Automatic calibration device for online boron meter in nuclear power plant

Abstract

The invention discloses an automatic calibration device for an online boron meter in a nuclear power plant, which is connected to an online boron meter and includes a PLC control cabinet, a calibration water tank, a waste discharge device, a first three-way solenoid valve, and a liquid dispensing device. When in use, the control cabinet controls the first three-way solenoid valve to point to one side of the waste discharge device, so that the calibration water tank is connected to the waste discharge device, and the calibration water tank discharges a target volume of boron solution to the waste discharge device; the PLC control cabinet controls the liquid dispensing device to add a target volume of aqueous solution or boron solution to the calibration water tank to complete a calibration process or a verification process. The invention improves the degree of automation of online boron meter calibration work, realizes the automatic liquid dispensing function of the online boron meter calibration device, simplifies the process, and improves the calibration efficiency; effectively reduces the risk of radioactive contamination of personnel and equipment; improves the accuracy of liquid dispensing, and improves the quality of online boron meter calibration; improves the stability of the equipment, and makes temperature control more accurate; saves labor costs, and improves the flexibility of job operation.

Description

Technical Field

[0001] The invention relates to an automatic calibration device for an online boron meter in a nuclear power plant, which is used for calibration of an online boron meter during overhaul of the nuclear power plant. Background Art

[0002] Energy in nuclear power plants is obtained through self-sustaining chain nuclear fission reactions, and the reactor power depends on the core neutron flux density level. In pressurized water reactor nuclear power plants, one of the methods to control the reactor power operation is to add neutron absorber - boric acid to the primary coolant, and control the reactor chain reaction by adjusting the boron concentration in the primary coolant. Therefore, it is particularly important to monitor the boron concentration in the primary coolant in real time, and the online boron meter is the only instrument in a nuclear power plant that can monitor the boron concentration in the primary coolant in real time.

[0003] Generally, the online boron meter needs to be calibrated once in each fuel cycle to ensure the accuracy of the boron meter. When calibrating the online boron meter, the online boron meter needs to be connected to the mobile online boron meter calibration device through two metal hoses (such as Figure 1 As shown). During the calibration of the boron meter, different gradients of boron concentration solutions are manually prepared in the calibration water tank, and the vacuum pump M1 is started using the PID control module and the switch combination P1 to circulate the boron solution to the online boron meter. At the same time, the electric heater G1 is controlled to heat the calibration water tank solution, and the temperature detector T1 monitors the loop temperature in real time. The temperature of the calibration loop is controlled to be stable at 30±1°C through the PID control module and the switch combination P1. The neutron receiving cabinet in the boron meter reads the average neutron count rate, and the boron solution in the calibration water tank needs to be sampled and chemically titrated to the corresponding boron concentration. The neutron receiving cabinet in the boron meter performs a quadratic fit based on the read neutron count rate and the boron concentration of the sample titration, and calculates the coefficient of this calibration, thereby realizing the calibration of the online boron meter.

[0004] When using the existing online boron meter calibration device to prepare boron solutions of different gradients, it is necessary to manually calculate the volume of the displaced liquid first, and then use a 10L plastic beaker to scoop out the boron solution in the calibration water tank according to the calculated volume, visually adjust the volume according to the scale on the beaker wall, visually confirm that the volume is correct and pour it into the waste water tank, and then use a 10L beaker to add SED water or boric acid solution of the same volume to the calibration water tank to achieve the purpose of preparing the target boron solution. Therefore, the existing online boron meter calibration device has the following main deficiencies:

[0005] 1. Boron solution needs to be prepared manually, the process is complicated and the work efficiency is low

[0006] When using the existing online boron meter calibration device to perform the boron meter calibration task, it is necessary to manually calculate the volume of SED water or boric acid solution to be replaced according to the target boron concentration, and then manually replace the boron solution in the calibration water tank with the same volume according to the calculated result. The entire workflow is complicated. When calibrating the online boron meter, 16 target boron concentrations need to be manually prepared. After the boron meter calibration is completed, 4 verification boron concentrations need to be manually prepared. It takes about 3 minutes to prepare each boron concentration point on average, a total of 60 minutes, which is time-consuming and inefficient.

