A method for centering design of a multi-working-condition operation steam turbine generator unit shaft system

Abstract

The application discloses a kind of multi-working condition operation steam turbine generator unit shafting centering design methods, comprising the following steps: S1 calculates each bearing cold state elevation adjustment amount;S2 is carried out to working condition A under the shafting rotor dynamics calculation, obtains each bearing ideal elevation and each bearing specific pressure;S3 calculates working condition A low pressure vacuum variation and each bearing elevation and each bearing specific pressure under stable running state;S4 if working condition A low pressure vacuum variation and the specific pressure of certain bearing under stable running state does not comply with bearing specific pressure examination standard, then adjust corresponding bearing cold state elevation adjustment amount, repeat step S3, until each bearing specific pressure complies with examination standard;S5 determines each bearing cold state installation elevation according to the final determination of each bearing cold state elevation adjustment amount, connects each rotor in shafting according to the requirement of coupling alignment under working condition A, completes working condition A under the shafting centering installation of whole unit.The shafting centering design method can ensure that the performance of steam turbine generator unit reaches excellent level when running.

Description

Technical Field

[0001] This invention belongs to the field of shaft alignment technology, specifically relating to a shaft alignment design method for multi-condition operating steam turbine generator sets. Background Technology

[0002] With advancements in steam turbine technology, steam turbine units are transitioning from single-condition operation to multi-condition operation. Steam turbine units operating under multiple conditions must consider the impact of each condition on the turbine shaft system performance. The shaft alignment requirements also differ depending on the operating conditions. For example, the increasingly popular high-back-pressure heating steam turbine generator units use a dedicated heating low-pressure rotor during the heating season and revert to the original pure condensing low-pressure rotor during the non-heating season. This necessitates designing different shaft alignment methods for different operating conditions of the high-back-pressure heating steam turbine generator units. Summary of the Invention

[0003] This invention provides a shaft alignment design method for a steam turbine generator set operating under multiple operating conditions. This shaft alignment design method solves the problems of poor shaft stability and substandard shaft performance that may occur when the steam turbine generator set is operating under multiple operating conditions, and ensures that the shaft performance reaches an excellent level during operation.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] A method for shaft alignment design of a multi-condition operating steam turbine generator set includes the following steps:

[0006] S1. Calculate the cold-state elevation adjustment of each bearing in the turbine generator set shaft system;

[0007] S2. Perform rotor dynamics calculations on the shaft system under working condition A to obtain the ideal elevation and specific pressure of each bearing.

[0008] S3. Calculate the bearing elevation and specific pressure under low-pressure vacuum change and stable operation conditions in working condition A.

[0009] S4. Perform rotor dynamics calculations on the shaft system under working condition B to obtain the ideal elevation and specific pressure of each bearing.

[0010] S5. Calculate the elevation and specific pressure of each bearing under stable operating condition B.

[0011] S6. If the specific pressure of a certain bearing under the low-pressure vacuum change and stable operation conditions of working condition A does not meet the bearing specific pressure assessment standard, or the specific pressure of a certain bearing under the stable operation conditions of working condition B does not meet the bearing specific pressure assessment standard, then adjust the corresponding cold state elevation adjustment amount of the bearing, repeat steps S3 and S5, until the specific pressure of each bearing meets the assessment standard, and finally determine the cold state elevation adjustment amount of each bearing.

[0012] S7. Determine the cold installation elevation of each bearing based on the final determined cold elevation adjustment amount, and connect each rotor in the shaft system according to the alignment requirements of the turbine generator set coupling under operating conditions A and B, to complete the alignment and installation of the entire turbine generator set shaft system under operating conditions A and B.

