JP2005188841A - Thermoacoustic engine and thermoacoustic refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoacoustic engine and a thermoacoustic refrigerator capable of reliably generating desired acoustic output and refrigeration output.
An energy recovery device 20 includes an air column tube 21 in which a working fluid is enclosed, a heat accumulator 25 disposed in the air column tube 21, and one end of the heat accumulator 25 using exhaust gas of the internal combustion engine 1 as a heat source. A high-temperature heat exchanger 26 that heats the heat exchanger and a low-temperature heat exchanger 27 that cools the other end of the heat accumulator 25 with the cooling water of the internal combustion engine 1, and forms a temperature gradient between both ends of the heat accumulator 25. To generate thermoacoustic self-excited vibration of the working fluid. And the heat accumulator 25 which comprises a thermoacoustic engine with the high temperature and low temperature heat exchangers 26 and 27 contains the expansion-contraction stack 251, and the actuator 252 which expands-contracts this expansion-contraction stack 251, The temperature formed between the both ends The slope can be changed.
[Selection] Figure 1

Description

  The present invention relates to a thermoacoustic engine for generating a thermoacoustic self-excited vibration of a working fluid in an air column tube by forming a temperature gradient between both end portions of a heat storage means disposed in the air column tube, and an interior of the air column tube The present invention relates to a thermoacoustic refrigerator that vibrates a working fluid and generates cold using a temperature gradient formed between both end portions of a cold storage means by the vibration of the working fluid.

  Conventionally, a refrigerator utilizing a thermoacoustic phenomenon has been proposed (see, for example, Patent Document 1). This refrigerator includes a pipe filled with gas, a stack disposed inside the pipe and sandwiched between a high temperature side heat exchanger and a low temperature side heat exchanger, and a high temperature side at a position asymmetric with the stack. And a regenerator arranged together with the heat exchanger and the low temperature side heat exchanger. This refrigerator generates a self-excited vibration of gas in the stack by forming a temperature gradient between both ends of the stack, and stores it in the regenerator by propagation of standing waves and traveling waves obtained thereby. It is.

  Conventionally, an apparatus for recovering waste heat of an internal combustion engine using a thermoacoustic phenomenon has been proposed (see, for example, Patent Document 2). This device includes a resonance pipe connected to an exhaust gas purification catalytic converter of an internal combustion engine, a stack provided at one end of the resonance pipe, and a transducer provided at the other end of the resonance pipe. In this apparatus, one end of the stack is heated by heat generated from the catalytic converter, and a temperature gradient is applied between both ends of the stack. Thereby, sound waves are generated in the stack, and the energy of the sound waves is converted into electric energy by the transducer.

Japanese Patent No. 3015786 JP 2002-122020 A

  As described above, if the thermoacoustic phenomenon is used, acoustic energy can be obtained by forming a temperature gradient between both ends of the stack. However, it is not always easy to control the amount of heat applied to the stack, particularly when a temperature gradient is formed between both ends of the stack using waste heat of an internal combustion engine or the like. For this reason, in the above-mentioned thermoacoustic apparatus, it is difficult to obtain desired acoustic energy, for example, excessive self-excited vibration of the working fluid may occur, and as a result, a desired refrigeration output can be obtained. Sometimes not.

  Then, an object of this invention is to provide the thermoacoustic engine which can generate | occur | produce a desired acoustic output reliably, and the thermoacoustic refrigerator which can generate | occur | produce a desired refrigeration output reliably.

  The thermoacoustic engine according to the present invention has an air column tube in which a working fluid is enclosed, and heat storage means disposed inside the air column tube, and operates by forming a temperature gradient between both ends of the heat storage unit. In a thermoacoustic engine that generates thermoacoustic self-excited vibration of a fluid, the heat storage means is configured to change the temperature gradient.

  Since this thermoacoustic engine is provided with a heat storage means configured to change the temperature gradient formed between both ends thereof, the amount of heat for forming the temperature gradient is not strictly controlled. However, a desired temperature gradient can be reliably obtained in the heat storage means. Therefore, according to the present invention, it is possible to reliably generate a desired acoustic output in the thermoacoustic engine.

  In this case, it is preferable that the total length of the heat storage means can be changed. Thus, by making it possible to change the total length of the heat storage means, it is possible to easily and reliably form a desired temperature gradient between both end portions of the heat storage means.

