Main machine and complete machine system of low-temperature turbo expander

Abstract

The invention relates to the technical field of low-temperature turbo-expanders, in particular to a low-temperature turbo-expander main machine and a complete machine system, and the low-temperature turbo-expander main machine is designed around a main shaft. The main shaft sequentially penetrates through and integrates the impeller assembly, the braking assembly, the lubricating assembly and the sealing assembly which are located at the two ends, and the braking assembly is matched with an external braking sleeve through bidirectional braking oil grooves formed in a braking section of the main shaft and opposite in rotating direction to form a hydraulic braking system. The lubricating assembly comprises a thrust bearing structure comprising a plurality of tilting pads and thrust tiles, and an oil retainer is integrated to form a closed lubricating cavity. According to the sealing assembly, a multi-stage sealing structure at least comprising two sealing sections is adopted at the two ends of the main shaft, and sealing gas is introduced into a sealing groove to effectively block leakage of an internal working medium. A nozzle part in the impeller assembly synchronously drives a plurality of rotatable blades through a linkage ring, and the end gaps of the blades are dynamically controlled through a pressing ring mechanism capable of axially moving.

Description

Technical Field

[0001] This invention relates to the field of cryogenic turbine expander technology, specifically to a cryogenic turbine expander main unit and complete system. Background Technology

[0002] As a core component of cryogenic equipment, the cryogenic turbine expander plays a crucial role in industrial fields such as air separation, liquefied natural gas, and helium recovery. Its working principle involves the adiabatic expansion of a high-pressure working gas within a turbine. This expansion serves two purposes: firstly, it outputs power to drive a compressor; secondly, it significantly reduces the gas's own temperature, thereby obtaining the required cooling capacity.

[0003] In existing technologies, braking systems mostly employ either pneumatic braking or a single hydraulic braking method. The former has limited braking capacity under high pressure conditions, while the latter, although providing greater braking torque, often has a relatively simple hydraulic circuit design. For example, it may only have a single-directional oil groove in the braking section, which can lead to eddies or uneven distribution of lubricating oil within the cavity. This not only reduces braking efficiency but may also cause unit vibration due to localized overheating or frictional instability, affecting the smooth operation of the main shaft. On the other hand, the support and sealing at both ends of the main shaft are crucial for ensuring the long-term reliable operation of the expander. Existing bearing structures, especially thrust bearings, need to improve their axial positioning and load-bearing capabilities for the main shaft. During changes in operating conditions or start-up and shutdown, fluctuations in axial force can easily lead to shaft displacement, affecting the clearance between the impeller and the volute, thereby reducing efficiency and even causing wear. At the same time, there is a risk of low-temperature working gas leakage at the part of the main shaft that penetrates the housing. Conventional labyrinth seals or single dry gas seals may have reduced sealing effectiveness under extreme conditions such as low temperature and high pressure differential, resulting in higher sealing gas consumption. Furthermore, if the seal fails, it will not only cause a loss of cooling capacity, but the intrusion of external humid air will also lead to internal icing, seriously threatening equipment safety. Summary of the Invention

[0004] The purpose of this invention is to provide a cryogenic turbine expander main unit and complete system, which can comprehensively improve the braking performance, mechanical stability, sealing reliability and operating efficiency of the cryogenic turbine expander.

[0005] In a first aspect, embodiments of this application provide a cryogenic turbine expander main unit, comprising,

[0006] The housing assembly includes a main outer shell and two sets of mounting shells. The two sets of mounting shells are coaxially arranged at both ends of the main outer shell. A hollow working cavity is opened inside the main outer shell, and an outlet is opened on the main outer shell. A main shaft is rotatably arranged coaxially inside the working cavity. Both ends of the main shaft extend out of the housing assembly, and impeller assemblies are coaxially arranged on the two ends of the extended ends. An expansion volute and a pressure boosting volute are adapted to be arranged on both sides of the main outer shell, and the impeller assemblies at both ends are located in the expansion volute and the pressure boosting volute, respectively.

[0007] A braking assembly is provided on the main shaft, the braking section is located in the working chamber, and the braking assembly is coaxially arranged on the braking section;

[0008] A lubrication assembly is provided on the main shaft, the lubrication section is located at the openings at both ends of the housing body, and the lubrication assembly is coaxially arranged on the lubrication section;

[0009] The sealing assembly includes an end sealing section on the main shaft, the end sealing section being located at the extended end of the main shaft, and two sets of the sealing assembly being provided, each coaxially disposed on the end sealing section at both ends, and respectively located between the two sets of the impeller assembly and the lubrication assembly.

[0010] In some embodiments, the braking section includes a first braking section and a second braking section. The first braking section is provided with a threaded first brake oil groove, and the second braking section is provided with a second brake oil groove with a rotation direction opposite to that of the first brake oil groove. An oil inlet groove is provided circumferentially between the first braking section and the second braking section, which is connected to both the first brake oil groove and the second brake oil groove.

