate. In this embodiment, the main refrigeration tank 61 includes a first pump body 612 and a refrigeration machine 611 connected to each other. The main refrigeration tank 61 refrigerates by a refrigerant refrigeration principle. The first pump body 612 sends the cooling medium into the refrigeration machine 611. The refrigeration machine 611 sends the cooling medium cooled by refrigeration into the cooling channel of the superconducting cable 3. The backup refrigeration tank 62 includes a second pump body 622 and a vacuum pump 621 connected to each other. The backup refrigeration tank 62 refrigerates by a pressure reduction refrigeration principle. The second pump body 622 sends the cooling medium into the vacuum pump 621. The vacuum pump 621 cools and refrigerates the cooling medium by the pressure reduction refrigeration principle, and sends the cooled cooling medium into the cooling channel of the superconducting cable 3. By providing the main refrigeration tank 61 and the backup refrigeration tank 62 with different refrigeration principles, when the main refrigeration tank 61 fails, the backup refrigeration tank 62 can still operate normally, which makes up for the shortcomings of single refrigeration mode and improves the reliability of the refrigeration operation of the refrigeration station 6.

[0054] Currently, the superconducting cable 3 demonstration project mainly adopts the refrigeration mode of the refrigerating machine 611 to ensure that the superconducting cable 3 has a 77K low-temperature environment. The refrigerating machine 611 for the superconducting cable 3 mainly includes a Stirling refrigerating machine, a G-M refrigerating machine and an inverse Brayton refrigerating machine.

[0055] In the embodiment, the cooling medium is liquid nitrogen. Currently, the equipment structure of the pressure-reducing refrigeration principle is simple, and the operation is convenient, but the consumption of liquid nitrogen is large, and the maintenance is difficult. The pressure-reducing refrigeration is used as a standby refrigeration scheme, so that the number of standby refrigeration boxes 62 and the redundant amount of liquid nitrogen can be reduced, and the waste of standby resources can be reduced. The refrigeration station 6 adopts a refrigeration mode in which refrigeration by the refrigerating machine 611 is mainly used, and pressure-reducing refrigeration is used as a supplement. When the refrigerating machine 611 enters a maintenance period, the pressure-reducing refrigeration is used to temporarily provide cold energy to make up for the shortcomings of a single refrigeration mode, and the reliability of the refrigeration system is improved.

[0056] In the embodiment, the cooling medium is liquid nitrogen, the first pump body 612 and the second pump body 622 are liquid nitrogen pumps, the refrigeration station 6 is provided with a seawater corrosion-resistant shell, the main refrigeration box 61, the standby refrigeration box 62 and the controller are arranged in the shell, the controller includes a sensing module 64 and a control module 63, the sensing module 64 mainly monitors the working states of the first pump body 612, the second pump body 622, the valve 4, the refrigerating machine 611 and the vacuum pump 621, and transmits signals to the control module 63 to control the working of the refrigerating machine 611 and the vacuum pump 621, and transmits signals to the first pump body 612, the second pump body 622 and the valve 4 to control the inflow and outflow amounts of the cooling medium.

[0057] Further, a temperature sensor is arranged on the superconducting cable 3, and the temperature sensor is used to detect the temperature along the line of the superconducting cable 3. By arranging the temperature sensor, the working temperature of the superconducting cable 3 can be detected at any time, and the overheating phenomenon of the superconducting cable 3 can be avoided. By monitoring the temperature of the superconducting cable 3, the refrigeration condition of the refrigeration station 6 can be judged, so that refrigeration faults and other problems can be checked in time, and the overheating phenomenon of the wind turbine generator 2 can be avoided.