  Moreover, it is preferable that the heat storage means includes a porous member formed so as to be stretchable and a driving means for expanding and contracting the porous member. If such a structure is employ | adopted, it will become possible to change the full length of a thermal storage means easily.

  Furthermore, it is preferable that a high-temperature heat exchanger disposed on one end side of the heat storage means is further provided, and the high-temperature heat exchanger uses exhaust gas from the internal combustion engine as a heat source. As a result, the exhaust heat of the internal combustion engine can be efficiently recovered using the thermoacoustic engine.

  The thermoacoustic refrigerator according to the present invention includes an air column tube in which a working fluid is sealed, and cold storage means disposed inside the air column tube, and vibrates the working fluid inside the air column tube. In a thermoacoustic refrigerator that generates cold using a temperature gradient formed between both ends of the cold storage means by vibration of the working fluid, the cold storage means is configured to change the temperature gradient. It is characterized by.

  Since this thermoacoustic refrigerator is equipped with cold storage means configured to be able to change the temperature gradient formed between its both ends, vibration (sound waves) is strictly applied to form the temperature gradient. Even if it is not controlled, a desired temperature gradient can be reliably obtained in the cold storage means. Therefore, according to the present invention, it is possible to reliably generate a desired refrigeration output in the thermoacoustic refrigerator.

  In this case, it is preferable that the total length of the cold storage means can be changed. The cold storage means preferably includes a porous member formed to be stretchable and a drive means for extending and retracting the porous member.

  According to the present invention, it is possible to realize a thermoacoustic engine that can reliably generate a desired acoustic output and a thermoacoustic refrigerator that can reliably generate a desired refrigeration output.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram illustrating an energy recovery apparatus including a thermoacoustic engine according to the present invention. As shown in the figure, the energy recovery device 20 is applied to, for example, an internal combustion engine 1 used as a traveling drive source of a vehicle. First, the internal combustion engine 1 to which the energy recovery device 20 is applied will be briefly described. The internal combustion engine 1 burns a mixture of fuel and air inside a combustion chamber 3 formed in the cylinder block 2 and burns it. The piston 4 is reciprocated in the chamber 3 to generate power.

  The intake port of the combustion chamber 3 is connected to the intake manifold 5, and the exhaust port of the combustion chamber 3 is connected to the exhaust manifold 6. In addition, an intake valve Vi that opens and closes an intake port, an exhaust valve Ve that opens and closes an exhaust port, a spark plug 7, and an injector 8 are disposed for each combustion chamber 3 in the cylinder head of the internal combustion engine 1. The intake manifold 5 is connected to a surge tank 9, and an air supply pipe L <b> 1 is connected to the surge tank 9. The air supply pipe L1 is connected to an air intake port (not shown) via the air cleaner 10. Further, a throttle valve 11 is incorporated in the middle of the supply pipe L1 (between the surge tank 9 and the air cleaner 10). On the other hand, the exhaust manifold 6 is connected to an exhaust pipe L2, and a front-stage catalyst device 12a and a rear-stage catalyst device 12b are incorporated in the exhaust pipe L2.

  The energy recovery device 20 of the present invention is used to recover the exhaust heat of the internal combustion engine 1 as described above. The energy recovery device 20 has an air column tube 21 formed of stainless steel or the like so as to have a circular cross section, and inside the air column tube 21 is an operation such as nitrogen, helium, argon, a mixed gas of helium and argon. A fluid (inert gas) is enclosed. As shown in FIG. 1, the air column tube 21 includes a loop portion 22 formed in a substantially rectangular loop shape and a resonance portion 23 connected to one corner portion of the loop portion 22. The resonance part 23 includes a tube part 23a having a circular cross section approximately the same diameter as the loop part 22, and a closed end part 23b connected to the tip of the tube part 23a, and functions as a resonator. The diameter of the closed end portion 23b is gradually increased from the distal end of the tube portion 23a toward the closed end.

  A heat accumulator (heat storage means) 25 is disposed inside the loop portion 22 of the air column tube 21. A high temperature heat exchanger 26 is disposed on one end side of the heat accumulator 25, and a low temperature heat exchanger 27 is disposed on the other end side of the heat accumulator 25. As shown in FIGS. 1 to 3, the heat accumulator 25 is a stretchable stack (porous member) configured to be stretchable by folding a flexible mesh material made of metal or the like and a porous plate made of thin metal or the like into a bellows shape. ) 251. Only one end of the expansion / contraction stack 251 is fixed to the low-temperature heat exchanger 27, and a rod 252a of an actuator 252 such as a fluid pressure cylinder is fixed to its free end (end on the high-temperature heat exchanger 26 side). ing.

