CN103742440B - A kind of pyromagnetic sliding sleeve parking sealing arrangement of core main pump - Google Patents

Abstract

A thermomagnetic sliding sleeve parking sealing device for a nuclear main pump, including a sliding sleeve base and a sliding sleeve, the sliding sleeve base is connected to the shaft with interference, the sliding sleeve is connected to the shaft with a gap, and the sliding sleeve is sleeved inside the sliding sleeve base, The sliding sleeve is provided with a first sealing ring, a second sealing ring and a third sealing ring. The sliding sleeve is made of metal material, and the base of the sliding sleeve is made of magnetic material. There are two symmetrical spring chambers inside the sliding sleeve. There is a spring, and there is a small hole on the base of the sliding sleeve. The base of the sliding sleeve is attracted to the sliding sleeve, compressing the spring, and at the same time, the sliding sleeve seals the small hole. When the main seal of the nuclear main pump fails, the high temperature process fluid will make the sliding sleeve The base of the sleeve loses its magnetism, and the magnetic force between the sliding sleeve and the base of the sliding sleeve disappears. Under the action of the spring force and the high temperature fluid pressure in the pump chamber, the sliding sleeve moves to the main seal side until the sliding sleeve is pressed against the wall of the pump chamber. On the one hand, the high-temperature process fluid in the pump cavity is prevented from leaking out, and the present invention does not require an external air source, and is passive.

Description

A thermal magnetic sliding sleeve parking sealing device for nuclear main pump

technical field

The invention belongs to the technical field of nuclear main pumps, and in particular relates to a thermomagnetic sliding sleeve parking sealing device for nuclear main pumps.

Background technique

In severe accidents, in order to ensure that the radioactive fluid in the nuclear main pump of the reactor does not leak, the nuclear main pump needs to be equipped with a shutdown seal. One of the existing nuclear main pump parking seals is driven by high-pressure nitrogen. The high-pressure gas generates pressure on the sealing piston, pushing the sealing piston to move towards the stepped shaft, and compressing it on the stepped shaft. The sealing ring on the contact surface realizes the sealing of the radioactive fluid. . There are also devices that rely on thermal fluid to drive molten metal. This device requires a relatively large amount of thermal fluid, and therefore requires a certain amount of leakage.

Inadequacies of the existing technology and design: the shutdown sealing device for the nuclear main pump does not have passive characteristics, and is dependent on the external high-pressure nitrogen gas source, and the reliability is not enough. If the high-pressure gas source is lost at the same time in a serious accident, the shutdown sealing Impossible to move, the sealing function fails, and a large amount of radioactive fluid leaks. In the method of melting low-melting-point metals with thermal fluid, the amount of leakage is relatively large.

Contents of the invention

In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a thermomagnetic sliding sleeve parking sealing device for nuclear main pumps, which changes the driving mode of parking sealing, does not require an external air source, and is passive.

In order to achieve the above object, the technical scheme that the present invention takes is:

A thermomagnetic sliding sleeve parking sealing device for a nuclear main pump, including a sliding sleeve base 1 and a sliding sleeve 2, the sliding sleeve base 1 is in interference connection with the shaft I, the sliding sleeve 2 is connected with the shaft I in a gap, and the sliding sleeve 2 Set inside the sliding sleeve base 1, the sliding sleeve 2 is provided with a first sealing ring 3, a second sealing ring 5 and a third sealing ring 6, the first sealing ring 3 is installed on the sliding sleeve 2 opposite to the pump chamber wall II On the plane, the second sealing ring 5 and the third sealing ring 6 are respectively installed on the curved surface where the sliding sleeve 2 is in contact with the rotating shaft 1,

The sliding sleeve 2 is made of metal material;

The sliding sleeve base 1 is made of magnetic material whose Curie temperature is lower than the temperature of the process fluid in the pump body;

The sliding sleeve 2 is provided with two symmetrical spring chambers D, and the spring chamber D is provided with a spring 4, and the sliding sleeve base 1 is provided with a small hole E, and the sliding sleeve base 1 and the sliding sleeve 2 attract each other, and the spring 4 Compression, while the sliding sleeve 2 seals the small hole E.

The side of the sliding sleeve 2 is provided with a symmetrical chute G, and the sliding sleeve base 1 is provided with a boss of the same size at the corresponding position, and the boss is embedded in the chute G, so that the sliding sleeve 2 and the sliding Mutual positioning between sets of bases 1 .

The beneficial effect of the present invention is that the driving mode of the parking sealing work is changed, no external air source is needed, and the device is passive.

Description of drawings

Fig. 1 is a front sectional structure diagram of the present invention under normal operation.

Fig. 2 is a front sectional structural view of the present invention under a fault condition.

Figure 3 is a side view of the sliding sleeve.

detailed description

The present invention will be further described below in conjunction with the accompanying drawings.

