TOC sensor self-calibration method, TOC sensor and water purification equipment

Abstract

The present invention discloses a TOC sensor self-calibration method, a TOC sensor and a water purification device. The TOC sensor self-calibration method comprises the steps of collecting raw water TOC value, comparing it with a preset raw water TOC threshold, collecting pure water TOC value, comparing it with a preset pure water TOC threshold, and determining whether to perform self-calibration or not according to the comparison result. The self-calibration includes two modes: immediate calibration and delayed calibration. The TOC sensor self-calibration method proposed by the present invention can realize self-calibration, overcome the data drift problem generated during the long-term use of the TOC sensor, and be applied to water purification equipment, so that the water quality monitoring data of the equipment can be more accurate and more reliable.

Description

Technical Field

[0001] The invention belongs to the technical field of water purification, and in particular relates to a TOC sensor self-calibration method, a TOC sensor and water purification equipment. Background Art

[0002] TOC sensor is a device used to detect the total organic carbon (TOC) content in water. It is widely used in various water quality monitoring equipment or water purification equipment. If the TOC sensor is not calibrated during long-term use, data drift is likely to occur. The main reason for data drift is circuit instability caused by equipment aging.

[0003] The patent application with publication number WO2022043997A1 and name Fluid quality monitoring system and method provides a method for cloud-based data comparison and verification and local data self-verification; the patent application with patent number US11293430B2 and name Smart pump controller provides a calibration method that mainly controls the circuit by adjusting parameters such as valves, heat exchangers, and heating elements.

[0004] Although the above-mentioned prior arts involve processing of TOC calibration data, none of them is based on the sensor itself for calibration and needs to be calibrated with the help of external equipment. Therefore, it is not conducive to improving data processing efficiency and is not conducive to reducing the equipment used by TOC sensors. Summary of the invention

[0005] Technical purpose: In view of the above technical problems, the present invention proposes a TOC sensor self-calibration method, a TOC sensor and a water purification device. The TOC sensor self-calibration method can perform sensor self-calibration and overcome problems such as data drift generated during the long-term use of the TOC sensor.

[0006] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0007] A TOC sensor self-calibration method, characterized in that:

[0008] Raw water self-calibration: collect raw water TOC value, compare it with the preset raw water TOC threshold, and determine whether to perform immediate calibration based on the comparison result;

[0009] Pure water self-calibration: collect pure water TOC value, compare it with the preset pure water TOC threshold, and determine whether to perform immediate calibration or delayed calibration based on the comparison result;

[0010] Among them, the immediate calibration is to calibrate the current single sampling result, and the delayed calibration is to comprehensively calibrate the multiple sampling results. When calibration is not required, the corresponding raw water TOC value or pure water TOC value is output.

[0011] Preferably, the TOC sensor self-calibration method alternately performs raw water self-calibration and pure water self-calibration steps;

[0012] There are multiple preset pure water TOC thresholds for dividing pure water TOC into multiple standards.

[0013] Preferably, it includes the steps:

[0014] During raw water self-calibration, the raw water TOC value X is collected and compared with the preset raw water TOC threshold R. If X ≤ R, calibration is not required; if X > R, immediate calibration is performed;

[0015] During pure water self-calibration, the pure water TOC value Y is collected and compared with the preset pure water TOC thresholds P1, P2, and P3, where P1 < P2 < P3, that is:

[0016] If Y < P1, it is judged whether the current is in the delayed calibration state. If so, the delayed calibration is exited and immediate calibration is performed; if not, immediate calibration is performed;

[0017] If P1 ≤ Y < P2, it is judged whether the current is in the delayed calibration state. If so, after multiple delayed calibrations are accumulated, the delayed calibration is exited; if not, calibration is not required;

[0018] If P2 ≤ Y < P3, immediate calibration is performed, and after the immediate calibration ends, delayed calibration is started;

[0019] If Y ≥ P3, immediate calibration is performed; if Y meets the requirement of Y > P3 after accumulating the preset number of times, after the immediate calibration ends, delayed calibration is started;

[0020] Among them, after immediately calibrating the raw water TOC value, the first calibrated TOC value is output X’ , and after immediately calibrating the pure water TOC value, the second calibrated TOC value is output Y’ , and the third calibrated TOC value is output after delayed calibration Y’’ .

