Cooling tower circulating water quality automatic control system

Abstract

The utility model provides a cooling tower circulating water quality automatic control system. The cooling tower circulating water quality automatic control system comprises a water replenishing device, a first blowdown system, a second blowdown system and a cooling tower, one end of the water replenishing device is connected with the industrial water pipe network, the other end of the water replenishing device is connected with the cooling tower inlet, one end of the first blowdown system is connected with the cooling tower water outlet, the other end of the first blowdown system is connected with the three-return-water filter, the three-return-water filter is connected with the cooling tower inlet, and the second blowdown system is connected with the cooling tower water outlet. A liquid level meter and a water quality on-line monitor are arranged in the cooling tower; the water replenishing device, the first blowdown system and the second blowdown system are respectively provided with a manual valve, an electric control valve and a flow meter; according to the utility model, a set of automatic water replenishing and draining and on-line monitoring system is established, the water quality is ensured to stably reach the standard, the industrial water is subjected to gradient utilization through the automatic grading drainage device, and the water consumption is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of circulating water treatment, and in particular relates to an automatic control system for circulating water quality of a cooling tower. Background Art

[0002] Currently, cooling tower circulating water quality control relies primarily on regular manual sampling and laboratory analysis. The amount of wastewater discharged and the amount of chemical dosing are adjusted based on parameters such as the circulating water concentration ratio. System water replenishment is performed manually and regularly based on the cooling tower water level. Both chemical dosing and drainage are performed manually by operators based on the results of manual laboratory tests. The water quality contractor takes samples daily for testing, and then, based on the test results, reminds each team to replenish water, discharge wastewater, and dosing. This method clearly cannot control circulating water quality in real time. On the one hand, it can lead to untimely chemical dosing and water quality data exceeding standards, which can cause corrosion and scaling of tube bundles in condensers, oil coolers, etc. On the other hand, manual drainage wastes water resources and increases water consumption. Summary of the Invention

[0003] Purpose of the invention: In view of the shortcomings of the existing technology, the purpose of this utility model is to provide an automatic control system for the water quality of circulating water in a cooling tower.

[0004] Technical solution: The utility model provides an automatic control system for circulating water quality of a cooling tower, comprising a water replenishment device, a first sewage discharge system, a second sewage discharge system, and a cooling tower; one end of the water replenishment device is connected to the industrial water network, and the other end is connected to the cooling tower inlet; one end of the first sewage discharge system is connected to the cooling tower drain outlet, and the other end is connected to the three-return water filter tank; the three-return water filter tank is connected to the cooling tower inlet; one end of the second sewage discharge system is connected to the cooling tower drain outlet, and the other end is connected to the ditch;

[0005] The cooling tower is equipped with a liquid level meter and a water quality online monitor, and the water replenishment device, the first sewage system, and the second sewage system are all equipped with manual valves, electric regulating valves, and flow meters;

[0006] The liquid level gauge is interlocked with the electric regulating valve in the water supply device to increase the opening of the electric regulating valve when the water level of the cooling tower is lower than the water level setting value, and to reduce the opening of the electric regulating valve in the water supply device when the water level of the cooling tower is higher than the water level setting value;

[0007] The water quality online monitor is interlocked with the first sewage discharge system and the second sewage discharge system for control. The water quality online monitor controls the first sewage discharge system and the second sewage discharge system to open and close according to the monitored water quality indicators.

[0008] Furthermore, the cooling tower circulating water quality automatic control system is equipped with a DCS program control system, which is electrically connected to the liquid level meter, water quality online monitor, and electric regulating valve. The DCS configuration controls the electric regulating valve to achieve remote control and monitoring.

[0009] Furthermore, the signal output terminals of the liquid level gauge and the online water quality monitor are connected to the signal input terminals of the DCS program control system, and the output terminals of the DCS program control system are connected to the control terminals of the electric regulating valves in the water replenishment device, the first sewage discharge system, and the second sewage discharge system. The signal output terminals of the liquid level gauge and the online water quality monitor are connected to the signal input terminals of the DCS program control system, and the output terminals of the DCS program control system are connected to the control terminals of the electric regulating valves in the water replenishment device, the first sewage discharge system, and the second sewage discharge system.

