A method and device for online monitoring of cooling water inlet pipes of generator stator windings

Abstract

This invention relates to an online monitoring method and device for generator stator winding cooling water inlet pipes. The online monitoring method includes: sequentially numbering the stator upper layer bars, stator lower layer bars, annular leads, and outlet bushing water inlet pipes, and dividing them into zones according to the numbering order: upper layer bar zone, lower layer bar zone, annular lead zone, and outlet bushing zone; simultaneously acquiring the flow rates of normal and abnormal water inlet pipes in each zone in real time; and obtaining the flow rate deviation value of all abnormal water inlet pipes based on the flow rate value of a single abnormal water inlet pipe and the average flow rate of all normal water inlet pipes; determining whether the flow rate deviation value of the abnormal water inlet pipe is greater than a set value; if it is greater than the set value, issuing a maintenance reminder for the corresponding abnormal water inlet pipe according to its number. This invention can determine whether the water inlet pipe needs maintenance by monitoring the flow rate value online, thereby reducing the risk of generator insulation damage caused by water inlet pipe blockage and improving operation monitoring capabilities.

Description

Technical Field

[0001] This invention relates to the field of generator monitoring technology, and in particular to a method and device for online monitoring of the cooling water inlet pipe of a generator stator winding. Background Technology

[0002] The generator stator cooling water system is a closed-loop cooling device mainly used for heat dissipation of the generator stator windings and high-voltage bushings on the outgoing side. The main function of the stator cooling water system is to ensure that cooling water flows continuously through the inside of the stator coils, thereby carrying away the heat caused by losses in the generator stator coils, so as to ensure that the temperature rise of the stator coils meets the relevant requirements for generator operation.

[0003] Both the factory and maintenance tests of generators require the measurement of the water flow rate in each of the generator stator winding cooling water inlet pipes to avoid blockages. However, during generator operation, maintenance personnel often do not have the conditions to enter the generator stator winding end, requiring the generator to be shut down for inspection, which increases the time and labor costs of generator inspection. Summary of the Invention

[0004] This invention provides a method and device for online monitoring of cooling water inlet pipes of generator stator windings. It can determine whether the inlet pipe needs maintenance by monitoring the flow rate of the inlet pipe online, thereby reducing the risk of generator insulation damage caused by inlet pipe blockage, improving operation monitoring capabilities, providing data support for generator condition-based maintenance, and reducing the detection costs caused by generator downtime.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for online monitoring of cooling water inlet pipes of generator stator windings includes: The upper stator bars, lower stator bars, annular leads, outlet sleeves, and water inlet pipes are numbered sequentially, and then divided into zones of the same type according to the numbering order, namely the upper bar zone, lower bar zone, annular lead zone, and outlet sleeve zone. The flow rate values ​​of normal and abnormal water pipes in each area are obtained in real time. Based on the flow rate value of a single abnormal water pipe and the average flow rate of all normal water pipes, the flow rate deviation value of all abnormal water pipes is obtained. Determine if the flow deviation of the abnormal water inlet pipe exceeds the set value. If it does, issue a maintenance reminder for the corresponding abnormal water inlet pipe based on its number.

[0006] Preferably, the online monitoring method further includes: storing the real-time flow values ​​of normal and abnormal water pipes in each area, the average flow value of all normal water pipes, and the flow deviation value of the abnormal water pipes, and constructing a database based on the above values.

[0007] Preferably, the online monitoring method further includes: based on all traffic deviation values ​​of each area within any time period in the above database, the average traffic deviation can be obtained, and it can be determined whether the average traffic deviation is greater than a set value. If it is greater than the set value, a maintenance reminder is issued.

[0008] Preferably, the criterion for judging a normal water inlet pipe is: based on the pipe diameter, the theoretical flow rate of the water inlet pipe is obtained by time-difference ultrasonic method; Compare the theoretical flow rate and the real-time flow rate of a single water pipe. Check if the deviation between the two is greater than the set difference. If it is greater than the set difference, determine that the water pipe is not a normal water pipe and store the deviation in the database.

[0009] Preferably, if the flow deviation value of at least half of the water pipes in each area is greater than the set value, the flow of the water pipes is monitored for a certain period of time. After a certain period of time, if the flow deviation value of less than half of the water pipes in each area is greater than the set value, a reminder to maintain the water pipes is issued again based on the judgment result of the flow deviation value of the water pipes.

