Environment-friendly scale and corrosion inhibitor for recycling reclaimed water of power plant as well as preparation method and application of environment-friendly scale and corrosion inhibitor

Abstract

The invention discloses an environment-friendly scale and corrosion inhibitor for recycling water in a power plant as well as a preparation method and application of the environment-friendly scale and corrosion inhibitor, and belongs to the technical field of water treatment. According to the environment-friendly scale and corrosion inhibitor for recycling the reclaimed water of the power plant, disclosed by the invention, the scale and corrosion conditions of a cooling water system can be effectively prevented through the synergistic effect of various functional groups contained in the components, the scale and corrosion inhibition performance of the scale and corrosion inhibitor is greatly improved after the scale and corrosion inhibitor is compounded, and the scale and corrosion inhibitor is suitable for a high-alkalinity and high-hardness circulating cooling water system for recycling the reclaimed water; on the premise that phosphorus and zinc are not contained, the water quality stability in a circulating cooling water system and the use performance in corrosion prevention of metal parts are remarkably improved, and the environment-friendly performance is good.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to an environmentally friendly scale and corrosion inhibitor for water reuse in a power plant, and a preparation method and application thereof. Background Art

[0002] The open circulating cooling water system is an indispensable equipment for heat exchange in power plants. At present, some domestic power plants reuse the treated urban sewage water in the circulating water system of the power plants to achieve industrial water saving and environmental protection.

[0003] Due to the high salt content, phosphorus and COD of reclaimed water, the circulating cooling water system is more prone to scaling, corrosion and microbial reproduction. Relevant scale inhibitors have been developed to address these problems, but the scale inhibitors currently used are mainly phosphorus-zinc series. The use of scale inhibitors containing phosphorus and zinc will also bring many disadvantages. For example, excessive use and discharge of phosphorus-containing scale inhibitors will cause wastewater with excessively high phosphate content to enter the natural environment, which will promote the growth of algae and plants in the water and form eutrophication. Eutrophication may cause algae to reproduce in large numbers, consume oxygen in the water, cause aquatic organisms to die due to lack of oxygen, and destroy aquatic ecosystems; zinc ions may react with other chemicals (such as phosphates, silicates, etc.) in aqueous solution to form precipitates or complexes, which may adhere to the surface of pipes and equipment to form new dirt or scale layers; as the country continues to strengthen its efforts in environmental protection, scale inhibitors containing phosphorus and zinc will be gradually restricted and eliminated. Therefore, it is of great application value to research and develop an environmentally friendly phosphorus-free and zinc-free scale and corrosion inhibitor for reclaimed water reuse. Summary of the invention

[0004] The purpose of the present invention is to provide an environmentally friendly scale and corrosion inhibitor for water reuse in power plants, and a preparation method and application thereof, so as to solve the technical problem that the existing scale and corrosion inhibitors contain phosphorus and zinc and are difficult to meet environmental protection requirements.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The invention discloses an environmentally friendly scale inhibitor and corrosion inhibitor for water reuse in a power plant. The scale inhibitor and corrosion inhibitor comprises, by mass percentage, 5.0-20.0% of polyepoxysuccinic acid, 1.0-5.0% of sodium gluconate, 5-25% of sulfonic acid copolymer, 2.0-10.0% of molybdate, 5.0-10.0% of imidazoline derivative, 1.0-2.0% of pH regulator and the balance of deionized water; the total proportion of each component is 100%.

[0007] Furthermore, the limiting viscosity of the polyepoxysuccinic acid is 0.025 to 0.035 dL / g.

[0008] Further, the sulfonic acid copolymer is one or more of acrylic acid-styrene sulfonic acid copolymer, acrylic acid-maleic acid-methallyl copolymer, hydroxyethyl methacrylate-acrylamide-methacrylic acid sulfonic acid copolymer, itaconic acid-acrylamide-methacrylic acid sulfonic acid copolymer and maleic acid-propylene sulfonate copolymer.

[0009] Furthermore, the molybdate is one or more of sodium molybdate, ammonium molybdate and potassium molybdate.

[0010] Furthermore, the pH adjuster is one or more of citric acid, acetic acid and oxalic acid.

[0011] The present invention also discloses a method for preparing the environmentally friendly scale and corrosion inhibitor for water reuse in power plants, comprising the following steps:

[0012] Mixing molybdate, sodium gluconate and deionized water according to the mass percentage of claim 1 to obtain a sodium gluconate solution;

[0013] Polyepoxysuccinic acid, sulfonic acid copolymer and imidazoline derivative are added to sodium gluconate solution, ultrasonically treated, heated and stirred, cooled after stirring, pH regulator is added, stirred and filtered to obtain environmentally friendly scale inhibitor and corrosion inhibitor for water reuse in power plants.

