A device for calibrating a float type liquid level gauge

Abstract

The present invention belongs to the technical field of liquid level gauge calibration, and specifically relates to a device for calibrating a float-type liquid level gauge. The device comprises a specific measuring container, a small water pump, a regulating valve A, a regulating valve B, a valve position sensor A, a valve position sensor B, a standard liquid level sensor, a computer, and a controller; the regulating valve A and the regulating valve B are respectively installed at the input and output ports of the specific measuring container, a small water pump is installed at the front end of the regulating valve A, the regulating valve A and the regulating valve B are respectively connected to the valve position sensor A and the valve position sensor B, a standard liquid level sensor is installed under the specific measuring container, the calibrated float-type liquid level gauge is installed at the upper end of the specific measuring container, the valve position sensor A, the valve position sensor B, the standard liquid level sensor, and the calibrated float-type liquid level gauge are all connected to the computer, the computer is connected to the controller, and the controller is connected to the regulating valve A and the regulating valve B. The present invention realizes fast and accurate calibration of the float-type liquid level gauge.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid level gauge calibration, and in particular relates to a device for calibrating a float type liquid level gauge. Background Art

[0002] The common liquid level gauges in nuclear power plants include differential pressure level gauges, float level gauges, and radar level gauges. Among them, the float level gauge is widely used in the refueling water tank and pit level gauge in the nuclear island. The level gauge is based on the Archimedean principle: the buoyancy of an object invading a liquid is equal to the weight of the liquid it displaces. The buoyancy of the float, with the help of the upper spring (the buoyancy at this time can be regarded as the effective reduction of the weight of the float original), causes the spring to contract, and the iron core in the pressure tube supports the spring. When the spring is contracted or extended by force, the iron core moves up or down, and the output of the LVDT (linear differential transformer) changes proportionally. At this time, the voltage difference signal of the two secondary coils of the LVDT is fed back to the electronic components controlled by the microprocessor and converted into a 4-20mA output signal, which is converted into the water level of the water tank at this time.

[0003] This type of level meter is installed in the nuclear island, which belongs to the radiation control area. Due to the special feature that this level meter cannot be calibrated by pressure, the meter calibration needs to be taken away from the site for calibration. In addition, this type of meter generally has a narrow range (the maximum range does not exceed 1 meter) and requires high accuracy. The traditional calibration method is to use manual drainage and manual measurement of water level height for calibration. This method is time-consuming, inefficient, and has poor accuracy. In view of this, a specific calibration device is specially invented and designed to calibrate this type of float-type level meter. Summary of the invention

[0004] The object of the present invention is to provide a device for calibrating a float type liquid level gauge, so as to realize rapid and accurate calibration of the float type liquid level gauge.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A device for calibrating a float-type liquid level gauge comprises a specific measuring container, a small water pump, a regulating valve A, a regulating valve B, a valve position sensor A, a valve position sensor B, a standard liquid level sensor, a computer and a controller; the regulating valve A and the regulating valve B are respectively installed at the input and output ports of the specific measuring container, a small water pump is installed at the front end of the regulating valve A, the regulating valve A and the regulating valve B are respectively connected to the valve position sensor A and the valve position sensor B, a standard liquid level sensor is installed below the specific measuring container, the calibrated float-type liquid level gauge is installed at the upper end of the specific measuring container, the valve position sensor A, the valve position sensor B, the standard liquid level sensor and the calibrated float-type liquid level gauge are all connected to the computer, the computer is connected to the controller, and the controller is connected to the regulating valve A and the regulating valve B.

[0007] The computer collects the current information of the standard liquid level sensor, the current information of the calibrated float-type liquid level gauge, and the valve opening information of the valve position sensor A and the valve position sensor B, and displays the information on the computer page and performs PID calculation; the controller receives the command from the computer and compiles and analyzes it, and the controller controls the regulating valve A and the regulating valve B to realize the rise and fall of the water level of a specific measuring container and realize the requirements of different water levels of the calibration device platform; the computer judges the calibrated float-type liquid level gauge according to the current information of the standard liquid level sensor and the calibrated float-type liquid level gauge, and obtains the calibration result.

