Method for installing a water turbine base ring without on-site machining

Abstract

The embodiment of the application provides a method for installing a water turbine base ring without on-site processing, and relates to the technical field of hydropower station equipment installation, which comprises the following steps: assembling a split base ring in advance in an installation room and welding the split base ring under the constraint of pre-tightening force, wherein the split base ring comprises a plurality of sub-base rings; hoisting the split base ring into a pit for adjustment and temporarily installing a water guide mechanism, wherein the water guide mechanism comprises a bottom ring, movable guide vanes and a top cover; under the constraint of the water guide mechanism, hanging and installing each pipe section of a spiral case, and welding the combined weld of the spiral case; under the constraint of the water guide mechanism, pouring pit concrete to the generator layer; hoisting the water guide mechanism out of the pit and placing it on the corresponding work station in the installation room for use in the installation of the water turbine of the hydropower station. According to the technical scheme, the deformation of the base ring caused by the factors such as base ring assembly welding, spiral case welding and concrete pouring can be eliminated, the on-site processing process of the base ring is cancelled, the installation quality and precision of the unit are ensured, the work efficiency is improved, and the construction cost is saved.

Description

Technical Field

[0001] This application relates to the field of hydropower station equipment installation technology, and more specifically, to a method for installing turbine mounting rings without on-site processing. Background Technology

[0002] The turbine mounting ring is a crucial component of a hydroelectric turbine, and its installation quality determines the overall operating efficiency of the turbine. Currently, turbine mounting rings for hydroelectric power stations are generally manufactured in the factory and then transported to the construction site either as a whole or disassembled. After arriving at the site, the mounting ring is assembled and welded into a single unit, hoisted into the turbine pit for installation and adjustment, followed by the installation, welding, and concrete pouring of the spiral casing. To eliminate mounting ring deformation caused by factors such as mounting ring assembly, spiral casing welding, and concrete pouring, on-site machining or grinding of the mounting ring is necessary to compensate for this deformation. This ensures improved installation quality and precision, guaranteeing the safe, stable, and efficient operation of the unit. Therefore, on-site machining of the mounting ring has become a unique procedure in hydroelectric power station mounting ring installation, and it is the most common and widespread method for addressing mounting ring deformation, especially in large and medium-sized hydroelectric power stations.

[0003] After the pit is poured up to the generator floor, the amount of on-site machining is determined based on the pit measurement data, and on-site machining of the mounting rings is carried out. Although on-site machining of the mounting rings can improve the installation quality and accuracy of the unit, it requires the investment of expensive on-site special machining equipment (such as vertical milling machines or grinding machines, vertical drilling machines, etc.), which significantly reduces the linear construction period of the unit installation (for example, the on-site machining period of mounting rings for large and medium-sized hydropower stations is about 2 months), and increases the on-site workload, which is time-consuming and labor-intensive. Summary of the Invention

[0004] The embodiments of this application provide a method for installing turbine seat rings without on-site processing, thereby eliminating seat ring deformation caused by seat ring assembly welding, volute welding and concrete pouring, simplifying construction procedures, shortening construction period, improving construction efficiency and saving construction costs.

[0005] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part by practice of this application.

[0006] According to a first aspect of the embodiments of this application, a method for installing a turbine mounting ring without on-site machining is provided, comprising:

[0007] The segmented seat ring is pre-assembled in the installation room and welded under pre-tightening force constraint, wherein the segmented seat ring includes multiple sub-seat rings;

[0008] The split seat ring is hoisted into the machine pit and positioned for adjustment. A water guiding mechanism is temporarily installed, wherein the water guiding mechanism includes a bottom ring, a movable guide vane, and a top cover.

[0009] Under the constraint of the water guiding mechanism, each pipe section of the spiral casing is installed, and the combined weld of the spiral casing is welded.

[0010] Under the constraint of the water diversion mechanism, the concrete in the machine pit was poured up to the generator floor;

[0011] The water guide mechanism is lifted out of the pit and placed in the corresponding position in the installation room, ready for the installation and use of the power station's turbine.