[0010] Preferably, the flow rate of a single water pipe is calculated in real time using a time-difference ultrasonic method.

[0011] An online monitoring device for cooling water inlet pipes of generator stator windings is used to implement the above-mentioned online monitoring method. It includes a measuring terminal and multiple ultrasonic measuring components, wherein the multiple ultrasonic measuring components are correspondingly installed on multiple water inlet pipes at the upper layer bar, the lower layer bar of the stator, the annular lead wire, and the outlet sleeve. The ultrasonic measurement assembly includes an ultrasonic probe and a fixing component. The fixing component is installed on the outside of the cooling water inlet pipe, and the ultrasonic probe is installed on the fixing component. The ultrasonic probe is electrically connected to the measurement terminal.

[0012] Preferably, the fixing member includes two semi-annular cylindrical parts, the ends of which are connected to each other to be sleeved on the outside of the water inlet pipe; The ultrasonic probe includes a probe one for emitting signals and a probe two for receiving signals, wherein the probe one and the probe two are respectively embedded in the inner walls of two semi-annular cylindrical parts.

[0013] Preferably, the semi-annular cylindrical component is made of polytetrafluoroethylene, and the inner sides of the two semi-annular cylindrical components are coated with a coupling agent layer.

[0014] Preferably, the ultrasonic probes on the upper layer bar, lower layer bar, annular lead wire, and multiple water inlet pipes at the outlet sleeve are connected in sequence to channels numbered 1 to N at the measurement terminal via shielded cables.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Number all water pipes so that they can be easily identified by number, making it convenient for maintenance personnel to know which pipes need to be inspected and maintained.

[0016] 2. It can identify normal and abnormal water pipes online by monitoring the flow rate of the water pipes, so that maintenance personnel can know in real time which water pipes are normal and which are abnormal, so as to facilitate flexible maintenance.

[0017] 3. By comparing the flow rate of the abnormal water inlet pipe with the average flow rate of the normal water inlet pipe, the flow rate deviation of the abnormal water inlet pipe is obtained. Compared with the set value, it can be determined whether there is a water inlet pipe in the abnormal water inlet pipe that needs maintenance. This is simple and intuitive, reduces the risk of generator insulation damage caused by water inlet pipe blockage, improves operation monitoring capabilities, provides data support for generator condition maintenance, and reduces the detection costs caused by generator shutdown. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a block diagram of the online monitoring method in an embodiment of the present invention; Figure 2 This is a schematic diagram of the online monitoring device in an embodiment of the present invention; Figure 3 This is a schematic diagram of the ultrasonic measuring component fixed to the water pipe in an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Water inlet pipe; 2. Fixing component; 21. Semi-annular cylindrical component; 22. Coupling agent layer; 3. Probe one; 4. Probe two. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] This invention provides an online monitoring method for the cooling water inlet pipe of a generator stator winding. The online monitoring method is as follows: Figure 1 As shown below: First, the upper stator windings, lower stator windings, ring leads, and outlet bushing water pipes are numbered sequentially from 1 to N. There are many upper stator windings, and thus many corresponding water pipes. Similarly, there are many lower stator windings, and thus many corresponding water pipes. There are also many water pipes corresponding to the ring leads and outlet bushings. In other words, there are many water pipes corresponding to the generator stator windings. The water pipes corresponding to the upper stator windings, lower stator windings, ring leads, and outlet bushings are numbered sequentially from 1 to N.

[0025] The multiple water inlet pipes corresponding to the upper stator bars, the lower stator bars, the annular leads, and the outlet sleeves are divided into zones. Specifically, the multiple water inlet pipes corresponding to the upper stator bars are designated as the upper stator bar area, the multiple water inlet pipes corresponding to the lower stator bars are designated as the lower stator bar area, the multiple water inlet pipes corresponding to the annular leads are designated as the outlet sleeve area, and the multiple water inlet pipes corresponding to the outlet sleeves are designated as the outlet sleeve area. For example, taking the upper stator bar area as an example, the upper stator bar area includes not only the measurement area of ​​the multiple inlet pipes corresponding to the upper stator bars, but also the data area of ​​the measured water flow of the multiple water inlet pipes. The two are corresponding.

