Dual Ejector Fuel Cell Flow Control for Retained Water Drainage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel cell systems with dual ejectors of different capacities face challenges in optimizing drainage from the fuel cell, particularly in managing retained water that affects power generation stability and electrode performance.
Innovation Solution
A fuel cell system with dual injectors and ejectors, where the first injector supplies fuel gas at a higher rate but for a shorter duration, and the second injector supplies at a lower rate but for a longer duration, controlled by an ECU to optimize drainage based on power requirements, ensuring efficient discharge of retained water.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single ejector with high circulation capacity is used, then fuel gas supply efficiency is improved, but drainage of retained water from the fuel cell deteriorates
Solution Approach 1:
The patent divides the single ejector into two separate ejectors with different circulation capacities. The first ejector has higher circulation capacity for efficient fuel gas supply, while the second ejector has lower circulation capacity but provides sustained flow for effective water drainage. This segmentation allows each ejector to specialize in different functions, resolving the contradiction between supply efficiency and drainage performance.
Solution Approach 2:
The patent applies different local qualities to the two ejectors by designing them with different circulation capacities. The first ejector is optimized for high-volume fuel gas supply with higher circulation capacity, while the second ejector is optimized for sustained drainage operations with lower circulation capacity. This local differentiation enables each component to perform its specific function optimally.
2Power
If the first injector supplies fuel gas at high rate for short duration, then power generation response is improved, but drainage velocity maintenance deteriorates
Solution Approach 1:
The patent implements periodic action by controlling the injectors to operate in alternating cycles. The first injector operates at high rate for short duration to meet power demands, then the second injector operates to maintain drainage velocity. This periodic switching between injectors ensures both rapid power response and sustained drainage performance.
Solution Approach 2:
The patent ensures continuity of useful action by coordinating the operation of two injectors so that while one injector is performing power generation supply, the other maintains drainage velocity. This continuous coordination prevents interruption in either function, maintaining both power response and drainage effectiveness throughout operation.
3Object-generated harmful factors
If dual ejectors with different circulation capacities are used, then drainage optimization is improved, but system complexity increases
Solution Approach 1:
The patent applies universality by designing both ejectors to perform multiple functions. Each ejector can contribute to both fuel gas supply and water drainage depending on operational conditions. This multi-functionality reduces the need for completely separate systems for supply and drainage, thereby limiting the increase in system complexity while achieving drainage optimization.
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
The system effectively enhances drainage of retained water, maintaining optimal drainage velocity and reducing power generation instability by ensuring continuous differential pressure and kinetic energy for efficient water removal.
Implementation Method 1
a first ejector provided between the first injector and the gas inlet portion to guide the fuel gas flowing out through the gas outlet portion to the first supply flow path through a first circulation flow path
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A fuel cell system includes a first supply part including a first injector and a first ejector and supplying fuel gas to a fuel cell through a first supply flow path connected to a gas inlet portion, a second supply part including a second injector and a second ejector and supplying the fuel gas to the fuel cell through a second supply flow path connected to the inlet portion, and a control unit controlling the first injector and the second injector. A circulation flow rate of the second ejector is larger than a circulation flow rate of the first ejector. The control unit controls the first injector and the second injector so that when either the first injector or the second injector injects the fuel gas at a predetermined cycle, the other of the first injector and the second injector injects the fuel gas during the predetermined cycle.