Turbine expander adjustable nozzle device based on circumferential-axial two-degree-of-freedom adjustment

Abstract

The invention discloses a turbo expander adjustable nozzle device based on circumferential-axial two-degree-of-freedom adjustment. Comprising a fixed adjusting disc, an axial adjusting gear, a sealing plate ring and a nozzle base which are coaxially arranged in sequence, the fixed adjusting disc is provided with a connecting shaft, the connecting shaft is in threaded fit with a center hole of the axial adjusting gear, and the axial adjusting gear is in transmission connection with a driving unit and is driven by the driving unit to rotate; a nozzle blade adjusting mechanism array is arranged between the axial adjusting gear and the nozzle base and is mainly formed by arranging N nozzle blade adjusting mechanisms in the circumferential direction, one end of each nozzle blade adjusting mechanism is in transmission connection with the axial adjusting gear, and the middle of each nozzle blade adjusting mechanism is connected with the sealing plate ring through a bearing. And the other end is movably connected with the nozzle base. The axial distance is adjusted while the angle of the nozzle is controlled, the adjusting dimension of the nozzle is widened, and the turbine impeller can adapt to complex variable working condition scenes through multi-dimensional control over the nozzle.

Description

Technical Field

[0001] The present invention relates to the technical field of turboexpanders, and particularly to an adjustable nozzle device for a turboexpander based on circumferential-axial two-degree-of-freedom adjustment. Background Art

[0002] As a core device in the fields of energy recovery and cryogenic refrigeration, the performance of a turboexpander directly depends on the energy conversion efficiency of the working medium gas during the expansion process. The adjustable nozzle technology of traditional turboexpanders mainly relies on a circumferential angle adjustment mechanism. By changing the installation angle of the nozzle blades, the throat flow area is adjusted to achieve a rough control of the flow rate and expansion ratio. Although this single-degree-of-freedom adjustment mode can adapt to some working condition changes, it gradually exposes significant limitations in complex variable working condition scenarios (such as load fluctuations in natural gas liquefaction processes, transient responses in residual pressure power generation systems, etc.):

[0003] 1. Angle adjustment can only change the throat opening within a limited range, and there is a non-linear coupling effect between the blade angle and the air velocity field, resulting in uneven velocity distribution under low-load working conditions and easily inducing air flow separation and vortex losses;

[0004] 2. The fixed axial installation position results in an unadjustable nozzle throat length, and it is impossible to finely control the intake velocity through the collaborative optimization of the flow channel geometry. Especially when the expansion ratio fluctuates greatly, traditional nozzles are difficult to meet the dual requirements of expanding the high-efficiency area and improving the surge margin.

[0005] Therefore, there is an urgent need for a turboexpander nozzle technology that can break through the limitations of traditional circumferential angle adjustment and achieve multi-dimensional collaborative control, so as to fundamentally improve the aerodynamic performance and energy recovery efficiency of the expander under complex working conditions. Summary of the Invention

[0006] In order to solve the problems existing in the background art, the present invention provides an adjustable nozzle device for a turboexpander based on circumferential-axial two-degree-of-freedom adjustment. By introducing an axial degree-of-freedom adjustment mechanism, the present invention reconstructs the dynamic characteristics of the flow field and improves the aerodynamic performance and energy recovery efficiency of the expander under complex working conditions.

[0007] The technical solution adopted by the present invention is:

[0008] I. An adjustable nozzle device for a turboexpander based on circumferential-axial two-degree-of-freedom adjustment

[0009] The adjustable nozzle device of the turbine expander includes a fixed adjustment disc, a drive unit, an axial adjustment gear, a sealing plate ring, a nozzle base, and an array of nozzle blade adjustment mechanisms; the fixed adjustment disc, the axial adjustment gear, the sealing plate ring, and the nozzle base are coaxially arranged in sequence. The fixed adjustment disc is in threaded cooperation with the central hole of the axial adjustment gear through a connecting shaft, and the axial adjustment gear is driven to rotate by the drive unit; an array of nozzle blade adjustment mechanisms is arranged between the axial adjustment gear and the nozzle base. The array of nozzle blade adjustment mechanisms is mainly composed of N nozzle blade adjustment mechanisms arranged circumferentially. One end of the nozzle blade adjustment mechanism is in transmission connection with the axial adjustment gear, the middle part is connected to the sealing plate ring through a bearing, and the other end is movably connected to the nozzle base.

