JP2019207040A - Thermoacoustic device - Google Patents

Abstract

To improve responsiveness from heat input to an energy conversion part to the start of a thermoacoustic self-excited vibration in a thermoacoustic device.SOLUTION: A thermoacoustic device includes acoustic transmission pipes 101, 201 and 300 in which working fluid is encapsulated; an energy conversion unit 102a provided in the acoustic transmission pipe for generating a thermoacoustic self-excited vibration by the establishment of a predetermined condition and converting thermal energy to acoustic energy; an energy consumption unit 202a provided in the acoustic transmission pipe for converting the acoustic energy to energy of a different kind; and vibration generation units 301, 320, 321, 331, 340, and 503 for changing at least any one of a flow rate, pressure, and temperature in a part of the working fluid when a predetermined condition is established, and starting the thermoacoustic self-excited vibration.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a thermoacoustic apparatus that converts energy between thermal energy and acoustic energy.

  2. Description of the Related Art Conventionally, thermoacoustic apparatuses that perform energy conversion between thermal energy and acoustic energy using a thermoacoustic phenomenon are known. The thermoacoustic device is provided with an energy conversion unit that converts thermal energy and acoustic energy inside a pipe filled with a working fluid. By forming a temperature gradient at both ends of the energy conversion unit, the thermoacoustic self-excitation is performed. Sound waves that are vibrations are generated.

  In such a thermoacoustic apparatus, in Patent Document 1, when the thermoacoustic self-excited vibration is not started in the energy conversion unit, the exhaust gas of the internal combustion engine is introduced into the energy conversion unit, and the thermoacoustic self-excited oscillation is accelerated. It has been proposed to encourage outbreaks.

JP 2006-170022 A

  However, as a result of intensive studies by the present inventors, it has been found that oscillation does not start immediately even if exhaust heat equal to or higher than the oscillation temperature of thermoacoustic self-excited vibration is introduced into the energy conversion unit. For this reason, the responsiveness from the introduction of exhaust heat to the energy conversion section until the start of generation of acoustic energy cannot be improved, and the thermoacoustic apparatus cannot be operated efficiently.

  In view of the above points, an object of the present invention is to improve the responsiveness of a thermoacoustic device from the heat input to the energy conversion unit to the start of thermoacoustic self-excited vibration.

  In order to achieve the above object, according to the first aspect of the present invention, the acoustic transmission tube (101, 201, 300) in which the working fluid is enclosed, and the acoustic transmission tube provided in the acoustic transmission tube, and when the predetermined condition is satisfied, An energy conversion unit (102a) that generates vibration and converts thermal energy into acoustic energy, an energy consumption unit (202a) that is provided in the acoustic transmission tube and converts acoustic energy into different types of energy, and a predetermined condition is established And a vibration generating unit (301, 320, 321, 331, 340, 503) that starts thermoacoustic self-excited vibration by changing at least one of flow velocity, pressure, and temperature in a part of the working fluid. It is characterized by that.

  According to the present invention, when a predetermined condition is satisfied, by changing at least one of the flow velocity, pressure, and temperature in a part of the working fluid, an initial bidirectional flow velocity that triggers oscillation can be provided. it can. Thereby, the responsiveness from the heat input of a thermoacoustic apparatus to an oscillation can be improved.

  In addition, the code | symbol in the bracket | parenthesis of each said component shows a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a conceptual diagram which shows the thermoacoustic apparatus of 1st Embodiment. It is a figure which shows the relationship of the action | operation of an on-off valve, the sound pressure in piping, and the edge part temperature of a thermal storage part. It is a conceptual diagram which shows the thermoacoustic apparatus of 2nd Embodiment. It is a figure which shows arrangement | positioning of the thermal storage part and temperature sensor of 2nd Embodiment. It is a flowchart which shows the action | operation of the thermoacoustic apparatus of 2nd Embodiment. It is a conceptual diagram which shows the thermoacoustic apparatus of 3rd Embodiment. It is a conceptual diagram which shows the thermoacoustic apparatus of 4th Embodiment. It is a figure which shows the voltage waveform of 4th Embodiment. It is a figure which shows the voltage waveform of 4th Embodiment. It is a figure which shows the voltage waveform of 5th Embodiment. It is a figure which shows the voltage waveform of 5th Embodiment. It is a conceptual diagram which shows the thermoacoustic apparatus of 6th Embodiment. It is a conceptual diagram which shows the thermoacoustic apparatus of 7th Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the thermoacoustic apparatus 1 according to the first embodiment includes a thermoacoustic engine unit 100 that converts thermal energy into acoustic energy, and a thermoacoustic consumption unit 200 that consumes acoustic energy.

  The thermoacoustic engine unit 100 includes an input loop pipe 101 and an input unit 102. The thermoacoustic consumption unit 200 includes an output loop pipe 201 and an output unit 202.

  The loop pipes 101 and 201 are connected by a connecting pipe 300. These acoustic transmission tubes 101, 201, and 300 are hollow cylindrical members that constitute a sealed space. As the acoustic transmission tubes 101, 201, 300, for example, cylindrical stainless steel pipes can be used. The thermoacoustic apparatus 1 of this embodiment is a double loop type in which two loop pipes 101 and 201 are connected by a connecting pipe 300.

  The acoustic transmission tubes 101, 201, and 300 have working fluid sealed in the internal space. The acoustic transmission tubes 101, 201, and 300 are acoustic transmission tubes that can transmit acoustic energy via a working fluid.

