Low-vibration thermo-acoustic magnetohydrodynamic power generation device

Abstract

The invention relates to the technical field of thermo-acoustic power generation, and provides a low-vibration thermo-acoustic magnetohydrodynamic power generation device which comprises a thermo-acoustic engine and a liquid metal magnetohydrodynamic power generator, and the thermo-acoustic engine comprises an engine assembly and an air reservoir; the liquid metal magnetohydrodynamic generator comprises at least two magnetohydrodynamic power generation channels, every two magnetohydrodynamic power generation channels are symmetrically arranged, one end of each magnetohydrodynamic power generation channel is connected with the engine assembly, the other end of each magnetohydrodynamic power generation channel is connected with the air reservoir, and each magnetohydrodynamic power generation channel is filled with liquid metal. A first magnet and a second magnet are arranged on the outer wall of the magnetofluid power generation channel, and at least one electrode pair is embedded in an insulating layer of the magnetofluid power generation channel and located on the channel wall parallel to the magnetic field direction. In the operation process, force generated by liquid metal flowing, magnetic field interaction and the like counteracts in the symmetrical direction, force balance and moment balance are achieved on the whole, and ultra-low vibration operation is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermoacoustic power generation, and in particular to a low-vibration thermoacoustic magnetofluid power generation device. Background Art

[0002] Thermoacoustic power generation technology is a new type of power generation technology that couples a thermoacoustic engine with an acoustic-to-electric conversion device (generator). Currently, the main acoustic-to-electric conversion devices include linear motors, piezoelectric devices, friction nanogenerators, magnetohydrodynamic generators, etc.

[0003] Among them, the presence of mechanical moving parts (piston, motor rotor, etc.) in linear motors weakens the high reliability advantage of thermoacoustic engines without mechanical moving parts; piezoelectric power generation is based on the high-frequency vibration of piezoelectric devices, which is only suitable for micro-thermoacoustic power generation scenarios, and the thermoelectric conversion efficiency is low (less than 10%); friction nanogenerators generate electricity based on the electrostatic effect between friction materials, and their power generation is low (less than 1W), and there are problems such as wear between friction parts caused by long-term work, and their reliability is low; magnetohydrodynamic generators use the high-intensity pressure fluctuations generated by thermoacoustic engines to drive the magnetic fluid to reciprocate in a magnetic field environment. The magnetic fluid composed of electrons and positive ions cuts the magnetic lines of force to generate induced electromotive force and output AC power.

[0004] Compared with linear motors, piezoelectric devices and friction nanogenerators, magnetohydrodynamic generators do not have mechanical moving parts, have flexible power and high potential power generation efficiency, and are widely used in space power generation, wave power generation and other fields. Therefore, combining the thermoacoustic engine and the liquid metal magnetohydrodynamic generator can form a magnetohydrodynamic power generation device with no mechanical moving parts. Since the magnetohydrodynamic power generation device combines the characteristics of the thermoacoustic engine and the liquid metal magnetohydrodynamic generator, it has high reliability, long service life, high energy conversion rate and wide energy adaptability. Therefore, it can be widely used in various application scenarios that require extremely high reliability of the generator, such as space isotope power supply, space nuclear reactor power supply, etc.

[0005] In the related art, the US patent publication number is US4599551A, which discloses a thermoacoustic magnetohydrodynamic generator. Two opposing standing wave thermoacoustic engines generate periodic pressure fluctuations, thereby driving the liquid metal magnetohydrodynamic to cut the magnetic lines of force to generate induced electromotive force. The system uses a flat electrode installed on the inner wall of the standing wave engine resonance tube to collect and output electrical energy, realize the direct coupling design of the thermoacoustic engine and the magnetohydrodynamic generator, and make the overall structure relatively simple. However, the system still has the following limitations in practical applications: First, since the standing wave thermoacoustic engine is based on an irreversible thermodynamic cycle, its potential efficiency is low; second, the working fluids of the thermoacoustic engine and the magnetohydrodynamic generator are both liquid metal, and the design difficulty and production cost are high; third, the operating frequency of the thermoacoustic magnetohydrodynamic power generation system reaches the kHz level, which is far beyond the superelectric frequency (50~60Hz), which is not conducive to practical use; fourth, since the liquid metal has a high thermal conductivity, there is a serious axial heat conduction loss in the thermoacoustic engine, and the system thermoelectric efficiency is limited to a certain extent.

[0006] To this end, the Chinese patent publication number is CN101282074B, which discloses a thermoacoustic liquid magnetofluid AC power generation system. The system directly couples the resonance tube of the thermoacoustic engine with one end opening of the working pipe of the liquid metal magnetofluid generator, so that the pressure wave generated by the oscillation of the resonance tube drives the magnetofluid to flow in the working pipe. The working pipe is placed between the two-pole magnetic field. When the magnetofluid flows in the pipe, it cuts the magnetic lines of force to generate an induced electromotive force and output electrical energy. In this design, the thermoacoustic engine uses gas as the working medium. Compared with the traditional engine using liquid metal magnetofluid, the gas working fluid significantly simplifies the engine structure and reduces the manufacturing cost. In addition, the design of the thermoacoustic engine using gas working fluid as the driving medium effectively reduces the operating frequency to close to the mains frequency (50~60 Hz), which is more in line with the needs of actual power applications. At the same time, since the thermal conductivity of the gas working fluid is much lower than that of the liquid metal working fluid, the axial heat conduction loss is significantly reduced, thereby improving the overall efficiency of the system. However, the thermoacoustic engine used in the system is a traditional thermoacoustic engine, and the resonance tube is large in volume and weight, and the loss is serious. In addition, since the system uses a conductive magnetohydrodynamic generator, the output current is large and the voltage is small, the power transmission loss is large, and there is a large reciprocating vibration, which greatly limits the application occasions with low vibration requirements.

