A free-piston Stirling thermally-closed solar-thermal generator

Abstract

The present invention relates to the technical field of generators, and discloses a free-piston Stirling thermally-closed solar thermal generator, which includes a housing. A soft magnetic stator is installed inside the housing. A plurality of permanent magnets are evenly and symmetrically installed inside the soft magnetic stator. A soft magnetic mover that can move up and down is installed between the plurality of permanent magnets. A copper winding is wound around the soft magnetic stator. The present invention adopts a moving-iron type, which can greatly simplify the structure of the generator and greatly reduce its production cost. By cleverly designing the magnetic circuit, a plurality of magnetic circuits simultaneously form an alternating magnetic field, making the motor part more compact, reducing its weight while increasing the power. In the engine part of the present invention, the gas distribution piston and the power piston are respectively connected to the housing through matching piston rods, and their running trajectories do not coincide. Therefore, the diameters of the two pistons can be designed to be the same or different, greatly improving the flexibility of the engine design and simplifying the design process and processing technology of the generator.

Description

Technical Field

[0001] The present invention relates to the technical field of generators, and in particular to a free-piston Stirling thermally-closed solar thermal generator. Background Art

[0002] A Stirling generator is composed of a Stirling engine and an electric motor. The Stirling engine has the advantage of high efficiency. In a free-piston Stirling generator, there is no contact between the piston and the cylinder, and the clearance seal avoids the problem of piston side force caused by the crank-link mechanism of a traditional Stirling engine, greatly improving the service life of the generator, making it applicable to long-life power supply scenarios such as deep space exploration and deep sea.

[0003] The existing Stirling generators have a relatively complex structure. The structural design is restricted by various dimensions, with poor design flexibility, and the processing technology is complex, resulting in a high production cost. Summary of the Invention

[0004] The purpose of the present invention is to solve the disadvantages existing in the prior art, and to propose a free-piston Stirling thermally-closed solar thermal generator.

[0005] To achieve the above purpose, the present invention adopts the following technical scheme:

[0006] A free-piston Stirling thermally-closed solar thermal generator includes a housing. A soft magnetic stator is installed inside the housing. A plurality of permanent magnets are evenly and symmetrically installed inside the soft magnetic stator. A soft magnetic mover that can move up and down is installed between the plurality of permanent magnets. A copper winding is wound around the soft magnetic stator. A power mechanism is also installed on the housing.

[0007] As a further scheme of the present invention, the power mechanism includes a hot-end external heater and a cold-end external radiator respectively installed outside the housing. A hot-end internal heat exchanger and a cold-end internal heat exchanger are respectively installed inside the housing corresponding to the hot-end external heater and the cold-end external radiator. A regenerator is installed between the hot-end internal heat exchanger and the cold-end internal heat exchanger. A power piston is installed inside the housing. A connecting shaft is installed between the power piston and the soft magnetic mover. A leaf spring is installed inside the housing. The connecting shaft penetrates through the leaf spring. A gas distribution piston is also installed inside the housing. The gas distribution piston is installed between the hot-end internal heat exchanger, the cold-end internal heat exchanger and the regenerator.

[0008] As a further solution of the present invention, a temperature control mechanism is installed on the outer surface of the outer shell near the hot end external heater, and the temperature control mechanism includes a cover shell fixedly installed on the outer surface of the outer shell, and the hot end external heater is installed inside the cover shell, and the outer periphery of the cover shell is respectively fixedly installed with a heat source inlet pipe and a waste heat outlet pipe connected to the interior thereof, and a rotating cover is rotatably installed inside the cover shell, and the outer surface of the rotating cover near the heat source inlet pipe and the waste heat outlet pipe is penetrated by through holes, and a temperature control component is installed inside the cover shell.

