JPH02147928A - Temperature distribution measurement by ultrasonic wave - Google Patents

Abstract

PURPOSE:To measure a temperature distribution within a liquid or a solid in a non-contact manner by measuring a distribution of an average sound velocity turning several pairs of ultrasonic transmitting and receiving vibrators to determine a distribution of a water temperature from a value thereof. CONSTITUTION:A first switching circuit 6 is changed over sequentially to send a signal to vibrators 2a, 3a and 4a from a transmitter 7 and an ultrasonic wave is outputted into a tube body 1 from the vibrators 2a, 3a and 4a. As a result, the ultrasonic waves are received with vibrators 2b, 3b and 4b separately to be converted into electrical signals, which are converted into signals of distance with a propagation time measuring circuit 9 for ultrasonic waves through a second switching circuit 8 and furthermore, these signals undergo a Fourier transform and an inverse transform processing with a Fourier transform circuit 10 and a Fourier inverse transform circuit 11 thereby plotting a temperature at each position with a plotter 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for measuring temperature distribution using ultrasonic waves for non-contact measurement of temperature distribution in a liquid or solid using ultrasonic waves [Prior Art] Generally For example, to measure the temperature distribution inside a circular pipe, an electric thermometer such as a thermocouple or resistance thermometer is installed inside the pipe, and the temperature gradient between them is estimated from the values measured at each location. We were measuring the distribution.

[Problems to be Solved by the Invention] However, in such a conventional temperature recognition device, for example, when a temperature measuring element is installed in a fluid, the fluid flow changes and the temperature in the original fluid flow changes. There is a problem that the temperature distribution is not measured, and when measuring the temperature of a solid, it is necessary to insert multiple temperature measurement elements inside the solid, which changes the temperature distribution of the solid. There was a problem.

In the present invention, a plurality of vibrators are mounted around a circular tube.

The object of the present invention is to provide a method and apparatus for measuring temperature distribution using ultrasonic waves, in which ultrasonic waves sent from a transmitting transducer are received by a receiving transducer, and thereby the temperature distribution is measured from the distribution of the average sound velocity. .

[Problems to be Solved by the Invention] In order to achieve the above object, the present invention arranges at least a pair of ultrasonic transmitting transducers and a receiving transducer with one circular tube in between, and the A method of measuring the average sound speed from the propagation time of the ultrasonic waves, measuring the distribution of the average sound speed while rotating the plurality of pairs of ultrasonic transmitting transducers and receiving transducers, and calculating the water temperature distribution from this value, Also, a plurality of pairs of ultrasonic transmitting transducers and receiving transducers facing each other across a circular tube, a switching circuit for sequentially switching the plurality of pairs of ultrasonic transmitting transducers and receiving transducers, and each pair of ultrasonic transmitting transducers A measurement circuit that measures the speed of sound from the propagation time of the ultrasonic wave between the pair of ultrasonic transmitting and receiving transducers using the outputs of the ultrasonic transducer and the receiving transducer, and a Fourier transform circuit that Fourier transforms the sound velocity measured by the measuring circuit. , a Fourier inverse circuit that inversely transforms the Fourier transform output, and a circuit that records or displays the output of the Fourier inverse transform circuit. Furthermore, multiple omnidirectional transducers are attached to a circular tube, and the transducers that transmit ultrasonic waves are sequentially switched, and the transducers other than those that transmit ultrasonic waves are used as receiving transducers to receive ultrasonic waves and measure the distribution of the average sound speed. This method uses a plurality of oscillators installed around a circular tube, one of which is used as an ultrasonic transmitting oscillator, and the other oscillators. a switching circuit that sequentially switches the ultrasonic wave as a receiving transducer, a measuring circuit that measures the sound speed from the propagation time of the ultrasonic wave between the transmitting transducer and the receiving transducer, and a Fourier transform of the sound velocity value measured by the measuring circuit. This device includes a transform circuit, a Fourier inverse circuit that inversely transforms the output of the Fourier transform, and a circuit that records or displays the output of the inverse Fourier transform circuit.

[Function] According to the present invention, since ultrasonic waves are relatively difficult to attenuate in a liquid, and the propagation speed of ultrasonic waves is temperature dependent, the pair of transducers provided around the circular tube operate sequentially. Alternatively, by sequentially operating one transducer for transmission, it is possible to measure changes in the propagation time of ultrasonic waves with each transducer, and to measure the temperature distribution from this measured value.

[Embodiment] Referring to FIG. 1, in the embodiment of the present invention, pairs of vibrators 2a, 2b, 3a,
3b, 4a, 4b are attached, and these vibrators 2a, 2
b, 3a, 3b, 4a, and 4b are configured to be rotated by a motor 5 as shown in FIG. Also, the vibrator 2
a, 3a, and 4a are connected to a transmitter 7 via a first switch circuit 6, and transducers 2b, 3b, and 4b are connected to an ultrasonic propagation time measuring circuit 9 via a second switch circuit 8. ing. Further, the output of the ultrasonic propagation time measurement circuit 9 is connected to a Fourier transform circuit 10, the output of the Fourier transform circuit 10 is connected to an inverse Fourier transform circuit 11, and the output of the inverse Fourier transform circuit 1 is connected to a plotter. 12. Note that the rotation of the motor 5 and the first and second
Switching of the switch circuits 6 and 8 is controlled by the CPU 13.

