I. Overview In the open circulating cooling water system of the power plant, the temperature of the cooling water is usually between 20 and 42 ° C. This temperature range is particularly favorable for the growth of microorganisms. The cooling water is dissolved in the spray aeration process in the cooling tower. Oxygen provides the necessary conditions for the growth of aerobic bacteria. The cooling tower is exposed to the sun and the algae undergo photosynthesis, so the algae multiply. Especially in the summer season from April to June each year, due to the rapid increase of temperature, the circulating water system has a higher concentration of operation, and the water purification capacity of the water itself is reduced, which is very beneficial to the rapid growth of algae microorganisms and easy to grow out of control. The formation of organic matter is closely related to the growth of microorganisms, because microorganisms release mucus during growth and reproduction. These mucus adheres the slime and plant residues in the water to form a green sticky scale, which adheres to the circulating water system. in. Second, the problem The breeding of algae and algae will bring a series of problems: (1) Producing a large amount of microbial slime to increase the turbidity of the water, accumulating slime in the low flow rate zone of the heat exchange equipment such as the head, tube, packing, etc., causing blockage and siltation, affecting the transmission of the heat exchanger Thermal efficiency and efficiency of cooling equipment. Technical scheme for sterilization and algae removal and slime stripping in circulating water system of thermal power plant (2) The microbial microorganisms produce various types of acidic substances in their own metabolic processes, causing acid corrosion of system equipment. (3) Microbial slime deposits unevenly on the surface of metal equipment, which will form a battery effect due to oxygen concentration, causing corrosion under scale. (4) The walls and pillars of the cool water tower and some of the equipment are covered with moss and covered with algae slime, which seriously deteriorates the quality of the circulating water. In the rapid breeding and breeding of microbial microorganisms, effective killing control and intervention, and changing the living environment, is the key to the sterilization and algae treatment of the circulating water system. Therefore, the circulating water treatment of power plants mainly includes corrosion and scale inhibition treatment, sterilization and algae removal, and slime stripping treatment. Third, the processing method The sterilization control of the circulating water system is preferably an alternate use of an oxidizing biocide and a non-oxidizing biocide to prevent microbial resistance. The oxidizing bactericide has a low dosage and fast sterilization. Non-oxidizing bactericides generally contain a surfactant, which, in addition to having a bactericidal action, can also remove a small amount of microbial slime that has formed on the surface of the device. The slime stripper will continue to kill and remove the residual bacteria and algae slime, and discharge the sterilized and stripped products out of the system as soon as possible to achieve long-term effective control. Fourth, the introduction of pharmacy (1) Oxidizing fungicide Oxidizing fungicides have strong oxidizing properties and achieve rapid and strong sterilization by oxidation with metabolic enzymes in bacteria, such as chlorine, bromine and bromine and chlorine compounds in halogens (sodium hypochlorite, chlorine dioxide, isocyanine chloride). Uric acid, halogenated hydantoin, etc., ozone, hydrogen peroxide, peracetic acid. The bactericidal and algae-killing scheme can use sodium dichloroisocyanurate and sodium hypochlorite as oxidizing bactericides to kill the active organisms of the surface and shallow layers of the moss and the slime, and continue to inhibit the growth of the algae by using the residual agent. ; (2) Non-oxidizing fungicides The non-oxidizing bactericide acts on a special part of the microorganism in the form of a toxic agent, thereby destroying the cells or living parts of the microorganism to achieve a bactericidal effect. At present, non-oxidizing fungicides used in water treatment systems in China mainly include chlorophenols, aldehydes, quaternary ammonium salts, quaternary phosphonium salts, and isothiazolinones. Since recycled water is used in subsequent production, it is required that the circulating water does not have too much foam. Therefore, the non-oxidizing fungicide selected for the sterilization and algae-killing scheme is the isothiazolinone series. (3) slime stripper Non-oxidizing bactericides can inhibit the synthesis of proteins, kill and adsorb bacterial proteins on the cell wall, and control the permeability of cell plasma membranes to kill cells. It can effectively kill good bacteria, anaerobic bacteria, fungi, algae and other microorganisms. The biological slime can be dispersed and peeled off over a wide range of pH values. After adding the bactericidal algaecide, and then adding the slime stripping agent according to the bactericidal condition, the residual bacterium algae slime continues to be killed and stripped, and the sterilized and stripped product is discharged out of the system as soon as possible to achieve