Air conditioner outdoor unit
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Solution Overview
Problem
Existing air conditioner outdoor units face challenges in simultaneously preventing corrosion and reducing electromagnetic noise, particularly due to the use of dissimilar metals for the heat exchanger and casing, which leads to structural complexity and increased manufacturing steps.
Innovation Solution
The air conditioner outdoor unit incorporates a capacitance connection sheet metal made of a metal that does not cause dissimilar metal corrosion, which is electrically connected to the casing and disposed with a space between the heat exchanger and the capacitance connection sheet metal, allowing for electrical connection through capacitance generated between the two components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a non-conductive member is interposed between the heat exchanger and the casing to prevent corrosion, then corrosion prevention is improved, but electromagnetic noise increases due to parasitic capacitance
Solution Approach 1:
The patent introduces a conductive member as an intermediary between the heat exchanger and the casing. This conductive member serves dual purposes: it prevents direct contact between dissimilar metals (avoiding corrosion) while providing a controlled electrical connection path that reduces parasitic capacitance effects. The conductive member acts as a mediator that resolves the conflict between corrosion prevention and electromagnetic noise reduction.
Solution Approach 2:
The patent changes the electrical conductivity parameter of the connection between heat exchanger and casing. Instead of using a non-conductive member (zero conductivity), it uses a conductive member with specific conductivity properties. This parameter change allows the system to maintain electrical continuity for noise reduction while still preventing direct metal-to-metal contact for corrosion prevention.
2Object-generated harmful factors
If a conductive connecting member with insulating layer is used to reduce electromagnetic noise, then electromagnetic noise is reduced, but device complexity increases due to multiple metal types and manufacturing steps
Solution Approach 1:
The patent extracts the insulating function from the connecting member itself and places it on the heat exchanger surface. Instead of having a complex multi-layer connecting member with integrated insulation, the insulation is separated as a coating on the heat exchanger, simplifying the connecting member to essentially a single conductive element.
Solution Approach 2:
The patent uses a composite structure where the heat exchanger surface combines a base metal layer with an insulating coating layer. This composite approach allows the heat exchanger to maintain its structural and thermal properties while the coating provides electrical insulation, eliminating the need for separate insulating components.
3Object-generated harmful factors
If the heat exchanger and casing are placed in direct contact to improve conductivity, then electromagnetic noise is reduced, but corrosion occurs at the contact portion
Solution Approach 1:
The conductive member serves as an intermediary that provides electrical connection without direct metal-to-metal contact. It creates a controlled electrical pathway that reduces parasitic capacitance and electromagnetic noise while physically preventing the galvanic corrosion that would occur with direct dissimilar metal contact.
Solution Approach 2:
The patent replaces the mechanical direct-contact connection system with an electrostatic field-based connection. By using the conductive member and insulating coating combination, the system utilizes electrical field effects rather than direct mechanical contact, achieving electrical continuity without physical metal-to-metal contact.
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 configuration effectively prevents corrosion by avoiding direct contact between dissimilar metals and reduces electromagnetic noise by enhancing conductivity between the heat exchanger and the casing at high frequencies, thereby achieving a simpler structure with improved performance.
Implementation Method 1
the capacitance connection sheet metal is disposed with a space between the heat exchanger and the capacitance connection sheet metal and electrically connected to the heat exchanger through capacitance generated between the heat exchanger and the capacitance connection sheet metal
Data Source
AI summary
An air conditioner outdoor unit includes a box-shaped casing formed of a first metal, a heat exchanger that is at least partly formed of a second metal different in natural potential from the first metal and is disposed in the casing and fixed to the casing with a non-conductive member interposed therebetween, and capacitance connection sheet metal that is formed of the first metal or a third metal that does not cause dissimilar metal corrosion with the first metal and is disposed in the casing. The capacitance connection sheet metal is fixed to the casing and electrically connected to the casing, and is disposed with a space between the heat exchanger and the capacitance connection sheet metal and electrically connected to the heat exchanger through capacitance generated between the heat exchanger and the capacitance connection sheet metal.