A circulating water purification system and control method

Abstract

The present invention relates to the technical field of water treatment, and in particular to a circulating water purification treatment system and a control method, comprising a dissolved oxygen meter, a first valve, a mixed bed, a second valve and a third valve, wherein the first valve and the mixed bed are arranged in parallel, and a water inlet of the first valve is communicated with a water inlet of the mixed bed and is arranged as a circulating water inlet of a treatment system, and a water outlet of the first valve is communicated with a water outlet of the mixed bed and is arranged as a circulating water outlet of the treatment system; the present invention detects the state of water quality by a pH meter, a conductivity meter and a dissolved oxygen meter, and when the pH or conductivity is abnormal, the circulating water quality is adjusted by closing or opening the first valve and the mixed bed; the dissolved oxygen concentration can also be monitored by the dissolved oxygen meter, and desalted water is supplemented as needed to maintain the dissolved oxygen within the range of 50-200 ppb.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to a circulating water purification system and a control method. Background Art

[0002] In the indirect air cooling system, due to the deterioration of circulating water quality such as increased pH, increased dissolved oxygen concentration, and increased hydrogen conductivity, the aluminum radiator and carbon steel pipes will be corroded, which will lead to leakage of circulating water. The widely used treatment technologies currently include adding slow-release agents, water replacement, and setting up bypass treatment systems. However, there is currently no practical application of low-toxic and effective slow-release agents; water replacement will cause waste of water resources; setting up a bypass treatment system only controls pH and delays the corrosion of aluminum heat exchangers, but cannot control the dissolved oxygen concentration of circulating water, and still cannot protect the circulating water pipes made of carbon steel. Therefore, from the perspective of energy saving, green environmental protection, and high efficiency, an automatic purification system is needed to adjust the quality of circulating water. Summary of the invention

[0003] The technical problem to be solved by the present invention is that in the existing circulating water indirect air cooling system, the pH of the circulating water is abnormally high, the conductivity is high, and the dissolved oxygen concentration is difficult to control, which leads to corrosion of the aluminum radiator and the carbon steel circulating water pipeline, thereby affecting the operating stability and life of the equipment. The purpose is to provide a circulating water purification system and a water quality control method, which realizes precise control of the pH, conductivity and dissolved oxygen concentration of the circulating water, reduces the corrosion of the aluminum radiator and the circulating water pipeline, and improves the operating efficiency of the system and the service life of the equipment.

[0004] The present invention is achieved through the following technical solutions:

[0005] A circulating water purification treatment system, characterized in that it comprises: a dissolved oxygen meter, a first valve, a mixed bed, a second valve, and a third valve, wherein the first valve and the mixed bed are arranged in parallel, and a water inlet of the first valve is communicated with a water inlet of the mixed bed and is arranged as a circulating water inlet of the treatment system, and a water outlet of the first valve is communicated with a water outlet of the mixed bed and is arranged as a circulating water outlet of the treatment system;

[0006] The water inlet of the second valve is set as the desalted water inlet of the treatment system, and the outlet of the second valve is set as the desalted water outlet of the treatment system; the water inlet of the third valve is set as the condensed water inlet of the treatment system, and the water outlet of the third valve is set as the condensed water outlet of the treatment system;

[0007] The detection unit of the dissolved oxygen meter is arranged at the circulating water inlet of the treatment system.

[0008] The circulating water inlet is connected to the original circulating water pipeline, the circulating water outlet is connected to the condensate water tank inside the condenser, the desalted water inlet is connected to the original desalted water pipeline, the desalted water outlet is connected to the original circulating water pipeline, the condensate water inlet is connected to the original condensate water pipeline, and the condensate water outlet is connected to the original circulating water pipeline; the detection unit of the pH meter and the detection unit of the conductivity meter are both arranged at the circulating water inlet of the treatment system.

[0009] The original circulating water pipeline is connected with a circulating water pump, the original condensate water pipeline is connected with a condensate water pump and a condensate water polishing device, and the original condensate water pipeline is connected to a deaerator.

