JPH04187802A - Bearing metal temperature monitor - Google Patents

Abstract

PURPOSE:To realize precise monitoring so as to perform a stable operation all the time independent of experience of an operator by comparing an alarm set value of an alarm setter with a detection value of a temperature detector during an operation of a rotary machine so as to decide whether it is an alarm state or not, and providing a deciding means for outputting the decision result. CONSTITUTION:A bearing supply oil temperature detection value is input into a deciding portion 6(n) from a bearing supply oil temperature detector via an input line 7. An alarm setter sets an alarm set value on the basis of a normal bearing metal temperature pattern in a memory portion 5(n). The deciding portion 6(n) corrects a bearing metal temperature upon receipt of a detection value of a temperature detector 1(n) and the bearing supply oil temperature detection value. Whether a normal state or an abnormal state is decided on the basis of the comparison of the bearing metal temperature value with the alarm set value. The above decision result of the deciding portion 6(n) is output as an alarm and an upper limit contact. Therefore, even an inexperienced operator can monitor the bearing metal temperature to decide normality or abnormality.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a bearing metal temperature monitoring device for monitoring the bearing metal temperature of a turbine or the like used in a thermal power plant, a nuclear power plant, etc. Regarding.

(Prior Art) Temperature monitoring of bearings of steam turbines and generators used in thermal power plants, nuclear power plants, etc. is one of the essential monitoring items for the safety of turbines and generators.

Bearing temperature monitoring of turbines and generators includes monitoring of the bearing metal temperature and monitoring of the temperature of lubricating oil supplied to the bearing. In any of these, if a temperature rise occurs, abnormalities such as seizure will occur in the bearing, so it is necessary to quickly detect changes in this temperature rise. When operating a turbine or generator, as the rotational speed increases, the temperature of the bearing metal and its lubricating oil also rise. For this reason, the determination of whether the bearing is in an abnormal state or a normal state has been made by setting fixed reference values for each of the bearing metal and the lubricating oil.

However, the bearing metal temperature responds more sensitively to the rotation speed than the lubricating oil temperature, and the temperature of the bearing metal can be directly measured. Therefore, in recent years, there has been a tendency for bearing metal temperature monitoring to be increasingly adopted.

FIG. 5 is a block diagram of a bearing metal temperature monitoring device showing the above-mentioned conventional example.

Generally, the temperature detector 1 (n) uses a double-element thermocouple or a resistance temperature detector, and is appropriately placed at several locations on the bearing metal of a turbine or generator. One element of this temperature detector 1 (n) is connected to the recorder 2, and the other element is connected to the alarm setting device 3.

Recorder 2 records the detected value of temperature detector 1 (n).

Further, the alarm setting device 3(n) compares the detected value with first and second preset values and outputs an alarm and a contact output. That is, when the detected value is larger than the first set value, an alarm is output, and furthermore, when the detected value is larger than the second set value, an alarm is output.
When the value is greater than the set value, upper limit contact output and alarm output are performed. This alarm output notifies the operator of the abnormality by means such as voice (not shown). Also, at the upper limit contact output, the device is tripped, etc. Here, the first set value and the second set value have a relationship of the first set value and the second set value.

With the above configuration, when operating the turbine or generator, the operator 1 noter pays attention to the alarm output and upper limit contact output of the alarm setting device 3 (n). Furthermore, the recording trajectory of the recorder 2 is observed to monitor whether or not a particularly rapid temperature change is occurring. In addition, the broken lines in the figure indicate n temperature detectors l(1) to 1(n) and n corresponding to the bearing metal temperature monitoring locations.
This shows that a recorder 2 having a recording function of n detected values and n alarm setting devices 3(1) to 3(n) are provided. In addition, the above-mentioned first set value and second set value of the alarm setting device 3(n)
The set value may be the same depending on the monitoring location of the bearing metal.

(Problems to be Solved by the Invention) However, with the above-described bearing metal temperature monitoring device, there is no large change in the bearing metal temperature during the rated rotation of the turbine or generator, so there is no problem, but the following problem occurs at startup. That is, when a turbine or a generator is started, the temperature of the bearing metal rapidly increases as the rotational speed of the rotating shaft increases. In such a case, it is not easy to determine whether the rise in temperature of the bearing metal is normal or abnormal using only the results recorded by the recorder 2 of the conventional bearing metal temperature monitoring device described above. In other words, for the operator to make this determination,
Abundant experience in the normal temperature rise of the bearing metal during startup in the past and prompt response were required. Further, the first set value and second set value of the alarm setting device 3(n) may be too high at the time of startup, and it is also necessary to change the set values at the time of startup and rated rotation.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a bearing metal temperature monitoring device that allows even an operator without extensive experience to monitor the bearing metal temperature and determine whether it is normal or abnormal.

