Thermoacoustic power generation system
By setting an expansion tube inside the resonant tube, the dynamic pressure energy at the point of maximum fluid velocity is converted into static pressure energy, thus solving the viscous loss problem caused by the length of the resonant tube and improving the efficiency of the thermoacoustic power generation system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HONDA MOTOR CO LTD
- Filing Date
- 2025-07-07
- Publication Date
- 2026-05-12
AI Technical Summary
In existing thermoacoustic power generation systems, the long length of the resonant tube leads to severe viscous losses, which reduces power generation efficiency.
An expansion tube is installed inside the resonant tube, and the position where the fluid velocity is maximum corresponds to the antinode of the velocity amplitude. The dynamic pressure energy is converted into static pressure energy through the expansion tube to suppress viscous loss.
This effectively reduces the viscous loss within the resonant tube and improves the power generation efficiency of the thermoacoustic power generation system.
Smart Images
Figure CN224228799U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a power generation system, and more particularly to a thermoacoustic power generation system. Background Technology
[0002] In recent years, research and development efforts have been made to contribute to energy efficiency in order to ensure access to affordable, reliable, sustainable and advanced energy for more people.
[0003] In existing technologies, a thermoacoustic generator has been proposed that converts thermal energy from a prime mover into mechanical energy in the form of sound waves. This mechanical energy drives the piston of a linear generator to reciprocate along its central axis, thereby enabling the linear generator to further convert the mechanical energy into electrical energy output. However, in existing thermoacoustic power generation systems, depending on the target frequency, the length of the resonant tube placed between the prime mover and the linear generator can reach several meters, which exacerbates viscous losses and leads to a reduction in power output. Therefore, researching and developing a structure to improve the power generation efficiency of thermoacoustic generators is an important research topic. Utility Model Content
[0004] This invention provides a thermoacoustic power generation system that can reduce the performance degradation caused by viscous losses within the resonant tube.
[0005] According to an embodiment of the present invention, a thermoacoustic power generation system includes: a linear generator having a piston that vibrates back and forth within a cylinder to convert acoustic energy into electrical energy; an annular tube connected to the linear generator via a resonant tube; and a prime mover disposed within the annular tube and including a cooler, a heat accumulator, and a heater arranged in sequence. The resonant tube has an expansion section located at the position of maximum fluid velocity within the resonant tube, the position corresponding to an antinode representing the amplitude of the fluid velocity. The expansion section includes an expanding section and a contracting section, the contracting section being located between the expanding section and the linear generator. The inner diameter of the expanding section gradually increases along the direction from the annular tube to the linear generator, and the inner diameter of the contracting section gradually decreases along the same direction.
[0006] In an embodiment according to the present invention, the center of the expansion tube corresponds to the center of the amplitude.
[0007] In an embodiment of the present invention, the expansion tube includes a planar portion located between the expansion portion and the contraction portion, the planar portion corresponding to the antinode of the amplitude.
[0008] In an embodiment of the present invention, the connection position of the linear generator and the resonant tube corresponds to the node of the amplitude.
[0009] Based on the above, in the thermoacoustic power generation system of this invention, an expansion tube is provided at the position of the antinode of the velocity amplitude where the fluid velocity in the resonant tube is maximum. Through the expansion tube, the dynamic pressure energy at the point of maximum fluid velocity in the resonant tube can be converted into static pressure energy, thereby reducing the flow velocity and suppressing viscous losses. Thus, the thermoacoustic power generation system of this invention can reduce the performance degradation caused by viscous losses within the resonant tube.
[0010] To make the above-mentioned features and advantages of this utility model more apparent and understandable, specific embodiments are described below, and detailed descriptions are provided in conjunction with the accompanying drawings. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of a thermoacoustic power generation system according to an embodiment of the present invention;
[0012] Figure 2 Show Figure 1 The relationship between the resonant tube and its fluid velocity, fluid pressure, expansion angle, and expansion area ratio.
