JP2002361470A - Heat treatment device and heat treatment method of heating tube panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment device and a heat treatment method of a heating tube panel in which the high quality of welded parts of a product can be maintained, and the efficient work can be improved. SOLUTION: The heat treatment device of the heating tube panel comprises a heating furnace 22 for accommodating welded parts WA, WA1 , and WA2 of headers 17a and 17b, a heating means 21 provided on the heating furnace 22 to heat the welded parts WA, WA1 , and WA2 , and an automatic control device 25 for maintaining the temperature in the heating furnace 22 to be constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for heat treatment of a heat transfer tube panel for maintaining a high quality of a welded portion after welding.

[0002]

2. Description of the Related Art Recent thermal power plants have been evaluated for their high thermal efficiency and short start-up time. Combined cycle power plants, which combine a gas turbine plant with a steam turbine plant and a waste heat recovery boiler, dominate. It is getting.

An exhaust heat recovery boiler incorporated in a combined cycle power plant uses exhaust gas from a gas turbine plant as a heat source and heats water supplied from a steam turbine plant to generate steam, and the configuration thereof is shown in FIG. There is something.

[0004] The exhaust heat recovery boiler contains, for example, a large number of heat exchangers 2 in a horizontally long tubular casing 1.

The heat exchanger 2 includes a high-pressure second superheater 3, a reheater 4, a high-pressure first superheater 5, a high-pressure evaporator 7 having a high-pressure steam drum 6, and a A medium-pressure evaporator 9 equipped with a high-pressure steam drum 8, a high-pressure first economizer 10,
A low-pressure evaporator 12 having a low-pressure steam drum 11 is used as a low-pressure economizer 13, which is divided and supplied from a steam turbine plant (not shown) to the low-pressure economizer 13. The preheating is performed by the exhaust gas EG, and heating and evaporation are repeated to generate superheated steam.

As described above, heat exchangers 2 having different product names due to differences in the types and roles of generated steam, etc.
In consideration of reduction of manufacturing cost and reduction of labor of workers at the time of assembly / installation, the module is so-called modularized so that it can be easily assembled / installed even in a power plant, for example.

FIG. 4 shows an example of the modularized heat exchanger 2 and corresponds to a block including, for example, the low-pressure steam drum 11 shown in FIG.

The heat exchanger 2 has a low-pressure steam drum 11 installed outside the top of the casing 1, and has a low-pressure evaporator (not shown) inserted through the low-pressure steam drum 11 and housed in the casing 1. A low-pressure economizer 13 is provided downstream of the low-pressure evaporator.

Such a heat exchanger 2 is provided with headers 14 on the top and bottom sides regardless of the product name.
a, 14b and the headers 14a, 14b
The space is welded and connected by a heat transfer tube 15. Each single unit of such a configuration is called a heat transfer tube panel in industry terms, and unless otherwise specified,
Apply this term.

Conventionally, when heat transfer tube panels are produced in a factory, they are previously formed into headers 14a, 14a.
B and the heat transfer tube 15 were subjected to bevel connection by welding, and after connection, a heating coil was wound around the welded portion to perform heat treatment.

[0011]

The conventional heat treatment of a heat transfer tube panel has several problems.

Conventionally, in heat treatment, a heat transfer tube panel is
After welding the heat transfer tube 15 to the headers 14a, 14b, a heating coil is manually wound around the welded portion, and the headers 14a, 14b are heated.
The heat treatment temperature was adjusted while monitoring the temperature sensor attached to 4b.

However, in the heat transfer tube panel, the winding state of the heating coil varies depending on the installation position of the nozzle, etc., and accordingly, the temperature rise may fluctuate or the temperature distribution may become uneven. Was. For this reason, a residual stress locally remains in the welded portion, which is not preferable in terms of quality assurance.

Further, since the winding operation of the heating coil at the welded portion relies exclusively on manual labor, a large amount of time is required for the preparation operation, and improvement is required also from the viewpoint of work efficiency. .

Furthermore, when a heating coil wound around a welding portion is energized, heat dissipation is increased, and it takes a long time to raise the temperature to a predetermined temperature. For this reason, the heat insulating material is coated in order to reduce the heat radiation loss, but as a result of long-term use, it has been difficult to treat the waste such as the heat insulating material.

The present invention has been made in view of the above circumstances, and provides a heat treatment apparatus and a heat treatment method for a heat transfer tube panel which maintain the quality of a welded part of a product at a high level and improve the work efficiency. The purpose is to do.

