Integrated device for pH online measurement and calibration

Abstract

The utility model discloses an integrated device for on-line pH measurement and calibration, which comprises a calibration unit used for carrying out regular on-line calibration on a pH electrode; the measuring unit is used for continuously monitoring the pH value of the sample water on line; and the control and driving unit is used for performing logic control on a measurement flow or a calibration flow of the whole system, and the logic control comprises liquid level sensor signal processing, pH electrode signal processing and electromagnetic valve sequential logic processing. The device is simple in overall structure and high in reliability, and can be widely applied to online measurement of the pH value of sample water and calibration of a measuring device in the industrial process; automatic addition and switching of the pH standard solution and the sample water are realized through automatic logic program control, so that the workload of manual maintenance can be greatly reduced; the constant-current online calibration is more accurate to reduce the working condition of the electrode, and the measurement accuracy can be greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of on-line water quality monitoring in industrial processes, in particular to an integrated device for on-line pH measurement and calibration. Background Art

[0002] With the rapid development of China's power industry, large-capacity and high-parameter units have become the industry development trend. The pH value of the sample water in the boiler water vapor system is an important control index. Continuously and accurately measuring and controlling the pH value of the water vapor system in power plants is the main means to control the metal corrosion of the water vapor system. At the same time, the water quality of the water vapor system in the generator set is very pure, and generally no corrosion inhibitor is allowed to be added. In order to prevent the corrosion of steel and copper in the water vapor system, it is required to control the pH value of the water within a strict range. The prerequisite for strictly controlling the pH value is to accurately measure the pH value of the water sample. Therefore, convenient and accurate pH electrode calibration is an important guarantee for ensuring the safe and economic operation of the water vapor system. With the development of smart power plants, unattended operation, especially the intelligent and automated operation of instrument equipment, has gradually become an important research content.

[0003] For the traditional on-line instrument pH electrode calibration, it is necessary for manual to disassemble the electrode and place it in the standard solution container for calibration. There are frequent calibrations and regular disassembly of the on-line instrument electrode device, resulting in a large amount of manual maintenance work. And there is a greater risk of damage to the glass electrode during the manual maintenance process. At the same time, the electrode cable and the grounding wire are also extremely easy to be damaged. During the operation process, the standard solution is static, while in the actual measurement process, in the low-conductivity water sample, a water sample with a constant flow rate is required to prevent the charge enrichment and potential change around the electrode glass membrane. Therefore, the working conditions during the calibration process are different from those during the measurement process, which will cause the calibrated instrument to be unable to accurately measure the flowing sample water.

[0004] In summary, this application aims to develop a new type of pH on-line measurement and calibration device, which can automatically add and switch the pH standard solution and the sample water through an automated logic program control, greatly reducing the manual maintenance workload, and the constant-flow on-line calibration can also improve the measurement accuracy. Content of the Utility Model

[0005] The technical problem to be solved by this application is that the traditional on-line instrument pH electrode calibration relies on manual operation and maintenance, and the standard solution is static during the operation process, resulting in inaccurate measurement results.

[0006] To solve the above technical problems, the present application provides an integrated device for on-line pH measurement and calibration, including: a calibration unit, including a first standard solution tank and a second standard solution tank. The outlet end of the first standard solution tank is provided with a first outlet solenoid valve, and the inlet end is provided with a first inlet solenoid valve. The first standard solution tank is equipped with a first liquid level sensor; the outlet end of the second standard solution tank is provided with a second outlet solenoid valve, and the inlet end is provided with a second inlet solenoid valve. The second standard solution tank is equipped with a second liquid level sensor; a measurement unit, including a flow cell provided with a pH electrode. The upper part of the flow cell is provided with a sample inlet valve and an air vent valve in parallel, and the bottom of the flow cell is provided with a sample inlet valve and a drain valve in parallel; the connection pipelines of the first outlet solenoid valve and the second outlet solenoid valve are both connected to the lower part of the flow cell through a drain pump, and the first inlet solenoid valve and the second inlet solenoid valve are both connected to the upper part of the flow cell through pipelines; and a control and drive unit, including a processor module and a pH electrode signal module, a power module, a driver module and a liquid level signal module connected to the processor module. The pH electrode signal module is connected to the pH electrode, the driver module is connected to all solenoid valves and the drain pump, and the liquid level signal module is connected to the first liquid level sensor and the second liquid level sensor.

