JP7244118B2 - Measuring device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a measuring device, and more particularly to a measuring device for measuring the temperature and vibration of a steam trap.

In a plant or the like having a steam piping system, condensate (drainage) may occur in the piping system due to heat exchange or heat radiation. If this condensate stays in the piping system, it will cause a decrease in operating efficiency. I have to.

If the sealing performance of the steam trap is impaired due to aged deterioration, malfunction, or the like, steam in the steam piping system leaks to the outside through the steam trap, resulting in unnecessary steam loss. Therefore, the operation of checking the state of the steam trap is performed periodically, such as once a year.

Patent Literature 1 listed below discloses a measuring device and a diagnostic device for diagnosing the state of a steam trap. The measuring device is a portable measuring device, the diagnostic device is a tablet terminal, a laptop computer, or the like, and wireless communication is possible between the measuring device and the diagnostic device. The measuring device includes a temperature sensor that measures the surface temperature of each steam trap, a vibration sensor that measures the vibration intensity of each steam trap, a storage unit that stores measurement data output from the temperature sensor and the vibration sensor, and the measurement A communication unit for transmitting data to the diagnostic device and a display unit are provided. The diagnostic device diagnoses the state (normal or abnormal) of each steam trap based on the measurement data received from the measurement device, and transmits diagnostic data indicating the result of the diagnosis to the measurement device. Based on the diagnostic data received from the diagnostic device, the measuring device displays the diagnostic result of each steam trap on the display unit.

JP 2018-84418 A

The measuring device incorporates a circuit board on which an electric circuit is formed, and driving power is supplied to the electric circuit from a power supply circuit.

FIG. 3 is a diagram showing the configuration of the power supply circuit 100 included in the measuring device. The power supply circuit 100 includes a battery 161, a fuse element 162, and a power supply IC 164 such as a series regulator. The power supply circuit 100 supplies driving power from the battery 161 to the electric circuit 103 .

The power IC 164 has a protection circuit 171 . The protection circuit 171 stops the operation of the power supply IC 164 when a current equal to or greater than a first current value, which is larger than the current value during normal operation, flows through the electric circuit 103 . This protects the electric circuit 103 from an overcurrent equal to or greater than the first current value.

The fuse element 162 cuts off the connection between the battery 161 and the power supply IC 164 when a second current value (for example, several amperes) larger than the first current value flows. This protects the power supply IC 164 and the electric circuit 103 from overcurrent of the second current value or more.

By the way, in the measuring device, if the electrolyte leaks from the battery 161 due to changes in the environment such as temperature or humidity, the electrolyte flows onto the circuit board and causes a partial short circuit in the electric circuit 103 . short) may occur. Partial short-circuiting may occur not only due to leakage of electrolyte from the battery, but also due to dew condensation and the like.

Since a partial short is not a 0 ohm short but a several ohm short, when a partial short occurs, a current larger than the current value during normal operation but smaller than the first current value flows through the electric circuit 103. . Therefore, even if current flows through the electric circuit 103 due to the partial short, the protection circuit 171 and the fuse element 162 do not perform a protection operation. As a result, a current larger than the current value during normal operation continues to flow through the electric circuit 103, which may induce thermal runaway and cause the semiconductor elements and the like forming the electric circuit 103 to emit smoke.

Some plants, such as petroleum complexes, where steam traps are installed, have strict explosion-proof standards. Since a measuring device having an electric circuit 103 that may generate smoke cannot be brought into such a facility, countermeasures against smoke generation when a partial short occurs are an important issue for the measuring device.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and it is an object of the present invention to obtain a measuring device capable of suppressing or avoiding smoke emission from an electric circuit even when a partial short circuit occurs in the electric circuit. With the goal.

A measuring device according to an aspect of the present invention is a measuring device for measuring the temperature and vibration of a steam trap, comprising a probe in contact with the steam trap, and the temperature and vibration of the steam trap transmitted from the probe. An electric circuit that outputs temperature data and vibration data of the steam trap by applying electrical processing including conversion to an electric signal to the vibration, and a power supply circuit that supplies driving power to the electric circuit. and wherein the power supply circuit includes a battery, a power supply IC connected between the battery and the electric circuit, and a resistive element connected between the battery and the electric circuit. The power supply IC includes a protection circuit that stops the operation of the power supply IC when a current equal to or greater than a first current value flows through the electric circuit, and the resistance element prevents current flowing through the electric circuit when a partial short occurs. has a resistance value capable of limiting the current value of to less than a second current value that is smaller than the first current value.

