Method and system for regulating and controlling circulating water of cooling crystallization kettle of potassium alkali light salt brine desulfurization system

Abstract

The invention relates to the technical field of potassium alkali desulfurization, in particular to a cooling crystallization kettle circulating water regulation and control method and system of a potassium alkali light salt brine desulfurization system. According to the method, the temperature, turbidity, circulating water flow velocity and stirrer power of the nitrate-rich strong brine are collected in real time, the crystallization period is judged based on the turbidity of the brine and the stirrer power, the temperature and the flow velocity of the circulating water are dynamically adjusted, and in the crystallization induction period, the temperature of the circulating water is kept 5-10 DEG C lower than that of the brine, and the flow velocity is an initial value; the temperature difference is increased to 15-20 DEG C in the crystallization growth period, and the flow velocity is increased by 20-30%, and the temperature difference is reduced to 3-5 DEG C in the crystallization maturation period, and the flow velocity is reduced by 20-40%; the system comprises a temperature, turbidity, flow velocity and power acquisition module and a control execution module. The problems that in the prior art, circulating water control depends on experience, the crystallization precision is low, and violent crystal abnormity treatment is insufficient are solved, accurate control over the circulating water consumption is achieved, energy consumption is reduced, the crystallization process is fine and controllable, and production stability is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of potassium base desulfurization, in particular to a cooling crystallization kettle circulating water regulation and control method and system of a potassium base light brine desulfurization system. BACKGROUND

[0002] Huaxin Chemical Co., Ltd. applied for a Chinese patent with the publication number CN114620746B and the name "A method and system for removing sulfate ions from potassium base light brine" on April 18, 2022; in the technical solution disclosed by the patent, the nitrate-rich concentrated brine is placed in a cooling crystallization kettle for cooling to cause potassium sulfate to crystallize and precipitate, thereby obtaining denitrate concentrated brine.

[0003] In actual production, a circulating water jacket is arranged on the cooling crystallization kettle to achieve cooling, and a constant-speed stirrer is provided in the kettle to promote uniform cooling of the solution and crystal growth.

[0004] From a theoretical point of view, to treat 1 ton of nitrate-rich concentrated brine (consisting of 18% KCl and 3.1% K2SO4, at a temperature of 35°C) by crystallizing K2SO4 and increasing the KCl concentration to 25%, 1.76 tons of circulating water need to be injected into the circulating water jacket to achieve the required cooling and crystallization. However, in actual production, due to the lack of real-time regulation means for the circulating water flow rate, only constant flow rate or manual adjustment of the circulating water flow rate can be used for control, which results in the need to inject 2 to 3 tons of circulating water into the circulating water jacket to treat 1 ton of nitrate-rich concentrated brine (consisting of 18% KCl and 3.1% K2SO4, at a temperature of 35°C) by increasing the KCl concentration to 25%, thereby increasing the energy consumption of the cooling circulating water equipment and increasing production costs, which is not conducive to green and environmentally friendly production. SUMMARY

[0005] The present application aims to provide a cooling crystallization kettle circulating water regulation and control method and system of a potassium base light brine desulfurization system, which uses real-time acquisition of brine turbidity, circulating water flow rate, and stirrer power, and dynamically adjusts the circulating water temperature and flow rate based on the crystallization state, to solve the problems of existing technology, such as dependence on experience or manual constant flow rate for circulating water control, low crystallization control accuracy, uneven or incomplete crystallization, and insufficient abnormal crystal handling capacity, and to produce beneficial effects such as accurate control of circulating water consumption, reduced energy consumption and production costs, fine controllability of the crystallization process, improved product quality, and enhanced production stability.

[0006] To achieve the foregoing purpose, the technical solution adopted by the present application is as follows: A cooling crystallization kettle circulating water regulation and control method of a potassium base light brine desulfurization system, comprising the following steps: Step S1: obtaining the initial brine temperature of the nitrate-rich concentrated brine, and based on the initial brine temperature, determining the initial circulating water temperature of the circulating water in the cooling water flow channel on the outer wall of the cooling crystallization kettle, while presetting the initial circulating water flow rate and the initial agitator power of the constant-speed agitator on the cooling crystallization kettle; wherein the temperature of the initial brine temperature is higher than that of the initial circulating water temperature; Step S2: collecting the real-time brine temperature, real-time brine turbidity, real-time circulating water flow rate and real-time agitator power of the nitrate-rich concentrated brine; Step S3: based on the real-time brine temperature, real-time brine turbidity and real-time agitator power, dynamically adjusting the real-time circulating water temperature and real-time circulating water flow rate of the circulating water.

