THERMOELECTRIC GENERATOR AND VIBRATION DETECTION SYSTEM

A thermoelectric generator includes: a thermoelectric generator module; a vibration sensor driven by power generated by the thermoelectric generator module; and a wireless communication device that transmits detection data of the vibration sensor.

FIELD

The present invention relates to a thermoelectric generator and a vibration detection system.

BACKGROUND

It is known a technique for detecting vibration generated during operation of an apparatus by using an acceleration sensor in order to diagnose whether or not the apparatus is abnormal.

CITATION LIST

Patent Literature

Patent Literature 1: JP 2009-020090 A

SUMMARY

Technical Problem

In a case where a cable is used to connect an acceleration sensor and a power supply in order to supply power to the acceleration sensor, an installation position of the acceleration sensor may be restricted. In a case where a primary cell is used, it is necessary to replace the primary cell every certain period of time. In a case where a secondary cell is used, it is necessary to charge the secondary cell every certain period of time. In a case where a cable or a battery is used, it may be difficult to efficiently diagnose whether or not an apparatus is abnormal.

An object of an aspect of the present invention is to efficiently diagnose whether or not an apparatus is abnormal.

Solution to Problem

According to an aspect of the present invention, a thermoelectric generator, comprises: a thermoelectric generator module; a vibration sensor driven by power generated by the thermoelectric generator module; and a wireless communication device that transmits detection data of the vibration sensor.

Advantageous Effects of Invention

According to an aspect of the present invention, it is possible to efficiently diagnose whether or not an apparatus is abnormal.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments according to the present invention will be described with reference to the drawings, but the present invention is not limited thereto. Components of the embodiments described below can be appropriately combined. Further, some components may not be used in some cases.

In the following description, an XYZ orthogonal coordinate system is set, and positional relationships between units will be described with reference to this XYZ orthogonal coordinate system. A direction parallel to an X axis in a predetermined plane is defined as an X-axis direction, a direction parallel to a Y axis orthogonal to the X axis in the predetermined plane is defined as a Y-axis direction, and a direction parallel to a Z axis orthogonal to the predetermined plane is defined as a Z-axis direction. An XY plane including the X axis and the Y axis is parallel to the predetermined plane.

First Embodiment

A first embodiment will be described.FIG. 1is a cross-sectional view of a thermoelectric generator1according to the present embodiment. The thermoelectric generator1is installed on an apparatus B. The apparatus B is provided in an industrial facility such as a factory. Examples of the apparatus B encompass a motor for operating a pump. The apparatus B functions as a heat source of the thermoelectric generator1.

As illustrated inFIG. 1, the thermoelectric generator1includes a heat receiver2, a heat radiator3, a peripheral wall4, a thermoelectric generator module5, a power storage unit16, a vibration sensor6, a temperature sensor7, a microcomputer8, a wireless communication device9, a heat transfer member10, and a substrate11.

The heat receiver2is installed on the apparatus B. The heat receiver2is a plate-like member. The heat receiver2is made from a metal material such as aluminum or copper. The heat receiver2receives heat from the apparatus B. The heat of the heat receiver2is transferred to the thermoelectric generator module5via the heat transfer member10.

The heat radiator3faces the heat receiver2with a gap interposed therebetween. The heat radiator3is a plate-like member. The heat radiator3is made from a metal material such as aluminum or copper. The heat radiator3receives heat from the thermoelectric generator module5. The heat of the heat radiator3is radiated into an atmospheric space around the thermoelectric generator1.

The heat receiver2has a heat receiving surface2A facing a surface of the apparatus B and an inner surface2B facing in a direction opposite to a direction of the heat receiving surface2A. The heat receiving surface2A faces in the −Z direction. The inner surface2B faces in the +Z direction. Both the heat receiving surface2A and the inner surface2B are plane. Both the heat receiving surface2A and the inner surface2B are parallel to the XY plane. In the XY plane, the heat receiver2has a substantially quadrangular outer shape. Note that the heat receiver2does not need to have a quadrangular outer shape. The heat receiver2may have a circular, elliptical, or any polygonal outer shape.

The heat radiator3has a heat radiating surface3A facing the atmospheric space and an inner surface3B facing in a direction opposite to a direction of the heat radiating surface3A. The heat radiating surface3A faces in the +Z direction. The inner surface3B faces in the −Z direction. Both the heat radiating surface3A and the inner surface3B are plane. Both the heat radiating surface3A and the inner surface3B are parallel to the XY plane. In the XY plane, the heat radiator3has a substantially quadrangular outer shape. Note that the heat radiator3does not need to have a quadrangular outer shape. The heat radiator3may have a circular, elliptical, or any polygonal outer shape.

In the XY plane, the outer shape and dimensions of the heat receiver2are substantially equal to the outer shape and dimensions of the heat radiator3. Note that the outer shape and dimensions of the heat receiver2may be different from the outer shape and dimensions of the heat radiator3.