[0011] The braking assembly includes a brake sleeve with a brake chamber inside. The brake sleeve is sleeved on the braking section and rotatably connected to the main shaft. The brake sleeve has a first oil inlet hole for communicating the oil inlet groove with the outside.

[0012] In some embodiments, the lubrication assembly includes a thrust bearing assembly, which includes a thrust bearing body rotatably sleeved on the lubrication section and an oil baffle ring. The thrust bearing body has a rotating cavity for the main shaft to rotate. The side wall of the rotating cavity has a receiving groove and a second oil inlet hole communicating with the outside along the circumferential direction. A plurality of pads that are in frictional contact with the main shaft are fixedly disposed in the receiving groove. A plurality of thrust pads are disposed on the side wall of one end of the thrust bearing assembly. The oil baffle ring is coaxially fixedly disposed at the end of the thrust bearing assembly opposite to the thrust pads and engages with the receiving groove to form a receiving cavity. The oil baffle ring has an oil outlet hole for communicating with the receiving groove.

[0013] In some embodiments, the end sealing section includes a first sealing section and a second sealing section, the sealing assembly includes a first sealing part and a second sealing part, a first air inlet groove is provided between the first sealing part and the first sealing section, a second air inlet groove is provided between the second sealing part and the second sealing part, an exhaust chamber is formed between the first sealing part and the first sealing section, and the outer shell body is provided with a first air inlet hole communicating with the first air inlet groove, a second air inlet hole communicating with the second air inlet groove, and an exhaust hole communicating with the exhaust chamber.

[0014] In some embodiments, the first sealing part includes a first sealing ring and an end cap body. The first sealing ring is fixedly sleeved on the first sealing interval, and the end cap body is rotatably sleeved on the first sealing ring. The first air inlet groove is formed on the inner wall of the end cap body, and sealing teeth are provided on both sides of the first air inlet groove. An air passage is formed inside the end cap body that connects the first air inlet hole and the first air inlet groove.

[0015] In some embodiments, the second sealing part includes a second sealing ring and a sealing sleeve. The second sealing ring is sleeved on the second sealing interval, and the sealing sleeve is sleeved on the second sealing ring. The second sealing groove is formed on the inner wall of the second sealing ring. An air passage is formed in the end cap body and the sealing sleeve to communicate with the second air inlet and the second air inlet groove.

[0016] In some embodiments, the second sealing part further includes a pressure relief sealing ring, which is disposed on a second sealing ring near the side of the booster impeller, and the inner wall of the pressure relief sealing ring is provided with a pressure relief groove communicating with the outside.

[0017] In some embodiments, the impeller assembly includes a nozzle portion, the nozzle portion comprising:

[0018] A fixing ring and a pressure cap ring, wherein the fixing ring and the pressure cap ring are spaced apart;

[0019] The blades are provided in multiple sets, and the multiple sets of blades are rotatably arranged on the side wall of the fixed ring facing the pressure ring at uniform intervals in the circumferential direction. An opening is formed between two adjacent blades and between the fixed ring and the pressure ring.

[0020] The linkage assembly includes a linkage ring and a drive rod. A linkage groove is provided on the fixed ring. The linkage ring is rotatably disposed in the linkage groove. The drive rod is rotatably disposed on the fixed ring and is drivenly connected to the linkage ring to drive the linkage ring to rotate. The linkage ring is drivenly connected to multiple sets of blades to drive the multiple sets of blades to rotate synchronously.

[0021] In some embodiments, the impeller assembly further includes an adjustment section, which includes a clamping ring, a driving member, and a baffle. The clamping ring has a clamping groove on the side facing the blades. The clamping ring is slidably disposed in the clamping groove along the axial direction. The driving member is disposed between the clamping ring and the clamping ring to drive the clamping ring to make close contact with multiple sets of blades. The outer diameter of the clamping groove is larger than the outer diameter of the clamping ring so that there is a gap between the outer ring of the clamping ring and the clamping groove. The baffle is sealed between the inner ring of the clamping ring and the clamping groove.

[0022] Secondly, this application provides a cryogenic turbine expander system, including the aforementioned cryogenic turbine expander main unit, and further including a working oil supply device and a sealing gas supply device. The working oil supply device is connected to the braking assembly and the lubrication assembly, and the sealing gas supply device is connected to the sealing device.

