Intelligent control method and regulator for industrial circulating cooling water system

Abstract

The invention discloses an intelligent control method for an industrial circulating cooling water system and a regulator, the industrial circulating cooling water system comprises a cooling tower, a main water pump, a tail end valve and production equipment, and the intelligent control method comprises the following steps: S1, obtaining the water distribution pressure of the cooling tower; s2, the outlet temperature of a cooled medium of the production equipment is obtained; s3, the opening degree of a tail end valve is controlled according to the outlet temperature of the cooled medium; s4, a tail end flow alarm signal is obtained according to the outlet temperature of the cooled medium and the opening degree of a tail end valve; and S5, controlling the operation frequency of the main water pump according to the water distribution pressure of the cooling tower and the tail end flow alarm signal. Automatic adjustment of the main water pump and the tail end valve is achieved, under the condition that actual requirements are met, unnecessary energy loss is reduced, the production cost is reduced, and the energy efficiency of the industrial circulating cooling water system is remarkably improved.

Description

Technical Field

[0001] The invention relates to the field of industrial circulating cooling water systems, and more specifically to an intelligent control method and a regulator for an industrial circulating cooling water system. Background Art

[0002] Traditional open-loop cooling water systems are widely used in industry. Open-loop cooling water systems usually include one or more heat exchangers (such as cooling towers), water pumps, filtration devices, and control systems. After hot water flows out of the production equipment, it enters the heat exchanger, where it exchanges heat with cooler air or cold water to reduce the temperature. The cooled water is then pumped back to the production equipment for continued circulation.

[0003] However, the current industrial circulating water cooling water system, especially the circulating cooling water system in the thermal power plant established in the early years, is still mainly controlled by manual control. The operator manually adjusts the opening size of the terminal cooling water valve and the operating frequency of the main water pump based on experience. This control method is not only inefficient, but also prone to operating errors, and cannot respond to load changes in time, affecting system stability. While failing to achieve refined control, it is also prone to energy waste. Summary of the invention

[0004] To solve the above problems, the present invention provides the following technical solutions:

[0005] An intelligent control method for an industrial circulating cooling water system, wherein the industrial circulating cooling water system comprises a cooling tower, a main water pump, and a terminal valve, and comprises the following steps:

[0006] S1: Get the water distribution pressure of the cooling tower;

[0007] S2: Obtain the outlet temperature of the cooled medium of the production equipment;

[0008] S3: controlling the opening of the terminal valve according to the outlet temperature of the cooled medium;

[0009] S4: obtaining a terminal flow alarm signal according to the outlet temperature of the cooled medium and the opening degree of the terminal valve;

[0010] S5: Controlling the operating frequency of the main water pump according to the cooling tower water pressure and the terminal flow alarm signal.

[0011] The present invention is further configured as follows: in step S4, when the opening of the terminal valve has reached the set maximum opening and the outlet temperature of the cooled medium is still greater than the target value, a terminal flow alarm signal of too small flow is obtained; when the outlet temperature of the cooled medium is less than the target value and the opening of the terminal valve is less than the set minimum opening, a terminal flow alarm signal of too large flow is obtained.

[0012] The present invention is further configured as follows: in step S3, according to the target value of the temperature of the cooled medium and the outlet temperature of the cooled medium, pi controls the opening size of the terminal valve.

[0013] The present invention is further configured as follows: in step S5, when the cooling tower water pressure is greater than the cooling tower water pressure setting value - Xkpa, and the terminal flow alarm signal is that the flow rate is too small, the operating frequency of the main water pump is increased; when the cooling tower water pressure is greater than the cooling tower water pressure setting value - Xkpa, and the terminal flow alarm signal is that the flow rate is too large, the operating frequency of the main water pump is reduced.

[0014] The present invention is further configured as follows: in step S5, increasing the operating frequency of the main water pump specifically includes increasing the frequency by 1 Hz every 2 minutes, and decreasing the operating frequency of the main water pump specifically includes decreasing the frequency by 1 Hz every 5 minutes.

[0015] The present invention is further configured as follows: in step S5, when the cooling tower water pressure is less than the cooling tower water pressure setting value - Xkpa, the cooling tower water pressure setting value is controlled according to the operating frequency of the main water pump.

