Flexible piston expander system

Abstract

This application discloses a flexible piston expander system, including a main piston top cover, a main piston bottom cover, a secondary piston bottom cover, and a secondary piston top cover. An intake valve housing and an exhaust valve housing are connected between the main piston bottom cover and the secondary piston bottom cover to form a stationary part. An intake valve movable component is installed inside the intake valve housing, and an exhaust valve movable component is installed inside the exhaust valve housing. The main piston top cover and the secondary piston top cover are connected by a connector to form a moving part. The moving part can reciprocate relative to the stationary part in a preset direction. When the moving part moves to a first position, the main piston top cover pushes the intake valve movable component and the exhaust valve movable component to move to open the main intake passage and the secondary exhaust passage. When the moving part moves to a second position, the secondary piston top cover pushes the intake valve movable component and the exhaust valve movable component to move to open the secondary intake passage and the main exhaust passage, thereby realizing the effective utilization and conversion of heat from a low-temperature heat source and reducing mechanical losses.

Description

Technical Field

[0001] This application relates to the field of engine technology, and in particular to a flexible piston expander system. Background Technology

[0002] Energy conservation and emission reduction have always been key concerns for various industries, including energy, chemicals, electrical engineering, and construction, in the new era. The development and utilization of low-temperature heat sources has been a particular focus. Low-temperature heat sources are widespread and abundant, including geothermal energy, industrial waste heat, and solar energy. Currently, the utilization of low-temperature heat sources mainly involves developing geothermal hot springs for bathing, geothermal heat pumps, and industrial waste heat heating. However, this heat is difficult to utilize effectively during non-heating seasons such as summer or in areas where heating is not required.

[0003] The relevant technology utilizes a rigid piston expander to convert the heat from a low-temperature heat source into mechanical energy. However, the rigid piston expander suffers from significant mechanical losses, sometimes exceeding the energy converted from the low-temperature heat source itself, thus affecting the effective conversion of heat from the low-temperature heat source. Summary of the Invention

[0004] To solve the above-mentioned technical problems, or at least partially solve them, embodiments of this application provide a flexible piston expander system suitable for the efficient recovery and conversion of heat from low-temperature heat sources.

[0005] This application provides a flexible piston expander system, including a main piston top cover, a main piston bottom cover, a secondary piston bottom cover, a secondary piston top cover, an intake valve housing, and an exhaust valve housing. The main piston bottom cover and the auxiliary piston bottom cover are arranged opposite to each other, and the intake valve housing and the exhaust valve housing are respectively connected between the main piston bottom cover and the auxiliary piston bottom cover to form a stationary part together; The main piston top cover is located on the side of the main piston bottom cover away from the auxiliary piston bottom cover, and a main piston flexible membrane is sealed between the main piston top cover and the main piston bottom cover to form a main piston cavity; a piston rod is connected to the side of the main piston top cover away from the main piston bottom cover; the auxiliary piston top cover is located on the side of the auxiliary piston bottom cover away from the main piston bottom cover, and a auxiliary piston flexible membrane is sealed between the auxiliary piston top cover and the auxiliary piston bottom cover to form a auxiliary piston cavity; An intake valve movable assembly is installed inside the intake valve housing, and an exhaust valve movable assembly is installed inside the exhaust valve housing. A main intake channel is provided between the intake valve housing and the main piston chamber, and a secondary intake channel is provided between the intake valve housing and the secondary piston chamber. A main exhaust channel is provided between the exhaust valve housing and the main piston chamber, and a secondary exhaust channel is provided between the exhaust valve housing and the secondary piston chamber. The main piston top cover and the auxiliary piston top cover are connected by a connector to form a moving part. The moving part can reciprocate relative to the stationary part in a preset direction. When the moving part moves to a first position in the preset direction, the main piston top cover pushes the intake valve moving assembly and the exhaust valve moving assembly to open the main intake passage and the auxiliary exhaust passage, and close the auxiliary intake passage and the main exhaust passage. When the moving part moves to a second position in the preset direction, the auxiliary piston top cover pushes the intake valve moving assembly and the exhaust valve moving assembly to open the auxiliary intake passage and the main exhaust passage, and close the main intake passage and the auxiliary exhaust passage.

[0006] Optionally, a main air intake hole is provided at one end of the side wall of the intake valve housing near the main piston chamber, and the main air intake hole forms the inlet of the main air intake channel; a secondary air intake hole is provided at one end of the side wall of the intake valve housing near the secondary piston chamber, and the secondary air intake hole forms the inlet of the secondary air intake channel. The intake valve movable assembly includes an intake valve stem and intake valve cores disposed at both ends of the intake valve stem along its axial direction, and the intake valve cores are provided with vent holes.

[0007] Optionally, a main exhaust port is provided at one end of the side wall of the exhaust valve housing near the main piston chamber, and the main exhaust port forms the outlet of the main exhaust channel; a secondary exhaust port is provided at one end of the side wall of the exhaust valve housing near the secondary piston chamber, and the secondary exhaust port forms the outlet of the secondary exhaust channel. The exhaust valve movable assembly includes an exhaust valve stem and exhaust valve cores disposed at both axial ends of the exhaust valve stem. A main vent hole is provided on the exhaust valve core near the main piston chamber; a secondary vent hole is provided on the exhaust valve core near the secondary piston chamber.

