Ship ballast water residual chlorine neutralization system and dosing control method and controller thereof

Abstract

This invention provides a dosing control method for a ship ballast water residual chlorine neutralization system, comprising: S10: obtaining the holding time T of ballast water in the ballast tank; S20: calculating the dynamic standard dosing concentration C, the maximum dosing concentration Cmax, and the minimum dosing concentration Cmin of the neutralizing agent; wherein, C=a*T^(-b), Cmax=m*C, Cmin=n*C; S30: after the start of unloading, adding the neutralizing agent to the unloading pipeline through the dosing pump according to the maximum dosing concentration Cmax and the maximum dosing flow rate; S40: detecting the current residual chlorine concentration X of the neutralized ballast water in the unloading pipeline, comparing the current residual chlorine concentration X with the set value, and adjusting the dosing concentration of the neutralizing agent in the neutralization dosing tank and / or the dosing flow rate of the dosing pump according to the relationship between the two; S50: repeating the above steps S40 until the unloading is completed. This invention also provides a ship ballast water residual chlorine neutralization system and controller.

Description

Technical Field

[0001] This invention relates to the field of ship ballast water treatment technology, and in particular to a ship ballast water residual chlorine neutralization system and its dosing control method and controller. Background Technology

[0002] To control factors such as list, trim, draft, stability, and stress concentration, almost all ships are equipped with ballast water tanks, and additional ballast water is added according to the ship's actual cargo load to ensure navigational safety. Untreated ballast water discharge can cause a series of problems, including biological invasion and marine pollution. Therefore, the International Maritime Organization (IMO) and the U.S. Environmental Protection Agency have established strict regulations for ballast water discharge to protect the marine environment. To meet these regulations, ballast water treatment systems have emerged.

[0003] To kill bacteria and plankton in ballast water, active substances such as sodium hypochlorite are typically added to disinfect it. To prevent potential environmental risks to receiving water bodies from TRO (Total Residual Oxidant) during discharge, both the IMO and the US Environmental Protection Agency require that management systems using active substances to treat ballast water be equipped with neutralization devices. These devices add neutralizing agents to the discharged water to neutralize residual chlorine. Residual chlorine detection devices are installed outside the discharge hull to monitor the residual chlorine concentration in real time, ensuring it remains below 0.1 ppm.

[0004] Currently, during the ballast water treatment process, the minimum concentration of neutralizing agents is generally calculated based on the residual chlorine concentration 24 hours after ballast water treatment. However, according to research, the holding time of ballast water treatment on most ships worldwide is generally more than 10 days. In order to ensure the stable operation of the ship's ballast water treatment system, ships often over-add chemicals during the ballast water treatment process, resulting in a great waste of neutralizing agents. Summary of the Invention

[0005] The purpose of this invention is to provide a method for controlling the dosing of neutralizing agents in a ship's ballast water residual chlorine neutralization system. This method can determine the concentration of neutralizing agents based on the actual holding time of the ballast water in the ballast tank, thereby greatly reducing the amount of neutralizing agents used and avoiding waste while ensuring the neutralization effect.

[0006] This invention provides a dosing control method for a residual chlorine neutralization system in ship ballast water. The ship ballast water residual chlorine neutralization system includes a ballast tank, a discharge pipeline, and a neutralization dosing device. The discharge pipeline is connected to the ballast tank. The neutralization dosing device includes a neutralization dosing tank and a dosing pump. The inlet of the dosing pump is connected to the neutralization dosing tank, and the outlet of the dosing pump is connected to the discharge pipeline. The dosing control method includes:

[0007] S10: Obtain the retention time T of the ballast water in the ballast tank;

[0008] S20: Based on the ballast water retention time T, calculate the dynamic standard concentration C, maximum concentration Cmax, and minimum concentration Cmin of the neutralizing agent; where C = a*T^(-b), a is the concentration coefficient, and b is the dynamic correction factor; Cmax = m*C, Cmin = n*C, m is a control coefficient greater than 1, and n is a control coefficient less than 1; prepare the neutralizing agent in the neutralization dosing tank according to the maximum concentration Cmax, and set the maximum and minimum dosing flow rates of the dosing pump;

[0009] S30: After the discharge begins, neutralizing agent is added to the discharge pipeline through the dosing pump according to the maximum dosing concentration Cmax and the maximum dosing flow rate;

[0010] S40: Detect the current residual chlorine concentration X of the neutralized ballast water in the discharge pipeline, and compare the current residual chlorine concentration X with a set value. Adjust the concentration of the neutralizing agent in the neutralization dosing tank and / or the dosing flow rate of the dosing pump according to the relationship between the two. If the current residual chlorine concentration X is greater than the set value, increase the concentration of the neutralizing agent in the neutralization dosing tank and / or the dosing flow rate of the dosing pump. If the current residual chlorine concentration X is less than or equal to the set value, decrease the concentration of the neutralizing agent in the neutralization dosing tank and / or the dosing flow rate of the dosing pump.