  The actuator 252 is connected to a fluid source (not shown) via the on-off valve 253. By operating the on-off valve 253 to activate the actuator 252, the actuator 252 is connected between the high-temperature heat exchanger 26 and the low-temperature heat exchanger 27. The total length of the elastic stack 251 can be easily changed by expanding and contracting the elastic stack 251 (see FIGS. 2 and 3). Therefore, after grasping the amount of heat (temperature difference between both ends) applied between both ends of the heat accumulator 25, the actuator 252 is operated to change the total length of the expansion / contraction stack 251 to thereby change both ends of the heat accumulator 25. It is possible to easily and reliably form a desired temperature gradient between the parts. In the present embodiment, the main body (cylinder) of the actuator 252 is disposed outside the air column tube 21, and only the rod 252 a is inserted into the air column tube 21.

  Exhaust gas flowing through the exhaust pipe L2 of the internal combustion engine 1 is supplied to the heat transfer tubes constituting the high temperature heat exchanger 26, and the high temperature heat exchanger 26 uses the exhaust gas of the internal combustion engine 1 as a heat source. In the present embodiment, the high-temperature heat exchanger (its heat transfer pipe) 26 is incorporated in the exhaust pipe L2 between the front-stage catalyst apparatus 12a and the rear-stage catalyst apparatus 12b. The heat transfer tubes constituting the low-temperature heat exchanger 27 are incorporated in the cooling system L3 of the internal combustion engine 1, and the low-temperature heat exchanger 27 uses the cooling water flowing through the cooling system L3 as a heat source (cold heat source). . An exhaust supply adjustment valve 15 is provided at the exhaust gas inlet of the high temperature heat exchanger (its heat transfer tube) 26, and the exhaust gas to the high temperature heat exchanger 26 is closed by closing the exhaust supply adjustment valve 15. Can be stopped. Similarly, the cooling system L3 includes an on-off valve 16. By closing the on-off valve 16, the supply of cooling water to the low-temperature heat exchanger (its heat transfer tube) 27 can be stopped.

  Further, the regenerator 125, the regenerator high-temperature heat exchanger 126, and the regenerator low-temperature heat exchanger 127 are arranged in the loop portion 22 of the air column tube 21. In this case, the cold storage high-temperature heat exchanger 126 is configured so that one end portion of the cold storage 125 can be maintained at approximately room temperature (20 to 25 ° C.). The cold storage heat exchanger 127 is disposed adjacent to the above-described low-temperature heat exchanger 27, and a predetermined refrigerant is circulated and supplied to the cold storage heat exchanger 127 (the heat transfer tube). In this embodiment, instead of disposing the regenerator 125 and the high and low temperature heat exchangers 126 and 127 for regenerator inside the loop portion 22, a transducer (sound) is provided inside the closed end portion 23 b of the resonance portion 23. / Electric conversion means) may be arranged, and acoustic energy may be collected to obtain electric energy. Further, both the unit such as the regenerator 125 and the transducer may be arranged for the air column tube 21.

  The energy recovery device 20 is controlled by an electronic control unit (hereinafter referred to as “ECU”) 40 that functions as control means of the internal combustion engine 1. The ECU 40 includes a CPU, a ROM, a RAM, an input / output port, a storage device, etc., all not shown. The above-described exhaust supply adjustment valve 15, the on-off valve 16 of the cooling system L3, and the on-off valve 253 for the actuator 252 are respectively connected to the input / output ports of the ECU 40, and these are controlled by the ECU 40.

  In addition, a pressure sensor 28 is installed in the air column tube 21 of the energy recovery device 20 in the vicinity of a connection portion between the loop portion 22 and the resonance portion 23. The pressure sensor 28 is also connected to the ECU 40, and the sensor 28 detects the pressure of the working fluid in the air column tube 21 and gives a signal indicating the detected value to the ECU 40. Furthermore, in this embodiment, the catalyst temperature sensor T1 is installed with respect to the pre-stage catalyst device 12a, and the water temperature sensor T2 is installed with respect to the cooling system L3. The catalyst temperature sensor T1 detects the catalyst temperature in the pre-stage catalyst device 12a and gives a signal indicating the detected value to the ECU 40. The water temperature sensor T2 detects the temperature of the cooling water supplied to the low-temperature heat exchanger 27, and gives a signal indicating the detected value to the ECU 40.