[0021] Preferably, the self-calibration target of the raw water TOC value X is to make the output raw water TOC value less than or equal to the raw water TOC threshold R;

[0022] The self-calibration target of the pure water TOC value Y is to make the output pure water TOC value within the range of (P1, P2).

[0023] A TOC sensor, characterized in that it includes a water inlet, a drain and a detection chamber, wherein a TOC value acquisition device and a microprocessor are provided in the detection chamber, and a self-calibration module is provided in the microprocessor. The TOC value acquisition device is used to collect the raw water TOC value or the pure water TOC value input from the water inlet and send it to the self-calibration module, the self-calibration module is used to determine whether to perform raw water self-calibration or pure water self-calibration according to the received data, and the microprocessor is used to output a TOC value that does not require calibration or a TOC value after self-calibration.

[0024] Preferably, the microprocessor is also provided with a data interaction module for receiving instructions sent by an external device.

[0025] A water purification device, characterized in that it comprises a processor and the TOC sensor, wherein the processor is connected to the TOC sensor, and the TOC sensor sends a TOC value that does not require calibration or a TOC value after self-calibration to the processor.

[0026] Preferably, the water purification equipment further comprises a water inlet, a wastewater outlet, a water outlet, a filter element, a raw water solenoid valve, a pure water solenoid valve and a water intake valve;

[0027] The water inlet is used to input raw water, and the water inlet is connected to the raw water solenoid valve and the input end of the filter element through a three-way pipeline; the raw water is filtered by the filter element to produce pure water and waste water, and the waste water is discharged through the waste water outlet, and the pure water is connected to the water intake valve and the input end of the pure water solenoid valve through the three-way pipeline; the water intake valve is arranged at the water outlet;

[0028] The output ends of the raw water solenoid valve and the pure water solenoid valve are connected to the water inlet of the TOC sensor, and the drain outlet of the TOC sensor is connected to the wastewater outlet through a pipeline;

[0029] The processor comprises a control module, and the control module is connected to a TOC sensor, a water intake valve, a raw water solenoid valve and a pure water solenoid valve.

[0030] Beneficial effects: Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0031] The TOC sensor self-calibration method proposed in the present invention can achieve self-calibration, takes into account the natural aging of the equipment, uses a self-calibration algorithm to return the drift data to a normal level, overcomes the data drift problem generated during the long-term use of the TOC sensor, and applies it to water purification equipment, which can make the water quality monitoring data of the equipment more accurate and more reliable, and extend the service life of the water purification equipment and the TOC sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the structure of a water purification device proposed in Embodiment 2 of the present invention;

[0033] Figure 2 It is the flowchart for the TOC sensor in Example 2 to perform self-calibration of the raw water TOC value;

[0034] Figure 3 It is the flowchart for the TOC sensor in Example 2 to perform self-calibration of the pure water TOC value;

[0035] Figure 4 It is Example 1 for the sensor to perform self-calibration on the collected pure water TOC value;

[0036] Figure 5 It is Example 2 for the sensor to perform self-calibration on the collected pure water TOC value;

[0037] Figure 6 It is Example 3 for the sensor to perform self-calibration on the collected pure water TOC value. Detailed implementation manners

[0038] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Embodiment

[0039] This embodiment provides a TOC sensor self-calibration method, including the steps:

[0040] Raw water self-calibration: Collect the raw water TOC value X, compare it with the preset raw water TOC threshold, and determine whether to perform immediate calibration according to the comparison result;

[0041] Pure water self-calibration: Collect the pure water TOC value, compare it with the preset pure water TOC threshold, and determine whether to perform immediate calibration and delayed calibration according to the comparison result;

[0042] Among them, the immediate calibration is to calibrate the current single sampling result, and the delayed calibration is to comprehensively calibrate the multiple sampling results. When calibration is not required, the corresponding raw water TOC value or pure water TOC value is output.

