Gas wellhead expander
By designing a two-stage centrifugal expansion mode gas wellhead expander, the problem of energy utilization at the high-pressure gas wellhead has been solved, achieving efficient energy conversion and safety, and improving energy utilization efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2024-12-06
- Publication Date
- 2026-06-09
AI Technical Summary
In existing technologies, expanders at the wellhead of high-pressure gas wells cannot effectively utilize the energy of high-pressure gas, especially when the gas entrains liquid, leading to energy waste and increased equipment complexity.
A gas wellhead expander was designed, which adopts a two-stage centrifugal expansion mode, including a shell, a rotating component, and primary and secondary expansion components. It converts high-pressure gas energy into mechanical energy in a progressive manner, and achieves orderly energy conversion by using a parabolic structure and a precision impeller.
It improves energy utilization efficiency, ensures safety and stability under high pressure and high liquid conditions, reduces energy loss, and achieves efficient mechanical energy conversion.
Smart Images
Figure CN122169892A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy conservation and environmental protection, and in particular to a gas wellhead expander. Background Technology
[0002] A high-pressure natural gas wellhead energy-saving expander is a device used in natural gas extraction. Its working principle is based on the expansion and depressurization process of high-pressure natural gas. When high-pressure natural gas passes through the expander, the gas's pressure energy is converted into mechanical energy, thereby driving a generator to produce electricity or for other purposes. The application of this equipment can effectively utilize the residual pressure of natural gas, reduce energy waste, and improve energy efficiency.
[0003] In related technologies, gas fields have adopted high-pressure gas gathering technology, but the average gas gathering pressure is relatively low, at approximately 12.5 MPa. This phenomenon is mainly due to the fact that gas wells generally require multi-stage throttling and pressure reduction processes during the gas gathering process to meet the gas gathering pressure requirements. This not only increases the complexity of the equipment but also results in a huge waste of energy.
[0004] Currently, there is a lack of expanders to achieve efficient conversion of mechanical energy in situations where wellhead pressure is high and gas carries a large amount of liquid. Summary of the Invention
[0005] This application provides a gas wellhead expander to solve the problem that expanders in related technologies are difficult to use at high-pressure wellheads.
[0006] On the one hand, this application provides a gas wellhead expander, comprising:
[0007] The shell has a flow cavity inside, and the shell is provided with an inlet and an outlet communicating with the flow cavity;
[0008] A rotating component is inserted into the housing and located within the flow cavity, forming an expansion channel between the rotating component and the inner wall of the housing;
[0009] The primary expansion assembly and the secondary expansion assembly are spaced apart in the expansion channel along the axial direction of the rotating assembly, so that the flowing medium entering from the inlet passes through the primary expansion assembly and the secondary expansion assembly in sequence and is discharged from the outlet.
[0010] In some embodiments, the rotating assembly has a rotation axis, and the expansion channel includes a first channel segment, a second channel segment, and a third channel segment connected sequentially in the direction from the inlet to the outlet;
[0011] The first channel section is curved and gradually moves away from the axis of rotation in the direction from the inlet to the outlet;
[0012] The second channel section is curved and gradually approaches the axis of rotation in the direction from the inlet to the outlet;
[0013] The third channel section is curved and gradually moves away from the axis of rotation in the direction from the inlet to the outlet.
[0014] In some embodiments, the primary expansion component is disposed within the first channel segment;
[0015] The secondary expansion component is located within the third channel segment.
[0016] In some embodiments, the primary expansion assembly includes a primary stationary impeller and a primary moving impeller;
[0017] The primary stationary impeller is located on the housing, and the primary moving impeller is located on the rotating assembly. The primary moving impeller is located on the circumferential outer side of the primary stationary impeller, and the primary stationary impeller and the primary moving impeller are rotated together.