[0009] As a further solution of the present invention, the temperature control component includes a heat-conducting head that is fixedly installed inside the cover shell, the outer surface of the heat-conducting head extending outside the cover shell is fixedly installed with a mercury tube, a sealing plug is slidably installed inside the mercury tube, a clearance groove is penetrated through the outer surface of the rotating cover close to the heat-conducting head, and a pushing assembly is installed between the sealing plug and the rotating cover.

[0010] As a further solution of the present invention, the pushing assembly includes a guide rod fixedly mounted on the outer surface of the sealing plug, a retaining frame is fixedly mounted on the inner wall of the mercury tube away from the thermal head, the guide rod passes through the outer surface of the retaining frame and is slidably mounted therewith, a push plate is fixedly mounted on the outer surface of the rotating cover close to the guide rod, a rectangular opening is penetrated through the outer surface of the cover shell for the push plate to move, and a connecting assembly is installed between the push plate and the guide rod.

[0011] As a further solution of the present invention, the connecting assembly includes a guide column fixedly mounted on the outer surface of one end of the guide rod away from the sealing plug, the outer surface of the push plate is provided with a rectangular groove, the end of the guide rod is inserted into the rectangular groove, the inner wall of the rectangular groove is provided with a guide groove matching the guide column, and the guide column is slidably mounted on the inner wall of the guide groove.

[0012] As a further solution of the present invention, a return spring is sleeved on the outer surface of the guide rod, and the return spring is arranged between the sealing plug and the retaining frame.

[0013] As a further solution of the present invention, the interior of the mercury tube is filled with mercury, and the mercury is filled between the thermal conductive head and the sealing plug.

[0014] The beneficial effects of the present invention are:

[0015] 1. Traditional free piston Stirling generators generally use moving coil or moving magnet linear motors. The present invention uses a moving iron type, which can greatly simplify the structure of the generator and greatly reduce its production cost;

[0016] 2. The soft magnetic part of the present invention adopts 4, 6, 8 or more equal arms, and through the clever design of the magnetic circuit, multiple magnetic circuits simultaneously form an alternating magnetic field, making the motor part more compact, reducing its weight and increasing its power;

[0017] 3. The gas distribution piston and the power piston of the engine part of the present invention are respectively connected to the outer shell through the supporting piston rods, and their running trajectories do not coincide. Therefore, the diameters of the two pistons can be designed to be the same or different, greatly improving the flexibility of the engine design and simplifying the design process and processing technology of the generator. Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the external structure of a free-piston Stirling thermally closed solar thermal generator proposed by the present invention;

[0019] Figure 2 It is a schematic diagram of the internal structure of the outer shell of a free-piston Stirling thermally closed solar thermal generator proposed by the present invention;

[0020] Figure 3 It is a schematic diagram of the sectional structure of a free-piston Stirling thermally closed solar thermal generator proposed by the present invention;

[0021] Figure 4 It is a schematic diagram of the structure of the soft magnetic stator and the soft magnetic mover of a free-piston Stirling thermally closed solar thermal generator proposed by the present invention;

[0022] Figure 5 It is a schematic diagram of the magnetic induction lines when the soft magnetic mover of a free-piston Stirling thermally closed solar thermal generator proposed by the present invention is in the upper part;

[0023] Figure 6 It is a schematic diagram of the magnetic induction lines when the soft magnetic mover of a free-piston Stirling thermally closed solar thermal generator proposed by the present invention is in the lower part;

[0024] Figure 7 It is a schematic diagram of the structure of the cover of a free-piston Stirling thermally closed solar thermal generator proposed by the present invention;

[0025] Figure 8 It is a schematic diagram of the structure of the rotating cover of a free-piston Stirling thermally closed solar thermal generator proposed by the present invention;

[0026] Figure 9 It is a schematic diagram of the internal structure of the mercury tube of a free-piston Stirling thermally closed solar thermal generator proposed by the present invention;