[0008] Optionally, the main piston top cover includes a main top cover body and a first main protrusion and a second main protrusion disposed on the side of the main top cover body facing the main piston bottom cover. The first main protrusion corresponds to the intake valve movable assembly and is used to push the intake valve movable assembly to move when the moving part moves to the first position. The second main protrusion corresponds to the exhaust valve movable assembly and is used to push the exhaust valve movable assembly to move when the moving part moves to the first position. The secondary piston top cover includes a secondary top cover body and a first secondary protrusion and a second secondary protrusion disposed on the side of the secondary top cover body facing the secondary piston bottom cover. The first secondary protrusion corresponds to the intake valve movable assembly and is used to push the intake valve movable assembly to move when the moving part moves to the second position. The second secondary protrusion corresponds to the exhaust valve movable assembly and is used to push the exhaust valve movable assembly to move when the moving part moves to the second position.

[0009] Optionally, the moving part is configured to reciprocate along an arc-shaped trajectory; The connector is an arc-shaped connector adapted to the arc trajectory; the first main protrusion, the second main protrusion, the first secondary protrusion, and the second secondary protrusion are all arc-shaped protrusions adapted to the arc trajectory.

[0010] Optionally, the moving part is configured to reciprocate along a straight trajectory.

[0011] Optionally, the flexible piston expander system also includes a mounting plate; The stationary part is connected to the mounting plate, which is used to install the flexible piston expander system in a preset position.

[0012] Optionally, the flexible piston expander system further includes a guide support structure for guiding and supporting the piston rod.

[0013] Optionally, the guide support structure includes a bearing housing and a linear bearing disposed on the bearing housing, with the piston rod passing through the linear bearing.

[0014] Optionally, a piston head is provided at the end of the piston rod away from the main piston top cover, and the piston head has a top roller for rolling contact with an external transmission mechanism.

[0015] The flexible piston expander system provided in this application embodiment comprises a main piston top cover, a main piston bottom cover, an auxiliary piston bottom cover, an auxiliary piston top cover, an intake valve housing, and an exhaust valve housing. The main piston bottom cover and the auxiliary piston bottom cover are positioned opposite each other. The intake valve housing and the exhaust valve housing are respectively connected between the main piston bottom cover and the auxiliary piston bottom cover to form a stationary portion. A flexible membrane for the main piston is sealed between the main piston top cover and the main piston bottom cover to form a main piston cavity. A flexible membrane for the auxiliary piston is sealed between the auxiliary piston top cover and the auxiliary piston bottom cover to form a secondary piston cavity. An intake valve moving assembly is installed inside the intake valve housing, and an exhaust valve housing is installed inside the exhaust valve housing. The exhaust valve moving assembly connects the main piston top cover and the auxiliary piston top cover via a connector to form a moving part. This moving part can reciprocate in a preset direction relative to the stationary part. The main piston top cover or the auxiliary piston top cover pushes the intake valve moving assembly and the exhaust valve moving assembly to switch the intake and exhaust channels. In other words, by adopting an opposed twin-cylinder structure, the intake and exhaust valve moving assemblies are integrated between the main and auxiliary pistons, and the piston movement directly drives the valve moving assembly to switch the intake and exhaust channels. This, in turn, enables the reciprocating motion of the piston rod and achieves the effective conversion of heat from the low-temperature heat source.

[0016] Since both the main piston chamber and the auxiliary piston chamber are sealed with flexible membranes, sliding friction between the traditional rigid piston and the cylinder wall is avoided, thus reducing mechanical losses to a certain extent. Furthermore, because the intake and exhaust valve moving components are only pushed back and forth by the main piston cap and auxiliary piston cap, respectively, and only contact occurs after the moving parts reach the first and second positions, disengaging at other times, continuous pulling or rigid connection is not required. This significantly reduces the movement resistance and frictional losses of the intake and exhaust valve moving components, thereby reducing mechanical losses. Simultaneously, by directly pushing the intake and exhaust valve moving components through the main and auxiliary piston caps, a complex internal pulling mechanism is unnecessary, reducing the number of parts and assembly complexity, further lowering mechanical frictional losses.

[0017] Furthermore, since the intake valve moving assembly and the exhaust valve moving assembly are located inside the cavity formed by the main piston bottom cover, the secondary piston bottom cover and the corresponding valve housing, and the driving force of the intake valve moving assembly and the exhaust valve moving assembly originates from the inside of the piston top cover, the risk of leakage is reduced to a certain extent, ensuring the sealing and stability of the gas working fluid circulation, thereby improving the low-temperature heat source conversion efficiency. Attached Figure Description

