A regenerator of a Stirling engine with low flow resistance

Abstract

A Stirling engine regenerator with low flow resistance, comprising a hot-end regenerator and a cold-end regenerator. The hot-end regenerator includes a hot-end regenerative ring body, and a hot-end regenerative channel is arranged in the hot-end regenerative ring body. The hot-end regenerative channel adopts a Tesla valve structure. The Tesla valve extends longitudinally from one open end of the hot-end regenerative ring body to the other open end and is distributed circumferentially along the hot-end regenerative ring body in the transverse direction. The Tesla valve of the hot-end regenerative channel enables the working medium to conduct forward from the hot end to the cold end and blocks the reverse flow from the cold end to the hot end. The cold-end regenerator includes a cold-end regenerative ring body, and the cold-end regenerative channel adopts a Tesla valve structure. The Tesla valve extends longitudinally from one open end of the cold-end regenerative ring body to the other open end and is distributed circumferentially along the cold-end regenerative ring body in the transverse direction. The Tesla valve of the cold-end regenerative channel enables the working medium to conduct forward from the cold end to the hot end and blocks the reverse flow from the hot end to the cold end. The regenerator of the present invention has strong heat storage capacity, small flow resistance, and high regenerator efficiency.

Description

Technical Field

[0001] The present invention relates to a regenerator of a Stirling engine, and more particularly to a Stirling engine regenerator with low flow resistance. Background Art

[0002] A Stirling generator is a coupled system of a Stirling engine and a linear motor, which can convert thermal energy into electrical energy or kinetic energy. As an external combustion engine, it has a wide range of energy sources, can utilize almost all existing heat sources, and has low requirements for the quality of the heat source. Most importantly, during the thermoelectric conversion process, it will not cause any environmental pollution problems. In addition, the Stirling engine follows the Stirling cycle, and its ideal efficiency can reach the highest thermodynamic efficiency. Therefore, the Stirling generator composed of it also has a high power generation efficiency.

[0003] According to the different piston support forms and transmission mechanisms, Stirling engines can be further divided into crank - connecting rod Stirling engines and free - piston Stirling engines. The latter cancels the crankshaft - connecting rod structure of the traditional Stirling engine, and the movement of its power piston and gas - distribution piston is not restricted by mechanical structures. Therefore, it has the advantages of small wear, high mechanical efficiency, maintenance - free, self - starting, low noise, and small vibration. The free - piston Stirling engine mainly consists of a heater, a regenerator, a cooler, a gas - distribution piston, a power piston, and a leaf spring, etc. The heater, regenerator, and cooler together form the heat - exchange components of the Stirling engine, realizing the thermal expansion and contraction of the internal working fluid to push the piston to move. When the operating frequency of the Stirling generator is relatively high, the heat exchange is more frequent, and the flow - resistance loss in the regenerator continuously increases, resulting in a serious decline in the working efficiency of the Stirling generator.

[0004] The regenerator of a traditional free - piston Stirling generator is like a thermal sponge. During the hot half - cycle, the working fluid flows from the hot end to the cold end, and the regenerator absorbs and stores the heat of the working fluid; during the cold half - cycle, the working fluid flows from the cold end to the hot end, and the regenerator releases the stored heat to the working fluid. In this way, heat absorption and release are alternately carried out to achieve the regeneration of the Stirling engine and improve the thermal efficiency. Therefore, the traditional free - piston Stirling generator relies on a porous wire - mesh structure as the heat - storage device. The porous wire - mesh structure is generally made of metal materials such as stainless steel and aluminum, and has good thermal conductivity and radial stiffness. However, the porous wire - mesh has a large flow - resistance loss, and the flow - resistance loss in the regenerator accounts for more than 87% of the total flow - resistance loss of the entire Stirling generator. As the Stirling generator gradually operates at a higher frequency, the flow - resistance loss also gradually increases, seriously restricting the improvement of the power and efficiency of the Stirling generator. Reducing the flow - resistance loss requires the regenerator wire - mesh to have a larger flow - through volume and a larger porosity; while to improve the heat - transfer capacity of the regenerator, it requires the regenerator to have a large heat - transfer area and a small porosity, which are mutually contradictory and seriously restrict the improvement of the regenerator efficiency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the above-mentioned background technology, and provide a Stirling engine regenerator with low flow resistance, which reduces the flow resistance while ensuring high heat storage capacity, greatly improves the efficiency of the regenerator; in addition, it prevents the occurrence of orifice blockage and the phenomenon of non-flow of the working fluid, and improves the reliability and service life.

