KR102125655B1 - Enamel heating element for ggh and gah of power plant with enamel glaze composition with excellent thermal conductivity and anti-fouling - Google Patents

Abstract

The present invention provides a heating element (thermal element) for a power plant which has excellent thermal conductivity to increase thermal efficiency, and realizes an effect improved by an anti-fouling effect to markedly prevent corrosion and blockage to extend a period required for equipment replacement to secure the stability of the operation of the power plant. According to an embodiment of the present invention, the enamel heating element (EHE) for GGH and GAH of a power plant with an enamel glaze composition with excellent thermal conductivity and anti-fouling comprises: a plurality of first thermal element sheets arranged on a thermal element to form a plurality of division spaces which are divided spaces on the thermal element; a second thermal element sheet formed in the division spaces and formed by coupling a plurality of unit sheets having a corrugated surface shape with ridges and grooves; and an enamel coating layer formed on the surface of the first thermal element sheet and the second thermal element sheet to protect the surface of the first thermal element sheet and the second thermal element sheet. The enamel coating layer is formed by enamel coating using an enamel glaze composition in which a composite compound of acetic acid and nickel, clay, and additives are mixed.

Description

Enamel heating element (EHE) for power plants GGH and GAH with an enamel glaze composition with excellent thermal conductivity and anti-fouling properties {ENAMEL HEATING ELEMENT FOR GGH AND GAH OF POWER PLANT WITH ENAMEL GLAZE COMPOSITION WITH EXCELLENT THERMAL CONDUCTIVITY AND ANTI-FOULING}

The present invention relates to an enamel heating element (EHE) for a gas gas heater (Gas Gas Heater) and a gas air heater (GAH) to which an enamel glaze composition having excellent thermal conductivity and anti-fouling properties is applied, more specifically, excellent thermal conductivity This increases the thermal efficiency, and the effect improved by the anti-fouling effect is realized to significantly prevent corrosion and clogging, so it is possible to extend the period required for facility replacement, thereby securing the stability of the power plant operation. It relates to a heating element (heat element) for a power plant that can be.

In recent years, in the production of electricity from thermal power plants, the use of relatively low-quality coal is increasing to reduce costs, and when the power consumption is increased within a short time, the thermal power plants perform operations that meet the threshold, and accordingly, the thermal power plants The load on internal equipment may increase. Therefore, there is an increasing demand for increased durability of facilities inside a thermal power plant.

In addition, the flue gas contains nitrogen oxides, sulfur oxides, chlorine and fluorine oxides, as well as dust/ash, and contains various pollutants with very strong corrosive properties.

In the case of APH (Air PreHeater) among the internal facilities of a thermal power plant, damage due to thermal shock and wear due to high-speed coal dust occurs faster than damage caused by sulfuric acid corrosion due to a relatively high temperature. In the case of GGH (Gas Gas Heater) among the internal facilities of the thermal power plant, the role of preheating by increasing the temperature of the smoke exiting the stack to the gas temperature before discharging the gas generated in the desulfurization process to the atmosphere. However, the damage caused by the low-temperature corrosion of sulfuric acid corrosion is mainly caused, and the equipment is corroded, and the clogging of deposits, etc., causes a large loss of cost due to the shutdown and maintenance of the entire power plant.

As the most common preventive measure against corrosion, there is a method of changing the material of the element. That is, the corrosion resistance can be improved by changing the composition of the metal material. For example, there are examples of corrosion resistance improvement of STS316 made by adding 2 to 3% of Mo to STS304, and superstainless steel superior in corrosion resistance to superalloy or titanium. There are, for example, such new materials are not easy to develop, and the developed materials are practically unusable because they are outside the range that can be easily used by industry in terms of cost.

Accordingly, recently, enamel coating is also applied to the thermal element of the low-temperature layer in the thermal element of the APH formed of the three-stage temperature layer. In addition, enamel coating is mainly applied to the thermal element of GGH.

Enamel, a vitreous-metal compound fired at high temperatures with a glassy coating on several types of metal surfaces, shares the special properties of metals and non-metals. Enamels exhibit the chemical, physical and aesthetic sensibility of glass and the strength and durability properties of metals. By sharing and improving its characteristics by sharing, the HRSG (Heat Recovery Steam Generator) and GGH (Gas Gas Heater) for power plants are facilities that are easily corroded by being exposed to complex shapes and high temperatures and strong acids. A method of applying enamel coating is being considered due to the development of glazes with enhanced properties.

However, in the case of such a conventional corrosion prevention method, the effect is not certain and the cost is excessively high, and the conditions such as heat resistance, durability, and oxidation resistance for power plant facilities are not satisfied, and thus there are difficulties in facility replacement and maintenance. This is true.

In addition, when the heat exchanger of the power plant is continuously used, there is a problem in that the heat exchange effect is reduced because sediment and the like are accumulated and fixed inside.

In Korean Patent Publication No. 10-2003-0061635 (invention name: enamel composition for building materials and method for manufacturing improved enamel building material using the same), silicon dioxide (SiO ₂ ) 29~35%, lead oxide (PbO ₂ ) 30~35%, sodium oxide (Na ₂ O) 10~25%, titanium (TiO ₂ ) 5~15%, antimony oxide (Sb ₂ O ₃ ) 0.2~1%, boron oxide (B ₂ O ₃ ) 0.2~ 1% is mixed and melted, the melt is quenched to form a frit, and the molded frit is crushed to mix the frit and water in a ratio of 4:6, but 2~5% of sodium silicate (Na ₂ SiO ₂ ), aero seed Rica 3~7%, boric acid(H ₃ BO ₃ )(B ₂ O ₃ ), methyl alcohol 0.3~0.7% is added and mixed, and it is a method of manufacturing enamel composition for building materials and improved enamel building material using the same. This is disclosed.

