CN107244753A - The special special efficacy environment-friendly type organic anti-scale corrosion inhibiter of heat supply network of steam power plant - Google Patents

Abstract

The invention relates to a special-effect and environment-friendly organic scale and corrosion inhibitor specially used for the primary heating network of a thermal power plant, which belongs to a scale and corrosion inhibitor. 2-phosphonobutane-1,2,4-tricarboxylic acid 20mg/L; poly 1-phosphono-1,2,3-tricarboxybutane 50mg/L; ammonium molybdate 5mg/L; Sodium Ascorbate 5mg/L; Zinc Sulfate 3mg/L; Butyl Glycol 100mg/L; Benzotriazole 1mg/L; Sodium Dodecylbenzene Sulfonate 50mg/L; Ethoxylated Sodium Alkyl Sulfate 20mg/L; fatty alcohol polyoxyethylene ether 15mg/L; polyoxyethylene oxypropylene glycerin 1mg/L. The advantage is that it is not sensitive to changes in electrolyte concentration and pH in water; it can quickly capture a large number of metal ions, and is suitable for water environments with high hardness, high alkalinity, and large temperature changes; it is suitable for both copper and copper-free systems; low cost, high cost The amount of ingredients is small; it has a good cleaning effect on the inlet of the heat exchanger with a lot of organic matter and slime, effectively preventing under-scale corrosion and tube sheet corrosion, and the corrosion rate is far lower than the standard value; scale inhibition, corrosion inhibition and descaling Excellent effect, low phosphorus and environmental protection.

Description

Special effect and environment-friendly organic scale and corrosion inhibitor for primary heating network of thermal power plant

technical field

The invention belongs to a scale and corrosion inhibitor and belongs to the field of water treatment in thermal power plants.

Background technique

Centralized heating is generally used in winter in northern my country. Since there is no domestic heating system water quality and heating network operation management standards, each heating network system is managed based on experience. The demineralized water used as supplementary water is often replaced by raw water due to water shortage. Therefore The heat exchange equipment and the main pipeline are frequently corroded due to scaling. At present, the scale and corrosion inhibitors sold in the market have poor effect and high cost. Therefore, in order to save costs, many enterprises do not purchase scale and corrosion inhibitors and do not carry out any anti-corrosion treatment, which leads to intensified corrosion accidents. The leaking and bursting pipes caused by this not only affect the normal heating of users, but also cause huge economic losses. The life of equipment is greatly shortened, and the main pipeline of some heating networks can only reach 1/3-1/2 of the design life.

The development of scale and corrosion inhibitors has gone through the development of inorganic and organic copolymers, from high phosphorus and low phosphorus to no phosphorus. At present, it is rare to use a single scale and corrosion inhibitor in water treatment. The reason is that although The use of low-phosphorus chemicals is easy to meet the environmental protection requirements, but the application effect is often not as good as that of high-phosphorus chemicals. Therefore, composite scale and corrosion inhibitors are regarded as a technological breakthrough and become the most widely studied and used water treatment agent. The winter heating in Jilin Province mainly adopts power station boilers with a rated outlet steam pressure greater than 3.8MPa, which are connected to the heating network through heat exchangers. The water supply temperature of a heating network operation is 110-150°C, and the return water temperature is 40-70°C. The water quality is characterized by large temperature changes, high hardness, high alkalinity, and high pH value. The primary network pipes have been facing serious corrosion and scaling problems all year round, resulting in damage to the heating network and accidents of stopping heating in winter many times.

Contents of the invention

The invention provides a special-effect and environment-friendly organic scale and corrosion inhibitor for the primary heating network of a thermal power plant, which can be applied to the primary heating network constructed of various materials such as 304 stainless steel, copper and carbon steel, so as to solve the structural problems of various primary heating networks. Scale corrosion problem.

