Method for Liquid Level Control of Turbid Ring Water System in ESP Production Line

Abstract

The present invention discloses a method for liquid level control of the turbid circulating water system in the ESP production line, including: Step S1: Obtain the ESP production line status signals, where the ESP production line status signals include: casting signal, coiling signal, resetting the production plate signal, and billet stagnation signal; Step S2: Obtain the ESP production line operation mode according to the ESP production line status signals, where the ESP production line operation mode includes: casting mode, non-casting mode, production plate mode, and billet stagnation mode; Step S3: According to the ESP production line operation mode, control the number of pumps running in the turbid circulating cold water tank, the set pressure of the pumps, and the current balance of the pumps. Among them, the pump group in the turbid circulating cold water tank includes: three pump groups, namely, the turbid circulating high-pressure pump group, the turbid circulating low-pressure pump group, and the secondary cooling water pump group; Step S4: According to different ESP production line operation modes, adopt a fuzzy control algorithm to control the number of pumps running and the regulating valves in two pump groups, namely, the swirl well water tank pump group and the rare earth magnetic disk water tank pump group, so as to realize the water supply function required by the ESP production line.

Description

Technical Field

[0001] The present invention relates to the technical field of strip steel headless continuous casting and rolling, and in particular to a method for controlling the liquid level of a turbid circulating water system of an ESP production line. Background Art

[0002] The control process of the turbid circulating water system of the ESP production line is relatively complex, mainly manifested in the following aspects: First, it controls a large number of pump groups, including high-pressure pump groups, low-pressure pump groups, secondary cooling water pump groups, vortex well pump groups, and rare earth magnetic disk water tank pump groups. The pump groups must automatically control the number of pumps running according to the water demand of the production line, and the current of each pump group must be balanced. Second, the turbid circulating water system includes: turbid circulating cooling water tank, vortex well water tank, and rare earth magnetic disk water tank. The water level and the balance of the three water tanks are difficult to control. Third, the water flow rate is determined by the user and adjusted in real time with the process, and the required water volume cannot be obtained. Fourth, the ESP production line and water system are independent of each other. Finally, the ESP production line has high requirements for water supply pressure, which cannot fluctuate.

[0003] Due to the aforementioned reasons, in related technologies, the turbid water system of the ESP production line is generally controlled manually. When a process adjustment is required on the production line, the water system is notified by phone to make the adjustment.

[0004] In the process of implementing the embodiments of the present disclosure, it was found that at least the following problems exist in the related art: manual control cannot dynamically track the water demand of the production line, manual operation and real-time monitoring are labor-intensive and have slow real-time response. Summary of the Invention

[0005] The disclosed embodiments provide a method for controlling the liquid level of a turbid circulating water system in an ESP production line, so as to solve the technical problems in the prior art where manual control cannot dynamically track the water demand of the production line, manual operation for real-time monitoring is labor-intensive, and real-time response is slow.

[0006] In a first aspect, a method for liquid level control of a turbid water system of an ESP production line is provided, comprising: step S1: obtaining an ESP production line status signal, wherein the ESP production line status signal comprises a pouring signal, a curling signal, a plate production reset signal, and a billet delay signal; step S2: obtaining an ESP production line operation mode according to the ESP production line status signal, wherein the ESP production line operation mode comprises a pouring mode, a pouring stop mode, a plate production mode, and a billet delay mode; step S3: controlling the number of operating pumps, the set pressure of the pumps, and the current balance of the pumps in a turbid water cooling pool according to the ESP production line operation mode, wherein the turbid water cooling pool comprises three pump groups, namely, a turbid water high-pressure pump group, a turbid water low-pressure pump group, and a secondary cooling water pump group; step S4: controlling the number of operating pumps and regulating valves in two water pools, namely, a vortex well water pool and a rare earth magnetic disk water pool, according to different ESP production line operation modes.

[0007] Combined with the first aspect, in the first possible implementation manner of the first aspect, the step S3 further includes: adopting a PID algorithm to control the pump speed according to the deviation between the actual feedback pressure of the pump and the set pressure of the pump, where the deviation value between the current PID output and the previous PID output does not exceed the limit value, and the limit value = (maximum motor frequency ÷ frequency conversion acceleration and deceleration time) × (PID execution cycle ÷ frequency conversion acceleration and deceleration time).