[0006] The technical solution adopted by the present invention to solve its technical problems is a Stirling engine regenerator with low flow resistance, including a hot-end regenerator and a cold-end regenerator. The hot-end regenerator includes a hot-end regenerative ring body, and a hot-end regenerative channel is arranged in the hot-end regenerative ring body. The hot-end regenerative channel adopts a Tesla valve structure. The Tesla valve extends longitudinally from one open end of the hot-end regenerative ring body to the other open end, and the Tesla valve is distributed circumferentially along the circumference of the hot-end regenerative ring body; the Tesla valve of the hot-end regenerative channel enables the working fluid to conduct forward from the hot end to the cold end and blocks the reverse flow of the working fluid from the cold end to the hot end.

[0007] The cold-end regenerator includes a cold-end regenerative ring body, and a cold-end regenerative channel is arranged in the cold-end regenerative ring body. The cold-end regenerative channel adopts a Tesla valve structure; the Tesla valve extends longitudinally from one open end of the cold-end regenerative ring body to the other open end, and the Tesla valve is distributed circumferentially along the circumference of the cold-end regenerative ring body; the Tesla valve of the cold-end regenerative channel enables the working fluid to conduct forward from the cold end to the hot end and blocks the reverse flow of the working fluid from the hot end to the cold end.

[0008] Furthermore, the Tesla valve is composed of multiple valve units. Each valve unit is provided with a wing-shaped flow blocker. Each valve unit is divided into a main valve channel unit and a branch valve channel unit by the wing-shaped flow blocker. When longitudinally sectioned along the hot-end regenerative channel, the cross-sectional shape of the main valve channel unit is: the main valve channel unit is a straight flow channel; the cross-sectional shape of the branch valve channel unit is: the branch valve channel unit is a curved flow channel. The branch valve channel unit includes a bottom arc section and two side straight sections, and the bottom arc section and the two side straight sections are connected to form a curved flow channel. The main valve channel unit is connected to the branch valve channel unit. The cross-section of the main valve channel unit extends along the circumference of the hot-end regenerative ring body or the cold-end regenerative ring body to form a ring-shaped main valve channel unit. The cross-section of the branch valve channel unit extends along the circumference of the hot-end regenerative ring body or the cold-end regenerative ring body to form a ring-shaped branch valve channel unit. Multiple main valve channel units form a main valve channel, and the main valve channel is the main channel for the flow of the working fluid. Multiple branch valve channel units form a branch valve channel, and the branch valve channel is the auxiliary channel for the flow of the working fluid.

[0009] Furthermore, the wing-shaped flow blocker is a circular ring structure. The center position of the wing-shaped flow blocker coincides with the center position of the branch valve channel, and the wing-shaped flow blocker is fixed in the valve unit through a fixing plate.

[0010] Furthermore, a stainless steel wire mesh is arranged in each branch valve channel unit. The stainless steel wire mesh is a circular ring structure, and the stainless steel wire mesh is arranged in the bottom arc structure of the branch valve channel unit.

[0011] Furthermore, the stainless - steel wire mesh is formed by stacking single - piece wire meshes. The wire mesh is a square - hole mesh, and there are pores between the meshes for gas circulation.

[0012] Compared with the prior art, the advantages of the present invention are as follows:

[0013] The regenerator of the present invention adopts a Tesla - valve structure and improves the Tesla valve. By means of the stainless - steel wire mesh, the flow resistance when the regenerator is reversely blocked is greatly increased, making it more difficult for the gas working medium to flow through. At the same time, the stainless - steel wire mesh has a large heat - transfer area, enhancing its heat - exchange ability and retaining the heat of the gas. While ensuring high heat - storage capacity, the flow resistance is reduced, and the efficiency of the regenerator is greatly improved. In addition, it prevents the occurrence of pore blockage and the phenomenon of non - flowing working medium, improving the reliability and service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic structural diagram of an embodiment of the present invention.