[0018] Figure 1 This is a front sectional view of a flexible piston expander system according to an embodiment of this application; Figure 2 This is a side sectional view of a flexible piston expander system according to an embodiment of this application; Figure 3This is a schematic diagram of the stationary part of a flexible piston expander system according to an embodiment of this application; Figure 4 for Figure 3 Corresponding exploded structure diagram; Figure 5 This is a schematic diagram of the moving parts in a flexible piston expander system according to an embodiment of this application; Figure 6 for Figure 5 Corresponding exploded structure diagram; Figure 7 This is a schematic diagram of the intake valve housing in a flexible piston expander system according to an embodiment of this application; Figure 8 This is a structural cross-sectional view of the intake valve housing in a flexible piston expander system according to an embodiment of this application; Figure 9 This is a schematic diagram of the exhaust valve housing in a flexible piston expander system according to an embodiment of this application; Figure 10 This is a structural cross-sectional view of the exhaust valve housing in a flexible piston expander system according to an embodiment of this application; Figure 11 This is a schematic diagram of the structure of the intake valve movable component in a flexible piston expander system according to an embodiment of this application; Figure 12 This is a schematic diagram of the structure of the exhaust valve movable component in a flexible piston expander system according to an embodiment of this application; Figure 13 This is a schematic diagram of the intake and exhaust process of the flexible piston expander system described in one embodiment of this application. Figure 1 ; Figure 14 This is a schematic diagram of the intake and exhaust process of the flexible piston expander system described in one embodiment of this application. Figure 2 ; Figure 15 This is another structural schematic diagram of the flexible piston expander system described in one embodiment of this application; Figure 16 for Figure 15 The corresponding exploded structure diagram.

[0019] Explanation of reference numerals in the attached figures: 1. Main piston top cover; 10. Piston rod; 101. Piston head; 102. Head roller; 11. Main top cover body; 12. First main protrusion; 13. Second main protrusion; 2. Main piston bottom cover; 3. Main piston flexible diaphragm; 30. Main piston chamber; 4. Secondary piston top cover; 41. Secondary top cover body; 42. First secondary protrusion; 43. Secondary secondary protrusion; 5. Secondary piston bottom cover; 6. Secondary piston flexible diaphragm; 60. Secondary piston chamber; 7. Intake valve housing; 70. Intake valve. Valve moving assembly; 701, Intake valve stem; 702, Intake valve core; 703, Vent hole; 71, Main intake hole; 72, Secondary intake hole; 8, Exhaust valve housing; 80, Exhaust valve moving assembly; 801, Exhaust valve stem; 802, Exhaust valve core; 803, Main vent hole; 804, Secondary vent hole; 81, Main exhaust hole; 82, Secondary exhaust hole; 9, Connecting piece; 100, Guide support structure; 110, Bearing housing; 120, Linear bearing; 130, Mounting plate. Detailed Implementation

[0020] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present application, not the entire structure.

[0021] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to". The concepts of "first," "second," etc., used in this application are only used to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies. It should be noted that the modifications "a" or "a plurality of" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless explicitly stated in the context, they should be understood as "one or more".

[0022] Reference Figures 1 to 14 As shown in the figure, this application provides a flexible piston expander system, which enables the effective conversion of heat from a low-temperature heat source.

[0023] The flexible piston expander system includes: a main piston top cover 1, a main piston bottom cover 2, a secondary piston bottom cover 5, a secondary piston top cover 4, an intake valve housing 7, and an exhaust valve housing 8.

[0024] The main piston bottom cover 2 and the auxiliary piston bottom cover 5 are arranged opposite to each other, and the intake valve housing 7 and the exhaust valve housing 8 are respectively connected between the main piston bottom cover 2 and the auxiliary piston bottom cover 5 to form a stationary part together.

[0025] The main piston top cover 1 is located on the side of the main piston bottom cover 2 away from the auxiliary piston bottom cover 5. A main piston flexible membrane 3 is connected between the main piston top cover 1 and the main piston bottom cover 2 to form the main piston cavity 30. It can be understood that the main piston flexible membrane 3 is a flexible cylindrical structure that can dynamically expand and contract, serving as the cavity wall of the main piston working chamber.

[0026] The auxiliary piston top cover 4 is located on the side of the auxiliary piston bottom cover 5 away from the main piston bottom cover 2. A flexible auxiliary piston membrane 6 connects the auxiliary piston top cover 4 and the auxiliary piston bottom cover 5 to form the auxiliary piston cavity 60. It can be understood that the flexible auxiliary piston membrane 6 is a flexible cylindrical structure that can dynamically expand and contract, serving as the cavity wall of the auxiliary piston working chamber.

[0027] The intake valve housing 7 is provided with an intake valve movable assembly 70, and the exhaust valve housing 8 is provided with an exhaust valve movable assembly 80. The intake valve housing 7 and the main piston chamber 30 have a main intake passage, the intake valve housing 7 and the auxiliary piston chamber 60 have a secondary intake passage, the exhaust valve housing 8 and the main piston chamber 30 have a main exhaust passage, and the exhaust valve housing 8 and the auxiliary piston chamber 60 have a secondary exhaust passage.

[0028] The main piston top cover 1 and the auxiliary piston top cover 4 are connected by a connector 9 to form a moving part. The moving part can reciprocate relative to the stationary part in a preset direction. When the moving part moves to a first position in the preset direction, the main piston top cover 1 pushes the intake valve moving assembly 70 and the exhaust valve moving assembly 80 to move, thereby opening the main intake passage and the auxiliary exhaust passage, and closing the auxiliary intake passage and the main exhaust passage. When the moving part moves to a second position in the preset direction, the auxiliary piston top cover 4 pushes the intake valve moving assembly 70 and the exhaust valve moving assembly 80 to move, thereby opening the auxiliary intake passage and the main exhaust passage, and closing the main intake passage and the auxiliary exhaust passage.