[0043] The TOC sensor self-calibration method can alternately perform the raw water self-calibration and pure water self-calibration steps. For example, it is set to first collect the raw water by default, then collect the purified water, and then alternate. There are multiple preset pure water TOC thresholds, which are used to divide the pure water TOC into multiple standards. For example, the pure water TOC thresholds P1, P2, and P3 are set, where P1 < P2 < P3, corresponding to the three standards of excellent, good, and poor.

[0044] Specifically, it includes the steps:

[0045] During raw water self-calibration, collect the raw water TOC value X, compare X with the preset raw water TOC threshold R. If X ≤ R, no calibration is required; if X > R, immediate calibration is performed;

[0046] When the raw water is self-calibrated, the TOC value Y of pure water is collected, and Y is compared with the preset pure water TOC thresholds P1, P2, and P3, where P1 < P2 < P3, that is:

[0047] If Y < P1, it is judged whether the current is in the delayed calibration state. If so, the delayed calibration is exited and immediate calibration is performed; if not, immediate calibration is performed.

[0048] If P1 ≤ Y < P2, it is judged whether the current is in the delayed calibration state. If so, after multiple delayed calibrations are accumulated, the delayed calibration is exited; if not, no calibration is required.

[0049] If P2 ≤ Y < P3, immediate calibration is performed. After the immediate calibration ends, delayed calibration is started.

[0050] If Y ≥ P3, immediate calibration is performed; if the cumulative number of times of Y meets Y > P3, after the immediate calibration ends, delayed calibration is started.

[0051] Among them, after the immediate calibration of the raw water TOC value, the first calibrated TOC value is output X’ , after the immediate calibration of the pure water TOC value, the second calibrated TOC value is output Y’ , and the third calibrated TOC value is output after the delayed calibration Y’’ .

[0052] The self-calibration target of the raw water TOC value X is to make the output raw water TOC value less than or equal to the raw water TOC threshold R;

[0053] The self-calibration target of the pure water TOC value Y is to make the output pure water TOC value within the range of (P1, P2). Embodiment

[0054] This embodiment provides a TOC sensor, including a water inlet, a water outlet, and a detection chamber. A TOC value acquisition device and a microprocessor are provided in the detection chamber. A self-calibration module is provided in the microprocessor. Among them, the TOC value acquisition device is used to collect the raw water TOC value or the pure water TOC value input from the water inlet and send it to the self-calibration module. The self-calibration module is used to determine whether to perform raw water self-calibration or pure water self-calibration according to the received data. The microprocessor is used to output the TOC value that does not require calibration or the self-calibrated TOC value.

[0055] Preferably, a data interaction module is further provided in the microprocessor for receiving instructions sent by external devices. If the TOC sensor has a single water inlet, the TOC sensor itself cannot know whether the currently collected is raw water or purified water. It can be known whether the current input is raw water or purified water through the processor of the device to which the TOC sensor is applied, such as a water purification device. The TOC sensor can also be provided with an independent raw water inlet and a pure water inlet. Example

[0056] like Figure 1 As shown, a water purification device capable of automatically calibrating a TOC sensor includes an RO filter element, a raw water solenoid valve, a pure water solenoid valve, a water intake valve, a TOC sensor and a processor. Figure 1 In the process, the processor is the processor of the water purification equipment, which is responsible for the control of the water purification equipment, the module status control, and the summary of the module reported data. The TOC sensor has a microprocessor inside, which is responsible for controlling the TOC sensor to collect data and judge the collected data. When the data is normal, it is directly sent to the water purification equipment processor, and when the data is abnormal, it is self-calibrated.