The technical scheme that the present invention takes is: take water as solvent, and the component composition in the aqueous solution is as follows:

Organic phosphine scale inhibitor: 2-phosphonobutane-1,2,4-tricarboxylic acid 10~30mg/L;

Polymer low phosphine scale inhibitor: poly 1-phosphonic acid-1,2,3-tricarboxybutane 40~60mg/L;

Carbon steel corrosion inhibitor: ammonium molybdate 4~6mg/L;

Oxygen scavenger: sodium erythorbate 4-6mg/L;

Cathodic precipitation model corrosion inhibitor: zinc sulfate 1~3mg/L;

Co-solvent: butyl glycol 100~300mg/L;

Copper corrosion inhibitor: benzotriazole 1~3mg/L;

Anionic surfactant: sodium dodecylbenzenesulfonate 40~60mg/L;

Anionic surfactant: Sodium ethoxylated alkyl sulfate 10~30mg/L;

Nonionic surfactant: fatty alcohol polyoxyethylene ether 5~15mg/L;

Antifoaming agent: polyoxyethylene oxypropylene glycerin 1~3mg/L.

Preferably: using water as a solvent, the composition of the components in the aqueous solution is as follows:

Organic phosphine scale inhibitor: 2-phosphonobutane-1,2,4-tricarboxylic acid 20mg/L;

Polymer low phosphine scale inhibitor: poly 1-phosphonic acid-1,2,3-tricarboxybutane 50mg/L;

Carbon steel corrosion inhibitor: ammonium molybdate 5mg/L;

Oxygen scavenger: sodium erythorbate 5mg/L;

Cathodic precipitation model corrosion inhibitor: zinc sulfate 3mg/L;

Co-solvent: butyl glycol 100mg/L;

Copper corrosion inhibitor: benzotriazole 1mg/L;

Anionic surfactant: sodium dodecylbenzenesulfonate 50mg/L;

Anionic surfactant: sodium ethoxylated alkyl sulfate 20mg/L;

Nonionic surfactant: fatty alcohol polyoxyethylene ether 15mg/L;

Defoamer: polyoxyethylene oxypropylene glycerin 1mg/L.

In the present invention, 2-phosphonobutane-1,2,4-tricarboxylic acid is an organic phosphine scale inhibitor, and poly 1-phosphonobutane-1,2,3-tricarboxybutane is a high molecular weight low phosphine scale inhibitor. Scale agent, functional groups form chelates with Ca, Mg, Fe, Ba and other metal ions to reduce the particle size of CaCO ₃ , thereby affecting crystal deposition, preventing hard scale formation, and forming a dense molecular film on the metal surface to prevent further corrosion corrosion. At the same time, the presence of covalent and non-covalent bonds between small molecules and polymer agents can form a multiple network structure to capture various inorganic and organic impurities and slime to prevent sedimentation. Ammonium molybdate is a corrosion inhibitor for carbon steel and can form Fe-MoO4-Fe ₂ O ₃ film. Sodium erythorbate is an oxygen scavenger, which can effectively prevent the cathodic corrosion of oxygen. Zinc sulfate is a model corrosion inhibitor for cathodic precipitation. Butyl glycol, co-solvent. Benzotriazole is a copper corrosion inhibitor. Sodium Dodecylbenzene Sulfonate, Sodium Alkyl Ethoxylate Sulfate is an anionic surfactant. Fatty alcohol polyoxyethylene ether is a nonionic surfactant. Polyoxyethylene oxypropylene glycerin is a defoamer.

The action mechanism of each component is to clean the organic matter and slime in the pipeline and the metal surface in the heat exchanger through the decontamination effect of the surfactant, and at the same time change the surface tension between the scale and corrosion inhibitor film and the metal. Good for forming a protective film. The chelating effect of carboxylic acid groups and phosphonic acid groups in organic phosphine scale inhibitors and metal ions in water can disperse and soften CaCO ₃ . A large number of carboxylic acid groups in the polymer antiscalant can enhance the chelation with metal ions in high hardness and high alkalinity water. In addition to dispersing and softening scale, it can also form a relatively dense polymer film on the metal surface, effectively Prevent under-deposit corrosion, good stability, high temperature resistance. The composite form of small molecule and polymer antiscalant forms a multiple network structure through covalent bonds and non-covalent bonds, and has strong capture ability. The addition of zinc salt makes up for the slow film-forming shortcomings of organic agents, and can quickly form inorganic films. Through chemical and physical actions, and through the synergistic effect of chemical bonds, hydrogen bonds, and van der Waals forces, the compound drug can take advantage of the advantages of each component, and adjust the electrode potential and surface tension through the complementarity of each component to achieve the ultimate scale and corrosion inhibition. Excellent effect.