[0029] A piston rod 10 is connected to the side of the main piston top cover 1 away from the main piston bottom cover 2. The piston rod 10 is specifically used to connect with an external transmission mechanism. That is, under the action of the gaseous working fluid (derived from the heat of the low-temperature heat source), when the moving part reciprocates relative to the stationary part, the moving part drives the piston rod 10 to reciprocate. Through the movement of the piston rod 10, mechanical work is output to the outside, realizing the effective conversion of the heat of the low-temperature heat source.

[0030] The external transmission mechanism can be, for example, a star-shaped parallel mechanism or a crankshaft connecting rod mechanism. For instance, a flexible piston expander system converts heat from a low-temperature heat source into mechanical energy, which then drives a generator to produce electricity, thus converting mechanical energy into electrical energy.

[0031] Reference Figures 1 to 14As shown, for example, the main piston bottom cover 2 is located above the auxiliary piston bottom cover 5, the main piston top cover 1 is located above the main piston bottom cover 2, the auxiliary piston top cover 4 is located below the auxiliary piston bottom cover 5, the intake valve housing 7 and the exhaust valve housing 8 are arranged side by side in the left-right direction, the intake valve housing 7 is connected between the main piston bottom cover 2 and the auxiliary piston bottom cover 5, and the exhaust valve housing 8 is connected between the main piston bottom cover 2 and the auxiliary piston bottom cover 5.

[0032] It is understandable that both the intake valve housing 7 and the exhaust valve housing 8 are hollow structures with openings at both ends. The main piston bottom cover 2 forms clearance through holes corresponding to the positions of the intake valve housing 7 and the exhaust valve housing 8. The auxiliary piston bottom cover 5 also forms clearance through holes corresponding to the positions of the intake valve housing 7 and the exhaust valve housing 8. This allows the intake valve moving assembly 70 and the exhaust valve moving assembly 80 to move downward under the push of the main piston top cover 1 and upward under the push of the auxiliary piston top cover 4.

[0033] In other words, the flexible piston expander system is based on the alternating entry of gaseous working fluid into the main piston chamber 30 and the auxiliary piston chamber 60, generating alternating thrust to drive the main piston top cover 1 or the auxiliary piston top cover 4 to move. When it moves to the first position and the second position, it triggers the movement of the intake valve moving assembly 70 and the exhaust valve moving assembly 80 to realize the switching of the intake and exhaust channels and realize the automatic reversal of the gaseous working fluid flow direction.

[0034] The following, with reference to the accompanying drawings, further explains the specific working process of the flexible piston expander system: Assuming the initial state, refer to Figure 14 As shown, the moving part is at top dead center (i.e., the highest position). The auxiliary piston top cover 4 has pushed the intake valve moving assembly 70 and the exhaust valve moving assembly 80 to their highest positions. At this time, for the main piston chamber 30: the main intake passage is closed and the main exhaust passage is open. For the auxiliary piston chamber 60: the auxiliary intake passage is open and the auxiliary exhaust passage is closed.

[0035] The gaseous working fluid enters the secondary piston chamber 60 through the open secondary intake channel. Under the action of the gas, the flexible membrane 6 of the secondary piston elastically expands and deforms downward. The expanded flexible membrane 6 of the secondary piston converts the gas pressure into a downward thrust on the top cover 4 of the secondary piston, doing work externally, thereby causing the entire moving part to begin to move downward. This motion is transmitted to the external transmission mechanism through the piston rod 10, outputting mechanical work.

[0036] During the downward movement (i.e., movement from Y+ to Y-), the volume of the main piston chamber 30 gradually decreases, and gas is discharged through the main exhaust passage. The volume of the secondary piston chamber 60 gradually increases, and gas continuously enters. When the moving part moves downward to the first position, the main piston top cover 1 contacts the intake valve moving assembly 70 and the exhaust valve moving assembly 80, and pushes the intake valve moving assembly 70 and the exhaust valve moving assembly 80 downward, as shown in the reference. Figure 13 As shown, when the moving part reaches the bottom dead center (i.e., the lowest position), for the main piston chamber 30: the main intake passage is open and the main exhaust passage is closed. For the secondary piston chamber 60: the secondary intake passage is closed and the secondary exhaust passage is open.

[0037] After the intake and exhaust channels are switched, the gas enters the main piston chamber 30 through the opened main intake channel. The gas acts on the main piston flexible membrane 3 in the main piston chamber 30, causing it to expand and deform elastically upwards, doing work externally, thereby generating an upward thrust on the main piston top cover 1. At the same time, the gas in the auxiliary piston chamber 60 is discharged through the auxiliary exhaust channel, and the moving part begins to move upwards (i.e., from Y- to Y+). This movement is transmitted to the external transmission mechanism through the piston rod 10, outputting mechanical work externally.

[0038] When the moving part moves to the second position again, the auxiliary piston top cover 4 contacts the intake valve moving assembly 70 and the exhaust valve moving assembly 80, and pushes the intake valve moving assembly 70 and the exhaust valve moving assembly 80 upward, referring again to... Figure 14 As shown, when the moving part reaches the top dead center, the valve state switches back to the initial state, that is, the main intake passage is closed, the main exhaust passage is open, the auxiliary intake passage is open, and the auxiliary exhaust passage is closed.