[0057] The water inlet of the water purification equipment passes through a three-way pipe, the first output is the input of the raw water solenoid valve, and the second output is the input of the RO filter element; the raw water is filtered by the RO filter element to produce pure water and part of the waste water, and the waste water output is the waste water outlet of the water purification equipment. A three-way pipe is set for the pure water output, the first output is the water intake valve, and the second output is the input of the pure water solenoid valve; the water intake valve output is the water outlet of the water purification equipment, the raw water solenoid valve and the pure water solenoid valve output are the TOC sensor input, and the TOC sensor output is the waste water outlet of the water purification equipment.

[0058] The processor includes a control module, the output end of the control module is connected with the raw water solenoid valve, the pure water solenoid valve, the water intake valve, and the TOC sensor; the input end of the control module is connected with the TOC sensor.

[0059] Among them, the TOC sensor has a self-calibration function. Self-calibration includes immediate calibration and delayed calibration. Immediate calibration is to calibrate the current single sampling result, and delayed calibration is to perform a comprehensive calibration on multiple sampling results. Delayed calibration is only for pure water TOC sampling.

[0060] 1. The working principle of the water purification device capable of automatically calibrating the TOC sensor of this embodiment is as follows:

[0061] When the water purification equipment is working, the raw water solenoid valve, pure water solenoid valve and water intake valve cannot be opened at the same time; when the raw water solenoid valve is opened, the pure water solenoid valve and the water intake valve are closed, and the TOC sensor collects raw water TOC data; when the pure water solenoid valve is opened, the raw water solenoid valve and the water intake valve are closed, and the TOC sensor collects pure water TOC data; when the water intake valve is opened, the raw water solenoid valve and the pure water solenoid valve are closed, and the user is now in the water intake state.

[0062] (1) When collecting raw water TOC, the processor control module closes the pure water solenoid valve and the water intake valve, opens the raw water solenoid valve, and the raw water flows directly into the TOC sensor through the raw water solenoid valve and finally flows to the wastewater outlet for discharge. The TOC sensor can collect raw water TOC after a period of water flow, such as 10-30 seconds.

[0063] The process of self-calibration of raw water TOC reading is as follows: Figure 2 As shown in the figure, the TOC sensor collects the raw water TOC value X. If X∈(-∞, R], no calibration is required and the output result is X; if X∈(R, +∞), an immediate calibration is performed and the output result is X’ The goal of the raw water TOC reading self-calibration is to "keep the output raw water TOC sampling results within the range of (R, +∞), which is consistent with the normal raw water TOC reading range."

[0064] For example: Let R = 1.0. When the raw water TOC reading is <1.0, it is determined that no calibration is required; if the TOC reading is >1.0, it is determined that an immediate calibration is required.

[0065] (2) When collecting pure water TOC, the processor control module closes the raw water solenoid valve and the water intake valve, opens the pure water solenoid valve, and the raw water is first filtered through the RO filter element. Some waste water is discharged through the wastewater outlet. Pure water flows into the TOC sensor through the pure water solenoid valve and finally flows to the wastewater outlet for discharge. The TOC sensor can collect pure water TOC after a period of water flow.

[0066] Pure water TOC reading self-calibration process is as follows Figure 3 As shown, the TOC sensor reads the pure water TOC value as Y:

[0067] If Y satisfies the relationship Y∈[P3, +∞), then immediate calibration is performed and the output result is Y’ ; If the relationship Y∈(P3, +∞) is satisfied for M consecutive times, delay calibration is started, M≥Mmax, Max is the preset maximum number of times;

[0068] If Y satisfies the relationship Y∈[P2, P3), then immediate calibration is performed and the result is output Y’ , and turn on delay calibration;

[0069] If Y satisfies the relationship Y∈[P1, P2) and is in the delay calibration state, then delay calibration is performed and the output result is Y’’ , after performing delay calibration N times cumulatively, exit delay calibration, N ≥ Nmax, Nmax is the preset maximum number of times;

[0070] If Y satisfies the relationship Y∈[P1, P2) and is not currently in the delayed calibration state, no calibration is required and the result Y is output;

[0071] If Y satisfies the relationship Y∈(-∞, P1), then immediate calibration is performed and the output result is Y’ If the delay calibration has not been exited at this time, then exit the delay calibration.

