Loop free piston thermo-acoustic generator with built-in nuclear fuel

Abstract

The invention relates to the technical field of power generation devices, and provides a nuclear fuel built-in loop free piston thermo-acoustic generator which comprises a thermo-acoustic engine, a control drum, a neutron reflecting layer and a piston type generator, the thermo-acoustic engine comprises a low-temperature heat exchanger, a heat regenerator and a reactor core which are arranged in sequence, and the reactor core is provided with a channel for working medium gas to circulate; the control drum is arranged on the peripheral side of the thermoacoustic engine; the thermoacoustic engine and the control drum are both arranged in the neutron reflecting layer, the piston type generator is provided with a main piston air cylinder, the main piston air cylinder is in acoustic communication with the outlet end of the thermoacoustic engine through an expansion cavity side resonance tube, and the piston type generator is used for converting part of acoustic power into electric energy and adjusting the acoustic impedance phase angle. The reactor core is directly used as a heat source to be arranged in the thermoacoustic engine, so that the reactor core directly replaces a hot end heat exchanger in the traditional technology, the arrangement of a middle heat transfer structure is avoided, the structure is simple, and the problem of low heat transfer efficiency caused by the heat transfer structure is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power generation devices, in particular to a loop free piston thermoacoustic generator with built-in nuclear fuel. BACKGROUND

[0002] Thermoacoustic power generation technology is an energy conversion method based on thermoacoustic effect. A thermoacoustic engine utilizes the temperature gradient between the high-temperature end and the low-temperature end to excite acoustic oscillation in an acoustic resonance system filled with working gas, thereby directly converting thermal energy into acoustic energy, and further converting the acoustic energy into electrical energy through a piston generator or other conversion device.

[0003] The heat source of the high-temperature end of the thermoacoustic engine can be provided by various energy sources. However, in the prior art, the external energy source and the thermoacoustic engine are two independent units. A heat transfer structure needs to be provided between the external energy source and the high-temperature end of the thermoacoustic engine to transfer the heat generated by the external energy source to the high-temperature end of the thermoacoustic engine. The additional heat transfer structure increases the complexity of the system of the thermoacoustic generator, and the heat transfer efficiency is low. It also leads to a decrease in the heat transfer efficiency between the reactor and the free piston thermoacoustic generator.

[0004] Therefore, how to solve the problem of low heat transfer efficiency to the high-temperature end of the thermoacoustic engine and complex structure of the existing thermoacoustic generator has become an important technical problem to be solved by those skilled in the art. SUMMARY

[0005] The present application provides a loop free piston thermoacoustic generator with built-in nuclear fuel to solve the problem of low heat transfer efficiency to the high-temperature end of the thermoacoustic engine and complex structure of the existing thermoacoustic generator.

[0006] The present application provides a loop free piston thermoacoustic generator with built-in nuclear fuel, comprising: a thermoacoustic engine for converting thermal energy into acoustic work, the thermoacoustic engine comprising a low-temperature heat exchanger, a regenerator and a reactor core, the low-temperature heat exchanger, the regenerator and the reactor core being arranged in sequence, the reactor core having a passage for the flow of working gas; a control drum arranged on the side of the thermoacoustic engine; a neutron reflector, the thermoacoustic engine and the control drum being arranged in the neutron reflector; a piston generator having a main piston cylinder, the main piston cylinder being in acoustic communication with the outlet end of the thermoacoustic engine through an expansion cavity side resonant tube, the piston generator being used for converting part of the acoustic work into electrical energy and adjusting the phase angle of acoustic impedance.

[0007] According to the loop free piston thermoacoustic generator with built-in nuclear fuel provided by the present application, A shielding layer is arranged outside the neutron reflecting layer, and the control input end of the control drum and the piston generator are located outside the shielding layer.

[0008] According to the application, a loop free-piston thermoacoustic generator with built-in nuclear fuel is provided, and the piston generator comprises: A power piston is arranged in the main piston cylinder, and the power piston divides the main piston cylinder into a motor front cavity and a motor back cavity, and the motor front cavity is connected with the expansion cavity side resonant pipe.

