Energy-saving control system and method for high-pressure turbid circulating water system of heavy plate mill

Abstract

The invention discloses an energy-saving control system and method for a high-pressure turbid circulating water system of a heavy plate mill, and belongs to the field of energy conservation of metallurgical production lines. The system comprises a monitoring unit and a control unit, the monitoring unit is used for acquiring equipment system information, transmitting the information to the control unit, and receiving a control instruction sent by the control unit to control a controlled object; and the control unit is used for analyzing and judging according to the information acquired by the monitoring unit and sending a control instruction. Information of the rolling line and the water supply system is combined, invalid energy consumption loss caused by a pressure relief mode on the rolling line side can be reduced and even eliminated, and reliable water supply under the condition of information interruption of the rolling line side and the water supply side is guaranteed due to the fact that the actual output condition of the water supply side is considered. Due to the fact that a cascade control mode during rolling is adopted, under the condition that reliable water supply is guaranteed, a water supply system can rapidly respond to the dynamic economic requirement of a rolling mill for cooling water, and high tracking precision and excellent system stability are guaranteed.

Description

Technical Field

[0001] The invention relates to energy saving in a metallurgical production line, and in particular to an energy saving control system and method for a high-pressure turbid circulating water system of a thick plate rolling mill. Background Art

[0002] The plate mill is the main power-consuming equipment for hot processing of steel billets on the plate production line. During its operation, the working rollers come into contact with the hot steel billets, and a large amount of heat is released during the energy conversion process, which needs to be removed to maintain the normal operation of the mill. Therefore, it is usually necessary to set up a rolling mill turbid ring high-pressure cooling water system to provide cooling water to remove this heat. The rolling mill turbid ring high-pressure water supply system has high operating pressure and large flow rate, and it always runs continuously for a long time, and the energy consumption is very considerable. The system is designed according to the maximum cooling load, and the system delivery capacity is often surplus under actual working conditions. Generally, the high-pressure turbid ring water supply side and the water side of the rolling mill are independently controlled. The water supply side supplies water at a constant pressure, and the water side is refluxed and pressure-relieved through a regulating valve. This method has certain advantages in terms of reliability, but it will lead to a lot of energy waste. In fact, the economic demand for cooling water of the rolling mill is changing with changes in the system production conditions, changes in the environment, changes in the equipment status, and at different stages of the rolled pieces passing through the rolling mill. However, due to the disconnection of the signals between the water supply side and the water side, this change cannot be fed back to the water supply side in time, causing unnecessary energy consumption of the water supply pump group. Moreover, the economic demand for cooling water of the rolling mill fluctuates greatly, and it is difficult to achieve ultimate energy saving in conventional feedforward control mode and constant pressure control mode.

[0003] In summary, in order to stably and reliably realize the energy-saving and economical operation of the rolling mill high-pressure turbid ring cooling water system, it is necessary to closely combine the economic needs of the rolling mill cooling with the operation of the water supply pump group, and adopt a fast, reliable and accurate energy-saving control method.

[0004] There are many solutions that combine rolling line information with energy supply system to achieve energy saving at home and abroad. For example, the invention patent with patent application number 201010161820.0 provides a hot rolling cooling water control method based on rolling line control integration, which provides a feasible solution for energy saving of hot rolling cooling water system. The method provided is that the obtained rolling line information is transmitted to the cooling water control unit through the communication unit, and the control unit controls the cooling water supply according to the rolling line information, and adjusts the water supply by controlling the speed of the water supply pump or the opening of the outlet valve of the water supply pump. This control method has the following shortcomings: first, the water supply is adjusted only according to the rolling line data information, which may cause the water supply system to operate unreliably due to communication abnormalities, transmission delays, etc.; second, this control method does not consider the adjustment of the regulating valve on the rolling mill side and the control of the number of water supply pumps that are turned on, and it is difficult to achieve the ultimate energy saving effect, because the water distribution on the water side of the rolling mill and the operating efficiency of the pump group will also affect the energy consumption of the system. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide an energy-saving control system for a high-pressure turbid circulating water system of a thick plate rolling mill; another purpose of the present invention is to provide an energy-saving control method for a high-pressure turbid circulating water system of a thick plate rolling mill.

