Fuel Cell Humidity Control via Pressure Differential
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel cell arrangements face challenges in accurately controlling humidity due to susceptibility to interference from liquid water and complex calculations involving multiple input parameters, leading to potential malfunctions and increased costs.
Innovation Solution
A fuel cell arrangement using a fluid mass sensor and two pressure sensors to determine humidity, with a gas-gas humidifier and bypass line for controlled humidification, allowing for simple and cost-effective measurement and adjustment of reactant humidity, reducing the need for additional sensors and external water supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dew point measurement sensor is used to determine humidity, then humidity measurement is achieved, but the sensor is susceptible to interference from liquid water drops leading to errant measurements
Solution Approach 1:
The patent extracts the problematic dew point measurement sensor from the system and replaces it with a combination of pressure sensors and mass flow rate measurements. This removes the susceptibility to liquid water interference while maintaining humidity determination capability through alternative physical parameters (pressure differential and mass flow rate calculations).
Solution Approach 2:
The patent introduces pressure sensors as intermediary measurement devices that indirectly determine humidity through pressure differential measurements across the humidifier, rather than directly measuring dew point. This intermediary approach avoids direct contact with liquid water while still enabling humidity calculation.
2Measurement precision
If multiple sensors and complicated calculations are used to determine humidity, then humidity control is achieved, but the system becomes complex and susceptible to faults from sensor breakdowns
Solution Approach 1:
The patent removes the complicated multi-sensor calculation system and extracts only the essential measurements needed for humidity determination. By using a simplified approach with pressure differential and mass flow rate, it reduces the number of sensors and calculation steps while maintaining adequate humidity control capability.
Solution Approach 2:
The patent employs simple, robust pressure sensors that are less prone to failure compared to complex dew point sensors. These simpler measurement devices are more reliable and less susceptible to breakdowns, even if they require more frequent replacement or calibration.
3Measurement precision
If additional sensors are developed for accurate humidity measurement, then measurement accuracy is improved, but development costs increase
Solution Approach 1:
The patent makes existing pressure sensors and mass flow rate measurements serve multiple functions: they not only monitor system operation but also enable humidity determination through their combined readings. This eliminates the need for specialized humidity sensors, reducing development costs while maintaining measurement capability.
Solution Approach 2:
Instead of developing new specialized humidity sensors, the patent uses existing pressure sensor technology that is already proven and available. This copying of existing reliable technology avoids the high costs of developing and validating new sensor types while achieving the desired measurement function.
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 solution provides a robust, cost-effective method for reliably controlling humidity, ensuring optimal fuel cell operation with minimal variables and avoiding complex electronics, achieving accurate humidity control with ±20% accuracy.
Implementation Method 1
two pressure sensors, the fluid mass sensor and one of the pressure sensors being arranged upstream of the humidifying device and one of the pressure sensors being arranged downstream of the humidifying device
Implementation Method 2
the sensors are at least one fluid mass sensor and two pressure sensors, the fluid mass sensor and one of the pressure sensors being arranged upstream of the humidifying device
Implementation Method 3
A fuel cell arrangement using a fluid mass sensor and two pressure sensors to determine humidity, with a gas-gas humidifier and bypass line for controlled humidification
Data Source
AI summary
The invention relates to a fuel cell arrangement (1) having at least one fuel cell (2) with a cathode (3) and an anode. The cathode (3) and the anode each have a reactant feed (4) and a reactant discharge (5), a humidifying device (10) and sensors (12, 13, 14) being provided at least at one of the reactant feeds (4). In particular, the sensors (12, 13, 14) are at least one fluid mass sensor (12) and two pressure sensors (13, 14), the fluid mass sensor (12) and one of the pressure sensors (13) being arranged upstream of the humidifying device (10) and one of the pressure sensors (14) being arranged downstream of the humidifying device (10). The humidifying device (10) can be operated in a controlled manner on the basis of the measurements of the sensors (12, 13, 14). The invention further relates to a method for controlling the humidity of a reactant for such a fuel cell arrangement (1).