Fuel Cell System Anti-Freezing Control via Circulation Pump
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Solution Overview
Problem
Fuel cell systems face efficiency reduction due to water freezing in the fuel gas supply system, leading to pipe clogging, which existing methods cannot prevent without halting the fuel cell operation.
Innovation Solution
A fuel cell system with a control unit that increases the proportion of fuel gas supplied from a circulation pump when freezing is detected, using a T-shaped connecting pipe to efficiently flow warmer fuel gas and potentially halt the fuel supply device operation to prevent clogging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If scavenging treatment is performed by supplying dry gas to fuel cells after electricity generation is halted, then water discharge is achieved, but fuel cell operation must be halted and frozen water discharge becomes difficult
Solution Approach 1:
The system performs preliminary scavenging treatment by controlling the circulation pump to supply fuel off-gas to the fuel gas supply channel before frozen water can cause pipe clogging. This proactive approach removes moisture from the system while maintaining continuous fuel cell operation, preventing the harmful effect before it occurs.
Solution Approach 2:
The circulation pump operates continuously or in controlled intervals to maintain fuel off-gas circulation throughout the system, ensuring continuous scavenging action without requiring fuel cell shutdown. This keeps the system in a constantly protected state against freezing while maintaining productivity.
2Reliability
If the circulation pump increases fuel gas flow to prevent freezing, then pipe clogging is suppressed, but energy consumption increases
Solution Approach 1:
The control unit operates the circulation pump in periodic cycles rather than continuously, activating it at intervals to perform scavenging treatment. This periodic operation maintains reliable pipe clogging prevention while significantly reducing the energy consumption compared to continuous pump operation.
Solution Approach 2:
The system applies partial action by controlling the circulation pump to operate only when necessary for scavenging, rather than maintaining full continuous operation. This provides sufficient protection against freezing while minimizing energy waste from excessive pump 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
Effectively suppresses pipe clogging from water freezing without halting the fuel cell operation by increasing the fuel gas flow from the circulation pump and adjusting refrigerant temperature, ensuring continuous system efficiency.
Implementation Method 1
a circulation pump disposed in the circulation channel and adapted to pressure-feed the fuel off-gas to the fuel gas supply channel
Implementation Method 2
when freezing of water is presumed to be present downstream of the fuel supply device, the control unit relatively increases the proportion of the amount of the fuel gas to be supplied from the circulation pump to the amount of the fuel gas to be supplied from the fuel supply device
Data Source
AI summary
Provided is a fuel cell system that can effectively suppress clogging of a pipe due to freezing of water in a fuel gas supply system thereof without the need for halting the operation of the fuel cells, and thus is highly reliable. When possible freezing of water is detected or presumed to be present downstream of an injector, the amount of a fuel gas to be supplied from a circulation pump that is disposed in a circulation channel is relatively increased compared to the amount of the fuel gas to be supplied from the injector.