[0008] The float type liquid level gauge to be calibrated is fixedly installed on a specific measuring container. According to the range of the float type liquid level gauge, the range and accuracy requirements of the float type liquid level gauge are input into the computer through manual operation. The computer calculates the maximum and minimum values ​​allowed for the output current of the instrument to be calibrated at the calibrated point and the water level values ​​of the five points to be calibrated according to the accuracy requirements;

[0009] Verification starts: power the entire verification device, turn on the small water pump, and manually click on the verification start button on the computer. The computer transmits the instruction information to the controller, and the controller determines the regulating valve A that needs to be operated according to the instruction information, and the specific measuring container starts to fill with water; when the liquid level of the standard liquid level sensor reaches the five verification point liquid level values ​​one by one, the computer collects the information transmitted by the standard liquid level sensor, and when the liquid level value of each verification point is reached, the controller closes the regulating valve A in time, and determines the valve state according to the valve position sensor A, so that the liquid level value of the specific measuring container is maintained;

[0010] At the same time, the computer collects the current value of the float-type liquid level gauge being calibrated at this time, and judges and processes it according to the calculated value of the accuracy value to judge whether this current value meets the accuracy requirement, and records the judgment result. The current value is displayed on the computer; when the computer completes the data processing and recording of the previous calibration point, the computer continues to send instructions to the controller to calibrate the water level of the next calibration point, and processes and records the data one by one;

[0011] When the liquid level of a specific measuring container reaches the highest point of the measuring range, the computer processes, determines and records the current information at the highest point, and then sends a command to the controller to lower the water level and start the verification of the downstroke: at this time, the controller opens the regulating valve B, keeps the regulating valve A closed, and the liquid level value starts to drop. When the liquid level value of the specific measuring container reaches the verification point of the downstroke, the controller closes the regulating valve B in time and determines the valve state according to the valve position sensor B to keep the liquid level value of the specific measuring container.

[0012] The calibration device performs calibration and recording of the five calibration points of the up and down strokes in sequence according to this method. When the ten calibration values ​​of the up and down strokes are obtained, the computer further judges and processes and records the ten calibration values, and displays the processing results. If all the requirements are met, the calibration record sheet is directly output; if the values ​​do not meet the accuracy requirements, it is displayed that the float-type liquid level gauge is unqualified and needs to be adjusted.

[0013] Adjustment of float type liquid level gauge: through manual operation of computer, the computer sends instructions to the controller, the controller adjusts the liquid level value of the specific measuring container to the middle value of the range by adjusting regulating valve A and regulating valve B, at this time adjust the float type liquid level gauge LVDT, so that the current output value of the float type liquid level gauge is 12mA, after the adjustment is completed, re-calibrate according to the above calibration process until the computer determines that the calibration data meets the accuracy requirements, then output the calibration record and the inspection is completed.

[0014] The beneficial effects achieved by the present invention are:

[0015] The float type liquid level gauge is a common liquid level measuring instrument in nuclear power plants. This calibration device provides a new calibration method and calibration device for the float type liquid level gauge, thereby completing the calibration of the float type liquid level gauge more quickly and accurately.

[0016] 1) This calibration device can digitize and integrate the entire calibration process, and realize the calibration of the float-type liquid level gauge through digital operation control. The whole process does not have the measurement and visual errors in the original calibration method, which improves the accuracy of the calibration process.

[0017] 2) The entire inspection device is integrated into one, and the verification process only requires the calibrated float-type liquid level gauge to be connected and fixed, providing a stable and reliable verification platform. Compared with the original verification method, it saves working time and improves work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of the device used to calibrate the float type liquid level gauge. DETAILED DESCRIPTION

[0019] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] See attached Figure 1 The device for calibrating a float-type liquid level gauge of the present invention comprises a specific measuring container 1, a small water pump 2, a regulating valve A3, a regulating valve B4, a valve position sensor A5, a valve position sensor B6, a standard liquid level sensor 7, a computer 8, a controller 9 and a calibrated float-type liquid level gauge 10. The regulating valve A3 and the regulating valve B4 are installed at the input and output ports of the specific measuring container 1, the small water pump 2 is installed at the front end of the regulating valve A3, the regulating valve A3 and the regulating valve B4 are respectively connected with the valve position sensor A5 and the valve position sensor B6, the standard liquid level sensor 7 is installed under the specific measuring container 1, the calibrated float-type liquid level gauge 10 is installed at the upper end of the specific measuring container 1, the valve position sensor A5, the valve position sensor B6, the standard liquid level sensor 7, and the calibrated float-type liquid level gauge 10 are all connected to the computer 8, the computer 8 is connected to the controller 9, and the controller 9 is connected to the regulating valve A3 and the regulating valve B4.