[0015] Figure 2 is Figure 1 a schematic diagram showing the forward conduction of the hot - end regenerator and the reverse blockage of the cold - end regenerator of the shown embodiment.

[0016] Figure 3 is Figure 1 a schematic diagram showing the forward conduction of the cold - end regenerator and the reverse blockage of the hot - end regenerator of the shown embodiment.

[0017] Figure 4 is Figure 1 a schematic structural diagram of the wing - shaped flow - blocking object of the shown embodiment.

[0018] Figure 5 is Figure 1 a schematic structural diagram of the stainless - steel wire mesh of the shown embodiment.

[0019] In the figure, 1 - cold - end regenerator 1, 2 - hot - end regenerator, 3 - main valve channel unit, 4 - branch valve channel unit, 5 - fixing plate, 6 - wing - shaped flow - blocking object, 7 - stainless - steel wire mesh. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Refer to Figure 1, in this implementation, the regenerator of the Stirling engine with low flow resistance includes a hot-end regenerator 2 and a cold-end regenerator 1. The hot-end regenerator 2 includes a hot-end regenerative ring body, and a hot-end regenerative channel is provided inside the hot-end regenerative ring body. The hot-end regenerative channel longitudinally extends from one open end of the hot-end regenerative ring body to the other open end, and transversely distributes along the circumference of the hot-end regenerative ring body. The hot-end regenerative channel adopts a Tesla valve structure. The Tesla valve longitudinally extends from one open end of the hot-end regenerative ring body to the other open end, and transversely distributes along the circumference of the hot-end regenerative ring body. The Tesla valve of the hot-end regenerative channel enables the working fluid to flow from the hot end to the cold end through the main valve channel, thereby enabling the working fluid to conduct forward from the hot end to the cold end and blocking the reverse flow from the cold end to the hot end.

[0022] The cold-end regenerator 1 includes a cold-end regenerative ring body, and a cold-end regenerative channel is provided inside the cold-end regenerative ring body. The cold-end regenerative channel longitudinally extends from one open end of the cold-end regenerative ring body to the other open end, and transversely distributes along the circumference of the cold-end regenerative ring body. The cold-end regenerative channel adopts a Tesla valve structure. The Tesla valve longitudinally extends from one open end of the cold-end regenerative ring body to the other open end, and transversely distributes along the circumference of the cold-end regenerative ring body. The Tesla valve of the cold-end regenerative channel enables the working fluid to flow from the cold end to the hot end through the main valve channel, thereby enabling the working fluid to conduct forward from the cold end to the hot end and blocking the reverse flow from the hot end to the cold end.

[0023] The Tesla valve is composed of multiple valve units. Each valve unit is provided with a wing-shaped flow blocker 6. Each valve unit is divided into a main valve channel unit 3 and a branch valve channel unit 4 by the wing-shaped flow blocker 6. When longitudinally sectioned along the hot-end regenerative channel, the cross-sectional shape of the main valve channel unit 3 is: the main valve channel unit 3 presents a straight flow channel; the cross-sectional shape of the branch valve channel unit 4 is: the branch valve channel unit 4 presents a curved flow channel. The branch valve channel unit 4 includes a bottom arc section and two side straight sections, and the bottom arc section and the two side straight sections are connected to form a curved flow channel. The main valve channel unit 3 is connected to the branch valve channel unit 4 and is slightly wider than the branch valve channel unit 4. The cross-section of the main valve channel unit 3 extends along the circumference of the hot-end regenerative ring body or the cold-end regenerative ring body to form a ring-shaped main valve channel unit 3, and the cross-section of the branch valve channel unit 4 extends along the circumference of the hot-end regenerative ring body or the cold-end regenerative ring body to form a ring-shaped branch valve channel unit 4. Multiple main valve channel units 3 form the main valve channel, which is the main channel for the working fluid to flow through, and multiple branch valve channel units 4 form the branch valve channel, which is the auxiliary channel for the working fluid to flow through. Due to length limitations, the number of valve units cannot be too many. In this embodiment, the structure shown in the figure has 8 valve units.

