Steam turbine and cracking gas system for cracking gas device

Abstract

The present application provides a steam turbine and a cracking gas system for a cracking gas device, which relates to the technical field of steam turbines. The overall structure adopts a single-cylinder and single-exhaust arrangement, and the rotor system is supported by radial bearings of various types and sizes to ensure that it has sufficient avoidance intervals, excellent vibration performance and anti-interference performance. A full-circle steam inlet structure is adopted to optimize the steam inlet flow channel, strengthen the structural strength and rigidity, and design the flow as a reflux structure, which effectively reduces the axial thrust of the steam turbine; a high-temperature side guide structure is adopted to prevent the change of cold and hot clearances caused by high-temperature operating environments and sudden changes in operating conditions, and solve the problem of turbine cylinder centering; a detachable split-valve regulating valve fast closing valve structure is adopted to simplify the installation and disassembly and inspection methods; and the exhaust cylinder rigidity and thermal stability are optimized by multi-point support. Thus, a single-unit industrial steam turbine with a capacity of 100MW can drive an ethylene cracking gas compressor unit with an annual output of 1.5 million tons, ensuring the requirements of various operating conditions and speed changes of the compressor unit.

Description

Technical Field

[0001] The present application relates to the technical field of steam turbines, and in particular to a steam turbine and a cracking gas system for a cracking gas device. Background Art

[0002] In the cracking gas system of the prior art, the cold and hot deformation of the steam turbine is large during variable load conditions and start-up and shutdown, especially the axial expansion and lateral runout generated on the high-temperature steam inlet side. The axial expansion causes a large change in the relative position between the main cylinder and the bearing seat, reducing the reliability of the rotor rotation; and the lateral runout will make it difficult to align the steam turbine, resulting in collisions between the moving and static parts, leading to safety accidents.

[0003] In the prior art, the operating speed range of the turbine rotor driving the compressor project is usually 70% to 105% of the rated speed, which requires the dynamic characteristics of the rotor system to have a wide avoidance band. Compared with the steam turbine driving the generator, the vibration assessment standard for the steam turbine driving the compressor is much more stringent. Factors such as sudden changes in unit load caused by process fluid switching, large fluctuations in extraction pressure, changes in downstream equipment demand for extraction volume, and sudden jumps in extraction volume caused by downstream equipment failures will all produce transient impacts on the turbine rotor. It is estimated that the loss caused by a single shutdown of a 1.5 million tons / year ethylene project will reach tens of millions of yuan.

[0004] Due to the complex and changeable operating conditions of the unit, the extraction steam volume varies in a large range, accounting for 0 to 90% of the steam inlet volume, and the thrust of the two sections of flow before and after the extraction point affects each other. In order to reduce the extraction steam pressure protection shutdown rate caused by abnormal reasons, it is necessary to widen the extraction steam pressure fluctuation range, especially for the 1.5 million tons / year ethylene project, the extraction steam pressure fluctuation range is widened to 2.5 to 4.5 MPa. However, the single-cylinder downstream structure in the existing technology is difficult to solve the complex thrust problem of the unit.

[0005] In addition, large-scale high-temperature and high-pressure units usually use an integral steam inlet regulating valve fast-closing valve structure, which reduces the qualified rate of casting parts, increases casting costs, and has high disassembly and inspection costs. In addition, the large condensing steam turbine of large-scale high-temperature and high-pressure units has a large exhaust area, a large unit volume flow, and a low exhaust pressure. The exhaust cylinder and the rear bearing seat are greatly affected by vacuum suction. Summary of the invention

[0006] In view of this, the present application provides a steam turbine and a cracking gas system for a cracking gas device, with the aim of solving, to a certain extent, the technical problem in the prior art that the axial expansion generated on the high-temperature steam inlet side of the steam turbine causes a significant change in the relative position between the rotor and the bearing seat, thereby reducing the reliability of the rotor rotation.

[0007] The present application also solves to a certain extent the technical problem in the prior art that the lateral deflection of the steam turbine makes it difficult to center the steam turbine, causing collisions between moving and static parts, leading to safety accidents.

[0008] The present application also solves to a certain extent the technical problem in the prior art that the rotor system of the steam turbine is difficult to meet the vibration assessment standard and does not have the ability to resist interference.

[0009] The present application also solves to a certain extent the technical problem of complex unit thrust existing in the single-cylinder downstream structure of the steam turbine in the prior art.

[0010] The present application also solves to a certain extent the technical problems in the prior art of using an integral steam inlet regulating valve quick-closing valve structure, which reduces the qualified rate of casting parts, increases casting costs, and has high disassembly and inspection costs.