[0023] The beneficial effects of this invention are as follows: The main mechanism of the cryogenic turbine expander protected in this application is integrated around the main shaft. The main shaft sequentially integrates the impeller assemblies located at both ends, the braking assembly located in the working cavity of the housing, the lubrication assembly near the opening of the housing, and the sealing assembly at the outermost end. This layout constitutes a main unit with clearly defined functional areas and a compact structure. Specifically, the braking assembly forms a highly efficient hydraulic braking system by opening bidirectional brake oil grooves with opposite rotation directions on the braking section of the main shaft, in conjunction with an external brake sleeve. The lubrication assembly mainly adopts a thrust bearing structure containing multiple tilting pads and thrust pads, while integrating an oil retainer ring to form a closed lubrication cavity. The sealing assembly adopts a multi-stage sealing structure containing at least two sealing sections at both ends of the main shaft, effectively blocking internal working fluid leakage by introducing sealing gas into the sealing groove. In addition, the nozzle section in the impeller assembly adopts a design that synchronously drives multiple rotatable blades through a linkage ring, and is supplemented by an axially movable clamping ring mechanism to dynamically control the blade tip clearance.

[0024] First, the bidirectional swirling brake oil groove can generate greater hydraulic damping, effectively absorbing and dissipating the power generated by the impeller, ensuring the smoothness and reliability of the main shaft braking at high speeds, and solving the problem of insufficient or unstable braking capacity of traditional braking methods.

[0025] Secondly, the integrated design of the tilting pad bearing and thrust bearing in the lubrication assembly not only provides excellent radial support, but also greatly enhances axial load capacity and stability, effectively suppresses axial movement of the main shaft, and ensures a constant critical clearance between the impeller and the volute.

[0026] Third, the combined application of multi-stage sealing structure and sealing gas creates a reliable gas sealing barrier, which greatly reduces the leakage loss of cryogenic working gas, while preventing the intrusion of external impurities and improving the operational safety and efficiency of the main unit.

[0027] Finally, the adjustable design of the impeller nozzle and the gap control mechanism enable precise and flexible adjustment of the expander flow rate and expansion ratio, and minimize gap leakage losses, thus enabling the turbine expander to maintain a high isentropic efficiency under various operating conditions. Attached Figure Description

[0028] Figure 1 is a schematic diagram of the structure of the low-temperature turbine expander main unit in this invention;

[0029] Figure 2 is a side view of the main unit of the low-temperature turbine expander in this invention;

[0030] Figure 3 is a cross-sectional view of part AA in Figure 2;

[0031] Figure 4 is a structural diagram of the braking assembly in this invention;

[0032] Figure 5 is an exploded view of the lubrication assembly in this invention;

[0033] Figure 6 is a cross-sectional view of part BB in Figure 2;

[0034] Figure 7 is an enlarged view of part E in Figure 6;

[0035] Figure 8 is an enlarged view of part F in Figure 6;

[0036] Figure 9 is a cross-sectional view of the CC portion in Figure 2;

[0037] Figure 10 is an enlarged view of part G in Figure 9;

[0038] Figure 11 is a cross-sectional view of part DD in Figure 2;

[0039] Figure 12 is an enlarged view of part H in Figure 11;

[0040] Figure 13 is an exploded view of the nozzle section in this invention;

[0041] Figure 14 is a structural diagram of the adjustment part in this invention;

[0042] Figure 15 is an enlarged view of part I in Figure 14;

[0043] Figure 16 is a schematic diagram of the low-temperature turbine expander system in this invention.

[0044] Reference numerals: 1. Housing assembly; 11. Outer shell body; 12. Mounting shell; 13. Expansion volute; 14. Pressure boosting volute;

[0045] 2. Main shaft; 21. Impeller assembly; 22. Braking section; 221. First braking zone; 222. Second braking zone; 23. Lubrication section; 24. Sealing section; 241. First sealing zone; 242. Second sealing zone; 243. First brake oil groove; 244. Second brake oil groove; 245. Oil inlet groove; 25. Discharge port;

[0046] 3. Braking assembly; 31. Braking sleeve; 32. First oil inlet;

[0047] 4. Lubrication assembly; 41. Thrust bearing assembly; 42. Thrust bearing body; 43. Oil retainer ring; 44. Rotating cavity; 45. Second oil inlet; 46. Bearing block; 47. Oil outlet;

[0048] 5. First sealing part; 51. First air inlet groove; 52. First sealing ring; 53. End cap body; 54. First air inlet hole;

[0049] 6. Second sealing part; 61. Second air inlet groove; 62. Second sealing ring; 63. Sealing collar; 64. Second air inlet hole; 65. Pressure relief sealing ring; 66. Pressure relief groove;

[0050] 7. Exhaust chamber; 71. Exhaust port;

[0051] 8. Nozzle section; 81. Retaining ring; 82. Cover ring; 83. Blade; 84. Linkage assembly;

[0052] 9. Adjustment section; 91. Pressure ring; 92. Drive component; 93. Wind deflector; 94. Pressure groove;

[0053] 100. Working oil supply device; 200. Sealing gas supply device. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0055] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0056] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0057] In the description of the embodiments of the present invention, it should be noted that if terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first," "second," and "third" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0058] Furthermore, the use of terms such as "horizontal," "vertical," and "sag" does not imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0059] Example 1

[0060] The first aspect of this application provides a cryogenic turbine expander main unit, as shown in FIG1, including a housing assembly 1, a braking assembly 3, a lubrication assembly 4, and a sealing assembly 1.

