CN118387956B - Multi-effect evaporation intelligent control method and system for desulfurization wastewater - Google Patents

Abstract

The invention relates to the technical field of wastewater data processing, in particular to a multi-effect evaporation intelligent control method and system for desulfurization wastewater, comprising the following steps: acquiring a monitoring data sequence and an ion concentration data sequence of desulfurization wastewater in a plurality of evaporation processes of a single-effect evaporator in a multi-effect evaporation system; acquiring an evaporation achievement rate factor of each monitoring time; obtaining a comparative scaling index of the single-effect evaporator in each evaporation process; obtaining the scale formation grade of a single-effect evaporator; acquiring an adjusted proportional gain coefficient; and controlling and adjusting the multi-effect evaporation system according to the adjusted proportional gain coefficient. The invention improves the accuracy of adjusting and controlling the desulfurization wastewater in the evaporation operation process.

Description

A multi-effect evaporation intelligent control method and system for desulfurization wastewater

Technical Field

The present invention relates to the technical field of wastewater data processing, and in particular to an intelligent control method and system for multi-effect evaporation of desulfurized wastewater.

Background Art

Desulfurization wastewater is wastewater generated in industrial processes such as thermal power plants and steel mills. This wastewater contains high concentrations of sulfates, chlorides and other harmful substances, and direct discharge will cause serious pollution to the environment. In order to treat this wastewater, multi-effect evaporation technology is widely used. However, due to the relatively high influence of temperature on the precipitation of inorganic salts, it is very easy for inorganic salt compounds in desulfurization wastewater to precipitate and adhere to the multi-effect evaporator system. For the scaling problem of single-effect evaporators, the existing solution is mainly to acid wash and neutral clean the outer wall of the single-effect evaporator, but this method cannot optimize the desulfurization wastewater during the evaporation operation, and when the single-effect evaporator is scaled, it may affect the monitoring process of the sensor, further resulting in reduced control accuracy of the multi-effect evaporation system.

Summary of the invention

In order to solve the above problems, the present invention provides an intelligent control method and system for multi-effect evaporation of desulfurization wastewater.

An embodiment of the present invention provides an intelligent control method for multi-effect evaporation of desulfurized wastewater, the method comprising the following steps:

Obtaining a monitoring data sequence and an ion concentration data sequence of desulfurization wastewater in a single-effect evaporator in a multiple-effect evaporation system during several evaporation processes; the monitoring data sequence includes several dimensional monitoring data of several monitoring times; each dimensional monitoring data corresponds to a target data value; the ion concentration data sequence includes desulfurization wastewater concentrate volume data and initial ion concentration data of several ions; each ion corresponds to a solubility product constant;

According to the differences between different dimensional monitoring data at adjacent monitoring times, and the differences between different dimensional monitoring data and corresponding target data values, the evaporation achievement rate factor at each monitoring time is obtained; according to the evaporation achievement rate factor of the single-effect evaporator at different monitoring times in different evaporation processes, and the differences between the monitoring data sequences of desulfurization wastewater in different evaporation processes, the comparative scaling index of the single-effect evaporator in each evaporation process is obtained;

According to the comparison of scaling index and the difference between the initial ion concentration data of different ions in the ion concentration data sequence during different evaporation processes and the corresponding solubility product constant, the scaling level of the single-effect evaporator is obtained; and the adjusted proportional gain coefficient is obtained according to the scaling level of the single-effect evaporator;

The multi-effect evaporation system is controlled and adjusted according to the adjusted proportional gain coefficient.

Preferably, the evaporation achievement rate factor at each monitoring time is obtained according to the difference between the monitoring data of different dimensions at adjacent monitoring times, and the difference between the monitoring data of different dimensions and the corresponding target data value, including the specific method of:

For the monitoring data sequence of desulfurization wastewater in any evaporation process of the single-effect evaporator, the evaporation rate characteristic factor of each dimension monitoring data at each monitoring time is obtained according to the difference between the monitoring data of each dimension at adjacent monitoring times, and the difference between the monitoring data of each dimension and the corresponding target data value;

The monitoring data sequence of desulfurization wastewater The normalized value of the cumulative sum of the evaporation rate characteristic factors of all dimensional monitoring data at the monitoring time is taken as the first The evaporation rate factor for the monitoring time.

Preferably, the specific method of obtaining the evaporation rate characteristic factor of each dimension monitoring data at each monitoring time includes:

The monitoring data sequence of desulfurization wastewater The monitoring time The monitoring data of the first dimension and the The monitoring time The absolute value of the difference between the monitoring data of the first dimension is recorded as the difference between the left and right monitoring data. The monitoring time The monitoring data of the first dimension and the The monitoring time The absolute value of the difference between the monitoring data of the first dimension is recorded as the difference between the monitoring data on the right side; the average of the difference between the monitoring data on the left side and the monitoring data on the right side is recorded as The mean of the adjacent differences of the monitoring data in the dimension; The monitoring time The monitoring data of the first dimension and the The absolute value of the difference between the target data values corresponding to the monitoring data of the first dimension is recorded as The evaporation target factor of the monitoring data of the first dimension; The mean of adjacent differences of the monitoring data of the first dimension The ratio of the evaporation target factors of the monitoring data of the first dimension is used as the The monitoring time Evaporation rate characteristic factors of monitoring data in different dimensions.

