Circulating water dosing system and dosing method

Abstract

The invention provides a circulating water dosing system and a dosing method, and relates to the technical field of power plant circulating water. The system comprises a first chemical adding module, a second chemical adding module, a sampling module and a water quality monitoring module, comprising a sodium hypochlorite dosing pump, a scale inhibitor dosing pump, a corrosion inhibitor dosing pump and a copper corrosion inhibitor dosing pump, wherein the sodium hypochlorite dosing pump, the scale inhibitor dosing pump, the corrosion inhibitor dosing pump and the copper corrosion inhibitor dosing pump are correspondingly communicated with the sodium hypochlorite dosing box, the scale inhibitor dosing box, the corrosion inhibitor dosing box and the copper corrosion inhibitor dosing box through pipelines; the sampling module comprises a sampling pipe and a sampling door, and an outlet of each circulating pump is communicated with the sampling pipe through the sampling door; the water quality monitoring module is used for monitoring the corrosion rate, the conductivity, the PH value, the ORP value and pollutants of circulating water in real time; according to the method, the chemical adding proportion can be set in advance according to the difference of the water quality and the water supplementing amount of the circulating water, so that the chemical adding amount is automatically adjusted, and the water quality is controlled within a normal range.

Description

Technical Field

[0001] This invention relates to the field of power plant circulating water technology, and in particular to a circulating water dosing system and dosing method. Background Technology

[0002] Thermal power plants require a large amount of industrial circulating water, accounting for 50-80% of the total water consumption. Therefore, the effectiveness of circulating water treatment is closely related to the power plant's water conservation and emission reduction efficiency. During the operation of the circulating water, calcium and magnesium ions in the water continuously concentrate and combine with anions to form precipitates, which may cause problems such as pipe blockage, reduced circulating water flow, excessively high cooling equipment temperatures, and reduced heat exchange efficiency. At the same time, the proliferation of a large number of microorganisms causes pipe corrosion and microbial sludge, affecting the normal operation of the system.

[0003] To ensure the normal quality of circulating water, chemical agents are usually added to control the water quality, thereby solving problems such as scaling, corrosion, and microbial growth (sludge adhesion) caused by long-term use of circulating water, and avoiding equipment failure and efficiency decline.

[0004] The existing dosing system requires manual dosing by personnel at regular intervals. The dosing frequency is unstable, human error is significant, and the timeliness is poor, which affects the stable operation of the equipment.

[0005] In view of the above reasons, the present invention proposes a circulating water dosing system and dosing method to solve the above technical problems, thereby controlling the water quality of circulating water within the normal range in real time. Summary of the Invention

[0006] The purpose of this invention is to provide a circulating water dosing system and dosing method. This system can pre-set the dosing ratio according to the different qualities and quantities of the circulating water replenishment, thereby automatically adjusting the dosing amount to control the water quality within the normal range.

[0007] On one hand, the present invention provides a circulating water dosing system, comprising: a first dosing module, a second dosing module, a sampling module, and a water quality monitoring module. Both the first and second dosing modules are connected to the gravity flow channel of the circulating pump. The first dosing module includes a sodium hypochlorite tank and a sodium hypochlorite dosing pump, which are used to add sodium hypochlorite into the gravity flow channel of the circulating pump. The second dosing module includes a scale inhibitor tank, a corrosion inhibitor tank, a copper corrosion inhibitor tank, and scale inhibitor dosing pump, corrosion inhibitor dosing pump, and copper corrosion inhibitor dosing pump connected to them respectively through pipelines. The sampling module includes a sampling tube and a sampling gate, and the outlet of each circulation pump is connected to the sampling tube through the sampling gate; The water quality monitoring module is used to monitor the corrosion rate, conductivity, pH value, ORP value and pollutants of circulating water in real time.

[0008] Preferably, there are two sodium hypochlorite dosing pumps arranged in parallel, and each pump is connected to an electric valve and a column flow meter on its respective pipeline. The sodium hypochlorite tank is connected to the two sodium hypochlorite dosing pumps by a main dosing valve.

[0009] Preferably, the two sodium hypochlorite dosing pumps are connected to the gravity flow channels of the first and second unit circulating pumps via a first dosing main pipe, and electric valves are connected between the first dosing main pipe and the gravity flow channels of the first and second unit circulating pumps.

