阅读说明：本技术 一种锅炉水冷壁涂层制备双热源协同重熔方法 (Method for preparing double-heat-source synergistic remelting through boiler water wall coating ) 是由 曲作鹏 王海军 赵文博 田欣利 于 2020-05-19 设计创作，主要内容包括：本发明涉及管排重熔技术领域,且公开了一种锅炉水冷壁涂层制备双热源协同重熔方法,包括以下步骤：第一步：预整理,对场地进行清理和打扫,使得周围场地整洁,无异物。第二步：管排受热面喷砂处理,采用压缩空气为动力,以形成高速喷射束将喷料(铜矿砂、石英砂、金刚砂、铁砂、海砂)高速喷射到管排工件表面,磨料对管排工件表面产生冲击和切削作用,使管排工件的表面获得一定的粗糙度,增加管排和涂层之间的附着力,延长涂层的耐久性。第三步：检测材料设备,对管排进行表面检测,对多工位激光器或小型电弧或火焰喷枪进行预点火并检查,以检测其性能是否稳定。第四步：管排受热面火焰喷涂镍基自熔合金；第五步：高频感应重熔。(The invention relates to the technical field of tube bank remelting, and discloses a method for preparing a double-heat-source synergistic remelting coating on a water wall of a boiler, which comprises the following steps: the first step is as follows: and pre-finishing, namely cleaning and sweeping the field, so that the surrounding field is clean and tidy without foreign matters. The second step is that: the method comprises the following steps of performing sand blasting treatment on the heating surface of a tube bank, forming a high-speed spraying beam by using compressed air as power, spraying materials (copper ore sand, quartz sand, carborundum, iron sand and sea sand) onto the surface of a tube bank workpiece at a high speed, and enabling the abrasive to impact and cut the surface of the tube bank workpiece, so that the surface of the tube bank workpiece obtains certain roughness, the adhesive force between the tube bank and a coating is increased, and the durability of the coating is prolonged. The third step: and the material detection equipment is used for carrying out surface detection on the tube bank, pre-igniting and checking the multi-station laser or the small electric arc or flame spray gun to detect whether the performance of the device is stable. The fourth step: flame spraying nickel-based self-fluxing alloy on the heating surface of the tube bank; the fifth step: and (4) high-frequency induction remelting.)

1. A method for preparing double-heat-source synergistic remelting through a boiler water wall coating is characterized by comprising the following steps:

the first step is as follows: pre-finishing, namely cleaning and cleaning the field to ensure that the surrounding field is clean and tidy without foreign matters;

the second step is that: the material detection equipment is used for carrying out surface detection on the tube bank, igniting and checking a laser or a multi-station small electric arc or flame spray gun to detect whether the performance of the material detection equipment is stable;

the third step: performing sand blasting treatment on the heating surface of the tube bank, wherein compressed air is used as power to form a high-speed spray beam to spray materials (copper ore sand, quartz sand, carborundum, iron sand and sea sand) to the surface of a tube bank workpiece at a high speed, and the grinding materials have impact and cutting effects on the surface of the tube bank workpiece;

the fourth step: flame spraying nickel-based self-fluxing alloy on the heating surface of the tube bank;

the fifth step: the method comprises the following steps that a preheating terminal is selected, two types of preheating terminals are provided, firstly, an optical fiber terminal of a laser is preheated, a multi-station optical fiber laser or a YAG laser is coupled with a multi-station optical fiber, one or two laser hosts are adopted, and each host can drive a plurality of optical fiber terminals to work. When the remelting starts, the tube row moves forwards, the terminal starts to emit laser, and the vicinity of the root of the tube is heated firstly; preheating a multi-station small electric arc or flame spray gun, adopting 1-2 power supply hosts or 1-2 sets of oxyacetylene systems, placing a small spray gun between two tubes, aligning a gun muzzle to the center of a fin, and starting the spray gun to work when a tube row moves forwards after remelting starts;

and a sixth step: the method comprises the following steps that a preheating terminal is installed, a supporting metal frame is installed and fixed close to the end face of a high-frequency induction rectangular copper coil, optical fiber terminals of lasers with a plurality of stations are installed on the supporting frame at intervals along the transverse direction of a tube bank, a multi-station optical fiber laser or a YAG laser is adopted to couple multi-station optical fibers, two laser hosts are adopted, and each host can drive the optical fiber terminals to work;