[0007] To this end, China's patent publication number is CN106533119B, which discloses a liquid metal magnetohydrodynamic power generation system driven by a single-stage loop thermoacoustic engine. The system uses a single-stage loop thermoacoustic engine as a driving source, and divides the liquid metal flow channel in the magnetohydrodynamic generator into multiple layers of annular flow channels. Electrodes are arranged in each layer of the flow channel, and the electrodes in each layer of the flow channel are connected in series to reduce the output current and increase the output voltage. The thermoacoustic magnetohydrodynamic system has the characteristics of small volume and weight, high energy density, low starting and operating temperature, and easy use of output energy. However, since the liquid metal magnetohydrodynamic generator in the system is arranged in a single-tube manner, there is a problem of force and torque imbalance during operation, and the system vibrates greatly during operation, resulting in high energy loss. Summary of the invention

[0008] The present invention provides a low-vibration thermoacoustic magnetofluid power generation device, which is used to solve the defects of large vibration and high energy loss in the operation of magnetofluid power generation devices in the prior art; it achieves force balance and torque balance as a whole, effectively reduces mechanical vibration during operation, and realizes ultra-low vibration operation.

[0009] The present invention provides a low-vibration thermoacoustic magnetofluid power generation device, comprising: A thermoacoustic engine, comprising an engine assembly and an air reservoir, wherein the engine assembly is used to extract acoustic work and form a traveling wave phase, and the air reservoir is used to adjust acoustic impedance and resonance conditions; A liquid metal magnetohydrodynamic generator comprises at least two magnetohydrodynamic power generation channels, each two of which are symmetrically arranged, one end of each of which is connected to the engine assembly, and the other end of each of which is connected to the gas reservoir, the interior of each of which is filled with liquid metal or liquid metal containing nano-enhanced conductive material, the outer wall of the magnetohydrodynamic power generation channel is provided with a first magnet and a second magnet, the first magnet and the second magnet are used to construct a parallel magnetic field, and at least one pair of electrode pairs is embedded in the insulating layer of the magnetohydrodynamic power generation channel, and at least one pair of electrode pairs is located on the channel wall parallel to the direction of the magnetic field.

[0010] According to the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention, the magnetofluid power generation channel comprises a first pipe segment, a second pipe segment and a third pipe segment connected end to end in sequence, the second pipe segment is arranged horizontally, and the first pipe segment and the third pipe segment are vertically connected to both ends of the second pipe segment; The first pipe sections of the two symmetrically arranged magnetic fluid power generation channels overlap, the first pipe section is connected to the engine assembly, and the second pipe section and the third pipe section are symmetrically arranged with the axis of the first pipe section as the symmetry axis; The first magnet and the second magnet are arranged at positions corresponding to the second pipe section, and at least one pair of electrodes is located at positions corresponding to the second pipe section.

[0011] According to the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention, the cross-section of the second pipe segment is rectangular, and the cross-sections of the first pipe segment and the third pipe segment are both circular.

[0012] According to the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention, at least three pairs of electrode pairs are embedded in the insulating layer of the magnetofluid power generation channel, and two adjacent pairs of electrode pairs are arranged at intervals; and among the two adjacent pairs of electrode pairs, the negative electrode plate of one electrode pair and the positive electrode plate of the other electrode pair are connected in series through a wire, and the load is connected to the positive electrode plate of the first electrode pair and the negative electrode plate of the last electrode pair through the wire.

[0013] According to the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention, three pairs of electrodes are embedded on the insulating layer of the magnetofluid power generation channel, and two adjacent pairs of electrodes are arranged at intervals; The negative plate of the first electrode pair is connected to the positive plate of the second electrode pair by a wire, and the negative plate of the second electrode pair is connected to the positive plate of the third electrode pair by a wire; the load is connected to the positive plate of the first electrode pair and the negative plate of the third electrode pair by a wire to form an electrical circuit.

[0014] According to the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention, an insulating plate is provided inside the magnetofluid power generation channel, and the insulating plate is located in the gap between two adjacent pairs of electrodes. The insulating plate divides the magnetofluid power generation channel into at least three magnetofluid quantum power generation channels, and each pair of electrodes is located on both sides of the corresponding magnetofluid quantum power generation channel.

[0015] According to the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention, the engine assembly includes a main room temperature end heat exchanger, a regenerator, a heater, a secondary room temperature end heat exchanger, a resonance tube, a feedback tube and an acoustic volume connected in sequence; The main room temperature end heat exchanger and the secondary room temperature end heat exchanger exchange heat with an external low temperature heat source to form a room temperature end, the heater exchanges heat with an external high temperature heat source to form a high temperature end, and the regenerator is used to generate acoustic work; One end of each of the magnetic fluid power generation channels is connected to the resonance tube.

