Open Frame Chassis Passive Cooling for Harsh Environments
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Solution Overview
Problem
Conventional modular electronic systems face challenges in harsh environments due to reliance on forced-air cooling, which can fail and introduce dust and contaminants, leading to reduced Mean Time Between Failures (MTBF) and increased Mean Time to Repair (MTTR), and lack modularity and vibration resistance.
Innovation Solution
A passively cooled modular electronic system with an open-frame chassis and hot-swappable modules that use natural convection for cooling, featuring internal heat sinks and thermal interface materials to dissipate heat, along with unique key housings and guide pins for secure connection and vibration mitigation, ensuring modules are completely enclosed to prevent dust ingress and allowing for ambient air cooling without forced air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If forced-air cooling is used to dissipate heat from electrical components, then heat dissipation is improved, but reliability deteriorates due to fan failure risk and dust contamination
Solution Approach 1:
The patent removes the fan and forced-air cooling mechanism from the system, extracting the harmful element that causes reliability issues. Instead, it uses passive natural convection cooling where air flows naturally through openings in the chassis and modules, eliminating the need for active cooling components that can fail or introduce contaminants.
Solution Approach 2:
The cooling system is designed to be self-regulating through natural convection. The chassis and modules have strategic openings that allow air to enter and exit based on temperature-driven convection currents, automatically cooling components without requiring external control or active components.
2Object-affected harmful factors
If an enclosed chassis is used to protect components from harsh environments, then protection is improved, but modularity deteriorates as the entire chassis must be replaced when a component fails
Solution Approach 1:
The system is divided into separate modular units (chassis and interchangeable modules) that can be independently replaced. Each module contains specific electrical components and can be removed and replaced without affecting other modules, enabling selective maintenance while maintaining overall system protection.
Solution Approach 2:
The chassis acts as an intermediary protective structure that houses multiple removable modules. It provides the protective enclosure against harsh environments while allowing individual modules to be exchanged, mediating between the need for protection and the need for modularity.
3Object-affected harmful factors
If an enclosed chassis is used to protect components, then protection is improved, but ease of repair deteriorates as the entire chassis must be replaced
Solution Approach 1:
The system separates the protective chassis from the functional modules, allowing modules to be independently replaced. When a component fails, only the affected module needs to be removed and replaced, not the entire chassis, significantly reducing repair time and improving ease of maintenance.
4Temperature
If forced-air cooling is used, then heat dissipation is improved, but dust contamination increases leading to reduced MTBF
Solution Approach 1:
The patent eliminates the forced-air cooling system that draws dust-laden air through the equipment. Instead, it uses passive natural convection with carefully designed openings that minimize dust ingress while still allowing adequate cooling through natural air flow driven by temperature differences.
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 system achieves improved MTBF and reduced MTTR by utilizing natural convection for heat dissipation, preventing dust contamination, and providing vibration resistance, while allowing for modular reconfiguration and easy maintenance, enhancing reliability in harsh conditions.
Implementation Method 1
ambient air flow from the bottom opening across the heat sink area and out the top opening to passively cool the electrical components
Implementation Method 2
The electrical components are in thermal contact with the heat sink area of the module
Data Source
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AI summary
An open frame chassis has a top opening and a bottom opening permitting ambient air flow there through. A plurality of modules, each enclosing electrical components which are in thermal contact with a heat sink area of their corresponding module, and each of which can be inserted to an inserted position in the open frame chassis. When the modules are inserted into the open frame chassis, ambient air may flow from the bottom opening of the chassis across the heat sink area of each module to the top opening in order to passively cool the modules and the electrical components enclosed therein. The heat sink area has fins which are separated by a distance of 9mm to 12mm and have a height 10mm to 20mm. Key pins are associated with the electrical connectors of the chassis to guide the modules into place and prevent incorrect insertion of a different type of electrical module not corresponding to the electrical connection of the chassis for that slot. Guide pins are present on the corners of the modules to mate with guide holes in the chassis to secure the module to the open frame chassis and decrease vibration. Both sides of the chassis have side openings through which the fins of the modules inserted into the end slots of the chassis may be exposed. The power modules are inserted into the end slots. The chassis has an inverted connection at one end slot to accommodate identical power modules at both end slots such that the heat sink area always faces a side opening in the open frame chassis.