[0011] When adjusting the concentration of the neutralizing agent in the neutralization dosing tank and / or the dosing flow rate of the dosing pump, the dosing flow rate of the dosing pump is controlled between the maximum dosing flow rate and the minimum dosing flow rate, and when the concentration of the neutralizing agent in the neutralization dosing tank decreases to less than or equal to the minimum dosing concentration Cmin, the dosing is maintained at the minimum dosing concentration Cmin;

[0012] S50: Repeat step S40 above until the loading is complete.

[0013] Furthermore, in step S40 above, when adjusting the concentration of the neutralizing agent in the neutralization dosing tank and / or the flow rate of the dosing pump, the flow rate of the dosing pump is adjusted first. When the flow rate of the dosing pump exceeds the range between the maximum and minimum flow rates, the concentration of the neutralizing agent in the neutralization dosing tank is then adjusted.

[0014] Furthermore, in step S40 above, while maintaining the drug preparation at the minimum drug concentration Cmin, the current residual chlorine concentration X is continuously monitored. If the current residual chlorine concentration X is less than or equal to the set value, the drug preparation continues at the minimum drug concentration Cmin. If the current residual chlorine concentration X is greater than the set value, and the drug flow rate of the dosing pump exceeds the maximum drug flow rate, the concentration of the neutralizing agent is increased.

[0015] Furthermore, in step S40 above, the increase or decrease in the concentration of the neutralizing agent each time does not exceed 10% of the previous concentration, and the increase or decrease in the flow rate of the dosing pump each time does not exceed 10% of the previous flow rate.

[0016] Furthermore, in step S20 above, the control coefficient m ranges from 1.1 to 1.3, and the control coefficient n ranges from 0.6 to 0.8.

[0017] Furthermore, in step S40 above, no upper limit is set on the actual maximum concentration of the neutralizing agent during the loading process.

[0018] Furthermore, in step S20 above, the maximum dosing flow rate of the dosing pump is 80% of the maximum limit dosing flow rate of the dosing pump, and the minimum dosing flow rate of the dosing pump is 60% of the maximum limit dosing flow rate of the dosing pump;

[0019] In step S40 above, when adjusting the dosing flow rate of the dosing pump, the dosing flow rate of the dosing pump is controlled between 60% and 80% of the maximum limit dosing flow rate of the dosing pump.

[0020] Furthermore, the dosing control method also includes:

[0021] During the discharge process, obtain the actual maximum concentration C1 and the actual minimum concentration C2 of the neutralizing agent in the neutralization dosing tank. After the discharge is completed, update the database based on the actual maximum concentration C1, the actual minimum concentration C2 and the ballast water retention time T during the discharge process, and refit the equation for the dynamic standard concentration C to correct the concentration coefficient a and the dynamic correction factor b.

[0022] The present invention also provides a controller, comprising:

[0023] A memory, wherein instructions are stored;

[0024] The processor, when the instructions are executed by the processor, implements the dosing control method for the residual chlorine neutralization system of ship ballast water as described above.

[0025] This invention also provides a ship ballast water residual chlorine neutralization system, including the controller described above. The system further includes a ballast tank, a discharge pipeline, a neutralization dosing device, a residual chlorine detection device, and a timer. The discharge pipeline is connected to the ballast tank. The neutralization dosing device includes a neutralization dosing tank, a dosing pump, a freshwater pipeline, and a concentrated neutralizing agent storage tank. The inlet of the dosing pump is connected to the neutralization dosing tank, and the outlet of the dosing pump is connected to the discharge pipeline. The freshwater pipeline and the concentrated neutralizing agent storage tank are both connected to the neutralization dosing tank. A first regulating valve is provided on the water pipeline, and a second regulating valve is provided on the pipeline between the concentrated neutralizing agent storage tank and the neutralizing agent dosing tank; the residual chlorine detection device is connected to the discharge pipeline; the neutralizing agent dosing device is used to add neutralizing agent to the discharge pipeline, the residual chlorine detection device is used to detect the residual chlorine concentration of the neutralized ballast water in the discharge pipeline, and the timer is used to record the holding time of the ballast water in the ballast tank; the timer, the dosing pump, the residual chlorine detection device, the first regulating valve, and the second regulating valve are all electrically connected to the controller.

[0026] Furthermore, the neutralization dosing tank is equipped with a liquid level sensor, and the bottom of the concentrated neutralizing agent storage tank is equipped with a weighing sensor. Both the liquid level sensor and the weighing sensor are electrically connected to the controller.

[0027] Furthermore, the neutralization dosing tank is equipped with a filter screen, which divides the internal space of the neutralization dosing tank into a first cavity and a second cavity arranged vertically adjacent to each other, with the first cavity located above the second cavity; the fresh water pipeline and the concentrated neutralizing agent storage tank are respectively connected to the first cavity, and the inlet of the dosing pump is connected to the second cavity; a mixing device is provided in the second cavity.

