Vortex shedding flowmeter detection system and method

Abstract

The invention discloses a vortex shedding flowmeter detection system and method. The detection system comprises an industrial personal computer, a relay control unit and a measuring unit. Wherein the industrial personal computer is used for generating a control signal; the relay control unit is connected with the industrial personal computer, and the relay control unit is used for generating a first signal according to the control signal; the measuring unit is connected with the relay control unit, and the measuring unit switches the state to be on or off according to the first signal and generates a second signal when the measuring unit is on; the vortex shedding flowmeter to be measured is connected with the measuring unit and generates a third signal according to the second signal, and the industrial personal computer obtains the third signal and generates a calibration temperature signal according to the third signal. According to the invention, the detection efficiency can be improved, and the occupied space and cost of the detection system are reduced; and the calibration action of the industrial personal computer is delayed after the relay switching action, so that the electromagnetic interference caused by relay switching is further reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of vortex equipment detection, and in particular relates to a vortex flowmeter detection system and method. Background Art

[0002] At present, the vortex flowmeter requires that the temperature signal error is within the temperature difference threshold of the standard temperature signal. In the prior art, the detection method of the vortex flowmeter is often manual or uses a fixture for detection, and only one vortex flowmeter can be detected at a time. This detection method has the problems of low detection efficiency, high cost and large space occupied.

[0003] The reason why the current vortex flowmeter detection method can only be carried out one by one is because there are many technical obstacles. If the purpose of simultaneously detecting multiple vortex flowmeters is to be achieved, the detection system itself will often have a negative impact on the calibration of the temperature signal, thereby reducing the detection accuracy, and the electromagnetic interference generated by the same detection system when working at the same time will also reduce the detection accuracy.

[0004] Therefore, in view of the above technical problems, it is necessary to provide a vortex flowmeter detection system and method. Summary of the invention

[0005] The object of the present invention is to provide a vortex flowmeter detection system and method, which can solve the technical problems of low efficiency and low detection accuracy of vortex equipment detection methods in the prior art.

[0006] In order to achieve the above-mentioned object, a specific embodiment of the present invention provides a vortex flowmeter detection system, the detection system comprising: an industrial computer, a relay control unit and a measuring unit; wherein,

[0007] The industrial computer is used to generate a control signal;

[0008] The relay control unit is connected to the industrial computer, and the relay control unit is used to generate a first signal according to the control signal;

[0009] The measuring unit is connected to the relay control unit, and the measuring unit switches the state to on or off according to the first signal and generates a second signal when on;

[0010] The vortex flowmeter to be measured is connected to the measuring unit and generates a third signal according to the second signal. The industrial computer obtains the third signal and generates a calibration temperature signal according to the third signal.

[0011] In one or more embodiments of the present invention, a slot is provided on the industrial computer, a serial port card is provided in the slot, and the serial port card is connected to the relay control unit and the vortex flowmeter respectively.

[0012] In one or more embodiments of the present invention, the measuring unit includes a plurality of branches connected between a first input terminal and a second input terminal of the vortex flowmeter to be measured, and each branch is provided with a resistor and a relay connected in series.

[0013] In one or more embodiments of the present invention, the measuring unit includes at least two branches connected between a first input terminal and a second input terminal of the vortex flowmeter to be measured, and the resistance value of the resistor on each branch is different.

[0014] In one or more embodiments of the present invention, the branch circuit includes a relay and a resistor, wherein:

[0015] The first end of the relay is connected to the first input end of the vortex flowmeter to be measured, and the second end is connected to the second signal.

[0016] The first end of the resistor is connected to the second signal, and the second end is connected to the second input end of the vortex flowmeter to be measured.

[0017] In one or more embodiments of the present invention, the relay control unit includes a digital quantity input and output circuit, and the digital quantity input and output circuit is connected between the serial port card and the measuring unit.

[0018] In one or more embodiments of the present invention, the vortex flowmeter detection system includes a plurality of groups of measuring units, and each group of measuring units is connected to a group of vortex flowmeters to be tested.

[0019] In another aspect of the present invention, a vortex flowmeter detection method is provided, the detection method comprising the following steps:

[0020] The measuring unit connected to the vortex flowmeter to be measured is turned on, the vortex flowmeter generates a third signal, the industrial computer generates a calibration temperature signal according to the third signal, and the time from the measuring unit being turned on to the industrial computer generating the calibration temperature signal is set as the delay time T;

[0021] Compare the calibrated temperature signal of the industrial computer with the standard temperature signal, and take the minimum delay time T corresponding to the calibrated temperature signal with the smallest difference with the standard temperature signal. min ;

[0022] Control the industrial computer with the minimum delay time T min Calibrate the temperature signal.