[0010] Preferably, the second dosing module further includes a second dosing main pipe. There are two scale inhibitor dosing pumps and two corrosion inhibitor dosing pumps, and one copper corrosion inhibitor dosing pump. The two scale inhibitor dosing pumps are arranged in parallel, and each is connected to an electric valve and a column flow meter on its respective pipeline. A main dosing valve connects the two scale inhibitor dosing pumps to the scale inhibitor tank. Similarly, the two corrosion inhibitor dosing pumps are arranged in parallel, and each is connected to an electric valve and a column flow meter on its respective pipeline. A main dosing valve connects the two corrosion inhibitor dosing pumps to the corrosion inhibitor tank. An electric valve, a column flow meter, and a main dosing valve connect the copper corrosion inhibitor dosing pump to the copper corrosion inhibitor tank.

[0011] Preferably, there are four circulating pumps, each of which is connected to the sampling tube through a sampling gate. Each circulating pump is connected to the sampling gate via an electric valve. A vent is provided on one side of the sampling gate, and an electric valve is connected between the vent and the sampling gate.

[0012] Preferably, one end of the sampling tube is provided with a drain door, and a drain valve is provided at the drain door.

[0013] Preferably, the water quality monitoring module includes a detection pipe and multiple corrosion scrapers, corrosion rate measuring probes, conductivity meter electrodes, float flowmeters, pH meter probes, ORP meter probes, and fluorescent agents disposed therein. The corrosion rate measuring probes, conductivity meter electrodes, float flowmeters, pH meter probes, and ORP meter probes are all electrically connected to the monitoring instruments.

[0014] Preferably, the end of the detection pipeline near the ORP meter probe is connected to the second dosing module via a flow switch and an electric valve.

[0015] On the other hand, the present invention also provides a circulating water dosing method based on the above system, characterized by comprising the following steps: S1: Pre-commissioning inspection: Check that the circuit, dosing pipeline and all probes are installed properly; S2: Open the sampling door and take a sample from the outlet of the circulating pump into the sampling tube; S3: The corrosion rate, conductivity, pH value, ORP value and pollutant parameters of the circulating water in the sampling tube are detected by the water quality monitoring module; S4: Based on the various parameters tested, adjust the dosage of chemicals in the sodium hypochlorite tank, scale inhibitor tank, corrosion inhibitor tank, and copper corrosion inhibitor tank. Then, turn on the sodium hypochlorite dosing pump, scale inhibitor dosing pump, corrosion inhibitor dosing pump, and copper corrosion inhibitor dosing pump to add chemicals into the gravity flow channel of the circulation pump. S5: System shutdown: Close all sampling doors and dosing pumps, and drain the wastewater from the sampling pipes.

[0016] Preferably, the method further includes the following steps: When the outdoor temperature drops below 0 degrees Celsius in winter, the system will shut down and drain the water from the system pipes to prevent the pipes from freezing and expanding, which could cause them to burst. Before restarting, open the filter screen, flush the inlet pipes, and add routine water treatment agents after the water quality has recovered.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Install a dosing system at the outlet of the circulating water pump. The dosing ratio is set in advance according to the different water quality and amount of the circulating water replenishment, so as to automatically adjust the dosing amount and achieve the purpose of timely adjustment of water quality, thereby controlling the water quality within the normal range; 2. It frees up human resources, eliminating the need for personnel to regularly add medication, thus avoiding the problems of unstable medication frequency and poor timeliness. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a connection diagram of the circulating water dosing system of the present invention; Figure 2 This is a flowchart of the circulating water dosing method of the present invention. Detailed Implementation

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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. Therefore, they should not be construed as limiting this invention.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] To ensure the normal quality of circulating water, chemical agents are usually added to control the water quality and address issues such as scaling, corrosion, and microbial growth (sludge buildup) that occur with long-term use, thus preventing equipment malfunctions and decreased efficiency. Commonly added chemicals include the following categories: (1) Corrosion and scale inhibitors Used to control the scaling and deposition of calcium carbonate, calcium phosphate, calcium sulfate, zinc, and suspended solids in industrial circulating cooling water; Dosage / Dosage Point: The concentration in the circulating water is 20-35 ppm.

