An industrial circulating water pipeline corrosion control system and method

Abstract

This invention discloses a corrosion control system and method for industrial circulating water pipelines. The online corrosion testing unit includes a circulating water pump, a sampling flow meter, and an online corrosion rate tester. The circulating water pump inlet is connected to an industrial circulating water tower pool, and the circulating water pump outlet is connected to a connecting pipe, on which the sampling flow meter and the online corrosion rate tester are sequentially mounted. The water treatment unit includes a corrosion inhibitor section and a bypass water treatment section. The corrosion inhibitor section includes a corrosion inhibitor tank, and the outlet of the corrosion inhibitor tank is connected to the industrial circulating water tower pool via a corrosion inhibitor dosing pump. The bypass water treatment section includes a bypass water treatment system, and the inlet of the bypass water treatment system is connected to the outlet of the condenser cooling water. The PLC controller is electrically connected to the online corrosion measuring instrument, the sampling flow meter, the corrosion inhibitor dosing pump, and the bypass treatment system. This invention provides a convenient method for controlling corrosion in industrial circulating water pipelines without manual intervention.

Description

Technical Field

[0001] This invention relates to the field of industrial circulating water pipeline corrosion technology, and in particular to an industrial circulating water pipeline corrosion control system and method. Background Technology

[0002] Currently, most industrial circulating water systems do not have corrosion monitoring for pipelines, and water quality indicators are basically measured manually 1-2 times a day. Due to the long interval between manual sampling and the ease with which measurement errors are introduced, the operation of the circulating water system relies entirely on the experience of the operators, which increases the risk of corrosion of industrial circulating water pipelines and causes economic losses.

[0003] Since the control of corrosion in circulating water system pipelines includes two parts: corrosion inhibitors and circulating water bypass treatment, it is necessary to adjust the corrosion rate of the circulating water pipelines in real time. However, the application of online measurement of pipeline corrosion rate is relatively limited, which leads to non-standard operation of circulating water pipeline corrosion control and creates safety hazards. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention provides an industrial circulating water pipeline corrosion control system and method. Under normal operating conditions of the circulating water, the device automatically monitors the corrosion rate of the circulating water without manual intervention. After data collection, it automatically adjusts the dosage of corrosion inhibitor and the bypass system's treatment capacity to ensure that the pipeline corrosion rate operates near the expected value, thereby achieving corrosion control of industrial circulating water pipelines and facilitating the normal operation of the circulating water system.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An industrial circulating water pipeline corrosion control system includes an online corrosion testing unit, a water treatment system unit, and a control unit;

[0007] The online corrosion testing unit includes a circulating water pump, a sampling flow meter, and an online corrosion rate tester; the inlet of the circulating water pump is connected to the industrial circulating water tower pool, and the outlet of the circulating water pump is provided with a connecting pipeline, on which the sampling flow meter and the online corrosion rate tester are sequentially installed.

[0008] The water treatment unit includes a corrosion inhibitor section and a bypass water treatment section. The corrosion inhibitor section includes a corrosion inhibitor tank, and the outlet of the corrosion inhibitor tank is connected to the industrial circulating water tower pool through a corrosion inhibitor dosing pump. The bypass water treatment section includes a bypass water treatment system and a condenser. The inlet of the bypass water treatment system is connected to the outlet of the condenser cooling water, and the outlet of the bypass water treatment system is connected to the circulating water tower pool.

[0009] The control unit includes a PLC controller, which is electrically connected to the online corrosion measuring instrument, the sampling flow meter, the corrosion inhibitor dosing pump, and the bypass treatment system.

[0010] As a further improvement of the present invention, the outlet of the circulating water pump is also connected to the inlet of the condenser cooling water; the outlet of the condenser cooling water is also connected to the spray system of the circulating water tower.

[0011] As a further improvement of the present invention, the inlet of the sampling flow meter is also provided with a sampling inlet manual valve and a sampling flow electric valve; the sampling flow electric valve is electrically connected to the PLC controller.

