Nuclear power plant nuclear reactor coolant pump and static-pressure shaft seal assembly thereof

Abstract

The invention discloses a nuclear power plant nuclear reactor coolant pump and a static-pressure shaft seal assembly thereof. Peripheral sealing between a first sealing assembly of the static-pressure shaft seal assembly and a sealing shell arranged outside the first sealing assembly is achieved through a sealing ring and a high-molecular polymer ring. An annular accommodating groove is formed in the outer wall of the position, making contact with the sealing shell, of the first sealing assembly, the two ends of the cross section of the annular accommodating groove are different in width, and the larger accommodating end of the annular accommodating groove is closer to a coolant pump hydraulic component than the smaller extruding end of the annular accommodating groove. The high-molecular polymer ring is accommodated in the accommodating end of the annular accommodating groove under a normal working condition and becomes soft and is extruded into the extruding end of the annular accommodating groove by high-temperature high-pressure fluid under the condition that a whole plant has a power failure, and therefore the high-molecular polymer ring is tightly attached to the sealing shell and the first sealing assembly, and continuous sealing between the first sealing assembly and the sealing shell is guaranteed. Compared with the prior art, the reliance on a high-temperature-resistant O-shaped rubber ring is avoided, and the nuclear power plant reactor core damage probability is effectively lowered.

Description

technical field [0001] The invention belongs to the field of nuclear power, and more specifically, the invention relates to a nuclear reactor coolant pump of a nuclear power plant and a static pressure shaft seal assembly thereof. Background technique [0002] In a pressurized water reactor nuclear power plant, the hydrostatic shaft-sealed coolant pump is a single-stage, single-suction, vertical mixed-flow pump driven by a three-phase induction motor. figure 1 It is a structural diagram of an existing nuclear reactor coolant pump, which is composed of a motor 10, a hydrostatic shaft seal assembly 12 and a hydraulic component 14 from top to bottom, and the pump shaft runs through the center of the entire coolant pump; the reactor coolant is composed of a The impeller at the lower end of the pump shaft pumps, which is sucked in through the bottom of the pump casing and flows up through the impeller, and then discharged through the guide vanes and an outlet connection on the si...

AI Technical Summary

Problems solved by technology

However, due to the high cost of the high-temperature-resistant rubber O-ring 26, and the limited sealing performance it can maintain under high temperature, high pressure and high radioactive dose levels, it is still impossible to completely avoid shaft seal breach accidents

[0008] In view of this, it is really necessary to provide a nuclear power plant nuclear reactor coolant pump and its hydrostatic shaft seal assembly that can solve the sealing problem between stationary parts under the condition of power failure in the whole plant

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