Magnetic levitating (maglev) trains for transportation have been demonstrated that employ a bulk superconductor levitated above a permanent magnet guideway. The train is propelled using a linear motor due to a flux-pinning phenomenon of type-II superconductivity. Separately, superconducting cables have been used to transmit and store electrical power without losses over long distances. Such superconducting cables may have a significant advantage over current transmission cables, which can lose power due to resistance. Further, hydrogen (H2) provides an energy source that may be used to replace fossil fuels. For such systems, liquid H2 (LH2) pipelines may be used for the transportation and storage of the hydrogen. In addition, other liquids such as liquid nitrogen, liquid natural gas, etc. can also be stored and transported over long distance.
However, long-distance superconducting maglev trains require many high-cost permanent magnets positioned in the guideway. These magnets merely service the functions of high-speed mass transit and freight transport. Also, there are few long-distance applications of superconducting power transmission cables due to the technological deficiencies and high cost of the superconducting cables. In such systems, the superconducting cables merely service the functions of transmitting and storing the electrical power. Still further, a system of LH2 pipelines will require a high-cost thermal insulation to maintain the LH2 at 20 K (the condensation temperature). Currently, the manufacturing of such expensive LH2 pipelines for the purpose of LH2 transport and storage is not available. Furthermore, because hydrogen is the lightest element, the high pressure required to transport gaseous H2 may pose additional challenges.
Embodiments disclosed herein may overcome some of the above deficiencies by providing a novel superlev vehicle system capable of transporting and storing electrical power, fuel (gas or liquid), and/or people or goods. Embodiments include a superlev vehicle (e.g., train, bus, truck, car) levitating over superconducting cables cooled by a coolant. The superconducting cables and coolant may also be used to transport electricity and fuel (such as LH2), and these fuels can also be stored in the system.
In the following description, for purposes of explanation, numerous specific details are set forth to provide a thorough understanding of the disclosed concepts. As part of this description, some of this disclosure's drawings represent structures and devices in block diagram form to avoid obscuring the novel aspects of the disclosed embodiments. The language used in this disclosure has been principally selected for readability and instructional purposes and may not have been selected to delineate or circumscribe the disclosed subject matter. Reference in this disclosure to “one embodiment” or to “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment, and multiple references to “one embodiment” or to “an embodiment” should not be understood as necessarily all referring to the same embodiment or to different embodiments.
The figures and descriptions of the present invention may have been simplified to illustrate elements that are relevant for a clear understanding of the present embodiments while eliminating (for purposes of clarity) other elements found in, for example, a typical superlev vehicle system or typical method of transport using a superlev vehicle system, a typical electrical power transmission system including an electrical power delivery system or typical electrical power transmission/delivery method, or a typical fluid transportation system or typical fluid transportation method. Those of ordinary skill in the art will recognize that other elements may be desirable and/or required in order to implement the present embodiments. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present embodiments, a discussion of such elements may not be provided herein. It is also to be understood that the drawings included herewith only provide diagrammatic representations of the structures of the embodiments. The specific structure falling within the scope of the embodiments presented herein may include structures different than those shown in the drawings. It should also be understood that the phraseology and terminology employed herein are merely for descriptive purposes and should not be considered limiting.
In general, embodiments disclosed herein are directed to a superlev vehicle system capable of electrical power transmission/delivery; fuel (gas or liquid) transport; and/or the transportation of people (or other living or non-living entities) and/or goods (or other items). That is, embodiments include a superconductor levitated transportation system (referred to herein as a “superlev” system) that includes one or more superconductors and a coolant. Embodiments also include a combination of the superlev vehicle system and an electrical power transmission/delivery system that transports electrical power along the superconductor. Embodiments also include a combination of the superlev vehicle system and a fluid transportation system that transports fluid a distance within a conduit along a track that includes the superconductor. One of ordinary skill in the art will appreciate upon reading this disclosure that some or all of those embodiments may be combined in a single superlev transportation system.
