A circulating water system pressure control device

Abstract

The utility model provides a kind of circulating water system pressure control device, belong to chemical equipment automation control technical field.The device includes pressure monitoring component, water replenishing control component, drainage control component and control system, pressure monitoring component is set on circulating water system pipeline and monitors pressure in real time, water replenishing control component includes the water replenishing pipeline and water replenishing regulating valve of connecting desalted water source and circulating water system, drainage control component includes the drainage pipeline and drainage valve of connecting circulating water system, control system is signal connected with each component, and water replenishing regulating valve and drainage valve opening state are automatically controlled according to monitoring pressure.The utility model solves the technical problem that traditional bladder type constant pressure tank responds slowly, control precision is low, needs manual intervention, realizes the intelligent automatic control of circulating water system pressure.

Description

Technical Field

[0001] This utility model relates to the field of automated control of chemical equipment, specifically to a pressure control device for a circulating water system. Background Technology

[0002] Circulating water systems are widely used in chemical plants for cooling various heat exchange equipment and are an important component in ensuring the normal operation of production facilities. Pressure control of the circulating water system is crucial for ensuring stable system operation, preventing equipment damage, and maintaining good heat exchange efficiency.

[0003] Currently, pressure control in chemical plant circulating water systems primarily employs bladder-type pressure regulating tanks for water replenishment. This method works by utilizing the buffering effect of the highly compressible gas within the pressure tank to stabilize the system pressure within a preset range when changes in system water pressure or leakage cause changes in water volume. The bladder-type pressure regulating tank replenishes water when system pressure decreases, and manual pressure relief is required when pressure increases.

[0004] However, traditional bladder-type pressure tank water replenishment methods have several technical drawbacks. First, the water replenishment capacity of bladder-type pressure tanks is limited by their design capacity, failing to meet the rapidly changing load demands of chemical plants. During equipment operation, heat exchangers experience frequent pressure increases or decreases in the circulating water system due to leaks, displacement, sampling, or vaporization, and the response speed of bladder-type pressure tanks cannot keep up with these dynamic changes. Second, controlling the water replenishment rate is difficult; excessively rapid replenishment can lead to system overpressure, while insufficient replenishment fails to provide the required water, especially in cases of significant water shortage. Third, the water replenishment process causes drastic pressure fluctuations in the system, making precise pressure control difficult and affecting the stability and heat exchange efficiency of the entire circulating water system. Most importantly, existing technologies require central control personnel to constantly monitor system pressure changes. When water replenishment is delayed or system overpressure occurs, on-site inspectors must be contacted immediately for manual water replenishment or drainage, which not only increases labor costs but also carries the risk of equipment damage due to delayed response.

[0005] Besides bladder-type pressure regulating tanks, other pressure stabilization and control schemes exist in the prior art. For example, Chinese patent CN221303894U discloses an automatic pressure stabilization and water replenishment control system. This system adopts a dual-tank structure of a water replenishment tank and an expansion tank, and achieves water replenishment through nitrogen pressurization. However, this system is only suitable for specific application scenarios in polysilicon production and adopts an intermittent operation mode. It requires multiple steps such as depressurization, water replenishment, nitrogen pressurization, and transmission to complete one water replenishment cycle, making the operation complex and the response time long. In addition, Chinese patent CN209877743U discloses a pressure control water circulation system for circulating water stations. This system regulates water pressure through multi-layer sealed eccentric butterfly valves, adopting a mechanical pressure regulation method. However, this system mainly relies on the mechanical adjustment of valve opening to control flow and pressure, resulting in limited control accuracy and a relatively slow response speed, making it difficult to meet the requirements of modern chemical enterprises for rapid and accurate pressure control. Utility Model Content

[0006] The purpose of this invention is to provide a pressure control device for a circulating water system that can achieve rapid response, precise control, and high automation, so as to meet the growing production needs and automation management requirements of chemical enterprises.

[0007] To achieve the above objectives, this utility model employs the following technical solution:

[0008] A pressure control device for a circulating water system includes a pressure monitoring component, a water supply control component, a drainage control component, and a control system. The pressure monitoring component is installed on the pipeline of the circulating water system for real-time monitoring of the system pressure. The water supply control component includes a water supply pipe and a water supply regulating valve installed on the water supply pipe, the water supply pipe being connected to a desalination source and the circulating water system. The drainage control component includes a drainage pipe and a drainage valve installed on the drainage pipe, the drainage pipe being connected to the circulating water system. The control system is signal-connected to the pressure monitoring component, the water supply regulating valve, and the drainage valve, and is used to automatically control the opening state of the water supply regulating valve and the drainage valve based on the pressure value monitored by the pressure monitoring component.