  In the energy recovery device 20 configured as described above, when the internal combustion engine 1 is operated and the exhaust gas from the combustion chamber 3 (pre-catalyst device 12a) passes through the high temperature heat exchanger 26 of the energy recovery device 20. Start operation. In this case, the temperature of the exhaust gas of the internal combustion engine 1 reaches about 900 ° C. at the maximum, so that one end of the heat accumulator 25 is heated by the exhaust gas flowing through the high-temperature heat exchanger 26 to rise in temperature. . On the other hand, the low temperature heat exchanger 27 of the energy recovery device 20 is supplied with cooling water (approximately 80 to 100 ° C.) flowing through the cooling system L3, so that the other end of the heat accumulator 25 has a low temperature heat. Cooled by the cooling water flowing through the exchanger 27. As a result, a large temperature gradient is formed between both ends of the heat accumulator 25, and as a result, thermoacoustic self-excited vibration (sound wave) of the working fluid is generated. That is, the heat accumulator 25, the high temperature heat exchanger 26, and the low temperature heat exchanger 27 form a temperature gradient between both ends of the heat accumulator 25 using surplus energy (heat energy of exhaust gas) of the internal combustion engine 1, The thermoacoustic engine of the present invention that generates thermoacoustic self-excited vibration of the working fluid is configured.

  When the frequency of the self-excited vibration (sound wave) of the working fluid thus generated matches the frequency in the resonance part 23, a standing wave is formed in the resonance part 23, and in the loop part 22, A traveling wave traveling from the low temperature heat exchanger 27 to the high temperature heat exchanger 26 is formed. Then, due to the traveling wave generated due to the temperature gradient formed between both ends of the regenerator 25, the high temperature heat exchanger 126 for regenerator has a high temperature between both ends of the regenerator 125 of the loop portion 22. Thus, a temperature gradient is formed so that the cold storage low-temperature heat exchanger 127 side has a low temperature.

  At this time, one end of the regenerator 125 is maintained at a room temperature (20 to 25 ° C.) by the high temperature heat exchanger 126 for regenerator, so the other end of the regenerator 125 and the low temperature heat exchanger 127 for regenerator ( The heat transfer tube) drops in accordance with the temperature gradient. As described above, the units of the regenerator 125, the high temperature heat exchanger 126 for cold storage and the low temperature heat exchanger 127 for cold storage constitute a thermoacoustic refrigerator, so that the refrigerant flowing out of the low temperature heat exchanger 127 for cold storage passes through the refrigerant. It becomes possible to take out cold heat that can be used in an air conditioning unit (not shown).

  As described above, according to the energy recovery device 20, the working fluid itself is generated by forming a temperature gradient in both end pipes of the heat accumulator 25 using surplus energy of the internal combustion engine 1 (heat energy of exhaust gas, etc.). Excitation vibration can be generated, and energy (acoustic energy) of the vibration can be converted into thermal energy (cold heat). However, when a temperature gradient is formed between both ends of the heat accumulator 25 using the exhaust gas or cooling water of the internal combustion engine 1, the operating state of the internal combustion engine 1 changes from moment to moment. It is not always easy to control the amount of heat. For this reason, unless some measures are taken, excessive self-excited vibration of the working fluid occurs, and it may be difficult to obtain desired acoustic energy.

  In view of such a point, in the present embodiment, a desired temperature gradient is always formed between both ends of the heat accumulator 25 to obtain a desired acoustic output from the heat accumulator 25 (thermoacoustic engine) of the energy recovery device 20. Therefore, the ECU 40 repeatedly executes the regenerator control routine shown in FIG. 4 every predetermined time. That is, when it becomes the execution timing of the regenerator control routine, the ECU 40 acquires the required cold energy (target cold energy) Rt for the air conditioner and the like at that time (S10). After acquiring the target cold heat amount Rt, the ECU 40 calculates a target value (target length) of the total length of the regenerator 25 corresponding to the target cold heat amount Rt acquired in S10 using a predetermined function G. (S12). Here, the function G for obtaining the target length of the heat accumulator 25 includes the target cold heat amount Rt, the temperature Th of the high temperature heat exchanger 26, the temperature Tc of the low temperature heat exchanger 27, and the working fluid in the air column tube 21. It is determined as a function [G (Rt, Th, Tc, Pm, f)] of the average pressure Pm and the resonance frequency f, and is stored in the storage device of the ECU 40.

