JP2021102925A - Pump diagnostic method and pump diagnostic device - Google Patents

Abstract

To achieve a pump diagnostic method and a pump diagnostic device, which can perform effective diagnosis even in a state significantly different from a load environment at the time of actual use.SOLUTION: A method for diagnosing a pump having a mechanical seal on a shaft seal portion, includes a stopping-time temperature measurement step S20 for measuring a temperature of a lubrication oil flowing through the mechanical seal after an operation of the pump is stopped, and an oil amount estimation step S31 for estimating a filling amount of the lubrication oil on the basis of a change tendency of the temperature measured in the stopping-time temperature measurement step S20.SELECTED DRAWING: Figure 3

Description

The present invention relates to a pump diagnostic method and a pump diagnostic device.

In recent years, in relatively small waterways such as tributaries that join the main river, pump gates have been installed in addition to or in place of the existing gutter gates provided at the boundary between the upstream and downstream waterways. The number of cases is increasing. The pump gate has a structure in which a submersible pump for draining water from the upstream waterway to the downstream waterway is provided on a door body that can be opened and closed in the waterway. Since the pump gate can be installed directly in the existing waterway, there is no need for a bypass waterway or work space like a conventional drainage pump station, so the installation site civil engineering structure can be significantly reduced and the total cost can be significantly reduced. It is excellent in that it can be reduced.

The pump gate is closed when the water level in the downstream channel rises, for example during torrential rain, to prevent backflow from the downstream channel to the upstream channel. At this time, the submersible pump is operated to forcibly drain the water in the upstream channel to the downstream channel. On the contrary, when the water level on the downstream side becomes low as in fine weather, there is no risk of backflow as described above, so the door body is opened and the internal water of the upstream side waterway naturally flows down to the downstream side waterway.

Due to the above-mentioned properties, the operation of the pump gate is limited to an emergency such as a torrential rain, while the operation of the pump gate is required to be reliable. That is, it is required to reliably prevent the failure even though there are few opportunities to detect the failure or its sign based on the normal operating condition. Therefore, it is preferable that the installed pump gate is regularly managed (diagnosed). As a method of such a controlled operation, for a pump of a pump gate, a known controlled operation method relating to a rotating device (for example, Japanese Patent Application Laid-Open No. 2019-21305 (Patent Document 1), Japanese Patent No. 3053305 (Patent Document 2)). Etc.) can be applied.

Japanese Unexamined Patent Publication No. 2019-21305 Japanese Patent No. 3053305

By the way, since the pump of the pump gate is originally a device that is driven in water, it is desirable to arrange the pump in water during the management operation to perform the management operation. However, in order to place the pump in water, it is necessary to close the door to secure the water level in the upstream canal, which temporarily hinders the flow of the canal, but depending on the irrigation plan at the installation site. Even short-term closures can be difficult to implement. Further, when the amount of flowing water is small, even if the door body is closed, it may not be possible to secure a sufficient amount of water for arranging the pump in the water. Therefore, it is required to realize a technology that enables effective management operation even when the pump is placed above the water surface, that is, a state different from the original operating state of the pump, but a state close to the original operating conditions. The techniques such as Patent Documents 1 and 2 which are premised on the implementation in the above are not sufficient.

Therefore, it is required to realize a pump diagnostic method and a pump diagnostic device capable of performing effective diagnosis even in a state significantly different from the load environment at the time of actual use.

The first method for diagnosing a pump according to the present invention is a method for diagnosing a pump having a mechanical seal on a shaft seal portion, and determines the temperature of the lubricating oil flowing through the mechanical seal after the operation of the pump is stopped. It is characterized by having a stop temperature measuring step for measuring and an oil amount estimating step for estimating the filling amount of the lubricating oil based on the temperature change tendency measured in the stop temperature measuring step.