[0007] 2. Radioactive waste liquid will drip onto equipment and the ground, posing a risk of contamination

[0008] When using the existing online boron meter calibration device to prepare the boron solution, it is necessary to use a beaker to scoop out the boron solution in the calibration water tank. Since the liquid in the calibration water tank contains radioactivity, the beaker is in direct contact with the water when scooping it out, and a certain amount of radioactive liquid will remain on the wall of the cup, which will splash onto equipment, the ground or personnel, posing a great risk of radioactive material diffusion and radioactive contamination of personnel or equipment.

[0009] 3. Large sources of error affect the accuracy of online boron meter calibration

[0010] When using the existing online boron meter calibration device to manually prepare the target boron solution, it is necessary to use a beaker to determine the volume and manually confirm the volume by visual inspection. The beaker itself is not an accurate quantitative container, and visual inspection will artificially increase the deviation. There is also a risk of misreading, making it impossible to accurately determine the volume of the replaced boron solution, thereby affecting the accuracy of the online boron meter calibration.

[0011] 4. The PID control loop is single and has no comprehensive control capability

[0012] The existing online boron meter calibration device is equipped with a PID control module, and the PID itself only has a single feedback adjustment function, that is, it can only control the temperature of the boric acid solution in the calibration loop at 30±1°C according to the real-time temperature data collected by the temperature detector. Therefore, it is impossible to realize the comprehensive control function of the remaining electrical equipment in the online boron meter calibration device, and further requires manual pump start, pump stop or liquid preparation, thereby increasing the workload of on-site personnel.

[0013] 5. Increased human resource requirements

[0014] Normally, two people are required for online boron meter calibration during overhaul, one responsible for calculation and sampling for boron measurement, and one responsible for temperature control of the online boron meter calibration device and manual configuration of the target boric acid solution. In the case of tight human resources during overhaul, human resource demand will increase, adding additional burden to the position and reducing the position's operational capacity. Summary of the invention

[0015] The main purpose of the present invention is to provide an automatic calibration device for an online boron meter in a nuclear power plant.

[0016] To achieve the above-mentioned object, the present invention provides an automatic calibration device for an online boron meter in a nuclear power plant, which is connected to an online boron meter and comprises a PLC control cabinet, a calibration water tank, a waste discharge device, a first three-way solenoid valve D1, and a liquid dispensing device, wherein a first end of the first three-way solenoid valve D1 is connected to a first end of the calibration water tank, a second end of the first three-way solenoid valve D1 is connected to a first end of the online boron meter, a third end of the first three-way solenoid valve D1 is connected to the waste discharge device, a second end of the calibration water tank is connected to a second end of the online boron meter, a third end of the calibration water tank is connected to the liquid dispensing device, and the PLC control cabinet comprises ... calibration water tank, a waste discharge device, a first three-way solenoid valve D1, and a liquid dispensing device. The C control cabinet is electrically connected to the waste discharge device, the first three-way solenoid valve D1 and the liquid dispensing device. When in use, the PLC control cabinet controls the first three-way solenoid valve D1 to point to the side of the waste discharge device, so that the calibration water tank is connected to the waste discharge device, and the calibration water tank discharges a target volume of boron solution to the waste discharge device; after discharging the target volume of boron solution, the PLC control cabinet controls the first three-way solenoid valve D1 to point to the side of the calibration water tank; the PLC control cabinet controls the liquid dispensing device to add a target volume of aqueous solution or boron solution to the calibration water tank to complete the calibration process or verification process.

[0017] In the device provided by the present invention, the target volume is calculated based on the target boron concentration and the current boron concentration value in the calibration water tank.

[0018] In the device provided by the present invention, the waste discharge device includes a waste discharge box and a first turbine flowmeter S1, the waste discharge box is connected to the outlet of the first turbine flowmeter S1, the inlet of the first turbine flowmeter S1 is connected to the first three-way solenoid valve D1, and the first turbine flowmeter S1 records the cumulative waste discharge flow from the calibration water tank in real time. After the cumulative waste discharge flow reaches the target volume, the first three-way solenoid valve D1 points to one side of the waste discharge device to allow the solution to continue to circulate.