[0012] In some embodiments of this application, based on the foregoing scheme, the step of pre-assembling the segmented seat ring in the installation room and welding the segmented seat ring under preload constraint includes:

[0013] Positioning pins and double-ended bolts are installed on the split surface of each sub-seat ring;

[0014] Use a hydraulic tensioning tool or an electric heating tool to pre-tighten the double-ended bolts at the split surfaces of two adjacent sub-seat rings;

[0015] After all the double-headed bolts are pre-tightened, check the gap between the joints of the split surfaces of the two adjacent sub-seat rings to ensure that it meets the requirements;

[0016] Weld the combined weld of two adjacent sub-seat rings under preload constraint and eliminate welding stress;

[0017] After welding, a hydraulic tensioning tool or an electric heating tool is used to pre-tighten the double-headed bolts at the split surfaces of the two adjacent sub-seat rings.

[0018] After all the data of the split seat ring are qualified, the double-headed bolts and locating pins on the split surface of the sub-seat ring are spot welded firmly.

[0019] In some embodiments of this application, based on the foregoing scheme, the step of checking the gap between the combined seams of two adjacent sub-seat rings to ensure that they meet the requirements includes:

[0020] Use a feeler gauge to check the gap between the combined seams of two adjacent sub-seat rings. If the feeler gauge cannot pass through the gap, it indicates that the requirements are met; otherwise, it does not.

[0021] In some embodiments of this application, based on the foregoing scheme, in the first pre-tightening, the pre-tightening force or elongation of the double-ended bolt is 60% of the design value.

[0022] In some embodiments of this application, based on the foregoing scheme, in the secondary pre-tightening, the pre-tightening force or elongation value of the double-ended bolt is 100% of the design.

[0023] In some embodiments of this application, based on the aforementioned scheme, during the process of pouring concrete from the pit to the generator layer, the concrete pouring adopts a symmetrical, layered, and block-based pouring method.

[0024] Among them, the layer height is controlled between 1.0 and 1.5m, the concrete pouring speed is between 200 and 300mm / h, and the concrete height during pouring is controlled below 300mm.

[0025] In some embodiments of this application, based on the foregoing scheme, the top cover has a segmented structure.

[0026] In some embodiments of this application, based on the aforementioned scheme, the top cover is pre-assembled into a whole in the installation room before being hoisted into the machine pit for installation.

[0027] The technical solution of this application can eliminate the deformation of the seat ring caused by factors such as seat ring assembly welding, volute welding and concrete pouring, eliminate the on-site processing process of the seat ring, ensure the installation quality and accuracy of the unit, improve work efficiency and save construction costs.

[0028] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0029] 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. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0030] Figure 1 A schematic flowchart of a method for installing a turbine mounting ring without on-site machining according to an embodiment of this application is shown;

[0031] Figure 2 A diagram showing the segmented surface structure of a seat ring welded under preload constraint according to an embodiment of this application is provided.

[0032] Figure 3 A welding diagram of the volute under the constraint of a water guiding mechanism according to an embodiment of this application is shown;

[0033] Figure 4 A diagram showing the concrete pouring of the machine pit under the constraint of a water guiding mechanism according to an embodiment of this application is provided.

[0034] Explanation of reference numerals in the attached figures

[0035] 1-Split seat ring; 2-Double-ended bolt; 3-Positioning pin; 4-Bottom ring; 5-Modible guide vane; 6-Top cover; 7-Vortex housing. Detailed Implementation

[0036] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0037] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0038] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0039] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0041] The following detailed description of some embodiments of this application will be provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0042] See Figure 1 The diagram shows a flow chart of a method for installing a turbine mounting ring without on-site machining according to an embodiment of this application.

[0043] like Figure 1 As shown, a method for installing a turbine mounting ring without on-site machining is illustrated, specifically including steps S100 to S500.

[0044] Step S100: The segmented seat ring is pre-assembled in the installation room and welded under pre-tightening force constraint, wherein the segmented seat ring includes multiple sub-seat rings.

[0045] Understandably, welding segmented seat rings under preload constraints solves the technical problem of difficult deformation control during seat ring welding and can eliminate deformation caused by seat ring welding.

