A supercritical carbon dioxide turbine housing pressure test device and method

Abstract

The present invention discloses a supercritical carbon dioxide turbine housing pressure test device and method, which can ensure the safety and reliability of the housing pressure test. It includes a rough-machined housing part, and the rough-machined housing part has a large axial opening, a small axial opening, an inlet, and an outlet. The end face of the large axial opening is higher than the corresponding end face of the finished housing part, forming a boss. The diameters of the small axial opening, the inlet, and the outlet are smaller than the corresponding diameters of the finished housing part. Plug heads are axially positioned and installed in the small axial opening, the inlet, and the outlet respectively, and fixing plates are fixed to the outer sides of the plug heads by bolts. A clamping groove is provided in the large axial opening, and an end face sealing plate and a segmented retaining ring are installed in the large axial opening. The segmented retaining ring has a flange, and the flange is snapped into the clamping groove. A connecting plate is provided on the outer side of the segmented retaining ring, and the connecting plate and the end face sealing plate are fixed by bolts. Liquid injection holes and pressure gauge mounting holes are opened on the housing end face sealing plate.

Description

Technical Field

[0001] The present invention relates to the technical field of turbines, and in particular to a supercritical carbon dioxide turbine housing pressure test device and method. Background Art

[0002] The supercritical carbon dioxide power generation system has high efficiency, small volume, and wide heat source adaptability, and is considered to be the best solution for future power systems, so it has become a research hotspot around the world. Among them, the supercritical carbon dioxide turbine is the core power component in the system, working under high temperature and high pressure conditions. In order to achieve higher efficiency, the inlet pressure of the turbine in the current verification system is 20 - 30 MPa, and the temperature is 500 - 600 °C. In the future, system verification with higher pressure and temperature parameters will be carried out. The housing of the turbine must be subjected to a pressure test during the manufacturing process to verify the housing strength. The test pressure: P = 1.5ηP0

[0003] Where: P - test pressure;

[0004] P0 - working pressure;

[0005] η - the ratio of the high-temperature allowable stress of the material to the normal-temperature allowable stress, with a maximum value of 1.8;

[0006] Taking a 6MW turbine unit as an example, with an inlet temperature of 20 MPa and 600 °C, and the housing made of heat-resistant steel, the test pressure can reach 54 MPa.

[0007] The turbine housing adopts a non-radial split structure, with two large axial openings at both ends and two small openings for inlet and outlet. Among them, there is a circle of threaded holes at the two large axial openings at both ends for connecting with the flange. There are no threaded holes at the inlet and outlet, and they are connected to the inlet and outlet pipes by welding. Before the pressure test, the housing blank is rough-machined, leaving a certain machining allowance, and then machined to the final size after the test. In order to form a closed cavity, the traditional method is to install sealing plates on the outside of the two large axial openings at both ends and the inlet and outlet. Sealing rings are installed between the sealing plates and the housing, and the sealing plates are pressed tightly on the housing by tightening the fasteners. By controlling the pre-tightening force of the fasteners, the compression amount of the sealing ring under the working state is ensured to meet the allowable value, so as to ensure the seal. The traditional method completely relies on the pre-tightening force of the fasteners and the thickness of the sealing plate to ensure the compression amount of the sealing ring, and ensure that there is no leakage during the test.

[0008] The traditional method has three problems:

[0009] (1) The test pressure is high, and the single bolt bears a large working tensile force;

[0010] (2) The deformation of the sealing plate is large, the sealing surface between the sealing plate and the housing opens more, and the sealing ring is prone to failure;

[0011] (3) For machining threaded holes, the inlet and outlet need to extend a long distance, increasing the blank cost. Moreover, the machining volume is large, the number of fasteners is large, and the tightening operation is cumbersome. Summary of the Invention

[0012] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a supercritical carbon dioxide turbine housing pressure test device and method, which can ensure the safety and reliability of the housing pressure test, is easy to operate, reduces the blank cost, machining workload, and the usage amount of large-diameter fasteners.