[0006] Technical solution: An energy-saving control system for a high-pressure turbid circulating water system of a thick plate rolling mill, comprising a monitoring unit and a control unit; the monitoring unit is used to obtain equipment system information and then transmit it to the control unit, and receive control instructions issued by the control unit to control the controlled object; the control unit is used to analyze and judge according to the information obtained by the monitoring unit, and issue control instructions.

[0007] Preferably, the control instructions include setting the speed or frequency of the speed regulating device, the opening or position of the regulating valve, and the number of water supply pump groups to be opened.

[0008] A method for energy-saving control of a high-pressure turbid circulating water system of a thick plate rolling mill is provided, and the method is implemented based on the above-mentioned energy-saving control system of a high-pressure turbid circulating water system of a thick plate rolling mill, and specifically comprises:

[0009] (1) Adopt different control modes according to different operating conditions of the rolling mill;

[0010] (2) When the rolling mill is rolling, a cascade control method combining cooling water flow control on the rolling mill side and pressure control on the water supply side is adopted. At other times, the water supply side pressure control method is adopted, and the pressure control model gives control instructions.

[0011] Preferably, when flow and pressure cascade control is adopted, the output of the flow control model is used to compensate the set value of the pressure control model, and then the pressure control model gives a control instruction.

[0012] Beneficial effects:

[0013] (1) The present invention combines the information of the rolling line and the water supply system, which can reduce or even eliminate the ineffective energy loss caused by the pressure relief method on the rolling line side. It also takes into account the actual output of the water supply side, thereby ensuring reliable water supply when the information between the rolling line side and the water supply side is interrupted.

[0014] (2) The present invention adopts a cascade control mode during rolling, so that the water supply system can quickly respond to the dynamic economic demand of the rolling mill for cooling water while ensuring reliable water supply, thereby ensuring high tracking accuracy and excellent system stability.

[0015] (3) Since the present invention distinguishes between rolling and non-rolling conditions, it can further reduce the water supply pressure during the non-rolling period to achieve energy saving. It can also further save energy by adjusting the regulating valve on the rolling mill side and controlling the number of water supply pumps that are opened. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a process flow diagram of the system in the present invention;

[0017] Figure 2 It is a schematic diagram of the control principle of the present invention. DETAILED DESCRIPTION

[0018] In order to make the technical solution of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Example

[0020] The present invention obtains equipment system information and adopts different control modes according to different operating conditions of the rolling mill. When the rolling mill is rolling, a cascade control method combining cooling water flow control on the rolling mill side and pressure control on the water supply side is adopted. At other times, a water supply side pressure control method is adopted, thereby realizing the combination of water supply and economic water use of the rolling mill's high-pressure turbid circulating water system. While ensuring reliable water supply, the water supply system can quickly respond to the dynamic economic demand of the rolling mill for cooling water, thereby ensuring high tracking accuracy and excellent system stability and reducing system energy consumption.

[0021] like Figure 1 As shown, the energy-saving control system of the high-pressure turbid water system of the thick plate rolling mill includes: a monitoring unit and a control unit. The monitoring unit is used to obtain equipment system information including production process information, rolling piece information, rolling piece position information, temperature information, pressure information, rolling mill load information, rolling mill turbid water system information, and then transmit it to the control unit, and receive the control instructions issued by the control unit to control the controlled object; the control unit is used to analyze and judge according to the information obtained by the monitoring unit, and issue control instructions including setting the speed or frequency of the speed regulating device, the opening or position of the regulating valve, and the number of water supply pump groups to be opened.

