Measuring device, measuring method, and measuring program

Abstract

To accurately measure the velocity of a fluid.SOLUTION: A measurement device includes a change section, a coil, a detection section, a measurement section, and a calculation section. The change section is placed on a pipe through which a measurement object fluid flows and changes the charged state of the fluid flowing through the pipe. The coil is placed downstream of the change section on the pipe. The detection section and the measurement section detect a change in a magnetic field of the coil. The measurement section measures the time taken before a change in the magnetic field of the coil is detected by the detection section after a timing at which the charged state of the fluid is changed by the change section. The calculation section calculates the velocity of the fluid based on the time measured by the measurement section.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a measuring device, a measuring method, and a measurement program.

Background Art

[0002] There is known a measuring device for measuring the flow velocity of a fluid such as a gas flowing through a pipe. For example, in Patent Document 1, a pair of electrodes is provided in a pipe through which a fluid flows, a generating device is provided upstream of the electrodes, and the flow velocity of the fluid is measured from the induced voltage generated in the pair of electrodes by the fluid charged negatively by the generating device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the amount of charge with which the fluid is charged varies depending on the type and state of the fluid. For this reason, the induced voltage generated in the pair of electrodes changes depending on the type and state of the fluid, and there are cases where the flow velocity of the fluid cannot be measured accurately.

[0005] The present application is for solving such problems and aims to accurately measure the flow velocity of a fluid.

Means for Solving the Problems

[0006] The measuring device according to this application comprises a modification unit, a coil, a detection unit, a measurement unit, and a calculation unit. The modification unit is installed in a pipe through which the fluid to be measured flows and changes the charged state of the fluid flowing through the pipe. The coil is installed downstream of the modification unit in the pipe. The detection unit detects changes in the magnetic field of the coil. The measurement unit measures the time from the moment the charged state of the fluid is changed by the modification unit until the change in the magnetic field of the coil is detected by the detection unit. The calculation unit calculates the fluid velocity based on the time measured by the measurement unit.

[0007] In the above measuring device, the calculation unit may calculate the fluid velocity by dividing the distance between the change section in the piping and the coil by the time measured by the measuring unit.

[0008] In the above measuring device, the calculation unit may calculate the fluid flow rate by multiplying the calculated flow velocity by the cross-sectional area of ​​the pipe.

[0009] In the above measuring device, the detection unit may detect the dielectric current generated in the coil. The measuring unit may also measure the time from the moment the charged state of the fluid is changed until the dielectric current detected by the detection unit changes.

[0010] In the above measuring device, the modification unit may neutralize the fluid flowing through the piping and then change the fluid to a charged state. The measuring unit may also measure the time from the moment the charged state of the fluid is changed until the dielectric current is detected by the detection unit.

[0011] In the above measuring device, the coil may be arranged to surround the outer circumference of the piping. [Effects of the Invention]

[0012] According to the measuring device described above, the fluid velocity can be measured with high accuracy. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a diagram illustrating the schematic configuration of a measuring device according to an embodiment. [Figure 2] Figure 2 is a diagram illustrating an example of coil arrangement according to the embodiment. [Figure 3] Figure 3 shows an example in which the gas flowing through the piping according to the embodiment is changed to an electrically charged state. [Figure 4] Figure 4 is a diagram illustrating the induced current generated in the coil according to the embodiment. [Figure 5] Figure 5 is a flowchart showing an example of the measurement process procedure according to the embodiment. [Modes for carrying out the invention]

[0014] Next, embodiments (as appropriate, "embodiments") will be described with reference to the drawings. In the following description, components common to the embodiments will be denoted by the same reference numerals, and repeated descriptions will be omitted.

[0015] [Device configuration] Figure 1 is a diagram illustrating the schematic configuration of a measuring device 10 according to an embodiment. Figure 1 shows a pipe 1. The fluid to be measured flows through the pipe 1. The fluid to be measured is a gas. The gas flowing through pipe 1 may contain dust. In the following explanation, for simplicity, pipe 1 is assumed to be straight, the direction in which pipe 1 extends is the X direction, the upward direction perpendicular to the X direction is the Y direction, and the horizontal direction perpendicular to the X direction is the Z direction. The gas flows through pipe 1 in the X direction. The gas flowing through pipe 1 contains particles. The particles can be divided into those that are electrically charged positively or negatively, and those that are in a neutralized state with a balance of positive and negative charges.

