Automatic adding method and system for circulating water oxidizing bactericide

Abstract

The invention belongs to the technical field of circulating water quality monitoring, and provides an automatic feeding method and system for a circulating water oxidizing bactericide, which are used in a circulating water system and are used for monitoring an ORP (oxidation reduction potential) detection value and a residual chlorine detection value in real time and adjusting automatic feeding of the oxidizing bactericide according to the ORP detection value and the residual chlorine detection value. By means of the technical scheme, accurate control over the feeding amount of the oxidizing bactericide is achieved, so that continuous and stable operation of a circulating water system is maintained, the automatic feeding efficiency of the oxidizing bactericide of circulating water is improved, the using amount of the oxidizing bactericide is reduced, and the phenomenon of equipment corrosion caused by abnormal conditions such as leakage of reducing substances is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of circulating water quality monitoring, and particularly relates to an automatic dosing method and system for oxidizing biocides in circulating water. Background Art

[0002] At present, circulating water systems are widely used in various industries of modern industry. As a cooling medium, circulating water is widely used. During the continuous recycling process of circulating water in the system, it will be affected by various factors such as the hardness, pH value, concentration ratio, and massive reproduction of microorganisms of the circulating water, or due to the leakage of reducing substances, scaling or corrosion tendency will occur, affecting the safe and stable operation of the circulating water system, such as blocking pipelines, corroding equipment, etc., resulting in a reduction in the service life of the equipment. In order to inhibit the occurrence of scaling or corrosion, it is necessary to add chemicals, such as oxidizing biocides, to the circulating water pipeline to improve the water pipeline environment of the circulating water system and relieve corrosion and prevent scaling. However, the existing circulating water dosing process has a low degree of automation and mainly relies on manual dosing. On the one hand, the accuracy of manual dosing is poor, the labor intensity of personnel is high, and the interference of human factors is heavy, so the chemicals cannot be dosed in a timely and effective manner. On the other hand, manual dosing cannot make corresponding adjustments according to the changes in the quality of circulating water, and there are often phenomena of excessive dosing and insufficient dosing, with a certain lag.

[0003] Therefore, it is necessary to design an automatic dosing method or system for oxidizing biocides in circulating water that can solve at least some of the above problems and defects. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides an automatic dosing method and system for oxidizing biocides in circulating water. By real-time monitoring of the ORP detection value and the residual chlorine detection value, and accordingly adjusting the automatic dosing of the oxidizing biocide, precise control of the dosing amount of the oxidizing biocide is achieved, thereby maintaining the continuous and stable operation of the circulating water system, improving the automation dosing efficiency of the oxidizing biocide in circulating water, saving the usage amount of the oxidizing biocide, and reducing the occurrence of equipment corrosion caused by abnormal situations such as leakage of reducing substances.

[0005] The technical solution of the present invention is as follows: The present invention provides an automatic dosing method for oxidizing biocides in circulating water, and the method includes the following steps: S1, detecting the real-time ORP value of the circulating water; S2, determining whether the real-time ORP value is within the set range: If the real-time ORP value does not fall within the set range, jump to step S3; If the real-time ORP value falls within the set range, jump to step S5; S3. Determine whether it is necessary to add an oxidizing biocide based on the real-time ORP value and the upper and lower limit values of the set range: if it is necessary, jump to step S4; if it is not necessary, jump to step S7; S4. Adjust the dosing frequency of the oxidizing biocide according to the real-time ORP value; S5. Add the oxidizing biocide to the circulating water for a continuous dosing time of T; S6. Detect the real-time residual chlorine value of the circulating water and determine whether the real-time residual chlorine value reaches the set residual chlorine value: if the real-time residual chlorine value reaches the set residual chlorine value and the continuous dosing time T is within the system protection time T 0 then, jump to step S7; otherwise, perform a delay operation; S7. Stop adding the oxidizing biocide to the circulating water.

[0006] Preferably, S3 specifically includes the following steps: If the real-time ORP value is greater than the upper limit value of the set range, detect the real-time residual chlorine value of the circulating water and determine whether it reaches the set residual chlorine value: if the real-time residual chlorine value reaches the set residual chlorine value, jump to step S7; if the real-time residual chlorine value does not reach the set residual chlorine value, jump to step S4; If the real-time ORP value is less than the lower limit value of the set range, jump to step S4.