[0016] In addition, the present invention also proposes an intelligent controller for an industrial circulating cooling water system, which adopts the above-mentioned intelligent control method. The intelligent controller includes a main water pump control system and a terminal valve control system that are interconnected. The main water pump control system is used to control the operating frequency of the main water pump, and the terminal valve control system is used to control the opening of the terminal valve.

[0017] The present invention is further configured as follows: the main water pump control system includes a first data processing unit, a first communication module and a judgment module, the judgment module is used to read the terminal flow alarm signal, the main water pump control system is connected to a pressure sensor for monitoring the water pressure of the cooling tower cloth, and is also connected to a water pump inverter for controlling the start and stop and operating frequency of the main water pump.

[0018] The present invention is further configured as follows: the terminal valve control system includes a second data processing unit, a second communication module and a module, the alarm module is used to generate the terminal flow alarm signal, the terminal valve control system is connected to a temperature sensor for measuring the outlet temperature of the cooling medium, and the terminal valve control system outputs an opening control signal to control the opening size of the terminal valve.

[0019] The present invention is further configured as follows: the main water pump control system is also connected to a flow meter, and the flow meter is used to monitor the total flow rate of the cooling water circulation.

[0020] Compared with the prior art, the present invention has at least the following advantages:

[0021] By analyzing the collected parameters such as cooling tower water pressure and outlet temperature of the cooled medium, the adjustment targets of the main water pump and the terminal valve are determined, and the total cooling load and flow are matched by the speed of the main water pump to achieve flow regulation of the terminal cooling water. While meeting actual needs, unnecessary energy loss is reduced, production costs are reduced, and the energy efficiency of the industrial circulating cooling water system is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of the intelligent control method of this embodiment;

[0023] Figure 2 This is the schematic diagram of obtaining the terminal flow alarm signal;

[0024] Figure 3 It is the principle diagram of the terminal valve control method;

[0025] Figure 4 It is a schematic diagram of the main water pump control system;

[0026] Figure 5 It is a schematic diagram of the terminal valve control system. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] An intelligent control method for an industrial circulating cooling water system, such as Figures 1 to 3 As shown, the industrial circulating cooling water system includes a cooling tower, a main water pump, a terminal valve, and production equipment. The intelligent control method includes the following steps:

[0030] S1: Get the water distribution pressure of the cooling tower;

[0031] S2: Obtain the outlet temperature of the cooled medium of the production equipment;

[0032] S3: Control the opening of the terminal valve according to the outlet temperature of the cooled medium;

[0033] S4: Obtaining the terminal flow alarm signal according to the outlet temperature of the cooled medium and the opening size of the terminal valve;

[0034] S5: Controlling the operating frequency of the main water pump according to the cooling tower water pressure and the terminal flow alarm signal.

[0035] In step S1, the water distribution pressure of the cooling tower can be obtained by setting a pressure sensor, and in step S2, the outlet temperature of the cooled medium of the production equipment can be obtained by setting a temperature sensor. In step S3, according to the target temperature value of the cooled medium and the outlet temperature of the cooled medium, pi controls the opening size of the terminal valve.

[0036] like Figure 2 As shown, the opening of the terminal valve is set to Vo, the outlet temperature of the cooled medium is set to To, the flow rate is too small to Fs, and the flow rate is too large to Fb. In step S4, when the opening of the terminal valve has reached the set maximum opening VoMax, and the outlet temperature of the cooled medium is still greater than the target value ToSP, the terminal flow alarm signal of too small flow is obtained, that is, Fs=ON; when the outlet temperature of the cooled medium is less than the target value, and the opening of the terminal valve is less than the set minimum opening VoMin, the terminal flow alarm signal of too large flow is obtained, that is, Fb=ON.

[0037] like Figure 1As shown, the cooling tower water pressure is set to CTP, and the cooling tower water pressure setting value is CTPSP. In step S5, when the cooling tower water pressure CTP>CTPSP (cooling tower water pressure setting value)-Xkpa, and the terminal flow alarm signal is that the flow is too small, that is, Fs=ON, the operating frequency of the main water pump is increased; when the cooling tower water pressure CTP>CTPSP-Xkpa, and the terminal flow alarm signal is that the flow is too large, that is, Fb=ON, the operating frequency of the main water pump is reduced. Xkpa in this embodiment is preferably 5kpa.