[0010] Optionally, the desalted water outlet and the condensed water outlet are located on the original circulating water pipeline between the circulating water pump and the indirect air cooling tower;

[0011] The condensate inlet is located on the original condensate pipeline between the condensate polishing device and the ammonia adding point.

[0012] Furthermore, the treatment system also includes: a PLC, the pH meter, the conductivity meter, and the dissolved oxygen meter are all electrically connected to the PLC, the first valve, the second valve, and the third valve are electric control valves, and the PLC is electrically connected to the control ends of the first valve, the second valve, and the third valve.

[0013] Furthermore, the treatment system also includes: a first flow meter, a second flow meter and a third flow meter, the first flow meter is arranged at the circulating water outlet, the second flow meter is arranged at the desalted water outlet, and the third flow meter is arranged at the condensate water outlet.

[0014] A circulating water purification control method, based on the circulating water purification system as described above, the water quality control method comprises:

[0015] If the pH meter value is 7-8 or the conductivity meter value is less than , then open the first valve and the third valve;

[0016] If the pH meter value is greater than 8 or the conductivity meter value is not less than , then close the first valve and open the mixed bed and the third valve;

[0017] If the conductivity meter's detection value is less than , and the detection value of the dissolved oxygen meter is less than , then open the second valve until the detection value of the dissolved oxygen meter is greater than Then close the second valve.

[0018] Specifically, if the second valve is closed, the water flow rate of the circulating water outlet is equal to the water flow rate of the condensate water outlet; if the second valve is opened, the sum of the water flow rate of the desalted water outlet and the water flow rate of the condensate water outlet is equal to the water flow rate of the circulating water outlet.

[0019] Furthermore, the method may also include:

[0020] PLC receives detection signals from pH meter, conductivity meter and dissolved oxygen meter;

[0021] If the pH meter value is 7-8 or the conductivity meter value is less than , the PLC sends a valve opening instruction to the first valve and the third valve;

[0022] Open the first valve and the third valve;

[0023] If the pH meter value is greater than 8 or the conductivity meter value is not less than , the PLC sends a valve closing command to the first valve, a valve opening command to the third valve, and an opening command to the mixed bed;

[0024] Close the first valve, and open the third valve and the mixed bed;

[0025] If the conductivity meter's detection value is less than , and the detection value of the dissolved oxygen meter is less than , PLC sends a valve opening command to the second valve;

[0026] PLC continues to receive detection signals from the dissolved oxygen meter. When the detection value of the dissolved oxygen meter is greater than After that, the PLC sends a valve closing command to the second valve.

[0027] Furthermore, the method may further include:

[0028] PLC receives detection signals from pH meter, conductivity meter and dissolved oxygen meter;

[0029] If the pH meter value is 7-8 or the conductivity meter value is less than , the PLC sends a valve opening instruction to the first valve and the third valve;

[0030] Open the first valve and the third valve, the PLC receives the detection signals of the first flow meter and the third flow meter, and sends an opening control instruction to the first valve and the third valve, so that the detection flow of the first flow meter is equal to the detection flow of the third flow meter;

[0031] If the pH meter value is greater than 8 or the conductivity meter value is not less than , the PLC sends a valve closing command to the first valve, a valve opening command to the third valve, and an opening command to the mixed bed;

[0032] Close the first valve, open the third valve and the mixed bed; the PLC receives the detection signals of the first flow meter and the third flow meter, and sends an opening control instruction to the first valve and the third valve, so that the detection flow of the first flow meter is equal to the detection flow of the third flow meter;

[0033] If the conductivity meter's detection value is less than , and the detection value of the dissolved oxygen meter is less than , the PLC sends a valve opening instruction to the second valve; the PLC receives the detection signals of the first flow meter, the second flow meter and the third flow meter, and sends an opening control instruction to the first valve and the third valve, so that the sum of the detection flow of the second flow meter and the detection flow of the third flow meter is equal to the detection flow of the first flow meter;

[0034] PLC continues to receive detection signals from the dissolved oxygen meter. When the detection value of the dissolved oxygen meter is greater than After that, the PLC sends a valve closing instruction to the second valve; the PLC receives the detection signals of the first flow meter and the third flow meter, and sends an opening control instruction to the first valve and the third valve to make the detection flow of the first flow meter equal to the detection flow of the third flow meter.

