Fire-fighting water anti-corrosion dosing system and dosing concentration control method

Abstract

The invention relates to the field of nuclear power fire fighting, in particular to a fire-fighting water anti-corrosion dosing system and a dosing concentration control method. The method comprises the following steps: step 1, adding an agent into the fire-fighting water tank for the first time, wherein the adding amount of the agent is at least 120% of the upper limit of a target value; 2, starting at least one fire pump, and stopping the fire pump to maintain the pressure of the pipe network after the chemicals in the fire water tank and the main pipeline are uniformly mixed; analyzing and confirming the medicament concentration, and adjusting the medicament concentration to an upper limit of a target value; 3, all points at the tail end of the pipe network are selected for drainage, water in the pipe is replaced with fire fighting water containing chemicals, and the liquid level of the fire fighting water is maintained in the drainage period; and 4, after the spraying test, detecting the concentration of the medicament in the main pipeline and the pipe network, and if the concentration is lower than a target value, returning to the step 1. The chemical adding scheme is optimized, it is ensured that chemicals effectively enter all pipe networks, the concentration reaches the target value, the material corrosion rate is slowed down, and the risk of corrosion perforation leakage is reduced.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant fire protection, and in particular to a fire water anti-corrosion dosing system and a dosing concentration control method. Background Technology

[0002] The main functions of a nuclear power plant's fire-fighting water system are: 1. To extinguish indoor fires in plant buildings and structures via fire hydrants; 2. To supply water to the automatic water mist fire suppression system; 3. To maintain water pressure in the automatic water mist fire suppression system; 4. To ensure water supply to the activated carbon filter. The activated carbon filter contains sprinkler heads. During firefighting, the sprinkler head pipes are connected to nearby fire hydrants via hoses to supply water to the sprinklers.

[0003] The original design documents, operating procedures, and water quality standards did not consider the impact of water quality on the corrosion of the fire protection water system. The medium used was municipal water supply and natural water sources, without the addition of any corrosion inhibitors. The nuclear power plant's fire protection water system primarily uses materials such as carbon steel, cast iron, and stainless steel, with carbon steel exhibiting the worst corrosion resistance. This resulted in severe corrosion of the entire fire protection water system.

[0004] To mitigate corrosion in fire-fighting water systems, corrosion inhibitors need to be added. However, in actual production, it has been found that due to the large size of fire-fighting water systems, there are many "stagnant" areas, especially in the pipe network, which prevents corrosion inhibitors and bactericides from effectively penetrating various parts during operation. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a fire water anti-corrosion dosing system and a dosing concentration control method, optimize the dosing scheme, ensure that corrosion inhibitors and bactericides effectively enter each pipe network and reach the target concentration, slow down the material corrosion rate and reduce the risk of corrosion perforation and leakage, and ensure the safe and stable operation of the fire water system.

[0006] This invention provides a fire-fighting water corrosion prevention dosing system, comprising:

[0007] The fire water tank has its inlet connected to the fire water supply pipeline and is equipped with a chemical dosing point;

[0008] The circulation pipeline includes a first pipeline and a second pipeline connected in parallel, with both ends of the circulation pipeline connected to a fire water tank.

[0009] A circulation pump is installed on the first pipeline, and a fire pump is installed on the second pipeline;

[0010] The circulation pipeline is also connected to the automatic sprinkler fire protection system and the fire protection loop, respectively.

[0011] The pressure stabilizing pipeline is connected to the fire water tank at one end and to the automatic sprinkler fire protection system and the fire protection loop at the other end; a fire pressure stabilizing device water supply pump is installed on the pressure stabilizing pipeline.

[0012] In one specific embodiment of the present invention, the circulation pipeline further includes two pipelines connected in parallel with the second pipeline, and a fire pump is installed on each pipeline.

