Ship Gas Purging System With Direct Nitrogen Purging And Backflow Control

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Solution Overview

Problem

Conventional gas purging systems for ships fueled by liquefied gas face safety risks due to the placement of exhaust lines in the engine room, which requires double-walled pipes, increasing material quantity and cost, and lack efficient backflow prevention control.

Innovation Solution

A gas purging system that minimizes pipes in the engine room by directly discharging residual gas through a gas valve unit, using a backflow prevention valve set with integrated valves to prevent backflow, and a nitrogen supply system that purges the engine and fuel supply line directly, reducing the need for separate vent pipes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If exhaust lines are placed in the engine room for gas purging, then purging function is achieved, but safety risk increases and material quantity increases due to double-walled pipe requirement

Engineering Contradiction:
ImprovesafetyVSAvoidmaterial quantity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts the exhaust line from the engine room and relocates it to the exterior of the ship. The gas purging system discharges residual gas through an exhaust line that exits the engine room and terminates outside the ship's hull, eliminating the need for double-walled pipes within the engine room while maintaining effective purging functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary discharge path that routes residual gas from the engine room through a controlled exhaust line to an external discharge point. This intermediary pathway allows safe removal of hazardous gas without requiring complex double-walled construction within the engine room, reducing material quantity while preserving safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If separate vent pipes are installed for gas purging, then purging effectiveness is ensured, but device complexity and space utilization worsen

Engineering Contradiction:
Improvepurging effectivenessVSAvoidpipe system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the exhaust line with existing engine room ventilation or gas handling infrastructure. The exhaust line is integrated into the ship's existing piping system, combining multiple functions into a unified structure that maintains purging effectiveness while reducing overall system complexity and space requirements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The exhaust line is designed to serve multiple functions: it handles residual gas discharge during purging operations, integrates with existing ventilation systems, and can accommodate various purging scenarios. This multi-functional design eliminates the need for separate dedicated vent pipes, reducing device complexity while ensuring purging effectiveness.

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

3Reliability

If multiple valves are used for backflow prevention, then safety is improved, but device complexity and control logic complexity increase

Engineering Contradiction:
Improvebackflow preventionVSAvoidvalve system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple backflow prevention valves into a single integrated valve assembly. This unified valve unit incorporates check valve mechanisms and control logic in one compact component, maintaining reliable backflow prevention functionality while reducing the number of separate valves and simplifying the overall valve system architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated valve assembly performs multiple backflow prevention functions simultaneously through a single unified design. The valve unit incorporates various protection mechanisms (check valves, controlled closure mechanisms) that work together in one assembly, reducing control logic complexity while maintaining comprehensive backflow prevention capability.

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

4Reliability

If double-walled pipes are used in engine room, then safety is improved, but material quantity and construction cost increase

Engineering Contradiction:
Improveexplosion safetyVSAvoidpipe material quantity
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent removes the requirement for double-walled pipes from the engine room by extracting the exhaust function to an external discharge location. The exhaust line terminates outside the ship's hull, eliminating the need for complex double-walled construction within the engine room while maintaining explosion safety through proper external discharge design.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary external discharge path that mediates between the engine room gas handling system and the external environment. This intermediary exhaust line route allows safe gas discharge without requiring double-walled pipes within the engine room, reducing material quantity while preserving explosion safety through controlled external discharge.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enhances safety by minimizing pipes in the engine room, optimizing space utilization, and reducing material and construction costs while ensuring reliable and rapid purging of residual gas, thus improving operational safety and efficiency.

Implementation Method 1

the gas purging system is configured to push the residual fuel gas out of the engine system using an inert gas, such as nitrogen (N2)

Methodology Applied
Scientific EffectInert gas purging:

Data Source

PatentEP4588787A1Gas purging system for ship
Publication Date: 2025.07.23 HANWHA OCEAN CO LTD (KR)
  • EP4588787A1 patent drawingFigure 1
  • EP4588787A1 patent drawingFigure 2
  • EP4588787A1 patent drawingFigure 3

AI summary

Disclosed herein is a gas purging system for ships having an engine fueled by fuel gas. The gas purging system includes: a fuel supply line along which fuel gas is supplied to the engine; a gas valve unit disposed on the fuel supply line to control a pressure of the fuel gas; and a purge line along which nitrogen gas is supplied to the engine to purge an interior of the engine and an interior of the fuel supply line, wherein the nitrogen gas is directly supplied to the engine along the purge line, purges the interior of the engine and the fuel supply line, and is discharged to outside atmosphere through the gas valve unit.