The present invention uses water as a solvent, and the low-phosphorus organic polycarboxylic acid type multi-polymer scale and corrosion inhibitor requires that the performance of the agent has the characteristics of scale and corrosion inhibition of organic phosphonic acid and carboxylic acid polymers, and at the same time it should have Stable structure (containing C-P bond), low phosphorus content, low toxicity, no pollution to the environment, good compatibility with other chemicals, etc., suitable for use under harsh conditions such as high hardness, high alkalinity, high pH value, and large temperature changes .

The present invention has the advantages of (1) insensitivity to changes in electrolyte concentration and pH in water; (2) can quickly capture a large number of metal ions, and is suitable for water environments with high hardness, high alkalinity and large temperature changes; (3) has copper and Copper-free systems are applicable; (4) low cost, less high-cost components used; (5) better cleaning effect on the inlet of heat exchangers with more organic matter and slime, effectively preventing corrosion under scale and pipe The plate is corroded, and the corrosion rate is much lower than the standard value. (6) Excellent scale and corrosion inhibition and descaling effect, low phosphorus and environmental protection.

detailed description

Example 1

The composition of the components in the aqueous solution is as follows:

Organic phosphine scale inhibitor: 2-phosphonobutane-1,2,4-tricarboxylic acid 10mg/L;

Polymer low phosphine scale inhibitor: poly 1-phosphonic acid-1,2,3-tricarboxybutane 40mg/L;

Carbon steel corrosion inhibitor: ammonium molybdate 4mg/L;

Oxygen scavenger: sodium erythorbate 4mg/L;

Cathodic precipitation model corrosion inhibitor: zinc sulfate 1mg/L;

Co-solvent: butyl glycol 100mg/L;

Copper corrosion inhibitor: benzotriazole 1mg/L;

Anionic surfactant: sodium dodecylbenzenesulfonate 40mg/L;

Anionic surfactant: sodium ethoxylated alkyl sulfate 10mg/L;

Nonionic surfactant: fatty alcohol polyoxyethylene ether 5mg/L;

Defoamer: polyoxyethylene oxypropylene glycerin 1mg/L.

Example 2

The composition of the components in the aqueous solution is as follows:

Organic phosphine scale inhibitor: 2-phosphonobutane-1,2,4-tricarboxylic acid 20mg/L;

Polymer low phosphine scale inhibitor: poly 1-phosphonic acid-1,2,3-tricarboxybutane 50mg/L;

Carbon steel corrosion inhibitor: ammonium molybdate 5mg/L;

Oxygen scavenger: sodium erythorbate 5mg/L;

Cathodic precipitation model corrosion inhibitor: zinc sulfate 2mg/L;

Co-solvent: butyl glycol 200mg/L;

Copper corrosion inhibitor: benzotriazole 2mg/L;

Anionic surfactant: sodium dodecylbenzenesulfonate 50mg/L;

Anionic surfactant: sodium ethoxylated alkyl sulfate 20mg/L;

Nonionic surfactant: fatty alcohol polyoxyethylene ether 10mg/L;

Defoamer: polyoxyethylene oxypropylene glycerin 2mg/L.