In this embodiment configured in this way, the first switch circuit 6 is sequentially switched to connect the vibrators 2a and 3a.

A signal is sent from the transmitter 7 to the transducers 2a, 3a,
When an ultrasonic wave is output from 4a into the tube body 1, the transducer 2b,
Ultrasonic waves are received by 3b and 4b and converted into electrical signals. Each of the nine electric signals is converted into a distance signal by an ultrasonic propagation time measuring circuit 9 via a second switch circuit 8, and these signals are further converted into a distance signal by a Fourier transform circuit 10.
Fourier transform and inverse transform processing are performed in the Fourier inverse transform circuit 11, and the temperature at each position is plotted using a plotter 2.

In this embodiment, the transmitting transducers 2a, 3a, 4a
The ultrasonic waves transmitted by the transducers 2b, 3b, and 4b
By detecting changes in the respective distances from the propagation time of these ultrasonic waves, and performing Fourier transform and inverse transform on these signals, it is possible to detect changes in temperature. temperature distribution can be measured.

Incidentally, instead of the tube body 1, the cylindrical objects are provided with vibrators 2a, 2b,
When 3a, 3b, 4a, and 4b are asymmetrically opposed to each other, the temperature distribution inside the cylindrical object can be measured.

Referring to FIG. 3, in another embodiment of the present invention, non-directional vibrators 141゜14□, .
・,14. are attached, and these transducers 14□ to 14.
is connected to the switch circuit 15. Further, a transmitter 7 and a CPU 13 are connected to the switch circuit 1.5, and the output of the switch circuit 15 is connected to the output of an ultrasonic propagation time measuring circuit 9, a Fourier transform circuit 10, an inverse Fourier transform circuit 11, and a plotter 12. are connected sequentially.

In this embodiment configured in this way, when one transducer, for example, the transducer 141, is selected and a signal is sent to it from the transmitter 7, the transducer 141 emits an ultrasonic wave. This ultrasonic wave is transmitted by a vibrator installed on the inner wall of tube body 1】-4□～
14. The received signals are respectively received by the ultrasonic propagation time measurement circuit 9 via the switch circuit 15 and converted into velocity signals by the ultrasonic propagation time measuring circuit 9.Furthermore, these signals are converted into the velocity signals by the Fourier transform circuit 10 and the Fourier inverse transform circuit. Fourier transform and inverse transform processing are performed in step 11, and the temperature at each position is plotted by plotter 12.

[Effects of the Invention] Since the present invention is configured as described above, the average water temperature can be measured from the average sound velocity inside the pipe without contact, and the flow of the internal fluid is not changed by the vibrator. , it has the advantage of being able to measure more accurately than conventional contact type temperature distribution measuring devices.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention in which a vibrator is attached to a tube body, FIG. 2 is a configuration diagram of an embodiment of the present invention, and FIG. 3 is a configuration diagram of another embodiment of the present invention. be. 1... Tube body, 2a, 2b, 3a, 3b, 4a. 4b... Vibrator, 5... Motor, 6... Switch circuit, 7... Transmitter, 8... Second switch circuit, 9... Propagation time measurement circuit, 10 ...Fourier transform circuit, 11...Fourier inverse transform circuit, 12...
- Plotter, 13...CPU, 14□~14. ...
vibrator.

Claims (1)

[Claims] 1. At least a pair of ultrasonic transmitting transducers and a receiving transducer are arranged with a circular tube in between, and the average sound speed is measured from the propagation time of the ultrasonic waves between each pair of transducers, and A method for measuring temperature distribution using ultrasonic waves, characterized in that the distribution of average sound speed is measured while rotating the plurality of pairs of ultrasonic transmitting transducers and receiving transducers, and the distribution of water temperature is determined from this value. 2. Pairs of ultrasonic transmitting transducers and receiving transducers facing each other across a circular tube, a switching circuit that sequentially switches the plurality of pairs of ultrasonic transmitting transducers and receiving transducers, and each pair of ultrasonic transmitting transducers. By the output of the transducer and the receiving transducer,
A measurement circuit that measures the speed of sound from the propagation time of the ultrasound between a pair of ultrasonic transmitting transducers and receiving transducers, and a Fourier transform circuit that Fourier transforms the sound speed measured by the measuring circuit.
A temperature distribution measuring device using ultrasonic waves, comprising a Fourier inverse circuit that inversely transforms the Fourier transform output, and a circuit that records or displays the output of the Fourier inverse transform circuit. 3. Attach multiple omnidirectional transducers to a circular tube, sequentially switch the transducers that transmit ultrasonic waves, and measure the average sound velocity distribution by using the transducers other than the transmitting transducers as receiving transducers to receive the ultrasonic waves. A method for measuring temperature distribution using ultrasonic waves, which is characterized in that the distribution of water temperature is determined from this value. 4. A plurality of transducers provided around the circular tube, a switching circuit that sequentially switches any one of the plurality of transducers as an ultrasonic transmitting transducer and the other transducers as receiving transducers, and the transmitting vibration. A measurement circuit that measures the sound speed based on the propagation time of the ultrasonic wave between the transducer and the receiving transducer, a Fourier transform circuit that performs Fourier transform on the sound speed value measured by the measurement circuit, and a Fourier inverse transform that inversely transforms the Fourier transform output. 1. An ultrasonic temperature distribution measuring device comprising: a circuit; and a circuit for recording or displaying the output of the inverse Fourier transform circuit.