Preferably, the comparative scaling index of the single-effect evaporator in each evaporation process is obtained according to the evaporation rate factor of the single-effect evaporator at different monitoring times in different evaporation processes, and the difference between the monitoring data sequences of the desulfurization wastewater in different evaporation processes, including the specific method of:

For the single-effect evaporator During the second evaporation process, according to The second evaporation process and the The difference between the monitoring data series of desulfurization wastewater in the first evaporation process is obtained. The second evaporation process and the Comparison weight factor between sub-evaporation processes;

According to The difference in evaporation rate factor between the second evaporation process and other evaporation processes at different monitoring times is used to obtain the single-effect evaporator in the first The second evaporation process and the Factors affected by scaling between evaporation processes;

The single-effect evaporator is The second evaporation process and the The product of the inverse of the comparison weight factor between the evaporation processes and the scaling factor is recorded as the single-effect evaporator in the first The second evaporation process and the The first product between the evaporation processes; the single-effect evaporator in the The normalized value of the mean of the first product between the second evaporation process and all other evaporation processes is used as the value of the first product of the single-effect evaporator in the Comparative fouling index during secondary evaporation.

Preferably, the single-effect evaporator is obtained at The second evaporation process and the The comparison weight factor between the sub-evaporation processes includes the following specific methods:

The first The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The monitoring time The monitoring data of the first dimension and the The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The monitoring time The absolute value of the difference between the monitoring data of the first dimension is recorded as The second evaporation process and the The first The comparison factor of the monitoring data of the first dimension The second evaporation process and the The average value of the contrast factor of all dimensional monitoring data between the evaporation processes is used as the single-effect evaporator in the first The second evaporation process and the Weight factor for comparison between evaporation processes.

Preferably, the single-effect evaporator is obtained at The second evaporation process and the The factors affected by scaling between the sub-evaporation processes include the following specific methods:

The first The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The evaporation rate factor of the first monitoring time is The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The square value of the difference in the evaporation rate factor at each monitoring time is recorded as The second evaporation process and the During the evaporation process The first square value of the monitoring time; The second evaporation process and the The average of the first square values of all monitoring times during the first evaporation process is used as the value of the single-effect evaporator in the first The second evaporation process and the Factors affected by scaling between evaporation processes.

Preferably, the scaling level of the single-effect evaporator is obtained by comparing the scaling index and the difference between the initial ion concentration data of different ions in the ion concentration data sequence in different evaporation processes and the corresponding solubility product constant, including the specific method of:

According to the difference between the initial ion concentration data of different ions in the ion concentration data sequence during different evaporation processes and the corresponding solubility product constant, the precipitation scaling influencing parameters of the single-effect evaporator are obtained;

The average value of the comparative scaling index of the single-effect evaporator in all evaporation processes is recorded as the first average value; the first average value and the average value of the precipitation scaling influencing parameter of the single-effect evaporator are taken as the scaling grade of the single-effect evaporator.

Preferably, the obtaining of the precipitation scaling influencing parameters of the single-effect evaporator comprises the following specific methods:

For the single-effect evaporator During the second evaporation process, The ion concentration data series of desulfurization wastewater during the secondary evaporation process The ratio of the initial ion concentration data of the ion and its corresponding solubility product constant is used as the The precipitation possibility of the first ion The mean of the precipitation probability of all ions in the ion concentration data series of the desulfurization wastewater during the first evaporation process is used as the The possible factors for the precipitation of ions during the first evaporation process; The product of the desulfurization wastewater concentrate volume data in the desulfurization wastewater ion concentration data sequence during the first evaporation process and the precipitation possible factor is used as the first The precipitation scaling factor in the secondary evaporation process; the normalized value of the product of the cumulative sum of the precipitation scaling factors in all the secondary evaporation processes and the total number of all the secondary evaporation processes of the single-effect evaporator is used as the precipitation scaling influencing parameter of the single-effect evaporator.

Preferably, the method of obtaining the adjusted proportional gain coefficient according to the scaling level of the single-effect evaporator includes:

The initial proportional gain coefficient of the PID controller in the multi-effect evaporation system is obtained by the Ziegler-Nichols rule; the sum of the scaling level of the single-effect evaporator and 1 is recorded as the first sum value; the product of the first sum value and the initial proportional gain coefficient is used as the adjusted proportional gain coefficient.

The present invention also proposes an intelligent control system for multi-effect evaporation of desulfurized wastewater, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, any one of the steps of the intelligent control method for multi-effect evaporation of desulfurized wastewater is implemented.

