CN115015485A - Online monitoring model and system of available chlorine concentration in effluent of slightly acidic electrolyzed water generator - Google Patents

Abstract

The invention discloses an online monitoring model and system for the effective chlorine concentration in the effluent of a slightly acidic electrolyzed water generator. In practical application, under the guidance of the model and using several parameters collected online, the slightly acidic electrolysis can be better predicted. The effective chlorine concentration in the effluent of the water generator can quickly realize the rapid detection of the effective chlorine concentration in the effluent of the slightly acidic electrolyzed water generator, which has more production and application value.

Description

Model and system for online monitoring of available chlorine concentration in effluent from slightly acidic electrolyzed water generators

technical field

The invention relates to the field of artificial intelligence and on-line monitoring, in particular to an on-line monitoring model and system based on the effluent effective chlorine concentration of a slightly acidic electrolyzed water generator.

Background technique

Slightly acidic electrolyzed water generator refers to a device that uses a non-diaphragm electrolytic cell to electrolyze an aqueous hydrochloric acid solution to generate an acidic aqueous solution (pH 5.0-6.5) with hypochlorous acid as the main component. Slightly acidic electrolyzed water has developed rapidly in China in recent years due to its high sterilization efficiency, high safety, and no residue. .

The bactericidal ability of slightly acidic electrolyzed water is mainly affected by the concentration of available chlorine, so it is extremely important to detect the available chlorine concentration in the effluent of the slightly acidic electrolyzed water generator immediately. Currently, there are three main testing methods for available chlorine concentration:

(1) Iodometric titration method: The iodometric titration method uses available chlorine and potassium iodide in slightly acidic electrolyzed water to oxidize, and then uses sodium thiosulfate standard solution to titrate iodine, and calculates according to the consumption of sodium thiosulfate standard solution. Available chlorine content. This method is often used in laboratory testing, and the reagents used are cumbersome and cannot achieve instant and rapid testing.

(2) Portable instrument rapid detection method: The portable instrument rapid detection method is to use o-bitoluene to react with the residual chlorine in the water, the solution turns yellow, and the effective chlorine concentration is calculated by the absorbance. The detection speed of this method is fast, and the equipment is easy to carry, but it also has the problem that it cannot be tested in real time.

(3) Sensor online detection method: The sensor online detection method uses a Clark-type current sensor, which is manufactured by microelectronics technology, and is used to measure the concentration of hypochlorous acid (HOCl) in water. The sensor consists of small electrochemical three electrodes, one working electrode (WE), one counter electrode (CE) and one reference electrode (RE). The method of measuring the concentration of hypochlorous acid (HOCl) in water is based on measuring the current change of the working electrode due to the change of the concentration of hypochlorous acid.

However, the existing available chlorine online sensor technology is still immature, and there are problems such as poor stability and high cost.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the background technology, the purpose of the present invention is to provide a model machine system for online monitoring of available chlorine concentration in the effluent of a slightly acidic electrolyzed water generator. It can be fast, stable and can realize the real-time detection of the effective chlorine concentration value.

The technical scheme adopted by the present invention to solve its technical problems is:

An on-line monitoring model of available chlorine concentration in the effluent of a slightly acidic electrolyzed water generator, the on-line monitoring model is as follows:

Where: Y is the available chlorine concentration of slightly acidic electrolyzed water, mg/L;

I is the electrolytic current, A;

Q is the water flow rate, L/min;

C is the electrolyte concentration, g/100mL;

T is the inlet water temperature, °C;

P is the pH of the influent;

i is the first influence coefficient, when 0 < Q < 3, the value of i is between 0.9-0.95; when Q≥3 , i= 1,

α is the second influence coefficient, when C ≥ 2.5, α = 1; 0 < C < 2.5, α is between 0.95-0.98;

β represents the time node, which is a positive number, and Y ^β represents the available chlorine concentration Y of the slightly acidic electrolyzed water at the β time point.

In general, when it is used for daily surface disinfection of objects, the online monitoring model is simplified as follows:

Y = 38.101 + 40.298 I - 16.205 Q + 1.248 C - 0.303 T + 0.086 P

In the formula: Y is the concentration of available chlorine, mg/L; I is the electrolysis current, A; Q is the inlet water flow rate, L/min; C is the electrolyte concentration, g/100mL; T is the inlet water temperature, °C ; water pH.

