Water turbine polyurethane coating curing method and system

Abstract

The embodiment of the invention provides a water turbine polyurethane coating curing method and system. The water turbine polyurethane coating curing method comprises the steps that modified polyurethane comprising modified nano ceramic particles is selected as a surface layer of a coating; dividing a to-be-coated surface of the flow passage component of the water turbine into a plurality of to-be-coated areas, and performing a surface layer falling test on each to-be-coated area to determine the viscosity required by a surface layer coating of each to-be-coated area; mixing the surface layer paint of each to-be-coated area, grouping, and carrying out pre-curing treatment with different time lengths to determine the paint matched with the required viscosity of each to-be-coated area; and coating matched with the viscosity of the to-be-coated areas is adopted to spray the to-be-coated areas, and infrared light emergent light faces matched with the flatness of the to-be-coated areas are formed through guidance of the deformable light channels to irradiate the coating at the target position for curing treatment.

Description

Technical Field

[0001] The embodiments disclosed herein belong to the field of water turbine technology, specifically relating to a method and system for curing polyurethane coatings for water turbines. Background Technology

[0002] During the operation of a water turbine, the higher the sand content in the water flow, the more likely it is to experience wear and cavitation damage, affecting the safe and stable operation of the unit.

[0003] Currently, a two-phase composite coating design is used for surface protection of turbine flow components to address the bonding defects between the coating and the substrate. However, due to limitations in construction site and equipment, it is impossible to heat and cure the surface layer over a large area during on-site construction, especially when the surface to be coated is large and uneven, resulting in low coating curing efficiency and unstable quality.

[0004] Therefore, how to solve the above problems has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The embodiments disclosed herein aim to at least solve one of the technical problems existing in the prior art, and provide a method and system for curing polyurethane coatings on water turbines.

[0006] A first aspect of the embodiments of this disclosure provides a method for curing a polyurethane coating on a water turbine, comprising: selecting a modified polyurethane comprising modified nano-ceramic particles as the top layer of the coating. The surface to be coated on the flow-through components of the water turbine is divided into multiple areas to be coated, and a surface coating peeling test is performed on each area to determine the required viscosity of the surface coating for each area. The topcoat coatings for each area to be coated were mixed and grouped, and pre-cured for different durations to determine the coating with the required viscosity for each area to be coated. The coating with a viscosity matching that of the area to be coated is sprayed onto each area, and an infrared light emission surface adapted to the flatness of each area is guided by a deformable light channel to irradiate the coating at the target position for curing.

[0007] Optionally, the surface layer peeling test for each area to be coated includes: Select the highest point in each area to be coated as the reference point; Multiple test points are arranged around the reference point. The topcoat was divided into several groups, and each group was pre-cured for a different duration. The pre-cured coatings of each group were applied to each test point; Based on the location of the area to be coated and the curing rate of the coating, estimate the curing time t1 of the coating in the area to be coated; Based on the paint layer peeling off at each test point after curing at time t1, record the paint viscosity and pre-curing time t2 corresponding to that test point.

[0008] Optionally, the step of guiding the formation of an infrared emitted light surface adapted to the flatness of each area to be coated using a deformable light channel to irradiate the target position includes: The surface of the area to be coated is scanned by the ranging / scanning module to obtain the three-dimensional morphological parameters of the surface of the area to be coated; The irradiation position is adjusted by controlling the movement of the adjustment mechanism based on the three-dimensional topographic parameters and adjusting the distance between the infrared light source and the surface of the area to be coated.

[0009] A second aspect of the embodiments of this disclosure provides a polyurethane coating curing system for a water turbine, the system being capable of implementing the method described above, characterized in that it includes an adjustment mechanism, a spray curing head connected to the adjustment mechanism, and an infrared light source corresponding to and connected to the spray curing head and the adjustment mechanism, the adjustment mechanism being configured to adjust the distance between the infrared light source and the surface of the area to be coated, thereby adjusting the irradiation position.

[0010] Optionally, the spray curing head includes a housing, a substrate corresponding to the housing, and a nozzle disposed on the substrate; the infrared light source is disposed on the substrate at a distance from the nozzle; wherein the adjustment mechanism is configured to adjust the distance between the substrate and the housing.

