Device for calculating bearing position adjustment values

Abstract

The present invention relates to a device for calculating a bearing position adjustment value. The device for calculating a bearing position adjustment value comprises a reference rotor setting unit for setting one reference rotor among a plurality of rotors, a target value input unit for receiving a shaft alignment target value, and a calculation unit for calculating a height adjustment value of a first bearing and a second bearing at both ends of the adjustment rotor for each of the adjustment rotors excluding one reference rotor among the plurality of rotors, in order to reach the target value received by the target value input unit.

Description

Technology Field

[0001] The present invention relates to a device for calculating bearing position adjustment values. Background Technology

[0002] The steam turbine of a thermal power plant is a key piece of equipment that uses high-temperature, high-pressure steam produced in a boiler to rotate the turbine, and then uses this rotational force to rotate a generator connected to the turbine to generate electricity.

[0003] Figures 1 and 2 are exemplary diagrams for explaining the operation of a conventional standard coal-fired power plant turbine.

[0004] As shown in Fig. 1, the steam turbine rotor is configured with a structure in which 3 to 5 rotors are connected to each other by couplings. Each rotor is supported by 1 to 2 bearings, with 2 bearings per rotor being common.

[0005] The bearings supporting the turbine are sliding bearings, and an alignment pad is installed at the bottom of the bearing to allow for height adjustment and lateral movement. A thin plate is inserted into this pad to facilitate bearing movement. This process is called shaft alignment.

[0006] In Fig. 2, the scarlet pad is the alignment pad.

[0007] For example, in the case of steam turbine shaft alignment for a 500MW standard coal-fired power plant, it is performed after the turbine cools down. A height difference is created between the couplings of each rotor.

[0008] For example, in the case of an A-Coupling, the low-pressure turbine coupling is adjusted to be 0.685 mm higher than the high-pressure turbine (HIP) rotor. This adjustment is intended to predict in advance that the bearing support will undergo thermal expansion and the height of the coupling will change when the turbine is in operation, thereby ensuring that an appropriate load is applied to the bearing.

[0009] Figure 3 is an example diagram illustrating the height difference between couplings.

[0010] In Fig. 3, bearings #1, #3, #4, #5, and #6 are located on the reference line, bearing #2 is located 0.5 mm below the reference line, bearing #7 is located 0.02 mm above the reference line, and bearing #8 is located 4 mm above the reference line.

[0011] And the rim offset of the A-Coupling is 68.5 / 100mm higher for the LP-A rotor, and the face is 2.54mm bottom open. For the B-Coupling, the rim offset is "0", and the face is 16.7mm top open. For the C-Coupling, both the rim and face offsets are "0".

[0012] Figures 4a and 4b are reference diagrams for explaining axis alignment.

[0013] Shaft alignment is the process of adjusting the face and rim of the coupling between two rotors to a reference value.

[0014] As shown in Fig. 4a, Face refers to the degree of inclination of the two rotor couplings. Rim refers to the difference between the centerlines of the two rotor axes.

[0015] Axis alignment is the process of adjusting Face and Rim values ​​to reference values ​​using design or empirical data.

[0016] The method of adjusting the two variables, Face and Rim, is performed by inserting a Shim into the lower part of the bearing as shown in Fig. 4b. When inserting the Shim into the lower part of the bearing, the height is adjusted using the Sine and Cosine formulas according to the installation position of the Pad.

[0017] For example, as shown in Figure 4b, if the Pad is installed at 30, 60, 90, 120, and 150 degrees, 30 degrees becomes Vc3×con 30.

[0018] Figure 5 is an example of an Excel sheet for axis alignment calculation used in a conventional axis alignment method.

[0019] Generally, the axis alignment method is to check the rim and face values ​​while changing the face by 0.1mm using an Excel program such as Fig. 6.

