CN101805905A - Soil media inhibitor for grounded screen - Google Patents

Abstract

The invention relates to a soil medium corrosion inhibitor for grounding nets, which is prepared by using bentonite as a carrier and mixing an environmentally friendly and non-degradable organic corrosion inhibitor and an inorganic corrosion inhibitor. The corrosion inhibitor adopts a green formula, has no harm to the environment, has the advantages of convenient production and use, environmental friendliness, high corrosion inhibition efficiency and long-lasting effect, and can keep the grounding grid in a stable state for a long time.

Description

Soil Medium Corrosion Inhibitor for Grounding Grid

technical field

The invention belongs to the production technical field of anti-corrosion preparations, and relates to a corrosion inhibitor used to prevent substation grounding grids from corroding in soil.

Background technique

The substation grounding grid is an essential facility for working grounding, lightning protection grounding, and protective grounding. It is also an important link to ensure the safety of people, equipment, and systems. The role of pressure. As the capacity of the power system continues to increase, the short-circuit current flowing through the ground grid is also increasing. When an accident occurs, if the ground grid is defective, the short-circuit current cannot be fully diffused in the soil, which will cause the ground grid potential If it rises, the metal shell of the grounding equipment will be charged with high voltage, which will endanger personal safety and break down the insulation of the secondary protection device, and even damage the equipment, expand the accident, and destroy the stability of the power grid system.

In my country, due to resource and economic reasons, the materials used for grounding grids are mainly metal materials such as ordinary carbon steel. After being buried in the ground, the grounding grids of this type of material are prone to severe corrosion, resulting in reduced cross-section, insufficient thermal stability, and grounding resistance. increase. Since the grounding grid is buried underground, it takes a lot of manpower and material resources to inspect, maintain, and overhaul the grounding grid, making the operation difficult and costly. With the improvement of power grid transmission level, the importance of grid safety and stability becomes more obvious. Solve the problem of grounding grid corrosion resistance, improve the corrosion resistance of grounding grid materials, ensure the stability of grounding performance, prolong the service life of the grounding grid, and reduce grid operation. Cost has become an urgent issue to be solved for safe and economical production of power system today.

In the prior art, adding corrosion inhibitors to prevent metal corrosion is a very effective means, but its application range is limited to liquid and gas phase environments, such as chemical cleaning, circulating cooling water, machine rust prevention, oil collection and chemical industry, etc. . Searched by the applicant of the present invention, no relevant technical reports on corrosion inhibitors used in soil environment have been found so far.

The composition of the soil medium is complex, and the reasons for the corrosion of the grounding grid are various and the mechanism is complicated, and the service life of the grounding grid is required to be more than 30 years. Liquid and gas corrosion inhibitors usually have a service life of only a few hours, which cannot meet the needs of long-term corrosion protection. The experimental results show that after adding liquid medium corrosion inhibitors to the soil, some corrosion rates do not decrease significantly, and some corrosion rates increase. Therefore, for the substation grounding grid, it is necessary to develop an environmentally friendly and durable corrosion inhibitor to meet the anti-corrosion requirements of the grounding grid.

Contents of the invention

The object of the present invention is to solve the problems existing in the prior art, and further provide a soil medium corrosion inhibitor for grounding nets with reasonable composition and configuration, convenient production and use, environmental friendliness and long-lasting effect.

In order to achieve the above object, the technical solution of the present invention is: the soil medium corrosion inhibitor for the grounding grid uses bentonite as a carrier, mixes an environmentally friendly and non-degradable organic corrosion inhibitor and an inorganic corrosion inhibitor, and its raw materials The weight percent that component accounts for in preparation is:

Bentonite 70%～90%,

Organic corrosion inhibitor 5%～10%,

Inorganic corrosion inhibitor 5% to 20%,

In the raw material components of the above-mentioned materials, said organic corrosion inhibitor is urotropine (hexamethylenetetramine) or imidazoline (dihydroimidazole) or BTA (benzotriazole), and said inorganic inhibitor The etching agent is phosphate (such as trisodium phosphate) or polyphosphate (such as sodium polyphosphate) or molybdate (such as sodium molybdate) or zinc salt (such as zinc sulfate).

The principle of action of the soil medium corrosion inhibitor of the present invention is: bentonite is a porous substance, which is used as a carrier to accommodate a large amount of organic corrosion inhibitors and inorganic corrosion inhibitors in its internal pores; the organic corrosion inhibitor passes through it. Polar groups such as -NH ₂ , -OH, -SH, -COOH in the molecule form a coordination chelation film with the metal surface to play a protective role. The addition of inorganic corrosion inhibitors inhibits metal ionization by forming an oxide film The process and the effect of making the metal electrode potential reach the passivation potential slow down the corrosion of the metal, has a protective effect on the grounding grid, and can keep the grounding grid in a stable state for a long time.

In practical application, according to the mechanism of action of the soil medium corrosion inhibitor of the present invention, its protection process to the grounding grid can be roughly divided into two stages: the first stage, the initial stage of protection of the buried grounding grid, with bentonite, organic In the second stage, when the concentration of the organic corrosion inhibitor decreases so that it cannot provide effective protection for the metal, the protective effect of the inorganic corrosion inhibitor gradually increases. The action time of soil corrosion inhibitor is related to the amount of corrosion inhibitor added around the grounding grid. The larger the amount added, the longer the protective effect lasts. According to the local soil characteristics and climate characteristics of the grounding grid, the duration of the above three stages is different.

Compared with the existing similar technologies, the advantages of the present invention are: 1. The corrosion inhibitor adopts a green formula, has no harm to the environment, has the advantage of being environmentally friendly, and conforms to the development trend of corrosion inhibitors; 2. The corrosion inhibitor has the advantages of The corrosion inhibition efficiency is high, up to 87% or more; 3. The corrosion inhibition effect is long-lasting.

The preparation method of the soil medium corrosion inhibitor: weigh the corresponding mass according to the weight percentage of each component of the soil corrosion inhibitor, mechanically or manually stir it evenly, and then add water and stir it into a slurry for use.

How to use the soil medium corrosion inhibitor: Wrap the prepared soil medium corrosion inhibitor around the flat steel or copper wire of the grounding grid, with a thickness of not less than 200mm×200mm, and then fill it with natural soil.

Detailed ways

In the present invention, the corrosion rate of a metal material is measured by a weight loss method.

Example:

Take a certain amount of corrosion inhibitor, its composition is: bentonite + urotropine + sodium phosphate, the weight ratio of each component is: 90:5:5, put the same material as the grounding grid in the corrosion inhibitor Metal test pieces, adjust the humidity, and act at 50 degrees Celsius for 7 days. At the same time, a blank test was carried out with the soil of a substation. The results show that the corrosion rate of the blank test is 19.9419g/m ² ·a, while the corrosion rate of the test using the corrosion inhibitor is 2.4428g/m ² ·a, and the corrosion inhibition efficiency reaches 87%.

Claims (3)

1. a soil medium corrosion inhibitor for grounding net, is characterized in that it is made up of the material raw material of following percentage by weight: Bentonite 70%～90%, Organic corrosion inhibitor 5%～10%, Inorganic corrosion inhibitor 5% to 20%. 2. The soil medium corrosion inhibitor for ground grid according to claim 1, characterized in that said organic corrosion inhibitor is urotropine or imidazoline or BTA. 3. The soil medium corrosion inhibitor for ground grid according to claim 1, characterized in that said inorganic corrosion inhibitor is phosphate or polyphosphate or molybdate or zinc salt.