[0011] Optionally, there are multiple nozzles arranged in a linear array on the substrate, and the infrared light source includes multiple light units arranged in a linear array on the substrate, wherein the multiple nozzles and the multiple light units are arranged in a one-to-one correspondence.

[0012] Optionally, the adjustment mechanism includes a connecting rod disposed on the housing, a pressing rod with one end rotatably connected to the connecting rod and the other end slidably passing through the bottom shell of the housing, an adjustment rod disposed at a distance from the pressing rod and with one end rotatably connected to the connecting rod and the other end slidably passing through the bottom shell of the housing, and a power unit.

[0013] Optionally, the pressure rod includes: A fixed rod is rotatably connected to the end of the connecting rod away from the adjusting rod; A contact rod is coaxially arranged with the fixed rod and axially slidably connected to the end of the fixed rod away from the connecting rod, wherein the lower end of the contact rod is provided with a ball bearing; An elastic element is elastically compressed between the fixed rod and the contact rod.

[0014] Optionally, the power unit includes a linear drive unit, a bracket connected to the linear drive unit, a cross slide table disposed on the bracket, and a connecting frame slidably connected to the cross slide table, wherein the connecting frame is connected to the spray curing head.

[0015] Furthermore, it also includes a ranging / scanning module, which is disposed on the spray curing head.

[0016] The beneficial effects of the embodiments of this disclosure include: By selecting modified polyurethane containing modified nano-ceramic particles as the top layer of the coating, and conducting a surface layer peeling test on each area to be coated in advance, a coating with a viscosity matching each area to be coated is obtained. The coating is then pre-cured to increase its viscosity. Subsequently, a coating with an appropriate viscosity is sprayed onto each area to be coated, and the infrared light emission surface is adjusted to improve the coating curing effect of the flow-through components. Attached Figure Description

[0017] Figure 1 This is a schematic flowchart of a method for curing a polyurethane coating on a water turbine, according to an embodiment of the present disclosure.

[0018] Figure 2 This is a schematic diagram of the structure of a polyurethane coating curing system for a water turbine according to an embodiment of the present disclosure; Figure 3 This is a schematic diagram of a polyurethane coating curing system for a water turbine, according to another embodiment of the present disclosure.

[0019] 1. Corrugated pipe; 2. Spray curing head; 3. Adjustment mechanism; 4. Light unit; 5. Spray nozzle; 21. Housing; 22. Substrate; 31. Connecting rod; 32. Pressing rod; 33. Adjusting rod; 34. Power unit; 321. Fixing rod; 322. Contact rod; 323. Elastic element; 341. Connecting frame; 342. Support; 343. Cross slide; 344. Linear drive unit. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The detailed descriptions and accompanying drawings of the following embodiments are used to exemplarily illustrate the principles of this application, but should not be used to limit the scope of this application; that is, this application is not limited to the described embodiments. In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicating orientation or positional relationships are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range.

[0022] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0023] like Figure 1 As shown, a method for curing a polyurethane coating on a water turbine includes: S101. Select modified polyurethane containing modified nano-ceramic particles as the top layer of the coating.

[0024] S102. Divide the surface to be coated of the turbine flow components into multiple areas to be coated, and conduct a surface layer peeling test on each area to determine the required viscosity of the surface coating for each area.

[0025] S103. Mix the topcoat coatings for each area to be coated, group them, and perform pre-curing treatments for different durations to determine the coating with the required viscosity for each area to be coated.

[0026] S104. Apply a coating with a viscosity matching that of the area to be coated to each area, and use a deformable light channel to guide the infrared light emission direction adapted to the flatness of each area to be coated to irradiate the coating at the target position for curing.

[0027] In some embodiments, the surface layer peeling test on each area to be coated includes: The highest point in each area to be coated is selected as the reference point.

[0028] Multiple test points are arranged around the reference point.

[0029] The topcoat was divided into several groups, and each group was pre-cured for a different duration.

[0030] The pre-cured coatings of each group were applied to each test point.

[0031] Based on the location of the area to be coated and the curing rate of the coating, the curing time t1 of the coating in the area to be coated is estimated.

[0032] Based on the paint layer peeling off at each test point after curing at time t1, record the paint viscosity and pre-curing time t2 corresponding to that test point.

[0033] In some embodiments, the step of guiding the formation of an infrared emitted light surface adapted to the flatness of each area to be coated using a deformable light channel to irradiate the target position includes: The surface of the area to be coated is scanned by the ranging / scanning module to obtain the three-dimensional morphological parameters of the surface of the area to be coated.