[0007] According to an embodiment of the present application, the drain pump adopts a peristaltic pump, and the pumping or draining is realized by the forward and reverse rotation of the pump.

[0008] According to an embodiment of the present application, the control and drive unit is a programmable control device or a DCS control device.

[0009] According to an embodiment of the present application, the outlet end of the first standard solution tank is located at the bottom of the tank body, and the outlet end of the second standard solution tank is located at the bottom of the tank body.

[0010] According to an embodiment of the present application, the inlet end of the first standard solution tank is located at the upper part of the tank body, and the inlet end of the second standard solution tank is located at the bottom of the tank body.

[0011] According to an embodiment of the present application, both the first liquid level sensor and the second liquid level sensor are non-contact sensors.

[0012] According to an embodiment of the present application, the air vent valve is connected to the upper part of the flow cell through a pipeline and is opened during the process of discharging the liquid in the flow cell to achieve air pressure balance in the flow cell.

[0013] According to an embodiment of the present application, two different concentrations of calibration solutions for calibrating the pH electrode are respectively contained in the first standard solution tank and the second standard solution tank.

[0014] According to an embodiment of the present application, the first liquid level sensor and the second liquid level sensor are respectively installed on the outer sides of the bottoms of the first standard solution tank and the first standard solution tank to monitor the lowest liquid level of the calibration solution inside in real time.

[0015] According to an embodiment of the present application, the control and drive unit includes a housing and a control board disposed on the housing, and the control board is further connected to a display device.

[0016] Compared with the prior art, the technical solution of the present application has the following beneficial effects:

[0017] 1. The overall structure of the device of the present application is simple and highly reliable, and can be widely used in the on-line measurement of the pH value of the sample water in the industrial process and the calibration of the measuring device; through the automatic logic program control, the automatic addition and switching of the pH standard solution and the sample water can be realized, which can greatly reduce the manual maintenance workload; the constant current type on-line calibration can more accurately restore the electrode working condition, which can greatly improve the measurement accuracy.

[0018] 2. In each measurement of the present utility model, first, the solenoid valve at the outlet of the standard solution tank and the standard solution pump are opened, a small amount of the standard solution is extracted into the flow cell for rinsing, the solenoid valve at the outlet of the standard solution tank and the standard solution pump are closed, and the drain valve is opened to drain the standard solution for rinsing the flow cell, so that the pH measurement electrode can be cleaned during measurement to ensure its sensitivity. Through the automatic cleaning and maintenance of the pH measurement electrode, the detection accuracy is improved and the service life of the electrode is extended.

[0019] 3. Through the implementation of the logic program control by the control and drive unit of the present application, the pH measurement electrode is automatically calibrated and calibrated in a regular cyclic flow manner, solving the problem of when to calibrate the pH value on-line detection device, thereby optimizing the calibration period of the pH value on-line detection device and reducing the labor cost. Finally, the on-line high-precision detection of the pH value of the solution is realized, providing accurate information support for the optimization control of the later process. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present application and do not limit the present application.

[0021] Figure 1 It is a schematic structural diagram of an integrated device for pH on-line measurement and calibration according to an example of the present utility model;

[0022] Figure 2 It is a schematic composition diagram of the control and drive unit according to an example of the present utility model.

[0023] The description of the reference numerals is as follows:

[0024] 1. Outlet valve, 2. Air release valve, 3. PH electrode, 4. First liquid level sensor, 5. First standard solution tank, 6. Second standard solution tank, 7. Second liquid level sensor, 8. Second outlet solenoid valve, 9. Second inlet solenoid valve, 10. First outlet solenoid valve, 11. First inlet solenoid valve, 12. Flow cell, 13. Drain pump, 14. Drain valve, 15. Inlet valve, 201. PH electrode signal module, 202. Processor module, 203. Power supply module, 204. Driver module, 205. Liquid level signal module. Detailed implementation manners

[0025] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0026] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the art to which the present application pertains. The terms "first", "second" and similar terms used in the description and claims of the present patent application do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, the terms such as "a" or "one" do not denote a quantity limitation, but mean that there is at least one.

