Fuel Cell Warm-Up Control for Stable Cooling Circuit Transition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The starting process of a fuel cell system is prone to temperature fluctuations and gas humidity supersaturation, leading to unstable output power and potential failure, which affects the service life of the stack and system.
Innovation Solution
A warming-up control method that monitors cell voltage variance and adjusts the transition between small- and large-cycle cooling circuits using a three-way valve with varying rotating rates to stabilize the system, triggering alarms at different voltage thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a small-cycle cooling circuit is used to quickly warm up the stack, then the warming-up speed is improved, but temperature fluctuation increases and affects stable output power
Solution Approach 1:
The patent applies dynamics by making the cooling circuit configuration changeable during operation. The system dynamically switches between small-cycle and large-cycle cooling circuits based on real-time temperature monitoring, allowing the cooling capacity to adapt to the warming-up process stages, thus achieving both fast warming and temperature stability
Solution Approach 2:
The patent implements periodic action through cyclic switching between small-cycle and large-cycle cooling modes. The control method periodically alternates the cooling circuit operation to prevent temperature from rising too high while maintaining overall warming progress, creating a controlled oscillation that stabilizes temperature
2Temperature
If the cooling circuit is switched from small-cycle to large-cycle, then temperature control is improved, but system complexity increases due to multiple cooling circuits
Solution Approach 1:
The patent applies segmentation by dividing the cooling system into two distinct cooling circuits (small-cycle and large-cycle) with different functions. The small-cycle circuit handles rapid warming while the large-cycle circuit provides stable temperature control, allowing each segment to be optimized for its specific purpose rather than requiring one complex circuit to handle all scenarios
3Quantity of substance
If gas humidity supersaturation occurs inside the stack, then condensation increases, but gas diffusion is hindered and cell voltage decreases
Solution Approach 1:
The patent implements feedback by continuously monitoring cell voltage and temperature, then using this information to adjust cooling circuit operation and air/hydrogen flow rates. When cell voltage drops indicating supersaturation, the system responds by adjusting operating parameters to restore proper gas diffusion and voltage levels
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 method effectively reduces temperature fluctuations, stabilizes output power, prevents vapor supersaturation, and prolongs the service life of the fuel cell system by ensuring a smooth transition to a normal operating state.
Implementation Method 1
rotating a three-way valve at a first rotating rate, so as to gradually turn on a large-cycle cooling circuit and gradually turn off the small-cycle cooling circuit at the same time
Implementation Method 2
a small-cycle cooling circuit runs if the stack does not reach a predetermined temperature
Implementation Method 3
A hydrogen fuel cell is a kind of green energy conversion apparatuses
Data Source
AI summary
The present application relates to a warming-up control method for a fuel cell system in a starting process and a fuel cell system, applied to the technical field of fuel cells. The method includes: starting the fuel cell system, turning on a small-cycle cooling circuit, and pull-loading an output power to a first power; in response to an inlet temperature of a stack reaching a first temperature, rotating a three-way valve at a first rotating rate; calculating a variance of a cell voltage value; in response to the variance being smaller than a third threshold and reducing the variance to be within the first threshold, returning to the rotating the three-way valve at the first rotating rate until all turn-on of a large-cycle cooling circuit and all turn-off of the small-cycle cooling circuit; pull-loading the output power to a rated power.