[0034] The irradiation position is adjusted by controlling the movement of the adjustment mechanism based on the three-dimensional topographic parameters and adjusting the distance between the infrared light source and the surface of the area to be coated.

[0035] refer to Figure 2-3 A second aspect of the present disclosure provides a polyurethane coating curing system for a water turbine, the system being capable of implementing the method described above, characterized in that it includes an adjustment mechanism 3, a spray curing head 2 connected to the adjustment mechanism 3, and an infrared light source corresponding to and connected to the spray curing head 2 and the adjustment mechanism 3, the adjustment mechanism 3 being configured to adjust the distance between the infrared light source and the surface of the area to be coated, thereby adjusting the irradiation position.

[0036] In some embodiments, the spray curing head 2 includes a housing 21, a substrate 22 corresponding to the housing 21, and a nozzle 5 disposed on the substrate 22. The infrared light source is disposed on the substrate 22 at a distance from the nozzle 5. The adjustment mechanism 3 is configured to adjust the distance between the substrate 22 and the housing 21. Specifically, the adjustment mechanism 3 is configured to adjust the distance between the substrate 22 and the bottom shell of the housing 21.

[0037] In some embodiments, there are multiple nozzles 5 arranged in a linear array on the substrate 22, and the infrared light source includes multiple light units 4 arranged in a linear array on the substrate 22. Each nozzle 5 corresponds to one of the multiple light units 4.

[0038] In some embodiments, the adjustment mechanism 3 includes a connecting rod 31 disposed on the housing 21, a pressing rod 32 with one end rotatably connected to the connecting rod 31 and the other end slidably passing through the bottom shell of the housing 21, an adjustment rod 33 disposed at a distance from the pressing rod 32 and with one end rotatably connected to the connecting rod 31 and the other end slidably passing through the bottom shell of the housing 21, and a power unit 34.

[0039] In some embodiments, the pressing rod 32 includes a fixing rod 321, a contact rod 322, and an elastic element 323, wherein the fixing rod 321 is rotatably connected to the end of the connecting rod 31 away from the adjusting rod 33.

[0040] The contact rod 322 is coaxially arranged with the fixed rod 321 and is axially slidably connected to the end of the fixed rod 321 away from the connecting rod 31. The lower end of the contact rod 322 is provided with a ball bearing. The elastic element 323 is elastically compressed between the fixed rod 321 and the contact rod 322.

[0041] In some embodiments, the power unit 34 includes a linear drive unit 344, a bracket 342 connected to the linear drive unit 344, a cross slide 343 disposed on the bracket 342, and a connecting frame 341 slidably connected to the cross slide 343, wherein the connecting frame 341 is connected to the spray curing head 2.

[0042] In some embodiments, the curing system further includes a ranging / scanning module disposed on the spray curing head 2.

[0043] Specifically, this application discloses a method for curing polyurethane coatings on-site for water turbines.

[0044] This application takes into account that different locations of flow-through components on the construction site require different coating conditions. For example, a high-viscosity coating is required above the volute to ensure that it does not fall off before gelation. Therefore, it is necessary to adjust the viscosity of the coating and select the viscosity according to the construction location.

[0045] On-site curing methods for polyurethane coatings on water turbines include: Step 1: Select modified polyurethane containing modified nano-ceramic particles as the top layer of the coating.

[0046] Step 2, viscosity matching, includes: The flow-through components on site are divided into multiple areas to be coated based on the orientation of the surface to be coated.

[0047] A surface layer peeling test was conducted on each area to be coated to determine the required viscosity of the surface layer and record the differential viscosity distribution data, such as the required viscosity value for each area to be coated, to form a data table.

[0048] Step 3, pre-curing of the topcoat, includes: mixing the topcoat components, grouping them, and allowing them to stand for different durations to obtain a coating with a viscosity that matches the viscosity of each area to be coated.

[0049] It is understandable that by using polyurethane as the coating matrix and modifying it with organosilicon and fluorocarbon segments, the hard segments of the polyurethane itself and the ceramic particles can improve the wear resistance of the system after the addition of hard ceramic particles.