According to this aspect, the power supply circuit has a resistive element connected between the battery and the electric circuit, and the resistive element protects the current value of the current flowing through the electric circuit when a partial short occurs. It has a resistance value that can be limited to less than a second current value that is less than the first current value that is the current value at which the operation starts. As a result, since the current value of the current flowing through the electric circuit is limited to less than the second current value when the partial short occurs, even if the partial short of the electric circuit occurs, smoke emission from the electric circuit is suppressed or avoided. It becomes possible to

In the above aspect, the second current value is a smoking start current value of the electric circuit.

According to this aspect, the current value of the current flowing through the electric circuit when the partial short occurs is limited to be less than the second current value, which is the smoking start current value of the electric circuit. Therefore, even if a partial short-circuit occurs in the electric circuit, it is possible to effectively avoid smoke from the electric circuit.

In the above aspect, the resistive element is connected between the battery and the power supply IC.

According to this aspect, since the resistive element is connected between the battery and the power supply IC, the current flowing through the power supply IC can be effectively limited by the resistive element on the upstream side (battery side) of the power supply IC. becomes possible. Also, when a resistor element is connected between the power supply IC and the electric circuit, a voltage drop occurs due to the resistor element with respect to the output voltage from the power supply IC. , the voltage drop does not occur, so that the output voltage from the power supply IC can be efficiently input to the electric circuit.

Advantageous Effects of Invention According to the present invention, even when a partial short circuit occurs in an electric circuit, it is possible to suppress or avoid smoke emission from the electric circuit.

1 is a diagram showing a simplified configuration of a portable measuring device according to an embodiment of the present invention; FIG. 1 is a diagram showing a simplified configuration of a power supply circuit; FIG. It is a figure which shows the structure of the power supply circuit with which the measuring device which concerns on background art is provided.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Elements with the same reference numerals in different drawings represent the same or corresponding elements.

FIG. 1 is a diagram showing a simplified configuration of a portable measuring device 1 according to an embodiment of the present invention. The measuring device 1 has a function of measuring the temperature and vibration of the steam trap and a function of diagnosing the state of the steam trap based on the measurement results. However, the diagnostic function may be provided by an external device (diagnostic device, server device, or the like) of the measuring device 1 . In addition, the measuring device is not limited to a portable type, and may be an installation type measuring device.

2. Description of the Related Art In a plant or the like equipped with a steam piping system, a plurality of steam traps are installed at appropriate locations in the piping system in order to discharge condensate (drainage) generated in the piping system to the outside of the piping system. The condition of the steam trap is checked by periodic inspection such as once a year. A periodic inspection operator carries the portable measuring device 1 and moves around the plant to inspect each steam trap in turn using the measuring device 1 . Note that the inspection of the steam trap is not limited to periodic inspection, and may be irregular inspection.

The measuring device 1 includes probes (a temperature probe P1 and a vibration probe P2), a power supply circuit 2, and an electric circuit 3. The electric circuit 3 is formed on a circuit board incorporated in the measuring device 1, and includes a temperature sensor 11, an amplifier circuit 12, an AD converter circuit 13, a vibration sensor 21, a filter circuit 22, an amplifier circuit 23, an AD converter circuit 24, It has a control section 31 , an operation section 41 , a display section 42 , a storage section 43 and a communication section 44 .

The temperature probe P1 and the vibration probe P2 have external shapes of cylindrical pipes made of stainless steel, for example. The temperature probe P1 is arranged in a space inside the vibration probe P2 in a non-contact and concentric positional relationship with respect to the inner peripheral surface of the vibration probe P2. The temperature probe P1 and the vibration probe P2 transmit the temperature and vibration of the steam trap to the temperature sensor 11 and the vibration sensor 21 by being brought into contact with the steam trap to be measured.

