Anti-surge ring mechanism of cooling fan of control rod drive mechanism

Abstract

The invention discloses an anti-surge ring mechanism of a cooling fan of a control rod drive mechanism. An annular groove is formed outside an anti-surge ring, a plurality of flow deflectors are evenly arranged in the annular groove in the peripheral direction, and flow guide rings are arranged on the inner sides of the flow deflectors. The anti-surge ring is arranged on an air duct of the cooling fan, the air duct is fixed through a support, and a movable vane, a hub, a guide vane, an inner machine box, a drive fan and a diffusion tail cone are arranged inside the air duct. An air outlet in the upper end of the air duct is connected with an air outlet taper pipe, and an air valve is arranged inside the air outlet taper pipe. The anti-surge ring mechanism of the cooling fan of the control rod drive mechanism has the advantages of being simple and novel in structure, and capable of ensuring that the fan can still operate smoothly under small flow.

Description

technical field [0001] The invention relates to a cooling fan, in particular to an anti-surge ring mechanism for a cooling fan of a control rod drive mechanism. Background technique [0002] The control rod drive mechanism cooling fan is a ventilation and cooling system for the control rod drive mechanism of the integrated stack top assembly of the third-generation nuclear power unit. Its function is to provide forced cooling air for the control rod drive mechanism to maintain the coil assembly of the control rod drive mechanism The temperature required for normal operation does not exceed the limit value. The performance of the fan directly affects the safety and reliability of the reactor drive mechanism. [0003] The cooling fan of the control rod drive mechanism has the characteristics of large hub ratio and large blade installation angle, and is a typical high-pressure axial flow fan. The performance characteristic curve of high-pressure axial fans usually has obvi...

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Problems solved by technology

[0004] The cooling fan of the control rod drive mechanism is strictly forbidden to operate in the surge area. The harmfulness of operation in the surge area is as follows: the conveying air flow oscillates back and forth, causing the control rod drive mechanism system to fail to discharge heat normally, and the root of the blade bears a large aerodynamic alternating load , may lead to blade fatigue fracture

[0005] Relevant regulations and standards strictly prohibit the fan from working in the surge area, such as ASME-AG-1, the US nuclear air treatment regulation. However, there is an obvious surge area in the existing conventional control rod drive mechanism cooling fan. When running under low flow conditions, the fan will enter the surge area, posing safety hazards

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