[0039] The above process repeats itself, causing the moving parts to move continuously, which in turn drives the piston rod 10 to move back and forth in sequence, outputting continuous power to the outside, thereby realizing the recovery of heat from the low-temperature heat source or energy conversion.

[0040] Reference Figure 13 and Figure 14 As shown, it can be understood that the first position mentioned above is the position where the moving part moves downward to the point where the main piston top cover 1 just comes into contact with the intake valve moving assembly 70 and the exhaust valve moving assembly 80. The bottom dead center mentioned above is located below the first position. After the main piston top cover 1 comes into contact with the intake valve moving assembly 70 and the exhaust valve moving assembly 80, the intake valve moving assembly 70 and the exhaust valve moving assembly 80 move downward under the push of the main piston top cover 1 until the main intake passage is open, the main exhaust passage is closed, the auxiliary intake passage is closed, and the auxiliary exhaust passage is open. The position corresponding to the moving part at this time is the bottom dead center.

[0041] Correspondingly, the second position mentioned above is the position where the moving part moves upward to the point where the auxiliary piston top cover 4 just comes into contact with the intake valve moving assembly 70 and the exhaust valve moving assembly 80. The top dead center mentioned above is located above the second position. After the auxiliary piston top cover 4 comes into contact with the intake valve moving assembly 70 and the exhaust valve moving assembly 80, the intake valve moving assembly 70 and the exhaust valve moving assembly 80 move upward under the push of the auxiliary piston top cover 4 until the main intake passage is closed, the main exhaust passage is open, the auxiliary intake passage is open, and the auxiliary exhaust passage is closed. At this time, the position corresponding to the moving part is the top dead center.

[0042] By setting up a flexible membrane, compared with the existing piston and cylinder combination scheme, the flexible membrane can reduce friction loss and leakage loss, thereby reducing mechanical loss to a certain extent and providing the possibility for the conversion and utilization of low-temperature waste heat with a temperature of less than 150°C.

[0043] Reference Figure 5 and Figure 6 As shown, exemplarily, the connector 9 is specifically disposed around the main piston top cover 1 and the auxiliary piston top cover 4. For example, the top of the connector 9 is connected to the main piston top cover 1 by screw fasteners, and the bottom of the connector 9 is connected to the auxiliary piston top cover 4 by screw fasteners. The specific connection method between the connector 9 and the main piston top cover 1 and the auxiliary piston top cover 4 is not limited to this in the embodiments of this application.

[0044] The flexible piston expander system provided in this application embodiment comprises a main piston top cover 1, a main piston bottom cover 2, a secondary piston bottom cover 5, a secondary piston top cover 4, an intake valve housing 7, and an exhaust valve housing 8. The main piston bottom cover 2 and the secondary piston bottom cover 5 are positioned opposite each other. The intake valve housing 7 and the exhaust valve housing 8 are respectively connected between the main piston bottom cover 2 and the secondary piston bottom cover 5 to form a stationary portion. A main piston flexible membrane 3 is sealed between the main piston top cover 1 and the main piston bottom cover 2 to form a main piston cavity 30. A secondary piston flexible membrane 6 is sealed between the secondary piston top cover 4 and the secondary piston bottom cover 5 to form a secondary piston cavity 60. An intake valve movable assembly 70 passes through the intake valve housing 7. An exhaust valve movable assembly 80 is installed inside the valve housing 8, so that the main piston top cover 1 and the auxiliary piston top cover 4 are connected by the connector 9 to form a moving part. The moving part can reciprocate relative to the stationary part in a preset direction. The main piston top cover 1 or the auxiliary piston top cover 4 pushes the intake valve movable assembly 70 and the exhaust valve movable assembly 80 to move, thereby realizing the switching of intake and exhaust channels. In other words, by adopting a opposed double cylinder structure, the intake and exhaust valve movable assemblies are integrated between the main and auxiliary pistons, and the piston movement directly drives the valve movable assembly to move, thereby realizing the switching of intake and exhaust channels, and thus realizing the reciprocating motion of the piston rod 10, realizing the effective conversion of heat from the low-temperature heat source.

[0045] Since both the main piston chamber 30 and the auxiliary piston chamber 60 are sealed with flexible membranes, sliding friction between the traditional rigid piston and the cylinder wall is avoided, thus reducing mechanical losses to a certain extent. Furthermore, because the intake valve moving assembly 70 and the exhaust valve moving assembly 80 are only pushed back and forth by the main piston top cover 1 and the auxiliary piston top cover 4, and only contact is made after the moving parts reach the first and second positions, disengaging at other times, without the need for continuous pulling or rigid connection, the movement resistance and friction loss of the intake valve moving assembly 70 and the exhaust valve moving assembly 80 are significantly reduced, thereby reducing mechanical losses. Simultaneously, by directly pushing the intake valve moving assembly 70 and the exhaust valve moving assembly 80 through the main piston top cover 1 and the auxiliary piston top cover 4, there is no need for a complex built-in pulling mechanism, thus reducing the number of parts and assembly complexity, and further reducing mechanical friction losses.

