Natural gas differential pressure power generation device

Abstract

The utility model relates to the technical field of power generation equipment, in particular to a natural gas differential pressure power generation device. The device comprises a machine shell, a rotating shaft and a centrifugal impeller. Two ends of the casing are provided with an air inlet and an air outlet, the inner wall is enclosed to form a communicated air inlet channel, and the inner side is provided with a stator with a stator winding; the rotating shaft is rotatably installed in the casing, and a rotor with a rotor winding is arranged at a position corresponding to the stator. The centrifugal impeller comprises a wheel disc, an impeller shaft and blades, the impeller shaft is vertically installed on the wheel disc, the blades are in an involute shape and are obliquely arranged, the height is gradually reduced from inside to outside, adjacent blades form an airflow channel, and the impeller is installed at the end, close to the air inlet, of the rotating shaft through the impeller shaft. The device reduces boundary layer separation and kinetic energy loss through optimal design of blade molded lines and heights, enables fluid acting force distribution to be more uniform, reduces vibration, improves pressure energy conversion efficiency, and is suitable for natural gas differential pressure power generation scenes.

Description

Technical Field

[0001] The utility model relates to the technical field of power generation equipment, and in particular to a natural gas pressure difference power generation device. Background Art

[0002] In the field of efficient energy conversion and industrial fluid power utilization, natural gas pressure differential power generation technology captures the pressure energy of natural gas during pipeline transportation to drive the impeller to rotate and generate electricity. Its core lies in converting fluid pressure energy into mechanical energy through the impeller structure, and then outputting electrical energy through the motor winding.

[0003] However, existing impeller designs often use straight blades or simple curved lines, resulting in turbulent airflow between adjacent blades and low energy conversion efficiency. Existing impeller blade profiles, such as the NACA0015 airfoil, experience severe boundary layer separation on the suction side of the blades when the natural gas pressure differential exceeds 0.8 MPa. This causes the local pressure loss coefficient (Cd) to increase dramatically from 0.15 to 0.42, and reduces energy conversion efficiency by 15%-18% compared to the theoretical value. Utility Model Content

[0004] In response to the above-mentioned technical problems, a natural gas pressure difference power generation device is provided.

[0005] The technical means adopted by this utility model are as follows:

[0006] A natural gas pressure difference power generation device includes a casing, a rotating shaft and a centrifugal impeller, wherein an air inlet and an air outlet are respectively provided at both ends of the casing, and the inner wall of the casing encloses an air inlet channel connected to the air inlet and the air outlet, a stator is installed on the inner side of the casing, and a stator winding is wound around the inner side of the stator, the rotating shaft is rotatably installed in the casing, a rotor is installed on the rotating shaft at a position corresponding to the stator, and a rotor winding is wound around the rotor; the centrifugal impeller includes a wheel disc, an impeller shaft and blades, the impeller shaft is vertically installed on the wheel disc, the blades are installed on the wheel disc and connected to the impeller shaft, the blades are in an involute shape and are arranged obliquely, the height of the blades gradually decreases from the inside to the outside, and an air flow channel is formed between adjacent blades, and the centrifugal impeller is installed on one end of the rotating shaft close to the air inlet of the casing through the impeller shaft.

[0007] It also includes a first bearing seat, a second bearing seat and a first magnetic bearing. The first bearing seat and the second bearing seat are installed in the casing and are respectively located on both sides of the stator. The first magnetic bearing is installed in the first bearing seat and the second bearing seat, and the rotating shaft is installed in the first magnetic bearing.

[0008] A second magnetic bearing is installed in the first bearing seat and the second bearing seat on the rotating shaft, and the diameter of the shaft section on the rotating shaft that cooperates with the first magnetic bearing is smaller than the diameter of the shaft section on the rotating shaft that cooperates with the second magnetic bearing.

[0009] The first bearing seat is located on the side of the casing close to the air outlet, the second bearing seat is located on the side of the casing close to the air inlet, a radial protection bearing is installed in the second bearing seat on the rotating shaft, and an axial protection bearing is installed in the first bearing seat on the rotating shaft.

[0010] Furthermore, the blade inclination angle of the centrifugal impeller is 35°.

[0011] Furthermore, the number of the blades is eight, and the diameter of the wheel disc is 450 mm.

[0012] Furthermore, the stator is mounted on the inner wall of the casing through a stator bracket.

[0013] Compared with the prior art, the utility model has the following advantages:

[0014] The blades are in an involute shape and are tilted. Their profile is more consistent with the motion trajectory of the fluid under centrifugal force, which can reduce the boundary layer separation phenomenon on the blade surface and reduce local pressure loss. The blade height gradually decreases from the inside to the outside, so that the air flow channel cross-section between adjacent blades changes reasonably with the radial direction, adapting to the increasing velocity characteristics of the fluid when flowing from the center of the impeller to the periphery, avoiding sudden changes in flow velocity or stagnant areas in the channel, and further reducing kinetic energy loss. The combination of involute blades and tilted design can make the force exerted by the fluid on the blades, including radial force and axial force, more evenly distributed, reduce the unbalanced load during high-speed rotation, reduce the vibration amplitude of the shaft, and improve the conversion efficiency of fluid pressure energy into mechanical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0016] Figure 1 This is a cross-sectional view of a natural gas pressure difference power generation device according to the present invention.