[0046] In some feasible embodiments, based on the foregoing scheme, the step of pre-assembling the segmented seat ring in the installation room and welding the segmented seat ring under pre-tightening constraint includes:

[0047] Positioning pins and double-ended bolts are installed on the split surface of each sub-seat ring;

[0048] Use a hydraulic tensioning tool or an electric heating tool to pre-tighten the double-ended bolts at the split surfaces of two adjacent sub-seat rings;

[0049] After all the double-headed bolts are pre-tightened, check the gap between the joints of the split surfaces of the two adjacent sub-seat rings to ensure that it meets the requirements;

[0050] Weld the combined weld of two adjacent sub-seat rings under preload constraint and eliminate welding stress;

[0051] After welding, a hydraulic tensioning tool or an electric heating tool is used to pre-tighten the double-headed bolts at the split surfaces of the two adjacent sub-seat rings.

[0052] After all the data of the split seat ring are qualified, the double-headed bolts and locating pins on the split surface of the sub-seat ring are spot welded firmly.

[0053] It should be noted that in some examples, each sub-ring split surface needs to be set with at least 6 not less than Large double-ended bolt, 1 Locating pins are used to ensure that welding can be performed under preload constraints.

[0054] It should be noted that in some examples, during the welding of the combined weld of two adjacent sub-seat rings under preload constraint, it is necessary to follow a certain welding sequence, symmetrically, segmentedly, in multiple layers, and in multiple passes. The filling weld should use the hammering method to eliminate welding stress.

[0055] In some feasible embodiments, based on the foregoing scheme, ensuring that the gap between the combined seams of two adjacent sub-seat rings meets the requirements includes:

[0056] Use a feeler gauge to check the gap between the combined seams of two adjacent sub-seat rings. If the feeler gauge cannot pass through the gap, it indicates that the requirements are met; otherwise, it does not.

[0057] It should be noted that in some examples, the feeler gauge is 0.04mm in size, depending on the engineering requirements.

[0058] It should be noted that for gaps that do not meet the requirements, the split surfaces of the two adjacent sub-seat rings need to be pre-tightened again until the requirements are met.

[0059] In some feasible embodiments, based on the foregoing scheme, in the first preload, the preload or elongation of the double-ended bolt is 60% of the design value.

[0060] In some feasible embodiments, based on the foregoing scheme, in the secondary pre-tightening, the pre-tightening force or elongation of the double-ended bolt is 100% of the design value.

[0061] Continue to refer to Figure 1 In step S200, the split seat ring is hoisted into the machine pit and positioned for adjustment, and a water guiding mechanism is temporarily installed. The water guiding mechanism includes a bottom ring, a movable guide vane, and a top cover.

[0062] In some feasible embodiments, based on the aforementioned scheme, the top cover has a segmented structure.

[0063] Understandably, the split structure makes installation easier.

[0064] In some feasible embodiments, based on the aforementioned scheme, the top cover is pre-assembled into a whole in the installation room before being hoisted into the machine pit for installation.

[0065] Understandably, assembling the top cover in this way ensures that the assembly of the top cover does not occupy the straight-line construction period of the machine pit.

[0066] Continue to refer to Figure 1 In step S300, under the constraint of the water guiding mechanism, each pipe section of the volute is installed and the volute assembly weld is welded.

[0067] Continue to refer to Figure 1 In step S400, under the constraint of the water guiding mechanism, the concrete in the machine pit is poured up to the generator layer.

[0068] In some feasible embodiments, based on the aforementioned scheme, during the process of pouring concrete from the pit to the generator layer, the concrete pouring adopts a symmetrical, layered, and block-based pouring method.

[0069] Among them, the layer height is controlled between 1.0 and 1.5m, the concrete pouring speed is between 200 and 300mm / h, and the concrete height during pouring is controlled below 300mm.

[0070] Continue to refer to Figure 1 In step S500, the water guiding mechanism is lifted out of the pit and placed in the corresponding work position in the installation room, ready for the installation and use of the power station's turbine.