[0061] The housing assembly 1 includes a main housing 11 and two sets of mounting shells 12. The two sets of mounting shells 12 are coaxially arranged at both ends of the main housing 11. A hollow working cavity is formed inside the main housing 11. A main shaft 2 is coaxially rotatably arranged inside the working cavity. Both ends of the main shaft 2 extend out of the housing assembly 1, and impeller assemblies 21 are coaxially arranged on the extended ends. An expansion volute 13 and a booster volute 14 are adapted to fit on both sides of the main housing 11. The impeller assemblies 21 at both ends are located inside the expansion volute 13 and the booster volute 14, respectively.

[0062] The housing assembly 1 specifically includes a main housing body 11 for mounting the various internal components, and two sets of mounting shells 12 for end function integration. The two sets of mounting shells 12 are coaxially fixedly mounted on the axial end faces of the main housing body 11, forming a complete housing assembly. The main housing body 11 has a hollow working cavity machined inside to accommodate and protect the core rotating components. The main housing body also has an outlet 25 for discharging the internal working fluid oil. A main shaft 2, transmitting power and torque, is coaxially rotatably mounted within the main housing body 11 via bearing support systems at both ends. The two ends of the main shaft 2 precisely pass through and extend out of the mounting shells 12 on both sides of the housing assembly 1, forming a rotary power interface. Impeller assemblies 21 are coaxially mounted on the extended ends of the main shaft 2, allowing the impeller assemblies 21 to rotate synchronously with the main shaft 2 at high speed. On both sides of the main body 11, an expansion volute 13 and a booster volute 14 are respectively fitted. The expansion volute 13 is used to guide the high-pressure working gas to impact the impeller at the expansion end to do work, and the booster volute 14 is used to collect and guide the gas after being compressed by the impeller. Finally, the impeller assemblies 21 installed at both ends of the main shaft 2 are precisely positioned and respectively housed in the flow channel space inside the expansion volute 13 and the booster volute 14 to complete the energy conversion process.

[0063] Referring to Figures 2 to 4, a braking section 22 is provided on the main shaft 2. The braking section 22 is located inside the working chamber, and the braking assembly 3 is coaxially arranged on the braking section 22. In some embodiments, the braking section 22 includes a first braking interval 221 and a second braking interval 222. A threaded first brake oil groove 243 is formed on the first braking interval 221, and a second brake oil groove 244 with the opposite rotation direction to the first brake oil groove 243 is formed on the second braking interval 222. An oil inlet groove 245 is formed circumferentially between the first braking interval 221 and the second braking interval 222, which communicates with both the first brake oil groove 243 and the second brake oil groove 244.

[0064] The braking section 22 is used to generate a controllable and balanced braking force when the main shaft 2 rotates, and consists of two closely adjacent first braking sections 221 and second braking sections 222 along the axial direction. The first braking section 221 has a spiral first braking groove 243 (not shown in the figure) machined on its outer cylindrical working surface, while the adjacent second braking section 222 has a spiral second braking groove 244 (not shown in the figure) machined on its working surface. The spiral direction of the second braking groove 244 is intentionally designed to be opposite to that of the first braking groove 243. The rotation direction of the turbine expander remains unchanged during operation. Therefore, the spiral direction of the first braking groove 243 and the second braking groove 244 is determined according to the rotation direction of the main shaft 2 during operation. For example, in this embodiment, the rotation direction of the main shaft 2 is counterclockwise when viewed from the direction of the drive end. Therefore, the spiral direction of the first braking groove 243 is set to right-hand and the spiral direction of the second braking groove 244 is set to left-hand. If the working rotation direction of the main shaft 2 is opposite, the spiral direction of the first braking groove 243 is set to left-hand and the spiral direction of the second braking groove 244 is set to right-hand.

[0065] The braking assembly 3 includes a brake sleeve 31, which has a brake cavity. The brake sleeve 31 is fitted onto the braking section 22 and rotatably connected to the main shaft 2. The brake sleeve 31 has a first oil inlet hole 32 for communicating with the oil inlet groove 245 to the outside. The brake sleeve 31, which is matched with the main shaft 2, has a brake cavity machined inside. The size and shape of the cavity are adapted to the main shaft 2, so that it can be fitted onto the outside of the braking section 22 of the main shaft 2 with clearance fit and form a rotatable connection with the main shaft 2. On the sleeve wall of the brake sleeve 31, corresponding to the axial position of the annular oil inlet groove 245 on the braking section 22 of the main shaft 2, a first oil inlet hole 32 is provided. The first oil inlet hole 32 penetrates the sleeve wall thickness, with one end leading into the brake cavity and the other end connected to the external hydraulic system, so that pressurized oil can be injected into the brake cavity from the outside through the hole and directly reach the annular oil inlet groove 245 on the main shaft 2.