[0014] Furthermore, the temperature of the sodium gluconate solution is 40-60° C.; and the time of the ultrasonic treatment is 30-60 min.

[0015] Further, the temperature was raised to 85° C. and stirred for 60 min. After the stirring was completed, the temperature was lowered to 30° C. and a pH adjuster was added.

[0016] Furthermore, the preparation method of the imidazoline derivative is:

[0017] Heat 0.2 mol of nonanoic acid and 40 mL of toluene to 150-160°C with stirring, react for 1 hour, heat to 200°C, slowly add 0.2 mol of diethylenetriamine, react for 3 hours, cool to 120°C, dropwise add 0.10 mol of benzyl chloride, react at 140°C with stirring for 3-4 hours, stop heating, remove unreacted benzyl chloride by microvacuum device for 1 hour, and obtain an imidazoline derivative.

[0018] The present invention also discloses the application of the environmentally friendly scale inhibitor and corrosion inhibitor for water reuse in power plants, which is used as a chemical agent for stabilizing water quality in a circulating cooling water system and preventing corrosion of metal parts.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The invention discloses an environmentally friendly scale and corrosion inhibitor for reuse of reclaimed water in a power plant. The synergistic effect of various functional groups contained in each component can effectively prevent scaling and corrosion in a cooling water system. After compounding, the scale and corrosion inhibition performance is greatly improved, and the agent is suitable for a high-alkalinity and high-hardness circulating cooling water system for reuse of reclaimed water. The imidazoline derivative contains a five-membered heterocyclic ring containing N, and the lone pair of electrons in the outer layer of the core has the ability to provide electrons to the metal d orbital. At the same time, the alkyl hydrophobic side chain can form a hydrophobic layer on the metal surface to play a protective role, inhibit the migration of corrosive media to the metal surface, and has good corrosion inhibition ability for carbon steel. On the basis of the imidazoline structure, the product is quaternized by benzyl chloride to form a quaternary ammonium salt, thereby improving its water solubility. Under the premise of not containing phosphorus and zinc, the stability of water quality in the circulating cooling water system and the performance of metal parts in preventing corrosion are significantly improved, and the agent has good environmental friendliness.

[0021] Furthermore, the present invention also discloses a method for preparing the environmentally friendly scale and corrosion inhibitor for water reuse in power plants. The preparation process is simple, no "three wastes" are discharged, the agent has good stability and water solubility, the main ingredients are phosphorus-free and zinc-free, and the agent is biodegradable, non-toxic, pollution-free, green and environmentally friendly. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0023] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0024] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible sub-ranges and individual values ​​within the range (including integers and fractions).

[0025] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0026] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0027] The present invention provides an environmentally friendly scale and corrosion inhibitor for water reuse in a power plant. The components of the scale and corrosion inhibitor include, by mass percentage:

[0028] 5.0-20.0% polyepoxysuccinic acid; 1.0-5.0% sodium gluconate; 5-25% sulfonic acid copolymer; 2.0-10.0% molybdate; 5.0-10.0% imidazoline derivative; 1.0-2.0% pH regulator; the balance is deionized water; the total proportion of each component is 100%.

[0029] Preferably, the limiting viscosity (30° C.) of the polyepoxysuccinic acid is between 0.025 and 0.035 (dL / g).

[0030] Preferably, the sulfonic acid copolymer is one or more of acrylic acid-styrene sulfonic acid copolymer, acrylic acid-maleic acid-methallyl copolymer, hydroxyethyl methacrylate-acrylamide-methacrylic acid sulfonic acid copolymer, itaconic acid-acrylamide-methacrylic acid sulfonic acid copolymer, and maleic acid-propylene sulfonate copolymer.

[0031] Preferably, the molybdate is one or more of sodium molybdate, ammonium molybdate and potassium molybdate.

[0032] Preferably, the synthesis method of the imidazoline derivative is as follows: 0.2 mol of nonanoic acid and 40 ml of toluene are heated and stirred to 150-160° C., reacted for 1 hour, heated to 200° C., slowly added with 0.2 mol of diethylenetriamine, reacted for 3 hours, cooled to about 120° C., dropwise added with 0.10 mol of benzyl chloride, reacted at 140° C. with stirring for 3-4 hours, stopped heating, and removed the unreacted benzyl chloride by a microvacuum device for 1 hour to obtain the imidazoline derivative.