The peripheral wall4is placed between a peripheral edge of the inner surface2B of the heat receiver2and a peripheral edge of the inner surface3B of the heat radiator3. The peripheral wall4connects the heat receiver2and the heat radiator3. The peripheral wall4is made from synthetic resin.

In the XY plane, the peripheral wall4is annular. In the XY plane, the peripheral wall4has a substantially quadrangular outer shape. The heat receiver2, the heat radiator3, and the peripheral wall4define an internal space12of the thermoelectric generator1. The peripheral wall4has an inner surface4B facing the internal space12. The inner surface2B of the heat receiver2faces the internal space12. The inner surface3B of the heat radiator3faces the internal space12. The atmospheric space around the thermoelectric generator1is an external space of the thermoelectric generator1.

The heat receiver2, the heat radiator3, and the peripheral wall4function as a housing of the thermoelectric generator1that defines the internal space12. In the following description, the heat receiver2, the heat radiator3, and the peripheral wall4will be collectively referred to as “housing20” as appropriate.

A seal member13A is placed between the peripheral edge of the inner surface2B of the heat receiver2and a −Z-side end surface of the peripheral wall4. A seal member13B is placed between the peripheral edge of the inner surface3B of the heat radiator3and a +Z-side end surface of the peripheral wall4. Each of the seal members13A and13B includes, for example, an O-ring. The seal member13A is placed in a recess provided in the peripheral edge of the inner surface2B. The seal member13B is placed in a recess provided in the peripheral edge of the inner surface3B. The seal members13A and13B restrain a foreign object in the external space of the thermoelectric generator1from entering the internal space12.

The thermoelectric generator module5generates power by using the Seebeck effect. The thermoelectric generator module5is placed between the heat receiver2and the heat radiator3. The thermoelectric generator module5generates power when a −Z-side end surface51of the thermoelectric generator module5is heated to cause a temperature difference between the −Z-side end surface51and a +Z-side end surface52of the thermoelectric generator module5.

The end surface51faces in the −Z direction. The end surface52faces in the +Z direction. Both the end surfaces51and52are plane. Both the end surfaces51and52are parallel to the XY plane. In the XY plane, the thermoelectric generator module5has a substantially quadrangular outer shape.

The end surface52faces the inner surface3B of the heat radiator3. The thermoelectric generator module5is fixed to the heat radiator3. The heat radiator3and the thermoelectric generator module5are bonded to each other by, for example, an adhesive.

Note that, although the thermoelectric generator module5is in contact with the heat radiator3in the example ofFIG. 1, the thermoelectric generator module5may be in contact with the heat receiver2.

The power storage unit16stores power generated by the thermoelectric generator module5. Examples of the power storage unit16encompass a capacitor and a secondary cell.

The vibration sensor6detects vibration of the apparatus B. The vibration sensor6is driven by power generated by the thermoelectric generator module5. The vibration sensor6is placed in the internal space12. In the present embodiment, the vibration sensor6is supported by the inner surface2B of the heat receiver2.

Examples of the vibration sensor6encompass an acceleration sensor, a speed sensor, and a displacement sensor. In the present embodiment, the vibration sensor6can detect vibration of the apparatus B in three directions, i.e., the X-axis direction, the Y-axis direction, and the Z-axis direction.

The temperature sensor7detects a temperature of the apparatus B. The temperature sensor7is driven by power generated by the thermoelectric generator module5. The temperature sensor7is placed in the internal space12. In the present embodiment, the temperature sensor7is supported by the inner surface3B of the heat radiator3. Note that the temperature sensor7may be supported by the inner surface2B of the heat receiver2.

The microcomputer8controls the thermoelectric generator1. The microcomputer8is driven by power generated by the thermoelectric generator module5. The microcomputer8is placed in the internal space12. In the present embodiment, the microcomputer8is supported by the substrate11.

The wireless communication device9transmits detection data of the vibration sensor6. The wireless communication device9transmits detection data of the temperature sensor7. The wireless communication device9is driven by power generated by the thermoelectric generator module5. The wireless communication device9is placed in the internal space12. In the present embodiment, the wireless communication device9is supported by the substrate11.

The heat transfer member10connects the heat receiver2and the thermoelectric generator module5. The heat transfer member10transfers heat of the heat receiver2to the thermoelectric generator module5. The heat transfer member10is made from a metal material such as aluminum or copper. The heat transfer member10is a rod-like member elongated in the Z-axis direction. The heat transfer member10is placed in the internal space12.

The substrate11includes a control board. The substrate11is placed in the internal space12. The substrate11is connected to the heat receiver2via a support member11A. The substrate11is connected to the heat radiator3via a support member11B. The substrate11is supported by the support member11A and the support member11B so as to be apart from both the heat receiver2and the heat radiator3.

The substrate11supports the microcomputer8. Detection data of the vibration sensor6and detection data of the temperature sensor7are transmitted by the wireless communication device9to a management computer100existing outside the thermoelectric generator1.

