Linear generator of thermoacoustic power generation system and thermoacoustic power generation system

Abstract

The utility model provides a linear generator of a thermo-acoustic power generation system and the thermo-acoustic power generation system, which can improve the power generation efficiency of the linear generator of the thermo-acoustic power generation system. A linear generator of a thermoacoustic power generation system includes: a piston having a diaphragm and vibrating back and forth in a cylinder to convert acoustic energy into electric energy; and a diaphragm chamber formed in an annular shape for accommodating the diaphragm, an outer peripheral surface of the piston sliding with respect to the diaphragm chamber during back-and-forth vibration of the piston in the cylinder, and covering the diaphragm chamber without exposing the diaphragm chamber.

Description

TECHNICAL FIELD

[0001] The utility model relates to a linear generator of thermoacoustic power generation system and thermoacoustic power generation system. BACKGROUND

[0002] In recent years, in order to ensure that more people can afford, reliable, sustainable and advanced energy access, research and development are being made to contribute to the efficiency of energy.

[0003] In the prior art, a thermoacoustic generator is proposed, which can convert thermal energy into mechanical energy in the form of sound waves, drive the piston to reciprocate along its central axis, and further convert the mechanical energy into electrical energy output by the linear motor. However, in the structure of the prior art, since the piston is driven by the oscillation of pressure, a sealing space must be formed by a diaphragm or a bellows. However, in the case of sealing with a diaphragm, the diameter of the part for holding the diaphragm will be larger than the diameter of the piston, and during the back and forth vibration of the piston, a space is easily generated between the part for holding the diaphragm and the piston, which will cause the impedance of the sound wave to change, thereby affecting the power generation efficiency of the thermoacoustic generator. Therefore, it is an important topic to develop a structure that improves the power generation efficiency of the thermoacoustic generator.

[0004] The present case aims to improve the power generation efficiency of the thermoacoustic generator and further contribute to the efficiency of energy.

[0005] [Prior Art Document]

[0006] [Patent Document]

[0007] [Patent Document 1] Japanese Patent Publication No. 2011-179720

[0008] [Patent Document 2] Japanese Patent Publication No. 2012-112621 Utility Model Content

[0009] The utility model provides a linear generator of thermoacoustic power generation system and thermoacoustic power generation system can improve the power generation efficiency of linear generator of thermoacoustic power generation system.

[0010] The linear generator of thermoacoustic power generation system of the utility model, comprising: piston, with diaphragm, and the piston vibrates back and forth in the cylinder to convert acoustic energy into electrical energy;And diaphragm chamber, formed into a ring, for accommodating diaphragm, in the process of piston vibrating back and forth in the cylinder, the outer periphery of piston slides relative to diaphragm chamber, and covers diaphragm chamber in a manner that does not expose diaphragm chamber.

[0011] The linear generator of the thermoacoustic power generation system comprises the piston, an annular tube, a regenerator, a heater, a cooler and a resonant tube.

[0012] In an embodiment of the present application, the piston comprises a pair of cup-shaped members, and the diaphragm is clamped by the mating surfaces of the cup-shaped members.

[0013] In an embodiment of the present application, the piston further comprises a cover member having a flat surface, covering one of the cup-shaped members, and the flat surface of the cover member is formed as the sound wave pressure receiving portion of the piston.

[0014] In an embodiment of the present application, the linear generator further comprises a pressure container having an internal space accommodating the coil and the permanent magnet, wherein the linear generator is provided with a communication passage communicating the back surface portion of the piston with the internal space.

[0015] Based on the above, the linear generator of the thermoacoustic power generation system is configured with the piston and the diaphragm chamber, which can avoid the change of the inner diameter of the pipeline and prevent the change of the impedance of the sound wave, and is beneficial to the conversion of energy, thereby improving the power generation efficiency of the linear generator.