[0010] The nozzle blade adjustment mechanism is mainly composed of a linkage gear, a nozzle circumferential adjuster, and a nozzle blade connected coaxially in sequence; the linkage gear is meshed and connected with the axial adjustment gear, the linkage gear is connected to the first end of the nozzle circumferential adjuster, and the second end of the nozzle circumferential adjuster is connected to the sealing plate ring through a bearing; a clamping groove is formed on the end face of the second end of the nozzle circumferential adjuster, and one end of the nozzle blade is slidably installed in the clamping groove, and the other end is movably connected to the nozzle base.

[0011] The drive unit includes a drive motor and a drive gear. The central hole of the drive gear is connected to the output shaft of the drive motor; the axis of the drive gear is parallel to the axis of the axial adjustment gear and is arranged radially outside the axial adjustment gear, and the drive gear is meshed and connected with the axial adjustment gear; the drive motor is installed on the fixed adjustment disc.

[0012] On the outer peripheral surface of the axial adjustment gear, a main tooth part and a sub-tooth part are respectively arranged on both sides in the axial direction. The main tooth part is composed of several main gear teeth arranged circumferentially and evenly, and the sub-tooth part is composed of several groups of sub-gear teeth arranged circumferentially and at equal intervals. Each group of sub-gear teeth includes at least one gear tooth; the tooth pitches of the main tooth part and the sub-tooth part are the same, and the ratio of the number of teeth of the sub-tooth part to that of the linkage gear is 1:4; the number of groups of the sub-gear teeth is an integer multiple of the number of nozzle blade adjustment mechanisms.

[0013] A connection hole is formed on the fixed adjustment disc. After the output shaft of the drive motor passes through the connection hole, it is connected to the central hole of the drive gear, and the output shaft of the drive motor is connected to the connection hole through a second bearing.

[0014] The upper edge of the sealing plate ring is evenly provided with N mounting holes in the circumferential direction. The mounting holes correspond to the nozzle vane adjustment mechanisms one by one. The mounting holes are connected to the second ends of the nozzle circumferential regulators in the corresponding nozzle vane adjustment mechanisms through first bearings. Limiting rod arrays and annular chutes are respectively arranged on the opposite end faces of the sealing plate ring and the axial adjustment gear. The limiting rod array is mainly composed of a number of limiting rods evenly distributed at intervals in the circumferential direction. One end of the limiting rod is fixedly connected to the sealing plate ring, and the other end is slidably connected to the annular chute in an embedded manner.

[0015] II. A turboexpander adopting the above adjustable nozzle device.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1. By arranging a plurality of circumferential-axial two-degree-of-freedom nozzle vane adjustment mechanisms, the present invention can realize the intake control of the nozzle in two dimensions of circumferential and axial directions. The circumferential angle adjustment range is from 0° to 90°, and the axial adjustment range can be adjusted from the original nozzle intake working condition to almost no intake. The present invention broadens the adjustment dimension of the nozzle. Through the multi-dimensional control of the nozzle, the turbine impeller can adapt to complex working condition scenarios. By introducing the axial degree-of-freedom adjustment mechanism, the dynamic characteristics of the flow field are reconstructed, and the aerodynamic performance and energy recovery efficiency of the expander under complex working conditions are fundamentally improved.

[0018] 2. By arranging a driving motor to achieve precise adjustment, the whole system can complete the control of the nozzle in two dimensions of circumferential and axial directions without replacing the nozzle components. It can quickly respond to the change of working conditions and reduce various losses. Description of the Drawings

[0019] Figure 1 It is a three-dimensional structural schematic diagram when the nozzle intake passage of the device of the present invention is completely opened;

[0020] Figure 2 It is a sectional structural schematic diagram when the nozzle intake passage of the device of the present invention is completely opened;

[0021] Figure 3 It is a three-dimensional structural schematic diagram when the nozzle intake passage of the device of the present invention is completely closed;

[0022] Figure 4 It is a sectional structural schematic diagram when the nozzle intake passage of the device of the present invention is completely closed;

[0023] Figure 5 It is a three-dimensional structural schematic diagram of the fixed adjustment disk of the device of the present invention;

[0024] Figure 6 It is a three-dimensional structural schematic diagram of the axial adjustment gear of the device of the present invention;

[0025] Figure 7 It is a three-dimensional structural schematic diagram of the axial and circumferential nozzle blade adjustment mechanism, the sealing plate ring, and the nozzle base of the device of the present invention.

