Fuel Cell Ventilation Prevents Exhaust Gas Infiltration

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Solution Overview

Problem

In cogeneration systems, the exhaust gas from a water heater can flow into a fuel cell when the fuel cell is started up, reducing its power generation efficiency and durability.

Innovation Solution

A power generation system with a fuel cell, ventilator, controller, and combustion device, where the ventilator is activated when the fuel cell is in a power generation stop state and the combustion device is operating to prevent exhaust gas from flowing into the fuel cell, ensuring stable power generation and improved durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If a discharge passage is formed to cause the fuel cell case and combustion device exhaust port to communicate, then exhaust gas can be discharged to the atmosphere, but exhaust gas may flow into the fuel cell when the fuel cell is stopped and the combustion device is operating

Engineering Contradiction:
Improveexhaust gas dischargeVSAvoidfuel cell power generation efficiency
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The ventilator is activated in advance when the fuel cell stops operating, before the combustion device starts discharging exhaust gas. This preliminary action creates a protective airflow that prevents exhaust gas from entering the fuel cell case when the fuel cell is not generating power, thereby maintaining fuel cell reliability while allowing shared exhaust discharge

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the ventilator operates continuously to prevent exhaust gas infiltration, then fuel cell reliability is improved, but energy consumption increases

Engineering Contradiction:
Improvefuel cell power generation efficiencyVSAvoidventilator energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The ventilator operates periodically rather than continuously - it is activated only during specific transition periods when the fuel cell stops and the combustion device operates. This periodic operation maintains fuel cell protection while significantly reducing energy consumption compared to continuous operation

Inventive Principle:
Principle #19Periodic action

3Reliability

If separate exhaust passages are provided for fuel cell and combustion device, then exhaust gas contamination is prevented, but device complexity increases

Engineering Contradiction:
Improvefuel cell power generation efficiencyVSAvoidexhaust passage configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system segments the exhaust discharge function by controlling different devices (ventilator for fuel cell, combustion device fan for exhaust) to operate in different states. This functional segmentation allows a single physical discharge passage to serve both purposes without contamination, avoiding the complexity of separate physical passages

Inventive Principle:
Principle #1Segmentation

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

The system prevents the decrease in oxygen concentration within the fuel cell, thereby stabilizing power generation and enhancing the durability of the power generation system by ensuring that exhaust gas is discharged outside, even when the fuel cell is in a stop state.

Implementation Method 1

the ventilator is configured to discharge a gas in the case to the discharge passage to ventilate an inside of the case

Methodology Applied
Scientific EffectForced Convection: Forced Convection

Implementation Method 2

a fuel cell configured to generate electric power using a fuel gas and an oxidizing gas

Methodology Applied
Scientific EffectFuel Cell: Fuel Cell

Implementation Method 3

a combustion device; and a discharge passage formed to cause the case and an exhaust port of the combustion device to communicate with each other

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP2595228B1Power generation system and method of operating the same
Publication Date: 2014.08.06 PANASONIC HOLDINGS CORP
  • EP2595228B1 patent drawingFigure 1
  • EP2595228B1 patent drawingFigure 2
  • EP2595228B1 patent drawingFigure 3

AI summary

A power generation system according to the present invention includes: a fuel cell system (101) including a fuel cell (11) and a case (12); a ventilation fan (13); a controller (102); a combustion device (103); and a discharge passage (70) formed to cause the case (12) and an exhaust port (103A) of the combustion device (103) to communicate with each other and configured to discharge an exhaust gas from the fuel cell system (101) and an exhaust gas from the combustion device (103) to the atmosphere through an opening of the discharge passage (70), the opening being open to the atmosphere, and the ventilation fan (13) is configured to discharge a gas in the case (12) to the discharge passage (70) to ventilate the inside of the case (12), and the controller (102) causes the ventilation fan (13) to generate predetermined pressure or higher when the fuel cell system (101) is in a power generation stop state and the combustion device (103) is operating.