[0021] The computer 8 collects the current information of the standard liquid level sensor 7 on the calibration device, the current information of the calibrated float-type liquid level meter, and the information of the valve opening of the valve position sensor 5 and the valve position sensor 6 at the input and output ports of the specific measuring container 1, and displays such signals on the computer page and performs PID calculations; the controller 9 receives the command from the computer 8 and compiles and analyzes it, and the controller 9 controls the regulating valve 3 and the regulating valve 4 to achieve the rise and fall of the water level of the specific measuring container 1 and the requirements of different water levels on the calibration device platform. The computer judges the calibrated float-type liquid level meter based on the current information of the standard liquid level sensor 7 and the calibrated float-type liquid level meter, and obtains the calibration result.

[0022] Calibrate the standard liquid level sensor in advance before the calibration begins.

[0023] The float type liquid level gauge 10 to be inspected is fixedly installed on a specific measuring container 1. The range and accuracy requirement of the float type liquid level gauge are input into the computer 8 through manual operation according to the range of the float type liquid level gauge. The computer program will calculate the maximum and minimum values ​​allowed for the output current of the calibrated instrument at the calibrated point and the water level values ​​of the five points to be calibrated according to the accuracy requirements.

[0024] Verification starts: Power the entire verification device, turn on the small water pump 2, and manually click on the verification start on the computer 8. The computer 8 transmits the instruction information to the controller, and the controller determines the regulating valve 3 that needs to be operated according to the instruction information, and the specific measuring container 1 starts to fill with water. When the liquid level of the standard liquid level sensor 7 reaches the five verification point liquid level values ​​one by one, the computer 8 collects the information transmitted by the standard liquid level meter 7. When the liquid level value of each verification point is reached, the regulating valve 3 is closed in time through the controller 9, and the valve state is determined according to the valve position sensor 5 to maintain the liquid level value of the specific measuring container 1.

[0025] At the same time, the computer 8 collects the current value of the float-type liquid level gauge 10 being checked at this time, and performs judgment processing based on the calculated value of the accuracy value to determine whether the current value meets the accuracy requirement, and records the judgment result and the current value and displays it on the computer 8. After the computer 8 completes the data processing and recording of the previous check point, the computer 8 continues to send instructions to the controller 9 to check the water level of the next check point, and performs data processing and recording one by one.

[0026] When the liquid level of the specific measuring container 1 reaches the highest point of the measuring range, the computer 8 processes, judges and records the current information at the highest point, and then sends an instruction to the controller to lower the water level and start the verification of the downstroke: at this time, the controller 9 opens the regulating valve 4, the regulating valve 3 remains closed, and the liquid level value begins to drop. When the liquid level value of the specific measuring container 1 reaches the verification point liquid level value of the downstroke, the controller 9 closes the regulating valve 4 in time, and judges the valve state according to the valve position sensor 6 to maintain the liquid level value of the specific measuring container 1.

[0027] The calibration device calibrates and records the five calibration points of the up and down strokes in turn according to this method. When the ten calibration values ​​of the up and down strokes are obtained, the computer 8 further judges and processes and records the ten calibration values, and displays the processing results. If all the requirements are met, the calibration record sheet is directly output; if the values ​​do not meet the accuracy requirements, it is displayed that the float-type liquid level gauge is unqualified and the float-type liquid level gauge needs to be adjusted.

[0028] Adjustment of float type liquid level gauge: Computer 8 sends instructions to controller through manual operation. Controller 9 adjusts the liquid level value of specific measuring container 1 to the middle value of the measuring range by adjusting regulating valve 3 and regulating valve 4. At this time, adjust the float type liquid level gauge LVDT so that the current output value of the float type liquid level gauge is 12mA. After the adjustment is completed, re-calibrate according to the above-mentioned calibration process until computer 9 determines that the calibration data meets the accuracy requirements, then outputs the calibration record and the inspection is completed.