[0023] In one or more embodiments of the present invention, the vortex flowmeter detection method further includes:

[0024] At the minimum delay time T min Within, control any group of measurement units to be in the on state, and other measurement units to be in the off state; the measurement units are separated by a minimum delay time T in sequencemin To perform a turn-on or turn-off operation, the minimum delay time T min Equal to the sum of the times performed by all measuring units in the disconnected state.

[0025] In one or more embodiments of the present invention, the detection method further comprises:

[0026] The accuracy of the vortex flowmeter is judged according to the third signal, and a temperature difference threshold is set. If the calibration temperature signal is within the temperature difference threshold of the third signal, the accuracy of the vortex flowmeter is qualified; if the third signal is not within the temperature difference threshold of the third signal, the accuracy of the vortex flowmeter is unqualified.

[0027] Compared with the prior art, the vortex flowmeter detection system and method of the present invention can connect the vortex flowmeter to be tested through the measuring unit, so that the vortex flowmeter to be tested generates a third signal, and the industrial computer obtains the third signal to generate a calibration temperature signal, and judges whether the product is qualified according to the comparison between the third signal and the standard temperature signal. This automated detection method not only improves the detection efficiency, but also reduces the occupied space and cost of the detection system;

[0028] In addition, the present invention reduces mutual interference between measurement units by avoiding simultaneous switching of multiple measurement units, and further reduces electromagnetic interference caused by relays by delaying the calibration action of the industrial computer after the relay switching action. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 The circuit diagram of the temperature sensing circuit of the vortex flowmeter to be tested;

[0031] Figure 2 A schematic diagram of a module of a vortex flowmeter detection system in one embodiment of the present invention;

[0032] Figure 3 It is a schematic diagram of the principle of a vortex flowmeter detection system in one embodiment of the present invention;

[0033] Figure 4 A schematic diagram of the structure of a relay control module in one embodiment of the present invention;

[0034] Figure 5It is a schematic diagram of the detection result under electromagnetic interference of the relay unit in one embodiment of the present invention;

[0035] Figure 6 FIG. 4 is a curve diagram of electromagnetic interference amplitude-time in one embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0037] As described in the background technology, the prior art mostly uses manual or jig detection methods to detect vortex flowmeters. This detection method can only detect one vortex flowmeter at a time, and the detection efficiency is low. To solve the above problem, an industrial computer is used in conjunction with the host computer software to detect multiple vortex flowmeters at the same time. The principle is that the vortex flowmeter to be tested generates a conversion voltage through an external resistor and a built-in temperature conversion circuit, and this voltage is processed and converted into a temperature value. This temperature value is transmitted to the industrial computer through an external serial port card. Then the temperature is calibrated according to the product agreed method.

[0038] like Figure 1 The circuit diagram of the temperature conversion circuit of the vortex flowmeter to be measured is shown, and the temperature conversion circuit includes a first operational amplifier U1A, a second operational amplifier U1C, a third operational amplifier U1D, a forty-first resistor R41, a forty-second resistor R42, a forty-third resistor R43, a forty-fourth resistor R44, a forty-fifth resistor R45, a forty-sixth resistor R46, a forty-seventh resistor R47 and a first voltage stabilizing diode D1; wherein,

[0039] The first end of the forty-first resistor R41 is connected to the first power supply voltage VCC, the first end of the forty-third resistor R43 is connected to the second end of the forty-first resistor R41, and the first end of the forty-fourth resistor R44 is connected to the second end of the forty-first resistor R41; the first end of the first voltage zener diode D1 is connected to the second end of the forty-first resistor R41, and the second end is connected to the circuit common point; the same-direction input terminal of the first operational amplifier U1A is connected to the second end of the forty-fourth resistor R44 and the first input terminal PT+, and the reverse input terminal of the first operational amplifier U1A is connected to the output terminal of the first operational amplifier U1A; the same-direction input terminal of the second operational amplifier U1C is connected to the second end of the forty-third resistor R43, and the reverse input terminal of the second operational amplifier U1C is connected to the second The output end of the operational amplifier U1C is connected; the first end of the forty-seventh resistor R47 is connected to the same-direction input end of the second operational amplifier U1C, and the second end of the forty-seventh resistor R47 is connected to the second input terminal PT- and the circuit common point respectively; the same-direction input end of the third operational amplifier U1D is connected to the output end of the first operational amplifier U1A through the forty-fifth resistor R45, the reverse input end of the third operational amplifier U1D is connected to the output end of the second operational amplifier U1C through the forty-sixth resistor R46, the output end of the third operational amplifier U1D is connected to the chip sampling pin ADC1, the first end of the forty-second resistor R42 is connected to the reverse input end of the third operational amplifier U1D, and the second end is connected to the output end of the third operational amplifier U1D.