[0009] According to the application, a loop free-piston thermoacoustic generator with built-in nuclear fuel is provided, and the piston generator further comprises: A phase modulation device is arranged between the motor back cavity and the inlet end of the thermoacoustic engine, and the phase modulation device is used for adjusting the phase angle of acoustic impedance, the phase modulation device is connected with the motor back cavity through the back cavity side resonant pipe, and the phase modulation device is connected with the inlet end of the thermoacoustic engine through the compression cavity side resonant pipe.

[0010] According to the application, a loop free-piston thermoacoustic generator with built-in nuclear fuel is provided, and the phase modulation device comprises: A phase modulation piston cylinder; A phase modulation piston is arranged in the phase modulation piston cylinder, and the phase modulation piston divides the phase modulation piston cylinder into a phase modulation piston back cavity and a phase modulation piston front cavity, the phase modulation piston back cavity is connected with the back cavity side resonant pipe, and the phase modulation piston front cavity is connected with the compression cavity side resonant pipe.

[0011] According to the application, a loop free-piston thermoacoustic generator with built-in nuclear fuel is provided, and the thermoacoustic engine comprises a pair of low-temperature heat exchangers, a pair of regenerators and a pair of reactor cores, a space is arranged between the pair of reactor cores, and the regenerators and the low-temperature heat exchangers are arranged on the sides of the pair of reactor cores away from each other in sequence. The first end of the expansion cavity side resonant pipe is connected with the space between the pair of reactor cores, and the second end of the expansion cavity side resonant pipe has two branch pipes, the main piston cylinder, the back cavity side resonant pipe, the phase modulation piston cylinder and the compression cavity side resonant pipe are arranged in each branch pipe in correspondence, and the compression cavity side resonant pipe corresponding to each branch pipe is connected with one low-temperature heat exchanger.

[0012] According to the application, a loop free-piston thermoacoustic generator with built-in nuclear fuel is provided, and the piston generator further comprises: A thermal buffer cylinder is fixedly arranged on the side of the power piston facing the motor front cavity.

[0013] The loop free-piston thermoacoustic generator with built-in nuclear fuel further comprises: The thermal buffer tube and the sub-low temperature heat exchanger are sequentially arranged between the outlet end of the thermoacoustic engine and the expansion cavity side resonant tube.

[0014] The loop free-piston thermoacoustic generator with built-in nuclear fuel further comprises that the cross-sectional area of the phase modulation piston cylinder is greater than the cross-sectional area of the back cavity side resonant tube and the cross-sectional area of the compression cavity side resonant tube, and the cross-sectional area of the main piston cylinder is greater than the cross-sectional area of the expansion cavity side resonant tube and the cross-sectional area of the back cavity side resonant tube.

[0015] The loop free-piston thermoacoustic generator with built-in nuclear fuel further comprises that the phase modulation piston and the phase modulation piston cylinder are slidably connected through a gas bearing, and the power piston and the main piston cylinder are slidably connected through a gas bearing.

[0016] The loop free-piston thermoacoustic generator with built-in nuclear fuel comprises a thermoacoustic engine, a control drum, a neutron reflector and a piston generator. The thermoacoustic engine is used for converting heat energy into acoustic power. The piston generator has a main piston cylinder. The main piston cylinder is in acoustic communication with an outlet end of the thermoacoustic engine through an expansion cavity side resonant tube. The piston generator is used for converting part of the acoustic power into electric energy and adjusting the phase angle of acoustic impedance. The thermoacoustic engine comprises a low temperature heat exchanger, a regenerator and a reactor core. The low temperature heat exchanger, the regenerator and the reactor core are sequentially arranged. The control drum is arranged on the side of the thermoacoustic engine. The thermoacoustic engine and the control drum are arranged in the neutron reflector. The low temperature heat exchanger absorbs heat, so that one end of the regenerator is kept at a low temperature. The control drum can control the heat generation power of the reactor core. The heat generated by the reactor core directly acts on the regenerator, so that the other end of the regenerator is kept at a high temperature, thereby forming a temperature gradient in the regenerator. When the temperature gradient of the regenerator is higher than a certain value, spontaneous acoustic wave oscillation is generated in the regenerator, so that heat energy is converted into acoustic power. The end where the reactor core is located is the outlet end of the thermoacoustic engine, and the end where the low temperature heat exchanger is located is the inlet end of the thermoacoustic engine. The reactor core has a passage for the flow of working gas, so as to output acoustic power to the piston generator. In this way, the reactor core capable of releasing heat is directly arranged in the thermoacoustic engine as a heat source, so that the reactor core directly replaces the heat end heat exchanger in the conventional technology, avoids the arrangement of an intermediate heat transfer structure, has a simple structure, and can avoid the problem of low heat transfer efficiency caused by the heat transfer structure. The problems of low heat transfer efficiency and complex structure of the existing thermoacoustic generator are solved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor based on these drawings.