[0071] It should be noted that if the power station is a pumped storage power station, the top cover can only be hoisted into or out of the pit in sections because the upper opening of the pumped storage unit pit is relatively small. In other words, the top cover must be hoisted out of the pit in sections after the pit is dismantled and placed in the corresponding work position in the installation room. If the power station is a conventional hydropower station, the top cover can be directly hoisted out of the pit and placed in the corresponding work position in the installation room.

[0072] In summary, the technical solution of this application solves the technical problem of difficult deformation control in seat ring welding by setting up multiple large double-headed bolts and welding the seat ring under preload constraint, and can eliminate the deformation caused by seat ring welding.

[0073] The technical solution of this application avoids large deformation of the seat ring during the welding of the volute by using a water guiding mechanism under the constraint of the installation.

[0074] The technical solution of this application uses a method of concrete pouring for the volute and the pit under the constraint of a water guiding mechanism. The water guiding mechanism, seat ring, volute, water inside the volute, and special tools for water pressure testing of the volute far exceed the buoyancy force of the concrete pouring, which can prevent deformation caused by the buoyancy of the pit concrete during pouring.

[0075] The technical solution proposed in this application can eliminate the deformation of the seat ring caused by factors such as seat ring assembly welding, volute welding and concrete pouring, eliminate the need for on-site processing of the seat ring, and at the same time ensure the installation quality and accuracy of the unit. It does not require the investment of expensive on-site special processing equipment (such as vertical milling machines or grinding machines, vertical drilling machines, etc.), and saves at least 2 months of the straight-line construction period of the unit installation by on-site processing of the seat ring. It reduces the construction difficulty, improves work efficiency, saves construction costs, and adds a new process to the installation of hydropower station turbines.

[0076] Below is a specific implementation example.

[0077] See Figure 2 The diagram shows the segmented surface structure of the seat ring welded under preload constraint.

[0078] See Figure 3 The diagram shows the welding of the volute under the constraint of the water guiding mechanism.

[0079] See Figure 4 The diagram shows the concrete pouring of the machine pit under the constraint of the water guiding mechanism.

[0080] This implementation example provides a method for installing turbine mounting rings without on-site machining, specifically including:

[0081] Step 1: The segmented seat ring 1 is assembled into a whole in the installation room or machine pit. Under the constraint of pre-tightening force, the combined weld of the seat ring 1 is welded. After the welding is completed, the double-headed bolts 2 of the segmented surface are pre-tightened again.

[0082] Step 2: The split seat ring 1 is hoisted into the machine pit and positioned for adjustment. The bottom ring 4, movable guide vane 5, top cover 6 and other water guiding mechanisms are temporarily installed.

[0083] Step 3: Under the constraint of the water guiding mechanism, install each pipe section of the volute 7 and weld the combined weld of the volute 7.

[0084] Step 4: Under the constraint of the water guiding mechanism, the concrete in the machine pit is poured up to the generator layer.

[0085] Step 5: The water guiding mechanism is lifted out of the pit and placed in the corresponding work position in the installation room, ready for the installation and use of the power station's turbine.

[0086] Step 1 specifically includes:

[0087] (1) Each sub-ring split surface is set to at least 6 not less than 2 large double-ended bolts, 1 Positioning pin 3.

[0088] (2) Before welding, use a hydraulic tensioning tool or an electric heating tool to pre-tighten the double-headed bolts 2 at the two split surfaces of the symmetrical seat ring. The pre-tightening force or elongation of the double-headed bolts 2 is 60% of the design value.

[0089] (3) After all double-headed bolts 2 are pre-tightened, use a 0.04mm feeler gauge to check the gap of the split surface joint to ensure that the feeler gauge cannot pass through.

[0090] (4) Weld the seat ring assembly weld under pre-tightening constraint. Multiple welders weld symmetrically, in sections, in multiple layers, and in multiple passes according to a certain welding sequence. The filling weld should use the hammering method to eliminate welding stress.

[0091] (5) After welding, use a hydraulic tensioning tool or an electric heating tool to pre-tighten the double-headed bolts 2 at the two symmetrical split surfaces. The pre-tightening force or elongation value of the double-headed bolts 2 is 100% of the design value.