[0008] Combined with the first aspect, in the second possible implementation manner of the first aspect, in the step S3, controlling the current balance of the pumps in the dirty loop cooling water tank includes: under the condition of stable pressure, adjusting the speeds of the pumps with the maximum current and the minimum current at the same moment. After the adjustment is completed and the pressure remains stable for more than the preset duration, adjust again until the difference between the maximum current and the minimum current ≤ the first preset threshold.

[0009] Combined with the first aspect, in the third possible implementation manner of the first aspect, in the step S4, according to the fuzzy control algorithm, the interval time of the liquid level change is used instead of the liquid level change rate to control the number of operating pumps and the regulating valves in the two water tanks of the swirl well water tank and the rare earth disk pump water tank.

[0010] Combined with the first aspect or the third possible implementation manner of the first aspect, in the fourth possible implementation manner of the first aspect, in the step S4, the output time interval of the fuzzy control algorithm is dynamically changed, and the dynamic change value is adjusted according to the speed of the liquid level change rate.

[0011] Combined with the fourth possible implementation manner of the first aspect, in the fifth possible implementation manner of the first aspect, the pump group selection rules for different ESP production line operation modes include: in the casting mode, the number of operating pumps in the dirty loop high-pressure pump group is 4, the number of operating pumps in the dirty loop low-pressure pump group is 2, the number of operating pumps in the secondary cooling water pump group is 2, the number of operating pumps in the swirl well water tank pump group is 4, and the number of operating pumps in the rare earth disk water tank pump group is 3; in the stop-casting mode, the number of operating pumps in the dirty loop high-pressure pump group is 1, the number of operating pumps in the dirty loop low-pressure pump group is 1, the number of operating pumps in the secondary cooling water pump group is 1, the number of operating pumps in the swirl well water tank pump group is 1, and the number of operating pumps in the rare earth disk water tank pump group is 1; in the plate production mode, the number of operating pumps in the dirty loop high-pressure pump group is 4, the number of operating pumps in the dirty loop low-pressure pump group is 2, the number of operating pumps in the secondary cooling water pump group is 2, the number of operating pumps in the swirl well water tank pump group is 4, and the number of operating pumps in the rare earth disk water tank pump group is 3.

[0012] Combined with the fifth possible implementation manner of the first aspect, in the sixth possible implementation manner of the first aspect, in step S4, according to the pump group selection rule, the pump numbers of the newly added or shut-down pumps are obtained as the current controlled pumps, and the opening degrees of the pump outlet valves are adjusted.

[0013] Combined with the sixth possible implementation manner of the first aspect, in the seventh possible implementation manner of the first aspect, in step S4, the output value of the fuzzy control algorithm is the value for adjusting the opening degree of the return water valve. When the opening degree of the return water valve is adjusted to the limit, the opening degree of the pump outlet valve and the number of operating pumps are adjusted. The output value of the fuzzy control algorithm is multiplied by the proportionality coefficient to obtain the opening degree of the pump outlet valve, where the proportionality coefficient between the adjustment of the opening degree of the return water valve and the adjustment of the opening degree of the pump outlet valve = the diameter of the return water valve 2 ÷ the diameter of the pump outlet valve 2 。

[0014] Combined with the seventh possible implementation manner of the first aspect, in the eighth possible implementation manner of the first aspect, when the output value of the fuzzy control algorithm is greater than zero, the opening degree value of the return water valve = the last controlled opening degree of the return water valve + the output value of the fuzzy control algorithm. When the opening degree value of the return water valve exceeds the maximum value, according to the pump number of the currently stopped pump, the opening degree of the outlet valve of the stopped pump is reduced; the opening degree of the outlet valve of the stopped pump = the last controlled opening degree of the outlet valve of the stopped pump - the output value of the fuzzy control algorithm × the proportionality coefficient.

[0015] Combined with the first aspect, in the ninth possible implementation manner of the first aspect, step S2 further includes: in the non-plate production mode, when the pouring signal or the curling signal is obtained, the current mode is the pouring mode; or, in the plate production mode, when the pouring signal and the reset plate production signal are obtained, the current mode is the pouring mode; when both the pouring signal and the curling signal disappear and a preset time interval has elapsed, the current mode is the stop-pouring mode; in the pouring mode, when the pouring signal is normal and the curling signal disappears, the current mode is the plate production mode; when the billet jamming signal is obtained, the current mode is the billet jamming mode.