And, in the registered patent (Application No. 10-2018-0164535, name of the invention: enamel glaze composition for corrosion prevention and anti-fouling effect of element for GGH and GAH for power plants, and enamel coating method using same), coating The nickel acetate composite compound to prevent the formation of pores on the surface is an additive of 8 to 18% by weight, 80 to 90% by weight of powdered clay, and a mixture of silicate and zirconium oxide (zirconia) to improve heat resistance and corrosion resistance. An enamel glaze composition prepared by stirring 1 to 3% by weight and dispersing in a liquid solvent is disclosed.

The present invention is a related patent of the registered patent as described above, and when the elements of the power plant GGH and GAH are coated using the above-mentioned invention and the enamel glaze composition of the present invention, excellent anti-fouling function is added to the elements and at the same time In spite of being coated, the element is provided with excellent thermal conductivity.

Republic of Korea Patent Publication No. 10-2003-0061635

The object of the present invention for solving the above problems is to perform the enamel coating on the surface of the equipment used in the heat exchanger for power plants, thereby increasing the effects of heat resistance, acid resistance, hydrophilicity, and also increasing the anti-fouling effect. The purpose is to let.

In addition, an object of the present invention is to enable enamel coating on a metal surface on which a polishing process has not been performed.

And, an object of the present invention is to provide an element having excellent thermal conductivity even when enamel coating is performed.

The technical problem to be achieved by the present invention is not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary knowledge in the technical field to which the present invention belongs from the following description. There will be.

The technical problem to be achieved by the present invention is not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary knowledge in the technical field to which the present invention belongs from the following description. There will be.

The configuration of the present invention for achieving the above object is provided with a plurality of the thermal element, the first thermal element sheet to form a plurality of partition spaces that are partitioned spaces in the thermal element; A second column element sheet formed in the partition space and formed by combining a plurality of unit sheets having a shape of a corrugated curved surface having mountains and valleys; And an enamel coating layer formed on surfaces of the first thermal element sheet and the second thermal element sheet to protect the surfaces of the first thermal element sheet and the second thermal element sheet. The enamel coating layer includes nickel acetate It is characterized in that the composite compound, clay and additives are formed by enamel coating using a mixed enamel glaze composition.

In an embodiment of the present invention, the first thermal element sheet may be formed in a plate shape.

In an embodiment of the present invention, the second column element sheet may have a multi-stage wave shape curved surface.

In an embodiment of the present invention, the enamel glaze composition, for preventing the formation of pores on the coating surface 8 to 18% by weight of nickel acetate composite compound, 80 to 90% by weight of clay in the form of powder and for improving heat resistance and corrosion resistance It may be prepared by mixing 1 to 3% by weight of an additive mixed with silicate and oxide.

In an embodiment of the present invention, the nickel acetate composite compound may be formed in the form of a powder and mixed with the clay.

In an embodiment of the present invention, after impregnating the clay with the additive preferentially, the nickel acetate composite compound and the clay can be mixed.

In an embodiment of the present invention, the weight ratio ratio of the silicate and the oxide contained in the additive may be 2 to 3: 7 to 8.

In an embodiment of the present invention, the silicate may be any one material selected from the group consisting of aluminum silicate, iron silicate, calcium silicate, magnesium silicate, and alkali metal silicate.

In an embodiment of the present invention, the oxide may be any material selected from the group consisting of zirconium oxide (zirconia), aluminum oxide (alumina, alumina), titanium oxide (TiO ₂ ), and calcium oxide (CaO). .

The effect of the present invention according to the above configuration is that when enamel coating is performed on the surface of a metal product using the enamel glaze composition of the present invention, it is easy to form an enamel coating layer.

In addition, the effect of the present invention is that when performing enamel coating using the enamel glaze composition of the present invention, it is possible to improve properties such as heat resistance, corrosion resistance and anti-fouling function addition of the enamel coating layer.

Accordingly, it is possible to significantly prevent corrosion and clogging inside the heat exchanger of the power plant, so that the period required for facility replacement can be prolonged to ensure the stability of the power plant operation, as well as to reduce the cost required for facility replacement. There is an advantage.

And, the effect of the present invention is that even if enamel coating is performed, the thermal conductivity is excellent, and the thermal efficiency of the element can be increased.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a schematic diagram of a thermal element according to an embodiment of the present invention.
2 is a schematic diagram of a first row element sheet and a second row element sheet according to an embodiment of the present invention.
3 is a cross-sectional view of an enamel coating layer and a first thermal element sheet according to an embodiment of the present invention.
Each of FIGS. 4 to 6 is a SEM image comparing the surface of the enamel coating layer according to an embodiment of the present invention with the surface of the metal plate on which the enamel coating of the prior art was performed.
Each of FIGS. 7 to 9 is an SEM image comparing a cross-section of an enamel coating layer according to an embodiment of the present invention with a cross-section of a conventional enamel coating layer.
10 is an image of each surface after performing an impact experiment on the surface of the enamel coating layer and the surface of the metal plate on which the enamel coating of the prior art is performed according to an embodiment of the present invention.
11 is an image of each surface after performing an impact test on the surface of the enamel coating layer and the surface of the metal plate on which the enamel coating of the prior art was performed according to an embodiment of the present invention.
12 is an image of performing a decontamination experiment on the surface of the metal plate on which the enamel coating of the prior art was performed.
13 is an image of performing a decontamination experiment on the surface of a metal plate on which the EHE enamel coating of the prior art was performed.
14 is an image for performing a decontamination experiment on the surface of the enamel coating layer according to an embodiment of the present invention.
15 is an image for performing a decontamination experiment on the surface of the metal plate on which the enamel coating of the prior art was performed.
16 is an image of performing a decontamination experiment on the surface of the metal plate on which the EHE enamel coating of the prior art was performed.
17 is an image for performing a decontamination experiment on the surface of the enamel coating layer according to an embodiment of the present invention.
18 is an image of a hydrophilic experiment of the surface of the metal plate on which the enamel coating of the prior art was performed.
19 is an image of a hydrophilic experiment of the surface of the metal plate on which the EHE enamel coating of the prior art was performed.
20 is an image of the hydrophilicity test of the surface of the enamel coating layer according to an embodiment of the present invention.
FIG. 21 is an image of a corrosive experiment of a metal plate surface on which a prior art enamel coating is performed, a metal plate surface on which a conventional EHE enamel coating is performed, and a surface of the enamel coating layer according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in various different forms, and thus is not limited to the embodiments described herein. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and like reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part is "connected (connected, contacted, coupled)" with another part, it is not only "directly connected", but also "indirectly connected" with another member in between. "It also includes the case where it is. Also, when a part “includes” a certain component, this means that other components may be further provided instead of excluding other components, unless otherwise stated.

The terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “include” or “have” are intended to indicate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, and that one or more other features are present. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of a thermal element 100 according to an embodiment of the present invention, and FIG. 2 is a first thermal element sheet 110 and a second thermal element sheet 120 according to an embodiment of the present invention. 3 is a cross-sectional view of the enamel coating layer 130 and the first thermal element sheet 110 according to an embodiment of the present invention.

1 to 3, the thermal element 100 of the present invention, which is a thermal element for a power plant, is provided with a plurality of thermal elements 100, the partition space 101, which is a space partitioned by the thermal element 100 A first column element sheet 110 to form a plurality of; A second column element sheet 120 formed in the partition space 101 and formed by combining a plurality of unit sheets 121 having a shape of a curved surface having mountains and valleys; And enamel coating layers 130 formed on the surfaces of the first thermal element sheet 110 and the second thermal element sheet 120 to protect the surfaces of the first thermal element sheet 110 and the second thermal element sheet 120. ;. In addition, the enamel coating layer 130 may be formed by enamel coating using an enamel glaze composition in which a nickel acetate composite compound, clay, and additives are mixed.

As shown in FIG. 1, a partition space 101 is formed between one first row element sheet 110 and another first row element sheet 110, and a second row element sheet is formed in the partition space 101. 120 may be formed. Here, the first thermal element sheet 110 may be formed in a plate shape. In addition, the second row element sheet 120 may have a multi-stage corrugated curved shape.

In the embodiment of the present invention, the first thermal element sheet 110 is described as a flat plate shape, but is not limited thereto, and may be a plate shape having a curved surface. And, the second thermal element sheet 120 is in contact with any one or more of the first thermal element sheet 110 of the first thermal element sheet 110 disposed vertically, or, the first thermal element sheet disposed vertically It may be formed to be spaced from (110).

1 and 2, the second column element sheet 120 may be formed by combining a plurality of unit sheets 121, one unit sheet 121 and the other unit sheet 121 of The other end may be combined, or one end of the unit sheet 121 and the other end of the unit sheet 121 may be combined. That is, each unit sheet 121 may be combined by being positioned in the same or opposite directions to each other.

As shown in FIG. 2, a multi-stage curved surface shape may be formed, such as a central portion of the unit sheet 121, among the curved surface shapes of the unit sheet 121. Such a multi-stage curved surface shape can increase the surface area of the second thermal element sheet 120, and accordingly, the heat exchange efficiency of the thermal element 100 of the present invention can be increased.

The enamel glaze composition of the present invention is used to form an enamel coating layer 130 on the surface of the first thermal element sheet 110 or the second thermal element sheet 120, which is a metal, as shown in FIG. 3. , It may be suitable for enamel coating for the surface of a metal body that is not easy to enamel coating.

Specifically, enamel coating using the enamel glaze composition of the present invention may be performed on the thermal element 100 as shown in FIGS. 1 to 3. Here, the thermal element 100 of the present invention, APH (Air PreHeater, air preheater) or GGH (Gas Gas Heater, gas gas heater) may be provided.

APH is a facility that improves thermal efficiency by heating the air supplied during the process of burning coal by using the combustion gas coming directly from the boiler. It is usually composed of three stages, and there are parts over 200℃ to 400℃. Can. And, GGH is a device that increases the temperature of the exhaust gas for the purpose of increasing the temperature of the smoke exiting the chimney and scattering it far into the atmosphere, and may have a temperature range of 60° C. to 200° C. or less. In particular, GGH may be damaged by corrosion due to sulfuric acid due to low temperature corrosion in a range slightly above 80°C.

In the case of APH, compared to GGH, the temperature is relatively high, and thus damage due to thermal shock and wear due to high-speed coal dust may occur more than damage caused by sulfuric acid corrosion. And, in the case of GGH, damage due to low temperature corrosion of sulfuric acid corrosion may occur mainly.

When the thermal element 100 of APH is formed of metal and enamel coating is performed on the thermal element 100 of APH using the enamel glaze composition of the present invention, sand is applied to the surface of the thermal element 100 of APH. Enamel coating may be easy without performing a polishing process such as Sand Bluster. In addition, the thermal element 100 of the APH increases corrosion resistance, prevents damage due to thermal shock or external impact, adsorbs on the enamel surface by ammonium sulfate ((NH ₄ ) ₂ SO ₄ ) and dust, and corrosion thereof. And it is possible to implement an effect that is improved by the anti-fouling (Anti-Fouling) effect, such as problems caused by defects in product fluidity.

When the enamel coating is performed on the thermal element 100 of APH using the enamel glaze composition of the present invention, the above-described effect is realized, for the thermal element 100 of GGH using the enamel glaze composition of the present invention. The same can be realized even when enamel coating is performed.