[0026] In the figure: 1. fixed adjustment disk, 2. drive motor, 3. drive gear, 4. axial adjustment gear, 5. linkage gear, 6. nozzle circumferential adjuster, 7. nozzle blade, 8. sealing plate ring, 9. nozzle base, 10. first bearing, 11. second bearing, 12. limit rod. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The present invention provides an adjustable nozzle device for a turbine expander based on circumferential-axial dual-degree-of-freedom adjustment. The device of the present invention includes a fixed disk group (a fixed adjustment disk 1 and a nozzle base 9), an axial adjustment gear 4, and a plurality of nozzle blade adjustment mechanisms. The fixed disk group is fixed on the turbine housing, and the turbine main shaft passes through the center of the disk body. At the same time, the fixed disk group also serves to limit the axial movement of the nozzle adjustment mechanism. The axial adjustment gear 4 and the screw-like mechanism in the fixed disk group (i.e., the connecting shaft of the fixed adjustment disk 1) realize the axial adjustment function and mesh with the linkage gear 5 in the nozzle blade adjustment mechanism to realize the axial movement and circumferential adjustment of the nozzle blade adjustment mechanism. The nozzle blade adjustment mechanism, the first bearing 10 and the sealing plate ring 8 cooperate to realize the control of the nozzle circumferential angle and the nozzle intake axial distance.

[0029] The adjustable nozzle device of the turbine expander includes a fixed adjustment disk 1, a driving unit, an axial adjustment gear 4, a sealing plate ring 8, a nozzle base 9 and a nozzle blade adjustment mechanism array; the fixed adjustment disk 1, the axial adjustment gear 4, the sealing plate ring 8 and the nozzle base 9 are coaxially arranged in sequence, a connecting shaft is provided at the center of the fixed adjustment disk 1, the connecting shaft is threadedly matched with the center hole of the axial adjustment gear 4, the axial adjustment gear 4 is transmission-connected with the driving unit and driven to rotate by the driving unit; a nozzle blade adjustment mechanism array is arranged between the axial adjustment gear 4 and the nozzle base 9, the nozzle blade adjustment mechanism array is mainly composed of N nozzle blade adjustment mechanisms arranged along the circumferential direction, one end of the nozzle blade adjustment mechanism is transmission-connected with the axial adjustment gear 4, the middle part is connected to the sealing plate ring 8 through a bearing, and the other end is movably connected to the nozzle base 9.

[0030] For the nozzle vane adjusting mechanism, the axis of the nozzle vane adjusting mechanism is parallel to the axis of the axial adjusting gear 4 and is arranged outside the axial adjusting gear 4. The nozzle vane adjusting mechanism is mainly composed of a linkage gear 5, a nozzle circumferential adjuster 6 and a nozzle vane 7 connected coaxially in sequence; the linkage gear 5 is meshed with the axial adjusting gear 4, the linkage gear 5 is connected to the first end of the nozzle circumferential adjuster 6, and the second end of the nozzle circumferential adjuster 6 is connected to a sealing plate ring 8 through a bearing; a clamping groove is formed on the end surface of the second end of the nozzle circumferential adjuster 6, and one end of the nozzle vane 7 is slidably fitted into the clamping groove, and the other end is movably connected to a nozzle base 9.

[0031] In specific implementation, the end of the nozzle vane 7 and the surface of the nozzle base 9 can be connected through a rotating shaft, and the axis of the rotating shaft is consistent with the rotation axis of the nozzle circumferential adjuster 6, so that the nozzle vane 7 can rotate synchronously with the nozzle circumferential adjuster 6.

[0032] Specifically, the clamping groove is adapted to the shape of the nozzle vane 7.

[0033] Preferably, the nozzle vane 7 adopts a blade profile, and is designed with a blunt leading edge and a thin trailing edge.

[0034] Preferably, N blade mounting rods are connected to the nozzle base 9. The number of the blade mounting rods is the same as that of the nozzle vanes 7 and they are arranged axially in one-to-one correspondence and alignment. The nozzle vanes 7 are sleeved on the corresponding blade mounting rods to limit the nozzle vanes 7 and enable the nozzle vanes 7 to rotate.

