A supplementing reverse osmosis water heating pipe network corrosion inhibitor and method

Abstract

The application discloses a kind of supplementary reverse osmosis water heat supply pipe network corrosion inhibitor and method, belong to the field of thermal power system equipment corrosion prevention, the corrosion inhibitor is used to slow down and inhibit heat exchange surface scale and carbon steel corrosion in heat network system;By weight percentage, including: amino trimethyl phosphonic acid tetrasodium 10-30%, 2-hydroxy phosphono acetic acid 10-15%, zinc sulfate 5-20%, sodium molybdate 1-5%, the rest water.This kind of corrosion inhibitor has certain scale inhibition effect, can provide scale inhibition effect to relatively low hardness water quality condition.Each component in corrosion inhibitor has good temperature resistance, can produce good corrosion inhibition effect at high temperature (<150 DEG C).

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of anti-corrosion technology of thermal power system equipment, and particularly relates to a supplementary reverse osmosis water heat supply pipe network corrosion inhibitor and method. BACKGROUND

[0002] The heat supply pipe network is an important infrastructure for ensuring the winter heating of residents in the north, mainly including heat exchange equipment, heat network circulating water pipelines and circulating water pumps, etc. The safe and stable operation of the heat supply pipe network is crucial for heat transmission, and about 70% of the accidents of the heat supply pipe network are caused by material corrosion.

[0003] At present, the water supplement sources of the heat supply pipe network can be divided into three categories, namely, supplement of raw water, supplement of softened water and supplement of reverse osmosis water. Combined heat and power generation is a new breakthrough in the development of thermal power plants, and the first station heater of part of the heat supply pipe network is maintained and operated by the power plant. The strong water treatment capacity of the power plant can guarantee the supplement of reverse osmosis water in the first-stage pipe network. Using reverse osmosis water as the supplement water has many advantages. Since the reverse osmosis water removes most of the hardness in the raw water and reduces the content of chloride ions, the problems of scale formation and pitting corrosion on the heat exchange surface are better solved. However, compared with the softened water, the corrosion rate of carbon steel is higher after the removal of alkalinity and hardness by the reverse osmosis water. Therefore, the corrosion of carbon steel material in the heat supply pipe network system using reverse osmosis water as the supplement water is the primary problem faced by the system.

[0004] The heat supply pipe network system often contains hundreds of thousands of tons of water. During the period of large water loss and pipe network water injection, the water quality cannot be guaranteed, and therefore there is still a small amount of scale formation risk in the pipe network. The buffering capacity of the reverse osmosis water system is poor, and the pH value is more prone to fluctuation. Although there are heat network scale and corrosion inhibitors on the market, their main components are still scale inhibitors, and for the system supplementing reverse osmosis water, corrosion inhibition is the primary requirement. In addition, the buffering capacity of the reverse osmosis water is poor, and after adding the acidic scale and corrosion inhibitor, the pH value of the heat network circulating water is prone to fluctuation.

[0005] Secondly, there are scale and corrosion inhibitors on the market, but the use environment temperature is less than 100 DEG C. With the increase of the water supply temperature of the heat supply pipe network, the highest water supply temperature has reached 130 DEG C, and the corrosion rate of the pipe is greatly improved, which puts higher requirements on the corrosion inhibition and heat decomposition resistance of the corrosion inhibitor. Due to these two reasons, there is no corrosion inhibitor for the high-temperature heat network system using reverse osmosis water as the supplement water at present. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a special corrosion inhibitor for reducing and inhibiting the corrosion of carbon steel in the high-temperature heat supply pipe network using reverse osmosis as the supplement water, which overcomes the shortcomings of the prior art, and the corrosion inhibitor has a certain scale inhibition effect and can provide scale inhibition effect for relatively low hardness water quality conditions.

[0007] The technical scheme adopted by the present application is:

[0008] The first aspect of the present application provides a supplement reverse osmosis water heat supply pipe network corrosion inhibitor, which is used in a heat network system using reverse osmosis water as make-up water, and includes, by weight percentage:

[0009] Tetrasodium aminotrimethylene phosphonate 10-30%

[0010] 2-Hydroxyphosphonooxyacetic acid 10-15%

[0011] Zinc sulfate 5-20%

[0012] Sodium molybdate 1-5%

[0013] The balance is water.