[0024] (2) Corrosion inhibitor It has a highly efficient function in inhibiting the corrosion of carbon steel. Dosage / Dosage Point: The concentration in the circulating water is 10-20 ppm.

[0025] (3) Copper corrosion inhibitor Dosage / Dosage Point: The concentration in the circulating water is 1-3 ppm.

[0026] (4) Sodium hypochlorite It is generally effective against bacteria, mold, algae and yeast, and its oxidizing properties also react with organic matter in water, such as ammonia, reduced iron, manganese and sulfides.

[0027] Dosage / Dosage Point: The dosage concentration in the circulating water is 2-5 ppm (10% available chlorine content), and the residual chlorine in the circulating water tank is generally controlled within the range of 0.2-0.5 ppm.

[0028] In addition to the four main agents mentioned above, biodispersants and defoamers can be added as needed. Biodispersants are used to remove and disperse microbial deposits on the packing material and heat exchangers inside the cooling tower, reducing the maintenance costs of the cooling tower and heat exchangers. The dosage / dosing point is: based on the amount of cooling water, add 10 ppm in an impact to the turbulent part of the cooling water system. The frequency of dosing depends on the microbial situation of the circulating water. The dosage / dosing point of defoamers is: add an appropriate amount, and the foam will dissipate quickly.

[0029] The above dosage is based on the existing water quality control plan for makeup water and circulating water. When the external environment changes, such as water intake restrictions, sewage discharge restrictions, or changes in the quality of makeup water, the above dosage concentration and water quality control plan need to be revised in a timely manner.

[0030] To add the above-mentioned agents, such as Figure 1As shown, this invention provides a circulating water dosing system, comprising: a first dosing module, a second dosing module, a sampling module, and a water quality monitoring module. Both the first and second dosing modules are connected to the circulating pump's gravity flow channel, which includes a #1 circulating pump gravity flow channel and a #2 circulating pump gravity flow channel. The first dosing module includes a sodium hypochlorite tank and a sodium hypochlorite dosing pump connected to it, used to add sodium hypochlorite into the circulating pump's gravity flow channel, thereby introducing it into the entire circulating water system. The second dosing module includes a scale inhibitor tank, a corrosion inhibitor tank, a copper corrosion inhibitor tank, and corresponding scale inhibitor dosing pumps and corrosion inhibitor dosing pumps connected to them via pipelines. The pumps and copper corrosion inhibitor dosing pumps can add various agents to the circulating water in proportion to improve water quality. The sampling module includes sampling tubes and sampling gates. The outlets of each circulating pump are connected to the sampling tubes through the sampling gates. The sampling module can sample the circulating water from the outlets of each circulating pump, which facilitates the water quality monitoring module to monitor various parameters of the circulating water. The water quality monitoring module is used to monitor the corrosion rate, conductivity, pH value, ORP value and pollutants of the circulating water in real time. This allows the first and second dosing modules to pre-set the dosing ratio according to the water quality conditions, thereby automatically adjusting the dosing amount to control the water quality within the normal range.

[0031] In this embodiment, there are two sodium hypochlorite dosing pumps, namely sodium hypochlorite dosing pump A and sodium hypochlorite dosing pump B arranged in parallel. Each pump is connected to an electric valve and a column flow meter on its respective pipeline, allowing one pump to operate while the other is on standby. The electric valve can switch the dosing branch, and the column flow meter can detect the dosing flow rate. The sodium hypochlorite tank is connected to the two sodium hypochlorite dosing pumps by a main dosing valve, which is a manual gate valve.

[0032] In this embodiment, two sodium hypochlorite dosing pumps are connected to the gravity flow channels of the #1 and #2 circulating pumps via a first dosing main pipe. Electric valves are connected between the first dosing main pipe and the gravity flow channels of the #1 and #2 circulating pumps to control the flow direction of the added agent.