[0035] Specifically, the third valve is in a normally open state.

[0036] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0037] The present invention detects the state of water quality by means of a pH meter, a conductivity meter and a dissolved oxygen meter. When the pH or conductivity is abnormal, the circulating water quality is adjusted by closing or opening the first valve and the mixed bed. The dissolved oxygen concentration can also be monitored by the dissolved oxygen meter, and desalted water is supplemented as needed to maintain the dissolved oxygen within the range of 50-200 ppb.

[0038] The treatment system of the present invention can effectively solve the problem of excessively high pH and conductivity of circulating water, prevent corrosion of aluminum radiators, and through dynamic monitoring and adjustment of dissolved oxygen concentration, the system can inhibit corrosion of carbon steel circulating water pipelines, extend the service life of equipment, reduce water resource waste, avoid the use of slow-release agents, and achieve more accurate water quality control through bypass treatment, thereby improving the stability of the circulating water system. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings illustrate exemplary embodiments of the present invention and, together with the description thereof, are used to explain the principles of the present invention. These drawings are included to provide a further understanding of the present invention, and the accompanying drawings are included in and constitute a part of this specification and do not constitute a limitation of the embodiments of the present invention.

[0040] Figure 1It is a structural schematic diagram of a circulating water purification system according to the present invention.

[0041] Figure 2 It is a schematic diagram of a circulating water purification treatment control method according to the present invention.

[0042] Figure markings: 1-treatment system, 2-PLC, 3-dissolved oxygen meter, 4-first valve, 5-first flow meter, 6-mixed bed, 7-condensate pump, 8-condensate polishing device, 9-pH meter, 10-conductivity meter, 11-second valve, 12-second flow meter, 13-third flow meter, 14-third valve. DETAILED DESCRIPTION

[0043] To make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and implementation methods. It is understood that the specific implementation methods described herein are only used to explain the relevant content, rather than to limit the present invention.

[0044] It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the drawings.

[0045] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] In the absence of conflict, the embodiments and features of the embodiments of the present invention may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0047] Embodiment 1

[0048] like Figure 1 As shown, a circulating water purification treatment system 1 is provided, and the treatment system 1 has a circulating water inlet, a circulating water outlet, a desalted water inlet, a desalted water outlet, a condensate water inlet and a condensate water outlet. The circulating water inlet is connected to the original circulating water pipeline, the circulating water outlet is connected to the condensate water tank inside the condenser, the desalted water inlet is connected to the original desalted water pipeline, the desalted water outlet is connected to the original circulating water pipeline, the condensate water inlet is connected to the original condensate water pipeline, and the condensate water outlet is connected to the original circulating water pipeline.

[0049] The circulating water inlet and the circulating water outlet are respectively connected to the water inlet pipe of the condenser and the internal condensate tank. The condenser is a device in the power plant used to condense steam into water. Through the above connection, the circulating water can be effectively introduced into the condenser and recycled.

[0050] The desalted water inlet and the desalted water outlet are connected to the pipeline of the desalted water, and the desalted water is used to adjust the purity of the water and reduce the conductive ions in the water to avoid the deterioration of the water quality.

[0051] The condensate inlet and the condensate outlet are connected to the condensate pipeline, and the condensate is reintroduced into the system after being treated.

[0052] The processing system 1 can be packaged as a whole, leaving only 6 interfaces, so that it can be directly installed into the original cooling pipeline.

[0053] The treatment system 1 includes: a dissolved oxygen meter 3, a first valve 4, a mixed bed 6, a second valve 11 and a third valve 14; the dissolved oxygen meter 3 is used to detect the dissolved oxygen content in the circulating water. Too high or too low dissolved oxygen will affect the anti-corrosion performance of the system. The mixed bed 6 is used to remove ionic impurities in the water, adjust the water quality, and optimize the conductivity and pH value in the water.