[0038] In step S5, in this embodiment, increasing the operating frequency of the main water pump specifically involves increasing the frequency by 1 Hz every 2 minutes, and decreasing the operating frequency of the main water pump specifically involves decreasing the frequency by 1 Hz every 5 minutes.

[0039] In step S5, when the cooling tower water pressure is less than the cooling tower water pressure setting value - 5 kPa, the cooling tower water pressure setting value is controlled according to the operating frequency of the main water pump.

[0040] The present invention also proposes an intelligent controller for an industrial circulating cooling water system, which adopts the above-mentioned intelligent control method. The intelligent controller includes a main water pump control system and a terminal valve control system that are interconnected. The main water pump control system is used to control the operating frequency of the main water pump, and the terminal valve control system is used to control the opening of the terminal valve.

[0041] The main water pump can be set to one or more. The main water pump control system can comprehensively adjust the cooling water flow by controlling the operating frequency of the main water pump and the number of main water pumps that are turned on. The end of the industrial circulating cooling water system can be connected to multiple production equipment. Each production equipment corresponds to a terminal valve control system. Each terminal valve control system has a special alarm code. For example, the alarm signal codes for valve 1's excessive flow and too small flow are Fb1 and Fs1 respectively, and the alarm signal codes for valve 2's excessive flow and too small flow are Fb2 and Fs2 respectively, and so on. When multiple production equipment are connected, CTP>CTPSP-5kpa, and the terminal submodule has an excessive flow alarm signal, that is, Fb=ON, and there is no low flow alarm, that is, Fs=Off, then the pump frequency is reduced by 1HZ every 5 minutes, otherwise the pump speed maintains the previous speed.

[0042] The condition for Fb=ON is that if any one of the terminal valve control systems has an excessive flow alarm signal, then Fb=ON; similarly, if any one of the terminal valve control systems has a low flow alarm signal, then Fs=ON.

[0043] The main water pump control system includes a first data processing unit, a first communication module and a judgment module. The first data processing unit has a built-in control algorithm and optimization logic. It processes the data obtained from the input and communication terminals and controls the number and speed of water pumps in operation through the output terminal. The first communication module can realize remote data reading, communicate with the terminal valve control system and the frequency converter, and obtain data such as the operating power and current of the water pump. The judgment module is used to read the terminal flow alarm signal and judge whether the terminal flow meets the requirements.

[0044] The input end of the main water pump control system is connected to a pressure sensor, which is used to monitor the cooling tower water pressure and the cooling pump inlet and outlet pressures. The input end is also connected to a temperature sensor and a flow meter, the temperature sensor is used to monitor the cooling tower inlet and outlet cooling water temperatures, and the flow meter is used to monitor the total cooling water circulation flow.

[0045] The output end of the main water pump control system is connected to a water pump frequency converter, which is used to control the start and stop and operating frequency of the main water pump. By outputting a switching signal to the water pump frequency converter, the start and stop of the main water pump and the number of units turned on are controlled by the water pump frequency converter. By outputting an analog signal to the water pump frequency converter, the operating frequency of the main water pump is controlled by the water pump frequency converter.

[0046] The terminal valve control system includes a second data processing unit, a second communication module and a module. The second data processing unit has a built-in control algorithm and optimization logic. By acquiring and processing the outlet temperature of the cooling water of the terminal production equipment and the outlet temperature of the cooled medium, the output signal controls the terminal valve opening. The second communication module is used to communicate with the main water pump control system so that the main water pump control system obtains the flow alarm signal from the terminal valve control system. The alarm module is used to generate a terminal flow alarm signal.

[0047] The input end of the terminal valve control system is connected to a temperature sensor, which is used to measure the outlet temperature of the cooling medium and the outlet temperature of the cooling water of the production equipment.

[0048] The output end of the terminal valve control system outputs an opening control signal, and controls the opening size of the terminal valve through an analog signal. The terminal valve adopts an electric regulating valve.

