Parallel Pressure Regulating Device for Fuel Cell Stacks
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Solution Overview
Problem
Existing pressure-regulating devices for fuel-cell stacks are expensive, especially when dealing with high fluid flow rates in systems with multiple fuel-cell stacks connected in parallel, as they typically rely on costly solenoid valves to precisely regulate anodic and cathodic channel pressures.
Innovation Solution
A pressure-regulating device with a dual-line system, where the first line includes a solenoid valve for pressure regulation based on downstream pressure measurements, and the second line uses expanders to match pressures, reducing costs by utilizing low-flow rate solenoid valves and inexpensive expanders, with additional features like non-return devices and pressure-reducing components to optimize fluid management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If solenoid valves are used to regulate pressure in fuel-cell stacks, then pressure control precision is improved, but system cost increases significantly
Solution Approach 1:
The pressure regulation system is divided into two independent lines: a first line with a solenoid valve for precise pressure sensing and control, and a second line with an expander for bulk pressure regulation. This segmentation allows each component to operate in its optimal range, reducing the need for expensive high-flow-rate solenoid valves while maintaining overall pressure control precision.
Solution Approach 2:
The expander acts as an intermediary device between the upstream channel and the downstream channel, handling the bulk of the pressure regulation task. This allows the solenoid valve to focus on precise control based on sensor feedback, rather than managing both bulk flow and precision control simultaneously, thereby reducing system cost.
2Productivity
If high flow rate solenoid valves are used to handle large fluid flow in parallel fuel-cell systems, then pressure regulation capability is improved, but device cost increases
Solution Approach 1:
The fluid flow path is segmented into two lines with different functional roles. The second line with the expander handles the high flow rate bulk regulation, while the first line with the solenoid valve handles low flow rate precision control. This allows using a low-flow-rate, low-cost solenoid valve instead of an expensive high-flow-rate model.
Solution Approach 2:
The expander utilizes pneumatic or hydraulic principles to regulate pressure in the second line, providing a cost-effective alternative to using solenoid valves for high flow rate pressure control. The expander mechanically adjusts the cross-sectional area of the fluid passage to control pressure and flow rate.
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 solution significantly reduces the overall cost of the pressure-regulating system while maintaining precise pressure control, allowing for efficient fluid management and reducing costs by using low-cost solenoid valves and expanders, and enabling fluid recycling during depressurization phases.
Implementation Method 1
a sensor measuring the fluid pressure in the second line, downstream from the second pressure regulator
Implementation Method 2
the first pressure regulator is capable of regulating the pressure in the downstream portion of the first line as a function of the pressure at the pressure sensor
Implementation Method 3
the second pressure regulator is capable of matching the pressure in the downstream portion of the second line to a reference pressure, measured at a first measuring point in the downstream portion of the first line
Implementation Method 4
the downstream portion of the first line comprises a non-return device for preventing fluid from rising from the downstream junction toward the first pressure regulator
Implementation Method 5
the downstream portion of the first line comprises a pressure-reducing device, to reduce the fluid pressure between the upstream and downstream of said device
Data Source
AI summary
A system of fuel-cell stacks is provided. The system includes fuel-cell stacks, a circuit for supplying each fuel-cell stack with an oxidizing fluid, a circuit for supplying each fuel-cell stack with a reducing fluid, and a pressure-regulating device fitted to the supply circuits so as to regulate the fluid pressure in each fuel-cell stack. The pressure-regulating device includes a first line for controlling the fluid pressure and a second line for passing the fluid, these two lines being placed in parallel between an upstream channel delivering fluid from a supply circuit and downstream channels connected to each fuel-cell stack. The first line comprises a first pressure regulator for regulating the pressure in an upstream portion of the first line depending on a pressure measured downstream of a second pressure regulator placed on the second line, and the second pressure regulator is capable of matching the pressure in the downstream portion of the second line to a reference pressure, measured in the downstream portion of the first line.