[0054] The water inlets of the mixed bed 6 and the first valve 4 are both connected to the circulating water inlet, and the water outlets of the mixed bed 6 and the first valve 4 are both connected to the circulating water outlet; the water inlet of the second valve 11 is connected to the desalted water inlet, and the outlet of the second valve 11 is connected to the desalted water outlet; the water inlet of the third valve 14 is connected to the condensate water inlet, and the water outlet of the third valve 14 is connected to the condensate water outlet; the first valve 4 controls whether the circulating water passes through the mixed bed 6, the second valve 11 controls whether the desalted water is replenished, and the third valve 14 controls whether the condensate water enters the condenser water inlet pipe.

[0055] The condenser water inlet pipe is connected with a pH meter 9 and a conductivity meter 10. The pH meter 9 and the conductivity meter 10 are used to detect the acidity and conductivity of water respectively.

[0056] The original circulating water pipeline is connected to a circulating water pump, the original condensate pipeline is connected to a condensate pump 7 and a condensate polishing device 8, and the original condensate pipeline is connected to a deaerator. The circulating water pump, condensate pump 7, condensate polishing device 8, deaerator, pH meter 9 and conductivity meter 10 are all original devices of the system.

[0057] The desalted water outlet and the condensate outlet are located on the original circulating water pipeline between the circulating water pump and the indirect air cooling tower; the condensate inlet is located on the original condensate pipeline between the condensate polishing device 8 and the ammonia adding point.

[0058] Embodiment 2

[0059] The structure in Example 1 lacks automatic control means. The treatment system 1 in this embodiment also includes: PLC2, pH meter 9, conductivity meter 10, dissolved oxygen meter 3 are all electrically connected to PLC2, the first valve 4, the second valve 11 and the third valve 14 are electric control valves, and PLC2 is electrically connected to the control ends of the first valve 4, the second valve 11 and the third valve 14.

[0060] PLC2 is a programmable logic controller, which monitors and controls various parts of the system in real time, receives signals from sensors such as pH meter 9, conductivity meter 10, dissolved oxygen meter 3, and controls the electric control valve in the system according to the set parameters.

[0061] PLC2 is directly connected to the control terminals of the three electric valves. When PLC2 detects that water quality indicators such as pH, conductivity or dissolved oxygen exceed the set range, it issues corresponding instructions to automatically adjust the opening and closing of the valves to ensure that the system water quality is maintained at an appropriate level. For example, when the dissolved oxygen is too low, PLC2 can open the second valve 11 to add desalted water to increase the dissolved oxygen concentration.

[0062] During the entire water quality control process, the pH meter 9, the conductivity meter 10 and the dissolved oxygen meter 3 monitor the water quality of the circulating water in real time and transmit the detection signal to PLC2. PLC2 determines whether the system needs to adjust the water quality based on the detection data, and issues corresponding control instructions to adjust the opening and closing states of the first, second and third valves 14. For example, when the conductivity exceeds the specified range, PLC2 will close the first valve 4 and open the mixed bed 6 for water quality treatment. When the dissolved oxygen concentration is lower than the set value, PLC2 opens the second valve 11 to supplement the desalted water until the dissolved oxygen concentration reaches the set range and then closes the valve. The system can maintain the optimal water quality of the circulating water under automated control.

[0063] Embodiment 3

[0064] This embodiment is further optimized on the basis of the second embodiment, and the treatment system 1 also includes: a first flow meter 5, a second flow meter 12 and a third flow meter 13, the first flow meter 5 is arranged at the circulating water outlet, the second flow meter 12 is arranged at the desalted water outlet, and the third flow meter 13 is arranged at the condensate water outlet.

[0065] The function of each flow meter is to monitor the water flow at its respective location in real time and feed the data back to PLC2. The first flow meter 5 ensures that the flow of circulating water is maintained within the specified range; the second flow meter 12 controls the flow of supplementary desalted water; and the third flow meter 13 monitors the flow of treated condensate. Through the data of these flow meters, PLC2 can calculate the balance of water flow in each part of the system, thereby automatically adjusting the opening of the relevant valves. For example, when desalted water needs to be supplemented, the second flow meter 12 will help determine the appropriate amount of replenished water so that it matches the condensate flow measured by the third flow meter 13 with the measurement value of the first flow meter 5, thereby ensuring the dynamic balance of the water volume in the system.