[0027] Figure 10 It is Figure 8 The enlarged view of the structure at A in

[0028] In the figure: 1. Outer shell; 2. External heater at the hot end; 3. Internal heat exchanger at the hot end; 4. External radiator at the cold end; 5. Internal heat exchanger at the cold end; 6. Regenerator; 7. Gas distribution piston; 8. Power piston; 9. Leaf spring; 10. Connecting shaft; 11. Soft magnetic mover; 12. Soft magnetic stator; 13. Permanent magnet; 14. Copper winding; 15. Cover; 16. Heat source inlet pipe; 17. Waste heat outlet pipe; 18. Rotating cover; 19. Through hole; 20. Relief groove; 21. Heat conducting head; 22. Mercury tube; 23. Sealing plug; 24. Guide rod; 25. Cage; 26. Return spring; 27. Guide post; 28. Push plate; 29. Rectangular groove; 30. Guide groove. Detailed implementation manners

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0030] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. Next, the present invention will be described in detail with reference to the drawings and in conjunction with the embodiments.

[0031] Referring to the attached Figure 1 - attached Figure 10 , a free-piston Stirling thermally closed solar thermal generator, including an outer shell 1, an internal soft magnetic stator 12 is installed inside the outer shell 1, a plurality of permanent magnets 13 are evenly and symmetrically installed inside the soft magnetic stator 12, a vertically movable soft magnetic mover 11 is installed between the plurality of permanent magnets 13, a copper winding 14 is wound around the soft magnetic stator 12, a power mechanism is further installed on the outer shell 1, the power mechanism includes an external heater 2 at the hot end and an external radiator 4 at the cold end respectively installed outside the outer shell 1, an internal heat exchanger 3 at the hot end and an internal heat exchanger 5 at the cold end are respectively installed inside the outer shell 1 corresponding to the external heater 2 at the hot end and the external radiator 4 at the cold end, a regenerator 6 is installed between the internal heat exchanger 3 at the hot end and the internal heat exchanger 5 at the cold end, a power piston 8 is installed inside the outer shell 1, a connecting shaft 10 is installed between the power piston 8 and the soft magnetic mover 11, a leaf spring 9 is installed inside the outer shell 1, the connecting shaft 10 penetrates through the leaf spring 9, a gas distribution piston 7 is further installed inside the outer shell 1, and the gas distribution piston 7 is installed between the internal heat exchanger 3 at the hot end, the internal heat exchanger 5 at the cold end and the regenerator 6; a plurality of arm surfaces extend out of the outer periphery of the soft magnetic mover 11, and an equal number of arm surfaces also extend out of the inner side of the soft magnetic stator 12, and permanent magnets 13 (the magnetic pole directions are N and S respectively) are fixed on the arm surfaces.

[0032] In use, heat is introduced into the interior of the Stirling generator through the hot-end external heater 2, and then transferred to the hot-end internal heat exchanger 3, and then to the working gas; the working gas transfers the waste heat to the outer shell 1 through the cold-end internal heat exchanger 5, and then dissipates the heat to the environment through the cold-end external radiator 4; when the gas expands due to heat, it pushes the power piston 8 to expand and do work, and the leaf spring 9 of the power piston 8 plays the role of returning to the equilibrium position after expansion and then to the compression position. At the same time, the distribution piston 7 also reciprocates under the action of gas pressure fluctuations. When the distribution piston 7 moves downward, the gas sequentially passes through the cold-end internal heat exchanger 5, the regenerator 6, and the hot-end internal heat exchanger 3, and the gas is sequentially heated to a high temperature, further promoting the expansion and work of the working gas; when the distribution piston 7 moves upward, the gas sequentially passes through the hot-end internal heat exchanger 3, the regenerator 6, and the cold-end internal heat exchanger 5, and the gas is sequentially cooled to a low temperature, further promoting the compression process of the working gas. The distribution piston 7 plays the role of driving the working gas to the hot and cold cavities, while the power piston 8 is responsible for outputting the work of the engine to the soft magnetic mover 11 of the linear motor, driving the reciprocating motion of the soft magnetic mover 11 of the linear motor, and realizing the power generation operation.