  As the working fluid in the acoustic transmission tubes 101, 201, and 300, for example, a low molecular weight inert gas such as helium, nitrogen, and argon, air, hydrogen, or a mixture thereof can be suitably used. It may be used. In order to improve output, the pressure can be increased to atmospheric pressure or higher.

  As the working fluid, a mixture of a non-condensable fluid and a condensable fluid can also be used. The non-condensable medium is a fluid that does not change in the gas-liquid phase in the operating temperature range of the thermoacoustic device 1. The condensable medium is a fluid that undergoes a gas-liquid phase change in the operating temperature range of the thermoacoustic apparatus 1. The condensable fluid is held in the input unit 102 mainly in a liquid state.

  As the non-condensable fluid, for example, a low molecular weight inert gas such as helium, nitrogen, and argon, air, hydrogen, or a mixture thereof can be preferably used, but different types of non-condensable fluids may be used. . As the condensable fluid, for example, water, carbonic acid, and chlorofluorocarbon can be suitably used, but different types of condensable fluids may be used.

  In the present embodiment, unless otherwise specified, helium above atmospheric pressure is used as the working fluid.

  The input loop pipe 101 is a loop pipe for a thermoacoustic prime mover. The output loop pipe 201 is a loop pipe for a thermoacoustic passive device.

  The input loop pipe 101 is provided with an input unit 102 for inputting heat energy from the outside. The input unit 102 is a prime mover and can convert heat energy input from the outside into acoustic energy. That is, the input unit 102 performs conversion from a heat flow to a work flow.

  The input unit 102 includes a regenerator 102a, a high temperature heat exchange unit 102b, and a low temperature heat exchange unit 102c. These are arranged along the longitudinal direction of the input loop pipe 101.

  The heat accumulator 102a is an energy conversion unit that converts thermal energy into acoustic energy, and is configured as a stack in which a large number of pores are formed. As the heat accumulator 102a, for example, a structure provided with a fine flow path such as a ceramic honeycomb, or a structure obtained by laminating fine metal nets such as a metal mesh such as stainless steel can be used.

  The high temperature heat exchange part 102b is a heat input device, and heats the high temperature side end part of the regenerator 102a by the input of heat energy. For example, an electric heater can be used as the high-temperature heat exchange unit 102b. Alternatively, exhaust heat of an internal combustion engine (not shown) or a secondary battery can be used as the high temperature heat exchange unit 102b.

  The low-temperature heat exchange unit 102c cools the other end side of the heat accumulator 102a by exchanging heat with, for example, cooling water or outside air. If the operation of the thermoacoustic apparatus 1 is short, the cooling heat exchanger 102b can be omitted. However, if the operation of the thermoacoustic apparatus 1 is long, the heat accumulator 102a Since heat is gradually transported from the high temperature side end to the low temperature side end, it is desirable to provide a cooling heat exchanger 102b.

  The high temperature heat exchange unit 101b and the low temperature heat exchange unit 101c cause a temperature difference at both ends of the heat accumulator 101a, and a temperature gradient is formed in the flow direction of the working fluid. When the temperature at both ends of the heat accumulator 101a satisfies a predetermined temperature condition, a predetermined condition is established in which thermoacoustic self-excited vibration can be generated. Hereinafter, the “predetermined condition that allows the thermoacoustic self-excited vibration to be generated” is also referred to as an oscillation enabling condition. In an ideal device in which the working fluid is an ideal gas and nonlinear effects and the like can be ignored, the oscillation enabling condition is satisfied when the absolute temperature ratio at both ends of the heat accumulator 101a exceeds a predetermined value. In this embodiment, the thermoacoustic apparatus 1 that can oscillate when the absolute temperature ratio between both ends of the heat accumulator 101a exceeds a predetermined value will be described. However, the technology disclosed here is a general thermoacoustic apparatus. It is applicable to.

  In the heat storage unit 101a, when the absolute temperature ratio between both ends of the heat storage device 101a exceeds a predetermined value, the working fluid existing inside is pressurized by heating and depressurized by cooling, and a sound wave that is thermoacoustic self-excited vibration. Occurs. That is, the heat storage unit 101a of the input unit 101 performs conversion from thermal energy to acoustic energy.

  The output loop pipe 201 is provided with an output unit 202 that outputs energy to the outside. The output unit 202 is a passive machine, and converts acoustic energy into thermal energy. That is, in the output unit 202, conversion from work flow to heat flow is performed. The output unit 202 is an acoustic energy consumption unit that consumes acoustic energy.

  The output unit 202 includes a heat storage unit 202a, a low temperature heat exchange unit 202b, and a high temperature heat exchange unit 202c. The heat storage unit 202a is similar to the heat storage unit 102a of the input unit 102, for example, a structure provided with fine flow paths such as a ceramic honeycomb, or a structure in which fine metal meshes such as a metal mesh such as stainless steel are laminated. Etc. can be used. The heat storage unit 202a of the output unit 202 is an energy consuming unit that converts acoustic energy into different types of energy. In this embodiment, a temperature gradient is generated at both ends of the heat storage unit 202a by transmitting acoustic energy to the heat storage unit 202a.