[0007] Preferably, the dynamic adjustment method in step S3 comprises: Step S3.1: setting a first turbidity value, a second turbidity value, a first power value and a second power value; wherein the first turbidity value is less than the second turbidity value, and the first power value is less than the second power value; Step S3.2: comparing the real-time brine turbidity with the first turbidity value and the second turbidity value respectively, and comparing the real-time agitator power with the first power value and the second power value respectively, to determine the crystallization period; Wherein, the real-time brine turbidity is less than the first turbidity value, and the real-time agitator power is less than the first power value, it is determined that the current is in the crystallization induction period; The real-time brine turbidity is between the first turbidity value and the second turbidity value, and the real-time agitator power is between the first power value and the second power value, it is determined that the current is in the crystallization growth period; The real-time brine turbidity is greater than the second turbidity value, and the real-time agitator power is greater than the second power value, it is determined that the current is in the crystallization mature period; Step S3.3: based on the crystallization state, adjusting the real-time circulating water temperature and real-time circulating water flow rate of the circulating water.

[0008] Preferably, the method of adjusting the real-time circulating water temperature and real-time circulating water flow rate of the circulating water based on the crystallization state in step S3.3 comprises: When the current is in the crystallization induction period, the real-time circulating water temperature is kept 5-10℃ lower than the real-time brine temperature, and the real-time circulating water flow rate is kept the initial circulating water flow rate; When the current is in the crystallization growth period, the real-time circulating water temperature is kept 15-20℃ lower than the real-time brine temperature, and the real-time circulating water flow rate is kept 20-30% higher than the initial circulating water flow rate; When the current is in the crystallization mature period, the real-time circulating water temperature is kept 3-5℃ lower than the real-time brine temperature, and the real-time circulating water flow rate is kept 20-40% lower than the initial circulating water flow rate.

[0009] Preferably, step S3.2 further comprises a method for determining the crystallization point and the maturation point: Step S3.2.1: Calculate the real-time change rate of brine turbidity based on the real-time brine turbidity, and set a first turbidity change rate threshold and a second turbidity change rate threshold; Step S3.2.2: When the real-time change rate of brine turbidity is within the first turbidity change rate threshold, and the real-time brine turbidity and the real-time agitator power are close to the first turbidity value and the first power value respectively, it is determined that the current is the crystallization point, and the crystallization growth period is started; When the real-time change rate of brine turbidity is within the second turbidity change rate threshold, and the real-time brine turbidity and the real-time agitator power are close to the second turbidity value and the second power value respectively, it is determined that the current is the crystallization point, and the crystallization maturation period is started.

[0010] Preferably, the method for setting the first turbidity change rate threshold and the second turbidity change rate threshold in step S3.2.1 comprises: Collect multiple sets of brine turbidity time series data under the same process parameters, labeled with the crystallization point and the maturation point, and calculate the brine turbidity change rate corresponding to the crystallization point and the maturation point, respectively, to construct a crystallization point change rate sample set and a maturation point change rate sample set; Take 1-1.1 times of the arithmetic mean of the crystallization point change rate sample set as the first turbidity change rate threshold, and take 0.9-1.1 times of the arithmetic mean of the maturation point change rate sample set as the second turbidity change rate threshold.

[0011] Preferably, the crystallization point and the maturation point are labeled in the brine turbidity time series data by manually observing the crystallization conditions to obtain the brine turbidity time series data labeled with the crystallization point and the maturation point.

[0012] Preferably, it further comprises a method for identifying and processing the burst crystallization anomaly: When the real-time change rate of brine turbidity is greater than 2 times the arithmetic mean of the crystallization point change rate sample set, and the duration is greater than the preset duration, it is determined that the burst crystallization anomaly occurs; When the burst crystallization anomaly occurs, the real-time brine temperature is collected, and the real-time circulating water temperature is adjusted to be equal to the real-time brine temperature; When the real-time change rate of brine turbidity falls within 2 times the arithmetic mean of the crystallization point change rate sample set, it is determined that the burst crystallization anomaly is resolved, and the control parameters in the crystallization growth period are restored.