Example 3

The composition of the components in the aqueous solution is as follows:

Organic phosphine scale inhibitor: 2-phosphonobutane-1,2,4-tricarboxylic acid 30mg/L;

Polymer low phosphine scale inhibitor: poly 1-phosphonic acid-1,2,3-tricarboxybutane 60mg/L;

Carbon steel corrosion inhibitor: ammonium molybdate 6mg/L;

Oxygen scavenger: sodium erythorbate 6mg/L;

Cathodic precipitation model corrosion inhibitor: zinc sulfate 3mg/L;

Co-solvent: butyl glycol 300mg/L;

Copper corrosion inhibitor: benzotriazole 3mg/L;

Anionic surfactant: sodium dodecylbenzenesulfonate 60mg/L;

Anionic surfactant: sodium ethoxylated alkyl sulfate 30mg/L;

Nonionic surfactant: fatty alcohol polyoxyethylene ether 15mg/L;

Defoamer: polyoxyethylene oxypropylene glycerin 3mg/L.

Example 4

The composition of the components in the aqueous solution is as follows:

Organic phosphine scale inhibitor: 2-phosphonobutane-1,2,4-tricarboxylic acid 20mg/L;

Polymer low phosphine scale inhibitor: poly 1-phosphonic acid-1,2,3-tricarboxybutane 50mg/L;

Carbon steel corrosion inhibitor: ammonium molybdate 5mg/L;

Oxygen scavenger: sodium erythorbate 5mg/L;

Cathodic precipitation model corrosion inhibitor: zinc sulfate 3mg/L;

Co-solvent: butyl glycol 100mg/L;

Copper corrosion inhibitor: benzotriazole 1mg/L;

Anionic surfactant: sodium dodecylbenzenesulfonate 50mg/L;

Anionic surfactant: sodium ethoxylated alkyl sulfate 20mg/L;

Nonionic surfactant: fatty alcohol polyoxyethylene ether 15mg/L;

Defoamer: polyoxyethylene oxypropylene glycerin 1mg/L.

The present invention will be further described below by experiment and application.

1. Experimental content:

1.1 formula test of the present invention

The primary heating network water sample of a thermal power plant was taken at 70°C, and the test results are shown in Table 1.

Table 1 Water samples of heating network

Project indicators value pH 8.56 Hardness/(mg·L ^-1 ) 550 Turbidity/NTU 6.10 Alkalinity/(mg·L ^-1 ) 480 Cl ^- /(mg·L ^-1 ) 71 Solid solution mass concentration/(mg·L ^-1 ) 1000 Total iron/(mg·L ^-1 ) 0.2

Calculation of scaling or corrosion tendency by calculating the Ryzna Stability Index (I _RSI ):

_IRSI = 2pHs-pH

pHs=(9.30+A+B)-(C+D)

In the formula: A is the total dissolved solids coefficient; B is the temperature coefficient; C is the calcium hardness coefficient; D to M are the alkalinity coefficients.

According to the measured results in Table 1, it is calculated that I _RSI =2.1<3.7, indicating that the water sample has a serious scaling tendency.

Through the "Determination of Corrosion Inhibition Performance of Water Treatment Agents-Rotary Coupon Method" (GB/T18175-2014), the relevant tests for the determination of corrosion rate were carried out on the RCC-Ⅱ Rotary Coupon Corrosion Tester.

Table 2 The codes of each component of the drug

Table 3 Effects of scale inhibitor concentration compatibility on scale inhibition effect

Table 4 Influence of concentration compatibility of descaling components on descaling effect

After mixing the formula with the best scale inhibition rate and the formula with the highest descaling effect, it is found that the scale inhibition rate, corrosion inhibition rate and scale removal rate are all greater than when they are used alone.

Table 5 Scale inhibition, corrosion inhibition and descaling effects of optimal concentration compatibility

1.2 The effect stability experiment of the best formula

The performance experiment of the present invention is mainly to observe the scale inhibition, corrosion inhibition, scale removal rate and effect by adjusting the electrolyte concentration, pH change, hardness, alkalinity, temperature and copper ion concentration of the water sample.

CJJ34 only stipulates the water quality of the supplementary water of the heating network, and has no clear requirements for the operating water of the heating network.

