Cabin Roof Hydrogen Tank Cooling and Protection in Fuel Cell Tractors

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Solution Overview

Problem

High-pressure hydrogen tanks in fuel cell vehicles, when used in agricultural tractors, face temperature increases due to rapid gas charging and high outside temperatures, and are vulnerable to vibration and falls, posing challenges in maintaining safety and preventing global warming.

Innovation Solution

The hydrogen tanks are positioned in the upper portion of the cabin with a ventilation system and air conditioning unit to manage temperature, and are protected by a double-walled ceiling structure and a housing case with vibration-absorbing members, along with a hydrogen gas detection system for leak management.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the hydrogen tank is disposed in the hood together with the fuel cell, then the overall structure is compact, but the temperature of the hydrogen tank increases excessively due to heat generation from the fuel cell and high outside temperatures

Engineering Contradiction:
Improveoverall structure compactnessVSAvoidhydrogen tank temperature
Core Design Contradiction:
Volume of moving objectVSTemperature

Solution Approach 1:

The hydrogen tank is extracted from the hood and relocated to the upper portion of the cabin internal space. This separates the hydrogen tank from the heat-generating fuel cell in the hood, eliminating the temperature increase problem while maintaining overall vehicle compactness through efficient space utilization in the cabin.

Inventive Principle:
Principle #2Taking out (Extraction)

2Temperature

If the hydrogen tank is disposed in the upper portion of the cabin, then the temperature increase is suppressed, but the tank becomes vulnerable to vibration and falls

Engineering Contradiction:
Improvehydrogen tank temperatureVSAvoidtank protection from vibration and falls
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

A ceiling structure is provided above the hydrogen tank in the upper cabin portion. This ceiling acts as a protective barrier that prevents the tank from falling and provides cushioning against vibrations, thereby ensuring reliability and safety while maintaining the temperature advantages of the upper position.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Productivity

If rapid hydrogen gas charging is performed, then refueling efficiency is improved, but the temperature inside the hydrogen tank rises sharply

Engineering Contradiction:
Improverefueling efficiencyVSAvoidhydrogen gas temperature inside tank
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

By relocating the hydrogen tank to the upper cabin portion away from heat-generating components, the system can perform rapid charging more effectively. The improved thermal environment allows for faster refueling while the temperature rise is better managed due to the cooler ambient conditions in the upper cabin space.

Inventive Principle:
Principle #2Taking out (Extraction)

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 suppresses hydrogen tank temperature increases, protects against vibration and falls, and enhances safety while contributing to environmental sustainability by efficiently managing hydrogen gas in fuel cell vehicles.

Implementation Method 1

a cooling passage through which the cooling air introduced from the air conditioning unit passes the outer periphery of the hydrogen tank

Methodology Applied
Scientific EffectHeat convection: Convection

Implementation Method 2

a guide passage through which the outside air taken in from the outside-air intake port passes the outer periphery of the hydrogen tank

Methodology Applied
Scientific EffectHeat convection: Convection

Data Source

PatentEP4119379B1Working machine
Publication Date: 2024.06.12 KUBOTA CORP
  • EP4119379B1 patent drawingFigure 1
  • EP4119379B1 patent drawingFigure 2
  • EP4119379B1 patent drawingFigure 3

AI summary

A working machine (1) includes a vehicle body (2); a traveling device (6) that supports the vehicle body (2); a drive (7) that drives the traveling device (6); and a cabin (5) that accommodates an operator seat (4). The drive (7) has a drive motor (21) that drives the traveling device (6); a fuel cell (22) that supplies electric power to the drive motor (21); a controller (23) that controls power supply from the fuel cell (22) to the drive motor (21); and a hydrogen tank (25) that supplies a hydrogen gas for fuel to the fuel cell (22). The hydrogen tank (25) is disposed in an upper portion of an internal space (S1) of the cabin (5).