Low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system for superconducting energy storage

Abstract

This invention relates to the field of cryogenic technology for superconducting magnets, specifically to a low-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage. The system includes: a double-layer vacuum helium input tube; a multi-channel shunt, the inlet of which is connected to the double-layer vacuum helium input tube, and the multi-channel shunt being arc-shaped; and a concentric solenoid coil assembly, connected to the outlet of the multi-channel shunt. The center of the multi-channel shunt and the center of the concentric solenoid coil assembly are located on the same axis. The helium forced flow from the double-layer vacuum helium input tube is shunted by the multi-channel shunt and flows radially into the concentric solenoid coil assembly, thereby solving the problem of deviation between the helium flow direction and the conductor's travel direction. This further improves the inconsistent inlet temperature of individual coils, optimizes the inconsistent helium pressure drop during long-distance, multi-layer, single-coil cooling, and ultimately reduces the critical temperature and improves the critical characteristics of the energy storage magnet.

Description

Technical Field

[0001] This invention relates to the field of cryogenic technology for superconducting magnets, and particularly to a low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage. Background Technology

[0002] Superconducting energy storage utilizes the low-loss and fast-response capabilities of superconducting magnets to store energy. It is a fast-response device that interfaces with the power system through a modern power electronic converter, capable of both storing (rectifying) and releasing (inverting) electrical energy. It leverages the zero-resistance characteristic of superconductors, allowing for lossless energy storage within superconducting inductors. This enables large-capacity energy storage, improved power quality, and increased system capacity. Furthermore, it allows for rapid exchange of active and reactive power with external systems via power electronic converters, enhancing overall power system stability and power quality. It typically consists of a superconducting coil, cryogenic container, refrigeration unit, converter, and monitoring and control system components. Superconducting energy storage offers numerous advantages, including high power output, light weight, small size, low loss, and fast response, making it widely applicable. For example, high-power lasers require the extraction of thousands or even tens of thousands of joules of energy instantaneously, which can be handled by superconducting energy storage devices. Superconducting energy storage can also be used in power grids. When the load on the power grid is low, the excess electrical energy is stored, and when the load is high, the electrical energy is sent back to the grid. This can avoid supply and demand imbalances during peak and off-peak electricity consumption periods.

[0003] The cryogenic system, a crucial component of this superconducting energy storage magnet, provides the necessary cryogenic environment for its various cryogenic parts. The entire cryogenic system is complex, involving a 4.2K / 3.5bar helium forced flow. In superconducting energy storage using helium forced flow, friction between internal fluid components and between the fluid and the pipe wall consumes energy, resulting in pressure drops along the flow path. When the fluid flows through pipe fittings with inconsistent flow directions and velocities, localized vortices and impacts are generated due to these deviations, further consuming energy and causing localized pressure drops. This leads to inconsistent helium pressure drops during the cooling process. Summary of the Invention

[0004] The purpose of this invention is to provide a low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system and method for superconducting energy storage, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, one aspect of the present invention provides the following technical solution:

[0006] A low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage includes:

[0007] Double-layer vacuum helium input tube;

[0008] A multi-channel splitter, wherein the inlet of the multi-channel splitter is connected to the double-layer vacuum helium input tube, and the multi-channel splitter is arc-shaped;

[0009] A concentric solenoid coil assembly is connected to the outlet of the multi-channel shunt, and the center of the multi-channel shunt and the center of the concentric solenoid coil assembly are located on the same axis.

[0010] Preferably, the double-layer vacuum helium input tube comprises:

[0011] External Dewar connection piping;

[0012] An internal helium tube channel is provided inside the external Dewar connection pipe, and a vacuum environment exists between the internal helium tube channel and the external Dewar connection pipe;

[0013] A helium forced flow inlet pipe, which is connected to the bottom of the internal helium tube channel.

[0014] Preferably, the double-layer vacuum helium input tube further includes a helium inlet sealing flange, which is welded to the bottom of the internal helium tube channel and sealed with polytetrafluoroethylene.

