Heat-Pump Dryer Compressor Frequency Control by Laundry Load
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Solution Overview
Problem
Existing heat-pump laundry dryers face challenges in efficiently managing energy consumption and drying time due to fixed compressor frequency settings, which do not adapt to varying laundry amounts, leading to inefficient drying and increased energy use.
Innovation Solution
A control method for a heat-pump laundry dryer that adjusts the compressor frequency based on the amount of laundry, increasing frequency for larger loads to enhance drying efficiency and reducing frequency for smaller loads to conserve energy, using sensors to detect laundry quantity and temperature differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the compressor runs at a high frequency to achieve better drying performance, then drying efficiency is improved, but energy consumption increases
Solution Approach 1:
The patent applies dynamics by making the compressor frequency adjustable rather than fixed. The control system dynamically changes the compressor's operating frequency based on detected laundry amount, allowing the system to optimize between drying efficiency and energy consumption for different load conditions.
Solution Approach 2:
The patent changes the operational parameter (compressor frequency) based on the laundry amount. By detecting whether the laundry amount is above or below a threshold, the system adjusts the compressor frequency between a first frequency (for larger loads) and a second frequency (for smaller loads), optimizing performance and energy usage.
2Use of energy by moving object
If the compressor frequency is reduced to save energy for small laundry loads, then energy consumption decreases, but drying time increases
Solution Approach 1:
The system changes the compressor frequency parameter based on laundry amount detection. For small laundry loads, it reduces the frequency to the second frequency to save energy, while for larger loads, it maintains the first frequency to ensure adequate drying speed, thus optimizing the energy-time tradeoff.
Solution Approach 2:
The control system uses feedback from the laundry amount detection to adjust compressor frequency. The detector provides information about the laundry load, and the control system responds by selecting the appropriate frequency, creating a closed-loop control that adapts to different drying conditions.
3Ease of operation
If a fixed compressor frequency is used, then the system is simple to control, but it cannot adapt to varying laundry amounts leading to inefficient drying
Solution Approach 1:
The patent introduces a detector that provides feedback about the laundry amount to the control system. This feedback mechanism allows the system to automatically adapt its compressor frequency based on the actual load, improving versatility while maintaining automated control simplicity.
Solution Approach 2:
The system changes the compressor frequency parameter based on detected laundry amount. By implementing adjustable frequency control tied to load detection, the system achieves adaptability to varying laundry amounts while keeping the control logic relatively simple through automated threshold-based adjustments.
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 energy consumption and drying time by setting minimum compressor frequencies according to laundry amount, ensuring better drying performance and reduced energy usage.
Implementation Method 1
heated air that is heated by a condenser in a heat-pump circulation system
Implementation Method 2
wet air obtained after taking moisture from the laundry is delivered back to an evaporator for dehumidification
Implementation Method 3
saturation pressure of a refrigerant in an evaporator is high, a load of a compressor system is great
Data Source
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AI summary
Disclosed is a control method for a laundry dryer. The laundry dryer is a heat-pump laundry dryer, and a compressor is a variable-frequency compressor. According to the amount of laundry, a minimum running frequency of the compressor is set, and the more the laundry is, the greater the set minimum running frequency is. Specifically, when laundry drying is started, the amount of laundry is detected, and according to the detected information, a minimum running frequency, corresponding to the information, of the compressor, is invoked, and a minimum running frequency of the compressor of the current laundry drying process is set. In the improved control method for a compressor in a heat-pump laundry dryer of the present invention, when there is a large amount of laundry, a set minimum running frequency of the compressor is increased, so as to increase the drying temperature inside the cylinder, shorten the drying duration, and eventually achieve a more desirable laundry drying effect; when there is a small amount of laundry, because the laundry is relatively loose, the moisture inside the laundry can easily evaporate, and through comprehensive comparison of the energy consumption and drying efficiency of the compressor, a low minimum running frequency of the compressor can be set, thereby lowering energy consumption in comparison.