[0013] Explanation of reference numerals in the attached figures:
[0014] 10: Linear Generator
[0015] 11: Piston
[0016] 12: Cylinder block
[0017] 13: Pressure Vessel
[0018] 100: Thermoacoustic power generation system
[0019] 110: Circular pipe
[0020] 120: Prime Motion Machine
[0021] 121: Heat accumulator
[0022] 122: Cooler
[0023] 123: Heater
[0024] 130: Resonant tube
[0025] 132: Expansion tube section
[0026] 1321: Expanded Diameter Section
[0027] 1322: Reduction section
[0028] 1323: Planar section
[0029] 132a: Antinode
[0030] CL: Coil
[0031] D: Direction
[0032] PM: Permanent magnet. Detailed Implementation
[0033] Figure 1 This is a schematic diagram of a thermoacoustic power generation system according to an embodiment of the present invention. Please refer to... Figure 1 In this embodiment, the thermoacoustic power generation system 100 includes a linear generator 10, a ring tube 110, a prime mover 120, and a resonant tube 130. In this embodiment, the ring tube 110 is sealed with a working gas. Figure 1 As shown, in this embodiment, the prime mover 120 is disposed in the annular tube 110 and includes a cooler 122, a heat accumulator 121 and a heater 123 arranged sequentially along the tube axis of the annular tube 110. The heat accumulator 121 is installed in the annular tube 110 and is a narrow flow channel. The heater 123 is disposed at one end of the heat accumulator 121 and the cooler 122 is disposed at the other end of the heat accumulator 121.
[0034] On the other hand, one end of the resonant tube 130 is connected to the annular tube 110, and the other end of the resonant tube 130 is connected to the linear generator 10. That is, the annular tube 110 is connected to the linear generator 10 through the resonant tube 130. Specifically, in this embodiment, the thermoacoustic power generation system 100 generates a temperature gradient through the heater 123 and cooler 122 at both ends of the heat accumulator 121. When the temperature ratio at both ends of the heat accumulator 121 exceeds a certain critical value, the working gas in the pipe generates self-excited vibration, so that the thermal energy is converted into acoustic energy in the prime mover 120 and is transferred to the linear generator 10 through the annular tube 110 and the resonant tube 130.
[0035] Furthermore, such as Figure 1 As shown, in this embodiment, the linear generator 10 includes a piston 11, a cylinder 12, and a pressure vessel 13. Specifically, at least a portion of the piston 11 is located in the cylinder 12 and is capable of reciprocating within the cylinder 12. The pressure vessel 13 has an internal space for accommodating the coil CL and the permanent magnet PM. When the acoustic energy generated in the annular tube 110 propagates to the linear generator 10 through the resonant tube 130, it causes the piston 11 to vibrate back and forth within the cylinder 12, driving the magnetic yoke in the linear generator 10. Through the movement of the magnetic yoke in the linear generator 10, the magnetic flux of the permanent magnet PM in the coil CL changes, generating an electromotive force. In this way, acoustic energy is converted into electrical energy in the linear generator 10.
[0036] Figure 2 Show Figure 1 The relationship between the resonant tube and its fluid velocity, fluid pressure, expansion angle, and expansion area ratio, among which... Figure 2The resonant tube 130 in the uppermost thermoacoustic power generation system 100 is shown without the expansion tube section 132. Please refer to... Figure 1 and Figure 2 In this embodiment, the resonant tube 130 has an expansion tube portion 132, which is located at the position where the fluid velocity is the greatest within the resonant tube 130. This position corresponds to the antinode 132a, which represents the amplitude of the fluid velocity.
[0037] As described above, in the thermoacoustic power generation system 100 of this embodiment, an expansion tube section 132 is provided at the position of the antinode 132a, which corresponds to the velocity amplitude and is the location of maximum fluid velocity in the resonant tube 130. Through the expansion tube section 132, the dynamic pressure energy at the location of maximum fluid velocity in the resonant tube 130 can be converted into static pressure energy to reduce the flow velocity and suppress viscous losses. Therefore, the thermoacoustic power generation system 100 of this embodiment can reduce the performance degradation caused by viscous losses within the resonant tube 130.
