Method for coating inner wall of 6.25 MW wind power tower drum

Abstract

The invention provides a coating method for the inner wall of a 6.25 MW wind power tower drum, and relates to the technical field of wind power tower drum coating. According to the coating method, after a diluent is adopted to adjust the viscosity of paint on the inner wall of the tower drum, a high-pressure airless spray gun is selected, spraying parameters of the high-pressure airless spray gun are adjusted, the paint is sprayed to the inner wall of the wind power tower drum through multiple steps, and the spraying time and the dry film thickness need to be controlled in each spraying step. According to the coating method disclosed by the invention, the process time is greatly shortened; the problem of paint film sagging is avoided, the use amount of the paint can be saved, the surface effect of the paint film is improved, and the paint film defects of dry spraying, orange peel and the like are avoided; and the generation of solid hazardous wastes can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of wind power tower coating, and in particular to a coating method for the inner wall of a 6.25MW wind power tower. Background Art

[0002] At present, a 6.25MW wind turbine tower is generally composed of 5 sections, and the area of ​​each section is slightly different. Generally, the area of ​​T3 and T4 sections is larger, and the area of ​​T1 and T5 sections is smaller. For example, the single-layer area of ​​the T1 section of a 6.25MW model of a domestic design institute is 305m 2 , the single-layer area of ​​T2 section is 322m 2 , the single-layer area of ​​T3 section is 358m 2 , the single-story area of ​​T4 section is 353m 2 , the single-story area of ​​T5 section is 310m 2 .

[0003] At present, most of the onshore wind power towers in China are designed according to the C3 environment. The design scheme is generally divided into two coating systems. The first coating system uses two different coatings, such as epoxy zinc-rich primer (60um) + epoxy thick paste paint (100um). The second coating system uses the same product for two coatings, such as epoxy zinc phosphate primer, epoxy micaceous iron paint, epoxy thick paste paint, etc. The first coating uses a high-zinc-rich primer, which results in higher coating and substrate processing costs than the second coating system. Therefore, if there is no specified plan by the owner of the wind power project, the tower manufacturer generally paints the inner wall of the tower according to the second coating system. For example, the largest domestic OEM Goldwind Technology Co., Ltd. clearly provides the paint manufacturers and varieties that can be used in the guidance of C3-02 (inner surface) in the C3-level paint anti-corrosion in the "General Anti-corrosion Technical Specifications for Onshore Wind Turbine Towers" (such as Hempel epoxy high build paint, Jotun epoxy micaceous iron intermediate paint, Yongxin epoxy zinc phosphate primer, etc., the volume solid content of these products is required to be ≥80%, and the sag is greater than 650um), and the same paint is applied in two coats, each coat is 90μm, and the total paint film thickness is 180μm. Zhejiang Yunda Wind Power Co., Ltd. clearly stipulates in the "Technical Specifications for Megawatt Wind Turbine Towers" that the paint manufacturers and varieties that can be used in C3 environments (such as Hempel epoxy high build paint, Jotun epoxy micaceous iron intermediate paint, Yongxin epoxy zinc phosphate primer), and the same paint is applied in two coats, each coat is 90μm, and the total paint film thickness is 180μm.

[0004] Although the current design requirements for painting the inner wall of wind turbine towers are to apply two coats of paint, each coat is 90μm, but in specific tower manufacturers, there are currently two mainstream painting processes. The first is to paint in full accordance with the design process, with the first coat being 90μm, and then another 90μm after the paint film is dry. The main problems with this process are: 1. Large loss, the thinner the film, the greater the loss; 2. Long process time, generally the ambient temperature is above 20℃, and the second coat can be applied 24 hours later. If the construction ambient temperature in winter is below 10℃, it generally takes more than 48 hours before the second coat can be applied; 3. The appearance of the paint film is poor, and the paint film color is uneven due to reasons such as paint mist and poor leveling in high summer temperatures. The second process is to coat to 180μm at one time. This process can be used in high temperatures in summer, but it is easy to miss coating points and requires high coating skills of the coating personnel. If the fan overlap area is too large, the spraying speed is too slow, and the distance between the nozzle and the substrate is too close during the coating process, the paint film is prone to sagging; the original paint sag standard requirement for wind power intermediate paint is greater than 650um, but during the spraying process, a certain amount of diluent must be added to adjust the construction viscosity, which will cause the sag to decrease. Although the designed film thickness is 180μm, in the specific construction process, due to manual operation, the paint film thickness is a range value, and some areas must be over-thick. In most normal projects, the thickest area during construction exceeds 1.3-1.5 times the design value, and some projects even have over-thick areas that can reach more than 2 times the design value. Especially in winter, this method is not feasible. This process is constructed under low temperatures in winter (temperature <10℃), and large-area sagging of the paint film will occur. Summary of the invention

