A high-power and high-efficiency gas expander

Abstract

A high-power and efficient gas expander provided by the present invention includes: a first rotor shaft and a second rotor shaft connected coaxially, and multiple stages of moving blades are provided on both the first rotor shaft and the second rotor shaft; a first expansion cylinder is sleeved on the first rotor shaft, and an air inlet / outlet communicating with the outside is provided on the first expansion cylinder, and the first rotor shaft rotates in the first expansion cylinder to output work; a second expansion cylinder is sleeved on the second rotor shaft, and an air inlet / outlet communicating with the outside is provided on the second expansion cylinder, and the second rotor shaft rotates in the second expansion cylinder to output work; multiple stages of nozzle rings are provided in both the first expansion cylinder and the second expansion cylinder, and the nozzle rings and the moving blades are arranged alternately. The double-cylinder and single-shaft system structure of the present invention realizes multi-stage expansion, achieves a greater power output, has a large power density and a low unit power cost; the high-power output enables the rotational speed of the shaft system to directly meet the requirements of the grid frequency, eliminating the need for a gearbox to change the output rotational speed, reducing mechanical energy loss, and having a high energy conversion efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of turbomachinery, and particularly relates to a gas expander. Background Art

[0002] Energy storage systems can improve the economy, security, and stability of the power grid and have been significantly developed in recent years. In order to further improve the efficiency of compressed air energy storage systems and supercritical carbon dioxide energy storage systems, as well as the promotion effects on power grid peak shaving, carbon peak, and carbon neutrality, high-power energy storage systems urgently need to be developed and put into operation.

[0003] Currently, the power levels of chemical and flywheel energy storage systems are generally small. High-power energy storage systems are only pumped storage, compressed air energy storage, and supercritical carbon dioxide energy storage. However, pumped storage systems have a long construction period, special requirements for site selection, and high construction costs. Therefore, it is urgent to develop high-power compressed air energy storage systems and supercritical carbon dioxide energy storage systems to fill the corresponding technical application gaps. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of low power level of the existing energy storage systems, so as to provide a high-power and efficient gas expander.

[0005] To solve the above technical problem, the gas expander provided by the present invention includes:

[0006] A first rotor shaft and a second rotor shaft connected coaxially, and both the first rotor shaft and the second rotor shaft are provided with multiple stages of moving blades;

[0007] A first expansion cylinder sleeved on the first rotor shaft, the first expansion cylinder is provided with an inlet / outlet port communicating with the outside, and the first rotor shaft rotates in the first expansion cylinder to output work;

[0008] A second expansion cylinder sleeved on the second rotor shaft, the second expansion cylinder is provided with an inlet / outlet port communicating with the outside, and the second rotor shaft rotates in the second expansion cylinder to output work;

[0009] Multiple stages of nozzle rings are provided in both the first expansion cylinder and the second expansion cylinder, and the nozzle rings and the moving blades are arranged alternately.

[0010] As a preferred solution, the first expansion cylinder is divided into multiple expansion chambers, and each expansion chamber is provided with an inlet / outlet port.

[0011] As a preferred solution, the multiple expansion chambers in the first expansion cylinder are distributed oppositely, and the gas flow directions in two symmetrically arranged expansion chambers are opposite.

[0012] As a preferred solution, a thrust bearing is sleeved on the end of the first rotor shaft.

[0013] As a preferred solution, the second expansion cylinder is divided into two expansion chambers. The intake ends of the two expansion chambers converge into an intake port, and the exhaust ends of the two expansion chambers converge into an exhaust port.

[0014] As a preferred solution, the flow-through structures in the two expansion chambers in the second expansion cylinder are arranged in mirror symmetry, and the gas flow directions in the two expansion chambers are opposite.

[0015] As a preferred solution, the direction of the exhaust port on the second expansion cylinder is set downward.

[0016] As a preferred solution, the first rotor shaft and the second rotor shaft are connected by a rotor half coupling, and the first rotor shaft and the second rotor shaft are supported by a first radial bearing, a second radial bearing, and a third radial bearing arranged at intervals in sequence.