  By exchanging heat with one of the high-temperature heat exchanging section 202b or the low-temperature heat exchanging section 202c with room-temperature cooling water, the other heat exchanging section can generate cold or warm heat. For example, cold heat can be generated in the low-temperature heat exchange unit 202c by exchanging heat with normal-temperature cooling water in the high-temperature heat exchange unit 202b. In addition, heat can be generated in the high-temperature heat exchange unit 202b by exchanging heat with the normal temperature cooling water in the low-temperature heat exchange unit 202c.

  The thermoacoustic apparatus 1 is provided with a high-pressure fluid container 310. The high pressure fluid container 310 is filled with a working fluid having a pressure higher than that of the working fluid in the acoustic transmission tubes 101, 201, and 300. The high-pressure fluid container 310 is connected to the connection pipe 300 via the communication pipe 311. The high-pressure fluid container 310 corresponds to the vibration generating unit of the present invention.

  The communication pipe 311 is provided with an on-off valve 312 that opens and closes the flow path of the communication pipe 311. By opening the on-off valve 312, the inside of the high pressure fluid container 310 and the inside of the acoustic transmission pipes 101, 201, 300 are communicated, and the working fluid is supplied from the high pressure fluid container 310 to the acoustic transmission pipes 101, 201, 300. By closing the on-off valve 312, communication between the high-pressure fluid container 310 and the acoustic transmission pipes 101, 201, 300 is blocked, and the working fluid is supplied from the high-pressure fluid container 310 to the acoustic transmission pipes 101, 201, 300. Is stopped.

  As described above, since the working fluid in the acoustic transmission pipes 101, 201, and 300 has a pressure higher than atmospheric pressure, the working fluid may leak from the acoustic transmission pipes 101, 201, and 300. When the pressure of the working fluid in the acoustic transmission pipes 101, 201, and 300 decreases below a predetermined pressure, the on-off valve 312 is opened, and the working fluid in the high-pressure fluid container 310 is moved into the acoustic transmission pipes 101, 201, and 300. To be supplied.

  In the present embodiment, the opening / closing operation of the release valve 312 is performed when the absolute temperature ratio at both ends of the heat accumulator 101a exceeds a predetermined value and the oscillation enabling condition is satisfied.

  Next, the operation of the thermoacoustic apparatus 1 will be described with reference to FIG. In the input unit 101, when heat energy is input from the outside to the high temperature heat exchange unit 101b, the temperature of the high temperature side end of the heat storage unit 101a rises, and a temperature gradient is formed in the heat storage unit 101a.

  When the absolute temperature ratio at both ends of the heat accumulator 101a exceeds a predetermined value and the oscillation enabling condition is satisfied, the on-off valve 312 is opened and immediately closed. Thereby, due to the differential pressure between the inside of the high-pressure fluid container 310 and the inside of the acoustic transmission pipes 101, 201, 300, the pressure locally increases in a part of the working fluid in the acoustic transmission pipes 101, 201, 300.

  In response to the local pressure change of the working fluid, the heat storage unit 101a compresses, heats, expands, and cools the working fluid present inside, generates a sound wave that is thermoacoustic self-excited vibration, and transmits the sound. The sound pressure in the tubes 101, 201, 300 is increased. That is, the heat storage unit 101a of the input unit 101 performs conversion from thermal energy to acoustic energy.

  The broken lines in FIG. 2 indicate changes in sound pressure in the acoustic transmission tubes 101, 201, 300 when there is no local pressure fluctuation of the working fluid in the acoustic transmission tubes 101, 201, 300. When there is no local pressure fluctuation of the working fluid, a certain amount of time is required from the start of oscillation to the start of oscillation. On the other hand, in this embodiment, the oscillation can be started early by giving a local pressure change in a part of the working fluid when the oscillation enabling condition is satisfied.

  Part of the acoustic energy generated by the output unit 102 circulates through the input loop pipe 101 and is re-input to the input unit 102, and the rest passes through the connection pipe 300 and circulates through the output loop pipe 201. In the heat storage unit 202a of the output unit 202, acoustic energy is transmitted, so that one end side where the high temperature heat exchange unit 202c is provided becomes high temperature and the other end side where the low temperature heat exchange unit 202b is provided becomes low temperature. That is, in the heat storage unit 202a of the output unit 202, thermal energy is converted from acoustic energy, and a temperature difference is generated between both ends of the heat storage unit 202a. As a result, in the output unit 202, warm heat is generated in the high temperature heat exchange unit 202c, and cold heat is generated in the low temperature heat exchange unit 202b.

  The output unit 202 can use the heat generated by the high temperature heat exchange unit 202c or the cold generated by the low temperature heat exchange unit 202b. For example, the heat generation capability of the low-temperature heat exchange unit 202b can be improved by exchanging heat with normal-temperature cooling water in the high-temperature heat exchange unit 202c, and the thermoacoustic apparatus 1 can be used as a refrigerator. Alternatively, the heat generation capacity of the high-temperature heat exchange unit 202c can be improved by exchanging heat with the normal temperature cooling water in the low-temperature cold-heat heat exchange unit 202c, and the thermoacoustic device 1 can be used as a heater.

  Here, the start of oscillation of thermoacoustic self-excited vibration when the temperature ratio at both ends of the heat storage unit 101a exceeds a predetermined value will be described.