the seventh step: preheating is started, under the traction of a transmission chain below the tube bank, the tube bank moves forwards, and meanwhile, a preheating system is started, namely, the root (fins) of the tube of the laser beam is started to be heated firstly;

eighth step: heating and remelting the high-frequency induction coil, and enabling the tube row to enter a heating area of the high-frequency induction coil;

the ninth step: cooling, wherein the surface of the tube bank is naturally cooled to room temperature along with the tube bank continuously moving forwards;

the tenth step: correcting, namely correcting thermal deformation in the remelting process;

the eleventh step: and detecting the tube bank coating, and comprehensively testing the coating quality.

Technical Field

The invention relates to the technical field of tube bank remelting, in particular to a method for preparing a double-heat-source synergistic remelting coating on a boiler water wall.

Background

In recent years, along with the implementation of major policy and policy of national circular economy, the waste incineration power generation in China enters a rapid development track, and the scale of the waste incineration power generation installation and the well-jet type high-speed development of the generated energy are the first in the world at present. The membrane type water-cooled wall heating surface is a main heating part of the boiler, is an airtight tube bank structure formed by welding tubes and fins, and is laid on an evaporation heating surface formed by the inner wall of a boiler hearth. The function of the membrane type water wall tube bank is to absorb the radiation heat of high-temperature flame or smoke in the hearth, generate hot water and steam in the tube for power generation, reduce the temperature of the furnace wall and protect the furnace wall. The flame temperature in the furnace is over 1000 ℃ at most. More than 50% of the heat in the boiler is absorbed by the membrane walls. However, the existing high-frequency remelting process of the water wall tube bank has a troublesome problem that because the distances between each point on the coating surface of the tube bank and the inner upper surface of the coil are unequal, the tube top part closest to the upper surface of the coil (about 5-10mm) is undoubtedly melted firstly during remelting, and the distance between the tube top and the tube root part is about 25mm, when the tube root and the fins are melted by continuous heating, the tube top part is melted and even flows towards two sides gradually in a liquid phase locally. The result of this is that the coating thickness is not uniform from top to bottom; secondly, the heavy melt quality is greatly influenced, for example, the surface performance of a coating on the upper part of the pipe is poor due to large grains after long heating time; the service life of the root of the tube may be affected by insufficient remelting.

In order to solve the problem, profiling coil tests are carried out, but the effect is still unsatisfactory, one reason is that although the profiling coil structure is designed and manufactured according to the shape of the tube bank, namely the distance between the inner surface of the coil and the tube top and the fins of the heating surface of the tube bank is about 20mm, the deformation and manufacturing error caused by the welding structure of the tube bank are large actually, namely the consistency of the structure of each tube bank is poor, when the upper surface of the coil is too close to the surface of a certain position of the tube bank, the surface touch is inevitably caused to cause local overheating of the coating of the tube bank, and even the coil is damaged; secondly, the electromagnetic field eddy current effect is distorted due to the special-shaped structure of the coil, and even if the surface gaps of the tube rows are completely consistent, the heating is still difficult to be uniform.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a method for preparing a double-heat-source synergistic remelting coating on a boiler water wall.

(II) technical scheme

A method for preparing double-heat-source synergistic remelting by using a boiler water wall coating comprises the following steps:

the first step is as follows: the field is cleaned and cleaned, so that the surrounding field is clean and tidy without foreign matters.

The second step is that: and the material detection equipment is used for detecting the surface of the tube bank and checking the laser or the multi-station small electric arc or flame spray gun to detect whether the performance of the device is stable.

The third step: the method comprises the following steps of performing sand blasting treatment on the heating surface of a tube bank, forming a high-speed spraying beam by using compressed air as power, spraying materials (copper ore sand, quartz sand, carborundum, iron sand and sea sand) onto the surface of a tube bank workpiece at a high speed, and enabling the abrasive to impact and cut the surface of the tube bank workpiece, so that the surface of the tube bank workpiece obtains certain roughness, the adhesive force between the tube bank and a coating is increased, and the durability of the coating is prolonged.

