Switchgear Conductor Cooling via Axial Blower Circulation
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Solution Overview
Problem
Conventional power-generation main circuit switchgear configurations face challenges in efficiently cooling internal conductors to allow larger electric currents, either requiring large blowers and coolers for forced air cooling or relying on inefficient natural convection, which limits the ability to handle high currents in compact designs.
Innovation Solution
A power-generation main circuit switchgear design featuring a casing with ducts and vent holes that allow wind from a small blower to directly hit internal conductors, enhancing heat transfer without the need for a cooler, by creating a high-speed air circulation within the casing and ducts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If forced air cooling is used with a large blower to cool the isolated-phase bus, then the cooling effect increases, but the blower size becomes large
Solution Approach 1:
The isolated-phase bus is divided into multiple sections with individual blowers for each phase, rather than using one large blower for the entire system. Each blower handles a smaller, localized cooling zone, reducing the size requirement for each individual blower while maintaining effective cooling coverage.
Solution Approach 2:
Cooling is applied locally at specific hot spots on the isolated-phase bus rather than uniformly across the entire structure. Blow fans are positioned to target specific conductor sections that generate the most heat, allowing smaller blowers to achieve effective cooling where it is most needed.
2Power
If a cooler is added to increase the cooling effect, then larger electric current can flow, but the cooling device becomes large
Solution Approach 1:
The cooler component is completely removed from the system. Instead of using a cooler to reduce air temperature, the invention relies solely on forced convection through blow fans to increase heat transfer from the conductors to the surrounding air, achieving the same cooling effect without the additional volume of a cooler unit.
Solution Approach 2:
The system uses forced air flow generated by blow fans to enhance convective heat transfer from the conductors. By controlling the velocity and direction of air flow through pneumatic means (blow fans), the system achieves effective cooling without requiring thermal exchange equipment like coolers.
3Device complexity
If natural convection is used to cool the switchgear, then the device complexity is reduced, but the heat transfer coefficient becomes low and large electric current cannot flow
Solution Approach 1:
The system transitions from static natural convection to dynamic forced convection using blow fans. The fans actively move air through the switchgear, creating variable air flow patterns that enhance heat transfer coefficients. This dynamic approach allows the system to achieve high cooling effectiveness without requiring complex multi-component cooling 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
This design effectively cools internal conductors using a small blower, enabling higher electric currents while reducing the size of the cooling system and maintaining the upper temperature limit, thus improving the power-handling capacity of the switchgear.
Implementation Method 1
a blower arranged in the duct to blow wind in the axial direction to allow the wind to circulate inside the duct and inside the casing through the vent holes
Implementation Method 2
wind blowing from the blower through an inside of the duct out of the first vent hole into the casing directly hits at least a part of the internal conductor in a vertical direction perpendicular to the internal conductor for cooling the internal conductor
Data Source
Figure 1
Figure 2
AI summary
A power-generation main circuit switchgear 1 includes a casing 1e with an axial direction thereof being an extending direction of an isolated-phase bus 2, internal conductors 1a and 1b arranged in the casing 1e and constituting a breaking unit 10, a duct 5 provided on the casing 1e and communicating with a space inside the casing 1e through a plurality of vent holes 5a and 5b, and a blower 4 arranged in the duct 5 to blow wind in the axial direction. The vent hole 5a is provided on the upstream side of the blower 4 and the vent holes 5b are provided on the downstream side of the blower 4. Wind blowing from the blower 4 circulates inside the duct 5 and inside the casing 1e through the vent holes 5a and 5b, and wind blowing from the inside of the duct 5 to the inside of the casing 1e through the vent holes 5b directly hits the internal conductors 1a and 1b