[0027] As Figure 1 and Figure 2 shown, an integrated device for on-line pH measurement and calibration according to an example of the present utility model includes a calibration unit, a measurement unit, and a control and drive unit (not shown in Figure 1 ). The calibration unit is used to perform regular on-line calibration on the PH electrode 3 to ensure the accuracy and reliability of the measurement data during the measurement process of the entire device; the measurement unit is used to continuously monitor the pH value of the sample water on-line; the control and drive unit is used to perform logical control on the measurement process or calibration process of the overall system, including processing liquid level sensor signals, pH electrode signals, solenoid valve timing logic, etc. Compared with the prior art, the device of the present application can not only perform real-time on-line monitoring of the sample water, but also perform regular cyclic flow-type automatic calibration and calibration on the monitoring instrument and the electrode. The overall structure is simple and reliable, which can greatly reduce the manual maintenance workload. At the same time, the constant flow on-line calibration can more accurately restore the electrode working condition and greatly improve the measurement accuracy.

[0028] In this embodiment, the calibration unit is used to perform regular on-line calibration on the pH electrode 3 to ensure the accuracy and reliability of the measurement data during the measurement process of the entire device. The calibration unit includes a first standard solution tank 5 and a second standard solution tank 6. The outlet end of the first standard solution tank 5 is provided with a first outlet solenoid valve 10, and the inlet end is provided with a first inlet solenoid valve 11. The first standard solution tank 5 is equipped with a first liquid level sensor 4; the outlet end of the second standard solution tank 6 is provided with a second outlet solenoid valve, and the inlet end is provided with a second inlet solenoid valve 9. The second standard solution tank 6 is equipped with a second liquid level sensor 7.

[0029] Furthermore, the first standard solution tank 5 and the second standard solution tank 6 respectively contain two calibration solutions with different concentrations for calibrating the pH electrode 3. The standard solution in the first standard solution tank 5 is used to enter the measurement unit for the first-point calibration. After the first-point calibration is completed, the calibration solution in the second standard solution tank 6 enters the measurement unit for the second-point calibration. After two calibrations, the device process automatically enters the measurement process to achieve a cycle. The first liquid level sensor 4 and the second liquid level sensor 7 are respectively installed on the outer sides of the bottoms of the first standard solution tank 5 and the first standard solution tank 5 to monitor the lowest liquid levels of the calibration solutions inside in real time.

[0030] Furthermore, the outlet end of the first standard solution tank 5 is located at the bottom of the tank body, and the outlet end of the second standard solution tank 6 is located at the bottom of the tank body. The inlet end of the first standard solution tank 5 is located at the upper part of the tank body, and the inlet end of the second standard solution tank 6 is located at the bottom of the tank body. These designs clearly distinguish the positions of the inlet and outlet, and also prevent the access of pipelines.

[0031] Furthermore, both the first liquid level sensor 4 and the second liquid level sensor 7 are non-contact sensors, including but not limited to photoelectric and capacitive sensors.

[0032] In this embodiment, the measurement unit is used to continuously monitor the pH value of the sample water on-line. The measurement unit includes a flow cell 12 provided with a pH electrode 3. The upper part of the flow cell 12 is provided with a sample inlet valve 15 and an air vent valve 2 in parallel, and the bottom of the flow cell 12 is provided with a sample inlet valve 15 and a drain valve 14 in parallel; the connecting pipelines of the first outlet solenoid valve 10 and the second outlet solenoid valve 8 are both connected to the lower part of the flow cell 12 through a drain pump 13, and the first inlet solenoid valve 11 and the second inlet solenoid valve 9 are both connected to the upper part of the flow cell 12 through pipelines.

[0033] Furthermore, the drain pump 13 is preferably a peristaltic pump, and the pumping or draining is realized by the forward and reverse rotation of the pump.

[0034] Further, all valves are connected to the flow cell 12 through pipelines. Among them, the vent valve 2 and the drain valve 14 can be used as auxiliary units of the whole device to realize the discharge of calibration liquid and the pressure balance in the flow cell 12 during the calibration process. The vent valve 2 is connected to the upper part of the flow cell 12 through a pipeline and is opened during the process of discharging the liquid in the flow cell 12 to achieve the air pressure balance in the flow cell 12; the drain valve 14 is connected to the bottom of the flow cell 12 through a pipeline and is used to discharge the calibration liquid for rinsing and the calibration liquid for calibration respectively at the beginning and end of the calibration.

[0035] In this embodiment, the control and drive unit realizes the logical control of the measurement process or calibration process of the whole system, including processing the signals of the liquid level sensor, pH electrode signal, solenoid valve timing logic, etc. The control and drive unit includes a processor module 202 and a PH electrode signal module 201, a power supply module 203, a driver module 204, and a liquid level signal module 205 connected to the processor module 202. The PH electrode signal module 201 is connected to the PH electrode 3, the driver module 204 is connected to all solenoid valves and the drain pump 13, and the liquid level signal module 205 is connected to the first liquid level sensor 4 and the second liquid level sensor 7.

