Hydrogen Venting Orifice Layout for Uniform Steam-Gas Removal

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Solution Overview

Problem

In pressurized-water nuclear power plants, existing hydrogen removal systems suffer from high wear rates and excessive temperature cycles, leading to frequent inspections and repairs, and cannot control hydrogen removal externally, posing safety risks due to potential explosions and thermal insulation issues.

Innovation Solution

A method and equipment that utilize throttling measurement orifice plates and a pressure energy reducer to separate and remove steam-gas mixtures from multiple accumulation points, ensuring a controlled pressure loss and flow rate, with integrated filters to prevent clogging and ensure long service life, allowing for remote operation and capacity adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing hydrogen removal systems are used in pressurized-water nuclear power plants, then hydrogen can be removed from the primary circuit, but the systems suffer from high wear rates and excessive temperature cycles leading to frequent inspections and repairs

Engineering Contradiction:
Improveservice life of hydrogen removal systemVSAvoidmaintenance frequency
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The system divides the primary circuit into multiple accumulation places (pressurizer, hot leg, cold leg, steam generator) with separate removal points, each equipped with throttling measurement orifice plates. This segmentation allows distributed hydrogen removal, reducing temperature cycling on any single component and lowering wear rates while maintaining continuous operation.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If existing hydrogen removal systems are used, then hydrogen can be removed, but they cannot control hydrogen removal externally, posing safety risks due to potential explosions and thermal insulation issues

Engineering Contradiction:
Improvecontrollability of hydrogen removalVSAvoidsafety against explosions and thermal damage
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system incorporates feedback control through hydrogen concentration measurement in the primary circuit water, which triggers automatic opening of isolation valves and activation of the hydrogen removal system. This external controllability allows operators to respond to hydrogen accumulation risks, preventing explosion hazards and thermal insulation problems while maintaining safety.

Inventive Principle:
Principle #23Feedback

3Manufacturing precision

If throttling measurement orifice plates are installed to ensure required pressure loss and flow rate, then uniform gas removal from multiple points is achieved, but the system complexity increases

Engineering Contradiction:
Improveuniformity of gas removalVSAvoidnumber of orifice plates and interconnecting pipes
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system uses multiple throttling measurement orifice plates installed at different accumulation places (pressurizer, hot leg, cold leg, steam generator) to create uniform pressure loss and flow rate distribution. This segmented approach ensures each removal point operates under controlled conditions, achieving uniform hydrogen removal across the entire primary circuit despite the increased number of components.

Inventive Principle:
Principle #1Segmentation

4Duration of action of stationary object

If filters are installed in the orifice plates to prevent clogging, then component lifespan is extended, but the device complexity and initial wear increase

Engineering Contradiction:
Improveservice life of orifice platesVSAvoidstructure of orifice plates with filters
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

Filters are pre-installed within the throttling measurement orifice plates to prevent clogging by debris and impurities in the primary circuit water. This preliminary protective action extends the service life of the orifice plates by preventing wear and blockage, ensuring long-term reliable operation of the hydrogen removal system without requiring frequent maintenance or replacement.

Inventive Principle:
Principle #10Preliminary action

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 solution provides continuous and safe removal of non-condensable gases, reducing temperature cycling and extending component lifespan, enhancing safety by preventing hydrogen accumulation and ensuring uniform gas removal from multiple points, thus reducing the risk of explosions and component damage.

Implementation Method 1

the said throttling measurement orifice plate also provides the required flow-rate in each branch of the interconnecting pipe between the place of steam-gas mixture accumulation and the collecting pipe

Methodology Applied
Scientific EffectPressure loss: Pressure Drop

Implementation Method 2

a throttling measurement orifice plate installed to ensure a required pressure loss between the steam-gas mixture accumulation place from which it is removed and the collecting pipe

Methodology Applied
Scientific EffectThrottling:

Implementation Method 3

there is an energy reducer installed in the equipment according to the present invention at the collecting pipe outlet, designed to let out the pre-defined quantity of steam-gas mixture

Methodology Applied
Scientific EffectEnergy reduction:

Implementation Method 4

the place of steam-gas mixture accumulation also means the point of steam-gas mixture removal, and both terms can be used interchangeably in the present application. The place of accumulation/removal of the steam-gas mixture is always the highest point in a certain technology section where the steam-gas mixture accumulates because the non-condensable gas is lighter than the steam from the given pressure medium and, therefore, it rises upwards

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP3847674B1Method for removal of a steam-gas mixture containing at least one non-condensable gas, especially hydrogen, and steam from a pressure system technology and an equipment for such removal
Publication Date: 2024.10.23 SKODA JS AS
  • EP3847674B1 patent drawingFigure 1~2
  • EP3847674B1 patent drawingFigure 3~4
  • EP3847674B1 patent drawingFigure 5

AI summary

Method of removal of a steam-gas mixture of at least one non-condensable gas and steam from a pressure system technology (1) where the said steam-gas mixture accumulates in at least two places (la) from which the steam-gas mixture is removed and routed through interconnecting pipes (3) to a collecting pipe (4) through which it is let out for further processing, while in all the accumulation places (la) a pressure loss is created between the accumulation place (la) and the collecting pipe(4), being at least 10 times higher than that in the interconnecting pipe (3) with the highest pressure loss, and, at the same time, the required proportion of steam-gas mixture removal, the total required quantity of the steam-gas mixture removed from the technology (1) and the required pressure drop are set for the individual accumulation places (la). The equipment for removal of a steam-gas mixture of at least one non-condensable gas and steam from the pressure system technology (1) containing at least two accumulation places (la) where the steam-gas mixture accumulates has each accumulation place (la) connected via interconnecting pipe (3) with a throttling measurement orifice place (2) with the collecting pipe (4), through which the steam-gas mixture is removed from the accumulation place (la) over a pressure energy reducer (6).