[0015] Preferably, the multi-channel splitter includes:

[0016] A helium forced flow inlet, wherein the helium forced flow inlet is connected to the helium forced flow inlet pipe;

[0017] A cold storage block, wherein the helium forced flow inlet is located at the upper end of the cold storage block, and the cold storage block divides and cools the helium forced flow;

[0018] Multiple L-shaped flow divider pipes, the inlets of which are connected to the cold storage block, are arranged radially along the multi-channel flow divider;

[0019] A constant temperature difference balance block, wherein the outlets of the plurality of L-shaped diversion regulating pipes are connected to the constant temperature difference balance block;

[0020] Multiple helium forced flow diversion outlets are provided on the side of the constant temperature difference balance block facing the concentric solenoid coil assembly, and the multiple helium forced flow diversion outlets correspond to the multiple L-shaped diversion regulating tubes.

[0021] Preferably, the multi-channel distributor further includes a finned cooling strip, the two ends of which are connected to the cold storage block and the constant temperature difference balance block, respectively.

[0022] Preferably, the concentric solenoid coil assembly includes:

[0023] Multiple single-coil inlet pipes, the inlets of which are respectively connected to the multiple helium forced flow split outlets, and the multiple single-coil inlet pipes are arranged radially along the concentric solenoid coil assembly;

[0024] Multiple solenoid superconducting coils are arranged concentrically in multiple layers, and the inlets at the bottom of the multiple solenoid superconducting coils are respectively connected to the outlets of the multiple single coil inlet pipes;

[0025] Multiple single-coil outlet pipes are provided, with the outlets at the top of the multiple solenoid superconducting coils respectively connected to the inlets of the multiple single-coil outlet pipes, and the multiple single-coil outlet pipes are spaced 15° apart.

[0026] Preferably, the multiple single-coil outlet pipelines are equipped with cryogenic valves and flow meters.

[0027] Compared with the prior art, the beneficial effects of the present invention are:

[0028] The superconducting energy storage low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system provided by the embodiments of the present invention, by concentrically arranging the multi-channel shunt and the concentric solenoid coil assembly, and arranging multiple L-shaped shunt regulating pipes and multiple single-coil inlet pipes along the radial direction of the concentric solenoid coil assembly, allows the helium forced flow input from the double-layer vacuum helium input pipe to flow radially into the concentric solenoid coil assembly after being shunt by the multi-channel shunt. This solves the problem of deviation between the helium flow direction and the conductor along the path direction, further improves the inconsistency of the inlet temperature of a single coil, optimizes the problem of inconsistent helium flow pressure drop during long-distance multi-layer single-coil cooling, and ultimately reduces the critical temperature and improves the critical characteristics of the energy storage magnet. Attached Figure Description

[0029] Figure 1 A schematic diagram of the structure of a low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system for superconducting energy storage provided for an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of the structure of the double-layer vacuum helium input tube of the low flow resistance constant temperature difference multi-channel single-cycle helium forced flow cryogenic system for superconducting energy storage provided by the embodiments of the present invention.

[0031] Figure 3 A schematic diagram of the structure of the multi-channel shunt of the low flow resistance constant temperature difference multi-channel single-cycle helium forced flow cryogenic system for superconducting energy storage provided for an embodiment of the present invention.

[0032] Figure 4 A schematic diagram of the concentric solenoid coil assembly of a low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system for superconducting energy storage, provided for an embodiment of the present invention.

[0033] In the diagram: 1. Double-layer vacuum helium input pipe; 11. External Dewar connection pipe; 12. Internal helium pipe channel; 13. Helium inlet sealing flange; 14. Helium forced flow inlet pipe; 2. Multi-channel distributor; 21. Helium forced flow inlet; 22. Cold storage block; 23. Multiple L-shaped flow regulating pipes; 24. Constant temperature difference balance block; 25. Helium forced flow outlet; 26. Finned cooling strip; 3. Concentric solenoid coil assembly; 31. Multiple single-coil inlet pipes; 32. Multiple solenoid superconducting coils; 33. Multiple single-coil outlet pipes; 34. Cryogenic valve; 35. Flow meter. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Figure 1 A schematic diagram of a low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage, provided as an embodiment of the present invention. The embodiments of the present invention provide a low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage, such as... Figure 1 As shown, it includes:

[0036] Double-layer vacuum helium input tube 1;

[0037] Multi-channel splitter 2, the inlet of multi-channel splitter 2 is connected to double-layer vacuum helium input tube 1, and the shape of multi-channel splitter 2 is arc-shaped;

[0038] The concentric solenoid coil assembly 3 is connected to the outlet of the multi-channel splitter 2. The center of the multi-channel splitter 2 and the center of the concentric solenoid coil assembly 3 are located on the same axis. The helium forced flow input by the double-layer vacuum helium input tube 1 is split by the multi-channel splitter 2 and flows into the radial direction of the concentric solenoid coil assembly 3.