[0011] The present application also solves the technical problem in the prior art that the exhaust cylinder and the rear bearing seat are greatly affected by the vacuum suction force to a certain extent.

[0012] In a first aspect, the present application provides a steam turbine for a cracking gas device, comprising:

[0013] The main and exhaust cylinders are located next to each other;

[0014] A rotor is rotatably disposed inside the main cylinder and the exhaust cylinder, wherein the first end and the second end of the rotor are supported by a first bearing seat and a second bearing seat respectively; the steam turbine for the cracking gas device also includes:

[0015] A first guide portion is formed on the first bearing seat, wherein the first guide portion is formed with a first accommodation portion;

[0016] a second guide portion formed on the master cylinder, the second guide portion being formed with a second accommodation portion;

[0017] an inserting member disposed in the first accommodating portion and the second accommodating portion, wherein an outer side of the inserting member contacts an inner side of the first accommodating portion;

[0018] A first spacing member is disposed between an outer side of the insertion member and an inner side of the second receiving portion, and the outer side of the insertion member forces the first spacing member against the inner side of the second receiving portion.

[0019] Preferably, the number of the second guide portions is 2n+1, the number of the first guide portions is 2n+2, and n is a natural number and n≥1;

[0020] The first guide portions and the second guide portions are arranged alternately with each other, and the (n+1)th second guide portion is symmetrical with respect to the axis of the master cylinder.

[0021] Preferably, the steam turbine for the cracking gas device further comprises:

[0022] A second spacing member and a third spacing member are arranged on the first guide portion between two adjacent second guide portions, and the second spacing member and the third spacing member are respectively arranged on two side portions of the first guide portion facing the second guide portion;

[0023] The second spacing member is disposed on a first side portion of the second guide portion close to the axis of the master cylinder, and the third spacing member is disposed on a second side portion of the second guide portion away from the axis of the master cylinder;

[0024] A first reserved gap is formed between the second spacing member and the first guide portion, and a second reserved gap is formed between the third spacing member and the second guide portion, and the first reserved gap is larger than the second reserved gap.

[0025] Preferably, the steam turbine for the cracking gas device is used for a 1.5 million tons / year ethylene cracking gas device;

[0026] The master cylinder also includes a steam inlet chamber arranged inside the master cylinder, and two steam interfaces are respectively arranged at the upper end and the lower end of the steam inlet chamber, so that the steam inlet chamber can take in steam all around through the steam interfaces; the steam inlet chamber is a reflux structure.

[0027] Preferably, the steam turbine for the cracking gas device also includes a quick-closing valve and a regulating steam valve arranged on the main cylinder, the valve housings of the quick-closing valve and the regulating steam valve are integrally formed, and the valve housings of the quick-closing valve and the regulating steam valve are detachably connected to the main cylinder.

[0028] Preferably, the master cylinder also includes a steam inlet interface, which is connected to two steam interfaces at the upper end or the lower end of the steam inlet chamber, and the valve shells of the quick-closing valve and the regulating steam valve are connected to the steam inlet interface, so that the regulating steam valve can adjust the flow rate of steam flowing through the steam interface.

[0029] Preferably, the main cylinder further comprises a first guide vane holding ring and a second guide vane holding ring, and the exhaust cylinder further comprises a third guide vane holding ring;

[0030] The steam inlet chamber is equipped with 1-stage regulating stage straight blades and 4-stage pressure stage straight blades, the first guide vane holding ring is equipped with 6-stage pressure stage straight blades, the second guide vane holding ring is equipped with 16-stage pressure stage straight blades, and the third guide vane holding ring is equipped with 3-stage twisted blades.

[0031] Preferably, the first bearing seat is further provided with a first adjusting ring, and the first adjusting ring matches with the outer ring of the bearing for supporting the rotation of the rotor;

[0032] The second bearing seat is also equipped with a second adjustment ring, and the second adjustment ring cooperates with the outer ring of the bearing used to support the rotation of the rotor. Preferably, the steam turbine for the cracking gas device also includes:

[0033] A base, disposed at the lower end of the second bearing seat;

[0034] A basic chassis, used for mounting the base;

[0035] The exhaust cylinder is further formed with an exhaust cylinder protrusion, and the exhaust cylinder protrusion is mounted on the base chassis so that the axial dead points of the exhaust cylinder and the master cylinder fall on the exhaust cylinder protrusion and the lateral dead points of the exhaust cylinder and the master cylinder fall on the geometric center of the exhaust cylinder protrusion;

[0036] The lower end of the exhaust cylinder is connected to the lower end of the second bearing seat.