[0066] Embodiment 4

[0067] This embodiment is a circulating water purification control method provided on the basis of the first embodiment. It does not rely on PLC2 and flow meter. Through the monitoring results of pH meter 9, conductivity meter 10 and dissolved oxygen meter 3, the opening and closing of each valve is manually controlled to adjust the water quality of the circulating water and ensure the stable operation of the system.

[0068] like Figure 2 As shown, water quality control methods include:

[0069] If the detection value of the pH meter 9 is 7-8 or the detection value of the conductivity meter 10 is less than 0.2μS / cm, the first valve 4 and the third valve 14 are opened; at this time, the water quality of the circulating water is within the normal range. The system opens the first valve 4 and the third valve 14 to allow the circulating water to flow and mix with the condensed water to maintain the water quality of the system stable.

[0070] If the detection value of the pH meter 9 is greater than 8 or the detection value of the conductivity meter 10 is not less than 0.2μS / cm, the first valve 4 is closed, and the mixed bed 6 and the third valve 14 are opened; at this time, there is a problem with the water quality, such as an increase in the pH value or an increase in the ion concentration in the water, which may cause corrosion to the equipment. Therefore, the system closes the first valve 4, allowing the circulating water to pass through the mixed bed 6, and the water is treated by the mixed bed 6 to reduce the conductivity and adjust the pH value.

[0071] If the detection value of the conductivity meter 10 is less than 0.2μS / cm, and the detection value of the dissolved oxygen meter 3 is less than 50ppb, the second valve 11 is opened until the detection value of the dissolved oxygen meter 3 is greater than 200ppb, and then the second valve 11 is closed. At this time, the oxygen content in the water is too low, and the second valve 11 is opened to allow deionized water to enter the system to supplement the dissolved oxygen until the dissolved oxygen content reaches 200ppb, and then the second valve 11 is closed.

[0072] In order to ensure the stability of water flow in the entire cooling system, if the second valve 11 is closed, the water flow at the circulating water outlet is equal to the water flow at the condensate water outlet; if the second valve 11 is opened, the sum of the water flow at the desalted water outlet and the water flow at the condensate water outlet is equal to the water flow at the circulating water outlet.

[0073] Embodiment 5

[0074] This embodiment is a circulating water purification control method provided on the basis of the second embodiment, and is a water quality control method for a circulating water indirect air cooling system that uses PLC2 for automatic control. In this method, PLC2 automatically controls the opening and closing states of each valve according to the detection signals of the pH meter 9, the conductivity meter 10 and the dissolved oxygen meter 3, thereby realizing dynamic regulation and management of the water quality.

[0075] like Figure 2 As shown, the method includes:

[0076] PLC2 receives detection signals from the pH meter 9, the conductivity meter 10 and the dissolved oxygen meter 3; the detection signals from the pH meter 9, the conductivity meter 10 and the dissolved oxygen meter 3 are transmitted to PLC2 in real time, and PLC2 determines the current water quality status based on these signals and makes corresponding control decisions based on preset conditions.

[0077] If the detection value of the pH meter 9 is 7-8 or the detection value of the conductivity meter 10 is less than 0.2 μS / cm, the PLC 2 sends a valve opening instruction to the first valve 4 and the third valve 14 .

[0078] Open the first valve 4 and the third valve 14; the electric control valve automatically opens after receiving the valve opening instruction from PLC2.

[0079] If the detection value of the pH meter 9 is greater than 8 or the detection value of the conductivity meter 10 is not less than 0.2 μS / cm, the PLC2 sends a valve closing command to the first valve 4 , sends a valve opening command to the third valve 14 , and sends an opening command to the mixed bed 6 .

[0080] Close the first valve 4 and open the third valve 14 and the mixed bed 6.

[0081] If the detection value of the conductivity meter 10 is less than 0.2 μS / cm and the detection value of the dissolved oxygen meter 3 is less than 50 ppb, PLC2 sends a valve opening command to the second valve 11; after receiving the valve opening command, the second valve 11 opens to allow deionized water to enter the system to replenish dissolved oxygen.

