Outdoor Unit Drainage Channel Heating to Prevent Panel Freezing

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Solution Overview

Problem

Conventional outdoor units face the risk of the open-close panel freezing in low outdoor temperatures due to water freezing in the drainage channel, which can lead to operational failures and maintenance issues.

Innovation Solution

An outdoor unit design featuring a drainage channel inclined downward below the open-close panel-facing heat exchanger, combined with a heating energy supply unit that includes a refrigerant pipe passing high-temperature refrigerant adjacent to the drainage channel, ensuring the channel remains above the freezing point of water.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a drainage channel is provided below the heat source side heat exchanger to drain condensation water and rainwater, then drainage function is improved, but in low outdoor temperatures the water in the drainage channel may freeze causing the open-close panel to freeze

Engineering Contradiction:

Improvedrainage functionVSAvoidfreezing of open-close panel

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent utilizes the high-temperature refrigerant that would otherwise be waste heat and directs it through the drainage channel to prevent freezing. This converts the harmful cold environment into a beneficial heating source, preventing the open-close panel from freezing while maintaining drainage functionality.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The refrigerant pipe serving the heat source side heat exchanger is made to serve a dual function: cooling/heating the heat exchanger and simultaneously heating the drainage channel to prevent freezing. This multi-functionality eliminates the need for separate heating components.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Productivity

If the drainage channel is inclined downward to facilitate water drainage, then drainage efficiency is improved, but the open-close panel remains exposed to freezing temperatures

Engineering Contradiction:

Improvedrainage efficiencyVSAvoidfreezing risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The inclined drainage channel is heated by the high-temperature refrigerant flowing through it, converting the cold environment that causes freezing into a beneficial heating mechanism. This maintains efficient drainage while preventing freezing of the open-close panel.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Device complexity

If no additional heating components are added to prevent freezing, then device complexity is reduced, but the open-close panel freezes in low temperatures

Engineering Contradiction:

Improveheating system complexityVSAvoidopen-close panel operation

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The refrigerant pipe is designed to serve dual purposes: its primary function of heat exchange and a secondary function of heating the drainage channel to prevent freezing. This eliminates the need for additional heating components while ensuring reliable operation of the open-close panel.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses its own refrigerant, which is already at high temperature, to heat the drainage channel and prevent freezing. This self-service approach eliminates the need for external heating sources or additional energy input.

Inventive Principle:

Principle #25Self-service

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 reduces the risk of the open-close panel freezing and maintains efficient drainage, even in low outdoor temperatures, by ensuring the drainage channel remains unfrozen and functional.

Implementation Method 1

a heating energy supply unit disposed adjacent to, or in abutment with, at least part of the drainage channel, wherein the heating energy supply unit includes a refrigerant pipe configured to pass refrigerant higher in temperature than a freezing point of water

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS10386082B2Outdoor unit

Publication Date: 2019.08.20 MITSUBISHI ELECTRIC CORP

AI summary

An outdoor unit being part of a refrigeration cycle apparatus in which refrigerant circulates and having a maintenance opening port includes an open-close panel configured to cover the maintenance opening port by being attached openably and closably to the outdoor unit, a heat source side heat exchanger disposed above the maintenance opening port and provided at least with an open-close panel-facing heat exchange unit facing a plane containing the open-close panel, a drainage channel located at least below the open-close panel-facing heat exchange unit of the heat source side heat exchanger, wherein the heating energy supply unit includes a refrigerant pipe configured to pass refrigerant higher in temperature than a freezing point of water in an upstream direction from a downstream direction of the drainage channel.