[0018] In some embodiments, the secondary expansion assembly includes a secondary stationary impeller and a secondary moving impeller;
[0019] The secondary stationary impeller is located on the casing, and the secondary moving impeller is located on the rotating assembly. The secondary moving impeller is located on the circumferential outer side of the secondary stationary impeller, and the secondary stationary impeller and the secondary moving impeller are rotated together.
[0020] In some embodiments, the rotating assembly includes a rotating shaft and a radial bearing disposed on the rotating shaft, wherein a power groove is provided on the inner wall of the bearing bush of the radial bearing.
[0021] In some embodiments, the rotating assembly further includes a thrust bearing disposed on the rotating shaft. The thrust bearing includes a bushing and a thrust block located inside the bushing. A left helical groove and a right helical groove are respectively disposed on the two end faces of the thrust block.
[0022] In some embodiments, the housing includes an inlet section, an outlet section, and a transition section located between the inlet section and the outlet section;
[0023] A first channel section is formed between the inlet section and the rotating assembly;
[0024] A second channel segment is formed between the transition section and the rotating assembly;
[0025] A third channel section is formed between the outlet section and the rotating assembly.
[0026] In some embodiments, the pressure profile equation of the first-stage stationary blade ring is:
[0027] Y p =f(ξ)=a0+a1ξ+a2ξ 2 +a3ξ 3 +a4ξ 4 +a5ξ 5
[0028] Among them, Y pξ is the coordinate value of the pressure surface at a specific location; a0 to a5 are the specific parameters that determine the specific blade profile; ξ is the dimensionless coordinate value.
[0029] In some embodiments, the suction surface shape equation of the first-stage stationary blade ring is:
[0030] Y s =g(ξ)=b0+b1ξ+b2ξ 2 +b3ξ 3 +b4ξ 4 +b5ξ 5
[0031] Among them, Y s ξ represents the coordinates of the suction surface at a specific location; b0 to b5 are the specific parameters that determine the specific blade profile; ξ is the dimensionless coordinate value.
[0032] The gas wellhead expander provided in this application maximizes the use of gas energy. Through a step-by-step approach, the expander can be applied to high-pressure and gas-encapsulated liquid conditions. The energy originally contained in the high-pressure gas is gradually and orderly converted into usable mechanical work. Through this series of steps, energy utilization efficiency is effectively improved, and the safety and stability of the entire process are also guaranteed. Attached Figure Description
[0033] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0034] Figure 1 A cross-sectional view of a gas wellhead expander provided in an embodiment of this application;
[0035] Figure 2 for Figure 1 A sectional view of the gas wellhead expander along the AA direction;
[0036] Figure 3 for Figure 1 A BB-direction cross-sectional view of the gas wellhead expander;
[0037] Figure 4 for Figure 1 A partial structural diagram of a gas wellhead expander;
[0038] Figure 5 A cross-sectional view of the thrust block of a gas wellhead expander provided in this application embodiment;
[0039] Figure 6 for Figure 5 A side view of the thrust block from a first-person perspective;
[0040] Figure 7for Figure 5 A side view of the thrust block from a second perspective;
[0041] Figure 8 A perspective view of the bearing of a gas wellhead expander provided in the embodiments of this application;
[0042] Figure 9 for Figure 8 A cross-sectional view of the bearing bush.