[0020] However, since this method involves adjusting the Face and Rim by making small changes, it is cumbersome to have to check and adjust the changes in shaft alignment status individually when moving the first (#1) bearing and the second (#2) bearing one by one, and to calculate multiple times using the Trial and Error method when moving the first (#1) bearing and the second (#2) bearing simultaneously.

[0021] In addition, since changing the reference rotor requires repeating the aforementioned process, it consumes a significant amount of time for shaft alignment calculations and may limit the ability to find the optimal method.

[0022] Meanwhile, if the shaft alignment is incorrect, the temperature of the bearings under heavy load rises due to the improper bearing load, and in severe cases, it may result in the need to disassemble and re-maintain the turbine. In this case, the construction period for the power plant's planned preventive maintenance may need to be extended.

[0023] Furthermore, fluid-induced vibration may occur when the proper load is not applied to the sliding bearings. Therefore, shaft alignment is a critical task during the disassembly and assembly of the steam turbine. Prior art literature

[0024] (Patent Document 0001) KR 10-1972353 B1 The problem to be solved

[0025] The present invention is derived from this technical background and aims to provide a device for calculating bearing position adjustment values ​​that can reduce the calculation time required for shaft alignment of a steam turbine rotor. means of solving the problem

[0026] The present invention for achieving the above objectives includes the following configuration.

[0027] That is, a method for calculating a bearing adjustment value for shaft alignment of a rotor of a multi-axis steam turbine, performed in a device for calculating a bearing position adjustment value according to one embodiment of the present invention, is characterized by comprising the steps of: setting a reference rotor among a plurality of rotors; receiving a shaft alignment target value; and calculating a height adjustment value of a first bearing and a second bearing at both ends of the adjustment rotor to reach the target value for each of the adjustment rotors excluding the reference rotor among the plurality of rotors.

[0028] Meanwhile, the device for calculating bearing position adjustment values ​​is characterized by including a reference rotor setting unit for setting one reference rotor among a plurality of rotors, a target value input unit for receiving a shaft alignment target value, and a calculation unit for calculating height adjustment values ​​of a first bearing and a second bearing at both ends of the adjustment rotor to reach the target value received by the target value input unit for each of the adjustment rotors excluding one reference rotor among the plurality of rotors. Effects of the invention

[0029] According to the present invention, the effect of providing an apparatus and method for calculating bearing position adjustment values ​​that can reduce the calculation time required for shaft alignment of a steam turbine rotor is derived.

[0030] In addition, an apparatus and method for calculating bearing position adjustment values ​​that can minimize the amount of shim used for shaft alignment can be provided.

[0031] Accordingly, the time typically required for shaft alignment during the disassembly and assembly of steam turbines can be reduced by 2 to 3 days.

[0032] In other words, by shortening the shaft alignment time through an automatic shaft alignment calculation process, a saving effect of approximately 200 million won—the cost of one day's power plant shutdown—can be achieved. If applied to 10 steam turbines, a saving effect of approximately 2 billion won can be obtained. Brief explanation of the drawing

[0033] FIGS. 1 and 2 are exemplary diagrams for explaining the operation of a conventional standard coal-fired power plant turbine. Figure 3 is an example diagram to explain the height difference between couplings, Figures 4a and 4b are reference diagrams for explaining axis alignment, FIG. 5 is an example of an Excel sheet for axis alignment calculation used in a conventional axis alignment method. FIG. 6 is a block diagram illustrating the configuration of a device for calculating a bearing position adjustment value according to an embodiment of the present invention. FIG. 7 is a flowchart of a method for calculating bearing adjustment values ​​for shaft alignment of a rotor of a multi-axis steam turbine according to an embodiment of the present invention. Figures 8 and 9 are reference diagrams for explaining the detailed procedure of axis alignment, FIG. 10 is a table including bearing height adjustment values ​​calculated by changing a reference rotor to rotors A through C according to an embodiment of the present invention, FIGS. 11a and FIGS. 11b are reference diagrams for explaining a method of aligning shafts by moving two bearings simultaneously. Figure 12 is a flowchart illustrating the process of calculating the amount of shim for bearing adjustment. Specific details for implementing the invention

[0034] It should be noted that the technical terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Furthermore, unless specifically defined otherwise in this invention, the technical terms used in this invention should be interpreted in the sense generally understood by those skilled in the art to which this invention pertains, and should not be interpreted in an overly broad or overly narrow sense.

