Fuel Cell System Cooling Water Pump Sequence for Low-Temperature Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In fuel cell systems, condensation of moisture in the fuel gas pump occurs when the system is stopped in a low-temperature environment, leading to potential freezing of the pump components.
Innovation Solution
The fuel cell system employs a cooling water pump to lower the temperature of the fuel cell below that of the fuel gas pump after operation is stopped, inhibiting condensation in the fuel gas pump and allowing the fuel gas pump to function effectively by controlling the sequence of pump operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the fuel gas pump operates after the fuel cell is stopped to pump discharged fuel gas, then the fuel gas can be recirculated and reused, but moisture condenses in the fuel gas pump causing freezing in low-temperature environments
Solution Approach 1:
The cooling water pump operates in advance to lower the fuel cell temperature before the fuel gas pump starts operating after shutdown. This preliminary cooling action prevents moisture condensation in the fuel gas pump by establishing a temperature gradient where the fuel cell is colder than the pump, causing moisture to condense in the fuel cell instead.
2Adaptability or versatility
If the system operates in a low-temperature environment, then the fuel cell can generate power in cold climates, but the valves and pumps may freeze due to remaining moisture
Solution Approach 1:
The system creates a localized temperature difference where the fuel cell is cooled to a lower temperature than the fuel gas pump. This local quality difference (temperature gradient) directs moisture condensation to occur in the fuel cell rather than in the pump or valves, protecting the pump components from freezing while allowing cold climate operation.
3Reliability
If the fuel cell is cooled to lower temperatures to prevent condensation, then pump freezing is inhibited, but the cooling process requires additional time and energy
Solution Approach 1:
The cooling water pump uses the system's own cooling water circulation infrastructure to cool the fuel cell, rather than requiring an external cooling system. The cooling water is circulated through the fuel cell to extract heat, and this self-service cooling process efficiently lowers the fuel cell temperature without requiring additional time or external resources.
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 prevents condensation in the fuel gas pump, inhibits freezing, and enables the pumping of fuel gas, ensuring reliable operation even in low-temperature conditions by maintaining the fuel cell temperature lower than the fuel gas pump temperature.
Implementation Method 1
the cooling water is pumped by the cooling water pump to cool the fuel cell and lower a temperature of the fuel cell to a lower temperature than a temperature of the fuel gas pump
Implementation Method 2
a fuel gas pump which is provided on the fuel gas circulation piping and which pumps the fuel gas discharged from the fuel cell to the fuel gas supply piping
Data Source
AI summary
A fuel cell system having a cooling water pump provided in cooling water piping that sends cooling water to a fuel cell and sending the cooling water under pressure, fuel gas supply piping connected to the fuel cell and supplying fuel gas to the fuel cell, fuel gas circulation piping connected to both the fuel cell and the fuel gas supply piping and circulating fuel gas, discharged from the fuel cell, in the fuel gas supply piping, and a fuel gas pump provided in the fuel gas circulation piping and sending under pressure the fuel gas, discharged from the fuel cell, to the fuel gas supply piping. After operation of the fuel cell is stopped, the fuel gas, discharged from the fuel cell, is sent under pressure by the fuel gas pump, and cooling water is send under pressure by the cooling water pump to cool the fuel cell to thereby reduce the temperature of the fuel cell to a level lower than the temperature of the fuel gas pump.