FIG. 2is a perspective view schematically illustrating the thermoelectric generator module5according to the present embodiment. The thermoelectric generator module5includes p-type thermoelectric semiconductor elements5P, n-type thermoelectric semiconductor elements5N, first electrodes53, second electrodes54, a first substrate51S, and a second substrate52S. In the XY plane, the p-type thermoelectric semiconductor elements5P and the n-type thermoelectric semiconductor elements5N are alternately arranged. Each of the first electrodes53is connected to both the p-type thermoelectric semiconductor element5P and the n-type thermoelectric semiconductor element5N. Each of the second electrodes54is connected to both the p-type thermoelectric semiconductor element5P and the n-type thermoelectric semiconductor element5N. A lower surface of the p-type thermoelectric semiconductor element5P and a lower surface of the n-type thermoelectric semiconductor element5N are connected to the first electrode53. An upper surface of the p-type thermoelectric semiconductor element5P and an upper surface of the n-type thermoelectric semiconductor element5N are connected to the second electrode54. The first electrode53is connected to the first substrate51S. The second electrode54is connected to the second substrate52S.

Both the p-type thermoelectric semiconductor element5P and the n-type thermoelectric semiconductor element5N include, for example, a BiTe-based thermoelectric material. Both the first substrate51S and the second substrate52S are made from an electrical insulating material such as ceramics or polyimide.

The first substrate51S has the end surface51. The second substrate52S has the end surface52. The first substrate51S is heated to cause a temperature difference between a +Z-side end and a −Z-side end of each of the p-type and n-type thermoelectric semiconductor elements5P and5N. When the temperature difference is caused between the +Z-side end and the −Z-side end of the p-type thermoelectric semiconductor element5P, holes move in the p-type thermoelectric semiconductor element5P. When the temperature difference is caused between the +Z-side end and the −Z-side end of the n-type thermoelectric semiconductor element5N, electrons move in the n-type thermoelectric semiconductor element5N. The p-type thermoelectric semiconductor element5P and the n-type thermoelectric semiconductor element5N are connected via the first electrode53and the second electrode54. The holes and the electrons cause a potential difference between the first electrode53and the second electrode54. When the potential difference is caused between the first electrode53and the second electrode54, the thermoelectric generator module5generates power. A lead wire55is connected to the first electrodes53. The thermoelectric generator module5outputs power via the lead wire55.

FIG. 3is a block diagram of the thermoelectric generator1according to the present embodiment. As illustrated inFIG. 3, the thermoelectric generator module5, the vibration sensor6, the temperature sensor7, the microcomputer8, and the wireless communication device9are placed in the internal space12of the housing20.

The microcomputer8includes a detection data acquisition unit81, a processing unit82, and a change unit83.

The detection data acquisition unit81acquires detection data of the vibration sensor6. The detection data acquisition unit81acquires detection data of the temperature sensor7.

The processing unit82processes the detection data of the vibration sensor6acquired by the detection data acquisition unit81and outputs processed data. The processed data is data generated by performing data processing on the detection data. The processing unit82can process the detection data of the vibration sensor6on the basis of a vibration analysis method such as fast Fourier transform (FFT) and output the processed data.

The processed data generated by the processing unit82includes at least one of peak values, a root mean square value, and a frequency of vibration of the apparatus B calculated from the detection data of the vibration sensor6.

The processing unit82processes the detection data of the vibration sensor6, thereby calculating peak values of the vibration of the apparatus B. The peak values of the vibration include a maximum value Ph and a minimum value Pl of the vibration. The peak values of the vibration may be peak values of acceleration, peak values of speed, or peak values of displacement.

The processing unit82processes the detection data of the vibration sensor6, thereby calculating a root mean square (RMS) value of the vibration of the apparatus B. The RMS value of the vibration may be an RMS value of acceleration, an RMS value of speed, or an RMS value of displacement.

The processing unit82processes the detection data of the vibration sensor6, thereby calculating a frequency of the vibration of the apparatus B. Note that the processing unit82may calculate an overall value of the vibration by processing the detection data of the vibration sensor6.

The change unit83changes a sampling frequency of the detection data of the vibration sensor6for use in the processing executed by the processing unit82. In the present embodiment, the detection data acquisition unit81acquires detection data from the vibration sensor6on the basis of the sampling frequency set by the change unit83. The change unit83changes the sampling frequency of the detection data of the vibration sensor6acquired by the detection data acquisition unit81.

In the present embodiment, an operating device15such as a dip switch is provided on an outer surface of the housing20. Note that the operating device15may be provided on an inner surface of the housing20. An operator can operate the operating device15so as to change the sampling frequency. The change unit83changes the sampling frequency on the basis of operation data generated by operating the operating device15.

The wireless communication device9transmits the detection data of the vibration sensor6acquired by the detection data acquisition unit81to the management computer100existing outside the thermoelectric generator1. The wireless communication device9further transmits, to the management computer100, the processed data serving as the detection data processed by the processing unit82. The wireless communication device9further transmits, to the management computer100, the detection data of the temperature sensor7acquired by the detection data acquisition unit81.