[0005] The present invention aims to solve the deficiencies in the prior art and to provide a method for coating the inner wall of a 6.25MW wind turbine tower. The method is suitable for two-layer coating of the inner wall of a 6.25MW wind turbine tower under a C3 environment, and the two layers of coating are the same coating product.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: The present invention provides a coating method for the inner wall of a 6.25MW wind power tower, comprising the following steps: Step (1): Use a diluent to adjust the viscosity of the tower inner wall paint. The amount of the diluent added is 10-15% of the volume of the tower inner wall paint. The adjusted paint is used within 10-60 minutes at 20-35°C in summer and within 20-90 minutes at 5-20°C. Step (2): Use a high-pressure airless spray gun and adjust its spraying parameters. The spraying pressure is controlled at 25-30 MPa. The nozzle is a Changjiang 17B30 nozzle. The tower is rotated so that the 90° point is at the lowest surface. The distance between the spray gun and the substrate is maintained at 40-60 cm. The fan overlap area is 1 / 4. The gun travel speed is 50-70 cm / s. Start spraying the 0-180° area from the large end of the tower and spray to the small end. This step takes 10-14 minutes to complete, and the dry film thickness is controlled at 60±6 μm. Step (3): Adjust the spraying parameters, keep the distance between the spray gun and the substrate at 30-50 cm, the fan overlap area is 1 / 4, the gun speed is 40-60 cm / s, and continue to spray the 0-180° area from the large end of the tower to the small end. This step takes 14-17 minutes to complete, and the dry film thickness is controlled at 120±12μm; Step (4): Rotate the tower so that the 270° point is at the lowest surface, keep the distance between the spray gun and the substrate at 40-60 cm, overlap the fan area by 1 / 4, move the gun at a speed of 50-70 cm / s, start spraying the 180-240° and 300-360° areas from the large end of the tower, do not spray the 240-300° area, and spray to the small end. This step takes 7-10 minutes to complete, and the dry film thickness is controlled at 60±6μm. Step (5): Adjust the spraying parameters, keep the distance between the spray gun and the substrate at 30-50 cm, the fan-shaped overlap area is 1 / 4, and the gun speed is 40-60 cm / s. Continue to spray the 180-360° area from the large end of the tower to the small end. When spraying to the 240-300° area, adjust the spraying parameters, keep the distance between the spray gun and the substrate at 30-50 cm, the fan-shaped overlap area is 1 / 2, and the gun speed is 40-60 cm / s. This step takes 17-22 minutes to complete. In this step, the dry film thickness of the 180-240° and 300-360° areas is controlled at 120±12μm, and the dry film thickness of the 240-300° area is controlled at 180±18μm.

[0007] Furthermore, in step (1), the diluent is prepared by 70-80wt% of xylene and 20-30wt% of butanol.

[0008] Furthermore, in step (1), the tower inner wall paint adopts epoxy zinc phosphate primer.

[0009] Furthermore, in step (1), the viscosity is controlled at 70-80 KU.

[0010] Compared with the prior art, the beneficial technical effects of the present invention are: The coating method of the present invention solves the problem of long time consumption when coating the inner wall of the existing wind turbine tower with two layers of coating. The overall coating of the inner wall of the tower can be completed in 1 hour, which greatly shortens the process time; it also solves the problem of paint film sagging when the existing wind turbine tower inner wall coating adopts one-time coating to achieve the required coating thickness; it can save the amount of paint, and the loss coefficient is 1.4; it can improve the surface effect of the paint film, and avoid the occurrence of paint film defects such as dry spraying and orange peel; it can also reduce the generation of solid hazardous waste. Taking the 6.25MW model as an example, the model is composed of 5 tower sections. Each tower section can reduce the generation of 0.25-0.5kg of solid particles by coating construction using this method, and the reduction for each model is 1.25-2.5kg. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 This is an overall effect diagram of the paint film of a 6.25MW wind power tower coated in summer using the method of Example 1; Figure 2 This is an overall effect diagram of the paint film of a 6.25MW wind power tower coated in summer using the method of Example 2; Figure 3 This is the overall effect diagram of the paint film of a 6.25MW wind power tower coated in summer using the method of Comparative Example 1; Figure 4 This is the overall effect diagram of the paint film of a 6.25MW wind power tower coated in summer using the method of Comparative Example 2; Figure 5 This is a partial effect diagram of the paint film of a 6.25MW wind power tower coated in summer using the method of Comparative Example 1; Figure 6 This is a partial effect diagram of the paint film of a 6.25MW wind power tower coated in summer using the method of Comparative Example 2; Figure 7 This is a picture of the paint film effect observed with a 50x magnifying glass after coating a 6.25MW wind power tower in summer using the method of Example 1; Figure 8 This is a picture of the paint film effect observed with a 50x magnifying glass after coating a 6.25MW wind power tower in summer using the method of Comparative Example 1; Fig. 9 This is a picture of the paint film effect observed with a 50x magnifying glass after a 6.25MW wind power tower was painted in summer using the method of Comparative Example 2. DETAILED DESCRIPTION