[0050] With the above setup, the uneven distribution of ceramic particles due to sedimentation before surface curing results in a coating surface with little to no ceramic content and a high ceramic content at the coating interface. This uneven distribution of ceramic particle content leads to two problems: 1) Due to the low ceramic content, the surface layer has lower wear resistance and cavitation resistance than designed values; 2) The excessively high ceramic content near the interface below the coating reduces the strength of the coating material, resulting in a cross-sectional bonding energy lower than designed values.

[0051] To minimize the settling of ceramic particles, the viscosity of the coating needs to be properly controlled, and different viscosities should be selected for different construction areas. There are various methods to adjust the viscosity, such as adding thickeners or pre-curing. Considering that the addition of thickeners will bring complexity to the process, this application adopts the pre-curing method to increase the viscosity. After mixing the components of the coating, it is left to pre-cur for a certain period of time. After the viscosity gradually increases to a certain value as the curing reaction proceeds, the construction can be carried out.

[0052] Step four, spraying and curing, includes: A coating with matching viscosity is selected and sprayed onto each area to be coated one by one, while an infrared light source is excited at the same time. A deformable light channel guides the output light to form an output light surface adapted to the flatness of each area to be coated, irradiating the target position.

[0053] By using the above settings, modified polyurethane containing modified nano-ceramic particles is selected as the top layer of the coating. A surface layer peeling test is performed on each area to be coated in advance to obtain a coating with a viscosity that matches each area to be coated. The coating is then pre-cured to increase its viscosity. After that, a coating with an appropriate viscosity is sprayed onto each area to be coated and the emission surface of the infrared light source is adjusted to improve the coating curing effect of the flow-through components.

[0054] Regarding the surface layer peeling test, it includes: 1) Select the highest point of the area to be coated and define it as Hn, where n is the order of the areas to be coated; It is understandable that the surface layer peeling test is performed on each area to be coated, so n is the sequence number of each area to be coated.

[0055] 2) Select multiple test points around point Hn (there are multiple test points within a single area to be coated); 3) Divide the mixture of the surface layer components into multiple portions, and pre-cur each portion for a different time (e.g., pre-curing times of 0.5, 5, 10, 15 and 20 minutes). 4) Apply each group of materials to its respective test points; (this can be done using existing automated application equipment). 5) Estimate the waiting time t1 of the area to be coated based on the location of the area to be coated on the flow-through components and the curing rate. It is understandable that different areas of the flow-through components on site will have different effects on coating peeling. For example, areas located on convex surfaces will accelerate coating peeling. Therefore, it is necessary to estimate the waiting time t1 based on different locations and the curing rate of the coating, as well as the experience of the experimenters.

[0056] 6) Take any test point on the coating that shows material detachment after time t1 as a standard sample, and record its corresponding viscosity and pre-curing time t2.

[0057] Understandably, after the estimated waiting time t1, the first test point where material detachment occurs is designated as the standard sample. The pre-curing time and corresponding viscosity of this standard sample are recorded. For example, if the pre-curing time of the standard sample (coating) before being applied to each test point is 10 minutes, the corresponding viscosity is 30 Pa•s, indicating that the suitable coating viscosity for this area to be coated is 30 Pa•s. Then, the remaining areas to be coated are tested for surface layer detachment one by one. It is important to note that different pre-curing times correspond to different viscosities; the longer the pre-curing time, the higher the viscosity. The specific relationship between pre-curing time and coating viscosity can be obtained experimentally and recorded.

[0058] By setting up the above parameters, surface layer peeling tests are conducted on each area to be coated, which can determine the required viscosity of the coating for each area. This allows for the appropriate selection of viscosity based on the application location, thereby improving coating quality.

[0059] refer to Figure 2-3 Regarding the use of deformable light channels to guide the formation of outgoing light surfaces adapted to the flatness of each area to be coated, illuminating the target position, it includes: A corrugated pipe 1 is provided for electrical conduits, and a spray curing head 2 for mounting an infrared light source and a nozzle 5 is provided at one end of the corrugated pipe 1. An adjustment mechanism 3 is installed on the spray curing head 2 and the corrugated pipe 1. A ranging / scanning module is set up to scan the area to be coated to obtain the distribution parameters of the working surface, and the adjustment mechanism 3 is controlled to adjust the distance between the infrared light source and the working surface according to the distribution parameters of the working surface.