  The temperature Th of the high-temperature heat exchanger 26 used in S12 is obtained by the ECU 40 based on a signal from the catalyst temperature sensor T1 of the pre-stage catalyst device 12a, and the temperature Tc of the low-temperature heat exchanger 27 is cooled by the ECU 40. It is obtained based on a signal from the water temperature sensor T2 of the system L3. Further, the average pressure Pm of the working fluid in the air column tube 21 obtains the maximum pressure and the minimum pressure of the working fluid that self-oscillates in the air column tube 21 based on the signal from the pressure sensor 28, and It is obtained by taking the average of the maximum pressure and the minimum pressure.

  Further, the resonance frequency f of the working fluid is determined based on the time between the pressure peaks of the working fluid that self-oscillates in the air column tube 21 based on the signal from the pressure sensor 28 (the time when the pressure is maximum and the time when the pressure is minimum Is obtained from the time between the pressure peaks. The ECU 40 obtains the target cold energy Rt, the temperature Th of the high-temperature heat exchanger 26, the temperature Tc of the low-temperature heat exchanger 27, the average pressure Pm of the working fluid, and the resonance frequency f in S10 in the function G. The target length of the regenerator 25 corresponding to the target cold heat amount Rt is obtained by substituting with the cold heat amount Rt.

  Thereafter, the ECU 40 controls the actuator 252 (open / close valve 253) so that the total length of the heat accumulator 25 becomes the target length obtained in S12 (S14). Thereby, the total length of the expansion / contraction stack 251 is changed according to the amount of heat applied between both ends of the heat accumulator 25 (temperature difference between the high temperature heat exchanger 26 and the low temperature heat exchanger 27). A desired temperature gradient corresponding to the target cold heat amount Rt (required cold heat amount) is formed between both ends. Thus, in the energy recovery apparatus 20, it is not necessary to strictly control the amount of heat for forming a temperature gradient in the heat accumulator 25, and a desired temperature gradient can be obtained in the heat accumulator 25 only by controlling the actuator 252. Therefore, a desired sound output corresponding to the target example heat quantity Rt can be obtained with certainty.

  Further, when the high-temperature heat exchanger 26 uses the exhaust gas of the internal combustion engine 1 as a heat source as in the energy recovery device 20 of FIG. 1, the heat accumulator 25 that can change the temperature gradient formed between both ends thereof is This is extremely useful for distributing the heat of the exhaust gas by generating the acoustic output and warming up the catalyst. As described above, when calculating the target length of the heat accumulator 25 corresponding to the target cold heat amount Rt, it is necessary to obtain the temperature Th of the high temperature heat exchanger 26, but the temperature Th of the high temperature heat exchanger 26 is Instead of the catalyst temperature of the pre-catalyst device 12a, it may be obtained based on the temperature of the exhaust gas flowing into the high temperature heat exchanger 26, or may be directly detected by a temperature sensor installed in the high temperature heat exchanger 26. Good. Similarly, the temperature Tc of the low temperature heat exchanger 27 may be directly detected by a temperature sensor installed in the low temperature heat exchanger 27.

  5 and 6 are schematic views showing other heat accumulators applicable to the thermoacoustic engine of FIG. The heat accumulator 25A shown in FIG. 5 and the like can also change the temperature gradient formed between both ends thereof, and a flexible mesh material made of metal or the like, or a porous plate made of thin metal or the like in a bellows shape. A telescopic stack (porous member) 251 configured to be stretchable by being folded is included. Also in this case, only one end of the telescopic stack 251 is fixed to the low temperature heat exchanger 27, and the other end (end on the high temperature heat exchanger 26 side) is connected to the high temperature heat exchanger 26 via the actuator 252A. ing.

  As shown in FIG. 5, the actuator 252 </ b> A includes a plurality of connecting members 255 that connect the other end of the telescopic stack 251 and the end of the high-temperature heat exchanger 26. Each connecting member 255 is made of a shape memory alloy, for example, flattened at room temperature (see FIG. 5), and memorized in a shape so as to be bent when heated (see FIG. 6). In addition, a plurality of connection springs (compression springs) 256 are arranged between the other end of the expansion / contraction stack 251 and the end of the high-temperature heat exchanger 26 so as to be positioned outside each connection member 255. Furthermore, a heating wire 257 as a heater is attached (or embedded) to each connecting member 255, and each heating wire 257 is connected to a power source 259 via a switch 258 that is ON / OFF controlled by the ECU 40. Is connected.