[0013] Further, in step S1, the cold-state elevation adjustment of each bearing in the turbine generator set shaft system is calculated, specifically including the following steps:

[0014] S1-1. First, calculate the deformation of the low-pressure outer cylinder caused by the change in exhaust temperature of the steam turbine generator set under operating condition A. Obtain the average change d in the vertical direction of the low-pressure outer cylinder deformation as each bearing changes from cold installation to hot operation, denoted as d1, d2, ... d n ;

[0015] S1-2, The influence of low-pressure vacuum change on the elevation of each bearing, c, is denoted as c1, c2...c n ;

[0016] S1-3. Calculate the cold-state elevation adjustment amount b for each bearing, where the initial value b = -(d+c) / 2, denoted as b1, b2...b n .

[0017] Further, in step S2: Rotor dynamics calculations are performed on the shaft system under operating condition A. Following the principle that the bearing elevations on both sides of the low-pressure rotor are zero, the ideal elevations a of each bearing are obtained, denoted as a1, a2…0, 0…a n The specific pressure PS0 of each bearing is obtained and denoted as PS. 01 PS 02 ...PS 0n .

[0018] Furthermore, the following steps are included between steps S2 and S3:

[0019] The cold-state elevation adjustment amount b is added to the ideal elevation a to obtain the new installation elevation a′ of each bearing, where a′=a+b;

[0020] The newly installed elevation a′ is corrected to obtain the pseudo-cold state installation elevation of each bearing.

[0021] Furthermore, following the principle that the bearing elevations on both sides of the low-pressure rotor are zero, the newly installed elevations a′ of the remaining bearings are corrected to obtain the pseudo-cold installation elevations a″ of each bearing, denoted as a1″, a2″...0, 0...a n ".

[0022] Furthermore, in step S3:

[0023] Under operating condition A, with low-pressure vacuum variation, the bearing elevation e is the sum of the ideal bearing elevation a, the cold-state elevation adjustment b, and the influence of low-pressure vacuum variation on the bearing elevation c, i.e., e = a + b + c. Following the principle that the bearing elevations on both sides of the low-pressure rotor are zero, e is corrected to obtain the bearing elevation e′, denoted as e1′, e2′…0, 0…e. n ′, and calculate the specific pressure PS1 of each bearing at this time, denoted as PS. 11 PS 12 ...PS 1n ;

[0024] Under stable operating condition A, the bearing elevation f is the sum of the bearing elevation e′ under low-pressure vacuum changing operating condition and the elevation change d caused by the deformation of the low-pressure outer cylinder due to the change in exhaust temperature, i.e., f = e′ + d. The specific pressure PS2 of each bearing at this time is calculated and denoted as PS. 21 PS 22 ...PS 2n .

[0025] Further, in step S4: Rotor dynamics calculations are performed on the shaft system under operating condition B. Following the principle that the bearing elevations on both sides of the low-pressure rotor are zero, the ideal elevations g of each bearing are obtained, denoted as g1, g2…0, 0…g n And calculate the specific pressure PS3 of each bearing, denoted as PS. 31 PS 32 ...PS 3n .

[0026] Furthermore, in step S5: under stable operating condition B, the elevation h of each bearing is the sum of the simulated cold installation elevation a" of each bearing and the influence c of the low-pressure vacuum change on the elevation of each bearing, denoted as h1, h2...h n And calculate the specific pressure PS4 of each bearing at this time, denoted as PS. 41 PS 42 ...PS 4n .

[0027] Further, in step S6: if the specific pressure PS1 of a bearing under the low-pressure vacuum change operation condition A exceeds ±30% of the specific pressure PS0 of the corresponding bearing under the ideal elevation of condition A, or the specific pressure PS2 of a bearing under the stable operation condition A exceeds ±30% of the specific pressure PS0 of the corresponding bearing under the ideal elevation of condition A, or the specific pressure PS4 of a bearing under the stable operation condition B exceeds ±30% of the specific pressure PS3 of the corresponding bearing under the ideal elevation of condition B, then adjust the cold elevation adjustment amount b of the corresponding bearing, and repeat each step between steps S2 and S3, step S3 and step S5 until the specific pressure change of each bearing is within ±30% to meet the assessment standard, and finally determine the cold elevation adjustment amount of each bearing.