[0060] It is understandable that the ranging / scanning module can be a module integrating a laser triangulation ranging sensor and a structured light 3D scanning module. It calculates distance through the triangulation relationship between laser point projection and camera imaging, and projects an coded pattern (stripes / dot matrix) and decodes the deformation through the camera. This can be achieved using existing technology, so it will not be elaborated upon here. The working surface distribution parameters should at least include the location and distance difference of each point in the working surface area.

[0061] Continue to refer to Figure 2 and Figure 3 The infrared light source includes multiple linearly arrayed light units 4, which can be infrared LEDs. Multiple nozzles 5 are arranged in a linear array, with the number of nozzles 5 matching the number of light units 4. The spray curing head 2 includes a rectangular strip-shaped housing 21 and multiple linearly arrayed substrates 22. The substrates 22 are arranged along the length of the housing 21, with the number of substrates 22 matching the number of light units 4. One end of each substrate 22 is fixed to a light unit 4, and the other end is fixed to a nozzle 5. It should be noted that the spraying end of the nozzle 5 faces away from the light unit 4. The nozzle's injection tube can bypass the housing and be hidden inside a corrugated pipe 1. The power circuit board of the light unit 4 can be mounted on the substrate 22, and the power wires can be hidden inside the corrugated pipe 1. The specific wiring method can be adjusted according to the actual situation.

[0062] Since the flatness of different surfaces to be coated varies, if the distance between the substrate 22 and the housing 21 is always kept fixed, the distance between the infrared light source on the substrate 22 and each surface to be coated will be different when the spray curing head 2 moves above different surfaces to be coated, thus affecting the curing effect. Therefore, the distance between the substrate 22 and the housing 21 is changed by the adjustment mechanism 3.

[0063] Reference Figure 3 In another embodiment of this application, the adjustment mechanism 3 includes a connecting rod 31, a pressing rod 32, an adjusting rod 33, and a power unit 34. The adjusting rod 33 and the pressing rod 32 are parallel to each other and slide through the housing 21. The lower ends of the adjusting rod 33 and the pressing rod 32 both extend out of the lower surface of the housing 21. The lower end of the adjusting rod 33 is fixedly connected to the upper surface of the substrate 22.

[0064] It should be noted that in this embodiment, a connecting rod 31, a pressing rod 32 and an adjusting rod 33 are a group, which work together to adjust a substrate 22. Since there are multiple substrates 22, the number of connecting rods 31, pressing rods 32 and adjusting rods 33 is the same as the number of substrates 22. In addition, the housing 21 is divided into multiple partition cavities for setting the connecting rods 31.

[0065] The connecting rod 31 is a telescopic structure, with both ends being hollow and open. Telescopic rods slide through the open ends of the connecting rod 31. The connecting rod 31 is rotatably connected to the inner wall of the housing 21 via bearings. One telescopic rod is hinged to the upper end of the pressing rod 32, and the other telescopic rod is hinged to the upper end of the adjusting rod 33. The length of the pressing rod 32 is greater than the length of the adjusting rod 33, and the length of the pressing rod 32 extending out of the housing 21 is greater than the length of the adjusting rod 33 extending out of the housing 21. The power unit 34 is used to control the position of the moving housing 21 according to the distribution parameters of the working surface, so that when the bottom of the pressing rod 32 contacts the surface to be coated, the substrate 22 can maintain a gap with the surface to be coated, preventing the light unit 4 and the nozzle 5 from contacting the surface to be coated.

[0066] Since the surfaces to be coated will not maintain the same flatness, the pressure rod 32 is an elastic telescopic structure to better adapt to surfaces with different flatness. Specifically, the pressure rod 32 includes a fixed rod 321, a contact rod 322, and an elastic element 323. The upper end of the fixed rod 321 is hinged to the telescopic rod end of the connecting rod 31. The upper end of the contact rod 322 is fixedly connected to a limit rod, which slides through the lower end of the fixed rod 321. The elastic element 323 is sleeved on the outside of the limit rod, and one end of the elastic element 323 is fixed. Connected to the lower end of the fixed rod 321, the other end of the elastic element 323 is fixed to the upper end of the contact rod 322. Thus, the power unit 34 drives the spray curing head 2, causing the bottom of the contact rod 322 to contact the surface to be coated. The elastic element 323 deforms and contracts. As the spray curing head 2 moves, the contact rod 322 remains in contact with the surface to be coated, driving the substrate 22 to move and adjusting the distance between the substrate 22 and the housing 21. This ensures that the distance between the substrate 22 and each surface to be coated remains relatively consistent, improving the curing effect and consistency. To reduce friction, a ball bearing is rolled at the lower end of the contact rod 322.