[0033] Preferably, the pH adjuster is one or more of citric acid, acetic acid and oxalic acid.

[0034] The preparation method of the environmentally friendly scale inhibitor and corrosion inhibitor for water reuse in power plants is as follows: (1) adding corresponding components of molybdate, sodium gluconate and an appropriate amount of deionized water into a glass fiber reinforced plastic reactor, stirring and controlling the temperature at 40-60°C until the mixture is completely dissolved; (2) sequentially adding polyepoxysuccinic acid, sulfonic acid copolymer and imidazoline derivative in proportion, ultrasonically treating for 30-60 minutes, then heating to 85°C and stirring for 60 minutes, then cooling the material to 30°C, adding a pH regulator, stirring for 30 minutes, filtering with an 80-mesh filter and packaging, thereby preparing the scale inhibitor and corrosion inhibitor.

[0035] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0036] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0037] Example 1

[0038] A method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in a power plant comprises the following steps:

[0039] In terms of mass percentage, the components of the environmentally friendly scale and corrosion inhibitor for water reuse in power plants in this embodiment include:

[0040] 20% polyepoxysuccinic acid, 4% sodium gluconate, 20% acrylic acid-styrene sulfonic acid copolymer (sulfonic acid copolymer), 5% sodium molybdate (molybdate), 5% imidazoline derivative, 1% acetic acid (PH regulator) and the balance deionized water; the total proportion of each component is 100%;

[0041] Wherein, the preparation method of imidazoline derivative is:

[0042] 0.2 mol of nonanoic acid and 40 mL of toluene were heated and stirred to 160°C, reacted for 1 hour, heated to 200°C, slowly added with 0.2 mol of diethylenetriamine, reacted for 3 hours, cooled to about 120°C, and dropwise added with 0.10 mol of benzyl chloride, reacted at 140°C with stirring for 4 hours, and then stopped heating. The unreacted benzyl chloride was removed by a microvacuum device for 1 hour to obtain an imidazoline derivative;

[0043] According to the above mass percentages, molybdate, sodium gluconate and deionized water are mixed at 40° C. to obtain a sodium gluconate solution;

[0044] Polyepoxysuccinic acid, sulfonic acid copolymer and imidazoline derivative were added to sodium gluconate solution, and after ultrasonic treatment for 60 minutes, the temperature was raised to 85°C and stirred for 60 minutes. After stirring, the temperature was lowered to 30°C and a pH regulator was added. After stirring for 30 minutes, the solution was filtered through an 80-mesh filter and packaged to obtain an environmentally friendly scale inhibitor for water reuse in power plants.

[0045] Example 2

[0046] A method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in a power plant comprises the following steps:

[0047] In terms of mass percentage, the components of the environmentally friendly scale and corrosion inhibitor for water reuse in power plants in this embodiment include:

[0048] 20% polyepoxysuccinic acid, 5% sodium gluconate, 25% hydroxyethyl methacrylate-acrylamide-methacrylic acid copolymer (sulfonic acid copolymer), 8% potassium molybdate (molybdate), 10% (imidazoline derivative), 2% oxalic acid (PH regulator) and the balance deionized water; the total proportion of each component is 100%;

[0049] Wherein, the preparation method of imidazoline derivative is:

[0050] 0.2 mol of nonanoic acid and 40 mL of toluene were heated and stirred to 150°C, reacted for 1 hour, heated to 200°C, slowly added with 0.2 mol of diethylenetriamine, reacted for 3 hours, cooled to about 120°C, and 0.10 mol of benzyl chloride was added dropwise. The reaction was stirred at 140°C for 3 hours, and heating was stopped. The unreacted benzyl chloride was removed by a microvacuum device for 1 hour to obtain an imidazoline derivative.

[0051] According to the above mass percentage, molybdate, sodium gluconate and deionized water are mixed at 50° C. to obtain a sodium gluconate solution;

[0052] Polyepoxysuccinic acid, sulfonic acid copolymer and imidazoline derivative were added to sodium gluconate solution, and after ultrasonic treatment for 60 minutes, the temperature was raised to 85°C and stirred for 60 minutes. After stirring, the temperature was lowered to 30°C and a pH regulator was added. After stirring for 30 minutes, the solution was filtered through an 80-mesh filter and packaged to obtain an environmentally friendly scale inhibitor for water reuse in power plants.