[0028] Furthermore, operating condition A is a high back pressure condition, and operating condition B is a pure condensation condition.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] The multi-condition operation turbine generator set shaft alignment design method of this invention includes the following steps: S1, calculating the cold-state elevation adjustment of each bearing in the turbine generator set shaft system; S2, performing rotor dynamics calculations on the shaft system under condition A to obtain the ideal elevation and specific pressure of each bearing; S3, calculating the elevation and specific pressure of each bearing under conditions A (low-pressure vacuum change and stable operation); S4, performing rotor dynamics calculations on the shaft system under condition B to obtain the ideal elevation and specific pressure of each bearing; S5, calculating the elevation and specific pressure of each bearing under conditions B (stable operation); S6, if the specific pressure of a certain bearing under conditions A (low-pressure vacuum change and stable operation) does not meet the bearing specific pressure assessment standard, or if the specific pressure of a certain bearing under conditions B (stable operation) does not meet the bearing specific pressure assessment standard... If the assessment criteria are not met, adjust the corresponding cold-state elevation adjustment amount of the bearings, and repeat steps S3 and S5 until the specific pressure of each bearing meets the assessment criteria, and finally determine the cold-state elevation adjustment amount of each bearing; S7, determine the cold-state installation elevation of each bearing according to the finally determined cold-state elevation adjustment amount of each bearing, and connect each rotor in the shaft system according to the alignment requirements of the turbine generator set coupling under operating conditions A and B, and complete the alignment and installation of the entire turbine generator set shaft system under operating conditions A and B; therefore, this shaft alignment design method solves the problem of shaft alignment and installation of multi-operating turbine generator sets under operating conditions A and B, and at the same time solves the problems of poor shaft system stability and substandard shaft system performance that may occur under operating conditions A and B, ensuring that the shaft system performance reaches an excellent level under operating conditions A and B.

[0031] In summary, this shaft alignment design method solves the problem of shaft alignment and installation for steam turbine generator sets operating under multiple conditions. It also addresses the issues of poor shaft stability and substandard shaft performance that may result from operating under multiple conditions, ensuring excellent shaft performance during multi-condition operation. Furthermore, this shaft alignment design method makes shaft alignment for steam turbine generator sets operating under multiple conditions convenient and quick. Attached Figure Description

[0032] Figure 1 This is a flowchart illustrating the calculation of the simulated cold-state installation elevation of each bearing under operating condition A in this invention.

[0033] Figure 2 The flowchart shows the calculation process for the elevation and specific pressure of each bearing under operating conditions A: low-pressure vacuum variation and stable operation.

[0034] Figure 3 The flowchart shows the calculation process for the elevation and specific pressure of each bearing under stable operating conditions B.

[0035] Figure 4 This is a schematic diagram of the shaft system of the high back pressure heating turbine generator set in this invention.

[0036] The following are the labels in the attached diagram: 1. Bearing No. 1, 2. Bearing No. 2, 3. Bearing No. 3, 4. Bearing No. 4, 5. Bearing No. 5, 6. Bearing No. 6, 7. Bearing No. 7, 8. High and medium pressure outer cylinder, 9. Low pressure outer cylinder, 10. Generator, 11. Exciter. Detailed Implementation

[0037] like Figure 4 As shown, this invention uses a high back-pressure heating turbine generator set with 7 bearings operating under multiple conditions as an example to illustrate the shaft alignment design method. Bearing 1 and bearing 2 are the bearings supporting the rotor on both sides of the high- and medium-pressure outer cylinder 8; bearing 3 and bearing 4 are the bearings supporting the rotor on both sides of the low-pressure outer cylinder 9 (the rotor of the low-pressure outer cylinder is simply referred to as the low-pressure rotor); bearing 5 and bearing 6 are the bearings supporting the rotor on both sides of the generator 10; and bearing 7 is the bearing supporting one side of the exciter 11 rotor. The shaft alignment design method specifically includes the following steps:

[0038] S1. First, calculate the deformation of the low-pressure outer cylinder 9 caused by the change in exhaust temperature of the steam turbine generator set under operating condition A. Obtain the average change d in the vertical direction of the deformation of the low-pressure outer cylinder 9 as each bearing changes from cold installation to hot operation, denoted as d1, d2...d7, where operating condition A is a high back pressure condition.

