Heat-Pump Dryer Compressor Frequency Control for Variable Loads
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Solution Overview
Problem
Existing heat-pump laundry dryers face challenges in efficiently managing power consumption and drying time due to the inability to adjust compressor frequency beyond a preset minimum, especially when the amount of clothes varies, leading to inconsistent drying performance 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 clothes, increasing the minimum running frequency for larger loads to enhance drying efficiency and reducing it for smaller loads to minimize power consumption, by detecting clothes quantity through various methods such as weight change, temperature differences, or humidity levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If the compressor runs at a fixed minimum frequency regardless of load size, then the drying process is simple to control, but energy consumption increases and drying efficiency decreases for small loads
Solution Approach 1:
The patent implements dynamic adjustment of the compressor's minimum running frequency based on the detected amount of clothes. The control system dynamically sets different minimum frequencies (e.g., 20Hz for small loads, 30Hz for medium loads, 40Hz for large loads) rather than using a fixed frequency, allowing the system to adapt to varying load conditions and optimize energy consumption accordingly.
Solution Approach 2:
The patent changes the operational parameters of the compressor by adjusting its minimum running frequency according to the clothes load. The control system modifies the frequency parameter based on detected load size, enabling the compressor to operate at optimal frequencies for different drying scenarios, thereby reducing energy waste on small loads while maintaining efficiency on large loads.
2Use of energy by stationary object
If the compressor frequency is reduced for small loads to save energy, then power consumption decreases, but drying time increases
Solution Approach 1:
The system dynamically adjusts the compressor frequency based on real-time detection of clothes amount. For small loads, it sets a lower minimum frequency (20Hz) to reduce energy consumption, while for large loads, it sets a higher minimum frequency (40Hz) to maintain efficient drying speed, thus balancing energy savings with drying time requirements.
Solution Approach 2:
The control system changes the compressor's operating frequency parameter according to the detected load size. By setting appropriate minimum frequencies for different load categories, the system optimizes the balance between energy consumption and drying time, preventing excessive energy use on small loads while ensuring timely drying of large loads.
3Productivity
If the compressor runs at high frequency for all loads, then drying efficiency is maintained, but energy consumption increases unnecessarily for small loads
Solution Approach 1:
The patent implements a dynamic control strategy where the compressor's minimum running frequency is adjusted according to the detected clothes load. Small loads receive a lower minimum frequency (20Hz) to reduce energy consumption, while large loads receive a higher minimum frequency (40Hz) to maintain high drying efficiency, thus avoiding unnecessary energy waste.
Solution Approach 2:
The control system modifies the compressor's frequency parameter based on the amount of clothes detected. By setting different minimum frequencies for different load sizes, the system ensures that drying efficiency is maintained for large loads while significantly reducing energy consumption for small loads, achieving an optimal balance between productivity and energy use.
4Ease of operation
If the minimum running frequency is fixed, then the control system is simple, but drying performance becomes inconsistent for varying amounts of clothes
Solution Approach 1:
The patent transitions from a static fixed-frequency control system to a dynamic adaptive control system. The compressor's minimum running frequency is automatically adjusted based on the detected clothes load, ensuring consistent and reliable drying performance across different load sizes while maintaining reasonable control system complexity through automated detection and adjustment.
Solution Approach 2:
The control system dynamically changes the compressor's operating frequency parameter according to the detected load size. This parameter adjustment ensures that the drying performance remains consistent and reliable whether the drum contains a small, medium, or large amount of clothes, eliminating the performance inconsistency that would result from using a fixed minimum frequency.
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 allows for optimized drying time and reduced power consumption by dynamically adjusting compressor frequency according to the amount of clothes, improving drying efficiency and energy usage.
Implementation Method 1
a heat pump circulation system... an evaporator for dehumidification... a condenser... heated air heated by a condenser
Data Source
AI summary
The present invention relates to a control method for a laundry dryer. The laundry dryer is a heat-pump type laundry dryer and a compressor of the laundry dryer is a variable-frequency compressor. The control method includes setting a minimum running frequency of the compressor according to an amount of clothes to be dried, where the more the clothes are, the larger the set minimum running frequency is. Specifically, when laundry drying is started, the amount of the clothes being dried is detected. According to the detected information, a minimum running frequency of the compressor, corresponding to the information, is invoked, and the minimum running frequency of the compressor in the current laundry drying process is set.