The temperature sensor 11 includes, for example, a pair of thermocouple wires and a temperature measurement circuit, converts the temperature transmitted from the temperature probe P1 into an electric signal, and outputs the electric signal. An electrical signal output from the temperature sensor 11 is input to the amplifier circuit 12 . The amplifier circuit 12 amplifies the input electrical signal and outputs it. An electrical signal output from the amplifier circuit 12 is input to the AD conversion circuit 13 . The AD conversion circuit 13 converts the input analog electrical signal into digital data and outputs the digital data. Digital data (temperature data) indicating a temperature measurement value output from the AD conversion circuit 13 is input to the control unit 31 .

The vibration sensor 21 includes, for example, a piezoelectric acceleration sensor, converts the vibration transmitted from the vibration probe P2 into an electric signal, and outputs the electric signal. An electrical signal output from the vibration sensor 21 is input to the filter circuit 22 . The filter circuit 22 passes and outputs an electrical signal in a predetermined frequency band among the input electrical signals. The electrical signal output from the filter circuit 22 is input to the amplifier circuit 23 . The amplifier circuit 23 amplifies the input electrical signal and outputs it. The electrical signal output from the amplifier circuit 23 is input to the AD conversion circuit 24 . The AD conversion circuit 24 converts the input analog electrical signal into digital data and outputs the digital data. Digital data (vibration data) indicating the vibration measurement value output from the AD conversion circuit 24 is input to the control unit 31 .

The operation unit 41 includes operation switches and the like for the operator to input various kinds of information. The display unit 42 is configured using a liquid crystal display, an organic EL display, or the like. However, the operation unit 41 and the display unit 42 may be integrated by using a touch panel display. The storage unit 43 is configured using a rewritable semiconductor memory such as a flash memory. The communication unit 44 includes a communication module compatible with any communication method such as Bluetooth (registered trademark).

The control unit 31 is configured including a CPU and the like. The control unit 31 has a diagnosis unit 51 as a function realized by the CPU executing a predetermined program. The diagnosis unit 51 diagnoses the state of the steam trap based on the measurement data (temperature data and vibration data) input from the AD conversion circuits 13 and 24, and outputs diagnosis data indicating the diagnosis result. For example, the diagnosis unit 51 compares the input temperature data with a predetermined temperature threshold, and compares the input vibration data with a predetermined vibration threshold. . The diagnosis unit 51 diagnoses whether the steam trap is normal or abnormal (steam leakage, drain discharge failure, or blockage) according to a combination of these two comparison results. The control unit 31 creates diagnosis result information (inspection date, diagnosis result, etc.) including the diagnosis data of the steam trap, and stores the diagnosis result information in the storage unit 43 . Also, the control unit 31 inputs diagnostic data to the display unit 42 . Thereby, the diagnosis result of the steam trap is displayed on the display unit 42 . Further, the control unit 31 inputs the steam trap diagnosis result information to the communication unit 44 . The communication unit 44 transmits the input diagnostic result information to a data processing device external to the measuring device 1 .

The power supply circuit 2 supplies electric power to the electric circuit 3 for driving each of a plurality of elements (elements, circuits, devices, etc.) included in the electric circuit 3 .

FIG. 2 is a diagram showing a simplified configuration of the power supply circuit 2. As shown in FIG. The power supply circuit 2 includes a battery 61, a fuse element 62, a resistance element 63, and a power supply IC 64. A fuse element 62 is connected after the battery 61, a resistance element 63 is connected after the fuse element 62, a power supply IC 64 is connected after the resistance element 63, and a load is connected after the power supply IC 64. An electric circuit 3 is connected. The battery 61 is, for example, an alkaline dry battery. The power supply IC 64 includes, for example, a switching regulator. The power supply circuit 2 supplies drive power from the battery 61 to the electric circuit 3 .

The power supply IC 64 has a protection circuit 71 . The protection circuit 71 stops the operation of the power supply IC 64 when a current equal to or greater than a first current value I1 larger than the current value during normal operation flows through the electric circuit 3 . This protects the electric circuit 3 from an overcurrent equal to or greater than the first current value I1.

In the measuring device 1, if the electrolyte leaks from the battery 61 due to changes in the environment such as temperature or humidity, the electrolyte flows onto the circuit board and causes a partial short circuit in the electric circuit 3. ) may occur. A partial short may occur not only due to leakage of electrolyte from the battery 61 but also due to dew condensation or the like.