[0067] The power unit 34 includes a connecting frame 341, a bracket 342, a cross slide 343, a linear drive unit 344, and a controller. The bracket 342 is used to support and install the cross slide 343. The bottom of the bracket 342 is fixed to the moving part of the linear drive unit 344. The first end of the connecting frame 341 is connected to the spray curing head 2, and the second end is fixed to the sliding part of the cross slide 343. Thus, the spray curing head 2 is driven to move in three axes through the cross slide 343 and the linear drive unit 344. The corrugated pipe 1 can be fixed to the connecting frame 341 by a pipe clamp to play a supporting role.

[0068] In this embodiment, the spray curing head 2 is shown as a vertical working surface. In other embodiments, the orientation of the spray curing head 2 can be adaptively adjusted according to the on-site construction conditions and the coating position of the disassembled flow-through components. The orientation of the spray curing head 2 can be towards the side, top, or bottom of the flow-through components. The spray curing head 2 can also rotate around its center to adjust the working angle. After adjustment, it is then tightened by locking components such as screws. To achieve the above functions, the connection between the spray curing head 2 and the connecting frame 341 is as follows: a rotating seat is rotatably connected to the back of the housing 21 of the spray curing head 2. The rotating seat is connected to the connecting frame 341 by a hinge. The housing 21 and the rotating seat, as well as the rotating seat and the connecting frame 341, are fixed by screws and nuts to prevent the position of the rotating seat and the housing 21 from changing during the spray curing process.

[0069] The controller is electrically connected to the cross slide 343, the linear drive unit 344, the ranging / scanning module, and the opening and closing system of the infrared light source and nozzle 5, and is configured as follows: Based on the analysis of differential viscosity distribution data and the working surface distribution parameters fed back by the ranging / scanning module, the working surfaces with coatings matching the same viscosity are grouped together, and the corresponding matching viscosity generation group number is marked. The group numbers are arranged in order to obtain the working sequence.

[0070] Understandably, since the above operation steps have already conducted surface peeling tests on each area to be coated, obtaining differentiated viscosity distribution data, i.e., the viscosity required for each area, and combining this with the distribution parameters of the work surface for one-to-one matching analysis, it is possible to determine the viscosity value of the coating required for each work surface. Work surfaces that are suitable for the same viscosity of coating are grouped together, and the corresponding viscosity is marked. At the same time, each work surface within each group is also numbered. For example, the group numbers of each group are a30, b50, c60...; the work surfaces within group a30 are numbered a30 / 1, a30 / 2, a30 / 3... where 30, 50, and 60 are the coating viscosity values, and a, b, and c are the group numbers. The work is carried out in the order of abc... to obtain the work sequence. Based on the above example, the work surface with a viscosity of 30 Pa•s can be sprayed first, and then the work surface with a viscosity of 50 Pa•s can be sprayed by injecting coating with nozzle 5. This eliminates the need to repeatedly change different viscosities and reduces the probability of spraying errors.

[0071] Based on the preset rules of spraying before curing and the viscosity matching each working surface, the cross slide 343 and the linear drive unit 344 control the spraying and curing head 2 to move to the working surface according to the working sequence, and control the infrared light source and the opening and closing system of the nozzle 5 to respond.

[0072] Understandably, the cross slide 343 and the linear drive unit 344 drive the spray curing head 2 to move to the working surface numbered 1 in group a, and control the spray head 5 to spray paint with a viscosity of 30 Pa•s. After spraying, the infrared light source is turned on for infrared curing. Then it moves to the working surface numbered 2 in group a and continues to spray paint with a viscosity of 30 Pa•s, and then infrared curing, until all areas in group a are sprayed and cured. Then group b is sprayed, and so on. In another embodiment of this application, in order to facilitate the movement and control of the ranging / scanning module, the ranging / scanning module can be installed outside the housing 21 of the spray curing head 2, so that the position of the spray curing head 2 can be moved by the cross slide 343 and the linear drive unit 344, so that the ranging / scanning module can scan the area to be coated.