[0013] This invention provides a method for controlling the dosing concentration of a fire-fighting water corrosion prevention dosing system, comprising the following steps:

[0014] Step 1: Add corrosion inhibitor and bactericide to the fire water tank for the first time, and the amount of corrosion inhibitor and bactericide added shall be at least 120% of the upper limit of the target value;

[0015] Step 2: Start at least one fire pump to ensure that the corrosion inhibitor and bactericide in the fire water tank and main pipeline are mixed evenly, then stop the fire pump to maintain the pipeline pressure; analyze and confirm the concentration of the corrosion inhibitor and bactericide, and adjust the concentration of the corrosion inhibitor and bactericide to the upper limit of the target value;

[0016] Step 3: Select various points at the end of the pipeline network for drainage, replace the water in the pipeline with fire-fighting water containing corrosion inhibitors and bactericides, and maintain the fire-fighting water level during drainage;

[0017] Step 4: After the spray test, check the concentration of corrosion inhibitor and bactericide in the main pipeline and pipe network. If it is lower than the target value, return to step 1.

[0018] In one specific embodiment of the present invention, in step 2, one fire pump is started first, and then other fire pumps are started in sequence. After the water in the pipeline is replaced with fire water containing corrosion inhibitors and bactericides, they are stopped in sequence.

[0019] In one specific embodiment of the present invention, the target value of the corrosion inhibitor is 55-70 mg / L, and the target value of the bactericide is 5-15 mg / L.

[0020] In one specific embodiment of the present invention, in step 2, the start-up time of the fire pump is not less than 1 hour.

[0021] In one specific embodiment of the present invention, when detecting the concentration of corrosion inhibitor and bactericide, the conductivity value of the water sample is detected to determine the concentration of corrosion inhibitor and bactericide.

[0022] In one specific embodiment of the present invention, a correspondence table between conductivity value and drug concentration is formed. If the conductivity value reaches a threshold, the drug concentration is considered to have reached the target value.

[0023] In one specific embodiment of the present invention, step 4 further includes: performing corrosion inhibitor and bactericide concentration analysis once a month; if the concentration is lower than the target value, returning to step 1 until the requirements are met.

[0024] Compared with the prior art, the fire-fighting water corrosion prevention dosing system and dosing concentration control method of the present invention have the following beneficial effects:

[0025] (1) The amount of medicine added was quantified, which enabled precise replenishment of medicine and reduced medicine waste;

[0026] (2) By utilizing the operation mode of the fire pump, the agent was evenly distributed in each pipeline;

[0027] (3) Differentiated management of main pipelines and pipe networks: The method of pipe network drainage-fire water tank replenishment is adopted to achieve uniform distribution of agents in the pipe network; Two pumps are used to circulate the main pipeline to achieve uniform distribution of agents in the fire water tank and the main pipeline.

[0028] (4) Use conductivity value to quickly determine drug concentration.

[0029] After implementing the above methods, sampling and analysis of fire water tanks and the ends of various pipe networks showed that the chemical concentrations all met the target requirements. A two-year comparison with an untreated fire water system revealed a significant reduction in corrosion defects in the treated system. Further comparison of corrosion conditions in test pipe sections showed that after chemical treatment, the number and density of corrosion nodules in the pipes were lower, and the sulfur content in both corrosion nodules and non-corrosion nodule products decreased, indicating that the added chemical slowed down microbial corrosion. Statistical calculations based on pipe corrosion nodules showed a slow-release rate of approximately 80%. This method of chemical concentration control effectively slowed down the material corrosion rate and reduced the risk of equipment blockage, ensuring the safe and stable operation of the fire water system. Attached Figure Description

[0030] Figure 1 This diagram shows the structure of a fire-fighting water corrosion prevention and chemical dosing system.

[0031] In the diagram, 1-fire water supply pipeline, 2-fire water tank, 3-circulating pump, 4-dosing point, 5-fire pressure stabilizing device water supply pump, 6-fire pump, 7-automatic sprinkler fire protection system, 8-fire loop. Detailed Implementation

[0032] To further understand the present invention, embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the present invention.

[0033] An embodiment of the present invention discloses a fire-fighting water corrosion prevention dosing system, such as... Figure 1 As shown, it includes:

[0034] Fire water tank 2, whose inlet is connected to fire water supply pipeline 1, and is equipped with chemical dosing point 4;

[0035] The circulation pipeline includes a first pipeline and a second pipeline connected in parallel, with both ends of the circulation pipeline connected to the fire water tank 2.

[0036] A circulation pump 3 is installed on the first pipeline, and a fire pump 6 is installed on the second pipeline;

[0037] The circulation pipeline is also connected to the automatic sprinkler fire protection system and the fire protection loop, respectively.