  The sound can be decomposed into a flow rate corresponding to the vibration of the working fluid and a fluctuating pressure corresponding to the expansion and contraction of the working fluid. When the temperature ratio is given to both ends of the heat storage unit 101a, if the working fluid on the low temperature side in the heat storage unit 101a moves to the high temperature side, the heat of the heat storage unit 101a is transferred to the working fluid and the working fluid expands. When the working fluid moves on the high temperature side in the heat storage unit 101a to the low temperature side, the heat of the working fluid is transmitted to the heat storage unit 101a and the working fluid contracts. That is, the fluctuating pressure increases with the flow rate of the working fluid.

  Even if the temperature ratio is given to both ends of the heat storage unit 101a and the working fluid expands or contracts according to the temperature of each part, if there is no flow rate of the working fluid in the heat storage unit 101a, it periodically fluctuates at a fixed point. The pressure does not go up and down. Moreover, even if the flow rate of the working fluid in the heat storage unit 101a is a unidirectional flow, the working fluid only expands or contracts unilaterally, and the fluctuating pressure does not rise or fall periodically at a fixed point. .

  On the other hand, if the flow rate of the working fluid in the heat storage unit 101a is a bidirectional flow, expansion and contraction occur in the same cycle as the bidirectional flow. Since the fluctuating pressure and the flow velocity increase and decrease at the same time, only work can be propagated without moving the average working fluid. For this reason, the escape of the heat given to the working fluid can be suppressed, and the efficiency of the heat storage unit 101a can be improved.

  In other words, since the timing of heat entering and leaving the working fluid is determined by the flow velocity that is a bidirectional flow, which leads to acoustic amplification, if there is no flow velocity that is a bidirectional flow, thermal energy is converted to sound energy. I can't.

  Once the sound is amplified and oscillation starts, the timing of heat input / exhaust to the working fluid is determined by the flow rate of the amplified sound, and the sound is amplified again. For this reason, the thermoacoustic apparatus 1 that has started oscillating continuously oscillates.

  That is, if the initial bidirectional flow is introduced with the temperature ratio at both ends of the heat storage unit 101a exceeding a predetermined value, the thermoacoustic device 1 oscillates continuously. On the other hand, if the initial bidirectional flow that triggers oscillation is insufficient, the bidirectional flow does not reach the heat storage unit 101a, so that the sound is not amplified and a predetermined temperature ratio that allows continuous oscillation is obtained. Oscillation does not start even when applied to the heat storage unit 101a.

  In order to provide an initial bidirectional flow rate that triggers oscillation, at least one of the flow rate, pressure, and temperature may be changed in part of the working fluid. In the present embodiment, when the oscillation enabling condition is satisfied, the high-pressure fluid container 310 and the acoustic transmission pipes 101, 201, and 300 are communicated with each other by opening and closing the on-off valve 312 so that the pressure in the acoustic transmission pipes 101, 201, and 300 is Is changing locally.

  In this way, by initially increasing the pressure of the working fluid, it is possible to provide an initial bidirectional flow rate that triggers oscillation. This will be described by discretizing the fluid elements constituting the working fluid.

  The fluid element having increased pressure is defined as a first fluid element, and the fluid element adjacent to the first fluid element is defined as a second fluid element. At this time, the pressure of the first fluid element is higher than that of the second fluid element. Since the force is transmitted from the first fluid element to the second fluid element having a lower pressure than the first fluid element, the second fluid element travels away from the first fluid element.

  Thereafter, since the flow rate of the second fluid element becomes larger than that of the first fluid element, the first fluid element expands, and thus the pressure decreases. Further, since the pressure of the first fluid element is reduced, the flow velocity of the second fluid element advances in a direction approaching the first fluid element due to the differential pressure with the second fluid element. From this, when the pressure of the first fluid element is increased, it is possible to generate a bidirectional flow rate that triggers the start of oscillation of thermoacoustic self-excited vibration.

  According to the present embodiment described above, when the oscillating condition is satisfied, the opening / closing valve 312 is opened and closed, and the high-pressure fluid container 310 and the acoustic transmission pipes 101, 201, and 300 are communicated for a short time. As a result, it is possible to change the pressure in a part of the working fluid in the acoustic transmission tubes 101, 201, and 300, and to provide an initial bidirectional flow velocity that triggers oscillation. As a result, the responsiveness from heat input to oscillation of the thermoacoustic device 1 can be improved.

(Second Embodiment)
Next, a second embodiment of the present invention will be described. Only the parts different from the first embodiment will be described below.

  As shown in FIG. 3, in the second embodiment, a control unit 400 and temperature sensors 401 and 402 are provided in the same thermoacoustic apparatus 1 as in the first embodiment.

  The control unit 400 includes a known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. The control unit 400 performs various calculations and processes based on a control program stored in the ROM. Various devices to be controlled are connected to the output side of the control unit 400.

  The control unit 400 controls the operation of various control target devices. The control target devices controlled by the control unit 400 are the on-off valve 312 and the like.

  The temperature sensors 401 and 402 measure the temperature of the heat storage unit 102 a of the input unit 102. The 1st temperature sensor 401 measures the temperature of the high temperature side edge part of the thermal storage part 102a, and the 2nd temperature sensor 402 measures the temperature of the low temperature side edge part of the thermal storage part 102a.

  FIG. 4A to FIG. 4F show various aspects of the temperature measurement site of the heat storage unit 102 a by the temperature sensors 401 and 402.