[0011] The technical solution of the present invention will be described clearly and completely in conjunction with the embodiments below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0012] Example 1 The single-sided area of ​​the T1 section of a 6.25MW wind power tower project is 305m2. The inner wall of the tower is designed with epoxy zinc phosphate primer, with a film thickness of 180μm, and 2 coats of coating, each coat is 90μm. The specific steps of coating using this method are as follows: Step (1): Use a diluent to adjust the viscosity of the tower inner wall paint, with the diluent added in an amount of 10% (volume ratio). The adjusted paint should be used within 10-60 minutes in a summer temperature of 20-35°C, and within 20-90 minutes in a winter temperature of 5-20°C; Step (2): Adjust the spraying parameters of the high-pressure airless spray gun, control the spraying pressure at 30 MPa, select the Changjiang 17B30 nozzle, rotate the tower so that the 90° point is at the lowest surface, keep the distance between the spray gun and the substrate at 60 cm, and the fan overlap area is 1 / 4. The gun travel speed is 60 cm / s. Start spraying the 0-180° area from the large end of the tower and spray to the small end. This step takes 10-11 minutes to complete. The dry film thickness of this step is controlled at 60±6μm. Step (4): Adjust the spraying parameters, keep the distance between the spray gun and the substrate at 45 cm, the overlap area of ​​the fan is 1 / 4, the spraying speed is 60 cm / s, and continue to spray the 0-180° area from the large end of the tower to the small end. This step takes 14-15 minutes to complete. The dry film thickness of the paint in this step is controlled at 120±12μm; Step (5): Rotate the tower so that the 270° point is at the lowest surface, keep the distance between the spray gun and the substrate at 60 cm, overlap the fan area by 1 / 4, move the gun at a speed of 60 cm / s, start spraying the 180-240° and 300-360° areas from the large end of the tower, do not spray the 240-300° area in this step, spray to the small end, and complete this step in 7-8 minutes. The dry film thickness of this step is controlled at 60±6μm; Step (6): Adjust the spraying parameters, keep the distance between the spray gun and the substrate at 40 cm, the fan-shaped overlap area is 1 / 4, and the gun speed is 50 cm / s. Continue to spray the 180-360° area from the large end of the tower to the small end. When spraying to the 240-300° area, adjust the spraying parameters, keep the distance between the spray gun and the substrate at 40 cm, the fan-shaped overlap area is 1 / 4, and the gun speed is 30 cm / s. This step takes 17-18 minutes to complete. In this step, the dry film thickness of the 180-240° and 300-360° areas is controlled to be 120±12μm, and the dry film thickness of the 240-300° area is controlled to be 180±18μm.

