A high-precision on-site heat treatment device for steam turbine blades

Abstract

The present invention discloses a high-precision on-site heat treatment device for steam turbine blades, which includes an infrared heater housing, an infrared reflector-mounting base sleeved inside the infrared heater housing, and infrared heating tubes installed in the infrared reflector-mounting base through infrared lamp tube clamps; wherein, both ends of the infrared reflector-mounting base are provided with end limit protection plates for protecting the infrared heating tubes; a heating space is formed between the infrared heating tubes and the infrared reflector-mounting base, a joint installation hole is opened at the top of the infrared reflector-mounting base and a cooling pipeline joint is provided, and the cooling pipeline joint is communicated with the heating space. A plurality of cooling ports communicated with the heating space are opened on the side wall of the infrared reflector-mounting base, and gaps communicated with the cooling ports are provided between the middle of the two side surfaces of the infrared heater housing and the infrared reflector-mounting base. The present invention has the advantages of large heating area, high heating precision, good temperature uniformity, and clean and pollution-free.

Description

Technical Field

[0001] The present invention belongs to the technical field of steam turbine blade heat treatment, and particularly relates to a high-precision on-site heat treatment device for steam turbine blades, especially suitable for the heat treatment process after welding repair of steam turbine blades. This device is based on quartz lamp infrared radiation heating technology, and has the advantages of large heating area, high heating precision, good temperature uniformity, and clean and pollution-free compared with traditional gas heating type heat treatment devices and resistance band wrapping heating type heat treatment devices. Background Art

[0002] Steam turbines are the core power equipment of modern thermal power plants, and are also applied in the metallurgical industry, chemical industry and ship power plants. They mainly drive the turbine blades to do work externally through high-temperature and high-pressure steam. As the core power device in the energy field, its output power can reach dozens to hundreds of megawatts, and the average cost exceeds 100 million yuan. As one of the core components of the steam turbine, the cost of a single turbine blade is high. However, during the service of the steam turbine, the turbine blades are corroded by high-temperature gases, and damage and failure will occur at the blade ends. Therefore, after a period of service (usually ranging from half a year to one year), the blades need to be repaired and remanufactured, which is an important means to extend the life of the steam turbine and reduce the operation and maintenance costs.

[0003] At present, one of the main means of repairing and remanufacturing the blades is to perform welding treatment on the damaged parts. After welding, local heat treatment must be carried out on the welded parts. By annealing the newly welded parts, the thermal stress is released and the microstructure is toughened, alleviating the stress mismatch between the newly welded parts and the original blade parts, and extending the service life of the blades. In order to speed up the repair progress and shorten the repair cycle, the repair and remanufacturing of the steam turbine must be carried out on-site during the operation of the steam turbine, and the blades cannot be removed, which poses high requirements for the on-site heat treatment of steam turbine blades.

[0004] The current main means of heat treatment after the repair of steam turbine blades are as follows:

[0005] 1. Oxygen-acetylene or oxygen-propane gas heating. The specific operation process is that workers hold an oxygen-acetylene or oxygen-propane gas torch to heat the welded part. The advantage is fast heating speed. However, due to the small nozzle of the gas torch, only the area within a diameter of 30 mm can be heated simultaneously. Therefore, it has the disadvantages of small heating area, uneven temperature of the heated part, and large temperature error (plus or minus 20 °C); and due to the introduction of gas, it will also cause pollution, and at the same time, there is a lot of noise, and it has a strong dependence on manual experience and proficiency.

[0006] 2. Resistance band wrapping heating. In this method, the entire welding area is wrapped with a resistance band and heated through the thermal resistance effect. The advantage is that the entire welding area can be heated, while the disadvantages are slow heating speed, poor temperature uniformity (±20 °C), and uncontrollability in the low-temperature section.

[0007] In summary, the current post-repair heat treatment methods for steam turbine blades have common drawbacks such as low precision, large errors, and low efficiency. At the same time, there is no high-precision dedicated equipment on the market that can be applied to the post-repair heat treatment of steam turbine blades. Therefore, it is very necessary to invent a set of post-repair heat treatment equipment for blades that has a large heating area, high heating precision, and no pollution. Summary of the Invention

[0008] The purpose of the present invention is to provide a high-precision on-site heat treatment device for steam turbine blades, which realizes high-precision full-field heating of the welding area through quartz lamp infrared radiation technology. The heating range can reach 300 mm × 40 mm, and the heating precision can reach 1 - 2 °C.