[0016] According to the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention, the engine assembly further comprises a heat buffer tube, one end of the heat buffer tube is connected to the heater, and the other end of the heat buffer tube is connected to the sub-room temperature end heat exchanger; The cross-sectional areas of the main room temperature end heat exchanger, the regenerator, and the heater are all larger than the cross-sectional areas of any one of the thermal buffer tube, the secondary room temperature end heat exchanger, and the resonance tube.

[0017] According to the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention, the liquid metal includes any one of mercury, gallium, gallium-indium-tin alloy and sodium-potassium liquid alloy; the nano-enhanced conductive material includes nano-copper, silver or carbon nanotubes.

[0018] According to the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention, the electrode is made of gold, silver, platinum, aluminum, nickel, copper, titanium or chromium, or the electrode is made of an alloy formed by at least two of gold, silver, platinum, aluminum, nickel, copper, titanium or chromium.

[0019] The low-vibration thermoacoustic magnetofluid power generation device provided by the present invention, the liquid metal magnetofluid power generator includes at least two magnetofluid power generation channels, and each two magnetofluid power generation channels are symmetrically arranged, presenting a regular and stable structure, so that during the operation of the thermoacoustic magnetofluid power generation device, the forces generated by the reciprocating flow of liquid metal, the interaction of the magnetic field, etc., cancel each other out in the symmetrical direction. For example, for two symmetrical magnetofluid power generation channels, if the liquid metal generates a thrust to the left in one of the magnetofluid power generation channels, due to the symmetrical relationship, a thrust of equal magnitude and direction to the right will be generated in the other magnetofluid power generation channel, thereby achieving a force balance as a whole, effectively reducing the mechanical vibration during operation, and achieving ultra-low vibration operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram of a low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention.

[0022] Figure 2 It is a schematic diagram of the internal structure of a liquid metal magnetohydrodynamic generator in a low-vibration thermoacoustic magnetohydrodynamic power generation device provided in an embodiment of the present invention.

[0023] Figure 3 It is a schematic diagram of the external structure of a liquid metal magnetohydrodynamic generator in a low-vibration thermoacoustic magnetohydrodynamic power generation device provided in an embodiment of the present invention.

[0024] Figure 4 yes Figure 3Sectional view along line AA.

[0025] Figure 5 It is a schematic diagram of the working principle of the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention.

[0026] Reference numerals: 1. Thermoacoustic engine; 11. Main room temperature end heat exchanger; 12. Regenerator; 13. Heater; 14. Heat buffer tube; 15. Secondary room temperature end heat exchanger; 16. Resonance tube; 17. Feedback tube; 18. Acoustic volume; 19. Gas reservoir; 2. Liquid metal magnetohydrodynamic generator; 211. first magnet; 212. second magnet; 221. first magnetohydrodynamic quantum power generation channel; 222. second magnetohydrodynamic quantum power generation channel; 223. third magnetohydrodynamic quantum power generation channel; 231-1. positive electrode plate of first pair of electrodes; 231-2. negative electrode of first pair of electrodes; 232-1. positive electrode plate of second pair of electrodes; 232-2. negative electrode of second pair of electrodes; 233-1. positive electrode plate of third pair of electrodes; 233-2. negative electrode of third pair of electrodes; 3. Magnetic fluid power generation channel; 31. First pipe section; 32. Second pipe section; 33. Third pipe section; 4. Liquid metal. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0029] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0030] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0031] Figure 1 It is a structural schematic diagram of a low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention. Figure 2 It is a schematic diagram of the internal structure of a liquid metal magnetohydrodynamic generator in a low-vibration thermoacoustic magnetohydrodynamic power generation device provided in an embodiment of the present invention.

[0032] See also Figure 1 and Figure 2 An embodiment of the present invention provides a low-vibration thermoacoustic magnetohydrodynamic power generation device, including a thermoacoustic engine 1 and a liquid metal magnetohydrodynamic generator 2.

[0033] The thermoacoustic engine 1 includes an engine assembly and an air reservoir 19. The engine assembly is used to extract acoustic power and form a traveling wave phase. The air reservoir 19 is used to adjust acoustic impedance and resonance conditions. The thermoacoustic engine 1 is filled with high-pressure gas working fluid, which is helium, nitrogen or carbon dioxide.

[0034] The engine assembly is a device that can efficiently convert thermal energy into high-intensity acoustic energy. That is, when there is an appropriate temperature gradient and acoustic field in a pipe, acoustic oscillations will spontaneously occur, converting thermal energy into mechanical energy in the form of acoustic waves. The engine assembly is based on a reversible Stirling cycle, has no mechanical moving parts, and has high operating reliability, long life and high potential thermal efficiency.

[0035] Among them, the engine assembly includes a main room temperature end heat exchanger 11, a regenerator 12, a heater 13, a secondary room temperature end heat exchanger 15, a resonance tube 16, a feedback tube 17 and a sound volume 18 connected in sequence; the main room temperature end heat exchanger 11 and the secondary room temperature end heat exchanger 15 exchange heat with an external low-temperature heat source to form a room temperature end, the heater 13 exchanges heat with an external high-temperature heat source to form a high-temperature end, and the regenerator 12 is used to generate sound work.