[0026] During the operation of the generator stator winding, the flow rate of multiple water inlet pipes corresponding to the above-mentioned areas is acquired in real time and simultaneously through an online monitoring device. Since the water inlet pipes may become blocked during use, the water inlet pipes in each area include both normal and abnormal water inlet pipes. The average flow rate is calculated based on the flow rate of all normal water inlet pipes. By comparing the flow rate of a single abnormal water inlet pipe with the average flow rate of all normal water inlet pipes, the flow rate deviation of all abnormal water inlet pipes is obtained. It should be noted that the number of abnormal water inlet pipes may be zero, that is, the flow of all water inlet pipes is normal, and the abnormal water inlet pipes here do not mean that the blockage of the water inlet pipes has reached the maintenance requirement.

[0027] Based on the flow deviation values ​​of the abnormal water inlet pipes obtained above, they are compared with the set values. If the flow deviation value of a certain abnormal water inlet pipe is greater than the set value, a maintenance reminder is issued according to the number of the abnormal water inlet pipe. It should be noted that the comparison of the flow deviation values ​​of all abnormal water inlet pipes with the set values ​​is carried out simultaneously. If the flow value of one or more abnormal water inlet pipes is greater than the deviation value, a maintenance reminder is issued simultaneously according to the corresponding number.

[0028] In summary, firstly, all water pipes are numbered to facilitate identification of the corresponding pipes, allowing maintenance personnel to easily identify the pipes requiring inspection and maintenance. Secondly, the system can distinguish between normal and abnormal water pipes by monitoring their flow rates online, enabling maintenance personnel to know in real time which pipes are normal and which are abnormal, facilitating flexible maintenance. Then, by comparing the flow rate values ​​of abnormal water pipes with the average flow rate of normal water pipes, the flow rate deviation value of abnormal water pipes is obtained. Comparing this deviation with a set value determines whether any abnormal water pipes require maintenance. This method is simple and intuitive, reduces the risk of generator insulation damage caused by water pipe blockage, improves operational monitoring capabilities, and provides data support for generator condition-based maintenance.

[0029] Specifically, let the total number of water pipes in a certain area be m+n, the number of normal water pipes in that area be m, and the flow rate be Q. m (where m ranges from 1 to m), the number of abnormal water pipes is n, and the flow rate is Q. n (Where n takes values ​​from 0 to n), the average flow rate of all normal water inlet pipes is P, then the flow rate deviation value of a single pipe is S. n The calculation method is as follows: S n =|(Q n -P)| / P×100%; The set value for judging the flow deviation is 15%. If the flow deviation of a certain abnormal water pipe is greater than 15%, maintenance is required.

[0030] Specifically, the aforementioned online monitoring method further includes: while acquiring data, storing the real-time flow rates of normal and abnormal water pipes in each area, the average flow rate of all normal water pipes, and the flow deviation values ​​of each individual water pipe, and constructing a database based on these values. This allows maintenance personnel to review and analyze the usage process of the water pipes using the data in the database, enabling more accurate analysis of the blockage process and causes of blockages, thus facilitating maintenance. It should be noted that once the flow rates of normal and abnormal water pipes, the average flow rate of all normal water pipes, and the flow deviation values ​​of individual water pipes are obtained, they are stored in the database. Then, the flow deviation values ​​of abnormal water pipes are retrieved from the database and compared with the set values.

[0031] Furthermore, based on the flow deviation values ​​of all abnormal water pipes in each zone within the aforementioned database for any given time period, the average flow deviation for each zone during that time period can be obtained. By determining whether the average flow deviation is greater than a set value, it can be determined whether the cooling capacity of the water pipes within each zone is lower than the usage requirements, thus providing maintenance personnel with an overall online cooling capacity for each zone. Of course, if the average flow deviation of a certain zone is greater than the set value, a maintenance reminder will be issued for that zone. The water pipes requiring maintenance are all abnormal water pipes, and maintenance is required if the flow deviation value of an abnormal water pipe exceeds or approaches the set value. Specifically, the average flow deviation is S. 平 S 平 Then it equals multiple S n The average value of (where n ranges from 0 to n) is the average value of the flow deviation. The set value of the average flow deviation can also be 15%, which can be set by the maintenance personnel according to the maintenance requirements.