[0043] Explanation of reference numerals in the attached figures:
[0044] 10. Expander;
[0045] 100. Shell; 101. Inlet; 102. Outlet; 110. Inlet section; 120. Outlet section; 130. Transition section;
[0046] 200, Rotating assembly; 210, Rotating shaft; 220, Radial bearing; 221, Bearing bush; 2211, Power groove; 230, Thrust bearing; 231, Bushing; 232, Thrust block; 2321, Left helical groove; 2322, Right helical groove; 240, First hub; 250, Second hub;
[0047] 300. Expansion channel; 310. First channel segment; 320. Second channel segment; 330. Third channel segment;
[0048] 400. First-stage expansion assembly; 410. First-stage stationary impeller; 420. First-stage moving impeller;
[0049] 500, Secondary expansion assembly; 510, Secondary stationary impeller; 520, Secondary moving impeller. Detailed Implementation
[0050] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0051] As a revolutionary technology in the field of natural gas extraction, the high-pressure natural gas wellhead energy-saving expander's core value lies in its ingenious utilization of the inherent high-pressure gas potential, converting it into practical mechanical energy. This process not only greatly improves energy utilization efficiency but also contributes to green and sustainable development. Domestically and internationally, the recovery and utilization of residual pressure at gas wellheads mainly includes residual pressure power generation, residual pressure refrigeration, and combined cooling and power (CCHP). The key to realizing these technologies lies in first converting pressure energy into mechanical energy; therefore, installing an expander at the wellhead is a prerequisite for the effective utilization of residual pressure in gas wells. By utilizing expander technology, the pressure energy at the natural gas wellhead can be efficiently converted into mechanical shaft work and electrical energy. This conversion process has significant energy-saving benefits and can effectively reduce energy loss.
[0052] In related technologies, gas fields have adopted high-pressure gas gathering technology, but the average gas gathering pressure is relatively low, approximately 12.5 MPa. This phenomenon is mainly due to the fact that gas wells generally require multi-stage throttling and pressure reduction processes during gas gathering to meet the required gas gathering pressure. This not only increases the complexity of the equipment but also results in significant energy waste. In actual production, many gas wells have wellhead pressures exceeding 50 MPa, and some even exceed 100 MPa. This high-pressure characteristic presents numerous challenges to gas field development.
[0053] However, no turbine expanders suitable for high-pressure gas wells have yet been developed on the market. Furthermore, suitable models are lacking for gas wells operating under high pressure and with significant fluid content. This technological gap restricts the further development of high-pressure gas well residual pressure recovery and utilization. Therefore, innovation in the design and manufacture of turbine expanders is urgently needed to meet the specific requirements of high-pressure gas wells.
[0054] The purpose of this invention is to provide a gas wellhead expander 10, which can be applied to the wellhead of high-pressure natural gas wells. In response to high-pressure and high-liquid conditions, it adopts a two-stage centrifugal expansion mode to form a high-pressure expander for natural gas wellheads, making it possible to directly utilize the residual pressure at the wellhead.
[0055] The gas wellhead expander of this application embodiment is described below with reference to the accompanying drawings.
[0056] like Figure 1 and Figure 4 As shown, the gas wellhead expander of this embodiment includes: a housing 100, a rotating assembly 200, a primary expansion assembly 400, and a secondary expansion assembly 500.
[0057] The housing 100 has a flow cavity, and the housing 100 is provided with an inlet 101 and an outlet 102 communicating with the flow cavity. The structure of the housing 100 ensures the stability of the internal pressure environment and provides a strength guarantee for the subsequent gas expansion process.
[0058] The rotating component 200 passes through the housing 100 and is located in the flow cavity. An expansion channel 300 is formed between the rotating component 200 and the inner wall of the housing 100. The expansion channel 300 is the core area of the entire energy conversion. The gas will experience significant pressure and temperature changes as it passes through this narrow path.
[0059] The primary expansion assembly 400 and the secondary expansion assembly 500 are spaced apart within the expansion channel 300 along the axial direction of the rotating assembly 200, so that the flowing medium entering from the inlet 101 passes through the primary expansion assembly 400 and the secondary expansion assembly 500 sequentially before being discharged from the outlet 102. The primary expansion assembly 400 and the secondary expansion assembly 500 form a two-stage expansion process connected in series. The high-pressure gas entering from the inlet 101 first enters the primary expansion assembly 400, undergoes an initial pressure drop and acceleration; then the gas continues to move forward, reaching the secondary expansion assembly 500, where it again undergoes pressure regulation and energy release, and finally flows out smoothly from the outlet 102 at a lower pressure.