[0035] Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0036] FIG. 6 is a block diagram illustrating the configuration of a device for calculating a bearing position adjustment value according to an embodiment of the present invention.

[0037] FIG. 7 is a flowchart of a method for calculating bearing adjustment values ​​for axial alignment of a rotor of a multi-axis steam turbine according to one embodiment of the present invention.

[0038] As shown in FIG. 6, a bearing adjustment value calculation device (10) according to one embodiment includes a reference rotor setting unit (110), a target value input unit (120), a calculation unit (130), and a limit value input unit (140).

[0039] The reference rotor setting unit (110) sets one of the reference rotors (S700). Then, the target value input unit (120) receives the shaft alignment target value (S710).

[0040] The calculation unit (130) calculates the height adjustment values ​​of the first bearing and the second bearing at both ends of the adjustment rotor for each of the adjustment rotors, excluding one reference rotor among the multiple rotors, to reach the target value received by the target value input unit (120) (S720).

[0041] In one aspect of the present invention, the calculation unit (130) calculates and further provides a height adjustment value of the bearing when one of the first bearing and the second bearing at both ends of the adjustment rotor is adjusted first for each of the adjustment rotors.

[0042] At this time, the height adjustment value of the bearing calculated by the calculation unit (130) is characterized as being for adjusting the amount of shim inserted into the bearing.

[0043] And in one aspect, the calculation unit (130) is a height change amount (Δh1) when adjusting the face of the first bearing. total Identify ) and the amount of height change (Δh2) when adjusting the face of the second bearing total By determining ) and the height change amount (Δh1) when adjusting the face of the first bearing determined above total ) and the amount of height change (Δh2) when adjusting the face of the second bearing total It is characterized by including a step of adjusting the amount of shim inserted into the bearing so that ) becomes equal.

[0044] According to another aspect of the present invention, a limit value of a shim is received through a limit value input unit (140).

[0045] And the output unit (130) limits the insertion of the shim when the amount of shim inserted into the first bearing or the second bearing exceeds the limit value of the shim, and controls the amount of shim inserted into the other bearing.

[0046] According to another aspect of the present invention, the output unit (130) removes the amount of shim inserted into the other bearing when the amount of shim inserted into the first bearing or the second bearing exceeds the amount of the existing shim.

[0047] Additionally, the calculation unit (130) sets all of the multiple rotors as reference rotors and repeats the step of calculating the height adjustment value (S730). Then, the calculation unit (130) calculates the height adjustment value when the height adjustment value of the bearing for adjusting the amount of shim among the height adjustment values ​​calculated as a result of the repetition is the minimum value.

[0048] Figures 8 and 9 are reference diagrams for explaining the detailed procedure of axis alignment.

[0049] Looking at the detailed procedure for shaft alignment, the reference rotor must first be set. The reference rotor is a rotor that does not require adjustment, and the rotors before and after it are adjusted based on this rotor.

[0050] Then, based on the selected reference rotor, input the shaft alignment target value (design value or empirical value) and align the faces of the rotor coupling front and back.

[0051] The method of adjusting the face is to adjust the height of the first (#1) bearing or the second (#2) bearing in Fig. 8 to match the reference value, in which case not only the face but also the rim changes.

[0052] In other words, assuming the bearing (#2) closest to the reference rotor is moved, the other bearing (#1) remains fixed, so Face=f and Rim=c'.

