Nuclear power station steam generator secondary side pressure test device

Abstract

The utility model discloses a nuclear power station steam generator secondary side pressure test device which is characterized in that the nuclear power station steam generator secondary side pressure test device comprises a water tank, a heating device, a circulation pipeline, at least two pressing devices and at least two sets of interface assemblies connected with a steam generator, and the heating device is installed on the water tank and partially extends into the water tank; a water inlet and a water return port of the circulating pipeline are respectively connected to the water tank, a water injection pipeline is connected to the circulating pipeline, and a water injection valve is arranged on the water injection pipeline; each pressing device is respectively connected with the water injection pipeline and one set of interface assembly; the capacity of the water tank is greater than or equal to the demanded quantity of the secondary side pressure test of at least two steam generators; in the heating stage, the water injection valve is closed, and the circulating pipeline is opened for small-flow water circulating heating; in the water injection stage, the water injection valve is opened, the circulating pipeline is opened to communicate with the water injection pipeline, and the two pressing devices operate simultaneously and inject water into the two steam generators respectively. The device reduces the water injection time and the overall pressure test time, and reduces the on-site human factor safety risk.

Description

Technical Field

[0001] The utility model relates to the technical field of nuclear power engineering, in particular to a secondary side pressure test device for a steam generator in a nuclear power station. Background Art

[0002] After on-site installation, nuclear power plant steam generators require secondary-side hydraulic testing to verify the quality of the steam generator itself and the associated secondary piping system. This test, conducted individually on the secondary side of the steam generator using specialized pressure testing equipment, follows the standard testing process. This is estimated to take 1.5 months and is a critical step in the process leading to the start of hot testing at the nuclear power plant.

[0003] Currently, the secondary side pressure test scheme for steam generators uses a temporary water tank equipped with hydrazine, which is then filled with water into the hydraulic circuit. Once the hydraulic circuit is filled with water, the heat is conducted by circulating the fluid medium in the pressure test device's heater. The pressure test is performed sequentially on three steam generators, completing the test. This pressure test scheme has the following drawbacks:

[0004] (1) Due to the small capacity of the temporary water tank, only 30m 3 , it takes 7 operations to fill the water pressure circuit with water, and the filling time is long;

[0005] (2) The heater of the pressure test device is only 120KW, the heat conduction process is slow, and the heating time is long;

[0006] (3) The components of a single pressure device can only be removed after the circuit is drained, and it takes a long time to switch to another water pressure circuit for drainage;

[0007] (4) The secondary side pressure test is high-risk. After water enters, personnel need to be arranged for 24-hour inspection on site, and the on-site safety and human risk is relatively high. Utility Model Content

[0008] The technical problem to be solved by the utility model is to provide a secondary side pressure test device for a steam generator in a nuclear power plant.

[0009] The technical solution adopted by the utility model to solve the technical problem is: a secondary side pressure test device for a steam generator in a nuclear power plant, comprising a water tank, a heating device, a circulation pipeline, at least two pressure testing devices and at least two sets of interface components connected to the steam generator, wherein the heating device is installed on the water tank and partially extends into the interior of the water tank; the water inlet and the water return port of the circulation pipeline are respectively connected to the water tank, and the circulation pipeline is connected to a water injection pipeline, and the water injection pipeline is provided with a water injection valve; each of the pressure testing devices is respectively connected to the water injection pipeline and to a set of the interface components;

[0010] The capacity of the water tank is greater than or equal to the required capacity for secondary side pressure testing of at least two steam generators;

[0011] During the heating phase, the water injection valve is closed and the circulation pipeline is opened to perform small-flow water circulation heating;

[0012] During the water injection stage, the water injection valve is opened, the circulation line is opened to connect to the water injection pipe, and the two pressure devices are operated simultaneously to inject water into the two steam generators respectively.

[0013] In some embodiments, the circulation pipeline includes an outlet pipe, a water supply pump and a return pipe, the outlet pipe is respectively connected to the water outlet of the water tank and the water inlet of the water supply pump, and the return pipe is respectively connected to the water outlet of the water supply pump and the water inlet of the water tank.

[0014] In some embodiments, the water injection pipe is connected to the water return pipe.

[0015] In some embodiments, the circulation line further comprises a return valve, which is connected to the return pipe and located between the water tank and the water injection pipe;

[0016] During the heating stage, the return water valve is opened; during the water injection stage, the return water valve is closed.

[0017] In some embodiments, the water supply pump is a low-flow circulation pump.

[0018] In some embodiments, the heating device includes a main body and an electric heating tube bundle, the main body is connected to the electric heating tube bundle and is externally connected to a power source, and the electric heating tube bundle extends into the interior of the water tank.

