Switchgear Cooling Flap Layout for Internal Arc Sealing
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Solution Overview
Problem
Medium voltage air insulated switchgear requires effective cooling while meeting Internal Arc Classification (IAC) requirements, but existing radial fans are bulky, expensive, noisy, and have limited lifetimes, and fail to protect air flow paths from hot gases and particles during internal arc faults.
Innovation Solution
A cooling system comprising a housing, a fan, and a flap where the fan's rotational axis does not extend through the flap, allowing the flap to open and close due to pressure differences, creating a sealed compartment that prevents direct gas or air passage through the fan, and includes a control spring and lock for reliable closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radial fans are used for cooling, then cooling function is provided, but the fans are bulky, expensive, noisy, and have limited lifetimes
Solution Approach 1:
The patent replaces the traditional radial fan mechanical cooling system with an axial fan system that uses a flap mechanism controlled by pressure differences. This substitution reduces mechanical complexity, noise, and maintenance requirements while improving reliability and lifetime.
Solution Approach 2:
The invention uses pressure difference (pneumatic principle) to control the flap opening and closing automatically. The pressure differential caused by internal arc faults or normal operation drives the flap to seal or open, eliminating the need for complex mechanical actuators and control systems.
2Object-affected harmful factors
If radial fans are used for cooling, then cooling is achieved, but air flow paths are not protected from hot gases and particles during internal arc faults
Solution Approach 1:
The flap acts as an intermediary element between the cooling system and the hot gas/particle environment. It selectively opens to allow cooling air flow during normal operation and closes to seal the compartment during internal arc faults, protecting the air flow path from harmful substances.
Solution Approach 2:
The flap transitions from a static barrier to a dynamic control element that automatically adjusts its position based on operating conditions. It rotates between open and closed positions in response to pressure differences, providing adaptive protection without complex control systems.
3Object-affected harmful factors
If a flap is added to seal the compartment, then protection from hot gases is improved, but device complexity increases
Solution Approach 1:
The flap system is self-actuating through pressure difference control. The internal pressure changes during arc faults or cooling operations automatically drive the flap to the appropriate position without external control signals, motors, or actuators, minimizing added complexity.
Solution Approach 2:
The system uses pressure difference as a control parameter to trigger flap movement. By monitoring and responding to pressure changes rather than using complex control systems, the invention achieves effective sealing with minimal additional components.
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 provides improved cooling efficiency, increased speed of operation, higher reliability, lower costs, reduced noise, and enhanced closure tightness, meeting IAC requirements with faster reaction times and longer fan lifetimes.
Implementation Method 1
The flap is configured to move from an open position to a closed position due to a pressure difference from one side of the flap to the other side of the flap
Data Source
AI summary
A cooling system for an air insulated switchgear compartment includes: a housing; a fan; and a flap. The fan is mounted to the housing. The flap is mounted to the housing. The flap is positioned adjacent to the fan such that a rotational axis of the fan does not extend through the flap.