[0036] In addition, the engine assembly also includes a heat buffer tube 14, one end of which is connected to the heater 13, and the other end of the heat buffer tube 14 is connected to the sub-room temperature end heat exchanger 15; the cross-sectional areas of the main room temperature end heat exchanger 11, the regenerator 12, and the heater 13 are all larger than the cross-sectional areas of any one of the heat buffer tube 14, the sub-room temperature end heat exchanger 15, and the resonance tube 16. Such an arrangement can reduce the oscillation speed of the gas working medium in the regenerator 12, reduce viscosity loss, and improve energy conversion efficiency.

[0037] It is equivalent to that the main room temperature end heat exchanger 11 is located above the regenerator 12, and its function is to take away heat and cool the gas working medium at the room temperature end of the regenerator 12 to establish a temperature gradient on the thermoacoustic regenerator 12. The regenerator 12 is located below the main room temperature end heat exchanger 11, and is usually made of a stainless steel wire mesh filled in a stainless steel pipe. It is a key component for generating and strengthening the thermoacoustic effect. The thermoacoustic effect here generates or enhances the acoustic work. The function of the heater 13 is to provide a high-temperature heat source at the other end of the regenerator 12 relative to the main room temperature end heat exchanger 11, and together with the ambient temperature at the main room temperature end heat exchanger 11, a temperature gradient is formed on the regenerator 12 to provide power for the engine. The heat buffer tube 14 is located between the heater 13 and the secondary room temperature end heat exchanger 15. The upper half of the heat buffer tube 14 is a straight tube, and the lower half of the heat buffer tube 14 is a tapered tube. The inner surface of the heat buffer tube 14 needs to be polished. The function of the heat buffer tube 14 is to achieve thermal isolation between the heater 13 and the sub-room temperature end heat exchanger 15, reduce heat leakage from the hot end heat exchanger to the sub-room temperature end heat exchanger 15, maintain the temperature gradient and transfer the acoustic power from the high temperature area of ​​the engine to the outside.

[0038] The sub-room temperature end heat exchanger 15 is located below the heat buffer tube 14. The sub-room temperature end heat exchanger 15 adopts a structure similar to the main room temperature end heat exchanger 11. The function of the sub-room temperature end heat exchanger 15 is to reduce the temperature of the gas that transmits the acoustic power, so as to facilitate the extraction of the acoustic power and provide power for the magnetohydrodynamic generator. The function of the feedback tube 17 is to provide a passage for the traveling wave component and also act as a sound sensing component. The sound volume 18 is a cavity with a large volume, which together with the feedback tube 17 realizes the traveling wave phase at one end of the main room temperature end heat exchanger 11. The function of the resonance tube 16 is to provide an infinite space with continuously changing acoustic impedance.

[0039] In the embodiment of the present invention, the sub-room temperature end heat exchanger 15 is connected to the feedback pipe 17 and the resonance tube 16 through a tee pipe; the feedback pipe 17 connects the various pipe fittings in sequence to form a passage, and the acoustic capacitor 18 spans the left and right branches of the loop; the resonance tube 16 is connected to the liquid metal magnetohydrodynamic generator 2 through an interface cone tube.

[0040] The liquid metal magnetohydrodynamic generator 2 includes at least two magnetohydrodynamic power generation channels 3, which can be understood as a tube body. Every two magnetohydrodynamic power generation channels 3 are symmetrically arranged, one end of each magnetohydrodynamic power generation channel 3 is connected to the engine assembly, and the other end of each magnetohydrodynamic power generation channel 3 is connected to the gas reservoir 19. The interior of each magnetohydrodynamic power generation channel 3 is filled with liquid metal 4. The outer wall of the magnetohydrodynamic power generation channel is provided with a first magnet 211 (i.e., an upper magnet) and a second magnet 212 (i.e., a lower magnet). The first magnet 211 and the second magnet 212 are permanent magnets such as magnets, which are used to construct a parallel magnetic field. At least one pair of electrode pairs is embedded in the insulating layer of the magnetohydrodynamic power generation channel 3, and at least one pair of electrode pairs is located on the channel wall parallel to the direction of the magnetic field. This design can ensure that the electrodes can effectively collect the current generated by the movement of liquid metal in the magnetic field, thereby improving the power generation efficiency.

[0041] In other words, the liquid metal magnetohydrodynamic generator 2 includes at least two magnetohydrodynamic power generation channels 3 made of insulating material, and each two magnetohydrodynamic power generation channels 3 are symmetrically arranged, presenting a regular and stable structure. One end of each magnetohydrodynamic power generation channel 3 is tightly connected to the engine assembly, which provides a power source for the entire system, so that the magnetohydrodynamic can flow smoothly in the magnetohydrodynamic power generation channel 3. The other end of each magnetohydrodynamic power generation channel 3 is connected to the gas reservoir 19, which plays an important role in adjusting the acoustic impedance and resonance conditions in the system.

[0042] Each magnetic fluid power generation channel 3 is filled with liquid metal 4 or liquid metal 4 containing nano-enhanced conductive materials. The liquid metal 4 includes any one of mercury, gallium, gallium-indium-tin alloy and sodium-potassium liquid alloy; the nano-enhanced conductive material includes nano copper, silver or carbon nanotubes. The liquid metal 4 has good conductivity and fluidity and can generate current under the action of a magnetic field. The parallel magnetic field provides conditions for the directional movement of charged particles in the liquid metal 4, thereby realizing the conversion of electrical energy.