[0058] With reference to Figure 5 , Figure 9 and Figure 10, if three rows of wind turbines 2 are arranged in the offshore wind farm, the refrigeration station 6 is arranged at the center of the wind turbines 2 in the middle. If the length of the superconducting cable 3 connecting the edge wind turbines 2 is too long, a large temperature rise may occur along the superconducting cable 3, which threatens the safe operation of the superconducting cable 3. At this time, a plurality of distributed refrigerators 7 are arranged at the position where the temperature rise of the superconducting cable 3 is large to assist in cooling the superconducting cable 3. The distributed refrigerators 7 can use G-M refrigerator, pulse tube refrigerator, Stirling refrigerator and inverse Brayton refrigerator, and the compact Stirling refrigerator and pulse tube refrigerator are preferred. The low-temperature components 701 (such as cold head) of the distributed refrigerator 7 are connected with the cooling channel of the superconducting cable 3 and in contact with the flowing liquid nitrogen to cool it. The distributed refrigerator 7 can also be arranged as needed Figure 1 as shown in the system, and the connection of the superconducting cable 3 and the flow direction of the liquid nitrogen are as shown in Figure 9 .

[0059] Figure 11 and Figure 12 The auxiliary power supply system 8 includes power generation equipment, a storage battery 803, an auxiliary power supply power electronic conversion module 804 and an auxiliary power supply input switch 805. The power generation equipment can be wave energy power generation equipment 801, solar power generation equipment 802 or other types of power generation equipment to realize different forms of power generation and ensure the supply of electric energy. During normal operation, the refrigeration station 6 can take power from the refrigeration station main power supply system 9 when the offshore centralized refrigeration system is normally operated. The refrigeration station main power supply system 9 includes a main power supply power electronic conversion module 902 and a main power supply switch 901. The arrangement of the refrigeration station main power supply system 9 can make the refrigeration station 6 automatically close the auxiliary power supply input switch 805 to connect the auxiliary power supply system 8 to the offshore centralized refrigeration system, thereby providing uninterrupted power supply for the refrigeration station 6, and ensuring continuous power supply for the refrigeration station 6 in the case of complete removal of the wind turbine 201, thereby providing reliable support for black start after failure of the offshore wind farm. The distributed refrigerator is powered by the auxiliary power supply system 8.

[0060] In the embodiment, by selectively arranging the distributed refrigerators 7, not only the superconducting cable 3 with a large length can be assisted to cool, so as to avoid the temperature rise along the superconducting cable 3 being too high due to the superconducting cable 3 being too long, but also the cost can be not significantly increased, and the economy is high. By arranging the auxiliary power supply system 8, in the off-grid working condition of the offshore wind farm, the refrigeration station 6 and the distributed refrigerators 7 can have a reliable power source, effective refrigeration can be provided for the superconducting cable 3, the online black start of the offshore wind power system is prepared, and the reliability of the system is improved. By reasonably arranging the distributed refrigerators, the superconducting cable 3 with a long length can be assisted to cool, so as to avoid the temperature rise along the superconducting cable 3 being too high due to the superconducting cable 3 being too long, and the cost can be not significantly increased. By arranging the auxiliary power supply system 8, in the off-grid working condition of the offshore wind farm, the refrigeration station 6 and the distributed refrigerators 7 can have a reliable power source, effective refrigeration can be provided for the superconducting cable 3, the online black start of the offshore wind power system is prepared, and the reliability of the system is improved.

[0061] In the embodiment, the distributed refrigerators 7 are arranged at positions with a large temperature rise of the superconducting cable 3 with a long length. Since the internal cooling channel of the superconducting cable 3 has sufficient pressure to drive the internal cooling medium to flow, the distributed refrigerators 7 can not be arranged with a hydraulic pump or other power source to drive the cooling medium to flow.

[0062] In the description herein, it should be understood that the terms “upper”, “lower”, “left”, “right”, and the like, orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms “first”, “second”, are only used to distinguish in the description, and do not have special meanings.

[0063] In the description of the present specification, the description referring to the terms “an embodiment”, “an example” and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0064] In addition, it should be understood that although the present specification is described in terms of embodiments, each embodiment does not necessarily contain only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

[0065] The technical principles of the present application are described above in combination with specific embodiments. These descriptions are only for explaining the principles of the present application, and cannot be interpreted as limiting the protection scope of the present application in any way. Based on the explanations herein, other specific embodiments of the present application can be conceived by those skilled in the art without any creative effort, and these embodiments will all fall within the protection scope of the present application.