[0016] In order to make the above features and advantages of the present application more obvious and easy to understand, the following embodiments are described in detail below, and the detailed description is as follows in combination with the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic view of the thermoacoustic power generation system according to an embodiment of the present application;

[0018] Figure 2 is Figure 1 a schematic view of the linear generator of the thermoacoustic power generation system shown in FIG.

[0019] Figures 3A to 3C is Figure 2 a schematic view of the state of the diaphragm when the piston vibrates back and forth;

[0020] Figure 4 is a schematic view of the linear generator near the piston according to another embodiment of the present application;

[0021] Figure 5 is a schematic view of the linear generator according to still another embodiment of the present application.

[0022] BRIEF DESCRIPTION OF DRAWINGS

[0023] 10, 20, 30: linear generator

[0024] 11, 21: piston

[0025] 11a, 11b: cup-shaped member

[0026] 12: cylinder

[0027] 12a: diaphragm chamber

[0028] 13: pressure vessel

[0029] 21: cover member

[0030] 31: communication passage

[0031] 100: thermoacoustic power generation system

[0032] 110: annular tube

[0033] 120: prime mover

[0034] 121: accumulator

[0035] 122: heater

[0036] 123: cooler

[0037] 130: resonator

[0038] DF: diaphragm

[0039] CL: coil

[0040] PM: permanent magnet DETAILED DESCRIPTION

[0041] Figure 1 is a schematic view of a thermoacoustic power generation system according to an embodiment of the present application; Figure 2 is Figure 1 is a schematic view of a linear generator of the thermoacoustic power generation system shown in FIG. 1 near a piston; Figures 3A to 3C is Figure 2 is a schematic view of a state of a diaphragm when the piston is reciprocated. Hereinafter, the detailed structure of the thermoacoustic power generation system 100 and the linear generator 10 will be described. Figures 1 to 3C

[0042] Referring to Figure 1 In the present embodiment, the thermoacoustic power generation system 100 includes a linear generator 10, an annular tube 110, a prime mover 120, and a resonator 130. In the present embodiment, the annular tube 110 is filled with working gas. As shown in FIG. 1, the linear generator 10 is connected to the annular tube 110 via a communication passage 31. The linear generator 10 is connected to the resonator 130 via the communication passage 31. The linear generator 10 is connected to the prime mover 120 via the communication passage 31. Figure 1 ​As shown, in the present embodiment, the prime mover 120 has a heater 122, a regenerator 121 and a cooler 123 arranged along the tube axis direction of the annular tube 110, wherein the regenerator 121 is installed inside the annular tube 110 as a narrow flow channel, and the heater 122 is arranged at one end of the regenerator 121, and the cooler 123 is arranged at the other end of the regenerator 121. 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. Specifically, in the present embodiment, the thermoacoustic power generation system 100 generates a temperature gradient through the heater 122 and the cooler 123 at both ends of the regenerator 121, and when the temperature difference at both ends of the regenerator 121 exceeds a certain critical value, the working gas in the tube generates self-excited vibration, so that the thermal energy is converted into acoustic energy in the prime mover 120, and is transmitted to the linear generator 10 through the annular tube 110 and the resonant tube 130.

[0043] Further, as shown in FIG. 1, Figure 1 and Figure 2 As shown, in the present embodiment, the linear generator 10 includes a piston 11, a cylinder 12, a diaphragm chamber 12a and a pressure vessel 13. Specifically, at least a part of the piston 11 is located in the cylinder 12 and is capable of reciprocating motion within the cylinder 12. The pressure vessel 13 has an internal space for accommodating a coil CL and a permanent magnet PM. The piston 11 has a diaphragm DF, and the diaphragm chamber 12a is formed in a ring shape for accommodating the diaphragm DF, and the piston 11 and the inner wall of the cylinder 12 are sealed by the arrangement of the diaphragm DF to separate the internal space of the resonant tube 130 and the pressure vessel 13, so as to prevent the pressure generated in the front part of the piston 11 close to the resonant tube 130 from escaping to the rear part of the piston 11 close to the pressure vessel 13 through the gap between the piston 11 and the cylinder 12, thereby reducing the energy conversion efficiency.