[0028] The present invention provides a method for controlling the dosing of a residual chlorine neutralization system in ship ballast water. This method determines the maximum and minimum concentrations (Cmax and Cmin) of the neutralizing agent based on the retention time (T) of the ballast water in the ballast tank. After unloading begins, the agent is first added according to the maximum concentration (Cmax) and maximum flow rate. Simultaneously, the current residual chlorine concentration (X) is monitored and compared with the set value to determine the neutralization effect. Based on this, the concentration and flow rate of the neutralizing agent are adjusted. This allows the ship's ballast water residual chlorine neutralization system to add agents according to the actual amount required during unloading, significantly reducing the amount of neutralizing agent used while ensuring the neutralization effect and avoiding waste. Furthermore, by setting a minimum concentration (Cmin), when the concentration of the neutralizing agent decreases to less than or equal to the minimum concentration (Cmin), dosing is maintained at the minimum concentration (Cmin). This reduces the amount of neutralizing agent used and avoids frequent system fluctuations, thus contributing to system stability. Furthermore, by setting the maximum and minimum dosing flow rates of the dosing pump, the dosing flow rate can be controlled between the maximum and minimum dosing flow rates when adjusting the dosing flow rate. This not only extends the service life of the dosing pump but also improves the accuracy of the dosing flow rate adjustment, thereby ensuring the effectiveness of neutralization dosing. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the residual chlorine neutralization system for ship ballast water in an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the neutralization and dosing device in an embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram of the control logic of the controller in an embodiment of the present invention.

[0032] Figure 4 This is a flowchart of the dosing control method for the residual chlorine neutralization system of ship ballast water in an embodiment of the present invention.

[0033] Figure 5 This is a schematic diagram illustrating the relationship between the TRO concentration of ballast water and the retention time of ballast water in an embodiment of the present invention. Detailed Implementation

[0034] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0035] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0036] The directional terms such as "up," "down," "left," "right," "front," "back," "top," and "bottom" (if present) used in the specification and claims of this invention are defined by the position of the structures in the drawings and the relative positions of the structures, and are only for the clarity and convenience of expressing the technical solution. It should be understood that the use of directional terms should not limit the scope of protection claimed in this application.

[0037] like Figures 1 to 4 As shown, this embodiment of the invention provides a dosing control method for a ship ballast water residual chlorine neutralization system. The ship ballast water residual chlorine neutralization system includes a ballast tank 1, a discharge pipeline 2, and a neutralization dosing device 3. The discharge pipeline 2 is connected to the ballast tank 1. The neutralization dosing device 3 includes a neutralization dosing tank 31 and a dosing pump 32. The inlet of the dosing pump 32 is connected to the neutralization dosing tank 31, and the outlet of the dosing pump 32 is connected to the discharge pipeline 2. The dosing control method includes:

[0038] S10: Obtain the retention time T of the ballast water in ballast tank 1 (i.e., the residence time of the ballast water in ballast tank 1);

[0039] S20: Based on the ballast water retention time T, calculate the dynamic standard concentration C, maximum concentration Cmax, and minimum concentration Cmin of the neutralizing agent; where C = a*T^(-b), a is the concentration coefficient, b is the dynamic correction factor, and both a and b are positive numbers; Cmax = m*C, Cmin = n*C, m is a control coefficient greater than 1, n is a control coefficient less than 1, and n is a positive number. Prepare the neutralizing agent in the neutralization dosing tank 31 according to the maximum concentration Cmax, and set the maximum and minimum dosing flow rates of the dosing pump 32.

[0040] S30: After the discharge begins, neutralizing agent is added to the discharge pipeline 2 by the dosing pump 32 according to the maximum dosing concentration Cmax and the maximum dosing flow rate (to ensure the neutralization effect at the initial discharge and prevent the discharge water quality from being unqualified due to insufficient dosing at the beginning).

[0041] S40: Detect the current residual chlorine concentration X of the neutralized ballast water in the discharge pipeline 2, compare the current residual chlorine concentration X with the set value, and adjust the concentration of the neutralizing agent in the neutralization dosing tank 31 and / or the dosing flow rate of the dosing pump 32 according to the relationship between the two; if the current residual chlorine concentration X is greater than the set value, increase the concentration of the neutralizing agent in the neutralization dosing tank 31 and / or the dosing flow rate of the dosing pump 32; if the current residual chlorine concentration X is less than or equal to the set value, decrease the concentration of the neutralizing agent in the neutralization dosing tank 31 and / or the dosing flow rate of the dosing pump 32.

