JP4772573B2 - Turbine parts scale removal method and inspection method - Google Patents

Description

  The present invention relates to a scale removal method and an inspection method for turbine parts such as moving blades and stationary blades.

  On the surfaces of moving blades, stationary blades, rotors, casings, and the like of gas turbines and steam turbines, scales mainly made of metal oxide are formed as the turbine operates. The scale grows up if left unattended, and there is a risk of detaching it into pieces and damaging the turbine parts and piping. Therefore, it is necessary to remove the scale during periodic inspections.

  As a conventionally known scale removal method, there is a method in which a high-pressure liquid is injected into a chemical cleaning liquid at a high speed and collides with the scale. In the invention described in Patent Document 1 below, the inside of a boiler of a power plant is cleaned. In this case, the scale adhering to the inner surface of the boiler evaporator tube is removed by circulation of high-temperature steam and an acidic chemical cleaning solution.

In addition, the invention described in Patent Document 2 is a method for removing a chromium oxide coating layer from a nickel-base alloy component in a gas turbine engine, purifying the component in an alkaline degreasing / rusting solution at 82 to 93 ° C., and 54 The turbine component coating layer is dissolved in an acidic stripping solution containing hydrochloric acid and an etch inhibitor at -60 ° C.
Japanese Patent Laid-Open No. 9-87877 JP 2003-193276 A

  As described above, the method for removing the oxide scale of the boiler system and the method and temperature for removing the coating layer of the component by chemical dissolution in order to repair the special coating used in the gas turbine are known, A method for descaling and inspecting turbine parts having complex shapes, such as moving blades and stationary blades of steam turbines, has not yet been invented.

  SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and a turbine component descaling method and inspection capable of removing and inspecting a scale formed on the surface of a turbine component having a complicated shape with good workability. It aims to provide a method.

In order to solve the above-mentioned problems, the invention of claim 1 is a method of attaching a tray made of silicone resin to the surface of a turbine component and injecting a cleaning liquid into the tray to remove the scale on the surface of the turbine component.

The invention according to claim 6 is a method for inspecting a surface of the turbine part that cannot be directly observed after performing descaling by the method of claim 1 using a reflecting mirror made of metal or metal-plated.

  According to the present invention, a scale formed on the surface of a turbine part having a complicated shape can be removed and inspected with good workability.

The turbine component scale removal method and inspection method according to the embodiment of the present invention will be described below with reference to FIGS.
The present invention can be applied to steam turbine components. The steam turbine is composed of a high / medium pressure steam turbine and a low pressure steam turbine, and the objects of descaling and inspection according to the present invention are the moving blade, stationary blade, rotor and casing of the steam turbine. The shape of the steam turbine varies depending on the model. The present invention can also be applied to gas turbine components. The objects of descaling and inspection according to the present invention are the moving blades, stationary blades, rotor and casing of the gas turbine compressor. The shape of the gas turbine varies depending on the model.

  FIG. 1 shows how to make a scale removing tray 14 used in the embodiment of the present invention and how to attach the steam turbine to the moving blade 4. That is, as shown in FIG. 1A, a silicone resin material 13 in which a base material 11 and a curing material 12 are kneaded is used, and the scale removing tray 14 is attached to the moving blade 4 as shown in FIG. 1B. make. Since the base material 11 and the curing material 12 are cured in 5 to 30 minutes after being kneaded, the tray 14 is made before curing. In the present invention, the tray 14 includes a tray and a container for receiving “drip” such as fluid, which is a general definition of the tray, and includes a fluid as described in FIG. It shall include a simple container surrounded by a bank-like object provided in the portion to be stored.

  FIG. 2 shows a cleaning liquid injection method, a cleaning liquid heating method, and an ultrasonic cleaning method according to this embodiment. As shown in FIG. 2 (a), a cleaning liquid 21 is injected by a syringe 15 into a scale removing tray 14 attached to a moving blade 4 of a steam turbine. The cleaning liquid 21 is a phosphoric acid based cleaning liquid to which a corrosion inhibitor, an amphoteric surfactant, a cationic surfactant and a nonionic surfactant are added.