[0017] As a preferred solution, there are a plurality of spaced-apart comb teeth at the blade tip of the moving blade. The comb teeth include first comb teeth and second comb teeth arranged alternately in sequence, and the length of the first comb teeth is greater than the length of the second comb teeth;

[0018] Both the first expansion cylinder and the second expansion cylinder have abutting parts that are in clearance fit with the moving blade. The abutting parts have alternately arranged grooves and protrusions; a part of the first comb teeth extends into the grooves and is spaced relatively from the grooves, and the second comb teeth are spaced relatively from the protrusions.

[0019] As a preferred solution, a relief groove is provided on one side of the protrusion facing the intake end.

[0020] The technical solution of the present invention has the following advantages:

[0021] 1. The high-power and high-efficiency gas expander provided by the present invention has the first rotor shaft and the second rotor shaft coaxially connected, and it is still a single-shaft system structure; the double cylinders achieve multi-stage expansion to complete a greater power output, with the characteristics of large power density and low unit power cost; at the same time, with a large power output, the rotational speed of the rotating shaft system can directly meet the requirements of the power grid frequency, eliminating the need for a gearbox to change the output rotational speed, minimizing mechanical energy loss, and having a high energy conversion efficiency; in addition, the sizes of all components are relatively small, the structure is compact, and it is convenient for processing, assembly, and transportation.

[0022] 2. The high-power and high-efficiency gas expander provided by the present invention has a multi-stage expansion chamber structure in the first expansion cylinder to achieve multi-stage expansion and can obtain a greater power output. The flow-through structures in the two expansion chambers in the second expansion cylinder are arranged in mirror symmetry, and the gas flow directions in the two chambers are opposite, so that the second rotor shaft is hardly affected by axial thrust, thereby reducing the axial thrust of the entire shafting.

[0023] 3. The high-power and high-efficiency gas expander provided by the present invention has the two expansion chambers in the second expansion cylinder for split expansion, which improves the energy conversion efficiency of the whole machine and the rationality of the structural strength.

[0024] 4. The high-power and high-efficiency gas expander provided by the present invention has the exhaust port on the second expansion cylinder arranged downward, and the exhaust thrust can offset part of the gravity acting on the cylinder block and the bearing seat, so as to reduce the structural stress level of the second expansion cylinder and the deformation caused by the force.

[0025] 5. The high-power and high-efficiency gas expander provided by the present invention is provided with a relief groove on the side of the protrusion facing the intake end, which can enable the high-speed gas flow passing through the tooth tip to flow back through the relief groove, so as to increase the resistance on the outlet side of the comb teeth, further reduce the leakage amount at the tip clearance, and improve the energy conversion efficiency of the expander. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is a schematic structural diagram of the gas expander provided in the present invention.

[0028] Figure 2 It is a schematic structural diagram of the first expansion cylinder.

[0029] Figure 3 It is a schematic structural diagram of the second expansion cylinder.

[0030] Figure 4 It is a schematic diagram of the gas seal structure of the moving blade.

[0031] Description of the reference numerals:

[0032] 1. First rotor shaft; 2. Second rotor shaft; 3. First expansion cylinder; 4. Second expansion cylinder; 5. Rotor half coupling; 6. First bearing housing; 7. First radial bearing; 8. Third bearing housing; 9. Third radial bearing; 10. Second bearing housing; 11. Second radial bearing; 12. Thrust bearing; 13. Tachogenerator gear; 14. Oil seal; 15. First expansion chamber; 16. Second expansion chamber; 17. Third expansion chamber; 18. First air inlet; 19. First exhaust port; 20. Second air inlet; 21. Second exhaust port; 22. Third air inlet; 23. Third exhaust port; 24. Nozzle ring; 25. Shaft seal; 26. Moving blade; 27. Fourth expansion chamber; 28. Fourth air inlet; 29. Fourth exhaust port; 30. First comb tooth; 31. Second comb tooth; 32. Protrusion; 33. Groove; 34. Relief groove; 35. Shaft seal component. Detailed implementation manners

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0036] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0037] The high-power and high-efficiency gas expander provided by this embodiment includes: a first rotor shaft 1, a second rotor shaft 2, a first expansion cylinder 3, and a second expansion cylinder 4.

