Air conditioner and method of controlling the same

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Solution Overview

Problem

Conventional air conditioners perform defrosting operations uniformly regardless of outdoor humidity, leading to suboptimal defrosting and heating efficiency due to the lack of consideration for humidity conditions, resulting in increased defrosting frequency and duration.

Innovation Solution

An air conditioner system equipped with outdoor temperature and humidity sensors, a low pressure sensor, and a control unit that adjusts the compressor operation frequency based on dew-point temperature and evaporation pressure to prevent frosting, utilizing a memory-mapped strategy to adjust compressor frequency according to specific humidity and pressure thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the air conditioner performs defrosting operation according to a predetermined time interval, then the evaporator can be defrosted periodically, but the heating performance decreases due to frequent and prolonged defrosting operations

Engineering Contradiction:
Improvedefrosting effectivenessVSAvoidheating performance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the control parameter from fixed time interval to dynamic control based on evaporation pressure and outdoor humidity. The control part adjusts the compressor operation frequency based on real-time evaporation pressure feedback and predetermined humidity thresholds, allowing the system to perform defrosting only when necessary rather than periodically, thus maintaining heating performance while ensuring effective defrosting when needed.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces feedback control by using a low pressure sensor to continuously monitor evaporation pressure and comparing it with predetermined reference values. The control part receives this feedback and adjusts compressor operation accordingly, creating a closed-loop control system that responds to actual system conditions rather than following a predetermined schedule, thereby optimizing both defrosting effectiveness and heating performance.

Inventive Principle:
Principle #23Feedback

2Productivity

If the evaporation pressure is allowed to decrease to absorb more heat from outdoor air, then heating efficiency improves, but frosting of the evaporator increases

Engineering Contradiction:
Improveheating efficiencyVSAvoidevaporator frosting
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent makes the compressor operation frequency dynamic rather than fixed. The control part continuously adjusts the compressor frequency based on real-time evaporation pressure feedback and outdoor humidity conditions. This dynamic adjustment allows the system to optimize heating efficiency by allowing evaporation pressure to decrease when humidity is low, while preventing frosting by increasing frequency when humidity is high, adapting to changing conditions in real-time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent takes preliminary action by using outdoor humidity information to predict frosting risk before it occurs. The control part compares current outdoor humidity with predetermined reference humidity values and proactively adjusts compressor operation frequency to prevent frosting, rather than waiting for frosting to occur and then responding. This preventive approach allows the system to maintain optimal heating efficiency while avoiding frosting issues.

Inventive Principle:
Principle #10Preliminary action

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 optimizes defrosting efficiency and heating performance by dynamically adjusting compressor operation in response to humidity and pressure conditions, minimizing defrosting frequency and duration while maintaining optimal heating performance.

Implementation Method 1

an outdoor temperature sensor installed on the outdoor unit to sense outdoor temperature

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 2

an outdoor humidity recognition part installed on the outdoor unit to recognize information about outdoor humidity

Methodology Applied
Scientific EffectHumidity sensing:

Implementation Method 3

a low pressure sensor that senses an evaporation pressure of the evaporator

Methodology Applied
Scientific EffectPressure sensing:

Implementation Method 4

an outdoor heat exchanger installed in an outdoor unit functions as a condenser, and an indoor heat exchanger installed in an indoor unit functions as an evaporator

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 5

when the surface temperature of the evaporator decreases to be equal to or lower than dew-point temperature, condensate water is produced on an outer surface of the evaporator

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 6

When the surface temperature of the evaporator decreases to be equal to or lower than the freezing point, the condensate water is frozen to frost the outer surface of the evaporator

Methodology Applied
Scientific EffectFreezing: Freezing

Data Source

PatentEP3026358B1Air conditioner and method of controlling the same
Publication Date: 2017.05.10 LG ELECTRONICS INC
  • EP3026358B1 patent drawingFigure 1~2
  • EP3026358B1 patent drawingFigure 3
  • EP3026358B1 patent drawingFigure 4

AI summary

An air conditioner and a method of controlling the same are provided. The air conditioner includes an outdoor unit, which is provided with a compressor and an evaporator, an outdoor temperature sensor installed on the outdoor unit to sense outdoor temperature, an outdoor humidity recognition part installed on the outdoor unit to recognize information about outdoor humidity, a low pressure sensor that senses an evaporation pressure of the evaporator, and a control part that controls an operation of the compressor, based on both information about dew-point temperature sensed from the outdoor temperature sensor and the outdoor humidity recognition part and information about the evaporation pressure sensed from the low pressure sensor. The control part changes an operation frequency of the compressor according to whether the evaporation pressure is not lower than a preset reference low pressure, to prevent frosting of the evaporator.