[0039] S2. The influence of low-pressure vacuum change on the elevation of each bearing, c, is denoted as c1, c2...c7;

[0040] S3. Calculate the cold-state elevation adjustment amount b for each bearing, where the initial value b = -(d+c) / 2, denoted as b1, b2...b7;

[0041] S4. Perform rotor dynamics calculations on the shaft system under operating condition A. Following the principle that the bearing elevations on both sides of the low-pressure rotor are zero, obtain the ideal elevation 'a' for each bearing, denoted as a1, a2, 0, 0, a5, a6, and a7. Also obtain the specific pressure PS0 for each bearing, denoted as PS. 01 PS 02 ...PS 07 ;

[0042] S5, such as Figure 1 As shown, the cold-state elevation adjustment amount b of each bearing is superimposed on the ideal elevation a of each bearing to obtain the new installation elevation a′ of each bearing, where a′=a+b;

[0043] S6. Based on the principle that the bearing elevations on both sides of the low-pressure rotor are zero, the newly installed elevations a′ of the remaining bearings are corrected to obtain the pseudo-cold installation elevations a″ of each bearing, which are denoted as a1″, a2″, 0, 0, a5″, a6″, and a7″.

[0044] S7, such as Figure 2 As shown, under operating condition A with low-pressure vacuum variation, the bearing elevation e is the sum of the ideal bearing elevation a, the cold-state elevation adjustment b, and the influence of low-pressure vacuum variation on the bearing elevation c, i.e., e = a + b + c. Following the principle that the bearing elevations on both sides of the low-pressure rotor are zero, e is corrected to obtain the bearing elevations e′, denoted as e1′, e2′, 0, 0, e5′, e6′, and e7′. The specific pressure PS1 of each bearing at this time is then calculated and denoted as PS. 11 PS 12 ...PS 17 ;

[0045] S8, such as Figure 2 As shown, under stable operating condition A, the bearing elevation f is the bearing elevation e′ under low-pressure vacuum changing operating condition, plus the bearing elevation change d caused by the deformation of the low-pressure outer cylinder 9 due to the change in exhaust temperature, i.e., f = e′ + d. The specific pressure PS2 of each bearing at this time is calculated and denoted as PS. 21 PS 22 ...PS 27 ;

[0046] S9. Perform rotor dynamics calculations on the shaft system under operating condition B. Based on the principle that the bearing elevations on both sides of the low-pressure rotor are zero, obtain the ideal elevation g of each bearing, denoted as g1, g2, 0, 0, g5, g6, and g7. Calculate the specific pressure PS3 of each bearing, denoted as PS. 31 PS 32 ...PS 37 Among them, condition B is a pure condensation condition;

[0047] S10, such as Figure 3 As shown, under stable operating condition B, the elevation h of each bearing is the sum of the simulated cold installation elevation a" of each bearing and the influence c of the low-pressure vacuum change on the elevation of each bearing, denoted as h1, h2...h7. The specific pressure PS4 of each bearing at this time is also calculated and denoted as PS. 41 PS 42 ...PS 47 ;