[0010] Furthermore, the DCS program control system sets two set values ​​for the chloride ion content in the cooling tower. When the water quality online monitor shows that the water quality exceeds the standard but the chloride ion content is between the low set value and the high set value, the first sewage system is turned on, the electric regulating valve in the first sewage system is opened, and the discharged sewage is treated in the three-return water filter and then replenished into the cooling tower through the cooling tower inlet for recycling. When the water quality online monitor shows that the water quality exceeds the standard and the chloride ion content is higher than the high set value, the second sewage system is turned on, the electric regulating valve in the second sewage system is opened, and the sewage is discharged into the ditch.

[0011] When the water quality online monitor detects that the chloride ion content is less than the low set value, the water in the cooling tower is directly discharged for recycling.

[0012] Furthermore, the low setting value is 400ppm and the high setting value is 600ppm.

[0013] Furthermore, the water level in the cooling tower is set at 1.9 m.

[0014] Beneficial effects: Compared with the existing technology, the present invention has the following advantages: (1) A set of automatic water supply and drainage and online monitoring systems are established to ensure that the water quality is stable and meets the standards; (2) An automatic graded drainage device is established. According to the water quality, it is normally discharged to the three-return water filter tank of the water plant for recycling. When the water quality is particularly poor, it is directly discharged to the ditch, so that industrial water is utilized in a cascade manner to reduce water consumption; (3) The automatic water supply and drainage and online monitoring system reduces manual operations through chain control, and achieves precise control and refined management. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the automatic control system for circulating water quality in a cooling tower provided by the utility model. DETAILED DESCRIPTION

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] like Figure 1As shown, the cooling tower circulating water quality automatic control system provided by the utility model includes a water replenishment device, a first sewage discharge system, a second sewage discharge system, and a cooling tower; one end of the water replenishment device is connected to the industrial water network, and the other end is connected to the cooling tower inlet, one end of the first sewage discharge system is connected to the cooling tower drain outlet, and the other end is connected to the three-return water filter, the three-return water filter is connected to the cooling tower inlet, one end of the second sewage discharge system is connected to the cooling tower drain outlet, and the other end is connected to the ditch; a liquid level meter 1 and an online water quality monitor 2 are provided in the cooling tower, and the water replenishment device, the first sewage discharge system, and the second sewage discharge system are all provided with a manual valve 3, an electric regulating valve 4, and a flow meter 5; the liquid level meter 1 is interlocked with the electric regulating valve 4 in the water replenishment device for control.

[0018] The cooling tower's circulating water quality automatic control system features a DCS program control system. The DCS configures and controls the electric regulating valve 4, enabling remote control and monitoring. The signal outputs of the liquid level gauge 1 and the online water quality monitor 2 are connected to the signal inputs of the DCS program control system. The DCS program control system outputs are connected to the control terminals of the electric regulating valve 4 in the water replenishment device, the primary sewage system, and the secondary sewage system.

[0019] The system operates as follows: a liquid level meter 1 and an online water quality monitor 2 output real-time cooling tower water level and quality data to the DCS program control system. When the cooling tower water level falls below the set point, the opening of the electric control valve 4 in the water replenishment system is increased. When the cooling tower water level rises above the set point, the opening of the electric control valve 4 in the water replenishment system is decreased. When the online water quality monitor 2 indicates that the water quality exceeds the standard but the chloride ion content is within the low and high set points, the first sewage system is activated, and the electric control valve 4 in the first sewage system opens. The discharged sewage is treated in the three-return water filter and then recirculated into the cooling tower through the cooling tower inlet. When the online water quality monitor 2 indicates that the water quality exceeds the standard and the chloride ion content is above the high set point, the second sewage system is activated, and the electric control valve 4 in the second sewage system opens, discharging the sewage into the drain. When the online water quality monitor detects that the chloride ion content is below the low set point, the water in the cooling tower is directly discharged for recycling.