[0016] The measuring device 10 measures the flow velocity of the gas flowing through the pipe 1. In this embodiment, the measuring device 10 measures the flow velocity of the gas flowing through the pipe 1. The measuring device 10 includes a changing unit 20, a coil 21, a detection unit 22, a control unit 23, and a display unit 24.

[0017] The modification part 20 is provided in the pipe 1. The modification part 20 changes the charged state of the gas flowing through the pipe 1. For example, the modification part 20 is configured as an ionizer. An ionizer is a device that applies a high voltage to an electrode needle to release ions with positive or negative charges to particles in the air, neutralize them, and remove static electricity. The modification part 20 has a signal generation part 20a and an electrode needle 20b.

[0018] The electrode needle 20b is provided on the wall surface of the pipe 1, and its tip reaches inside the pipe 1. The signal generation part 20a is connected to the electrode needle 20b.

[0019] The signal generation part 20a is connected to the control part 23, and supplies a signal with a predetermined frequency to the electrode needle 20b according to the control of the control part 23. Also, the signal generation part 20a can change the voltage of the signal supplied to the electrode needle 20b according to the control of the control part 23.

[0020] The modification part 20 changes the charged state of the gas flowing through the pipe 1 by irradiating the ions generated by causing corona discharge at the electrode needle 20b by supplying a signal from the signal generation part 20a based on the control of the control part 23 into the pipe 1. For example, the modification part 20 releases ions with positive or negative charges to the gas flowing through the pipe 1, and makes the particles in the gas in an electrically neutral state. Also, the modification part 20 charges the particles in the gas flowing through the pipe 1 positively or negatively by changing the voltage applied to the electrode needle 20b according to the control of the control part 23.

[0021] The coil 21 is provided on the downstream side of the modification part 20 with respect to the gas flow in the pipe 1. FIG. 2 is a diagram for explaining an example of the arrangement of the coil 21 according to the embodiment. FIG. 2 shows a cross-section in the YZ plane of the pipe 1. The coil 21 is arranged so as to surround the outer periphery of the pipe 1. For example, the coil 21 is wound such that the winding is orthogonal to the circumference of the pipe 1. Also, the wound winding of the coil 21 is arranged so as to wind around the outer periphery of the pipe 1 largely. The coil 21 detects the magnetic field generated by the gas flowing through the pipe 1. For example, when the magnetic field generated by the gas flowing through the pipe 1 changes, an eddy current is generated in the coil 21.

[0022] Returning to FIG. 1. The coil 21 is connected to the detection unit 22. The detection unit 22 detects the change in the magnetic field of the coil 21. For example, the detection unit 22 detects the eddy current generated in the coil 21. The detection unit 22 is connected to the control unit 23. The detection unit 22 outputs the detection result to the control unit 23.

[0023] The control unit 23 is a device that controls the measuring device 10. The control unit 23 includes electronic circuits such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit), and integrated circuits such as an ASIC (Application Specific Integrated Circuit) and an FPGA (Field Programmable Gate Array). The control unit 23 has an internal memory for storing programs and control data that define various processing procedures, and executes various processes by the electronic circuits and integrated circuits. The control unit 23 functions as various processing units when various programs operate. For example, the control unit 23 includes a measurement unit 23a, a calculation unit 23b, and an output control unit 23c. In the present embodiment, the control unit 23 corresponds to the computer of the present disclosure.

[0024] The control unit 23 controls the modification unit 20 to change the charged state of the gas flowing through the pipe 1. For example, the control unit 23 releases positively or negatively charged ions into the gas flowing through the pipe 1 to neutralize the static charge and electrically neutralize the particles in the gas. Subsequently, the control unit 23 changes the charged state of the gas flowing through the pipe 1 using the modification unit 20.

[0025] The measurement unit 23a measures the time from the moment the charge state of the gas is changed by the modification unit 20 until the change in the magnetic field of the coil 21 is detected by the detection unit 22. For example, the measurement unit 23a measures the time from the moment the charge state of the gas is changed by the modification unit 20 until the dielectric current detected by the detection unit 22 changes. For example, the measurement unit 23a measures the time from the moment the gas flowing through the pipe 1 is neutralized and then changed back to a charged state until the dielectric current is detected by the detection unit 22.