Since there is no domestic water quality standard for heating network operation water, according to the "Code for Design of Industrial Circulating Cooling Water Treatment" GB50050-2007, the corrosion rate of carbon steel should be less than 0.075mm/a, and the corrosion rate of copper, copper alloy and stainless steel pipe walls should be less than 0.005mm /a, the water quality requirements for intercooled open cooling water are shown in Table 5, which can be selectively applied to the running water of the heating network.

Table 6 Operating water standard value

Select different items in the scope of this standard to test the scale inhibition rate, corrosion inhibition rate and scale removal rate. The results are shown in Tables 7-12.

Table 7 Effect of chloride ions on scale inhibition rate, corrosion inhibition rate and scale removal rate

Cl ^- (mg/L) ion concentration Scale inhibition rate (%) Corrosion inhibition rate (%) Descaling rate (%) 700 97.22 97.21 95.32 600 97.30 97.60 95.44 500 97.43 97.86 95.65 400 97.99 98.01 95.88 300 98.02 98.13 95.92 200 98.12 98.21 96.02 100 98.23 98.36 96.43 5 99.00 99.21 98.69

Table 8 Effect of sulfate ion on scale inhibition rate, corrosion inhibition rate and scale removal rate

SO ₄ ^2- (mg/L) ion concentration Scale inhibition rate (%) Corrosion inhibition rate (%) Descaling rate (%) 500 94.21 94.41 95.12 400 96.33 97.60 95.34 300 97.43 97.82 95.57 200 97.92 98.01 95.88 150 98.12 98.13 96.02 100 98.19 98.21 96.52 50 98.78 98.46 97.33 5 99.00 99.21 98.69

Table 9 Effect of pH value on scale inhibition rate, corrosion inhibition rate and scale removal rate

pH Scale inhibition rate (%) Corrosion inhibition rate (%) Descaling rate (%) 6.5 97.21 97.11 96.01 7.5 97.45 97.76 96.09 8.5 98.21 98.12 96.21 9.5 98.02 97.64 96.00 10.5 98.00 97.56 95.32

Table 10 Effect of calcium hardness on scale inhibition rate, corrosion inhibition rate and scale removal rate

YD _Ca (mg/L) Scale inhibition rate (%) Corrosion inhibition rate (%) Descaling rate (%) 1100 96.21 96.21 95.11 900 96.45 96.45 95.39 700 97.21 97.21 95.71 500 97.02 97.02 95.90 300 98.00 98.00 95.99 100 98.21 98.21 96.03 50 98.33 98.33 96.12

Table 11 Effect of temperature on scale inhibition rate, corrosion inhibition rate and scale removal rate

T(°C) Scale inhibition rate (%) Corrosion inhibition rate (%) Descaling rate (%) 40 98.45 98.23 95.32 50 98.25 98.15 96.21 60 98.12 98.11 96.31 70 98.03 97.96 96.29 80 97.50 97.49 96.43 90 97.25 97.33 96.21 100 95.52 95.24 95.45 110 95.32 95.21 95.21 120 95.13 95.10 95.13 130 94.21 94.89 94.84 140 94.01 94.54 94.11 150 94.00 94.25 94.02

Table 12 Effect of copper ions on scale inhibition rate, corrosion inhibition rate and scale removal rate

Cu ²⁺ (mg/L) ion concentration Scale inhibition rate (%) Corrosion inhibition rate (%) Descaling rate (%) 0.2 96.78 96.39 95.34 0.1 97.54 97.56 96.21 0.05 97.92 97.74 96.22 0 98.12 98.33 96.30

According to the above experimental results, it is found that the application effect of the scale and corrosion inhibitor is not greatly affected by the electrolyte concentration, pH value, hardness, alkalinity, temperature, copper ion concentration and other environmental conditions of the water sample. The effect of scale inhibition, corrosion inhibition and scale removal is excellent and stable, and the best effect can reach more than 98%.

2. Application examples

Example 1

A thermal power plant in Changchun has a primary heating network, the pipes are made of 304 stainless steel, and the circulating water volume is 340t/h. The supply water of the heating network meets the requirements of GB/T 12145 "Water Vapor Quality of Thermal Power Generating Units and Steam Power Equipment" and CJJ 34 "Code for Design of Urban Heating Network Management", Chapter 4). See Table 13.