[0046] Furthermore, since the intake valve moving assembly 70 and the exhaust valve moving assembly 80 are located inside the cavity formed by the main piston bottom cover 2, the secondary piston bottom cover 5 and the corresponding valve housing, and the driving force of the intake valve moving assembly 70 and the exhaust valve moving assembly 80 originates from the inside of the piston top cover, the risk of leakage is reduced to a certain extent, ensuring the sealing and stability of the gas working fluid circulation, thereby improving the low-temperature heat source conversion efficiency.

[0047] Continue to refer to Figures 1 to 14 As shown, in some embodiments, a main intake port 71 is provided at the end of the side wall of the intake valve housing 7 near the main piston chamber 30, forming the inlet of the main intake channel. A secondary intake port 72 is provided at the end of the side wall of the intake valve housing 7 near the secondary piston chamber 60, forming the inlet of the secondary intake channel. This arrangement simplifies the structure and allows for more precise switching between the main and secondary intake channels.

[0048] The intake valve moving assembly 70 includes an intake valve stem 701 and an intake valve core 702 disposed at both ends of the intake valve stem 701 along the axial direction. The intake valve core 702 is provided with a vent hole 703.

[0049] By opening a vent hole 703 on the intake valve core 702, the pressure in the intake chamber can be balanced, avoiding valve core jamming or vibration caused by pressure difference, improving the stability of intake, further reducing flow loss, and realizing efficient conversion of heat from low temperature heat source.

[0050] In some embodiments, a main exhaust port 81 is provided at the end of the side wall of the exhaust valve housing 8 near the main piston chamber 30, and the main exhaust port 81 forms the outlet of the main exhaust passage. A secondary exhaust port 82 is provided at the end of the side wall of the exhaust valve housing 8 near the secondary piston chamber 60, and the secondary exhaust port 82 forms the outlet of the secondary exhaust passage. This configuration is simple and allows for more precise switching between the main and secondary exhaust passages.

[0051] The exhaust valve movable assembly 80 includes an exhaust valve stem 801 and exhaust valve cores 802 disposed at both axial ends of the exhaust valve stem 801. A main vent hole 803 is provided on the exhaust valve core 802 near the main piston chamber 30, which connects the main piston chamber 30 and the main exhaust port 81 when the moving part reaches the top dead center. A secondary vent hole 804 is provided on the exhaust valve core 802 near the secondary piston chamber 60, which connects the secondary piston chamber 60 and the secondary exhaust port 82 when the moving part reaches the bottom dead center.

[0052] By setting a vent hole on the exhaust valve core 802, the vent hole is precisely connected to the corresponding piston chamber and exhaust hole, so that the expanded low-pressure gas can be discharged quickly, thereby improving the working efficiency.

[0053] Specifically, when the moving part moves downward to the first position, the intake valve moving assembly 70 and the exhaust valve moving assembly 80 move downward under the pushing action of the main piston top cover 1. When they move to the bottom dead center, the main intake port 71 is exposed, the secondary intake port 72 is blocked by the intake valve core 702 located at the bottom, the main exhaust port 81 is blocked by the exhaust valve core 802 located at the top, and the secondary exhaust port 82 is exposed. Since the main intake port 71 is above the intake valve core 702 located at the top, the gas directly enters the main piston chamber 30 and balances the intake chamber pressure through the vent hole 703 on the intake valve core 702. The secondary exhaust port 82 is above the exhaust valve core 802 located at the bottom. The gas in the secondary piston chamber 60 passes through the secondary vent hole 804 on the bottom exhaust valve core 802 and is discharged from the secondary exhaust port 82. Figure 13 As shown.

[0054] When the moving parts move upward to the second position, the intake valve moving assembly 70 and the exhaust valve moving assembly 80 move upward under the pushing action of the auxiliary piston top cover 4. When they move to the top dead center, the auxiliary intake port 72 is exposed, the main intake port 71 is blocked by the top intake valve core 702, the auxiliary exhaust port 82 is blocked by the bottom exhaust valve core 802, and the main exhaust port 81 is exposed. Since the auxiliary intake port 72 is located below the bottom intake valve core 702, the gas directly enters the auxiliary piston chamber 60 from the auxiliary intake port 72, and the pressure in the intake chamber is balanced by the vent hole 703 on the bottom intake valve core 702. The main exhaust port 81 is located below the top exhaust valve core 802, and the gas in the main piston chamber 30 passes through the main vent hole 803 on the top exhaust valve core 802 and flows out from the main exhaust port 81. Figure 14 As shown in the diagram, the above setup is simple in structure and improves the smoothness of intake and exhaust, thereby increasing conversion efficiency.

[0055] Continue to refer to Figures 1 to 14As shown, in some embodiments, the main piston top cover 1 includes a main top cover body 11 and a first main protrusion 12 and a second main protrusion 13 disposed on the side of the main top cover body 11 facing the main piston bottom cover 2. The first main protrusion 12 corresponds to the intake valve movable assembly 70 and is used to push the intake valve movable assembly 70 to move when the moving part moves to the first position. The second main protrusion 13 corresponds to the exhaust valve movable assembly 80 and is used to push the exhaust valve movable assembly 80 to move when the moving part moves to the first position.