[0017] Figure 2 This is a structural diagram of a centrifugal impeller of a natural gas pressure difference power generation device according to the present invention.

[0018] Figure 3 This is a front view of a centrifugal impeller of a natural gas pressure difference power generation device according to the present invention.

[0019] Figure 4 This is a top view of a centrifugal impeller of a natural gas pressure difference power generation device according to the present invention.

[0020] In the figure: 1. casing; 2. rotating shaft; 3. air inlet; 4. air outlet; 5. air inlet channel; 6. stator; 7. rotor; 8. centrifugal impeller; 9. impeller; 10. impeller shaft; 11. blades; 12. air flow channel; 13. first bearing seat; 14. first magnetic bearing; 15. second magnetic bearing; 16. radial protection bearing; 17. axial protection bearing; 18. fastening bolts; 19. stator bracket; 20. second bearing seat. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0022] like Figure 1 As shown, an embodiment of the present utility model discloses a natural gas pressure difference power generation device, including a casing 1, a rotating shaft 2 and a centrifugal impeller 8. An air inlet 3 and an air outlet 4 are respectively provided at both ends of the casing 1. The inner wall of the casing 1 encloses an air inlet channel 5 connected to the air inlet 3 and the air outlet 4. A stator 6 is installed on the inner wall of the casing 1 through a stator bracket 19, and a stator winding is wound on the inner side of the stator 6. The rotating shaft 2 is rotatably installed in the casing 1, and a rotor 7 is installed on the rotating shaft 2 at a position corresponding to the stator 6, and a rotor winding is wound on the rotor 7.

[0023] Centrifugal impeller 8 Figure 2-Figure 4 As shown, it includes a wheel disc 9, an impeller shaft 10 and blades 11. The impeller shaft 10 is vertically mounted on the wheel disc 9. The blades 11 are mounted on the wheel disc 9 and connected to the impeller shaft 10. The blades 11 are in an involute shape and are tilted. The height of the blades 11 gradually decreases from the inside to the outside. An air flow channel 12 is formed between adjacent blades 11. The centrifugal impeller 8 is mounted on one end of the rotating shaft 2 close to the air inlet 3 of the casing 1 through the impeller shaft 10. During operation, natural gas blows toward the centrifugal impeller 8, causing the centrifugal impeller 8 to rotate, driving the rotating shaft 2 to rotate, causing the rotor winding and the stator winding to rotate relative to each other to generate electromotive force; the gas enters the air inlet channel 5 in the casing 1 through the air flow channel 12 and the air inlet 3, and leaves the inside of the casing 1 through the air outlet 4. The gas forms a single-direction flow to avoid air flow turbulence, and the natural gas can dissipate heat from the inside of the power generation device through the air inlet channel 5; by adopting an involute centrifugal impeller structure, the inlet air kinetic energy can be utilized to the maximum extent, and the pressure gradient distribution can be gradually reduced. The structure of the centrifugal impeller 8 is 8000 Under the conditions of natural gas flow and 1MPa inlet pressure, the gas passing efficiency is increased by more than 25%, the gas momentum conversion efficiency is increased by 15%-20%, the airflow distribution between the blades is optimized, the velocity distribution unevenness is reduced by 30%, local airflow separation is avoided, and the aerodynamic resistance is reduced by more than 25%, effectively avoiding the energy loss caused by airflow separation, effectively reducing the local vortex area of ​​the gas, and reducing the turbulence intensity inside the motor by 40%, thereby improving the airflow stability and utilization efficiency. When the natural gas flow is 8000 When the inlet temperature is 20℃ and the inlet pressure is 1MPa, the power generation efficiency is improved by 18%-22% compared with the traditional structure, which meets the efficient operation requirements of the magnetic levitation natural gas pressure difference power generation equipment, and can adapt to pipeline pressure difference fluctuations, reduce the risk of impeller vibration, and extend the service life of the equipment.

[0024] like Figure 1 As shown, the housing 1 further includes a first bearing seat 13, a second bearing seat 20, and a first magnetic bearing 14. The first bearing seat 13 and the second bearing seat 20 are mounted in the housing 1 and are respectively located on either side of the stator 6. The first magnetic bearing 14 is mounted in each of the first bearing seat 13 and the second bearing seat 20, and the rotating shaft 2 is mounted in the first magnetic bearing 14. The first magnetic bearing 14 provides suspension support for the rotating shaft 2, reducing energy lost by bearing friction during the rotation of the rotating shaft 2.