[0009] The present invention is realized by adopting the following technical solutions:

[0010] A high-precision on-site heat treatment device for steam turbine blades includes an infrared heater housing, an infrared reflector - mounting matrix sleeved inside the infrared heater housing, and infrared heating tubes installed in the infrared reflector - mounting matrix through infrared lamp tube clamps. Among them, both ends of the infrared reflector - mounting matrix are provided with end - limit protection plates for protecting the infrared heating tubes. A heating space is formed between the infrared heating tubes and the infrared reflector - mounting matrix. The top of the infrared reflector - mounting matrix is provided with a joint installation hole and a cooling pipeline joint, and the cooling pipeline joint is communicated with the heating space. A plurality of cooling ports communicated with the heating space are provided on the side wall of the infrared reflector - mounting matrix, and gaps communicated with the cooling ports are provided in the middle of the two side surfaces of the infrared heater housing and the infrared reflector - mounting matrix.

[0011] A further improvement of the present invention is that the cross - sections of the infrared heater housing, the infrared reflector - mounting matrix, and the infrared heating tubes are all U - shaped.

[0012] A further improvement of the present invention is that the inner arc radius of the end - limit protection plate is smaller than the inner arc radius of the infrared heating tube.

[0013] A further improvement of the present invention is that the infrared lamp tube clamp includes an infrared lamp tube upper clamp and an infrared lamp tube lower clamp.

[0014] A further improvement of the present invention is that the infrared heater housing is welded to the top of the infrared reflector - mounting matrix.

[0015] A further improvement of the present invention lies in that a housing mounting gasket is installed in the middle of the two side surfaces of the infrared heater housing and the infrared reflective - mounting base to form a gap with a predetermined thickness. Cooling gas is introduced through the cooling pipe joint, and the cooling gas exits from the cooling port, enters the gap channel between the infrared heater housing and the side surface of the infrared reflective - mounting base, and finally exits from the bottom.

[0016] A further improvement of the present invention lies in that the heating range of the device reaches 300mm×40mm, and the heating accuracy reaches 1 - 2°C.

[0017] The present invention has at least the following beneficial technical effects:

[0018] A high - precision on - site heat treatment device for steam turbine blades provided by the present invention mainly includes key components such as an infrared heater, a cooling pipe joint, and an end - limit protection plate. The device is designed for pre - heating treatment during the circumferential installation of the blade. It is a small infrared heater, which is convenient for assembling with the blade for heating. Among them, multiple infrared heaters are fixed in the infrared reflective - mounting base through the upper fixture and the lower fixture on the infrared lamp tube to heat the blade in the heating space. The infrared heater housing is welded to the top of the infrared reflective - mounting base, and a gap with a certain thickness is formed in the middle of the two side surfaces. Cooling gas is introduced into the gap through the cooling port to cool the two sides, ensuring that the surface temperature of the infrared heater housing reaches the required temperature. The end - limit protection plate is installed at the two end faces of the infrared reflective - mounting base to limit the blade and prevent the blade from hitting the infrared heating tube at the same time.

[0019] In summary, the present invention is a high - precision on - site heat treatment device for steam turbine blades. Through the quartz lamp infrared radiation technology, it realizes high - precision full - field heating of the local part of the blade. Compared with the traditional gas - heating heat treatment device and the resistance - band - wrapped heating heat treatment device, it has the advantages of large heating area, high heating accuracy, good temperature uniformity, and clean and pollution - free. Brief Description of the Drawings

[0020] Figure 1 It is the structural assembly drawing of the present invention.

[0021] Figure 2 It is the structural axonometric drawing of the present invention.

[0022] Figure 3 It is the front view of the structure of the present invention.

[0023] Description of the Reference Numerals:

[0024] 1 is the cooling pipe joint, 2 is the infrared heater housing, 3 is the end - limit protection plate, 4 is the infrared reflective - mounting base, 5 is the upper fixture on the infrared lamp tube, 6 is the housing mounting gasket, 7 is the lower fixture on the infrared lamp tube, 8 is the infrared heating tube, 9 is the cooling port, 10 is the joint mounting hole. Detailed implementation manners

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] As Figures 1 to 3 shown, a high-precision on-site heat treatment device for steam turbine blades provided by the present invention mainly consists of 10 parts: a cooling pipe joint 1, an infrared heater housing 2, an end limit protection plate 3, an infrared reflector - mounting base 4, an upper fixture for infrared lamp tubes 5, a housing mounting gasket 6, a lower fixture for infrared lamp tubes 7, an infrared heating tube 8, a cooling port 9, and a joint mounting hole 10.