[0092] (6) After all the data of the seat ring are qualified, the double-headed bolts 2 and the positioning pins 3 on the split surface of the seat ring are spot welded firmly.

[0093] like Figure 3 As shown, in step 2, the top cover 6 is a segmented structure. It is assembled into a whole in the installation room and then hoisted into the machine pit for temporary installation. The assembly of the top cover 6 in the installation room does not occupy the straight-line construction period of the machine pit.

[0094] like Figure 4 As shown, when the top cover 6 is installed, the concrete pouring adopts a reasonable pouring method of symmetry, layering, and segmentation. The layer height is controlled between 1.0 and 1.5m, the concrete pouring rising speed is between 200 and 300mm / h, and the concrete height during pouring is controlled below 300mm.

[0095] If the power station is a pumped storage power station, due to the small size of the upper opening of the pumped storage unit pit lining, the top cover 6 can only be hoisted into or out of the pit in sections. That is, the top cover 6 must be hoisted out of the pit in sections after the pit is dismantled and placed in the corresponding work position in the installation room. If the power station is a conventional hydropower station, the top cover 6 can be directly hoisted out of the pit and placed in the corresponding work position in the installation room.

[0096] Other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. It should be understood that this application is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for installing a turbine mounting ring without on-site machining, characterized in that, include: The segmented seat ring is pre-assembled in the installation room and welded under pre-tightening force constraint, wherein the segmented seat ring includes multiple sub-seat rings; The split seat ring is hoisted into the machine pit and positioned for adjustment. A water guiding mechanism is temporarily installed, wherein the water guiding mechanism includes a bottom ring, a movable guide vane, and a top cover. Under the constraint of the water guiding mechanism, each pipe section of the spiral casing is installed, and the combined weld of the spiral casing is welded. Under the constraint of the water diversion mechanism, the concrete in the machine pit was poured up to the generator floor; The water guide mechanism is lifted out of the pit and placed in the corresponding position in the installation room, ready for the installation and use of the power station's turbine.

2. The method according to claim 1, characterized in that, The process of pre-assembling the segmented seat ring in the installation room and welding the segmented seat ring under pre-tightening constraint includes: Positioning pins and double-ended bolts are installed on the split surface of each sub-seat ring; Use a hydraulic tensioning tool or an electric heating tool to pre-tighten the double-ended bolts at the split surfaces of two adjacent sub-seat rings; After all the double-headed bolts are pre-tightened, check the gap between the joints of the split surfaces of the two adjacent sub-seat rings to ensure that it meets the requirements; Weld the combined weld of two adjacent sub-seat rings under preload constraint and eliminate welding stress; After welding, a hydraulic tensioning tool or an electric heating tool is used to pre-tighten the double-headed bolts at the split surfaces of the two adjacent sub-seat rings. After all the data of the split seat ring are qualified, the double-headed bolts and locating pins on the split surface of the sub-seat ring are spot welded firmly.

3. The method according to claim 2, characterized in that, The inspection of the gap between the combined seams of two adjacent sub-seat rings to ensure they meet the requirements includes: Use a feeler gauge to check the gap between the combined seams of two adjacent sub-seat rings. If the feeler gauge cannot pass through the gap, it indicates that the requirements are met; otherwise, it does not.

4. The method according to claim 2, characterized in that, In the first pre-tightening, the pre-tightening force or elongation of the double-ended bolt is 60% of the design value.

5. The method according to claim 4, characterized in that, In the secondary pre-tightening, the pre-tightening force or elongation of the double-ended bolt is 100% of the design value.

6. The method according to claim 1, characterized in that, During the process of pouring concrete from the pit to the generator floor, the concrete pouring adopts a symmetrical, layered, and block-based pouring method. Among them, the layer height is controlled between 1.0 and 1.5m, the concrete pouring speed is between 200 and 300mm / h, and the concrete height during pouring is controlled below 300mm.

7. The method according to claim 1, characterized in that, The top cover has a segmented structure.

8. The method according to claim 7, characterized in that, The top cover is pre-assembled into a whole in the installation room before being hoisted into the machine pit for installation.

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