The second method for diagnosing a pump according to the present invention is a method for diagnosing a pump having a mechanical seal on a shaft seal portion, and is a lubricating oil that flows to the mechanical seal after the pump is started from a stopped state. It is characterized by having an operating temperature measuring step for measuring the temperature of the pump and a calorific value estimating step for estimating the calorific value in the pump based on the change tendency of the temperature measured in the operating temperature measuring step. To do.

Further, the pump diagnostic device according to the present invention is a pump diagnostic device capable of diagnosing a pump having a mechanical seal on the shaft seal portion, and includes a temperature measuring unit capable of measuring the temperature of the lubricating oil flowing through the mechanical seal. A diagnostic unit capable of diagnosing the state of the pump based on the change tendency of the temperature measured by the temperature measuring unit is provided, and the diagnostic unit determines the filling amount of the lubricating oil based on the change tendency. It is characterized by having at least one of an estimateable oil food estimation unit and a calorific value estimation unit capable of estimating the calorific value in the pump based on the change tendency.

According to these configurations, effective diagnosis can be performed even in a state significantly different from the load environment at the time of actual use. In particular, when the present invention is carried out in a manner in which the filling amount of lubricating oil can be estimated, the oil amount can be estimated without installing an oil level gauge which is difficult to retrofit to the pump. Further, when estimating the filling amount of the lubricating oil in the present invention, the estimation is performed based on the temperature of the lubricating oil, but the temperature of the lubricating oil itself is also an important control item of the pump. According to this, measurement of a single important item enables diagnosis of two important items.

Hereinafter, preferred embodiments of the present invention will be described. However, the scope of the present invention is not limited by the preferred embodiments described below.

The first method for diagnosing a pump according to the present invention is, as one aspect, in an operating temperature measuring step of measuring the temperature of the lubricating oil after the pump is started from a stopped state, and in the operating temperature measuring step. It is preferable to further include a calorific value estimation step of estimating the calorific value in the pump based on the measured temperature change tendency.

According to this configuration, it is possible to more accurately determine the presence or absence of a pump abnormality or a sign thereof based on a plurality of control items related to the lubricating oil.

One aspect of the first pump diagnostic method according to the present invention is to correct the estimated calorific value based on the filling amount estimated in the oil amount estimation step in the previous calorific value estimation step. Is preferable.

According to this configuration, the calorific value can be estimated more accurately.

As one aspect, the first method for diagnosing a pump according to the present invention further includes an ambient temperature measuring step for measuring the ambient temperature of the pump, and the oil amount estimation step is corrected based on the ambient temperature. It is preferable to estimate the filling amount of the lubricating oil based on the change tendency.

According to this configuration, it is possible to suppress the influence of disturbance caused by the ambient temperature when determining the presence or absence of an abnormality or a sign thereof of the pump.

One aspect of the method for diagnosing the first or second pump according to the present invention is that, in the calorific value estimation step, when the estimated calorific value falls below a predetermined threshold value, the filling amount of the lubricating oil is increased. It is preferable to determine that it is insufficient.

With this configuration, it is easy to detect a lack of lubricating oil before a serious failure occurs in the pump due to a lack of lubricating oil.

Further features and advantages of the present invention will be further clarified by the following illustration of exemplary and non-limiting embodiments described with reference to the drawings.

Schematic diagram of the open state of the pump gate according to this embodiment Schematic diagram of the closed state of the pump gate according to this embodiment Flow chart of the diagnostic method of the pump according to this embodiment The figure which shows the installation state of the thermometer which concerns on this embodiment An example of a change over time in the temperature value measured in the pump diagnostic method according to the present embodiment.

The pump diagnostic method and the embodiment of the pump diagnostic apparatus according to the present invention will be described with reference to the drawings. Hereinafter, an example in which the method for diagnosing the pump according to the present invention is applied to the diagnosis of the submersible pump 3 of the pump gate 1 installed in the flow channel 100 (example of the flow path) will be described.