[0019] In the device provided by the present invention, the waste discharge device further includes a first manual stop valve V1 connected between the inlet of the first turbine flowmeter S1 and the first three-way solenoid valve D1.

[0020] In the device provided by the present invention, the liquid dispensing device includes a second turbine flowmeter S2, a second three-way solenoid valve D2, a delivery pump M2, a switch solenoid valve D3, and a first liquid storage device, wherein the first liquid storage device is connected to the first end of the second three-way solenoid valve D2, the second end of the second three-way solenoid valve D2 is connected to the inlet of the delivery pump M2, the outlet of the delivery pump M2 is connected to the inlet of the second turbine flowmeter S2 via the switch solenoid valve D3, and the outlet of the second turbine flowmeter S2 is connected to the calibration water tank. During the calibration process, the PLC control cabinet controls the second three-way solenoid valve D2 to point to one side of the first liquid storage device, the switch solenoid valve D3 is opened, the delivery pump M2 is started, and the aqueous solution is added to the calibration water tank. The second turbine flowmeter S2 records the cumulative flow of the aqueous solution in real time. When the cumulative flow is equal to the target volume, the delivery pump M2 stops running, the switch solenoid valve D3 is closed, and the calibration process is completed.

[0021] In the device provided by the present invention, the liquid dispensing device also includes a second liquid storage device connected to the third end of the second three-way solenoid valve D2. When performing the verification process, the PLC control cabinet controls the second three-way solenoid valve D2 to point to one side of the second liquid storage device, the switch solenoid valve D3 is opened, the delivery pump M2 is started, and the boron solution is added to the calibration water tank. The second turbine flowmeter S2 records the cumulative flow of the boron solution in real time. When the cumulative flow is equal to the target volume, the delivery pump M2 stops running, the switch solenoid valve D3 is closed, and the verification process is completed.

[0022] In the device provided by the present invention, the liquid dispensing device also includes a second manual stop valve V2 connected between the second end of the second three-way solenoid valve D2 and the first liquid storage device, and a third manual stop valve V3 connected between the third end of the second three-way solenoid valve D2 and the second liquid storage device.

[0023] The device provided by the present invention also includes a vacuum pump M1 electrically connected to the PLC control cabinet 20, the inlet of the vacuum pump M1 is connected to the second end of the calibration water tank, the outlet of the vacuum pump M1 is connected to the online boron meter, and the vacuum pump M1 transports the calibration solution in the calibration water tank to the online boron meter.

[0024] The device provided by the present invention also includes a temperature detector T1 and an electric heater G1 electrically connected to the PLC control cabinet 20. The temperature detector T1 is arranged between the inlet of the vacuum pump M1 and the second end of the calibration water tank, and the electric heater G1 is arranged on the outside of the calibration water tank. The PLC control cabinet 20 controls the electric heater G1 to start and heat the calibration solution in the calibration water tank; the temperature detector T1 monitors the temperature in the loop in real time.

[0025] The automatic calibration device for online boron meters in nuclear power plants of the present invention has the following beneficial effects: using the calibration device provided by the present invention can improve the degree of automation of online boron meter calibration work, realize the automatic liquid preparation function of the online boron meter calibration device, simplify the process, and improve the calibration efficiency; using this device can effectively reduce the risk of radioactive contamination of personnel and equipment; improve the accuracy of liquid preparation, improve the quality of online boron meter calibration; improve the stability of the equipment, make temperature control more accurate; save labor costs, and improve the flexibility of job operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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 description of the prior art are briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without creative work:

[0027] Figure 1 It is the principle diagram of the existing calibration device;

[0028] Figure 2 A schematic diagram of an automatic calibration device for an online boron meter in a nuclear power plant provided by the present invention. DETAILED DESCRIPTION