[0038] The pressure stabilizing pipeline is connected at one end to the fire water tank 1 and at the other end to the automatic sprinkler fire protection system 7 and the fire loop 8 respectively; a fire pressure stabilizing device water supply pump 5 is installed on the pressure stabilizing pipeline.

[0039] The circulation pipeline also includes two pipelines connected in parallel with the second pipeline, and a fire pump is installed on each pipeline.

[0040] In actual operation without adding chemicals, the power of fire pump 6 is greater than that of circulation pump 3. Circulation pump 3 is used for daily operation, while fire pump 6 is only activated when the automatic sprinkler fire system 7 uses a large amount of water.

[0041] An embodiment of the present invention discloses a method for controlling the dosing concentration of a fire-fighting water corrosion prevention dosing system as described above, comprising the following steps:

[0042] Step 1: Add corrosion inhibitor and bactericide to the fire water tank for the first time, and the amount of corrosion inhibitor and bactericide added shall be at least 120% of the upper limit of the target value;

[0043] The corrosion inhibitor used is an imidazoline corrosion inhibitor;

[0044] The bactericide used is isothiazolinone bactericide;

[0045] The target value of the corrosion inhibitor is 55-70 mg / L, preferably 60-65 mg / L; the target value of the bactericide is 5-15 mg / L, preferably 10-12 mg / L.

[0046] Step 2: Start at least one fire pump to ensure that the corrosion inhibitor and bactericide in the fire water tank and main pipeline are mixed evenly. Then, stop the fire pump to maintain the pipeline pressure. Analyze and confirm the concentration of the corrosion inhibitor and bactericide, and adjust the concentration of the corrosion inhibitor and bactericide to the upper limit of the target value. After adjusting the concentration, measure the conductivity of the water sample and record it.

[0047] Specifically, start one fire pump first, then start the other fire pumps in sequence. After the water in the pipeline is replaced with fire water containing corrosion inhibitors and bactericides, shut them down one by one.

[0048] The start-up time of the fire pump shall not be less than 1 hour.

[0049] Step 3: Select various points at the end of the pipeline network for drainage, replacing the water in the pipes with fire-fighting water containing corrosion inhibitors and bactericides. After the water sample becomes clear, use a conductivity meter to compare it with the water sample in the fire-fighting water tank to quickly confirm the concentration of the chemicals in the drainage. Maintain the fire-fighting water level during drainage;

[0050] The end of the pipeline network includes a factory water spray fire extinguishing system or an indoor fire hydrant system in a fire pump room;

[0051] The water level in the tank must not be lower than the required value.

[0052] When the liquid level is low, replenish the domestic water to the rated level, then add the chemical again, and follow step 2 to stir and sample the chemical for corrosion prevention in the fire water tank and main pipeline to confirm the concentration of the corrosion inhibitor.

[0053] Step 4: After the spray test, check the concentration of corrosion inhibitor and bactericide in the main pipeline and pipe network. If it is lower than the target value, return to step 1.

[0054] When detecting the concentration of corrosion inhibitors and bactericides, the conductivity value of the water sample is measured to determine the concentration of the corrosion inhibitors and bactericides. Preferably, a table mapping conductivity values ​​to agent concentrations is created. If the conductivity value reaches a threshold, the agent concentration is considered to have reached the target value, thus achieving rapid detection of agent concentrations.

[0055] Many companies perform monthly analysis of corrosion inhibitor and bactericide concentrations. If the concentration is lower than the target value, they return to step 1 until the requirements are met.

[0056] To further understand the present invention, the following detailed description of the fire-fighting water anti-corrosion dosing system and dosing concentration control method provided by the present invention is provided in conjunction with embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0057] Example 1

[0058] Step 1: Add corrosion inhibitors and bactericides to the system. The amount added is calculated based on the volume of the fire water system and 120% of the target value.

[0059] Step 2: Start a fire pump to mix the water, and the mixing time shall not be less than 1 hour.

[0060] Step 3: Start the other fire pumps in sequence to replace the water in the pipeline with fire water containing corrosion inhibitors and bactericides. The start-up time for each pump should be no less than 1 hour, and then shut them down in sequence. Take samples to analyze the concentration of corrosion inhibitors and bactericides, and record the conductivity values.

[0061] Step 4: During this period, keep the pressure stabilizing pump running normally to maintain the pipeline pressure.