[0033] Specifically, the second dosing module also includes a second dosing main pipe, with two scale inhibitor dosing pumps and two corrosion inhibitor dosing pumps, namely scale inhibitor dosing pump A, scale inhibitor dosing pump B, corrosion inhibitor dosing pump A, and corrosion inhibitor dosing pump B, and one copper corrosion inhibitor dosing pump. Scale inhibitor dosing pumps A and B are arranged in parallel, and each of their respective branches is connected to an electric valve and a column flow meter, allowing one to work and one to standby. The dosing branch can be switched via the electric valve, and the column flow meter can detect the dosing flow rate. The two scale inhibitor dosing pumps are connected to the scale inhibitor tank via a manual main dosing valve. Corrosion inhibitor dosing pumps A and B are arranged in parallel, with each pump's branch connected to an electric valve and a column flow meter, respectively. This allows for one pump to operate while the other remains on standby. The electric valves allow switching between dosing branches, and the column flow meters monitor the dosing flow rate. A manual main dosing valve connects both pumps to the corrosion inhibitor tank. For copper corrosion inhibitor pumps, an electric valve, a column flow meter, and a main dosing valve are connected to the copper corrosion inhibitor tank to control dosing and agent flow rate.

[0034] The specifications for each dosing pump are shown in Table 1 below:

[0035] Table 1 In this embodiment, there are four circulation pumps: circulation pump A, circulation pump B, circulation pump C, and circulation pump D. Each circulation pump is connected to a sampling tube via a sampling gate. Circulation pump A is connected to sampling gate A, circulation pump B to sampling gate B, circulation pump C to sampling gate C, and circulation pump D to sampling gate D. Each circulation pump is connected to an electric valve between itself and a sampling gate. A vent is provided on one side of each sampling gate, and an electric valve is connected to the vent. A drain gate with a drain valve is provided at one end of the sampling tube to discharge wastewater from the sampling tube after testing. An electric valve is provided in the middle of the sampling tube to separate circulation pumps A and B from circulation pumps C and D.

[0036] Specifically, the water quality monitoring module includes a detection pipe and multiple corrosion scrapers 1 and 2, corrosion rate measuring probes 1 and 2, conductivity meter electrode C, float flow meter F, pH meter probe, ORP meter probe, and fluorescent agent installed within it. The corrosion rate measuring probe, conductivity meter electrode C, float flow meter F, pH meter probe, and ORP meter probe are all electrically connected to the monitoring instrument. The monitoring instrument adopts a 3D TRASAR instrument, which can continuously monitor the corrosion, scaling, and microbial status of the circulating water system online, and can transmit the monitoring data to the central control room via signal lines or network systems.

[0037] The end of the detection pipeline near the ORP meter probe is connected to the second dosing module via flow switch F1 and an electric valve. A sampling tube is connected to one side of flow switch F1, and the detection pipeline is connected to a water source to flush the sampling tube.

[0038] The recommended and control ranges for each water sample item that the water quality monitoring module can measure are shown in Table 2 below:

[0039] Table 2 On the other hand, the present invention also provides a circulating water dosing method based on the above system, comprising the following steps: S1: Pre-commissioning inspection: Check that the circuit, dosing pipeline and all probes are installed properly; The specific steps are as follows: S11: Inspection personnel at the circulating water dosing system site have been evacuated and the site has been cleaned up; S12: Check that the power supply of the circulating water dosing system is normal and there is no tripping. In winter, check that the electric heat tracing control cabinet of the circulating water dosing pipeline is powered on and operating normally. S13: Check that the liquid level in each medicine tank is above 1 / 3 and that the air inlet of the medicine tank is unobstructed; S14: Ensure that all components of the dosing system are properly connected and undamaged; S15: Check that the filter screen of the inlet pipe of the dosing system is clean and free of debris; S16: Check that all probe measuring points of the dosing system have been installed; S2: Open the sampling door and take a sample from the outlet of the circulation pump into the sampling tube. Before sampling, perform the following steps: (1) Confirm the unit's operating mode, and pay attention to selecting the sampling gate, dosing and return water manual gate, and sodium hypochlorite dosing gate for the operating unit; (2) Open the manual valves and connecting valves of the circulating water dosing and return water to the cooling towers of Units #1 and #2 (select the manual valve to the operating unit according to the unit's operating mode); (3) Close the drain valve of the sampling tube; (4) Open the sampling gates A and B corresponding to the circulating pumps A and B of Unit #1 and the sampling gates C and D corresponding to the circulating pumps C and D of Unit #2; (5) Open the filter cups of the inlet pipes of the first and second dosing modules, open their water inlet valves, and rinse the sampling tubes; (6) After rinsing, install the filter cup, open the fluorescent agent bypass door and close the fluorescent agent outlet door to allow circulating water to enter the detection pipeline through the sampling tube; (7) Check whether the water outlet of each unit's chemical dosing and return water pipeline is normal, then open the fluorescent agent outlet valve and close the fluorescent agent bypass valve; S3: The corrosion rate, conductivity, pH value, ORP value and pollutant parameters of the circulating water in the sampling tube are detected by the water quality monitoring module; S4: Open the main dosing valves at the outlets of the sodium hypochlorite tank, scale inhibitor tank, corrosion inhibitor tank, and copper corrosion inhibitor tank. Turn on the sodium hypochlorite, copper corrosion inhibitor, corrosion inhibitor, and scale inhibitor dosing pumps to automatic operation mode. Adjust the dosage of chemicals in the sodium hypochlorite tank, scale inhibitor tank, corrosion inhibitor tank, and copper corrosion inhibitor tank according to the detected parameters of the circulating water. Then, turn on the sodium hypochlorite dosing pump, scale inhibitor dosing pump, corrosion inhibitor dosing pump, and copper corrosion inhibitor dosing pump to add chemicals to the gravity flow channel of the circulating pump. S5: System shutdown: Close all sampling gates and dosing pumps, drain the sewage from the sampling pipes, and close the inlet gates of the first and second dosing modules.

