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

Abstract

The application discloses a kind of thick plate rolling mill high-pressure turbid water system energy-saving control system and method, belong to metallurgical production line energy-saving field.The system includes monitoring unit and control unit;Monitoring unit is used to obtain equipment system information and then pass to control unit, and receives the control instruction sent by control unit to control controlled object;Control unit is used to analyze and judge according to the information obtained by monitoring unit, and sends control instruction.The application combines the information of rolling line and water supply system, can reduce, even eliminate the invalid energy consumption loss caused by pressure relief mode on the side of rolling line, also considers the actual output situation of water supply side, ensures reliable water supply under the condition of information interruption between rolling line side and water supply side.Due to the cascade control mode during rolling, the dynamic economic demand of water supply system to rolling mill for cooling water can be quickly responded under the condition of ensuring reliable water supply, which ensures high tracking accuracy and excellent system stability.

Description

TECHNICAL FIELD

[0001] The present application relates to energy saving of metallurgical production line, and in particular to a kind of thick plate rolling mill high-pressure turbid ring water system energy-saving control system and method. BACKGROUND

[0002] Thick plate rolling mill is the main power consumption equipment for hot processing of billet in thick plate production line. During its working process, working roll contacts with hot billet and a large amount of heat is released in the process of energy conversion, which needs to be taken away to maintain the normal operation of the rolling mill. Therefore, a rolling mill turbid ring high-pressure cooling water system is usually provided to take away the heat. The rolling mill turbid ring high-pressure water supply system has high operating pressure and large flow rate, and is always continuously operated for a long time, so its energy consumption is considerable. The system is designed according to the maximum cooling load, and the system conveying capacity is often redundant under actual working conditions. Generally, the rolling mill high-pressure turbid ring water supply side and the rolling mill water consumption side are independently controlled, the water supply side supplies water in a constant pressure mode, and the water consumption side releases pressure through a regulating valve backflow, which has certain advantages in terms of reliability, but leads to a large amount of energy waste. In fact, the production conditions of the system, the environment, the state of the equipment, and the economic demand of the rolling mill for cooling water are changing in different stages of the rolling piece passing through the rolling mill, but due to the disconnection of the signals of the water supply side and the water consumption side, the changes cannot be fed back to the water supply pump set in time, causing unnecessary energy consumption of the water supply pump set. Moreover, the economic demand of the rolling mill for cooling water fluctuates greatly, and the conventional feedforward control mode and constant pressure control mode cannot achieve the best energy saving.

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

[0004] There are many schemes at home and abroad to combine rolling line information with energy supply system to achieve energy saving, such as the invention patent with the patent application number 201010161820.0, which provides a hot rolling cooling water control method based on rolling line control integration, and provides a feasible scheme for the energy saving of hot rolling cooling water system. The provided method is to transmit the obtained rolling line information to the cooling water control unit through a 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 rotating speed of the water supply pump or the opening degree of the water supply pump outlet valve. This control method has the following disadvantages: first, the water supply is adjusted only according to the rolling line data information, which may cause unreliable operation of the water supply system due to communication abnormalities, transmission time delay, 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 pump sets started, so it is difficult to achieve the best energy saving effect, because the water distribution on the rolling mill water consumption side and the efficiency of the pump set operation also affect the system energy consumption. SUMMARY

[0005] The purpose of the present application is to provide a thick plate rolling mill high-pressure turbid circulating water system energy-saving control system, and another purpose of the present application is to provide a thick plate rolling mill high-pressure turbid circulating water system energy-saving control method.

[0006] The technical scheme is a thick plate rolling mill high-pressure turbid circulating water system energy-saving control system, comprising a monitoring unit and a control unit; the monitoring unit is used for obtaining device system information and then transmitting the information to the control unit, and receiving control instructions from the control unit to control the controlled object; the control unit is used for analyzing and judging based on the information obtained by the monitoring unit, and issuing control instructions.

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

[0008] A thick plate rolling mill high-pressure turbid circulating water system energy-saving control method is realized based on the above-mentioned thick plate rolling mill high-pressure turbid circulating water system energy-saving control system, and specifically includes:

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

[0010] (2) When the rolling mill is rolling, a cascade control mode combining rolling mill side cooling water flow control and water supply side pressure control is adopted, and during other time, a water supply side pressure control mode is adopted, and the control instructions are given by the pressure control model.

[0011] Preferably, 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 control instructions are given by the pressure control model.

[0012] Advantages:

[0013] (1) The present application combines the information of the rolling line and the water supply system, which can reduce or even eliminate the invalid energy loss caused by the pressure relief mode of the rolling line side, and also ensures reliable water supply in the case of information interruption of the rolling line side and the water supply side by considering the actual output of the water supply side.

[0014] (2) The present application adopts a cascade control mode during rolling, so that the dynamic economic demand of the water supply system for the rolling mill for cooling water can be quickly responded under the condition of ensuring reliable water supply, and high tracking accuracy and excellent system stability are ensured.