[0049] The working process of this embodiment is as follows:

[0050] The terminal valve control system obtains the cooling medium outlet temperature To according to the temperature sensor, and controls the opening Vo of the terminal valve according to the cooling medium temperature target value ToSP and the outlet temperature To,pi of the cooled medium. The alarm module determines whether the cooling water flow of the production equipment meets the requirements and generates terminal flow alarm signals Fs and Fb according to the opening Vo of the terminal valve and the cooling medium outlet temperature To;

[0051] The main water pump control system obtains the cooling tower water pressure CTP according to the pressure sensor, and controls the main water pump frequency to increase or decrease or maintain the previous speed by detecting the cooling tower water pressure CTP and the terminal flow alarm signal.

[0052] 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 design concept of the present invention should be included in the protection scope of the present invention.

Claims

1. An intelligent control method for an industrial circulating cooling water system, the industrial circulating cooling water system comprising a cooling tower, a main water pump, and a terminal valve, characterized in that: The following steps are involved: S1: Get the water distribution pressure of the cooling tower; S2: Obtain the outlet temperature of the cooled medium of the production equipment; S3: Control the opening of the terminal valve according to the outlet temperature of the cooled medium; S4: Obtaining the terminal flow alarm signal according to the outlet temperature of the cooled medium and the opening size of the terminal valve; S5: Controlling the operating frequency of the main water pump according to the cooling tower water pressure and the terminal flow alarm signal.

2. The intelligent control method for an industrial circulating cooling water system according to claim 1 is characterized in that: In step S4, when the opening of the terminal valve has reached the set maximum opening and the outlet temperature of the cooled medium is still greater than the target value, a terminal flow alarm signal of too small flow is obtained; when the outlet temperature of the cooled medium is less than the target value and the opening of the terminal valve is less than the set minimum opening, a terminal flow alarm signal of too large flow is obtained.

3. The intelligent control method for an industrial circulating cooling water system according to claim 2 is characterized in that: In step S3, the opening degree of the terminal valve is controlled according to the target temperature value of the cooled medium and the outlet temperature of the cooled medium.

4. The intelligent control method for an industrial circulating cooling water system according to claim 2 is characterized in that: In step S5, when the cooling tower water pressure is greater than the cooling tower water pressure setting value - Xkpa, and the terminal flow alarm signal is that the flow rate is too small, the operating frequency of the main water pump is increased; when the cooling tower water pressure is greater than the cooling tower water pressure setting value - Xkpa, and the terminal flow alarm signal is that the flow rate is too large, the operating frequency of the main water pump is reduced.

5. The intelligent control method for an industrial circulating cooling water system according to claim 4 is characterized in that: In step S5, increasing the operating frequency of the main water pump specifically includes increasing the frequency by 1 Hz every 2 minutes, and decreasing the operating frequency of the main water pump specifically includes decreasing the frequency by 1 Hz every 5 minutes.

6. The intelligent control method for an industrial circulating cooling water system according to claim 4 is characterized in that: In step S5, when the cooling tower water pressure is less than the cooling tower water pressure setting value - X kpa, the cooling tower water pressure setting value is controlled according to the operating frequency of the main water pump.

7. An intelligent controller for an industrial circulating cooling water system, characterized in that: The intelligent control method described in any one of claims 1 to 6 is adopted, and the intelligent controller includes a main water pump control system and a terminal valve control system that are interconnected. The main water pump control system is used to control the operating frequency of the main water pump, and the terminal valve control system is used to control the opening of the terminal valve.

8. The intelligent controller for an industrial circulating cooling water system according to claim 7 is characterized in that: The main water pump control system includes a first data processing unit, a first communication module and a judgment module. The judgment module is used to read the terminal flow alarm signal. The main water pump control system is connected to a pressure sensor for monitoring the water pressure of the cooling tower cloth, and is also connected to a water pump inverter for controlling the start and stop and operating frequency of the main water pump.

9. The intelligent controller for an industrial circulating cooling water system according to claim 7, characterized in that: The terminal valve control system includes a second data processing unit, a second communication module and a module. The alarm module is used to generate the terminal flow alarm signal. The terminal valve control system is connected to a temperature sensor for measuring the outlet temperature of the cooling medium. The terminal valve control system outputs an opening control signal to control the opening size of the terminal valve.

10. The intelligent controller for industrial circulating cooling water system according to claim 8, characterized in that: The main water pump control system is also connected to a flow meter, which is used to monitor the total flow of cooling water circulation.

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