  FIG. 4A shows an example in which the temperature sensors 401 and 402 directly measure the temperatures at both ends of the heat storage unit 102a. In the example shown in FIG. 4A, the temperature sensors 401 and 402 measure the temperature near the center of the cross section of the heat storage section 102a. In addition, you may change the measurement site | part by the temperature sensors 401 and 402 as FIG.4 (b)-FIG.4 (f).

  In the case where the heat exchange units 102b and 102c are configured with narrow flow paths, the heat exchange units 102b and 102c may play the same role as the heat storage unit 102a. Therefore, as shown in FIGS. 4B to 4D, the temperature of the high-temperature heat exchange unit 102b may be measured by the first temperature sensor 401, and the low-temperature heat exchange by the second temperature sensor 402. The temperature of the part 102c may be measured.

  Moreover, when it is anticipated that the cross section of the heat storage part 102a is isothermal, you may shift the temperature-measurement location by the temperature sensor 402 from the center part of a cross section like FIG.4 (e).

  Moreover, when the heat conductivity of the heat exchange parts 102b and 102c is favorable, it can be judged that it is isothermal from the end surface of the heat storage part 102a to the heat exchange parts 102b and 102c. For this reason, you may measure the temperature of the heat exchange part 102c shifted from the end surface of the thermal storage part 102a like FIG.4 (f).

  Next, the oscillation start process of the thermoacoustic apparatus 1 of the second embodiment will be described using the flowchart of FIG. The oscillation start process of the thermoacoustic device 1 is executed under the control of the control unit 400.

  First, the temperature sensors 401 and 402 measure the temperature at both ends of the heat storage unit 102a (S10). Next, it is determined whether or not the temperature ratio at both ends of the heat storage unit 102a is greater than or equal to a predetermined value (S11).

  As a result, when it is determined that the temperature ratio at both ends of the heat storage unit 102a is not equal to or greater than the predetermined value (S11: NO), the oscillation start process is terminated. On the other hand, when it is determined that the temperature ratio at both ends of the heat storage unit 102a is equal to or greater than the predetermined value (S11: YES), the opening / closing operation of the opening / closing valve 312 is performed (S12).

  Thereby, a pressure is fluctuate | varied by a part of working fluid in the acoustic transmission pipes 101, 201, and 300, and the initial bidirectional flow velocity that triggers oscillation can be given. As a result, the responsiveness from heat input to oscillation of the thermoacoustic device 1 can be improved.

  In the second embodiment described above, the on-off valve 312 is opened and closed based on the temperatures at both ends of the heat storage unit 102a measured by the temperature sensors 401 and 402, and the thermoacoustic device 1 starts oscillating using this as an opportunity. . Thereby, the oscillation start timing of the thermoacoustic apparatus 1 can be determined accurately.

(Third embodiment)
Next, a third embodiment of the present invention will be described. Only the parts different from the above embodiments will be described below.

  As shown in FIG. 6, in the third embodiment, an external communication pipe 320 is connected to the input loop pipe 101. The input loop pipe 101 communicates with the outside via the external communication pipe 320. The external communication pipe 320 is provided with a first on-off valve 321 on the side close to the input loop pipe 101 and a second on-off valve 322 on the side far from the input loop pipe 101. The first on-off valve 321 corresponds to the vibration generating unit of the present invention.

  The first on-off valve 321 is opened, and the second on-off valve 322 is closed. Then, when the temperature ratio at both ends of the heat storage unit 101a exceeds a predetermined value and the oscillation enabling condition is satisfied, the opened first on-off valve 321 is closed.

  At this time, the first on-off valve 321 vibrates with the opening / closing operation of the first on-off valve 321, and the working fluid in the input loop pipe 101 vibrates. The vibration of the working fluid is propagated to the heat storage unit 102a, and the thermoacoustic device 1 starts to oscillate.

  According to the third embodiment described above, the thermoacoustic device 1 can be started to oscillate by opening and closing the on-off valve 321 provided in the communication pipe 320 communicating with the acoustic transmission pipes 101, 201, and 300. Further, by connecting the external communication pipe 320 to the input loop pipe 101, the vibration of the working fluid reaching the heat storage section 102a is suppressed.

  In addition, not only when changing the 1st on-off valve 321 from an open state to a closed state, the oscillation of the thermoacoustic apparatus 1 can be started also by changing the 1st on-off valve 321 from a closed state to an open state. it can. Further, when the vibration of the working fluid generated by the opening / closing operation of the first opening / closing valve 321 is weak and the thermoacoustic device 1 does not start oscillation, the opening / closing operation of the first opening / closing valve 321 may be repeated.

  Moreover, the vibration generation of the working fluid can also be generated by reducing the pressure in the acoustic transmission tubes 101, 201, 300. For example, the pressure of the working fluid in the acoustic transmission pipes 101, 201, and 300 is set to atmospheric pressure or higher, the first on-off valve 321 is opened, and the second on-off valve 322 is closed. Then, by opening the second on-off valve 322 and closing it immediately, the pressure of the working fluid in the acoustic transmission pipes 101, 201, 300 can be reduced, and the working fluid vibration can be caused. Start oscillation.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. Only the parts different from the above embodiments will be described below.

  As shown in FIG. 7, the thermoacoustic apparatus 1 of the fourth embodiment is a single loop type in which an input unit 102 and an output unit 202 are provided in one loop pipe 330.

