Fuel Cell Chamber Venting to Block Exhaust Gas Reverse Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In fuel cell systems, there is a concern that exhaust gases from a boiler can flow reversely into the fuel cell chamber when the ventilation fan is stopped, leading to potential failures and erroneous gas leakage alarms, and existing solutions struggle to effectively suppress this reverse flow.
Innovation Solution
The integration of a check valve at the intake unit of the ventilation exhaust line, along with a first fan driven during the fuel cell system's standby state, prevents exhaust gas from flowing into the fuel cell chamber, and a second fan is used to maintain positive pressure and promptly open the check valve, ensuring air-tightness and preventing reverse flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a ventilation fan is used to suction and discharge air in the fuel cell system, then air circulation is achieved, but the pressure inside the system becomes lower than external pressure causing potential gas leakage into indoor places
Solution Approach 1:
The patent inverts the pressure relationship by using a pressurization fan instead of a suction fan. The fan pressurizes the air inside the fuel cell system to be higher than external atmospheric pressure, so that any potential gas leakage is prevented from entering indoor places and instead flows outward through the exhaust duct.
2Object-affected harmful factors
If a check valve is provided in the exhaust duct to prevent reverse flow, then exhaust gas reverse flow is suppressed, but the check valve may fail due to adhesion of condensed water
Solution Approach 1:
The patent replaces the mechanical check valve with an electronically controlled shutter valve that can be opened or closed based on control signals. This substitution eliminates the reliability issue of mechanical check valves being stuck by condensed water, as the electronic shutter valve can be actively controlled to remain open when needed and closed when reverse flow prevention is required.
3Device complexity
If the same intake and exhaust duct is shared by both fuel cell system and combustion device, then space is saved, but exhaust gas from combustion device can flow into fuel cell chamber
Solution Approach 1:
The patent introduces dynamically controllable shutter valves at strategic positions in the shared duct system. These shutter valves can be opened or closed based on the operational state of the fuel cell system and combustion device, allowing flexible control of gas flow paths. When the fuel cell system is operating, the shutter valves remain open to allow normal air intake and exhaust discharge. When the combustion device is operating independently, the shutter valves close to prevent combustion exhaust gas from entering the fuel cell chamber.
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 effectively suppresses the reverse flow of exhaust gases from the combustion device into the fuel cell chamber, preventing operational failures and erroneous gas leakage alarms, while maintaining air-tightness and cooling electrical appliances within the system.
Implementation Method 1
a check valve which is provided at the intake unit of the ventilation exhaust line and allows air to circulate into the inside of the fuel cell chamber from the ventilation exhaust line
Implementation Method 2
a first fan which is provided at the exhaust unit of the ventilation exhaust line and discharges air from the inside of the fuel cell chamber
Implementation Method 3
a second fan which is provided at the suction side or the discharge side of the check valve and forces air into the inside of the fuel cell chamber
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A fuel cell system 100 comprises a fuel cell chamber R1 which is provided in an indoor place and accommodates the housing 10a which accommodates the fuel cell 34 and the combustion unit 36, a ventilation exhaust line KL which includes an intake unit 10c introducing air into the fuel cell chamber and an exhaust unit 10d discharging the air to the outdoor place, a first fan 42 which is provided at the exhaust unit to discharge air from the fuel cell chamber, and a check valve 41 which is provided at the intake unit and configured to suppress the circulation of the air into the fuel cell chamber from the outside thereof in a normal state and to allow the circulation of the air while being opened when the inside of the fuel cell chamber becomes a negative pressure state.