In the following description, a mode for transmitting the detection data of the vibration sensor6to the management computer100will be appropriately referred to as “detection data transmission mode”, and a mode for transmitting the processed data generated by the processing in the processing unit82to the management computer100will be appropriately referred to as “processed data transmission mode”.

Next, there will be described an example of operation of the thermoelectric generator1according to the present embodiment. The thermoelectric generator1is installed on the apparatus B provided in an industrial facility. In driving the apparatus B, the vibration sensor6detects vibration of the apparatus B, and the temperature sensor7detects a temperature of the apparatus B.

When the apparatus B is driven, the apparatus B generates heat. The heat of the apparatus B is transferred to the thermoelectric generator module5via the heat receiver2and the heat transfer member10. The thermoelectric generator module5that has received the heat generates power. The vibration sensor6, the temperature sensor7, the microcomputer8, and the wireless communication device9are driven by the power generated by the thermoelectric generator module5. In the detection data transmission mode, the microcomputer8transmits the detection data of the vibration sensor6and the detection data of the temperature sensor7to the management computer100of the industrial facility existing outside the thermoelectric generator1via the wireless communication device9. The thermoelectric generator1is installed on each of a plurality of apparatuses B in the industrial facility. The management computer100can monitor and manage a state of each of the plurality of apparatuses B on the basis of the detection data of the vibration sensor6and the detection data of the temperature sensor7transmitted from corresponding one of the plurality of thermoelectric generators1. Based on the detection data of the vibration sensor6and the detection data of the temperature sensor7transmitted from the thermoelectric generator1, the management computer100can diagnose whether or not the apparatus B is abnormal.

In the processed data transmission mode, the microcomputer8transmits the processed data generated by the processing unit82to the management computer100of the industrial facility existing outside the thermoelectric generator1via the wireless communication device9. The management computer100can monitor and manage the state of each of the plurality of apparatuses B on the basis of the processed data transmitted from corresponding one of the plurality of thermoelectric generators1. Based on the processed data transmitted from the thermoelectric generator1, the management computer100can diagnose whether or not the apparatus B is abnormal.

The detection data transmission mode will be described.FIG. 4illustrates detection data of the vibration sensor6according to the present embodiment. In the graph ofFIG. 4, the vertical axis represents acceleration detected by the vibration sensor6, and the horizontal axis represents time. As illustrated inFIG. 4, the change unit83changes a sampling frequency of the detection data of the vibration sensor6acquired by the detection data acquisition unit81. The change unit83can change the sampling frequency from one of first and second sampling frequency to the other. The first sampling frequency is larger than the second sampling frequency. In the following description, the first sampling frequency is 1000 Hz, and the second sampling frequency is 100 Hz.

In a case where the change unit83sets the first sampling frequency (1000 Hz) as the sampling frequency, the detection data acquisition unit81acquires detection data of the vibration sensor6at the first sampling frequency. Thus, the detection data acquisition unit81can acquire vibration waveform data indicated by line La inFIG. 4.

In a case where the change unit83sets the second sampling frequency (100 Hz) as the sampling frequency, the detection data acquisition unit81acquires detection data of the vibration sensor6at the second sampling frequency. Thus, the detection data acquisition unit81can acquire vibration waveform data indicated by line Lb inFIG. 4.

The detection data acquisition unit81acquires the detection data of the vibration sensor6in a first specified time period. The first specified time period is, for example, 0.1 seconds. Note that the first specified time period may be any value from 0.01 seconds to 10 seconds. The first specified time period is determined on the basis of, for example, performance of the microcomputer8.

In a case where the first specified time period is 0.1 seconds and the first sampling frequency is 1000 Hz, the detection data acquisition unit81acquires one hundred pieces of detection data in the first specified time period. In a case where the first specified time period is 0.1 seconds and the second sampling frequency is 100 Hz, the detection data acquisition unit81acquires ten pieces of detection data in the first specified time period.

The wireless communication device9transmits the detection data of the vibration sensor6acquired by the detection data acquisition unit81to the management computer100. The wireless communication device9transmits the detection data of the vibration sensor6to the management computer100every second specified time period. The second specified time period is, for example, 20 seconds. Note that the second specified time period may be any value from 10 seconds to 500 seconds. The wireless communication device9is driven by power generated by the thermoelectric generator module5. The power generated by the thermoelectric generator module5is stored in the power storage unit16. When the power stored in the power storage unit16exceeds a predetermined amount, the wireless communication device9transmits the detection data. Therefore, the second specified time period is determined on the basis of, for example, the power generated by the thermoelectric generator module5.

An amount of the detection data acquired at the first sampling frequency is large. For example, it may be difficult to smoothly transmit the detection data acquired at the first sampling frequency from the thermoelectric generator1to the management computer100due to a data communication capability of a communication line. The change unit83can set, as the sampling frequency, the second sampling frequency smaller than the first sampling frequency on the basis of the data communication capability of the communication line.