[Structure of the Invention] (Means for Solving the Problems) In the present invention, the storage means stores over time the detected values of a temperature detector disposed on a bearing of a rotating machine during normal operation under various operating conditions in advance. . The alarm setting means sets an alarm setting value based on the temporal temperature pattern data stored in the storage means. The determining means compares the alarm setting value of the alarm setting means with the detection value of the temperature detector during operation of the rotating machine to determine whether or not an alarm state is present, and outputs the result of this determination.

(Function) When operating a rotating machine, it is determined whether or not it is in an alarm state based on the alarm setting value based on the temperature data over time during normal operation in the past and the temperature detected by the temperature detector.

Therefore, it is possible to easily and accurately determine the temperature abnormality of the bearing of the rotating machine and output it.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a turbine bearing metal temperature monitoring device showing an embodiment of the present invention.

The difference from Fig. 5 is that the recorder 2 and the alarm setting device 3 (n
), a monitoring section 4 is provided, and this monitoring section 4 is composed of a storage section 5(n) and a determination section 6(n). In addition, in this embodiment, the detection unit 6 (n) inputs a detected bearing oil temperature value from a bearing oil temperature detector (not shown) through an input line 7.
I am trying to input it into .

Here, the storage unit 5(n) reads the past normal bearing metal temperature over time for each process of starting, stopping, and changing the rated rotation speed of each bearing, and stores this as a normal bearing metal temperature pattern. There is.

An alarm set value is set by an alarm setting section (not shown) based on the normal bearing metal temperature pattern in the storage section 5(n). The determination unit 6 (n) inputs the detection value of the temperature detector 1 (n) and the bearing oil supply temperature detection value, and corrects the bearing metal temperature. The value of this bearing metal temperature is then compared with an alarm setting value to determine whether it is in a normal state or an abnormal state. The above judgment result of the judgment section 6(n) is output as an alarm and an upper limit contact. Note that since there are usually about 4 to 12 bearings in a turbine, the number of temperature detectors 1 (n) corresponding to the bearings is equal to the number of bearings, or for example, if the turbine has a large capacity, there are two temperature detectors per bearing. vessel 1 (n)
will be established. The temperature detector 1 is also used for the determination unit 6(n).
A number corresponding to (n) is provided.

Regarding the storage section 5(n), as described later, the number may correspond to the number of temperature detectors 1(n), but there are also cases where only one storage section is required.

With the above configuration, the monitoring section 4 monitors the temperature of the bearing metal according to the processing procedure shown in FIG.

First, a normal bearing metal temperature pattern is selected and the data is read into the storage section 5(n) (101).

This temperature pattern varies depending on the capacity of the turbine, the length of the shutdown time before startup, and various conditions such as whether the turbine is started hot or cold. For this reason, the optimum temperature pattern is selected from the patterns prepared in advance according to the current operating conditions. Note that this temperature pattern selects a normal temperature pattern for stopping not only when starting but also when stopping.

Next, set values for the temperature alarm from the first set value to the sixth set value are set and read into the storage unit 5(n) (102). For example, when starting up, as shown in Figure 3, the horizontal axis shows time and the vertical axis shows rotational speed and bearing metal temperature.The normal bearing metal temperature pattern is A.
Then, the first set value is set to the upper limit side of the normal bearing metal temperature pattern A as the first set value=A(t)+α.

The second set value is further on the upper limit side of the first set value.
Set as A (t)+β. Here, the above setting part α
The relationship between and β is α<β.

The third set value and the fourth set value are set by providing a predetermined two-stage setting section in the normal bearing metal temperature pattern at the time of stop, and setting the third set value and the fourth set value in the same way as at the time of starting. . Here, the third set value and the fourth set value are the third set value and the fourth set value.

The fifth set value and the sixth set value are the setting pattern when the rotation speed is at the rated speed other than when starting and stopping.
Set the setting values. Here, the fifth set value and the sixth set value are the fifth set value and the sixth set value. Next, if it is determined whether the turbine has stopped or not and the result is No (103), the temperature sensor 1
Read the metal temperature rM(t) from (n) (104
).