[0040] When the outdoor temperature is below 0 degrees Celsius in winter, the system should be shut down, the water in the system pipes should be drained, and the electric heating should be checked to ensure that the pipes are operating normally to prevent them from bursting due to water freezing and expansion. Before restarting, the filter screen should be opened and the inlet pipes should be flushed. After the water quality is restored, the usual water treatment agents should be added for treatment.

[0041] In addition, the following checks need to be performed on the equipment during operation: 1. Check all pipelines in the circulating water dosing system for blockages and leaks; 2. Check if the liquid level in each medicine tank is normal; if the liquid level is low, contact us immediately to add medicine. 3. Check whether the inlet valve, outlet valve, and inlet valve of the dosing device and the dosing pump are in the open position. If they are closed, restore them in time after confirming that there is no related work. 4. Check whether the concentration of each agent is within the control range. If there is a large deviation from the control value, investigate the cause immediately and make timely adjustments. 5. Check whether each dosing pump is operating normally and whether it is running automatically. If any abnormality is found, contact us immediately to report it. 6. Check the dosing system for alarms. If there are alarms, investigate the cause and reset the alarm to clear it. 7. Check if the system inlet filter cup is clean. If it is clogged, close the inlet valve, remove the filter cup, clean it, reinstall it, and then open the inlet valve again.

[0042] 8. In winter, check whether the electric heat tracing control cabinet is functioning properly; contact us immediately if any abnormalities are found. 9. Handling of common abnormal circulating water indicators.

[0043] In addition, the processing methods for the various parameters of the circulating water being tested are as follows: 1) The normal pH range is 7.0-8.6. If the pH value of the cooling water is lower than the lower limit, the following measures should be taken: check for cross-contamination in the pipes or excessive sewage discharge; if it is caused by excessive acid addition, stop adding acid. If the pH value of the cooling water is higher than the upper limit, the following measures should be taken: Check whether the conductivity of the cooling water system is too high. A high pH value is generally caused by the conductivity / concentration factor of the cooling water system being too high. The amount of sulfuric acid can be increased or the concentration factor of the system can be reduced to lower the pH value of the system. 2) Chemical concentration control: The chemical concentration shall be based on the circulating water quality control indicators. If the measured drug concentration is below the lower limit, the following measures should be taken: Check if the conductivity of the circulating water system is too low. If the conductivity is low, it indicates that there is water overflow or leakage. Water overflow or leakage will lead to low reagent concentration. Increase the reagent dosage appropriately. If a standard solution (water) is injected into the fluorometer and the reading deviation is large, the equipment may be reading incorrect and needs to be cleaned and calibrated. If the actual amount of chemicals used is not significantly different from before, and the concentration of chemicals in the circulating water remains very low, it is necessary to check whether there are leaks in the pipeline that are causing excessive consumption of chemicals.