[0012] As a further improvement of the present invention, the outlet of the online corrosion rate tester is also provided with a manual sampling outlet valve.

[0013] As a further improvement of the present invention, the inlet and outlet of the corrosion inhibitor dosing pump are respectively provided with a manual valve for the inlet of the corrosion inhibitor dosing pump and a manual valve for the outlet of the corrosion inhibitor dosing pump.

[0014] As a further improvement of the present invention, the PLC controller is connected to a touch screen.

[0015] A control method for an industrial circulating water pipeline corrosion control system includes the following steps:

[0016] The PLC controller receives the online corrosion instrument signal, compares it with the expected corrosion rate, calculates the difference, and then calculates the error value of the corrosion inhibitor dosing pump by multiplying the difference by the corrosion inhibitor allocation parameter Kj according to the allocation ratio coefficient. The frequency at this time is calculated using a PID control algorithm. The error value of the bypass water treatment system is multiplied by the bypass water treatment system allocation parameter Ks and used as the error value of the bypass water treatment system. The treatment capacity of the water treatment system at this time is calculated using a PID control algorithm.

[0017] As a further improvement of the present invention, the PLC controller controls the opening of the flow regulating electric valve through a PID control algorithm, so that the flow rate of the sampled water flowing through the corrosion online measuring instrument is consistent with the flow rate of the circulating water system itself.

[0018] As a further improvement of the present invention, the PLC controller further includes the following before receiving the online corrosion instrument signal:

[0019] Set the sampling flow rate PID, corrosion inhibitor dosing pump PID parameters, bypass water treatment system PID parameters, corrosion inhibitor distribution parameter Kj, bypass water treatment system distribution parameter Ks, and expected corrosion value for circulating water pipelines.

[0020] As a further improvement of the present invention, after the sampling flow meter collects the flow signal, it transmits the signal to the PLC controller. The PID calculation formula is as follows:

[0021]

[0022] Where Kp T is the proportionality coefficient. i Let T be the integration time constant. d Let e(t) be the differential time constant, e(t) be the difference between the expected value and the sampled value, and u(t) be the control variable.

[0023] e f (t) is the difference between the expected and actual flow rates, KF p TF is the flow ratio factor. i TF is the integral time constant of the flow rate. d The differential time constant of the flow rate is shown in the following equation.

[0024]

[0025] u F (t) represents the sampled flow rate calculated by the PID algorithm, indicating the opening degree of the electric valve. The PLC will then process u. F The magnitude of the (t) signal directly affects the sampling flow electric valve;

[0026] The online corrosion instrument signal is transmitted to the PLC controller and compared with the expected corrosion rate value to obtain the difference e. C (t) is calculated using the PID formula for the corrosion inhibitor dosing pump, where Kj is the distribution coefficient of the corrosion inhibitor dosing pump, and KP p TP is the proportional coefficient of the dosing pump. i TP is the integral time constant of the dosing pump. d The differential time constant of the dosing pump is shown in the following formula.

[0027]

[0028] u p (t) represents the frequency of the corrosion inhibitor dosing pump calculated by the PID algorithm, and the PLC will use u p The magnitude of the (t) signal directly affects the corrosion inhibitor dosing pump;

[0029] The calculation is performed using the PID formula for the bypass water treatment system, where Ks is the allocation coefficient of the bypass water treatment system, and KC... p TC is the proportional coefficient for the bypass water treatment system. i TC is the integral time constant of the bypass water treatment system. d The differential time constant of the bypass water treatment system is shown in the following equation.