Furthermore, the bearing oil supply temperature To (t) is read from a temperature detector (not shown) via the input line 7 (105).

As a result, the metal temperature correction value T
Find (t).

T (t) = TM (t) - To (t) ・・
- (1) This is for more accurate temperature monitoring since the metal temperature changes depending on the bearing oil supply temperature To.

Subsequently, it is determined whether or not it is a starting process (107).

If this determination is a startup process, YES is determined and it is determined whether the condition of equation (2) is satisfied (108).

Metal temperature T (t) >th] Set value A (t) + α・
(2) When this condition is met, an alarm is output because the metal temperature is higher than the first set value (109).

Furthermore, it is determined whether the condition of formula (3) is satisfied or not (
110).

Metal temperature T(t)>second set value A(t)+β...
(3) In this case, if the above conditions are satisfied, a contact output is made as YES (111). By the way, if it is determined in step 107 that the process is not a start-up process, the answer is No, and it is determined in the next step whether the process is a stop process (112). Here, in the stopping process, the following equation (4) is determined as YES and in the same way as in the starting process (113).

At this time, if YES, an alarm is output (114).

Metal temperature T (t) > third set value (4) Furthermore, the following equation (5) is determined (115), and if YES, a contact output is made (116).

Metal temperature T (t) > Fourth set value (5) On the other hand, when there is no starting or stopping process, that is, when the rated rotation speed is determined as No at step 112, the following equation (6 ) is determined (117), and if YES, an alarm is output (118).

Metal temperature T(t)〉5th set value...(6) And,
If the above is YES, check the formula (7) of the method (119)
, If this judgment is YES, output the contact (120)
.

Metal temperature T (t) > 6th set value (7) The process explained above is repeated, and when the turbine stops, YES is determined in step 103 (103), and the process ends. Note that the above-mentioned alarm output is notified to the operator by an alarm means (not shown). In addition, the contact output is a contact output that trips the entire device or notifies the central monitoring unit, etc., that there is a risk of causing a serious accident when the metal temperature rises more than that.

In this way, it is possible to divide the processes into startup, stop, and rated rotational speed, and compare each of them with the two-step set value based on the normal bearing metal temperature pattern. Therefore, temperature monitoring can be performed using set values based on normal temperature patterns that change over time, rather than fixed settings as in the past, making it possible to make correct judgments and ensure safe operation.

Although this embodiment has been described with respect to temperature monitoring of a turbine bearing, the present invention is not limited thereto, and can be similarly implemented on a rotating body equipped with a bearing, and can also be applied to temperature monitoring of lubricating oil of a bearing. Further, since the storage unit 5(n) of this embodiment uses a computer, it can be stored for each bearing or for - units depending on its capacity. Furthermore, as shown in FIG. 4, a recorder 2 may be connected to simultaneously and continuously record the bearing temperature.

[Effects of the Invention] As described above, according to the present invention, the bearing metal temperature is monitored using an alarm setting value based on the temporal temperature data during normal operation of the rotating body in the past. Therefore, accurate monitoring is possible regardless of the operator's experience, and safe operation is always possible.

[Brief explanation of the drawing]

Fig. 1 is a block configuration diagram of a bearing metal temperature monitoring device showing an embodiment of the present invention, Fig. 2 is a flowchart showing the processing procedure of the monitoring section, and Fig. 3 shows set values for metal temperature changes during the startup process. FIG. 4 is a block configuration diagram of a bearing metal temperature monitoring device showing another embodiment of the present invention, and FIG. 5 is a block configuration diagram of a bearing metal temperature monitoring device showing a conventional example. 1 (1) to l (n)...Temperature detector, 2...
Recorder, 4... Monitoring unit, 5(1) to 5(n)... Storage unit, 6(1) to 6(n)... Judgment unit. Agent Patent Attorney Crest 1) Makoto Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] A temperature detector disposed on a bearing of a rotating machine; and a storage means for storing various temperature pattern data over time of temperature detection values obtained from the detector during normal operation under various operating conditions of the rotating machine. , determination means for retrieving temperature pattern data corresponding to the operating conditions at that time from the storage means when the rotary machine is in operation, and comparing it with a temperature detection value obtained from the temperature detector to determine whether or not an alarm state is present; 1. A bearing metal temperature monitoring device for a rotating machine, comprising output means for outputting a determination result of the determination means.