[0033] In this embodiment, a temperature control mechanism is installed on the outer surface of the housing 1 near the external heater 2 at the hot end. The temperature control mechanism includes a cover 15 fixedly installed on the outer surface of the housing 1. The external heater 2 at the hot end is installed inside the cover 15. A heat source inlet pipe 16 and a waste heat outlet pipe 17 communicating with the inside thereof are fixedly installed on the outer periphery of the cover 15 respectively. A rotating cover 18 is rotatably installed inside the cover 15. Through holes 19 are respectively formed through the outer surfaces of the rotating cover 18 close to the heat source inlet pipe 16 and the waste heat outlet pipe 17. A temperature control component is installed inside the cover 15. The temperature control component includes a heat conducting head 21 fixedly installed through the inside of the cover 15. A mercury tube 22 is fixedly installed on the outer surface of the heat conducting head 21 extending outside the cover 15. A sealing plug 23 is slidably installed inside the mercury tube 22. A relief groove 20 is formed through the outer surface of the rotating cover 18 close to the heat conducting head 21. A pushing component is installed between the sealing plug 23 and the rotating cover 18. Mercury is filled inside the mercury tube 22, and the mercury is filled between the heat conducting head 21 and the sealing plug 23. The pushing component includes a guide rod 24 fixedly installed on the outer surface of the sealing plug 23. A cage 25 is fixedly installed on the inner wall of the mercury tube 22 at the end away from the heat conducting head 21. The guide rod 24 penetrates through the outer surface of the cage 25 and is slidably installed therewith. A push plate 28 is fixedly installed on the outer surface of the rotating cover 18 close to the guide rod 24. A rectangular opening for the movement of the push plate 28 is formed through the outer surface of the cover 15. A connecting component is installed between the push plate 28 and the guide rod 24. The connecting component includes a guide post 27 fixedly installed on the outer surface of the end of the guide rod 24 away from the sealing plug 23. A rectangular groove 29 is formed through the outer surface of the push plate 28. The end of the guide rod 24 is inserted into the rectangular groove 29. A guide groove 30 matching the guide post 27 is formed on the inner wall of the rectangular groove 29. The guide post 27 is slidably installed with the inner wall of the guide groove 30.

[0034] When the temperature inside the cover 15 is on the high side, the heat inside the cover 15 will be conducted to the heat conducting head 21, heating the mercury inside the mercury tube 22 by the heat conducting head 21, causing the mercury to expand due to heat and pushing the sealing plug 23, making the sealing plug 23 drive the guide rod 24 to move. Since the guide post 27 installed at the end of the guide rod 24 is slidably installed inside the guide groove 30 formed on the push plate 28, when the guide rod 24 is pushed, the rotating cover 18 can be pushed through the push plate 28, making the two through holes 19 formed on the rotating cover 18 be misaligned with the heat source inlet pipe 16 and the waste heat outlet pipe 17 respectively, reducing the orifice of the heat source inlet pipe 16 and enlarging the orifice of the waste heat outlet pipe 17, so as to reduce the entry of the heat source, avoid continuous heating of the external heater 2 at the hot end, and at the same time enable the heat inside the cover 15 to be discharged from the waste heat outlet pipe 17 more quickly, achieving the temperature control effect of the temperature inside the cover 15.

[0035] In this embodiment, a return spring 26 is sleeved on the outer surface of the guide rod 24, and the return spring 26 is arranged between the sealing plug 23 and the cage 25.

[0036] After the temperature inside the housing 15 decreases, the mercury cools and contracts, enabling the return spring 26 to push the sealing plug 23 to return to its original position, and driving the rotating cover 18 to return to its original position through the guide rod 24 and the push plate 28, achieving the effect of automatically controlling the temperature inside the housing 15, ensuring that the Stirling generator maintains the optimal working temperature difference, and thus improving the thermal efficiency.