[0072] The goal of the pure water TOC reading self-calibration is to "keep the output pure water TOC sampling results within the range of (P1, P2) and in line with the normal pure water TOC reading range."

[0073] The above thresholds R, P1, P2, and P3 are all set according to the TOC content requirements of raw water and pure water. For example, the TOC value of raw water is generally not less than 1.0, and the TOC of pure water after passing through the RO filter should generally be between 0 and 0.3. The TOC sensor has no clear restriction on the calibration order of raw water and pure water TOC values, and they can be performed alternately.

[0074] 2. Self-calibration example of three sets of collected pure water TOC readings

[0075] like Figures 4 to 6 As shown in the figure, according to the characteristics of the RO filter element, in the three examples, P1 is set to 0, P2 is set to 0.3, P3 is set to 1, N=10, and M=20. In the example, the horizontal axis is the sampling number, and the vertical axis is the TOC sampling result output after algorithm calibration, in mg / L.

[0076] like Figure 4 As shown, the data of the TOC sensor in this example has a downward drift problem. In the figure, the original pure water TOC readings of sampling points 1-4 are less than 0. After confirming that the delayed calibration state has been exited, the sensor immediately calibrates the pure water data of sampling points 1-4 according to the self-calibration algorithm. After calibration, the output data is between 0-0.1, and the pure water TOC readings are effectively corrected. In the figure, the original pure water TOC readings of sampling points 5-35 are between 0-0.3, and the sensor has exited the delayed calibration state, so the original pure water TOC readings are directly output. Figure 4 It can be seen that the pure water TOC reading after correction by the self-calibration algorithm is basically stable in the range of 0.1±0.05.

[0077] like Figure 5 As shown, the data of the TOC sensor in this example has an upward drift problem. In the figure, the original pure water TOC readings of sampling points 1-20 are greater than 1. The sensor immediately calibrates the pure water data of sampling points 1-20 according to the self-calibration algorithm; the pure water TOC data outputted by 20 immediate calibrations is 0.3, so the sensor turns on the delayed calibration mode, and performs 10 delayed calibrations on the original pure water TOC readings in sampling times 21-30. After calibration, the output pure water TOC readings gradually decrease from 0.3 to 0.1; after 10 delayed calibrations, the original pure water TOC readings of the sampling points starting from the 31st are between 0-0.3, and the sensor has undergone 10 delayed calibrations. At this time, the sensor exits the delayed calibration state and directly outputs the original pure water TOC readings as the final result. Figure 5 It can be seen that the pure water TOC reading after correction by the self-calibration algorithm is basically stable in the range of 0.1±0.05.

[0078] like Figure 6 In this example, the TOC sensor sampling time is magnified to facilitate observation of the actual occurrence of sensor drift issues. Figure 5 Example 2: After 20 immediate calibrations and 10 delayed calibrations, the sensor's pure water TOC readings returned to the range of 0.1±0.05. From the pure water TOC readings at the 30th to 120th sampling points, it can be seen that the TOC sensor has an obvious upward drift problem. At the 121st sampling, the original pure water TOC reading reached between 0.3-1. The sensor performed an immediate calibration and turned on the delayed calibration mode. Ten delayed calibrations were performed on the original pure water TOC readings of the 122-131 samplings. After 10 delayed calibrations, the sensor's pure water TOC readings returned to the range of 0.1±0.05 starting from the 131st sampling. The sensor stopped delayed calibration and directly output the original pure water TOC reading. Figure 6 As shown in the figure, long-term use of normal TOC sensors will cause drift problems, which will interfere with the accuracy of TOC sampling data. However, through the optimization of the self-calibration algorithm, the accuracy of TOC sensor sampling data has been significantly improved.

