Nuclear power GFR vertical plunger pump inlet pipeline

Abstract

The utility model provides a nuclear power GFR vertical plunger pump inlet pipeline which comprises a first pipe section, a second pipe section and a third pipe section which are communicated in sequence, the first pipe section is used for being connected with a GFR oil pump, the second pipe section is a straight pipe and is perpendicular to the first pipe section and extends downwards, and the third pipe section is an elbow so that the tail end of the inlet pipeline can be horizontally arranged. The third pipe section at the tail end of the inlet pipe adopts the elbow design, so that macroscopic bubbles in a medium can be effectively prevented from directly entering a pipeline in the rising process, the gas accumulation phenomenon at the inlet of the GFR vertical plunger pump can be effectively avoided, and the problems of abnormal pressure building and unsuccessful switching of the GFR vertical plunger pump are successfully solved. Compared with other methods, the application of the novel inlet pipe has the advantages of simplicity in implementation, remarkable effect, small influence on an original system, low implementation cost and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of nuclear power, and particularly relates to an inlet pipeline of a vertical plunger pump for nuclear power GFR. Background Technique

[0002] The GFR regulating oil system of a domestic nuclear power plant adopts a modular design and is designed with three independent oil supply stations. Its main functions are to provide power oil sources for the high and low pressure oil motors of the steam turbine GRE / GSE respectively. Among them, the GFR high-pressure oil supply module (EH1 oil station) provides a power oil source for the high-pressure steam valve drive mechanism, and the other two GFR low-pressure oil supply modules (EH2 / 3 oil stations) provide power oil sources for the low-pressure steam valve drive mechanisms respectively.

[0003] The GFR main oil pump of the GFR regulating oil system is a Rexroth axial swash plate type plunger pump, and the oil pump is vertically arranged under the tank cover plate. Two GFR main oil pumps (one in use and one in standby) are set in each oil station. During the regular transfer and switching every week, the standby GFR main oil pump frequently fails to switch successfully (after the GFR main oil pump starts, the outlet pressure < 1 MPa, and within 4S of delay, it is judged that the main oil pump is working abnormally, and the pump operation is automatically stopped).

[0004] Regarding the problem that the standby main oil pump of GFR cannot build pressure quickly after starting and the standby oil pump loses the emergency standby function, the engineer combines the structure and principle, operation and maintenance experience of the GFR equipment in the nuclear power plant to analyze the root cause of the problem. The original GFR system design, the structure principle and layout method of the main oil pump have the following problems:

[0005] A: When the anti-fuel oil medium is disturbed in the system (such as oil filtering, throttling, etc.), a large number of macroscopic bubbles will be generated inside the medium.

[0006] B: Due to the system design and layout reasons, a large amount of medium of the cooling return oil (including the return oil of the oil filter) needs to flow in a large range in the tank to the inlet of the cooling oil pump, and passes through the inlet pipe of the main oil pump along the way.

[0007] C: The inlet pipe of the GFR main oil pump is arranged vertically downward. During the upward movement of the macroscopic bubbles in the anti-fuel oil medium, it is easy to enter the inlet pipe and accumulate at the inlet for a long time.

[0008] D: When the GFR main oil pump starts with the outlet check valve closed, due to the presence of air at the inlet, the oil pump pumps an empty pump, cannot suck oil, and cannot build oil pressure within 4S.

[0009] That is to say, since the GFR main oil pump is vertically arranged above the oil tank, the gas-containing medium brought into the oil tank during normal oil filtering operation accumulates in large quantities for a long time when flowing through the inlet of the standby oil pump. At the same time, the gas spontaneously separated from the superimposed oil (the gas separated after changes in temperature, pressure, throttling, etc.) will gather at the suction pipe of the main oil pump and the plunger suction port. When the oil pump starts with the outlet closed, the plunger has low work efficiency on the gas, resulting in the main oil pump outlet pressure not being able to reach 1 MPa in 4s, triggering the start-up pump trip logic. Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a nuclear power GFR vertical plunger pump inlet pipeline, which can effectively avoid the phenomenon of gas accumulation at the inlet of the GFR vertical plunger pump and solve the problems of abnormal pressure building and unsuccessful switching of the GFR regulating oil vertical plunger pump, in view of the above-mentioned defects of the prior art.

[0011] The technical solution adopted by the present invention to solve its technical problems is: a nuclear power GFR vertical plunger pump inlet pipeline, including a first pipe section, a second pipe section, and a third pipe section that are connected in sequence. The first pipe section is used to connect to the GFR oil pump. The second pipe section is a straight pipe and extends vertically downward from the first pipe section. The third pipe section is an elbow so that the end of the inlet pipeline is horizontally arranged. This design structure can reduce the accumulation of bubbles at the pipeline inlet, ensure that the oil pump can quickly suck in oil when starting, and make the main oil pump outlet pressure reach 1 MPa in 4s.

