Fuel Cell Hydrogen Recirculation via Jet Pump and Solenoid Valve
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Solution Overview
Problem
Conventional fuel cell systems face inefficiencies and durability issues during low power applications due to insufficient hydrogen recirculation flow, particularly when using jet pumps, which struggle to generate required recirculation flows under low system loads, and blower systems are prone to corrosion and require expensive components.
Innovation Solution
The integration of a proportional control solenoid valve with a jet pump in the hydrogen supply line, controlled using a pulse flow control method during low power applications and a proportional control method during high power applications, to manage hydrogen recirculation flow efficiently without additional recirculation components like blowers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a jet pump is used for hydrogen recirculation, then the system structure is simplified, but the recirculation flow becomes insufficient at low power applications
Solution Approach 1:
The patent applies dynamics by making the hydrogen supply flow variable through a proportional control solenoid valve that adjusts the flow rate dynamically based on power application levels. At low power applications, the valve increases hydrogen supply to the jet pump to maintain sufficient recirculation flow, while at high power applications, it reduces the supply to match lower recirculation requirements.
Solution Approach 2:
The patent changes the parameter of hydrogen supply flow rate using a proportional control solenoid valve that can vary the flow continuously. By adjusting the valve opening degree according to power application, the system maintains optimal recirculation flow across different operating conditions, resolving the contradiction between simplified structure and sufficient flow at low power.
2Quantity of substance
If a blower is used for hydrogen recirculation, then the recirculation flow is sufficient, but the system cost increases and components are prone to corrosion
Solution Approach 1:
The patent replaces the mechanical blower system with a jet pump that uses fluid dynamics (compressed hydrogen gas) to create recirculation flow. This substitution eliminates mechanical components prone to corrosion from condensation water, while the proportional control solenoid valve provides the necessary flow control to maintain sufficient recirculation without the blower's mechanical complexity.
Solution Approach 2:
The jet pump system uses the compressed hydrogen gas itself to generate the recirculation flow through pressure differential and vacuum generation, rather than requiring an external motor-driven blower. This self-service approach eliminates the need for separate motor and bearing components that would be susceptible to corrosion.
3Quantity of substance
If a proportional control solenoid valve is controlled using pulse flow control method at low power, then the recirculation flow is sufficient, but the control complexity increases
Solution Approach 1:
The patent applies periodic action through pulse flow control at low power applications, where the proportional control solenoid valve is opened and closed in periodic pulses to maintain sufficient average recirculation flow. This periodic operation allows the system to achieve adequate flow with simpler control logic compared to continuous proportional control, reducing the effective control complexity at low power modes.
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 configuration ensures sufficient hydrogen recirculation flow even at low power levels, improves jet pump efficiency, and reduces noise and abrasion, leading to enhanced fuel cell system performance and durability.
Implementation Method 1
The jet pump 16 may generate a vacuum by injecting compressed hydrogen supplied from a high pressure tank through a nozzle
Implementation Method 2
a proportional control solenoid valve connected to a hydrogen supply line and communicating with a nozzle inlet of the jet pump to control the hydrogen supply to the jet pump
Data Source
AI summary
The present invention provides an apparatus for controlling hydrogen supply of a fuel cell system and a method for controlling the same. The apparatus includes a jet pump, a proportional control solenoid valve, and a controller. The jet pump is disposed at the side of an inlet of a fuel cell stack and performs supply and recirculation of hydrogen into the fuel cell stack. The proportional control solenoid valve is connected to a hydrogen supply line and fluidly communicates with a nozzle inlet of the jet pump to control the hydrogen supply to the jet pump. The controller controls an operation of the proportional control solenoid valve according to a power of the fuel cell system. Here, the controller controls the operation of the proportional control solenoid valve according to a pulse flow control method at a low power section in which a current power is lower than a predetermined reference power.