[0082] PLC2 continuously receives the detection signal of the dissolved oxygen meter 3 , and when the detection value of the dissolved oxygen meter 3 is greater than 200 ppb, PLC2 sends a valve closing instruction to the second valve 11 .

[0083] Embodiment 6

[0084] This embodiment is a circulating water purification control method provided on the basis of the third embodiment. It receives signals from various sensors through PLC2 and automatically adjusts the opening of each valve in combination with the detection results of the flow meter to ensure that the water quality and water flow of the circulating water system operate in a balanced manner within a reasonable range.

[0085] like Figure 2 As shown, the method includes:

[0086] PLC2 receives detection signals from the pH meter 9, the conductivity meter 10, and the dissolved oxygen meter 3; PLC2 monitors the water quality in real time by continuously receiving data from these sensors to ensure that parameters such as pH, conductivity, and dissolved oxygen concentration are maintained within a preset range.

[0087] If the detection value of the pH meter 9 is 7-8 or the detection value of the conductivity meter 10 is less than 0.2 μS / cm, the PLC 2 sends a valve opening instruction to the first valve 4 and the third valve 14;

[0088] Open the first valve 4 and the third valve 14, PLC2 receives the detection signals of the first flow meter 5 and the third flow meter 13, and sends opening control instructions to the first valve 4 and the third valve 14 to make the detection flow of the first flow meter 5 equal to the detection flow of the third flow meter 13; detect the flow of circulating water and condensate water through the flow meter, and PLC2 sends opening control instructions to the first valve 4 and the third valve 14 according to the data of the flow meter to ensure that the detection flow of the first flow meter 5 is equal to the detection flow of the third flow meter 13 to maintain water flow balance.

[0089] If the detection value of the pH meter 9 is greater than 8 or the detection value of the conductivity meter 10 is not less than 0.2 μS / cm, the PLC 2 sends a valve closing command to the first valve 4, a valve opening command to the third valve 14, and an opening command to the mixed bed 6;

[0090] Close the first valve 4, open the third valve 14 and the mixed bed 6; PLC2 receives the detection signals of the first flow meter 5 and the third flow meter 13, and sends an opening control instruction to the first valve 4 and the third valve 14, so that the detection flow of the first flow meter 5 is equal to the detection flow of the third flow meter 13;

[0091] If the detection value of the conductivity meter 10 is less than 0.2μS / cm, and the detection value of the dissolved oxygen meter 3 is less than 50ppb, PLC2 sends a valve opening instruction to the second valve 11; PLC2 receives the detection signals of the first flow meter 5, the second flow meter 12 and the third flow meter 13, and sends an opening control instruction to the first valve 4 and the third valve 14, so that the sum of the detection flow of the second flow meter 12 and the detection flow of the third flow meter 13 is equal to the detection flow of the first flow meter 5; at this time, PLC2 still monitors the flow through the first flow meter 5 and the third flow meter 13, and adjusts the valve opening according to the detection results, so that the detection flow of the two flow meters remains equal, ensuring that the water flow of the system remains balanced.

[0092] PLC2 continuously receives the detection signal of dissolved oxygen meter 3. When the detection value of dissolved oxygen meter 3 is greater than 200ppb, PLC2 sends a valve closing instruction to second valve 11. PLC2 receives the detection signal of first flow meter 5 and third flow meter 13, and sends an opening control instruction to first valve 4 and third valve 14, so that the detection flow of first flow meter 5 is equal to the detection flow of third flow meter 13. During water replenishment, PLC2 will simultaneously receive the signals of first flow meter 5, second flow meter 12 and third flow meter 13 to ensure that the total flow of desalted water and condensed water is equal to the flow of circulating water.

[0093] In this method, PLC2 monitors water quality parameters by continuously receiving signals from pH meter 9, conductivity meter 10 and dissolved oxygen meter 3, and makes corresponding controls according to different water quality conditions. The introduction of the flow meter enables the system to accurately control the water flow while treating the water quality, and maintain the dynamic balance of the water volume in the system. When the water quality is normal, PLC2 adjusts the opening of the first and third valves 14 to make the flow of circulating water and condensate water equal; when the water quality is abnormal, the mixed bed 6 and the regulating valve are opened to treat the water quality and maintain the flow balance. When the dissolved oxygen is too low, PLC2 will add desalted water, and adjust the water flow according to the signal of the flow meter to ensure that the water quality returns to normal.