[0043] Compared with the gallium indium tin liquid metal working fluid commonly used in existing thermoacoustic magnetohydrodynamic power generation devices, the liquid metal 4 in the embodiment of the present invention uses low-density NaK alloy to replace the traditional gallium indium tin alloy, and evenly distributes conductive reinforcing materials such as copper nanoparticles and carbon nanotubes in the NaK alloy magnetic fluid, which significantly reduces the density of the magnetic fluid while maintaining high conductivity, thereby improving the flexibility, stability and power generation efficiency of the system operation.

[0044] It can be understood that in the low-vibration thermoacoustic magnetofluid power generation device provided by the embodiment of the present invention, the liquid metal magnetofluid power generator 2 includes at least two magnetofluid power generation channels 3, and each two magnetofluid power generation channels 3 are symmetrically arranged, presenting a regular and stable structure, so that during the operation of the thermoacoustic magnetofluid power generation device, the forces and torques generated by the flow of liquid metal, the interaction of the magnetic field, etc., cancel each other out in the symmetrical direction. For example, for two symmetrical magnetofluid power generation channels 3, if the liquid metal 4 generates a thrust to the left in one of the magnetofluid power generation channels 3, due to the symmetry relationship, a thrust of equal magnitude and direction to the right will be generated in the other magnetofluid power generation channel 3, thereby achieving a force balance as a whole, effectively reducing the mechanical vibration during operation, and achieving ultra-low vibration operation.

[0045] It should be noted that the embodiment of the present invention needs to ensure the consistency of the internal structure of each magnetic fluid power generation channel 3, including the length, inner diameter, curvature and cross-sectional area of ​​the pipeline, as well as the flow distribution of the liquid metal 4, the parameters of the magnetic field generator, etc.

[0046] Taking the magnetic field generator as an example, if the magnetic field strength and direction distribution in the two symmetrically distributed magnetic fluid power generation channels 3 are inconsistent, the liquid metal will be subjected to uneven force, thereby generating unbalanced force and torque. When the internal structure of the magnetic fluid power generation channels 3 is consistent, the movement state of the liquid metal 4 in each magnetic fluid power generation channel 3 is similar, and the electromagnetic force, fluid resistance, etc. generated are also similar, which helps to maintain the balance of force and torque.

[0047] Therefore, the magnetic field around each magnetic fluid power generation channel 3 can be controlled to ensure the uniformity and stability of the magnetic field. The uniformity of the magnetic field can be achieved by using a high-precision magnetic field generator, such as a superconducting magnet, or optimizing the arrangement of traditional permanent magnets. This avoids uneven forces on the liquid metal 4 due to uneven magnetic fields, thereby generating unbalanced electromagnetic forces.

[0048] When the external environment changes (such as temperature, electromagnetic field interference, etc.), a feedback control system can be used to adjust the parameters of the magnetic field generator in real time to ensure the stability of the magnetic field, thereby maintaining the stability of the force on the liquid metal 4 and helping to maintain the balance of force and torque.

[0049] In addition, an effective flow control system of the liquid metal 4 can be established to ensure that the flow of the liquid metal 4 in each magnetic fluid power generation channel 3 is balanced. For example, a combination of a flow sensor and a regulating valve is used to monitor and adjust the flow of the liquid metal 4 in real time. When the flow of the liquid metal 4 is balanced, the electromagnetic force generated by it in the magnetic field is also relatively balanced, which is conducive to achieving a balance between force and torque.

[0050] Continue reading Figure 1In some embodiments of the present invention, the magnetic fluid power generation channel 3 includes a first pipe segment 31, a second pipe segment 32 and a third pipe segment 33 which are connected end to end in sequence, the second pipe segment 32 is arranged horizontally, and the first pipe segment 31 and the third pipe segment 33 are vertically connected to both ends of the second pipe segment 32 to form a "U"-shaped structure; the first pipe segments 31 of the two symmetrically arranged magnetic fluid power generation channels 3 overlap, the first pipe segment 31 is connected to the engine assembly, and the second pipe segment 32 and the third pipe segment 33 are symmetrically arranged with the axis of the first pipe segment 31 as the symmetry axis.

[0051] The first magnet 211 and the second magnet 212 are disposed at positions corresponding to the second pipe section 32 , and at least one pair of electrode pairs is located at positions corresponding to the second pipe section 32 .

[0052] When the thermoacoustic magnetofluid power generation device is in operation, two symmetrically arranged magnetofluid power generation channels 3 generate a thrust to the left in one magnetofluid power generation channel 3, and an equal thrust to the right in the other magnetofluid power generation channel 3. The forces generated by the flow of liquid metal 4, the interaction of magnetic fields, etc., offset each other in the symmetrical direction, thereby achieving a force balance as a whole, effectively reducing the mechanical vibration during operation, and achieving ultra-low vibration operation.

[0053] The first pipe section 31, the second pipe section 32 and the third pipe section 33 can be arranged in sections and connected by connecting parts such as flanges, or the first pipe section 31, the second pipe section 32 and the third pipe section 33 can be arranged as an integrally formed structure.

[0054] Continue reading Figure 1 In some embodiments of the present invention, the cross-section of the second pipe segment 32 is rectangular, and the cross-sections of the first pipe segment 31 and the third pipe segment 33 are both circular.