[0022] like Figure 2 As shown in the figure, the energy-saving control system of the high-pressure turbid circulating water system of the thick plate rolling mill includes: adopting different control modes according to the different operating conditions of the rolling mill; when the rolling mill is rolling, a cascade control method combining the cooling water flow control on the rolling mill side and the pressure control on the water supply side is adopted. When the flow and pressure cascade control is adopted, the output of the flow control model is used to compensate the set value of the pressure control model, and then the pressure control model gives the control instruction. At other times, the water supply side pressure control method is adopted, and the pressure control model gives the control instruction.

[0023] When the rolling mill is rolling, the flow demand and various temperatures T are established by the mechanism model or big data model based on the collected equipment system information. i , size (and position) L i , time t i , force F iThe model with the same influencing factors, Q = f0(T i ,L i ,t i ,F i ), obtain the rolling mill's demand for high-pressure water in the turbid ring, and pass it to the flow control model. The flow control model analyzes and judges the actual flow feedback value, and outputs the flow required by the water supply system. The pressure control model calculates the flow rate according to the pipeline resistance characteristic P 管路 =f1(Q), nozzle pressure flow characteristic P 喷头 =f2(Q), as well as the equipment system information and pressure feedback information, conduct a comprehensive analysis, output control instructions, adjust the regulating valve on the rolling mill side to achieve the best water distribution, adjust the speed and number of pumps opened, so as to achieve ultimate energy saving of the system.

[0024] When the rolling mill is not rolling, the pressure control model conducts a comprehensive analysis based on the collected equipment system information and pressure feedback information, outputs control instructions, adjusts the regulating valve on the rolling mill side to reduce the amount of reflux water, and adjusts the speed and number of pumps opened, thereby achieving ultimate energy saving for the system.

[0025] By combining the information of the rolling line and the water supply system, the ineffective energy loss caused by the pressure relief method on the rolling line side can be reduced or even eliminated. Because the actual output of the water supply side is taken into consideration, reliable water supply is guaranteed when the information between the rolling line and the water supply side is interrupted. The proposed control method adopts a cascade control mode during rolling, so that the water supply system can quickly respond to the dynamic economic demand of the rolling mill for cooling water while ensuring reliable water supply, thereby ensuring high tracking accuracy and excellent system stability. The proposed control method distinguishes between rolling and non-rolling conditions, and can further reduce the water supply pressure during the non-rolling period to achieve energy saving. It can also achieve deeper energy saving by adjusting the regulating valve on the rolling mill side and controlling the number of water supply pump groups that are turned on.

[0026] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An energy-saving control system for a high-pressure turbid circulating water system of a thick plate rolling mill, characterized in that: It includes a monitoring unit and a control unit; the monitoring unit is used to obtain equipment system information and then transmit it to the control unit, and receive control instructions issued by the control unit to control the controlled object; the control unit is used to analyze and judge according to the information obtained by the monitoring unit and issue control instructions.

2. The energy-saving control system for the high-pressure turbid circulating water system of a thick plate rolling mill according to claim 1 is characterized in that: The control instructions include setting the speed or frequency of the speed regulating device, the opening or position of the regulating valve, and the number of water supply pump groups to be opened.

3. A method for energy-saving control of a high-pressure turbid circulating water system of a thick plate rolling mill, characterized in that: The method is implemented based on the energy-saving control system of the high-pressure turbid circulating water system of the thick plate rolling mill according to any one of claims 1-2, and specifically comprises: (1) Adopt different control modes according to different operating conditions of the rolling mill; (2) When the rolling mill is rolling, a cascade control method combining cooling water flow control on the rolling mill side and pressure control on the water supply side is adopted. At other times, the water supply side pressure control method is adopted, and the pressure control model gives control instructions.

4. The energy-saving control method for the high-pressure turbid circulating water system of a thick plate rolling mill according to claim 3 is characterized in that: When flow and pressure cascade control is adopted, the output of the flow control model is used to compensate the set value of the pressure control model, and then the pressure control model gives the control instruction.

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