[0060] By applying the technical solution of this embodiment, the gas wellhead expander maximizes the use of gas energy. Through a step-by-step approach, the expander can be applied to high-pressure and gas-encapsulated liquid conditions. The energy originally contained in the high-pressure gas is gradually and orderly converted into usable mechanical work. Through this series of steps, energy utilization efficiency is effectively improved, and the safety and stability of the entire process are also guaranteed.
[0061] Continue to refer to Figure 1 and Figure 4 As shown, the rotating assembly 200 has a rotating shaft 210 line, and the expansion channel 300 includes a first channel segment 310, a second channel segment 320 and a third channel segment 330 connected in sequence in the direction from the inlet 101 to the outlet 102.
[0062] The first channel segment 310 is curved and gradually moves away from the rotation axis 210 line in the direction from inlet 101 to outlet 102;
[0063] The second channel section 320 is curved and gradually approaches the rotation axis 210 line in the direction from inlet 101 to outlet 102;
[0064] The third channel segment 330 is curved and gradually moves away from the rotation axis 210 line in the direction from inlet 101 to outlet 102.
[0065] The arrangement of the three channel segments creates a curved expansion channel 300, which facilitates the construction of multiple parabolic structures, allowing for multiple expansions during gas flow and improving the expander's efficiency. Through these continuous curved sections, the gas undergoes multiple localized expansion stages, rather than a single large-span decompression. This staged expansion strategy promotes the gradual release of gas energy, ensuring the continuity and efficiency of energy conversion. The parabolic path provides optimal hydrodynamic characteristics; its smooth curved surface reduces turbulence, lowers drag, and promotes smooth gas flow. At each parabolic inflection point, the gas velocity and direction are optimized, further improving energy transfer efficiency.
[0066] In some embodiments, the primary expansion component 400 may be disposed within the first channel segment 310, and the secondary expansion component 500 may be disposed within the third channel segment 330.
[0067] The first channel section 310 is designed as the starting point for the initial entry of gas into the expander. Its curved structure and the characteristic of gradually moving away from the rotation axis 210 provide initial guidance for the gas. The first-stage expansion assembly 400 plays its role at this node, responsible for receiving high-pressure gas and initiating the initial stage of energy conversion.
[0068] The second channel section 320 serves as a connection between the first channel section 310 and the third channel section 330, providing ample space for gas expansion.
[0069] After the gas undergoes expansion and intermediate regulation in the first two stages, it reaches the third channel segment 330, ready to receive further energy conversion from the secondary expansion component 500. Here, the gas state is close to ideal; the secondary component's task is to further refine the remaining energy, ensuring that every expansion opportunity is fully utilized.
[0070] like Figure 1 and Figure 2 As shown, in some embodiments, the primary expansion assembly 400 may include a primary stationary impeller 410 and a primary moving impeller 420;
[0071] A primary stationary impeller 410 is disposed on the housing 100, and a primary moving impeller 420 is disposed on the rotating assembly 200. The primary moving impeller 420 is located on the circumferential outer side of the primary stationary impeller 410, and the primary stationary impeller 410 and the primary moving impeller 420 are in rotational engagement with each other.
[0072] In the above structure, the first-stage stationary impeller 410 can create a pre-flow of gas and preliminary energy regulation. The angle and shape of the blades of the first-stage stationary impeller 410 can be designed according to actual conditions, with the aim of capturing the incoming high-pressure gas and injecting power into the subsequent gas entering the first-stage moving impeller 420 by changing the gas flow direction and velocity.
[0073] The primary stationary impeller 410 and the primary moving impeller 420 form a highly efficient energy conversion unit. When high-pressure gas passes through the primary stationary impeller, the flow direction of the gas is optimized and its velocity is increased due to the guiding effect of the blades. Subsequently, this gas with a certain kinetic energy impacts the primary moving impeller 420, achieving a successful conversion from high-pressure gas to mechanical energy. Moreover, the rotation of the moving impeller can also drive the connected shaft or other mechanical parts to operate, generating additional power output for use by external systems.