[0013] Example 2 The single-sided area of ​​the T5 section of a 6.25MW wind power tower project is 358m 2The inner wall of the tower is designed with epoxy zinc phosphate primer, with a film thickness of 180μm, and painted twice, each time 90μm. The specific steps of painting using this method are as follows: Step (1): Use a diluent to adjust the viscosity of the tower inner wall paint. The amount of diluent added is 15% (volume ratio). The adjusted paint should be used within 10-60 minutes in a summer temperature of 20-35°C, and within 20-90 minutes in a winter temperature of 5-20°C. Step (2): Adjust the high-pressure airless spraying parameters, control the spraying pressure at 25 MPa, select the Changjiang 17B30 nozzle, rotate the tower so that the 90° point is at the lowest surface, keep the distance between the spray gun and the substrate at 60 cm, and the fan overlap area is 1 / 4. The gun travel speed is 55 cm / s. Start spraying the 0-180° area from the large end of the tower and spray to the small end. This step takes 13-14 minutes to complete. The dry film thickness of this step is controlled at 60±6μm. Step (3): Adjust the spraying parameters, keep the vertical distance between the spray gun and the substrate at 45 cm, the fan overlap area is 1 / 4, the gun speed is 60 cm / s, and continue to spray the 0-180° area from the large end of the tower to the small end. This step takes 16-17 minutes to complete. The dry film thickness of this step is controlled at 120±12μm; Step (4): Rotate the tower so that the 270° point is at the lowest surface, keep the distance between the spray gun and the substrate at 60 cm, and the fan overlap area is 1 / 4. The gun travel speed is 60 cm / s. Start spraying the 180-240° and 300-360° areas from the large end of the tower. Do not spray the 240-300° area in this step. Spray to the small end. This step takes 9-10 minutes to complete. The dry film thickness of this step is controlled at 60±6μm. Step (5): Adjust the spraying parameters, keep the distance between the spray gun and the substrate at 40 cm, the fan-shaped overlap area is 1 / 4, the gun speed is 50 cm / s, continue to spray the 180-360° area from the large end of the tower, spray to the small end, and adjust the spraying parameters when spraying to the 240-300° area, keep the distance between the spray gun and the substrate at 40 cm, the fan-shaped overlap area is 1 / 4, and the gun speed is 30 cm / s. This step is completed in 20-21 minutes. In this step, the dry film thickness of the 180-240° and 300-360° areas is controlled to 120±12μm, and the dry film thickness of the 240-300° area is controlled to 180±18μm.

[0014] Comparative Example 1 This comparative example adopts the first traditional coating method, that is, the coating is carried out completely according to the process of the designer, the first coating is 90μm, and then another 90μm is coated after the paint film is dry.

[0015] Comparative Example 2 This comparative example adopts the second traditional coating method, that is, coating to 180μm in one time.

[0016] Test Case The 6.25MW wind power tower was coated using the methods of Examples 1-2 and Comparative Examples 1-2. The coating results are shown in Tables 1 and 2. Figure 1-9 shown.

[0017] Table 1 Comparison results of summer coating Example 1 Example 2 Comparative Example 1 Comparative Example 2 temperature 30℃ 30℃ 30℃ 30 Nozzle size 17B30 17B30 17B30 17B30 Spraying distance 40-60cm 40-60 40-60 40-60 Dry film thickness 180-200 180-200 180-200 160-220 Duration 1h 1h 24h 1h Paint film surface effect Smooth surface Smooth surface The surface is dry sprayed, rough, and has missing spots The surface is partially sag, and some areas are missing Paint loss rate 1.4 1.4 1.6 1.55 Solid waste none none 0.25-0.3KG none Table 2 Comparison results of winter coating Example 1 Example 2 Comparative Example 1 Comparative Example 2 temperature 10℃ 10℃ 10℃ 10℃ Nozzle size 17B25 17B25 17B25 17B25 Spraying distance 40-60cm 40-60 40-60 40-60 Dry film thickness 180-200 180-200 180-200 160-220 Duration 1h 1h 48h 1h Paint film surface effect Smooth surface Smooth surface The surface is relatively flat, with some missing spots Surface sagging, some areas of coating missing Paint loss rate 1.4 1.4 1.6 1.5 Solid waste none none none none like Figure 1 and 7 As shown, the method of Example 1 is used to paint a 6.25MW wind power tower in summer, and the surface of the paint film is flat and smooth; Figure 2 As shown, the method of Example 2 is used to paint a 6.25MW wind power tower in summer, and the surface of the paint film is flat and smooth; Figure 3 , 5 As shown in Figure 8, the method of comparative example 1 was used to paint a 6.25MW wind power tower in summer, and dry spray and paint powder appeared on the surface of the paint film; Figure 4 , 6 As shown in Figure 9, when the method of Comparative Example 2 is used to paint a 6.25MW wind power tower in summer, dry spray and paint powder will appear on the surface of the paint film, and there will also be missing paint and local bluish color.

[0018] According to the test results: 1. Traditional painting in full accordance with the designer's process generally requires at least 24 hours in summer and at least 48 hours in winter at low temperatures. However, by adopting the painting method of the present invention, the entire painting of the inner wall of the tower can be completed in 1 hour, which greatly shortens the process time.

[0019] 2. It can avoid the sagging of paint film. In order to meet the construction deadline, some projects generally require construction workers to achieve the required coating thickness at one time, but this method generally causes the paint film to sag (the original paint sag standard requirement for wind power intermediate paint is greater than 650um, but during the spraying process, a certain amount of diluent must be added to adjust the construction viscosity, which will cause the sag to decrease, and although the designed film thickness is 180 microns, in the specific construction process, due to manual operation, the paint film thickness is a range value, and some areas are definitely over-thick. In most normal projects, the thickest area during construction exceeds 1.3-1.5 times the design value, and some projects even have over-thick areas that can reach more than 2 times the design value). This method is not feasible, especially in winter. The method of the present invention combines the process of paint film sagging and solvent volatilization to avoid paint film sagging.

