A heat pipe type air-cooled standing wave thermo-acoustic engine

Abstract

The present application relates to low-grade heat recovery and utilization technical field, particularly relates to a heat pipe type air cooling standing wave thermoacoustic engine. It includes resonance tube, hot end heat exchanger, regenerator and cold end heat exchanger; wherein, hot end heat exchanger, regenerator and cold end heat exchanger are sequentially connected, hot end heat exchanger end is heated by high temperature fluid, cold end heat exchanger is cooled by heat pipe and heat dissipation fin on resonance straight pipe, regenerator forms temperature gradient under the action of cold and hot end heat exchangers, when temperature gradient is higher than a critical value, gas in resonance tube occurs self-excitation oscillation, and sound power is generated. The sound power generated by thermoacoustic engine belongs to mechanical energy, and can be further used to do work, generate electricity or refrigeration. The thermoacoustic engine of the present application adopts heat pipe type air cooling heat exchanger to replace traditional electric pump driven water cooling heat exchanger, completely relies on heat driving, does not need to consume additional electric energy, and has the advantages of energy saving and consumption reduction, simple structure, high reliability, low maintenance cost and the like.

Description

Technical Field

[0001] This invention relates to the field of low-grade heat energy recovery and utilization technology, and in particular to a heat pipe type air-cooled standing wave thermoacoustic engine. Background Technology

[0002] Thermoacoustic technology is a novel energy utilization technology that utilizes the thermoacoustic effect to achieve the mutual conversion of thermal energy and acoustic energy (or mechanical energy) between oscillating fluids and stationary solids. It has broad application prospects in fields such as solar energy utilization, geothermal energy development, and industrial waste heat recovery. Compared with traditional heat engines (such as Stirling engines), thermoacoustic engines have no moving parts, use inert gas as the working medium, and have advantages such as simple structure, high reliability, low manufacturing cost, and environmental friendliness. In recent years, it has become one of the research hotspots in the field of energy utilization. Traditional thermoacoustic engines rely on water-cooled heat exchangers to maintain the cold end temperature of the regenerator at room temperature. However, water-cooled heat exchangers use electric pumps to circulate water, requiring additional electrical energy and having a complex structure, which limits the application prospects of thermoacoustic engines. Therefore, it is necessary to carry out research on the design of novel thermoacoustic systems to expand the application prospects of thermoacoustic technology in the field of low-grade heat energy recovery and utilization, and promote energy conservation and emission reduction in industrial production. Summary of the Invention

[0003] The purpose of this invention is to address the problems existing in the background technology by proposing a method that uses a heat pipe air-cooled heat exchanger to replace the traditional electric pump-driven water-cooled heat exchanger. This allows the thermoacoustic engine to operate efficiently without the need for electricity, and has the significant advantages of simple and compact structure, thus expanding the application prospects of thermoacoustic technology in the field of low-grade heat energy recovery and utilization.

[0004] The technical solution of the present invention is a heat pipe type air-cooled standing wave thermoacoustic engine, including a resonant tube, a hollow copper tube, and a heat sink, wherein a hot end heat exchanger, a regenerator, and a cold end heat exchanger are sequentially arranged in the resonant tube.

[0005] Hollow copper tubes are inserted into the through holes on the surface of the resonant tube and the through holes inside the hot-end heat exchanger; heat pipes are inserted into the through holes on the surface of the resonant tube and the through holes inside the cold-end heat exchanger, and the heat pipes are bent outside the resonant tube and inserted into the through holes of the heat sink.

[0006] The resonant tube is a cylindrical straight tube with one closed end and one open end; the inner diameter of the resonant tube is much smaller than the tube length.

[0007] Preferably, the working gas inside the resonant tube is air, the temperature is room temperature, and the pressure is ambient pressure.

[0008] Preferably, the hot-end heat exchanger and the cold-end heat exchanger are plate-fin structures, and the gas flow direction between the plates and fins is parallel to the central axis of the resonant tube.

[0009] Preferably, the regenerator is a stack of parallel plates, with the gas flow direction between the parallel plates parallel to the central axis of the resonant tube. The hot-end heat exchanger and the cold-end heat exchanger are in close contact with the regenerator. The hot-end heat exchanger faces the closed end of the resonant tube, and the cold-end heat exchanger faces the open end of the resonant tube. The distance between the regenerator and the closed end is 1 / 3 of the total length of the resonant tube.