[0053] When the second (#2) bearing is moved, the change is that ΔMON, ΔTOP, ΔQTP, and ΔSQR are triangles of the same shape, so the relationship a:h=d:f=b:c' holds.

[0054] Since the second (#2) bearing displacement (h) = a / d × f, f = d / a × h, so modifying f changes h. Because h changes, the rim also changes according to the formula for the change in rim (c') = (a+b) / a × h. A similar result is obtained when moving the bearing (#1) far from the reference rotor.

[0055] Then, after adjusting the Face, the height of the coupling shaft centerline, i.e., the Rim, is adjusted by inserting or removing identical Shims from the first (#1) bearing and the second (#2) bearing. In this case, since identical Shims are inserted, the Face value, which is the inclination of the rotor, does not change.

[0056] Then, the first adjusted rotor becomes the reference rotor, and the rotors before and after the first adjusted rotor are aligned similarly.

[0057] In the case of the generator rotor, shims are inserted into the casing feet rather than the generator bearings, but the calculation method is similar. Adjusting the face and rim yields the 'h' value, which is the bearing height adjustment, and this value can be used to perform final shaft alignment.

[0058] Then, when the reference rotor is changed, the reference rotor is reset, and the aforementioned process is repeated to perform shaft alignment.

[0059] When axially aligning one of the front or rear rotors around a reference rotor, there are two methods: first aligning the face with one of the two bearings and then adjusting the rim value, or adjusting the faces of both bearings and then adjusting the rim. The reason for axially aligning by simultaneously adjusting the faces of both bearings is to ensure even distribution of shim material or to minimize the amount of shim inserted.

[0060] For example, as shown in FIG. 9, when axially aligning five rotors, the C-rotor is selected as the reference rotor, and the B-rotor and D-rotor are axially aligned. In this case, the axial alignment method for each rotor results in three possible cases (movement of bearings 1 and 2 alone, and movement of bearings 1 and 2 simultaneously), and four couplings are adjusted.

[0061] Since adjustments are required, the total number of cases becomes 3 (bearing movement methods) x 4 = 12 (total rotor shaft alignment methods). That is, since the number of cases for shaft alignment centered on one reference rotor is 12, when calculating by changing 5 rotors to reference rotors, 12 x 5 = 60 cases occur.

[0062] Considerations regarding shim insertion include the fact that an excessive amount of shim can cause spring-like action leading to inaccurate shaft alignment results, and that increased shim insertion necessitates additional machining of curved bearing casings, thereby increasing maintenance time; therefore, it is preferable to use as little shim as possible. However, conventional manual calculation methods require calculating each case individually and comparing the results manually, which consumes a significant amount of time during shaft alignment calculations.

[0063] FIG. 10 is a table containing the height adjustment values ​​of the bearings calculated by changing the reference rotor to rotors A through C according to one embodiment of the present invention.

[0064] By automating shaft alignment, calculation time can be minimized or automatic calculations can be performed. Rotor A is designated as the reference rotor, and the shaft alignment of couplings A, B, and C is calculated. Subsequently, B and C are selected as reference rotors, and the calculation is performed in the same manner.

[0065] Additionally, when a target value is entered during shaft alignment calculation, the results are displayed for two methods: adjusting the ends of the adjustment rotor (i.e., the front and rear bearings first) and adjusting both bearings simultaneously. The method prioritizing the front and rear bearings means adjusting the Face first, followed by adjusting the Rim equally.

[0066] By referring to the result value of Fig. 10, a method to minimize the amount of shim or minimize bearing movement can be found, and since it is automatically calculated by a computer, the calculation time can be drastically reduced.

[0067] Figures 11a and 11b are reference diagrams for explaining a method of aligning shafts by moving two bearings simultaneously.

[0068] The method of adjusting the shims of two bearings is as shown in Figures 11a and 11b, in which one bearing is raised by a predetermined rule and the other bearing is adjusted according to the remaining value. There may be three rules for adjusting the two bearings, namely the first bearing and the second bearing.