[0009] Furthermore, the pressure monitoring component is a remote pressure transmitter.

[0010] Furthermore, the water supply regulating valve is an electric regulating valve or a pneumatic regulating valve.

[0011] Furthermore, the drain valve is a solenoid valve.

[0012] Furthermore, the water replenishment control component also includes a water replenishment shut-off valve disposed on the water replenishment pipeline, the water replenishment shut-off valve being located upstream of the water replenishment regulating valve.

[0013] Furthermore, the water supply shut-off valve is an electric shut-off valve or a pneumatic shut-off valve.

[0014] Furthermore, the drainage pipe is connected downstream of the water supply pipe.

[0015] Furthermore, the control system is a DCS distributed control system.

[0016] Furthermore, the DCS distributed control system is equipped with a PID control algorithm for precise control of the water supply regulating valve.

[0017] Furthermore, the control system sets the pressure control range of the circulating water system to 0.45MPa to 0.55MPa. When the monitored pressure is lower than the set lower limit, the water replenishment regulating valve is automatically opened to replenish water, and when the monitored pressure is higher than the set upper limit, the drain valve is automatically opened to drain water.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] I. This utility model monitors the pressure of the circulating water system in real time through a pressure monitoring component. The control system automatically controls the water supply regulating valve and the drain valve according to the monitoring results, realizing fully automatic pressure control. This solves the technical problems of traditional technology, which requires central control personnel to pay attention to the system pressure at all times and on-site inspectors to operate manually, and significantly reduces the need for manual intervention.

[0020] Second, this utility model uses a water replenishment regulating valve to replace the traditional on / off water replenishment method, which can accurately adjust the water replenishment flow according to the system pressure changes, effectively solving the technical problem of system overpressure caused by excessive water replenishment speed, and avoiding pressure shock during the water replenishment process.

[0021] Third, this utility model uses a DCS distributed control system with a PID control algorithm to achieve precise control of the water replenishment process. Compared with the mechanical buffering method of traditional bladder-type pressure tanks, it can significantly reduce system pressure fluctuations caused by water replenishment and improve the stability of pressure control.

[0022] Fourth, this utility model is the first to realize bidirectional automatic adjustment of water replenishment and drainage in a circulating water system. It is not limited by the water storage capacity of traditional bladder-type pressure tanks, and can quickly respond to the large water shortage demand during the operation of chemical plants, solving the technical problem of not being able to replenish water in time when there is a large water shortage. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the pressure control device for the circulating water system of this utility model;

[0024] In the picture:

[0025] 1. Pressure transmitter; 2. DCS distributed control system; 3. Drain valve; 4. Water supply shut-off valve; 5. Water supply regulating valve; 6. Flow indicator; 7. Circulating water system. Detailed Implementation

[0026] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0027] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] The circulating water system pressure control device provided by this utility model includes four core parts: a pressure monitoring component, a water replenishment control component, a drainage control component, and a control system.

[0029] A pressure monitoring component is installed on the pipeline of the circulating water system 7 to monitor the pressure of the circulating water system 7 in real time. In specific implementation, the pressure monitoring component adopts a remote pressure transmitter 1, which can convert the detected pressure signal into a standard electrical signal or digital signal and transmit it to the control system for processing. The remote pressure transmitter 1 has the characteristics of high measurement accuracy, fast response speed, and stable signal transmission, and can accurately reflect the real-time pressure status of the circulating water system 7.

[0030] The water replenishment control assembly includes a water replenishment pipe and a water replenishment regulating valve 5 installed on the water replenishment pipe. The water replenishment pipe connects the demineralized water source and the circulating water system 7. The demineralized water outlet pressure is approximately 0.6 MPa, which can provide sufficient water replenishment pressure for the circulating water system 7. The water replenishment regulating valve 5 is an electric or pneumatic regulating valve. Compared with traditional on / off valves, the regulating valve can continuously adjust its opening degree according to the control signal, achieving precise control of the water replenishment flow. To improve the safety and reliability of the system, the water replenishment control assembly also includes a water replenishment shut-off valve 4 installed on the water replenishment pipe. This water replenishment shut-off valve 4 is located upstream of the water replenishment regulating valve 5 and is an electric or pneumatic shut-off valve. The water replenishment shut-off valve 4 remains open during normal operation. When the system malfunctions or requires maintenance, it can quickly shut off the water replenishment channel to prevent safety hazards caused by misoperation. A flow indicator 6 is also installed on the water replenishment pipe, which is installed upstream of the water replenishment shut-off valve 4.

[0031] The drainage control component includes a drainage pipe and a drain valve 3 installed on the drainage pipe. The drainage pipe is connected to the circulating water system 7. The drainage pipe is located downstream of the water supply pipe, which effectively removes excess water and prevents system overpressure. The drain valve 3 is a solenoid valve, which features rapid action, good sealing, and easy control. It can quickly open or close under the command of the control system, achieving rapid regulation of system pressure.