[0013] Preferably, it further comprises an abnormal condition identification method: When the real-time agitator power is greater than 1.2 times the initial agitator power for more than 5 minutes, it is identified as a crystal adhesion anomaly; When 10 times the real-time agitator power is less than the first power value for more than 35 minutes, it is identified as a nucleation failure anomaly.

[0014] A circulating water control system for the cooling crystallization vessel of a potassium-alkali brine desulfurization system is provided for implementing the circulating water control method for the cooling crystallization vessel of the aforementioned potassium-alkali brine desulfurization system. The system includes a temperature acquisition module, a turbidity acquisition module, a flow rate acquisition module, a stirrer power acquisition module, a control calculation module, an execution adjustment module, a data storage management module, and an anomaly detection module.

[0015] The beneficial effects of this invention are: Precise control of circulating water usage reduces energy consumption and production costs: This invention collects real-time data on the turbidity of the brine in the crystallization vessel and the power of the agitator, determines the crystallization stage based on the rate of change and threshold, and dynamically adjusts the circulating water flow rate and temperature. Compared with existing technologies that rely solely on experience or manual constant flow rate, this method achieves precise control of circulating water. This significantly reduces circulating water usage, lowers energy consumption of cooling equipment, and thus reduces production costs.

[0016] Improving crystallization control precision and product quality: By analyzing the change rate of brine turbidity, this invention can accurately determine the crystallization point and maturity point, and achieve fine control over the crystallization process, thereby avoiding uneven crystallization or incomplete crystallization caused by premature or late cooling. Strong anomaly handling capability ensures production stability: This invention provides identification and handling strategies for crystallization anomalies. When the rate of change of brine turbidity increases abnormally and continues, the circulating water temperature and flow rate are automatically adjusted to avoid losses caused by uncontrolled crystallization. This enhances the stability and safety of the system and ensures the reliability of continuous production. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart of the cooling crystallization kettle circulating water control method for a potassium-alkali brine desulfurization system; Detailed Implementation

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0020] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, these are merely examples and are not intended to limit the present invention.

[0021] The embodiments of the invention will now be described in detail with reference to the accompanying drawings.

[0022] Example 1

[0023] Reference Figure 1 This embodiment describes the basic method of regulating the circulating water in the cooling crystallization vessel of a potassium alkali brine desulfurization system.

[0024] This embodiment is applicable to a cooling crystallization vessel equipped with a circulating water jacket and a constant-speed stirrer; wherein, the circulating water jacket is set on the outer wall of the cooling crystallization vessel, and the circulating water jacket is provided with a cooling water flow channel to reduce the temperature of the solution in the crystallization vessel, and a water supply device for circulating water to the circulating water flow channel in the circulating water jacket can change the flow rate and temperature of the circulating water; wherein, the constant-speed stirrer is used to stir the solution in the vessel at a constant speed, and the power value of the constant-speed stirrer can be provided; In addition, a turbidity sensor is installed inside the crystallization vessel to detect the turbidity of the solution, so as to reflect the change in the number of crystal particles in the solution in real time. A water pump or regulating valve is also installed to adjust the flow rate of the circulating water injected into the circulating water jacket, so as to achieve precise control of the circulating water flow rate. When implementing this method, in order to ensure the repeatability and stability of experimental or production conditions, the process parameters should be kept consistent, that is, the concentration and temperature of the nitrate-rich brine entering the cooling crystallization vessel each time should be kept constant. For example, this application is applicable to nitrate-rich brine with a composition of 18% KCl, 3.1% K2SO4 and a temperature of 35°C, which crystallizes K2SO4 in the nitrate-rich brine and increases the KCl concentration in the nitrate-rich brine to 25%.