[0007] Preferably, the formula for adjusting the dosing frequency of the oxidizing biocide in S4 is as follows: , , wherein, F is the adjusted dosing frequency of the oxidizing biocide; is the initial dosing frequency of the oxidizing biocide before adjustment; M is the real-time ORP value; is the lower limit value of the ORP set range; RR is the unit time circulation volume of the circulating water; A is the preset value of the concentration of the oxidizing biocide in the circulating water; E is the full-load dosing frequency of the oxidizing biocide; is the density of the oxidizing biocide; Q is the maximum rated flow rate of the oxidizing biocide dosing.

[0008] Preferably, the delay operation in S6 specifically includes the following steps: Continue to add the oxidizing biocide to the circulating water for a continuous dosing time of t; If the real-time residual chlorine value reaches the set residual chlorine value, jump to step S7; If the real-time residual chlorine value still fails to reach the set residual chlorine value, stop adding the oxidizing biocide to the circulating water and issue an alarm.

[0009] Preferably, the present invention also provides an automatic dosing system for an oxidizing biocide in circulating water, including a central control unit storing the above-mentioned automatic dosing method for the oxidizing biocide in circulating water, and an on-line monitoring unit and a chemical dosing unit electrically connected to the central control unit; Both the on-line monitoring unit and the chemical dosing unit are connected to the circulating water.

[0010] Preferably, the automatic dosing system for the oxidizing biocide in circulating water provided by the present invention further includes a learning unit connected to the central control unit, and the learning unit is provided with a data learning model.

[0011] The present invention has the following advantages and effects compared with the prior art: The automatic dosing method and system for the oxidizing biocide in circulating water provided by the present invention realize precise control of the dosing amount of the oxidizing biocide by real-time monitoring of the ORP detection value and the residual chlorine detection value, and accordingly adjusting the automatic dosing of the oxidizing biocide, reducing the dosing amount of unnecessary oxidizing biocide, reducing the consumption of corrosion inhibitor in the circulating water, thus maintaining the continuous and stable operation of the circulating water system, improving the automatic dosing efficiency of the oxidizing biocide in the circulating water, saving the usage amount of the oxidizing biocide, reducing the occurrence of equipment corrosion caused by abnormal situations such as leakage of reducing substances, reducing the corrosion pressure of the circulating water system equipment and the increase of COD (chemical oxygen demand) caused by increasing the dosing amount of the corrosion inhibitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic flow chart of the automatic dosing method for the oxidizing biocide in circulating water in Embodiment 1 of the present invention; Figure 2 is a schematic structural diagram of the automatic dosing system for the oxidizing biocide in circulating water in Embodiment 2 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] In order to enable those skilled in the art to better understand the present invention, the present invention will be further described in more detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only for explaining and illustrating the present invention, and are not used to limit the present invention.

[0014] Embodiment 1: As Figure 1 shown, the present invention provides an automatic dosing method for an oxidizing biocide in circulating water, which is used in a circulating water system. The method includes the following steps: S1. Detect the real-time ORP value of the circulating water through an ORP monitor connected to the circulating water. S2. Determine whether the real-time ORP value is within the set range. For example, set the peak value of residual chlorine in a certain circulating water system to 0.2 mg / L, and the corresponding ORP value is 300 mv (for the same circulating water system, the residual chlorine and the ORP value are relatively stable and corresponding). The set range of ORP is 150 mv - 350 mv: If the real-time ORP value does not fall within the set range, jump to step S3; If the real-time ORP value falls within the set range, jump to step S5; S3. Determine whether to add an oxidizing biocide (in this embodiment, sodium hypochlorite with a mass concentration of 10% is used) based on the real-time ORP value and the upper and lower limit values of the set range: If it is necessary, jump to step S4; if it is not necessary, jump to step S7. It should be noted that under normal circumstances, when the residual chlorine value reaches the set peak value once a day, the addition of the oxidizing biocide for that day can be stopped.

[0015] Specifically, determining whether to add an oxidizing biocide based on the real-time ORP value and the upper and lower limit values of the set range in S3 includes the following steps: If the real-time ORP value is greater than the upper limit value of the set range, detect the real-time residual chlorine value of the circulating water and determine whether it reaches the set residual chlorine value: If the real-time residual chlorine value reaches the set residual chlorine value, jump to step S7; if the real-time residual chlorine value does not reach the set residual chlorine value, jump to step S4. That is, first, detect and judge whether to add an oxidizing biocide through the real-time ORP, and then adjust the dosage of the oxidizing biocide by detecting and judging the residual chlorine value. Compared with controlling the addition of the oxidizing biocide solely by the ORP value or the residual chlorine value, the dosage of the unnecessary oxidizing biocide can be reduced, thereby reducing the consumption of corrosion inhibitors (including carbon steel corrosion inhibitors and copper corrosion inhibitors, etc.) in the circulating water, reducing the corrosion pressure of the equipment in the circulating water system, and the phenomenon of increased COD in the circulating water caused by increasing the dosage of the corrosion inhibitor.

