Method and system for dynamically judging displacement variation of unsteady-state bearing

Abstract

The invention relates to a dynamic judgment method and system for unsteady state bearing displacement variation. The method comprises the following steps that a starting signal of a jacking oil pump and a bearing displacement measurement real-time value are obtained; identifying a starting signal of the jacking oil pump; if the starting signal of the jacking oil pump is a low-level signal, performing assignment operation; if the starting signal of the jacking oil pump is a high-level signal, latching based on a bearing displacement measurement real-time value to obtain static position initial data of the bearing; determining the displacement variation of the bearing based on the static position initial data of the bearing; and judging whether to trigger allowable start based on the bearing displacement variation. According to the method, the influence of different zero positions caused by the change of the rotation angle when the bearing is static can be avoided during the measurement of the displacement variation of the bearing, whether the starting condition of the displacement variation of the circulating water pump bearing meets the requirement can be accurately judged, the pump body can be prevented from being burnt after being started by false permission signals, the field technical difficulty is effectively solved, and the working efficiency is improved. The burning loss event of the pump set is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of nuclear power plant water pump displacement measurement, and more specifically to a method and system for dynamically judging the displacement variation of a non-steady-state bearing. Background Art

[0002] The function of the circulating water system (CRF) in a nuclear power plant is to provide filtered cooling water to the condenser and auxiliary cooling water system of each unit through an independent water inlet channel by a circulating water pump (vertical centrifugal pump). The pump body of a single circulating water pump in a nuclear power plant adopts a rolling bearing. Because rolling bearings have many failures, high installation difficulty, high maintenance cost, and insufficient reliability, they need to be converted to sliding bearings. Due to changes in system equipment, the circulating water pump body needs to add pump body displacement monitoring. The real-time measurement value of the shaft displacement and the control logic of the circulating water pump startup and operation are all realized in the DCS distributed control system.

[0003] In the existing shaft displacement measurement method, the displacement sensor is a fixed measuring point. It is assumed that the corresponding bearing top position when calibrated to zero position is c; because the circulating water pump may have to go through a shaft turn, test run, etc. before it is officially put into operation, the corresponding measurement position of the displacement sensor becomes d when it is stationary again. Since the top end of the bearing is not flat (μm level dimension), point d deviates from the original calibration zero position, that is, the static position of the bearing is in a non-zero position state (non-steady state) after each stop. According to manual cranking state monitoring, point d may deviate from the zero point by (-80μm~40μm), while the total lifting height is only about 120μm. The comparison method of the real-time displacement measurement value with the threshold value of 50μm cannot determine whether the jacking oil has lifted the bearing to the required position. If there is an abnormality in the system, there is a risk of damage to the circulating water pump if it is directly started. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method and system for dynamically judging the displacement variation of a non-steady-state bearing in view of the problems existing in the prior art.

[0005] The technical solution adopted by the present invention to solve the technical problem is: constructing a dynamic judgment method for the change in displacement of a non-steady-state bearing, comprising the following steps:

[0006] Obtain the start signal of the top shaft oil pump and the real-time value of the bearing displacement measurement;

[0007] Identifying a start signal of the jack oil pump;

[0008] If the start signal of the top shaft oil pump is a low level signal, the assignment operation is performed;

[0009] If the start signal of the top shaft oil pump is a high-level signal, the real-time value of the bearing displacement measurement is latched to obtain the initial static position data of the bearing;

[0010] Determining a bearing displacement change based on initial static position data of the bearing;

[0011] Whether to trigger the start permission is determined based on the bearing displacement change.

[0012] In the dynamic determination method of the non-steady-state bearing displacement variation of the present invention, if the start signal of the top shaft oil pump is a low-level signal, executing the assignment operation includes:

[0013] If the start signal of the top shaft oil pump is a low-level signal, the real-time value of the bearing displacement measurement is used as the shaft displacement measurement value at the previous moment to complete the assignment operation.

[0014] In the dynamic determination method of the non-steady-state bearing displacement variation of the present invention, if the start signal of the top shaft oil pump is a high-level signal, latching is performed based on the real-time value of the bearing displacement measurement to obtain the initial static position data of the bearing, which includes:

[0015] If the start signal of the top shaft oil pump is a high-level signal, the output value is switched to the real-time value of the bearing displacement measurement and maintained to obtain the initial static position data of the bearing.