[0014] As a further improvement of the present application, it includes, by weight percentage:

[0015] Tetrasodium aminotrimethylene phosphonate 8-20%

[0016] 2-Hydroxyphosphonooxyacetic acid 10-12%

[0017] Zinc sulfate 5-12%

[0018] Sodium molybdate 3-5%

[0019] The balance is water.

[0020] As a further improvement of the present application, it includes, by weight percentage:

[0021] Tetrasodium aminotrimethylene phosphonate 15%

[0022] 2-Hydroxyphosphonooxyacetic acid 10%

[0023] Zinc sulfate 10%

[0024] Sodium molybdate 4%

[0025] The balance is water.

[0026] As a further improvement of the present application, the use temperature of the scale and corrosion inhibitor is 100-150℃.

[0027] As a further improvement of the present application, the pipe material of the heat network system is carbon steel.

[0028] The second aspect of the present application provides a dosing method of a supplement reverse osmosis water heat supply pipe network corrosion inhibitor, which includes the following steps:

[0029] Tetrasodium aminotrimethylene phosphonate, 2-hydroxyphosphonooxyacetic acid, zinc sulfate, sodium molybdate and water are prepared in a dosing tank according to weight percentage, and then mixed uniformly and injected into the heat supply pipe network system by a metering pump.

[0030] As a further improvement of the present application, the corrosion inhibitor is added at a dosage of 50-200 mg / L.

[0031] As a further improvement of the present application, the mixed solution is injected into the heating pipe network circulating water system by a metering pump with a flow rate of 400 L / h.

[0032] As a further improvement of the present application, the temperature of the heating pipe network circulating water system is 100-150℃.

[0033] The beneficial effects of the present application are:

[0034] The present application is directed to a high-temperature heating pipe network system using reverse osmosis water as make-up water, and the corrosion inhibitor component used in the present application contains ATMP·Na4, which is a neutral sodium salt of ATMP and can prevent the formation of scale-forming salts in water, especially calcium carbonate scale. ATMP·Na4 is suitable for use in circulating cooling water systems in thermal power plants and oil refineries, oilfield reinjection water systems, and reverse osmosis membrane scale inhibitors. ATMP·Na4 also has good compatibility with other additives. ATMP·Na4 is particularly suitable for use in neutral to acidic formulations without the generation of ammonia odor. HPAA has good chemical stability, is not easily hydrolyzed, and is not easily destroyed by acids and bases, making it safe and reliable to use, non-toxic, and non-polluting. HPAA can improve the solubility of zinc and has very strong corrosion inhibition, with better corrosion inhibition performance than HEDP and EDTMP. HPAA is mainly used as a cathodic corrosion inhibitor for metals and is suitable for use as a corrosion inhibitor for low-hardness, easily-corroded water. The addition of zinc sulfate and sodium molybdate in the present formulation can form a synergistic effect with HPAA to improve the scale inhibition effect of carbon steel. The components in the corrosion inhibitor of the present application are environmentally friendly and low in toxicity, do not contain nitrite salts, and can reduce damage to the ecological environment and harm to the health of operating personnel. The components in the corrosion inhibitor have good temperature resistance and can produce good corrosion inhibition effect at high temperatures (<150℃). BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or the prior art. Obviously, the drawings described below are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0036] Figure 1 A flow chart of a dosing method for supplementing a reverse osmosis water heating pipe network corrosion inhibitor is given. DETAILED DESCRIPTION

[0037] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, and not to limit the present application.

[0038] In the present application, the term "and / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone. Wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after it.

[0039] In the present application, "at least one" means one or more, and "multiple" means two or more. "At least one of the following" or similar expressions means any combination of these items, including any combination of single item or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can represent a, b, c, a~b (i.e. a and b), a~c, b~c, or a~b~c, wherein a, b, and c can be single or multiple.