[0053] Example 3

[0054] A method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in a power plant comprises the following steps:

[0055] In terms of mass percentage, the components of the environmentally friendly scale and corrosion inhibitor for water reuse in power plants in this embodiment include:

[0056] 15% polyepoxysuccinic acid, 5% sodium gluconate, 20% itaconic acid-acrylamide-methyl propylene sulfonic acid copolymer (sulfonic acid copolymer), 5% ammonium molybdate (molybdate), 5% (imidazoline derivative), 1% citric acid (PH regulator) and the balance deionized water; the total proportion of each component is 100%;

[0057] Wherein, the preparation method of imidazoline derivative is:

[0058] 0.2 mol of nonanoic acid and 40 mL of toluene were heated and stirred to 150°C, reacted for 1 hour, heated to 200°C, slowly added with 0.2 mol of diethylenetriamine, reacted for 3 hours, cooled to about 120°C, and 0.10 mol of benzyl chloride was added dropwise. The mixture was stirred at 140°C for 4 hours and then stopped heating. The unreacted benzyl chloride was removed by a microvacuum device for 1 hour to obtain an imidazoline derivative.

[0059] According to the above mass percentages, molybdate, sodium gluconate and deionized water are mixed at 40° C. to obtain a sodium gluconate solution;

[0060] Polyepoxysuccinic acid, sulfonic acid copolymer and imidazoline derivative were added to sodium gluconate solution, and after ultrasonic treatment for 50 minutes, the temperature was raised to 85°C and stirred for 60 minutes. After stirring, the temperature was lowered to 30°C and a pH regulator was added. After stirring for 30 minutes, the solution was filtered through an 80-mesh filter and packaged to obtain an environmentally friendly scale inhibitor for water reuse in power plants.

[0061] Example 4

[0062] A method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in a power plant comprises the following steps:

[0063] In terms of mass percentage, the components of the environmentally friendly scale and corrosion inhibitor for water reuse in power plants in this embodiment include:

[0064] 15% polyepoxysuccinic acid, 5% sodium gluconate, 25% acrylic acid-maleic acid-methylallyl copolymer (sulfonic acid copolymer), 2% ammonium molybdate (molybdate), 5% (imidazoline derivative), 1% citric acid (PH regulator) and the balance deionized water; the total proportion of each component is 100%;

[0065] Wherein, the preparation method of imidazoline derivative is:

[0066] 0.2 mol of nonanoic acid and 40 mL of toluene were heated and stirred to 160°C, reacted for 1 hour, heated to 200°C, slowly added with 0.2 mol of diethylenetriamine, reacted for 3 hours, cooled to about 120°C, and dropwise added with 0.10 mol of benzyl chloride, reacted at 140°C with stirring for 4 hours, and then stopped heating. The unreacted benzyl chloride was removed by a microvacuum device for 1 hour to obtain an imidazoline derivative;

[0067] According to the above mass percentage, molybdate, sodium gluconate and deionized water are mixed at 50° C. to obtain a sodium gluconate solution;

[0068] Polyepoxysuccinic acid, sulfonic acid copolymer and imidazoline derivative were added to sodium gluconate solution, and after ultrasonic treatment for 60 minutes, the temperature was raised to 85°C and stirred for 60 minutes. After stirring, the temperature was lowered to 30°C and a pH regulator was added. After stirring for 30 minutes, the solution was filtered through an 80-mesh filter and packaged to obtain an environmentally friendly scale inhibitor for water reuse in power plants.

[0069] Example 5

[0070] A method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in a power plant comprises the following steps:

[0071] In terms of mass percentage, the components of the environmentally friendly scale and corrosion inhibitor for water reuse in power plants in this embodiment include:

[0072] 10% polyepoxysuccinic acid, 5% sodium gluconate, 20% maleic acid-propylene sulfonate copolymer (sulfonic acid copolymer), 8% ammonium molybdate (molybdate), 10% (imidazoline derivative), 2% oxalic acid (PH regulator) and the balance deionized water; the total proportion of each component is 100%;

[0073] Wherein, the preparation method of imidazoline derivative is:

[0074] 0.2 mol of nonanoic acid and 40 mL of toluene were heated and stirred to 150°C, reacted for 1 hour, heated to 200°C, slowly added with 0.2 mol of diethylenetriamine, reacted for 3 hours, cooled to about 120°C, and 0.10 mol of benzyl chloride was added dropwise. The reaction was stirred at 140°C for 3 hours, and heating was stopped. The unreacted benzyl chloride was removed by a microvacuum device for 1 hour to obtain an imidazoline derivative.