[0036] Further, the control and drive unit is a programmable control device or a DCS control device. The functions of each module of the control and drive unit are as follows: the PH electrode signal module 201 processes and calculates the analog electrical signals of the electrode; the processor module 202 realizes the overall timing process control, logical operation, and logical control; the power supply module 203 realizes the conversion of the power supply into different voltages and currents required by each module; the driver module 204 realizes the opening and closing of each pump and valve during the process of process implementation and logical timing implementation; the liquid level signal module 205 monitors and analyzes the liquid levels of the calibration liquids in the two calibration liquid tanks in real time, and sends the liquid level data to the processor module 202 to realize the prompt for calibration liquid replenishment.

[0037] Further, the control and drive unit includes a housing and a control board placed on the housing, and the control board is also connected with a display device.

[0038] In this embodiment, the working process of an integrated device for on-line pH measurement and calibration is as follows: During the measurement process, the sample water enters the flow cell 12 through the sample inlet valve 15 and flows out through the sample outlet valve 1 to realize the on-line monitoring of the pH value of the sample water; through the implementation of logic program control by the control and drive unit, during the calibration process, the sample inlet valve 15 and the sample outlet valve 1 are closed, the vent valve 2 and the drain valve 14 are opened, and the residual sample water in the flow cell 12 flows out through the drain valve 14. After the drain valve 14 is closed, the first outlet solenoid valve 10 of the first standard solution tank 5 and the drain pump 13 are opened, and a small amount of standard solution in the first standard solution tank 5 is pumped into the flow cell 12 for rinsing. After the first outlet solenoid valve 10 and the drain pump 13 are closed, the drain valve 14 is opened to drain the standard solution for rinsing the flow cell 12. After the vent valve 2 and the drain valve 14 are closed, the first outlet solenoid valve 10, the drain pump 13, and the first inlet solenoid valve 11 are opened to make the standard solution in the first standard solution tank 5 flow into the flow cell 12 from the bottom and flow out from the upper part to realize circular flow, so as to perform the first-point calibration on the instrument; after the first-point calibration is completed, the first outlet solenoid valve 10, the drain pump 13, and the first inlet solenoid valve 11 are closed, the vent valve 2 and the drain valve 14 are opened to drain the standard solution remaining in the flow cell 12. After the residual standard solution is drained, the drain valve 14 is closed, the second outlet solenoid valve 8 and the drain pump 13 are opened, and a small amount of standard solution in the second standard solution tank 6 is pumped into the flow cell 12 for rinsing. After the second outlet solenoid valve 8 and the drain pump 13 of the second standard solution tank 6 are closed, the drain valve 14 is opened to drain the standard solution for rinsing the flow cell 12. After the vent valve 2 and the drain valve 14 are closed, the second outlet solenoid valve 8, the drain pump 13, and the second inlet solenoid valve 9 are opened to make the standard solution in the second standard solution tank 6 flow into the flow cell 12 from the bottom and flow out from the upper part to realize circular flow, so as to perform the second-point calibration on the instrument. After the second-point calibration is completed, the device process automatically enters the measurement process to realize cyclic repetition.

[0039] During the whole measurement or calibration process, the PH electrode signal module 201 processes and calculates the electrode analog electrical signal, the processor module 202 realizes the overall timing process control as well as logical operation and logical control, the power supply module 203 realizes the conversion of the power supply into different voltages and currents required by each module, the driver module 204 realizes the opening and closing of each pump and valve during the process of process implementation and logical timing implementation, the liquid level signal module 205 monitors and analyzes the liquid levels of the standard solutions in the two standard solution tanks in real time, and sends the liquid level data to the processor module 202 to realize the prompt for standard solution replenishment.

[0040] In summary, the technical solution of this application has the following beneficial effects:

[0041] 1. The overall structure of the device of the present application is simple and highly reliable, and it can be widely used in the on-line measurement of the pH value of sample water in industrial processes and the calibration of measurement devices; through automatic logic program control, the automatic addition and switching of pH standard solution and sample water can be realized, which can greatly reduce the manual maintenance workload; the constant-current on-line calibration can more accurately restore the electrode working conditions and greatly improve the measurement accuracy.