[0079] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A TOC sensor self-calibration method, characterized in that: Including the steps: Raw water self - calibration: Collect the raw water TOC value, compare it with the preset raw water TOC threshold, and determine whether to perform immediate calibration according to the comparison result; Pure water self - calibration: Collect the pure water TOC value, compare it with the preset pure water TOC thresholds, and determine whether to perform immediate calibration and delayed calibration according to the comparison result. The immediate calibration is to calibrate the current single - sampling result, and the delayed calibration is to comprehensively calibrate the results of multiple samplings. When calibration is not required, output the corresponding raw water TOC value or pure water TOC value; During raw water self - calibration, collect the raw water TOC value X, compare X with the preset raw water TOC threshold R. If X ≤ R, then no calibration is required; if X > R, then perform immediate calibration; During pure water self - calibration, collect the pure water TOC value Y, compare Y with the preset pure water TOC thresholds P1, P2, P3, where P1 < P2 < P3, that is: If Y < P1, then determine whether the current is in the state of delayed calibration. If so, exit the delayed calibration and perform immediate calibration; if not, perform immediate calibration; If P1 ≤ Y < P2, then determine whether the current is in the state of delayed calibration. If so, perform multiple delayed calibrations cumulatively and then exit the delayed calibration; if not, no calibration is required; If P2 ≤ Y < P3, then perform immediate calibration. After the immediate calibration ends, start delayed calibration; If Y ≥ P3, then perform immediate calibration; if the cumulative preset number of immediate calibrations satisfies Y > P3, then after the immediate calibration ends, start delayed calibration; Among them, the raw water TOC value is immediately calibrated and the first calibration TOC value is output X’ , immediately calibrate the pure water TOC value and then output the second calibration TOC value Y’ , output the third calibration TOC value after delayed calibration Y’’ ; The self - calibration target of the raw water TOC value X is to make the output raw water TOC value less than or equal to the preset raw water TOC threshold R; The self - calibration target of the pure water TOC value Y is to make the output pure water TOC value within the range of the preset pure water TOC thresholds (P1, P2).

2. A TOC sensor, characterized in that: It includes a water inlet, a drain outlet, and a detection chamber. In the detection chamber, there is a TOC value collection device and a microprocessor. In the microprocessor, there is a self - calibration module. The TOC value collection device is used to collect the raw water TOC value or pure water TOC value input from the water inlet and send it to the self - calibration module. The self - calibration module is used to determine whether to perform raw water self - calibration or pure water self - calibration according to the received data. The self - calibration module executes the TOC sensor self - calibration method described in claim 1. The microprocessor is used to output the TOC value that does not require calibration or the self - calibrated TOC value.

3. A TOC sensor according to claim 2, characterized in that: The microprocessor also has a data interaction module for receiving instructions sent by external devices.

4. A water purification device, characterized in that: It includes a processor and the TOC sensor described in any one of claims 2 and 3. The processor is connected to the TOC sensor, and the TOC sensor sends the TOC value that does not require calibration or the self - calibrated TOC value to the processor.

5. A water purification device according to claim 4, characterized in that: The water purification device further includes a water inlet, a wastewater outlet, a water outlet, a filter element, a raw water solenoid valve, a pure water solenoid valve, and a water intake valve; The water inlet is used to input raw water. The water inlet is connected to the raw water solenoid valve and the input end of the filter element through a three - way pipeline. After the raw water is filtered by the filter element, pure water and wastewater are generated. The wastewater is discharged through the wastewater outlet, and the pure water is connected to the input ends of the water intake valve and the pure water solenoid valve through a three - way pipeline. The water intake valve is arranged at the water outlet. The output ends of the raw water solenoid valve and the pure water solenoid valve are connected to the water inlet of the TOC sensor, and the drain outlet of the TOC sensor is connected to the wastewater outlet through a pipeline; The processor comprises a control module, and the control module is connected to a TOC sensor, a water intake valve, a raw water solenoid valve and a pure water solenoid valve.

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