The beneficial effects of the technical solution of the present invention are as follows: the present invention obtains the comparative scaling index of the single-effect evaporator in each evaporation process according to the evaporation rate factor of the single-effect evaporator at different monitoring times in different evaporation processes and the difference between the monitoring data sequences of desulfurization wastewater in different evaporation processes; compares the monitoring data of various dimensions of the single-effect evaporator in several evaporation processes, and analyzes the evaporation rate factor of the single-effect evaporator at different monitoring times in different evaporation processes, thereby reflecting the comparative scaling index of the single-effect evaporator; according to the comparative scaling index, and the initial ion concentration data of different ions in the ion concentration data sequence in different evaporation processes and the comparison of the scaling index, the comparative scaling index of the single-effect evaporator is obtained. The scaling level of the single-effect evaporator is obtained according to the difference in solubility product constants; the adjusted proportional gain coefficient is obtained according to the scaling level of the single-effect evaporator; the scaling level of the single-effect evaporator is obtained in combination with the difference between the ion concentration data sequences in different evaporation processes; during the evaporation process, the greater the scaling level of the single-effect evaporator, the greater the impact on the heat transfer efficiency of the evaporation process, so it is necessary to adjust the proportional gain coefficient so that PID can output the control amount stably as much as possible under the nonlinear operating state; the multi-effect evaporation system is controlled and adjusted according to the adjusted proportional gain coefficient; thereby improving the accuracy of adjustment and control of desulfurization wastewater during the evaporation operation process.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a flow chart of the steps of an intelligent control method for multi-effect evaporation of desulfurized wastewater according to the present invention;

FIG. 2 is a characteristic relationship flow chart of intelligent control of multi-effect evaporation for desulfurization wastewater according to the present invention.

DETAILED DESCRIPTION

In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of the intelligent control method and system for multi-effect evaporation of desulfurized wastewater proposed by the present invention, its specific implementation method, structure, characteristics and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The specific scheme of the intelligent control method and system for multi-effect evaporation of desulfurization wastewater provided by the present invention is described in detail below with reference to the accompanying drawings.

Please refer to FIG. 1 , which shows a flowchart of a multi-effect evaporation intelligent control method for desulfurization wastewater provided by an embodiment of the present invention. The method comprises the following steps:

Step S001: Obtain a monitoring data sequence and an ion concentration data sequence of desulfurization wastewater during several evaporation processes of a single-effect evaporator in a multiple-effect evaporation system; the monitoring data sequence includes several dimensional monitoring data of several monitoring times; each dimensional monitoring data corresponds to a target data value; the ion concentration data sequence includes the desulfurization wastewater concentrate volume data and the initial ion concentration data of several ions; each ion corresponds to a solubility product constant.

It should be noted that the treatment of desulfurization wastewater requires a multi-step process. The typical treatment method is to use the waste heat of low-temperature flue gas to evaporate and concentrate in the evaporator. As the evaporation and concentration proceed, the concentration of some desulfurization wastewater increases, requiring subsequent pressure filtration, flash evaporation and other treatments. When evaporating and concentrating, the method usually adopted is the multiple-effect evaporation method. The principle of this method is to connect multiple single-effect evaporators in series, and the secondary steam of the previous single-effect evaporator is used as the heating steam for the next single-effect evaporator. The heating chamber of the next single-effect evaporator is the condenser of the previous single-effect evaporator. When the desulfurization wastewater is heated in the heating system of the multiple-effect evaporation, it is very easy for the compounds in the desulfurization wastewater to precipitate and attach to the single-effect evaporator or heater to form dirt, affecting the accuracy of evaporation control. Therefore, it is necessary to combine the monitoring data of multiple single-effect evaporators in the multiple-effect evaporation system to control and adjust the multiple-effect evaporation.

Specifically, it is necessary to first collect the monitoring data series and ion concentration data series of the desulfurization wastewater during several evaporation processes of the single-effect evaporator. The specific process is as follows:

For any single-effect evaporator in the multi-effect evaporation system, a temperature sensor, a liquid level sensor, a concentration sensor and an ion concentration detector are installed on the single-effect evaporator. For any evaporation process of the single-effect evaporator, one minute is a monitoring time, and each time the sensor is used to collect three dimensional data types, namely, wastewater temperature data, wastewater liquid level data and wastewater concentration data, in turn, for a total of 3 hours; the three dimensional data of wastewater temperature data, wastewater liquid level data and wastewater concentration data at each monitoring time are used as the monitoring data sequence of the desulfurization wastewater during the evaporation process of the single-effect evaporator; the ion concentration detector is used to collect the concentrated liquid volume data of the desulfurization wastewater during the evaporation process of the single-effect evaporator and the initial ion concentration data of each ion in the desulfurization wastewater as the ion concentration data sequence of the desulfurization wastewater during the evaporation process of the single-effect evaporator.

Among them, the monitoring data sequence of desulfurization wastewater in any evaporation process of the single-effect evaporator includes several dimensional monitoring data of several monitoring times; each dimensional monitoring data corresponds to a target data value; the ion concentration data sequence of desulfurization wastewater includes the desulfurization wastewater concentrate volume data and the initial ion concentration data of several ions; each ion corresponds to a solubility product constant.

So far, the monitoring data sequence and ion concentration data sequence of the desulfurization wastewater in the single-effect evaporator during several evaporation processes are obtained through the above method.

Step S002: According to the differences between the monitoring data of different dimensions at adjacent monitoring times, and the differences between the monitoring data of different dimensions and the corresponding target data values, the evaporation achievement rate factor at each monitoring time is obtained; according to the evaporation achievement rate factor of the single-effect evaporator at different monitoring times in different evaporation processes, and the differences between the monitoring data sequences of the desulfurization wastewater in different evaporation processes, the comparative scaling index of the single-effect evaporator in each evaporation process is obtained.