Table 13 Water quality standards for heating network make-up water

Take a water sample of heating network operation at 70°C, and the test results are shown in Table 14.

Table 14 Water samples

Project indicators value pH 9.46 Hardness/(mg·L ^-1 ) 500 Turbidity/NTU 6.20 Alkalinity/(mg·L ^-1 ) 500 Cl ^- /(mg·L ^-1 ) 80 Solid solution mass concentration/(mg·L ^-1 ) 900 Total Iron mg/L 0.2

Calculation of scaling or corrosion tendency by calculating the Ryzna Stability Index (I _RSI ):

_IRSI = 2pHs-pH

pHs=(9.30+A+B)-(C+D)

In the formula: A is the total dissolved solids coefficient; B is the temperature coefficient; C is the calcium hardness coefficient; D to M are the alkalinity coefficients.

According to the results in Table 14, I _RSI <3.7 is calculated, indicating that the water sample has a serious scaling tendency. And there were many pipe burst accidents caused by under-deposit corrosion.

After the addition of the present invention in 2014, the I _RSI rose to 6.0, the scaling tendency was weakened, and the scale inhibition, corrosion inhibition, and scaling rates reached 98.11%, 98.21%, and 97.32%, respectively. After adding the operating water, the detected phosphorus content is only 0.01%, which is far less than the conventional value of 5%. Leakage of the pipe wall will not pollute the surrounding environment. It has been in safe operation for more than 3 years. The pipe cutting inspection and hanging piece test show that the corrosion rate of the stainless steel pipe wall is only 0.002mm/a, which is less than the specified value of 0.005mm/a. Ensure the safety of production.

Example 2

A thermal power plant in Baishan has a primary heating network, the pipes are made of carbon steel, and the circulating water volume is 240t/h. The supply water of the heating network meets the requirements of GB/T 12145 "Water Vapor Quality of Thermal Power Generating Units and Steam Power Equipment" and CJJ 34 "Code for Design of Urban Heating Network Management", Chapter 4). See Table 15.

Table 15 Water quality standards for heating network make-up water

Take a water sample of heating network operation at 50°C, and the test results are shown in Table 16.

Table 16 Water samples

Calculation of scaling or corrosion tendency by calculating the Ryzna Stability Index (I _RSI ):

_IRSI = 2pHs-pH

pHs=(9.30+A+B)-(C+D)

In the formula: A is the total dissolved solids coefficient; B is the temperature coefficient; C is the calcium hardness coefficient; D to M are the alkalinity coefficients.

According to the results in Table 16, I _RSI <3.7 is calculated, indicating that the water sample has a serious scaling tendency. And there were many pipe burst accidents caused by under-deposit corrosion.

After the addition of the present invention in 2015, the I _RSI rose to 6.0, the scaling tendency was weakened, and the scale inhibition, corrosion inhibition, and scaling rates reached 98.27%, 98.23%, and 97.45%, respectively. After adding the operating water, the detected phosphorus content is only 0.005%, which is far less than the specified value of 5%. Leakage of the pipe wall will not pollute the surrounding environment. It has been in safe operation for more than 2 years. The pipe cutting inspection and hanging piece test show that the corrosion rate of the carbon steel pipe wall is only 0.050mm/a, which is less than the specified value of 0.075mm/a, which ensures the safe production.

Example 3

A thermal power plant in Baicheng has a primary heating network, the pipes are made of copper, and the circulating water volume is 240t/h. The supply water of the heating network meets the requirements of GB/T 12145 "Water Vapor Quality of Thermal Power Generating Units and Steam Power Equipment" and CJJ 34 "Code for Design of Urban Heating Network Management", Chapter 4). See Table 17.

Table 17 Water quality standards for heating network make-up water

Take a water sample of heating network operation at 60°C, and the test results are shown in Table 18.