[0019] In some embodiments, a mounting window is provided on the top of the water tank, and a diameter of the mounting window is larger than a maximum diameter of the electric heating tube bundle and smaller than a maximum diameter of the main body.

[0020] In some embodiments, the interface assembly includes a plurality of fasteners and a flange welded to a pipe of the steam generator, and the flange is detachably connected to the pressure device via the plurality of fasteners;

[0021] The first end of the flange is inclined outward to form a weld for welding, the second end of the flange is a plane, and a plurality of through holes for fastener connection are provided on the circumference of the flange.

[0022] In some embodiments, the water tank has a capacity of 550m 3 ~750m 3 .

[0023] In some embodiments, the power of the heating device is 80 kW to 120 kW.

[0024] By implementing the utility model, the following beneficial effects are achieved:

[0025] The utility model discloses a secondary side pressure test device for a steam generator in a nuclear power plant, comprising a water tank, a heating device, a circulation pipeline, at least two pressure devices and at least two sets of interface components connected to the steam generator, wherein the heating device is mounted on the water tank and partially extends into the interior of the water tank; the water inlet and the water return port of the circulation pipeline are respectively connected to the water tank, and the circulation pipeline is connected to a water injection pipeline, and the water injection pipeline is provided with a water injection valve; each of the pressure devices is respectively connected to the water injection pipeline and to a set of interface components; the capacity of the water tank is greater than or equal to the required amount for the secondary side pressure test of at least two steam generators; in the heating stage, the water injection valve is closed, and the circulation pipeline is opened for small-flow water circulation heating; in the water injection stage, the water injection valve is opened, and the circulation pipeline is opened to connect to the water injection pipeline, and the two pressure devices operate simultaneously and inject water into the two steam generators respectively. The water tank can be used to configure the test water that meets the secondary side pressure test requirements of two steam generators at one time, and the secondary side pressure tests of two steam generators can be carried out simultaneously through two pressure testing devices, which reduces the water injection time, the overall pressure test time and the human safety risks on site. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0027] Figure 1 The utility model is a structural schematic diagram of a secondary side pressure test device of a steam generator in a nuclear power plant according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation methods of the present invention are now described in detail with reference to the accompanying drawings.

[0029] In the description of the utility model, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the utility model, unless otherwise specified, "multiple" means two or more.

[0030] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or chemical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0031] See also Figure 1 One embodiment of the utility model discloses a secondary side pressure test device for a steam generator in a nuclear power plant, comprising a water tank 1, a heating device 2, a circulation pipeline 3, at least two pressure devices 6 and at least two sets of interface components 7 connected to the steam generator 8, wherein the heating device 2 is mounted on the water tank 1 and partially extends into the interior of the water tank 1. The water inlet and the water return port of the circulation pipeline 3 are respectively connected to the water tank 1, and the circulation pipeline 3 is connected to a water injection pipeline 4, and the water injection pipeline 4 is provided with a water injection valve 5. Each pressure device 6 is respectively connected to the water injection pipeline 4 and to a set of interface components 7. The capacity of the water tank 1 is greater than or equal to the required capacity for the secondary side pressure test of at least two steam generators 8. During the heating stage, the water injection valve 5 is closed, and the circulation pipeline 3 is opened for small-flow water circulation heating. During the water injection stage, the water injection valve 5 is opened, the circulation pipeline 3 is opened and connected to the water injection pipeline 4, and the two pressure devices 6 operate simultaneously and inject water into the two steam generators 8 respectively. Preferably, there are three sets of interface components 7, and the capacity of the water tank 1 is 550m 3 ~750m 3 , for example 600m 3 , 700m 3 The power of the heating device 2 is 80 kW to 120 kW, for example, 100 kW, 110 kW, etc.

[0032] The secondary side water pressure test of steam generator 8 is a high-risk operation. During the secondary side water pressure test of steam generator 8 in previous projects, there have been problems such as TSD (temporary special device) water leakage and wetting equipment, temporary pump failure affecting water inlet, etc. The use of the nuclear power plant steam generator secondary side pressure test device of this utility model can greatly shorten the overall water pressure test period. Compared with the traditional single unit steam generator 8 secondary side water pressure test period of 45 days, the implementation period of this solution only takes 5 days, which can optimize the construction period by 40 days. It also reduces the risk of water leakage caused by accidental contact of construction workers after water enters the secondary side circuit, and reduces the risk of personal injury caused by fatigue of patrol personnel working at night.