It should be noted that in order to analyze the scaling condition of the single-effect evaporator through the monitoring data sequence of desulfurization wastewater, it is necessary to analyze the impact of scaling on the sensor and obtain the evaporation achievement rate factor at each monitoring time; the evaporation achievement rate factor mainly reflects the target achievement rate of the monitoring data of various dimensions of the single-effect evaporator during this evaporation process. This value can reflect the current evaporation efficiency, and since scaling may exist in the single-effect evaporator, it leads to heat transfer efficiency problems; in order to further improve the accuracy of scaling degree analysis, it is necessary to compare the monitoring data of various dimensions of the single-effect evaporator during several evaporation processes, and analyze the evaporation achievement rate factors of the single-effect evaporator at different monitoring times in different evaporation processes, thereby reflecting the comparative scaling index of the single-effect evaporator.

1. Obtain the evaporation rate factor at each monitoring time in the monitoring data sequence of desulfurization wastewater.

It should be noted that in order to analyze the scaling condition of the single-effect evaporator through the monitoring data sequence of desulfurization wastewater, it is necessary to analyze the impact of scaling on the sensor. As the evaporation process of desulfurization wastewater progresses, the monitoring data of the sensor is also constantly changing. Under normal circumstances, when the sensor detects that the monitoring data of any dimension of the monitoring data sequence in the evaporation process reaches the target data, the concentrated liquid produced after evaporation and the secondary evaporator enter the separator for separation, and the separated concentrated liquid enters the next single-effect evaporator for further evaporation, and the secondary steam is separated and enters the heating chamber of the next single-effect evaporator as heating steam. In the last single-effect evaporator, the concentrated liquid reaching the specified concentration is discharged through the material pump, and all the secondary steam is sent to the condenser for condensation. When the scaling degree of the condenser is different, the heat transfer efficiency and sensor accuracy of the single-effect evaporator are affected differently: scaling will increase the thickness of the heat exchanger wall, resulting in different degrees of thermal resistance; which in turn affects the change process of the sensor monitoring data within the same time. Therefore, it is necessary to evaluate the scaling condition of the single-effect evaporator, and first analyze the change process of the monitoring data of its sensor.

Preferably, in some implementations of the embodiments of the present invention, according to the difference between different dimensional monitoring data at adjacent monitoring times, and the difference between different dimensional monitoring data and corresponding target data values, the calculation method for obtaining the evaporation achievement rate factor at each monitoring time is:

For the monitoring data sequence of desulfurization wastewater in any evaporation process of the single-effect evaporator, the evaporation rate characteristic factor of each dimension of monitoring data at each monitoring time is obtained according to the difference between the monitoring data of each dimension at adjacent monitoring times, and the difference between the monitoring data of each dimension and the corresponding target data value;

The monitoring data sequence of desulfurization wastewater The normalized value of the cumulative sum of the evaporation rate characteristic factors of all dimensional monitoring data at the monitoring time is taken as the first The evaporation rate factor for the monitoring time.

The specific formula is:

In the formula, Indicates the monitoring data sequence of desulfurization wastewater Evaporation achievement rate factor for each monitoring time; Indicates the monitoring data sequence of desulfurization wastewater The monitoring time Evaporation rate characteristic factors of monitoring data in different dimensions; Indicates the number of types of monitoring data of all dimensions in the monitoring data sequence of desulfurization wastewater; represents the linear normalization function.

It should be noted that The monitoring time The larger the evaporation rate characteristic factor of the monitoring data in the first dimension is, the The monitoring time The faster the overall change rate of the monitoring data in the first dimension, the The greater the evaporation rate achieved during a monitoring period.

Preferably, in some implementations of the embodiments of the present invention, the method for obtaining the evaporation rate characteristic factor of each dimension of monitoring data at each monitoring time includes:

The monitoring data sequence of desulfurization wastewater The monitoring time The monitoring data of the first dimension and the The monitoring time The absolute value of the difference between the monitoring data of the first dimension is recorded as the difference between the left and right monitoring data. The monitoring time The monitoring data of the first dimension and the The monitoring time The absolute value of the difference between the monitoring data of the first dimension is recorded as the difference between the monitoring data on the right side; the average of the difference between the monitoring data on the left side and the monitoring data on the right side is recorded as The mean of the adjacent differences of the monitoring data in the dimension; The monitoring time The monitoring data of the first dimension and the The absolute value of the difference between the target data values corresponding to the monitoring data of the first dimension is recorded as The evaporation target factor of the monitoring data of the first dimension; The mean of adjacent differences of the monitoring data of the first dimension The ratio of the evaporation target factors of the monitoring data of the first dimension is used as the The monitoring time Evaporation rate characteristic factors of monitoring data in different dimensions.

The specific formula is:

In the formula, Indicates The monitoring time Evaporation rate characteristic factors of monitoring data in different dimensions; Indicates The monitoring time Dimensional monitoring data; Indicates The monitoring time The target data value of the monitoring data in each dimension; Indicates The monitoring time Dimensional monitoring data; Indicates The monitoring time Dimensional monitoring data; Indicates taking the absolute value.