[0013] The purpose of the present invention is achieved as follows:

[0014] A supercritical carbon dioxide turbine housing pressure test device,

[0015] It includes a rough-machined housing part, which has a large axial opening, a small axial opening, an inlet, and an outlet. The end face of the large axial opening is higher than the corresponding end face of the finished housing part, forming a boss. The diameters of the small axial opening, the inlet, and the outlet are smaller than the corresponding diameters of the finished housing part;

[0016] Plugs are respectively installed in the small axial opening, the inlet, and the outlet. The plugs are stepped. The large ends of the plugs are located inside the rough-machined housing part, and the diameter of the large ends of the plugs is smaller than the diameter of the large axial opening. Corresponding stop mouths are provided in the small axial opening, the inlet, and the outlet to cooperate with the stepped surfaces of the plugs for positioning. Axial sealing rings are provided on the stepped surfaces for sealing. Fixing plates are fixed to the outside of the plugs by bolts, and the fixing plates press on the rough-machined housing part to form the sealing and positioning of the plugs;

[0017] An annular clamping groove is provided in the large axial opening, corresponding to the boss. A end face sealing plate and a segmented retaining ring are successively installed in the large axial opening from the inside to the outside. A radial sealing ring is sleeved on the outer peripheral surface of the end face sealing plate to cooperate with the large axial opening for sealing. The segmented retaining ring has a flange, and the flange is clamped into the clamping groove to form axial positioning. A connecting plate is provided on the outside of the segmented retaining ring, and the connecting plate and the end face sealing plate are fixed by bolts to clamp and fix the connecting plate and the end face sealing plate on the segmented retaining ring;

[0018] Liquid injection holes are provided on the housing end face sealing plate for injecting test media, and pressure gauge mounting holes are provided on the housing end face sealing plate for exhausting air and installing pressure gauges.

[0019] Preferably, the segmented retaining ring is divided into four segments, two of which are splicing segments. The two splicing segments are symmetrically arranged and have parallel sides for horizontally moving and splicing to form a circular segmented retaining ring.

[0020] A supercritical carbon dioxide turbine housing pressure test method, the method includes the following steps:

[0021] S1. Assembly

[0022] S11. Respectively install the plug and the axial sealing ring into the small axial opening, the inlet, and the outlet from the large axial opening, and tighten the corresponding bolts to form seals for the small axial opening, the inlet, and the outlet of the rough-machined housing part.

[0023] S12. Push the end face sealing plate and the radial sealing ring into the inner side of the large axial opening from the large axial opening.

[0024] S13. Install the segmented retaining ring into the card slot.

[0025] S14. Clamp and fix the connecting plate and the end face sealing plate on the segmented retaining ring through bolts.

[0026] S2. Test

[0027] S21. With the large axial opening facing upward, inject the test medium through the liquid injection hole, exhaust the air through the pressure gauge installation hole, and then install the pressure gauge.

[0028] S22. Conduct a pressure test to verify the strength of the rough-machined housing part.

[0029] Due to the adoption of the above technical solution, the bolts of the present invention do not bear the working tension, the seal is reliable, the safety and reliability of the pressure test of the housing can be guaranteed, the operation is simple, the blank cost, the processing workload, and the usage amount of large-diameter fasteners are reduced. Description of the Drawings

[0030] Figure 1 is the structural schematic diagram of the present invention;

[0031] Figure 2 is Figure 1 the A-A cross-sectional schematic diagram of

[0032] Figure 3 is the structural schematic diagram of the segmented retaining ring;

[0033] Figure 4 is Figure 3 the B-B cross-sectional schematic diagram of

[0034] Reference Signs

[0035] In the attached drawings, 1 is a rough-machined housing part; 1-1 is a large axial opening; 1-1-1 is the end face of the large axial opening; 1-1-2 is the large axial end face after the housing is finish-machined; 1-2 is a small axial opening; 1-2-1 is the small axial opening after the housing is finish-machined; 1-3 is an inlet; 1-3-1 is the inlet after the housing is finish-machined; 1-4 is an outlet; 1-4-1 is the outlet after the housing is finish-machined; 1-5 is a clamping groove; 2, 3, and 4 are plugs; 5, 6, and 7 are axial sealing rings; 8 is an end face sealing plate; 8-1 is a liquid injection hole, and 8-2 is a pressure gauge mounting hole; 9 is a segmented retaining ring; 9-1 is retaining ring one; 9-2 is retaining ring two; 9-3 is retaining ring three; 9-4 is retaining ring four; 10 and 11 are radial sealing rings; 12, 14, and 16 are fixing plates; 18 is a connecting plate; 13, 15, 17, and 19 are bolts. Detailed implementation mode