[0048] S11. The specific pressure of each bearing under each operating condition should meet the bearing specific pressure assessment standard requirements. Specifically, when the turbine generator set is running under operating condition A, the specific pressures PS1 and PS2 of each bearing under the low-pressure vacuum change and stable operation conditions of operating condition A should be compared with the specific pressure PS0 of each bearing under the ideal elevation of operating condition A to obtain the change in specific pressure of each bearing under the low-pressure vacuum change and stable operation conditions of operating condition A. The change in specific pressure of each bearing under the low-pressure vacuum change and stable operation conditions of operating condition A should be within ±30%. When the turbine generator set is running under operating condition B, the specific pressure PS4 of each bearing under the stable operation condition of operating condition B should be compared with the specific pressure PS3 of each bearing under the ideal elevation of operating condition B to obtain the change in specific pressure of each bearing under the stable operation condition of operating condition B. The change in specific pressure of each bearing under the stable operation condition of operating condition B should be within ±30%.

[0049] S12. If the specific pressure of a certain bearing does not meet the bearing specific pressure assessment standard, that is, the specific pressure of a certain bearing exceeds ±30% of the specific pressure of the corresponding bearing under the ideal elevation of the corresponding working condition, then adjust the cold elevation adjustment amount b of the corresponding bearing, and repeat the above steps S5-S8 and steps S10 until the specific pressure of each bearing and its change amount meet the assessment standard, and finally determine the cold elevation adjustment amount of each bearing.

[0050] S13. Determine the cold installation elevation of each bearing based on the final determined cold elevation adjustment amount, and connect each rotor in the shaft system according to the alignment requirements of the turbine generator set coupling under different working conditions to complete the alignment and installation of the entire turbine generator set shaft system.

[0051] The shaft alignment design method of the present invention solves the problem of shaft alignment and installation in steam turbine generator sets under multiple operating conditions. It also solves the problems of poor shaft stability and substandard shaft performance that may occur under multiple operating conditions, ensuring that the shaft performance reaches an excellent level under multiple operating conditions.

[0052] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A method for shaft alignment design of a multi-condition operating steam turbine generator set, characterized in that... Includes the following steps: S1. Calculate the cold-state elevation adjustment of each bearing in the turbine generator set shaft system; S2. Perform rotor dynamics calculations on the shaft system under working condition A to obtain the ideal elevation and specific pressure of each bearing. S3. Calculate the bearing elevation and specific pressure under low-pressure vacuum change and stable operation conditions in working condition A. S4. Perform rotor dynamics calculations on the shaft system under working condition B to obtain the ideal elevation and specific pressure of each bearing. S5. Calculate the elevation and specific pressure of each bearing under stable operating condition B. S6. If the specific pressure of a certain bearing under the low-pressure vacuum change and stable operation conditions of working condition A does not meet the bearing specific pressure assessment standard, or the specific pressure of a certain bearing under the stable operation conditions of working condition B does not meet the bearing specific pressure assessment standard, then adjust the corresponding cold state elevation adjustment amount of the bearing, repeat steps S3 and S5, until the specific pressure of each bearing meets the assessment standard, and finally determine the cold state elevation adjustment amount of each bearing. S7. Determine the cold installation elevation of each bearing based on the final determined cold elevation adjustment amount of each bearing, and connect each rotor in the shaft system according to the alignment requirements of the turbine generator set coupling under operating conditions A and B, and complete the alignment and installation of the entire turbine generator set shaft system under operating conditions A and B. In step S1, the cold-state elevation adjustment of each bearing in the turbine generator set shaft system is calculated, which specifically includes the following steps: S1-1. First, calculate the deformation of the low-pressure outer cylinder caused by the change in exhaust temperature of the steam turbine generator set under operating condition A. Obtain the average change d in the vertical direction of the low-pressure outer cylinder deformation as each bearing changes from cold installation to hot operation, denoted as d1, d2, ... d n ; S1-2, The influence of low-pressure vacuum change on the elevation of each bearing, c, is denoted as c1, c2...c n ; S1-3. Calculate the cold-state elevation adjustment amount b for each bearing, where the initial value b = -(d + c) / 2, denoted as b1, b2, ... b n ; In step S6: If the specific pressure PS1 of a bearing under the low-pressure vacuum change operation condition A exceeds ±30% of the specific pressure PS0 of the corresponding bearing under the ideal elevation of condition A, or the specific pressure PS2 of a bearing under the stable operation condition A exceeds ±30% of the specific pressure PS0 of the corresponding bearing under the ideal elevation of condition A, or the specific pressure PS4 of a bearing under the stable operation condition B exceeds ±30% of the specific pressure PS3 of the corresponding bearing under the ideal elevation of condition B, then adjust the cold elevation adjustment amount b of the corresponding bearing, and repeat steps S3 and S5 until the specific pressure change of each bearing is within ±30% to meet the assessment standard, and finally determine the cold elevation adjustment amount of each bearing. Condition A is a high back pressure condition, and condition B is a pure condensation condition.