Embodiments disclosed herein overcome the high cost associated with individual systems directed to vehicle levitation, electricity transportation, and fuel transportation to provide a “superlev” system that may combine these multiple functions. Embodiments may combine lossless electrical power transmission and storage, transport and storage of liquid hydrogen (LH2), liquid nitrogen (LN2), and/or liquid natural gas (LNG), and high-speed levitated transport of people and/or goods over long distances in a single, economical system. In this superlev system, vehicles with magnets (or electromagnets) are levitated above a superconductor guideway (i.e., a “superlev”) that is also transmitting and storing electrical power. In some embodiments, LH2 is transported by the system while cooling the superconductor. Additionally or alternatively, embodiments may also include LN2 and/or LNG (and a vacuum layer to thermally insulate the LH2).
The superlev vehicles may travel at 500-800 km/h (or even 1000 km/h if the system is further built inside a partially evacuated tube). Thus, embodiments disclosed herein have the potential to make continental passenger air travel and airborne freight transport obsolete when appropriately adapted personal vehicles, buses, and trucks are employed. In embodiments disclosed herein, additional land may not need to be acquired because the superlev system may be built into existing highway infrastructures. Thus, embodiments may provide superlev access to vehicles adapted for use on both standard roads and superlev system roads.
In contrast to current long-distance, high-speed mass transit and freight transport systems, the superlev system may provide additional flexibility because individuals may not be dependent on schedules and, further, goods may not have to be loaded or unloaded at specific points. The cost of each of the superlev system's many functions is only a fraction of the total costs. Also, the costs to maintain and operate the levitated components are minimal due to lack of friction, making the superlev system economically feasible overall.
Embodiments of the superlev vehicle and electrical power transmission system include a guideway with a superconductor and a coolant coupled to the superconductor. The superconductor may be configured to transmit electrical power. The coolant is configured to cool the superconductor. The coolant may include liquids such as hydrogen, nitrogen, and/or methane. The system also includes a vehicle configured to be levitated a distance from the track via interaction between a magnetic field of the vehicle and the magnetic field from the superconductor. The interaction of levitation is both repulsive and attractive, suspending the vehicle while also keeping the vehicle from exceeding a maximum distance from the track.
Embodiments also include an electrical power delivery system electrically coupled to the superconductor. For example, the superconductor may be in the form of a cable. Superconducting cables, such as high temperature superconducting (HTS) type, are known to provide power-dense electrical transmissions. In accordance with embodiments disclosed herein, the superconductors are capable of efficiently carrying large amounts of electrical power over long distances. Superconducting cables may be a potential replacement for conventional high-voltage cables as the backbone of a transmission grid. Embodiments disclosed herein are not limited to HTS type superconductors. Low Tc superconducting cable may also be considered based on the specific designs and costs. Superconducting cables are ideal for power transmission over long distances due to the absence of energy loss. Embodiments may use high-temperature superconductors to transmit power at the liquid-hydrogen temperature of 20 K or liquid nitrogen temperature of 77 K or even room temperature when superconductors superconducts above room temperature.
Embodiments also include a superconductor levitated vehicle and fluid transportation system. In such embodiments, the conduit includes the superconductor and the fluid for transporting. The fluid may be configured to be transported a distance within the conduit along the guideway. For example, if the production and usage of the fluid are at different places, embodiments may be used to transport the fluid accordingly. The fluid may be liquid fuel, for example hydrogen, methane, gasoline, and/or diesel.
Hydrogen is one of the cleanest energy source and may be part of a future clean energy landscape. For example, hydrogen may be produced by water electrolysis using surplus grid power during off-peak hours and/or renewable power generated by solar panels and wind turbines. When the grid requires more power, a portion of the stored electrical power in the superconductor can be immediately be provided to the grid or the liquid hydrogen may be converted back into electrical power to meet the demand. Accordingly, hydrogen transport built into the guideway in accordance with embodiments disclosed herein may help alleviate the high cost of transporting hydrogen, helping to move society to a cleaner landscape while helping to literally move people and/or goods.