[0035] For the driving unit, the driving unit includes a driving motor 2 and a driving gear 3. The central hole of the driving gear 3 is connected to the output shaft of the driving motor 2; the axis of the driving gear 3 is parallel to the axis of the axial adjusting gear 4 and is arranged radially outside the axial adjusting gear 4. The driving gear 3 is meshed with the axial adjusting gear 4, and the driving motor 2 is installed on one side of the fixed adjusting disk 1 away from the axial adjusting gear 4.

[0036] For the axial adjusting gear 4, main tooth parts and auxiliary tooth parts are respectively arranged on both sides of the outer peripheral surface of the axial adjusting gear 4 in the axial direction. The main tooth part is composed of a plurality of main teeth arranged evenly in the circumferential direction, and the auxiliary tooth part is composed of a plurality of groups of auxiliary teeth arranged evenly at intervals in the circumferential direction. Each group of auxiliary teeth includes at least one tooth; the tooth pitches of the main tooth part and the auxiliary tooth part are the same.

[0037] Specifically, the ratio of the number of teeth of the secondary gear part to the number of teeth of the linkage gear 5 is 1:4; the number of groups of secondary gear teeth is an integer multiple of the number of nozzle vane adjustment mechanisms, such that the rotation angle ratio of the axial adjustment gear 4 to the linkage gear 5 is 4:1. Specifically: To achieve the adjustment of the nozzle vane angle in the range of 0° to 90° and reduce the installation space of the device, it is necessary to limit the axial movement of the adjustment gear 4 to achieve a small distance. Therefore, the axial adjustment gear 4 is threadedly engaged with the fixed adjustment disk 1 to enable the axial adjustment gear 4 to rotate circumferentially by 0° to 360° (i.e., the axial adjustment gear 4 can only rotate one circle). Based on the above two conditions, the rotation angle of the linkage gear 5 can be obtained as 1 / 4 of the rotation angle of the adjustment gear 4. Therefore, when the adjustment gear 4 rotates 360° in the required direction, the opening angle of the nozzle vane is adjusted from 90° to 0°, that is, from the fully open state as shown in Figure 1 to Figure 3 the fully closed state shown. If the rotation direction is changed and rotated 360°, the opening angle of the nozzle vane is adjusted from 0° to 90°, that is, from the fully closed state as shown in Figure 3 to Figure 1 the fully open state shown.

[0038] In a specific embodiment of the present invention, the number of teeth of the linkage gear 5 is 96, and the number of nozzle vane adjustment mechanisms is 6. On the contact surface where the axial adjustment gear 4 meshes with the driving gear 3, the teeth are evenly arranged. On the contact surface where the axial adjustment gear 4 meshes with the linkage gear 5, the teeth are grouped in pairs of two consecutive teeth, and 12 groups of teeth are evenly spaced circumferentially to achieve a special ratio of the rotation angles of the axial adjustment gear 4 and the linkage gear 5.

[0039] For the fixed adjustment disk 1, connection holes are provided on the fixed adjustment disk 1. The output shaft of the driving motor 2 passes through the connection hole and is connected to the central hole of the driving gear 3. The output shaft of the driving motor 2 is connected to the connection hole through the second bearing 11.

[0040] Specifically, a ring structure is connected to the surface of the fixed adjustment disk 1 near the axial adjustment gear 4. The ring structure is arranged radially outside the connecting shaft. Connection holes are provided on the ring structure. The output shaft of the driving motor 2 passes through the connection hole from the side away from the axial adjustment gear 4 and is connected to the central hole of the driving gear 3. The output shaft of the driving motor 2 is connected to the connection hole through the second bearing 11.

[0041] For the sealing plate ring 8, N mounting holes are evenly provided on the sealing plate ring 8 in the circumferential direction. The mounting holes correspond to the nozzle vane adjustment mechanisms one by one and are arranged axially corresponding and aligned. The mounting holes are connected to the second end of the nozzle circumferential adjuster 6 in the corresponding nozzle vane adjustment mechanism through the first bearing 10.

[0042] The limiting rod 12 and the sealing plate ring 8 do not undergo relative displacement, and the limiting rod 12 and the adjusting gear 4 do not undergo axial displacement and axial rotation, but only undergo circumferential relative sliding in the annular sliding groove. Since the linkage gear 5 and the sealing plate ring 8 do not undergo relative axial movement, the linkage gear 5 and the axial adjusting gear 4 do not undergo axial relative movement.