[0073] The on-site polyurethane coating fixing system for a water turbine in this embodiment of the application further includes a memory and a processor. The memory stores a computer program that can be loaded by the processor and executed as any of the water turbine polyurethane coating curing methods described above.

[0074] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A method for curing a polyurethane coating on a water turbine, characterized in that, include: Modified polyurethane containing modified nano-ceramic particles was selected as the top layer of the coating. The surface to be coated on the flow-through components of the water turbine is divided into multiple areas to be coated, and a surface coating peeling test is performed on each area to determine the required viscosity of the surface coating for each area. The topcoat coatings for each area to be coated were mixed and grouped, and pre-cured for different durations to determine the coating with the required viscosity for each area to be coated. The coating with a viscosity matching that of the area to be coated is sprayed onto each area, and an infrared light emission surface adapted to the flatness of each area is guided by a deformable light channel to irradiate the coating at the target position for curing.

2. The method for curing polyurethane coating on a water turbine according to claim 1, characterized in that, The surface layer peeling test for each area to be coated includes: Select the highest point in each area to be coated as the reference point; Multiple test points are arranged around the reference point. The topcoat was divided into several groups, and each group was pre-cured for a different duration. The pre-cured coatings of each group were applied to each test point; Based on the location of the area to be coated and the curing rate of the coating, estimate the curing time t1 of the coating in the area to be coated; Based on the paint layer peeling off at each test point after curing at time t1, record the paint viscosity and pre-curing time t2 corresponding to that test point.

3. The method for curing polyurethane coating on a water turbine according to claim 1, characterized in that, The method of guiding infrared emitted light to the target position using a deformable light channel to adapt to the flatness of each area to be coated includes: The surface of the area to be coated is scanned by the ranging / scanning module to obtain the three-dimensional morphological parameters of the surface of the area to be coated; The irradiation position is adjusted by controlling the movement of the adjustment mechanism based on the three-dimensional topographic parameters and adjusting the distance between the infrared light source and the surface of the area to be coated.

4. A polyurethane coating curing system for a water turbine, said system being capable of implementing the method described in any one of claims 1-3, characterized in that, It includes an adjustment mechanism, a spray curing head connected to the adjustment mechanism, and an infrared light source that is correspondingly arranged with and connected to the adjustment mechanism. The adjustment mechanism is configured to adjust the distance between the infrared light source and the surface of the area to be coated, so as to achieve irradiation position adjustment.

5. The polyurethane coating curing system for water turbines according to claim 4, characterized in that, The spray curing head includes a housing, a substrate corresponding to the housing, and a nozzle disposed on the substrate; the infrared light source is disposed on the substrate at a distance from the nozzle; wherein the adjustment mechanism is configured to adjust the distance between the substrate and the housing.

6. The polyurethane coating curing system for water turbines according to claim 5, characterized in that, The nozzles are multiple and arranged in a linear array on the substrate. The infrared light source includes multiple light units and is arranged in a linear array on the substrate. The multiple nozzles and the multiple light units are arranged in a one-to-one correspondence.

7. The polyurethane coating curing system for water turbines according to claim 5, characterized in that, The adjustment mechanism includes a connecting rod disposed on the housing, a pressing rod with one end rotatably connected to the connecting rod and the other end slidably passing through the bottom shell of the housing, an adjustment rod disposed at a distance from the pressing rod and with one end rotatably connected to the connecting rod and the other end slidably passing through the bottom shell of the housing, and a power unit.

8. The polyurethane coating curing system for water turbines according to claim 7, characterized in that, The pressure rod includes: A fixed rod is rotatably connected to the end of the connecting rod away from the adjusting rod; A contact rod is coaxially arranged with the fixed rod and axially slidably connected to the end of the fixed rod away from the connecting rod, wherein the lower end of the contact rod is provided with a ball bearing; An elastic element is elastically compressed between the fixed rod and the contact rod.

9. The polyurethane coating curing system for water turbines according to claim 7, characterized in that, The power unit includes a linear drive unit, a bracket connected to the linear drive unit, a cross slide table disposed on the bracket, and a connecting frame slidably connected to the cross slide table, wherein the connecting frame is connected to the spray curing head.

10. The polyurethane coating curing system for a water turbine according to claim 4, characterized in that, Also includes: The ranging / scanning module is located on the spray curing head.

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