Since a partial short is not a 0 ohm short but a few ohm short, when a partial short occurs, a current larger than the current value I0 during normal operation but smaller than the first current value I1 is supplied to the electric circuit 3. flows. Therefore, even if current flows through the electric circuit 3 due to the partial short, the protection circuit 71 does not perform the protection operation.

The resistance element 63 has a resistance value capable of limiting the current value of the current flowing through the electric circuit 3 when a partial short occurs to less than a second current value I2 which is less than the first current value I1. The second current value I2 is a current value at which the electric circuit 3 starts to emit smoke due to thermal runaway or the like, and is larger than the current value I0 and smaller than the first current value I1. The output voltage value of the battery 61, the voltage drop value at the fuse element 62, the voltage drop value at the power supply IC 64, the voltage drop value at the electric circuit 3, and the second current value I2 are all known. Therefore, it is possible to set the resistance value of the resistance element 63 to an appropriate value so that the current value of the current flowing through the electric circuit 3 when the partial short occurs is less than the second current value I2.

The fuse element 62 cuts off the connection between the battery 61 and the resistance element 63 when a current of a third current value I3 (for example, several amperes) larger than the first current value I1 flows. As a result, the power supply IC 64 and the electric circuit 3 are protected from an overcurrent equal to or greater than the third current value I3.

According to the measuring device 1 according to this embodiment, the power supply circuit 2 has the resistive element 63 connected between the battery 61 and the electric circuit 3 . The resistance element 63 has a resistance value that can limit the current value of the current flowing through the electric circuit 3 to less than the second current value I2, which is less than the first current value I1 at which the protection circuit 71 starts the protection operation when a partial short occurs. have. As a result, the current value of the current flowing through the electric circuit 3 when a partial short occurs is limited to less than the second current value I2. can be suppressed or avoided.

In addition, according to the measuring device 1 according to the present embodiment, the current value of the current flowing through the electric circuit 3 when a partial short occurs is limited to less than the second current value I2, which is the smoking start current value of the electric circuit 3. . Therefore, even if a partial short-circuit occurs in the electric circuit 3, it is possible to effectively avoid smoke from the electric circuit 3.

Further, according to the measuring device 1 according to the present embodiment, since the resistance element 63 is connected between the battery 61 and the power supply IC 64, the resistance element 63 on the upstream side (battery 61 side) of the power supply IC 64 , the current flowing through the power supply IC 64 can be effectively limited. Also, when a resistance element is connected between the power supply IC 64 and the electric circuit 3, a voltage drop occurs due to the resistance element with respect to the output voltage from the power supply IC 64. Since the voltage drop does not occur in the case of connection between , the output voltage from the power supply IC 64 can be efficiently input to the electric circuit 3 .

Further, according to the measuring device 1 according to the present embodiment, the power supply IC 64 includes a switching regulator instead of a conventional series regulator, so that it becomes possible to improve the decrease in efficiency due to the addition of the resistance element 63. .

REFERENCE SIGNS LIST 1 measuring device 2 power supply circuit 3 electric circuit 61 battery 63 resistive element 64 power supply IC
71 protection circuit P1 temperature probe P2 vibration probe

Claims (3)

A measuring device for measuring the temperature and vibration of a steam trap,
a probe abutted against the steam trap;
an electrical circuit that outputs temperature data and vibration data of the steam trap by performing electrical processing including conversion into electrical signals on the temperature and vibration of the steam trap transmitted from the probe; ,
a power supply circuit that supplies drive power to the electric circuit;
with
The power supply circuit
a battery;
a power supply IC connected between the battery and the electric circuit;
a resistive element connected between the battery and the electrical circuit;
has
the power supply IC includes a protection circuit that stops the operation of the power supply IC when a current equal to or greater than a first current value flows through the electric circuit;
The measuring device according to claim 1, wherein the resistive element has a resistance value capable of limiting a current value of current flowing through the electric circuit to less than a second current value that is smaller than the first current value when a partial short occurs. 2. The measuring device according to claim 1, wherein said second current value is a smoking start current value of said electric circuit. 3. The measuring device according to claim 1, wherein said resistance element is connected between said battery and said power supply IC.

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