[0026] The calculation unit 23b calculates the gas flow velocity based on the time measured by the measurement unit 23a. For example, the calculation unit 23b calculates the gas flow velocity by dividing the distance between the change section 20 and the coil 21 in the piping 1 by the time measured by the measurement unit 23a. The calculation unit 23b also calculates the gas flow rate by multiplying the calculated flow velocity by the cross-sectional area of ​​the piping 1.

[0027] The output control unit 23c controls the output of the calculation results from the calculation unit 23b. For example, the output control unit 23c outputs the calculated gas flow velocity and gas flow rate to the display unit 24 for display. The output control unit 23c may also output the calculated gas flow velocity and gas flow rate data to an external device. Alternatively, the output control unit 23c may output the calculated gas flow velocity and gas flow rate data to a storage device for storage.

[0028] Here, I will explain a specific example of measurement.

[0029] Figure 1 shows an example of the charge state of particles in the gas flowing through pipe 1 during measurement. The control unit 23 discharges positively or negatively charged ions into the gas flowing through pipe 1 to neutralize the charge, thereby electrically neutralizing the particles in the gas. In Figure 1, upstream of the electrode needle 20b, the gas flowing through pipe 1 contains positively charged particles, negatively charged particles, and neutralized particles. However, downstream of the electrode needle 20b, the particles become neutralized due to the neutralization process. Neutralized particles generate almost no electric or magnetic fields around them, and even when they pass through coil 21, no induced current is generated in coil 21.

[0030] Subsequently, the control unit 23 changes the charged state of the gas flowing through the pipe 1 using the modification unit 20. For example, the control unit 23 controls the modification unit 20 to change the voltage applied to the electrode needle 20b, thereby positively or negatively charging the particles in the gas flowing through the pipe 1. For example, the control unit 23 controls the modification unit 20 to release positively charged ions, thereby positively charging the particles in the gas flowing through the pipe 1.

[0031] Figure 3 shows an example of changing the charged state of the gas flowing through the pipe 1 according to the embodiment. In Figure 3, downstream of the position of the electrode needle 20b, the particles become positively charged by positively charging from the electrode needle 20b. The control unit 23 may control the modification unit 20 to release negatively charged ions and negatively charge the particles in the gas flowing through the pipe 1.

[0032] When an charged object moves, for example, along pipe 1 in the X direction, a magnetic field is generated in the YZ plane of that charge. Figure 4 illustrates the induced current generated in coil 21 according to an embodiment. Figure 4 shows a cross-section of pipe 1. When a positively charged particle moves in the X direction and passes through coil 21, the magnetic flux passing through the inside of coil 21 changes. This generates an induced current in coil 21.

[0033] The measurement unit 23a measures the time from the moment the gas charge state is changed by the modification unit 20 until the change in the magnetic field of the coil 21 is detected by the detection unit 22. For example, the measurement unit 23a stores the time T1 when the control unit 23 controls the modification unit 20 to release positive or negative ions from the modification unit 20, and stores the time T2 (where T2 > T1) when the dielectric current detected by the detection unit 22 is detected. The measurement unit 23a measures the time by calculating time T2 - time T1.

[0034] The calculation unit 23b calculates the gas flow velocity based on the time (T2-T1) measured by the measurement unit 23a. If the distance between the modification unit 20 and the coil 21 is L, the gas flow velocity U can be calculated from the following equation (1).

[0035] U = L / (T2-T1) (1)

[0036] As shown in equation (1), the calculation unit 23b calculates the gas flow velocity U by dividing the distance L between the modification section 20 and the coil 21 in the piping 1 by the time (T2-T1) measured by the measurement unit 23a. The value of the distance L is set in advance in the control unit 23.

[0037] If the cross-sectional area of ​​pipe 1 is S, the gas flow rate FL can be calculated from the following equation (2).

[0038] FL = S × U (2)

[0039] The calculation unit 23b calculates the gas flow rate FL by multiplying the calculated flow velocity U by the cross-sectional area S of the pipe 1, as shown in equation (2). The value of the cross-sectional area S is set in advance in the control unit 23.

[0040] The output control unit 23c controls the output of the calculation results from the calculation unit 23b. For example, the output control unit 23c outputs the calculated gas flow velocity and gas flow rate to the display unit 24 for display.

