Fuel Cell Refrigerant Control for Low-Temperature Start
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Solution Overview
Problem
Existing fuel cell systems face inefficiencies in refrigerant control during system stop, leading to potential waste and impaired power generation due to inadequate temperature management, especially when freezing occurs in the catalyst layer.
Innovation Solution
A fuel cell system with a refrigerant control mechanism that stops and resumes refrigerant supply based on temperature predictions for the next system start, promoting evaporation of water content and managing temperature differences to prevent thermal shock, while allowing power generation to continue even with blocked reactive gas supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If refrigerant control is performed without considering next system start temperature, then cooling performance is maintained during stop, but waste refrigerant control occurs and power generation efficiency is impaired
Solution Approach 1:
The control device performs preliminary temperature prediction to determine whether refrigerant control is necessary before actually executing refrigerant supply. By predicting the next start temperature in advance and comparing it with the reference temperature, the system determines whether refrigerant control should be performed, thereby avoiding unnecessary refrigerant control and associated energy waste while ensuring power generation efficiency is maintained.
2Temperature
If refrigerant is continuously supplied during system stop, then fuel cell temperature is controlled, but thermal shock may occur and catalyst layer freezing is not prevented
Solution Approach 1:
The control device uses a feedback mechanism where the predicted next start temperature is fed back into the refrigerant control decision process. By continuously monitoring and predicting temperature conditions, the system adjusts refrigerant supply accordingly - supplying refrigerant only when the predicted temperature exceeds the reference temperature, thereby preventing thermal shock and catalyst layer freezing while maintaining appropriate temperature control.
3Loss of energy
If refrigerant supply is stopped during system stop, then refrigerant control waste is suppressed, but fuel cell temperature may drop too low causing catalyst layer freezing
Solution Approach 1:
The control device performs preliminary temperature prediction to determine whether refrigerant control is necessary before actually executing refrigerant supply. By predicting the next start temperature in advance and comparing it with the reference temperature, the system determines whether refrigerant control should be performed, thereby avoiding unnecessary refrigerant control and associated energy waste while ensuring power generation efficiency is maintained.
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 approach effectively suppresses refrigerant control waste, inhibits catalyst layer freezing, and reduces the risk of thermal shock, thereby improving fuel cell durability and maintaining power generation efficiency.
Implementation Method 1
a refrigerant system which supplies a refrigerant to this fuel cell to control a temperature of the fuel cell
Implementation Method 2
evaporation of a water content in the fuel cell is promoted by heat generation accompanying the power generation
Implementation Method 3
a fuel cell which has a catalyst layer therein and which receives supply of a reactive gas to generate a power
Implementation Method 4
When the temperature difference between the fuel cell and the refrigerant to be supplied to the fuel cell has the predetermined value or more, there is a possibility that breakage such as crack is generated in the fuel cell owing to a thermal shock due to such a temperature difference
Data Source
AI summary
A fuel cell system includes a fuel cell which has a catalyst layer therein and which receives supply of a reactive gas to generate power, and a refrigerant system which supplies a refrigerant to the fuel cell to control its temperature. A method for stopping an operation of the system is also provided. When operated in a low-temperature environment, the system cannot be restarted due to freezing in the fuel cell. When the temperature of the fuel cell during the next system start is a predetermined temperature or less, the supply of the refrigerant is stopped during the system stop, and the supply of the refrigerant is resumed after elapse of a predetermined time.