[0016] In the method for dynamically judging the displacement variation of a non-steady-state bearing according to the present invention, the determination of the displacement variation of the bearing based on the initial static position data of the bearing includes:

[0017] The bearing displacement variation is obtained by subtracting the initial static position data of the bearing from the current real-time value of the bearing displacement measurement.

[0018] In the method for dynamically determining the amount of non-steady-state bearing displacement change described in the present invention, determining whether to trigger the start-up permission condition based on the amount of bearing displacement change includes:

[0019] comparing the bearing displacement change with a threshold value;

[0020] If the bearing displacement change is greater than the threshold, it is determined that the bearing displacement change meets the condition and triggers the start permission;

[0021] If the bearing displacement change is less than the threshold, it is determined that the bearing displacement change does not meet the condition and the startup is not triggered.

[0022] The present invention also provides a dynamic determination system for the change in displacement of a non-steady-state bearing, comprising:

[0023] Analog switching unit, used for:

[0024] Obtain the start signal of the top shaft oil pump and the real-time value of the bearing displacement measurement;

[0025] Identifying a start signal of the jack oil pump;

[0026] If the start signal of the top shaft oil pump is a low level signal, the assignment operation is performed;

[0027] If the start signal of the top shaft oil pump is a high-level signal, the real-time value of the bearing displacement measurement is latched to obtain the initial static position data of the bearing;

[0028] Bearing displacement change determination unit, used for:

[0029] Determining a bearing displacement change based on initial static position data of the bearing;

[0030] Whether to trigger the start permission is determined based on the bearing displacement change.

[0031] In the dynamic determination system for the change in displacement of a non-steady-state bearing according to the present invention, the analog quantity switching unit comprises:

[0032] A switching module is used to collect the start signal of the top shaft oil pump and the real-time value of the bearing displacement measurement, identify the start signal, and perform an assignment operation or a latching operation based on the start signal.

[0033] In the dynamic determination system for the non-steady-state bearing displacement variation of the present invention, the bearing displacement variation determination unit comprises:

[0034] A subtraction module, the subtraction module is used to collect the real-time value of the bearing displacement measurement, and perform calculation processing on the real-time value of the bearing displacement measurement and the output value of the switching module to obtain the bearing displacement change;

[0035] A comparison module is used to determine whether to trigger the start-up permission based on the bearing displacement change.

[0036] In the dynamic determination system for the change in displacement of the non-steady-state bearing described in the present invention, the comparison module is specifically used for:

[0037] comparing the bearing displacement change with a threshold value;

[0038] If the bearing displacement change is greater than the threshold, it is determined that the bearing displacement change meets the condition and triggers the start permission;

[0039] If the bearing displacement change is less than the threshold, it is determined that the bearing displacement change does not meet the condition and the startup is not triggered.

[0040] The dynamic determination system for the displacement variation of the non-steady-state bearing of the present invention further includes: an output display unit;

[0041] The output unit is connected to the switching module and is used to output and display the initial data of the static position of the bearing and the real-time value of the bearing displacement measurement.

[0042] The implementation of the method and system for dynamically judging the change in the non-steady-state bearing displacement of the present invention has the following beneficial effects: including the following steps: obtaining the start signal of the top shaft oil pump and the real-time value of the bearing displacement measurement; identifying the start signal of the top shaft oil pump; if the start signal of the top shaft oil pump is a low-level signal, performing the assignment operation; if the start signal of the top shaft oil pump is a high-level signal, latching is performed based on the real-time value of the bearing displacement measurement to obtain the initial data of the static position of the bearing; determining the change in the bearing displacement based on the initial data of the static position of the bearing; judging whether to trigger the start permission based on the change in the bearing displacement. The present invention can measure the change in the bearing displacement without being affected by the different zero positions caused by the change in the rotation angle of the bearing when it is stationary, can accurately judge whether the start conditions of the bearing displacement change of the circulating water pump meet the requirements, can prevent the false permission signal from causing the pump body to burn after starting, effectively solves the technical difficulties on site, and prevents the pump group from burning. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0044] Figure 1 It is a schematic flow chart of a method for dynamically determining a change in displacement of a non-steady-state bearing provided by the present invention;

[0045] Figure 2 It is a principle block diagram of the dynamic judgment system of the non-steady-state bearing displacement variation provided by the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In order to solve the design defects of the existing shaft displacement measurement, the present invention provides a measurement method for judging the change in displacement of an asymmetric bearing in a nuclear power plant. When measuring the change in bearing displacement, this method is not affected by the different zero positions caused by the change in the rotation angle of the bearing when it is stationary, which effectively solves the on-site technical difficulties and avoids the risk of burning of the circulating water pump due to insufficient top shaft displacement when starting.