[Overview of pump gate]
First, an outline of the pump gate 1 in which the submersible pump 3 to be diagnosed is installed in the pump diagnosis method according to the present embodiment will be described. The pump gate 1 includes a door body 2, a submersible pump 3 provided on the door body, and a drive device 4 capable of moving the door body 2 up and down (FIG. 1). The pump gate 1 is installed in the flow channel 100 at a point where the main stream and the tributary of the river meet. The flow channel 100 has a tributary side flow channel 101 and a main stream side flow channel 102.

In normal times, as shown in FIG. 1, the door body 2 is arranged above the water surface 103 (example of the liquid level) of the water (example of the fluid) flowing through the flow channel 100, and the operation of the submersible pump 3 is stopped. ing. Water naturally flows down from the tributary side flow channel 101 toward the main stream side flow channel 102.

When the water level rises due to torrential rain or the like, the main stream may rise and the water level of the main stream side flow channel 102 may rise. In such a case, in order to prevent water from flowing back from the main stream side flow channel 102 toward the tributary side flow channel 101, the door body 2 is lowered to block the flow channel 100 (FIG. 2). At this time, the submersible pump 3 is arranged below the water surface 103. Here, when the submersible pump 3 is operated, water can be urged from the tributary side flow channel 101 to the main stream side flow channel 102, and this can be forcibly discharged.

The submersible pump 3 is a known submersible pump, and has a motor, a drive shaft X rotationally driven by the motor, and an impeller attached to the drive shaft X. When the motor is driven, the impeller rotates, and the rotation of the impeller urges water from the tributary side flow channel 101 side to the main stream side flow channel 102 side. Here, the shaft sealing portion of the drive shaft X is sealed by a known mechanical seal 7. The mechanical seal 7 has a fixed ring 71 fixed to the casing C of the submersible pump 3 and a rotary ring 72 fixed to the drive shaft X, and a seal portion 73a is provided between the fixed ring 71 and the rotary ring 72. , 73b is formed. The seal portions 73a and 73b are lubricated by the lubricating oil filled in the lubricating oil chamber 5, which is the internal space of the casing C (FIG. 4).

[Diagnosis of pump gate]
Due to the nature of the pump gate 1, the submersible pump 3 is not operated in normal times, but is operated only in the case of torrential rain. On the other hand, when it is necessary to operate the submersible pump 3, it is a case where urgent drainage is required, so that the submersible pump 3 is required to be able to operate reliably. That is, it is required to reliably prevent the failure even though there are few opportunities to detect the failure or its sign based on the normal operating condition. In view of such requirements, the submersible pump 3 is routinely diagnosed for failure and its signs. The method for diagnosing the pump according to the present embodiment includes a temperature measurement step S10 during operation, a temperature measurement step S20 during stoppage, and an estimation step S30. Here, the estimation step includes an oil amount estimation step S31 and a calorific value estimation step S32 (FIG. 3). The contents of each step will be described below.

Before making a diagnosis, a thermometer 6 (example of a temperature measuring unit) is installed in the lubricating oil chamber 5 of the submersible pump 3. More specifically, the probe of the thermometer 6 mounted as a thermocouple is installed in the lubricating oil chamber 5 so that the tip 61 thereof is arranged below the liquid level L1 of the lubricating oil (FIG. 4). The detailed position of the tip 61 will be described later. Further, the temperature value measured by the thermometer 6 is input to a computer (not shown) that can be connected to the thermometer 6 (examples of a diagnostic unit, an oil amount estimation unit, and a calorific value estimation unit), and is displayed on the computer. Temperature values can be used in the analysis process. Known thermometers 6 and computers can be used.

The operating temperature measuring step S10 is a step performed as the first step of the pump diagnostic method according to the present embodiment, and is a step of measuring the temperature of the lubricating oil while operating the submersible pump 3. At the time when the temperature measurement step S10 during operation is started, the submersible pump 3 is in a completely stopped state, and the submersible pump 3 is started from the completely stopped state. In the operating temperature measurement step S10, the door body 2 is arranged above the water surface 103 of the water flowing through the water flow channel 100, that is, the state of the pump gate 1 in normal times, and therefore the submersible pump 3 is above the water surface 103. It is carried out in the state of being arranged in (Fig. 1).

