JP5609159B2 - Thermoacoustic engine - Google Patents

Description

  The present invention relates to a thermoacoustic engine in which a loop tube, a resonance tube, and a generator are connected to each other, and more particularly to a thermoacoustic engine that can generate a large power generation with a small temperature difference.

  As shown in FIG. 3, in the conventional thermoacoustic engine 31, one end of the resonance tube 7 is connected to the loop tube 2 including the prime mover 6, and the generator 9 is connected to the other end of the resonance tube 7 via the piston 8. Is connected.

  In the thermoacoustic engine 31, the prime mover 6 includes the heater 3, the regenerator 4, and the cooler 5 arranged in the tube axis direction of the loop pipe 2, whereby heat energy is converted into acoustic energy in the prime mover 6, and the loop pipe 2 has a standing wave.

  The acoustic energy generated in the loop tube 2 propagates as a traveling wave through the resonance tube 7 to the piston 8, and the vibrator of the generator 9 is vibrated by the piston 8. In the generator 9, the positional relationship between the stator and the vibrator varies due to the vibration of the vibrator, and the magnetic flux changes. A change in magnetic flux acts on the winding to generate an electromotive force.

  Thus, the heat energy is converted into acoustic energy in the prime mover 6, and the acoustic energy is finally converted into electrical energy in the generator 9.

Japanese Patent No. 3050543 JP 2007-237020 A

  In the thermoacoustic engine 31 of FIG. 3, standing waves and traveling waves are mixed in the resonance tube 7. That is, the standing wave component in the resonance tube 7 causes the working fluid in the loop tube 2 and the resonance tube 7 to vibrate at a stable frequency, while acoustic energy is transported by the traveling wave.

  However, in the thermoacoustic engine 31 of FIG. 3, depending on the energy supply capability of the prime mover 6, the generator 9 may not be able to supply sufficient power for the power demand.

  Further, as a use application of the thermoacoustic engine 31, for example, when electric power is to be obtained from waste heat of a vehicle, the temperature difference between the waste heat temperature and the atmospheric temperature (or cooling water temperature) is small, so that power generation is performed. The power that can be extracted from the machine 9 cannot be increased.

  Therefore, an object of the present invention is to solve the above-described problems and provide a thermoacoustic engine capable of obtaining a large power generation with a small temperature difference.

In order to achieve the above object, the present invention provides a loop tube in which a cylindrical tube is bent at four bent portions and closed in a rectangular loop shape, and a heater and a regenerator in the tube axis direction of the loop tube. By having a cooler, a prime mover that converts thermal energy into acoustic energy, a resonance tube that is connected to one end of the bent portion of the loop tube and extends linearly, and an opposite end of the resonance tube In a thermoacoustic engine comprising a piston inserted and vibrated with acoustic energy, and a generator for converting vibration energy of the piston into electrical energy, the resonance tube is arranged in the tube axis direction of the resonance tube. Having a heater, regenerator, and cooler having the same structure as that used for the prime mover, and having only an amplifying device that amplifies a traveling wave traveling from the loop tube toward the piston in the resonance tube A.

  A plurality of amplifiers may be provided in the tube axis direction of the resonance tube.

  The present invention exhibits the following excellent effects.

  (1) A large power generation can be obtained with a small temperature difference.

It is a block diagram of the thermoacoustic engine which shows one Embodiment of this invention. FIG. 2 is an acoustic power distribution diagram in a tube axis direction of a resonance tube in the thermoacoustic engine of FIG. 1. It is a block diagram of the conventional thermoacoustic engine.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, a thermoacoustic engine 1 according to the present invention includes a loop tube 2 and a heater 3, a regenerator 4, and a cooler 5 in the tube axis direction of the loop tube 2, thereby generating thermal energy. A prime mover 6 for converting to acoustic energy, a resonance pipe 7 having one end connected to the loop pipe 2 and extending linearly, a piston 8 inserted at the opposite end of the resonance pipe 7 and vibrated with acoustic energy, and a piston 8 In the thermoacoustic engine 1 provided with the generator 9 that converts the vibration energy of this into electrical energy, the resonance tube 7 has a heater 10, a regenerator 11, and a cooler 12 in the tube axis direction of the resonance tube 7. And an amplifying device 13 for amplifying a traveling wave traveling from the loop tube 2 toward the piston 8 in the resonance tube 7.

  The loop tube 2 is closed in a substantially rectangular loop shape by a circular cylindrical tube having a circular cross section and bent at 90 ° at four bent portions. The resonance tube 7 is connected to the one bent portion. The resonance tube 7 is a hollow cylindrical tube having a circular cross section and no bending from one end to the other end. The working fluid filled in the loop tube 2 and the resonance tube 7 is a sonic medium, and is preferably a gas such as air, helium, nitrogen, or argon. The loop tube 2 and the resonance tube 7 are made of metal such as stainless steel.