[0044] Further, as shown in FIG. 1, Figure 1 , Figures 3A to 3C As shown, in the present embodiment, when the acoustic energy generated in the annular tube 110 is transmitted to the linear generator 10 through the resonant tube 130, the piston 11 can vibrate back and forth in the cylinder 12, and drive the magnetic yoke in the linear generator 10, and 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, and an electromotive force is generated. In this way, the acoustic energy is converted into electrical energy in the linear generator 10.

[0045] However, based on the sealing requirement, the outer diameter of the diaphragm DF needs to be larger than the inner diameter of the cylinder 12, and the impedance of the acoustic wave will change with the change of the inner diameter of the tube through which the acoustic wave is transmitted, and the change of the impedance of the acoustic wave will also affect the energy conversion efficiency. In this regard, the piston 11 in the linear generator 10 is arranged as shown in FIG. 1, Figure 1 , Figures 3A to 3CAs shown, in the present embodiment, the outer circumferential surface of the piston 11 slides relative to the diaphragm chamber 12a during the reciprocating movement of the piston 11 within the cylinder 12, and covers the diaphragm chamber 12a in a manner that does not expose the diaphragm chamber 12a. In this way, even during the reciprocating movement of the piston 11 within the cylinder 12, the outer diameter of the diaphragm DF (i.e. the end portion) is not exposed, and the communication between the resonant tube 130 and other parts of the linear generator 10 is blocked. Furthermore, by increasing the range of contact between the piston 11 and the inner wall of the cylinder 12 (i.e. increasing the thickness of the piston 11) to prevent the diaphragm chamber 12a from being exposed, the diameter of the tube near the front portion of the piston 11 will not change during the reciprocating movement of the piston 11 within the cylinder 12, and thus the change in the inner diameter of the tube and the change in the impedance of the sound wave can be avoided, which is conducive to the conversion of energy, and thus improves the power generation efficiency of the linear generator 10.

[0046] Furthermore, as shown in Figure 2 the present embodiment, the piston 11 comprises a pair of cup-shaped members 11a, 11b, and the diaphragm DF is clamped by the mating surfaces of the pair of cup-shaped members 11a, 11b that face each other. In this way, by the contour of the cup-shaped members 11a, 11b, even if the thickness of the piston 11 is increased, the increase in the weight of the piston 11 can be suppressed, and the natural value of the vibration characteristics of the structure of the piston 11 can be increased.

[0047] Furthermore, as shown in Figures 2 to 3C the present embodiment, the cylinder 12 is provided with the diaphragm chamber 12a as a relief portion near the diaphragm DF, and the contour of the diaphragm chamber 12a is designed to predict the displacement of the piston 11 and the deformation of the diaphragm DF caused by the sound wave pressure by computer simulation software, and to exclude the possibility of being provided at a position that will interfere with the diaphragm DF. In this way, as shown in Figures 3A to 3C during the reciprocating movement of the piston 11 within the cylinder 12, there will be no interference between the diaphragm DF and the cylinder 12, and thus the diaphragm DF can also be prevented from being worn and damaged.

[0048] Figure 4 is a schematic view of a linear generator according to another embodiment of the present application near the piston. Please refer to FIG. 4, in Figure 4 the present embodiment, the piston 21 of the linear generator 20 is similar to the piston 11 of the linear generator 10, and the difference between the two is described as follows. In the present embodiment, the piston 21 of the linear generator 20 further comprises a cover member 21 having a flat surface, covering one of the pair of cup-shaped members 11a, 11b, and the flat surface of the cover member 21 is formed as the sound wave pressure receiving portion of the piston 21.

[0049] Thus, the cup-shaped member 11b of the piston 21 near the resonant tube 130 is covered by the cover member 21, so that the sound wave pressure part of the piston 21 can be flattened, easily aligned with the pressure amplitude antinode, effectively utilize the pressure surface, and also inhibit the increase of the weight of the piston 21.