[0012] Further, it is preferably that the open end of the third pipe section is a vertical port perpendicular to the horizontal plane.

[0013] Further, it is preferably that the orientation of the third pipe section is arranged along the medium flow direction of the GFR oil pump.

[0014] Further, it is preferably that the connection end of the first pipe section is provided with an installation port for connecting to the GFR oil pump.

[0015] Further, it is preferably that the first pipe section, the second pipe section, and the third pipe section are all stainless steel pipes.

[0016] Further, it is preferably that the pipeline length of the inlet pipeline is 265 - 275 mm.

[0017] Further, it is preferably that the pipe diameter of the inlet pipeline is 46 - 50 mm.

[0018] Further, it is preferably that it further includes a fourth pipe section connected to the third pipe section. The fourth pipe section is an elbow connected to the third pipe section and the pipe orifice is arranged upward.

[0019] Further, it is preferably that the open end of the third pipe section is a flat port.

[0020] The inlet pipeline of the nuclear power GFR vertical plunger pump of the present utility model has at least the following effects: The third pipe section at the end of the inlet pipe adopts an elbow design, which can effectively prevent macroscopic bubbles in the medium from directly entering the pipeline during the rising process, effectively avoid the phenomenon of gas accumulation at the inlet of the GFR vertical plunger pump, and successfully solve the problems of abnormal pressure build-up and unsuccessful switching of the GFR regulating oil vertical plunger pump. And the application of the new inlet pipe has the advantages of simple implementation, remarkable effect, small impact on the original system, and low implementation cost compared with other methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the inlet pipeline of the original GFR regulating oil vertical plunger pump;

[0022] Figure 2 is a schematic structural diagram of some embodiments of the inlet pipeline of the nuclear power GFR vertical plunger pump of the present utility model;

[0023] Figure 3 is a schematic structural diagram of other embodiments of the inlet pipeline of the nuclear power GFR vertical plunger pump of the utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To further elaborate on the technical means and technical effects of the present utility model, the following describes the preferred embodiments of the present utility model with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present utility model.

[0025] As Figures 2 - 3 shown, a nuclear power GFR vertical plunger pump inlet pipeline provided by the present utility model includes a first pipe section 10, a second pipe section 20, and a third pipe section 30 that are connected in sequence. The first pipe section 10 is used to connect the GFR oil pump. The second pipe section 20 is a straight pipe and extends vertically downward from the first pipe section 10. The third pipe section 30 is an elbow so that the end of the inlet pipeline is horizontally arranged. The third pipe section 30 at the end of the new inlet pipeline of the present utility model adopts an elbow design, changing from the original vertical pipe to an elbow, preferably a right-angle elbow. On the premise of keeping the center elevation unchanged and not affecting the liquid level standard of the original system, it effectively prevents macroscopic bubbles in the medium from directly entering the pipeline and prevents bubbles from accumulating in the inlet pipe for a long time.

[0026] Starting from the source of the problem, the inlet pipeline of the nuclear power GFR vertical plunger pump can effectively avoid the phenomenon of air accumulation at the inlet of the GFR vertical plunger pump, and successfully solve the problems of abnormal pressure building and unsuccessful switching of the GFR regulating oil vertical plunger pump. Moreover, compared with other methods, the application of the new inlet pipe has the advantages of simple implementation, remarkable effect, little impact on the original system, and low implementation cost.

[0027] In a preferred embodiment, the open end of the third pipe section 30 is a vertical opening perpendicular to the horizontal plane. The open end of the end pipe section in the original inlet pipeline of the GFR regulating oil system vertical plunger pump is an inclined opening facing downward. As Figure 1 shown, the open end of the end of the inlet pipeline of the present invention is changed to a vertical opening perpendicular to the horizontal plane. As Figure 2 shown, it can effectively prevent the macroscopic bubbles in the medium from directly entering the pipeline during the rising process.

[0028] In a specific embodiment, the third pipe section 30 is arranged along the medium flow direction of the GFR oil pump, which can effectively reduce the bubbles in the medium from entering the pipeline following the oil flow and prevent the bubbles from accumulating in the inlet pipe for a long time.

[0029] In a specific embodiment, to improve the connection stability and sealing performance, the connection end of the first pipe section 10 is provided with an installation port 11, which is specifically used for connecting with the GFR oil pump.

[0030] At the same time, considering corrosion resistance and service life, the first pipe section 10, the second pipe section 20, and the third pipe section 30 can all be made of stainless steel materials.

[0031] In a specific embodiment, the pipeline length of the inlet pipeline is 265 - 275 mm, that is, the total pipeline length of the first pipe section 10, the second pipe section 20, and the third pipe section 30 is 265 - 275 mm. Preferably, the pipeline length of the inlet pipeline is 270 mm, which can keep the center elevation unchanged and does not affect the liquid level standard of the original system.