[0020] 3. The loss coefficient of the traditional coating process is between 1.5 and 1.6, but according to the coating method of the present invention, the coating loss coefficient is 1.4, which saves the amount of paint.

[0021] 4. The traditional coating process is prone to paint film defects such as orange peel caused by dry spraying or poor leveling. The coating method of the present invention avoids the occurrence of paint film defects such as dry spraying and orange peel, and improves the surface effect of the paint film.

[0022] 5. If the traditional coating process encounters high temperature weather or improper construction, a large amount of paint mist particles will be generated on the surface of the paint film after the first coat. Such paint mist particles need to be treated in time before the second coat is sprayed. Failure to treat them will cause paint film defects such as shrinkage holes and missing coatings. The treated paint mist particles will cause solid hazardous waste. Taking the 6.25MW model as an example, the model consists of 5 tower sections. The construction of each tower section reduces the generation of 0.25-0.5kg of solid particles, and the reduction for each model is 1.25-2.5kg. Taking the data reported by China News Network as an example, the installed capacity of grid-connected power generation equipment in a certain province in China in 2023 is 69.611 million kilowatts. If the wind power projects in the province in 2023 all adopt the method of the present invention to paint the inner wall of the tower, up to 14-29 tons of solid hazardous waste can be saved.

[0023] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the technical solution and conceptual invention of the present invention should be included in the protection scope of the present invention.

Claims

1. A coating method for the inner wall of a 6.25MW wind power tower, characterized in that: The following steps are involved: Step (1): Use a diluent to adjust the viscosity of the tower inner wall paint. The amount of the diluent added is 10-15% of the volume of the tower inner wall paint. The adjusted paint is used within 10-60 minutes at 20-35°C in summer and within 20-90 minutes at 5-20°C. Step (2): Use a high-pressure airless spray gun and adjust its spraying parameters. The spraying pressure is controlled at 25-30 MPa. The nozzle is a Changjiang 17B30 nozzle. The tower is rotated so that the 90° point is at the lowest surface. The distance between the spray gun and the substrate is maintained at 40-60 cm. The fan overlap area is 1 / 4. The gun travel speed is 50-70 cm / s. Start spraying the 0-180° area from the large end of the tower and spray to the small end. This step takes 10-14 minutes to complete, and the dry film thickness is controlled at 60±6 μm. Step (3): Adjust the spraying parameters, keep the distance between the spray gun and the substrate at 30-50 cm, the fan overlap area is 1 / 4, the gun speed is 40-60 cm / s, and continue to spray the 0-180° area from the large end of the tower to the small end. This step takes 14-17 minutes to complete, and the dry film thickness is controlled at 120±12μm; Step (4): Rotate the tower so that the 270° point is at the lowest surface, keep the distance between the spray gun and the substrate at 40-60 cm, overlap the fan area by 1 / 4, move the gun at a speed of 50-70 cm / s, start spraying the 180-240° and 300-360° areas from the large end of the tower, do not spray the 240-300° area, and spray to the small end. This step takes 7-10 minutes to complete, and the dry film thickness is controlled at 60±6μm. Step (5): Adjust the spraying parameters, keep the distance between the spray gun and the substrate at 30-50 cm, the fan-shaped overlap area is 1 / 4, and the gun speed is 40-60 cm / s. Continue to spray the 180-360° area from the large end of the tower to the small end. When spraying to the 240-300° area, adjust the spraying parameters, keep the distance between the spray gun and the substrate at 30-50 cm, the fan-shaped overlap area is 1 / 2, and the gun speed is 40-60 cm / s. This step takes 17-22 minutes to complete. In this step, the dry film thickness of the 180-240° and 300-360° areas is controlled at 120±12μm, and the dry film thickness of the 240-300° area is controlled at 180±18μm.

2. A coating method for the inner wall of a 6.25MW wind power tower according to claim 1, characterized in that: In step (1), the diluent is prepared from 70-80 wt % of xylene and 20-30 wt % of butanol.

3. The coating method for the inner wall of a 6.25MW wind power tower according to claim 1 is characterized in that: In step (1), in step (1), the tower inner wall paint adopts epoxy zinc phosphate primer.

4. The coating method for the inner wall of a 6.25MW wind power tower according to claim 1 is characterized in that: In step (1), in step (1), the viscosity is controlled at 70-80 KU.

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