  As a heating method of the cleaning liquid 21, as shown in FIG. 2B, the heater 16 is inserted into the cleaning liquid 21, and the cleaning liquid 21 is heated to 30 to 90 ° C. and then held for 10 to 60 minutes. As an ultrasonic cleaning method, as shown in FIG. 2C, an ultrasonic oscillator 17 is inserted into the cleaning liquid 21, and ultrasonic vibration is applied to the surface of the moving blade 4 to remove the scale.

  Next, FIG. 3 shows a method of discharging the cleaning liquid after removing the scale, a method of drying the blade surface, and an inspection method according to the present embodiment. After removing the scale, as shown in FIG. 3 (a), the washing liquid inside the tray 14 is discharged by the syringe 15, the tray 14 is removed from the blade 4, and the surface of the blade 4 is cleaned with pure water, ethanol, or acetone. . Next, as shown in FIG.3 (b), 35-95 degreeC air is sent using the warm air dryer 18, and the surface of the moving blade 4 is dried. Next, as shown in FIG. 3C, surface inspection is performed using a microscope 19 and a reflecting mirror 20. The reflector 20 is made of metal or surface metal plating.

According to the present embodiment, by using the silicone resin material 13, it is possible to make and attach the scale removing tray 14 according to the complicated shape of the moving blade 4.
Further, by using a phosphoric acid-based cleaning liquid 21, the scale can be efficiently removed without adversely affecting the moving blade 4. Further, by using the heater 16 and the ultrasonic oscillator 17, the effect of the cleaning liquid 21 can be enhanced and the scale can be efficiently removed. Further, by using the pump and the syringe 15, the cleaning liquid 21 can be easily injected and discharged even in a narrow inspection work place. Further, by using the warm air dryer 18 after cleaning with pure water, ethanol or acetone, the moving blade 4 after the scale removal can be dried and rusting can be prevented.

  Moreover, according to this Embodiment, the narrow location between the moving blade 4 and a stationary blade can be test | inspected by using the reflective mirror 20. FIG. Further, the surface of the moving blade 4 can be directly reflected and inspected by using the reflecting mirror 20 having a metal or metal-plated surface, thereby preventing the influence of the reflection of the glass itself such as a glass mirror. it can.

  Although the present embodiment has been described by taking a moving blade as a turbine component for performing scale removal and inspection, scale removal and inspection can also be performed for a stationary blade, a rotor, a casing, and the like by a similar process.

The figure which shows the (a) resin preparation process and (b) saucer attachment process in embodiment of this invention. The figure which shows the (a) washing | cleaning liquid injection | pouring process to a receiving tray in embodiment of this invention, the (b) washing | cleaning liquid heating process, and the (c) ultrasonic vibration process. The figure which shows the (a) washing | cleaning liquid discharge | emission process from a tray, (b) drying process, and (c) inspection process in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 4 ... Rotor blade, 11 ... Base material, 12 ... Hardening material, 13 ... Silicone resin material, 14 ... Saucer, 15 ... Syringe, 16 ... Heater, 17 ... Ultrasonic oscillator, 18 ... Hot-air dryer, 19 ... Microscope 20 ... reflecting mirror, 21 ... cleaning liquid.

Claims (6)

A turbine component descaling method comprising: mounting a tray made of silicone resin on a surface of a turbine component; and pouring a cleaning liquid into the tray to remove scale on the surface of the turbine component.   2. The turbine component scale removal method according to claim 1, wherein the cleaning liquid is a phosphoric acid-based cleaning liquid to which a surfactant and a rust preventive agent are added.   The scale removal method for a turbine part according to claim 1, wherein the scale is removed by heating the cleaning liquid to 30 to 90 ° C.   The scale removal method for a turbine part according to claim 1, wherein the scale removal is performed by applying ultrasonic vibration to the surface of the turbine part via the cleaning liquid.   The scale removal method for a turbine part according to claim 1, wherein after removing the scale, the cleaning liquid is discharged from the tray and the surface of the turbine part is cleaned with pure water, ethanol or acetone.   A turbine component inspection method, comprising: inspecting a surface of the turbine component that is not directly observable using a metal or a metal-plated reflector after performing the turbine component descaling method according to claim 1. .

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