Air Conditioner Damper Control for Low-Temperature Cooling Stability

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Solution Overview

Problem

Air conditioners face efficiency degradation and freezing issues during cooling operations in low outdoor temperatures due to excessive heat exchange, leading to high condensing and evaporation pressures, which hinder continuous operation.

Innovation Solution

The implementation of a method to control airflow through adjustable dampers in the outdoor unit, managing airflow passages to limit condensing rates and maintain stable operating pressures, including the use of a hood and skirt with dampers to regulate air flow and prevent excessive heat exchange.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the air conditioner performs cooling operation with outdoor air at low temperature, then cooling function is provided, but condensing temperature is reduced and condensing rate increases excessively

Engineering Contradiction:
Improvecooling temperatureVSAvoidcondensing rate
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The patent applies dynamics by making the air inlet passage dynamically adjustable through a damper that can change its opening degree based on operating conditions. The control unit adjusts the damper's opening degree to regulate airflow quantity to the heat exchanger, transforming a static system into a dynamic one that adapts to varying outdoor temperatures and cooling loads, thereby optimizing condensing rate control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of airflow quantity by controlling the damper's opening degree. By adjusting this parameter, the system modifies the amount of air entering the heat exchanger, which directly affects the heat exchange rate and condensing temperature. This parameter change allows the system to maintain optimal condensing rate even when outdoor air temperature is low.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If condensing rate increases excessively due to low outdoor temperature, then cooling operation occurs, but evaporation pressure and temperature are reduced causing freezing

Engineering Contradiction:
Improvecooling temperatureVSAvoidcontinuous operation
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent implements feedback control where the control unit continuously monitors outdoor air temperature and system operating parameters, then adjusts the damper's opening degree accordingly. This closed-loop feedback mechanism ensures that when outdoor temperature is low and condensing rate tends to increase excessively, the system responds by reducing airflow to maintain proper evaporation pressure and temperature, preventing freezing and ensuring continuous reliable operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies preliminary action by proactively adjusting the damper opening degree before freezing conditions develop. The control unit detects low outdoor temperatures and anticipates the risk of excessive condensing rate leading to low evaporation pressure, so it preemptively reduces airflow to prevent freezing of the evaporator, ensuring continuous operation.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If airflow is increased to enhance cooling, then cooling efficiency improves, but heat exchange becomes excessive at low temperatures degrading system efficiency

Engineering Contradiction:
Improvecooling efficiencyVSAvoidsystem efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent uses dynamics to make airflow adjustable through the damper mechanism. Instead of operating at fixed high airflow, the system dynamically optimizes airflow quantity based on outdoor temperature and cooling demand, reducing energy loss from excessive heat exchange while maintaining adequate cooling efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the airflow parameter by controlling damper opening degree. This allows the system to optimize the balance between cooling efficiency and energy loss by adjusting airflow to match actual cooling needs, particularly reducing airflow when outdoor temperatures are low to prevent excessive heat exchange and energy waste.

Inventive Principle:
Principle #35Parameter changes

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 approach allows for continuous operation by controlling condensing rates and pressures, preventing freezing and maintaining efficiency without additional power consumption, even in low outdoor temperatures.

Implementation Method 1

Outdoor air flows into the outdoor device 1 through the air inlet 3, is heat-exchanged in the heat exchanger, and then is discharged to the outside through the air outlet 2

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

the air conditioner includes an outdoor unit or device 1, in which a compressor and a heat exchanger are provided

Methodology Applied
Scientific EffectAirflow generation: Fan

Data Source

PatentEP3150929B1Air conditioner and method for controlling an air conditioner
Publication Date: 2019.12.25 LG ELECTRONICS INC
  • EP3150929B1 patent drawingFigure 1
  • EP3150929B1 patent drawingFigure 2
  • EP3150929B1 patent drawingFigure 3

AI summary

An air conditioner and a method for controlling an air conditioner are provided. The air conditioner may include a first guide provided on at least one surface of an outdoor device of the air conditioner to guide outdoor air to an air inlet, a second guide provided on one surface of the outdoor device to guide air discharged from an air outlet to an outside, and a third guide that guides the air discharged from the air outlet to flow from the second guide to the first guide