[0030]

[0031] u C (t) represents the processing capacity of the bypass water treatment system calculated by the PID algorithm, and the PLC will output u CThe magnitude of the (t) signal directly affects the bypass water treatment system.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] This invention involves installing an online corrosion rate measuring instrument at the outlet of a circulating water pump, equipped with an electric regulating valve and a flow meter. By dynamically adjusting the flow rate of the circulating water corrosion rate measuring instrument based on the real-time signal of the circulating water flow, the corrosion rate of the circulating water pipeline can be dynamically measured. Based on the error between the corrosion rate signal and the desired value, the dosage of corrosion inhibitor is dynamically adjusted. Simultaneously, the treatment volume of a bypass system is used to ensure that the corrosion rate of the circulating water system pipeline remains stable at the desired value. This invention provides a convenient method for controlling corrosion in industrial circulating water pipelines without manual intervention.

[0034] This invention employs a segmented control method to manage the corrosion rate of a circulating water system, ensuring adequate dosage of corrosion inhibitor while fully utilizing the bypass treatment system. Continuous and automatic control of the corrosion rate without manual intervention improves the safety and economy of industrial circulating water system operation. Attached Figure Description

[0035] Figure 1 This invention relates to a corrosion control system for industrial circulating water pipelines.

[0036] Figure 2 This is a flowchart of the corrosion control method for industrial circulating water pipelines according to the present invention.

[0037] The components include: 1. Manual valve at the inlet of the corrosion inhibitor dosing pump; 2. Corrosion inhibitor dosing pump; 3. Manual valve at the outlet of the corrosion inhibitor dosing pump; 4. Circulating water pump; 5. Manual valve at the sampling inlet; 6. Electric valve for sampling flow; 7. Sampling flow meter; 8. Online corrosion rate tester; 9. Manual valve at the sampling outlet; 10. PLC controller; 11. Touch screen; 12. Corrosion inhibitor tank; 13. Circulating water tower; 14. Condenser; and 15. Bypass treatment system. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0039] The first objective of this invention is to provide an industrial circulating water pipeline corrosion control system, including an online corrosion testing unit, a water treatment system unit, and a control unit;

[0040] The online corrosion testing unit includes a circulating water pump 4, a sampling flow meter 7, and an online corrosion rate tester 8. The inlet of the circulating water pump 4 is connected to the water tank of the industrial circulating water tower 13, and the outlet of the circulating water pump 4 is provided with a connecting pipeline, on which the sampling flow meter 7 and the online corrosion rate tester 8 are sequentially installed.

[0041] The water treatment unit includes a corrosion inhibitor section and a bypass water treatment section. The corrosion inhibitor section includes a corrosion inhibitor tank 12, and the outlet of the corrosion inhibitor tank 12 is connected to the water tank of the industrial circulating water tower 13 via a corrosion inhibitor dosing pump 2. The bypass water treatment section includes a bypass water treatment system 15 and a condenser 14. The inlet of the bypass water treatment system 15 is connected to the outlet of the cooling water of the condenser 14, and the outlet of the bypass water treatment system 15 is connected to the water tank of the circulating water tower 13.

[0042] The control unit includes a PLC controller 10, which is electrically connected to the online corrosion measuring instrument 8, the sampling flow meter 7, the corrosion inhibitor dosing pump 2, and the bypass treatment system 15.

[0043] The system of this invention can conveniently control corrosion of industrial circulating water pipelines without human intervention.

[0044] The second objective of this invention is to provide a control method for an industrial circulating water pipeline corrosion control system, comprising the following steps:

[0045] The PLC controller receives the online corrosion instrument signal, compares it with the expected corrosion rate, calculates the difference, and then calculates the error value of the corrosion inhibitor dosing pump by multiplying the difference by the corrosion inhibitor allocation parameter Kj according to the allocation ratio coefficient. The frequency at this time is calculated using a PID control algorithm. The error value of the bypass water treatment system is multiplied by the bypass water treatment system allocation parameter Ks and used as the error value of the bypass water treatment system. The treatment capacity of the water treatment system at this time is calculated using a PID control algorithm.

