Fuel Cell Ejector for Condensed Water Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In fuel cell systems, excessive moisture supplied to the stack can block channels, reducing fuel gas supply rates and leading to output deterioration and pressure differences, which affects the stability and efficiency of electricity generation.
Innovation Solution
A fuel cell system with an ejector that includes a vacuum suction pipe, a fuel gas spray nozzle, and a porous inner housing to effectively remove condensed water from the circulating fuel gas, using a condensed water reservoir and drain pipe to manage humidity and prevent water blockage, ensuring stable fuel gas supply and humidification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If liquid state condensed water is supplied to the stack directly, then moisture supply to the stack is improved, but channel blockage occurs reducing fuel gas supply rate
Solution Approach 1:
The ejector is segmented into distinct functional zones: a vaporization chamber for evaporating condensed water, a separation chamber for separating moisture from fuel gas, and a supply channel for delivering dried fuel gas to the stack. This segmentation allows moisture to be removed in controlled stages, preventing channel blockage while maintaining adequate humidification.
Solution Approach 2:
The ejector acts as an intermediary device between the condensed water source and the stack. It introduces the condensed water into a vaporization chamber where it evaporates and mixes with fuel gas, then separates the moisture through controlled flow dynamics before supplying the treated fuel gas to the stack, thereby mediating the moisture supply problem.
2Productivity
If moisture is removed from fuel gas, then channel blockage is prevented, but humidification of the stack becomes insufficient
Solution Approach 1:
The ejector changes the physical parameters of moisture removal by controlling evaporation rate, mixing intensity, and separation conditions. By adjusting these parameters, the system achieves optimal moisture content in the fuel gas supplied to the stack - removing enough to prevent blockage while retaining sufficient humidity for proper stack operation.
3Reliability
If condensed water is collected and drained, then water blockage is prevented, but system complexity increases
Solution Approach 1:
The ejector merges multiple functions into a single integrated device: it vaporizes condensed water, mixes it with fuel gas, separates moisture through flow dynamics, and supplies treated fuel gas to the stack. This consolidation eliminates the need for separate collection tanks, drainage systems, and humidity control devices, reducing overall system complexity while maintaining reliable operation.
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 prevents excessive water supply to the stack, reduces output deterioration, enhances fuel gas circulating efficiency, and improves humidification efficiency, maintaining stable electricity generation by managing pressure differences and ensuring proper fuel gas circulation.
Implementation Method 1
A fuel gas spray nozzle is mounted to the vacuum suction pipe for spraying the fuel gas to form a vacuum
Implementation Method 2
The inner housing drains water from an inside of the inner housing to the condensed water space
Data Source
AI summary
A fuel cell system having an ejector includes a stack for generating electricity by using air and fuel gas being supplied thereto. A fuel gas circulating line re-circulates the fuel gas from an outlet of the stack to an inlet of the stack. An ejector is mounted to the fuel gas circulating line for supplying fresh fuel gas and circulating the fuel gas. The ejector includes a vacuum suction pipe having one side connected to the fuel gas re-circulating line and a fuel gas spray nozzle mounted to the vacuum suction pipe for spraying the fuel gas to form a vacuum. An inner housing through which the fuel gas sprayed from the fuel gas spray nozzle passes. An outer housing is arranged on an outside of the inner housing to construct a condensed water space with the inner housing. The inner housing drains water from an inside of the inner housing to the condensed water space.