In a case where the data communication capability of the communication line is sufficient to smoothly transmit the detection data acquired at the first sampling frequency from the thermoelectric generator1to the management computer100, the change unit83sets the first sampling frequency (1000 Hz) as the sampling frequency. Thus, a large amount of detection data of the vibration sensor6is transmitted to the management computer100. Based on the large amount of detection data of the vibration sensor6transmitted from the thermoelectric generator1, the management computer100can accurately diagnose whether or not the apparatus B is abnormal.

In a case where the data communication capability of the communication line is insufficient to smoothly transmit the detection data acquired at the first sampling frequency from the thermoelectric generator1to the management computer100, the change unit83sets the second sampling frequency (100 Hz) as the sampling frequency. Thus, a small amount of detection data of the vibration sensor6is transmitted to the management computer100. Based on the small amount of detection data of the vibration sensor6transmitted from the thermoelectric generator1, the management computer100can smoothly diagnose whether or not the apparatus B is abnormal.

Next, the processed data transmission mode will be described. As described above, the processed data generated by the processing unit82includes at least one of peak values, an RMS value, and a frequency of vibration. In the following description, an example of transmitting peak values of vibration as the processed data will be described. In the processed data transmission mode, the detection data of the vibration sensor6is not transmitted.

The processing unit82processes the detection data of the vibration sensor6acquired by the detection data acquisition unit81, thereby calculating the peak values (maximum value Ph and minimum value Pl) of vibration as the processed data. The wireless communication device9can transmit, to the management computer100, the maximum value Ph and the minimum value Pl serving as the processed data output from the processing unit82.

The processing unit82can calculate the maximum value Ph and the minimum value Pl of vibration from both the detection data acquired at the first sampling frequency (1000 Hz) and the detection data acquired at the second sampling frequency (100 Hz).

In the following description, the maximum value Ph and the minimum value Pl of vibration calculated from the detection data acquired at the first sampling frequency (1000 Hz) will be appropriately referred to as “maximum value Pha” and “minimum value Pla”, respectively. Further, the maximum value Ph and the minimum value Pl of vibration calculated from the detection data acquired at the second sampling frequency (100 Hz) will be appropriately referred to as “maximum value Phb” and “minimum value Plb”, respectively.

When the detection data acquired at the first sampling frequency is processed, the maximum value Pha and the minimum value Pla are accurately calculated. When the detection data acquired at the second sampling frequency is processed, an operation load on the processing unit82to calculate the maximum value Phb and the minimum value Plb is reduced.

The wireless communication device9transmits, to the management computer100, the maximum value Ph and the minimum value Pl serving as the processed data output from the processing unit82. The amount of processed data (maximum value Ph and minimum value Pl) is smaller than the amount of detection data (raw data). Because the processed data is transmitted, the wireless communication device9can smoothly transmit the processed data from the thermoelectric generator1to the management computer100even in a case where the data communication capability of the communication line is insufficient. Based on the processed data transmitted from the thermoelectric generator1, the management computer100can diagnose whether or not the apparatus B is abnormal. For example, in a case where the peak values exceed predetermined thresholds, the management computer100can diagnose that the apparatus B is abnormal.

As illustrated inFIG. 4, the maximum value Pha and the maximum value Phb may be different. Similarly, the minimum value Pla and the minimum value Plb may be different. That is, in a case where the sampling frequency is small, it may be difficult to accurately calculate the peak values.

In the present embodiment, in a case where the second sampling frequency is set as the sampling frequency, the detection data acquisition unit81acquires detection data in the first specified time period, and the processing unit82calculates a maximum value Ph_i and a minimum value Pl_i of vibration in the first specified time period.

FIG. 5is a diagram for describing a method of calculating the maximum value Ph and the minimum value Pl of vibration according to the present embodiment. In the graph ofFIG. 5, the vertical axis represents acceleration detected by the vibration sensor6, and the horizontal axis represents time.

As first detection-data acquisition processing, the detection data acquisition unit81acquires detection data of the vibration sensor6at the second sampling frequency (100 Hz) in the first specified time period (0.1 seconds). As first processed-data calculation processing, the processing unit82calculates the maximum value Ph_1and the minimum value Pl_1of vibration in the first specified time period which have been acquired in the first acquisition processing.

As second detection-data acquisition processing, the detection data acquisition unit81acquires detection data of the vibration sensor6at the second sampling frequency (100 Hz) in the first specified time period (0.1 seconds). As second processed-data calculation processing, the processing unit82calculates the maximum value Ph_2and the minimum value Pl_2of vibration in the first specified time period which have been acquired in the second acquisition processing.

As i-th detection-data acquisition processing, the detection data acquisition unit81acquires detection data of the vibration sensor6at the second sampling frequency (100 Hz) in the first specified time period (0.1 seconds). As i-th processed-data calculation processing, the processing unit82calculates the maximum value Ph_i and the minimum value Pl_i of vibration in the first specified time period which have been acquired in the i-th acquisition processing.

As N-th detection-data acquisition processing, the detection data acquisition unit81acquires detection data of the vibration sensor6at the second sampling frequency (100 Hz) in the first specified time period (0.1 seconds). As N-th processed-data calculation processing, the processing unit82calculates the maximum value Ph_N and the minimum value Pl_N of vibration in the first specified time period which have been acquired in the N-th acquisition processing.