2. The shaft alignment design method for a multi-condition operating steam turbine generator set according to claim 1, characterized in that: In step S2: Rotor dynamics calculations are performed on the shaft system under operating condition A. Following the principle that the bearing elevations on both sides of the low-pressure rotor are zero, the ideal elevation 'a' of each bearing is obtained and denoted as a1, a2…0, 0…a n The specific pressure PS0 of each bearing is obtained and denoted as PS. 01 PS 02 ...PS 0n ; In step S4: Rotor dynamics calculations are performed on the shaft system under operating condition B. Following the principle that the bearing elevations on both sides of the low-pressure rotor are zero, the ideal elevations g of each bearing are obtained and denoted as g1, g2…0, 0…g n And calculate the specific pressure PS3 of each bearing, denoted as PS. 31 PS 32 ...PS 3n .

3. The shaft alignment design method for a multi-condition operating steam turbine generator set according to claim 2, characterized in that... The following steps are also included between steps S2 and S3: The cold-state elevation adjustment amount b is added to the ideal elevation a to obtain the new installation elevation a' of each bearing, where a' = a + b; The newly installed elevation a´ is corrected to obtain the pseudo-cold state installation elevation of each bearing.

4. The shaft alignment design method for a multi-condition operating steam turbine generator set according to claim 3, characterized in that: Based on the principle that the bearing elevations on both sides of the low-pressure rotor are zero, the newly installed elevations a' of the remaining bearings are corrected to obtain the pseudo-cold installation elevations a" of each bearing, denoted as a1", a2", ..., 0, 0...a n ".

5. The shaft alignment design method for a multi-condition operating steam turbine generator set according to claim 2, characterized in that... In step S3: Under operating condition A, with low-pressure vacuum variation, the bearing elevation e is the sum of the ideal bearing elevation a, the cold-state elevation adjustment b, and the influence of low-pressure vacuum variation on the bearing elevation c, i.e., e = a + b + c. Following the principle that the bearing elevations on both sides of the low-pressure rotor are zero, e is corrected to obtain the bearing elevation e', denoted as e1', e2', ..., 0, 0...e'. n ´, and calculate the specific pressure PS1 of each bearing at this time, denoted as PS 11 PS 12 ...PS 1n ; Under stable operating condition A, the bearing elevation f is the sum of the bearing elevation e´ under low-pressure vacuum changing operating condition and the bearing elevation change d caused by the deformation of the low-pressure outer cylinder due to the change in exhaust steam temperature, i.e., f = e´ + d. The specific pressure PS2 of each bearing at this time is calculated and denoted as PS. 21 PS 22 ...PS 2n .

6. The shaft alignment design method for a multi-condition operating steam turbine generator set according to claim 4, characterized in that... In step S5: Under stable operating condition B, the elevation h of each bearing is the sum of the simulated cold installation elevation a" of each bearing and the influence c of the low-pressure vacuum change on the elevation of each bearing, denoted as h1, h2...h n And calculate the specific pressure PS4 of each bearing at this time, denoted as PS. 41 PS 42 ...PS 4n .

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