Rail Vehicle Fuel Cell Cooling Circuit Integration

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Solution Overview

Problem

Rail vehicles equipped with fuel cell systems for non-electrified routes face challenges in cooling due to different temperature requirements for fuel cell stacks and electrical components, leading to the need for multiple coolant circuits and increased space and energy consumption.

Innovation Solution

Integrating the cooling of electrical components of the fuel cell system into the existing coolant circuit of the traction device, using a dual coolant circuit system where the fuel cell stack is cooled separately with a second circuit optimized for its temperature needs, reducing the number of components and energy required.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If separate coolant circuits are provided for fuel cell stack and electrical components, then each component can be cooled at its optimal temperature, but the number of cooling components and space required increases

Engineering Contradiction:
Improvecooling temperature optimizationVSAvoidnumber of cooling components
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the cooling of electrical components into the existing traction device coolant circuit (first coolant circuit), eliminating the need for a separate cooling circuit for these components. Only the fuel cell stack retains a dedicated second coolant circuit, reducing overall system complexity while maintaining optimal cooling for each component type.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cooling system is segmented into two parts: a shared first coolant circuit for electrical components and a dedicated second coolant circuit for the fuel cell stack. This segmentation allows optimal temperature control for the fuel cell stack while using the existing cooling infrastructure for other components.

Inventive Principle:
Principle #1Segmentation

2Reliability

If multiple coolant circuits and cooling components are used, then cooling requirements are met, but energy consumption increases

Engineering Contradiction:
Improvecooling effectivenessVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

By combining the cooling of electrical components with the traction device cooling system, the patent eliminates redundant cooling operations. The single forced flow cooling air stream serves both the first and second heat exchangers, reducing the total energy required for cooling operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cooling system uses a single forced flow cooling air stream that sequentially cools both the first heat exchanger (electrical components) and the second heat exchanger (fuel cell stack). This self-service approach eliminates the need for separate fans or cooling systems for different components.

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If separate cooling systems are provided for fuel cell system and traction device, then each can be optimized independently, but the space required increases

Engineering Contradiction:
Improveindependent optimization capabilityVSAvoidspace for cooling components
Core Design Contradiction:
Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent combines the cooling infrastructure by using the existing traction device coolant circuit for electrical components while maintaining a separate circuit for the fuel cell stack. This merging reduces the total space required for cooling components while preserving the ability to independently optimize cooling parameters for each system.

Inventive Principle:
Principle #5Merging (Combining)

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

This solution simplifies cooling, reduces the number of components needed, and optimizes energy usage by allowing for efficient cooling of both fuel cell system and traction device components with a common cooling air flow, while ensuring the fuel cell stack maintains optimal temperature.

Implementation Method 1

at least one electrical component of the fuel cell system can be cooled using the liquid coolant circulating in the first coolant circuit

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

only the at least one fuel cell stack of the fuel cell system can be cooled using a liquid coolant circulating in a second coolant circuit

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

by means of a forced flow of cooling air, both the coolant in the first heat exchanger and the coolant in the second heat exchanger can be cooled

Methodology Applied
Scientific EffectForced convection: Forced Convection

Data Source

PatentEP3859848B1Rail vehicle with cooling device for a fuel cell assembly
Publication Date: 2023.04.12 SIEMENS MOBILITY GMBH
  • EP3859848B1 patent drawingFigure 1
  • EP3859848B1 patent drawingFigure 2

AI summary

The rail vehicle according to the invention comprises at least one fuel cell system with at least one fuel cell stack and at least one electrical component for its operation, wherein electrical energy can be generated by means of the fuel cell system. Furthermore, the rail vehicle comprises a traction device which can be operated by means of the electrical energy generated by the fuel cell system, wherein at least one electrical component of the traction device can be cooled by means of a liquid coolant circulating in a first coolant circuit. Characteristically, the at least one electrical component of the fuel cell system can be cooled by means of the liquid coolant circulating in the first coolant circuit, and only the at least one fuel cell stack of the fuel cell system can be cooled by means of a liquid coolant circulating in a second coolant circuit.