Boric acid delivery pump for nuclear power station

Abstract

The invention discloses a boric acid delivery pump for a nuclear power station. A volute chamber has a double volute structure, so that radial force generated during the operation of an impeller is effectively balanced; a pump cover seal has a single-end-face containerization type mechanical seal structure, is convenient to assemble, disassemble and maintain and can effectively prevent media fromleaking outwards; a bearing oil seal has a labyrinth seal structure, so that an ideal sealing effect is achieved; a cooling cavity on a pump cover is eliminated, and the axial length of the pump cover is shortened, so that the integral pump set has a compact structure, and the space for installation and maintenance is effectively reduced; a sealing structure formed by combining a pump seal with an impeller seal is changed into a single pump body sealing structure, so that the delivery pump has a simple and reliable structure and is convenient to mount and maintain; and a supporting rib plate is arranged on a bearing bracket, so that the stability of the pump set is improved.

Description

technical field [0001] The invention relates to a pump, in particular to a boric acid delivery pump used in nuclear power plants. Background technique [0002] The functions of the boric acid transfer pump used in nuclear power plants are: to inject or supplement 4% boric acid solution to the boric acid storage tank for the first time; to add boric acid solution to the chemical capacity system (RCV) at the rated flow rate; to add boric acid solution to the main coolant through the direct boronation pipeline 4% boric acid solution; inject or supplement 1.25% boric acid solution into the refueling water tank for the first time. [0003] The existing boric acid delivery pump used in nuclear power plants also has the following defects (see figure 1 ): [0004] 1. The volute chamber 10 of the pump body 1 adopts a single volute structure, and the impeller 4 will generate a large radial force during operation, especially in non-design conditions, which will directly affect the st...

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Problems solved by technology

[0004] 1. The volute chamber 10 of the pump body 1 adopts a single volute structure, and the impeller 4 will generate a large radial force during operation, especially in non-design conditions, which will directly affect the strength of the pump shaft 7 and the use of bearings life;

[0005] 2. The pump cover sealing device 17 adopts a bulk mechanical seal, which is inconvenient to disassemble and maintain, and may easily cause medium leakage;

[0006] 3. The bearing oil seal device is a labyrinth seal groove on the inner surface of the bearing end cover 9 directly facing the pump shaft 7. When the rotor rotates at high speed, it is easy to cause lubricating oil to leak along the surface of the pump shaft 7;

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