  The loop pipe 330 is provided with a discharge part 331. The discharge part 331 performs gas discharge in the internal space of the loop pipe 330. In the present embodiment, an arc discharge device is used as the discharge unit 331. In addition, the discharge part 331 is equivalent to the vibration production | generation part of this invention.

  In the present embodiment, a discharge unit 331 is provided between the high temperature side end of the input unit 102 and the output unit 202 in the loop pipe 330. Although the discharge part 331 can be provided in the arbitrary places of the loop piping 330, since it generate | occur | produces high temperature by discharge, providing in the high temperature side heat exchange part 102b side is desirable.

  The discharge part 331 discharges when the absolute temperature ratio of the both ends of the thermal accumulator 102a exceeds predetermined value, and the oscillation possible condition is satisfied. The working fluid thermally expands due to the discharge by the discharge unit 331, and the temperature changes in a part of the working fluid. By changing the temperature of the working fluid, the pressure of the working fluid can be changed, and an initial bidirectional flow velocity that triggers oscillation can be provided.

  An appropriate voltage can be selected from a plurality of patterns so that the thermoacoustic self-excited vibration is easily started in the heat accumulator 102a as the applied voltage when performing gas discharge in the discharge unit 331. 8 and 9 illustrate the waveform of the voltage applied to the discharge unit 331. FIG.

  As shown in FIGS. 8A to 8E, it is possible to prepare a plurality of applied voltage patterns having different voltage heights and output times and select an appropriate pattern from these patterns. it can. Further, as shown in FIGS. 9A to 9F, a plurality of patterns of applied voltages having different waveform shapes are prepared, and an appropriate pattern can be selected from these patterns.

  According to the fourth embodiment described above, the thermoacoustic self-excited vibration in the heat accumulator 102a can be easily started by appropriately selecting the voltage height, output time, or waveform shape of the applied voltage of the discharge unit 331. can do.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described. Only the parts different from the above embodiments will be described below.

  The thermoacoustic apparatus 1 according to the fifth embodiment has the same configuration as that of the fourth embodiment described with reference to FIG. In the fifth embodiment, gas discharge by the discharge unit 331 is continuously performed a plurality of times.

  As shown in FIGS. 10A to 10C, a plurality of applied voltage patterns having different output intervals and voltage waveforms are prepared, and an appropriate pattern can be selected from these patterns. . A plurality of gas discharges by the discharge unit 331 may be performed until thermoacoustic self-excited vibration starts.

  Further, as shown in FIG. 11, when the discharge unit 331 performs a plurality of discharges, the voltage level may be gradually increased. In this case, the temperature change of the working fluid can be increased stepwise by the discharge of the discharge unit 331 a plurality of times.

  According to the fifth embodiment described above, even if the thermoacoustic self-excited vibration does not start in one discharge, the thermoacoustic self-excited vibration is generated by performing the gas discharge a plurality of times by the discharge unit 331. It can be started reliably.

  In addition, when the magnitude of the applied voltage of the discharge unit 331 is gradually increased, it is possible to search for an output at which thermoacoustic self-excited vibration can be started in order from a lower voltage. Thereby, it is possible to prevent the applied voltage of the discharge part 331 from becoming higher than necessary, and energy saving can be realized.

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described. Only the parts different from the above embodiments will be described below.

  As shown in FIG. 12, the thermoacoustic device 1 of the sixth embodiment is mounted on a vehicle 500. The vehicle 500 includes an internal combustion engine 501 for obtaining a driving force for traveling the vehicle. The thermoacoustic device 1 is a double loop type including two loop pipes 101 and 201.

  The heat medium flowing through the first heat medium pipe 103 circulates in the high temperature side heat exchange unit 102b of the input unit 102. For example, cooling water can be used as the heat medium. The first heat medium pipe 103 is provided with a heat exchanging unit 104 that transfers the heat of the internal combustion engine 501 to the heat medium, and a pump 105 that circulates the heat medium. As the heat of the internal combustion engine 501 that heats the heat medium in the heat exchange unit 104, for example, the heat of the exhaust gas of the internal combustion engine 501 can be used.

  The heat medium flowing through the second heat medium pipe 203 circulates in the heat exchange units 202b and 202c of the output unit 202. For example, cooling water can be used as the heat medium. The second heat medium pipe 203 is provided with a first heat exchange unit 204 that adjusts the temperature of the front seat of the vehicle, a second heat exchange unit 205 that adjusts the temperature of the rear seat of the vehicle, and a pump 206 that circulates the heat medium. Yes.

  The heat medium flowing through the second heat medium pipe 203 can pass through either the high temperature heat exchange unit 202b or the low temperature heat exchange unit 202c. A first switching valve 207 is provided on the high temperature heat exchange unit 202b side, and a second switching valve 208 is provided on the low temperature heat exchange unit 202c side.

  When the first switching valve 207 is opened and the second switching valve 208 is closed, the heat medium is heated by the high-temperature heat exchange unit 202b. In this case, the seat is warmed by the first heat exchange unit 204 and the second heat exchange unit 205. In addition, when the first switching valve 207 is closed and the second switching valve 208 is opened, the heat medium is cooled by the low-temperature heat exchange unit 202c. In this case, the seat is cooled by the first heat exchange unit 204 and the second heat exchange unit 205.

  The heat medium flowing through the second heat medium pipe 203 can bypass the second heat exchange unit 205. The second heat medium pipe 203 is provided with two switching valves 209 and 210 for switching whether the heat medium is circulated to the second heat exchange unit 205 or bypassed.