Since the submersible pump 3 is started from a completely stopped state as described above, the temperature of the lubricating oil at the time when the submersible pump 3 is started is equivalent to the air temperature (example of ambient temperature). Then, when the submersible pump 3 is operated, frictional heat is generated in the mechanical seal, so that the temperature of the lubricating oil gradually rises. FIG. 5 shows a change over time in the temperature of the lubricating oil, and the section P1 in FIG. 5 corresponds to the temperature measurement step S10 during operation. More specifically, the submersible pump 3 is started at the start point P1a of the section P1, and the submersible pump 3 is stopped at the end point P1b of the section P1.

The subsequent stop temperature measurement step S20 is a step starting from the time when the submersible pump 3 is stopped at the end of the operation temperature measurement step S10, and measures the temperature of the lubricating oil after the operation of the submersible pump 3 is stopped. It is a process. In the temperature measurement step S20 at the time of stop, since the operation of the submersible pump 3 is stopped, frictional heat that raises the temperature of the lubricating oil is not generated. On the other hand, since the temperature of the lubricating oil rises to a temperature higher than the air temperature in the temperature measuring step S10 during operation, the temperature of the lubricating oil gradually decreases due to heat dissipation. In FIG. 5, the section P2 starting from the end point P1b of the operating temperature measuring process S10 (section P1) corresponds to the stopped temperature measuring process S20. If the operation of the submersible pump 3 continues to be stopped, the temperature measurement step S20 at the time of stop is terminated after a lapse of a predetermined time.

The estimation step S30 estimates the filling amount of the lubricating oil and the calorific value in the submersible pump 3 based on the temperature values collected in the operating temperature measuring step S10 and the stopped temperature measuring step S20. These estimated information can be used as a material for determining whether or not the submersible pump 3 can be operated normally. Hereinafter, the oil amount estimation step S31 and the calorific value estimation step S32 included in the estimation step S30 will be described in order.

The oil amount estimation step S31 is a step of estimating the filling amount of the lubricating oil in the lubricating oil chamber 5. If the filling amount of the lubricating oil is less than the predetermined lower limit, the mechanical seal cannot be lubricated, which may cause a problem such as damage to the mechanical seal. Therefore, the filling amount of the lubricating oil is an important control item of the submersible pump 3. In the following description, the state in which the filling amount of the lubricating oil is within the range of a predetermined reference value is referred to as a "reference state".

_{In the oil amount estimation step S31, the temperature change ΔT off} (example of temperature change tendency) per unit time is calculated based on the temperature value collected in the stop temperature measurement step S20. In FIG. 5, the slope of the temperature in the section P2 represents _{ΔT off.} Here, since the temperature of the lubricating oil gradually decreases in the stop temperature measurement step S20, ΔT _off becomes a negative value.

When the filling amount of the lubricating oil is less than a predetermined lower limit, the liquid level of the lubricating oil becomes low (two-dot chain line L2 in FIG. 5). At this time, the tip 61 is exposed above the liquid surface, and the thermometer 6 detects the temperature of the air instead of the temperature of the lubricating oil. Here, the frictional heat in the mechanical seal raises the temperature of the lubricating oil, but since the heat hardly transfers to the air, the temperature rise width accompanying the operation of the submersible pump 3 becomes small (two points in FIG. 5). Chain wire). Therefore, _{the absolute value of ΔT off} becomes smaller than the reference value. _{Therefore, when the ΔT off} calculated in the stop temperature measurement step S20 is larger than the predetermined reference value (the absolute value is small), it can be determined that the filling amount of the lubricating oil is below the predetermined lower limit. The above reference value is set based on the temperature change per unit time when the filling amount of the lubricating oil is at a predetermined lower limit.