[0018] Fig. 1 Figure is a structural schematic diagram of a loop free piston thermoacoustic generator with built-in nuclear fuel provided by the present application.

[0019] Fig. 2 Figure is a structural schematic diagram of a loop free piston thermoacoustic generator with built-in nuclear fuel provided by the present application when using an opposed thermoacoustic engine.

[0020] Reference signs: 1, neutron reflector; 2, control drum; 3, low temperature heat exchanger; 4, regenerator; 5, reactor core; 6, expansion chamber side resonator; 7, piston generator; 8, shielding layer; 9, compression chamber side resonator; 10, power piston; 11, motor front chamber; 12, motor back chamber; 13, thermal buffer tube; 14, secondary low temperature heat exchanger; 15, thermal buffer cylinder; 16, phase modulation piston; 17, phase modulation piston back chamber; 18, phase modulation piston front chamber; 19, back chamber side resonator. DETAILED DESCRIPTION

[0021] In order to make the objects, technical solutions and advantages of the present application clearer, the following will combine the drawings in the present application to clearly and completely describe the technical solutions in the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0022] In the description of the embodiments of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In addition, the terms "first", "second", "third" are only for description purposes, and cannot be understood as indicating or implying relative importance.

[0023] In the description of the embodiments of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "connected", "connected to", "connection" should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0024] In the embodiments of the present application, unless specifically defined and limited otherwise, the first feature is "on" or "under" the second feature can be 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, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0025] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0026] The following will be described in conjunction with Figs. 1-2 The present application describes a loop free piston thermoacoustic generator with inbuilt nuclear fuel.

[0027] As Figs. 1-2 shown, the loop free piston thermoacoustic generator with inbuilt nuclear fuel provided by the embodiments of the present application comprises a thermoacoustic engine, a neutron reflector 1, a control drum 2 and a piston generator 7.

[0028] Specifically, the thermoacoustic engine is used to convert thermal energy into acoustic power. The piston generator 7 has a main piston cylinder, which is in acoustic communication with the outlet end of the thermoacoustic engine through an expansion cavity side harmonic tube 6. The piston generator is used to convert part of the acoustic power into electrical energy and adjust the phase angle of the acoustic impedance.

[0029] The thermoacoustic engine comprises a low-temperature heat exchanger 3, a regenerator 4 and a reactor core 5 arranged in sequence.

[0030] The control drum 2 is arranged at the periphery of the thermoacoustic engine, and the thermoacoustic engine and the control drum 2 are arranged in the neutron reflector 1.

[0031] The low-temperature heat exchanger 3 corresponds to the inlet end of the thermoacoustic engine, and the reactor core 5 corresponds to the outlet end of the thermoacoustic engine. The low-temperature heat exchanger 3 absorbs heat to keep one end of the regenerator 4 at a low temperature.

[0032] The reactor core 5 comprises nuclear fuel. The control drum 2 can control the heat generation power of the reactor core 5, and the heat released by the reactor core 5 directly acts on the regenerator 4 to keep the other end of the regenerator 4 at a high temperature, thereby forming a temperature gradient in the regenerator 4.

[0033] When the temperature gradient of the regenerator 4 is higher than a certain value, spontaneous acoustic wave oscillation will occur in the regenerator 4, converting heat energy into acoustic power. The end where the reactor core 5 is located is the outlet end of the thermoacoustic engine, and the end where the low-temperature heat exchanger 3 is located is the inlet end of the thermoacoustic engine. The reactor core 5 has a passage for the working gas to flow through, so that the acoustic power can be output to the piston generator 7, ensuring that the heat energy generated by the reactor core 5 can be efficiently converted into acoustic power.

[0034] In this way, the reactor core 5 capable of releasing heat is directly arranged as a heat source in the interior of the thermoacoustic engine, so that the reactor core 5 directly replaces the heat end heat exchanger in the conventional technology, avoiding the arrangement of an intermediate heat transfer structure, simplifying the structure, and avoiding the problem of low heat transfer efficiency caused by the heat transfer structure. The problems of low heat transfer efficiency and complex structure of the existing thermoacoustic generator are solved.