[0016] If the real-time ORP value is less than the lower limit value of the set range, jump to step S4.

[0017] S4. Adjust the dosing frequency of the oxidizing biocide according to the real-time ORP value. Among them, the formula for adjusting the dosing frequency of the oxidizing biocide is as follows: , , In the formula, F is the adjusted dosing frequency of the oxidizing biocide, with the unit of Hz; is the initial dosing frequency before the adjustment of the oxidizing biocide, with the unit of Hz; M is the real-time ORP value, with the unit of mv; is the lower limit value of the ORP set range, with the unit of mv; RR is the circulation volume per unit time of the circulating water, with the unit of m³ / h; A is the preset value of the concentration of the oxidizing biocide in the circulating water, with the unit of mg / L; E is the full-load dosing frequency of the oxidizing biocide, with the unit of Hz; is the density of the oxidizing biocide, with the unit of g / L; Q is the maximum rated flow rate of the oxidizing biocide dosing, with the unit of L / h; Among them, is the lower limit value of the set range of the oxidation-reduction potential (ORP) set by the technical personnel according to the circulating water and the actual on-site situation, and is determined by the initial ORP value of the circulating water. When the real-time ORP value M is lower than this value At this time, we believe that there are reducing substances in the circulating water (including reducing gases in the air, such as H 2 S, etc. absorbed by the circulating water) entering the circulating water, resulting in the real-time ORP value M in the circulating water , making 0 < 1 - M / ≤1 (generally, M ≥ 0). At this time, it is necessary to increase the dosing amount of the oxidizing biocide to maintain the concentration of the oxidizing biocide in the circulating water. At the same time, because the real-time ORP value M is lower than the lower limit value of the set range , if the dosing is carried out according to the initial dosing frequency , it will cause the dosing amount of the oxidizing biocide to increase but be insufficient to quickly and efficiently restore the concentration of the oxidizing biocide in the circulating water to the set concentration A. Therefore, it is necessary to increase the dosing frequency, that is .

[0018] Similarly, if the circulating water does not leak and due to the relatively large dosing amount of the oxidizing biocide before, resulting in the real-time ORP value M > (the real-time ORP value is within the set range), making -1 < 1 - M / M 0 <0, so that 0 < 1 + 1 - M / M 0 <1. At this time, it is necessary to reduce the dosing amount of the oxidizing biocide to avoid over-dosing. Therefore, the dosing frequency F of the oxidizing biocide needs to be adjusted and reduced.

[0019] In addition, the initial dosing frequency before the adjustment of the oxidizing biocide It is set under the condition that there is no leakage in the circulating water initially. Among them, the circulating volume RR of the circulating water per unit time, the preset value A of the concentration of the oxidizing biocide in the circulating water, the dosing frequency E of the oxidizing biocide under the full-load state of the circulating water system, and the maximum rated flow rate Q of the oxidizing biocide dosing are all set according to the actual situation of the circulating water. The density of the oxidizing biocide is set according to the specific oxidizing biocide adopted. At the same time, since the commonly used oxidizing biocides in circulating water are chlorine-based and bromine-based (of course, other types of oxidizing biocides can also be used), which are substances that are easily decomposed by heat and light, the normal dosing amount is usually calculated according to the circulating volume of the circulating water. For example, the common oxidizing biocide is sodium hypochlorite with a mass concentration of 10%.

[0020] The oxidizing biocide mentioned in this application can specifically be any one or more of aqueous sodium hypochlorite solution (generally with an available chlorine of 8% - 12%), sodium hypobromite, liquid chlorine, chlorine dioxide, sodium dichloroisocyanurate, trichloroisocyanuric acid, and sodium trichloroisocyanurate. The dosing methods for the above-mentioned oxidizing biocides are all applicable to this application. It should be noted that the above-mentioned oxidizing biocides are only listed, not exhaustive. At the same time, the oxidizing biocide specifically used in Example 1 is sodium hypochlorite with a mass concentration of 10%.