[0036] See Figures 1-3 , which is a supercritical carbon dioxide turbine housing pressure test device, including a rough-machined housing part 1. The rough-machined housing part 1 includes a large axial opening 1-1, a small axial opening 1-2, an inlet 1-3, and an outlet 1-4. The end face 1-1-1 of the large axial opening extends a certain distance outward compared with the large axial end face 1-1-2 after the housing is finish-machined, and it can be machined off after the test. The small axial opening 1-2 is smaller than the small axial opening 1-2-1 after the housing is finish-machined, and it can be machined off after the test. The inlet 1-3 is smaller than the inlet 1-3-1 after the housing is finish-machined, and it can be machined off after the test. The outlet 1-4 is smaller than the outlet 1-4-1 after the housing is finish-machined, and it can be machined off after the test.

[0037] To form a closed cavity, plugs 2, 3, and 4 are respectively installed on the small axial opening 1-2, the inlet 1-3, and the outlet 1-4. An axial sealing ring 6 is provided on the plug 2 for sealing, an axial sealing ring 5 is provided on the plug 3 for sealing, and an axial sealing ring 7 is provided on the plug 4 for sealing; An end face sealing plate 8 and a segmented retaining ring 9 are installed in the large axial opening 1-1. The end face sealing plate 8 is on the inner side of the rough-machined housing part 1, and the segmented retaining ring 9 is on the outer side of the rough-machined housing part 1. Radial sealing rings 10 and 11 are provided on the housing end face sealing plate 8 for sealing. A liquid injection hole 8-1 is opened on the housing end face sealing plate 8 for injecting test medium, and a pressure gauge mounting hole 8-2 is used for exhausting air and installing a pressure gauge. The segmented retaining ring 9 is divided into four retaining rings: 9-1, 9-2, 9-3, and 9-4 are all installed in the clamping groove 1-5. Two of them are splicing segments 9-2 and 9-4. The two splicing segments 9-2 and 9-4 are symmetrically arranged and have parallel sides for horizontally moving and splicing to form a circular segmented retaining ring 9.

[0038] On the outer side of the plug 2, there is a fixing plate 12. The bolt 13 presses the plug 2 and the fixing plate 12 against the rough machining housing part 1. On the outer side of the plug 3, there is a fixing plate 14. The bolt 15 presses the plug 3 and the fixing plate 14 against the rough machining housing part 1. On the outer side of the plug 4, there is a fixing plate 16. The bolt 17 presses the plug 4 and the fixing plate 16 against the rough machining housing part 1. On the outer side of the segmented retaining ring 9, there is a connecting plate 18. Four bolts 19 press the connecting plate 18 and the baffle 8 against the segmented retaining ring 9, preventing the plugs 2, 3, 4 and the baffle 8 from falling into the rough machining housing part 1 when the inside of the rough machining housing part 1 is not pressurized.

[0039] A method for pressure testing the housing of a supercritical carbon dioxide turbine

[0040] The assembly process is as follows:

[0041] 1. Install the plug 2 and the axial sealing ring 5 from the large axial opening 1-1 to the small axial opening 1-2, and tighten the bolt 13 to press the plug 2 and the fixing plate 12 against the rough machining housing part 1;

[0042] 2. Install the plug 3 and the axial sealing ring 6 from the large axial opening 1-1 to the inlet 1-3, and tighten the bolt 15 to press the plug 3 and the fixing plate 14 against the rough machining housing part 1;

[0043] 3. Install the plug 4 and the axial sealing ring 7 from the large axial opening 1-1 to the outlet 1-4, and tighten the bolt 17 to press the plug 4 and the fixing plate 16 against the rough machining housing part 1;

[0044] The above steps 1 to 3 can be in any order;

[0045] 4. Push the end face sealing plate 8 and the radial sealing rings 10, 11 into the rough machining housing part 1 from the large axial opening 1-1;

[0046] 5. Install the segmented retaining ring 9 into the card slot 1-5: First, radially snap the retaining ring one 9-1 and the retaining ring three 9-3 into the card slot 1-5, then radially install the retaining ring two 9-2 and the retaining ring four 9-4, and radially wedge the whole retaining ring 9 tightly. The segmented retaining ring 9 is designed novelly and ingeniously, solving the problem of axial positioning when the sealing plate 8 is pressed outward, and converting the force on the fastener into the force on the segmented retaining ring 9 and the card slot 1-5, increasing the force-bearing area, reducing the stress, and reducing the radial deformation of the sealing plate 8 when it is pressed, ensuring the sealing ability of the sealing rings 10 and 11.