[0044] If the measured concentration of the reagent exceeds the upper limit, the following measures should be taken: Check if the dosing controller is in an alarm lockout state. If so, the controller can be temporarily turned off and then on again, or relevant personnel can be notified to perform remote diagnostics on the controller. Check if the conductivity of the cooling water system is too high. If the conductivity is high, the system's sewage discharge volume needs to be increased. Check whether there are significant discrepancies between the actual dosage of the pesticide and the dosage in the plan; If the concentration of the agent is too high, the addition of the relevant agent can be temporarily stopped until the concentration of the agent is reduced to the normal range; If the concentration of the agent remains consistently high, the agent dosing plan needs to be adjusted.

[0045] 3) Electrical conductivity If the conductivity is greater than 5500 μS / cm, the following measures should be taken: Open the drain valve to drain the wastewater until the conductivity is less than 5500μs / cm. The main reason for the excessive conductivity is due to evaporation from the cooling tower, insufficient water replenishment, or failure to drain the wastewater in time. It is recommended to control the concentration ratio to about 7 times.

[0046] 4) Calcium hardness + total alkalinity (calculated as CaCO3) Recommended value ≤1100. If it is higher than this value, check if it is caused by high concentration ratio (high conductivity, high chloride ion). You can increase the amount of sulfuric acid to reduce pH (alkalinity). If the calcium hardness is high, you need to increase the amount of sewage discharge, increase the amount of weak acid water to make up the water, and increase the concentration of scale inhibitor and dispersant 3DT120.

[0047] 5) Total iron The control range is ≤2.0. If it is higher than this value, it is necessary to check whether the iron ion content of the makeup water has increased. If there is no obvious change, it indicates that the system corrosion has intensified. It is necessary to drain the sewage as soon as possible to reduce the iron ions and check the concentration of the reagent.

[0048] 6) Total alkali (calculated as CaCO3) The control range is <300, controlled by concentrated sulfuric acid. If the system has high calcium hardness, the amount of sulfuric acid needs to be increased to reduce alkalinity, so that the total alkalinity + calcium hardness of the circulating water can be ≤1100. 7) Turbidity The normal control range for turbidity is below 20 NTU. If the turbidity of the cooling water exceeds the upper limit, the following measures should be taken: Check if the conductivity of the cooling water system is too high. If the sewage is not discharged in time, impurities in the circulating water system cannot be discharged in time, resulting in high turbidity in the system. Check for pollution sources around the cooling tower, such as nearby exhaust vents or dust. The cooling tower will draw these impurities into the system, causing the system to have high turbidity. If the cooling water system has high turbidity for a long time or even sludge deposits in the tower pool, the first thing to do is to pump out the sludge from the tower pool. Secondly, it is necessary to assess whether the system needs to be equipped with a side filter.

[0049] 8) Residual chlorine, ORP Sodium hypochlorite was chosen as the disinfectant. When adding sodium hypochlorite, the residual chlorine in the circulating water return was measured to be between 0.2-1.0. If the ORP was greater than 400mv, it indicated that the amount of sodium hypochlorite added for disinfection was sufficient; otherwise, it was necessary to continue adding it.

[0050] 9) Total phosphorus The control range is 2-8 mg / L. If it is below 2 mg / L, check whether 3DT129 is being added normally and whether there is any leakage. If it is above 8 mg / L, it indicates that the dosage is too high. Stop adding the dosage, check whether the instrument reading is correct, calibrate the equipment, and reset the control value.

[0051] 10) Stainless steel / copper corrosion rate The control range is 0.005 mm / a (2 mpy). If it exceeds this value, it indicates that corrosion is intensifying. The concentration of the circulating water chemicals needs to be checked, the cause investigated, and adjustments made promptly.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A circulating water dosing system, characterized in that, include: The system consists of a first dosing module, a second dosing module, a sampling module, and a water quality monitoring module. Both the first and second dosing modules are connected to the gravity flow channel of the circulating pump. The first dosing module includes a sodium hypochlorite tank and a sodium hypochlorite dosing pump, which are used to add sodium hypochlorite into the gravity flow channel of the circulating pump. The second dosing module includes a scale inhibitor tank, a corrosion inhibitor tank, a copper corrosion inhibitor tank, and scale inhibitor dosing pump, corrosion inhibitor dosing pump, and copper corrosion inhibitor dosing pump connected to them respectively through pipelines. The sampling module includes a sampling tube and a sampling gate, and the outlet of each circulation pump is connected to the sampling tube through the sampling gate; The water quality monitoring module is used to monitor the corrosion rate, conductivity, pH value, ORP value and pollutants of circulating water in real time.