[0041] Conventional measuring devices detect flow rate from changes in weak electromotive force caused by charged particles in the gas passing through the pipe. However, due to factors such as the non-uniformity of the gas's conductivity distribution, the electromotive force changes, leading to errors and making it impossible to accurately measure the gas flow velocity.

[0042] On the other hand, the measuring device 10 according to the embodiment changes the state of the gas flowing through the pipe 1 by the modification unit 20, and measures the time (T2-T1) until the particles whose state has been changed pass through the coil 21 by observing the change in the magnetic field of the coil 21. Since the measuring device 10 detects the timing of the change in the magnetic field of the coil 21, it can stably measure the time (T2-T1) even if the conductivity distribution of the gas is non-uniform, and can accurately measure the flow velocity of the gas. The gas flowing through the pipe 1 may contain dust. Since the amount of charge by the modification unit 20 is expected to be large in gas containing dust, it is advantageous for detecting the change in the magnetic field of the coil 21. Dust includes soot, fine dust, etc., and is assumed to be all particulate matter with a particle size of 1 μm to 100 μm, for example.

[0043] [Measurement Processing Flow] Next, the flow of the measurement process in which the measuring device 10 measures the gas flow velocity and gas flow rate will be described. Figure 5 is a flowchart showing an example of the procedure for the measurement process according to the embodiment. This measurement process is performed at predetermined timings, for example, at the timings for measuring the flow velocity and flow rate.

[0044] The control unit 23 controls the modification unit 20 to change the charged state of the gas flowing through the pipe 1 (step S10). For example, the control unit 23 releases positively or negatively charged ions into the gas flowing through the pipe 1, electrically neutralizing the particles in the gas. Subsequently, the control unit 23 changes the charged state of the gas flowing through the pipe 1 using the modification unit 20.

[0045] The measurement unit 23a measures the time from the moment the charge state of the gas is changed by the modification unit 20 until the change in the magnetic field of the coil 21 is detected by the detection unit 22 (step S11). For example, the measurement unit 23a measures the time from the moment the gas flowing through the pipe 1 is neutralized and then changed to a charged state until the dielectric current is detected by the detection unit 22.

[0046] The calculation unit 23b calculates the gas flow velocity based on the time measured by the measurement unit 23a. For example, the calculation unit 23b calculates the gas flow velocity by dividing the distance between the change section 20 and the coil 21 in the piping 1 by the time measured by the measurement unit 23a. The calculation unit 23b also calculates the gas flow rate by multiplying the calculated flow velocity by the cross-sectional area of ​​the piping 1 (step S12).

[0047] The output control unit 23c outputs the calculated gas flow velocity and gas flow rate to the display unit 24 for display (step S13), and then terminates the process.

[0048] In the above embodiment, the example described was the measurement of the time from the moment the gas flowing through pipe 1 is temporarily neutralized and then changed to a charged state until the dielectric current is detected by the detection unit 22. However, it is not limited to this. For example, the measurement unit 23a, which may temporarily neutralize the gas flowing through pipe 1 using the modification unit 20 and then change the gas to a neutral state, may measure the time from the moment the gas is changed to a neutral state until the dielectric current is no longer detected by the detection unit 22. Alternatively, for example, the modification unit 20 may first make the gas flowing through pipe 1 positively or negatively charged, and then change the gas to the other charged state. The measurement unit 23a may measure the time from the moment the gas is changed to the other charged state until the dielectric current flow reverses or the dielectric current temporarily becomes zero, as measured by the detection unit 22.

[0049] Furthermore, the above embodiments were described using the case where the fluid to be measured is a gas as an example. However, the invention is not limited to this. The fluid to be measured may be a liquid, as long as its charge state can be changed.

[0050] 〔effect〕 As described above, the measuring device 10 according to the embodiment includes a modification unit 20, a coil 21, a detection unit 22, a measurement unit 23a, and a calculation unit 23b. The modification unit 20 is provided in the pipe 1 through which the fluid to be measured flows, and changes the charged state of the fluid flowing through the pipe 1. The coil 21 is provided downstream of the modification unit 20 in the pipe 1. The detection unit 22 detects changes in the magnetic field of the coil 21. The measurement unit 23a measures the time from the moment the charged state of the fluid is changed by the modification unit 20 until the change in the magnetic field of the coil 21 is detected by the detection unit 22. The calculation unit 23b calculates the fluid velocity based on the time measured by the measurement unit 23a. As a result, the measuring device 10 according to the embodiment can accurately measure the fluid velocity.