[0037] In a second aspect, the present application further provides a cracking gas system, comprising the steam turbine for a cracking gas device as described above, and also comprising a cracking gas device, wherein the steam turbine for the cracking gas device provides power for the cracking gas device.

[0038] The present application installs the insertion component in the first accommodating portion and the second accommodating portion through the first spacing component, so that when the second guide portion expands axially with the main cylinder, it can drive the first guide portion through the insertion component and then drive the first bearing seat and the main cylinder to move synchronously, ensuring that the relative positions of the two remain unchanged. To a certain extent, it solves the technical problem in the prior art that the axial expansion generated on the high-temperature steam inlet side of the turbine causes a large change in the relative position between the rotor and the bearing seat, thereby reducing the reliability of the rotor rotation.

[0039] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 A schematic diagram showing an assembly drawing of a steam turbine for a cracked gas plant;

[0042] Figure 2 Shows Figure 1A schematic diagram of the view in the direction of A;

[0043] Figure 3 A schematic diagram showing a first perspective view of a steam inlet chamber of a steam turbine for a cracking gas plant;

[0044] Figure 4 A schematic diagram showing a second perspective of a steam inlet chamber of a steam turbine for a cracking gas plant;

[0045] Figure 5 A schematic diagram showing the cooperation between the first guide portion and the second guide portion of a steam turbine for a cracking gas device is shown;

[0046] Figure 6 Shows Figure 5 A schematic diagram of a cross-sectional view taken along the CC direction;

[0047] Figure 7 Shows Figure 5 A schematic diagram of a cross-sectional view taken along the DD direction;

[0048] Figure 8 A schematic diagram showing the installation of an exhaust cylinder of a steam turbine for a cracking gas plant.

[0049] Reference numerals:

[0050] 1-first bearing seat; 2-thrust bearing; 3-first radial bearing; 4-first adjusting ring; 5-first steam seal; 6-main cylinder; 7-steam inlet chamber; 8-valve regulating quick closing valve; 9-overflow outlet; 10-first guide vane holding ring; 11-second steam seal; 12-second guide vane holding ring; 13-third guide vane holding ring; 14-exhaust cylinder; 15-third steam seal; 16-turning device; 17-second adjusting ring; 18-second radial bearing; 19 -second bearing seat; 20-rotor; 21-overflow inlet; 22-steam extraction interface; 23-steam inlet interface; 24-first guide portion; 25-second guide portion; 26-insertion member; 27-first spacing member; 28-third spacing member; 29-second spacing member; 30-exhaust cylinder protrusion; 31-adjusting lap joint; 32-base; 33-axial dead point; a-steam interface; b-first reserved gap; c-second reserved gap. DETAILED DESCRIPTION

[0051] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0052] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0053] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0054] In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0055] Figure 1 A schematic diagram showing an assembly drawing of a steam turbine for a cracked gas plant; Figure 2 Shows Figure 1 A schematic diagram of the view in the direction of A; Figure 3 A schematic diagram showing a first perspective view of a steam inlet chamber of a steam turbine for a cracking gas plant; Figure 4 A schematic diagram showing a second perspective of a steam inlet chamber of a steam turbine for a cracking gas plant; Figure 5 A schematic diagram showing the cooperation between the first guide portion and the second guide portion of a steam turbine for a cracking gas device is shown; Figure 6 Shows Figure 5 A schematic diagram of a cross-sectional view taken along CC direction; Figure 7 Shows Figure 5 A schematic diagram of a cross-sectional view taken along the DD direction; Figure 8 A schematic diagram showing the installation of an exhaust cylinder of a steam turbine for a cracking gas plant.

[0056] See also Figures 1 to 8 The steam turbine for cracking gas device provided in this embodiment comprises: a first bearing seat, a main cylinder, a regulating valve and a quick closing valve, an exhaust cylinder, a turning device, a second bearing seat, a rotor and a base. The connection relationship and working principle of the above components will be described in detail below.

[0057] In this embodiment, the main cylinder 6 and the exhaust cylinder 14 are arranged adjacent to each other, and the exhaust cylinder 14 is connected to the main cylinder 6 through a vertical flange. In the prior art, large-scale steam turbine units usually adopt a double-cylinder structure, but the double-cylinder structure will increase more equipment failure points compared to the single-cylinder structure, which is contrary to the system design principles of related projects in the petrochemical field. Therefore, the steam turbine used for the cracking gas device in this embodiment is a single-cylinder single-exhaust setting, and the single-cylinder single-exhaust arrangement will make the bearing span of the unit longer, which will have a certain degree of adverse effect on the vibration of the unit. In response to this adverse effect, this embodiment starts with improving the bearing setting, and its setting method will be described in detail below.