According to this, since sufficient enamel coating performance such as heat resistance, acid resistance, hydrophilicity, etc. for the heat exchange element of the heat exchanger used in the past can be secured, corrosion and clogging in the heat exchanger of a power plant can be significantly prevented, so it is necessary to replace equipment. Since it is possible to extend the required period, it is possible to secure the stability of the operation of the power plant, and also has the advantage of significantly reducing the cost of facility replacement.

Hereinafter, the enamel glaze composition used for forming the enamel coating layer 130 of the present invention will be described in detail.

The enamel glaze composition used for forming the enamel coating layer 130 on the surface of the first thermal element sheet 110 or the second thermal element sheet 120 is a nickel acetate composite compound 8 to 18 weight to prevent pore formation on the coating surface %, 80 to 90% by weight of the clay in powder form, and 1 to 3% by weight of an additive in which silicate and oxide are mixed to improve heat resistance and corrosion resistance.

The nickel acetate composite compound may be formed in the form of a powder. Components such as copper (Cu), chromium (Cr), and manganese (Mn), which are unsuitable for enamel coating, may be present on the surface of the metal. In particular, molten aluminum and carbon may be present, and carbon is scaled. Or it may be a cause factor of chipping. When these materials are combined to perform enamel coating on the surface of the metal using an existing enamel glaze composition, large pores can be created by pushing the gelled enamel layer due to surface tension during firing. In order to prevent such a phenomenon, it is to include the nickel acetate composite compound of the powder in the enamel glaze composition of the present invention. In addition, the nickel acetate composite compound can be used as a component for enhancing heat resistance and corrosion resistance.

And, the powder of the nickel acetate composite compound may be heat-treated at a temperature of 300 to 600 degrees (℃). When the powder of the nickel acetate composite compound is heat-treated at a temperature of less than 300 degrees (°C) or at a temperature of more than 600 (°C), the heat resistance and corrosion resistance of the enamel coating layer 100 using the enamel glaze composition of the present invention may be reduced. Can.

The clay may be in the form of a powder or in the form of a lump with a larger diameter than the powder particles. After impregnating the additive with such clay preferentially, the nickel acetate composite compound and the clay can be mixed.

The weight ratio ratio of the silicate and the oxide contained in the additive may be 2 to 3: 7 to 8. Here, the silicate may be any material selected from the group consisting of aluminum silicate, iron silicate, calcium silicate, magnesium silicate, and alkali metal silicate. Silicate may be used as a heat-resistant strengthening component, and may be included in the clay in the above ratio.

In addition, the oxide may be any one material selected from the group consisting of zirconium oxide (zirconia), aluminum oxide (alumina, alumina), titanium oxide (TiO ₂ ), and calcium oxide (CaO). Aluminum oxide (Al ₂ O ₃ ) is a component for improving heat resistance and corrosion resistance, and may be included in the clay in the same ratio as above. And, zirconium oxide (ZrO ₂ ) is a component for improving corrosion resistance, it may be included in the clay in the same ratio as above.

Hereinafter, a method of forming the enamel coating layer 130 will be described.

In the first step, the thermal element 100 of the present invention can be formed. Here, after forming the plurality of first thermal element sheets 110, the second thermal element sheet 120 may be installed in each of the partition spaces 101 to manufacture the thermal element 100 of the present invention.

In the second step, heat treatment may be performed on the powdered nickel acetate composite compound. Thereafter, in the third step, the additive can be impregnated with the clay. Next, in the fourth step, the enamel glaze composition may be formed by mixing the nickel acetate composite compound and the clay impregnated with the additive. Then, in the fifth step, the enamel glaze composition may be dispersed in water to form an enamel coating solution. Here, although it is described that the enamel glaze composition of the present invention is dispersed in water to form an enamel coating solution, the present invention is not limited thereto, and the enamel glaze composition of the present invention can be dispersed in another liquid to form an enamel coating solution. .

In the sixth step, the enamel coating layer 130 is performed by performing enamel coating on the surfaces of the thermal element 100 using the enamel coating solution, that is, the surfaces of the first thermal element sheet 110 and the second thermal element sheet 120. Can form. Here, the enamel coating may be performed by dipping or spray spraying. In the embodiment of the present invention, it is described that enamel coating is performed by the above method, but is not limited thereto.

In the seventh step, the enamel-coated thermal element 100 may be fired after drying. Here, the drying of the thermal element 100 on which the enamel coating layer 130 is formed is a temperature at which the surface is sufficiently dry, which varies depending on the shape and size of the product, but can be seen below 400 degrees (℃) above 100 degrees (℃). have.

In addition, in order to further strengthen the coated enamel glaze, a process of baking for 10 to 20 minutes at a temperature of 830 ± 30 degrees (°C) may be performed.

The thermal element of the air preheater (APH) or the gas-gas heater (GGH) having the enamel coating layer using the enamel coating method of the present invention may be manufactured.

Therefore, when the enamel coating layer 130 is formed by performing the enamel coating using the enamel glaze composition for excellent thermal conductivity and anti-fouling effect according to the present invention, the heat resistance, corrosion resistance and anti-fouling function of the enamel coating layer 130 Characteristics such as addition can be improved, and accordingly, corrosion and clogging inside the heat exchanger of the power plant can be significantly prevented, so that the period required for facility replacement can be extended to ensure the stability of the power plant operation. , It has the advantage of reducing the cost required for equipment replacement.

And, experimentally, the thermal conductivity (conductivity) of the element to which the enamel glaze composition of the present invention is applied is measured as 45.356 (W/mK), while the ceramic material is applied to the element of the same shape as the element to which the enamel glaze composition of the present invention is applied. In the case of coating, the thermal conductivity was measured to be 26.647 (W/mK), and when the phenolic resin was coated on the element having the same shape as the element to which the enamel glaze composition of the present invention was applied, the thermal conductivity was 18.535 (W/mK). Was measured. As shown in these experimental values, when performing the coating on the element using the enamel glaze composition of the present invention, it can be seen that it has excellent thermal conductivity compared to other materials coated for the protection of the element.