[0021] It should be noted that in this embodiment, a dosing pump connected to the circulating water is used to dose the oxidizing biocide. Therefore, the corresponding dosing frequency is in the unit of Hz, and E corresponds to the dosing frequency of the dosing pump in the full-load state in the circulating water. For example, 50 Hz. At the same time, the preset value A of the concentration of the oxidizing biocide in the circulating water can be set according to actual needs, such as 5 mg / L.

[0022] S5, Add an oxidizing biocide to the circulating water, and the continuous dosing time is T; S6, Detect the real-time residual chlorine value of the circulating water, and judge whether the real-time residual chlorine value reaches the set residual chlorine value: If the real-time residual chlorine value reaches the set residual chlorine value and the continuous dosing time T is within the system protection time then jump to step S7, otherwise perform a delay operation; It should be noted that the dosing time T of the oxidizing biocide should not be greater than the system protection time , where the system protection time can be changed and set according to different circulating water systems, such as 3 hours or 4 hours.

[0023] Among them, the delay operation specifically includes the following steps: Continue to add an oxidizing biocide to the circulating water, and the continuous dosing time is t, where t is less than the continuous dosing time T in step S5, for example, 1 hour; If the real-time residual chlorine value reaches the set residual chlorine value, then jump to step S7; If the real-time residual chlorine value still fails to reach the set residual chlorine value, stop adding the oxidizing biocide to the circulating water and issue an alarm to request manual intervention. The equipment supplier will remotely assist in preliminarily determining the reason for the excessive addition of the oxidizing biocide on-site. If the problem can be solved through remote assistance, it will reduce the cost of the equipment supplier and the time required for on-site timely response to the problem, and avoid the corrosion of the circulating water system caused by the automatic addition of the oxidizing biocide by the equipment, especially the corrosion of copper materials.

[0024] S7. Stop adding the oxidizing biocide to the circulating water, that is, stop adding the oxidizing biocide within the current day. Specifically, the equipment for adding the oxidizing biocide can use a variable-frequency diaphragm metering pump, so as to automatically adjust the operating frequency of the pump body according to the dosing frequency F in step S4, so as to ensure that the oxidizing biocide in the circulating water system is at a relatively stable concentration level of reasonable dosing, avoid large fluctuations in the chemical agent concentration caused by abnormal consumption of the system, and avoid the consumption of the oxidizing biocide due to the leakage of reducing substances in the environment or heat exchange system, so that the circulating water system is always in a stable operating state, and avoid the loss of control of microorganisms in the circulating water system caused by a short-term decrease in the chemical agent concentration, resulting in the deposition of microbial slime on the heat exchanger of the circulating water system. It should be noted that the actual specific setting value can be adjusted according to the actual situation control and operation indicators of the circulating water system.

[0025] Embodiment 2: For Embodiment 2 of the present invention, use Figure 2 to illustrate. In addition, the parts that are not different from Embodiment 1 are omitted from the description.

[0026] As Figure 2 shown, the automatic dosing system for oxidizing biocide in circulating water involved in the present invention includes a central control unit storing the automatic dosing method for oxidizing biocide in circulating water described in Embodiment 1, and an on-line monitoring unit and a chemical agent dosing unit electrically connected to the central control unit; the on-line monitoring unit and the chemical agent dosing unit are both connected to the circulating water.

[0027] The on-line monitoring unit includes an ORP monitor and a residual chlorine monitor respectively connected to the circulating water. Specifically, the ORP monitor and the residual chlorine monitor each have at least one monitoring probe immersed in the circulating water. The chemical dosing unit includes a regulating valve and a chemical dosing pump connected to the circulating water, wherein the chemical dosing pump is a variable-frequency diaphragm metering pump, and the central control unit includes a DCS control module. The ORP monitor and the residual chlorine monitor of the on-line monitoring unit are both electrically connected to the central control unit to transmit the on-line real-time monitored circulating water quality state data to the central control unit. The central control unit calculates the chemical dosing control data of the oxidizing biocide (including dosing frequency, dosing time, dosing amount) according to the data obtained from the above detections. The chemical dosing unit is electrically connected to the central control unit to receive the chemical dosing control data of the central control unit, and thus automatically doses the chemical according to the dosing control data.