[0058] In this embodiment, the rotor 20 is arranged inside the main cylinder 6 and the exhaust cylinder 14, and the rotation of the rotor 20 is supported by the bearings installed inside the first bearing seat 1 and the second bearing seat 19. The first bearing seat 1 and the second bearing seat 19 are respectively provided with a first radial bearing 3 and a second radial bearing 18 that bear the radial load during the rotation of the rotor 20. In this embodiment, the first radial bearing 3 and the second radial bearing 18 can be installed on the corresponding bearing seat through the first adjustment ring 4 and the second adjustment ring 17.

[0059] In this embodiment, the first radial bearing 3 and the first adjustment ring 4 are taken as examples to illustrate the above installation method. The inner ring of the first radial bearing 3 can be sleeved on the outer side of the first axial end of the rotor 20 by means of interference fit, and the first adjustment ring 4 is arranged in the first bearing seat 1, and the first adjustment ring 4 can be sleeved on the outer ring of the first radial bearing 3 by means of interference fit. Since the above bearing seat is usually a welded part, the size of the position where the bearing is accommodated is usually fixed. By adding an adjustment ring, the adjustment ring with different inner diameters can be replaced to adapt to radial bearings with different outer diameters. This arrangement ensures good interchangeability during the assembly process and increases the applicability of the bearing. Therefore, the rotor 20 has sufficient avoidance intervals, excellent vibration performance and anti-interference performance under various types and sizes of radial support bearings, which can meet the vibration assessment standards of the steam turbine and greatly improve the vibration performance and rotation reliability of the rotor 20.

[0060] In addition, a thrust bearing 2 is also housed inside the first bearing seat 1 , and the thrust bearing 2 is used to prevent the rotor 20 from axial movement during the rotation process.

[0061] In this embodiment, a first steam seal 5 is arranged between the first axial end of the rotor 20 and the main cylinder 6, and a third steam seal 15 is arranged between the second axial end of the rotor 20 and the exhaust cylinder 14. A second steam seal 11 is also arranged inside the main cylinder 6. The sealing method of these steam seals is the labyrinth seal commonly seen in the art. The arrangement of the steam seals ensures the relative stability of the steam pressure inside each working section of the main cylinder 6 and the exhaust cylinder 14.

[0062] In this embodiment, the main cylinder 6 is also formed with a steam extraction interface 22, an overflow inlet 21 and an overflow outlet 9. The steam extraction interface 22 is used to extract steam from the inside of the main cylinder 6. The pipeline of the steam extraction interface 22 and the pipeline of the steam inlet chamber 7 described below are respectively provided with differential pressure protection interfaces. By setting a pressure measuring element on the differential pressure protection interface, remote monitoring of the steam extraction interface 22 and the steam inlet chamber 7 is realized. When the differential pressure between the two exceeds a predetermined value, the operator can timely control the steam extraction amount and other related measures to ensure safe and stable operation of the steam turbine. The overflow outlet 9 is connected to the overflow inlet 21 through a pipeline to introduce steam into the chamber behind the second steam seal 11.

[0063] In this embodiment, the rotor 20 can be a whole forged drum rotor. The interior of the above-mentioned main cylinder 6 also includes a steam inlet chamber 7, a first guide vane holding ring 10 (that is, a high-pressure guide vane holding ring in this field), and a second guide vane holding ring 12 (that is, a medium-pressure guide vane holding ring in this field). The interior of the exhaust cylinder 14 also includes a third guide vane holding ring 13 (that is, a low-pressure guide vane holding ring in this field). The rotor 20 rotates inside the steam inlet chamber 7 and these guide vane holding rings.

[0064] In this embodiment, the regulating stage of the steam turbine used for the cracking gas device can be an impulse design, and the pressure stage can be a reaction design. In this embodiment, the steam turbine used for the cracking gas device is used for a 1.5 million tons / year ethylene cracking gas device, and its single-unit power can reach 100MW. Therefore, preferably, the steam inlet chamber 7 can be equipped with 1-stage regulating stage straight blades and 4-stage pressure stage straight blades, the first guide vane holding ring 10 can be equipped with 6-stage pressure stage straight blades, and the second guide vane holding ring 12 can be equipped with 16-stage pressure stage straight blades. It is also preferred that they can be divided into two second guide vane holding rings 12, and the third guide vane holding ring 13 is equipped with 3-stage twisted blades (i.e., low-pressure twisted blades in this field) to meet the power requirements of the steam turbine used for the cracking gas device.