[0040] It should be understood that in various embodiments of the present application, the size of the sequence number of the above processes does not mean the order of execution, and part or all of the steps can be executed in parallel or in sequence. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0041] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0042] The weight of the related components mentioned in the specification of the embodiments of the present application can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of each component. Therefore, as long as the content of the related components in the specification of the embodiments of the present application is enlarged or reduced in proportion, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass mentioned in the specification of the embodiments of the present application can be µg, mg, g, kg, and other mass units commonly known in the chemical field.

[0043] The first object of the present application is to provide a supplementary reverse osmosis water heat supply pipe network corrosion inhibitor, which is used to slow down and inhibit the corrosion of carbon steel and the scaling of heat exchange surface in the heat network system. The corrosion inhibitor formula is composed of the following components with the following weight percentages:

[0044] Tetrasodium Aminotri(methylene Phosphonate) 10-30%

[0045] 2-Hydroxyphosphonocarboxylic Acid 10-15%

[0046] Zinc Sulfate 5-20%

[0047] Sodium Molybdate 1-5%

[0048] The balance is water.

[0049] The corrosion inhibitor is used to slow down and inhibit the fouling of the heat exchange surface and the corrosion of carbon steel in the heat network system; the corrosion inhibitor comprises, by weight percentage, tetrasodium aminotri(methylene phosphonate) ATMP·Na410-30%, 2-hydroxyphosphonocarboxylic acid HPAA 10-15%, zinc sulfate 5-20%, sodium molybdate 1-5%, and the balance is water.

[0050] The corrosion inhibitor has certain scale inhibition effect and can provide scale inhibition effect for relatively low-hardness water quality. The components in the corrosion inhibitor have good temperature resistance and can produce good corrosion inhibition effect at high temperature (< 150 DEG C).

[0051] The principle of the present application is as follows:

[0052] ATMP·Na4 is a neutral sodium salt of ATMP, which can prevent scale-forming salts in water from forming scale, especially calcium carbonate scale. ATMP·Na4 is suitable for circulating cooling water of thermal power plants and oil refineries, oilfield reinjection water systems, and scale inhibitors for reverse osmosis membranes.

[0053] ATMP·Na4 has good compatibility with other additives. ATMP·Na4 is particularly suitable for use in neutral to acidic formulations without ammonia odor.

[0054] HPAA has good chemical stability, is not easy to hydrolyze, and is not easy to be destroyed by acid and alkali, and is safe and reliable to use, non-toxic and non-polluting. HPAA can improve the solubility of zinc and has extremely strong corrosion inhibition effect. The corrosion inhibition performance of HPAA is higher than that of HEDP and EDTMP.

[0055] PAA is mainly used as a cathodic corrosion inhibitor for metals and is suitable for use as a corrosion inhibitor for low-hardness and easily-corroded water quality. The addition of zinc sulfate and sodium molybdate in the present formulation can form a synergistic effect with HPAA to improve the scale inhibition effect of carbon steel.

[0056] In the composition of the scale and corrosion inhibitor of the present application, the content of tetrasodium aminotri(methylene phosphonate) ATMP·Na4 can be 15-30%, 20-30%, 15-20%, 10-30%, 10-25%, for example, 15%, 18%, 20%, 22%, 25%, 26%, 28%, 30%, etc.

[0057] In the composition of the scale and corrosion inhibitor of the present invention, the content of 2-hydroxyphosphonoacetic acid (HPAA) can be 10-15%, 10-13%, 10-12%, 11-13%, 12-15%, 12-14%, for example: 10%, 11%, 12%, 13%, 14%, 15%, etc.

[0058] In the composition of the scale and corrosion inhibitor of the present invention, zinc sulfate can be 5-20%, 10-20%, 15-20%, 5-10%, 10-20%, 15-19%, 12-18%, for example: 5%, 8%, 10%, 12%, 18%, 19%, 20%, etc.

[0059] In the composition of the scale and corrosion inhibitor of the present invention, sodium molybdate can be 3-5%, 4-5%, 3-4%, for example: 3%, 4%, 5%, 3.5%, 4.5%, etc.