[0075] According to the above mass percentage, molybdate, sodium gluconate and deionized water are mixed at 60° C. to obtain a sodium gluconate solution;

[0076] Polyepoxysuccinic acid, sulfonic acid copolymer and imidazoline derivative were added to sodium gluconate solution, and after ultrasonic treatment for 60 minutes, the temperature was raised to 85°C and stirred for 60 minutes. After stirring, the temperature was lowered to 30°C and a pH regulator was added. After stirring for 30 minutes, the solution was filtered through an 80-mesh filter and packaged to obtain an environmentally friendly scale inhibitor for water reuse in power plants.

[0077] Example 6

[0078] A method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in a power plant comprises the following steps:

[0079] In terms of mass percentage, the components of the environmentally friendly scale and corrosion inhibitor for water reuse in power plants in this embodiment include:

[0080] 20% polyepoxysuccinic acid, 5% sodium gluconate, 20% acrylic acid-maleic acid-methylallyl copolymer (sulfonic acid copolymer), 2% potassium molybdate (molybdate), 10% (imidazoline derivative), 2% citric acid (PH regulator) and the balance deionized water; the total proportion of each component is 100%;

[0081] Wherein, the preparation method of imidazoline derivative is:

[0082] 0.2 mol of nonanoic acid and 40 mL of toluene were heated and stirred to 150°C, reacted for 1 hour, heated to 200°C, slowly added with 0.2 mol of diethylenetriamine, reacted for 3 hours, cooled to about 120°C, and 0.10 mol of benzyl chloride was added dropwise. The reaction was stirred at 140°C for 3 hours, and heating was stopped. The unreacted benzyl chloride was removed by a microvacuum device for 1 hour to obtain an imidazoline derivative.

[0083] According to the above mass percentages, molybdate, sodium gluconate and deionized water are mixed at 40° C. to obtain a sodium gluconate solution;

[0084] Polyepoxysuccinic acid, sulfonic acid copolymer and imidazoline derivative were added to sodium gluconate solution, and after ultrasonic treatment for 60 minutes, the temperature was raised to 85°C and stirred for 60 minutes. After stirring, the temperature was lowered to 30°C and a pH regulator was added. After stirring for 30 minutes, the solution was filtered through an 80-mesh filter and packaged to obtain an environmentally friendly scale inhibitor for water reuse in power plants.

[0085] Example 7

[0086] A method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in a power plant comprises the following steps:

[0087] In terms of mass percentage, the components of the environmentally friendly scale and corrosion inhibitor for water reuse in power plants in this embodiment include:

[0088] 15% polyepoxysuccinic acid, 1% sodium gluconate, 25% acrylic acid-maleic acid-methylallyl copolymer (sulfonic acid copolymer), 10% potassium molybdate (molybdate), 5% (imidazoline derivative), 2% citric acid (PH regulator) and the balance deionized water; the total proportion of each component is 100%;

[0089] Wherein, the preparation method of imidazoline derivative is:

[0090] 0.2 mol of nonanoic acid and 40 mL of toluene were heated and stirred to 150°C, reacted for 1 hour, heated to 200°C, slowly added with 0.2 mol of diethylenetriamine, reacted for 3 hours, cooled to about 120°C, and 0.10 mol of benzyl chloride was added dropwise. The reaction was stirred at 140°C for 3 hours, and heating was stopped. The unreacted benzyl chloride was removed by a microvacuum device for 1 hour to obtain an imidazoline derivative.

[0091] According to the above mass percentages, molybdate, sodium gluconate and deionized water are mixed at 40° C. to obtain a sodium gluconate solution;

[0092] Polyepoxysuccinic acid, sulfonic acid copolymer and imidazoline derivative were added to sodium gluconate solution, and after ultrasonic treatment for 60 minutes, the temperature was raised to 85°C and stirred for 60 minutes. After stirring, the temperature was lowered to 30°C and a pH regulator was added. After stirring for 30 minutes, the solution was filtered through an 80-mesh filter and packaged to obtain an environmentally friendly scale inhibitor for water reuse in power plants.