[0056] In this way, the first main protrusion 12 pushes the intake valve moving assembly 70, and the second main protrusion 13 pushes the exhaust valve moving assembly 80. That is, each protrusion corresponds precisely to the valve moving assembly, which improves the accuracy and controllability of valve switching, makes the driving force transmission more direct, avoids valve core jamming or incomplete switching, and further reduces losses.

[0057] In some embodiments, the secondary piston top cover 4 includes a secondary top cover body 41 and a first secondary protrusion 42 and a second secondary protrusion 43 disposed on the side of the secondary top cover body 41 facing the secondary piston bottom cover 5. The first secondary protrusion 42 corresponds to the intake valve movable assembly 70 and is used to push the intake valve movable assembly 70 to move when the moving part moves to the second position. The second secondary protrusion 43 corresponds to the exhaust valve movable assembly 80 and is used to push the exhaust valve movable assembly 80 to move when the moving part moves to the second position.

[0058] In this way, the first protrusion 42 pushes the intake valve moving assembly 70, and the second protrusion 43 pushes the exhaust valve moving assembly 80. That is, each protrusion corresponds precisely to the valve moving assembly, which improves the accuracy and controllability of valve switching, makes the driving force transmission more direct, avoids valve core jamming or incomplete switching, and further reduces losses.

[0059] Continue to refer to Figure 1 , Figure 13 and Figure 14 As shown, in some embodiments, the moving part is configured to reciprocate along a straight trajectory, that is, to reciprocate between the Y+ and Y- directions.

[0060] By making the moving parts reciprocate along a straight trajectory, the structure is simpler, and the straight trajectory can reduce the additional stress on the moving parts, such as the centrifugal force of the arc motion, thereby further reducing mechanical wear.

[0061] Reference Figures 1 to 4 As shown, in some embodiments, the flexible piston expander system further includes a mounting plate 130. A stationary portion is connected to the mounting plate 130, which is used to mount the flexible piston expander system in a predetermined position.

[0062] For example, refer to Figure 3 As shown, specifically, the main piston bottom cover 2 can be connected to the mounting plate 130.

[0063] By providing the mounting plate 130, the expander system can be quickly installed in a preset position, such as on a generator frame, improving assembly convenience. Furthermore, the mounting plate 130 provides a uniform support reference for stationary parts, further enhancing the overall system's operational stability and preventing wear and tear.

[0064] Combination Figures 1 to 4 , Figure 13 and Figure 14 As shown, in some embodiments, the flexible piston expander system further includes a guide support structure 100 for guiding and supporting the piston rod 10.

[0065] The guide support structure 100 provides precise guidance for the piston rod 10, ensuring the stability of the piston rod 10's movement direction and avoiding lateral forces and frictional losses caused by piston rod 10 offset, thereby further reducing mechanical losses and further improving system output efficiency.

[0066] In some embodiments, the guide support structure 100 includes a bearing housing 110 and a linear bearing 120 disposed on the bearing housing 110, with the piston rod 10 passing through the linear bearing 120.

[0067] The low-friction characteristics of the linear bearing 120 and its sliding fit with the piston rod 10 further reduce the motion resistance of the piston rod 10 and further improve the overall energy conversion efficiency.

[0068] Of course, in other implementations, the guide support structure 100 may also include an arc-shaped bracket, the shape of which is adapted to the shape of the piston rod 10. The arc-shaped bracket is used to support the piston rod 10, and the piston rod 10 can slide relative to the arc-shaped bracket.

[0069] Reference Figures 1 to 6 , Figure 13 and Figure 14 As shown, in some embodiments, a piston head 101 is provided at the end of the piston rod 10 away from the main piston top cover 1, and a piston head 101 has a top roller 102, which is used to make rolling contact with an external transmission mechanism.

[0070] The piston head 101's roller 102 makes rolling contact with the external transmission mechanism, which significantly reduces frictional losses during power transmission and further improves mechanical energy output efficiency. Furthermore, the rolling contact buffers the instantaneous impact force of the external transmission mechanism, reducing vibration and wear of moving parts and enhancing the operational stability and service life of the expander system.

[0071] Reference Figure 15 and Figure 16 As shown, in some other embodiments, the moving part is configured to reciprocate along an arc-shaped trajectory. The connector 9 is an arc-shaped connector adapted to the arc-shaped trajectory. The first main protrusion 12, the second main protrusion 13, the first secondary protrusion 42, and the second secondary protrusion 43 are all arc-shaped protrusions adapted to the arc-shaped trajectory.

[0072] Understandably, the structures of the intake valve housing 7 and the exhaust valve housing 8 remain unchanged, and the intake valve moving assembly 70 and the exhaust valve moving assembly 80 still move in a straight line, while the moving parts reciprocate along an arc trajectory. This ensures that when the moving parts move along an arc, the contact pressure between the corresponding protrusions and the valve core is uniform, reducing local wear.

[0073] Other features and implementation principles are the same as those in the above embodiments, and specific details can be found in the description of the above embodiments.

[0074] This design allows the flexible piston expander system to adapt to scenarios with limited space or those requiring matching with an arc-shaped transmission mechanism, thus broadening the application range of the expander system.