[0029] In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Typical embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0031] In order to better understand the above-mentioned technical scheme, the above-mentioned technical scheme will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical scheme of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0032] Figure 2 The schematic diagram of the automatic calibration device for online boron meter in nuclear power plant provided by the present invention. Figure 2 As shown, the automatic calibration device for online boron meter of nuclear power plant provided by the present invention is connected to the online boron meter 10, and is used to realize the automatic liquid dispensing function when calibrating the online boron meter. The device comprises a PLC control cabinet 20, a calibration water tank 30, a waste discharge device 40, a first three-way solenoid valve D1 and a liquid dispensing device 50, wherein the first end of the first three-way solenoid valve D1 is connected to the first end of the calibration water tank 30, the second end of the first three-way solenoid valve D1 is connected to the first end of the online boron meter 10, the third end of the first three-way solenoid valve D1 is connected to the waste discharge device 40, the second end of the calibration water tank 30 is connected to the second end of the online boron meter 10, the third end of the calibration water tank 30 is connected to the liquid dispensing device 50, and the PLC control cabinet 20 is electrically connected to the waste discharge device 40, the first three-way solenoid valve D1 and the liquid dispensing device 50. When in use, the PLC control cabinet 20 controls the first three-way solenoid valve D1 to point to the side of the waste discharge device 40, so that the calibration water tank 30 is connected to the waste discharge device 40, and the calibration water tank 30 discharges the target volume of boron solution to the waste discharge device 40; after discharging the target volume of boron solution, the PLC control cabinet 20 controls the first three-way solenoid valve D1 to point to the side of the calibration water tank 30; the PLC control cabinet 20 controls the liquid dispensing device 50 to add the target volume of aqueous solution or boron solution to the calibration water tank 30 to complete the calibration process or verification process.

[0033] Specifically, it also includes a vacuum pump M1 electrically connected to the PLC control cabinet 20, the inlet of the vacuum pump M1 is connected to the second end of the calibration water tank 30, and the outlet of the vacuum pump M1 is connected to the online boron meter 10, and the vacuum pump M1 transports the calibration solution in the calibration water tank 20 to the online boron meter 10. When calibrating the online boron meter, by clicking the start button of the programmable PLC control cabinet 20, the vacuum pump M1 is started, and the PLC control cabinet 20 controls the first three-way solenoid valve D1 to point to one side of the calibration water tank, transports the calibration solution in the calibration water tank to the online boron meter, and returns water from the quick connector A1 to the calibration water tank, so that the boron solution in the calibration water tank is self-circulated.

[0034] Specifically, the waste discharge device 40 includes a waste discharge box 410 and a first turbine flowmeter S1, wherein the waste discharge box 410 is connected to the outlet of the first turbine flowmeter S1, and the inlet of the first turbine flowmeter S1 is connected to the first three-way solenoid valve D1. Further, the waste discharge device 40 also includes a first manual stop valve V1 connected between the inlet of the first turbine flowmeter S1 and the first three-way solenoid valve D1. The liquid dispensing device 50 includes a second turbine flowmeter S2, a second three-way solenoid valve D2, a delivery pump M2, a switch solenoid valve D3, and a first liquid storage device 510, wherein the first liquid storage device 510 is connected to the first end of the second three-way solenoid valve D2, the second end of the second three-way solenoid valve D2 is connected to the inlet of the delivery pump M2, the outlet of the delivery pump M2 is connected to the inlet of the second turbine flowmeter S2 via the switch solenoid valve D3, and the outlet of the second turbine flowmeter S2 is connected to the calibration water tank 30. The liquid dispensing device 50 also includes a second manual stop valve V2 connected between the second end of the second three-way solenoid valve D2 and the first liquid storage device 510 , and a third manual stop valve V3 connected between the third end of the second three-way solenoid valve D2 and the second liquid storage device 520 . When the target boric acid solution needs to be configured, click the corresponding button of the programmable PLC control cabinet 20 to control the first electromagnetic three-way valve D1 to point to the side of the waste tank 410, so that the boron solution in the calibration water tank discharges the target volume into the waste tank, wherein the target volume is calculated based on the target boron concentration and the current boron concentration value in the calibration water tank 30; the first turbine flowmeter S1 records the cumulative waste flow, and when the flow reaches the target volume, the first three-way solenoid valve D1 points to the side of the calibration water tank to continue circulating, and then the second three-way solenoid valve D2 points to the side of the first liquid storage device storing SED water, the switch solenoid valve D3 is opened, the delivery pump M2 is started, and SED water of equal volume is added to the calibration water tank, and the second turbine flowmeter S2 records the cumulative flow, and when the flow is met, the delivery pump M2 stops running, and the switch solenoid valve D3 is closed, so as to achieve the purpose of automatically preparing the boric acid solution.