[0016] The method for controlling the liquid level of the turbidity circulating water system for the ESP production line provided by the embodiments of the present disclosure can achieve the following technical effects:

[0017] By collecting the signals of the ESP production line, the operating mode status of the production line is obtained. According to the operating mode status of the production line, the number of operating pumps and the set pressure in the pump group are automatically controlled, realizing the water supply function required by the ESP production line. At the same time, by improving the control algorithm of the pump group, stable constant-pressure water supply for the continuous casting secondary cooling water, low-pressure rolling, and high-pressure rolling pump groups in the turbidity ring cooling water tank and the current balance of the pumps are achieved. The liquid level balance control of the three water tanks, namely the turbidity ring cooling water tank, the whirling well water tank, and the rare earth disk water tank, is realized, and the automatic control of the turbidity ring water system is achieved, ensuring that the turbidity ring water system automatically and dynamically tracks the water demand of the production line, eliminating the disadvantages of high labor intensity and slow real-time response of manual operation, and reducing equipment accidents caused by the failure of manual operators to observe and adjust the liquid level of the whirling well in a timely manner.

[0018] The above general description and the description in the following text are only exemplary and explanatory, and are not used to limit this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] One or more embodiments are exemplarily illustrated by corresponding drawings. These exemplary illustrations and the drawings do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation, and among them:

[0020] Figure 1 is a schematic flowchart of a method for liquid level control of the turbidity ring water system for the ESP production line provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions, and advantages of this application clearer, the following describes and explains this application in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application. Based on the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

[0022] Obviously, the accompanying drawings in the following description are only some examples or embodiments of this application. For those of ordinary skill in the art, without creative efforts, this application can also be applied to other similar scenarios based on these drawings. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in this application, some designs, manufacturing, or production changes made based on the technical content disclosed in this application are only conventional technical means and should not be understood as the content disclosed in this application being insufficient.

[0023] References to "embodiments" in this application mean that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase may not necessarily refer to the same embodiment each time it appears in the specification, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the ordinary meanings understood by those of ordinary skill in the technical field to which this application pertains. The similar words such as "a", "an", "one", and "the" involved in this application do not indicate a limitation in quantity and may mean singular or plural. The terms "include", "comprise", "have" and any variations thereof involved in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may further include unlisted steps or units, or may further include other steps or units inherent to these processes, methods, products, or devices.

[0025] For ease of understanding, the concepts involved in the embodiments of the present disclosure are introduced below. Endless strip production (ESP), a new generation of hot-rolled strip production technology developed by improving the original ISP line, is one of the thin slab continuous casting and rolling processes.

[0026] The PID algorithm, an abbreviation of Proportional, Integral, and Differential, is a control algorithm that combines the three links of proportional, integral, and differential. According to the input deviation value, it performs operations according to the functional relationships of proportional, integral, and differential, and the operation result is used to control the output.

[0027] Fuzzy control is a control algorithm based on fuzzy logic to describe a process. It can be used for objects where it is difficult to obtain an accurate mathematical model for the water tank liquid level and the mathematical model is uncertain or constantly changing. However, it is difficult to obtain the change amount of the liquid level, mainly because the liquid level itself has a large lag, the sampling period of the liquid level is too long to respond to the rapid change of the liquid level in real time, resulting in a sudden rise or fall of the liquid level, and even accidents caused by a high liquid level; if the sampling period of the liquid level is too short, an effective change amount of the liquid level cannot be obtained. It is precisely because it is difficult to obtain the change amount of the liquid level that the liquid level control can only be achieved based on the high or low of the liquid level, but it cannot meet the real-time response brought by the sudden rise and fall of the liquid level. Therefore, overshoot often occurs in the liquid level control and the liquid level cannot be stabilized.

[0028] Figure 1 is a schematic flow chart of the method for controlling the liquid level of the turbid circulating water system in the ESP production line provided by the embodiments of the present disclosure. As Figure 1 shown, the embodiments of the present disclosure provide a method for controlling the liquid level of the turbid circulating water system in the ESP production line, including: Step S1: Obtain the ESP production line status signals, where the ESP production line status signals include: casting signal, coiling signal, resetting production plate signal, and billet jamming signal; Step S2: Obtain the ESP production line operation mode according to the ESP production line status signals, where the ESP production line operation mode includes: casting mode, non-casting mode, production plate mode, and billet jamming mode; Step S3: According to the ESP production line operation mode, control the number of operating pumps, the set pressure of the pumps, and the current balance in the turbid circulating cold water tank, where the turbid circulating cold water tank includes three pump groups: turbid circulating high-pressure pump group, turbid circulating low-pressure pump group, and secondary cooling water pump group; Step S4: According to different ESP production line operation modes, adopt a fuzzy control algorithm to control the number of operating pumps and regulating valves in two water tanks, namely the swirl well water tank and the rare earth disk water tank.