[0074] Accordingly, such as Figure 1 and Figure 3 As shown, in some embodiments, the secondary expansion assembly 500 includes a secondary stationary impeller 510 and a secondary moving impeller 520. The secondary stationary impeller 510 is disposed in the housing 100, and the secondary moving impeller 520 is disposed in the rotating assembly 200. The secondary moving impeller 520 is located circumferentially outside the secondary stationary impeller 510, and the secondary stationary impeller 510 and the secondary moving impeller 520 are rotatably coupled. Similar to the primary expansion assembly 400, the secondary expansion assembly 500 can also generate significant mechanical work to drive connected mechanical systems or power generation equipment.
[0075] The precise fit between the secondary stationary impeller 510 and the secondary moving impeller 520 constitutes the core of the second energy conversion. As the gas flows through this stage, its energy is further refined, and the conversion efficiency is significantly improved.
[0076] Of course, in other embodiments, the expander may also include more stages of expansion components to further release the pressure of the high-pressure gas.
[0077] like Figure 1 , Figure 4 and Figure 8 as well as Figure 9 As shown, in some embodiments, the rotating assembly 200 includes a rotating shaft 210 and a radial bearing 220 disposed on the rotating shaft 210, and a power groove 2211 is provided on the inner wall of the bearing bush 221 of the radial bearing 220.
[0078] The bearing bush 221 is an important component that provides support and damping between the rotating shaft 210 and the fixed structure. Its function is to reduce friction and wear between the shaft and the support, and to ensure smooth rotation of the shaft.
[0079] The dynamic groove 2211 is mainly used to improve the formation of the lubricating oil film between the bearing bush 221 and the shaft, thereby enhancing lubrication, increasing load-bearing capacity, and reducing frictional losses. The layout and design of the dynamic groove 2211 are crucial, as they help establish a stable oil film between the shaft and the bearing bush 221, ensuring sufficient lubrication even under high-speed and heavy-load conditions, extending the service life of the bearing bush 221, reducing maintenance frequency, and improving the overall operating efficiency and reliability of the equipment.
[0080] In some embodiments, the dynamic grooves 2211 can be arranged in multiple rows along the axial direction of the rotating shaft 210. Each row of dynamic grooves 2211 helps to generate an independent and continuous oil film layer, thereby better distributing the load and ensuring good lubrication between the bearing bush 221 and the shaft throughout the entire operating range. This design of multiple rows of dynamic grooves 2211, especially in large or high-performance equipment, can significantly improve the dynamic response characteristics and long-term operational stability of the shaft system.
[0081] For example, the power slot 2211 can be arranged in 2-6 rows, preferably in 4 rows.
[0082] like Figure 1 as well as Figures 5 to 7 As shown, in some embodiments, the rotating assembly 200 further includes a thrust bearing 230 disposed on the rotating shaft 210. The thrust bearing 230 includes a bushing 231 and a thrust block 232 located inside the bushing 231. A left helical groove 2321 and a right helical groove 2322 are respectively disposed on the two end faces of the thrust block 232.
[0083] The left helical groove 2321 and the right helical groove 2322 are located on the left and right sides of the thrust block 232, respectively. Their design purpose is mainly to cope with the bidirectional axial force that the rotating shaft 210 may generate during operation. When the rotating shaft 210 rotates, due to inertia and external loads, it may experience forward or backward thrust along its axis. At this time, the left helical groove 2321 and the right helical groove 2322 can play a role by changing the oil flow on the contact surface, automatically forming a hydraulic balance to counteract the axial force, thereby keeping the shaft in the correct position and reducing the burden on the shaft shoulder or other support structures.