[0040] Among them, the temperature conversion circuit connects the resistance signal through the first input terminal PT+ and the second input terminal PT-, and outputs the conversion voltage at the output terminal. When the temperature calibration is realized by multi-threaded detection of multiple vortex flowmeters, the sampling process is controlled by the detection system control device. Common control devices such as relays, but relays are generally driven by electromagnetic attraction. When switching actions, EMC electromagnetic interference will be generated. Multiple switching interferences will be superimposed and more serious, affecting the internal conversion results of the product. This interference is divided into two parts: conducted interference and radiated interference. Conducted interference will interfere with the vortex flowmeter to be tested and the detection system through the connected lines; radiated interference will generate induced voltage inside the vortex flowmeter to be tested and the detection system through spatial coupling, causing instability of the product and the system. Specifically for the vortex temperature signal, it will cause the product to calibrate the temperature inaccurately, causing the industrial computer to misjudge the temperature calibration and test function of the vortex flowmeter to be tested.

[0041] like Figure 2 As shown, in view of the above technical problems, a vortex flowmeter 40 detection system in an embodiment of the present invention includes: an industrial computer 10, a relay control unit 20 and a measuring unit 30; wherein,

[0042] The industrial computer 10 is used to generate a control signal;

[0043] The relay control unit 20 is connected to the industrial computer 10, and the relay control unit 20 is used to generate a first signal according to the control signal;

[0044] The measuring unit 30 is connected to the relay control unit 20, and the measuring unit 30 switches the state to on or off according to the first signal and generates a second signal when on;

[0045] The vortex flowmeter 40 to be measured is connected to the measuring unit 30 and generates a third signal according to the second signal. The industrial computer 10 obtains the third signal and generates a calibration temperature signal according to the third signal.

[0046] The industrial computer 10 controls the switching action of the relay unit 30 through the control signal control and the relay control unit 20, so as to achieve temperature calibration of the vortex flowmeter 40 to be measured according to a predetermined sequence.

[0047] The industrial computer 10 is provided with a slot 101, and a serial port card 102 is provided in the slot 101. The serial port card 102 is connected to the relay control unit 20 and the vortex flowmeter 40 to be measured, respectively, and the serial port card 102 is used to transmit the control signal and the third signal. The industrial computer 10 is provided with two groups of slots 101, and each group of slots 101 is provided with a serial port card 102, and the serial port card 102 is a MOXA serial port card 102, and the serial port card 102 is connected to each group of vortex flowmeters 40 to be measured. In this embodiment, the number of vortex flowmeters 40 to be measured is 10 groups, and each group of vortex flowmeters 40 to be measured is connected to the measuring unit 30 through the first input terminal PT+ and the first input terminal PT-.

[0048] like Figure 4 As shown, in this embodiment, the relay control unit 20 includes a digital input and output circuit, which is connected to the serial port card 102. The digital input and output circuit is used to turn on or off the measuring unit 30 according to the control signal, wherein the digital input and output circuit is a 48 digital input and output circuit.

[0049] In this embodiment, the measuring unit 30 includes a plurality of branches 301 connected between a first input terminal PT+ and a second input terminal PT- of the vortex flowmeter 40 to be measured, and each branch 301 is provided with a resistor and a relay arranged in series.

[0050] Among them, the first end of the relay is connected to the first input terminal PT+ of the vortex flowmeter 40 to be measured, and the second end is connected to the second signal. The first end of the resistor is connected to the second signal, and the second end is connected to the second input terminal PT- of the vortex flowmeter 40 to be measured.

[0051] In this embodiment, the measuring unit 30 includes at least two branches 301 connected between the first input terminal PT+ and the second input terminal PT- of the vortex flowmeter 40 to be measured, and the resistance value of the resistor on each branch 301 is different.