Hereinafter, examples and experimental examples of the enamel coating using the enamel glaze composition of the present invention will be described.

[Example 1]

An enamel glaze composition comprising a nickel acetate composite compound powder heat-treated at a temperature of 300 to 600 degrees (°C) was formed. Here, the enamel glaze composition includes 8 to 18% by weight of the nickel acetate composite compound, 80 to 90% by weight of clay, and 1 to 3% by weight of additives. Further, the additives are aluminum silicate and zirconium oxide among silicates, and are impregnated with clay in a weight ratio ratio of 2-3 to 7-8. Then, the nickel acetate composite compound powder and clay were mixed and pulverized.

Next, after preparing the enamel coating solution by dispersing the enamel glaze composition formed as described above in water, the enamel coating solution was applied to a metal plate formed of iron having a width of 20 cm, a length of 20 cm, and a thickness of 1 cm. Then, the metal plate coated with the enamel coating solution was dried at a temperature of 200 ± 50 degrees (°C) for 5 to 10 minutes, followed by firing to perform enamel coating, thereby obtaining a metal plate on which the enamel coating layer of the present invention was formed.

[Example 2]

A ceramic coating liquid, which is a liquid for coating a commercially available ceramic material, was prepared. Thereafter, the ceramic coating solution was applied to a metal plate formed of iron having a width of 20 cm, a height of 20 cm, and a thickness of 1 cm. Then, the metal plate coated with the ceramic coating solution was dried at room temperature and fired to perform coating.

[Example 3]

A phenolic resin coating liquid, which is a commercially available liquid for coating phenolic resin materials, was prepared. Thereafter, the phenol resin coating solution was applied to a metal plate formed of iron having a width of 20 cm, a height of 20 cm, and a thickness of 1 cm. Then, the metal plate coated with the phenol resin coating solution was dried at room temperature and fired, followed by coating.

[Comparative Example 1]

After applying the commercially available composition for enamel coating to a metal plate formed of iron having a width of 20 cm, a length of 20 cm, and a thickness of 1 cm, the metal plate coated with the enamel glaze composition was dried at a temperature of 200 ± 50 degrees (°C) for 5 to 10 minutes. After firing to perform enamel coating, an enamel coated metal plate was obtained.

[Comparative Example 2]

After applying a commercially available acid-resistant enamel coating (EHE) composition liquid to a metal plate formed of iron having a width of 20 cm, a height of 20 cm, and a thickness of 1 cm, the metal plate coated with the enamel glaze composition is 5 to 5 at a temperature of 200 ± 50 degrees (℃). After drying for 10 minutes and firing, enamel coating was performed to obtain an enamel coated metal plate.

Each of FIGS. 4 to 6 is a SEM image comparing the surface of the enamel coating layer according to an embodiment of the present invention with the surface of the metal plate on which the enamel coating of the prior art was performed. Here, Figure 4 (a) is a 50-fold SEM image of the surface of the metal plate obtained by [Comparative Example 1], Figure 4 (b) is a 50-fold magnification of the enamel coating layer surface obtained by [Example] SEM image. In addition, Figure 5 (a) is a 150-fold SEM image of the surface of the metal plate obtained by [Comparative Example 1], Figure 5 (b) is a 150-times magnification of the enamel coating layer surface obtained by [Example] SEM image. And, Figure 6 (a) is a 1,000-fold SEM image of the surface of the metal plate obtained by [Comparative Example 1], Figure 6 (b) is a 1,000-fold magnification of the enamel coating layer surface obtained by [Example] SEM image.

4 (a) and (b), 5 (a) and (b), and as shown in Figures 6 (a) and (b), formed of iron using the enamel glaze composition of the present invention When the enamel coating is performed on the metal plate, foreign matters (protrusions indicated by circles in FIG. 5(a) and pin holes) on the surface of the enamel coating layer using the enamel glaze composition of the present invention compared with the enamel coating surface of the prior art ) Can be confirmed to be significantly reduced. Accordingly, the adsorption efficiency of foreign substances on the enamel coating surface using the enamel glaze composition of the present invention can be significantly reduced. That is, an acid-resistant and pin-hole reduction effect, and an easy cleaning or anti fouling function may be implemented.

Each of FIGS. 7 to 9 is an SEM image comparing a cross-section of an enamel coating layer according to an embodiment of the present invention with a cross-section of a conventional enamel coating layer. Here, Figure 7 (a) is a 50-times SEM image of the cross-section of the enamel coating layer obtained by [Comparative Example 1], Figure 7 (b) is a cross-section of the enamel coating layer obtained by [Example] SEM image for 50x magnification. In addition, Figure 8 (a) is a 150-fold SEM image of the cross-section of the enamel coating layer obtained by [Comparative Example 1], Figure 8 (b) is a cross-section of the enamel coating layer obtained by [Example] This is a 150x SEM image. And, Figure 9 (a) is a 1,000 times SEM image of the cross-section of the enamel coating layer obtained by [Comparative Example 1], Figure 9 (b) is a cross-section of the enamel coating layer obtained by [Example] This is a 1,000x SEM image.

7(a) and (b), 8(a) and (b), and 9(a) and (b), as shown in FIGS. 9(a) and (b), were formed of iron using the enamel glaze composition of the present invention. When enamel coating is performed on the metal plate, relatively significantly smaller pores are formed on the cross-section of the enamel coating layer using the enamel glaze composition of the present invention, compared to the cross-section of the enamel coating layer of the prior art. It can be seen that the bonding strength between the enamel coating layer using the enamel glaze composition and the surface of the metal plate formed of iron increases, and the resistance to the thermal shock of the enamel coating layer using the enamel glaze composition of the present invention is significantly increased. In addition, the pin hole on the surface of the enamel coating layer using the enamel glaze composition of the present invention may be significantly reduced as described above.