[0075] The above description is merely an embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A flexible piston expander system, characterized in that, Includes the main piston top cover, main piston bottom cover, auxiliary piston bottom cover, auxiliary piston top cover, intake valve housing, and exhaust valve housing; The main piston bottom cover and the auxiliary piston bottom cover are arranged opposite to each other, and the intake valve housing and the exhaust valve housing are respectively connected between the main piston bottom cover and the auxiliary piston bottom cover to form a stationary part together; The main piston top cover is located on the side of the main piston bottom cover away from the auxiliary piston bottom cover, and a main piston flexible membrane is sealed between the main piston top cover and the main piston bottom cover to form a main piston cavity; a piston rod is connected to the side of the main piston top cover away from the main piston bottom cover; the auxiliary piston top cover is located on the side of the auxiliary piston bottom cover away from the main piston bottom cover, and a auxiliary piston flexible membrane is sealed between the auxiliary piston top cover and the auxiliary piston bottom cover to form a auxiliary piston cavity; An intake valve movable assembly is installed inside the intake valve housing, and an exhaust valve movable assembly is installed inside the exhaust valve housing. A main intake channel is provided between the intake valve housing and the main piston chamber, and a secondary intake channel is provided between the intake valve housing and the secondary piston chamber. A main exhaust channel is provided between the exhaust valve housing and the main piston chamber, and a secondary exhaust channel is provided between the exhaust valve housing and the secondary piston chamber. The main piston top cover and the auxiliary piston top cover are connected by a connector to form a moving part. The moving part can reciprocate relative to the stationary part in a preset direction. When the moving part moves to a first position in the preset direction, the main piston top cover pushes the intake valve moving assembly and the exhaust valve moving assembly to open the main intake passage and the auxiliary exhaust passage, and close the auxiliary intake passage and the main exhaust passage. When the moving part moves to a second position in the preset direction, the auxiliary piston top cover pushes the intake valve moving assembly and the exhaust valve moving assembly to open the auxiliary intake passage and the main exhaust passage, and close the main intake passage and the auxiliary exhaust passage.

2. The flexible piston expander system according to claim 1, characterized in that, The side wall of the intake valve housing is provided with a main intake port at the end near the main piston chamber, and the main intake port forms the inlet of the main intake channel; the side wall of the intake valve housing is provided with a secondary intake port at the end near the secondary piston chamber, and the secondary intake port forms the inlet of the secondary intake channel. The intake valve movable assembly includes an intake valve stem and intake valve cores disposed at both ends of the intake valve stem along its axial direction, and the intake valve cores are provided with vent holes.

3. The flexible piston expander system according to claim 1, characterized in that, The exhaust valve housing has a main exhaust port at one end of its sidewall near the main piston chamber, which serves as the outlet of the main exhaust channel; the exhaust valve housing also has a secondary exhaust port at one end of its sidewall near the secondary piston chamber, which serves as the outlet of the secondary exhaust channel. The exhaust valve movable assembly includes an exhaust valve stem and exhaust valve cores disposed at both axial ends of the exhaust valve stem. A main vent hole is provided on the exhaust valve core near the main piston chamber; a secondary vent hole is provided on the exhaust valve core near the secondary piston chamber.

4. The flexible piston expander system according to claim 1, characterized in that, The main piston top cover includes a main top cover body and a first main protrusion and a second main protrusion disposed on the side of the main top cover body facing the main piston bottom cover. The first main protrusion corresponds to the intake valve movable assembly and is used to push the intake valve movable assembly to move when the moving part moves to the first position. The second main protrusion corresponds to the exhaust valve movable assembly and is used to push the exhaust valve movable assembly to move when the moving part moves to the first position; The secondary piston top cover includes a secondary top cover body and a first secondary protrusion and a second secondary protrusion disposed on the side of the secondary top cover body facing the secondary piston bottom cover. The first secondary protrusion corresponds to the intake valve movable assembly and is used to push the intake valve movable assembly to move when the moving part moves to the second position. The second secondary protrusion corresponds to the exhaust valve movable assembly and is used to push the exhaust valve movable assembly to move when the moving part moves to the second position.

5. The flexible piston expander system according to claim 4, characterized in that, The moving part is configured to reciprocate along an arc trajectory; The connector is an arc-shaped connector adapted to the arc trajectory; the first main protrusion, the second main protrusion, the first secondary protrusion, and the second secondary protrusion are all arc-shaped protrusions adapted to the arc trajectory.

6. The flexible piston expander system according to any one of claims 1 to 4, characterized in that, The moving part is configured to reciprocate along a straight trajectory.

7. The flexible piston expander system according to any one of claims 1 to 4, characterized in that, The flexible piston expander system also includes a mounting plate; The stationary part is connected to the mounting plate, which is used to install the flexible piston expander system in a preset position.

8. The flexible piston expander system according to any one of claims 1 to 4, characterized in that, The flexible piston expander system also includes a guide support structure, which is used to guide and support the piston rod.

9. The flexible piston expander system according to claim 8, characterized in that, The guide support structure includes a bearing housing and a linear bearing disposed on the bearing housing, and the piston rod passes through the linear bearing.

10. The flexible piston expander system according to any one of claims 1 to 4, characterized in that, A piston head is provided at the end of the piston rod away from the main piston top cover. The piston head has a top roller, which is used to make rolling contact with an external transmission mechanism.

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