It should be noted that since the target data values corresponding to monitoring data in different dimensions are different, it is difficult to obtain the evaporation rate characteristic factor of the monitoring data in each dimension only through the difference between the monitoring data in each dimension at adjacent monitoring times; therefore, it is necessary to constrain the difference between the monitoring data in each dimension and the corresponding target data value, and then obtain the evaporation rate characteristic factor of the monitoring data in each dimension at each monitoring time.

At this point, the evaporation achievement rate factor at each monitoring time in the monitoring data sequence of the desulfurization wastewater is obtained.

2. Obtain the comparative scaling index of the single-effect evaporator during each evaporation process.

It should be noted that the evaporation achievement rate factor mainly reflects the target rate of the monitoring data of various dimensions of the single-effect evaporator during this evaporation process. This value can reflect the current evaporation efficiency. However, since scaling may exist in the single-effect evaporator, it will lead to heat transfer efficiency problems. In order to further improve the accuracy of scaling analysis, it is necessary to compare the monitoring data of various dimensions of the single-effect evaporator during several evaporation processes, and analyze the evaporation achievement rate factors of the single-effect evaporator at different monitoring times in different evaporation processes, so as to reflect the comparative scaling index of the single-effect evaporator.

Preferably, in some implementations of the embodiments of the present invention, according to the evaporation rate factor of the single-effect evaporator at different monitoring times in different evaporation processes, and the difference between the monitoring data sequences of the desulfurization wastewater in different evaporation processes, the calculation method for obtaining the comparative scaling index of the single-effect evaporator in each evaporation process is:

For the single-effect evaporator During the second evaporation process, according to The second evaporation process and the The difference between the monitoring data series of desulfurization wastewater in the first evaporation process is obtained. The second evaporation process and the Comparison weight factor between sub-evaporation processes;

According to The difference in evaporation rate factor between the second evaporation process and other evaporation processes at different monitoring times is used to obtain the single-effect evaporator in the first The second evaporation process and the Factors affected by scaling between evaporation processes;

The single-effect evaporator is The second evaporation process and the The product of the inverse of the comparison weight factor between the evaporation processes and the scaling factor is recorded as the single-effect evaporator in the first The second evaporation process and the The first product between the evaporation processes; the single-effect evaporator in the The normalized value of the mean of the first product between the second evaporation process and all other evaporation processes is used as the value of the first product of the single-effect evaporator in the Comparative fouling index during secondary evaporation.

The specific formula is:

In the formula, Indicates that the single-effect evaporator is Comparative fouling index during secondary evaporation; Represents the total number of all sub-evaporation processes of a single-effect evaporator; Indicates that the single-effect evaporator is The second evaporation process and the Comparison weight factor between sub-evaporation processes; Indicates that the single-effect evaporator is The second evaporation process and the Factors affected by scaling between evaporation processes; represents the hyperbolic tangent function.

It should be noted that the single-effect evaporator The second evaporation process and the The smaller the comparison weight factor between the evaporation processes, the The initial state of the monitoring data sequence of desulfurization wastewater during the first evaporation process is different from that of the first The conditions in the first evaporation process are similar, so the comparison of these two data is more referenceable; the single-effect evaporator The second evaporation process and the The greater the scaling factor between the evaporation processes, the The greater the degree of influence on the evaporation rate of the secondary evaporation process, the greater the comparative scaling index.

Preferably, in some implementations of the embodiments of the present invention, the single-effect evaporator is The second evaporation process and the The method for obtaining the comparison weight factor between the sub-evaporation processes includes:

The first The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The monitoring time The monitoring data of the first dimension and the The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The monitoring time The absolute value of the difference between the monitoring data of the first dimension is recorded as The second evaporation process and the The first The comparison factor of the monitoring data of the first dimension The second evaporation process and the The average value of the contrast factor of all dimensional monitoring data between the evaporation processes is used as the single-effect evaporator in the first The second evaporation process and the Weight factor for comparison between evaporation processes.

The specific formula is:

In the formula, Indicates that the single-effect evaporator is The second evaporation process and the Comparison weight factor between sub-evaporation processes; Indicates the number of types of monitoring data of all dimensions in the monitoring data sequence of desulfurization wastewater; Indicates The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The monitoring time Dimensional monitoring data; Indicates The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The monitoring time Dimensional monitoring data; Indicates taking the absolute value.

It should be noted that due to the different initial conditions of desulfurization wastewater in different evaporation processes, the evaporation rate will also be different. The accuracy of the comparison of the monitoring data between the first evaporation process and other evaporation processes can be improved by amplifying the comparison between other evaporation processes and the first The comparison of the initial conditions of the desulfurized wastewater between the evaporation processes; the single-effect evaporator in the first The second evaporation process and the The smaller the comparison weight factor between the evaporation processes, the The initial state of the monitoring data sequence of desulfurization wastewater during the first evaporation process is different from that of the first The conditions during the two evaporation processes are similar, so the comparison of these two data is more relevant. The larger the scaling index, the better.

Preferably, in some implementations of the embodiments of the present invention, the single-effect evaporator is The second evaporation process and the The method for obtaining the factors affected by scaling between the sub-evaporation processes includes:

The first The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The evaporation rate factor of the first monitoring time is The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The square value of the difference in the evaporation rate factor at each monitoring time is recorded as The second evaporation process and the During the evaporation process The first square value of the monitoring time; The second evaporation process and the The average of the first square values of all monitoring times during the first evaporation process is used as the value of the single-effect evaporator in the first The second evaporation process and the Factors affected by scaling between evaporation processes.