[0039] The superconducting energy storage low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system provided by the present invention solves the problem of deviation between the helium flow direction and the conductor along the path direction by allowing the helium forced flow input from the double-layer vacuum helium input tube 1 to be split by the multi-channel splitter 2 and then flow radially into the concentric solenoid coil assembly 3. This further improves the inconsistent inlet temperature of a single coil, optimizes the inconsistent change of helium flow pressure drop during long-distance multi-layer single coil cooling, and ultimately reduces the critical temperature and improves the critical characteristics of the energy storage magnet.

[0040] Figure 2A schematic diagram of the double-layer vacuum helium input tube of a low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage provided by an embodiment of the present invention. In one embodiment of the present invention, as... Figure 2 As shown, the double-layer vacuum helium input tube 1 of the low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system for superconducting energy storage may include:

[0041] External Dewar connection pipe 11;

[0042] An internal helium tube channel 12 is located inside the external Dewar connection pipe 11, and a vacuum environment exists between the internal helium tube channel 12 and the external Dewar connection pipe 11.

[0043] The helium forced flow inlet pipe 14 is connected to the bottom of the internal helium tube channel 12.

[0044] Through the above technical solution, the vacuum level between the external Dewar connecting pipe 11 and the internal helium tube channel 12 in the double-layer vacuum helium input tube 1 of the present invention is the same as that of the external vacuum Dewar, forming a vacuum interlayer. A helium infusion tube can be inserted into the internal helium tube channel 12 to form a double-layer vacuum. The helium forced flow inlet pipe 14 has a relatively long length, thereby extending to the bottom of the concentric solenoid coil assembly 3 to enter the helium forced flow. In this way, the influence of the lower density of helium than that of air is utilized to reduce the inlet pressure and form a stable inlet temperature.

[0045] Furthermore, such as Figure 2 As shown, the double-layer vacuum helium input pipe 1 of the low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system for superconducting energy storage also includes a helium inlet sealing flange 13. The helium inlet sealing flange 13 is welded to the bottom of the internal helium pipe channel 12 and sealed with polytetrafluoroethylene (PTFE). The use of PTFE to seal the helium inlet sealing flange 13 ensures that helium forced flow does not leak.

[0046] Figure 3 A schematic diagram of the structure of a multi-channel shunt in a low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage, provided for an embodiment of the present invention. In one embodiment of the present invention, as... Figure 3 As shown, the multi-channel shunt 2 of the low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system for superconducting energy storage may include:

[0047] Helium forced flow inlet 21 is connected to helium forced flow inlet pipe 14;

[0048] The cold storage block 22 has a helium forced flow inlet 21 located at the upper end of it, and the cold storage block 22 has a hollow structure.

[0049] Multiple L-shaped diversion regulating pipes 23 are connected to the inlet of the multiple L-shaped diversion regulating pipes 23 and are arranged radially along the multi-channel diverter 2.

[0050] The outlets of multiple L-shaped diversion regulating pipes 23 are connected to the constant temperature difference balance block 24.

[0051] Multiple helium forced flow diversion outlets 25 are located on the side of the constant temperature difference balance block 24 facing the concentric solenoid coil assembly 3, and the multiple helium forced flow diversion outlets 25 correspond to multiple L-shaped diversion regulating tubes 23.

[0052] The superconducting energy storage low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced flow cryogenic system provided by the embodiments of the present invention receives helium forced flow through a double-layer vacuum helium input pipe 1. The helium forced flow enters from the helium forced flow inlet pipe 14, flows through the helium forced flow inlet 21 into the cold storage block 22, is split by multiple L-shaped flow-splitting pipes 23, flows through the constant-temperature-difference balance block 24 to multiple helium forced flow split outlets 25, and then flows into the concentric solenoid coil assembly 3. The multiple L-shaped flow-splitting pipes 23 serve as a connecting and transport mechanism between the helium forced flow inlet 21 and the concentric solenoid coil assembly 3. The function is that, because multiple L-shaped flow regulating pipes 23 are arranged radially along the multi-channel flow divider 2, the direction of the helium forced flow can be adjusted to enter the concentric solenoid coil assembly 3 perpendicularly. The constant temperature difference balance block 24 provides a balance channel when the pipeline is split and the diameter changes, preventing a sharp rise in pressure, ensuring the temperature of the helium forced flow entering the single coil, balancing the temperature of each helium flow to be consistent, and reducing the temperature difference. Multiple helium forced flow split outlets 25 are connected to the concentric solenoid coil assembly 3 to ensure that the direction of the helium flow is perpendicular to the pipeline cross-section, and to provide the maximum mass flow of helium at the inlet.