[0043] Preferably, a limiting rod array and an annular sliding groove are respectively provided on the relative end faces of the sealing plate ring 8 and the axial adjusting gear 4. The limiting rod array is mainly composed of a number of limiting rods 12 evenly distributed at intervals in the circumferential direction. One end of the limiting rod 12 is fixedly connected to the sealing plate ring 8, and the other end is slidably connected to the annular sliding groove in an embedded manner.

[0044] Optionally, the embedded sliding connection can be achieved by means of a slider and a slide rail structure, a limiting block and a limiting groove structure, a dovetail block and a dovetail groove structure, etc.

[0045] Optionally, the annular sliding groove is a stepped groove, and a convex portion is provided at the end of the limiting rod 12, and the convex portion is slidably fitted into the annular stepped groove.

[0046] Optionally, the limiting rod 12 and the sealing plate ring 8 are fixedly connected by means of integral molding or the like.

[0047] Preferably, in the specific implementation of the present invention, the number of nozzle blade adjustment mechanisms is six.

[0048] The working principle of the present invention is as follows:

[0049] In the present invention, the driving motor 2 drives the driving gear 3, the driving gear 3 drives the axial adjusting gear 4 to rotate, the axial adjusting gear 4 realizes axial movement by means of a spiral fit with the fixed adjusting disk 1, and the axial adjusting gear 4 further drives the nozzle circumferential adjuster 6 through the linkage gear 5, so as to realize the axial movement and circumferential rotation of the nozzle circumferential adjuster 6 and the linkage gear 5, and then transmit the axial movement and circumferential rotation of the nozzle circumferential adjuster 6 and the linkage gear 5 to the nozzle blade 7 and the sealing plate ring 8, so as to realize the circumferential rotation of the nozzle blade 7 and the axial movement of the sealing plate ring 8, and finally achieve the purpose of adjusting the circumferential angle and axial width of the nozzle air inlet passage.

[0050] The present invention also provides a turboexpander, and the turboexpander adopts the adjustable nozzle device as described above. The adjustable nozzle device is installed on the turboexpander by means of an embedded installation method, and the air flow path in the adjustable nozzle device is as follows: the air flow enters the adjustable nozzle device from the radial outside of the axial variable channel between the sealing plate ring 8 and the nozzle base 9, passes through the nozzle inter-flow channel, and then discharges from the radial inside of the axial variable channel between the sealing plate ring 8 and the nozzle base 9 and flows into the impeller mechanism.

[0051] The specific embodiments of the present invention are as follows:

[0052] In this embodiment, the number of nozzle vane adjustment mechanisms is six.

[0053] In this embodiment, the adjustable nozzle device includes a fixed adjustment disk 1, a driving motor 2, a driving gear 3, an axial adjustment gear 4, a linkage gear 5, a nozzle circumferential adjuster 6, nozzle vanes 7, a sealing plate ring 8, a nozzle base 9, a first bearing 10, a second bearing 11, and a limiting rod 12.

[0054] As Figure 1 and Figure 2 shown, two second bearings 11 are installed in the connection holes of the fixed adjustment disk 1, and the output shaft of the driving motor 2 passes through the connection hole from right to left and is connected to the driving gear 3. The axial adjustment gear 4 is sleeved outside the connection shaft at the center of the left side of the fixed adjustment disk 1 and is in spiral fit with it. Teeth are provided on the outer peripheral surface of the axial adjustment gear 4. The linkage gear 5 rotates and moves axially following the engagement with the axial adjustment gear 4. A nozzle circumferential adjuster 6 is coaxially connected to the left side of the linkage gear 5. A groove is formed on the left end face of the nozzle circumferential adjuster 6, and the nozzle vane 7 is slidably fitted in the groove. The nozzle circumferential adjuster 6 is connected to the sealing plate ring 8 through the first bearing 10, and the nozzle vane 7 is movably connected to the nozzle base 9.

[0055] As Figure 1 and Figure 3 shown, the driving motor 2 is connected to the driving gear 3 to achieve synchronous rotation, and the driving gear 3 does not move axially with respect to the fixed adjustment disk 1.