[0042] When adjusting the concentration of the neutralizing agent in the neutralization dosing tank 31 and / or the dosing flow rate of the dosing pump 32, the dosing flow rate of the dosing pump 32 shall be controlled between the maximum dosing flow rate and the minimum dosing flow rate. When the concentration of the neutralizing agent in the neutralization dosing tank 31 is reduced to less than or equal to the minimum dosing concentration Cmin, the dosing shall be performed at the minimum dosing concentration Cmin (i.e., when the calculated value of the dosing concentration is less than or equal to the minimum dosing concentration Cmin, the dosing shall be performed at the minimum dosing concentration Cmin).

[0043] Specifically, when adjusting the concentration of the neutralizing agent in the neutralization dosing tank 31 and / or the flow rate of the dosing pump 32, the flow rate of the dosing pump 32 should be adjusted first (adjusting the flow rate of the dosing pump 32 is more convenient and allows for faster adjustment of the TRO concentration; while adjusting the concentration of the neutralizing agent in the neutralization dosing tank 31 has a certain lag); when the flow rate of the dosing pump 32 exceeds the range between the maximum and minimum flow rates, the concentration of the neutralizing agent in the neutralization dosing tank 31 should then be adjusted.

[0044] During the dosing process, while maintaining the minimum dosing concentration Cmin, it is still necessary to continuously monitor the current residual chlorine concentration X. If the current residual chlorine concentration X is less than or equal to the set value, the dosing process continues at the minimum dosing concentration Cmin. If the current residual chlorine concentration X is greater than the set value, and the dosing flow rate of the dosing pump 32 exceeds the maximum dosing flow rate, the concentration of the neutralizing agent is increased. This is to prevent the residual chlorine concentration from exceeding the standard during the ballast water discharge process.

[0045] S50: Repeat step S40 above until the loading is complete.

[0046] Specifically, when using active substances such as sodium hypochlorite to treat the ballast water in ballast tank 1, the residual concentration (TRO concentration) of the active substances after reacting with harmful organisms in the ballast water is related to the salinity, temperature, dissolved oxygen, pH value of the ballast water, and the holding time T of the ballast water in ballast tank 1 (i.e., the reaction time between the active substances and harmful organisms in the ballast water). However, based on experimental results and actual operating conditions, considering that: 1. Changes in the salinity, temperature, dissolved oxygen, and pH value of the ballast water have a relatively small impact on the TRO concentration of the ballast water; 2. Changes in the salinity, temperature, dissolved oxygen, and pH value of the ballast water have a relatively small impact on the TRO concentration of the ballast water. Temperature, dissolved oxygen, and pH do not change much during actual shipboard operation. When formulating the equation for the dynamic standard dosing concentration C, the design margin is fully considered. Therefore, the relationship between the TRO concentration of ballast water and the salinity, temperature, dissolved oxygen, pH value, and the holding time T of ballast water in ballast tank 1 can be simplified to the relationship between the TRO concentration of ballast water and the holding time T of ballast water in ballast tank 1. At the same time, by combining mathematical statistics and curve fitting, the relationship between the dynamic standard dosing concentration C and the holding time T of ballast water can be obtained, namely C=a*T^(-b).

[0047] At the same time, such as Figure 5 As shown, the TRO concentration of ballast water decreases with increasing ballast water retention time T, and the rate of TRO concentration decay slows down with increasing time. Therefore, C and T have an inverse proportional relationship. Figure 5 The figure illustrates the relationship curves between the TRO concentration and the holding time T of ballast water in three groups; where the horizontal axis represents the holding time T of ballast water in hours, and the vertical axis represents the TRO concentration of ballast water in mg / L. According to actual engineering simulation calculations, the above exponential inverse proportional function C=a*T^(-b) fits well with the relationship curve between the TRO concentration and the holding time T of ballast water.

[0048] The chemical dosing control method for a ship ballast water residual chlorine neutralization system provided in this invention determines the maximum and minimum concentrations of the neutralizing agent (Cmax and Cmin) based on the retention time T of the ballast water in ballast tank 1. After unloading begins, the agent is first added according to the maximum concentration Cmax and the maximum dosing flow rate. Simultaneously, the current residual chlorine concentration X is detected and compared with the set value to determine the neutralization effect. Based on this, the concentration and flow rate of the neutralizing agent are adjusted. This allows the ship's ballast water residual chlorine neutralization system to add chemicals according to the actual amount of neutralizing agent required during unloading. While ensuring the neutralization effect, this method can significantly reduce the amount of neutralizing agent used and avoid waste (according to tests, it can save at least 30% of the neutralizing agent usage). Furthermore, by setting a minimum concentration Cmin, when the concentration of the neutralizing agent decreases to less than or equal to the minimum concentration Cmin, the dosing is maintained at the minimum concentration Cmin. This reduces the amount of neutralizing agent used and avoids frequent system fluctuations, thus contributing to system stability. Furthermore, by setting the maximum and minimum dosing flow rates of the dosing pump 32, the dosing flow rate of the dosing pump 32 is controlled between the maximum and minimum dosing flow rates when adjusting the dosing flow rate. This not only extends the service life of the dosing pump 32, but also improves the accuracy of the dosing flow rate adjustment, thereby ensuring the neutralization effect of the dosing.