[0060] Preferably, the scale and corrosion inhibitor formulation consists of the following components by weight percentage:

[0061] Tetrasodium aminotrimethylphosphonate (ATMP·Na 48-20%)

[0062] 2-Hydroxyphosphonoacetic acid (HPAA) 10-12%

[0063] Zinc sulfate 5-12%

[0064] Sodium molybdate 3-5%

[0065] Remaining water.

[0066] The second objective of this invention is to provide a corrosion inhibitor and method for use in high-temperature heating pipe network systems that use reverse osmosis water as makeup water. The method includes two steps: preparing the corrosion inhibitor and adding the corrosion inhibitor to the heating pipe network system. The corrosion inhibitor is prepared by mixing tetrasodium aminotrimethylphosphonate (ATMP·Na4), 2-hydroxyphosphonoacetic acid (HPAA), zinc sulfate, sodium molybdate, and water in a dosing tank according to the weight percentage. After mixing, the mixture is injected into the heating pipe network system by a metering pump. The dosage of the corrosion inhibitor is 50-200 mg / L.

[0067] The corrosion inhibitor can slow down and inhibit the corrosion of carbon steel in a high-temperature heating pipe network using reverse osmosis as water replenishment, and has certain scale inhibition effect; the present application comprises two steps of preparation of the corrosion inhibitor and addition of the corrosion inhibitor, and the scale and corrosion inhibitor is prepared by mixing amino trimethylene phosphonic acid tetrasodium ATMP Na4, 2-hydroxy phosphono acetic acid HPAA, zinc sulfate, sodium molybdate and water in a dosing tank according to the weight percentage, and then injected into the heating pipe network system by a metering pump after mixing, and the dosage of the scale and corrosion inhibitor is 50-200 mg / L. The beneficial effects of the present application are that the scale and corrosion inhibitor contains neutral sodium salt and HPAA, the neutral sodium salt can prevent the formation of carbonate scale in water, HPAA can improve the solubility of zinc, and has good stability and strong corrosion inhibition effect; and the scale and corrosion inhibitor is environmentally friendly and low in toxicity, does not contain nitrite, and can reduce the damage to the ecological environment and the health damage to the operating personnel.

[0068] As shown in Figure 1 , the preparation steps of the scale and corrosion inhibitor are as follows:

[0069] Step 1, inject 1000L of water into the dosing tank. Add each component of the corrosion inhibitor to the dosing tank, and start the dosing tank stirring for 2 hours.

[0070] Step 2, use a metering pump to add the scale and corrosion inhibitor, and the flow rate of the dosage pump is 400L / h. Stop when the dosing amount in the equipment cooling water reaches the target value.

[0071] The present application will be further described in detail below in conjunction with examples, but not limit the scope of the present application.

[0072] Example 1:

[0073] (1) Test the corrosion rate of the material in the heating pipe network system before adding the corrosion inhibitor:

[0074] In the heating pipe network system using reverse osmosis water as water replenishment without adding the corrosion inhibitor, the corrosion rate of carbon steel material (Q235B) is tested, the test time is 72 hours, the test temperature is 130℃, and the hanging piece position flow rate is 3m / s. The results show that the corrosion rate of carbon steel Q235B in the heating pipe network system without adding the corrosion inhibitor is 1.2337mm / a.

[0075] (2) Test the corrosion rate of the material in the heating pipe network system after implementing the corrosion inhibitor corrosion prevention process:

[0076] For the heating pipe network system using reverse osmosis water as water replenishment, a corrosion inhibitor suitable for the system is added, and the corrosion inhibitor is composed of the following components by weight percentage:

[0077] Amino trimethylene phosphonic acid tetrasodium ATMP Na4 15%

[0078] 2-hydroxy phosphono acetic acid HPAA 10%

[0079] 10% zinc sulfate

[0080] Sodium molybdate 4%

[0081] Remaining water.

[0082] After preparing the corrosion inhibitor in the dosing tank and stirring thoroughly, it was added to the heating pipe network system using a dosing pump at a concentration of 150 mg / L. A 72-hour corrosion inhibition test was conducted using carbon steel test pieces in this environment. The test results showed that after adding the corrosion inhibitor, the corrosion rate of Q235B carbon steel in the heating pipe network system was less than 0.0422 mm / a, with a corrosion inhibition efficiency of 96.6%.