[0025] A second magnetic bearing 15 is mounted on the rotating shaft 2, located within the first bearing seat 13 and the second bearing seat 20. The diameter of the shaft segment of the rotating shaft 2 that mates with the first magnetic bearing 14 is smaller than the diameter of the shaft segment of the rotating shaft 2 that mates with the second magnetic bearing 15. If the first magnetic bearing 14 fails, the second magnetic bearing 15 protects the rotating shaft 2 and absorbs its radial load. By mate- ing with the bearings on shaft segments of different diameters, the second magnetic bearing 15 absorbs the axial load of the rotating shaft 2.

[0026] First bearing seat 13 is located on the side of housing 1 near air outlet 4, and second bearing seat 20 is located on the side of housing 1 near air inlet 3. A radial protection bearing 16 is installed on shaft 2 in second bearing seat 20, and an axial protection bearing 17 is installed on shaft 2 in first bearing seat 13. Axial protection bearing 17 is installed on the end of shaft 2. If either magnetic bearing fails, radial protection bearing 16 and axial protection bearing 17 will bear the load generated by the movement of shaft 2, protecting shaft 2 and other components.

[0027] The power generation device is mounted on an external device by fastening bolts 18 to achieve detachable installation of the power generation device, which is convenient for installation and maintenance.

[0028] The centrifugal impeller 8 has eight blades 11 with a 35° inclination angle. The impeller disc 9 has a diameter of 450 mm. The generator shaft 2 rotates at a speed of 1200 rpm, with a lift of 75 m and a power output of 10 kW. First, adaptive meshing technology is used to dynamically adjust the mesh density. A mixed-precision simulation method is then used to partition the computational domain and analyze the flow field. Combining multiple simulation analysis results, the impeller's parameters, such as the blade profile and flow path curvature, are iteratively optimized to ultimately determine the centrifugal impeller structure and its parameters.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A natural gas pressure difference power generation device, characterized in that: The invention comprises a casing (1), a rotating shaft (2) and a centrifugal impeller (8), wherein an air inlet (3) and an air outlet (4) are respectively provided at both ends of the casing (1), an inner wall of the casing (1) encloses an air inlet channel (5) communicating with the air inlet (3) and the air outlet (4), a stator (6) is installed inside the casing (1), a stator winding is wound around the inside of the stator (6), the rotating shaft (2) is rotatably installed inside the casing (1), a rotor (7) is installed on the rotating shaft (2) at a position corresponding to the stator (6), and a rotor winding is wound around the rotor (7); the centrifugal impeller (8) comprises a rotor (7) and a centrifugal impeller (8), wherein the rotor (7) comprises a rotor (7) and a centrifugal impeller (8), wherein the rotor (7) comprises a rotor (7) and a centrifugal impeller (8), wherein the centrifugal impeller (8 ... The centrifugal impeller (8) includes a wheel disc (9), an impeller shaft (10) and blades (11). The impeller shaft (10) is vertically mounted on the wheel disc (9). The blades (11) are mounted on the wheel disc (9) and connected to the impeller shaft (10). The blades (11) are in an involute shape and are tilted. The height of the blades (11) gradually decreases from the inside to the outside. An air flow channel (12) is formed between two adjacent blades (11). The centrifugal impeller (8) is mounted on one end of the rotating shaft (2) close to the air inlet (3) of the casing (1) through the impeller shaft (10).

2. A natural gas pressure difference power generation device according to claim 1, characterized in that: The invention also includes a first bearing seat (13), a second bearing seat (20) and a first magnetic suspension bearing (14), wherein the first bearing seat (13) and the second bearing seat (20) are installed in the housing (1) and are respectively located on both sides of the stator (6), the first magnetic suspension bearing (14) is installed in the first bearing seat (13) and the second bearing seat (20), and the rotating shaft (2) is installed in the first magnetic suspension bearing (14).

3. A natural gas pressure difference power generation device according to claim 2, characterized in that: A second magnetic suspension bearing (15) is installed on the rotating shaft (2) in the first bearing seat (13) and the second bearing seat (20), and the diameter of the shaft section on the rotating shaft (2) that cooperates with the first magnetic suspension bearing (14) is smaller than the diameter of the shaft section on the rotating shaft (2) that cooperates with the second magnetic suspension bearing (15).

4. A natural gas pressure difference power generation device according to claim 2, characterized in that: The first bearing seat (13) is located on a side of the housing (1) close to the air outlet (4), the second bearing seat (20) is located on a side of the housing (1) close to the air inlet (3), a radial protection bearing (16) is installed on the rotating shaft (2) in the second bearing seat (20), and an axial protection bearing (17) is installed on the rotating shaft (2) in the first bearing seat (13).

5. The natural gas pressure difference power generation device according to claim 1, characterized in that: The blades (11) of the centrifugal impeller (8) have an inclination angle of 35°.

6. The natural gas pressure difference power generation device according to claim 1, characterized in that: The number of blades (11) is eight, and the diameter of the wheel disc (9) is 450 mm.

7. The natural gas pressure difference power generation device according to claim 1, characterized in that: The stator (6) is mounted on the inner wall of the casing (1) via a stator bracket (19).

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