[0038] In this embodiment, the expansion tube 132 is, for example, a 2θ expansion tube. Specifically, the 2θ expansion tube is defined as follows: the expansion tube 132 includes an expanding section 1321 and a reducing section 1322. The reducing section 1322 is located between the expanding section 1321 and the linear generator 10. The inner diameter of the expanding section 1321 gradually increases along the direction D from the annular tube 110 to the linear generator 10 with an expansion angle of 2θ, and the inner diameter of the reducing section 1322 gradually decreases along the direction D with an expansion angle of 2θ. In this embodiment, the expansion angle 2θ may be less than or equal to 30 degrees, or the expansion angle 2θ may be equal to 7 to 15 degrees. If the cross-sectional area of the resonant tube 130 at the antinode 132a is A1 (without expansion tube 132), and the cross-sectional area of the resonant tube 130 at the antinode 132a is A2 (without expansion tube 132), and the tube diameter at the antinode 132a is D1 (without expansion tube 132), and the tube diameter at the antinode 132a is D2 (without expansion tube 132), and the fluid velocity at the antinode 132a is u1, then the fluid velocity at the node 132b of the amplitude is u. piston Therefore, the expansion area ratio is equal to A2 / A1, and also equal to (D2 / D1). 2 It is also equal to u1 / u piston .
[0039] In this embodiment, the center of the expansion tube 132 ( Figure 2 The antinode 132a corresponds to the center of the amplitude ( Figure 2 At the antinode 132a, viscous losses are reliably controlled. Furthermore, in this embodiment, the connection position between the linear generator 10 and the resonant tube 130 corresponds to the node 132b of the amplitude, thereby achieving efficient energy conversion and reducing losses.
[0040] In this embodiment, the expansion tube section 132 further includes a planar section 1323, which is located between the diameter expansion section 1321 and the diameter reduction section 1322, and corresponds to the antinode 132a of the amplitude. If the diameter of the resonant tube 130 at the antinode 132a is D1 and the diameter of the resonant tube 130 at the antinode 132a is D2, then the required length of the planar section 1323 is, for example, tanθ divided by (D2-D1) / 2.
[0041] In summary, in the thermoacoustic power generation system of this invention, an expansion tube is provided at the position of the antinode of the velocity amplitude, where the fluid velocity in the resonant tube is maximum. Through the expansion tube, the dynamic pressure energy at the point of maximum fluid velocity in the resonant tube can be converted into static pressure energy, thereby suppressing viscous losses. Therefore, the thermoacoustic power generation system of this invention can reduce the performance degradation caused by viscous losses within the resonant tube.
[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A thermoacoustic power generation system, characterized in that, include: A linear generator having a piston that vibrates back and forth within a cylinder to convert acoustic energy into electrical energy; A ring tube is connected to the linear generator via a resonant tube; as well as The prime mover, located within the annular tube, includes a cooler, a heat accumulator, and a heater arranged in sequence. The resonant tube has an expansion tube section. The expansion tube is located at the position of maximum fluid velocity within the resonant tube, and this position corresponds to the antinode of the wave that represents the amplitude of the fluid velocity. The expansion tube section includes an expansion section and a reduction section. The reduction section is located between the expansion section and the linear generator. The inner diameter of the expansion section gradually increases along the direction from the annular tube to the linear generator, and the inner diameter of the reduction section gradually decreases along the same direction.
2. The thermoacoustic power generation system according to claim 1, characterized in that, The center of the expansion tube corresponds to the center of the amplitude.
3. The thermoacoustic power generation system according to claim 2, characterized in that, The expansion tube includes a planar portion located between the diameter-expanding portion and the diameter-reducing portion. The planar portion corresponds to the antinode of the amplitude.
4. The thermoacoustic power generation system according to any one of claims 1 to 3, characterized in that, The connection point between the linear generator and the resonant tube corresponds to the node of the amplitude.