Further, since the lubricating oil overall heat capacity increases as the loading of the lubricating oil is large, the absolute value of [Delta] T _off is reduced. For example, comparing the solid line in FIG. 5 with the alternate long and short dash line, the alternate long and short dash line has a larger absolute value of _{ΔT off.} Therefore, the alternate long and short dash line in FIG. 5 represents a state in which the filling amount of the lubricating oil is smaller than that of the solid line. In this way, if the relationship between the filling amount of the lubricating oil and ΔT _off is clarified in advance, the filling amount V of the lubricating oil can be estimated based on _{the calculated value of ΔT off.}

The calorific value estimation step S32 is a step of estimating the calorific value in the submersible pump 3. In the submersible pump 3, the calorific value changes when the sliding state of the mechanical seal changes. For example, when the sliding state is bad, the amount of heat generated becomes large. On the contrary, when the sliding state is good, the calorific value is small, but when the calorific value is excessively small, there is abundant fluid in the sliding part, that is, the leakage of lubricating oil or water becomes large. Suspected to be. Therefore, if the calorific value can be estimated, it will be an important clue to detect the failure of the mechanical seal or its sign.

In the heat generation amount estimation step S32, based on the value of collected at operation time temperature measurement step S10 temperatures, it calculates a temperature change [Delta] T _on per unit time _(example of a change tendency of the temperature). In Figure 5, the slope of the temperature represents the [Delta] T _on the interval P1. Since the temperature of the lubricating oil at the operating time of the temperature measurement step S10 is gradually increased, [Delta] T _on becomes a positive value. Here, if the calculated [Delta] T _on is larger than the predetermined reference value is likely mechanical seal is in a state calorific value is large in comparison with the normal state. Conversely, if the calculated [Delta] T _on is smaller than a predetermined reference value is likely to leak amount in the sliding portion is increased. Thus, the calculated [Delta] T _on values, the possibility that there are faults or symptomatology thereof is shown. The above reference value is set based on the temperature change per unit time in a state where the submersible pump 3 is guaranteed to be normal (after a completion inspection at the time of manufacturing, etc.).

Further, [Delta] T _on the temperature change per unit of time the lubricating oil, in addition to the calorific value, affected by parameters such as heat capacity and heat dissipation of the entire lubricating oil. Here, assuming that the parameters other than the calorific value are constant, the calorific value Q can be calculated based _{on ΔTon (Equation (1)).}
Q = C ・ d ・ V ₀・ ΔT _on + H equation (1)
However, in the formula (1), C is the specific heat of the lubricating oil, d is the density of the lubricating oil, V ₀ is the volume of the lubricating oil, and H is the heat dissipation amount. Here, C and d are constants based on the substance of the lubricating oil, and V ₀ and H are constants based on the standard value of the structure of the submersible pump 3 and the filling amount of the lubricating oil.

Further, in the equation (1), the volume of the lubricating oil _{is assumed to be a constant value V 0} , but if this is replaced with the filling amount V of the lubricating oil calculated in the oil amount estimation step S31, the calorific value estimation is more accurate. become. The corrected calorific value Q _c is expressed by the following equation (2).
Q _c = (Q-H) · V / V ₀ + H formula (2)

By the above procedure, the filling amount V and the calorific value Q _c (or Q) of the lubricating oil in the submersible pump 3 can be estimated. Administrators of the pump gate 1 detects the failure or symptoms thereof in water pump 3 based on the estimated loading V and calorific value Q _c, it is possible to perform the maintenance water pump 3.