[0052] like Figure 3 As shown, in this embodiment, the number of the vortex flowmeters 40 to be measured is 10 groups, and each group of the vortex flowmeters 40 to be measured is connected to a corresponding group of measuring units 30 .

[0053] In this embodiment, there are four branches 301. Taking the first branch 301 as an example, it includes a first resistor R1 and a first relay K1, wherein:

[0054] The first end of the first relay K1 is connected to the first input terminal PT+ of the vortex flowmeter 40 to be measured, and the second end is connected to the second signal. The first end of the first resistor R1 is connected to the second signal, and the second end is connected to the second input terminal PT- of the vortex flowmeter 40 to be measured.

[0055] Among them, the external resistance of the vortex flowmeter 40 to be measured is obtained by switching different external resistances by an external relay according to a control command. In this embodiment, the resistance value of the first resistor R1 is 1000Ω, the resistance value of the second resistor R2 is 1100Ω, the resistance value of the third resistor R3 is 1200Ω, and the resistance value of the fourth resistor R4 is 1300Ω, and the types of resistors are the same. The detection system requires that the error value of the calibrated temperature signal is within 0.5°C. According to the PT1000 resistance graduation table, it can be known that approximately every 0.4Ω resistance corresponds to a temperature value of 1°C, so the error value of the PT1000 resistance must be guaranteed to be within 0.2Ω.

[0056] When testing the vortex flowmeter 40 to be tested, four resistors with different resistance values ​​need to be replaced. The calibration temperature signal corresponding to each resistor is required not to exceed the standard temperature signal of the corresponding resistor, so the resistance error is required to be only 0.2Ω. Therefore, in this embodiment, the relay uses a metal contact relay for switching.

[0057] like Figure 5 As shown, the metal contact relay is driven by electromagnetic attraction when it is in action, and EMC electromagnetic interference will be generated during the switching action. When multiple metal contact relays are in action, the multiple EMC electromagnetic interferences generated will be superimposed, thereby causing more serious electromagnetic interference, reducing the accuracy of the industrial computer 10 when calibrating the temperature signal. In this embodiment, the standard signal temperature signal is 25°C~26°C. Due to the existence of electromagnetic interference, the calibration temperatures of the 10 groups of vortex flowmeters 40 to be tested are rarely within the range required by the standard temperature signal.

[0058] In view of the above technical problems, the present invention further provides a vortex flowmeter 40 detection method, the detection method comprising the following steps:

[0059] The measuring unit 30 connected to the vortex flowmeter 40 to be measured is turned on, the vortex flowmeter 40 generates a third signal, the industrial computer 10 generates a calibration temperature signal according to the third signal, and the time from the measuring unit 30 being turned on to the industrial computer 10 generating the calibration temperature signal is set as the delay time T;

[0060] The calibration temperature signal of the industrial computer 10 is compared with the standard temperature signal, and the minimum delay time T corresponding to the calibration temperature signal with the smallest difference with the standard temperature signal is taken. min ;

[0061] Control the industrial computer 10 with the minimum delay time T min Calibrate the temperature signal.

[0062] The temperature signal calibrated by the industrial computer 10 is compared with the standard temperature signal, and the delay time T corresponding to the calibrated temperature signal with the smallest difference with the standard temperature signal is taken as the minimum delay time T. min , control the industrial computer 10 according to the minimum delay time T min Set the time from when the control signal conducts the measurement unit 30 to when the industrial computer 10 generates the calibration temperature signal. Figure 6 As shown, by setting the minimum delay time T min Thereby avoiding the peak of electromagnetic interference.

[0063] In this embodiment, at the minimum delay time T min Within, any group of measuring units 30 is controlled to be in the on state, and the other measuring units 30 are in the off state.

[0064] When any one of the 10 groups of measuring units 30 is in the on state, the other relays are in the off state, so as to avoid superposition of electromagnetic interference between the measuring units 30 .

[0065] In this embodiment, the relays are sequentially spaced apart by a minimum delay time T min Perform turn-on or turn-off operation, minimum delay time T min Equal to the sum of the times performed by all relays in the open state.

[0066] In order to avoid the superposition of electromagnetic interference between different measuring units 30 in the above steps, the minimum delay time T min During the period of time, only one group of measuring units 30 is in the on state, and the other measuring units 30 are in the off state. In the industrial computer 10, the sum of the execution time of all the statements of the measuring units 30 in the off state and the minimum delay time T min equal.