[0033] In some embodiments, the circulation pipeline 3 includes an outlet pipe 31, a water supply pump 32, and a return pipe 33. The outlet pipe 31 is respectively connected to the water outlet of the water tank 1 and the water inlet of the water supply pump 32, and the return pipe 33 is respectively connected to the water outlet of the water supply pump 32 and the water inlet of the water tank 1. The outlet pipe 31 has an inlet connected to the water outlet of the water tank 1, and the return pipe 33 has a return port connected to the water inlet of the water tank 1. Preferably, the water supply pump 32 is a low-flow circulation pump.

[0034] In some embodiments, the injection pipe 4 is connected to the return pipe 33. The injection pipe 4 and the return pipe 33 can share a water supply pump 32 and a water outlet pipe 31, reducing redundant equipment and lowering costs. It is understood that in other embodiments, a high-flow water supply pump 32 can be provided, connected to the water outlet pipe 31, and connected in parallel with a low-flow circulation pump. The low-flow circulation pump is activated during the heating phase, while the high-flow water supply pump 32 is activated during the injection phase, with each pump operating independently to save flushing time.

[0035] In some embodiments, the circulation line 3 further includes a return valve 34, which is connected to the return pipe 33 and located between the water tank 1 and the water injection pipe 4. During the heating phase, the return valve 34 is open, and during the water injection phase, the return valve 34 is closed.

[0036] In some embodiments, the heating device 2 includes a main body 21 and an electric heating tube bundle 22. The main body 21 is connected to the electric heating tube bundle 22 and is connected to an external power source. The electric heating tube bundle 22 extends into the interior of the water tank 1. Preferably, the main body 21 and the water tank 1 are detachably connected and fixed by fasteners. The electric heating tube bundle 22 is composed of a plurality of heating tubes.

[0037] In some embodiments, a mounting window is provided at the top of the water tank 1. The diameter of the mounting window is larger than the maximum diameter of the electric heating tube bundle 22 and smaller than the maximum diameter of the main body 21. The main body 21 is mounted above the mounting window and fixedly connected to the outer edge of the mounting window. The electric heating tube bundle 22 extends through the mounting window into the water tank 1 to heat the water inside the water tank 1. The mounting window is not shown in the figure.

[0038] In some embodiments, the interface assembly 7 includes a plurality of fasteners and a flange welded to the pipe of the steam generator 8. The flange is detachably connected to the pressure device 6 via the plurality of fasteners. The first end of the flange is tilted outward to form a weld for welding, the second end of the flange is flat, and the flange is circumferentially provided with a plurality of through-holes for connection of the fasteners.

[0039] The method of using the secondary side pressure test device of the nuclear power plant steam generator of the utility model is as follows:

[0040] Prerequisite: There are three steam generators 8, but only two are shown in the figure.

[0041] 1. Preparation before the secondary pressure test of steam generator 8: (1) Prepare a water tank 1 with enough hydrazine water to meet the water demand of the secondary pressure test of two steam generators 8. Generally, the design capacity of water tank 1 is 650m3. 3 , configure 500m 3 Ammonia water. Conduct tests in advance to determine the mixing ratio of ammonia water and desalted water, and monitor the water injection volume through the instrument in the water tank 1 to ensure that the prepared ammonia water is qualified for the first water production sampling. Use the circulating mixing pump of the water tank 1 (the mixing pump is the existing technology), and after the ammonia water is injected, use the mixing pump to mix the ammonia in the water tank 1 evenly. 2 Pre-heat the ammonia water through the heating device 2 and the water feed pump 32 at a small flow rate, and advance the heating operation. Because the outer surface temperature of the steam generator 8 should be between 30°C and 60°C during the secondary side water pressure test, in order to ensure that the surface temperature of the tube plate during the secondary side water pressure boosting process can always meet the requirements, the ammonia water in the water tank 1 is heated in advance, and 45°C is generally selected as the secondary side boosting prerequisite.

[0042] 2. Secondary side pressure test of steam generator 8: Water is injected into steam generator 8 through a low-flow circulation pump or a high-flow feed water pump 32. Two pressure devices 6 are connected in parallel and equipped with three sets of interface components 7 to implement a "double-row parallel secondary side water pressure" pressure application scheme. This ensures that when the first two steam generators 8 are undergoing water pressure tests, the work before the third steam generator 8 is injected with water can be completed (when conducting the water pressure tests on the first two steam generators 8, the water tank 1 is again configured with enough ammonia water to guarantee the water demand for the secondary side water pressure test of one steam generator 8, and the ammonia water is pre-heated by continuous circulation at a low flow rate through the heating device 2 and the feed water pump 32). After the pressure of one of the first two steam generators 8 is relieved, the pressure device 6 can be connected to the third steam generator 8 to start the water pressure test of the third steam generator 8, without having to wait for the pressure of the previous steam generator 8 to be relieved and the water to be drained before switching the interface components 7.