[0094] In the description of this specification, the description with reference to the terms "one embodiment / method", "some embodiments / methods", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / method or example are included in at least one embodiment / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments / methods or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are contradictory.

[0095] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0096] It should be understood by those skilled in the art that the above embodiments are only for the purpose of clearly illustrating the present invention, and are not intended to limit the scope of the present invention. For those skilled in the art, other changes or modifications may be made based on the above invention, and these changes or modifications are still within the scope of the present invention.

Claims

1. A circulating water purification system, characterized in that: include: A dissolved oxygen meter (3), a first valve (4), a mixed bed (6), a second valve (11) and a third valve (14), wherein the first valve (4) and the mixed bed (6) are arranged in parallel, and a water inlet of the first valve (4) is connected to a water inlet of the mixed bed (6) and is arranged as a circulating water inlet of the treatment system (1), and a water outlet of the first valve (4) is connected to a water outlet of the mixed bed (6) and is arranged as a circulating water outlet of the treatment system (1); The water inlet of the second valve (11) is arranged as the desalted water inlet of the treatment system (1), and the outlet of the second valve (11) is arranged as the desalted water outlet of the treatment system (1); the water inlet of the third valve (14) is arranged as the condensed water inlet of the treatment system (1), and the water outlet of the third valve (14) is arranged as the condensed water outlet of the treatment system (1); The detection unit of the dissolved oxygen meter (3) is arranged at the circulating water inlet of the treatment system (1); The circulating water inlet is connected to the original circulating water pipeline, the circulating water outlet is connected to the condensate tank inside the condenser, the desalted water inlet is connected to the original desalted water pipeline, the desalted water outlet is connected to the original circulating water pipeline, the condensate water inlet is connected to the original condensate water pipeline, the condensate water outlet is connected to the original circulating water pipeline, and the detection unit of the pH meter (9) and the detection unit of the conductivity meter (10) are both arranged at the circulating water inlet of the treatment system (1); The original circulating water pipeline is connected to a circulating water pump, the original condensate water pipeline is connected to a condensate water pump (7) and a condensate water polishing device (8), and the original condensate water pipeline is connected to a deaerator.

2. A circulating water purification system according to claim 1, characterized in that: The demineralized water outlet and the condensed water outlet are located on the original circulating water pipeline between the circulating water pump and the indirect air cooling tower; The condensate inlet is located on the original condensate pipeline between the condensate polishing device (8) and the ammonia addition point.

3. A circulating water purification system according to claim 1, characterized in that: The treatment system (1) further comprises: a PLC (2); the pH meter (9), the conductivity meter (10), and the dissolved oxygen meter (3) are all electrically connected to the PLC (2); the first valve (4), the second valve (11), and the third valve (14) are electrically controlled valves; and the PLC (2) is electrically connected to control ends of the first valve (4), the second valve (11), and the third valve (14).

4. A circulating water purification system according to claim 3, characterized in that: The treatment system (1) further comprises: a first flow meter (5), a second flow meter (12) and a third flow meter (13), wherein the first flow meter (5) is arranged at the circulating water outlet, the second flow meter (12) is arranged at the desalted water outlet, and the third flow meter (13) is arranged at the condensate water outlet.