[0038] As Figure 1 shown, the first rotor shaft 1 and the second rotor shaft 2 are coaxially connected through a rotor half-coupling 5 to form a single-shaft system structure; a part of the first rotor shaft 1 extends into the first bearing housing 6, and a first radial bearing 7 in the first bearing housing 6 rotatably supports it; a part of the second rotor shaft 2 extends into the third bearing housing 8, and a third radial bearing 9 in the third bearing housing 8 rotatably supports it; the connection part of the first rotor shaft 1 and the second rotor shaft 2 extends into the second bearing housing 10, and a second radial bearing 11 in the second bearing housing 10 rotatably supports the first rotor shaft 1. A thrust bearing 12 is provided in the first bearing housing 6, and the thrust bearing 12 rotatably supports the first rotor shaft 1, and the thrust bearing 12 is used to offset the total axial thrust on the first rotor shaft 1 and the second rotor shaft 2. A speed-measuring gear 13 is sleeved on the end of the second rotor shaft 2, and the speed-measuring gear 13 is used to measure the output speed of the second rotor shaft 2. Among them, the bearing housing and the rotor shaft are hermetically connected through a oil seal 14.

[0039] As Figure 1 、 Figure 2 shown, the first expansion cylinder 3 is sleeved on the first rotor shaft 1 through a shaft seal 35, and the first rotor shaft 1 can rotate in the first expansion cylinder 3; the interior of the first expansion cylinder 3 is divided into non-communicating first expansion chamber 15, second expansion chamber 16, and third expansion chamber 17. A first air inlet 18 and a first air outlet 19 are provided on the first expansion chamber 15, a second air inlet 20 and a second air outlet 21 are provided on the second expansion chamber 16, and a third air inlet 22 and a third air outlet 23 are provided on the third expansion chamber 17. A plurality of nozzle rings 24 are provided in the first expansion chamber 15, second expansion chamber 16, and third expansion chamber 17. The nozzle rings 24 are concentrically sleeved with the first rotor shaft 1 through a shaft seal 25. The nozzle rings 24 and the moving blades 26 on the first rotor shaft 1 are arranged alternately, and there is a gap for air flow between the nozzle rings 24 and the moving blades 26. Among them, the first expansion chamber 15 and the second expansion chamber 16 are arranged oppositely, and the air flow direction in the first expansion chamber 15 is opposite to the air flow direction in the second expansion chamber 16. The exhaust ports of the first expansion chamber 15, second expansion chamber 16, and third expansion chamber 17 can be connected to a heat exchanger, and the heat exchanger is used to heat the exhausted gas to increase the overall machine output power.

[0040] As Figure 1 、 Figure 3As shown in the figure, the second expansion cylinder 4 is sleeved on the second rotor shaft 2 through a shaft seal 35, and the second rotor shaft 2 can rotate in the second expansion cylinder 4 to output work; the interior of the second expansion cylinder 4 is divided into two fourth expansion chambers 27, and the intake ends of the two fourth expansion chambers 27 converge into a fourth intake port 28, and the exhaust ends of the two fourth expansion chambers 27 converge into a fourth exhaust port 29 facing downward. A plurality of nozzle rings 24 are provided in each of the two fourth expansion chambers 27. The nozzle rings 24 are concentrically sleeved on the second rotor shaft 2 through shaft seals 25. The nozzle rings 24 and the moving blades 26 on the second rotor shaft 2 are arranged alternately, and there is a gap for air flow between the nozzle rings 24 and the moving blades 26. Among them, the flow-through structures in the two fourth expansion chambers 27 are arranged in mirror symmetry, and the air flow directions in the two fourth expansion chambers 27 are opposite.

[0041] As Figure 4 shown in the figure, the moving blades 26 on the rotor shaft are hermetically connected to the expansion cylinder through a gas seal structure, and the gas seal structure includes the comb teeth on the moving blades 26 and the abutting portions in the expansion cylinder. At the tip of the moving blade 26, there are a plurality of comb teeth arranged at intervals. The comb teeth include first comb teeth 30 and second comb teeth 31 arranged alternately in sequence. The length of the first comb teeth 30 is greater than that of the second comb teeth 31; there are a plurality of protrusions 32 arranged at intervals on the abutting portion, and a groove 33 is formed between two adjacent protrusions 32; a part of the first comb teeth 30 extends into the groove 33 and is spaced opposite to the groove 33, and the second comb teeth 31 are spaced opposite to the protrusions 32; among them, a relief groove 34 is provided on one side of the protrusion 32 facing the intake end, and the relief groove 34 can enable the high-speed air flow flowing through the tip of the tooth to flow back through the relief groove 34, so as to increase the resistance on the outlet side of the comb teeth, further reduce the leakage amount at the tip clearance, and increase the energy conversion efficiency of the expander.

