Control Rod Drive Line Thermal Test Device Centering

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Solution Overview

Problem

Existing test devices for control rod drive lines in nuclear power plants fail to meet stringent high-temperature (≥300°C) and high-pressure (≥15MPa) operating conditions, and lack effective centering and alignment mechanisms for the upper core plate, lower core plate, and guide tube support plate during hot state operations.

Innovation Solution

A hot test device with a segmented pressure shell configuration and adjustable baffle, upper plate, and guide tube support plate adjusting members, utilizing stainless steel forgings and metal O-rings for precise centering and alignment, and a pressure block for horizontal adjustment, ensuring accurate positioning and reliability under extreme conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If a segmented pressure shell configuration is used to enable disassembly and reassembly for inspection, then the ease of repair and inspection is improved, but the manufacturing precision and alignment accuracy deteriorate

Engineering Contradiction:
Improveinspection accessibilityVSAvoidalignment accuracy
Core Design Contradiction:
Ease of repairVSManufacturing precision

Solution Approach 1:

The pressure shell is divided into multiple detachable segments (first pressure shell, second pressure shell, third pressure shell) that can be separated for inspection and reassembled for operation. This segmentation enables easy disassembly and reassembly while maintaining structural integrity through flange connections.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Adjusting members with adjustable lengths are used to modify the position parameters of plates (upper core plate, lower core plate, guide tube support plate) during assembly. By changing the length parameter of adjusting members, precise centering and alignment can be achieved after reassembly, compensating for any dimensional variations introduced by segmentation.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If adjustable members are added to achieve precise centering and alignment under high temperature and pressure, then the manufacturing precision is improved, but the device complexity increases

Engineering Contradiction:
Improvecentering precisionVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Adjustable members with adjustable lengths are incorporated into the structure, allowing dynamic modification of plate positions during assembly. This dynamic adjustment capability enables precise centering and alignment under high temperature and pressure conditions without requiring overly complex fixed structures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The adjustable members serve multiple functions: they provide structural support, enable position adjustment for centering, and allow alignment correction. This multi-functionality reduces the need for separate dedicated adjustment mechanisms, thereby limiting the increase in device complexity while achieving precise centering.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If stainless steel forgings and metal O-rings are used to ensure reliability under extreme conditions, then the reliability is improved, but the manufacturing cost increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The device employs composite material construction, specifically using stainless steel forgings for the pressure shells and metal O-rings for sealing. This combination of materials provides superior reliability under high temperature and pressure conditions while maintaining manufacturing feasibility through standardized components.

Inventive Principle:
Principle #40Composite materials

4Ease of operation

If the pressure shell is designed as detachable segments for easy assembly and disassembly, then the ease of operation is improved, but the sealing reliability may deteriorate

Engineering Contradiction:
Improveassembly convenienceVSAvoidsealing reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The pressure shell is segmented into detachable sections connected by flanges, enabling easy assembly and disassembly for inspection and maintenance. The segmentation is designed with standardized flange interfaces that maintain sealing integrity when properly assembled.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Metal O-rings are introduced as intermediary sealing elements between the detachable pressure shell segments. These O-rings serve as mediators that ensure reliable sealing at the joints between segments, preventing leakage while allowing the segments to be easily assembled and disassembled.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4060647B1Thermal state test device for control rod drive line, and centering method for control rod drive line
Publication Date: 2024.09.04 CHINA NUCLEAR POWER TECH RES INST CO LTD
  • EP4060647B1 patent drawingFigure 1
  • EP4060647B1 patent drawingFigure 2~3

AI summary

A hot test device for a control rod drive line includes a bottom connecting shell (1), a lower pressure shell (2), a middle pressure shell (3), an upper pressure shell (4), a lower core plate (5), a baffle assembly (6), an upper reactor core plate (7), a guide tube support plate (8), a guide tube (9), a tube base installation structure (10) and a tube base (0). An upper plate installation notch (22) and a lower plate installation notch (21) are respectively provided at two ends of the lower pressure shell (2); the lower core plate (5) is fixed onto the lower plate installation notch (21); a plurality of baffle adjusting members (61) arranged in a circumferential direction are provided at a position close to a top of the baffle assembly (6); the upper reactor core plate (1) is fixed onto the upper plate installation notch (22); a plurality of upper plate adjusting members (71) arranged in a circumferential direction are provided at the upper core plate (7); and a plurality of support plate adjusting members (81) arranged in a circumferential direction are provided at the guide tube support plate (8).