[0065] It should be noted that the above-mentioned setting methods of the regulating stage and the pressure stage are common settings in the prior art, and the installation method of the guide vane holding ring also belongs to the prior art. Only the specific blade installation levels are given here as a specific embodiment, and the rest will not be repeated.

[0066] In addition, in this embodiment, the steam inlet chamber 7 adopts a 360-degree full-circle steam inlet reflux type two-half inner cylinder structure, i.e., an upper inner cylinder and a lower inner cylinder, the two half inner cylinders are connected by bolts, and the upper and lower inner cylinders of the steam inlet chamber 7 are symmetrically provided with two steam interfaces a, and the two steam interfaces a formed in the lower inner cylinder are connected with the steam inlet interface 23 on the main cylinder 6. The working steam entering the steam turbine for the cracking gas device comes from the boiler, and its fresh steam parameters are relatively high, usually: temperature 510-540°C, fresh steam pressure 11-12MPa, and extraction pressure 2.5-4.5Mpa. This setting mode is suitable for large flow steam inflow, and can effectively solve the problem of insufficient strength of the steam inlet chamber 7 and the main cylinder 6 when the fresh steam parameters are relatively high. At the same time, the through-flow is designed as a reflux structure, which can effectively reduce the axial thrust of the steam turbine for the cracking gas device, ensure the safety and stability of the unit operation, and greatly reduce the installation and disassembly cost of the steam inlet chamber compared with the overall inner cylinder structure.

[0067] In addition, due to the adoption of the above-mentioned reflux inner cylinder structure, the thrust of the reverse flow of steam is utilized to balance the large changes in thrust caused by changes in operating conditions, and the complex and changeable steam thrust problem is effectively solved.

[0068] In this embodiment, the valve-regulating quick-closing valve 8 is obtained by integrally forming the valve housing of the quick-closing valve and the valve housing of the regulating steam valve (for example, by casting), and can be connected to the waist-shaped flange joint surface on the upper end face of the main cylinder 6 by bolts to achieve a detachable connection with the main cylinder 6. The valve-regulating quick-closing valve 8 is formed with two valve body interfaces, which are connected to the steam inlet interface 23 on the main cylinder 6 through a pipeline, and the steam flow is controlled by the valve disc of the regulating steam valve, or the steam supply is shut down.

[0069] The one-piece molding of the valve housings of the two valves reduces the manpower consumed in installation, disassembly and maintenance, saving costs. At the same time, the one-piece molding of the valve housings also improves safety. In addition, since the valve housings of the two valves are detachably connected to the main cylinder 6, compared with the integral setting in the prior art, the qualified rate of the casting parts is improved, the casting cost is reduced, and the maintenance cost is also reduced.

[0070] In this embodiment, the lower end of the second bearing seat 19 can be welded to the lower end of the exhaust cylinder 14 as a whole, and a base 32 can be provided at the lower end of the second bearing seat 19, and the base 32 is installed on the basic chassis (not shown in the figure) to ensure stable support for the exhaust cylinder 14. The exhaust cylinder 14 can also be formed with a protrusion (i.e., "cat's claw" as referred to in the art). In this embodiment, two protrusions are formed symmetrically with the axis of the exhaust cylinder 14, and the exhaust cylinder protrusion 30 is installed on the basic chassis, so that the axial dead point 33 of the exhaust cylinder 14 and the main cylinder 6 falls on the exhaust cylinder protrusion 30, and the lateral dead point of the exhaust cylinder 14 and the main cylinder 6 falls at the geometric center of the exhaust cylinder protrusion 30. This is because the above-mentioned dead point remains stationary when the exhaust cylinder 14 and the main cylinder 6 expand along the corresponding direction, so the support provided here is also stable and unchanged, thus ensuring the stability of the exhaust cylinder protrusion 30 supporting the exhaust cylinder 14.

[0071] Through the support of the above-mentioned exhaust cylinder protrusion 30 and the base 32, the exhaust cylinder 14 is supported at multiple points, which effectively improves the stiffness of the exhaust cylinder 14 and the second bearing seat 19, improves the thermal stability of the exhaust cylinder 14, and increases the stability of the exhaust cylinder 14 and the second bearing seat 19 during operation. In addition, during the operation of the exhaust cylinder 14, the internal air pressure is often lower than the external atmospheric pressure, which makes the second bearing seat 19 withstand a larger vacuum suction due to this pressure difference. The above-mentioned multi-point support setting also solves the problem of deformation of the second bearing seat 19 under vacuum suction.

