Compressor Frequency Control for Air Conditioner Frost Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional air conditioners perform defrosting operations based on predetermined time intervals, regardless of outdoor humidity conditions, leading to suboptimal defrosting and heating efficiency due to uniform defrosting operations.
Innovation Solution
An air conditioner system with an outdoor unit equipped with a compressor, outdoor temperature and humidity sensors, and a control unit that adjusts compressor operation frequency based on dew-point temperature and evaporation pressure to prevent frosting, using reference pressures and humidity mapping to optimize defrosting efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If defrosting operation is performed uniformly according to predetermined time interval, then defrosting operation is simple to implement, but defrosting efficiency and heating efficiency are compromised due to ignoring outdoor humidity conditions
Solution Approach 1:
The patent applies dynamics by making the defrosting operation adaptive rather than static. The control unit dynamically adjusts whether to perform defrosting based on real-time outdoor humidity conditions and evaporation pressure readings. When outdoor humidity is high and evaporation pressure is low (indicating frosting conditions), defrosting is triggered; otherwise, normal heating continues. This dynamic adaptation resolves the contradiction by maintaining operational simplicity while significantly improving heating efficiency.
Solution Approach 2:
The patent implements feedback mechanisms by using outdoor humidity sensors and evaporation pressure sensors to continuously monitor environmental conditions. The control unit receives this feedback and adjusts the defrosting operation accordingly. This feedback loop enables the system to make informed decisions about when defrosting is necessary, preventing unnecessary defrosting operations that would reduce heating efficiency while maintaining simple operation through automated control.
2Reliability
If defrosting operation is performed frequently to ensure evaporator is always defrosted, then evaporator frosting is prevented, but heating performance decreases due to restricted heating operation during defrosting
Solution Approach 1:
The patent applies parameter changes by using outdoor humidity and evaporation pressure as key parameters to determine defrosting necessity. Instead of using a fixed time-based schedule, the system monitors these parameters and triggers defrosting only when they indicate frosting conditions (high humidity, low pressure). This parameter-based approach ensures reliable evaporator defrosting while minimizing interruptions to heating performance.
Solution Approach 2:
The patent implements preliminary action by proactively monitoring outdoor humidity and evaporation pressure to predict frosting conditions before they severely impact performance. The system takes preliminary defrosting action when parameters indicate high risk of frosting, preventing complete evaporator blockage while avoiding unnecessary defrosting cycles, thus maintaining both reliability and heating performance.
3Power
If compressor operation frequency is increased to improve heating output, then heating capacity is enhanced, but evaporation pressure decreases leading to increased frosting risk on evaporator
Solution Approach 1:
The patent uses feedback control by continuously monitoring evaporation pressure and outdoor humidity. When the compressor operates at high frequency and evaporation pressure drops below a threshold (indicating increased frosting risk), the control unit adjusts the defrosting strategy or compressor frequency to prevent frosting. This feedback mechanism allows the system to maintain high heating capacity while dynamically managing the harmful frosting effect.
Solution Approach 2:
The patent applies preliminary anti-action by taking preventive measures against frosting before it severely impacts the evaporator. When outdoor humidity is high and evaporation pressure indicates risk, the system proactively triggers defrosting or adjusts compressor frequency to maintain evaporation pressure above critical levels. This preliminary action prevents the harmful frosting effect from developing while allowing high heating capacity operation.
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
The system effectively minimizes defrosting frequency and duration, enhancing heating performance by adapting compressor operation to outdoor humidity and pressure conditions, thereby optimizing defrosting and heating efficiency.
Implementation Method 1
an outdoor temperature sensor installed on the outdoor unit to sense outdoor temperature
Implementation Method 2
an outdoor humidity recognition part installed on the outdoor unit to recognize information about outdoor humidity
Implementation Method 3
a low pressure sensor that senses an evaporation pressure of the evaporator
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
Implementation Method 5
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
Implementation Method 6
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
Implementation Method 7
an air conditioner includes a compressor, a condenser, an expansion device, and an evaporator, and performs a refrigerating cycle for compressing, condensing, expanding, and evaporating refrigerant
Implementation Method 8
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
Data Source
AI summary
An air conditioner including an outside unit, which includes a compressor and an evaporator, an outside temperature sensor attached to the outside unit to sense outside temperature, an outside humidity recognition part attached to the outside unit to recognize information about outside 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 outside temperature sensor and the outside 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.