[0015] (3) The present application distinguishes between rolling and non-rolling conditions, so that energy saving can be further realized by reducing the water supply pressure during non-rolling, and more in-depth energy saving can be realized by adjusting the rolling mill side valve and controlling the number of water supply pump groups turned on. DETAILED DESCRIPTION

[0016] Figure 1 is the process flow diagram of the system in the application;

[0017] Figure 2 is the control principle diagram of the application. DETAILED DESCRIPTION

[0018] In order to make the technical scheme of the application clearer, the application will be further described in detail below in combination with the drawings and specific embodiments.

[0019] EMBODIMENT

[0020] The application realizes the combination of the high-pressure turbid circulating water system water supply and the economic water supply of the rolling mill by acquiring the equipment system information and adopting different control modes according to different operating conditions of the rolling mill. In the rolling mill rolling time, the cascade control mode combining the rolling mill side cooling water flow control and the water supply side pressure control is adopted, and in other time, the water supply side pressure control mode is adopted. In the case of ensuring reliable water supply, the dynamic economic demand of the water supply system to the cooling water of the rolling mill can quickly respond, ensuring high tracking accuracy and excellent system stability, and reducing the system energy consumption.

[0021] As shown in Figure 1 , the thick plate rolling mill high-pressure turbid circulating water system energy-saving control system comprises a monitoring unit and a control unit. The monitoring unit is used to acquire the 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 circulating high-pressure water system information, and then transfer to the control unit, and receive the control instruction issued by the control unit to control the controlled object. The control unit is used to analyze and judge according to the information acquired by the monitoring unit, and issue the control instruction including setting the speed or frequency of the speed regulating device, the opening or position of the regulating valve, and the opening number of the water supply pump group.

[0022] As shown in Figure 2 , the thick plate rolling mill high-pressure turbid circulating water system energy-saving control system comprises: different control modes are adopted according to different operating conditions of the rolling mill; when the rolling mill is rolling, the cascade control mode combining the rolling mill side cooling water flow control and the water supply side pressure control 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 control instruction is given by the pressure control model. In other time, the water supply side pressure control mode is adopted, and the control instruction is given by the pressure control model.

[0023] When the rolling mill is rolling, the flow demand and various temperature T i , size (and position) L i , time t i , force F iand other factors, Q=f0(T i , L i , t i , F i ), to obtain the demand of the rolling mill for the high-pressure water, and to transmit the demand to the flow control model, which combines the actual flow feedback value to analyze and judge, and outputs the flow required to be provided by the water supply system, the pressure control model analyzes comprehensively according to the pipeline resistance characteristics P 管路 =f1(Q), the nozzle pressure-flow characteristics P 喷头 =f2(Q), and the equipment system information and the pressure feedback information, and outputs the control instruction to adjust the rolling mill side regulating valve to perform the optimal water distribution, and to adjust the rotating speed and the number of opened pumps, so as to realize the extreme energy saving of the system.

[0024] When the rolling mill is not rolling, the pressure control model analyzes comprehensively according to the equipment system information and the pressure feedback information, and outputs the control instruction to adjust the rolling mill side regulating valve to reduce the backflow water, and to adjust the rotating speed and the number of opened pumps, so as to realize the extreme energy saving of the system.

[0025] By combining the information of the rolling line and the water supply system, the invalid energy loss caused by the pressure relief on the rolling line side can be reduced or even eliminated, and the reliable water supply under the information interruption of the rolling line side and the water supply side can be ensured due to the consideration of the actual output of the water supply side; the control method can quickly respond to the dynamic economic demand of the rolling mill for the cooling water under the condition of ensuring the reliable water supply, and can ensure the high tracking precision and excellent system stability; the control method can further reduce the water supply pressure during the non-rolling period to realize the energy saving, and can realize the further energy saving by adjusting the rolling mill side regulating valve and controlling the number of opened pumps of the water supply pump group.

[0026] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as the limitation of the patent scope of the present application. It should be noted that, for those skilled in the art, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A method for energy saving control of a high pressure turbid water system of a heavy plate mill, characterized by, The method is realized based on an energy-saving control system of a high-pressure turbid circulating water system of a heavy plate mill, and specifically comprises the following steps: (1) different control modes are adopted according to different running conditions of the mill; (2) when the mill is rolling, a cascade control mode combining mill-side cooling water flow control and water supply-side pressure control is adopted, and during other time, a water supply-side pressure control mode is adopted, a control instruction is given by a pressure control model; 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 a control instruction is given by the pressure control model; The system comprises a monitoring unit and a control unit; the monitoring unit is used to acquire device system information and then transfer the information to the control unit, and receive control instructions from the control unit to control the controlled object; the control unit is used to analyze and judge according to the information acquired by the monitoring unit, and send control instructions; wherein the control instructions include setting the speed or frequency of the speed regulating device, adjusting the opening or position of the valve, and the number of water supply pump groups to be started.

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