[0051] Furthermore, the calculation unit 23b calculates the fluid velocity by dividing the distance between the modification section 20 and the coil 21 in the piping 1 by the time measured by the measurement unit 23a. As a result, the measuring device 10 according to this embodiment can accurately measure the fluid velocity.

[0052] Furthermore, the calculation unit 23b calculates the fluid flow rate by multiplying the calculated flow velocity by the cross-sectional area of ​​the pipe 1. As a result, the measuring device 10 according to this embodiment can accurately measure the fluid flow rate.

[0053] Furthermore, the detection unit 22 detects the dielectric current generated in the coil 21. The measurement unit 23a measures the time from the moment the charged state of the fluid is changed until the dielectric current detected by the detection unit 22 changes. As a result, the measurement device 10 according to this embodiment can measure the time it takes for the particles of the fluid whose charged state has been changed to reach the coil 21.

[0054] Furthermore, the modification unit 20 neutralizes the fluid flowing through the pipe 1 and then changes the fluid to a charged state. The measurement unit 23a measures the time from the moment the charged state of the fluid is changed until the detection unit 22 detects the dielectric current. As a result, the measurement device 10 according to this embodiment can measure the time it takes for the particles of the fluid whose charged state has been changed to reach the coil 21.

[0055] Furthermore, the coil 21 is positioned to surround the outer circumference of the pipe 1. This allows the measuring device 10 according to this embodiment to accurately detect when fluid particles with a changed charge state have passed through the coil 21.

[0056] [Other Embodiments] Now, while embodiments of the present invention have been described, the present invention may be implemented in various other forms besides those described above. The configuration and details of the embodiments, including those described in the disclosure section of the invention, can be implemented in other forms with various modifications and improvements based on the knowledge of those skilled in the art. Furthermore, each embodiment can be combined in any way that does not contradict each other. [Explanation of symbols]

[0057] 1 Piping 10 Measuring devices 20 Changes 20a Signal generation unit 20b electrode needle 21 coils 22 Detection unit 23 Control Unit 23a Measurement section 23b Calculation part 23c Output control unit 24 Display

Claims

1. A modifying unit is provided in a pipe through which the fluid to be measured flows, and which modifies the charge state of the fluid flowing through the pipe, A coil provided downstream of the modified portion of the piping, A detection unit for detecting changes in the magnetic field of the coil, A measuring unit measures the time from the moment the charging state of the fluid is changed by the modification unit until the change in the magnetic field of the coil is detected by the detection unit. A calculation unit calculates the fluid velocity based on the time measured by the measurement unit, A measuring device having the following features.

2. The calculation unit calculates the fluid velocity by dividing the distance between the modification section and the coil in the piping by the time measured by the measurement unit. The measuring device according to claim 1.

3. The calculation unit calculates the fluid flow rate by multiplying the calculated flow velocity by the cross-sectional area of ​​the pipe. The measuring device according to claim 1.

4. The detection unit detects the dielectric current generated in the coil, The measurement unit measures the time from the moment the charged state of the fluid is changed until the dielectric current detected by the detection unit changes. The measuring device according to claim 1.

5. The modification unit neutralizes the fluid flowing through the piping, and then changes the fluid to an electrically charged state. The measurement unit measures the time from the moment the charged state of the fluid is changed until the detection unit detects the dielectric current. The measuring device according to claim 4.

6. The coil is arranged to surround the outer circumference of the piping. The measuring device according to claim 1.

7. Computers A modification section is provided in the piping through which the fluid to be measured flows, thereby changing the charge state of the fluid flowing through the piping. The time from the moment the charge state of the fluid is changed by the modification unit until the change in the magnetic field of the coil located downstream of the modification unit in the piping is detected by the detection unit is measured. Based on the measured time, the fluid velocity is calculated. A measurement method for executing a process.

8. On the computer, A modification section is provided in the piping through which the fluid to be measured flows, thereby changing the charge state of the fluid flowing through the piping. The time from the moment the charge state of the fluid is changed by the modification unit until the change in the magnetic field of the coil located downstream of the modification unit in the piping is detected by the detection unit is measured. Based on the measured time, the fluid velocity is calculated. A measurement program that executes the process.

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