[0062] Step 5: Drain water from various points of the factory's water spray fire extinguishing system or the indoor fire hydrant system in the fire pump room. After the water sample becomes clear, analyze it using a conductivity meter until the values ​​stabilize, then analyze the concentrations of corrosion inhibitors and bactericides. If the concentrations of corrosion inhibitors and bactericides do not meet the target values, repeat steps 1-2-3-4-5.

[0063] Step 6: Analyze the concentration of corrosion inhibitor and bactericide at least once a month. If the concentration is lower than the target value, repeat steps 1-2-3-4-5 to add the agent until the requirements are met.

[0064] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0065] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fire water corrosion inhibiting dosing system, characterised in that, The application relates to a fire-fighting water tank, a circulating pipeline and a stable pressure pipeline. The circulating pipeline is connected with the fire-fighting water tank at two ends and comprises a first pipeline and a second pipeline connected in parallel. The first pipeline is provided with a circulating pump, and the second pipeline is provided with a fire-fighting pump. The circulating pipeline is further connected with an automatic fire-fighting sprinkler system and a fire-fighting loop. The stable pressure pipeline is connected with the fire-fighting water tank at one end and connected with the automatic fire-fighting sprinkler system and the fire-fighting loop at the other end. The circulating pipeline further comprises two pipelines connected in parallel with the second pipeline, and each pipeline is provided with a fire-fighting pump.

2. The fire water corrosion inhibition dosing system of claim 1, wherein, The application further relates to a method for adding corrosion inhibitor and bactericide into a fire-fighting water tank.

3. A method for controlling the concentration of the medicament in the fire-fighting water anticorrosion medicating system according to claim 1 or 2, characterized in that, The method comprises the following steps: Step 1: adding corrosion inhibitor and bactericide into the fire-fighting water tank for the first time, and the adding amount of the corrosion inhibitor and the bactericide is at least 120% of the upper limit of a target value; Step 2: starting at least one fire-fighting pump, mixing the corrosion inhibitor and the bactericide in the fire-fighting water tank and the main pipeline, stopping the fire-fighting pump to maintain the pipeline network pressure, and analyzing and confirming the concentration of the corrosion inhibitor and the bactericide to adjust the concentration of the corrosion inhibitor and the bactericide to the upper limit of the target value; Step 3: selecting points at the end of the pipeline network to drain water, replacing the water in the pipeline with fire-fighting water containing the corrosion inhibitor and the bactericide, and maintaining the fire-fighting water level during the water draining process; Step 4: after the spray test, detecting the concentration of the corrosion inhibitor and the bactericide in the main pipeline and the pipeline network, and returning to step 1 if the concentration is lower than the target value.

4. The method of claim 3, wherein In step 2, one fire-fighting pump is started first, and then other fire-fighting pumps are started in sequence, and the water in the pipeline is replaced with fire-fighting water containing the corrosion inhibitor and the bactericide, and then the fire-fighting pumps are stopped in sequence.

5. The method of claim 3, wherein the concentration of the medicament is controlled by the amount of the medicament supplied to the reservoir. The target value of the corrosion inhibitor is 55-70 mg / L, and the target value of the bactericide is 5-15 mg / L.

6. The method of claim 3, wherein the concentration of the medicament is controlled by the amount of the medicament supplied to the reservoir. In step 2, the starting time of the fire-fighting pump is not less than 1 hour.

7. The method of claim 3, wherein the concentration of the medicament is controlled by the amount of the medicament supplied to the reservoir. When the concentration of the corrosion inhibitor and the bactericide is detected, the conductivity value of the water sample is detected to determine the concentration of the corrosion inhibitor and the bactericide.

8. The method of claim 4, wherein the concentration of the medicament is controlled by the amount of the medicament in the reservoir. A corresponding table of the conductivity value and the concentration of the corrosion inhibitor and the bactericide is formed, and if the conductivity value reaches a threshold value, it is determined that the concentration of the corrosion inhibitor and the bactericide reaches the target value.

9. The method of claim 3, wherein the concentration of the medicament is controlled by the amount of the medicament in the reservoir. In step 4, the concentration of the corrosion inhibitor and the bactericide is analyzed at least once a month, and if the concentration is lower than the target value, step 1 is returned to until the requirement is met.

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