[0035] In the embodiment of the present application, the loop free-piston thermoacoustic generator with built-in nuclear fuel further comprises a shielding layer 8.

[0036] The shielding layer 8 is arranged outside the neutron reflector 1 and can effectively shield the radiation leaked from the reactor core 5 and the neutron reflector 1, providing a safe operating and working environment for external equipment and personnel.

[0037] The control input end of the control drum 2 and the piston generator 7 are located outside the shielding layer 8. The key components such as the piston generator 7 can be protected from the radiation damage of strong radiation, improving the reliability and service life of the key components, and facilitating the maintenance and replacement of these key components, and effectively isolating them from the high-temperature environment of the reactor core 5.

[0038] In this embodiment, the piston generator 7 comprises a power piston 10. The power piston 10 is arranged in the main piston cylinder, and the piston generator 7 further comprises a rotor and a stator. The power piston 10 drives the rotor to reciprocate relative to the stator under the action of acoustic power. The rotor is a permanent magnet, and the stator is a coil. By cutting the magnetic induction lines, part of the acoustic power is converted into electrical energy.

[0039] The power piston 10 divides the main piston cylinder into a motor front cavity 11 and a motor back cavity 12. The motor front cavity 11 is connected to the expansion chamber side resonant tube 6, and is used to directly receive high-pressure sound waves from the outlet end of the thermoacoustic engine to drive the power piston 10 to move.

[0040] In a further embodiment, the loop free-piston thermoacoustic generator with built-in nuclear fuel further comprises a phase adjustment device. The phase adjustment device is arranged between the motor back cavity 12 and the inlet end of the thermoacoustic engine, and is used to adjust the phase angle of the acoustic impedance.

[0041] The phase adjustment device is connected to the motor back cavity 12 through the back cavity side resonant tube 19, and is connected to the inlet end of the thermoacoustic engine through the compression chamber side resonant tube 9. In this way, a complete sound wave loop is formed, providing a stable acoustic environment for the continuous propagation and amplification of sound waves.

[0042] The acoustic power output by the thermoacoustic engine enters the main piston cylinder, and part of the acoustic power is converted into reciprocating kinetic energy. The remaining acoustic power returns to the low-temperature heat exchanger 3 through the back cavity side resonant tube 19 and the phase adjustment device, and continues to undergo thermal power conversion, forming a complete thermodynamic cycle.

[0043] The piston generator 7 and the phase adjustment device can assist in phase adjustment, to some extent, can replace the gas resonance phase adjustment in each resonant tube, and no longer simply rely on each resonant tube to achieve phase matching. This is conducive to shortening the total length of the resonant tube (the total length of the resonant tube includes the sum of the lengths of the expansion chamber side resonant tube 6, the back cavity side resonant tube 19, and the compression chamber side resonant tube 9 corresponding to each loop), and improving the structural compactness and power density of the loop free-piston thermoacoustic generator with built-in nuclear fuel.

[0044] In this embodiment, the phase adjustment device comprises a phase adjustment piston cylinder and a phase adjustment piston 16. The phase adjustment piston 16 is arranged in the phase adjustment piston cylinder.

[0045] The phase adjustment piston 16 divides the phase adjustment piston cylinder into a phase adjustment piston back cavity 17 and a phase adjustment piston front cavity 18. The phase adjustment piston back cavity 17 is connected to the back cavity side resonant tube 19, and the phase adjustment piston front cavity 18 is connected to the compression chamber side resonant tube 9. The phase adjustment piston cylinder is directly connected in series between the back cavity side resonant tube 19 and the compression chamber side resonant tube 9, so that it can directly act on the sound field at the inlet end of the thermoacoustic engine to effectively adjust the acoustic impedance.

[0046] Under the action of the sound wave, the phase modulation piston 16 will produce reciprocating oscillation, the phase modulation piston back cavity 17 acts as a gas spring, the mass of the phase modulation piston 16 and the stiffness of the phase modulation piston back cavity 17 together constitute a mechanical resonance system, which can provide a specific acoustic impedance, and play a role of solid resonance phase modulation, thereby replacing the gas resonance phase modulation of part of the resonance tube in function.