Table 18 Water samples

Project indicators value pH 9.5 Hardness/(mg·L ^-1 ) 700 Turbidity/NTU 9.10 Alkalinity/(mg·L ^-1 ) 900 Cl ^- /(mg·L ^-1 ) 79 Solid solution mass concentration/(mg·L ^-1 ) 1000 Total iron/(mg·L ^-1 ) 0.1

Calculation of scaling or corrosion tendency by calculating the Ryzna Stability Index (I _RSI ):

_IRSI = 2pHs-pH

pHs=(9.30+A+B)-(C+D)

In the formula: A is the total dissolved solids coefficient; B is the temperature coefficient; C is the calcium hardness coefficient; D to M are the alkalinity coefficients.

According to the results in Table 17, I _RSI <3.7 is calculated, indicating that the water sample has a serious scaling tendency. And there were many pipe burst accidents caused by under-deposit corrosion.

After the addition of the present invention in 2014, the I _RSI rose to 6.0, the scaling tendency was weakened, and the scale inhibition, corrosion inhibition, and scaling rates reached 98.17%, 98.43%, and 97.27%, respectively. After adding the operating water, the detected phosphorus content is only 0.01%, which is far less than the conventional value of 5%. Leakage of the pipe wall will not pollute the surrounding environment. It has been in safe operation for more than 3 years. The pipe cutting inspection and hanging piece test show that the corrosion rate of the copper pipe wall is only 0.001mm/a, which is less than the specified value of 0.005mm/a, which ensures the safe production.

Through the application of examples, the present invention can be applied in the primary heat network of heat exchange pipes and heat exchangers using 304 stainless steel, carbon steel, and copper-containing pipe fittings, with excellent performance and stable effect.

Claims (2)

1. A special-effect environment-friendly organic scale and corrosion inhibitor for the primary heating network of a thermal power plant, characterized in that: water is used as a solvent, and the components in the aqueous solution are composed as follows: Organic phosphine scale inhibitor: 2-phosphonobutane-1,2,4-tricarboxylic acid 10~30mg/L; Polymer low phosphine scale inhibitor: poly 1-phosphonic acid-1,2,3-tricarboxybutane 40~60mg/L; Carbon steel corrosion inhibitor: ammonium molybdate 4~6mg/L; Oxygen scavenger: sodium erythorbate 4-6mg/L; Cathodic precipitation model corrosion inhibitor: zinc sulfate 1~3mg/L; Co-solvent: butyl glycol 100~300mg/L; Copper corrosion inhibitor: benzotriazole 1~3mg/L; Anionic surfactant: sodium dodecylbenzenesulfonate 40~60mg/L; Anionic surfactant: Sodium ethoxylated alkyl sulfate 10~30mg/L; Nonionic surfactant: fatty alcohol polyoxyethylene ether 5~15mg/L; Antifoaming agent: polyoxyethylene oxypropylene glycerin 1~3mg/L. 2. According to claim 1, a special-effect environment-friendly organic scale and corrosion inhibitor for the primary heating network of a thermal power plant is characterized in that: water is used as a solvent, and the composition of the aqueous solution is as follows: Organic phosphine scale inhibitor: 2-phosphonobutane-1,2,4-tricarboxylic acid 20mg/L; Polymer low phosphine scale inhibitor: poly 1-phosphonic acid-1,2,3-tricarboxybutane 50mg/L; Carbon steel corrosion inhibitor: ammonium molybdate 5mg/L; Oxygen scavenger: sodium erythorbate 5mg/L; Cathodic precipitation model corrosion inhibitor: zinc sulfate 3mg/L; Co-solvent: butyl glycol 100mg/L; Copper corrosion inhibitor: benzotriazole 1mg/L; Anionic surfactant: sodium dodecylbenzenesulfonate 50mg/L; Anionic surfactant: sodium ethoxylated alkyl sulfate 20mg/L; Nonionic surfactant: fatty alcohol polyoxyethylene ether 15mg/L; Defoamer: polyoxyethylene oxypropylene glycerin 1mg/L.