[0035] Furthermore, the liquid dispensing device 50 also includes a second liquid storage device 520 connected to the third end of the second three-way solenoid valve D2, and the second liquid storage device stores a boric acid solution. After calibration, the boric acid solution is added to the calibration water tank through the second liquid storage device to verify whether the calibration process is accurate. During the verification process, the PLC control cabinet 20 controls the second three-way solenoid valve D2 to point to the side of the second liquid storage device 520, the switch solenoid valve D3 is opened, the delivery pump M2 is started, and the boric solution is added to the calibration water tank 30. The second turbine flowmeter S2 records the cumulative flow of the boric solution in real time. When the cumulative flow is equal to the displacement volume, the delivery pump M2 stops running, and the switch solenoid valve D3 is closed to complete the verification process.

[0036] Furthermore, it also includes a temperature detector T1 and an electric heater G1 electrically connected to the PLC control cabinet 20, the temperature detector T1 is arranged between the inlet of the vacuum pump M1 and the second end of the calibration water tank 30, the electric heater G1 is arranged on the outside of the calibration water tank 30, the PLC control cabinet 20 controls the electric heater G1 to start, and heats the calibration solution in the calibration water tank 30; the temperature detector T1 monitors the temperature in the loop in real time.

[0037] The present invention is based on the existing online boron meter calibration device, and newly adds a delivery pump M2 with a delivery flow rate of 2-6L / min, a PLC control cabinet 20, turbine flowmeters S1 and S2, three-way solenoid valves D1 and D2, a switch solenoid valve D3, manual stop valves V1, V2 and V3, liquid storage devices 510 and 520, 1 / 8 inch stainless steel pipe and other components. Through the sophisticated design and connection of each part, programming of the PLC control cabinet, and integration of the original vacuum pump M1, electric heater G1 and temperature detector T1 into the PLC control module, the comprehensive control capability of the online boron meter calibration device of the nuclear power plant can be improved, and its automatic liquid distribution function can be realized.

[0038] When in use, assemble the components and ensure that the parts are tightly connected without leakage. The specific connection method is as follows: place the first liquid storage device 510 and the second liquid storage device 520 above the original model online boron meter calibration device, and connect them to the manual stop valves V3 and V2 respectively with 1 / 8-inch stainless steel pipes; connect the other ends of the manual stop valves V3 and V2 to the two ends of the second three-way solenoid valve D2 with 1 / 8-inch stainless steel pipes; connect one end of the second three-way solenoid valve D2 to the inlet of the delivery pump M2 with a 1 / 8-inch stainless steel pipe; connect the outlet of the delivery pump M2 to the switch solenoid valve D3 with a 1 / 8-inch stainless steel pipe; connect the other end of the switch solenoid valve D3 to the inlet of the second turbine flowmeter S2 with a 1 / 8-inch stainless steel pipe; connect the outlet of the turbine flowmeter S2 to the calibration water tank with a 1 / 8-inch stainless steel pipe; Use a 1 / 8-inch stainless steel pipe to connect the outlet of the first turbine flowmeter S1; use a 1 / 8-inch stainless steel pipe to connect the inlet of the first turbine flowmeter S1 to the manual stop valve V1; use a 1 / 8-inch stainless steel pipe to connect the other end of the manual stop valve V1 to one end of the first three-way solenoid valve D1; connect the other two ends of the first three-way solenoid valve D1 to a 1 / 8-inch stainless steel pipe and a metal hose respectively, wherein the 1 / 8-inch stainless steel pipe side is connected to the quick connector A1 of the original online boron meter calibration device; connect the wiring of turbine flowmeters S1 and S2, three-way solenoid valves D1 and D2, switch solenoid valve D3, small delivery pump M2, original equipment vacuum pump M1, original equipment electric heater G1, and original equipment temperature detector T1 to the PLC control cabinet 20; program the PLC control cabinet reasonably so that it can comprehensively control the above electrical components.