[0025] A method for regulating the circulating water in the cooling crystallization vessel of a potassium-alkali desulfurization system includes the following steps: Step S1: Obtain the initial brine temperature of the nitrate-rich concentrated brine. A specific case applies to a nitrate-rich concentrated brine with an initial brine temperature of 35℃ and a composition of 18% KCl and 3.1% K2SO4. Based on the initial brine temperature, determine the initial circulating water temperature in the cooling water channel on the outer wall of the crystallizing vessel during startup. The initial brine temperature should be higher than the initial circulating water temperature. The difference between the initial circulating water temperature and the initial brine temperature is related to the composition of the nitrate-rich concentrated brine. In the specific case mentioned above, the initial circulating water temperature is set 3-5℃ lower than the initial brine temperature, i.e., the initial circulating water temperature is set to 30-32℃. In addition, a circulating water temperature lower than the brine temperature can increase the supersaturation of the solution and induce crystal formation, but it should not be too low to avoid crystal bursting. Simultaneously, the initial circulating water flow rate and the initial agitator power of the constant-speed agitator on the cooling crystallizer are preset. In this embodiment, the method for presetting the initial circulating water flow rate includes: collecting historical operating data of multiple sets of cooling with different initial circulating water flow rates under the same process parameters (here, the same process parameters refer to concentrated brine with the same composition and initial brine temperature as in this embodiment, the same below), plotting the correspondence curve between circulating water flow rate and crystallization induction period duration, and taking the circulating water flow rate when the crystallization induction period duration is 30 min as the preset initial circulating water flow rate; the crystallization induction period duration selected in this embodiment is 30 min, which is determined based on the composition and temperature of the concentrated brine. In the specific implementation process, the initial circulating water flow rate suitable for production needs can be determined based on the composition and initial temperature of the concentrated brine. However, the crystallization induction period duration should not be too short, as too short a duration will lead to crystal precipitation too quickly and abnormal crystal bursting. The crystallization induction period duration should also not be too long, which will lead to an increase in production costs.

[0026] Step S2: Collect the real-time brine temperature, real-time brine turbidity, real-time circulating water flow rate, and real-time agitator power of the constant speed agitator on the cooling crystallization vessel. In this embodiment, the real-time turbidity of the nitrate-rich brine is collected by a turbidity sensor installed inside the crystallization vessel for detecting solution turbidity; the real-time circulating water flow rate is collected by a water supply device that provides circulating water to the circulating water channel inside the circulating water jacket; and the real-time agitator power of the constant-speed agitator is provided by the constant-speed agitator.

[0027] Step S3: Based on the real-time brine temperature, brine turbidity, and real-time mixer power, dynamically adjust the real-time circulating water temperature and real-time circulating water flow rate. In this embodiment, the specific method for dynamically adjusting the real-time circulating water temperature and real-time circulating water flow rate includes: Step S3.1: Set a first turbidity value, a second turbidity value, a first power value, and a second power value; wherein, the first turbidity value is less than the second turbidity value, and the first power value is less than the second power value; Simply setting the first turbidity value, the second turbidity value, the first power value, and the second power value can only roughly determine the crystallization point and maturity point of the crystallization process. Therefore, in this embodiment, the first turbidity value, the second turbidity value, the first power value, and the second power value do not need to be the precise values ​​at the crystallization point and maturity point, and in fact, it is impossible to determine the crystallization point and maturity point very accurately. Among them, the turbidity of the brine at the crystallization point is the first turbidity value, and the power of the agitator is the first power value; the turbidity of the brine at the maturity point is the second turbidity value, and the power of the agitator is the second power value.

[0028] Step S3.2: Compare the real-time brine turbidity with the first turbidity value and the second turbidity value respectively, and compare the real-time agitator power with the first power value and the second power value respectively, so as to determine the crystallization period; If the real-time brine turbidity is less than the first turbidity value and the real-time agitator power is less than the first power value, it is determined that the current period is in the crystallization induction phase. If the real-time brine turbidity is between the first turbidity value and the second turbidity value, and the real-time agitator power is between the first power value and the second power value, it is determined that the current stage is the crystallization growth stage. If the real-time brine turbidity is greater than the second turbidity value, and the real-time mixer power is greater than the second power value, it is determined that the current crystallization maturation period is underway.