[0029] The method for controlling the liquid level of the turbid circulating water system in the ESP production line provided by the embodiments of the present disclosure can achieve the following technical effects: By collecting the ESP production line signals, obtaining the status of the production line operation mode, and automatically controlling the number of operating pumps and the set pressure in the pump group according to the status of the production line operation mode, the function of supplying water according to the needs of the ESP production line is realized; At the same time, by improving the control algorithm of the pump group, stable constant-pressure water supply for the three pump groups of continuous casting secondary cooling water, rolling mill low pressure, and rolling mill high pressure in the turbid circulating cold water tank and the current balance of the pumps are realized; The liquid level balance control of the three water tanks, namely the turbid circulating cold water tank, the swirl well water tank, and the rare earth disk water tank, is realized, and the automatic control of the turbid circulating water system is realized, ensuring that the turbid circulating water system automatically and dynamically tracks the water demand of the production line, eliminating the disadvantages of large labor intensity and slow real-time response of manual operation, and reducing equipment accidents caused by the failure of manual timely observation and adjustment of the swirl well liquid level.

[0030] In some embodiments, the ESP production line signals can be obtained by adding a remote station.

[0031] In some embodiments, Step S2 further includes: When a casting signal or a coiling signal is obtained in the non-production plate mode, the current is the casting mode, or when a casting signal and a reset production plate signal are obtained in the production plate mode, the current is the casting mode; When both the casting signal and the coiling signal disappear and a preset time interval has elapsed, the current is the non-casting mode; In the casting mode, when the casting signal is normal and the coiling signal disappears, the current is the production plate mode; When a billet jamming signal is obtained, the current is the billet jamming mode.

[0032] In the embodiments of the present disclosure, the control strategies of each pump group under different operation modes of the ESP production line can also be as follows

[0033] As shown in Table 1.

[0034]

[0035]

[0036] Table 1

[0037] The control strategy in the stuck billet mode is not marked in Table 1 because the stuck billet mode is a production line fault state. In this mode, the water demand of the production line is complex and changeable, making it difficult to track in real time. Each device in the system maintains the last state and gives an audible and visual alarm. At this time, the system can be manually adjusted according to the on-site requirements.

[0038] In the embodiments of the present disclosure, each pump is controlled by frequency conversion and its speed can be adjusted. Moreover, each pump has an automatic or manual selection function. Manual control means manually operating to start and stop the pump. When the pump group is automatically controlled, the system controls the pumps selected in the automatic state according to the water demand of the production line to achieve automatic control of the number of pumps, pressure, and pump start-stop rules. Within each pump group, the number of pumps is 3 to 7, and the parameters of each pump in the pump group are the same and can be switched with each other. In case of a failure, a standby pump can be enabled. The number of pumps and the pressure required for the pump group to operate depend on the working mode of the production line. For details, refer to Table 1. There are multiple options for the start / stop selection control of the pumps in the pump group. It can be selected according to the pump number, in descending order or ascending order; it can be selected according to the single operation or stop time, the longest single operation time, the shortest single operation time, the longest single stop time, or the shortest single stop time; it can be selected according to the cumulative operation or stop time, the longest cumulative operation time, the shortest cumulative operation time, the longest cumulative stop time, or the shortest cumulative stop time.

[0039] The pump group pressure control can be achieved by using the PID control algorithm. However, it is difficult to achieve the current balance of each pump in the pump group while ensuring pressure stability, and the pump number control logic of the pump group is complex and needs to be automatically adjusted in combination with the production line state. The water tank liquid level control has typical hysteresis and uncertainty, with many controlled objects and no accurate mathematical model, so it is very difficult to implement with the conventional PID control algorithm.