[0066] Referring to Figures 2, 3, and 5, a lubrication section 23 is provided on the main shaft 2. The lubrication section 23 is located at the openings at both ends of the outer casing 11. The lubrication assembly 4 is coaxially arranged on the lubrication section 23. In some embodiments, the lubrication assembly 4 includes a thrust bearing assembly 41. The thrust bearing assembly 41 includes a thrust bearing body 42 rotatably sleeved on the lubrication section 23 and an oil retainer ring 43. A rotating cavity 44 for the main shaft 2 to rotate is opened in the thrust bearing body 42. A receiving groove and a second oil inlet hole 45 communicating with the outside are opened circumferentially on the side wall of the rotating cavity 44. A plurality of pads 46 that rub against the main shaft 2 are fixedly arranged in the receiving groove. A plurality of thrust pads are arranged on the side wall of one end of the thrust bearing assembly 41. The oil retainer ring 43 is coaxially fixedly arranged at the end of the thrust bearing assembly 41 away from the thrust pads and is engaged with the receiving groove to form a receiving cavity. An oil outlet hole 47 for communicating with the receiving groove is opened on the oil retainer ring 43.

[0067] The thrust bearing body 42 has a stepped exterior for fitting and mounting with other components. The interior of the thrust bearing body 42 is coaxially hollow to form a rotating cavity 44. A receiving groove is coaxially formed on the inner wall of the rotating cavity 44 for mounting the bearing pads 46. In this application, the cross-section of the bearing pads 46 is a segment of annular sector shape. The bearing pads 46 are coaxially aligned with the thrust bearing body 42. In this embodiment, multiple bearing pads 46 are evenly spaced circumferentially and fixedly mounted in the receiving groove. The thrust bearing body 42 has multiple fixing holes radially arranged, the number of which and the position of each fixing hole are adapted to the bearing pads 46. The bearing pads 46 also have matching fixing holes. The bearing pads 46 are fixedly connected to the thrust bearing body 42 by fixing bolts. The number of bearing pads 46 is determined according to actual conditions. When the bearing pad 46 is installed in the receiving groove, the inner wall of the bearing pad 46 is flush with the inner wall of the rotating cavity 44, thereby making rotational frictional contact with the first shoulder section of the main shaft 2. The friction grooves are circumferentially distributed on the side wall of the thrust bearing body 42 facing the middle section of the main shaft 2 with the axis of the thrust bearing body 42 as the center. Each friction groove is detachably provided with a thrust pad that matches the size of the friction groove. When the thrust bearing body 42 is installed on the first shoulder section, the thrust pad makes frictional contact with the vertical wall of the first shoulder section. When the main shaft 2 rotates, lubricating oil enters the receiving groove from the second oil inlet 45, and then enters the gap between the bearing pads 46 to form a radial pressure oil film, realizing radial "liquid friction" support and reducing radial frictional wear.

[0068] Referring to Figures 2 and 6, the main shaft 2 is provided with an end sealing section 24, which is located on the extended end of the main shaft 2. Two sets of sealing components are provided, which are coaxially arranged on the end sealing sections 24 at both ends and are located between the expansion impeller and / or the booster impeller and the lubrication component 4, respectively.

[0069] Referring to Figures 6 and 7, in some embodiments, the end sealing section 24 includes a first sealing section 241 and a second sealing section 242. The sealing assembly includes a first sealing part 5 and a second sealing part 6. A first air inlet groove 51 is provided between the first sealing part 5 and the first sealing section 241, and a second air inlet groove 61 is provided between the second sealing parts 6. Referring to Figures 11 and 12, an exhaust chamber 7 is formed between the first sealing part 5 and the first sealing section 241. The outer shell body 11 is provided with a first air inlet hole 54 communicating with the first air inlet groove 51, a second air inlet hole 64 communicating with the second air inlet groove 61, and an exhaust hole 71 communicating with the exhaust chamber 7.

[0070] The first sealing section 241 and the second sealing section 242 adopt a stepped shoulder structure. The diameter of the second sealing section 242 is smaller than that of the first sealing section 241 to provide an axial positioning reference for the end cover assembly. Through the transition of the shaft diameter, the airflow disturbance during high-speed rotation is reduced, allowing different components to be installed independently and facilitating local maintenance and replacement for different sealing sections 24 based on their wear conditions.

[0071] Referring to Figures 6 and 7, the first sealing part 5 includes a first sealing ring 52 and an end cap body 53. The first sealing ring 52 is fixedly sleeved on the first sealing section 241, and the end cap body 53 is rotatably sleeved on the first sealing ring 52. A first air inlet groove 51 is formed on the inner wall of the end cap body 53, and sealing teeth are provided on both sides of the first air inlet groove 51. An air passage is formed inside the end cap body 53, connecting the first air inlet hole 54 and the first air inlet groove 51. When the spindle 2 drives the first sealing ring 52 to rotate at high speed, a gas film is formed in the tiny gap between the sealing teeth and the end cap body 53. This not only avoids frictional contact between the two, but also forms a stable air resistance effect in the gap using the principle of gas dynamics, effectively blocking the flow of lubricating oil. At the same time, sealing gas is injected into it through the first air inlet hole 54, further improving the sealing performance of the entire structure.