[0043] By implementing the utility model, the following beneficial effects are achieved:

[0044] The nuclear power plant steam generator secondary side pressure test device of the present invention can configure the test water that meets the secondary side pressure test requirements of two steam generators 8 at one time through the water tank 1, and simultaneously perform the secondary side pressure test of the two steam generators 8 through the two pressure devices 6, thereby reducing the water injection time, the overall pressure test time and the on-site human safety risks.

[0045] It can be understood that the above embodiments only express the preferred implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, the above embodiments or technical features can be freely combined, and several deformations and improvements can be made, which all fall within the scope of protection of the present invention, that is, the embodiments described in "some embodiments" can be freely combined with any of the above and below embodiments. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should fall within the scope of coverage of the claims of the present invention.

Claims

1. A secondary side pressure test device for a steam generator in a nuclear power plant, characterized in that: The invention comprises a water tank (1), a heating device (2), a circulation pipeline (3), at least two pressure devices (6) and at least two sets of interface components (7) connected to the steam generator (8); the heating device (2) is installed on the water tank (1) and partially extends into the interior of the water tank (1); the water inlet and the water return port of the circulation pipeline (3) are respectively connected to the water tank (1), and the circulation pipeline (3) is connected to a water injection pipeline (4), and the water injection pipeline (4) is provided with a water injection valve (5); each pressure device (6) is respectively connected to the water injection pipeline (4) and to a set of interface components (7); The capacity of the water tank (1) is greater than or equal to the required capacity for secondary side pressure testing of at least two steam generators (8); During the heating phase, the water injection valve (5) is closed and the circulation pipeline (3) is opened to perform small-flow water circulation heating; During the water injection phase, the water injection valve (5) is opened, the circulation pipeline (3) is opened to connect to the water injection pipe (4), and the two pressure devices (6) operate simultaneously and inject water into the two steam generators (8) respectively.

2. The secondary side pressure test device for a steam generator in a nuclear power plant according to claim 1, characterized in that: The circulation pipeline (3) comprises a water outlet pipe (31), a water supply pump (32) and a water return pipe (33); the water outlet pipe (31) is respectively connected to the water outlet of the water tank (1) and the water inlet of the water supply pump (32); and the water return pipe (33) is respectively connected to the water outlet of the water supply pump (32) and the water inlet of the water tank (1).

3. The secondary side pressure test device for a steam generator in a nuclear power plant according to claim 2, characterized in that: The water injection pipe (4) is connected to the water return pipe (33).

4. The secondary side pressure test device for a steam generator in a nuclear power plant according to claim 3, characterized in that: The circulation pipeline (3) further comprises a return valve (34), which is connected to the return pipe (33) and is located between the water tank (1) and the water injection pipe (4); During the heating phase, the return water valve (34) is opened; during the water injection phase, the return water valve (34) is closed.

5. The secondary side pressure test device for a steam generator in a nuclear power plant according to claim 2, characterized in that: The water supply pump (32) is a small flow circulation pump.

6. The nuclear power plant steam generator secondary side pressure test device according to claim 1, characterized in that: The heating device (2) comprises a main body (21) and an electric heating tube bundle (22); the main body (21) is connected to the electric heating tube bundle (22) and is externally connected to a power source; the electric heating tube bundle (22) extends into the interior of the water tank (1).

7. The secondary side pressure test device for a steam generator in a nuclear power plant according to claim 6, characterized in that: An installation window is provided on the top of the water tank (1), and the diameter of the installation window is larger than the maximum diameter of the electric heating tube bundle (22) and smaller than the maximum diameter of the main body (21).

8. The secondary side pressure test device for a steam generator in a nuclear power plant according to claim 1, characterized in that: The interface assembly (7) includes a plurality of fasteners and a flange welded to a pipe of the steam generator (8), and the flange is detachably connected to the pressure device (6) via the plurality of fasteners; The first end of the flange is inclined outward to form a weld for welding, the second end of the flange is a plane, and a plurality of through holes for fastener connection are provided on the circumference of the flange.

9. The secondary side pressure test device for a steam generator in a nuclear power plant according to any one of claims 1 to 8, characterized in that: The capacity of the water tank (1) is 550m 3 ~750m 3 .

10. The secondary side pressure test device for a steam generator in a nuclear power plant according to any one of claims 1 to 8, characterized in that: The power of the heating device (2) is 80kw to 120kw.

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