[0039] The following is a detailed description of the workflow of the calibration device provided by the present invention:

[0040] 1. Start the device: Click the start button on the PLC control cabinet screen, the vacuum pump M1 starts to run, transports the calibration solution in the calibration water tank to the online boron meter, and returns water to the calibration water tank from the quick connector A1.

[0041] 2. Device heating: Click the temperature control button on the PLC control cabinet screen, set the temperature to 30°C, start the electric heater G1, and heat the calibration solution in the calibration water tank. The temperature detector T1 monitors the temperature in the loop in real time. When the temperature detector T1 detects that the temperature is higher than 31°C, the electric heater G1 stops heating; when the temperature detector T1 detects that the temperature is lower than 29°C, the electric heater G1 stops heating. A manual heating button is set in the PLC control cabinet for manual temperature adjustment in special circumstances.

[0042] 3. Liquid preparation of the online boron meter calibration device (calibration process): Click the calibration liquid preparation button on the PLC control cabinet screen, input the target boron concentration and the current boron concentration value, and the PLC control cabinet will automatically control the first three-way solenoid valve D1 to point to the side of the waste tank according to the predetermined program, so that the boron solution in the calibration water tank is discharged to the waste tank to the target volume calculated by the waste discharge program, and the first turbine flowmeter S1 records the cumulative waste discharge flow in real time. After the cumulative waste discharge flow reaches the target volume, the first three-way solenoid valve D1 will automatically point to the side of the calibration water tank to allow the solution to continue to circulate, and then the second three-way solenoid valve D2 will automatically point to the side of the first liquid storage device, the switch solenoid valve D3 is opened, and the small delivery pump M2 is started to add an equal volume of SED water to the calibration water tank. The second turbine flowmeter S2 records the cumulative flow of SED water in real time. When the cumulative flow is equal to the total waste discharge flow (i.e., the target volume), the small delivery pump M2 stops running and the switch solenoid valve D3 is closed to achieve the purpose of automatically preparing the boric acid solution. Among them, the target volume is calculated by the following formula (1), where V 总 is the current volume of boric acid solution in the calibration water tank, V 目标 is the target volume of boric acid solution to be discharged from the calibration water tank, P 测量 is the concentration of the boric acid solution in the calibration water tank, P 目标 It is the concentration value of the boric acid solution that needs to be prepared.

[0043]

[0044] 4. Liquid preparation of the online boron meter calibration device (verification process): Click the verification liquid preparation button on the PLC control cabinet screen, input the target boron concentration, the current boron concentration value and the boric acid water tank boron concentration (i.e., the boron concentration of the boric acid solution in the second liquid storage device), and the PLC control cabinet will automatically control the first three-way solenoid valve D1 to point to the side of the waste tank according to the predetermined program, so that the boron solution in the calibration water tank is discharged to the waste tank according to the replacement volume calculated by the waste discharge program, and the first turbine flowmeter S1 records the cumulative waste flow in real time. After the cumulative waste flow reaches the replacement volume, the first three-way solenoid valve D1 will automatically point to the side of the calibration water tank to continue circulating, and then the second three-way solenoid valve D2 will automatically point to the side of the second liquid storage device, the switch solenoid valve D3 is opened, and the small delivery pump M2 is started to add an equal volume of boric acid solution to the calibration water tank. The second turbine flowmeter S2 records the cumulative flow of the boric acid solution in real time. When the cumulative flow is equal to the replacement volume, the small delivery pump M2 stops running and the switch solenoid valve D3 is closed to achieve the purpose of automatically preparing the boric acid solution. The displacement volume is calculated according to the following formula (2), where V 总 is the current volume of boric acid solution in the calibration water tank, V 目标 is the displacement volume of boric acid solution that needs to be removed from the calibration water tank, P 测量 is the concentration of the boric acid solution in the calibration water tank, P 目标 is the concentration of the boric acid solution to be prepared, P 硼酸箱 is the boron concentration of the boric acid water tank (i.e., the boron concentration of the boric acid solution in the second liquid storage device). If the difference between the boric acid solution concentration measured by the online boron meter and the boron concentration value analyzed manually is within the preset range, it means that the calibration process is accurate.