[0072] In the present embodiment, since the temperature on the side of the main cylinder 6 into which the fresh steam flows is relatively high, the unit is greatly deformed in hot and cold states during variable load conditions and start-up and shutdown. In particular, the axial expansion on the high-temperature steam inlet side causes a significant change in the relative position between the rotor 20 and the bearing seat, reducing the rotation reliability of the rotor 20. The lateral runout will make it difficult to center the turbine, resulting in friction between the moving and static parts, leading to safety accidents. Therefore, for the first bearing seat 1 close to the high-temperature steam inlet side, the present embodiment adopts the following settings, which will be described in detail below.

[0073] In this embodiment, the master cylinder 6 is also formed with a protrusion similar to the exhaust cylinder protrusion 30 described above, and is overlapped on the upper end of the first bearing seat 1 to support the master cylinder 6.

[0074] In this embodiment, the lower end of the first bearing seat 1 can be moved along the axial direction of the master cylinder 6 by means of tracks or the like. The first bearing seat 1 is also formed with a first guide portion 24, and the first guide portion 24 is formed with a first accommodating portion. The master cylinder 6 is also formed with a second guide portion 25, and the second guide portion 25 is formed with a second accommodating portion. An insert member 26 is arranged in the above-mentioned first accommodating portion and the second accommodating portion. A first spacing member 27 (the first spacing member 27 is preferably a vertical key) is arranged between the outer side of the insert member 26 and the inner side of the second accommodating portion. The outer side of the insert member 26 forces the first spacing member 27 to press against the inner side of the second accommodating portion.

[0075] In this embodiment, the second accommodating portion may be a groove portion, and the first accommodating portion may be a hole portion. Preferably, the extension directions of the groove portion and the hole portion are both perpendicular to the axial direction of the master cylinder 6, and in a preferred arrangement, the insertion member 26 and the inner side of the hole portion are in contact with each other.

[0076] In the present embodiment, preferably, the insertion member 26 may be columnar, and its outer side may have three planes to facilitate cooperation with the first spacing member 27. In the present embodiment, the shape of the first spacing member 27 may be a member with an "L"-shaped cross-section. The insertion member 26 may be inserted into the above-mentioned first accommodating portion and the second accommodating portion, and then one end of the first spacing member 27 is arranged between the outer side of the insertion member 26 and the inner side of the second accommodating portion, and the other end is fixed to the insertion member 26 by screws. In the present embodiment, two of the above-mentioned first spacing members 27 are arranged between the outer side of the above-mentioned insertion member 26 and the inner side of the second accommodating portion in this way, which is equivalent to fixing the insertion member 26 to the second accommodating portion.

[0077] The above fixing method is easy to disassemble, such as Figure 5 As shown, when the master cylinder 6 expands along the axial direction, the second guide portion 25 moves to the left side in the figure, and the insertion member 26 will press against the inner side of the first accommodating portion, thereby forcing the first guide portion 24 to move together to ensure that the relative position between the first bearing seat 1 and the master cylinder 6 no longer changes.

[0078] The above arrangement solves the problem when the master cylinder 6 expands along the axial direction. As for the lateral deflection of the master cylinder 6, further, the present embodiment has the following arrangement.

[0079] In this embodiment, the number of the first guide portions 24 is 2n+2, and the number of the second guide portions 25 is 2n+1, wherein n is a natural number and n≥1. The first guide portions 24 and the second guide portions 25 can be arranged alternately with each other, and the n+1th second guide portion 25 is symmetrical about the axis of the master cylinder 6. Under this arrangement, there will inevitably be a first guide portion 24 located between two adjacent second guide portions 25. On this basis, a second spacing member 29 and a third spacing member 28 can also be provided, both of which are provided on the first guide portion 24 located between two adjacent second guide portions 25. The second spacing member 29 and the third spacing member 28 can be respectively arranged on the two sides of the first guide portion 24 facing the second guide portion 25, the second spacing member 29 can be arranged on the first side of the second guide portion 25 close to the axis of the master cylinder 6, the third spacing member 28 can be arranged on the second side of the second guide portion 25 away from the axis of the master cylinder 6, a first reserved gap b can be formed between the second spacing member 29 and the first guide portion 24, a second reserved gap c can be formed between the third spacing member 28 and the second guide portion 25, and the first reserved gap b is larger than the second reserved gap c.

[0080] In this embodiment, preferably, when n=1, that is, the number of the first guide portions 24 is four, the number of the second guide portions 25 is three, and the second guide portion 25 located in the middle (i.e. Figure 5 The second second guide portion 25 from top to bottom in the middle is symmetrical about the axis of the master cylinder 6 (the first guide portion 24 and the second guide portion 25 staggered with each other are also symmetrical about the axis of the master cylinder 6), and the first guide portions 24 on both sides of the second guide portion 25 are respectively provided with two sets of second spacing members 29 and third spacing members 28 in the above-mentioned arrangement manner, and are respectively provided at the positions located at Figure 5 The upper second guide portion 25 and the lower second guide portion 25 shown in FIG. 1 are provided with two sets of combinations of the first spacing member 27 , the insertion member 26 , the first accommodation portion and the second accommodation portion.