[0047] The power piston 10 and the phase modulation piston 16 can reciprocate at the balance position, and the direct current loss in the loop system can be eliminated. The thermoacoustic engine and the back cavity side resonance tube are separated by the phase modulation piston 16 and the power piston 10, and the pressure ratio of the thermoacoustic engine is no longer affected by the back cavity side resonance tube. The thermoacoustic engine can operate at a high pressure ratio to obtain a high-efficiency thermoacoustic conversion efficiency. Moreover, the back cavity side resonance tube works at a low pressure ratio, which can significantly reduce the flow loss of the sound wave in the long-distance propagation in the back cavity side resonance tube.

[0048] In the embodiment, the thermoacoustic engine includes a pair of low-temperature heat exchangers 3, a pair of regenerators 4 and a pair of reactor cores 5. The pair of reactor cores 5 has a space therebetween, and the reactor cores 5 away from each other are sequentially provided with the regenerators 4 and the low-temperature heat exchangers 3, respectively.

[0049] The space between the pair of reactor cores 5 corresponds to the outlet end of the thermoacoustic engine, and the pair of low-temperature heat exchangers 3 corresponds to the inlet end of the thermoacoustic engine. The first end of the expansion cavity side resonance tube 6 is connected to the space between the pair of reactor cores 5, that is, the first end of the expansion cavity side resonance tube 6 is connected to the outlet end of the thermoacoustic engine.

[0050] The second end of the expansion cavity side resonance tube 6 has two branch pipes, each of which is provided with a main piston cylinder, a back cavity side resonance tube 19, a phase modulation piston cylinder and a compression cavity side resonance tube 9, and each of the compression cavity side resonance tubes 9 corresponding to each branch pipe is connected to a low-temperature heat exchanger 3. As shown, the loop free-piston thermoacoustic generator with built-in nuclear fuel has two complete sound wave loops.

[0051] In this way, not only a stable acoustic environment is provided for the continuous propagation and amplification of the sound wave, but also the remaining sound function can smoothly return to the inlet end of the thermoacoustic engine after part of the sound work is extracted in the piston generator 7, to continue to participate in the conversion of thermal work, thereby forming a complete and efficient thermodynamic cycle.

[0052] It should be noted that the parameters of the pair of low-temperature heat exchangers 3, the pair of regenerators 4 and the pair of reactor cores 5 are consistent, which can reduce the vibration of the system.

[0053] In the embodiment of the application, the loop free-piston thermoacoustic generator with built-in nuclear fuel further comprises a thermal buffer cylinder 15 fixedly arranged on the side of the power piston 10 facing the motor front cavity 11.

[0054] The thermal buffer cylinder 15 can form a temperature gradient region between the high-temperature motor front cavity 11 and the normal-temperature power piston 10, and plays a role of thermal buffering, can effectively isolate the non-isothermal heat exchange between the high-temperature working gas in the motor front cavity 11 and the end surface of the power piston 10, avoids the increase in the size of the power piston 10 caused by the temperature rise of the power piston 10, and avoids the problem of the power piston 10 being stuck in the main piston cylinder. Moreover, the irreversible heat loss caused by the temperature difference between the power piston 10 and the working gas can be reduced, and the thermodynamic conversion efficiency of the whole device can be improved.

[0055] In the embodiment, the loop free-piston thermoacoustic generator with built-in nuclear fuel further comprises a thermal buffer pipe 13 and a sub-low-temperature heat exchanger 14, which are sequentially arranged between the outlet end of the thermoacoustic engine and the expansion cavity side resonant pipe 6.

[0056] The thermal buffer pipe 13 can effectively isolate the high-temperature region and the piston generator 7, a temperature gradient region is established between the two, the high-temperature gas at the outlet end of the thermoacoustic engine is prevented from directly contacting the power piston 10, unnecessary heat leakage is reduced, and the thermodynamic efficiency of the system is improved. The sub-low-temperature heat exchanger 14 can perform secondary cooling on the working gas, effectively reduce the viscosity of the working gas in the motor front cavity 11, reduce the viscous dissipation loss of the acoustic power in the transmission process, so that more acoustic power can be used to drive the power piston 10 to do work, and the energy conversion efficiency and output power are improved.