long-term effective control. . Five, dosing calculation Dosing amount Gs (kg) = (V × Cs) / 1000 among them: Cs - bactericidal algaecide (mud stripping agent) dosage, kg; V —— the system retains water, m3; Cs - Add the concentration of the drug, mg / L. A single circulating water system normally retains a water volume of 12,500 m3. When the sterilization and algae killing, it can be reduced to a minimum safety level of about 10,000 m3. If the water level cannot be lowered, it is calculated according to the maximum retained water quantity. Sixth, the specific dosage Considering the production cost and effect, etc., it is not recommended that your company adopt continuous feeding of sodium hypochlorite to ensure that the residual chlorine content is controlled at 0.1-0.5mg/L. It is recommended to use the impact dosing to sterilize and kill algae. (1) Dosing of oxidative bactericidal algaecide 1. When adding 10% sodium hypochlorite by impact, it is recommended to add 200mg/l, that is, 2000Kg per dose; 2, when the impact of adding sodium dichloroisocyanurate (physical and chemical indicators are as follows), it is recommended to add 50mg / l, that is, each dose is 500Kg; Depending on the condition of the bacteria in the circulating water system, the adhesion of the slime, etc., the annual oxidative sterilization and algae killing is generally carried out about 12 times. Physical and chemical indicators: in line with the standard HG/T3779-2005 "dichloroisocyanurate" indicators. project index White crystalline powder or white granules Effective chlorine content, % ≥55.0 Moisture content, % ≤3.0 PH value (10g / L aqueous solution) 5.5 to 7.0 Water insoluble matter,% 0.1 (2) Dosing of non-oxidizing bactericidal algaecide When the isothiazolinone is added by impact (physical and chemical index is as follows), it is recommended to add 25mg/l, that is, 250Kg per dose; Depending on the condition of the bacteria in the circulating water system, the adhesion of the slime, etc., the annual non-oxidative sterilization and algae killing is generally carried out about 12 times. Physical and chemical indicators: in line with HG/T3657-2008 "water treatment agent isothiazolinone derivatives" in the category I indicators. project index Exterior Colorless to pale yellow transparent liquid Active content% 14.0~15.0 Density (20 ° C) / (g / cm3) 1.26~1.32 Chlorine-containing actives / chlorine-free actives (mass ratio) 2.5 to 3.4 PH value (stock solution) 2.0 to 4.0 (3) Dosing of slime stripper When adding the slime stripping agent by impact (physical and chemical index is as follows), it is recommended to add 200mg/l, that is, 2000Kg per dose; Depending on the condition of the bacteria in the circulating water system, the adhesion of the slime, etc., the sticking agent is usually added about 6 times a year. The physical and chemical indicators of the slime stripper are as follows: project index Exterior Colorless or light yellow liquid PH value ≥8.0 Density (20 ° C), g / cm3 ≥1.05 Seven, work preparation before sterilization (1) Increase the discharge of circulating water before adding the bactericidal algaecide to minimize the concentration of circulating water. The liquid level of the cold water tower is reduced to the lowest water level that can maintain the safe operation of the system, so as to fully ensure the effective concentration of the bactericidal algaecide and the slime stripper to exert the effect of the medicament. (2) After dropping to the lowest water level, close the drain valve and stop the sewage. (3) Increase the flow rate of the circulating pump and maintain the circulation of the system at the maximum flow rate. Eight, sterilization specific operations and precautions (1) According to the water level of the cooling tower and the one-time impact, add the bactericidal algaecide or slime stripper to carry out bactericidal algae removal or slime stripping. And maintain the cycle for about 24 hours (specifically to observe the pathogens to kill, the degree of discoloration and the change in water turbidity). (2) If the floating material in the pool water is too much, after the oxygen sterilization and slime stripping are basically completed, the sewage should be discharged and the new water should be fully replaced. (3) After the sterilization and algae elimination is completed and the sewage is drained and replaced, the degree of killing of the algae and the residue of the slime are determined to be put into the slime stripping agent for bactericidal slime stripping. The stripping process time is maintained for about 24 hours, depending on the water turbidity. When it is no longer raised, the peeling ends. (4) After the end, the large-scale discharge should be carried out immediately. Replenish water and increase the amount of sewage to be effectively replaced, so that most of the suspended dirt under the sterilizing and peeling of the circulating water is removed, and the turbidity is "f20NTU, and the system is transferred to normal operation. (5) In the sterilization process (especially in the initial stage), strengthen the inspection of the inlet filter of the circulating water pump, and timely clean up the suspended solids to avoid clogging the filter. Face Spray,Water Mist Sprayer,Facial Hydrating Spray,Handheld Face Steamer Zhongshan Lianwei Electrical Technology Co., Ltd. , https://www.zslwwaterpump.com