[0032] Specifically, the criteria for distinguishing between normal and abnormal water inlet pipes are as follows: Based on the pipe diameter, the theoretical flow rate of a single water inlet pipe is obtained using time-of-flight ultrasonic testing. That is, in the initial stable operation phase of the water inlet pipe, before blockage, the theoretical flow rate of a single water inlet pipe is measured using time-of-flight ultrasonic testing and used as the standard flow rate value for that single pipe. Then, the theoretical flow rate Q of the single water inlet pipe is compared. 理 and real-time traffic value Q n The system checks whether the deviation between the theoretical flow rate and the real-time flow rate is greater than a set difference. If it is, the water pipe is determined to be a non-normal water pipe; otherwise, it is a normal water pipe. The deviation is stored in a database for maintenance personnel to review and analyze later. Specifically, the formula for calculating the deviation between the theoretical flow rate and the real-time flow rate of a single water pipe can be the same as the formula for calculating the average flow rate P, simply by replacing P with Q. 理That is, set the above-mentioned difference to about 5%, which is set by the maintenance personnel. It should be noted that the difference between the normal and abnormal water pipes is not significant. When the theoretical flow rate and real-time flow rate of the water pipe are near the difference, it indicates that the water pipe is just blocked and the blockage area is very small. This is to remind the maintenance personnel to pay attention to the water pipe with the deviation value near the difference.

[0033] Specifically, if it is determined that the flow deviation value of at least half of the water pipes in each zone is greater than the set value, the flow of the water pipes will continue to be monitored for a certain period of time. After a certain period of time, if the flow deviation value of less than half of the water pipes in each zone is greater than the set value, a reminder will be issued again to indicate whether each water pipe needs maintenance based on the judgment result of the flow deviation value of each water pipe. This is to avoid misjudging that the water pipe is blocked due to short-term fluctuations in the water pump load during the initial start-up or normal operation of the external water pump. If, after a certain period of time, the flow deviation value of at least half of the water pipes in each zone is still greater than the set value, then it is determined that there is a problem with the water pump, because during normal use of the water pump, it is unlikely that the flow deviation value of at least half of the water pipes in each zone will be greater than the set value.

[0034] Specifically, the online real-time flow rate of the aforementioned water inlet pipe is calculated using the time-of-flight ultrasonic method. The time-of-flight ultrasonic method features non-contact measurement, does not damage the pipeline, does not affect the safety of the unit, has no pressure loss, does not change the flow resistance of the water system, and has high measurement accuracy, good linearity, wide range, and is easy to install and maintain.

[0035] This invention provides an online monitoring device for the cooling water inlet pipe of a generator stator winding, used to implement the above-mentioned online monitoring method, such as... Figure 2 As shown, the online monitoring device includes a measurement terminal and multiple ultrasonic measurement components. These components are installed on multiple water inlet pipes 1 at the upper stator, lower stator, annular lead wire, and outlet sleeve. Each ultrasonic measurement component includes an ultrasonic probe and a fixing element 2. The fixing element 2 is installed on the outside of the cooling water inlet pipe 1, and the ultrasonic probe is mounted on the fixing element 2. The ultrasonic probe is electrically connected to the measurement terminal to feed back the measured flow rate value of the water inlet pipe 1 to the measurement terminal for calculation and judgment. This results in the flow rate values ​​of normal and abnormal water inlet pipes 1, the average flow rate of all normal water inlet pipes 1, and the flow rate deviation value of each abnormal water inlet pipe 1. A database is then created, and the flow rate deviation value of the abnormal water inlet pipe 1 in the database is compared with a set value to determine whether the abnormal water inlet pipe 1 requires maintenance. The measurement terminal can be a power plant monitoring terminal.

[0036] Specifically, such as Figure 3As shown, the fixing member 2 includes two semi-annular cylindrical parts 21, the ends of which are connected to fit around the outside of the water pipe 1. Correspondingly, the ultrasonic probe includes a probe 3 for emitting signals and a probe 4 for receiving signals. The probe 3 and the probe 4 are respectively embedded in the inner wall of the two semi-annular cylindrical parts 21. The probe 3 emits signals and the probe 4 receives signals. The flow rate of the water pipe 1 is calculated based on the time-difference ultrasonic principle.

[0037] Specifically, both semi-annular cylindrical components 21 are made of polytetrafluoroethylene (PTFE). The ends of the two semi-annular cylindrical components 21 are connected by epoxy resin bolts and nuts to form a cylindrical clamp, which has advantages such as corrosion resistance, high and low temperature applicability, self-lubrication and non-stick properties, electrical insulation, aging resistance, and long service life. The inner side of the two semi-annular cylindrical components 21 is coated with a coupling agent layer 22 so that the inner side of the two semi-annular cylindrical components 21 can be stably fixed to the outer periphery of the water inlet pipe 1 without affecting the transmission or reception of ultrasonic waves by the probe. Specifically, when fixing the cylindrical clamp, the inner side of the semi-annular cylindrical component 21 is coated with high-temperature coupling agent to form a coupling agent layer 22, and the semi-annular cylindrical component 21 is fixed to the outer periphery of the water inlet pipe 1 by the coupling agent.