[0028] Further, the automatic dosing system for the circulating water oxidizing biocide further includes a learning unit connected to the central control unit. The learning unit is provided with a data learning model, which can receive and process the historical data and set data stored in the central control unit, and can compare the real-time data detected by the on-line monitoring unit with the historical data and set data, so as to confirm whether the dosing amount of the oxidizing biocide is abnormal, and further determine whether there is an environmental leakage in the circulating water system or the circulating water system leakage causes a large consumption of the oxidizing biocide, avoiding the corrosion of the metal materials in the circulating water system caused by excessive dosing of the oxidizing biocide.

[0029] In summary, the automatic dosing method and system for the circulating water oxidizing biocide provided by the present invention realize the precise control of the dosing amount of the oxidizing biocide by real-time monitoring of the ORP detection value and the residual chlorine detection value, and accordingly cooperate to adjust the automatic dosing of the oxidizing biocide, thus maintaining the continuous and stable operation of the circulating water system, improving the automatic dosing efficiency of the oxidizing biocide in the circulating water, saving the usage amount of the oxidizing biocide, and reducing the occurrence of equipment corrosion caused by abnormal situations such as the leakage of reducing substances.

[0030] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent changes and modifications made according to the scope of the present invention should still fall within the scope covered by the present invention.

Claims

1. A method for automatically adding an oxidizing bactericide to circulating water, characterized in that: The method comprises the following steps: S1, detect the real-time ORP value of circulating water; S2, determine whether the real-time ORP value is within the set range: If the real-time ORP value does not fall within the set interval, jump to step S3; If the real-time ORP value falls within the set interval, jump to step S5; S3, judging whether it is necessary to add oxidizing bactericide according to the real-time ORP value and the upper and lower limits of the set interval range: if necessary, jump to step S4, if not, jump to step S7; S4, adjusting the dosing frequency of the oxidizing bactericide according to the real-time ORP value; S5, adding oxidizing bactericide to the circulating water for a continuous adding time of T; S6, detect the real-time residual chlorine value of the circulating water, and determine whether the real-time residual chlorine value reaches the set residual chlorine value: if the real-time residual chlorine value reaches the set residual chlorine value and the continuous addition time T is within the system protection time If yes, then jump to step S7, otherwise perform the delay operation; S7, stop adding oxidizing bactericide to the circulating water.

2. The method for automatically adding oxidizing bactericide to circulating water according to claim 1, characterized in that: S3 specifically includes the following steps: If the real-time ORP value is greater than the upper limit of the set interval, the real-time residual chlorine value of the circulating water is detected and it is determined whether it reaches the set residual chlorine value: if the real-time residual chlorine value reaches the set residual chlorine value, jump to step S7; if the real-time residual chlorine value does not reach the set residual chlorine value, jump to step S4; If the real-time ORP value is less than the lower limit of the set interval range, jump to step S4.

3. The method for automatically adding oxidizing bactericide to circulating water according to claim 1, characterized in that: The formula for adjusting the frequency of adding oxidizing fungicides in S4 is as follows: ， ， In the formula, F is the adjusted dosing frequency of the oxidizing bactericide; It is the initial dosing frequency of the oxidizing fungicide before adjustment; M is the real-time ORP value; Set the lower limit of the interval range for ORP; RR is the circulation volume of circulating water per unit time; A is the preset value of the concentration of oxidizing bactericide in the circulating water; E is the full-load dosing frequency of the oxidizing bactericide; is the density of the oxidizing bactericide; Q is the maximum rated flow rate of oxidizing bactericide.

4. The method for automatically adding oxidizing bactericide to circulating water according to claim 1, characterized in that: The delay operation in S6 specifically includes the following steps: Continue to add oxidizing bactericide to the circulating water for a continuous adding time of t; If the real-time residual chlorine value reaches the set residual chlorine value, jump to step S7; If the real-time residual chlorine value still does not reach the set residual chlorine value, stop adding oxidizing disinfectant to the circulating water and sound an alarm.

5. A circulating water oxidizing bactericide automatic dosing system, characterized by: It comprises a central control unit storing the method for automatically adding an oxidizing bactericide to circulating water according to any one of claims 1 to 4, and an online monitoring unit and a reagent adding unit electrically connected to the central control unit; The online monitoring unit and the drug adding unit are both connected to the circulating water.

6. The automatic dosing system of circulating water oxidizing bactericide according to claim 5 is characterized in that: It also includes a learning unit connected to the central control unit, and the learning unit is provided with a data learning model.

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