[0042] After two or all of the first expansion chamber 15, the second expansion chamber 16, and the third expansion chamber 17 in the first expansion cylinder 3 are connected in series through pipelines, and then connected in series with the second expansion cylinder 4, the first expansion cylinder 3 realizes the expansion work on high and medium pressure gases, and the second expansion cylinder 4 realizes the expansion work on low pressure gases.

[0043] Obviously, the above embodiments are only examples clearly described and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A high-power and high-efficiency gas expander, characterized in that, Comprising: A first rotor shaft (1) and a second rotor shaft (2) connected coaxially, both the first rotor shaft (1) and the second rotor shaft (2) are provided with multiple stages of moving blades (26); A first expansion cylinder (3) sleeved on the first rotor shaft (1), the first expansion cylinder (3) is provided with an inlet / exhaust port communicating with the outside, and the first rotor shaft (1) rotates in the first expansion cylinder (3) to output work; A second expansion cylinder (4) sleeved on the second rotor shaft (2), the second expansion cylinder (4) is provided with an inlet / exhaust port communicating with the outside, and the second rotor shaft (2) rotates in the second expansion cylinder (4) to output work; Both the first expansion cylinder (3) and the second expansion cylinder (4) are provided with multiple stages of nozzle rings (24), and the nozzle rings (24) and the moving blades (26) are arranged alternately; The first expansion cylinder (3) is divided into multiple expansion chambers, and each expansion chamber is provided with an inlet / exhaust port; The second expansion cylinder (4) is divided into two expansion chambers, the intake ends of the two expansion chambers converge into one intake port, and the exhaust ends of the two expansion chambers converge into one exhaust port; Two or all of the expansion chambers in the first expansion cylinder (3) are connected in series through pipelines and then connected in series with the second expansion cylinder (4); The flow-through structures in the two expansion chambers in the second expansion cylinder (4) are arranged in mirror symmetry, and the gas flow directions in the two expansion chambers are opposite; 2. The high-power and high-efficiency gas expander according to claim 1, characterized in that, The multiple expansion chambers in the first expansion cylinder (3) are distributed oppositely, and the gas flow directions in the two oppositely arranged expansion chambers are opposite; 3. The high-power and high-efficiency gas expander according to claim 1, characterized in that, A thrust bearing (12) is sleeved on the end of the first rotor shaft (1); 4. The high-power and high-efficiency gas expander according to claim 1, characterized in that, The direction of the exhaust port on the second expansion cylinder (4) is set downward; 5. The high-power and high-efficiency gas expander according to claim 1, characterized in that, The first rotor shaft (1) and the second rotor shaft (2) are connected by a rotor half coupling (5), and the first rotor shaft (1) and the second rotor shaft (2) are supported by a first radial bearing (7), a second radial bearing (11), and a third radial bearing (9) arranged at intervals in sequence; 6. The high-power and high-efficiency gas expander according to claim 1, characterized in that, Multiple spaced-apart comb teeth are provided at the tip of the moving blade (26), the comb teeth include first comb teeth (30) and second comb teeth (31) arranged alternately in sequence, and the length of the first comb teeth (30) is greater than the length of the second comb teeth (31); Both the first expansion cylinder (3) and the second expansion cylinder (4) are provided with abutting portions in clearance fit with the moving blade (26), and the abutting portions are provided with alternately arranged grooves (33) and protrusions (32); a part of the first comb teeth (30) extends into the grooves (33) and is spaced opposite to the grooves (33), and the second comb teeth (31) are spaced opposite to the protrusions (32); 7. The high-power and high-efficiency gas expander according to claim 6, characterized in that, A relief groove (34) is provided on one side of the protrusion (32) facing the intake end.

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