[0084] When the rotating shaft 210 is subjected to a rightward axial force, the left helical groove 2321 forces the lubricating oil from the wide side to the narrow side through centrifugal force and hydrodynamic effect, thereby establishing an oil wedge between the shaft and the thrust block 232 contact surface, generating a reverse thrust and playing a balancing role. Similarly, if the shaft is subjected to a leftward axial force, the right helical groove 2322 will have the same effect, counteracting the axial force through the opposite flow pattern. The biggest advantage of this thrust block 232 design with double helical grooves is that it achieves an automatic adjustment function, which can cope with changes in axial force without additional mechanical mechanisms, reducing system complexity and maintenance costs, while improving the stability and reliability of the mechanical system.
[0085] It should be noted that the depth of the power groove 2211 can be between 5 and 20 μm.
[0086] In some embodiments, the housing 100 includes an inlet section 101, an outlet section 102, and a transition section 130 located between the inlet section 101 and the outlet section 102; a first channel section 310 is formed between the inlet section 101 and the rotating assembly 200; a second channel section 320 is formed between the transition section 130 and the rotating assembly 200; and a third channel section 330 is formed between the outlet section 102 and the rotating assembly 200.
[0087] The multi-segment design of the shell 100 helps to construct a curved expansion channel 300 structure, which in turn helps to form a multi-level parabolic structure, enabling the gradual release of pressure.
[0088] For example, the expansion channel 300, the primary expansion component 400, and the secondary expansion component 500 can be constructed into five parabolic structures to achieve multi-stage pressure release.
[0089] It should also be noted that, in some embodiments, the pressure surface profile equation of the first-stage stationary blade ring is:
[0090] Y p =f(ξ)=a0+a1ξ+a2ξ 2 +a3ξ 3 +a4ξ 4 +a5ξ 5
[0091] Among them, Y p ξ represents the coordinates of the pressure surface at a specific location. a0 to a5 represent the specific parameters that determine the blade profile; the selection of these coefficients directly determines the shape characteristics of the pressure surface, such as thickness, curvature, and slope. ξ represents the dimensionless coordinate values that gradually increase along the blade surface from the root to the tip.
[0092] In some embodiments, the suction surface shape equation of the first-stage stationary blade ring is:
[0093] Y s =g(ξ)=b0+b1ξ+b2ξ 2 +b3ξ 3 +b4ξ 4 +b5ξ 5
[0094] Among them, Y s ξ represents the coordinates of the suction surface at a specific location; the selection of coefficients b0 to b5 directly determines the shape characteristics of the suction surface, such as thickness, curvature, and slope of the curve; ξ is a dimensionless coordinate along the length of the blade, varying from the blade root to the blade tip.
[0095] The aforementioned fifth-order polynomial function can be used to design and optimize blade geometry to meet specific hydrodynamic requirements. By adjusting these coefficients, the blade shape can be fine-tuned to achieve optimal aerodynamic performance. For example, changing the concavity and convexity of the curve, controlling the sharpness of the edges, or optimizing the blade inlet and outlet angles can directly affect the efficiency and noise level of gas flow.
[0096] It should be noted that the blade surface equation of the secondary expansion assembly is similar to that of the blade in the primary expansion assembly, and will not be repeated here.
[0097] The surface equations of the primary and secondary expansion components are given below as examples:
[0098] Equation of pressure surface of first-stage stationary blade ring:
[0099] Y = 9 × 10 -6 ξ 5 -9×10 -4 ξ 4 +0.0354ξ 3 -0.6966ξ 2 +7.4011ξ-1.9013;
[0100] First-stage blade pressure surface equation:
[0101] Y = 2 × 10 -6 ξ 5 -5×10 -4 ξ 4 +0.0587ξ 3 -3.0531ξ 2 +74.498ξ-646.43;
[0102] Equation of suction surface of first-stage stationary blade ring:
[0103] Y = 3 × 10 -6 ξ 5 -6×10 -4 ξ 4+0.0365ξ 3 -0.9629ξ 2 +12.095ξ-17.254;
[0104] Equation of suction surface of second-stage moving blade:
[0105] Y = -2 × 10 -6 ξ 5 +5×10 -4 ξ 4 -0.0466ξ 3 +2.2078ξ 2 -55.396ξ+612.76.