In contrast to traditional systems, embodiments disclosed herein are built with the guideway including a superconductor and with the magnets inside the vehicle. As such, the cost of the system may be dramatically reduced. Magnets are very expensive and the cost of magnets contributes to a huge portion of the cost in traditional maglev systems. By incorporating the magnets into the vehicle, the overall number of the expensive magnets may be reduced.
The superconductor may be in the form of a cable built inside the guideway. Such configurations may save an enormous amount of construction cost and require less infrastructure and footprint. In some embodiments, a superconducting cable is located inside a well-insulated tube in which the coolant is stored. In the example of LH2 as the coolant, with significant insulation, the loss of LH2 may be minimized.
Embodiments provide three separate systems (a superconductor for power transmission, fuel and non-fuel transport, and people/goods transport) combined into one superlev system. The cost of embodiments may be reduced by a factor of about 3-10 when compared to the sum of the costs of each traditional independent system.
The embodiments of
As described below, the superlev vehicle transport system includes a conduit 104 for transporting and storing a coolant 108 for cooling the superconductor 102 below the superconducting transition temperature of the superconductor 102. In the embodiment of
In embodiments disclosed herein, a vehicle 100 will be levitated in the air (or, potentially, within a vacuum tube similar to existing hyperloop-type maglev trains) by the interaction of a magnetic field from the vehicle 100 with a magnetic field from the cooled superconducting cable 102 in the conduit 104. For example, magnets (e.g., permanent magnets such as neodymium iron boron magnets, magnets generated by regular coils, or magnets generated by superconducting coils) may be included in one or more of the vehicles 100 to couple to the cooled superconducting cable 102 in the conduit 104. In accordance with embodiments disclosed herein, the superconductor 102 enables electrical power to be transmitted over long distances without losses. Meanwhile, only a tiny fraction of the electrical power from the superconductor 102 is needed to power each vehicle 100 overcome the air friction if not inside a vacuum tube.
In the examples demonstrated by
Further, the superlev system may include a vehicle control system for controlling the magnetization of the vehicle 100 and/or an electrical current control system for controlling the electrical current in the superconducting cable 102. In some embodiments, a central control system may be employed for controlling both the vehicle 100 and the electrical current in the superconducting cable 102.
The conduit 104 includes a coolant 108 to cool the superconductor 102 below the superconducting transition temperature of the superconductor 102. In some embodiments, LH2 (at 20 K) may be used as the coolant 108 to cool the superconductor 102. Meanwhile, because LH2 may also be used a fuel and energy source, in some embodiments the superlev system can be used to transport LH2 from location to location (to be used as a fuel) while also cooling the superconductor 102. In some embodiments, the conduit 104 may include a non-energy carrier, such as liquid nitrogen. The non-energy carrier may be used as a coolant 108 or in addition to the coolant 108. One of ordinary skill in the art will appreciate that selection of the coolant 108 depends on the specific superconductor 102 used to ensure that the superconductor 102 remains below the superconducting transition temperature of the superconductor 102. For example, the coolant 108 may include a liquid such as hydrogen, nitrogen, and/or methane.
In other embodiments, other coolants 108 such as gas-to-liquid (GTL) or non-liquid coolants (e.g., a supercritical fluid or a multiple-phase mixture) may alternatively be employed. The temperature of the coolant 108 may range from 4.2 K to 300 K, provided the superconducting transition temperature of the superconductor 102 is higher than the temperature of the coolant 108. For example, liquid helium for low temperature superconductors 102 such as Nb3Sn, NbTi, MgB2, FeSe, YBCO, Bi-2212 and Bi-2223, Tl-2212 and Tl-2223, Tl-1212 and Tl-1223, Hg-2212 and Hg-2223, Hg-1212 and Hg-1223, etc., may be used. Liquid hydrogen may be used for low temperature superconductors 102 such as Nb3Sn, NbTi, MgB2, FeSe, YBCO, Bi-2212 and Bi-2223, Tl-2212 and Tl-2223, Tl-1212 and Tl-1223, Hg-2212 and Hg-2223, Hg-1212 and Hg-1223, etc. Liquid nitrogen may be used for low and high temperature superconductors 102 such as YBCO, Bi-2212 and Bi-2223, Tl-2212 and Tl-2223, Tl-1212 and Tl-1223, Hg-2212 and Hg-2223, Hg-1212 and Hg-1223, etc. Other synthetic fluids such as specialized refrigeration fluids may be used provided the temperature is below the superconducting transition temperature of the superconductor 102.