[0038] Specifically, the ultrasonic probes on multiple water inlet pipes 1 at the upper layer bar, lower stator bar, annular lead wire, and outlet sleeve are connected in sequence to channels numbered 1 to N at the measurement terminal via shielded cables, so that the measurement terminal can partition all water inlet pipes 1 according to the correspondence between the upper layer bar, lower stator bar, annular lead wire, and outlet sleeve.

[0039] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for online monitoring of cooling water inlet pipes of generator stator windings, characterized in that, include: The upper stator bars, lower stator bars, annular leads, outlet sleeves, and water inlet pipes are numbered sequentially, and then divided into zones of the same type according to the numbering order, namely the upper bar zone, lower bar zone, annular lead zone, and outlet sleeve zone. The flow rate values ​​of normal and abnormal water pipes in each area are obtained in real time. Based on the flow rate value of a single abnormal water pipe and the average flow rate of all normal water pipes, the flow rate deviation value of all abnormal water pipes is obtained. Determine if the flow deviation of the abnormal water inlet pipe exceeds the set value. If it does, issue a maintenance reminder for the corresponding abnormal water inlet pipe based on its number.

2. The online monitoring method according to claim 1, characterized in that, Also includes: The flow rates of normal and abnormal water pipes in each region, the average flow rate of all normal water pipes, and the flow rate deviation of abnormal water pipes are stored in real time, and a database is constructed based on these values.

3. The online monitoring method according to claim 2, characterized in that, Also includes: Based on all traffic deviation values ​​of each area within any time period in the above database, the average traffic deviation can be obtained, and it can be determined whether the average traffic deviation is greater than the set value. If it is greater than the set value, a maintenance reminder will be issued.

4. The online monitoring method according to claim 2, characterized in that, The criteria for judging a normal water pipe are: based on the pipe diameter, the theoretical flow rate of the water pipe is obtained by time-of-flight ultrasonic testing. Compare the theoretical flow rate and the real-time flow rate of a single water pipe. Check if the deviation between the two is greater than the set difference. If it is greater than the set difference, determine that the water pipe is not a normal water pipe and store the deviation in the database.

5. The online monitoring method according to claim 1, characterized in that, If the flow deviation of at least half of the water pipes in each area is greater than the set value, the flow of the water pipes will continue to be monitored for a certain period of time. After a certain period of time, if the flow deviation of less than half of the water pipes in each area is greater than the set value, a reminder to maintain the water pipes will be issued again based on the judgment result of the flow deviation of the water pipes.

6. The online monitoring method according to claim 1, characterized in that, The flow rate of a single water pipe is calculated in real time using a time-difference ultrasonic method.

7. An online monitoring device for the cooling water inlet pipe of a generator stator winding, used to implement the online monitoring method according to any one of claims 1-6, characterized in that, It includes a measurement terminal and multiple ultrasonic measurement components, with the multiple ultrasonic measurement components corresponding to multiple water inlet pipes installed at the upper layer bar, the lower layer bar of the stator, the annular lead wire, and the outlet sleeve; The ultrasonic measurement assembly includes an ultrasonic probe and a fixing component. The fixing component is installed on the outside of the cooling water inlet pipe, and the ultrasonic probe is installed on the fixing component. The ultrasonic probe is electrically connected to the measurement terminal.

8. The online monitoring device according to claim 7, characterized in that, The fastener includes two semi-annular cylindrical parts, the ends of which are connected to each other to be fitted onto the outside of the water pipe. The ultrasonic probe includes a probe one for emitting signals and a probe two for receiving signals, wherein the probe one and the probe two are respectively embedded in the inner walls of two semi-annular cylindrical parts.

9. The online monitoring device according to claim 8, characterized in that, The semi-annular cylindrical components are made of polytetrafluoroethylene, and the inner sides of the two semi-annular cylindrical components are coated with a coupling agent layer.

10. The online monitoring device according to claim 7, characterized in that, The ultrasonic probes on the upper layer bar, lower layer bar, ring lead wire, and multiple water inlet pipes at the outlet sleeve are connected in sequence to channels numbered 1 to N at the measurement terminal via shielded cables.

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