[0049] Furthermore, in this embodiment, in step S40 above, the increase or decrease in the concentration of the neutralizing agent each time does not exceed 20% of the previous concentration, and the increase or decrease in the flow rate of the dosing pump 32 each time does not exceed 20% of the previous flow rate (for example, if the previous concentration was 1 mol / L, the adjustment range of the concentration does not exceed 0.2 mol / L; if the previous flow rate was 10 L / h, the adjustment range of the flow rate does not exceed 2 L / h). This avoids excessive adjustments to the concentration and flow rate each time, which could cause frequent fluctuations in the system. At the same time, it is beneficial for the system to adjust to a concentration and flow rate suitable for the current operating conditions during the dosing process.

[0050] Furthermore, in this embodiment, in step S40 above, the increase or decrease in the concentration of the neutralizing agent each time does not exceed 10% of the previous concentration, and the increase or decrease in the flow rate of the dosing pump 32 each time does not exceed 10% of the previous flow rate.

[0051] Furthermore, in this embodiment, in step S40 above, the actual maximum concentration of the neutralizing agent (i.e., C1 below) during the loading process is not set with an upper limit. That is, during the drug addition process, the actual maximum concentration is not set with an upper limit, and the actual minimum concentration is executed according to the minimum concentration Cmin.

[0052] Furthermore, in this embodiment, the values ​​of a and b in step S20 above can be calculated based on actual data. Meanwhile, besides being related to the decay rate of the TRO concentration of the ballast water with respect to the holding time T, a is also related to the discharge flow rate of the ballast water during the discharge process: the larger the discharge flow rate of the ballast water, the larger a is; the smaller the discharge flow rate of the ballast water, the smaller a is.

[0053] Furthermore, in this embodiment, in step S20 above, the control coefficient m ranges from 1.1 to 1.3, and the control coefficient n ranges from 0.6 to 0.8. Of course, in other embodiments, the ranges of control coefficients m and n can be selected according to the actual situation.

[0054] Furthermore, in this embodiment, the set value in step S40 above can be 0.1 ppm, that is, during the discharge process, the residual chlorine concentration of the ballast water does not exceed 0.1 ppm.

[0055] Furthermore, in this embodiment, in step S40 above, the interval between each detection of residual chlorine concentration can be set to 2 minutes.

[0056] Furthermore, in this embodiment, in the above-mentioned S20 step, the maximum dosing flow rate of the dosing pump 32 is 80% of the maximum limit dosing flow rate of the dosing pump 32, and the minimum dosing flow rate of the dosing pump 32 is 60% of the maximum limit dosing flow rate of the dosing pump 32.

[0057] In step S40 above, when adjusting the dosing flow rate of the dosing pump 32, the dosing flow rate of the dosing pump 32 is controlled between 60% and 80% of the maximum limit dosing flow rate of the dosing pump 32, thereby avoiding damage to the dosing pump 32 and ensuring the service life of the dosing pump 32 and the accuracy of the flow rate adjustment. The maximum limit dosing flow rate of the dosing pump 32 is determined based on the pump's own characteristics.

[0058] Furthermore, in this embodiment, the dosing control method further includes:

[0059] The actual maximum and minimum concentrations of the neutralizing agent in the neutralization dosing tank 31 are obtained during the discharge process. After discharge, the database is updated based on the actual maximum and minimum concentrations C1 and C2 and the ballast water holding time T during this discharge process, and the equation for the dynamic standard concentration C is fitted again to correct the concentration coefficient a and the dynamic correction factor b. This allows the dynamic standard concentration C to be continuously corrected and adapted to various operating conditions, improving the applicability of the dosing control method. This correction process can be performed manually or automatically by the system.

[0060] like Figure 3 As shown, this embodiment of the invention also provides a controller 7, comprising:

[0061] Memory, which stores instructions;

[0062] The processor, when the instructions are executed, implements the dosing control method of the residual chlorine neutralization system for ship ballast water described above.

[0063] Furthermore, in this embodiment, the controller 7 is a PLC control device.

[0064] like Figures 1 to 3 As shown in the figure, this embodiment of the invention also provides a ship ballast water residual chlorine neutralization system, including the controller 7 described above. The ship ballast water residual chlorine neutralization system also includes a ballast tank 1, a discharge pipeline 2, a neutralization dosing device 3, a residual chlorine detection device 4, and a timer 5. The ballast tank 1 is used to temporarily store ballast water, and the discharge pipeline 2 is connected to the ballast tank 1, allowing the ballast water in the ballast tank 1 to be discharged to the outside of the ship through the discharge pipeline 2.

