Fuel Cell Waste Heat Refrigeration for Rail Cold Rooms

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Solution Overview

Problem

Rail vehicles carrying perishable goods face high energy expenditure due to the need for refrigeration, which adds to the energy consumed for traction, necessitating a reduction in cold production energy.

Innovation Solution

A rail vehicle configuration featuring a fuel cell to produce electrical energy and unwanted heat, which is then utilized by a refrigeration unit to generate cold in the cold room, incorporating a cooling system and an auxiliary energy source to optimize energy use, with the refrigeration unit employing an ammonia-based absorption refrigeration cycle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a refrigeration unit is used to produce cold in the cold room, then the perishable goods are kept at required temperature, but the energy expenditure increases

Engineering Contradiction:
Improvecold room temperatureVSAvoidenergy expenditure for refrigeration
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The invention converts the waste heat produced by the fuel cell, which was previously a harmful byproduct, into a useful energy source for driving the refrigeration unit. The absorption refrigeration cycle uses this thermal energy to produce cooling effect, thereby eliminating waste heat while meeting refrigeration needs without additional energy expenditure.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The fuel cell system is designed to serve multiple functions: it provides electrical energy for traction and simultaneously generates waste heat that is reused by the refrigeration unit for cold production. This multi-functionality reduces the overall energy demand of the railway vehicle by utilizing one energy source for multiple purposes.

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

2Reliability

If the refrigeration unit operates independently with its own energy source, then reliable cold production is achieved, but the overall energy efficiency decreases

Engineering Contradiction:
Improverefrigeration reliabilityVSAvoidenergy efficiency
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The invention merges the refrigeration system with the fuel cell power system by using the waste heat from the fuel cell as the energy source for the absorption refrigeration cycle. This integration ensures reliable cold production while improving overall energy efficiency by utilizing otherwise wasted thermal energy that would otherwise be dissipated to the environment.

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 configuration effectively converts previously useless heat into cold, reducing the overall energy expenditure for refrigeration and enhancing the efficiency of cold production.

Implementation Method 1

a first car (14) comprising at least one fuel cell (16) adapted to produce electrical energy (18) and a flow of waste heat (20)

Methodology Applied
Scientific EffectFuel cell electrochemical conversion: Fuel Cell

Implementation Method 2

the refrigeration unit (28) comprises an absorption or absorption refrigeration cycle

Methodology Applied
Scientific EffectAbsorption refrigeration cycle: Adsorption Refrigerator

Implementation Method 3

The refrigeration cycle 48 is adapted to vaporize the liquid ammonia in the cold room (24) to produce the cold (30)

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 4

the cooling system 32, the fuel cell (16) and the refrigeration unit (28) are advantageously configured so that the first flow (34) is at a first temperature between 55°C and 70°C, and the second flow (36) at a second temperature higher than the first temperature and between 60°C and 75°C

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4019365B1Railway vehicle comprising a fuel cell and a refrigerated unit receiving a flow of free heat from the fuel cell
Publication Date: 2025.02.05 ALSTOM HOLDINGS SA
  • EP4019365B1 patent drawingFigure 1

AI summary

Rail vehicle (10) comprising: - a first car (14) having at least one fuel cell (16) adapted to produce electrical energy (18) and a waste heat flux (20), - a second car (22) comprising at least one cold room (24), and - at least one refrigeration unit (28) configured to receive at least a part (37) of the waste heat flux (20) as an energy source and to produce cold (30) in the cold room (24).