Heat Pump Dryer Filter Plugging Detection by Temperature Ratio
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Solution Overview
Problem
Heat pump cycle type laundry drying machines face challenges in sensing filter plugging due to minimal temperature changes, leading to reduced drying performance, as existing methods relying on temperature differences are not applicable and cannot effectively detect filter blockages.
Innovation Solution
Incorporating first and second temperature sensors to measure the compressor outlet temperature and drum outlet temperature, respectively, and using a controller to determine filter plugging based on a temperature difference, with notification for cleaning and compressor control to address the issue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature sensors are used to detect filter plugging in heat pump cycle type laundry drying machines, then filter plugging can be sensed, but the temperature difference is relatively small making it difficult to sense plugging accurately
Solution Approach 1:
The patent changes the detection parameter from temperature difference to temperature ratio. By calculating the ratio between the first temperature (compressor outlet) and the second temperature (drum outlet), the system can accurately detect filter plugging even when the absolute temperature difference is small. This parameter transformation resolves the contradiction by making the detection method sensitive to plugging conditions without requiring large temperature differences.
2Measurement precision
If continuous temperature sensing is performed to detect filter plugging, then accurate detection is achieved, but power consumption increases
Solution Approach 1:
The patent implements periodic temperature sensing instead of continuous sensing. The controller measures temperatures at specific intervals during the drying cycle and only performs plugging detection when necessary. This periodic approach maintains adequate detection accuracy while significantly reducing power consumption compared to continuous monitoring.
Solution Approach 2:
By changing from temperature difference comparison to temperature ratio calculation, the system achieves more sensitive detection with less frequent measurements. The ratio-based method can detect plugging conditions more reliably, allowing the system to reduce sensing frequency while maintaining detection accuracy, thereby lowering power consumption.
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
Accurate sensing and notification of filter plugging prevent reduced drying performance by allowing timely filter cleaning, while minimizing power consumption through specific criterion-based sensing.
Implementation Method 1
the compressor is driven to allow a refrigerant to be circulated by undergoing compression, condensation, expansion, and evaporation operations
Implementation Method 2
the compressor is driven to allow a refrigerant to be circulated by undergoing compression, condensation, expansion, and evaporation operations
Implementation Method 3
the compressor is driven to allow a refrigerant to be circulated by undergoing compression, condensation, expansion, and evaporation operations
Implementation Method 4
air flowing in the interior of the dry drum is heated at a high temperature by heat emitted from the compressor
Data Source
AI summary
Disclosed is a control method for a laundry drying machine. The control method includes driving a compressor configuring the heat pump cycle for generation of heated air, sensing a compressor outlet temperature (TE) and a drum outlet temperature (TD), and determining plugging of a filter, based on a difference between the compressor outlet temperature (TE) and the drum outlet temperature (TD).