[0040] In some embodiments, step S3 further includes: adopting a PID algorithm to control the pump speed according to the deviation between the actual feedback pressure of the pump and the set pressure of the pump. Among them, the deviation value between the current PID output and the previous PID output does not exceed the limit value, and the limit value = (maximum motor frequency ÷ variable frequency acceleration and deceleration time) × (PID execution cycle ÷ variable frequency acceleration and deceleration time). In practical applications, overshoot often occurs in PID control regulation. The reason is that after the PID algorithm outputs the pump speed to the frequency converter, the frequency converter response cannot follow the output, that is, the response lags. The result is that the output speed is much greater than the actual speed. Once the pressure is reached, a callback is required, and the callback is to decelerate from the control output speed. At this time, the deviation between the control output speed and the actual speed is large. At the current actual speed, the pressure requirement is already met. Although the control output speed is adjusted downward, it is still greater than the actual speed, which is manifested as the pump output speed still increasing and the pressure continuing to rise, resulting in overshoot. In the embodiments of the present disclosure, when the PID control outputs, the limit output for each time is limited. In this way, the constant pressure water supply adopts a variable PID parameter strategy, with fast dynamic response, and limits the output to track the frequency conversion output ability, eliminating the pressure overshoot caused by asynchronous frequency conversion output and eliminating the overshoot error.

[0041] The water supply of the pump group not only needs to ensure stable pressure, but also requires the same output of each pump, that is, the current of each pump in the pump group is the same. Otherwise, the pump with a small current will be blocked by pressure, resulting in the phenomenon of outputting power but not water, wasting electric energy. At the same time, for the pump with a large output, the blade loss accelerates, reducing the service life of the pump. If cascade PID control is used for current balance control, the main PID is for pressure control and the slave PID is for the current loop, the system cannot achieve stable pressure and the current regulation also fluctuates greatly. The main reason is that when adjusting the current by adjusting the pump speed, it causes pressure fluctuations. When adjusting the speed, it will inevitably cause pressure acceleration and deceleration adjustment, and the acceleration and deceleration current of the motor fluctuates greatly, which destroys the stability of the system. The result is manifested as pressure or current fluctuations and cannot be stabilized.

[0042] In some embodiments, in step S3, controlling the current balance of the pumps in the turbid ring cooling water tank includes: under the condition of stable pressure, adjusting the speeds of the pumps with the maximum and minimum currents at the same moment. After the adjustment is completed and the pressure remains stable for more than the preset duration, adjust again until the difference between the maximum current and the minimum current ≤ the first preset threshold. The preset duration can be set to 5 to 20 seconds, and the first preset threshold can be determined according to the on-site pump process and can be set to 0.8 to 2 amperes. In this way, the current balance of the pumps can be achieved, and the constant pressure water supply of the pump group can also be achieved, which can ensure the balanced processing of each pump, improve the service life of the equipment, and save electric energy.

[0043] It should be noted that in the embodiments of the present disclosure, the turbid circulating water system includes: a turbid circulating cold water tank, a whirling well, and a rare earth disk water tank. The water flow sequence of the three water tanks is that the water in the turbid circulating cold water tank flows to the whirling well water tank, the water in the whirling well water tank flows to the rare earth disk water tank, and the water in the rare earth disk water tank flows to the turbid circulating cold water tank. A liquid level balance control needs to be formed for the three water tanks. If the liquid level of a certain water tank is too low, there must be a phenomenon that the liquid level of other water tanks is too high, resulting in the overflow of the water tank liquid level. If the liquid level of the whirling well water tank is too high, all 6 pumps in the whirling well pump group will be flooded directly, causing equipment accidents. The liquid level of the turbid circulating cold water tank cannot be directly controlled, and its water outlet flow is completely determined by the water demand of the rolling line; the liquid levels of the whirling well water tank and the rare earth disk water tank can be directly controlled. In fact, the liquid level control of the whirling well water tank and the rare earth disk water tank has typical hysteresis and uncertainty. There are many control objects, involving multiple pumps and multiple valves, and an accurate mathematical model cannot be obtained. It is very difficult to implement conventional control algorithms.

[0044] In some embodiments, in step S4, according to the fuzzy control algorithm, the interval time of the liquid level change is used to replace the liquid level change rate to control the number of pumps running and the regulating valves in the two pump groups of the whirling well and the rare earth disk pumps. In this way, the accuracy problem caused by the inability to obtain an accurate sampling period for the liquid level change rate is solved. At the same time, the interval time of the system control output is adjusted according to the speed of the liquid level change, solving the problems of slow response and large hysteresis caused by the fixed execution period of the algorithm, improving the liquid level control accuracy and the dynamic response time, and thus realizing the balance control of the liquid levels of the three water tanks.