  In the heat accumulator 25A configured as described above, when the entire length of the expansion / contraction stack 251 is extended, each switch 258 is turned on to supply power to the heating wire 257 of each connecting member 255. Thereby, the connection member 255 is heated by each heating wire 257, and each connection member 255 is curved as shown in FIG. As a result, each connecting member 255 pulls the expansion / contraction stack 251 toward the high temperature heat exchanger 26 against the repulsive force of each connection spring 256, so that the entire length of the expansion / contraction stack 251 can be extended.

  If each switch 258 is turned off and heating of each connecting member 255 is stopped, the expansion / contraction stack 251 returns to its original flat state due to the shape memory effect, and the connection spring 256 which is a compression spring lowers the temperature. Since it presses toward the heat exchanger 27, the full length of the expansion-contraction stack 251 becomes small (it returns to the original). Therefore, also in the heat accumulator 25A configured as described above, the total length of the telescopic stack 251 can be easily set to a desired length.

  Next, an energy recovery apparatus including a thermoacoustic refrigerator according to the present invention will be described with reference to FIG. The same elements as those described in relation to the first embodiment described above are denoted by the same reference numerals, and redundant description is omitted.

  An energy recovery device 20A shown in FIG. 7 includes a heat accumulator 250 (a general one not having an expansion / contraction stack) constituting a thermoacoustic engine, a high-temperature heat exchanger 26 and a low-temperature heat exchanger 27 unit, In addition to the units of the regenerator 125A, the high-temperature heat exchanger 126 for regenerator 126, and the low-temperature heat exchanger 127 for regenerator constituting the thermoacoustic refrigerator according to the invention, a transducer disposed in the resonance unit 23 (closed end 23b) ( (Sound / electric conversion means) 24 is further provided. The transducer 24 can convert sound wave energy (acoustic energy) into electrical energy. And in this embodiment, what can change the temperature gradient formed between the both ends is employ | adopted as the regenerator 125A which comprises a thermoacoustic refrigerator. That is, the regenerator 125 </ b> A includes the expansion / contraction stack 1251 and the actuator 1252, similarly to the regenerator 25 described in relation to the first embodiment.

  In the energy recovery device 20A configured as described above, the self-excited vibration of the working fluid is formed by forming a temperature gradient in both end tubes of the heat accumulator 250 using surplus energy of the internal combustion engine 1 (heat energy of exhaust gas). (Sound wave) can be generated, and the energy (acoustic energy) of the vibration can be converted into electric energy by the transducer 24 and can be converted into thermal energy by a thermoacoustic refrigerator including the regenerator 125A.

  And in the energy recovery device 20A, since the regenerator 125A capable of changing the temperature gradient formed between both ends of the thermoacoustic refrigerator is applied, the temperature gradient is formed. Even if the vibration (sound wave) is not strictly controlled, it is possible to form a desired temperature gradient between both ends of the regenerator 125A and obtain a desired refrigeration output (cold heat). That is, in the energy recovery device 20A, by adjusting the temperature gradient formed between both ends of the regenerator 125A by changing the overall length of the expansion / contraction stack 1251, the thermoacoustic refrigerator and the transducer 24 including the regenerator 125A and the like The utilization ratio of the acoustic energy can be changed freely. Therefore, according to the energy recovery device 20A, it is possible to easily and reliably obtain a desired amount of electric energy and thermal energy.

  As shown in FIG. 7, the energy recovery device 20 </ b> A of the present embodiment includes a connection pipe part 29 that connects the exhaust pipe L <b> 2 and the pipe part 23 a of the air column pipe 21, and an exhaust pipe L <b> 2 of the connection pipe part 29. And a diaphragm 30 disposed in the end portion on the side. The diaphragm 30 functions as pulsation transmission means for preventing the exhaust gas from flowing into the air column tube 21 and transmitting the pulsation of the exhaust gas to the working fluid in the air column tube 21. Further, the energy recovery device 20A includes a presser member 31, a link mechanism 32, and an actuator 33 as pulsation transmission stopping means that stops vibration of the diaphragm 30 and stops transmission of pulsation to the working fluid in the air column tube 21. ing.

