Fuel Cell Purge Control for Abnormal Combustion Prevention
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Solution Overview
Problem
Fuel cell systems face issues with abnormal combustion during restart due to exposure to air when not in a normal condition, leading to potential damage and increased manufacturing and installation costs, especially when inert gas systems are not used effectively.
Innovation Solution
A fuel cell system with a controller that determines the normal condition of the system during shutdown and uses material gas to purge the hydrogen-containing gas flow path before ignition, eliminating the need for an inert gas feeding system and preventing abnormal combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an inert gas feeding system is used to purge the hydrogen-containing gas flow path during shutdown, then abnormal combustion is prevented, but manufacturing cost and installation space increase
Solution Approach 1:
The system uses the material gas feeder, which is already present for normal operation, to perform the purging function during shutdown. The material gas feeder supplies material gas to the hydrogen-containing gas flow path to replace air, eliminating the need for a separate inert gas feeding system while maintaining abnormal combustion prevention
Solution Approach 2:
The material gas feeder is designed to serve multiple functions: supplying material gas during normal operation and purging the hydrogen-containing gas flow path during shutdown by supplying material gas to replace air. This multi-functionality eliminates the need for dedicated inert gas equipment
2Reliability
If material gas is supplied continuously to purge the flow path, then abnormal combustion is prevented, but material gas is wasted when not needed
Solution Approach 1:
The system dynamically adjusts material gas supply based on operational status. The controller activates the material gas feeder to supply material gas only during shutdown periods when air may have entered the flow path, and stops supply during normal operation, preventing wasteful consumption while maintaining safety
Solution Approach 2:
The system performs purging action at specific times (during shutdown) when air entry is likely, rather than continuous purging. The controller determines shutdown status and activates material gas supply preemptively to replace air before ignition occurs, avoiding unnecessary material gas consumption during normal operation
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
Prevents abnormal combustion during combustor ignition without increasing manufacturing or installation costs, ensuring safe and efficient system operation by using material gas to purge air from the hydrogen-containing gas flow path.
Implementation Method 1
The hydrogen-containing gas is mainly generated through a steam reforming reaction between hydrocarbon-based material gas and steam
Implementation Method 2
a combustor configured to burn the material gas or the hydrogen-containing gas to supply heat to the reformer
Implementation Method 3
the hydrogen-containing gas is, in turn, used in an electrochemical reaction in the fuel cell
Data Source
AI summary
There is disclosed a fuel cell system according to the invention comprising; a material gas feeder (1); a reformer (3); a fuel cell (4); a combustor (5); communication passages (6A-6E); and a controller (20),wherein during a shutdown period of the fuel cell (4), the controller (20) determines whether the fuel cell system is in a normal condition where a shutdown operation of the fuel cell (4) is performed; and wherein if the controller (20) determines that the fuel cell system is not in the normal condition, the controller (20) controls the material gas feeder (1) to execute a material gas feed process before a next ignition of the combustor (5), the material gas feed process being performed such that the material gas is supplied to a hydrogen-containing gas flow path constituted by the reformer (3) and the communication passages (6A-6E) located between the reformer (3) and the combustor (5).