[0048] According to the on-site process requirements, the shaft displacement measurement needs to monitor the displacement change when the pump is started. The current method of using the difference between the real-time value and the fixed value does not meet the judgment requirements, because the initial value before each start of the top shaft oil pump is different and deviates from the zero position. Based on this, the present invention adopts a method of real-time updating and self-maintaining the measured value before the top shaft oil pump is started, and the initial state is latched when the pump start signal is triggered.

[0049] Specifically, in a preferred embodiment, Figure 1 As shown, the dynamic determination method of the non-steady-state bearing displacement variation comprises the following steps:

[0050] Step S101: obtaining a start signal of a top shaft oil pump and a real-time value of bearing displacement measurement.

[0051] Step S102: Identify the start signal of the top shaft oil pump.

[0052] Specifically, in the embodiment of the present invention, the start signal of the top shaft oil pump includes: a low level signal and a high level signal. By identifying the start signal of the top shaft oil pump, the start state of the top shaft oil pump can be determined. That is, when it is a low level signal, it can be determined that the top shaft oil pump is not started, and when it is a high level signal, it can be determined that the top shaft oil pump is started.

[0053] Step S103: If the start signal of the top shaft oil pump is a low level signal, the assignment operation is performed.

[0054] In an embodiment of the present invention, if the start signal of the top shaft oil pump is a low-level signal, executing the assignment operation includes: if the start signal of the top shaft oil pump is a low-level signal, using the real-time value of the bearing displacement measurement as the shaft displacement measurement value at the previous moment to complete the assignment operation.

[0055] Step S104: If the start signal of the top shaft oil pump is a high-level signal, the real-time value of the bearing displacement measurement is latched to obtain the initial static position data of the bearing.

[0056] In an embodiment of the present invention, if the start signal of the top shaft oil pump is a high-level signal, latching is performed based on the real-time value of the bearing displacement measurement, and obtaining the initial data of the static position of the bearing includes: if the start signal of the top shaft oil pump is a high-level signal, the output value is switched to the real-time value of the bearing displacement measurement and maintained, and the initial data of the static position of the bearing is obtained.

[0057] Step S105: determining the bearing displacement change based on the initial static position data of the bearing.

[0058] In an embodiment of the present invention, determining the bearing displacement change based on the initial static position data of the bearing includes: subtracting the initial static position data of the bearing from the current real-time value of the bearing displacement measurement to obtain the bearing displacement change.

[0059] Step S106: Determine whether to trigger the start permission based on the bearing displacement change.

[0060] In an embodiment of the present invention, judging whether to trigger the start-up permission condition based on the bearing displacement change includes: comparing the bearing displacement change with a threshold value; if the bearing displacement change is greater than the threshold value, judging that the bearing displacement change meets the condition and triggering the start-up permission; if the bearing displacement change is less than the threshold value, judging that the bearing displacement change does not meet the condition and does not trigger the start-up permission.

[0061] like Figure 2 As shown, the present invention also provides a dynamic determination system for the displacement variation of an unsteady bearing, wherein the dynamic determination system for the displacement variation of an unsteady bearing can be applied to the dynamic determination method for the displacement variation of an unsteady bearing disclosed in an embodiment of the present invention.

[0062] like Figure 2 As shown, the dynamic determination system of the non-steady-state bearing displacement variation comprises: an analog quantity switching unit 10 and a bearing displacement variation determination unit 20 .

[0063] Specifically, in the embodiment of the present invention, the analog switching unit 10 is used to: obtain the starting signal of the top shaft oil pump and the real-time value of the bearing displacement measurement; identify the starting signal of the top shaft oil pump; if the starting signal of the top shaft oil pump is a low-level signal, perform an assignment operation; if the starting signal of the top shaft oil pump is a high-level signal, latch it based on the real-time value of the bearing displacement measurement to obtain the initial data of the static position of the bearing.

[0064] Optionally, in an embodiment of the present invention, Figure 2 As shown, the analog switching unit 10 includes: a switching module, the switching module is used to collect the start signal of the top shaft oil pump and the real-time value of the bearing displacement measurement, and identify the start signal and perform an assignment operation or a latch operation based on the start signal. The switching module collects the start signal of the top shaft oil pump and the real-time value of the bearing displacement measurement in real time.