[0046] Under normal operating conditions of circulating water, without human intervention, the method of this invention automatically monitors the corrosion rate of circulating water. After data collection, it automatically adjusts the dosage of corrosion inhibitor and the bypass system's treatment capacity to ensure that the pipeline corrosion rate operates near the expected value, thereby achieving corrosion control of industrial circulating water pipelines and facilitating the normal operation of the circulating water system.

[0047] The following is in conjunction with the appendix Figure 1 and attached Figure 2 The specific embodiments of the present invention will be further described below.

[0048] Example

[0049] like Figure 1 As shown, the present invention provides an industrial circulating water pipeline corrosion control system, which includes an online corrosion testing unit, a water treatment system unit, and a control unit.

[0050] The online corrosion testing unit includes a circulating water pump 4 outlet and an industrial circulating water tower 13 water tank connected by a pipeline. The connecting pipeline has a sampling inlet manual valve 5, a sampling flow electric valve 6, a sampling flow meter 7, an online corrosion rate tester 8, and a sampling outlet manual valve 9 in sequence.

[0051] The water treatment unit includes a corrosion inhibitor section and a bypass water treatment section. The corrosion inhibitor section includes a corrosion inhibitor tank 12 and an industrial circulating water tower 13. The connecting pipeline has a manual valve 1 for the inlet of the corrosion inhibitor dosing pump, a manual valve 2 for the corrosion inhibitor dosing pump, and a manual valve 3 for the outlet of the corrosion inhibitor dosing pump. The inlet of the bypass water treatment system 15 is the outlet of the cooling water of the condenser 14. After treatment by the bypass water treatment system, the water flows back into the circulating water tower 13.

[0052] The control unit includes a touch screen 11 and a PLC controller 10. The PLC controller 10 is electrically connected to the corrosion online measuring instrument 8, the sampling flow electric valve 6, the sampling flow meter 7, the corrosion inhibitor dosing pump 2, and the bypass treatment system 15.

[0053] As attached Figure 1 As shown, to put the industrial circulating water pipeline corrosion control system into operation, open the sampling inlet manual valve 5 and the sampling outlet manual valve 9. On the touch screen, set the sampling flow rate PID, corrosion inhibitor dosing pump PID parameters, bypass water treatment system PID parameters, corrosion inhibitor distribution parameters Kj, bypass water treatment system distribution parameters Ks, and the expected value of circulating water pipeline corrosion. Then, click the automatic sampling button to put the industrial circulating water pipeline corrosion control system into automatic operation.

[0054] The control method based on the above-mentioned industrial circulating water pipeline corrosion control system includes the following steps:

[0055] This device features an online corrosion measurement instrument. A PID control algorithm controls the opening of the flow regulating electric valve to ensure that the sampled water flow through the online corrosion measurement instrument matches the flow rate of the circulating water system, thus improving the accuracy of the online corrosion measurement instrument. After receiving the signal from the online corrosion instrument, the PLC controller compares it with the expected corrosion rate, calculates the difference, and then uses a proportional coefficient to calculate the error value of the corrosion inhibitor dosing pump. The PID control algorithm is then used to calculate the frequency at this point. The difference is also multiplied by Ks to obtain the error value for the bypass water treatment system, and the PID control algorithm is used to calculate the current water treatment capacity of the system.

[0056] The method of this invention can conveniently control corrosion of industrial circulating water pipelines without human intervention, and also rationally allocates the operation modes of corrosion inhibitor dosing pumps and bypass water treatment systems.

[0057] As attached Figure 2 As shown, after the sampling flow meter 8 collects the flow signal, it transmits the signal to the PLC controller 10. The PLC controller uses the PID formula, as shown in the following equation.

[0058] The PID calculation formula is as follows:

[0059]

[0060] Where K p T is the proportionality coefficient. i Let T be the integration time constant. d Let e(t) be the differential time constant, e(t) be the difference between the expected value and the sampled value, and u(t) be the control variable.