The invention also discloses an on-line monitoring system based on the above-mentioned model, which mainly includes a water making part and a control part:

The described water production part includes an electrolysis system, a water inlet system and a sensor group; the electrolysis system is used for electrolysis to produce slightly acidic hypochlorous acid water; the water inlet system is used for mixing water with the slightly acidic hypochlorous acid water produced by electrolysis ; The sensor group includes a plurality of sensors for respectively acquiring the inlet water temperature value, the inlet water pH, and the electrolyte concentration value; the control part includes a calculation unit and a storage unit, the calculation unit calculates the beta time point micrometer according to the online monitoring model The available chlorine concentration Y ^β of the acidic electrolyzed water; the storage unit is used to record the available chlorine concentration Y β of the slightly acidic electrolyzed water at the time ^β .

More specifically, it also includes an analysis unit for analyzing |Y ^β -Y ^β-1 |, where |Y ^β -Y ^β-1 | means taking the absolute value of the difference between Y ^β and Y ^β-1 .

More specifically, it also includes an alarm unit, when |Y ^β -Y ^β-1 | is greater than the first set value, or when |Y ^β -Y ⁰ | is greater than the second set value, an alarm is issued, and Y ⁰ indicates slightly acidic The standard value of the available chlorine concentration of electrolyzed water, the first set value represents the fluctuation error of the available chlorine concentration of the slightly acidic electrolyzed water at adjacent times, and the second set value represents the deviation from the upper limit of the standard value of the available chlorine concentration of the slightly acidic electrolyzed water.

Further, the electrolysis system sequentially includes a peristaltic pump, an electrolytic cell and a mixer; the water inlet system sequentially includes a water inlet solenoid valve and a water inlet flowmeter; the sensor group includes an electrolyte concentration sensor, a temperature sensor and a pH sensor. Sensor; the electrolyte concentration sensor is set in the electrolysis system, and the temperature sensor and pH sensor are set in the water inlet system.

In addition, it also includes a digital display screen, which displays time, electrolysis current, inlet water flow rate, electrolyte concentration, inlet water temperature and inlet water pH in real time.

Compared with the background technology, the present invention has the following beneficial effects:

1) The rapid detection of the available chlorine concentration in the effluent of the slightly acidic electrolyzed water generator can be quickly realized;

2) The detection accuracy is not affected by the fluctuation of water flow. Compared with the traditional online detection method, the accuracy rate is higher;

3) Compared with the traditional online detection method, the hardware cost is greatly reduced, which has important practical significance.

Description of drawings

FIG. 1 is a schematic diagram of the online monitoring system of Embodiment 1. FIG.

In the figure, 1. Solenoid valve 2. Flow meter 3. Temperature sensor 4. pH sensor 5. Electrolyte concentration sensor 6. Peristaltic pump 7. Electrolyzer 8. Control module 9. Power supply 10. Mixer.

Detailed ways

Example 1

The present embodiment further specifically illustrates the on-line monitoring model and system of the available chlorine concentration in the effluent of the slightly acidic electrolyzed water generator of the present invention.

The online monitoring model of this example,

Where: Y is the available chlorine concentration of slightly acidic electrolyzed water, mg/L;

I is the electrolytic current, A;

Q is the water flow rate, L/min;

C is the electrolyte concentration, g/100mL;

T is the inlet water temperature, °C;

P is the pH of the influent;

i is the first influence coefficient, when 0 < Q < 3, the value of i is between 0.9-0.95; when Q≥3 , i= 1,

α is the second influence coefficient, when C ≥ 2.5, α = 1; 0 < C < 2.5, α is between 0.95-0.98;

β represents the time node, which is a positive number, and Y ^β represents the available chlorine concentration Y of the slightly acidic electrolyzed water at the β time point.

When the above formula is calculated, all parameters, according to the unit requirements, only take the value of each parameter.

In some scenarios, the requirements for the effective chlorine concentration of slightly acidic electrolyzed water need to be more precise, and the effective chlorine concentration value is relatively low, such as for the disinfection of human oral mucosa, the first influence coefficient and the second influence coefficient can be better corrected. Accuracy of available chlorine concentration in export slightly acidic electrolyzed water.

In many usage scenarios, when Q≥3 and C≥2.5 , it is used for daily surface disinfection of objects. The model is simplified as follows: Y = 38.101 + 40.298 I - 16.205 Q + 1.248 C - 0.303 T + 0.086 P .

In another embodiment, relying on the above simplified model, the online monitoring system of this example includes a water production part, a control part, an analysis unit, an alarm unit and a large digital display screen.