[0072] An oil-blocking edge is provided on the inner side of the first sealing ring 52. The oil-blocking edge is bent inward to form an installation groove that fits the end cover body 53. An oil return groove is provided at one end of the end cover body 53. The oil return groove is fitted into the installation groove. The oil return groove is continuously distributed along the circumferential direction of the inner wall of the end cover body 53. The cross-section is arc-shaped and the groove opening faces away from the main shaft 2. The two form a complete sealing and recycling system through structural cooperation. The oil return groove is connected to the lubricating oil circulation system of the equipment through the built-in oil return channel. When a small amount of lubricating oil passes through the first sealing ring 52 and enters the gap between the end cover body 53 and the first sealing ring 52, it will be thrown towards the inner wall of the end cover body 53 under the action of centrifugal force generated by the rotation of the main shaft 2. Then it slides down the wall into the oil return groove and finally flows back through the oil return channel, realizing the efficient recycling and reuse of lubricating oil and reducing the consumption of lubricating oil.

[0073] Referring to Figures 9 and 10, the second sealing part 6 includes a second sealing ring 62 and a sealing sleeve 63. The second sealing ring 62 is sleeved on the second sealing interval 242, and the sealing sleeve 63 is sleeved on the second sealing ring 62. The second sealing groove is opened on the inner wall of the second sealing ring 62. An air passage is opened in the end cap body 53 and the sealing sleeve 63 to communicate with the second air inlet hole 64 and the second air inlet groove 61.

[0074] The second sealing ring 62 adopts a segmented structure and is fitted onto the second sealing section 242 of the main shaft 2 with a clearance fit. The second sealing ring 62 consists of a first sealing tooth segment and a second sealing tooth segment arranged side by side, with an annular groove reserved between them to form a sealing air groove. The groove has a rectangular or isosceles trapezoidal cross-section. This shape allows the introduced sealing air to form a uniformly distributed annular airflow, enhancing the stability of the sealing pressure.

[0075] Referring to Figures 6 and 8, in some embodiments, the second sealing part 6 further includes a pressure relief sealing ring 65, which is disposed on the second sealing ring 62 near the side of the booster impeller. The inner wall of the pressure relief sealing ring 65 is provided with a pressure relief groove 66 communicating with the outside.

[0076] The pressure relief sealing ring 65 is located on the side closest to the pressure relief ring. The pressure relief groove 66 is circumferentially formed on the inner wall between the second sealing ring 62 and the pressure relief sealing ring 65. A pressure relief vent is formed on the bottom wall of the pressure relief groove 66. When the second sealing ring 62 is fitted on the second sealing interval 242, an annular airflow channel is formed between the pressure relief groove 66 and the main shaft 2. When high pressure is generated on one side of the impeller end, the pressure relief groove 66 is used to relieve and buffer the high pressure, and the high pressure air entering is discharged outward through the pressure relief vent, thereby reducing the impact of high pressure on the interior.

[0077] Referring to Figures 13 and 14, in some embodiments, the impeller assembly 21 includes a nozzle portion 8, which includes:

[0078] A fixing ring 81 and a pressure ring 82 are provided at intervals;

[0079] The blades 83 are provided in multiple sets. The multiple sets of blades 83 are evenly spaced around the circumference and rotated on the side wall of the fixed ring 81 facing the cover ring 82. An opening is formed between two adjacent blades 83 and between the fixed ring 81 and the cover ring 82.

[0080] The linkage assembly 84 includes a linkage ring and a drive rod. A linkage groove is provided on the fixed ring 81. The linkage ring is rotatably disposed in the linkage groove. The drive rod is rotatably disposed on the fixed ring 81 and is connected to the linkage ring to drive the linkage ring to rotate. The linkage ring is connected to multiple sets of blades 83 to drive the multiple sets of blades 83 to rotate synchronously.

[0081] The fixed ring 81 and the pressure ring 82 are arranged coaxially at intervals to form the basic structure for gas flow. Multiple sets of adjustable blades 83 are evenly distributed circumferentially on the side of the fixed ring 81 facing the pressure ring 82. Adjacent blades 83, together with the fixed ring 81 and the pressure ring 82, form a variable-opening airflow channel. The linkage assembly 84 includes a rotatable linkage ring and a drive rod. The linkage ring is installed through a linkage groove on the fixed ring 81. The drive rod is driven by the linkage ring and drives it to rotate. At the same time, the linkage ring is driven by all the blades 83, realizing the synchronous angle adjustment of multiple sets of blades 83. This device precisely controls the rotation angle of the linkage ring through the drive rod, thereby synchronously adjusting the opening and closing degree of all blades 83. This achieves precise control of gas flow, effectively improves airflow stability, avoids turbulence and energy loss, and prevents mutual interference between airflows, thus improving the working efficiency and performance stability of the expander.