[0056] As Figure 1 , Figure 3 and Figure 5 shown, the driving gear 3 meshes with the axial adjustment gear 4, and the adjustment gear 4 is in spiral fit with the fixed adjustment disk 1. When the driving gear 3 drives the adjustment gear 4 to rotate, the adjustment gear 4 can achieve axial movement.

[0057] As Figure 6 shown, the teeth on the contact surface where the axial adjustment gear 4 meshes with the driving gear 3 are evenly distributed, and the teeth on the contact surface where the axial adjustment gear 4 meshes with the linkage gear 5 are only in groups of two consecutive teeth, with a total of 12 groups evenly distributed on the gear, so as to achieve a rotation angle ratio of 4:1 between the axial adjustment gear 4 and the linkage gear 5.

[0058] As Figure 1 and Figure 3As shown, there is no relative axial movement between the linkage gear 5 and the axial adjustment gear 4. Specifically: Six limit rods 12 integrated with the sealing plate ring 8 are clamped on the circular sliding groove of the adjustment gear 4. There is no relative displacement between the limit rods 12 and the sealing plate ring 8, and there is no axial displacement and axial rotation between the limit rods 12 and the adjustment gear 4. Only relative sliding occurs in the card slots. Since there is no relative axial movement between the linkage gear 5 and the sealing plate ring 8, there is no relative axial movement between the linkage gear 5 and the axial adjustment gear 4.

[0059] As Figure 7 shown, the linkage gear 5, the nozzle circumferential regulator 6, and the adjustable nozzle 7 are connected to form a nozzle vane adjustment mechanism, and they rotate circumferentially simultaneously. Six groups of nozzle vane adjustment mechanisms are evenly externally meshed on the radial outside of the adjustment gear 4.

[0060] As Figure 7 shown, the nozzle vane 7 is embedded in the card slot on the left side of the nozzle circumferential regulator 6. The nozzle vane 7 rotates with the nozzle circumferential regulator 6 and can have relative axial movement.

[0061] As Figure 7 shown, the nozzle vane 7 is movably connected to the nozzle base 9, so that the nozzle vane 7 can only achieve circumferential rotation. Specifically, six vane mounting rods are connected to the right end face of the nozzle base 9. The nozzle vane 7 is sleeved on the corresponding vane mounting rod to limit the nozzle vane 7 and enable the nozzle vane 7 to rotate.

[0062] As Figure 7 shown, the sealing plate ring 8 is connected to six groups of circumferential regulators 6 by the first bearing 11. The sealing plate ring 8 does not rotate circumferentially and only moves radially with the circumferential regulator 6.

[0063] When the turbine impeller operates under off-design conditions, by adjusting the axial dimension of the nozzle inlet flow passage, the impeller approaches the design conditions. When the gas flow pressure is too high and the flow velocity is low, by adjusting the adjustable nozzle, the flow passage cross-sectional area is reduced, the pressure is reduced, and the flow velocity increases significantly to improve the working efficiency of the impeller. On the contrary, when the gas flow pressure is too low and the flow velocity is high, by adjusting the adjustable nozzle, the flow passage cross-sectional area is increased, the pressure is increased, and the flow velocity is significantly reduced to improve the working efficiency of the impeller. At the same time, the changing nozzle outlet angle changes the relative velocity direction of the gas flow impacting the moving blades of the impeller, enabling the gas flow to enter the moving blades in a more appropriate direction, maximizing the circumferential component force that pushes the impeller to rotate, and improving the energy conversion efficiency. Therefore, in complex and variable working condition scenarios, this nozzle can cover a wider flow rate and enthalpy drop range, reduce energy losses under various working conditions, suppress gas flow separation, recirculation, and stall, enhance flow stability, and achieve both the expansion of the high-efficiency region of the expander and the improvement of the surge margin.

[0064] In summary, the device of the present invention realizes the adjustment of the axial distance while controlling the nozzle angle, broadens the adjustment dimension of the nozzle, and enables the turbine impeller to adapt to complex variable operating conditions through the multi-dimensional control of the nozzle.