[0017]

According to a first aspect of the present invention, there is provided a heat treatment apparatus for a heat transfer tube panel, comprising: a heating furnace accommodating a welded portion of a header; A heating means provided on the inner wall of the heating furnace, for applying heat to the welding portion, and an automatic control device for turning off the heating means when the temperature in the heating furnace exceeds a predetermined temperature. It is provided.

Further, in the heat treatment apparatus for a heat transfer tube panel according to the present invention, in order to achieve the above-described object, the heating furnace is provided with a caster.

In order to achieve the above object, the heat treatment apparatus for a heat transfer tube panel according to the present invention is characterized in that the heating means is a far-infrared heater. It is.

According to a fourth aspect of the present invention, in the heat treatment apparatus for a heat transfer tube panel according to the present invention, the heating furnace is formed in a box shape, and one side of the box shape is provided. Is formed at a free end, and the free end is covered with a heat insulating material.

According to a fifth aspect of the present invention, there is provided a method for heat-treating a heat transfer tube panel, wherein the heat transfer tube is welded to a header and then housed in a heating furnace. Heating is performed by a heating means provided in the heating furnace to heat-treat the welded portion of the header.

Further, in order to achieve the above object, a heat treatment method for a heat transfer tube panel according to the present invention is characterized in that the heat transfer tube is welded to the header and then housed in a heating furnace. While heating the welded portion of the header by the heating means provided in the heating furnace, when the temperature exceeds a predetermined temperature, the heat applied to the welded portion of the header from the heating means is turned off. It is.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a heat transfer apparatus and a heat treatment method for a heat transfer tube panel according to the present invention will be described with reference to the drawings and reference numerals attached to the drawings.

FIG. 1 is a schematic perspective view showing a heat transfer tube panel itself applied to the heat transfer tube panel heat treatment apparatus according to the present invention.

The heat transfer tube panel has lids 16a, 16b at both ends.
Headers 17a, 17b and header 17
The heat transfer tube 18 is connected by welding between a and 17b.

At least one of the headers 17a, 17b is provided with a water supply inlet / outlet nozzle stub 19a, 19b, and is provided with a hanger 20a, 20b.

With respect to the heat transfer tube panel having such a configuration, the heat treatment apparatus according to the present embodiment heats a welded portion WA between the headers 17a and 17b and the heat transfer tube 18 as shown in FIG. It is housed in a furnace 22.

The heating furnace 22 has a caster 22a which can be freely moved while being formed in a box shape, and has a far-infrared heater 21 stretched on an inner wall.

The heating furnace 22 is opened with one box-shaped side surface as a free end, accommodates headers 17a, 17b, and is closed with a heat insulating material 23. This insulation 2
No. 2 is durable, has excellent heat shielding properties even when used many times, and is considered so as not to be treated as industrial waste after several uses.

The heating furnace 22 includes the headers 17a, 17
b, welding portion WA between heat transfer tube 18 and headers 17a, 17
b and welded portion WA between feed water inlet / outlet nozzles 19a and 19b
1. A temperature sensor 24 for controlling a heating temperature when a heat treatment is performed on a welded portion WA2 between the headers 17a, 17b and the hanging members 20a, 20b.

As shown in FIG. 3, the temperature sensor 23 is connected to an automatic control device 25 via a lead wire 26.
The automatic control device 25 includes, for example, headers 17a, 17
b and a temperature signal from a temperature sensor 24 provided in each of the heat transfer tubes 18, and receives a predetermined temperature setting,
Turns off the far infrared heater 21 when the measured temperature exceeds
It is configured to be.

As described above, in the present embodiment, the far-infrared heater 21 is provided in the box-shaped heating furnace 22 having the casters 22a which can move forward and backward, and the header 1 is provided.
A temperature sensor 24 is provided at a welding portion WA such as 7a, 17b, etc., and a calculation is performed based on an actually measured temperature signal of the temperature sensor 24. When the calculation signal exceeds a predetermined set value, the far infrared heater 21 is turned off. Automatic control device 2
5, the quality of the welded portion can be maintained at a high level under appropriate temperature control, and the preparatory action can be facilitated to greatly reduce the labor of the operator.

Next, a heat treatment method for a heat transfer tube panel according to the present invention will be described.