[0010] Preferably, multiple hollow copper tubes are provided, with a length greater than the outer diameter of the resonant tube; the middle part of the hollow copper tube is located inside the resonant tube, and both ends are located outside the resonant tube.

[0011] Preferably, multiple heat pipes are provided, the length of which is greater than the outer diameter of the resonant tube, and the portion located in the cold end heat exchanger and heat sink is a straight pipe.

[0012] Preferably, there are 8 to 10 heat sinks, which are ring-shaped and 1 mm thick, and are evenly spaced on the resonant tube with a spacing of 2 mm. The inner diameter of the heat sink is equal to the outer diameter of the resonant tube, and the outer diameter is twice the inner diameter.

[0013] Preferably, a high-temperature fluid flows through the hollow copper tube, with the flow direction of the high-temperature fluid perpendicular to the central axis of the resonant tube. The hollow copper tube is in close contact with the hot-end heat exchanger, transferring the heat of the high-temperature fluid to the hot-end heat exchanger.

[0014] Compared with the prior art, the present invention has the following beneficial technical effects:

[0015] 1. The heat pipe-type air-cooled standing wave thermoacoustic engine proposed in this invention includes a resonant tube, a hollow copper tube, and heat sinks. A hot-end heat exchanger, a regenerator, and a cold-end heat exchanger are sequentially arranged within the resonant tube. Heat is rapidly dissipated into the ambient air through the heat pipe and heat sinks at both ends. Because the regenerator is in close contact with the hot-end and cold-end heat exchangers, a temperature gradient is generated between the parallel plates of the regenerator. Air particles between the parallel plates exchange heat with the surrounding solid walls during the disturbance process. When the temperature gradient exceeds a certain critical value, the air particles absorb heat during compression and release heat during expansion, thus forming a positive thermodynamic cycle. Thermal energy is converted into acoustic energy, generating self-excited oscillations. Compared to traditional water-cooled thermoacoustic engines, this invention eliminates the need for electricity and water consumption, has a wider range of applications, and can provide a simple and low-cost power device for arid regions and areas without power grid coverage.

[0016] 2. The heat exchanger of the present invention uses annular fins for heat dissipation, which is not only compact and beautiful in structure, but also has a large heat dissipation area and good effect, and can quickly remove heat from the end of the heat pipe. Attached Figure Description

[0017] Figure 1 This is an overall schematic diagram of a heat pipe-type air-cooled standing wave thermoacoustic engine according to the present invention;

[0018] Figure 2This is a schematic diagram of the internal structure of the thermoacoustic engine in this invention;

[0019] Figure 3 This is a schematic diagram of the resonant tube in this invention;

[0020] Figure 4 This is a top view of the resonant tube in this invention;

[0021] Figure 5 This is a schematic diagram of the hot-end heat exchanger in this invention;

[0022] Figure 6 This is a schematic diagram of the regenerator in this invention;

[0023] Figure 7 This is a schematic diagram of the cold-end heat exchanger in this invention;

[0024] Figure 8 This is a top view of the cold-end heat exchanger in this invention;

[0025] Figure 9 This is a schematic diagram of the hollow copper tube in this invention;

[0026] Figure 10 This is a top view of the hollow copper tube in this invention;

[0027] Figure 11 This is a schematic diagram of the heat pipe structure in this invention;

[0028] Figure 12 This is a schematic diagram of the heat sink structure in this invention;

[0029] Figure 13 This is a schematic diagram of the combination of hollow copper tube and hot-end heat exchanger in this invention;

[0030] Figure 14 This is a front view of the combined structure of the hollow copper tube and the hot-end heat exchanger in this invention;

[0031] Figure 15 This is a top view of the combined structure of the hollow copper tube and the hot-end heat exchanger in this invention;

[0032] Figure 16 This is a schematic diagram of the combined structure of the cold-end heat exchanger, heat pipe and heat sink in the present invention;

[0033] Figure 17 This is a front view of the combined structure of the cold-end heat exchanger, heat pipe, and heat sink in this invention;

[0034] Figure 18 This is a top view of the combined structure of the cold-end heat exchanger, heat pipe, and heat sink in this invention;

[0035] Figure 19This is a schematic diagram of the combined structure of the hot-end heat exchanger, the regenerator and the cold-end heat exchanger in this invention.

[0036] Figure 20 This is a top view of the combined structure of the hot-end heat exchanger, the regenerator and the cold-end heat exchanger in this invention.