[0082] Referring to Figures 14 and 15, in some embodiments, the impeller assembly 21 further includes an adjustment section 9. The adjustment section 9 includes a clamping ring 91, a driving member 92, and a baffle member 93. The pressure cover ring 82 has a clamping groove 94 on the side facing the blade 83. The clamping ring 91 is slidably disposed in the clamping groove 94 along the axial direction. The driving member 92 is disposed between the clamping ring 91 and the pressure cover ring 82 to drive the clamping ring 91 to make close contact with multiple sets of blades 83. The outer diameter of the clamping groove 94 is larger than the outer diameter of the clamping ring 91 so that there is a gap between the outer ring of the clamping ring 91 and the clamping groove 94. The baffle member 93 is sealed between the inner ring of the clamping ring 91 and the clamping groove 94.

[0083] An annular clamping groove 94 with a cross-section adapted to the clamping ring 91 is provided on the annular sidewall of the limiting ring facing the blade 83. The clamping ring 91 is slidably disposed in the clamping groove 94 along the axial direction of the device. The side of the clamping ring 91 facing the blade 83 is leveled to ensure that it can form a large area of ​​contact with the clamping surfaces of all blades 83. A driving component 92 is installed between the clamping ring 91 and the limiting ring. When the driving component 92 is activated, it generates an axial thrust, which pushes the clamping ring 91 to slide in the clamping groove 94 toward the blade 83. Finally, the working surface of the clamping ring 91 is pressed tightly and evenly against the corresponding surfaces of all blades 83. The clamping force effectively locks the current angular position of the blade 83, preventing it from deflecting or vibrating unexpectedly under the impact of high-speed airflow. The friction force restricts the rotation of the blade 83, improving the limiting effect on the blade 83.

[0084] Example 2

[0085] Referring to FIG16, in a second aspect, this application provides a cryogenic turbine expander system, including the above-mentioned cryogenic turbine expander main unit, and further including a working oil supply device 100 and a sealing gas supply device 200. The working oil supply device 100 is connected to the braking assembly 3 and the lubrication assembly 4, and the sealing gas supply device 200 is connected to the sealing device.

[0086] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

Claims

1. A cryogenic turbine expander main unit, characterized in that, include, The housing assembly (1) includes a housing body (11) and two sets of mounting shells (12). The two sets of mounting shells (12) are coaxially arranged at both ends of the housing body (11). A hollow working cavity is opened in the housing body (11). An outlet (25) is opened on the housing body (11). A main shaft (2) is coaxially rotatably arranged in the working cavity. Both ends of the main shaft (2) extend out of the housing assembly (1). Impeller assemblies (21) are coaxially arranged on the two ends of the main shaft (2). An expansion volute (13) and a booster volute (14) are adapted to be arranged on both sides of the housing body (11). The impeller assemblies (21) at both ends are located in the expansion volute (13) and the booster volute (14) respectively. Braking assembly (3), the main shaft (2) is provided with a braking section (22), the braking section (22) is located in the working cavity, and the braking assembly (3) is coaxially arranged on the braking section (22); Lubrication assembly (4), the main shaft (2) is provided with a lubrication section (23), the lubrication section (23) is located at the openings at both ends of the outer shell body (11), and the lubrication assembly (4) is coaxially arranged on the lubrication section (23); The sealing assembly has an end sealing section (24) on the main shaft (2). The end sealing section (24) is located on the extended end of the main shaft (2). The sealing assembly has two sets, which are coaxially arranged on the end sealing sections (24) at both ends and are located between the two sets of impeller assemblies (21) and the lubrication assembly (4).

2. The cryogenic turbine expander main unit according to claim 1, characterized in that, The braking section (22) includes a first braking section (221) and a second braking section (222). The first braking section (221) is provided with a threaded first brake oil groove (243), and the second braking section (222) is provided with a second brake oil groove (244) with the opposite rotation direction to the first brake oil groove (243). An oil inlet groove (245) is provided circumferentially between the first braking section (221) and the second braking section (222) and is connected to both the first brake oil groove (243) and the second brake oil groove (244). The braking assembly (3) includes a brake sleeve (31), which has a brake cavity. The brake sleeve (31) is sleeved on the brake section (22) and rotatably connected to the main shaft (2). The brake sleeve (31) has a first oil inlet hole (32) for communicating the oil inlet groove (245) with the outside.