[0032] The control system is connected to the pressure monitoring component, the water supply regulating valve 5, and the drain valve 3 via signal connections. It automatically controls the opening states of the water supply regulating valve 5 and the drain valve 3 based on the pressure value monitored by the pressure monitoring component. The control system employs a DCS distributed control system 2, which boasts powerful data processing capabilities and high reliability. The DCS distributed control system 2 is equipped with a PID control algorithm. This algorithm calculates the optimal control output based on the deviation between the current pressure value and the setpoint, as well as the rate of change and cumulative value of the deviation, thereby precisely controlling the water supply regulating valve 5 and achieving stable system pressure regulation.

[0033] In the specific operation process, the control system sets the pressure control range of the circulating water system 7 to 0.45MPa to 0.55MPa. When the remote pressure transmitter 1 detects that the pressure of the circulating water system 7 is lower than 0.45MPa, the control system automatically issues a command to open the water supply regulating valve 5 to supply water. The opening degree of the water supply regulating valve 5 is adjusted according to the pressure deviation; the greater the pressure deviation, the larger the valve opening and the greater the water supply flow. As the system pressure gradually approaches the set value, the valve opening gradually decreases until the pressure stabilizes within the set range. When the remote pressure transmitter 1 detects that the pressure of the circulating water system 7 is higher than 0.55MPa, the control system automatically issues a command to open the drain valve 3 to drain water, quickly reducing the system pressure and preventing overpressure from damaging the equipment.

[0034] The entire control process is fully automated, requiring no manual intervention. The control system can quickly respond to pressure changes caused by leakage, displacement, sampling, or vaporization of heat exchangers during the operation of the chemical plant, and perform corresponding water replenishment or drainage operations to ensure that the pressure of the circulating water system 7 remains stable within the set range, thus guaranteeing the safe and stable operation of the system and good heat exchange performance.

[0035] By adopting the technical solution of this utility model, the existing DCS system can realize automatic pressure control of the circulating water system 7 through software and hardware modification. Compared with the traditional bladder-type pressure tank water replenishment method, it has significant advantages such as fast response speed, high control accuracy and high degree of automation, providing an effective technical solution for the intelligent upgrading of the circulating water system 7 of chemical enterprises.

[0036] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent transformations or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A pressure control device for a circulating water system, characterized in that: The system includes a pressure monitoring component, a water supply control component, a drainage control component, and a control system. The pressure monitoring component is installed on the pipeline of the circulating water system to monitor the pressure of the circulating water system in real time. The water supply control component includes a water supply pipe and a water supply regulating valve installed on the water supply pipe, the water supply pipe being connected to the desalination source and the circulating water system. The drainage control component includes a drainage pipe and a drainage valve installed on the drainage pipe, the drainage pipe being connected to the circulating water system. The control system is signal-connected to the pressure monitoring component, the water supply regulating valve, and the drainage valve, and is used to automatically control the opening state of the water supply regulating valve and the drainage valve according to the pressure value monitored by the pressure monitoring component.

2. The pressure control device for a circulating water system according to claim 1, characterized in that: The pressure monitoring component is a remote pressure transmitter.

3. The pressure control device for a circulating water system according to claim 1, characterized in that: The water supply regulating valve is either an electric regulating valve or a pneumatic regulating valve.

4. The pressure control device for a circulating water system according to claim 1, characterized in that: The drain valve is a solenoid valve.

5. The pressure control device for a circulating water system according to claim 1, characterized in that: The water replenishment control component also includes a water replenishment shut-off valve installed on the water replenishment pipeline, which is located upstream of the water replenishment regulating valve.

6. The pressure control device for a circulating water system according to claim 5, characterized in that: The water supply shut-off valve is either an electric shut-off valve or a pneumatic shut-off valve.

7. The pressure control device for a circulating water system according to claim 1, characterized in that: The drainage pipe is connected downstream of the water supply pipe.

8. The pressure control device for a circulating water system according to claim 1, characterized in that: The control system is a DCS distributed control system.

9. The pressure control device for a circulating water system according to claim 8, characterized in that: The DCS distributed control system is equipped with a PID control algorithm for precise control of the water supply regulating valve.

10. The pressure control device for a circulating water system according to claim 1, characterized in that: The control system sets the pressure control range of the circulating water system to 0.45MPa to 0.55MPa. When the monitored pressure is lower than the set lower limit, the water replenishment regulating valve is automatically opened to replenish water. When the monitored pressure is higher than the set upper limit, the drain valve is automatically opened to drain water.

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