Heat Pump Dryer Compressor Frequency Control for Time-Energy Tradeoffs
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Solution Overview
Problem
Conventional clothes dryers with heat pumps face a challenge in achieving a balance between reducing drying time and electric power consumption, as these factors often conflict with each other.
Innovation Solution
A clothes dryer with a variable frequency drive for the compressor, allowing for a fast-drying course with higher frequency for quicker drying and an economy course with lower frequency for reduced power consumption, while maintaining a higher coefficient of performance in the economy course to enhance efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the compressor operates at higher drive frequency to reduce drying time, then the drying speed increases, but the electric power consumption increases
Solution Approach 1:
The patent applies dynamics by making the compressor's drive frequency variable rather than fixed. The control device dynamically adjusts the compressor's operating frequency based on real-time detection of drying conditions (such as temperature and humidity sensors), allowing the system to optimize between drying speed and energy consumption during different phases of the drying process.
Solution Approach 2:
The patent implements parameter changes by varying the drive frequency of the compressor as a controllable parameter. The system changes the operational parameters (frequency, temperature, humidity) based on detected drying conditions, enabling flexible adjustment between fast-drying mode (higher frequency) and energy-saving mode (lower frequency) to resolve the contradiction between drying time and power consumption.
2Use of energy by moving object
If the compressor operates at lower drive frequency to reduce electric power consumption, then the energy efficiency improves, but the drying time increases
Solution Approach 1:
The system dynamically adjusts the compressor frequency based on real-time drying conditions. When energy efficiency is prioritized, the control device operates the compressor at lower frequencies, and when drying speed is needed, it increases the frequency, making the system adaptable to different user needs and environmental conditions.
Solution Approach 2:
The patent changes the operational parameters of the compressor (drive frequency) based on detected drying conditions. By adjusting this key parameter, the system can operate in different modes (economy mode with lower frequency for energy saving, or accelerated mode with higher frequency for faster drying) to balance energy consumption and drying time according to specific requirements.
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 enables better compatibility between time and energy savings for both drying courses, with the fast-drying course completing faster and the economy course using less power, and achieving higher energy efficiency.
Implementation Method 1
The evaporator and the condenser are connected to the compressor and the throttle so that the heat pump constitutes a refrigeration cycle which circulates refrigerant through the compressor, the condenser, the throttle and the evaporator
Implementation Method 2
moisture evaporated by drying the laundry is condensed by the evaporator
Implementation Method 3
moisture evaporated by drying the laundry is condensed by the evaporator
Implementation Method 4
Latent heat obtained by moisture condensation is used for the heating of refrigerant in a compressor
Implementation Method 5
Heat of the heated refrigerant is applied to air flowing through the air flow passage, by the condenser
Implementation Method 6
Air flowing through the air flow passage is cooled and dehumidified by the evaporator
Data Source
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AI summary
A clothes dryer provided with washing tub, an air circulator and a heat pump and drying laundry by operation of the air circulator and the heat pump. The rotational speed of a compressor is changed by controlling frequency, and the clothes dryer can be operated by selection of either a quick-drying mode for drying the laundry in a relatively short time by changing a drive frequency of the compressor or a saving mode for drying the laundry in a time longer than the time of the quick-drying mode. In the saving mode, the compressor is driven in a frequency band providing a high coefficient of performance.