  When the third switching valve 209 is opened and the fourth switching valve 210 is closed, the heat medium flows through the second heat exchange unit 205. On the other hand, when the third switching valve 209 is closed and the fourth switching valve 210 is opened, the heat medium bypasses the second heat exchange unit 205.

  In the sixth embodiment, a buffer gas container 503 is provided on the chassis 502. The buffer gas container 503 is an elastic container. The buffer gas container 503 is provided with a protected device 504 for stabilizing the buffer gas container 503 when vibration of the vehicle 500 occurs. The buffer gas container 503 corresponds to the vibration generating unit of the present invention.

  Vehicle equipment such as the thermoacoustic device 1 is provided on the buffer gas container 503. Since the buffer gas container 503 absorbs vibrations of the vehicle 500, vehicle equipment such as the protected device 504 can be protected from vibrations during vehicle travel.

  The buffer gas container 503 is filled with the same fluid as the working fluid in the acoustic transmission pipes 101, 201, and 300 as a buffer gas. The buffer gas container 503 communicates with the inside of the acoustic transmission tubes 101, 201, and 300 through a communication tube 505. The communication pipe 505 is provided with an open / close valve 506.

  Here, the operation of the thermoacoustic apparatus 1 of the sixth embodiment will be described. When the internal combustion engine 501 starts operation, the high temperature side heat exchange unit 102b of the input unit 102 is heated by the heat of the internal combustion engine 501. Thereby, a predetermined temperature ratio capable of oscillation is given to both ends of the heat storage unit 102a.

  When the vehicle 500 starts traveling, vibration of the vehicle 500 is generated. Accordingly, the pressure of the buffer gas in the buffer gas container 503 varies in order to absorb the vibration of the vehicle 500. At this time, by opening the on-off valve 506, the pressure fluctuation in the buffer gas container 503 is transmitted to the working fluid in the acoustic transmission pipes 101, 201, 300, and this can be used as a trigger to start thermoacoustic self-excited vibration. it can.

  When thermoacoustic self-excited vibration starts in the thermoacoustic device 1, the initial flow velocity that triggered the oscillation starts to grow. When the temperature ratio at both ends of the heat storage unit 102a becomes sufficiently high, the flow velocity of the working fluid in the thermoacoustic device 1 becomes sufficiently larger than the vibration obtained from the buffer gas container 503, so that the fluid vibration from the buffer gas container 503 is thermoacoustic. The device 1 is no longer affected. For this reason, the introduction of fluid vibration from the buffer gas container 503 to the acoustic transmission tubes 101, 201, and 300 may be continued. However, when a large fluid vibration is expected in the buffer gas container 503 due to the vibration of the vehicle 500, the on-off valve 506 is closed after the oscillation starts and the buffer gas container 503 is connected to the acoustic transmission tubes 101, 201, 300. It is desirable to stop the introduction of fluid vibration.

  According to the sixth embodiment described above, by mounting the thermoacoustic device 1 on the vehicle 500, the temperature of the vehicle seat can be adjusted by the heat or cold generated by the thermoacoustic device 1. Furthermore, in the sixth embodiment, a predetermined temperature ratio can be given to both ends of the heat accumulator 102a using the exhaust heat of the internal combustion engine 501, and the oscillation enabling condition can be established.

  In the sixth embodiment, a buffer gas container 503 that absorbs the vibration of the vehicle 500 is provided, and the pressure fluctuation of the buffer gas generated by the vibration caused by the traveling of the vehicle is introduced into the working fluid of the acoustic transmission tubes 101, 201, 300. It has become so. As a result, the buffer gas container 503 can function not only for protecting the vehicle equipment but also as a thermoacoustic oscillation device that starts thermoacoustic self-excited vibration using vibration associated with vehicle travel.

(Seventh embodiment)
Next, a seventh embodiment of the present invention will be described. Only the parts different from the above embodiments will be described below.

  As shown in FIG. 13, in the thermoacoustic apparatus 1 of the seventh embodiment, the input loop pipe 101 is connected to one end side of the connecting pipe 300, and the linear generator 600 is provided to the other end side of the connecting pipe 300. Yes. The linear generator 600 is an energy consuming unit that converts acoustic energy into electrical energy.

  The linear generator 600 includes a diaphragm 601. The diaphragm 601 is displaced by acoustic energy generated by the input unit 200. The linear generator 600 generates power when the diaphragm 601 is displaced.

  The thermoacoustic apparatus 1 according to the seventh embodiment is provided with a sound collection unit 340 that collects external sound. The sound collection unit 340 of the seventh embodiment collects operation sounds of the internal combustion engine 501. The sound collection unit 340 corresponds to the vibration generation unit of the present invention.

  The sound collection unit 340 is provided with a diaphragm 341. The diaphragm 341 converts acoustic energy into kinetic energy, and vibrates due to the sound collected by the sound collection unit 340.

  The sound collection unit 340 communicates with the acoustic transmission tubes 101, 201, and 300 through the communication tube 342. The vibration of the diaphragm 341 is transmitted to the inside of the acoustic transmission pipes 101, 201, and 300 through the communication pipe 342, and the working fluid in the acoustic transmission pipes 101, 201, and 300 can be vibrated.