[0024] Refer to Figure 4 , the wing-shaped flow blocker 6 is a ring structure. The center position of the wing-shaped flow blocker 6 coincides with the center position of the branch valve channel. The wing-shaped flow blocker 6 is fixed inside the valve unit through a fixing plate 5. The wing-shaped flow blocker 6 is used to control the flow resistance suffered by the working fluid during circulation.

[0025] Refer toFigure 5 , a stainless steel wire mesh 7 is provided in each branch valve passage unit 4. The stainless steel wire mesh 7 is in a circular ring structure and is arranged in the bottom arc structure of the branch valve passage unit 4. The stainless steel wire mesh 7 is stacked by single-piece wire meshes. The wire mesh is a square-hole mesh, and there are pores between the meshes for gas to flow through, which has the characteristics of simple structure and large heat transfer area. The stainless steel wire mesh 7 is used to increase the resistance suffered by the working medium during circulation, and at the same time plays the role of heat absorption and heat release.

[0026] The working principle of the regenerator is as Figure 2 , Figure 3 shown. When the regenerator works in the cold half-cycle, the cold working medium flows from the cold end to the hot end. The cold working medium can flow through the main valve passage and the branch valve passage of the cold-end regenerative passage at an accelerated speed, and exchange heat with the hot working medium remaining in the cold-end regenerative passage during the hot half-cycle, so that the working medium is heated and flows to the hot end, playing the role of heat exchange and energy storage; while in the hot-end regenerative passage, every time the cold working medium passes through a branch valve passage, it will flow through a wing-shaped flow blocker 6 and a stainless steel wire mesh 7. The cold working medium will pass through the stainless steel wire mesh 7, suffer a certain flow resistance, and at the same time absorb the heat of the stainless steel wire mesh. When the working medium passes through the wing-shaped flow blocker 6 and flows back from the branch valve passage to the main valve passage, the backflow will cause the flow to be blocked and the flow velocity to slow down. The more flow blockers the cold working medium passes through, the slower the flow velocity, resulting in the cold working medium being blocked in several branch valve passages near the hot end, preventing the cold working medium from flowing from the cold end to the hot end, and a large amount of cold working medium accumulating in the flow passage.

[0027] At the end of the cold half-cycle, the regenerator starts to work in the hot half-cycle. The hot working medium flows from the hot end to the cold end. The hot working medium can flow through the main valve passage and the branch valve passage of the hot-end regenerative passage at an accelerated speed, and exchange heat with the cold working medium remaining in the hot-end regenerative passage during the cold half-cycle, so that the working medium is cooled and flows to the cold end, playing the role of heat exchange and energy storage; while in the cold-end regenerative passage, every time the hot working medium passes through a branch valve passage, it will flow through a wing-shaped flow blocker 6 and a stainless steel wire mesh 7. The hot working medium will pass through the stainless steel wire mesh 7, suffer a certain flow resistance, and at the same time release heat to the stainless steel wire mesh 7.

[0028] When the working medium passes through the wing-shaped flow blocker 6 and flows back from the branch valve passage to the main valve passage, the backflow will cause the flow to be blocked and the flow velocity to slow down. The more flow blockers the hot working medium passes through, the slower the flow velocity, resulting in the hot working medium being blocked in several branch valve passages near the cold end, preventing the hot working medium from flowing from the hot end to the cold end, and a large amount of hot working medium accumulating in the flow passage, and exchanging heat with the cold working medium during the cold half-cycle, so that the working medium is heated and flows to the hot end. Working in such an alternating manner can not only meet the heat exchange requirements, but also significantly reduce the flow resistance.