Claims

1. A device for calibrating a float type liquid level gauge, characterized in that: The apparatus comprises a measuring container, a small water pump, a regulating valve A, a regulating valve B, a valve position sensor A, a valve position sensor B, a standard liquid level sensor, a computer and a controller; the regulating valve A and the regulating valve B are respectively installed at the input and output ports of the measuring container, a small water pump is installed at the front end of the regulating valve A, the regulating valve A and the regulating valve B are respectively connected with the valve position sensor A and the valve position sensor B, a standard liquid level sensor is installed under the measuring container, a buoy-type liquid level gauge to be checked is installed at the upper end of the measuring container, the valve position sensor A, the valve position sensor B, the standard liquid level sensor and the buoy-type liquid level gauge to be checked are all connected with the computer, the computer is connected with the controller, and the controller is connected with Regulating valve A and regulating valve B; the computer collects the current information of the standard liquid level sensor, the current information of the calibrated float-type liquid level gauge and the valve opening information of valve position sensor A and valve position sensor B, and displays the information on the computer page and performs PID calculation; the controller receives the command from the computer and compiles and analyzes it, and the controller controls regulating valve A and regulating valve B to realize the rise and fall of the water level in the measuring container and realize the requirements of different water levels of the calibration device platform; the computer judges the calibrated float-type liquid level gauge according to the current information of the standard liquid level sensor and the calibrated float-type liquid level gauge, and obtains the calibration result.

2. The device for calibrating a float type liquid level gauge according to claim 1, characterized in that: The calibrated float type liquid level gauge is fixedly installed on the measuring container, and the range and accuracy requirements of the float type liquid level gauge are input into the computer through manual operation according to the range of the float type liquid level gauge. The computer calculates the maximum and minimum values ​​allowed by the output current of the calibrated instrument at the calibrated point and the water level values ​​of the five points to be calibrated according to the accuracy requirements; Verification starts: power the entire verification device, turn on the small water pump, and manually click on the verification start button on the computer. The computer transmits the instruction information to the controller, and the controller determines the regulating valve A that needs to be operated according to the instruction information, and the measuring container starts to fill with water. When the liquid level of the standard liquid level sensor reaches the liquid level values ​​of the five verification points one by one, the computer collects the information transmitted by the standard liquid level sensor. When the liquid level value of each verification point is reached, the controller closes the regulating valve A in time, and determines the valve state according to the valve position sensor A, so that the liquid level value of the measuring container is maintained; At the same time, the computer collects the current value of the float-type liquid level gauge being calibrated at this time, and judges and processes it according to the calculated value of the accuracy value to judge whether this current value meets the accuracy requirement, and records the judgment result. The current value is displayed on the computer; when the computer completes the data processing and recording of the previous calibration point, the computer continues to send instructions to the controller to calibrate the water level of the next calibration point, and processes and records the data one by one; When the liquid level in the measuring container reaches the highest point of the measuring range, the computer processes, determines and records the current information at the highest point, and then sends a command to the controller to lower the water level and start the verification of the downstroke: at this time, the controller opens the regulating valve B, keeps the regulating valve A closed, and the liquid level value starts to drop. When the liquid level value of the measuring container reaches the verification point of the downstroke, the controller closes the regulating valve B in time and determines the valve state according to the valve position sensor B to keep the liquid level value of the measuring container. The calibration device performs calibration and recording of the five calibration points of the up and down strokes in sequence according to this method. When the ten calibration values ​​of the up and down strokes are obtained, the computer further judges and processes and records the ten calibration values, and displays the processing results. If all the requirements are met, the calibration record sheet is directly output; if the values ​​do not meet the accuracy requirements, it is displayed that the float-type liquid level gauge is unqualified and needs to be adjusted. Adjustment of float type liquid level gauge: through manual operation of computer, the computer sends instructions to the controller, the controller adjusts the liquid level value of the measuring container to the middle value of the range by adjusting regulating valve A and regulating valve B, at this time adjust the float type liquid level gauge LVDT, so that the current output value of the float type liquid level gauge is 12mA, after the adjustment is completed, re-calibrate according to the above calibration process until the computer determines that the calibration data meets the accuracy requirements, then output the calibration record and the inspection is completed.

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