[0045] In some embodiments, in step S4, the output time interval of the fuzzy control algorithm is dynamically changed, and the dynamic change value is adjusted according to the speed of the liquid level change rate. Due to the large hysteresis of the system, after controlling the actions of the pumps and valves according to the liquid level deviation and the interval time of the liquid level change, the system needs to delay for a period of time before the effect can be shown. How to control the interval time of the execution output of the algorithm will also affect the system control effect. If the interval time is too long, although the effect of the control output under the large hysteresis condition can be obtained, it cannot meet the liquid level out-of-control caused by the rapid change of the liquid level; if the interval time is too short, the hysteresis effect of the previous output cannot be fully reflected, resulting in the system repeating the output and causing the system to overshoot. Therefore, in the embodiments of the present disclosure, the interval time of the fuzzy control output no longer uses a fixed interval time, and the interval time is dynamically changed, and the dynamic change value is adjusted according to the speed of the liquid level change rate, thus solving the problems of slow response and large hysteresis caused by the fixed execution period of the algorithm.

[0046] In some embodiments, the pump group selection rules for different ESP production line operation modes are as follows: In the casting mode, the number of operating pumps in the turbidity ring high-pressure pump group is 4 and the number of standby pumps is 2; the number of operating pumps in the turbidity ring low-pressure pump group is 2 and the number of standby pumps is 1; the number of operating pumps in the secondary cooling water pump group is 2 and the number of standby pumps is 1; the number of operating pumps in the swirl well water tank pump group is 4 and the number of standby pumps is 2; the number of operating pumps in the rare earth disk water tank pump group is 3 and the number of standby pumps is 3. In the stoppage of casting mode, the number of operating pumps in the turbidity ring high-pressure pump group is 1 and the number of standby pumps is 5; the number of operating pumps in the turbidity ring low-pressure pump group is 1 and the number of standby pumps is 2; the number of operating pumps in the secondary cooling water pump group is 1 and the number of standby pumps is 2; the number of operating pumps in the swirl well water tank pump group is 1 and the number of standby pumps is 5; the number of operating pumps in the rare earth disk water tank pump group is 1 and the number of standby pumps is 5. In the plate production mode, the number of operating pumps in the turbidity ring high-pressure pump group is 4 and the number of standby pumps is 2; the number of operating pumps in the turbidity ring low-pressure pump group is 2 and the number of standby pumps is 1; the number of operating pumps in the secondary cooling water pump group is 2 and the number of standby pumps is 1; the number of operating pumps in the swirl well water tank pump group is 4 and the number of standby pumps is 2; the number of operating pumps in the rare earth disk water tank pump group is 3 and the number of standby pumps is 3.

[0047] In some embodiments, in step S3, according to the ESP production line operation mode, controlling the set pressure of the pumps in the turbidity ring cold water tank pump group includes: In the casting mode, the set pressure of the turbidity ring high-pressure pump group is 1.27 MPa, the set pressure of the turbidity ring low-pressure pump group is 0.58 MPa, and the set pressure of the secondary cooling water pump group is 1.3 MPa. In the stoppage of casting mode, the set pressure of the turbidity ring high-pressure pump group is 0.7 MPa, the set pressure of the turbidity ring low-pressure pump group is 0.58 MPa, and the set pressure of the secondary cooling water pump group is 1.3 MPa. In the plate production mode, the set pressure of the turbidity ring high-pressure pump group is 1.27 MPa, the set pressure of the turbidity ring low-pressure pump group is 0.58 MPa, and the set pressure of the secondary cooling water pump group is 1.3 MPa.

[0048] In some embodiments, in step S4, according to the pump group selection rules, the pump numbers of the newly added or shut-down pumps are obtained as the current controlled pumps, and the opening degrees of the pump outlet valves are adjusted.

[0049] In some embodiments, in step S4, the output value of the fuzzy control algorithm is the value for adjusting the opening degree of the return water valve. When the opening degree of the return water valve is adjusted to the limit, the opening degrees of the pump outlet valves are adjusted and the number of operating pumps is increased or decreased. The output value of the fuzzy control algorithm is multiplied by the proportionality coefficient to obtain the opening degree of the pump outlet valve, where the proportionality coefficient between the adjustment of the opening degree of the return water valve and the adjustment of the opening degree of the pump outlet valve = the diameter of the return water valve 2 ÷ the diameter of the pump outlet valve 2 . The control opening degree of the return water valve is output at the maximum value of 100%, indicating that the adjustment ability of the return water valve has reached the limit. If the water tank liquid level continues to be low, the water output of the pump needs to be reduced.