[0055] Designing the cross section of the second pipe section 32 to be rectangular not only provides a larger plane area, but also helps the magnetic fluid to be more evenly distributed and flow in the pipe, creating good conditions for subsequent electromagnetic interaction. Moreover, it is convenient to install and arrange each pair of electrodes, which is conducive to setting the uniformity of the magnetic field.

[0056] Different from the cross-sectional shape of the second pipe segment 32, the cross-sectional shapes of the first pipe segment 31 and the third pipe segment 33 are both circular, which have lower flow resistance in fluid mechanics and can ensure that the magnetic fluid maintains a relatively stable flow velocity and flow when entering and leaving the second pipe segment 32 to reduce energy loss.

[0057] The first pipe section 31 and the second pipe section 32 , as well as the second pipe section 32 and the third pipe section 33 , can be connected by a variable cross-section pipe.

[0058] Continue reading Figure 1In some embodiments of the present invention, at least three pairs of electrodes are embedded in the insulating layer of the magnetic fluid power generation channel, and two adjacent pairs of electrodes are arranged at intervals. Among the two adjacent pairs of electrodes, the negative electrode plate of one pair of electrodes and the positive electrode plate of another pair of electrodes are connected in series through a wire, and the load is connected to the positive electrode plate of the first pair of electrodes and the negative electrode plate of the last pair of electrodes through the wire.

[0059] This is equivalent to using a multi-layer flow channel electrically insulated and divided electrical series structure in the magnetohydrodynamic power generation channel, which can be equivalent to multiple generators connected in series, and can improve the problems of large current and low voltage losses and inconvenience in use of traditional thermoacoustic magnetohydrodynamic power generation devices.

[0060] Figure 3 It is a schematic diagram of the external structure of a liquid metal magnetohydrodynamic generator in a low-vibration thermoacoustic magnetohydrodynamic power generation device provided in an embodiment of the present invention. Figure 4 yes Figure 3 Sectional view along line AA.

[0061] See also Figure 3 and Figure 4 An insulating plate is arranged inside the magnetic fluid power generation channel, and the insulating plate is located in the gap between two adjacent pairs of electrode pairs. The insulating plate divides the magnetic fluid power generation channel 3 into at least three magnetic fluid electron power generation channels, and each pair of electrode pairs is located on both sides of the corresponding magnetic fluid electron power generation channel.

[0062] This embodiment is described by taking three layers of rectangular magnetofluid quantum power generation channels as an example, and the three layers of rectangular magnetofluid quantum power generation channels are respectively the first magnetofluid quantum power generation channel 221, the second magnetofluid quantum power generation channel 222 and the third magnetofluid quantum power generation channel 223 from top to bottom. A pair of flat electrodes is provided in each layer of rectangular magnetofluid quantum power generation channel, and the magnetofluid quantum power generation channel is filled with liquid metal 4, and the total volume of the liquid metal 4 is less than the total volume of the two symmetrically arranged magnetofluid quantum power generation channels 3.

[0063] The three layers of rectangular magnetohydrodynamic quantum power generation channels are evenly spaced in the vertical direction (i.e., the height direction of the magnetohydrodynamic quantum power generation channels 3), and the magnetic field B passes through all layers of magnetohydrodynamic quantum power generation channels in the vertical direction; each pair of electrodes is located on both sides of the corresponding layer of rectangular magnetohydrodynamic quantum power generation channels, and each pair of electrodes includes two flat electrodes, which are thin flat plates made of conductive materials. The materials of the flat electrodes can be selected from metal conductors such as gold, silver, platinum, aluminum, nickel, copper, titanium, chromium, etc., or the flat electrodes are made of an alloy formed by at least two of gold, silver, platinum, aluminum, nickel, copper, titanium or chromium.

[0064] The length of each flat plate electrode is equal to the length of each rectangular magnetic fluid electron power generation channel, and the height of each flat plate electrode is equal to the height of each rectangular magnetic fluid electron power generation channel. In each rectangular magnetic fluid electron power generation channel, the two facing surfaces of the two flat plate electrodes are in contact with the liquid metal, and the two opposite surfaces are connected to the external circuit.

[0065] Equivalently, the liquid metal magnetohydrodynamic generator 2 includes a first magnet 211 (i.e., an upper magnet), a second magnet 212 (i.e., a lower magnet), and at least N layers of rectangular magnetohydrodynamic quantum power generation channels. The first magnet 211 (i.e., an upper magnet), at least N layers of rectangular magnetohydrodynamic quantum power generation channels, and the second magnet 212 (i.e., a lower magnet) are arranged along the height direction of the magnetohydrodynamic quantum power generation channel 3, wherein N is a positive integer ≥ 3. A pair of flat plate electrodes is located in each layer of rectangular magnetohydrodynamic quantum power generation channels.