[0042] 2. In each measurement of the present utility model, first, the solenoid valve at the outlet of the standard solution tank and the standard solution pump are opened, a small amount of standard solution is extracted into the flow cell for rinsing, the solenoid valve at the outlet of the standard solution tank and the standard solution pump are closed, and the drain valve is opened to discharge the standard solution for rinsing the flow cell, so that the pH measurement electrode can be cleaned during measurement to ensure its sensitivity. Through the automatic cleaning and maintenance of the pH measurement electrode, the accuracy of detection is improved and the service life of the electrode is extended.

[0043] 3. Through the implementation of logic program control by the control and drive unit of the present application, the pH measurement electrode is automatically calibrated and calibrated in a regular cyclic flow manner, solving the problem of when to calibrate the pH value on-line detection device, thereby optimizing the calibration period of the pH value on-line detection device and reducing the labor cost. Finally, the on-line high-precision detection of the pH value of the solution is realized, providing accurate information support for the optimization control of the later process.

[0044] The above is only the exemplary implementation mode of the present application, rather than being used to limit the protection scope of the present application. The protection scope of the present application is determined by the appended claims.

Claims

1. An integrated device for online pH measurement and calibration, characterized in that: include: The calibration unit comprises a first standard liquid tank and a second standard liquid tank, wherein the outlet end of the first standard liquid tank is provided with a first outlet solenoid valve, the inlet end is provided with a first inlet solenoid valve, and the first standard liquid tank is equipped with a first liquid level sensor; the outlet end of the second standard liquid tank is provided with a second outlet solenoid valve, the inlet end is provided with a second inlet solenoid valve, and the second standard liquid tank is equipped with a second liquid level sensor; The measuring unit comprises a flow cell provided with a pH electrode, wherein a sample inlet valve and an air valve are provided in parallel at the upper portion of the flow cell, and a sample inlet valve and a liquid discharge valve are provided in parallel at the bottom of the flow cell; the connecting pipelines of the first outlet solenoid valve and the second outlet solenoid valve are both connected to the lower portion of the flow cell through a liquid discharge pump, and the first inlet solenoid valve and the second inlet solenoid valve are both connected to the upper portion of the flow cell through pipelines; and The control and drive unit includes a processor module and a pH electrode signal module, a power module, a driver module and a liquid level signal module connected to the processor module, wherein the pH electrode signal module is connected to the pH electrode, the driver module is connected to all solenoid valves and a liquid displacement pump, and the liquid level signal module is connected to the first liquid level sensor and the second liquid level sensor.

2. An integrated device for online pH measurement and calibration according to claim 1, characterized in that: The liquid discharge pump adopts a peristaltic pump, and the pumping or discharging of liquid is achieved by the forward and reverse rotation of the pump.

3. An integrated device for online pH measurement and calibration according to claim 1, characterized in that: The control and drive unit is a programmable control device or a DCS control device.

4. The integrated device for online pH measurement and calibration according to claim 1, characterized in that: The outlet end of the first standard liquid tank is located at the bottom of the tank body, and the outlet end of the second standard liquid tank is located at the bottom of the tank body.

5. The integrated device for online pH measurement and calibration according to claim 1, characterized in that: The inlet end of the first standard liquid tank is located at the upper part of the tank body, and the inlet end of the second standard liquid tank is located at the bottom of the tank body.

6. The integrated device for online pH measurement and calibration according to claim 1, characterized in that: The first liquid level sensor and the second liquid level sensor are both non-contact sensors.

7. The integrated device for online pH measurement and calibration according to claim 1, characterized in that: The air valve is connected to the upper part of the circulation pool through a pipeline, and is opened during the process of discharging the liquid in the circulation pool to achieve air pressure balance in the circulation pool.

8. The integrated device for online pH measurement and calibration according to claim 1, characterized in that: The first standard liquid tank and the second standard liquid tank respectively contain two calibration solutions of different concentrations for calibrating the pH electrode.

9. An integrated device for online pH measurement and calibration according to claim 8, characterized in that: The first liquid level sensor and the second liquid level sensor are respectively installed on the outside of the bottom of the first standard liquid tank and the second standard liquid tank to monitor the lowest liquid level of the calibration solution therein in real time.

10. The integrated device for online pH measurement and calibration according to claim 1, characterized in that: The control and drive unit comprises a shell and a control panel placed on the shell, and the control panel is also connected to a display device.

Images