[0029] Step S3.3: Based on the crystallization state, adjust the real-time circulating water temperature and real-time circulating water flow rate; In this embodiment, the specific method for adjusting the real-time circulating water temperature and real-time circulating water flow rate based on the crystallization state in step S3.3 includes: When the crystallization induction period is in progress, keep the real-time circulating water temperature 5-10℃ lower than the real-time brine temperature, and keep the real-time circulating water flow rate at the initial circulating water flow rate. When the crystallization growth phase is underway, maintain the real-time circulating water temperature 15-20°C lower than the real-time brine temperature, and maintain the real-time circulating water flow rate 20-30% higher than the initial circulating water flow rate. When the crystallization process is in progress, the real-time circulating water temperature should be kept 3-5°C lower than the real-time brine temperature, and the real-time circulating water flow rate should be kept 20-40% lower than the initial circulating water flow rate.

[0030] The specific values ​​for real-time circulating water temperature regulation and real-time circulating water flow rate regulation involved in the above-mentioned specific methods for regulating the real-time circulating water temperature and real-time circulating water flow rate are related to the composition and initial temperature of the nitrate-rich brine. The dynamic adjustment principle of circulating water temperature and flow rate is as follows: during the induction period, the temperature and flow rate are kept stable to control the number of crystal nuclei; during the growth period, the temperature is reduced and the flow rate is increased to accelerate crystal growth; during the maturation period, the temperature is slightly increased and the flow rate is reduced to slow down crystal growth and improve crystal integrity. Through this control, crystals with uniform particle size and regular shape can be obtained, preventing crystal bursting and improving production efficiency and product qualification rate.

[0031] Example 2 Based on the above Example 1, in order to more accurately and timely determine the crystallization point and maturity point of the crystallization process, and thus accurately determine the crystallization state.

[0032] Step S3.2 also includes methods for determining the crystallization point and maturity point: Step S3.2.1: Calculate the real-time turbidity change rate of brine based on the real-time brine turbidity, and set the first turbidity change rate threshold and the second turbidity change rate threshold.

[0033] Step S3.2.2: When the real-time change rate of brine turbidity is at the first turbidity change rate threshold, and the real-time brine turbidity and the real-time agitator power are close to the first turbidity value and the first power value respectively, it is determined that the current point is the crystallization point and the crystallization growth period begins. The phrase "the real-time brine turbidity and the real-time mixer power are close to the first turbidity value and the first power value, respectively" means that the real-time brine turbidity and the first turbidity value are within a certain error range, and the real-time mixer power and the first power value are also within a certain error range. In a specific case, the real-time brine turbidity is 95-105% of the first turbidity value, and the real-time mixer power is 95-105% of the first power value.

[0034] When the real-time change rate of brine turbidity is at the second turbidity change rate threshold, and the real-time brine turbidity and the real-time mixer power are close to the second turbidity value and the second power value respectively, it is determined that the current point is the crystallization point and the crystallization maturation period begins.

[0035] In this embodiment, the specific method for setting the first turbidity change rate threshold and the second turbidity change rate threshold in step S3.2.1 includes: Collect brine turbidity time series data with crystallization point and maturity point marked under multiple sets of the same process parameters, and calculate the brine turbidity change rate corresponding to the crystallization point and maturity point, and construct crystallization point change rate sample set and maturity point change rate sample set respectively. The turbidity change rate of the brine is ΔT / Δt, where ΔT is the turbidity change rate, ΔT is the change in brine turbidity before and after the sampling interval, and Δt is the sampling interval of the turbidity sensor. This step can reveal the dynamic change characteristics of brine turbidity at the crystallization point and maturity point. The brine turbidity time series data marked with crystallization points and maturity points were obtained by manually observing the crystallization process and marking the crystallization points and maturity points in the brine turbidity time series data; the specific brine turbidity time series data marked with crystallization points and maturity points can be obtained through multiple previous experiments.

[0036] The first turbidity change rate threshold is set at 1-1.1 times the arithmetic mean of the crystallization point change rate sample set, and the second turbidity change rate threshold is set at 0.9-1.1 times the arithmetic mean of the maturity point change rate sample set.

[0037] Example 3 Based on the above embodiment 2, in order to further identify abnormal situations in production, the following steps are also included: It also includes methods for identifying and handling crystal burst anomalies.

[0038] Crystal bursting anomalies are usually caused by excessively high solution supersaturation, leading to uncontrolled crystal nucleation and growth. Crystal bursting anomalies only occur during the crystallization growth period.