[0066] Among them, the positive electrode of the first flat electrode pair and the negative electrode of the Nth flat electrode pair are connected to the load respectively; the flat electrodes in two adjacent rectangular magnetic fluid electron power generation channels are connected in series through wires, and the connection method is: the negative electrode of the first flat electrode pair is connected to the positive electrode of the second flat electrode pair through a wire, the negative electrode of the second flat electrode pair is connected to the positive electrode of the third flat electrode pair through a wire, ..., the negative electrode of the (N-1)th flat electrode pair is connected to the positive electrode of the Nth flat electrode pair through a wire. The current conduction path is: the negative electrode of the Nth flat electrode pair, liquid metal, the positive electrode of the Nth flat electrode pair, the negative electrode of the (N-1)th flat electrode pair, liquid metal, the positive electrode of the (N-1)th flat electrode pair, ..., the negative electrode of the first flat electrode pair, liquid metal, the positive electrode of the first flat electrode pair, load, negative electrode of the Nth flat electrode pair, forming an electric circuit.

[0067] When the rectangular magnetic fluid quantum power generation channel is provided with three layers, the corresponding electrode pairs are provided with three pairs. The positive electrode plate 231-1 of the first electrode pair and the negative electrode 233-2 of the third electrode pair are respectively connected to the load; the negative electrode 231-2 of the first electrode pair is connected to the positive electrode plate 232-1 of the second electrode pair through a wire, and the negative electrode 232-2 of the second electrode pair is connected to the positive electrode plate 233-1 of the third electrode pair through a wire. The current conduction path is: the negative electrode 233-2 of the third electrode pair, the liquid metal 4, the positive electrode plate 233-1 of the third electrode pair, the negative electrode 232-2 of the second electrode pair, the liquid metal 4, the positive electrode plate 232-1 of the second electrode pair, the negative electrode 231-2 of the first electrode pair, the liquid metal 4, the positive electrode plate 231-1 of the first electrode pair, the load, and the negative electrode 233-2 of the third electrode pair, forming an electric circuit.

[0068] The working process of the low-vibration thermoacoustic magnetofluid power generation device provided by the embodiment of the present invention is as follows: The heater 13 of the thermoacoustic engine 1 absorbs heat from an external high-temperature heat source to form a high-temperature end, and the main room-temperature end heat exchanger 11 exchanges heat with external circulating cooling water to form a room-temperature end, thereby establishing a temperature gradient in the regenerator 12 .

[0069] When the temperature gradient of the regenerator 12 exceeds the critical temperature gradient, the thermoacoustic engine 1 starts to work, the gas self-excites to produce reciprocating pressure fluctuations, and the regenerator 12 continuously converts the heat energy of the external high-temperature heat source into acoustic work (mechanical energy). The propagation direction of the acoustic work is along the positive direction of the temperature gradient, and is first transmitted to the heat buffer tube 14 and the secondary room temperature end heat exchanger 15. After passing through the room temperature end heat exchanger 15, the acoustic work is transmitted in two directions: a part of the acoustic work passes through the resonance tube 16 and reaches the electrical insulation pipes of the two symmetrically arranged magnetohydrodynamic power generation channels 3, pushing the liquid metal 4 in the electrical insulation pipe to reciprocate horizontally in the rectangular magnetohydrodynamic power generation channel, cutting the magnetic flux lines and generating electrical power output. The remaining acoustic work is transmitted to the main room temperature end heat exchanger 11 along the feedback tube 17 and the acoustic volume 18, and is amplified again by the regenerator 12, and the cycle is repeated, continuously converting the heat source heat into electrical energy output.

[0070] The feedback tube 17 and the acoustic capacitor 18 can adjust the acoustic field in the loop where the thermoacoustic engine 1 is located, so that the traveling wave component in the regenerator 12 is absolutely dominant, thereby reducing the starting temperature and viscous loss of the thermoacoustic engine 1.

[0071] Figure 5 It is a schematic diagram of the working principle of the low-vibration thermoacoustic magnetofluid power generation device provided by an embodiment of the present invention.

[0072] See also Figure 5 When the liquid metal 4 reciprocates along the length direction of the rectangular magnetofluidic power generation channel, the liquid metal 4 cuts the magnetic flux lines and generates an induced electromotive force. Under uniform magnetic field strength, the induced electromotive force generated in two adjacent rectangular magnetofluidic power generation channels has the same direction and magnitude; the current is output through the electrode pairs in the rectangular magnetofluidic power generation channel. According to the right-hand rule, the direction of the generated induced current is along the width direction of the rectangular magnetofluidic power generation channel, perpendicular to the magnetic force direction, and the positive and negative charges are respectively gathered on the positive and negative plates of each pair of electrodes.