[0050] In addition, the linear generator 20 can also avoid the change of the pipe inner diameter and prevent the change of the sound wave impedance by the arrangement of the cup-shaped members 11a, 11b of the piston 21 and the diaphragm chamber 12a, which is beneficial to the energy conversion. Thus, when the linear generator 20 is applied to the thermoacoustic power generation system 100, the thermoacoustic power generation system 100 can also achieve the above-mentioned effects and advantages, which will not be described here.

[0051] Figure 5 is a schematic view of a linear generator according to another embodiment of the present application. Please refer to FIG. 4, in Figure 4 In the embodiment, the linear generator 30 is similar to the linear generator 10, and the difference is described as follows. In the embodiment, the linear generator 30 is provided with a communication passage 31 which communicates the back surface of the piston 11 and the inner space of the pressure container 13. For example, in the embodiment, the communication passage 31 can be a communication hole. Thus, even when the piston 11 moves due to the sound pressure, the back surface of the piston 11 will not increase the internal pressure due to the compression of the space and the resulting reaction force, so that the stroke amount of the piston 11 and the smooth vibration of the piston 11 in the cylinder 12 can be ensured, and the decrease of the power generation efficiency of the linear generator 30 can be effectively inhibited.

[0052] In addition, the linear generator 30 can also avoid the change of the pipe inner diameter and prevent the change of the sound wave impedance by the arrangement of the cup-shaped members 11a, 11b of the piston 11 and the diaphragm chamber 12a, which is beneficial to the energy conversion. Thus, when the linear generator 30 is applied to the thermoacoustic power generation system 100, the thermoacoustic power generation system 100 can also achieve the above-mentioned effects and advantages, which will not be described here.

[0053] In summary, the thermoacoustic power generation system and the linear generator can avoid the change of the pipe inner diameter and prevent the change of the sound wave impedance by the arrangement of the piston and the diaphragm chamber of the linear generator, which is beneficial to the energy conversion, and further improves the power generation efficiency of the linear generator.

[0054] Finally, it should be noted that: the above embodiments are used to illustrate the technical solutions of the present application, but not limited to them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A linear generator for a thermoacoustic power generation system, characterized in that, include: A piston having a diaphragm, and the piston vibrating back and forth within a cylinder to convert acoustic energy into electrical energy; as well as A diaphragm chamber, formed in an annular shape, is used to house the diaphragm. During the reciprocating motion of the piston within the cylinder, the outer peripheral surface of the piston slides relative to the diaphragm chamber and covers the diaphragm chamber in a manner that does not expose it.

2. The linear generator of the thermoacoustic power generation system according to claim 1, characterized in that, The piston includes a pair of cup-shaped members, and the diaphragm is held by mating surfaces of the pair of cup-shaped members that are opposite to each other.

3. The linear generator of the thermoacoustic power generation system according to claim 2, characterized in that, The piston also includes a cover member having a flat surface that covers one of the pair of cup-shaped members, and the flat surface of the cover member forms the acoustic pressure portion of the piston.

4. The linear generator of the thermoacoustic power generation system according to claim 1, characterized in that, Also includes: A pressure vessel having an internal space for accommodating a coil and a permanent magnet, wherein the linear generator is provided with a communication channel connecting the rear portion of the piston to the internal space.

5. A thermoacoustic power generation system, characterized in that, include: A linear generator as claimed in any one of claims 1 to 4; A ring-shaped tube, sealed with working gas; The heat accumulator is installed inside the annular pipe; A heater is disposed at one end of the heat accumulator; A cooler is provided at the other end of the heat accumulator; as well as A resonant tube, wherein one end of the resonant tube is connected to the annular tube and the other end of the resonant tube is connected to the linear generator, and the thermoacoustic power generation system generates a temperature gradient through the heaters and coolers at both ends of the heat storage device to cause the working gas to generate self-excited vibration.

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