[0050] In some embodiments, when the output value of the fuzzy control algorithm is greater than zero, the opening value of the return water valve = the previous control opening of the return water valve + the output value of the fuzzy control algorithm. When the opening value of the return water valve exceeds the maximum value, according to the pump number of the currently stopped pump, reduce the opening of the outlet valve of the stopped pump; the opening of the outlet valve of the stopped pump = the previous control opening of the outlet valve of the stopped pump - the output value of the fuzzy control algorithm × the proportionality coefficient. When the control opening of the outlet valve of the stopped pump < 30%, control it at 30% opening. If it operates below this value, the opening of the pump outlet valve is too small, and the pump is in a state of being blocked for a long time. If the opening of the outlet valve of the stopped pump < 10%, it indicates that the pump can be closed, and the system automatically closes the pump, reducing the operation of one pump.

[0051] In some embodiments, when the output value of the fuzzy control algorithm is less than zero, the opening of the outlet valve of the stopped pump = the previous control opening of the outlet valve of the stopped pump - the output value of the fuzzy control algorithm × the proportionality coefficient. When the control opening of the outlet valve of the stopped pump > 100%, control it at 100% opening. The pump has been adjusted to the limit, and the opening of the return water valve needs to be adjusted. The opening value of the return water valve = the previous control opening of the return water valve - (the opening of the outlet valve of the stopped pump - 100%) ÷ the proportionality coefficient. When the opening value of the return water valve is lower than the minimum value of 0%, the opening value of the return water valve is output according to the minimum value of 0%, indicating that both the return water valve and the pump outlet valve have reached the limit, the water level in the water tank continues to rise, and the number of pumps in operation needs to be increased to increase the water discharge flow. According to the new pump selection rule, find the new pump number and start the pump. After the pump is started, the direct control opening of the return water valve is set to the maximum of 100%, and at the same time, the control value of the outlet valve of the pump is set to the minimum of 30%. After the method for controlling the water level of the turbidity circulating water system in the ESP production line provided by the embodiments of the present disclosure is put into use, the automatic control of the turbidity circulating water system in the ESP production line is realized, the dynamic response of the pressure is fast, and when the pressure deviation is 0.5 MPa, the time to reach the stable set value ≤ 10 seconds, and the water level control accuracy is high, with an accuracy ≤ 0.2 meters.

[0052] The embodiments of the present disclosure also provide a computer-readable storage medium, on which computer instructions are stored, and when the instructions are executed by a processor, the method for controlling the water level of the turbidity circulating water system in the ESP production line in any of the foregoing embodiments is implemented.

[0053] The present disclosure is described with reference to the flowcharts and / or block diagrams of computer program products according to the embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram, and the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate for implementing in the process Figure 1 a process or multiple processes and / or blocks Figure 1A device for the functions specified in one or more boxes.

[0054] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory include a manufactured article of instruction means that implements the functions specified in one Figure 1 process or more processes and / or boxes Figure 1 A box or the functions specified in multiple boxes.

[0055] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operating steps are performed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide for implementing the functions of the steps specified in one Figure 1 process or more processes and / or boxes Figure 1 A box or the functions specified in multiple boxes.

[0056] The above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for liquid level control of the turbid circulating water system in the ESP production line, characterized in that, Including: Step S1: Obtain the ESP production line status signals, where the ESP production line status signals include: pouring signal, coiling signal, reset production plate signal, and billet stagnation signal; Step S2: Obtain the ESP production line operation mode according to the ESP production line status signals, where the ESP production line operation mode includes: pouring mode, stop pouring mode, production plate mode, and billet stagnation mode; Step S3: According to the ESP production line operation mode, control the number of pumps running in the turbocyclone cooling water tank, the set pressure of the pumps, and the current balance of the pumps. Among them, the turbocyclone cooling water tank includes: three pump groups, namely, the turbocyclone high-pressure pump group, the turbocyclone low-pressure pump group, and the secondary cooling water pump group; Step S4: According to different ESP production line operation modes, adopt a fuzzy control algorithm to control the number of pumps running and the regulating valves in two water tanks, namely, the swirl well water tank and the rare earth disk water tank.