[0065] The bearing displacement variation determination unit 20 is used to: determine the bearing displacement variation based on the initial data of the static position of the bearing; and determine whether to trigger the start permission based on the bearing displacement variation.

[0066] Optionally, in an embodiment of the present invention, Figure 2 As shown, the bearing displacement change determination unit 20 includes: a subtraction module, which is used to collect the real-time value of the bearing displacement measurement, and to perform calculations on the real-time value of the bearing displacement measurement and the output value of the switching module to obtain the bearing displacement change; and a comparison module, which is used to determine whether to trigger the start-up permission based on the bearing displacement change. It should be noted that the subtraction module collects the real-time value of the bearing displacement measurement in real time.

[0067] Specifically, the comparison module is used to compare the bearing displacement change with the threshold; if the bearing displacement change is greater than the threshold, it is judged that the bearing displacement change meets the conditions and triggers the start-up permission; if the bearing displacement change is less than the threshold, it is judged that the bearing displacement change does not meet the conditions and does not trigger the start-up permission. The threshold is 50um. That is, when the deviation between the bearing displacement change and the threshold is greater than 0, it means that the bearing displacement change is greater than the threshold. At this time, it means that the bearing has been monitored to be lifted to a safe position, triggering the start-up permission condition.

[0068] Further, in the embodiment of the present invention, if Figure 2 As shown, the dynamic judgment system for the non-steady-state bearing displacement change also includes: an output display unit 30; the output unit is connected to the switching module and is used to output and display the initial data of the static position of the bearing and the real-time value of the bearing displacement measurement. By outputting and displaying the initial data of the static position of the bearing and the real-time value of the bearing displacement measurement, the user can intuitively grasp the initial data of the static position of the bearing and the real-time displacement of the bearing, which is convenient for data comparison and monitoring.

[0069] like Figure 2 As shown, the pin IN of the switching module is the switching condition, and X1 and X2 are two 4-20mA analog signals. When the IN condition is false (i.e. 0), the switching module outputs the value of X1; when the IN condition is true (i.e. 1), the switching module outputs the value of X2.

[0070] The present invention adopts the top shaft oil pump start signal as the trigger to lock the latest shaft displacement data when the bearing is static.

[0071] Specifically, Figure 2As shown in the figure, when the top shaft oil pump is not started, the start signal of the top shaft oil pump is low level. At this time, the real-time value of the bearing displacement measurement is input and output by X1 and assigned to X2. In this process, X2 follows the value change of X1, that is, X2 is the shaft displacement measurement value at the previous moment. At this time, the difference obtained by the subtraction module by subtracting the two values ​​of X1 and X2 is 0. When the top shaft pump start signal is triggered, the output value of the switching module is instantly selected as X2 (that is, the shaft displacement measurement value at the previous moment) and is maintained, that is, the static position initial data of the bearing is latched (that is, the latest static position initial data of the bearing). At this time, the input end X1 of the subtraction module is the real-time value of the bearing displacement measurement (that is, the current real-time value of the bearing displacement measurement, that is, the displacement measurement value at the current moment), and X2 is the static position initial data of the bearing. As the top shaft oil lifts the bearing, the bearing displacement changes, and the input value of the input end X1 of the subtraction module also changes (that is, the input is the real-time measurement value of the bearing displacement). Therefore, through the action of the subtraction module, when the change (that is, the output end of the subtraction module) is greater than the threshold (50μm), it means that the bearing has been monitored to the safe position, which can trigger the start-up. At the same time, the initial static position data is also sent to the output display unit 30, which is output and displayed (that is, the screen display) by the output display unit 30 for subsequent monitoring.

[0072] In the existing scheme, the original configuration design has defects. When the jacking oil system is abnormal, due to the inherent defects of the shaft displacement measurement system, the system may mistakenly judge that the bearing displacement has reached a safe position, automatically start the circulating water pump and burn the pump body. Through the present invention, during measurement, it is not affected by the different zero positions caused by the change in the rotation angle of the bearing when it is stationary, and can accurately judge whether the starting conditions of the circulating water pump bearing displacement change meet the requirements (whether the bearing is pushed to a safe position by the jacking oil), and can prevent false permission signals from causing the pump body to burn after starting; the new measurement method and measurement system can also lock the initial shaft displacement data before each bearing start, which can be sent to the operation monitoring screen to facilitate displacement monitoring after the pump body is running, effectively solving on-site technical difficulties and preventing pump group burning events.