[0081] Since the first reserved gap b is larger than the second reserved gap c, when the master cylinder 6 sways laterally, the third spacing member 28 always contacts the second guide portion 25 first. Figure 5As shown in the figure, for example, when the master cylinder 6 deflects upward as shown in the figure, the third spacing member 28 located at the bottom of the figure first abuts against the second guide portion 25 below it, limiting the continued deflection of the master cylinder 6. When the master cylinder 6 deflects downward as shown in the figure, the third spacing member 28 located at the top of the figure first abuts against the second guide portion 25 above it, limiting the continued deflection of the master cylinder 6. In this embodiment, the second guide portion 25 close to the axis of the master cylinder 6 is heated to a greater extent and its own expansion is also greater. Therefore, the purpose of the first reserved gap b being greater than the second reserved gap c is to reserve a larger space for the second guide portion 25 with a larger self-expansion to expand.

[0082] According to the features described above, it can be known that when the second guide portion 25 expands itself so that the first reserved gap b is equal to the second reserved gap c, the second spacing member 29 will participate in limiting the lateral swing of the master cylinder 6 together with the third spacing member 28. When the first reserved gap b is smaller than the second reserved gap c, the second spacing member 29 will replace the third spacing member 28 to limit the lateral swing of the master cylinder 6. The process is opposite to the limiting process of the third spacing member 28, which will not be repeated here.

[0083] In addition, since the second guide portion 25 will move laterally during lateral deflection, a lubricant may be further applied between the first spacing member 27 and the second guide portion 25 to facilitate the second guide portion 25 to move relative to the first spacing member 27 within a small range.

[0084] It should be noted that:

[0085] Firstly, the first guide portion 24 and the second guide portion 25 are symmetrically arranged about the axis of the master cylinder 6 in order to symmetrically limit the lateral deflection of the master cylinder 6 .

[0086] Secondly, the value of n is not infinite, but is a limit value that can be achieved by technical personnel in this field according to actual production needs.

[0087] Third, when the value of n is greater than 1, the second spacing member 29 and the third spacing member 28 can still be installed according to the above-mentioned setting method, and for the insertion member 26 and the first spacing member 27, only the second accommodating portion can be set on the second guide portion 25 on both sides, and the first accommodating portion can be set on the first guide portion 24 on both sides of the two second guide portions 25 to install the insertion member 26 and the first spacing member 27. This is because, under this installation method, it is beneficial for the structure to have good assembly performance, while avoiding the opening of too many accommodating portions to reduce the rigidity of the first guide portion 24 and the second guide portion 25.

[0088] In addition, an adjusting member is provided on the base 32, and an adjusting lap member 31 is provided at the lower end of the exhaust cylinder 14. The matching manner of the adjusting member and the adjusting lap member 31 is similar to the setting manner of the above-mentioned first guide portion 24, the second guide portion 25, the second spacer member 29 and the third spacer member 28, so as to center the exhaust cylinder 14 with the second bearing seat 19, which will not be repeated here.

[0089] In addition, in this embodiment, the steam turbine for the cracking gas device further includes a cranking device 16 disposed at the exhaust cylinder 14, which is used for cranking after the steam turbine for the cracking gas device is shut down or before it is started.

[0090] This embodiment also provides a cracking gas system, including the steam turbine for the cracking gas device as described above, and also including the cracking gas device. The beneficial effects of the cracking gas system also include the above beneficial effects, which will not be repeated here.

[0091] The above description is only a preferred embodiment of the present application, and does not limit the protection scope of the present application. All equivalent structural changes made by using the contents of the present application specification and drawings under the innovative concept of the present application, or direct / indirect application in other related technical fields are included in the protection scope of the present application.