[0106] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0107] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.
[0108] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein.
[0109] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.
[0110] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
Claims
1. A gas wellhead expander, characterized in that, include: A housing having a flow cavity inside, the housing being provided with an inlet and an outlet communicating with the flow cavity; A rotating assembly is inserted through the housing and located within the flow cavity, forming an expansion channel between the rotating assembly and the inner wall of the housing; A primary expansion assembly and a secondary expansion assembly are spaced apart within the expansion channel along the axial direction of the rotating assembly, so that the flowing medium entering from the inlet passes through the primary expansion assembly and the secondary expansion assembly in sequence and is discharged from the outlet.
2. The gas wellhead expander according to claim 1, characterized in that, The rotating assembly has a rotation axis, and the expansion channel includes a first channel segment, a second channel segment, and a third channel segment connected in sequence in the direction from the inlet to the outlet; The first channel segment is curved and gradually moves away from the axis of rotation in the direction from the inlet to the outlet; The second channel segment is curved and gradually approaches the axis of rotation in the direction from inlet to outlet; The third channel segment is curved and gradually moves away from the axis of rotation in the direction from the inlet to the outlet.
3. The gas wellhead expander according to claim 2, characterized in that, The primary expansion component is disposed within the first channel segment; The secondary expansion component is disposed within the third channel segment.
4. The gas wellhead expander according to claim 1, characterized in that, The primary expansion assembly includes a primary stationary impeller and a primary moving impeller; The primary stationary impeller is disposed on the housing, and the primary moving impeller is disposed on the rotating assembly. The primary moving impeller is located circumferentially outside the primary stationary impeller, and the primary stationary impeller and the primary moving impeller are rotatably coupled.
5. The gas wellhead expander according to claim 1, characterized in that, The secondary expansion assembly includes a secondary stationary impeller and a secondary moving impeller; The secondary stationary impeller is disposed on the housing, and the secondary moving impeller is disposed on the rotating assembly. The secondary moving impeller is located circumferentially outside the secondary stationary impeller, and the secondary stationary impeller and the secondary moving impeller are rotatably coupled.
6. The gas wellhead expander according to claim 1, characterized in that, The rotating assembly includes a rotating shaft and a radial bearing disposed on the rotating shaft, wherein a power groove is provided on the inner wall of the bearing bush of the radial bearing.
7. The gas wellhead expander according to claim 6, characterized in that, The rotating assembly also includes a thrust bearing disposed on the rotating shaft. The thrust bearing includes a bushing and a thrust block located inside the bushing. A left helical groove and a right helical groove are respectively disposed on the two end faces of the thrust block.
8. The gas wellhead expander according to claim 2, characterized in that, The housing includes an inlet section, an outlet section, and a transition section located between the inlet section and the outlet section; The first channel segment is formed between the inlet section and the rotating assembly; The second channel segment is formed between the transition section and the rotating assembly; The third channel segment is formed between the outlet section and the rotating assembly.
9. The gas wellhead expander according to any one of claims 1 to 8, characterized in that, The pressure profile equation of the first-stage stationary blade ring is: Y p =f(ξ)=a0+a1ξ+a2ξ 2 +a3ξ 3 +a4ξ 4 +a5ξ 5 Among them, Y p ξ is the coordinate value of the pressure surface at a specific location; a0 to a5 are the specific parameters that determine the specific blade profile; ξ is the dimensionless coordinate value.
10. The gas wellhead expander according to any one of claims 1 to 8, characterized in that, The suction surface shape equation of the first-stage stationary blade ring is: Y s =g(ξ)=b0+b1ξ+b2ξ 2 +b3ξ 3 +b4ξ 4 +b5ξ 5 Among them, Y s ξ represents the coordinates of the suction surface at a specific location; b0 to b5 are the specific parameters that determine the specific blade profile; ξ is the dimensionless coordinate value.