[0032] In a specific embodiment, the pipe diameter of the inlet pipeline is 46 - 50 mm. Preferably, the pipe diameter of the inlet pipeline is 48 mm, that is, the pipe diameters of the first pipe section 10, the second pipe section 20, and the third pipe section 30 are all 46 - 50 mm, ensuring sufficient oil supply and improving work efficiency.

[0033] In another specific embodiment, as Figure 2 shown, the inlet pipeline of the nuclear power GFR vertical plunger pump further includes a fourth pipe section 40 connected to the third pipe section 30. The fourth pipe section 40 is connected to the third pipe section 30 by an elbow and the pipe opening is arranged upward. The upward pipe opening design makes it almost impossible for the macroscopic bubbles in the medium to enter the inlet pipe of the oil pump during the upward dispersion process, ensuring that no gas accumulation occurs.

[0034] Further, it is preferable that the open end of the fourth pipe segment 40 is a flat end, which can further prevent macroscopic bubbles in the medium from directly entering the pipeline during the rising process.

[0035] The inlet pipe of the novel GFR vertical plunger pump has been successfully implemented in a domestic nuclear power plant. The implementation during the overhaul process is simple, and the equipment is successfully re-identified once after the overhaul. The unit has been operating for about half a year, the GFR system equipment is stable, the parameters are normal, and there is no abnormality during the daily regular switching. Through the implementation and application of the novel GFR vertical plunger pump inlet pipe, starting from the source, the air accumulation during the standby period of the vertical plunger pump is blocked, the reliability of the power plant unit is improved, and a new solution to solve the problem of unsuccessful switching of the main oil pump of nuclear power GFR is created. The process of technical implementation is simple, the effect is remarkable, and the cost is less, which contributes to the lean management of the power plant.

[0036] Compared with the prior art, the inlet pipeline of the nuclear power GFR vertical plunger pump of the present utility model has the following remarkable advantages:

[0037] 1. Through a special pipeline layout, the accumulation of bubbles at the inlet is effectively reduced, thereby preventing the phenomenon of the oil pump running dry due to excessive gas inhalation during startup.

[0038] 2. The working efficiency of the oil pump is improved, ensuring that the required oil pressure can be quickly established within a specified time (such as within 4 seconds), and avoiding the pump trip logic triggered by insufficient oil pressure.

[0039] 3. The pipeline is made of stainless steel material, enhancing the corrosion resistance and service life, and reducing the maintenance cost.

[0040] 4. The structural design is flexible, and the fourth pipe segment can be added according to actual needs to further optimize the oil flow and bubble discharge effect.

[0041] The above embodiments are only for illustrating the technical concept and characteristics of the present utility model, and the purpose is to enable those skilled in the art to understand the content of the present utility model and implement it accordingly, and cannot limit the protection scope of the present utility model. All equivalent changes and modifications made to the scope of the claims of the present utility model shall fall within the scope covered by the claims of the present utility model.

Claims

1. A nuclear power GFR vertical plunger pump inlet pipeline, characterized in that: It comprises a first pipe section, a second pipe section and a third pipe section which are connected in sequence. The first pipe section is used to connect the GFR oil pump. The second pipe section is a straight pipe and extends downward perpendicularly to the first pipe section. The third pipe section is an elbow so that the end of the inlet pipe is arranged horizontally.

2. The nuclear power GFR vertical plunger pump inlet pipeline according to claim 1 is characterized in that: The open end of the third pipe section is a vertical opening perpendicular to the horizontal plane.

3. The nuclear power GFR vertical plunger pump inlet pipeline according to claim 1 is characterized in that: The third pipe section is arranged along the medium flow direction of the GFR oil pump.

4. The nuclear power GFR vertical plunger pump inlet pipeline according to claim 1, characterized in that: The connecting end of the first pipe section is provided with a mounting port, and the mounting port is used to connect with the GFR oil pump.

5. The nuclear power GFR vertical plunger pump inlet pipeline according to claim 1, characterized in that: The first pipe section, the second pipe section and the third pipe section are all stainless steel pipes.

6. The nuclear power GFR vertical plunger pump inlet pipeline according to claim 1, characterized in that: The inlet pipe has a pipe length of 265-275 mm.

7. The nuclear power GFR vertical plunger pump inlet pipeline according to claim 1, characterized in that: The diameter of the inlet pipe is 46-50 mm.

8. The nuclear power GFR vertical plunger pump inlet pipeline according to claim 1, characterized in that: It also includes a fourth pipe segment connected to the third pipe segment. The fourth pipe segment is connected to the third pipe segment through an elbow and the pipe opening is arranged upward.

9. The nuclear power GFR vertical plunger pump inlet pipeline according to claim 8, characterized in that: The opening end of the fourth pipe section is flat.

10. The nuclear power GFR vertical plunger pump inlet pipeline according to claim 1, characterized in that: The third pipe section is a right-angle elbow.

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