In addition, in the enamel coating layer using the enamel glaze composition of the present invention, the nickel acetate composite compound performs a function of bonding other components, and the additive may perform a function of dispersing bubbles during firing to reduce the maximum diameter of the pores. have. This can be confirmed in Figure 9 (b), as shown in Figure 9 (b), the enamel coating layer using the enamel glaze composition of the present invention also has a number of shapes of a fiber structure such as a thread. , It can be seen that the fiber structure is maintained even after thermal shock, so that resistance to thermal shock is significantly increased.

[Experimental Example 1]

To the surface of the enamel coating layer of the metal plate obtained by [Example], a sphere of iron material having a weight of 2.56 kg and a diameter of 28 mm was dropped at a height of 430 mm to impact the surface of the metal plate obtained by [Example]. And the same impact was applied to the surface of the metal plate obtained by [Comparative Example 1].

FIG. 10 is an image of each surface after performing an impact test on the surface of the enamel coating layer and the surface of the metal plate on which the enamel coating of the prior art was performed according to an embodiment of the present invention. Here, FIG. 10(a) is an enlarged image of the surface of the metal plate obtained by [Comparative Example 1], and FIG. 10(b) is an enlarged image of the surface of the enamel coating layer obtained by [Example].

As shown in Figure 10, after the impact as described above, compared to the surface of the enamel coating layer obtained by [Example], it was confirmed that the metal surface of the white plate obtained by [Comparative Example 1] was significantly more. Accordingly, it can be confirmed that the durability of the enamel coating layer using the enamel glaze composition of the present invention is significantly increased.

[Experimental Example 2]

The metal plate obtained by the [Example] was left in a constant temperature furnace at 400° C. for 20 minutes, and then immersed in water at room temperature for 5 minutes, followed by thermal shock to repeat 10 cycles by drying for 5 minutes as 1 cycle. Surface defects were observed after providing. Then, the same thermal shock was performed on the metal plate surface obtained by [Comparative Example 1].

11 is an image of each surface after performing an impact test on the surface of the enamel coating layer and the surface of the metal plate on which the enamel coating of the prior art was performed according to an embodiment of the present invention. Here, FIG. 11(a) is an enlarged image of the surface of the metal plate obtained by [Comparative Example 1], and FIG. 11(b) is an enlarged image of the surface of the enamel coating layer obtained by [Example].

As shown in FIG. 11, during the thermal shock experiment as described above, chipping occurred while bubbles were broken in the thermal shock of 3 to 4 cycles on the surface of the metal plate obtained by [Comparative Example 1]. ] On the surface of the enamel coating layer obtained by [10], even in 10 cycles of thermal shock, chipping does not occur as described above, and thus, it can be confirmed that the enamel coating layer using the enamel glaze composition of the present invention significantly increases resistance to thermal shock.

[Experimental Example 3]

A contaminant is coated on the surface of the enamel coating layer obtained by [Example], and the metal plate obtained by [Example] is left at room temperature for 4 hours to form a contaminant on the surface of the enamel coating layer obtained by [Example] Did. And, the metal plate obtained by [Comparative Example 1] and the surface of the metal plate obtained by [Comparative Example 2] were formed in the same manner as above. Here, the contaminant was a mixture of ammonium sulfate and sludge (gypsum) in a ratio of 9:1, and was prepared in an amount of 20 g.

Next, washing was performed on the metal plate obtained by [Example] and the metal plate obtained by [Comparative Example 1] and the metal plate obtained by [Comparative Example 2] where contaminants were formed. Here, washing was performed by contacting each metal plate with running water for 10 minutes.

12 is an image for performing a decontamination experiment on the surface of a metal plate on which the enamel coating of the prior art is performed, and FIG. 13 is an image for performing a decontamination experiment on the surface of a metal plate on which the EHE enamel coating of the prior art is performed, and FIG. 14 is This is an image for performing a decontamination experiment on the surface of the enamel coating layer according to an embodiment of the present invention.

Here, Fig. 12 (a) is an image of the matter on which the contaminants are formed on the metal plate obtained by [Comparative Example 1], and Fig. 12 (b) is the pollution formed on the metal plate obtained by [Comparative Example 1] This is an image of the matter of washing the material under running water, and FIG. 12(c) is an image of the surface of the metal plate obtained by [Comparative Example 1] after the washing is completed.

In addition, Fig. 13 (a) is an image of the matter on which the contaminants are formed on the metal plate obtained by [Comparative Example 2], and Fig. 13 (b) is the pollution formed on the metal plate obtained by [Comparative Example 2] This is an image of the matter of washing the material under running water, and FIG. 13(c) is an image of the surface of the metal plate obtained by [Comparative Example 2] after the washing is completed.

And, Fig. 14 (a) is an image of the matter where the contaminants are formed on the enamel coating layer obtained by [Example], Figure 14 (b) is the pollution formed on the enamel coating layer obtained by [Example] This is an image of the matter of washing the material under running water, and FIG. 14(c) is an image of the surface of the enamel coating layer obtained by [Example] after the washing is completed.

12(c), the lower side of the contaminants formed on the surface of the metal plate obtained by [Comparative Example 1] was not completely removed, and corrosion was confirmed on the surface from which the contaminants were removed.

As shown in (b) and (c) of FIG. 13, the contaminants formed on the surface of the metal plate obtained by [Comparative Example 2] were washed at a relatively slower rate than other metal plates, and the contaminants were completely removed. It was not removed. However, no corrosion was found on the surface of the metal plate obtained by [Comparative Example 2].

As shown in (b) and (c) of FIG. 14, while the metal plate obtained by [Example] absorbs the flowing water, the contaminants on the metal plate obtained by [Example] are all between 1-2 minutes. It was cleaned and no corrosion was found.