[0083] Example 2:

[0084] All other conditions and methods are the same as in Comparative Document 1. The specific formulation of the corrosion inhibitor is as follows:

[0085] For heating network systems that use reverse osmosis water as makeup water, a corrosion inhibitor suitable for this system is added. This corrosion inhibitor consists of the following components by weight percentage:

[0086] Tetrasodium aminotrimethylphosphonate (ATMP·Na422%)

[0087] 2-Hydroxyphosphonoacetic acid (HPAA) 14%

[0088] Zinc sulfate 14%

[0089] Sodium molybdate 5%

[0090] Remaining water.

[0091] After preparing the corrosion inhibitor in the dosing tank and stirring thoroughly, it was added to the heating network system using a dosing pump at a concentration of 50 mg / L. A 72-hour coating test was conducted using carbon steel test pieces in this environment. The test results showed that after adding the corrosion inhibitor, the corrosion rate of Q235B carbon steel in the heating network circulating water system decreased, and the corrosion inhibition rate increased.

[0092] Example 3:

[0093] All other conditions and methods are the same as in Comparative Document 1. The specific formulation of the corrosion inhibitor is as follows:

[0094] For heating network systems that use reverse osmosis water as makeup water, a corrosion inhibitor suitable for this system is added. This corrosion inhibitor consists of the following components by weight percentage:

[0095] Tetrasodium aminotrimethylphosphonate (ATMP·Na418%)

[0096] 2-Hydroxyphosphonoacetic acid (HPAA) 13%

[0097] Zinc sulfate 16%

[0098] Sodium molybdate 4%

[0099] Remaining water.

[0100] After preparing the corrosion inhibitor in the dosing tank and stirring thoroughly, it was added to the heating network system using a dosing pump at a concentration of 100 mg / L. A 72-hour coating test was conducted using carbon steel test pieces in this environment. The test results showed that after adding the corrosion inhibitor, the corrosion rate of Q235B carbon steel in the heating network circulating water system decreased, and the corrosion inhibition rate increased.

[0101] Example 4:

[0102] All other conditions and methods are the same as in Comparative Document 1. The specific formulation of the corrosion inhibitor is as follows:

[0103] For heating network systems that use reverse osmosis water as makeup water, a corrosion inhibitor suitable for this system is added. This corrosion inhibitor consists of the following components by weight percentage:

[0104] Tetrasodium aminotrimethylphosphonate (ATMP·Na410%)

[0105] 2-Hydroxyphosphonoacetic acid (HPAA) 10%

[0106] Zinc sulfate 6%

[0107] 3% sodium molybdate

[0108] Remaining water.

[0109] After preparing the corrosion inhibitor in the dosing tank and stirring thoroughly, it was added to the heating network system using a dosing pump at a concentration of 200 mg / L. A 72-hour coating test was conducted using carbon steel test pieces in this environment. The test results showed that after adding the corrosion inhibitor, the corrosion rate of Q235B carbon steel in the heating network circulating water system decreased, and the corrosion inhibition rate increased.

[0110] Example 5:

[0111] All other conditions and methods are the same as in Comparative Document 1. The specific formulation of the corrosion inhibitor is as follows:

[0112] For heating network systems that use reverse osmosis water as makeup water, a corrosion inhibitor suitable for this system is added. This corrosion inhibitor consists of the following components by weight percentage:

[0113] Tetrasodium aminotrimethylphosphonate (ATMP·Na425%)

[0114] 2-Hydroxyphosphonoacetic acid (HPAA) 12%

[0115] Zinc sulfate 20%

[0116] Sodium molybdate 4%

[0117] Remaining water.

[0118] After preparing the corrosion inhibitor in the dosing tank and stirring thoroughly, it was added to the heating network system using a dosing pump at a concentration of 120 mg / L. A 72-hour coating test was conducted using carbon steel test pieces in this environment. The test results showed that after adding the corrosion inhibitor, the corrosion rate of Q235B carbon steel in the heating network circulating water system decreased, and the corrosion inhibition rate increased.

