Submarine Cooling Circuits with Parallel Pump Redundancy

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Solution Overview

Problem

Submarines using lithium-based batteries face critical temperature sensitivity issues due to the need for robust cooling systems, necessitating redundant cooling systems to ensure safe operation, while maintaining low weight and volume.

Innovation Solution

A submarine design with dual cooling circuits for heat-generating devices, incorporating a third circulation pump in parallel to provide redundancy, allowing power throttling and coolant rerouting to maintain operation in case of pump failure, thereby avoiding the need for separate redundancy systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a redundant cooling system is implemented for lithium-based batteries, then system reliability is improved, but weight and volume increase

Engineering Contradiction:
Improvecooling system reliabilityVSAvoidcooling system weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent merges the cooling circuits of the fuel cell and battery into a shared system. The battery cooling circuit and fuel cell cooling circuit are connected through common components including the heat exchanger, circulation pumps, and coolant distribution manifold. This integration allows a single cooling infrastructure to serve multiple heat-generating devices, providing redundancy without proportionally increasing system weight and volume.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cooling system is designed with multi-functionality where circulation pumps and heat exchangers can serve multiple purposes. The second circulation pump can circulate coolant for both the battery and fuel cell cooling circuits. The heat exchanger serves as a common thermal management component for both energy storage and fuel cell systems, reducing the need for dedicated redundant components.

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

2Reliability

If a redundant cooling system is implemented for lithium-based batteries, then system reliability is improved, but volume increases

Engineering Contradiction:
Improvecooling system reliabilityVSAvoidcooling system volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent merges the cooling circuits of the fuel cell and battery into a shared system. The battery cooling circuit and fuel cell cooling circuit are connected through common components including the heat exchanger, circulation pumps, and coolant distribution manifold. This integration allows a single cooling infrastructure to serve multiple heat-generating devices, providing redundancy without proportionally increasing system volume.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cooling system employs a nested architecture where the battery cooling circuit is integrated within the broader thermal management system that also serves the fuel cell. The coolant flow paths are arranged such that the battery cooling loops are nested within the overall cooling circuit topology, allowing shared use of pumps, heat exchangers, and coolant reservoirs across different functional subsystems.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If separate redundant cooling systems are used for each heat-generating device, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvecooling system reliabilityVSAvoidcooling system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the cooling circuits of the fuel cell and battery into a shared system. The battery cooling circuit and fuel cell cooling circuit are connected through common components including the heat exchanger, circulation pumps, and coolant distribution manifold. This integration allows a single cooling infrastructure to serve multiple heat-generating devices, providing redundancy without proportionally increasing system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cooling system is designed with multi-functionality where circulation pumps and heat exchangers can serve multiple purposes. The second circulation pump can circulate coolant for both the battery and fuel cell cooling circuits. The heat exchanger serves as a common thermal management component for both energy storage and fuel cell systems, reducing the need for dedicated redundant components.

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

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

Ensures safe and reliable operation with reduced weight and space requirements by providing redundant cooling without additional pumps, maintaining system reliability and efficiency.

Implementation Method 1

The second cooling circuit includes a third circulation pump, which is arranged in parallel to the second circulation pump

Methodology Applied
Scientific EffectFluid circulation: Pump

Implementation Method 2

a first switching valve is arranged in the first cooling circuit connection, a second switching valve is arranged in the second cooling circuit connection

Methodology Applied
Scientific EffectFluid routing: Valve

Implementation Method 3

The first heat-generating device, for example an energy storage device, is cooled via a second cooling circuit

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP4326576B1Submarine with jointly redundant cooling circuits, for example of a fuel cell and a battery
Publication Date: 2026.02.25 TKMS GMBH
  • EP4326576B1 patent drawingFigure 1
  • EP4326576B1 patent drawingFigure 2

AI summary

The present invention relates to a submarine with two cooling circuits and three circulating pumps.