12 to 14, the metal plate obtained by [Comparative Example 1] and the metal plate obtained by [Example] rather than the metal plate obtained by [Comparative Example 2] contaminants formed on the surface of the enamel coating layer It can be seen that it is significantly better washed.

[Experimental Example 4]

A contaminant was applied to the surface of the metal plate obtained by [Example], and the metal plate obtained by [Example] was left at room temperature for 4 hours to form a contaminant on the surface of the metal plate obtained by [Example]. And, the metal plate obtained by [Comparative Example 1] and the surface of the metal plate obtained by [Comparative Example 2] were formed in the same manner as above. Here, the contaminants were prepared in an amount of 20 g as 100% of the sludge (gypsum).

Next, washing was performed on the metal plate obtained by [Example] and the metal plate obtained by [Comparative Example 1] and the metal plate obtained by [Comparative Example 2] where contaminants were formed. Here, washing was performed by contacting each metal plate with running water for 10 minutes.

15 is an image for performing a decontamination experiment on the surface of a metal plate on which the enamel coating of the prior art is performed, and FIG. 16 is an image for performing a decontamination experiment on the surface of the metal plate on which the EHE enamel coating of the prior art is performed, and FIG. This is an image of performing a decontamination experiment on the surface of the enamel coating layer according to an embodiment of the present invention.

Here, Fig. 15 (a) is an image of the matter where the contaminants are formed on the metal plate obtained by [Comparative Example 1], and Fig. 15 (b) is the pollution formed on the metal plate obtained by [Comparative Example 1] This is an image of the matter of washing the material under running water, and FIG. 15(c) is an image of the surface of the metal plate obtained by [Comparative Example 1] after the washing is completed.

In addition, Figure 16 (a) is an image of the matter on which the contaminant is formed on the metal plate obtained by [Comparative Example 2], Figure 16 (b) is the pollution formed on the metal plate obtained by [Comparative Example 2] This is an image of the matter of washing the material with running water, and FIG. 16(c) is an image of the surface of the metal plate obtained by [Comparative Example 2] after the washing is completed.

And, Figure 17 (a) is an image of the matter on which the contaminants are formed on the enamel coating layer obtained by [Example], Figure 17 (b) is a contaminant formed on the metal plate obtained by [Example] Is an image of the matter to be washed in running water, and FIG. 17(c) is an image of the surface of the enamel coating layer obtained by [Example] after the washing is completed.

15(c), the contaminants formed on the surface of the metal plate obtained by [Comparative Example 1] were not completely removed, and surface corrosion was not confirmed.

As shown in (b) and (c) of FIG. 16, the contaminants formed on the surface of the metal plate obtained by [Comparative Example 2] were washed at a relatively slower rate than the other metal plates (8-9 minutes). ), the contaminants were completely removed, and no surface corrosion was found.

As shown in (b) and (c) of FIG. 17, contaminants on the surface of the enamel coating layer obtained by [Example] were all washed within 1 minute, and no corrosion was found.

15 to 17, the metal plate obtained by [Comparative Example 1] and the metal plate obtained by [Comparative Example 2] have significantly more contaminants formed on the surface of the enamel coating layer obtained by [Example] It can be seen that it is well washed.

[Experimental Example 5]

A contaminant was applied to the surface of the metal plate obtained by [Example], and the metal plate obtained by [Example] was left at room temperature for 4 hours to form a contaminant on the surface of the metal plate obtained by [Example]. Then, the metal plate obtained by [Comparative Example 1] and the surface of the metal plate obtained by [Comparative Example 2] were also formed in the same manner as above. Here, the pollutant was a mixture of ammonium sulfate and sludge (gypsum) in a ratio of 9:1, and was prepared in an amount of 20 g.

Next, immersion was performed on the metal plate obtained by [Comparative Example 1] and the metal plate obtained by [Comparative Example 1] and the metal plate obtained by [Comparative Example 2] where contaminants were formed. Here, immersion was performed by immersing each metal plate in water for 5 minutes.

18 is an image of the hydrophilicity test of the surface of the metal plate on which the enamel coating of the prior art is performed, and FIG. 19 is an image of the hydrophilicity test of the surface of the metal plate on which the EHE enamel coating of the prior art is performed, and FIG. 20 is an embodiment of the present invention. This is an image of the hydrophilicity experiment of the surface of the enamel coating layer according to the embodiment.

Here, Fig. 18 (a) is an image of the matter on which the contaminants are formed on the metal plate obtained by [Comparative Example 1], and Fig. 18 (b) is a metal plate obtained by [Comparative Example 1] for 5 minutes This is an image of the surface of a metal plate obtained by [Comparative Example 1] after immersion.

In addition, Fig. 19 (a) is an image of the matter on which the contaminants are formed on the metal plate obtained by [Comparative Example 2], and Fig. 19 (b) is a metal plate obtained by [Comparative Example 2] for 5 minutes. This is an image of the surface of the metal plate obtained by [Comparative Example 2] after immersion.

And, Figure 20 (a) is an image of the matter where the contaminants are formed on the enamel coating layer obtained by [Example], Figure 20 (b) is the metal plate obtained by [Example] is submerged for 5 minutes It is an image of the surface of the enamel coating layer obtained by the [Example].

As shown in FIG. 18(b), only a small amount of the contaminants formed on the surface of the metal plate obtained by [Comparative Example 1] scattered and remained mostly (about 80%).

As shown in FIG. 19(b), about 50% of the contaminants formed on the surface of the metal plate obtained by [Comparative Example 2] remained.

As shown in FIG. 20(b), only about 20% of the contaminants formed on the surface of the enamel coating layer obtained by [Example] remained.