[0037] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: during use, heat is introduced into the interior of the Stirling generator through the external heater 2 at the hot end, then the heat is transferred to the internal heat exchanger 3 at the hot end, and then to the working gas; the working gas transfers the waste heat to the housing 1 through the internal heat exchanger 5 at the cold end, and then dissipates the heat to the environment through the external radiator 4 at the cold end;

[0038] When the gas expands due to heat, it pushes the power piston 8 to expand and do work, and the leaf spring 9 of the power piston 8 plays a role in returning to the equilibrium position and then to the compressed position after expansion. At the same time, the distribution piston 7 also reciprocates under the action of gas pressure fluctuations. When the distribution piston 7 moves downward, the gas sequentially passes through the internal heat exchanger 5 at the cold end, the regenerator 6, and the internal heat exchanger 3 at the hot end, and the gas is sequentially heated to a high temperature, further promoting the expansion and work of the working gas; when the distribution piston 7 moves upward, the gas sequentially passes through the internal heat exchanger 3 at the hot end, the regenerator 6, and the internal heat exchanger 5 at the cold end, and the gas is sequentially cooled to a low temperature, further promoting the compression process of the working gas. The distribution piston 7 plays a role in driving the working gas to the hot and cold cavities, and the power piston 8 is responsible for outputting the work of the engine to the soft magnetic mover 11 of the linear motor, driving the reciprocating motion of the soft magnetic mover 11 of the linear motor, and realizing the power generation operation;

[0039] When the soft magnetic mover 11 is in the upper part, under the action of the permanent magnet 13, multiple magnetic flux circuits are formed in the soft magnetic stator 12, and their directions are respectively as Figure 5 shown by the arrows; when the soft magnetic mover 11 is in the lower part, four magnetic flux circuits are formed in the soft magnetic stator 12, and their directions are respectively as Figure 6 shown by the arrows. It can be seen that Figure 5 and Figure 6 the magnetic circuit directions in are exactly opposite; therefore, when the mover reciprocates, an alternating magnetic field is formed inside the soft magnetic stator 12, and then an alternating current is formed inside the copper winding 14, converting the kinetic energy of the soft magnetic mover 11 into electrical energy, achieving the purpose of power generation;

[0040] When the temperature inside the housing 15 is relatively high, the heat inside the housing 15 will be conducted to the heat conducting head 21, heating the mercury inside the mercury tube 22 by the heat conducting head 21, causing the mercury to expand due to heat and pushing the sealing plug 23, making the sealing plug 23 drive the guide rod 24 to move. Since the guide post 27 installed at the end of the guide rod 24 is slidably installed inside the guide groove 30 formed on the push plate 28, when the guide rod 24 is pushed, it can push the rotating cover 18 through the push plate 28, causing the two through holes 19 formed on the rotating cover 18 to be misaligned with the heat source inlet pipe 16 and the waste heat outlet pipe 17 respectively, reducing the orifice of the heat source inlet pipe 16 and enlarging the orifice of the waste heat outlet pipe 17, thereby achieving a reduction in the entry of the heat source, avoiding continuous heating of the external heater 2 at the hot end, and at the same time enabling the heat inside the housing 15 to be discharged from the waste heat outlet pipe 17 more quickly, achieving the temperature control effect of the temperature inside the housing 15, ensuring that the Stirling generator maintains the optimal working temperature difference, and thus improving the thermal efficiency.