In embodiments herein, the coolant 108 serving to cool the superconductor 102 while also being an energy carrier that is ultimately transported a distance within a conduit 104 along the guideway 106. In such embodiments, the “dual-duty” coolant 108 may be contained within a single conduit 104 of the guideway 106. Alternatively, the energy carrier may be separate from the coolant 108 in another conduit 104 of the guideway 106, separate from the coolant's conduit 104. In such embodiments, the energy carrier would not be in contact with the superconducting cable 102.
The system may also be used to transport LH2, LN2, and/or LNG in accordance with embodiments disclosed herein.
After a guideway 106 is constructed, the superconductor 102 may be cooled with or without the magnetic field required for levitation. This is referred to field-cooled (with magnetic field) or zero field-cooled (without magnetic field). In the case that a large amount of electrical power is not being transmitted in the superconductor 102 under zero field-cooled, magnetization of the superconductor 102 is needed to pin the magnetic flux in order to levitate and guide a vehicle.
In the case when a large amount of electrical power is being transmitted by the superconductor 102, the superconductor 102 will generate a magnetic field. In the case that the magnetic field generated is either too large or too small than the required magnetic field for levitation and control, additional adjustment on the amount of power in the superconducting cables 102 or additional magnetization may be needed. The levitation force to control and guide the vehicle 100 may be determined based on the weight of the vehicle 100, properties of the superconductor 102 (such as cable size), the amount of power being carried, the speed, acceleration and deceleration of the vehicle 100, etc. Typically, vehicles 100 are suspended about 2-20 cm above the guideway 106 to ensure the vehicle 100 does not exceed a maximum distance from the guideway 106.
Although YBCO superconductors 102 are commercially available in bulk and superconducting tape forms, embodiments disclosed herein are not limited to a YBCO SCG 200. In addition to the superconductors 102 mentioned above in relation to the coolants 108, other superconducting compounds, such as those in the bismuth (BSCCO) and mercury (HBCCO) families may be used. Further, provided the appropriate cooling and levitation requirements are achieved, unconventional superconducting materials like magnesium diboride (MgB2) may also be considered.
To cool the YBCO array to below its transition temperature Tc (and maintain that temperature), the array is thermally attached to a rectangular aluminum tube, the inner LN2 tube 240, that can store up to 250 mL LN2. To prevent warming, the YBCO array is wrapped with multi-layered insulation and, along with the inner LN2 tube 240, is housed in the outer vacuum casing 220, a rectangular aluminum tube that is 800 mm long with equal side widths of 60 mm.
The vacuum value 250 is used to provide evacuation to below 5×10−5 mbar, and the SCG 200 is cooled with LN2 via periodic pouring into the LN2-filling tubes 240. After 20 min and 1.5 L of LN2, thermal equilibrium of 77 K is achieved. Without further LN2 refilling, the moderate thermal loss of 2.5 W allows this temperature to be maintained for 3-4 h.
To activate the SCG 200, field cooling (FC) magnetization is applied by placing the PMM 260 between 3-6 mm above the SCG 200 using spacers (not shown) and cooling the SCG 200 down to 77 K. When thermal equilibrium is achieved in the SCG 200, a trapped magnetic flux density BT (hereafter BT indicates the |Bz|component of vector B) is retained throughout the a linear array of nine YBCO bars 230 after removal of the PMM 260 due to the trapped flux and resultant induced superconducting current.