As shown in FIGS. 18 to 20, the metal plate obtained by [Comparative Example 1] and the metal plate obtained by [Example] rather than the metal plate obtained by [Comparative Example 2] are significantly contaminant in water It was well dispersed, and it was confirmed that the hydrophilicity of the enamel coating layer obtained by [Example] was excellent.

[Experimental Example 6]

After contacting 2.2 mg of 30% sulfuric acid on the surface of the metal plate obtained by [Example], heating was performed at a temperature of 200° C. for 18 hours. Further, the same sulfuric acid corrosion was performed on the metal plate surface obtained by [Comparative Example 1] and the metal plate surface obtained by [Comparative Example 2].

FIG. 21 is an image of a corrosive experiment of a metal plate surface on which a prior art enamel coating is performed, a metal plate surface on which a conventional EHE enamel coating is performed, and a surface of the enamel coating layer according to an embodiment of the present invention. Here, Figure 21 (a) is an enlarged image of the surface of the metal plate obtained by [Comparative Example 1], Figure 21 (b) is an enlarged image of the surface of the metal plate obtained by [Comparative Example 2], 21(c) is an enlarged image of the surface of the enamel coating layer obtained by [Example].

After the corrosive experiment as described above, as shown in FIG. 21(a), it was confirmed that the peeling and thinning of the coating was serious on the surface of the metal plate obtained by [Comparative Example 1], revealing the material under the coating layer.

In addition, as shown in (b) of FIG. 21, compared with the surface of the metal plate obtained by [Comparative Example 1], the surface of the metal plate obtained by [Comparative Example 2] has no coating surface and a good thinning state. This was confirmed.

And, as shown in Figure 21 (c), it was confirmed that the coating and thinning state of the metal plate surface obtained by [Example] is better than the metal plate surface obtained by [Comparative Example 2].

Accordingly, it was confirmed that the corrosion resistance of the surface of the enamel coating layer obtained by [Example] is excellent.

[Experimental Example 7]

For the metal plate of [Example 1], the metal plate of [Example 2], and the metal plate of [Example 3], one end is fixed to a support at 0°C and the other end is fixed to a support at 100°C, and the thermal conductivity of each metal plate is fixed. (conductivity) was measured.

In the experimental results of [Experimental Example 7], the thermal conductivity (conductivity) of the element to which the enamel glaze composition of the present invention is applied is measured to be 45.356 (W/mK), while the element to which the enamel glaze composition of the present invention is applied is the same. When the ceramic material was coated on the element of the shape, the thermal conductivity was measured to be 26.647 (W/mK), and when the element of the same shape as the element to which the enamel glaze composition of the present invention was applied was coated with a phenol resin, the thermal conductivity was 18.535. (W/mK). As shown in these experimental values, when performing the coating on the element using the enamel glaze composition of the present invention, it can be seen that it has excellent thermal conductivity compared to other materials coated for the protection of the element.

The above description of the present invention is for illustration only, and those skilled in the art to which the present invention pertains can understand that the present invention can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all modifications or variations derived from the meaning and scope of the claims and their equivalent concepts should be interpreted to be included in the scope of the present invention.

100: thermal element
101: compartment space
110: first row element sheet
120: second row element sheet
121: unit sheet
130: enamel coating layer

Claims (9)

In an enamel heating element (EHE) which is a thermal element for a power plant gas gas heater (GGH) and gas air heater (GAH),
A first column element sheet provided in a plurality of the column elements to form a plurality of partition spaces, which are spaces partitioned from the column elements;
A second column element sheet formed in the partition space and formed by combining a plurality of unit sheets having a shape of a corrugated curved surface having mountains and valleys; And
It includes; enamel coating layer formed on the surface of the first thermal element sheet and the second thermal element sheet to protect the surfaces of the first thermal element sheet and the second thermal element sheet;
The enamel coating layer is formed by enamel coating using an enamel glaze composition in which nickel acetate composite compound, clay and additives are mixed,
The enamel glaze composition, the nickel acetate composite compound 8 to 18% by weight to prevent the formation of pores on the coating surface, 80 to 90% by weight of the clay in powder form and 1 to 3% by weight of additives mixed with silicate and oxide It is prepared by mixing,
The nickel acetate composite compound is formed in the form of a powder and heat-treated at a temperature of 300 to 600 degrees Celsius (℃) to be mixed with the clay,
Enamel heating element (EHE) for power plants GGH and GAH with an enamel glaze composition with excellent thermal conductivity and anti-fouling properties, characterized in that the clay is first impregnated with the additive and then mixed with the nickel acetate composite compound and the clay. ).
The method according to claim 1,
The first thermal element sheet is an enamel heating element (EHE) for power plants GGH and GAH to which an enamel glaze composition having excellent thermal conductivity and anti-fouling properties is formed, which is formed in a plate shape.
The method according to claim 1,
The second thermal element sheet has an enamel heating element (EHE) for power plants GGH and GAH to which an enamel glaze composition having excellent thermal conductivity and anti-fouling properties is characterized by having a multi-stage corrugated curved shape.
delete delete delete The method according to claim 1,
Enamel heating element for power plants GGH and GAH with an enamel glaze composition with excellent thermal conductivity and anti-fouling properties, characterized in that the weight ratio ratio of the silicate and the oxide contained in the additive is 2 to 3: 7 to 8. (EHE).
The method according to claim 7,
The silicate is an aluminum silicate, iron silicate, calcium silicate, magnesium silicate, and any one material selected from the group consisting of alkali metal silicate, GGH power plant applied with an enamel glaze composition having excellent thermal conductivity and anti-fouling properties, and Enamel heating element for GAH (EHE).
The method according to claim 7,
The oxide is any one material selected from the group consisting of zirconium oxide (zirconia), aluminum oxide (alumina, alumina), titanium oxide (TiO ₂ ) and calcium oxide (CaO). Enamel heating element (EHE) for power plants GGH and GAH with this excellent enamel glaze composition.

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