[Modified example of the above embodiment]
In addition to the operating temperature measuring step S10, the stopped temperature measuring step S20, and the estimating step S30 described in the above embodiment, an ambient temperature measuring step may be provided. The ambient temperature measuring step is a step of measuring the ambient temperature of the place where the submersible pump 3 is installed using a known thermometer. Here, air temperature, water temperature, and the like are exemplified as the ambient temperature, but in this modification, an embodiment in which the temperature is used as the ambient temperature will be described. The ambient temperature measurement step can be executed at any time within a period in which the temperature can be equated with the temperature measurement step S10 during operation and the temperature measurement step S20 during stop. For example, in the temperature measurement step S10 during operation. It can be executed immediately before, between the operating temperature measuring step S10 and the stopped temperature measuring step S20, immediately after the stopped temperature measuring step S20, and the like. At this time, the ambient temperature measurement step may be performed before installing the thermometer 6 in the lubricating oil chamber 5, and the air temperature may be measured using the thermometer 6. The measured temperature value is input to the computer.

Generally, the amount of heat radiated from an object in the air is proportional to the temperature difference between the object and the air temperature. Therefore, ΔT _off can be affected by temperature. That is, since the air temperature is the amount of heat to be dissipated from the water pump 3 to the air is increased when low, [Delta] T _off is small. On the contrary, when the temperature is high, ΔT _off becomes large. If the diagnostic method of the pump according to the present embodiment includes a temperature measuring step, it may correct the [Delta] T _off based on the measured value of the air temperature.

When measuring the air temperature in the above modification, it is not necessary to directly measure the temperature of the air. For example, when a sufficient amount of time has passed since the submersible pump 3 was last operated, the temperature and air temperature of the lubricating oil can be equated. Therefore, the temperature of the lubricating oil measured before the start of the operating temperature measurement step S10 may be used as the ambient temperature.

[Other Embodiments]
Finally, other embodiments of the pump diagnostic method according to the present invention will be described. The configurations disclosed in each of the following embodiments can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction.

In the above embodiment, a configuration in which the diagnostic method according to the present invention is applied to the diagnosis of the pump gate 1 (submersible pump 3) has been described as an example. However, the method for diagnosing pumps according to the present invention can also be applied to diagnosing pumps such as drainage pumps, manhole pumps, and land pumps.

In the above embodiment, an example of the method of diagnosing the pump according to the embodiment including the temperature measurement step S10 during operation and the temperature measurement step S20 during stop has been described. However, the method for diagnosing the pump according to the present invention does not have to include one of the temperature measurement step during operation and the temperature measurement step during stop.

In the above embodiment, an example of a method for diagnosing a pump in which the temperature measurement step S10 during operation and the temperature measurement step S20 during stop are included once has been described. However, the method for diagnosing a pump according to the present invention may include a temperature measurement step during operation and a temperature measurement step during stop a plurality of times. Further, the number of times of the temperature measurement step during operation and the temperature measurement step during stop may be different.

In the above embodiment, the configuration in which the operating temperature measuring step S10 and the stopped temperature measuring step S20 are carried out with the submersible pump 3 arranged above the water surface 103 has been described. However, in the method for diagnosing a pump according to the present invention, the temperature measurement step during operation and the temperature measurement step during stop may be performed with the pump placed in water. In this case, when the ambient temperature measuring step is provided, it is preferable to measure the water temperature as the ambient temperature.

In the above embodiment, a configuration in which the calorific value Q is corrected based on the lubricating oil filling amount V estimated in the oil amount estimation step S31 in the calorific value estimation step S32 has been described as an example. However, when the method for diagnosing the pump according to the present invention includes a calorific value estimation step, the calorific value correction based on the estimated calorific value filling amount may not be performed.

In the method for diagnosing a pump according to the present invention, the device for measuring the temperature may be installed at each diagnosis or may be permanently installed.

The method for diagnosing a pump according to the present invention is configured to determine that the filling amount of lubricating oil is insufficient when the estimated calorific value falls below a predetermined threshold value in the calorific value estimation step. Good. Further, in this case, when it is determined that the filling amount of the lubricating oil is insufficient, an alarm may be issued separately from the diagnosis result.

When the method for diagnosing the pump according to the present invention has an operating temperature measuring process and the temperature measured in the operating temperature measuring process exceeds a predetermined upper limit value, an alarm is issued separately from the diagnosis result. You may do so.