5. A circulating water purification control method, characterized in that: Based on the circulating water purification system according to claim 4, the control method comprises: If the detection value of the pH meter (9) is 7-8 or the detection value of the conductivity meter (10) is less than 0.2 μS / cm, the first valve (4) and the third valve (14) are opened; If the detection value of the pH meter (9) is greater than 8 or the detection value of the conductivity meter (10) is not less than 0.2 μS / cm, the first valve (4) is closed, and the mixed bed (6) and the third valve (14) are opened; If the detection value of the conductivity meter (10) is less than 0.2 μS / cm and the detection value of the dissolved oxygen meter (3) is less than 50 ppb, the second valve (11) is opened until the detection value of the dissolved oxygen meter (3) is greater than 200 ppb, and then the second valve (11) is closed; Wherein, the PLC (2) receives detection signals from the pH meter (9), the conductivity meter (10) and the dissolved oxygen meter (3); If the detection value of the pH meter (9) is 7-8 or the detection value of the conductivity meter (10) is less than 0.2 μS / cm, the PLC (2) sends a valve opening instruction to the first valve (4) and the third valve (14); Opening the first valve (4) and the third valve (14); If the detection value of the pH meter (9) is greater than 8 or the detection value of the conductivity meter (10) is not less than 0.2 μS / cm, the PLC (2) sends a valve closing command to the first valve (4), sends a valve opening command to the third valve (14), and sends an opening command to the mixed bed (6); closing the first valve (4), and opening the third valve (14) and the mixed bed (6); If the detection value of the conductivity meter (10) is less than 0.2 μS / cm, and the detection value of the dissolved oxygen meter (3) is less than 50 ppb, the PLC (2) sends a valve opening instruction to the second valve (11); The PLC (2) continuously receives the detection signal from the dissolved oxygen meter (3). When the detection value of the dissolved oxygen meter (3) is greater than 200 ppb, the PLC (2) sends a valve closing instruction to the second valve (11).

6. A circulating water purification control method according to claim 5, characterized in that: If the second valve (11) is closed, the water flow rate at the circulating water outlet is equal to the water flow rate at the condensate water outlet; if the second valve (11) is opened, the sum of the water flow rate at the desalted water outlet and the water flow rate at the condensate water outlet is equal to the water flow rate at the circulating water outlet.

7. A circulating water purification control method according to claim 5, characterized in that: The method comprises: The PLC (2) receives detection signals from the pH meter (9), the conductivity meter (10), and the dissolved oxygen meter (3); If the detection value of the pH meter (9) is 7-8 or the detection value of the conductivity meter (10) is less than 0.2 μS / cm, the PLC (2) sends a valve opening instruction to the first valve (4) and the third valve (14); The first valve (4) and the third valve (14) are opened, the PLC (2) receives detection signals from the first flow meter (5) and the third flow meter (13), and sends an opening control instruction to the first valve (4) and the third valve (14), so that the detection flow rate of the first flow meter (5) is equal to the detection flow rate of the third flow meter (13); If the detection value of the pH meter (9) is greater than 8 or the detection value of the conductivity meter (10) is not less than 0.2 μS / cm, the PLC (2) sends a valve closing command to the first valve (4), sends a valve opening command to the third valve (14), and sends an opening command to the mixed bed (6); The first valve (4) is closed, and the third valve (14) and the mixed bed (6) are opened; the PLC (2) receives detection signals from the first flow meter (5) and the third flow meter (13), and sends an opening control instruction to the first valve (4) and the third valve (14), so that the detection flow rate of the first flow meter (5) is equal to the detection flow rate of the third flow meter (13); If the detection value of the conductivity meter (10) is less than 0.2 μS / cm, and the detection value of the dissolved oxygen meter (3) is less than 50 ppb, the PLC (2) sends a valve opening instruction to the second valve (11); the PLC (2) receives the detection signals of the first flow meter (5), the second flow meter (12) and the third flow meter (13), and sends an opening control instruction to the first valve (4) and the third valve (14), so that the sum of the detection flow rate of the second flow meter (12) and the detection flow rate of the third flow meter (13) is equal to the detection flow rate of the first flow meter (5); The PLC (2) continuously receives detection signals from the dissolved oxygen meter (3), and when the detection value of the dissolved oxygen meter (3) is greater than 200 ppb, the PLC (2) sends a valve closing instruction to the second valve (11); the PLC (2) receives detection signals from the first flow meter (5) and the third flow meter (13), and sends an opening control instruction to the first valve (4) and the third valve (14), so that the detection flow of the first flow meter (5) is equal to the detection flow of the third flow meter (13).

8. A circulating water purification control method according to any one of claims 5 to 7, characterized in that: The third valve (14) is in a normally open state.

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