[0093] The environmentally friendly scale inhibitor and corrosion inhibitor for reuse of reclaimed water in power plants prepared in the above embodiment was tested. A certain amount of reclaimed water after coagulation and clarification treatment was taken, the total alkalinity of which was 1.0 mmol / L and the calcium hardness was 2.0 mmol / L. The amount of the above scale inhibitor and corrosion inhibitor added was 20 mg / L. The limit carbonate hardness tester was installed and adjusted according to standard HG / T 4541-2013, and the test temperature was set to 45°C. After reaching the specified temperature, the automatic liquid replenishment and aeration device were turned on for concentration. The limit carbonate hardness (total alkalinity + calcium hardness) of the test was 24.5 mmol / L.

[0094] Take 1.6L of water sample with a limiting carbonate hardness of 24.5mmol / L in the above test, set the rotating test piece linear speed to 0.35m / s, the test solution to test piece area ratio: 35-40ml / cm2, the ventilation volume to 150ml / min, and heat to 45℃. Carry out the rotating coupon test, and the test duration is 500h. Finally, the uniform corrosion rate of carbon steel is 0.065mm / a, and the uniform corrosion rate of stainless steel is 0.002mm / a, which meets the standard requirements.

[0095] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. An environmentally friendly scale and corrosion inhibitor for water reuse in power plants, characterized in that: Measured by mass percentage, the ingredients of the scale inhibitor and corrosion inhibitor include: 5.0-20.0% of polyepoxysuccinic acid, 1.0-5.0% of sodium gluconate, 5-25% of sulfonic acid copolymer, 2.0-10.0% of molybdate, 5.0-10.0% of imidazoline derivative, 1.0-2.0% of pH regulator and the balance of deionized water; the total proportion of each component is 100%.

2. The environmentally friendly scale and corrosion inhibitor for water reuse in power plants according to claim 1, characterized in that: The limiting viscosity of the polyepoxysuccinic acid is 0.025 to 0.035 dL / g.

3. The environmentally friendly scale and corrosion inhibitor for water reuse in power plants according to claim 1, characterized in that: The sulfonic acid copolymer is one or more of acrylic acid-styrene sulfonic acid copolymer, acrylic acid-maleic acid-methallyl copolymer, hydroxyethyl methacrylate-acrylamide-methacrylsulfonic acid copolymer, itaconic acid-acrylamide-methacrylsulfonic acid copolymer and maleic acid-propylene sulfonate copolymer.

4. The environmentally friendly scale and corrosion inhibitor for water reuse in power plants according to claim 1, characterized in that: The molybdate is one or more of sodium molybdate, ammonium molybdate and potassium molybdate.

5. The environmentally friendly scale and corrosion inhibitor for water reuse in power plants according to claim 1, characterized in that: The pH adjuster is one or more of citric acid, acetic acid and oxalic acid.

6. The method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in power plants according to any one of claims 1 to 5, characterized in that: The following steps are involved: Mixing molybdate, sodium gluconate and deionized water according to the mass percentage of claim 1 to obtain a sodium gluconate solution; Polyepoxysuccinic acid, sulfonic acid copolymer and imidazoline derivative are added to sodium gluconate solution, ultrasonically treated, heated and stirred, cooled after stirring, pH regulator is added, stirred and filtered to obtain environmentally friendly scale inhibitor and corrosion inhibitor for water reuse in power plants.

7. The method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in power plants according to claim 6, characterized in that: The temperature of the sodium gluconate solution is 40-60° C.; the time of the ultrasonic treatment is 30-60 min.

8. The method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in power plants according to claim 6, characterized in that: The temperature was raised to 85°C and stirred for 60 min. After stirring, the temperature was lowered to 30°C and the pH adjuster was added.

9. The method for preparing an environmentally friendly scale and corrosion inhibitor for water reuse in power plants according to claim 6, characterized in that: The preparation method of the imidazoline derivative is: Heat 0.2 mol of nonanoic acid and 40 mL of toluene to 150-160°C with stirring, react for 1 hour, heat to 200°C, slowly add 0.2 mol of diethylenetriamine, react for 3 hours, cool to 120°C, dropwise add 0.10 mol of benzyl chloride, react at 140°C with stirring for 3-4 hours, stop heating, remove unreacted benzyl chloride by microvacuum device for 1 hour, and obtain an imidazoline derivative.

10. The use of an environmentally friendly scale and corrosion inhibitor for water reuse in a power plant as claimed in any one of claims 1 to 5, characterized in that: The environmentally friendly scale and corrosion inhibitor for water reuse in power plants is used as a chemical agent for stabilizing water quality in a circulating cooling water system and preventing corrosion of metal parts.