  As a result, in the energy recovery device 20A, when the internal combustion engine 1 is operated in a state where the pressing of the diaphragm 30 by the pressing member 31 is released, the pulsation of the exhaust gas is caused to flow through the diaphragm 30 and the working fluid in the air column tube 21. The sound wave is formed in the air column tube 21. The sound wave energy generated by utilizing the pulsation of the exhaust gas is the same as the sound wave energy generated due to the temperature gradient formed between both ends of the heat accumulator 250. It is converted into thermal energy by the acoustic refrigerator and also converted into electrical energy by the transducer 24 in the resonance unit 23.

  That is, the thermoacoustic refrigerator of the present invention, as applied to the energy recovery device 20A of FIG. 7, is a sound wave generated by a thermoacoustic phenomenon (a sound wave generated by the heat accumulator 250) and an exhaust gas of the internal combustion engine 1. The energy (acoustic energy) of both the sound wave generated using the pulsation of gas (or intake air) may be converted into thermal energy. Of course, the thermoacoustic refrigerator of the present invention uses either energy of the sound wave generated by the thermoacoustic phenomenon and the sound wave generated by utilizing the pulsation of the exhaust gas or the intake air of the internal combustion engine 1 as thermal energy. Needless to say, it may be converted.

It is a schematic block diagram which shows the energy recovery apparatus provided with the thermoacoustic engine by this invention. It is a schematic diagram for demonstrating the thermal accumulator of the thermoacoustic engine contained in the energy recovery apparatus of FIG. It is a schematic diagram for demonstrating the thermal accumulator of the thermoacoustic engine contained in the energy recovery apparatus of FIG. It is a flowchart for demonstrating the heat accumulator control routine in the energy recovery apparatus shown by FIG. It is a schematic diagram which shows the other heat accumulator applicable to the thermoacoustic engine contained in the energy recovery apparatus of FIG. It is a schematic diagram which shows the other heat accumulator applicable to the thermoacoustic engine contained in the energy recovery apparatus of FIG. It is a schematic block diagram which shows the energy recovery apparatus provided with the thermoacoustic refrigerator by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 20, 20A Energy recovery apparatus 21 Air column pipe 22 Loop part 23 Resonance part 24 Transducer 25, 25A, 250 Heat storage 26 High temperature heat exchanger 27 Low temperature heat exchanger 28 Pressure sensor 29 Connection pipe part 30 Diaphragm 125, 125A Regenerator 126 High-temperature heat exchanger for regenerator 127 Low-temperature heat exchanger for regenerator 251, 1251 Stretch stack 252, 252 A, 1252 Actuator 253 On-off valve 255 Connection member 256 Connection spring 257 Heating wire 258 Switch 259 Power supply L1 Supply pipe L2 Exhaust pipe L3 Cooling system T1 Catalyst temperature sensor T2 Water temperature sensor

Claims (7)

An air column tube in which the working fluid is sealed, and heat storage means disposed inside the air column tube, and a temperature gradient is formed between both end portions of the heat storage unit so that the thermoacoustic self-excitation of the working fluid is performed. In a thermoacoustic engine that generates vibration,
The thermoacoustic engine, wherein the heat storage means is configured to change the temperature gradient.   The thermoacoustic engine according to claim 1, wherein the total length of the heat storage means can be changed.   3. The thermoacoustic engine according to claim 1, wherein the heat storage means includes a porous member formed to be stretchable and a drive means for expanding and contracting the porous member.   The high-temperature heat exchanger disposed on one end side of the heat storage means is further provided, and the high-temperature heat exchanger uses exhaust gas from the internal combustion engine as a heat source. Thermoacoustic engine. An air column tube in which the working fluid is sealed, and a cold storage means disposed inside the air column tube, the working fluid is vibrated inside the air column tube, and the cold storage means is vibrated by the vibration of the working fluid. In a thermoacoustic refrigerator that generates cold using a temperature gradient formed between both ends of the
The said cool storage means is comprised so that the said temperature gradient can be changed, The thermoacoustic refrigerator characterized by the above-mentioned.   The thermoacoustic refrigerator according to claim 5, wherein the total length of the cold storage means can be changed. The thermoacoustic refrigerator according to claim 5 or 6, wherein the cold storage means includes a porous member formed to be extendable and a drive means for expanding and contracting the porous member.

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