[0041] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A free-piston Stirling thermally closed solar thermal generator, comprising a housing (1), characterized in that, A soft magnetic stator (12) is installed inside the shell (1), a plurality of permanent magnets (13) are evenly and symmetrically installed on the inner side of the soft magnetic stator (12), a soft magnetic mover (11) that can move up and down is installed between the plurality of permanent magnets (13), a copper winding (14) is wound around the soft magnetic stator (12), a power mechanism is also installed on the shell (1), a temperature control mechanism is installed on the outer surface of the shell (1) close to the hot end external heater (2), the temperature control mechanism comprises a cover (15) fixedly installed on the outer surface of the shell (1), the hot end external heater (2) is installed inside the cover (15), and a heat source inlet pipe (16) and a waste heat outlet pipe (16) connected to the inside of the cover (15) are fixedly installed on the outer periphery of the cover (15). The cover (15) is provided with a rotating cover (18) rotatably mounted inside the cover shell (15), and the outer surface of the rotating cover (18) close to the heat source inlet pipe (16) and the waste heat outlet pipe (17) is penetrated with through holes (19), and the cover shell (15) is provided with a temperature control component, and the temperature control component comprises a heat conducting head (21) penetrated and fixedly mounted inside the cover shell (15), and the outer surface of the heat conducting head (21) extending outside the cover shell (15) is fixedly mounted with a mercury tube (22), and a sealing plug (23) is slidably mounted inside the mercury tube (22), and the outer surface of the rotating cover (18) close to the heat conducting head (21) is penetrated with a clearance groove (20), and a push assembly is installed between the sealing plug (23) and the rotating cover (18).

2. The free-piston Stirling thermally-closed solar thermal power generator according to claim 1, characterized in that, The power mechanism comprises a hot-end external heater (2) and a cold-end external radiator (4) respectively mounted on the outside of a shell (1); a hot-end internal heat exchanger (3) and a cold-end internal heat exchanger (5) are respectively mounted inside the shell (1) corresponding to the hot-end external heater (2) and the cold-end external radiator (4); a regenerator (6) is mounted between the hot-end internal heat exchanger (3) and the cold-end internal heat exchanger (5); a power piston (8) is mounted inside the shell (1); a connecting shaft (10) is mounted between the power piston (8) and the soft magnetic mover (11); a leaf spring (9) is mounted inside the shell (1); the connecting shaft (10) penetrates the leaf spring (9); a gas distribution piston (7) is also mounted inside the shell (1); the gas distribution piston (7) is mounted between the hot-end internal heat exchanger (3), the cold-end internal heat exchanger (5) and the regenerator (6).

3. A free-piston Stirling thermally-closed solar thermal generator according to claim 1, wherein The pushing assembly comprises a guide rod (24) fixedly mounted on the outer surface of the sealing plug (23); a retaining frame (25) is fixedly mounted on the inner wall of the end of the mercury tube (22) away from the heat conducting head (21); the guide rod (24) penetrates the outer surface of the retaining frame (25) and is slidably mounted thereon; a push plate (28) is fixedly mounted on the outer surface of the rotating cover (18) close to the guide rod (24); a rectangular opening is penetrated through the outer surface of the cover shell (15) for the push plate (28) to move; and a connecting assembly is installed between the push plate (28) and the guide rod (24).

4. A free-piston Stirling thermally-closed solar thermal generator according to claim 3, characterized in that, The connecting component includes a guide post (27) fixedly installed on the outer surface of one end of the guide rod (24) away from the sealing plug (23). A rectangular groove (29) is formed through the outer surface of the push plate (28). The end of the guide rod (24) is inserted into the interior of the rectangular groove (29). A guide groove (30) matching the guide post (27) is formed on the inner wall of the rectangular groove (29), and the guide post (27) is slidably installed on the inner wall of the guide groove (30).

5. A free-piston Stirling thermally-closed solar thermal power generator according to claim 4, characterized in that, A return spring (26) is sleeved on the outer surface of the guide rod (24), and the return spring (26) is arranged between the sealing plug (23) and the cage (25).

6. A free-piston Stirling thermally-closed solar thermal power generator according to claim 1, characterized in that, The interior of the mercury tube (22) is filled with mercury, and the mercury is filled between the heat conducting head (21) and the sealing plug (23).

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