2. The method according to claim 1, wherein The step S3 further includes: Adopt a PID algorithm to control the pump speed according to the deviation between the actual feedback pressure of the pump and the set pressure of the pump, where the deviation value between the current PID output and the previous PID output does not exceed the limit value, The limit value = (maximum motor frequency ÷ variable frequency acceleration and deceleration time) × (PID execution cycle ÷ variable frequency acceleration and deceleration time).

3. The method according to claim 1, wherein In the step S3, controlling the current balance of the pumps in the turbocyclone cooling water tank includes: Under the condition of stable pressure, adjust the speeds of the pumps with the maximum current and the minimum current at the same moment. After the adjustment is completed and the pressure remains stable for more than the preset duration, adjust again until the difference between the maximum current and the minimum current ≤ the first preset threshold.

4. The method according to claim 1, characterized in that, In the step S4, according to the fuzzy control algorithm, use the interval time of the liquid level change to replace the liquid level change rate to control the number of pumps running and the regulating valves in two water tanks, namely, the swirl well and the rare earth disk pumps.

5. The method according to claim 1 or 4, characterized in that, In the step S4, the output time interval of the fuzzy control algorithm is dynamically changed, and the dynamic change value is adjusted according to the speed of the liquid level change rate.

6. The method according to claim 5, wherein The pump group selection rules for different ESP production line operation modes include: In the pouring mode, the number of pumps running in the turbocyclone high-pressure pump group is 4, the number of pumps running in the turbocyclone low-pressure pump group is 2, the number of pumps running in the secondary cooling water pump group is 2, the number of pumps running in the swirl well water tank pump group is 4, and the number of pumps running in the rare earth disk water tank pump group is 3; In the stop pouring mode, the number of pumps running in the turbocyclone high-pressure pump group is 1, the number of pumps running in the turbocyclone low-pressure pump group is 1, the number of pumps running in the secondary cooling water pump group is 1, the number of pumps running in the swirl well water tank pump group is 1, and the number of pumps running in the rare earth disk water tank pump group is 1; In the production plate mode, the number of pumps running in the turbocyclone high-pressure pump group is 4, the number of pumps running in the turbocyclone low-pressure pump group is 2, the number of pumps running in the secondary cooling water pump group is 2, the number of pumps running in the swirl well water tank pump group is 4, and the number of pumps running in the rare earth disk water tank pump group is 3.

7. The method according to claim 6, characterized in that, In the step S4, according to the pump group selection rules, obtain the pump numbers of the newly added or shut-down pumps as the current controlled pumps, and adjust the opening degrees of the pump outlet valves.

8. The method according to claim 7, wherein In the step S4, the output value of the fuzzy control algorithm is the value for adjusting the opening degree of the return water valve. After the opening degree of the return water valve is adjusted to the limit, the opening degree of the pump outlet valve is adjusted and the number of operating pumps is increased or decreased. The output value of the fuzzy control algorithm is multiplied by a proportionality coefficient to obtain the opening degree of the pump outlet valve. Among them, the proportionality coefficient between the adjustment of the opening degree of the return water valve and the adjustment of the opening degree of the pump outlet valve = the diameter of the return water valve 2 ÷ the diameter of the pump outlet valve 2 .

9. The method according to claim 8, wherein When the output value of the fuzzy control algorithm is greater than zero, the opening value of the return water valve = the last control opening of the return water valve + the output value of the fuzzy control algorithm. When the opening value of the return water valve exceeds the maximum value, reduce the opening of the stop pump outlet valve according to the pump number of the currently stopped pump; The opening of the stop pump outlet valve = the last control opening of the stop pump outlet valve - the output value of the fuzzy control algorithm × the proportionality coefficient.

10. The method according to claim 1, characterized in that, Step S2 further includes: In the non-product plate mode, when the pouring signal or the curling signal is obtained, the current is the pouring mode. Or, in the product plate mode, when the pouring signal and the reset product plate signal are obtained, the current is the pouring mode; When both the pouring signal and the curling signal disappear and a preset time interval has elapsed, the current is the stop pouring mode; In the pouring mode, when the pouring signal is normal and the curling signal disappears, the current is the product plate mode; When the billet stagnation signal is obtained, the current is the billet stagnation mode.

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