PEEK-Coated Coil Assembly for Nuclear Control Rod Drivers

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Solution Overview

Problem

Control rod driving coils in nuclear power plants deteriorate due to high temperatures during continuous operations, leading to insulation breakdown and potential control rod falls, compromising safety and reliability.

Innovation Solution

A coil assembly with a polyether ether ketone (PEEK) coating layer on copper wires, wound in multiple layers, filled with varnish, and sealed with insulating tape and silicon molding, enhancing heat resistance and mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If enamel-based insulating material is used to cover coil wires, then the coil assembly can be manufactured with conventional materials and processes, but the coils deteriorate at temperatures above 220°C leading to insulation breakdown and control rod failure

Engineering Contradiction:
Improvecoil heat resistanceVSAvoidcoil deterioration at high temperature
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the material parameter of the insulating coating from conventional enamel-based material to polyether ether ketone (PEEK) coating material. This parameter change enables the coil assembly to withstand temperatures above 220°C without deterioration, directly resolving the heat resistance issue while maintaining manufacturing feasibility through established coating processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a composite structure consisting of copper coil wires covered with PEEK coating material. This composite material combination provides both the electrical conductivity required for coil operation and the high-temperature resistance needed to prevent deterioration during continuous operation, thereby improving reliability without sacrificing electrical performance

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If conventional enamel-based insulating material is used on coil wires, then manufacturing is simpler and more economical, but continuous operation during automatic load follow causes coil deterioration and insulation breakdown

Engineering Contradiction:
Improvecoil manufacturing simplicityVSAvoidcoil durability during continuous operation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent modifies the insulating material parameter from enamel-based coating to PEEK coating, which can be applied through conventional coating processes. This change maintains ease of manufacture while dramatically improving coil durability during continuous operation by enabling operation at temperatures above 220°C without material deterioration

Inventive Principle:
Principle #35Parameter changes

3Productivity

If coils operate at high temperatures during automatic load follow, then power generation efficiency is maintained, but insulation breakdown occurs leading to control rod falls and safety issues

Engineering Contradiction:
Improvepower generation during automatic load followVSAvoidinsulation breakdown and control rod fall
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the thermal parameter of the insulating material by using PEEK coating material with high heat resistance. This enables the coils to operate at high temperatures during automatic load follow operations without experiencing insulation breakdown, thereby maintaining power generation productivity while eliminating the safety hazard of control rod falls

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The PEEK coating material serves as a protective barrier that beforehand prevents insulation breakdown under high-temperature conditions. This prior protection allows the coil assembly to withstand the thermal stress of continuous operation during automatic load follow without deteriorating, thus preventing control rod failures before they can occur

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The coil assembly exhibits improved heat resistance and lifespan, reducing coil deterioration and control rod falls, thereby enhancing the safety and economic feasibility of nuclear power plants during automatic load follow operations.

Implementation Method 1

a covered wire including a coil wire and a polyether ether ketone (PEEK) coating layer covering an outer circumferential surface of the coil wire

Methodology Applied
Scientific EffectThermal resistance: Thermal Insulation

Implementation Method 2

configured to control the vertical movement of the control rod 3 by controlling motor driving using an electromagnetic force generated by power supplied to cables of the control rod driving coils

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP2669896B1Coil assembly for a control rod driver having improved thermal resistance, and method for manufacturing same
Publication Date: 2018.08.15 KOREA HYDRO & NUCLEAR POWER CO LTD
  • EP2669896B1 patent drawingFigure 1
  • EP2669896B1 patent drawingFigure 2
  • EP2669896B1 patent drawingFigure 3(a)~3(b)

AI summary

Provided is a coil assembly having improved heat resistance for use in a control rod driver, in which the heat resistance of coils is improved to increase the lifespan thereof and the deterioration of the coils and the fall of a control rod are thus securely prevented from occurring due to continuous operations of the control rod driver during an automatic load follow operation, thereby improving the safety and economic feasibility of a nuclear power plant, and a method for manufacturing the same. The coil assembly includes a covered wire (110) which includes a coil wire (111) and a polyether ether ketone (PEEK) coating layer (112) covering an outer circumferential surface of the coil wire (111) and is wound in multiple layers; a coil coating layer (130) formed by filling gaps in the covered wire (110) with varnish; an insulating tape layer (120) covering external sides of a wound layer of the covered wire (110) insulated by the coil coating layer (130); and silicon molding (140) covering external sides of the insulating tape layer (120).