Outdoor Unit Hot-Gas Bypass Layout for Bottom Plate Deicing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Air conditioning apparatuses face challenges in suppressing ice growth on the bottom plate of outdoor units without using a separate heater, which increases the number of parts and complicates the refrigeration cycle.

Innovation Solution

The air conditioning apparatus incorporates a bypass circuit that passes through the vicinity of the bottom plate below the blower and heat source-side heat exchanger, utilizing refrigerant to warm the area and prevent ice growth without a separate heat source, and includes features like drainage ports and inclined bypass gutters to enhance ice suppression.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a heater is provided on the bottom plate to suppress ice growth, then ice prevention is improved, but the number of parts increases and device complexity increases

Engineering Contradiction:
Improveice preventionVSAvoidnumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the ice prevention function with the existing refrigeration cycle by routing the refrigerant discharge line to pass through the bottom plate. The refrigerant itself serves as the heating medium, eliminating the need for a separate heater and reducing overall system complexity while maintaining reliable ice prevention.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The refrigerant discharge line serves dual functions: its primary function in the refrigeration cycle and a secondary function as a heating element for ice prevention. This multi-functionality eliminates the need for dedicated ice prevention components, reducing part count while maintaining effectiveness.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If a heater is provided on the bottom plate to suppress ice growth, then ice prevention is improved, but device complexity increases

Engineering Contradiction:
Improveice preventionVSAvoidconfiguration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the ice prevention function with the existing refrigeration cycle by routing the refrigerant discharge line to pass through the bottom plate. The refrigerant itself serves as the heating medium, eliminating the need for a separate heater and reducing overall system complexity while maintaining reliable ice prevention.

Inventive Principle:
Principle #5Merging (Combining)

3Loss of substance

If the bottom plate has an opening near the blower, then drainage is improved, but ice growth is promoted due to cold air flow

Engineering Contradiction:
ImprovedrainageVSAvoidice growth suppression
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent applies different functional qualities to different regions of the bottom plate. The drainage port is positioned in a region away from the blower to allow water drainage, while the refrigerant line is routed through a different region to provide localized heating where ice formation is most problematic, near the blower area.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The bottom plate is functionally segmented into distinct zones: a drainage zone with the drainage port for water removal, and a heating zone where the refrigerant line passes through to prevent ice formation. This segmentation allows each zone to optimize its specific function without interfering with the other.

Inventive Principle:
Principle #1Segmentation

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 solution effectively prevents ice growth on the bottom plate, ensuring the blower's operation is not hindered and heat exchange efficiency is maintained, while reducing the complexity of the refrigeration cycle by eliminating the need for a separate heater.

Implementation Method 1

the bypass circuit is provided so as to pass through the vicinity of the portion of the bottom plate of the housings below the blower and below the heat source-side heat exchanger. The vicinity of the portion through which the bypass circuit passes can therefore be warmed without the use of a separate heat source such as a heater.

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP2333438B1Air conditioning device
Publication Date: 2019.09.04 DAIKIN INDUSTRIES LTD
  • EP2333438B1 patent drawingFigure 1
  • EP2333438B1 patent drawingFigure 2
  • EP2333438B1 patent drawingFigure 3

AI summary

There is provided an air conditioning apparatus whereby the growth of ice on the bottom plate of the outdoor unit can be suppressed without the use of a configuration that is distinguished from the refrigeration cycle, such as heater. An air conditioning apparatus (1) having a compressor (21), an outdoor heat exchanger (23), an outdoor motor-driven expansion valve (24), and an indoor heat exchanger (41) comprises outdoor fans (26), an outdoor unit casing (2B), and a hot-gas bypass circuit (H). The outdoor unit casing (2B) has a bottom plate (2b) and accommodates the outdoor heat exchanger (23) and the outdoor fans (26) in a space above the bottom plate (2b). The hot-gas bypass circuit (H) is disposed so as to pass below the outdoor fans (26) and below the outdoor heat exchanger (23), and bypasses a discharge tube (A) on the discharge side of the compressor (21), and at least any one of an indoor-side liquid tube (C) which extends from the indoor heat exchanger (41) to the outdoor motor-driven expansion valve (24), and an outdoor-side liquid tube (D) which extends from the outdoor motor-driven expansion valve (24) to the outdoor heat exchanger (23).