Pit filter

Abstract

A pit filter comprises a filter unit, a pressure recovery unit and a flow stabilizing unit. The pressure recovery unit is fixedly installed between the filter unit and the flow stabilizing unit and shaped like a straight cylinder; the filter unit is shaped like a cylinder on the whole, the end of the filter unit is a closed spherical surface, and the side wall of the filter unit is a corrugated surface, and the filter unit is provided with multiple filter channels; the flow stabilizing unit is a pipeline with a streamlined side wall, and an outlet end of the flow stabilizing unit is connected with a processing pipe network. The pit filter has the advantages that by means of the end face of the closed spherical surface of the filter unit and the side wall of the corrugated surface, the filter area is increased, the flow capacity is stronger, a filter bed is not prone to being formed due to the cylindrical structure, and the pressure loss is small; the pressure recovery unit can convert the dynamic pressure entering from the filter channels into static pressure, the flow stabilizing unit with a streamlined channel divides the medium, the eddy current is eliminated, the pressure loss is further reduced, and the service life of equipment is prolonged.

Description

Technical field [0001] The invention relates to a safety system of a pressurized water reactor nuclear power plant, in particular to a pit filter used in a pressurized water reactor nuclear power plant. Background technique [0002] The pit located at the bottom of the containment vessel of the pressurized water reactor nuclear power plant is used to collect the coolant from the primary circuit in case of major leakage. After a basic accident such as a loss of coolant accident (LOCA) or a main steam line rupture accident (MSLB) occurs in a PWR nuclear power plant, the coolant enters the containment pit through the breach, and the coolant will be filtered through the containment pit filter, Then it enters the Safety Injection System (RIS) and the Containment Spray System (EAS) through the pump device and is used for reactor cooling to avoid severe damage to the core and overpressure of the containment vessel. [0003] Therefore, the containment pit filter is an important equ...

AI Technical Summary

Problems solved by technology

[0004] One of the existing pit filters is a single-layer columnar structure, which has a limited filtering area when occupying the same volume, and because the larger filtering area of ​​the structure is parallel to the pit, it is easy to form The filter bed has a large pressure loss, which reduces the service life of the filter; at the same time, because the columnar structure does not use a smooth transition mesh filter surface, but has a certain bending mesh filter surface, its processing technology is relatively Complicated, and concentrated stress is easily formed at the bend, which reduces the overall strength of the filter cartridge; the other is a double-layer nested structure. Compared with the previous structure, this structure strengthens the overall strength and increases the filtration area. The pressure loss is reduced to a certain extent, but the defect of stress concentration at the bend still exists, and the filter bed is still easy to form, and the pressure loss is relatively large after working for a certain period of time

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