Claims

1. An offshore centralized refrigeration system, characterized in that, The application relates to a marine wind farm, which comprises N rows of wind generating units, N>=1, the wind generating units in each row are arranged at intervals along a first direction, each row of the wind generating units comprises a plurality of wind power generators arranged at intervals along a second direction, the first direction and the second direction form an angle; a refrigeration station is arranged in a middle area of the marine wind farm, the refrigeration station has a liquid outlet and a liquid inlet; at least two superconducting cables are arranged, the wind power generators on both sides of the refrigeration station are connected by the superconducting cables in sequence, the superconducting cables are internally provided with cooling channels, the inlet end of the cooling channels is communicated with the liquid outlet, the outlet end of the cooling channels is communicated with the liquid inlet, and the cooling medium discharged from the refrigeration station sequentially cools all the wind power generators; each superconducting cable is provided with two cooling channels, the two cooling channels are a first channel and a second channel respectively, and the lengths of the first channel and the second channel extend along the length direction of the superconducting cable. When N=1, the inlet end of the first channel is communicated with the liquid outlet, the outlet end of the first channel is communicated with the inlet end of the second channel, and the outlet end of the second channel is communicated with the liquid inlet. When N>=2, the inlet ends of the first channel and the second channel are communicated with the liquid outlet, and the outlet ends of the first channel and the second channel are communicated with the liquid inlet. When N=2, the refrigeration station is arranged at the end of the two rows of wind generating units, and the wind power generators located at the end away from the refrigeration station in the two rows of wind generating units are communicated by the superconducting cables. When N>=3, along the first direction, the wind generating units located at the two ends of the marine wind farm are edge wind generating units, and the remaining wind generating units are center wind generating units, and the refrigeration station is arranged at the center of the center wind generating units.

2. The offshore centralized refrigeration system according to claim 1, characterized in that, A flow meter is arranged on the superconducting cable, and the flow meter is used for detecting the flow of the cooling medium in the cooling channel.

3. The offshore centralized refrigeration system according to claim 1, characterized in that, The outlet end and the inlet end of the superconducting cable are provided with the flow meter.

4. The offshore centralized refrigeration system according to claim 3, characterized in that, A pressure sensor is arranged on the superconducting cable, and the pressure sensor is used for detecting the pressure of the cooling medium in the cooling channel.

5. The offshore centralized refrigeration system according to claim 3, characterized in that, The refrigeration station comprises a controller, a main refrigeration box and a standby refrigeration box, the controller is communicated with the main refrigeration box and the standby refrigeration box respectively, the liquid inlet and the liquid outlet of the main refrigeration box are communicated with the cooling channels respectively, and the liquid inlet and the liquid outlet of the standby refrigeration box are communicated with the cooling channels respectively.

6. Offshore centralized refrigeration system according to any of the claims 1-5, characterized in that, The main refrigeration box comprises a first pump body and a refrigeration machine which are connected, the main refrigeration box is refrigerated by a refrigerant refrigeration principle, the standby refrigeration box comprises a second pump body and a vacuum pump which are connected, and the standby refrigeration box is refrigerated by a pressure reduction refrigeration principle.

7. The offshore centralized refrigeration system according to claim 6, characterized in that A temperature sensor is arranged on the superconducting cable, and the temperature sensor is used for detecting the temperature of the superconducting cable along the line.

8. The offshore centralized refrigeration system according to any of the claims 1-5, characterized in that, ​ 9. The offshore centralized refrigeration system according to any of the claims 1-5, characterized in that, ​ 10. The offshore centralized refrigeration system according to claim 9, characterized in that, ​ 11. Offshore centralized refrigeration system according to any of the claims 1-5, characterized in that, ​ 12. The offshore centralized refrigeration system according to any of the claims 1-5, characterized in that, The auxiliary power supply system is electrically connected with the refrigeration station, and is used for providing electric energy for the refrigeration station. The auxiliary power supply system comprises a power generation device and an auxiliary power supply power electronic conversion module, and the power generation device and the auxiliary power supply power electronic conversion module are electrically connected. The auxiliary power supply system comprises a storage battery and the auxiliary power supply power electronic conversion module, and the storage battery and the auxiliary power supply power electronic conversion module are electrically connected.

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