A device and method for solving the lubricating oil water ingress of the main feed water pump of a nuclear power plant

Abstract

The present application belongs to the technical field of high-temperature pump equipment management, and particularly relates to a device and method for solving the water ingress of lubricating oil of a main feed water pump of a nuclear power plant. The device for solving the water ingress of lubricating oil of the main feed water pump of the nuclear power plant comprises a pump shell, and a breathing hole is formed in the upper portion of the pump shell. The breathing hole is a through hole. The breathing hole is opposite to a mechanical seal leakage port on the pump shell, and the included angle between the breathing hole and the mechanical seal leakage port is 180°. The method for solving the water ingress of lubricating oil of the main feed water pump of the nuclear power plant comprises the following steps: 1. installing a drilling tool and a special tool on the upper portion of the pump shell; and 2. drilling a breathing hole on the pump shell by using the drilling tool and the special tool. The present application has the beneficial effect that the present application has been tested by two cycles of operation, and no rust is found when the bearing box is disassembled, and the water content of the lubricating oil is qualified in regular sampling inspection.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-temperature pump equipment management, and particularly relates to a device and method for solving lubricating oil water ingress of a main feed water pump of a nuclear power plant. BACKGROUND

[0002] The main feed water pump is a key important equipment of the secondary loop of the nuclear power plant. The main feed water pump of the nuclear power plant is prone to lubricating oil water ingress. In a serious case, a pump is used as an emergency standby pump for two cycles by connecting an online oil filter, which threatens the safe and stable power operation of the unit. SUMMARY

[0003] The application aims to provide a device and method for solving lubricating oil water ingress of a main feed water pump of a nuclear power plant, which can solve the common problem of lubricating oil water ingress of the main feed water pump and improve the reliability of equipment operation.

[0004] The technical scheme of the application is as follows: a device for solving lubricating oil water ingress of a main feed water pump of a nuclear power plant, comprising a pump shell, and a breathing hole is formed in the upper portion of the pump shell.

[0005] The breathing hole is a through hole.

[0006] The breathing hole is opposite to a mechanical seal leakage port on the pump shell, and the included angle between the two is 180°.

[0007] The diameter of the breathing hole is at least Φ30 mm.

[0008] A method for solving lubricating oil water ingress of a main feed water pump of a nuclear power plant, comprising the following steps:

[0009] Step 1: installing a drilling tool and a special tool on the upper portion of the pump shell.

[0010] Step 2: drilling a breathing hole on the pump shell by using the drilling tool and the special tool.

[0011] The breathing hole in step 2 is a through hole.

[0012] The breathing hole in step 2 is located in the upper portion corresponding to the position of the mechanical seal leakage port.

[0013] The diameter of the breathing hole in step 2 is at least Φ30 mm.

[0014] The application has the advantages that the application has been tested for two cycles of operation, and no rust is found when the bearing box is disassembled, and the water content of the lubricating oil is qualified in regular sampling inspection. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A device for solving lubricating oil water ingress of a main feed water pump of a nuclear power plant is provided.

[0016] In the figure, 1 is a breathing hole, 2 is a mechanical seal leakage port, and 3 is a pump shell. DETAILED DESCRIPTION

[0017] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0018] The application confirms that the reason is that the sealing design of the pump shell is unreasonable, the sealing of the high-temperature pump shell and the bearing box connection is without a breathing hole, and the water vapor leakage of the high-temperature pump mechanical seal during normal operation is much larger than that of the normal-temperature mechanical seal, which leads to the leakage of high-temperature water vapor into the bearing box, and a large amount of water enters the lubricating oil system of the main feed water pump set after long-term operation. The problem of water entering the lubricating oil is solved by making a reliable opening hole without affecting the strength of the pump shell, and no rust is found when the bearing is disassembled. The improvement means is a unique design, which provides an important reference for the design improvement of similar high-temperature pump shells.

[0019] The application analyzes that the main reason for the water entering the lubricating oil is that the water vapor generated by the high-temperature pump mechanical seal during normal operation accumulates in the sealed pump shell cavity and finally leaks into the bearing box of the free end of the pump. Because the high-temperature water vapor leakage of the pump mechanical seal exists objectively and cannot be completely zero leakage, the design of the sealed pump shell is unreasonable, so it is necessary to find a way to discharge the high-temperature water vapor from the sealed pump shell in order to reduce or even completely eliminate the water vapor leaking into the bearing chamber. A breathing hole needs to be opened to allow the high-temperature water vapor to be discharged to the atmosphere. The opening hole in the upper part of the pump shell is more conducive to discharging the high-temperature water vapor out of the sealed pump shell, and the internal mechanical seal state can be more easily observed. The newly opened breathing hole in the upper part is opposite to the original mechanical seal leakage port in the lower part, which helps to improve the ventilation capacity of the sealed chamber and more easily discharge the high-temperature water vapor.

[0020] As shown in Figure 1 A device for solving the problem of water entering the lubricating oil of the main feed water pump of a nuclear power plant, comprising a pump shell 3, a breathing hole 1 is opened in the upper part of the pump shell 3, the breathing hole 1 is a through hole, the breathing hole 1 is opposite to the mechanical seal leakage port on the pump shell 3, and the included angle between the two is 180°, and the hole diameter of the breathing hole 1 is at least Φ30mm.

[0021] A method for solving the problem of water entering the lubricating oil of the main feed water pump of a nuclear power plant, comprising the following steps:

[0022] Step 1: Install a drilling tool and a special tool on the upper part of the pump shell;

[0023] Step 2: Drill a breathing hole 1 in the upper pump shell body corresponding to the position of the mechanical seal leakage port through the drilling tool and the special tool, the breathing hole 1 is a through hole, and the hole diameter of the breathing hole 1 is at least Φ30mm.

Claims

1. A method for solving the problem of water ingress into the lubricating oil of a main feedwater pump in a nuclear power plant, the applied device comprising a pump casing, wherein the pump casing has a breather hole, the breather hole being a through hole, the breather hole being positioned opposite the mechanical seal leakage port on the pump casing, the included angle between the two being 180°, and the diameter of the breather hole being at least Ф30mm, characterized in that, Includes the following steps: Step 1: Install drilling tools and special fixtures on the upper part of the pump casing; Step 2: Drill a breather hole on the pump casing; In step 2, a breathing hole is drilled on the pump casing using drilling tools and special fixtures.

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