[0067] In this embodiment, the accuracy of the vortex flowmeter 40 is judged according to the third signal, and a temperature difference threshold is set. If the third signal is within the temperature difference threshold of the third signal, the accuracy of the vortex flowmeter 40 is qualified; if the third signal is not within the temperature difference threshold of the third signal, the accuracy of the vortex flowmeter 40 is unqualified, and the temperature difference threshold is 0.5°C.

[0068] The temperature difference threshold value may be set according to actual use requirements of the vortex flowmeter 40 . If a higher accuracy requirement is placed on the vortex flowmeter 40 in an application, the temperature difference threshold value may be reduced to obtain a vortex flowmeter 40 with higher accuracy.

[0069] This embodiment reduces mutual interference between the measuring units 30 by avoiding simultaneous switching of multiple measuring units 30, and further reduces electromagnetic interference caused by the relay by delaying the calibration action of the industrial computer 10 after the relay switching action.

[0070] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0071] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A vortex flowmeter detection system, It is characterized in that The detection system includes: an industrial computer, a relay control unit and a measuring unit; wherein, The industrial computer is used to generate a control signal; The relay control unit is connected to the industrial computer, and the relay control unit is used to generate a first signal according to the control signal; The measuring unit is connected to the relay control unit, and the measuring unit switches the state to on or off according to the first signal and generates a second signal when on; The vortex flowmeter to be measured is connected to the measuring unit and generates a third signal according to the second signal. The industrial computer obtains the third signal and generates a calibration temperature signal according to the third signal.

2. The vortex flowmeter detection system according to claim 1, It is characterized in that The industrial computer is provided with a slot, a serial port card is arranged in the slot, and the serial port card is connected with the relay control unit and the vortex flowmeter respectively.

3. The vortex flowmeter detection system according to claim 1, It is characterized in that The measuring unit comprises a plurality of branches connected between a first input terminal and a second input terminal of a vortex flowmeter to be measured, and each branch is provided with a resistor and a relay connected in series.

4. The vortex flowmeter detection system according to claim 1, It is characterized in that The measuring unit comprises at least two branches connected between a first input terminal and a second input terminal of a vortex flowmeter to be measured, and the resistance value of the resistor on each branch is different.

5. The vortex flowmeter detection system according to any one of claims 3 or 4, It is characterized in that The branch includes a relay and a resistor, wherein the first end of the relay is connected to the first input end of the vortex flowmeter to be measured, and the second end is connected to the second signal, the first end of the resistor is connected to the second signal, and the second end is connected to the second input end of the vortex flowmeter to be measured.

6. The vortex flowmeter detection system according to claim 2, It is characterized in that The relay control unit comprises a digital quantity input and output circuit, and the digital quantity input and output circuit is connected between the serial port card and the measuring unit.

7. The vortex flowmeter detection system according to claim 1, It is characterized in that The vortex flowmeter detection system comprises a plurality of groups of measuring units, and each group of measuring units is correspondingly connected to a group of vortex flowmeters to be tested.

8. A vortex flowmeter detection method, It is characterized in that The detection method comprises the following steps: The measuring unit connected to the vortex flowmeter to be measured is turned on, the vortex flowmeter generates a third signal, the industrial computer generates a calibration temperature signal according to the third signal, and the time from the measuring unit being turned on to the industrial computer generating the calibration temperature signal is set as the delay time T; The third signal obtained by the industrial computer is compared with the standard temperature signal, and the minimum delay time T corresponding to the calibration temperature signal with the smallest difference with the standard temperature signal is taken. min ; Control the industrial computer with the minimum delay time T min Calibrate the temperature signal.

9. The vortex flowmeter detection method according to claim 8, It is characterized in that The vortex flowmeter detection method also includes: At the minimum delay time T min Within, control any group of measurement units to be in the on state, and other measurement units to be in the off state; the measurement units are separated by a minimum delay time T in sequence min To perform a turn-on or turn-off operation, the minimum delay time T min Equal to the sum of the times performed by all measuring units in the disconnected state.

10. The vortex flowmeter detection method according to claim 8, It is characterized in that The detection method further comprises: The accuracy of the vortex flowmeter is judged according to the acquired third signal, and a temperature difference threshold is set. If the third signal is within the temperature difference threshold of the third signal, the accuracy of the vortex flowmeter is qualified; if the third signal is not within the temperature difference threshold of the third signal, the accuracy of the vortex flowmeter is unqualified.

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