The fourth step: and (4) flame spraying self-melting alloy on the heating surface of the tube bank.

The fifth step: selecting preheating terminals, wherein the preheating terminals are two types, one is that the optical fiber terminal of the laser is preheated, namely a multi-station optical fiber laser or a YAG laser is adopted to couple a multi-station optical fiber, one or two laser hosts are adopted, each host can drive a plurality of optical fiber terminals to work, each terminal is aligned to the root of a side pipe, namely the optical fiber terminal is inclined 45-60 degrees relative to the horizontal plane, the terminal port is 30-50mm away from the pipe root, when remelting starts, the pipe row moves forwards, the terminal starts to emit laser, the diameter of a laser spot is about 2-3mm, the vicinity of the pipe root is heated firstly, and the preheating can be carried out to 600-800 ℃ within 2-5 seconds; the other is preheating of multi-station small electric arc or flame spray gun, that is, 1-2 electric arc power main machines or 1-2 sets of oxyacetylene system are used, the preheating method is similar to the above, the difference is that the distance between the centers of two tubes of the tube row is only about 80mm, the width of the fin is about 20mm, even if the small spray gun can only be placed between the two tubes, the muzzle is aligned to the center of the fin, the muzzle is about 15-25mm away from the surface of the fin, when remelting begins, the tube row moves forwards, the spray gun begins to work, because the electric arc or flame has larger spraying area, the heating area can cover the tube root and the whole length of the fin, because the energy density of the electric arc or flame is lower than that of laser.

And a sixth step: the method comprises the steps of installing a preheating terminal, installing and fixing a supporting metal frame close to the end face of a high-frequency induction rectangular copper coil, installing optical fiber terminals of lasers with a plurality of stations arranged at intervals along a tube bank on the supporting frame, adopting a multi-station optical fiber laser or a YAG laser to couple multi-station optical fibers, and adopting one or two laser hosts, wherein each host can drive a plurality of optical fiber terminals to work, each domestic medium-power (200 and 500W) laser is used, each terminal is aligned to the root of a side tube, namely the optical fiber terminal is inclined 45-60 degrees relative to the horizontal plane, and the terminal port is 30-50mm away from the tube root.

The seventh step: preheating is started, the tube bank moves forwards under the traction of a transmission chain below the tube bank, and meanwhile, a preheating system is started, namely, the root (including fins) of a tube which emits a laser beam is heated firstly, the actual heating speed is determined according to the moving speed of the tube bank, the tube root is preheated to 500-800 ℃ within 2-5 seconds according to the energy density estimation of laser, the diameter of a laser spot is about 2-3mm, and the vicinity of the tube root is heated firstly.

Eighth step: and heating and remelting the high-frequency induction coil, and enabling the tube bank to enter a heating area of the high-frequency induction coil.

The ninth step: and cooling, and naturally cooling the surface of the tube bank to room temperature as the tube bank continues to move forwards.

The tenth step: and correcting the thermal deformation in the remelting process.

The eleventh step: and detecting the tube bank coating, and comprehensively testing the coating quality.

(III) advantageous effects

Compared with the prior art, the invention provides a method for preparing a double-heat-source synergistic remelting coating on a boiler water wall, which has the following beneficial effects:

1. according to the method for preparing the double-heat-source synergistic remelting coating on the water wall of the boiler, the remelting consistency of the surface of the coating of the tube bank is improved, the quality of high-frequency induction remelting is greatly improved, and the service life and the working reliability of the water wall tube bank are guaranteed while the porosity of the coating is reduced and the interface bonding strength is improved.

2. According to the method for preparing the double-heat-source synergistic remelting through the boiler water wall coating, the tube bank fins are preheated by using the laser terminal, so that the heating time of high-frequency induction remelting is obviously shortened, and the remelting efficiency is improved.

3. Although the one-time equipment investment and the corresponding energy consumption of the preheating system are increased, the total remelting time of the tube bank is shortened, the remelting power consumption far exceeds the energy consumption of the preheating system, the comprehensive electricity consumption is obviously saved, and the economy of coating preparation is improved.