[0065] The neutralization dosing device 3 is used to add neutralizing agent to the discharge pipeline 2. The neutralization dosing device 3 includes a neutralization dosing tank 31, a dosing pump 32, a fresh water pipeline 33, and a concentrated neutralizing agent storage tank 34. The inlet of the dosing pump 32 is connected to the neutralization dosing tank 31, and the outlet of the dosing pump 32 is connected to the discharge pipeline 2. The fresh water pipeline 33 and the concentrated neutralizing agent storage tank 34 are both connected to the neutralization dosing tank 31. A first regulating valve 35 is installed on the fresh water pipeline 33, and a second regulating valve 36 is installed on the pipeline between the concentrated neutralizing agent storage tank 34 and the neutralization dosing tank 31. Specifically, the concentrated neutralizing agent storage tank 34 stores concentrated neutralizing agent. The concentrated neutralizing agent storage tank 34 and the fresh water pipeline 33 are used to add concentrated neutralizing agent and fresh water to the neutralization dosing tank 31, thereby preparing a neutralizing agent of a certain concentration in the neutralization dosing tank 31. The first regulating valve 35 and the second regulating valve 36 are used to control the amount of fresh water and concentrated neutralizing agent added, respectively, thereby controlling the concentration of the neutralizing agent.

[0066] The residual chlorine detection device 4 is connected to the discharge pipeline 2 and is located downstream of the neutralization dosing device 3 (i.e., the residual chlorine detection device 4 is connected to the downstream pipeline after the neutralization dosing device 3). The residual chlorine detection device 4 is used to detect the residual chlorine concentration of the neutralized ballast water in the discharge pipeline 2. The timer 5 is used to record the holding time of the ballast water in the ballast tank 1 (i.e., the timer 5 records the time from the end of each ballast process to the start of the next discharge). The timer 5, the dosing pump 32, the residual chlorine detection device 4, the first regulating valve 35, and the second regulating valve 36 are all electrically connected to the controller 7. The controller 7 is used to control the neutralization dosing device 3 to perform dosing according to the above-mentioned dosing control method based on the holding time of the ballast water recorded by the timer 5 and the residual chlorine concentration detected by the residual chlorine detection device 4. Specifically, the controller 7 can calculate the dynamic standard concentration C, maximum concentration Cmax, and minimum concentration Cmin of the neutralizing agent based on the ballast water holding time recorded by the timer 5, and control the opening degree of the first regulating valve 35 and the second regulating valve 36 and the flow rate of the dosing pump 32 based on the residual chlorine concentration detected by the residual chlorine detection device 4, thereby controlling the concentration and flow rate of the neutralizing agent.

[0067] Furthermore, the timer 5 can be a timing device built into the controller 7, or it can be an external timing device.

[0068] Furthermore, such as Figure 1 As shown, in this embodiment, a discharge pump 6 is installed on the discharge pipeline 2. The neutralization dosing device 3 is connected to the pipeline before the inlet of the ballast tank 1 and the discharge pump 6. The residual chlorine detection device 4 is connected to the pipeline after the outlet of the discharge pump 6. The neutralizing agent added by the neutralization dosing device 3 can not only mix and react with the ballast water in the discharge pipeline 2 in the pipeline, but can also be further mixed by the discharge pump 6, thereby improving the neutralization reaction rate.

[0069] Furthermore, such as Figure 2 and Figure 3 As shown, in this embodiment, a level sensor 38 is provided on the neutralization dosing tank 31 to detect the level of the neutralizing agent in the neutralization dosing tank 31; a weighing sensor 37 is provided at the bottom of the concentrated neutralizing agent storage tank 34 to weigh the concentrated neutralizing agent storage tank 34. Both the level sensor 38 and the weighing sensor 37 are electrically connected to the controller 7. The controller 7 can calculate the amount of fresh water added based on the change in the level of the neutralizing agent in the neutralization dosing tank 31 measured by the level sensor 38 and the dosing flow rate of the dosing pump 32, and calculate the amount of concentrated neutralizing agent added based on the change in the weight of the concentrated neutralizing agent storage tank 34 measured by the weighing sensor 37, thereby obtaining the real-time concentration of the neutralizing agent in the neutralization dosing tank 31, and controlling the opening degree of the first regulating valve 35 and the second regulating valve 36 accordingly.

[0070] Furthermore, such as Figure 2 As shown, in this embodiment, a filter screen 30 is provided inside the neutralization dosing tank 31. The filter screen 30 divides the internal space of the neutralization dosing tank 31 into a first cavity 31A and a second cavity 31B arranged vertically adjacent to each other, with the first cavity 31A located above the second cavity 31B. The fresh water pipeline 33 and the concentrated neutralizing agent storage tank 34 are both connected to the first cavity 31A, and the inlet of the dosing pump 32 is connected to the second cavity 31B. A mixing device 39 is provided inside the second cavity 31B.