[0119] Example 6:

[0120] All other conditions and methods are the same as in Comparative Document 1. The specific formulation of the corrosion inhibitor is as follows:

[0121] For heating network systems that use reverse osmosis water as makeup water, a corrosion inhibitor suitable for this system is added. This corrosion inhibitor consists of the following components by weight percentage:

[0122] Tetrasodium aminotrimethylphosphonate (ATMP·Na430%)

[0123] 2-Hydroxyphosphonoacetic acid (HPAA) 10%

[0124] Zinc sulfate 18%

[0125] 3% sodium molybdate

[0126] Remaining water.

[0127] After preparing the corrosion inhibitor in the dosing tank and stirring thoroughly, it was added to the heating network system using a dosing pump at a concentration of 80 mg / L. A 72-hour coating test was conducted using carbon steel test pieces in this environment. The test results showed that after adding the corrosion inhibitor, the corrosion rate of Q235B carbon steel in the heating network circulating water system decreased, and the corrosion inhibition rate increased.

[0128] All articles and references disclosed above, including patent applications and publications, are incorporated herein by reference for various purposes. The term “substantially constitutes…” used to describe a combination should include the identified elements, components, parts, or steps, as well as other elements, components, parts, or steps that do not substantially affect the essential novelty of the combination. The use of the terms “comprising” or “including” to describe combinations of elements, components, parts, or steps herein also contemplates embodiments substantially constituted by such elements, components, parts, or steps. The use of the term “may” herein is intended to indicate that any described attribute included by “may” is optional.

[0129] Plural elements, ingredients, components or steps can be provided by a single integrated element, ingredient, component or step. Alternatively, a single integrated element, ingredient, component or step might be divided into separate plural elements, ingredients, components or steps. To the extent that any measurement is expressed in the preceding description in terms of "about" or "approximately," it is meant to encompass nominal values and variations that fall short of, or exceed, the nominal value. For example, depending on the particular context, the term "about" or "approximately" can mean ± 1% or ± 5% or ± 10% or ± 15% or ± 20% or ± 25% or ± 30% or ± 40% or ± 50% or ± 60% or ± 70% or ± 80% or ± 90% or ± 100% or any other value or range of values.

[0130] It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description. The scope of the technology should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for the purpose of the present disclosure. The omission of any aspect of the subject matter disclosed herein does not preclude coverage of such aspect, nor does it surrender the inventor's rights in such aspect of the disclosure, all of which are hereby incorporated by reference.

Claims

1. A corrosion inhibitor for supplementing reverse osmosis water heating pipe networks, characterized in that, For heating network systems using reverse osmosis water as makeup water, by weight percentage, it includes: Tetrasodium aminotrimethylphosphonate 10-30% 2-Hydroxyphosphonoacetic acid 10-15% Zinc sulfate 5-20% Sodium molybdate 1-5% Remaining water; The temperature of the circulating water system in the heating network is 100~150℃; The pipes of the heating network system are made of carbon steel.

2. The corrosion inhibitor for supplementing reverse osmosis water heating pipe networks according to claim 1, characterized in that, By weight percentage, including: Tetrasodium aminotrimethylphosphonate 15% 10% 2-Hydroxyphosphonoacetic acid 10% zinc sulfate Sodium molybdate 4% Remaining water.

3. The method for adding corrosion inhibitor to the reverse osmosis water heating pipe network according to any one of claims 1 to 2, characterized in that: The tetrasodium aminotrimethylphosphonate, 2-hydroxyphosphonoacetic acid, zinc sulfate, sodium molybdate, and water are prepared in a dosing tank according to the weight percentage, mixed thoroughly, and then injected into the heating network system by a metering pump.

4. The dosing method according to claim 3, characterized in that: The dosage of corrosion inhibitor is 50-200 mg / L.

5. The dosing method according to claim 3, characterized in that: After mixing, the mixture is injected into the heating network circulating water system by a metering pump with a flow rate of 400 L / h.

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