Claims

1. A steam turbine for a cracking gas device, comprising: The main and exhaust cylinders are located next to each other; A rotor is rotatably disposed inside the main cylinder and the exhaust cylinder, wherein the first end and the second end of the rotor are supported by a first bearing seat and a second bearing seat respectively; characterized in that the steam turbine for the cracking gas device further comprises: A first guide portion is formed on the first bearing seat, wherein the first guide portion is formed with a first accommodation portion; a second guide portion formed on the master cylinder, the second guide portion being formed with a second accommodation portion; an inserting member disposed in the first accommodating portion and the second accommodating portion, wherein an outer side of the inserting member contacts an inner side of the first accommodating portion; a first spacing member disposed between an outer side of the insertion member and an inner side of the second receiving portion, the outer side of the insertion member forcing the first spacing member against the inner side of the second receiving portion; Also includes: A base, disposed at the lower end of the second bearing seat; A basic chassis, used for mounting the base; The exhaust cylinder is further formed with an exhaust cylinder protrusion, and the exhaust cylinder protrusion is mounted on the base chassis so that the axial dead points of the exhaust cylinder and the master cylinder fall at the exhaust cylinder protrusion and the lateral dead points of the exhaust cylinder and the master cylinder fall at the geometric center of the exhaust cylinder protrusion; The lower end of the exhaust cylinder is connected to the lower end of the second bearing seat; Wherein, the exhaust cylinder is formed with two exhaust cylinder protrusions symmetrically about the exhaust cylinder axis; Among them, the exhaust cylinder protrusion and the base form multi-point support for the exhaust cylinder, so that when the internal air pressure of the exhaust cylinder is lower than the external atmospheric pressure, the deformation of the second bearing seat caused by the vacuum suction caused by the pressure difference between the internal air pressure of the exhaust cylinder and the external atmospheric pressure can be alleviated through the multi-point support.

2. The steam turbine for a cracking gas device according to claim 1, characterized in that: The number of the second guide portions is 2n+1, the number of the first guide portions is 2n+2, and n is a natural number and n≥1; The first guide portions and the second guide portions are arranged alternately with each other, and the (n+1)th second guide portion is symmetrical with respect to the axis of the master cylinder.

3. The steam turbine for a cracking gas device according to claim 2, characterized in that: The steam turbine for the cracking gas device also includes: A second spacing member and a third spacing member are arranged on the first guide portion between two adjacent second guide portions, and the second spacing member and the third spacing member are respectively arranged on two side portions of the first guide portion facing the second guide portion; The second spacing member is disposed on a first side portion of the second guide portion close to the axis of the master cylinder, and the third spacing member is disposed on a second side portion of the second guide portion away from the axis of the master cylinder; A first reserved gap is formed between the second spacing member and the first guide portion, and a second reserved gap is formed between the third spacing member and the second guide portion, and the first reserved gap is larger than the second reserved gap.

4. The steam turbine for a cracking gas device according to claim 1, characterized in that: The steam turbine for the cracking gas device is used for a 1.5 million tons / year ethylene cracking gas device; The master cylinder also includes a steam inlet chamber arranged inside the master cylinder, and two steam interfaces are respectively arranged at the upper end and the lower end of the steam inlet chamber, so that the steam inlet chamber can take in steam all around through the steam interfaces; the steam inlet chamber is a reflux structure.

5. The steam turbine for a cracking gas device according to claim 4, characterized in that: The steam turbine for the cracking gas device also includes a quick-closing valve and a regulating steam valve arranged on the main cylinder. The valve housings of the quick-closing valve and the regulating steam valve are integrally formed, and the valve housings of the quick-closing valve and the regulating steam valve are detachably connected to the main cylinder.

6. The steam turbine for a cracking gas device according to claim 5, characterized in that: The master cylinder also includes a steam inlet interface, which is connected to two steam interfaces at the upper end or the lower end of the steam inlet chamber. The valve shells of the quick-closing valve and the regulating steam valve are connected to the steam inlet interface, so that the regulating steam valve can adjust the flow rate of steam flowing through the steam interface.

7. The steam turbine for a cracking gas device according to claim 4, characterized in that: The main cylinder further comprises a first guide vane holding ring and a second guide vane holding ring, and the exhaust cylinder further comprises a third guide vane holding ring; The steam inlet chamber is equipped with 1-stage regulating stage straight blades and 4-stage pressure stage straight blades, the first guide vane holding ring is equipped with 6-stage pressure stage straight blades, the second guide vane holding ring is equipped with 16-stage pressure stage straight blades, and the third guide vane holding ring is equipped with 3-stage twisted blades.

8. The steam turbine for a cracking gas plant according to any one of claims 1 to 7, characterized in that: The first bearing seat is also equipped with a first adjusting ring, which matches the outer ring of the bearing used to support the rotation of the rotor; The second bearing seat is also equipped with a second adjusting ring, and the second adjusting ring matches with the outer ring of the bearing used for supporting the rotation of the rotor.

9. A cracking gas system, characterized in that: The method comprises the steam turbine for a cracking gas device as claimed in any one of claims 1 to 8, and also comprises a cracking gas device, wherein the steam turbine for the cracking gas device provides power for the cracking gas device.

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