[0039] Methods for identifying and handling abnormal crystallization: When the real-time change rate of saline turbidity is greater than twice the arithmetic mean of the crystallization point change rate sample set, and the duration is longer than the preset duration, such as 1 minute, an abnormal crystallization is determined to have occurred. When crystal bursting occurs, the real-time brine temperature is collected, and the real-time circulating water temperature is adjusted to be equal to the real-time brine temperature. When the real-time change rate of brine turbidity falls back to within twice the arithmetic mean of the crystallization point change rate sample set, the abnormal crystallization is determined to be resolved, and the control parameters are restored to those during the crystallization growth period.

[0040] It also includes methods for identifying abnormal operating conditions: When the real-time mixer power is greater than 1.2 times the initial mixer power and the duration exceeds 5 minutes, it is identified as an abnormal crystal adhesion. When the real-time mixer power is 10 times less than the first power value and the duration exceeds 35 minutes, it is identified as a nucleation failure anomaly; that is, no crystal nuclei appear for a long time.

[0041] Example 4 A circulating water control system for the cooling crystallization vessel of a potassium-alkali brine desulfurization system is provided for implementing the circulating water control method for the cooling crystallization vessel of the potassium-alkali brine desulfurization system described in Examples 1 to 3. The system includes a temperature acquisition module, a turbidity acquisition module, a flow rate acquisition module, a stirrer power acquisition module, a control calculation module, an execution adjustment module, a data storage management module, and an anomaly detection module.

[0042] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for regulating the circulating water in the cooling crystallization vessel of a potassium-alkali desulfurization system, characterized in that: Includes the following steps: Step S1: Obtain the initial brine temperature of the nitrate-rich concentrated brine, and based on the initial brine temperature, determine the initial circulating water temperature in the cooling water channel on the outer wall of the cooling crystallizer during startup, while simultaneously setting the initial circulating water flow rate and the initial agitator power of the constant-speed agitator on the cooling crystallizer; wherein, the initial brine temperature is higher than the initial circulating water temperature. Step S2: Collect real-time brine temperature, real-time brine turbidity, real-time circulating water flow rate, and real-time agitator power of the nitrate-rich concentrated brine. Step S3: Based on the real-time brine temperature, real-time brine turbidity, and real-time mixer power, dynamically adjust the real-time circulating water temperature and real-time circulating water flow rate.

2. The method for regulating the circulating water in the cooling crystallization vessel of the potassium alkali desulfurization system as described in claim 1, characterized in that: The dynamic adjustment method in step S3 includes: Step S3.1: Set a first turbidity value, a second turbidity value, a first power value, and a second power value; wherein, the first turbidity value is less than the second turbidity value, and the first power value is less than the second power value; Step S3.2: Compare the real-time brine turbidity with the first turbidity value and the second turbidity value respectively, and compare the real-time agitator power with the first power value and the second power value respectively to determine the crystallization period; If the real-time brine turbidity is less than the first turbidity value and the real-time agitator power is less than the first power value, it is determined that the current period is in the crystallization induction phase. If the real-time brine turbidity is between the first turbidity value and the second turbidity value, and the real-time agitator power is between the first power value and the second power value, it is determined that the current stage is the crystallization growth stage. If the real-time brine turbidity is greater than the second turbidity value, and the real-time agitator power is greater than the second power value, it is determined that the crystallization maturation period is currently underway. Step S3.3: Based on the crystallization state, adjust the real-time circulating water temperature and real-time circulating water flow rate.

3. The method for regulating the circulating water in the cooling crystallization vessel of the potassium alkali brine desulfurization system as described in claim 2, characterized in that: The method for adjusting the real-time circulating water temperature and real-time circulating water flow rate based on the crystallization state in step S3.3 includes: When the crystallization induction period is in progress, keep the real-time circulating water temperature 5-10℃ lower than the real-time brine temperature, and keep the real-time circulating water flow rate at the initial circulating water flow rate. When the crystallization growth phase is underway, maintain the real-time circulating water temperature 15-20°C lower than the real-time brine temperature, and maintain the real-time circulating water flow rate 20-30% higher than the initial circulating water flow rate. When the crystallization process is in progress, the real-time circulating water temperature should be kept 3-5°C lower than the real-time brine temperature, and the real-time circulating water flow rate should be kept 20-40% lower than the initial circulating water flow rate.

