Fuel Cell Ventilation Fan Speed Detection and Safety Shutdown

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Solution Overview

Problem

Existing fuel cell systems face challenges in reliably detecting and responding to ventilation unit abnormalities, leading to inadequate ventilation, which can compromise the safety and operation of the system.

Innovation Solution

A fuel cell system incorporating a ventilation fan, a first detection unit, a relay circuit unit, and a shut-off valve, where the detection unit monitors the ventilation fan's operation and sends a signal to the relay circuit unit to close the shut-off valve when the fan's revolutions drop below a reference value, ensuring the system stops operation and maintains high reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a ventilation unit is provided in the housing to evacuate fuel gas, then safety is improved, but the complexity of the system increases

Engineering Contradiction:
ImprovesafetyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by equipping the ventilation fan with a rotational speed detection unit that continuously monitors fan operation before fuel gas leakage can occur. The relay circuit is pre-configured to automatically close the shut-off valve when abnormal rotational speed is detected, preventing potential fuel gas accumulation and eliminating the need for complex post-detection safety systems

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces a relay circuit unit as an intermediary component that receives detection signals from the rotational speed detection unit and controls the shut-off valve. This intermediary hardware circuit simplifies the overall system architecture by providing direct signal transmission and control without requiring complex microcontroller-based monitoring systems

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a detection unit and control system are added to monitor ventilation fan operation, then reliability of stopping function is improved, but device complexity increases

Engineering Contradiction:
Improvestopping function reliabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The relay circuit unit serves as a simple intermediary hardware component that directly connects the rotational speed detection unit to the shut-off valve control. This intermediary circuit uses basic electrical signal transmission without requiring complex processing logic, achieving reliable automatic shutdown while maintaining simple system architecture

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex software-based or microcontroller-based control systems with a hardware-based relay circuit system. The relay circuit provides direct electrical signal control from the detection unit to the shut-off valve, eliminating the need for complex programming and processing while ensuring reliable automatic shutdown functionality

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3010077B1Fuel cell system
Publication Date: 2019.04.03 FUJI ELECTRIC CO LTD
  • EP3010077B1 patent drawingFigure 1
  • EP3010077B1 patent drawingFigure 2
  • EP3010077B1 patent drawingFigure 3

AI summary

A ventilation fan (180) is installed in a housing (100), and expels air in the housing (100), to outside the housing (100). A first detection unit (200) monitors operation of the ventilation fan (180). A relay circuit unit (210) outputs a signal for closing a shut-off valve (110), to the shut-off valve (110), when the detection result from the first detection unit (200) indicates that the number of revolutions of the ventilation fan (180) has become equal to or lower than a reference value. The shut-off valve (110) is provided in a pipe of a fuel gas supply unit which is disposed in the inlet of a fuel cell main body, and shuts off the supply of fuel gas to a fuel cell stack (150) upon receiving the abovementioned signal.