[0071] Specifically, the mixing device 39 can evenly mix the concentrated neutralizing agent and fresh water, thereby improving the neutralization effect. By installing a filter screen 30 inside the neutralization dosing tank 31, the filter screen 30 can intercept undissolved solid neutralizing agent in the concentrated neutralizing agent within the first chamber 31A, preventing the solid neutralizing agent from being directly pumped into the discharge pipeline 2 without mixing with the fresh water, thus avoiding waste. The solid neutralizing agent intercepted in the first chamber 31A can dissolve and enter the second chamber 31B, where it is further evenly mixed with the fresh water under the mixing action of the mixing device 39, thereby improving the neutralization effect. Simultaneously, the filter screen 30 can also intercept impurities in the fresh water and the concentrated neutralizing agent.

[0072] Furthermore, such as Figure 2 As shown, in this embodiment, the neutralization dosing tank 31 is provided with a drain port 311 above the filter screen 30, and the drain port 311 is connected to the first cavity 31A.

[0073] The chemical dosing control method for a ship ballast water residual chlorine neutralization system provided in this invention determines the maximum and minimum concentrations of the neutralizing agent (Cmax and Cmin) based on the retention time T of the ballast water in ballast tank 1. After unloading begins, the agent is first added according to the maximum concentration Cmax and the maximum dosing flow rate. Simultaneously, the current residual chlorine concentration X is detected and compared with the set value to determine the neutralization effect. Based on this, the concentration and flow rate of the neutralizing agent are adjusted. This allows the ship's ballast water residual chlorine neutralization system to add chemicals according to the actual amount of neutralizing agent required during unloading, greatly reducing the amount of neutralizing agent used while ensuring the neutralization effect and avoiding waste. Furthermore, by setting a minimum concentration Cmin, when the concentration of the neutralizing agent decreases to less than or equal to the minimum concentration Cmin, dosing is maintained at the minimum concentration Cmin. This reduces the amount of neutralizing agent used and avoids frequent system fluctuations, thus contributing to system stability. Furthermore, by setting the maximum and minimum dosing flow rates of the dosing pump 32, the dosing flow rate of the dosing pump 32 is controlled between the maximum and minimum dosing flow rates when adjusting the dosing flow rate. This not only extends the service life of the dosing pump 32, but also improves the accuracy of the dosing flow rate adjustment, thereby ensuring the neutralization effect of the dosing.

[0074] The above description is merely a specific 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 technical scope 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 method for controlling the dosing of chemicals in a ship's ballast water residual chlorine neutralization system, the ballast water residual chlorine neutralization system comprising a ballast tank, a discharge pipeline, and a neutralization dosing device, wherein the discharge pipeline is connected to the ballast tank, the neutralization dosing device comprising a neutralization dosing tank and a dosing pump, the inlet of the dosing pump being connected to the neutralization dosing tank, and the outlet of the dosing pump being connected to the discharge pipeline, characterized in that, The dosing control method includes: S10: Obtain the retention time T of the ballast water in the ballast tank; S20: Based on the ballast water retention time T, calculate the dynamic standard concentration C, maximum concentration Cmax, and minimum concentration Cmin of the neutralizing agent; where C = a*T^(-b), a is the concentration coefficient, and b is the dynamic correction factor; Cmax = m*C, Cmin = n*C, m is a control coefficient greater than 1, and n is a control coefficient less than 1; prepare the neutralizing agent in the neutralization dosing tank according to the maximum concentration Cmax, and set the maximum and minimum dosing flow rates of the dosing pump; S30: After the discharge begins, neutralizing agent is added to the discharge pipeline by the dosing pump according to the maximum dosing concentration Cmax and the maximum dosing flow rate; S40: Detect the current residual chlorine concentration X of the neutralized ballast water in the discharge pipeline, and compare the current residual chlorine concentration X with a set value. Adjust the concentration of the neutralizing agent in the neutralization dosing tank and / or the dosing flow rate of the dosing pump according to the relationship between the two. If the current residual chlorine concentration X is greater than the set value, increase the concentration of the neutralizing agent in the neutralization dosing tank and / or the dosing flow rate of the dosing pump. If the current residual chlorine concentration X is less than or equal to the set value, decrease the concentration of the neutralizing agent in the neutralization dosing tank and / or the dosing flow rate of the dosing pump. When adjusting the concentration of the neutralizing agent in the neutralization dosing tank and / or the dosing flow rate of the dosing pump, the dosing flow rate of the dosing pump is controlled between the maximum dosing flow rate and the minimum dosing flow rate, and when the concentration of the neutralizing agent in the neutralization dosing tank decreases to less than or equal to the minimum dosing concentration Cmin, the dosing is maintained at the minimum dosing concentration Cmin; S50: Repeat step S40 above until the loading is completed; S60: Obtain the actual maximum concentration C1 and the actual minimum concentration C2 of the neutralizing agent in the neutralization dosing tank during the discharge process; after the discharge is completed, update the database based on the actual maximum concentration C1, the actual minimum concentration C2 and the ballast water holding time T during this discharge process, and fit the equation of the dynamic standard concentration C again to correct the concentration coefficient a and the dynamic correction factor b.