[0029] The regenerator of the present invention adopts the Tesla valve structure and improves the Tesla valve. By means of the stainless steel wire mesh 7, the flow resistance when the regenerator is reversely cut off is greatly increased, making it more difficult for the gas working medium to flow; at the same time, the stainless steel wire mesh 7 has a large heat transfer area, enhancing its heat exchange capacity and retaining the heat of the gas. While ensuring high heat storage capacity, the flow resistance is reduced, and the efficiency of the regenerator is greatly improved; in addition, the occurrence of orifice blockage and the phenomenon of non-flow of the working medium are prevented, and the reliability and service life are improved.

[0030] Those skilled in the art can make various modifications and variations to the present invention. If these modifications and variations are within the scope of the claims of the present invention and its equivalent technologies, then these modifications and variations are also within the protection scope of the present invention.

[0031] The content not described in detail in the specification is the prior art well known to those skilled in the art.

Claims

1. A Stirling engine regenerator with low flow resistance, comprising a hot-end regenerator and a cold-end regenerator, characterized in that: The hot-end regenerator includes a hot-end regenerative ring body, and a hot-end regenerative channel is provided in the hot-end regenerative ring body. The hot-end regenerative channel adopts a Tesla valve structure. The Tesla valve longitudinally extends from one open end of the hot-end regenerative ring body to the other open end, and the Tesla valve is circumferentially distributed along the circumference of the hot-end regenerative ring body; the Tesla valve of the hot-end regenerative channel enables the working medium to conduct forward from the hot end to the cold end and blocks the reverse flow from the cold end to the hot end; The cold-end regenerator includes a cold-end regenerative ring body, and a cold-end regenerative channel is provided in the cold-end regenerative ring body. The cold-end regenerative channel adopts a Tesla valve structure; the Tesla valve longitudinally extends from one open end of the cold-end regenerative ring body to the other open end, and the Tesla valve is circumferentially distributed along the circumference of the cold-end regenerative ring body; the Tesla valve of the cold-end regenerative channel enables the working medium to conduct forward from the cold end to the hot end and blocks the reverse flow from the hot end to the cold end; The Tesla valve is composed of multiple valve units. Each valve unit is provided with a wing-shaped flow blocker. Each valve unit is divided into a main valve channel unit and a branch valve channel unit by the wing-shaped flow blocker. When longitudinally sectioned along the hot-end regenerative channel, the cross-sectional shape of the main valve channel unit is: the main valve channel unit is a straight flow channel; the cross-sectional shape of the branch valve channel unit is: the branch valve channel unit is a curved flow channel. The branch valve channel unit includes a bottom arc section and two side straight sections, and the bottom arc section and the two side straight sections are connected to form a curved flow channel. The main valve channel unit is connected to the branch valve channel unit. The cross-section of the main valve channel unit extends along the circumference of the hot-end regenerative ring body or the cold-end regenerative ring body to form a ring-shaped main valve channel unit, and the cross-section of the branch valve channel unit extends along the circumference of the hot-end regenerative ring body or the cold-end regenerative ring body to form a ring-shaped branch valve channel unit. Multiple main valve channel units form the main valve channel, and the main valve channel is the main channel for the working medium to flow through. Multiple branch valve channel units form the branch valve channel, and the branch valve channel is the auxiliary channel for the working medium to flow through.

2. The regenerator of the Stirling engine with low flow resistance according to claim 1, characterized in that: The wing-shaped flow blocker is a circular ring structure. The center position of the wing-shaped flow blocker coincides with the center position of the branch valve channel, and the wing-shaped flow blocker is fixed in the valve unit through a fixing plate.

3. The regenerator of the Stirling engine with low flow resistance according to claim 1, characterized in that: A stainless steel wire mesh is provided in each branch valve channel unit. The stainless steel wire mesh is a circular ring structure, and the stainless steel wire mesh is arranged in the bottom arc structure of the branch valve channel unit.

4. The low-flow-resistance regenerator of a Stirling engine according to claim 3, characterized in that: The stainless steel wire mesh is stacked by single-piece wire meshes. The wire mesh is a square-hole mesh, and there are pores between the meshes for gas to flow through.

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