[0061] Combining the above formula, we can derive that in the PID calculation formula for the flow control signal, e f (t) is the difference between the expected and actual flow rates, KF p TF is the flow ratio factor. i TF is the integral time constant of the flow rate. d The differential time constant of the flow rate is shown in the following equation.

[0062]

[0063] u F (t) represents the sampled flow rate calculated by the PID algorithm, indicating the opening degree of electric valve 6. The PLC will then process u. F The magnitude of the (t) signal directly affects the sampling flow electric valve 6, ensuring that the sampling flow of the online corrosion measuring instrument is consistent with the operating flow of the circulating water system.

[0064] The online corrosion instrument signal is transmitted to the PLC controller 10, compared with the expected corrosion rate value, and the difference e is obtained. C (t) is calculated using the PID formula for the corrosion inhibitor dosing pump, where Kj is the distribution coefficient of the corrosion inhibitor dosing pump, and KP p TP is the proportional coefficient of the dosing pump. i TP is the integral time constant of the dosing pump. d The differential time constant of the dosing pump is shown in the following formula.

[0065]

[0066] u p (t) is the frequency of corrosion inhibitor dosing pump 2 calculated by the PID algorithm, and the PLC will use u p The magnitude of the (t) signal directly affects the corrosion inhibitor dosing pump 2, ensuring the accuracy of the dosage during operation of the corrosion inhibitor dosing pump 2.

[0067] The calculation is performed using the PID formula for the bypass water treatment system, where Ks is the allocation coefficient of the bypass water treatment system, and KC... p TC is the proportional coefficient for the bypass water treatment system. i TC is the integral time constant of the bypass water treatment system. d The differential time constant of the bypass water treatment system is shown in the following equation.

[0068]

[0069] u C (t) represents the processing capacity of the bypass water treatment system 15 calculated by the PID algorithm. The PLC will then process u. C The magnitude of the (t) signal directly affects the bypass water treatment system 15, ensuring the accuracy of the water treatment volume during the operation of the bypass water treatment system 15.

[0070] The specific steps are as follows:

[0071] On the touch screen 11, set the sampling flow rate PID, corrosion inhibitor dosing pump PID parameters, bypass water treatment system PID parameters, corrosion inhibitor distribution parameters Kj, bypass water treatment system distribution parameters Ks, and expected corrosion values ​​for circulating water pipelines.

[0072] Click the automatic run button. When the PLC controller 10 calculates u using the PID calculation formula based on the error value between the sampled signal (sampled flow rate, online corrosion rate signal) and the expected value (circulating water flow rate, corrosion rate setpoint),... F (t) is the sampling flow rate signal of electric valve 6, u p (t) is the frequency signal of corrosion inhibitor dosing pump 2 and u C (t) serves as the processing volume signal of the bypass water treatment system 15, enabling corrosion control of industrial circulating water pipelines.

[0073] The above control methods are used to control corrosion in industrial circulating water pipelines.