[0037] Figure 21 This is a front view of the combined structure of the hot-end heat exchanger, the regenerator, and the cold-end heat exchanger in this invention.

[0038] Reference numerals in the attached diagram: 1. Resonant tube; 2. Closed end; 3. Open end; 4. Hot end heat exchanger; 5. Hollow copper tube; 6. Hollow copper tube inlet; 7. Hollow copper tube outlet; 8. Regenerator; 9. Cold end heat exchanger; 10. Heat pipe; 11. Heat sink. Detailed Implementation

[0039] Example 1

[0040] like Figure 1 The present invention discloses a heat pipe-type air-cooled standing wave thermoacoustic engine, comprising a resonant tube 1, a hot-end heat exchanger 4, a hollow copper tube 5, a regenerator 8, a cold-end heat exchanger 9, a heat pipe 10, and heat sinks 11. The resonant tube 1 is a straight tube with a closed end 2 and an open end 3, both made of aluminum alloy with a thickness of 5mm. The hot-end heat exchanger 4 and the cold-end heat exchanger 9 are both plate-fin structures with four through holes in the middle, made of copper, with a plate fin thickness of 1mm and a plate fin spacing of 1mm. The regenerator 8 is a parallel plate stacking structure made of alumina, with parallel plates having a thickness of 1mm and a parallel plate spacing of 1mm. The hollow copper tube 5 is a straight tube made of copper with a thickness of 1mm.

[0041] Specifically, the hot-end heat exchanger 4, the regenerator 8, and the cold-end heat exchanger 9 are placed into the resonant tube 1 in sequence. Four hollow copper tubes 5 are inserted into the four through holes of the hot-end heat exchanger 4. The high-temperature fluid flows in from the inlet 6 of the hollow copper tubes and flows out from the outlet 7 of the hollow copper tubes. Two heat pipes 10 are inserted into the four through holes of the cold-end heat exchanger 9, and then the two ends are bent and inserted into the parallel heat sink 11.

[0042] The heat pipe type air-cooled standing wave thermoacoustic engine of the present invention includes the following working process:

[0043] A high-temperature fluid, acting as a heat source, flows into the hollow copper tube through inlet 6 and out through outlet 7. The heat carried by the high-temperature fluid is transferred to the hot-end heat exchanger 4 through the wall of the hollow copper tube 5, thus increasing the temperature of the hot-end heat exchanger 4. The middle part of the heat pipe 10 is in close contact with the cold-end heat exchanger 9, rapidly transferring the heat from the cold-end heat exchanger 9 to both ends of the heat pipe 10. The two ends of the heat pipe are tightly connected to the heat sink 11, rapidly dissipating the heat into the ambient air. Due to the close contact between the regenerator 8 and the hot-end and cold-end heat exchangers 4 and 9, a temperature gradient is generated between the parallel plates of the regenerator 8. During the disturbance process, the air particles between the parallel plates of the regenerator 8 exchange heat with the surrounding solid walls. When the temperature gradient exceeds a certain critical value, the air particles absorb heat during compression and release heat during expansion, thus forming a positive thermodynamic cycle. Thermal energy is converted into acoustic energy, generating self-excited oscillation. In addition, one end of the resonant tube 1 is closed, reflecting the incident wave. The incident wave and the reflected wave are superimposed to form a standing wave sound field, in which the pressure wave antinode is located at the closed end 2 and the pressure wave node is located at the open end 3.

[0044] The heat pipe air-cooled heat exchanger proposed in this invention has high heat transfer efficiency and fast speed, and its heat dissipation effect is comparable to that of a water-cooled heat exchanger. The heat of the cold end heat exchanger 9 is released into the ambient air through the heat pipe 10 and the heat sink 11, which includes the following six interrelated working processes:

[0045] 1. The heat from the cold-end heat exchanger 9 is transferred to the liquid wick inside the heat pipe through the pipe wall;

[0046] 2. The liquid in the wick evaporates at the liquid-vapor interface, absorbing a large amount of heat;

[0047] 3. The steam in the steam chamber flows from the evaporation section located in the middle of the heat pipe to the condensation sections located at both ends of the heat pipe;

[0048] 4. Steam condenses at the vapor-liquid interface in the condensation section, releasing a large amount of heat;

[0049] 5. The released heat is transferred to the heat sink through the heat pipe wall, and the heat sink releases the heat to the ambient air;

[0050] 6. Due to capillary action, the condensed liquid flows back to the evaporation section within the wick.

