Heat Pump Dryer Temperature-Adaptive Control for Cold Environments
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Solution Overview
Problem
Laundry treatment apparatuses with heat pumps face performance degradation under low-temperature conditions, leading to increased drying times and difficulty in achieving desired dryness levels due to non-uniform air temperatures.
Innovation Solution
A control method that adjusts the output of the heat pump and fan based on the installation environment's temperature, using a secondary control procedure to maximize compressor and fan output when temperatures are low, and incorporates dryness measurement operations to set and adjust reference times for completing the drying process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the heat pump operates under low-temperature conditions, then the air temperature supplied to laundry can be raised to desired level, but a long time is required and drying time increases
Solution Approach 1:
The patent dynamically adjusts the heat pump's compressor output based on the measured air temperature. When the air temperature introduced into the evaporator is low, the controller increases the compressor's refrigerant compression capacity to accelerate heating. This dynamic adjustment allows the system to maintain effective drying performance while reducing the extended drying time that would otherwise occur under low-temperature conditions.
Solution Approach 2:
The system changes operational parameters by measuring the air temperature and adjusting the heat pump's compression ratio and refrigerant flow accordingly. This parameter adaptation enables the heat pump to optimize its heating efficiency under varying temperature conditions, preventing excessive drying time delays while still achieving the desired air temperature for effective laundry drying.
2Temperature
If the heat pump operates under low-temperature conditions, then heating can be achieved, but constant drying performance cannot be maintained
Solution Approach 1:
The patent implements a feedback control mechanism where a temperature sensor continuously monitors the air temperature introduced into the evaporator. Based on this feedback, the controller adjusts the heat pump's compressor output to compensate for temperature variations. This closed-loop control ensures consistent drying performance by maintaining appropriate heating capacity regardless of ambient temperature fluctuations or installation environment conditions.
3Productivity
If the heat pump operates at maximum output to reduce drying time, then drying speed increases, but energy consumption increases
Solution Approach 1:
The system dynamically adjusts the heat pump's compressor output based on actual operating conditions, specifically the air temperature measured by the sensor. Instead of operating at maximum output continuously, the controller modulates the compression ratio and refrigerant flow to match the heating demand. This dynamic operation achieves effective drying speed while avoiding unnecessary energy consumption that would result from constant maximum-power 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
This approach minimizes performance degradation by ensuring consistent drying performance across varying temperatures, reducing drying time and ensuring laundry reaches the desired dryness level, even in cold conditions.
Implementation Method 1
an evaporator configured to exchange heat with ambient air and, as such, to evaporate refrigerant present therein
Implementation Method 2
a condenser configured to condense refrigerant present therein and, as such, to heat ambient air
Implementation Method 3
a compressor configured to compress refrigerant discharged from the evaporator and to supply the compressed refrigerant
Data Source
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AI summary
A control method of a laundry treatment apparatus is disclosed which includes a course setting procedure (S10) receiving a control command including RPM control data of an impeller (751), RPM control data of a compressor (735) or opening degree control data of an expansion valve (737), a hot air supply procedure (S11, S13, S15) for supplying heated air to a drum through control of the impeller, compressor and expansion valve, a temperature measurement procedure (S20) measuring temperature of air introduced into the drum during execution of the hot air supply procedure, a first control procedure (S40) for controlling the impeller, compressor and expansion valve based on the control command when the measured temperature is equal to or higher than a reference temperature, and a second control procedure (S60) controlling the impeller, compressor and expansion valve based on a control command different from the control command set in the course setting procedure when the measured temperature is lower than the reference temperature.