The described water production part includes an electrolysis system, a water inlet system and a sensor group; the electrolysis system is used for electrolysis to produce slightly acidic hypochlorous acid water; the water inlet system is used for mixing water with the slightly acidic hypochlorous acid water produced by electrolysis ; The sensor group includes a plurality of sensors, which are used to obtain the temperature value of the influent water, the pH value of the influent water, and the concentration value of the electrolyte respectively; Take the attached drawing 1 as an example, the solenoid valve 1 is opened, and electrolysis is started at the same time, and the pipeline of the water inlet is sequentially A flowmeter 2, a temperature sensor 3 and a pH sensor 4 are provided. The flowmeter 2 collects the influent flow velocity, the temperature sensor 3 collects the influent temperature, and the pH sensor 4 collects the influent pH, and the data is transmitted to the control part 8 at the same time. Electrolyte concentration sensor 5 is set on this pipeline of electrolysis to collect electrolyte concentration, peristaltic pump 6 supplies 0.6% hydrochloric acid electrolyte, electrolytic cell 7 electrolyzes hydrochloric acid, and the electrolytic current in electrolytic cell 7 is sent back to control part 8 at the same time, mixer 10 will The tap water and the electrolyzed water are mixed and output, and the power supply 9 supplies power for the entire system.

The control part includes a calculation unit and a storage unit, the calculation unit calculates the available chlorine concentration Y ^β of the slightly acidic electrolyzed water at the beta time point according to the online monitoring model, and displays it on the large screen in real time, and the storage unit is used to record the beta time point. The available chlorine concentration Y ^β of slightly acidic electrolyzed water is used for analysis by the analysis unit.

The analysis unit is used to analyze the |Y ^β -Y ^β-1 | value, where |Y ^β -Y ^β-1 | means to take the absolute value of the difference between Y ^β and Y ^β-1 .

Alarm unit, when |Y ^β -Y ^β-1 | is greater than the first set value, or |Y ^β -Y ⁰ | is greater than the second set value, an alarm is issued, Y ⁰ represents the standard of available chlorine concentration in slightly acidic electrolyzed water The setting of this standard value is generally determined according to the usage scenario of effective chlorine. For example, it can be set at 50mg/L for surface disinfection of objects, and 30mg/L for disinfection of hands and other skin contact. The first set value represents the fluctuation error of the effective chlorine concentration of slightly acidic electrolyzed water at adjacent times. The disinfection error of hands and other skin contact is generally set at 2 mg/L, and the environmental spray disinfection error is generally set at 10 mg/L. When it exceeds the first set value, it means that the system is unstable, and the various parameters of the system need to be checked after the alarm system issues an alarm. The second set value represents the deviation from the upper limit of the standard value of available chlorine concentration in slightly acidic electrolyzed water. For example, for general skin contact disinfection, the concentration of 20-30mg/L is suitable. If Y ⁰ is 25, the second set value It is 5mg/L. When an alarm is received, it means that the effective chlorine concentration of the effluent is not within 20-30mg/L, and a shutdown inspection is also required.

Digital display screen, real-time display of time, electrolysis current, inlet water flow rate, electrolyte concentration, inlet water temperature, inlet water pH and effective chlorine concentration, which is convenient to obtain relevant data in time.

Take the system of accompanying drawing 1 as an example, carry out the following experiments:

Turn on the slightly acidic electrolyzed water generator, set the inlet water flow rate 4L/min, inlet water temperature 25°C, inlet water pH value 7.2, electrolysis current 1.7A and electrolyte concentration 6.0g/100mL, at this time i= 1, α= 1 , Y = 38.101 + 40.298 I - 16.205 Q + 1.248 C - 0.303 T + 0.086 P . After the startup and operation are stable, the available chlorine concentration values at three times are randomly obtained, which are 42.5, 42.3, and 42.8 mg/L, and 100 mL of slightly acidic electrolyzed water is simultaneously sampled. The available chlorine concentrations tested by the iodometric method are 42, 41.7, and 42.2. mg/L. Taking the data of 42.3mg/L and 41.7mg/L as an example, the difference between the two is 1.4%.

The following experiment is performed with the sampling time after 3 minutes of booting:

Example 2:

Turn on the slightly acidic electrolyzed water generator, set the inlet water flow rate to 4L/min, the inlet water temperature to 25°C, the inlet water pH value to 7.2, the electrolysis current to 1.7A and the electrolyte concentration to 3.0g/100mL. The effective chlorine concentration obtained by the present invention It was 38.6mg/L, and 100mL of slightly acidic electrolyzed water was sampled simultaneously. The effective chlorine concentration was 37.5mg/L tested by iodometric method, and the difference between the two was 2.9%.

Example 3:

Turn on the slightly acidic electrolyzed water generator, set the inlet water flow rate to 3.2L/min, the inlet water temperature to 25°C, the inlet water pH value to 7.2, the electrolysis current to 2.1A and the electrolyte concentration to 6.0g/100mL. The concentration was 71.4mg/L, and 100mL of slightly acidic electrolyzed water was sampled simultaneously. The available chlorine concentration was 69.3mg/L tested by iodometric method, and the difference between the two was 3.0%.

