Heat Pump Dryer Control for Waterproof Outdoor Textile Reactivation
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Solution Overview
Problem
Heat pump laundry dryers are not designed to operate at high temperatures required for effectively re-activating the waterproof characteristics of outdoor textiles with fluoropolymer-based durable water repellent treatments, which leads to reduced breathability and increased dirt attraction due to saturation and pore clogging.
Innovation Solution
A method for controlling a heat pump laundry drying machine that includes a specific outdoor drying cycle with settings for high temperature (above 55°C) and low humidity (below 5%), involving controlled drum rotation frequency, increased air flow rate, and compressor power to maintain high temperatures and minimize mechanical interference, ensuring the re-activation of waterproof layers in outdoor textiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a heat pump laundry dryer operates at high temperature (above 55°C) to re-activate waterproof characteristics of outdoor textiles, then the waterproof characteristics are re-activated, but the dryer is not designed to operate at such high temperatures
Solution Approach 1:
The drying process is divided into multiple stages: a first drying stage at lower temperature to remove bulk moisture, and a second drying stage at higher temperature (above 55°C) to re-activate the waterproof characteristics. This segmentation allows the dryer to safely achieve high temperatures only when necessary and for limited duration, rather than operating continuously at high temperature which would compromise reliability.
Solution Approach 2:
Before entering the high-temperature second drying stage, the dryer first performs moisture detection to determine when sufficient moisture has been removed. This preliminary action ensures that the high-temperature phase only begins at the appropriate time, preventing premature thermal stress on the dryer components while still achieving the necessary temperature for waterproof re-activation.
2Reliability
If standard drying cycles are used for outdoor textiles, then the textiles are dried, but the waterproof characteristics are not re-activated and breathability decreases
Solution Approach 1:
The invention changes the temperature parameter during the drying process by implementing a second drying stage with temperature above 55°C, which is specifically required to re-activate the fluoropolymer-based durable water repellent treatment. This parameter change transforms the drying process from merely removing moisture to also restoring the functional properties of the textile, thereby improving both waterproof characteristics and breathability.
Solution Approach 2:
The drying process dynamically adjusts temperature based on the drying stage and moisture content detection. The system transitions from a lower temperature first drying stage to a higher temperature second drying stage, creating a dynamic process that adapts to the changing needs of the textile throughout the drying cycle, thereby achieving both effective drying and waterproof re-activation.
3Productivity
If outdoor textiles are over-dried to remove all moisture, then the textiles are completely dry, but wrinkles occur and material damage happens
Solution Approach 1:
The dryer incorporates moisture detection capability that provides feedback during the drying process. This feedback mechanism allows the system to monitor moisture content and determine when sufficient drying has been achieved, preventing over-drying. The feedback signal triggers the transition between drying stages and controls the overall drying duration to maintain material integrity while achieving adequate dryness.
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 method effectively re-activates the waterproof characteristics of outdoor textiles, maintaining breathability and preventing dirt accumulation, as demonstrated by improved performance in rain and impact rain tests compared to standard drying cycles and ambient air drying.
Implementation Method 1
a heat pump system having a refrigerant circuit in which a refrigerant can flow, said refrigerant circuit including a first heat exchanger where the refrigerant is cooled off, a second heat exchanger where the refrigerant is heated up
Implementation Method 2
the outdoor textiles temperature and/or a process air temperature indicative of the temperature of the outdoor textiles is controlled to be equal or above 55°C
Implementation Method 3
said refrigerant circuit including a first heat exchanger where the refrigerant is cooled off, a second heat exchanger where the refrigerant is heated up, a compressor to pressurize and circulate the refrigerant through the refrigerant circuit
Implementation Method 4
a compressor to pressurize and circulate the refrigerant through the refrigerant circuit
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a method for controlling a heat pump laundry drying machine comprising a rotatable drum where textile is introduced and treated with a process air (A), said drum being driven in two rotation directions; a heat pump system (44) having a refrigerant circuit (40) in which a refrigerant can flow, said refrigerant circuit including a first heat exchanger (32) where the refrigerant is cooled off, a second heat exchanger (34) where the refrigerant is heated up, a compressor (36) to pressurize and circulate the refrigerant through the refrigerant circuit (40); said first and/or second heat exchanger being apt to perform heat exchange between said refrigerant flowing in said refrigerant circuit and said process air; a cooling device (42) for cooling a component (36) of the heat pump system;- a selector adapted to select alternatively at least an outdoor drying cycle for drying outdoor textiles which have a waterproof and breathable thin film material with a micro-porous structure, and at least an additional drying cycle for drying other types of textiles, wherein the outdoor drying cycle includes an outdoor main drying phase having settings for a frequency of reversion of rotations of the drum and for the heat pump operation and the additional drying cycle comprises an additional main drying phase having settings for a frequency of reversion of rotations of the drum and for the heat pump operation;wherein the method comprises: - selecting and starting the outdoor drying cycle, and entering the outdoor main drying phase, wherein the outdoor main drying phase includes an outdoor first sub-phase (S2) and an outdoor second sub-phase (S3); - reversing the rotation of the drum (16) in the outdoor first sub-phase at a frequency (F1) lower than a frequency in the additional main drying phase; - entering the outdoor second sub-phase when the humidity of said outdoor textile is equal or below a first threshold; - in the second sub-phase, reversing the rotation of the drum at a frequency (F2) lower than the drum rotation reversal frequency (F1) operated in the outdoor first sub-phase; and operating one or more of the following: • increasing a flow rate of the process air in the drum with respect to a flow rate in the outdoor first sub-phase and with respect to a flow rate in the additional main drying phase; • increasing a velocity of and/or a power supply to a motor (67) of the compressor (36) with respect to a velocity of and/or a power supply to a motor of the compressor in the outdoor first sub-phase and with respect to a velocity of and/or a power supply to a motor of the compressor in the additional main drying phase; • increasing a temperature at which the cooling device (42) is activated/deactivated with respect to a temperature at which the cooling device is activated/deactivated in the outdoor first sub-phase and with respect to a temperature at which the cooling device is activated/deactivated in the additional main drying phase.