[0045]

[0046] 5. Flushing the device: After the online boron meter calibration work is completed, add SED water to the boric acid water tank, click the flush button on the PLC control cabinet screen, the second three-way solenoid valve D2 automatically points to the side of the boric acid water tank, the switch solenoid valve D3 opens, and the small delivery pump M2 starts to transport the SED water in the boric acid water tank to the calibration water tank; the first three-way solenoid valve D1 automatically points to the side of the waste tank, and the solution in the calibration water tank is discharged to the side of the waste tank; the purpose of flushing the pipeline and the device is achieved.

[0047] 6. Stop: Click the stop button on the PLC control cabinet screen, the vacuum pump M1 stops running, and the electric heater G1 stops heating.

[0048] Compared with the prior art, the calibration device provided by the present invention has the following advantages:

[0049] 1. High degree of automation, simple process, and improved work efficiency

[0050] When the automated online boron meter calibration device provided by the present invention is used to perform boron meter calibration, the entire process is automatically controlled by PLC, and there is no need to manually prepare the solution. The process is simple, and it takes about 1 minute on average to prepare each target boron concentration, with a total time of about 20 minutes, which shortens the solution preparation time and improves work efficiency.

[0051] 2. Reduce the risk of radioactive contamination

[0052] When using the automated online boron meter calibration device provided by the present invention to prepare liquid, there is no need to use a beaker to manually replace the radioactive boric acid solution, and personnel do not need to directly contact the radioactive solution, thereby reducing the risk of radioactive contamination of equipment and personnel.

[0053] 3. Improve the accuracy of liquid preparation and the quality of online boron meter calibration

[0054] The target boric acid solution is prepared using the automated online boron meter calibration device provided by the present invention, and the turbine flowmeter records the total volume of the transmitted liquid in real time and makes corrections, and the displacement volume is more digitalized, thereby improving the accuracy of liquid preparation and the quality of online boron meter calibration in nuclear power plants.

[0055] 4.PLC has stronger comprehensive control capabilities

[0056] All electrical components of the automated online boron meter calibration device provided by the present invention are controlled by PLC. The PLC itself has the advantage of strong comprehensive control capability and can globally control the temperature and liquid distribution of the boron meter calibration device by software, which is very convenient and reduces the workload of on-site personnel.

[0057] 5. Save labor costs and improve job operation flexibility

[0058] The automated online boron meter calibration device provided by the present invention has a higher degree of automation. There is no need to manually configure the target boric acid solution. The staff only needs to operate the PLC control panel to complete the liquid preparation work. At the same time, the automatic temperature control capability is stronger. There is no need to frequently inspect and pay attention to the measured temperature of the calibration circuit. Only one person is needed for the calibration work, which saves the labor cost of this work, frees up manpower for the post, and improves the flexibility of post operation.

[0059] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0060] Similarly, it should be understood that in order to streamline the present disclosure and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the intention that the claimed invention requires more features than those explicitly recited in each claim. More specifically, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present invention.

[0061] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc., does not indicate any order. These words may be interpreted as names.

Claims

1. An automatic calibration device for an online boron meter in a nuclear power plant, connected to an online boron meter (10), characterized in that: The invention comprises a PLC control cabinet (20), a calibration water tank (30), a waste discharge device (40), a first three-way solenoid valve D1, and a liquid dispensing device (50), wherein a first end of the first three-way solenoid valve D1 is connected to a first end of the calibration water tank (30), a second end of the first three-way solenoid valve D1 is connected to a first end of the online boron meter (10), a third end of the first three-way solenoid valve D1 is connected to the waste discharge device (40), a second end of the calibration water tank (30) is connected to a second end of the online boron meter (10), a third end of the calibration water tank (30) is connected to the liquid dispensing device (50), the PLC control cabinet (20) is electrically connected to the waste discharge device (40), the The first three-way solenoid valve D1 and the liquid dispensing device (50) are used such that the PLC control cabinet (20) controls the first three-way solenoid valve D1 to point to the side of the waste discharge device (40), so that the calibration water tank (30) is connected to the waste discharge device (40), and the calibration water tank (30) discharges a target volume of boron solution into the waste discharge device (40); after discharging the target volume of boron solution, the PLC control cabinet (20) controls the first three-way solenoid valve D1 to point to the side of the calibration water tank (30); and the PLC control cabinet (20) controls the liquid dispensing device (50) to add a target volume of aqueous solution or boron solution into the calibration water tank (30), thereby completing a calibration process or a verification process.