Example 4:

Turn on the slightly acidic electrolyzed water generator, set the inlet water flow rate 3.2L/min, inlet water temperature 25°C, inlet water pH value 7.2, electrolysis current 1.6A and electrolyte concentration 3.0g/100mL, the effective chlorine obtained by the present invention The concentration was 47.5mg/L, and 100mL of slightly acidic electrolyzed water was sampled simultaneously. The available chlorine concentration was 46.6mg/L tested by iodometric method, and the difference between the two was 1.9%.

It has always been believed that the available chlorine concentration value determined by the iodometric method has high accuracy, but the disadvantage is that it is time-consuming. The test paper detection method is fast and portable, but at the same time compared with the data of the iodometric method, the subjective factor is large and the error is large, and the above-mentioned data of the present invention can fully illustrate: the method of the present invention is compared with the traditional iodometric method, and the method of real-time online monitoring , fast, portable and accurate.

Claims (7)

1. An on-line monitoring model for effective chlorine concentration of effluent of a subacid electrolyzed water generator is characterized by comprising the following steps:

wherein:Ythe unit is mg/L of the effective chlorine concentration of the subacid electrolyzed water;

Iis the electrolytic current, with unit A;

Qthe water inlet flow rate is L/min;

Cthe unit is g/100mL and is the concentration of electrolyte;

Tthe unit is the water inlet temperature;

Pis the influent pH;

ias the first coefficient of influence, when 0 <Q＜3，iThe value is between 0.9 and 0.95; when in useQ≥3，i=1，

αIs the second influence coefficient whenC≥2.5，α=1；0＜C＜2.5，αThe value is between 0.95 and 0.98;

beta represents a time node and takes the value of positive number, Y ^β Represents the effective chlorine concentration Y of the slightly acidic electrolyzed water at the time point of beta.

2. The on-line monitoring model of claim 1, wherein the on-line monitoring model is as follows:

Y = 38.101 + 40.298 I - 16.205 Q + 1.248C - 0.303 T + 0.086 P

in the formula:Yeffective chlorine concentration, mg/L;Iis the electrolysis current, A;Qthe water inlet flow rate is L/min;Cthe electrolyte concentration is g/100 mL;Tthe temperature of water inlet is DEG C;Pthe pH value of the inlet water is shown.

3. A system for on-line monitoring model according to claim 1, comprising a water production part and a control part:

the water making part comprises an electrolysis system, a water inlet system and a sensor group; the electrolysis system is used for electrolyzing to generate subacid hypochlorous acid water; the water inlet system is used for mixing water with subacidity hypochlorous acid water generated by electrolysis; the sensor group comprises a plurality of sensors for respectively acquiring an inlet water temperature value, an inlet water pH value and an electrolyte concentration value;

the control part comprises a calculation unit and a storage unit, wherein the calculation unit calculates the effective chlorine concentration Y of the beta-time-point subacid electrolyzed water according to an online monitoring model ^β (ii) a The storage unit is used for recording the effective chlorine concentration Y of the subacid electrolyzed water at the beta time point ^β 。

4. The on-line monitoring system of claim 3, further comprising an analysis unit for analyzing | Y |) ^β -Y ^β-1 |，|Y ^β -Y ^β-1 I represents taking Y ^β And Y ^β-1 The absolute value of the difference.

5. The on-line monitoring system of claim 4, further comprising an alarm unit, | Y ^β -Y ^β-1 If | is greater than the first set value, or | Y ^β -Y ⁰ When | is greater than the second set value, an alarm is given, Y ⁰ The effective chlorine concentration standard value of the subacid electrolyzed water is represented, the first set value represents the fluctuation error of the effective chlorine concentration of the subacid electrolyzed water at the adjacent moment, and the second set value represents the deviation from the upper limit of the effective chlorine concentration standard value of the subacid electrolyzed water.

6. The on-line monitoring system of claim 3, further comprising a digital display screen for displaying in real time the time, electrolysis current, influent water flow rate, electrolyte concentration, influent water temperature, influent water pH and available chlorine concentration.

7. The on-line monitoring system of claim 3, wherein the electrolysis system comprises a peristaltic pump, an electrolysis cell and a mixer in sequence; the water inlet system sequentially comprises a water inlet electromagnetic valve and a water inlet flowmeter; the sensor group comprises an electrolyte concentration sensor, a temperature sensor and a pH sensor; the electrolyte concentration sensor is arranged in the electrolysis system, and the temperature sensor and the pH sensor are arranged in the water inlet system.

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