As described above, the processing unit82executes, N times (a plurality of times), processing of calculating the maximum value Ph_i and the minimum value Pl_i of vibration in the first specified time period. The processing unit82calculates N maximum values Ph_i and N minimum values Pl_i. The NN maximum values Ph_i and minimum values Pl_i calculated by the processing unit82are transmitted from the wireless communication device9to the management computer100.

The management computer100determines the largest value among the acquired N (a plurality of) maximum values Ph_i as the maximum value Ph for use in diagnosis of the presence or absence of abnormality. The management computer100determines the smallest value among the N (a plurality of) minimum values Pl_i as the minimum value Pl for use in diagnosis of the presence or absence of abnormality.

As described above, in the present embodiment, the processing unit82executes, a plurality of times, the processing of calculating the peak values (maximum value Ph_i and minimum value Pl_i) of vibration in the detection data of the vibration sensor6acquired in the second specified time period (20 seconds). The management computer100determines the peak values (maximum value Ph and minimum value Pl) for use in diagnosis of the presence or absence of abnormality from the plurality of peak values (maximum values Ph_i and minimum values Pl_i) acquired from the calculation processing executed a plurality of times.

In a case where the sampling frequency is small, it is difficult to calculate an accurate maximum value Ph and minimum value Pl in the first specified time period (0.1 seconds). Even in this case, it is possible to determine an accurate maximum value Ph and minimum value Pl by executing the calculation processing of calculating the maximum value Ph_i and the minimum value Pl_i every first specified time period (every 0.1 seconds) a plurality of times, determining the maximum value Ph from the plurality of calculated maximum values Ph_i, and determining the minimum value Pl from the plurality of minimum values Pl_i. That is, executing the processing of calculating the maximum value Ph_i a plurality of times increases the probability of acquiring, from the plurality of maximum values Ph_i, the maximum value Ph identical to a true maximum value or the maximum value Ph approximate to the true maximum value. Similarly, executing the processing of calculating the minimum value Pl_i a plurality of times increases the probability of acquiring, from the plurality of minimum values Pl_i, the minimum value Pl identical to a true minimum value or the minimum value Pl approximate to the true minimum value. Therefore, the management computer100can determine the accurate maximum value Ph and minimum value Pl.

Note that the present embodiment describes an example in which peak values (maximum value Ph and minimum value Pl) for use in diagnosis of the presence or absence of abnormality are determined from a plurality of peak values (maximum values Ph_i and minimum values Pl_i) acquired from the calculation processing executed a plurality of times. As described above, as described above, the processed data generated by the processing unit82includes at least one of peak values, an RMS value, and a frequency of vibration. Processed data for use in diagnosis of the presence or absence of abnormality may be determined from the processed data including the peak values, RMS value, and frequency of vibration.

Effects

As described above, according to the present embodiment, the thermoelectric generator1including the thermoelectric generator module5, the vibration sensor6driven by power generated by the thermoelectric generator module5, and the wireless communication device9that transmits detection data of the vibration sensor6is installed on the apparatus B. The thermoelectric generator module5can generate power by a temperature difference between the heat receiver2and the heat radiator3. The vibration sensor6is driven by the power generated by the thermoelectric generator module5. In the detection data transmission mode, the wireless communication device9is driven by the power generated by the thermoelectric generator module5to transmit the detection data of the vibration sensor6. Thus, the vibration sensor6and the wireless communication device9are driven without using a cable or battery connecting the vibration sensor6and the power supply. The detection data of the vibration sensor6is transmitted to the management computer100only by installing the thermoelectric generator1on the apparatus B. Based on the detection data of the vibration sensor6, the management computer100can efficiently diagnose whether or not the apparatus B is abnormal. Even in a case where a plurality of apparatuses B exist in the industrial facility, the management computer100can efficiently diagnose whether or not each of the plurality of apparatuses B is abnormal only when the thermoelectric generator1is installed on each of the plurality of apparatuses B.

The microcomputer8includes the processing unit82that processes detection data of the vibration sensor6. An amount of processed data generated by the processing unit82is smaller than an amount of detection data acquired by the detection data acquisition unit81. Even in a case where the data communication capability of the communication line is insufficient, the wireless communication device9can smoothly transmit the small amount of processed data to the management computer100.

The processed data transmitted to the management computer100includes peak values (maximum value Ph and minimum value Pl) of vibration. Based on the maximum value Ph and the minimum value Pl of vibration, the management computer100can diagnose whether or not the apparatus B is abnormal. In a case where the maximum value Ph of vibration exceeds a predetermined upper threshold or in a case where the minimum value Pl of vibration falls below a predetermined lower threshold, the management computer100can diagnose that the apparatus B is abnormal. Further, the management computer100can diagnose that the apparatus B is abnormal on the basis of the RMS value or frequency of vibration.