[0053] Furthermore, such as Figure 3 As shown, the multi-channel splitter 2 of the low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system for superconducting energy storage also includes a finned cooling strip 26. The two ends of the finned cooling strip 26 are connected to a cold storage block 22 and a constant-temperature-difference balance block 24, respectively. The finned cooling strip 26 connects the cold storage block 22 and the constant-temperature-difference balance block 24 to prevent eddy currents from forming between the cooling structures, thus preventing AC losses.

[0054] Figure 4 A schematic diagram of the concentric solenoid coil assembly of a low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage is provided for an embodiment of the present invention. In one embodiment of the present invention, as shown... Figure 4 As shown, the concentric solenoid coil assembly 3 of the low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system for superconducting energy storage may include:

[0055] Multiple single-coil inlet pipes 31 are connected to multiple helium forced flow split outlets 25 respectively, and the multiple single-coil inlet pipes 31 are arranged radially along the concentric solenoid coil assembly 3.

[0056] Multiple solenoid superconducting coils 32 are arranged concentrically in multiple layers, and the inlets at the bottom of the multiple solenoid superconducting coils 32 are respectively connected to the outlets of the multiple single coil inlet pipes 31.

[0057] Multiple single-coil outlet pipes 33 are provided, and the outlets at the top of multiple solenoid superconducting coils 32 are respectively connected to the inlets of multiple single-coil outlet pipes 33. The multiple single-coil outlet pipes 33 are set at 15° intervals.

[0058] Through the above technical solution, the helium flow from multiple helium flow diversion outlets 25 flows into the inlets at the bottom of multiple solenoid superconducting coils 32 through multiple single-coil inlet pipes 31, and then flows into the single-coil outlet pipes 33 from the top outlets of the multiple solenoid superconducting coils 32, thus completing a single-cycle cryogenic cooling. The multiple single-coil inlet pipes 31 are arranged radially along the concentric solenoid coil assembly 3, which can balance the deviation of the helium flow direction and the conductor along the flow direction, further improving the inconsistency of the inlet temperature of individual coils. The multiple single-coil outlet pipes 33 are arranged at 15° intervals, which allows for the serial adjustment of the mass flow rate of the cooling medium according to the actual situation, further improving the stability and safety of the single coil temperature difference level.

[0059] Furthermore, such as Figure 4 As shown, the multiple single-coil outlet pipes 33 of the low-flow-resistance constant-temperature-difference multi-channel single-cycle helium forced-flow cryogenic system for superconducting energy storage are equipped with cryogenic valves 34 and flow meters 35. The solenoid superconducting coil 32, while meeting the temperature margin requirement, primarily depends on the process complexity of the achievable liquid helium temperature range. Since the boiling point of liquid helium at atmospheric pressure is 4.2K, when using helium forced-flow cooling, the cryogenic valves 34 and flow meters 35 are used to regulate the inlet and outlet pressure drop of a single loop to be less than 0.5 bar, preventing the helium operating temperature from rising with increasing pressure.

[0060] Working principle:

[0061] The embodiment of the present invention provides a low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage. In the double-layer vacuum helium input pipe 1, a vacuum interlayer is formed between the external Dewar connecting pipe 11 and the internal helium pipe channel 12. A helium infusion pipe can be inserted into the internal helium pipe channel 12 to form a double-layer vacuum. The input helium forced flow flows from the helium forced flow inlet pipe 14 through the helium forced flow inlet 21 into the cold storage block 22. It is then shunted through multiple L-shaped shunt regulating pipes 23, flows through the constant-temperature-difference balance block 24 to multiple helium forced flow shunt outlets 25, and flows out from the multiple helium forced flow shunt outlets 25 through multiple single-coil inlet pipes 31 into the inlets at the bottom of multiple solenoid superconducting coils 32. Finally, it flows from the multiple solenoid superconducting coils... Multiple single-coil outlet pipes 33 flow into the outlet at the top of 32, thus completing a single low-temperature cooling cycle. By setting the multi-channel shunt 2 concentrically with the concentric solenoid coil assembly 3, and setting multiple L-shaped shunt regulating pipes 23 and multiple single-coil inlet pipes 31 radially along the concentric solenoid coil assembly 3, the helium forced flow input from the double-layer vacuum helium input pipe 1 is shunted by the multi-channel shunt 2 and flows radially into the concentric solenoid coil assembly 3. This solves the problem of deviation between the helium flow direction and the conductor along the path, further improves the inconsistency of the inlet temperature of a single coil, optimizes the problem of inconsistent helium flow pressure drop during long-distance multi-layer single-coil cooling, and ultimately reduces the critical temperature and improves the critical characteristics of the energy storage magnet.

[0062] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage, characterized in that: include: Double-layer vacuum helium input tube (1); A multi-channel splitter (2) is provided, the inlet of which is connected to the double-layer vacuum helium input tube (1), and the multi-channel splitter (2) is arc-shaped. The concentric solenoid coil assembly (3) is connected to the outlet of the multi-channel splitter (2). The center of the multi-channel splitter (2) and the center of the concentric solenoid coil assembly (3) are located on the same axis. The helium forced flow input by the double-layer vacuum helium input tube (1) is split by the multi-channel splitter (2) and flows into the radial direction of the concentric solenoid coil assembly (3). The double-layer vacuum helium input tube (1) includes: External Dewar connection pipe (11); An internal helium tube channel (12) is provided inside the external Dewar connection pipe (11), and the internal helium tube channel (12) and the external Dewar connection pipe (11) are in a vacuum environment; Helium forced flow inlet pipe (14), which is connected to the bottom of the internal helium tube channel (12); The multi-channel splitter (2) includes: Helium forced flow inlet (21), which is connected to the helium forced flow inlet pipe (14); A cold storage block (22), wherein the helium forced flow inlet (21) is disposed at the upper end of the cold storage block (22), and the cold storage block (22) is a hollow structure; Multiple L-shaped diversion regulating pipes (23) are provided, the inlets of which are connected to the cold storage block (22), and the multiple L-shaped diversion regulating pipes (23) are arranged radially along the multi-channel diverter (2). The outlets of the plurality of L-shaped diversion regulating pipes (23) are connected to the constant temperature difference balance block (24); Multiple helium forced flow diversion outlets (25) are provided on the side of the constant temperature difference balance block (24) facing the concentric solenoid coil assembly (3), and the multiple helium forced flow diversion outlets (25) correspond to the multiple L-shaped diversion regulating tubes (23); The concentric solenoid coil assembly (3) includes: Multiple single-coil inlet pipes (31), the inlets of the multiple single-coil inlet pipes (31) are respectively connected to the multiple helium forced flow split outlets (25), and the multiple single-coil inlet pipes (31) are arranged radially along the concentric solenoid coil assembly (3); Multiple solenoid superconducting coils (32) are arranged concentrically in multiple layers, and the inlets at the bottom of the multiple solenoid superconducting coils (32) are respectively connected to the outlets of the multiple single coil inlet pipes (31); Multiple single-coil outlet pipes (33) are provided, with the outlets at the top of the multiple solenoid superconducting coils (32) respectively connected to the inlets of the multiple single-coil outlet pipes (33), and the multiple single-coil outlet pipes (33) are spaced 15° apart.

2. The low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage according to claim 1, characterized in that, The double-layer vacuum helium input tube (1) also includes a helium inlet sealing flange (13), which is welded to the bottom of the internal helium tube channel (12) and sealed with polytetrafluoroethylene.

3. The low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage according to claim 2, characterized in that, The multi-channel distributor (2) also includes a finned cooling strip (26), the two ends of which are connected to the cold storage block (22) and the constant temperature difference balance block (24), respectively.

4. The low-flow-resistance, constant-temperature-difference, multi-channel, single-cycle helium forced-flow cryogenic system for superconducting energy storage according to claim 3, characterized in that, The multiple single-coil outlet pipes (33) are equipped with cryogenic valves (34) and flow meters (35).

Images