[0073] Compared with the existing thermoacoustic magnetofluid power generation device, the thermoacoustic engine 1 in the thermoacoustic magnetofluid power generation device provided by the embodiment of the present invention has a small volume, high energy density, low starting and operating temperature, and is suitable for the utilization of heat sources in the medium and low temperature zones. At the same time, due to the symmetrical double "U"-shaped magnetofluid power generation channel design, the inertial force of the fluid working medium is symmetrically distributed along the movement direction of the two "U"-shaped magnetofluid power generation channels 3, and the inertial force of the fluid working medium in one "U"-shaped magnetofluid power generation channel 3 is offset by the reverse inertial force generated by the fluid working medium in the other "U"-shaped magnetofluid power generation channel 3. The thermoacoustic magnetofluid power generation device can achieve good force balance and torque balance during operation, the system vibration is low, and the output characteristics are well improved, which can better meet the needs of electrical equipment. In addition, the thermoacoustic magnetofluid power generation device provided by the embodiment of the present invention has the advantages of compact structure, no mechanical moving parts, high reliability, low vibration, and high potential efficiency, and has broad application prospects in the fields of solar energy utilization, biomass energy utilization, waste heat utilization, and power generation in extreme environments.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-vibration thermoacoustic magnetofluid power generation device, characterized in that: include: A thermoacoustic engine, comprising an engine assembly and an air reservoir, wherein the engine assembly is used to extract acoustic work and form a traveling wave phase, and the air reservoir is used to adjust acoustic impedance and resonance conditions; A liquid metal magnetohydrodynamic generator comprises at least two magnetohydrodynamic power generation channels, each two of which are symmetrically arranged, one end of each of which is connected to the engine assembly, and the other end of each of which is connected to the gas reservoir, the interior of each of which is filled with liquid metal or liquid metal containing nano-enhanced conductive material, the outer wall of the magnetohydrodynamic power generation channel is provided with a first magnet and a second magnet, the first magnet and the second magnet are used to construct a parallel magnetic field, and at least one pair of electrode pairs is embedded in the insulating layer of the magnetohydrodynamic power generation channel, and at least one pair of electrode pairs is located on the channel wall parallel to the direction of the magnetic field.

2. The low-vibration thermoacoustic magnetofluid power generation device according to claim 1, characterized in that: The magnetic fluid power generation channel comprises a first pipe section, a second pipe section and a third pipe section which are connected end to end in sequence, the second pipe section is arranged horizontally, and the first pipe section and the third pipe section are vertically connected to both ends of the second pipe section; The first pipe sections of the two symmetrically arranged magnetic fluid power generation channels overlap, the first pipe section is connected to the engine assembly, and the second pipe section and the third pipe section are symmetrically arranged with the axis of the first pipe section as the symmetry axis; The first magnet and the second magnet are arranged at positions corresponding to the second pipe section, and at least one pair of the electrode pairs is located at positions corresponding to the second pipe section.

3. The low-vibration thermoacoustic magnetofluid power generation device according to claim 2, characterized in that: The cross section of the second pipe segment is rectangular, and the cross sections of the first pipe segment and the third pipe segment are both circular.

4. The low-vibration thermoacoustic magnetofluid power generation device according to claim 1, characterized in that: At least three pairs of electrodes are embedded on the insulating layer of the magnetic fluid power generation channel, and two adjacent pairs of electrodes are arranged at intervals; and among the two adjacent pairs of electrodes, the negative electrode plate of one pair of electrodes and the positive electrode plate of the other pair of electrodes are connected in series through a wire, and the load is connected to the positive electrode plate of the first electrode pair and the negative electrode plate of the last electrode pair through the wire.

5. The low-vibration thermoacoustic magnetofluid power generation device according to claim 4, characterized in that: Three pairs of electrodes are embedded on the insulating layer of the magnetic fluid power generation channel, and two adjacent pairs of electrodes are arranged at intervals; The negative plate of the first electrode pair is connected to the positive plate of the second electrode pair by a wire, and the negative plate of the second electrode pair is connected to the positive plate of the third electrode pair by a wire; the load is connected to the positive plate of the first electrode pair and the negative plate of the third electrode pair by a wire to form an electrical circuit.

6. The low-vibration thermoacoustic magnetofluid power generation device according to claim 4, characterized in that: An insulating plate is provided inside the magnetic fluid power generation channel, and the insulating plate is located in the gap between two adjacent pairs of electrodes. The insulating plate divides the magnetic fluid power generation channel into at least three magnetic fluid quantum power generation channels, and each pair of electrodes is located on both sides of the corresponding magnetic fluid quantum power generation channel.

7. The low-vibration thermoacoustic magnetofluid power generation device according to any one of claims 1 to 6, characterized in that: The engine assembly includes a main room temperature end heat exchanger, a regenerator, a heater, a secondary room temperature end heat exchanger, a resonance tube, a feedback tube and a sound volume which are connected in sequence; The main room temperature end heat exchanger and the secondary room temperature end heat exchanger exchange heat with an external low temperature heat source to form a room temperature end, the heater exchanges heat with an external high temperature heat source to form a high temperature end, and the regenerator is used to generate acoustic work; One end of each of the magnetic fluid power generation channels is connected to the resonance tube.

8. The low-vibration thermoacoustic magnetofluid power generation device according to claim 7, characterized in that: The engine assembly further comprises a heat buffer tube, one end of which is connected to the heater, and the other end of which is connected to the sub-room temperature end heat exchanger; The cross-sectional areas of the main room temperature end heat exchanger, the regenerator, and the heater are all larger than the cross-sectional areas of any one of the thermal buffer tube, the secondary room temperature end heat exchanger, and the resonance tube.

9. The low-vibration thermoacoustic magnetofluid power generation device according to any one of claims 1 to 6, characterized in that: The liquid metal includes any one of mercury, gallium, gallium-indium-tin alloy and sodium-potassium liquid alloy; the nano-enhanced conductive material includes nano-copper, silver or carbon nanotube.

10. The low-vibration thermoacoustic magnetofluid power generation device according to any one of claims 1 to 6, characterized in that: The electrode is made of gold, silver, platinum, aluminum, nickel, copper, titanium or chromium, or the electrode is made of an alloy formed by at least two of gold, silver, platinum, aluminum, nickel, copper, titanium or chromium.

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