  The prime mover 6 includes a heater 3, a regenerator 4, and a cooler 5 that are sequentially arranged in the tube axis direction. The heater 3 is a heat exchanger that heats the working fluid in the cylindrical tube by having fins inside and outside the cylindrical tube. The regenerator 4 is composed of a wire mesh, a collection of a plurality of thin tubes, a porous ceramic, and the like. The cooler 5 is a heat exchanger that cools the working fluid in the cylindrical tube by having fins inside and outside the cylindrical tube. Since the cooler 5, the regenerator 4, and the heater 3 can use known ones, detailed description of the structure is omitted.

  The piston 8 has no frictional resistance against the inner wall of the resonance tube 7 and can slide while maintaining airtightness.

  The generator 9 is a combination of a vibrator to which a permanent magnet is attached and a stator to which a winding is wound, so that an electromotive force is generated in the winding when the vibrator connected to the piston 8 vibrates. It has become. The details of the generator 9 are not limited to this, and it is only necessary that the vibration energy of the piston 8 can be converted into electric energy in the generator 9.

  The amplifier 13 includes a heater 10, a regenerator 11, and a cooler 12 that are sequentially arranged in the tube axis direction, like the prime mover 6. The structures of the cooler 12, the regenerator 11, and the heater 10 are the same as those used for the prime mover 6.

  Arbitrary plural amplifiers 13 are arranged at appropriate intervals in the tube axis direction. Here, three amplifiers 13 are shown. A common cooling source can be applied to the cooler 12 in each amplifier 13, and a common heating source can be applied to the heater 10 in each amplifier 13. Here, the temperature of the cooler 10 in each amplifier 13 is Tc, and the temperature of the heater 10 is Th higher than Tc.

  Hereinafter, the operation of the thermoacoustic engine 1 will be described.

  In the prime mover 6, heat sources having different temperatures are applied to the heater 3 and the cooler 5, and a temperature gradient is generated in the regenerator 4, whereby heat energy is converted into acoustic energy and a standing wave is generated in the loop tube 2.

  The sound wave generated in the loop tube 2 travels in the resonance tube 7 as a traveling wave sound wave in the tube axis direction. The traveling wave sound wave is input to the first-stage amplifier 13. This traveling wave sound wave is amplified when a heat source having different temperatures is applied to the cooler 12 and the heater 10 when passing through the amplifier 13 and a temperature gradient is generated in the regenerator 11.

  The traveling wave sound wave output from the amplifier 13 travels in the resonance tube in the tube axis direction and is input to the second-stage amplifier 13. In this way, when traveling wave sound waves sequentially pass through the amplifying device 13, as shown in FIG. 2, every time it passes through the first-stage amplifying device, the second-stage amplifying device, and the third-stage amplifying device, Increases power.

  When the amplifier 13 is installed in the resonance tube 7 of the thermoacoustic engine 1, the acoustic power is amplified, and when the amplifiers 13 are arranged in series in the resonance tube 7, every time the amplifier 13 passes, The inventors have already confirmed through experiments that power has been amplified, and have applied for an invention.

  In this way, since the traveling wave sound wave is amplified in each stage of the amplifier 13, the final stage amplifier 13 can transport much larger acoustic energy to the generator 9. As a result, a larger power generation than in the prior art is obtained. Therefore, even when the energy supply capability of only the prime mover 6 is not sufficient for the power demand in the generator 9, the addition of the energy from the amplifier 13 enables sufficient power supply to the power demand.

  Further, in the prime mover 6 and the amplifiers 13 at each stage, for example, the temperature difference between the waste heat temperature and the atmospheric temperature (or the cooling water temperature) is small as in the case of obtaining power from the waste heat of the vehicle. However, the power that can be extracted from the generator 9 can be increased by performing amplification in stages.

  As described above, according to the present invention, the loop tube 2 includes the prime mover 6, and the resonance tube 7 connected to the loop tube 2 includes the amplifier 13. Is obtained.

  Further, due to the configuration in which the resonance tube 7 includes a plurality of amplifiers 13, even if the temperature difference between the individual amplifiers 13 is small, large acoustic energy is transported to the generator 9 by the stepwise amplification. Power generation is obtained.

DESCRIPTION OF SYMBOLS 1 Thermoacoustic engine 2 Loop pipe 3 Heater 4 Regenerator 5 Cooler 6 Prime mover 7 Resonance pipe 8 Piston 9 Generator 10 Heater 11 Regenerator 12 Cooler 13 Amplifier

Claims (2)

A cylindrical tube is bent at four bends and closed in a rectangular loop shape, and has a heater, a regenerator, and a cooler in the tube axis direction of the loop tube, so that heat energy can be acoustically transmitted. A prime mover for converting into energy, a resonance tube having one end connected to one of the bent portions of the loop tube and extending linearly, and a piston inserted at the opposite end of the resonance tube and vibrated with acoustic energy In a thermoacoustic engine comprising a generator that converts vibration energy of the piston into electric energy,
In the middle of the resonance tube, by having a heater, a regenerator, and a cooler having the same structure as that used for the prime mover in the tube axis direction of the resonance tube, the inside of the resonance tube is changed from the loop tube to the piston. A thermoacoustic engine comprising only an amplifying device that amplifies a traveling wave traveling toward.   The thermoacoustic engine according to claim 1, wherein a plurality of the amplifiers are provided in a tube axis direction of the resonance tube.

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