[0051] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A heat pipe type air-cooled standing wave thermoacoustic engine, comprising a resonant tube (1), a hollow copper tube (5), and a heat sink (11), characterized in that, A hot-end heat exchanger (4), a regenerator (8), and a cold-end heat exchanger (9) are sequentially arranged in the resonant tube (1). Hollow copper tube (5) is inserted into the surface through hole of resonant tube (1) and the internal through hole of hot end heat exchanger (4); heat pipe (10) is inserted into the surface through hole of resonant tube (1) and the internal through hole of cold end heat exchanger (9), and heat pipe (10) is bent outside resonant tube (1) and inserted into the through hole of heat sink (11); The resonant tube (1) is a cylindrical straight tube with one end closed (2) and the other end open (3); the inner diameter of the resonant tube (1) is much smaller than the tube length. High-temperature fluid flows in from the inlet (6) of the hollow copper tube as a heat source and flows out from the outlet (7) of the hollow copper tube. The flow direction of the high-temperature fluid is perpendicular to the central axis of the resonant tube (1). The hollow copper tube (5) is in close contact with the hot end heat exchanger (4) and transfers the heat of the high-temperature fluid to the hot end heat exchanger (4). The temperature of the hot end heat exchanger (4) rises, and the middle part of the heat pipe (10) is in close contact with the cold end heat exchanger (9) and quickly transfers the heat of the cold end heat exchanger (9) to both ends of the heat pipe (10). The two ends of the heat pipe (10) are in close contact with the heat sink (11) and quickly dissipate the heat into the ambient air. The regenerator (8) is a stack of parallel plates. The gas flow direction between the parallel plates is parallel to the central axis of the resonant tube (1). The hot end heat exchanger (4) and the cold end heat exchanger (9) are in close contact with the regenerator (8). The hot end heat exchanger (4) faces the closed end (2) of the resonant tube (1), and the cold end heat exchanger (9) faces the open end (3) of the resonant tube (1). The distance between the regenerator (8) and the closed end (2) is 1 / 3 of the total length of the resonant tube (1). The regenerator (8) is in close contact with the hot end heat exchanger (4) and the cold end heat exchanger (9). The parallel plates of the regenerator (8) generate a temperature gradient. The air particles between the parallel plates of the regenerator (8) exchange heat with the surrounding solid wall during the disturbance process. When the temperature gradient is greater than the critical value, the air particles absorb heat during the compression process and release heat during the expansion process, thus forming a positive thermodynamic cycle. The heat energy is converted into sound energy, generating self-excited oscillation. The resonant tube (1) is closed at one end, reflecting the incident wave. The incident wave and the reflected wave are superimposed to form a standing wave sound field, in which the pressure antinode is located at the closed end (2) and the pressure node is located at the open end (3).

2. The heat pipe type air-cooled standing wave thermoacoustic engine according to claim 1, characterized in that, The working gas inside the resonant tube (1) is air, the temperature is room temperature, and the pressure is ambient pressure.

3. The heat pipe type air-cooled standing wave thermoacoustic engine according to claim 1, characterized in that, The hot end heat exchanger (4) and the cold end heat exchanger (9) are plate-fin structures, and the gas flow direction between the plates and fins is parallel to the central axis of the resonant tube (1).

4. The heat pipe type air-cooled standing wave thermoacoustic engine according to claim 1, characterized in that, Multiple hollow copper tubes (5) are provided, with a length greater than the outer diameter of the resonant tube (1); the middle part of the hollow copper tube (5) is located inside the resonant tube (1), and both ends are located outside the resonant tube (1).

5. A heat pipe-type air-cooled standing wave thermoacoustic engine according to claim 1, characterized in that, Multiple heat pipes (10) are provided. The length of the heat pipe (10) is greater than the outer diameter of the resonant tube (1). The part located in the cold end heat exchanger (9) and heat sink (11) is a straight pipe.

6. A heat pipe type air-cooled standing wave thermoacoustic engine according to claim 1, characterized in that, There are 8 to 10 heat sinks (11), which are ring-shaped and 1 mm thick. They are evenly spaced on the resonant tube (1) with a spacing of 2 mm. The inner diameter of the heat sink (11) is equal to the outer diameter of the resonant tube (1), and the outer diameter is twice the inner diameter.

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