[0057] In a further embodiment, the cross-sectional area of the phase-adjusting piston cylinder is greater than the cross-sectional area of the back cavity side resonant pipe 19 and the cross-sectional area of the compression cavity side resonant pipe 9, so as to form a gas reservoir on the side of the phase-adjusting piston back cavity 17. The cross-sectional area of the main piston cylinder is greater than the cross-sectional area of the expansion cavity side resonant pipe 6 and the cross-sectional area of the back cavity side resonant pipe 19, so as to form a gas reservoir on the side of the motor back cavity 12. In this way, the total length of the resonant pipe can be further shortened.

[0058] In a specific embodiment, the cross-section of the phase-adjusting piston cylinder and the cross-section of the phase-adjusting piston 16 are both perpendicular to the movement direction of the phase-adjusting piston 16, and the cross-section of the main piston cylinder and the cross-section of the power piston 10 are both perpendicular to the movement direction of the power piston 10. The cross-section of the back cavity side resonant pipe 19, the cross-section of the compression cavity side resonant pipe 9 and the cross-section of the expansion cavity side resonant pipe 6 are all perpendicular to the respective extension directions.

[0059] The cross-sectional shape of the phase modulation piston cylinder, the cross-sectional shape of the phase modulation piston 16, the cross-sectional shape of the main piston cylinder, the cross-sectional shape of the power piston 10, the cross-sectional shape of the back cavity side resonant tube 19, the cross-sectional shape of the compression cavity side resonant tube 9, and the cross-sectional shape of the expansion cavity side resonant tube 6 are all set to be circular, the inner diameter of the phase modulation piston cylinder is greater than the inner diameter of the back cavity side resonant tube 19 and the inner diameter of the compression cavity side resonant tube 9, and the inner diameter of the main piston cylinder is greater than the inner diameter of the expansion cavity side resonant tube 6 and the inner diameter of the back cavity side resonant tube 19.

[0060] Specifically, the volume of the motor back cavity 12 is tens of times the swept volume of the power piston 10, and the volume of the phase modulation piston back cavity 17 is tens of times the swept volume of the phase modulation piston 16, wherein the volume of the motor back cavity 12 is greater than the volume of the phase modulation piston back cavity 17.

[0061] Furthermore, the compression cavity side resonant tube 9 and the expansion cavity side resonant tube 6 work in a high pressure ratio condition and mainly serve to connect the core of the thermoacoustic engine, the power piston 10, and the phase modulation piston 16, while the back cavity side resonant tube 19 works in a low pressure ratio condition and mainly serves to realize the resonance of the system. In contrast, the inner diameter of the back cavity side resonant tube 19 is greater than the inner diameter of the compression cavity side resonant tube 9 and the inner diameter of the expansion cavity side resonant tube 6.

[0062] In the embodiment, the phase modulation piston 16 and the phase modulation piston cylinder are in sliding fit through a gas bearing, and the power piston 10 and the main piston cylinder are in sliding fit through a gas bearing.

[0063] The support of the gas film ensures the smoothness of the reciprocating motion of the phase modulation piston 16 and the power piston 10, reduces friction and wear, improves the conversion efficiency of acoustic energy to kinetic energy, and is conducive to prolonging the service life and operation reliability of the loop free piston thermoacoustic generator with built-in nuclear fuel.

[0064] In the embodiment, the power piston 10, the motor back cavity 12, the back cavity side resonant tube 19, the phase modulation piston back cavity 17, and the phase modulation piston 16 are combined in series, which plays a role of phase modulation, and in combination with the phase modulation piston 16 and the gas reservoirs located at both ends of the back cavity side resonant tube 19, the total length of the resonant tube can be shortened to within one tenth to one half of the wavelength of the sound wave, so that the power density of the loop free piston thermoacoustic generator with built-in nuclear fuel is significantly improved.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A loop-free piston thermoacoustic generator with built-in nuclear fuel, characterized in that, include: The thermoacoustic engine is used to convert thermal energy into acoustic power. The thermoacoustic engine includes a cryogenic heat exchanger (3), a regenerator (4), and a reactor core (5). The cryogenic heat exchanger (3), the regenerator (4), and the reactor core (5) are arranged in sequence. The reactor core (5) has a channel for the working gas to flow. A control drum (2) is disposed around the thermoacoustic engine; The neutron reflector (1) is provided, and the thermoacoustic engine and the control drum (2) are both disposed within the neutron reflector (1); The piston generator (7) has a main piston cylinder, which is acoustically connected to the outlet end of the thermoacoustic engine through an expansion chamber side resonant tube (6). The piston generator (7) is used to convert part of the acoustic power into electrical energy and adjust the acoustic impedance phase angle.