4. According to the method for preparing the double-heat-source synergistic remelting through the boiler water wall coating, the root part (including the fins) of the tube is preheated in advance, so that the influence of inconsistent remelting quality caused by the heating speed difference caused by the surface distance difference between the high-frequency coil and the tube bank coating is basically eliminated, and the phenomenon that the coating material on the top of the long tube flows to the root part of the tube due to the heating time is fundamentally eliminated.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A method for preparing double-heat-source synergistic remelting by using a boiler water wall coating comprises the following steps:

the first step is as follows: and (4) preprocessing, namely cleaning and sweeping the field, so that the surrounding field is clean and tidy without foreign matters.

The second step is that: and the material detection equipment is used for carrying out surface detection on the tube bank and checking the laser and the multi-station small electric arc or flame spray gun to detect whether the performance is stable.

The third step: the method comprises the following steps of performing sand blasting treatment on the heating surface of a tube bank, forming a high-speed spraying beam by using compressed air as power, spraying materials (copper ore sand, quartz sand, carborundum, iron sand and sea sand) onto the surface of a tube bank workpiece at a high speed, and enabling the abrasive to impact and cut the surface of the tube bank workpiece, so that the surface of the tube bank workpiece obtains certain roughness, the adhesive force between the tube bank and a coating is increased, and the durability of the coating is prolonged.

The fourth step: and (4) flame spraying self-melting alloy on the heating surface of the tube bank.

The fifth step: selecting preheating terminals, wherein the preheating terminals are two types, one is that the optical fiber terminal of the laser is preheated, namely a multi-station optical fiber laser or a YAG laser is adopted to couple a multi-station optical fiber, one or two laser hosts are adopted, each host can drive a plurality of optical fiber terminals to work, each domestic medium power (200-; the other is preheating of multi-station small electric arc or flame spray gun, that is, 1-2 power supply main machines or 1-2 sets of oxyacetylene system are adopted, the preheating method is similar to the above, the difference is that the distance between the centers of two tubes of the tube row is only about 80mm, the width of the fin is about 20mm, even if the small spray gun can only be placed between the two tubes, the muzzle is aligned to the center of the fin, the muzzle is about 15-25mm away from the surface of the fin, when remelting begins, the tube row moves forwards, the spray gun begins to work, because the electric arc or flame has larger spraying area, the heating area can cover the tube root and the whole length of the fin, because the energy density of the electric arc or flame is lower than that of laser.

And a sixth step: the method comprises the steps of installing a preheating terminal, installing and fixing a supporting metal frame close to the end face of a high-frequency induction rectangular copper coil, installing optical fiber terminals of lasers with a plurality of stations arranged at intervals along a tube bank on the supporting frame, adopting a multi-station optical fiber laser or a YAG laser to couple multi-station optical fibers, and adopting one or two laser hosts, wherein each host can drive a plurality of optical fiber terminals to work, each domestic medium-power (200 and 500W) laser is used, each terminal is aligned to the root of a side tube, namely the optical fiber terminal is inclined 45-60 degrees relative to the horizontal plane, and the terminal port is 30-50mm away from the tube root.

The seventh step: preheating is started, the tube bank moves forwards under the traction of a transmission chain below the tube bank, and meanwhile, a preheating system is started, namely, the root (including fins) of a tube which emits a laser beam is heated firstly, the actual heating speed is determined according to the moving speed of the tube bank, the tube root is preheated to 500-800 ℃ within 3-5 seconds according to the energy density estimation of laser, the diameter of a laser spot is about 2-3mm, and the vicinity of the tube root is heated firstly.

Eighth step: and heating and remelting the high-frequency induction coil, and enabling the tube bank to enter a heating area of the high-frequency induction coil. Because the preheating procedure of the tube root is added, the moving speed of the tube bank can be 30-50% faster than the original speed, the remelting time is greatly shortened, and the phenomenon that the coating material on the top of the long tube flows to the tube root due to the heating time is fundamentally eliminated.

The ninth step: and cooling, wherein the tube bank in the red hot state after remelting is naturally cooled to normal temperature in air as the tube bank moves forwards continuously.

The tenth step: and correcting the thermal deformation in the remelting process.

The eleventh step: and detecting the tube bank coating, and comprehensively testing the coating quality.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.