[0065] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An adjustable nozzle device for a turbo expander based on circumferential-axial dual-degree-of-freedom adjustment, characterized in that: The adjustable nozzle device of the turbo expander comprises a fixed adjustment disk (1), a drive unit, an axial adjustment gear (4), a sealing plate ring (8), a nozzle base (9) and a nozzle blade adjustment mechanism array; The fixed adjustment disk (1), the axial adjustment gear (4), the sealing plate ring (8) and the nozzle base (9) are coaxially arranged in sequence, the fixed adjustment disk (1) is threadedly matched with the center hole of the axial adjustment gear (4) through a connecting shaft, and the axial adjustment gear (4) is driven to rotate by a driving unit; A nozzle blade adjustment mechanism array is arranged between the axial adjustment gear (4) and the nozzle base (9), and the nozzle blade adjustment mechanism array is mainly composed of N nozzle blade adjustment mechanisms arranged along the circumferential direction. One end of the nozzle blade adjustment mechanism is transmission-connected to the axial adjustment gear (4), the middle part is connected to the sealing plate ring (8) through a bearing, and the other end is movably connected to the nozzle base (9).

2. The adjustable nozzle device for a turbo expander based on circumferential-axial dual-degree-of-freedom adjustment according to claim 1, characterized in that: The nozzle blade adjustment mechanism is mainly composed of a linkage gear (5), a nozzle circumferential adjuster (6) and a nozzle blade (7) which are coaxially connected in sequence; the linkage gear (5) is meshedly connected with the axial adjustment gear (4), the linkage gear (5) is connected with the first end of the nozzle circumferential adjuster (6), and the second end of the nozzle circumferential adjuster (6) is connected with the sealing plate ring (8) through a bearing; a groove is provided on the end surface of the second end of the nozzle circumferential adjuster (6), one end of the nozzle blade (7) can be slidably embedded in the groove, and the other end is movably connected with the nozzle base (9).

3. The adjustable nozzle device for a turbo expander based on circumferential-axial dual-degree-of-freedom adjustment according to claim 2 is characterized in that: The drive unit comprises a drive motor (2) and a drive gear (3); the center hole of the drive gear (3) is connected to the output shaft of the drive motor (2); the axis of the drive gear (3) is parallel to the axis of the axial adjustment gear (4) and is arranged radially outside the axial adjustment gear (4); the drive gear (3) is meshingly connected with the axial adjustment gear (4); and the drive motor (2) is mounted on a fixed adjustment disk (1).

4. The adjustable nozzle device for a turbo expander based on circumferential-axial dual-degree-of-freedom adjustment according to claim 3 is characterized in that: The outer peripheral surface of the axial adjustment gear (4) is provided with a main tooth portion and a secondary tooth portion on both sides in the axial direction, the main tooth portion is formed by a plurality of main gear teeth evenly arranged in the circumferential direction, and the secondary gear portion is formed by a plurality of groups of secondary gear teeth evenly arranged in the circumferential direction at intervals, and each group of secondary gear teeth includes at least one gear tooth; the main gear portion and the secondary gear portion have the same tooth pitch, and the ratio of the number of gear teeth of the secondary gear portion to that of the linkage gear (5) is 1:4; the number of groups of the secondary gear teeth is an integer multiple of the number of nozzle blade adjustment mechanisms.

5. The adjustable nozzle device for a turbo expander based on circumferential-axial dual-degree-of-freedom adjustment according to claim 3 is characterized in that: The fixed adjustment disk (1) is provided with a connection hole, and the output shaft of the drive motor (2) passes through the connection hole and is connected to the center hole of the drive gear (3). The output shaft of the drive motor (2) is connected to the connection hole via a second bearing (11).

6. The adjustable nozzle device of a turbo expander based on circumferential-axial dual-degree-of-freedom adjustment according to claim 2, characterized in that: The sealing plate ring (8) is provided with N mounting holes evenly distributed along the circumference, and the mounting holes correspond to the nozzle blade adjustment mechanism one by one. The mounting holes are connected to the second end of the nozzle circumferential adjuster (6) in the corresponding nozzle blade adjustment mechanism through the first bearing (10); a limit rod array and an annular groove are respectively provided on the opposite end surfaces of the sealing plate ring (8) and the axial adjustment gear (4), and the limit rod array is mainly composed of a plurality of limit rods (12) evenly distributed along the circumference, one end of the limit rod (12) is fixedly connected to the sealing plate ring (8), and the other end is embedded and slidably connected to the annular groove.

7. A turboexpander, characterized in that: Adopt the adjustable nozzle device as described in any one of claims 1 to 6.

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