[0069] One is that since adjusting the face changes the amount of bearing shim, you must adjust it evenly to avoid inserting too much shim on one side, taking into account the changing amount of shim.

[0070] Also, when adjusting two bearing shims, one bearing adds shim while the other subtracts shim, so to minimize the amount of shim inserted, the removal of shim is prioritized, but if more is removed than the existing amount of shim, it must be adjusted to the other bearing.

[0071] The formula for adjusting two bearings is as shown in Table 1 below. First, adjust the Face, and then adjust the Rim on both bearings simultaneously.

[0072] First, the adjustment formula for one bearing, the first bearing, is as shown in Table 1 below.

[0073] Initial value Δf(f taget - f0) After adjustment After Δr adjustment f0(Face initial value) f target f target r0(Rim initial value) r11=b / d×f target r target h0=Shim0 h11=a / d×f target h2=r target Δh Δh11=h1-h0(=0)=a / d ×f target -0 Δh12=r target -r11=r target - b / d ×f target Δh1 total =h1 + Δh2 = (a / d ×f target ) +(r target - b / d ×f target)

[0074] And the adjustment formula for the other bearing, the second bearing, is as shown in Table 2 below.

[0075] Initial value Δf(f taget - f0) After adjustment After Δr adjustment f0(Face initial value) f target f target r0(Rim initial value) r21=b / d×f target r target h0=Shim0 h21=a / d×f target h22=r target Δh Δh21=h21-h0(=0)=a / d ×f target -0 Δh22=r target -r21r target - (a+b) / d ×f target Δh2 total =h21 + Δh22 = (a / d ×f targe+t ) + (r target -(a+b) / d×f target

[0076] There are two methods for simultaneously adjusting two bearings, namely the first bearing and the second bearing. The two methods are to minimize the amount of shim inserted into the bearings, and include distributing the amount of shim adjustment equally between both bearings, and prioritizing the removal of existing shims or limiting the amount of insertion between the two bearings.

[0077] In the case of equal distribution of shim adjustment amount, the shaft alignment calculation procedure is to first adjust the face and then move two bearings simultaneously to adjust the rim value.

[0078] In the following mathematical formulas 1 and 2, △h11 and △h21 represent the change in the amount of Shim during Face adjustment, and △h12 and △h22 represent the change in the amount of Rim, and the total amount of movement is the sum of the amount of Face movement and the amount of Rim movement.

[0079] [Mathematical Formula 1]

[0080] △h1 total = △h11 + △h12 = (a / dxf target ) + (r target - b / d × f target )

[0081] [Mathematical Formula 2]

[0082] △h2 total = △h21 + △h22 = (a / dxf target ) + (r target - (a+b) / dxf target )

[0083] First, f of the first (#1) bearing target △h1 when the value is changed total Observing the changing value, f of the second (#2) bearing target △h2 when the value is changed total Find the Face value that becomes equal to the value by comparing it with the value using a calculation formula.

[0084] And finally △h1 total = △h2 totalAdjust so that the shim amount adjustment value is smaller than when only one bearing is adjusted.

[0085] In addition, there are methods to prioritize the removal of existing shims or to limit the insertion amount.

[0086] When adjusting two bearing shims, one bearing adds shim while the other removes shim, so to minimize the amount of shim inserted, the removal of shim is prioritized, but when removing more than the existing amount of shim, the other bearing is used for adjustment.

[0087] As shown in FIGS. 11a and 11b, face adjustment must be performed by increasing the amount of shim on one bearing or decreasing the amount of shim on the other bearing.

[0088] The method for calculating the adjustment of bearings that reduce the amount of shim, while ensuring that the amount of shim inserted in the existing bearing is not exceeded, is as follows.

[0089] Figure 12 is a flowchart illustrating the process of calculating the amount of shim for bearing adjustment.