The specific formula is:

In the formula, Indicates that the single-effect evaporator is The second evaporation process and the Factors affected by scaling between evaporation processes; It represents the total number of all monitoring times in the monitoring data sequence of desulfurization wastewater during the evaporation process; Indicates The monitoring data sequence of desulfurization wastewater during the secondary evaporation process Evaporation achievement rate factor for each monitoring time; Indicates The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The evaporation rate factor for the monitoring time.

It should be noted that by comparing The second evaporation process and the The difference in evaporation rate factor at different monitoring times between evaporation processes reflects the heat difference at the same monitoring time of the evaporation process, and further reflects the impact of scaling on heat transfer efficiency.

So far, the comparative scaling index of the single-effect evaporator in each evaporation process is obtained by the above method.

Step S003: Obtain the scaling level of the single-effect evaporator according to the comparison of scaling index and the difference between the initial ion concentration data of different ions in the ion concentration data sequence in different evaporation processes and the corresponding solubility product constant; obtain the adjusted proportional gain coefficient according to the scaling level of the single-effect evaporator.

It should be noted that it is impossible to directly express the scaling degree of the single-effect evaporator by comparing the scaling index in different evaporation processes; therefore, it is necessary to obtain the scaling level of the single-effect evaporator in combination with the difference between the ion concentration data sequences in different evaporation processes; in the evaporation process, the greater the scaling level of the single-effect evaporator, the greater the impact on the heat transfer efficiency of the evaporation process, so it is necessary to adjust the proportional gain coefficient so that the PID can output the control amount as stably as possible under the nonlinear operating state.

1. Obtain the scaling level of the single-effect evaporator.

It should be noted that in order to accurately analyze the scaling degree of the single-effect evaporator, it is easy to cause scaling of the single-effect evaporator by various ions during multiple evaporation processes by comparing the monitoring data series of desulfurization wastewater; and thus it is impossible to directly express the scaling degree of the single-effect evaporator by comparing the scaling index in different evaporation processes; therefore, it is necessary to combine the differences between the ion concentration data series in different evaporation processes to obtain the scaling level of the single-effect evaporator.

Preferably, in some implementations of the embodiments of the present invention, the calculation method for obtaining the scaling level of the single-effect evaporator is as follows:

According to the difference between the initial ion concentration data of different ions in the ion concentration data sequence during different evaporation processes and the corresponding solubility product constant, the precipitation scaling influencing parameters of the single-effect evaporator are obtained;

The average value of the comparative scaling index of the single-effect evaporator in all evaporation processes is recorded as the first average value; the first average value and the average value of the precipitation scaling influencing parameter of the single-effect evaporator are taken as the scaling grade of the single-effect evaporator.

Preferably, in some implementations of the embodiments of the present invention, the method for obtaining the precipitation scaling influencing parameters of the single-effect evaporator includes:

For the single-effect evaporator During the second evaporation process, The ion concentration data series of desulfurization wastewater during the secondary evaporation process The ratio of the initial ion concentration data of the ion and its corresponding solubility product constant is used as the The precipitation possibility of the first ion The mean of the precipitation probability of all ions in the ion concentration data series of the desulfurization wastewater during the first evaporation process is used as the The possible factors for the precipitation of ions during the first evaporation process; The product of the desulfurization wastewater concentrate volume data in the desulfurization wastewater ion concentration data sequence during the first evaporation process and the precipitation possible factor is used as the first The precipitation scaling factor in the secondary evaporation process; the normalized value of the product of the cumulative sum of the precipitation scaling factors in all the secondary evaporation processes and the total number of all the secondary evaporation processes of the single-effect evaporator is used as the precipitation scaling influencing parameter of the single-effect evaporator.

The specific formula is:

In the formula, Indicates the parameters affecting the precipitation and scaling of the single-effect evaporator; Represents the total number of all sub-evaporation processes of a single-effect evaporator; Indicates The data of the concentrated liquid volume of desulfurized wastewater in the data series of the ion concentration of desulfurized wastewater during the secondary evaporation process; Indicates The total number of all ions in the ion concentration data series of desulfurization wastewater during the secondary evaporation process; Indicates The ion concentration data series of desulfurization wastewater during the secondary evaporation process Initial ion concentration data of the ions; Indicates The ion concentration data series of desulfurization wastewater during the secondary evaporation process The solubility product constant corresponding to the ion; represents the hyperbolic tangent function.

It should be noted that the more times the single-effect evaporator evaporates, the greater the probability of scaling in the single-effect evaporator and the greater the degree of scaling; the solubility product constant of the ion is used to evaluate the solubility of a specific compound ion in the solution. The smaller the value, the lower the solubility of the ion in the solution; using it as the denominator and The initial ion concentration data of the first ion is multiplied by The higher the initial ion concentration of the species and the lower the solubility product constant, the easier it is to form precipitation, and the greater the precipitation scaling influencing parameters of the single-effect evaporator.

At this point, the scaling level of the single-effect evaporator is obtained.