[0027] In this device, the upper fixture for infrared lamp tubes 5 and the lower fixture for infrared lamp tubes 7 fix the infrared heating tube 8 in the infrared reflector - mounting base 4 to form a heating space. The infrared heater housing 2 is welded to the top of the infrared reflector - mounting base 4, and the housing mounting gasket 6 is installed in the middle of both side surfaces, thus forming a gap with a certain thickness. The cooling pipe joint 1 is installed on the joint mounting hole 10, and cooling gas is introduced. The cooling gas exits from the cooling port 9 and enters the gap channel on the side surfaces of the infrared heater housing 2 and the infrared reflector - mounting base 4, and finally exits from the bottom. In this way, the cooling gas cools on both side surfaces, ensuring that the surface of the infrared heater housing 2 reaches the required temperature. The end limit protection plate 3 is installed on both end surfaces of the infrared reflector - mounting base 4, and the radius of its inner arc surface is smaller than the inner arc radius of the infrared heating tube 8, so as to limit the position on the blade and prevent the blade from hitting the infrared heating tube 8 at the same time.

[0028] A high-precision on-site heat treatment device for steam turbine blades provided by the present invention realizes high-precision full-field heating of the local part of the blade through the quartz lamp infrared radiation technology. Its heating range can reach 300mm×40mm, and the heating accuracy can reach 1 - 2°C. Compared with the traditional gas heating type heat treatment device and the resistance band wrapping heating type heat treatment device, it has the advantages of large heating area, high heating accuracy, good temperature uniformity, and clean and pollution-free. It belongs to the on-site welding post-treatment equipment in the technical field of steam turbine blade heat treatment.

Claims

1. A high-precision on-site heat treatment device for steam turbine blades, characterized in that, It includes an infrared heater housing (2), an infrared reflective - mounting matrix (4) sleeved inside the infrared heater housing (2), and an infrared heating tube (8) mounted inside the infrared reflective - mounting matrix (4) through an infrared lamp tube clamp; wherein, Both ends of the infrared reflective - mounting matrix (4) are provided with end - limit protection plates (3) for protecting the infrared heating tube (8); a heating space is formed between the infrared heating tube (8) and the infrared reflective - mounting matrix (4). A joint mounting hole (10) is opened at the top of the infrared reflective - mounting matrix (4) and a cooling pipe joint (1) is provided. The cooling pipe joint (1) is communicated with the heating space. A plurality of cooling ports (9) communicated with the heating space are opened on the side wall of the infrared reflective - mounting matrix (4). There are gaps communicated with the cooling ports (9) between the middle of the two side surfaces of the infrared heater housing (2) and the infrared reflective - mounting matrix (4); The cross - sections of the infrared heater housing (2), the infrared reflective - mounting matrix (4), and the infrared heating tube (8) are all U - shaped; An outer - housing mounting gasket (6) is installed between the middle of the two side surfaces of the infrared heater housing (2) and the infrared reflective - mounting matrix (4) to form a gap with a predetermined thickness. Cooling gas is introduced through the cooling pipe joint (1). The cooling gas comes out from the cooling ports (9), enters the gap channel between the side surfaces of the infrared heater housing (2) and the infrared reflective - mounting matrix (4), and finally comes out from the bottom; The inner arc radius of the end - limit protection plate (3) is smaller than the inner arc radius of the infrared heating tube (8); The heating range of this device reaches 300mm×40mm, and the heating accuracy reaches 1 - 2°C.

2. The on-site high-precision heat treatment device for steam turbine blades according to claim 1, characterized in that, The infrared lamp tube clamp includes an infrared lamp tube upper clamp (5) and an infrared lamp tube lower clamp (7).

3. The on-site high-precision heat treatment device for steam turbine blades according to claim 1, characterized in that, The infrared heater housing (2) is welded to the top of the infrared reflective - mounting matrix (4).

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