Referring to Figures 1 and 2, a thermomagnetic sliding sleeve parking sealing device for a nuclear main pump includes a sliding sleeve base 1 and a sliding sleeve 2, the sliding sleeve base 1 is in interference connection with the shaft I, and the sliding sleeve 2 is connected to the shaft I gap connection, the sliding sleeve 2 is set inside the sliding sleeve base 1, the sliding sleeve 2 is provided with the first sealing ring 3, the second sealing ring 5 and the third sealing ring 6, the first sealing ring 3 is installed on the sliding sleeve 2 On the plane opposite to the pump chamber wall II, the second sealing ring 5 and the third sealing ring 6 are respectively installed on the curved surface where the sliding sleeve 2 contacts the rotating shaft I,

The sliding sleeve 2 is made of metal material;

The sliding sleeve base 1 is made of magnetic material whose Curie temperature is lower than the temperature of the process fluid in the pump body;

The sliding sleeve 2 is provided with two symmetrical spring chambers D, and the spring chamber D is provided with a spring 4, and the sliding sleeve base 1 is provided with a small hole E, and the sliding sleeve base 1 and the sliding sleeve 2 attract each other, and the spring 4 Compression, while the sliding sleeve 2 seals the small hole E.

Referring to Figure 3, the side of the sliding sleeve 2 is provided with a symmetrical chute G, and the sliding sleeve base 1 is provided with a boss of the same size at the corresponding position, and the boss is embedded in the chute G to realize sliding Mutual positioning between sleeve 2 and sliding sleeve base 1.

Working principle of the present invention is:

When the main seal of the nuclear main pump is in normal operation, the clean low-temperature sealing medium flows from the side of the main seal A to the pump chamber B, and the sliding sleeve base 1 retains magnetism at low temperature. Since the sliding sleeve 2 is made of metal material, the sliding sleeve base 1 and the The sliding sleeves 2 attract each other, the spring 4 in the spring chamber D is compressed, but at this time the compression force is smaller than the magnetic force, and the first sealing ring 3 at the seal C between the sliding sleeve 2 and the pump chamber wall II is in an open state, clean and low temperature The sealing medium flows into the pump cavity;

When the main seal of the nuclear main pump fails, the supply of the low-temperature fluid originally flowing from the side of the main seal A to the pump cavity B stops, and the high-temperature process fluid in the pump cavity flows reversely through the seal C to the main seal side. The temperature of the high-temperature process fluid is higher than the Curie temperature of the magnetic material of the sliding sleeve base 1, the sliding sleeve base 1 loses its magnetism, and the magnetic force between the sliding sleeve 2 and the sliding sleeve base 1 disappears. The sliding sleeve 2 will move to the side of the main seal A under the spring force of the compressed spring 4, and at the same time, the high-temperature process fluid flows into the gap between the sliding sleeve base 1 and the sliding sleeve 2 through the small hole E of the sliding sleeve base 1 inside the cavity. Since the pressure on the side of the main seal A is much smaller than the pressure in the pump chamber B, the sliding sleeve 2 is under pressure to the side of the main seal A, and under this pressure, the sliding sleeve 2 further moves to the main sealing side A until the sliding sleeve 2 In contact with the pump chamber wall II, and pressed against the pump chamber wall II. At this time, the first sealing ring 3 acts as a seal to prevent the high-temperature process fluid in the pump cavity B from leaking outward.

Claims (2)

1. the pyromagnetic sliding sleeve parking sealing arrangement of a core main pump, comprise sliding sleeve pedestal (1) and sliding sleeve (2), it is characterized in that: sliding sleeve pedestal (1) is connected with axle (I) interference, sliding sleeve (2) and axle (I) recessed bond ing, it is inner that sliding sleeve (2) is enclosed within sliding sleeve pedestal (1), sliding sleeve (2) is provided with the first seal ring (3), second seal ring (5) and the 3rd seal ring (6), first seal ring (3) is arranged in sliding sleeve (2) plane relative with pump chamber wall (II), second seal ring (5) and the 3rd seal ring (6) are arranged on the curved surface that sliding sleeve (2) contacts with rotating shaft (I) respectively,

Sliding sleeve (2) adopts metallic material;

Sliding sleeve pedestal (1) adopts magnetic material manufacture, and the Curie temperature of this kind of magnetic material is lower than the temperature of process fluid in the pump housing;

The spring chamber (D) of two place's symmetries is provided with in sliding sleeve (2), spring (4) is provided with in spring chamber (D), sliding sleeve pedestal (1) is provided with aperture (E), sliding sleeve pedestal (1) is attracting with sliding sleeve (2), to spring (4) compression, sliding sleeve (2) seals aperture (E) simultaneously.

2. the pyromagnetic sliding sleeve parking sealing arrangement of a kind of core main pump according to claim 1, it is characterized in that: the sidepiece of described sliding sleeve (2) is provided with symmetrical chute (G), sliding sleeve pedestal (1) is provided with the boss of formed objects on relevant position, boss is embedded on chute (G), realizes the mutual location between sliding sleeve (2) and sliding sleeve pedestal (1).