In the method for diagnosing a pump according to the present invention, information on the temperature collected in the operating temperature measuring process and the stopped temperature measuring process and its change with time, information on the lubricating oil filling amount estimated in the oil amount estimation process, and Information on the calorific value of the lubricating oil estimated in the calorific value estimation step may be stored in a known server device. With this configuration, various information related to diagnosis stored in the server device can be confirmed at a remote location.

It should be understood that with respect to other configurations, the embodiments disclosed herein are exemplary in all respects and the scope of the invention is not limited thereto. Those skilled in the art will be able to easily understand that modifications can be made as appropriate without departing from the spirit of the present invention. Therefore, another embodiment modified without departing from the spirit of the present invention is naturally included in the scope of the present invention.

The present invention can be used, for example, as a method for diagnosing a submersible pump at a pump gate installed in a running channel.

1: Pump gate 2: Door body 3: Submersible pump 4: Drive device 5: Lubricating oil chamber 6: Thermometer 61: Thermometer probe tip 7: Mechanical seal 71: Fixed ring L1: Lubricant liquid level (reference) Status)
L2: Lubricating oil level (when filling amount decreases)
X: Drive shaft 100: Flow channel 101: Tributary side flow channel 102: Main stream side flow channel 103: Water surface P1: Section (Temperature measurement step S10 during operation)
P1a: Starting point (temperature measurement step S10 during operation)
P1b: End point (temperature measurement step S10 during operation)
P2: Section (temperature measurement step S20 when stopped)
ΔT _on : Temperature change (temperature measurement step S10 during operation)
ΔT _off : Temperature change (temperature measurement step S20 when stopped)

Claims (7)

This is a diagnostic method for pumps that have a mechanical seal on the shaft seal.
A stop temperature measuring step for measuring the temperature of the lubricating oil flowing through the mechanical seal after stopping the operation of the pump, and a stop temperature measuring step.
A method for diagnosing a pump, which comprises an oil amount estimation step of estimating a filling amount of the lubricating oil based on a temperature change tendency measured in the stopped temperature measuring step. An operating temperature measurement step for measuring the temperature of the lubricating oil after the pump is started from a stopped state, and
The method for diagnosing a pump according to claim 1, further comprising a calorific value estimation step of estimating a calorific value in the pump based on a temperature change tendency measured in the temperature measurement step during operation. The method for diagnosing a pump according to claim 2, wherein in the calorific value estimation step, the estimated calorific value is corrected based on the filling amount estimated in the oil amount estimation step. It further has an ambient temperature measuring step of measuring the ambient temperature of the pump.
The method for diagnosing a pump according to any one of claims 1 to 3, wherein in the oil amount estimation step, the filling amount of the lubricating oil is estimated based on the change tendency corrected based on the ambient temperature. This is a diagnostic method for pumps that have a mechanical seal on the shaft seal.
An operating temperature measurement process for measuring the temperature of the lubricating oil flowing through the mechanical seal after the pump is started from a stopped state, and
A method for diagnosing a pump, comprising: a calorific value estimation step for estimating a calorific value in the pump based on a temperature change tendency measured in the temperature measurement step during operation. Any one of claims 2, 3, and 5 for determining that the filling amount of the lubricating oil is insufficient when the estimated calorific value falls below a predetermined threshold value in the calorific value estimation step. The pump diagnostic method described in. A pump diagnostic device capable of diagnosing a pump having a mechanical seal on the shaft seal.
A temperature measuring unit capable of measuring the temperature of the lubricating oil flowing through the mechanical seal and a diagnostic unit capable of diagnosing the state of the pump based on the temperature change tendency measured by the temperature measuring unit are provided.
The diagnostic unit
An oil amount estimation unit that can estimate the filling amount of the lubricating oil based on the change tendency, and
A pump diagnostic device having at least one of a calorific value estimation unit capable of estimating a calorific value in the pump based on the change tendency.

Images