[0074] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A control method for an industrial circulating water pipeline corrosion control system, characterized in that, Includes an online corrosion testing unit, a water treatment system unit, and a control unit; The online corrosion testing unit includes a circulating water pump (4), a sampling flow meter (7), and an online corrosion rate tester (8); the inlet of the circulating water pump (4) is connected to the water tank of the industrial circulating water tower (13), and the outlet of the circulating water pump (4) is provided with a connecting pipeline, on which the sampling flow meter (7) and the online corrosion rate tester (8) are sequentially located. The water treatment system unit includes a corrosion inhibitor section and a bypass water treatment section. The corrosion inhibitor section includes a corrosion inhibitor tank (12), and the outlet of the corrosion inhibitor tank (12) is connected to the water tank of the industrial circulating water tower (13) through a corrosion inhibitor dosing pump (2). The bypass water treatment section includes a bypass water treatment system (15) and a condenser (14). The inlet of the bypass water treatment system (15) is connected to the outlet of the cooling water of the condenser (14), and the outlet of the bypass water treatment system (15) is connected to the water tank of the circulating water tower (13). The control unit includes a PLC controller (10), which is electrically connected to the corrosion rate online tester (8), the sampling flow meter (7), the corrosion inhibitor dosing pump (2), and the bypass water treatment system (15). The control method includes the following steps: The PLC controller controls the opening of the flow regulating electric valve through a PID control algorithm, so that the flow rate of the sampled water passing through the corrosion rate online testing instrument is consistent with the flow rate of the circulating water system itself. After the sampling flow meter (7) collects the flow signal, it transmits the signal to the PLC controller (10). The PID calculation formula is as follows: in This is the proportionality coefficient. The integral time constant is... The differential time constant is The difference between the expected value and the sampled value. To control the quantity; It is the difference between the expected and actual flow rates. This is the flow rate ratio coefficient. The integral time constant of the flow rate. The differential time constant of the flow rate is shown in the following equation. The PLC will calculate the opening degree of the electric valve (6) based on the sampled flow rate obtained by the PID algorithm. The magnitude of the signal directly affects the sampling flow electric valve (6); The online corrosion instrument signal is transmitted to the PLC controller (10) and compared with the expected corrosion rate value to obtain the difference. The calculation is performed using the PID formula for the corrosion inhibitor dosing pump, where, For the corrosion inhibitor dosing pump distribution coefficient, This is the proportional coefficient of the dosing pump. The integral time constant of the dosing pump, The differential time constant of the dosing pump is shown in the following formula. The PLC will use the frequency of the corrosion inhibitor dosing pump (2) calculated by the PID algorithm to... The magnitude of the signal directly affects the corrosion inhibitor dosing pump (2); The calculation is performed using the PID formula for the bypass water treatment system, where... Assign coefficients to the bypass water treatment system. This is the proportional coefficient for the bypass water treatment system. The integral time constant of the bypass water treatment system. The differential time constant of the bypass water treatment system is shown in the following equation. The PLC will calculate the throughput of the bypass water treatment system (15) based on the PID algorithm. The magnitude of the signal directly affects the bypass water treatment system (15).

2. The control method for the industrial circulating water pipeline corrosion control system according to claim 1, characterized in that, The outlet of the circulating water pump (4) is also connected to the inlet of the cooling water of the condenser (14); the outlet of the cooling water of the condenser (14) is also connected to the spray system of the circulating water tower (13).

3. The control method for the industrial circulating water pipeline corrosion control system according to claim 1, characterized in that, The sampling flow meter (7) is also equipped with a sampling inlet manual valve (5) and a sampling flow electric valve (6) at its inlet; the sampling flow electric valve (6) is electrically connected to the PLC controller (10).

4. The control method for the industrial circulating water pipeline corrosion control system according to claim 1, characterized in that, The online corrosion rate tester (8) is also equipped with a sampling outlet manual valve (9) at its outlet.

5. The control method for the industrial circulating water pipeline corrosion control system according to claim 1, characterized in that, The inlet and outlet of the corrosion inhibitor dosing pump (2) are respectively equipped with a manual valve (1) for the inlet of the corrosion inhibitor dosing pump and a manual valve (3) for the outlet of the corrosion inhibitor dosing pump.

6. The control method for the industrial circulating water pipeline corrosion control system according to claim 1, characterized in that, The PLC controller (10) is connected to a touch screen (11).

7. The control method for the industrial circulating water pipeline corrosion control system according to claim 1, characterized in that, Before the PLC controller receives the signal from the online corrosion instrument, it also includes: Set the sampling flow rate PID, corrosion inhibitor dosing pump PID parameters, bypass water treatment system PID parameters, corrosion inhibitor distribution parameter Kj, bypass water treatment system distribution parameter Ks, and expected corrosion value of circulating water pipeline.

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