[0073] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0074] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0075] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0076] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot limit the scope of protection of the present invention. All equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for dynamically determining the displacement variation of a non-steady-state bearing, characterized in that: The following steps are involved: Obtain the start signal of the top shaft oil pump and the real-time value of the bearing displacement measurement; Identifying a start signal of the jack oil pump; If the start signal of the top shaft oil pump is a low level signal, the assignment operation is performed; If the start signal of the top shaft oil pump is a high-level signal, the real-time value of the bearing displacement measurement is latched to obtain the initial static position data of the bearing; Determining a bearing displacement change based on initial static position data of the bearing; Whether to trigger the start permission is determined based on the bearing displacement change.

2. The method for dynamically determining the displacement variation of an unsteady-state bearing according to claim 1, characterized in that: If the start signal of the top shaft oil pump is a low level signal, executing the assignment operation includes: If the start signal of the top shaft oil pump is a low-level signal, the real-time value of the bearing displacement measurement is used as the shaft displacement measurement value at the previous moment to complete the assignment operation.

3. The method for dynamically determining the displacement variation of an unsteady-state bearing according to claim 1, characterized in that: If the start signal of the top shaft oil pump is a high level signal, latching is performed based on the real-time value of the bearing displacement measurement to obtain the initial static position data of the bearing, which includes: If the start signal of the top shaft oil pump is a high-level signal, the output value is switched to the real-time value of the bearing displacement measurement and maintained to obtain the initial static position data of the bearing.

4. The method for dynamically determining the displacement variation of an unsteady-state bearing according to claim 1, characterized in that: Determining the bearing displacement change based on the initial static position data of the bearing comprises: The bearing displacement variation is obtained by subtracting the initial static position data of the bearing from the current real-time value of the bearing displacement measurement.

5. The method for dynamically determining the displacement variation of an unsteady-state bearing according to claim 1, characterized in that: The determining whether to trigger the start-up permission condition based on the bearing displacement change includes: comparing the bearing displacement change with a threshold value; If the bearing displacement change is greater than the threshold, it is determined that the bearing displacement change meets the condition and triggers the start permission; If the bearing displacement change is less than the threshold, it is determined that the bearing displacement change does not meet the condition and the startup is not triggered.

6. A dynamic judgment system for the change in displacement of an unsteady bearing, characterized in that: include: Analog switching unit, used for: Obtain the start signal of the top shaft oil pump and the real-time value of the bearing displacement measurement; Identifying a start signal of the jack oil pump; If the start signal of the top shaft oil pump is a low level signal, the assignment operation is performed; If the start signal of the top shaft oil pump is a high-level signal, the real-time value of the bearing displacement measurement is latched to obtain the initial static position data of the bearing; Bearing displacement change determination unit, used for: Determining a bearing displacement change based on initial static position data of the bearing; Whether to trigger the start permission is determined based on the bearing displacement change.

7. The dynamic determination system of the non-steady-state bearing displacement variation according to claim 6 is characterized in that: The analog switching unit comprises: A switching module is used to collect the start signal of the top shaft oil pump and the real-time value of the bearing displacement measurement, identify the start signal, and perform an assignment operation or a latching operation based on the start signal.

8. The dynamic determination system of the non-steady-state bearing displacement variation according to claim 7 is characterized in that: The bearing displacement variation determination unit comprises: A subtraction module, the subtraction module is used to collect the real-time value of the bearing displacement measurement, and perform calculation processing on the real-time value of the bearing displacement measurement and the output value of the switching module to obtain the bearing displacement change; A comparison module is used to determine whether to trigger the start-up permission based on the bearing displacement change.

9. The dynamic determination system of the non-steady-state bearing displacement variation according to claim 8, characterized in that: The comparison module is specifically used for: comparing the bearing displacement change with a threshold value; If the bearing displacement change is greater than the threshold, it is determined that the bearing displacement change meets the condition and triggers the start permission; If the bearing displacement change is less than the threshold, it is determined that the bearing displacement change does not meet the condition and the startup is not triggered.

10. The dynamic determination system of the non-steady-state bearing displacement variation according to claim 7, characterized in that: Also includes: Output display unit; The output unit is connected to the switching module and is used to output and display the initial data of the static position of the bearing and the real-time value of the bearing displacement measurement.

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