2. Obtain the adjusted proportional gain coefficient.

It should be noted that scaling on the inner wall of the single-effect evaporator may lead to low heat transfer efficiency, affecting the dynamic characteristics of the evaporation process and making the original control strategy and parameters no longer applicable. During the evaporation process, the reduction in heat transfer efficiency mainly affects the temperature control process of the single-effect evaporator. For the multi-effect evaporation system, heat and temperature are controlled by adjusting the intake valve and the vacuum pump to combat the heat loss caused by scaling, that is, the intake valve controls the amount of steam entering the heater, and then the vacuum pump adjusts the air pressure in the evaporation chamber to reduce the boiling point of the liquid; when using a distributed control system (DCS) to control the evaporation process, a PID controller connected to the intake control valve and the vacuum pump is usually used for control. During the evaporation process, the greater the scaling level of the single-effect evaporator, the greater the impact on the heat transfer efficiency of the evaporation process. Therefore, it is necessary to adjust the proportional gain coefficient P so that the PID can output the control amount as stably as possible under the nonlinear operating state.

Preferably, the calculation method for obtaining the adjusted proportional gain coefficient according to the scaling level of the single-effect evaporator is:

The initial proportional gain coefficient of the PID controller in the multi-effect evaporation system is obtained by the Ziegler-Nichols rule; the sum of the scaling level of the single-effect evaporator and 1 is recorded as the first sum value; the product of the first sum value and the initial proportional gain coefficient is used as the adjusted proportional gain coefficient.

It should be noted that the Ziegler-Nichols rule is a prior art and will not be described in detail in this embodiment.

At this point, the adjusted proportional gain coefficient is obtained through the above method.

Step S004: Control and adjust the multi-effect evaporation system according to the adjusted proportional gain coefficient.

Specifically, the adjusted proportional gain coefficient is input into the PID controller to output a control signal; the air inlet valve and the vacuum pump in the multi-effect evaporation system are adjusted through the control signal to increase the amount of steam entering the heater and reduce the air pressure in the evaporation chamber, thereby realizing intelligent control of all single-effect evaporators with excessive scaling.

Please refer to FIG. 2 , which shows a characteristic relationship flow chart of intelligent control of multi-effect evaporation for desulfurization wastewater.

Through the above steps, a multi-effect evaporation intelligent control for desulfurization wastewater is completed.

The present invention also proposes an intelligent control system for multi-effect evaporation of desulfurized wastewater, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of a multi-effect evaporation intelligent control method for desulfurized wastewater in steps S001 to S004 are implemented.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims (2)