[0090] As shown in Fig. 12, when prioritizing Shim insertion, the logic is such that if a shim limit value is entered, the Shim is not inserted beyond that limit.

[0091] In this case, if the shim insertion limit value is s1, the rim adjustment value is r1, and the shim inserted for face adjustment is hf1, then the total shim movement amount (h) is = ±hf1 ± r1.

[0092] If the total amount of shim movement is greater than a preset limit value (s1), the shim is not inserted further. If h is smaller than s1, shim adjustment may be performed on only one bearing because it is smaller than the limit value.

[0093] To explain the case where h = ± hf1 ± r1 ≥ s1, first, the Rim value is subtracted from the Shim limit value to reflect the Rim value that needs to be adjusted later. If this subtracted value is denoted as h2, the adjustable Face value becomes d / ax h2. Subsequently, the remaining Face adjustment is performed using the other bearing, and the adjustment amount f3 = f1 - f2. Afterward, the Rim value is adjusted by inserting the same shim into both bearings. Finally, the shim amount for the bearing where the shim is inserted becomes h = h2 + r1, and the shim adjustment amount for the other bearing becomes h3 + r1.

[0094] Meanwhile, when prioritizing shim removal, it is similar to the method prioritizing shim insertion, but the only difference is that the target value is changed from the shim limit s1 to the existing inserted shim value s2. In this case, since the method was created with priority for shim removal, there is an advantage in that the amount of shim inserted can be minimized.

[0095] The above-described method may be implemented as an application or in the form of program instructions that can be executed through various computer components and recorded on a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures, etc., either individually or in combination.

[0096] The program instructions recorded on the above-mentioned computer-readable recording medium are those specifically designed and configured for the present invention, but may also be those known and available to those skilled in the art of computer software.

[0097] Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, and flash memory.

[0098] Examples of program instructions include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The hardware device may be configured to operate as one or more software modules to perform processing according to the present invention, and vice versa.

[0099] Although the invention has been described above with reference to embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as set forth in the following claims. Explanation of the symbols

[0100] 10: Bearing adjustment value calculation device 110: Reference rotor setting unit 120 : Target value input section 130 : Output section 140 : Limit value input section

Claims

Claim 1 A reference rotor setting unit for setting one reference rotor among a plurality of rotors; a target value input unit for receiving a shaft alignment target value; and a calculation unit for calculating a height adjustment value of a first bearing and a second bearing at both ends of the adjustment rotor for each of the adjustment rotors excluding one reference rotor among the plurality of rotors, in order to reach a target value received by the target value input unit; wherein the height adjustment value of the bearing is for adjusting the amount of shim inserted into the bearing, and the calculation unit comprises a height change amount (Δh1) when adjusting the face of the first bearing total Identify ) and the amount of height change (Δh2) when adjusting the face of the second bearing total By determining ) and the height change amount (Δh1) when adjusting the face of the first bearing determined above total ) and the amount of height change (Δh2) when adjusting the face of the second bearing identified above total A device for calculating a bearing position adjustment value, characterized in that the calculation unit adjusts the amount of shim inserted into the bearing so that the shims become equal, and if the amount of shim inserted into one of the first bearing and the second bearing exceeds the amount of the existing shim, the amount of shim inserted into the other is removed, and the calculation unit sets all of the plurality of rotors as reference rotors and repeatedly performs the step of calculating the height adjustment value. Claim 2 An apparatus for calculating a bearing position adjustment value according to claim 1, wherein the calculation unit further calculates and provides a height adjustment value of a bearing when one of the first bearing and the second bearing at both ends of the adjustment rotor is adjusted first for each of the adjustment rotors. Claim 3 An apparatus for calculating a bearing position adjustment value according to claim 1, wherein the calculation unit calculates a height adjustment value when the height adjustment value of the bearing for adjusting the amount of shim among the height adjustment values ​​calculated as a result of repeated execution in the calculation unit is a minimum value.

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