2. The circulating water dosing system according to claim 1, characterized in that, The sodium hypochlorite dosing pump consists of two units arranged in parallel, with electric valves and column flow meters connected to their respective pipelines. The sodium hypochlorite tank is connected to the two sodium hypochlorite dosing pumps by a main dosing valve.

3. The circulating water dosing system according to claim 2, characterized in that, The two sodium hypochlorite dosing pumps are connected to the gravity flow channels of the first and second unit circulating pumps via the first dosing main pipe. Electric valves are connected between the first dosing main pipe and the gravity flow channels of the first and second unit circulating pumps.

4. The circulating water dosing system according to claim 1, characterized in that, The second dosing module also includes a second dosing main pipe. There are two scale inhibitor dosing pumps and two corrosion inhibitor dosing pumps, and one copper corrosion inhibitor dosing pump. The two scale inhibitor dosing pumps are arranged in parallel, and each is connected to an electric valve and a column flow meter on its respective pipeline. A main dosing valve connects the two scale inhibitor dosing pumps to the scale inhibitor tank. Similarly, the two corrosion inhibitor dosing pumps are arranged in parallel, and each is connected to an electric valve and a column flow meter on its respective pipeline. A main dosing valve connects the two corrosion inhibitor dosing pumps to the corrosion inhibitor tank. An electric valve, a column flow meter, and a main dosing valve connect the copper corrosion inhibitor dosing pump to the copper corrosion inhibitor tank.

5. The circulating water dosing system according to claim 1, characterized in that, The number of circulation pumps is four. Each circulation pump is connected to the sampling tube through a sampling gate. Each circulation pump is connected to the sampling gate by an electric valve. A vent is provided on one side of the sampling gate. An electric valve is connected to the vent and the sampling gate.

6. The circulating water dosing system according to claim 1, characterized in that, One end of the sampling tube is equipped with a drain door, and a drain valve is installed at the drain door.

7. The circulating water dosing system according to claim 1, characterized in that, The water quality monitoring module includes a detection pipe and multiple corrosion scrapers, corrosion rate measuring probes, conductivity meter electrodes, float flowmeters, pH meter probes, ORP meter probes, and fluorescent agents installed therein. The corrosion rate measuring probes, conductivity meter electrodes, float flowmeters, pH meter probes, and ORP meter probes are all electrically connected to the monitoring instruments.

8. The circulating water dosing system according to claim 7, characterized in that, The end of the detection pipeline near the ORP meter probe is connected to the second dosing module via a flow switch and an electric valve.

9. A method for adding chemicals to circulating water based on the system described in any one of claims 1-8, characterized in that, Includes the following steps: S1: Pre-commissioning inspection: Check that the circuit, dosing pipeline and all probes are installed properly; S2: Open the sampling door and take a sample from the outlet of the circulating pump into the sampling tube; S3: The corrosion rate, conductivity, pH value, ORP value and pollutant parameters of the circulating water in the sampling tube are detected by the water quality monitoring module; S4: Based on the various parameters tested, adjust the dosage of chemicals in the sodium hypochlorite tank, scale inhibitor tank, corrosion inhibitor tank, and copper corrosion inhibitor tank. Then, turn on the sodium hypochlorite dosing pump, scale inhibitor dosing pump, corrosion inhibitor dosing pump, and copper corrosion inhibitor dosing pump to add chemicals into the gravity flow channel of the circulation pump. S5: System shutdown: Close all sampling doors and dosing pumps, and drain the wastewater from the sampling pipes.

10. The circulating water dosing method according to claim 9, characterized in that, It also includes the following steps: When the outdoor temperature drops below 0 degrees Celsius in winter, the system will shut down and drain the water from the system pipes to prevent the pipes from freezing and expanding, which could cause them to burst. Before restarting, open the filter screen, flush the inlet pipes, and add routine water treatment agents after the water quality has recovered.

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