The microcomputer8includes the change unit83that changes a sampling frequency of detection data of the vibration sensor6for use in the processing executed by the processing unit82. Accordingly, the change unit83can set an appropriate sampling frequency in consideration of the data communication capability of the communication line or the operation load on the processing unit82.

In the processed data transmission mode, the processing unit82executes, a plurality of times, the processing of calculating the peak values (maximum value Ph_i and the minimum value Pl_i) of vibration in the detection data of the vibration sensor6acquired in the first specified time period, and the management computer100determines the peak values (maximum value Ph and minimum value Pl) for use in diagnosis of the presence or absence of abnormality from the plurality of peak values (maximum values Ph_i and minimum values Pl_i) acquired from the calculation processing executed a plurality of times. Thus, even in a case where the sampling frequency is small and it is difficult to calculate an accurate maximum value Ph and minimum value Pl in the first specified time period, the management computer100can determine the accurate maximum value Ph and minimum value Pl because the calculation processing of calculating the maximum value Ph_i and the minimum value Pl_i is executed a plurality of times.

The temperature sensor7driven by power generated by the thermoelectric generator module5is provided, and detection data of the temperature sensor7is transmitted to the management computer100. Thus, the management computer100can accurately diagnose whether or not the apparatus B is abnormal on the basis of both the detection data of the vibration sensor6and the detection data of the temperature sensor7. In a case where an abnormality occurs in the apparatus B, only a change in vibration is detected immediately after the occurrence of the abnormality, and an increase in temperature is detected with the lapse of time in many cases. In a case where both the detection data of the vibration sensor6and the detection data of the temperature sensor7are acquired, it is possible to diagnose whether or not the apparatus B is abnormal more accurately.

The thermoelectric generator module5, the vibration sensor6, the temperature sensor7, the microcomputer8, and the wireless communication device9are housed in a single housing20. This reduces, for example, influence of noise on the detection data of the vibration sensor6or the detection data of the temperature sensor7.

Modification Examples

Note that, in the above embodiment, the sampling frequency is changed on the basis of operation of the operating device15. The sampling frequency may be changed on the basis of a change command transmitted from the management computer100. The wireless communication device9receives a change command transmitted from the management computer100. The wireless communication device9transmits the received change command to the processing unit82. Based on the change command, the processing unit82changes the sampling frequency of the detection data for use in the processing. Note that the management computer100can output not only the change command to change the sampling frequency but also various change commands to change settings regarding the processing of the detection data. The change of the settings regarding the processing of the detection data includes at least one of a change of the sampling frequency of the detection data for use in the processing executed by the processing unit82, a change of a frequency of wireless communication between the wireless communication device9and the management computer100, and a change of transmission times, per unit time, of the detection data transmitted from the wireless communication device9to the management computer100.

Note that the management computer100may be configured by a single computer or may be configured by a plurality of computers.

Second Embodiment

A second embodiment will be described. In the following description, the same or equivalent components as those of the above embodiment are denoted by the same reference signs, and description thereof is simplified or omitted.

In the above first embodiment, the thermoelectric generator module5, the vibration sensor6, the temperature sensor7, the microcomputer8, and the wireless communication device9are housed in the single housing20.

FIG. 6is a block diagram of the thermoelectric generator1according to the present embodiment. As illustrated inFIG. 6, the thermoelectric generator module5may be housed in a first housing21, and the vibration sensor6, the temperature sensor7, the microcomputer8, and the wireless communication device9may be housed in a second housing22. In the example ofFIG. 6, the power storage unit16is placed between the first housing21and the second housing22. The first housing21and the second housing22are different housings. The first housing21and the second housing22are connected by a cable23. Both the first housing21and the second housing22are installed on the apparatus B. Power generated by the thermoelectric generator module5is supplied to the vibration sensor6, the temperature sensor7, the microcomputer8, and the wireless communication device9housed in the second housing22via the cable23and the power storage unit16.

Third Embodiment

A third embodiment will be described. In the following description, the same or equivalent components as those of the above embodiment are denoted by the same reference signs, and description thereof is simplified or omitted.

FIG. 7is a schematic diagram of a vibration detection system200according to the present embodiment. As illustrated inFIG. 7, the vibration detection system200includes a plurality of thermoelectric generators1installed on the apparatus B. As described in the above embodiments, the thermoelectric generator1includes the thermoelectric generator module5, the vibration sensor6driven by power generated by the thermoelectric generator module5, and the wireless communication device9that transmits detection data of the vibration sensor6. The wireless communication device9wirelessly transmits the detection data of the vibration sensor6. The wireless communication device9can transmit such processed data as described in the above embodiments. The thermoelectric generator1further includes the temperature sensor7. As described in the above first embodiment, the thermoelectric generator module5, the vibration sensor6, the temperature sensor7, the microcomputer8, and the wireless communication device9may be housed in the single housing20. As described in the above second embodiment, the thermoelectric generator module5may be housed in the first housing21, and the vibration sensor6, the temperature sensor7, the microcomputer8, and the wireless communication device9may be housed in the second housing22.