Following the FC magnetization procedure, the spacers are removed from between the PMM 260 and the SCG 200 and the PMM 260 levitates above the SCG 200, as shown in
Following the FC magnetization procedure, the PMM 260 is removed and the miniature magnetic vehicle 270 is placed above the SCG 200. The miniature magnetic vehicle 270 levitates above the SCG 200 as shown in
Several FC magnetization procedures at distances in the 1-10 mm range were performed. At distances below 3 mm, the miniature magnetic vehicle 270 can collide with the SCG 200. At FC magnetization procedures at distances of 3-4 mm, the miniature magnetic vehicle 270 stably levitates and can move along the length of the SCG 200. However, at greater distances, the levitation can become unstable, particularly in the lateral direction, due to the arrangement of the magnets inside the miniature magnetic vehicle 270 and the narrowness of the SCG 200. Accordingly, embodiments disclosed herein may include arrangements of magnets in the vehicle configured in relation to the narrowness of the magnetic fields in the guideway 200 to avoid instabilities.
Also, the BT value decreases with increasing FC distance, along with a corresponding decrease in the BT(y) variation between maxima and minima. These observations are consistent with previous observations that found that the FC distance may play a functional role in changing the shape and magnitude of the BT distribution in trapped field applications. These observations also point out that a multi-seed YBCO bulk sample may provides superior levitation performance compared to a corresponding array of single-grain YBCO bulk samples due to the additional induced supercurrent in intergrain coupling.
To evaluate the field distribution in more detail, the 77 K FC magnetization procedure at a distance of 3 mm.
These maxima and minima may be easily eliminated by using two or more layers of YBCO bars, with each layer shifted a certain distance to overlap the maxima and minima. However, movement of a vehicle 100 along an SCG 200 may be negatively affected by the inhomogeneous BT(y) resulting from the grain boundaries in the YBCO bars and the joint gaps between them. Thus, embodiments disclosed herein may engineer the superconductor 102 to avoid such an inhomogeneous BT(y). This may be accomplished through engineered grain boundaries 445 and/or multiple layers of the superconductor 102 in the SCG 200. In this demonstration, HTS tapes may be used in place of (or in combination with) the YBCO bulk array to alleviate the inhomogenities.
Embodiments disclosed herein are further directed to a method of transport. The method of transport may be used to transport vehicles 100, electricity, coolant 108, and/or fuel. The method includes providing a guideway 106 that includes a superconductor 102 and a coolant 108 coupled to the superconductor 102, and cooling the superconductor 102 using the coolant 108. The method also includes generating a magnetic field from a vehicle 100 and generating a magnetic field from the superconductor 102 via conduction of electrical current in the superconducting cable 102. The vehicle is levitated a distance from the track via the interaction between the magnetic field from the vehicle and the magnetic field from the superconductor 102.
The method of transport may further include transmitting electrical power via the superconductor cable 102 for delivery of the electrical power. The method of transport may further include transporting a liquid or gas along the guideway 106 using a conduit 104 disposed with the superconductor 102.
The method steps in any of the embodiments described herein are not restricted to being performed in any particular order. Also, structures mentioned in any of the method embodiments may utilize structures mentioned in any of the device/system embodiments. Such structures may be described in detail with respect to the device/system embodiments only but are applicable to any of the method embodiments.
It's understood that the above description is intended to be illustrative, and not restrictive. The material has been presented to enable any person skilled in the art to make and use the concepts described herein, and is provided in the context of particular embodiments, variations of which will be readily apparent to those skilled in the art (e.g., some of the disclosed embodiments may be used in combination with each other). Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the embodiments herein therefore should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.”
This application claims the benefit of U.S. Provisional 63/304,366, filed Jan. 28, 2022, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
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63304366 | Jan 2022 | US |