The heat treatment method for the heat transfer tube panel according to the present embodiment includes, for example, connecting the heat transfer tube 18 to the headers 17a and 17b by welding, and connecting the welded portion WA to the box-shaped heating furnace 22.
After that, the free end of the heating furnace 22 is closed with a heat insulating material 23.

In the present embodiment, when the welding portion WA is accommodated in the heating furnace 22, the far-infrared heater 21 provided on the inner wall of the heating furnace 22 is turned on to heat the welding portion WA. At this time, if the measured temperature detected by the temperature sensor 24 exceeds a predetermined set value, the automatic controller 25
Turns off the far infrared heater 21, lowers the temperature to a predetermined set value, and performs automatic temperature management.

As described above, in this embodiment, the heat transfer tube 18 is welded from the free end of the box-shaped heating furnace 22 to the headers 17a and 17b, and the welded portion WA is accommodated in the heating furnace 22, and then heated. The free end of the furnace 22 is closed with a heat insulating material 23, and the heat treatment is performed by heating the welded portion WA with the far-infrared heater 21 under automatic temperature control, so that the residual stress in the welded portion WA is removed and the welded portion WA is made of high quality. Can be maintained.

[0037]

As described above, the heat treatment apparatus for a heat transfer tube panel according to the present invention uses a freely movable heating furnace and closes the free end of the heating furnace when heat-treating a welded portion such as a header. In addition to selecting insulation materials with high durability, the system is equipped with a means for automatically adjusting the temperature of the heating furnace, making preparation work easier and greatly reducing the labor of the operator. Can reduce the heat treatment of waste materials.

Further, in the heat treatment method for a heat transfer tube panel according to the present invention, when heat treatment is performed on a welded portion such as a header, the heat treatment temperature is automatically controlled and the temperature is maintained in a stable state. Can be maintained at a high quality.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a heat transfer tube panel applied to a heat treatment apparatus and a heat treatment method for a heat transfer tube panel according to the present invention.

FIG. 2 is a conceptual diagram used for explaining a heat treatment apparatus and a heat treatment method for a heat transfer tube panel according to the present invention.

FIG. 3 is a conceptual diagram used for explaining heat treatment temperature management in the heat treatment apparatus and heat treatment method for a heat transfer tube panel according to the present invention.

FIG. 4 is a partial perspective view showing a heat exchanger applied to a conventional exhaust heat recovery boiler.

FIG. 5 is a partial longitudinal sectional view showing a conventional exhaust heat recovery boiler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Heat exchanger 3 High pressure 2nd superheater 4 Reheater 5 High pressure 1st superheater 6 High pressure steam drum 7 High pressure evaporator 8 Medium pressure steam drum 9 Medium pressure evaporator 10 High pressure 1st coal saver 11 Low pressure steam Drum 12 Low-pressure evaporator 13 Low-pressure economizer 14 and 14b header 15 heat transfer tubes 16a and 16b lid 17a and 17b header 18 heat transfer tubes 19a and 19b feed water inlet / outlet nozzles 20a and 20b hanging fitting 21 far-infrared heater 22 heating furnace 22a Casters 23 Heat Insulation Material 24 Temperature Sensor 25 Automatic Controller 26 Lead Wire

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B23K 101: 14 B23K 101: 14 (72) Inventor Atsushi Komatsu 2-chome Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa No. 4 F-term in Toshiba Keihin Works (reference) 4K042 AA06 BA09 BA13 DA01 DB08 EA03

Claims (6)

[Claims] A heating furnace for accommodating a welded portion of the header;
A heating means provided on the inner wall of the heating furnace, for applying heat to the welding portion, and an automatic control device for turning off the heating means when the temperature in the heating furnace exceeds a predetermined temperature A heat treatment apparatus for a heat transfer tube panel. 2. The apparatus according to claim 1, wherein the heating furnace includes a caster. 3. The apparatus according to claim 1, wherein the heating means is a far-infrared heater. 4. The heat transfer tube according to claim 1, wherein the heating furnace is formed in a box shape, one side surface of the box shape is formed as a free end, and the free end is covered with a heat insulating material. Panel heat treatment equipment. 5. A heat transfer tube, wherein a heat transfer tube is welded to a header and then housed in a heating furnace and heated by a heating means provided in the heating furnace to heat-treat a welded portion of the header. Panel heat treatment method. 6. After welding the heat transfer tube to the header, the tube is housed in a heating furnace, and the temperature exceeds a predetermined temperature while the welded portion of the header is heated by heating means provided in the heating furnace. And turning off the heat applied from the heating means to the welded portion of the header.