A plurality of apparatuses B are provided in the industrial facility. Examples of the apparatus B encompass a motor for operating a pump. The apparatus B may be, for example, a motor for operating a pump for use in a sewer. The apparatus B may be installed underground. In the present embodiment, a plurality of thermoelectric generators1are installed on a single apparatus B. The apparatus B functions as a heat source of the thermoelectric generators1.

The vibration detection system200includes a communication device210and repeaters220. The communication device210receives detection data of the vibration sensor6transmitted from each of the plurality of thermoelectric generators1and transmits the detection data to the management computer100, and the repeaters220connect the thermoelectric generators1and the communication device210. The plurality of repeaters220are provided. The repeaters220and the communication device210wirelessly communicate with each other. The communication device210and the management computer100may perform wireless communication or wired communication.

When the apparatus B operates and generates heat, a temperature difference is caused between the heat receiver2and the heat radiator3. The thermoelectric generator module5can generate power by the temperature difference between the heat receiver2and the heat radiator3. The vibration sensor6is driven by the power generated by the thermoelectric generator module5. Further, the power generated by the thermoelectric generator module5is stored in the power storage unit16included in the thermoelectric generator1. When the power stored in the power storage unit16exceeds a predetermined amount, the wireless communication device9transmits detection data of the vibration sensor6. The wireless communication device9periodically transmits the detection data.

The detection data of the vibration sensor6from the wireless communication device9is transmitted to the communication device210via the repeater220. The detection data is transmitted from each of the plurality of thermoelectric generators1to the communication device210. The communication device210processes the detection data transmitted from each of the plurality of thermoelectric generators1in a predetermined format, and then transmits the detection data to the management computer100. The management computer100can monitor and manage a state of each of the plurality of apparatuses B on the basis of the detection data of the vibration sensor6transmitted from each of the plurality of thermoelectric generators1. The management computer100can diagnose whether or not the apparatus B is abnormal on the basis of the detection data of the vibration sensor6transmitted from each of the plurality of thermoelectric generators1.

The detection data from each of the plurality of thermoelectric generators1is collected by the communication device210and is then transmitted to the management computer100. The plurality of thermoelectric generators1can independently transmit the detection data. That is, the thermoelectric generator1can transmit the detection data without being affected by other thermoelectric generators1.

For example, in a case where the apparatuses B and the thermoelectric generators1exist in the underground while the communication device210and the management computer100exist on the ground, the vibration sensors6transmitted from the thermoelectric generators1are smoothly transmitted to the management computer100by providing the repeaters220.

Power generated by the thermoelectric generator module5increases as the temperature difference between the heat receiver2and the heat radiator3increases. That is, the power generated by the thermoelectric generator module5is stored in the power storage unit16in a shorter time as the temperature difference between the heat receiver2and the heat radiator3increases. Therefore, a period in which the wireless communication device9transmits the detection data becomes shorter as the temperature difference between the heat receiver2and the heat radiator3increases. In a case where the apparatus B becomes abnormal, it is highly possible that an amount of heat generated by the apparatus B increases. That is, in a case where the apparatus B becomes abnormal, it is highly possible that the temperature difference between the heat receiver2and the heat radiator3increases. Therefore, in a case where the apparatus B becomes abnormal, the period in which the wireless communication device9transmits the detection data becomes shorter. In a case where the apparatus B becomes abnormal, the amount of detection data transmitted from the thermoelectric generator1to the management computer100increases. Thus, the management computer100can efficiently analyze whether or not the apparatus B is abnormal.

As described above, according to the present embodiment, the vibration detection system200includes: the plurality of thermoelectric generators1installed on each of the plurality of apparatuses B; and the communication device210that receives detection data transmitted from each of the plurality of thermoelectric generators1and transmits the detection data to the management computer100. Therefore, the management computer100can monitor and manage the states of the plurality of apparatuses B and diagnose whether or not the plurality of apparatuses B are abnormal. Further, the thermoelectric generator module5functions as a power supply, and the wireless communication device9wirelessly transmits the detection data. Therefore, the detection data of the vibration sensor6can be easily collected only by installing the thermoelectric generator1on the apparatus B without, for example, providing a cable in the industrial facility.

Other Embodiments

In the above embodiments, the change unit83changes a sampling frequency in response to operation of the operating device15provided in the thermoelectric generator1. A change command to change the sampling frequency may be transmitted from the management computer100to the change unit83. For example, the management computer100may output the change command when an input device connected to the management computer100is operated by an administrator. Examples of the input device encompass a computer keyboard, a touchscreen, and a mouse.

In the above embodiments, the function of the processing unit82may be provided in the management computer100. The detection data of the vibration sensor6may be transmitted to the management computer100via the wireless communication device9, and the management computer100may generate processed data. Further, the function of the management computer100may be provided in the microcomputer8. For example, the processing unit82may calculate the maximum value Ph and the minimum value Pl of vibration for use in diagnosis of the presence or absence of abnormality.

REFERENCE SIGNS LIST