2. The loop-free piston thermoacoustic generator with built-in nuclear fuel according to claim 1, characterized in that, Also includes: The shielding layer (8) is located outside the neutron reflector layer (1), and the control input terminal of the control drum (2) and the piston generator (7) are both located outside the shielding layer (8).

3. The loop-free piston thermoacoustic generator with built-in nuclear fuel according to claim 1, characterized in that, The piston generator includes: The power piston (10) is disposed in the main piston cylinder. The power piston (10) divides the main piston cylinder into a motor front chamber (11) and a motor back chamber (12). The motor front chamber (11) is connected to the expansion chamber side resonant tube (6).

4. The loop-free piston thermoacoustic generator with built-in nuclear fuel according to claim 3, characterized in that, Also includes: A phase adjustment device is disposed between the back cavity of the motor (12) and the inlet end of the thermoacoustic engine. The phase adjustment device is used to adjust the acoustic impedance phase angle. The phase adjustment device is connected to the back cavity of the motor (12) through the back cavity side resonant tube (19). The phase adjustment device is connected to the inlet end of the thermoacoustic engine through the compression cavity side resonant tube (9).

5. The loop-free piston thermoacoustic generator with built-in nuclear fuel according to claim 4, characterized in that, The phase adjustment device includes: Phase-shifting piston cylinder; A phase-adjusting piston (16) is disposed in the phase-adjusting piston cylinder. The phase-adjusting piston (16) divides the phase-adjusting piston cylinder into a phase-adjusting piston back cavity (17) and a phase-adjusting piston front cavity (18). The phase-adjusting piston back cavity (17) is connected to the back cavity side resonant tube (19), and the phase-adjusting piston front cavity (18) is connected to the compression cavity side resonant tube (9).

6. The loop-free piston thermoacoustic generator with built-in nuclear fuel according to claim 5, characterized in that, The thermoacoustic engine includes a pair of cryogenic heat exchangers (3), a pair of regenerators (4) and a pair of reactor cores (5). There is a gap between the pair of reactor cores (5). The regenerators (4) and the cryogenic heat exchangers (3) are arranged sequentially on the opposite sides of the pair of reactor cores (5). The first end of the expansion cavity side resonant tube (6) is connected to the space between a pair of reactor cores (5). The second end of the expansion cavity side resonant tube (6) has two branch pipes. Each branch pipe is correspondingly provided with the main piston cylinder, the back cavity side resonant tube (19), the phase-adjusting piston cylinder and the compression cavity side resonant tube (9). The compression cavity side resonant tube (9) corresponding to each branch pipe is connected to a cryogenic heat exchanger (3).

7. The loop-free piston thermoacoustic generator with built-in nuclear fuel according to any one of claims 3-6, characterized in that, Also includes: A heat buffer cylinder (15) is fixedly disposed on the side of the power piston (10) facing the front cavity (11) of the motor.

8. The loop-free piston thermoacoustic generator with built-in nuclear fuel according to any one of claims 3-6, characterized in that, Also includes: The thermal buffer tube (13) and the sub-low temperature heat exchanger (14) are sequentially arranged between the outlet end of the thermoacoustic engine and the expansion cavity side resonant tube (6).

9. The loop-free piston thermoacoustic generator with built-in nuclear fuel according to claim 5 or 6, characterized in that, The cross-sectional area of ​​the phase-adjusting piston cylinder is greater than the cross-sectional area of ​​the back cavity side resonator (19) and the cross-sectional area of ​​the compression cavity side resonator (9), and the cross-sectional area of ​​the main piston cylinder is greater than the cross-sectional area of ​​the expansion cavity side resonator (6) and the cross-sectional area of ​​the back cavity side resonator (19).

10. The loop-free piston thermoacoustic generator with built-in nuclear fuel according to claim 5 or 6, characterized in that, The phase-adjusting piston (16) and the phase-adjusting piston cylinder are slidably coupled through a gas bearing, and the power piston (10) and the main piston cylinder are slidably coupled through a gas bearing.

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