Switchgear Ventilation Flap for Arc Fault Gas Isolation
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Solution Overview
Problem
In electrical switchgear, existing ventilation devices fail to prevent the unwanted ingress of hot and contaminated gases into adjacent compartments during an arc fault, leading to contamination and damage of electrical systems.
Innovation Solution
A ventilation device with a cover flap that closes a smaller flow cross-section on one side and opens a larger flow cross-section on the other side during a pressure wave, preventing the spread of gases into neighboring compartments, and utilizing two separate pivot axes to manage airflow effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single flow cross-section is provided for ventilation, then ventilation efficiency is improved, but the ability to prevent contamination during pressure waves deteriorates
Solution Approach 1:
The ventilation device is segmented into two distinct flow cross-sections: a first flow cross-section for normal ventilation operation and a second, larger flow cross-section for pressure wave discharge. This segmentation allows the system to optimize for both ventilation efficiency and contamination prevention by directing different flows through different pathways.
Solution Approach 2:
The cover flap is designed to dynamically switch between blocking the first flow cross-section and allowing the second flow cross-section to open. During normal operation, the cover flap blocks the second cross-section while allowing ventilation through the first. During pressure waves, the cover flap opens to allow the larger second cross-section to discharge the pressure wave, preventing contamination of adjacent compartments.
2Reliability
If a larger flow cross-section is used for pressure relief, then pressure wave discharge capability is improved, but the risk of gas penetration into ventilation ducts increases
Solution Approach 1:
The cover flap acts as an intermediary element that controls access to the second, larger flow cross-section. It remains closed during normal operation to prevent gas penetration into the ventilation duct, but opens during pressure waves to allow safe discharge. This intermediary mechanism enables the system to utilize the larger cross-section for pressure relief without the constant risk of contamination.
3Object-affected harmful factors
If a cover flap mechanism is added to control flow cross-sections, then contamination prevention is improved, but device complexity increases
Solution Approach 1:
The cover flap mechanism changes the flow cross-section parameter dynamically based on operating conditions. By pivoting the cover flap, the system transitions between two discrete states: normal ventilation mode (first cross-section open, second closed) and pressure wave discharge mode (first closed, second open). This parameter change approach provides effective contamination prevention without requiring complex continuous control systems.
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
Effectively prevents the contamination of adjacent compartments by directing pressure waves and hot gases away from unaffected areas, ensuring safe and controlled pressure relief during incidents.
Implementation Method 1
if a pressure wave occurs in a compartment due to an accident
Implementation Method 2
The cover flap can be pivoted about a first pivot axis, the first pivot axis being pivotable about a second pivot axis which is spaced apart from the first pivot axis
Implementation Method 3
the resulting pressure wave opens the second, larger flow cross-section, so that the pressure wave with hot and contaminated gases can escape into a ventilation duct
Data Source
Figure 1
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AI summary
A ventilation device for a bulkhead of an electrical switchgear comprises a cover flap (10) which closes a first flow cross-section when a pressure wave occurs on one side of the bulkhead. A second flow cross-section opens when a pressure wave with the opposite orientation occurs.