[0020] Example

[0021] A large steel plant in Jiangsu Province has an ultra-high temperature subcritical unit. It uses the cooling tower circulating water automatic control system described above, setting the chloride ion content as follows: a low setting value of 400ppm, a high setting value of 600ppm, and a cooling tower water level setting value of 1.9m. The liquid level meter 1 and the online water quality monitor 2 output the water level and water quality data in the cooling tower to the DCS program control system in real time. When the water level of the cooling tower is lower than the water level setting value of 1.9m, the DCS program control system increases the opening of the electric regulating valve 4 in the water replenishment device. When the water level of the cooling tower is higher than the water level setting value of 1.9m, the opening of the electric regulating valve 4 in the water replenishment device is reduced. When the online water quality monitor 2 shows that the water quality in the cooling tower exceeds the standard but the chloride ion content is between 400ppm and 600ppm, the first sewage system is opened, the electric regulating valve 4 in the first sewage system is opened, and the discharged sewage is treated in the three-return water filter and then replenished into the cooling tower through the cooling tower inlet for recycling. When the online water quality monitor 2 shows that the water quality exceeds the standard and the chloride ion content is higher than 600ppm, the second sewage system is opened, the electric regulating valve 4 in the second sewage system is opened, and the sewage is discharged into the ditch.

[0022] The utility model establishes a set of automatic replenishment and drainage and online monitoring systems to ensure that the water quality is stable and meets the standards; by establishing an automatic graded drainage device, when the water quality is normal, it is discharged to the three-return water filter for recycling; when the water quality is particularly poor, it is directly discharged to the ditch, so that industrial water is utilized in a cascade manner to reduce water consumption; by adding DCS program control, manual operation is reduced, replenishment and drainage are carried out in real time and accurately, avoiding the waste of water resources caused by large-scale drainage and replenishment, and at the same time ensuring that system parameters are controlled within the standard range, achieving stable operation.

Claims

1. A cooling tower circulating water quality automatic control system, characterized in that: Including water supply device, primary sewage system, secondary sewage system, cooling tower and DCS program control system; One end of the water replenishment device is connected to the industrial water network through a pipeline, and the other end is connected to the cooling tower inlet through a pipeline; One end of the first sewage system is connected to the cooling tower drain outlet through a pipeline, and the other end is connected to the three-return water filter tank through a pipeline, and the three-return water filter tank is connected to the cooling tower inlet through a pipeline; One end of the second sewage system is connected to the cooling tower drain through a pipe, and the other end is connected to the ditch through a pipe; A liquid level meter (1) and a water quality online monitor (2) are fixedly installed in the cooling tower, and a manual valve (3), an electric regulating valve (4) and a flow meter (5) are sequentially installed in series on the pipes of the water supply device, the pipes of the first sewage system, and the pipes of the second sewage system; The DCS program control system includes a signal input interface, a signal output interface and a control circuit board, the liquid level meter (1) and the water quality online monitor (2) are connected to the signal input interface of the DCS program control system via a signal cable, and the signal output interface of the DCS program control system is connected to the water replenishment device, the first sewage discharge system, and the electric regulating valve (4) in the second sewage discharge system via a control cable; A threshold comparator module is integrated on the control circuit board of the DCS program control system, and the output end of the threshold comparator module is connected to the electric regulating valve (4) control circuit of the first sewage discharge system and the second sewage discharge system respectively through hard wiring; When the water quality online monitor (2) detects that the chloride ion content is between the low set value and the high set value, the first sewage discharge system is turned on. When the water quality online monitor (2) detects that the chloride ion content is greater than the high set value, the second sewage discharge system is turned on.

2. The cooling tower circulating water quality automatic control system according to claim 1, characterized in that: The low setting value of the chloride ion concentration of the threshold comparator module is 400 ppm, and the high setting value is 600 ppm.

3. The cooling tower circulating water quality automatic control system according to claim 1, characterized in that: The water level in the cooling tower is set to 1.9 m.

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