3. The cryogenic turbine expander main unit according to claim 1, characterized in that, The lubrication assembly (4) includes a thrust bearing assembly (41), which includes a thrust bearing body (42) rotatably sleeved on the lubrication section (23) and an oil baffle ring (43). The thrust bearing body (42) has a rotating cavity (44) for the main shaft (2) to rotate. The side wall of the rotating cavity (44) has a circumferentially oriented receiving groove and a second oil inlet hole (45) communicating with the outside. Multiple pads (46) that rub against the main shaft (2) are fixedly arranged in the receiving groove. Multiple thrust pads are arranged on the side wall of one end of the thrust bearing assembly (41). The oil baffle ring (43) is coaxially fixedly arranged at the end of the thrust bearing assembly (41) away from the thrust pads and is engaged with the receiving groove to form a receiving cavity. The oil baffle ring (43) has an oil outlet hole (47) for communicating with the receiving groove.

4. The cryogenic turbine expander main unit according to claim 3, characterized in that, The end sealing section (24) includes a first sealing section (241) and a second sealing section (242). The sealing assembly includes a first sealing part (5) and a second sealing part (6). A first air inlet groove (51) is provided between the first sealing part (5) and the first sealing section (241). A second air inlet groove (61) is provided between the second sealing part (6) and the second sealing part (6). An exhaust chamber (7) is formed between the first sealing part (5) and the first sealing section (241). The outer shell body (11) is provided with a first air inlet hole (54) communicating with the first air inlet groove (51), a second air inlet hole (64) communicating with the second air inlet groove (61), and an exhaust hole (71) communicating with the exhaust chamber (7).

5. The cryogenic turbine expander main unit according to claim 4, characterized in that: The first sealing part (5) includes a first sealing ring (52) and an end cap body (53). The first sealing ring (52) is fixedly sleeved on the first sealing interval (241). The end cap body (53) is rotatably sleeved on the first sealing ring (52). The first air inlet groove (51) is opened on the inner wall of the end cap body (53). Sealing teeth are provided on both sides of the first air inlet groove (51). An air passage is opened in the end cap body (53) to connect the first air inlet hole (54) and the first air inlet groove (51).

6. The cryogenic turbine expander main unit according to claim 5, characterized in that, The second sealing part (6) includes a second sealing ring (62) and a sealing sleeve (63). The second sealing ring (62) is sleeved on the second sealing interval (242), and the sealing sleeve (63) is sleeved on the second sealing ring (62). The second sealing groove is opened on the inner wall of the second sealing ring (62). An air passage is opened in the end cap body (53) and the sealing sleeve (63) to communicate with the second air inlet (64) and the second air inlet groove (61).

7. The cryogenic turbine expander main unit according to claim 6, characterized in that, The second sealing part (6) further includes a pressure relief sealing ring (65), which is disposed on the second sealing ring (62) near the side of the booster impeller. The inner wall of the pressure relief sealing ring (65) is provided with a pressure relief groove (66) communicating with the outside.

8. The main unit of the low-temperature turbine expander according to claim 1, characterized in that, The impeller assembly (21) includes a nozzle section (8), which includes: A fixing ring (81) and a pressure cap ring (82) are provided at intervals; The blades (83) are provided in multiple sets. The multiple sets of blades (83) are rotatably arranged on the side wall of the fixed ring (81) facing the pressure ring (82) in a circumferentially evenly spaced manner. An opening is formed between two adjacent blades (83) and between the fixed ring (81) and the pressure ring (82). The linkage assembly (84) includes a linkage ring and a drive rod. A linkage groove is provided on the fixed ring (81). The linkage ring is rotatably disposed in the linkage groove. The drive rod is rotatably disposed on the fixed ring (81) and is connected to the linkage ring to drive the linkage ring to rotate. The linkage ring is connected to multiple sets of blades (83) to drive the multiple sets of blades (83) to rotate synchronously.

9. The main unit of the low-temperature turbine expander according to claim 8, characterized in that: The impeller assembly (21) further includes an adjustment part (9), which includes a clamping ring (91), a driving member (92), and a wind deflector (93). The clamping ring (82) has a clamping groove (94) on the side facing the blade (83). The clamping ring (91) is slidably disposed in the clamping groove (94) along the axial direction. The driving member (92) is disposed between the clamping ring (91) and the clamping ring (82) to drive the clamping ring (91) to make close contact with multiple sets of blades (83). The outer diameter of the clamping groove (94) is larger than the outer diameter of the clamping ring (91) so that there is a gap between the outer ring of the clamping ring (91) and the clamping groove (94). The wind deflector (93) is sealed between the inner ring of the clamping ring (91) and the clamping groove (94).

10. A cryogenic turbine expander system, characterized in that, The cryogenic turbine expander main unit according to any one of claims 1-9 further includes a working oil supply device (100) and a sealing gas supply device (200), wherein the working oil supply device (100) is connected to the braking assembly (3) and the lubrication assembly (4), and the sealing gas supply device (200) is connected to the sealing device.

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