4. The method for regulating the circulating water in the cooling crystallization vessel of the potassium alkali brine desulfurization system as described in claim 2, characterized in that: Step S3.2 also includes methods for determining the crystallization point and maturity point: Step S3.2.1: Calculate the real-time turbidity change rate of saline based on the real-time saline turbidity, and set the first turbidity change rate threshold and the second turbidity change rate threshold; Step S3.2.2: When the real-time change rate of brine turbidity is at the first turbidity change rate threshold, and the real-time brine turbidity and the real-time agitator power are close to the first turbidity value and the first power value respectively, it is determined that the current point is the crystallization point and the crystallization growth period begins. When the real-time change rate of brine turbidity is at the second turbidity change rate threshold, and the real-time brine turbidity and the real-time mixer power are close to the second turbidity value and the second power value respectively, it is determined that the current point is the crystallization point and the crystallization maturation period begins.

5. The method for regulating the circulating water in the cooling crystallization vessel of the potassium alkali brine desulfurization system as described in claim 4, characterized in that: The method for setting the first turbidity change rate threshold and the second turbidity change rate threshold in step S3.2.1 includes: Collect brine turbidity time series data with crystallization point and maturity point marked under multiple sets of the same process parameters, and calculate the brine turbidity change rate corresponding to the crystallization point and maturity point, and construct crystallization point change rate sample set and maturity point change rate sample set respectively. The first turbidity change rate threshold is set at 1-1.1 times the arithmetic mean of the crystallization point change rate sample set, and the second turbidity change rate threshold is set at 0.9-1.1 times the arithmetic mean of the maturity point change rate sample set.

6. The method for regulating the circulating water in the cooling crystallization vessel of the potassium alkali desulfurization system as described in claim 5, characterized in that: By manually observing the crystallization process, crystallization points and maturity points are marked in the brine turbidity time series data, resulting in brine turbidity time series data with marked crystallization points and maturity points.

7. The method for regulating the circulating water in the cooling crystallization vessel of the potassium alkali desulfurization system as described in claim 4, characterized in that: It also includes methods for identifying and handling crystal burst anomalies: When the real-time change rate of brine turbidity is greater than twice the arithmetic mean of the crystallization point change rate sample set, and the duration is longer than the preset duration, it is determined that a crystal bursting anomaly has occurred. When crystal bursting occurs, the real-time brine temperature is collected, and the real-time circulating water temperature is adjusted to be equal to the real-time brine temperature. When the real-time change rate of brine turbidity falls back to within twice the arithmetic mean of the crystallization point change rate sample set, the abnormal crystallization is determined to be resolved, and the control parameters are restored to those during the crystallization growth period.

8. The method for regulating the circulating water in the cooling crystallization vessel of the potassium alkali brine desulfurization system as described in claim 4, characterized in that: It also includes methods for identifying abnormal operating conditions: When the real-time mixer power is greater than 1.2 times the initial mixer power and the duration exceeds 5 minutes, it is identified as an abnormal crystal adhesion. When the real-time mixer power is 10 times less than the first power value and the duration exceeds 35 minutes, it is identified as a nucleation failure anomaly.

9. The method for regulating the circulating water in the cooling crystallization vessel of the potassium alkali desulfurization system as described in claim 1, characterized in that: The initial circulating water temperature is 3-5℃ lower than the initial brine temperature; Methods for preset initial circulating water flow rate include: Collect historical operating data of cooling with different initial circulating water flow rates under the same process parameters, plot the curve of the relationship between circulating water flow rate and the duration of crystallization induction period, and take the circulating water flow rate when the duration of crystallization induction period is 30 min as the preset initial circulating water flow rate.

10. A circulating water control system for the cooling crystallization vessel in a potassium-alkali brine desulfurization system, characterized in that: The method for regulating the circulating water of the cooling crystallization vessel in the potassium alkali brine desulfurization system according to claims 1-9 includes a temperature acquisition module, a turbidity acquisition module, a flow rate acquisition module, a stirrer power acquisition module, a control calculation module, an execution adjustment module, a data storage management module, and an anomaly detection module.

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