  When a temperature ratio capable of oscillation is generated at both ends of the heat storage unit 102a, vibration is generated in the diaphragm 341 based on external sound, and the thermoacoustic self-excited vibration is started in the heat storage unit 102a using this vibration as a trigger. Can do.

  According to the seventh embodiment described above, thermoacoustic self-excited vibration can be started using externally generated acoustic energy.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows without departing from the spirit of the present invention. Further, the means disclosed in each of the above embodiments may be appropriately combined within a practicable range.

  (1) In the said 1st Embodiment, by making the high-pressure fluid container 310 and the acoustic transmission pipes 101, 201, 300 communicate with each other and increasing the pressure in a part of the working fluid in the acoustic transmission pipes 101, 201, 300, Although it is configured to oscillate, the pressure is not limited to this, and the pressure may be lowered in a part of the working fluid in the acoustic transmission tubes 101, 201, and 300. As described above, it is possible to provide an initial bidirectional flow velocity that triggers oscillation also by reducing the pressure in a part of the working fluid in the acoustic transmission tubes 101, 201, and 300.

  (2) In the second embodiment, it is configured to oscillate by raising the temperature of a part of the working fluid in the acoustic transmission tubes 101, 201, 300 by the discharge by the discharge unit 331. However, the present invention is not limited to this. Instead, the temperature may be locally lowered at a part of the working fluid in the acoustic transmission tubes 101, 201, 300. In this way, it is possible to give an initial bidirectional flow velocity that triggers oscillation also by lowering the temperature of a part of the working fluid.

  (3) By changing any one of the flow velocity, pressure, and temperature in a part of the working fluid in the acoustic transmission pipes 101, 201, and 300, a bidirectional flow velocity that triggers oscillation can be generated. A plurality of types of changes among pressure and temperature may be combined.

  (4) In the fifth embodiment, the example in which the discharge by the discharge unit 331 is performed a plurality of times and the temperature change of the working fluid is performed a plurality of times has been described, but the flow velocity and pressure of the working fluid may be changed a plurality of times. Good. Further, the flow rate and pressure of the working fluid may be changed a plurality of times, and the amount of change may be increased stepwise.

  (5) In each of the above embodiments, acoustic energy is generated by thermoacoustic self-excited vibration at the input unit 102. However, the present invention is not limited thereto, and acoustic energy is input from the low temperature side of the heat storage unit 102a by a speaker or the like. It may be. In this case, the input acoustic energy can be amplified in the heat storage unit 102a in which a temperature difference is formed at both ends.

  (6) When a condensable fluid such as atmospheric air and water and a non-condensable fluid are used as the working fluid, both the initial stage that triggers oscillation even when the boiling of the condensable fluid contained starts or stops boiling. Direction of flow velocity. For example, boiling of the condensable fluid can be started by turning on the heater, and boiling of the condensable fluid can be stopped by turning off the heater in the high temperature side heat exchanging portion 102b made of an electric heater.

101 Input loop piping (acoustic transmission tube)
102 Input unit 102a Heat storage unit (energy conversion unit)
102b High temperature heat exchange section 102c Low temperature heat exchange section 201 Output loop piping (acoustic transmission pipe)
202 Output unit 202a Heat storage unit (energy consumption unit)
202b High-temperature heat exchange unit 202c Low-temperature heat exchange unit 300 Connection pipe (acoustic transmission pipe)
310 High-pressure fluid container (vibration generator)
320 External communication pipe (vibration generator)
321 First on-off valve (vibration generator)
331 Discharge unit (vibration generator)
340 Sound collector (vibration generator)
503 Buffer gas container (vibration generator)

Claims (6)

An acoustic transmission tube (101, 201, 300) enclosing a working fluid;
An energy conversion unit (102a) that is provided in the acoustic transmission tube and converts thermal energy into acoustic energy by generating self-excited thermoacoustic vibration when a predetermined condition is satisfied;
An energy consuming part (202a) provided in the acoustic transmission tube for converting the acoustic energy into different types of energy;
When the predetermined condition is satisfied, a vibration generator (301, 320, 321, 331, 331) that starts the thermoacoustic self-excited vibration by changing at least one of flow velocity, pressure, and temperature in a part of the working fluid 340, 503).   The thermoacoustic apparatus according to claim 1, wherein the predetermined condition is satisfied when an absolute temperature ratio between the one end side and the other end side exceeds a predetermined value in the energy conversion unit.   The vibration generating unit includes a high-pressure fluid container (310) filled with the working fluid having a pressure higher than that of the working fluid of the acoustic transmission tube, and the acoustic transmission tube and the high-pressure fluid when the predetermined condition is satisfied. The thermoacoustic apparatus of Claim 1 or 2 which makes a container communicate.   The vibration generating unit includes a communication pipe (320) communicating with the inside of the thermoacoustic transmission pipe and an open / close valve (321) for opening and closing the communication pipe, and the open / close valve when the predetermined condition is satisfied. The thermoacoustic apparatus of Claim 1 or 2 which performs opening / closing operation | movement of.   The heat according to claim 1 or 2, wherein the vibration generating unit includes a discharge unit (331) that performs gas discharge inside the acoustic transmission tube, and performs gas discharge by the discharge unit when the predetermined condition is satisfied. Acoustic device.   The vibration generation unit changes at least one of a flow velocity, pressure, and temperature in a part of the working fluid a plurality of times so that the amount of change increases in order when the predetermined condition is satisfied. The thermoacoustic device according to any one of 5.

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