[0047] 6. Tighten the four bolts 19 to press the connecting plate 18 and the sealing plate 8 against the segmented retaining ring 9;

[0048] During the test, the large axial opening 1-1 will face upward, which is convenient for exhausting air, installing the pressure gauge, and reading the pressure gauge value. The pressure test can adopt various conventional test methods.

[0049] Through simulation calculations, it is found that the maximum stress of the device of the present invention appears on the clamping groove 1-5, and is far less than the allowable stress of the material. The radial deformation of the sealing plate is small, meeting the deformation requirements of the radial sealing rings 10 and 11, indicating that the device of the present invention has reliable sealing performance.

[0050] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in terms of form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A supercritical carbon dioxide turbine housing pressure test device, characterized in that: It includes a rough - machined housing part, the rough - machined housing part has a large axial opening, a small axial opening, an inlet, and an outlet. The end face of the large axial opening is higher than the corresponding end face of the finished housing part, forming a boss. The diameters of the small axial opening, the inlet, and the outlet are smaller than the corresponding diameters of the finished housing part; Plugs are respectively installed in the small axial opening, the inlet, and the outlet. The plugs are stepped. The large ends of the plugs are located inside the rough - machined housing part. The diameter of the large ends of the plugs is smaller than the diameter of the large axial opening. Stoppers are correspondingly arranged in the small axial opening, the inlet, and the outlet to cooperate with the step surfaces of the plugs for positioning. Axial sealing rings are arranged on the step surfaces for sealing. Fixing plates are fixed to the outside of the plugs through bolts, and the fixing plates press on the rough - machined housing part to form the sealing and positioning of the plugs; An annular clamping groove is provided in the large axial opening, corresponding to the boss. A end - face sealing plate and a segmented retaining ring are successively installed in the large axial opening from the inside to the outside. A radial sealing ring is sleeved on the outer peripheral surface of the end - face sealing plate to cooperate with the large axial opening for sealing. The segmented retaining ring has a flange, and the flange is snapped into the clamping groove to form axial positioning. A connecting plate is provided on the outside of the segmented retaining ring, and the connecting plate and the end - face sealing plate are fixed through bolts to clamp and fix the connecting plate and the end - face sealing plate on the segmented retaining ring; Liquid injection holes are opened on the housing end - face sealing plate for injecting test media, and pressure - gauge installation holes are opened on the housing end - face sealing plate for exhausting air and installing pressure gauges.

2. The supercritical carbon dioxide turbine housing pressure test device according to claim 1, wherein: The segmented retaining ring is divided into four sections, two of which are splicing sections. The two splicing sections are symmetrically arranged and have parallel sides for horizontally moving and splicing into a circular - ring - shaped segmented retaining ring.

3. A method for pressure testing a supercritical carbon dioxide turbine housing, characterized in that, The method includes the following steps: S1. Assembly S11. Respectively install the plugs and axial sealing rings into the small axial opening, the inlet, and the outlet from the large axial opening, and tighten the corresponding bolts to form the sealing of the small axial opening, the inlet, and the outlet of the rough - machined housing part; S12. Push the end - face sealing plate and the radial sealing ring into the inner side of the large axial opening from the large axial opening; S13. Install the segmented retaining ring into the clamping groove; S14. Clamp and fix the connecting plate and the end - face sealing plate on the segmented retaining ring through bolts; S2. Test S21. Place the large axial opening facing upwards, inject the test medium through the liquid injection hole, exhaust the air through the pressure - gauge installation hole, and then install the pressure gauge; S22. Conduct a pressure test to verify the strength of the rough - machined housing part.

Images