2. The dosing control method for the residual chlorine neutralization system of ship ballast water as described in claim 1, characterized in that, In step S40 above, when adjusting the concentration of the neutralizing agent in the neutralization dosing tank and / or the flow rate of the dosing pump, the flow rate of the dosing pump is adjusted first; when the flow rate of the dosing pump exceeds the range between the maximum flow rate and the minimum flow rate, the concentration of the neutralizing agent in the neutralization dosing tank is then adjusted.

3. The dosing control method for the residual chlorine neutralization system of ship ballast water as described in claim 2, characterized in that, In step S40 above, while maintaining the minimum dosing concentration Cmin for drug preparation, the current residual chlorine concentration X is continuously monitored. If the current residual chlorine concentration X is less than or equal to the set value, the drug preparation continues at the minimum dosing concentration Cmin. If the current residual chlorine concentration X is greater than the set value and the dosing flow rate of the dosing pump exceeds the maximum dosing flow rate, the concentration of the neutralizing agent is increased.

4. The dosing control method for the residual chlorine neutralization system of ship ballast water as described in claim 1, characterized in that, In step S40 above, the increase or decrease in the concentration of the neutralizing agent each time shall not exceed 10% of the previous concentration, and the increase or decrease in the flow rate of the dosing pump each time shall not exceed 10% of the previous flow rate.

5. The dosing control method for the residual chlorine neutralization system of ship ballast water as described in claim 1, characterized in that, In step S20 above, the control coefficient m ranges from 1.1 to 1.3, and the control coefficient n ranges from 0.6 to 0.

8.

6. The dosing control method for the residual chlorine neutralization system of ship ballast water as described in claim 1, characterized in that, In step S20 above, the maximum dosing flow rate of the dosing pump is 80% of the maximum limit dosing flow rate of the dosing pump, and the minimum dosing flow rate of the dosing pump is 60% of the maximum limit dosing flow rate of the dosing pump. In step S40 above, when adjusting the dosing flow rate of the dosing pump, the dosing flow rate of the dosing pump is controlled between 60% and 80% of the maximum limit dosing flow rate of the dosing pump.

7. A controller, characterized in that, include: A memory, wherein instructions are stored; The processor, when the instructions are executed by the processor, implements the dosing control method for the residual chlorine neutralization system of ship ballast water as described in any one of claims 1 to 6.

8. A residual chlorine neutralization system for ship ballast water, characterized in that, Including the controller as described in claim 7, the ship's ballast water residual chlorine neutralization system further includes a ballast tank, a discharge pipeline, a neutralization dosing device, a residual chlorine detection device, and a timer; the discharge pipeline is connected to the ballast tank, the neutralization dosing device includes a neutralization dosing tank, a dosing pump, a freshwater pipeline, and a concentrated neutralizing agent storage tank, the inlet of the dosing pump is connected to the neutralization dosing tank, the outlet of the dosing pump is connected to the discharge pipeline, the freshwater pipeline and the concentrated neutralizing agent storage tank are both connected to the neutralization dosing tank, and the freshwater pipeline is equipped with a first A second regulating valve is provided on the pipeline between the concentrated neutralizing agent storage tank and the neutralizing agent dosing tank; the residual chlorine detection device is connected to the discharge pipeline; the neutralizing agent dosing device is used to add neutralizing agent to the discharge pipeline; the residual chlorine detection device is used to detect the residual chlorine concentration of the neutralized ballast water in the discharge pipeline; the timer is used to record the holding time of the ballast water in the ballast tank; the timer, the dosing pump, the residual chlorine detection device, the first regulating valve, and the second regulating valve are all electrically connected to the controller.

9. The ship ballast water residual chlorine neutralization system as described in claim 8, characterized in that, The neutralization dosing tank is equipped with a liquid level sensor, and the bottom of the concentrated neutralizing agent storage tank is equipped with a weighing sensor. Both the liquid level sensor and the weighing sensor are electrically connected to the controller.

10. The ship ballast water residual chlorine neutralization system as described in claim 8, characterized in that, The neutralization dosing tank is equipped with a filter screen, which divides the internal space of the neutralization dosing tank into a first cavity and a second cavity arranged vertically adjacent to each other. The first cavity is located above the second cavity. The fresh water pipeline and the concentrated neutralizing agent storage tank are respectively connected to the first cavity, and the inlet of the dosing pump is connected to the second cavity. A mixing device is provided in the second cavity.

Images