1. A multi-effect evaporation intelligent control method for desulfurization wastewater, characterized in that the method comprises the following steps: Obtain monitoring data sequences and ion concentration data sequences of desulfurized wastewater during several evaporation processes of a single-effect evaporator in a multiple-effect evaporation system; use three dimensional data, namely, wastewater temperature data, wastewater level data, and wastewater concentration data at each monitoring time, as monitoring data sequences of desulfurized wastewater during the evaporation process of the single-effect evaporator; each dimensional monitoring data corresponds to a target data value; the ion concentration data sequence includes desulfurized wastewater concentrate volume data and initial ion concentration data of several ions; each ion corresponds to a solubility product constant; According to the differences between different dimensional monitoring data at adjacent monitoring times, and the differences between different dimensional monitoring data and corresponding target data values, the evaporation achievement rate factor at each monitoring time is obtained; according to the evaporation achievement rate factor of the single-effect evaporator at different monitoring times in different evaporation processes, and the differences between the monitoring data sequences of desulfurization wastewater in different evaporation processes, the comparative scaling index of the single-effect evaporator in each evaporation process is obtained; According to the comparison of scaling index and the difference between the initial ion concentration data of different ions in the ion concentration data sequence during different evaporation processes and the corresponding solubility product constant, the scaling level of the single-effect evaporator is obtained; and the adjusted proportional gain coefficient is obtained according to the scaling level of the single-effect evaporator; Control and adjust the multiple-effect evaporation system according to the adjusted proportional gain coefficient; The method of obtaining the evaporation achievement rate factor at each monitoring time according to the difference between the monitoring data of different dimensions at adjacent monitoring times, and the difference between the monitoring data of different dimensions and the corresponding target data value, includes the following specific methods: For the monitoring data sequence of desulfurization wastewater in any evaporation process of the single-effect evaporator, the evaporation rate characteristic factor of each dimension of monitoring data at each monitoring time is obtained according to the difference between the monitoring data of each dimension at adjacent monitoring times, and the difference between the monitoring data of each dimension and the corresponding target data value; The monitoring data sequence of desulfurization wastewater The normalized value of the cumulative sum of the evaporation rate characteristic factors of all dimensional monitoring data at the monitoring time is taken as the first Evaporation achievement rate factor for each monitoring time; The specific method of obtaining the evaporation rate characteristic factor of each dimension monitoring data at each monitoring time includes: The monitoring data sequence of desulfurization wastewater The monitoring time The monitoring data of the first dimension and the The monitoring time The absolute value of the difference between the monitoring data of the first dimension is recorded as the difference between the left and right monitoring data. The monitoring time The monitoring data of the first dimension and the The monitoring time The absolute value of the difference between the monitoring data of the first dimension is recorded as the difference between the monitoring data on the right side; the average of the difference between the monitoring data on the left side and the monitoring data on the right side is recorded as The mean of the adjacent differences of the monitoring data in the dimension; The monitoring time The monitoring data of the first dimension and the The absolute value of the difference between the target data values corresponding to the monitoring data of the first dimension is recorded as The evaporation target factor of the monitoring data of the first dimension; The mean of adjacent differences of the monitoring data of the first dimension The ratio of the evaporation target factors of the monitoring data of the first dimension is used as the The monitoring time Evaporation rate characteristic factors of monitoring data in different dimensions; The comparative scaling index of the single-effect evaporator in each evaporation process is obtained according to the evaporation rate factor of the single-effect evaporator at different monitoring times in different evaporation processes, and the difference between the monitoring data sequences of the desulfurization wastewater in different evaporation processes, including the specific method of: For the single-effect evaporator During the second evaporation process, according to The second evaporation process and the The difference between the monitoring data series of desulfurization wastewater in the first evaporation process is obtained. The second evaporation process and the Comparison weight factor between sub-evaporation processes; According to The difference in evaporation rate factor between the second evaporation process and other evaporation processes at different monitoring times is used to obtain the single-effect evaporator in the first The second evaporation process and the Factors affected by scaling between evaporation processes; Single effect evaporator The formula corresponding to the comparative scaling index in the secondary evaporation process is: In the formula, Indicates that the single-effect evaporator is Comparative fouling index during secondary evaporation; Represents the total number of all sub-evaporation processes of a single-effect evaporator; Indicates that the single-effect evaporator is The second evaporation process and the Comparison weight factor between sub-evaporation processes; Indicates that the single-effect evaporator is The second evaporation process and the Factors affected by scaling between evaporation processes; represents the hyperbolic tangent function; The single-effect evaporator is obtained in the The second evaporation process and the The comparison weight factor between the sub-evaporation processes includes the following specific methods: The first The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The monitoring time The monitoring data of the first dimension and the The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The monitoring time The absolute value of the difference between the monitoring data of the first dimension is recorded as The second evaporation process and the The first The comparison factor of the monitoring data of the first dimension The second evaporation process and the The average value of the contrast factor of all dimensional monitoring data between the evaporation processes is used as the single-effect evaporator in the first The second evaporation process and the Comparison weight factor between sub-evaporation processes; The single-effect evaporator is obtained in the The second evaporation process and the The factors affected by scaling between the sub-evaporation processes include the following specific methods: The first The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The evaporation rate factor of the first monitoring time is The monitoring data sequence of desulfurization wastewater during the secondary evaporation process The square value of the difference in the evaporation rate factor at each monitoring time is recorded as The second evaporation process and the During the evaporation process The first square value of the monitoring time; The second evaporation process and the The average of the first square values of all monitoring times during the first evaporation process is used as the value of the single-effect evaporator in the first The second evaporation process and the Factors affected by scaling between evaporation processes; The scaling level of the single-effect evaporator is obtained by comparing the scaling index and the difference between the initial ion concentration data of different ions in the ion concentration data sequence in different evaporation processes and the corresponding solubility product constant, including the specific method as follows: According to the difference between the initial ion concentration data of different ions in the ion concentration data sequence during different evaporation processes and the corresponding solubility product constant, the precipitation scaling influencing parameters of the single-effect evaporator are obtained; The average value of the comparative scaling index of the single-effect evaporator in all evaporation processes is recorded as the first average value; the first average value and the average value of the precipitation scaling influencing parameter of the single-effect evaporator are taken as the scaling grade of the single-effect evaporator; The specific method of obtaining the precipitation scaling influencing parameters of the single-effect evaporator includes: For the single-effect evaporator During the second evaporation process, The ion concentration data series of desulfurization wastewater during the secondary evaporation process The ratio of the initial ion concentration data of the ion and its corresponding solubility product constant is used as the The precipitation possibility of the first ion The mean of the precipitation probability of all ions in the ion concentration data series of the desulfurization wastewater during the first evaporation process is used as the The possible factors for the precipitation of ions during the first evaporation process; The product of the desulfurization wastewater concentrate volume data in the desulfurization wastewater ion concentration data sequence during the first evaporation process and the precipitation possible factor is used as the first The precipitation scaling factor in the secondary evaporation process; the normalized value of the product of the cumulative sum of the precipitation scaling factors in all the secondary evaporation processes and the total number of all the secondary evaporation processes of the single-effect evaporator is used as the precipitation scaling influencing parameter of the single-effect evaporator; The specific method of obtaining the adjusted proportional gain coefficient according to the scaling level of the single-effect evaporator includes: The initial proportional gain coefficient of the PID controller in the multi-effect evaporation system is obtained by the Ziegler-Nichols rule; the sum of the scaling level of the single-effect evaporator and 1 is recorded as the first sum value; the product of the first sum value and the initial proportional gain coefficient is used as the adjusted proportional gain coefficient. 2. An intelligent control system for multi-effect evaporation of desulfurized wastewater, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that when the processor executes the computer program, the steps of the intelligent control method for multi-effect evaporation of desulfurized wastewater as claimed in claim 1 are implemented.