2. The device according to claim 1, characterized in that The target volume is calculated according to the target boron concentration and the current boron concentration value in the calibration water tank (30).

3. The device according to claim 1, characterized in that The waste discharge device (40) comprises a waste discharge box (410) and a first turbine flowmeter S1, wherein the waste discharge box (410) is connected to the outlet of the first turbine flowmeter S1, and the inlet of the first turbine flowmeter S1 is connected to the first three-way solenoid valve D1, and the first turbine flowmeter S1 records the accumulated waste discharge flow from the calibration water tank (30) in real time. After the accumulated waste discharge flow reaches a target volume, the first three-way solenoid valve D1 points to one side of the waste discharge device (40) to allow the solution to continue to circulate.

4. The device according to claim 3, characterized in that The waste discharge device (40) further comprises a first manual stop valve V1 connected between the inlet of the first turbine flowmeter S1 and the first three-way solenoid valve D1.

5. The device according to claim 1, characterized in that The liquid dispensing device (50) comprises a second turbine flowmeter S2, a second three-way solenoid valve D2, a delivery pump M2, a switch solenoid valve D3, and a first liquid storage device (510), wherein the first liquid storage device (510) is connected to a first end of the second three-way solenoid valve D2, a second end of the second three-way solenoid valve D2 is connected to an inlet of the delivery pump M2, an outlet of the delivery pump M2 is connected to an inlet of the second turbine flowmeter S2 via the switch solenoid valve D3, and an outlet of the second turbine flowmeter S2 is connected to the calibration water tank (30). During the calibration process, the PLC control cabinet (20) controls the second three-way solenoid valve D2 to point to one side of the first liquid storage device (510), the switch solenoid valve D3 is opened, the delivery pump M2 is started, and aqueous solution is added to the calibration water tank (30). The second turbine flowmeter S2 records the cumulative flow of the aqueous solution in real time. When the cumulative flow is equal to the target volume, the delivery pump M2 stops running, the switch solenoid valve D3 is closed, and the calibration process is completed.

6. The device according to claim 5, characterized in that The liquid dispensing device (50) also includes a second liquid storage device (520) connected to the third end of the second three-way solenoid valve D2. When performing a verification process, the PLC control cabinet (20) controls the second three-way solenoid valve D2 to point to one side of the second liquid storage device (520), the switch solenoid valve D3 is opened, the delivery pump M2 is started, and the boron solution is added to the calibration water tank (30). The second turbine flowmeter S2 records the cumulative flow of the boron solution in real time. When the cumulative flow is equal to the target volume, the delivery pump M2 stops running, the switch solenoid valve D3 is closed, and the verification process is completed.

7. The device according to claim 6, characterized in that The liquid dispensing device (50) further includes a second manual stop valve V2 connected between the second end of the second three-way solenoid valve D2 and the first liquid storage device (510), and a third manual stop valve V3 connected between the third end of the second three-way solenoid valve D2 and the second liquid storage device (520).

8. The device according to claim 1, characterized in that It also includes a vacuum pump M1 electrically connected to the PLC control cabinet (20), the inlet of the vacuum pump M1 is connected to the second end of the calibration water tank (30), the outlet of the vacuum pump M1 is connected to the online boron meter (10), and the vacuum pump M1 transports the calibration solution in the calibration water tank (30) to the online boron meter (10).

9. The device according to claim 8, characterized in that It also includes a temperature detector T1 and an electric heater G1 which are electrically connected to the PLC control cabinet (20); the temperature detector T1 is arranged between the inlet of the vacuum pump M1 and the second end of the calibration water tank (30); the electric heater G1 is arranged outside the calibration water tank (30); the PLC control cabinet (20) controls the electric heater G1 to start, and heats the calibration solution in the calibration water tank (30); the temperature detector T1 monitors the temperature in the circuit in real time.

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