Clothes Dryer Dryness Detection Using Surface Temperature Difference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional clothes dryers struggle with uneven drying times and energy inefficiency when drying clothes indoors, as they inaccurately determine dryness levels and fail to optimize heating times, leading to over-drying or under-drying of clothes.
Innovation Solution
A control method that measures the difference in surface temperature of clothes when air is blown and when it is not, to accurately determine dryness levels and predict drying times, using a blower, surface temperature sensor, absolute humidity sensor, and a controller to adjust heating accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the clothes dryer runs until the clothes requiring the longest drying time are dried, then all clothes can be dried, but other clothes requiring shorter drying time are over-dried and energy is wasted
Solution Approach 1:
The system uses surface temperature sensors to continuously monitor the temperature of clothes during drying. By detecting temperature changes, the controller determines the drying status of each piece of clothes and adjusts the heating operation accordingly, preventing over-drying and energy waste while ensuring all clothes are properly dried
Solution Approach 2:
The drying system dynamically adjusts the heating operation based on real-time drying status detection. The controller modifies heating power and duration for different pieces of clothes according to their individual drying progress, transitioning from a static fixed-time drying approach to a dynamic adaptive drying process
2Extent of automation
If conventional dry-control method uses surface temperature sensor to determine dryness, then drying control is automated, but the method erroneously determines wet clothes as dried when clothes get radiation heat such as sun light
Solution Approach 1:
The system performs periodic temperature measurements by alternating between blowing air to the clothes and not blowing air. By comparing temperature changes during these periodic cycles, the system can distinguish between temperature changes caused by radiation heat and those caused by evaporation, improving dryness detection accuracy
Solution Approach 2:
The air blowing function serves as an intermediary to create a controlled thermal environment. By blowing air to the clothes, the system enhances evaporative cooling effect, making the temperature difference between wet and dry clothes more pronounced and easier to detect accurately
3Loss of energy
If the clothes dryer blows air periodically to a large amount of clothes hung on a broad line, then energy consumption is reduced, but the drying time is prolonged because airflow speed to the washing is low
Solution Approach 1:
The system dynamically adjusts airflow distribution based on real-time detection of drying status across different areas. The controller increases airflow speed and concentration to areas where clothes are still wet, while reducing airflow to areas that are already dry, optimizing both energy consumption and drying time
Solution Approach 2:
The drying system applies different airflow characteristics to different spatial locations based on local drying needs. By directing higher velocity airflow to areas with wet clothes and lower velocity to areas that are drying well, the system achieves uniform drying across the entire load without excessive energy 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
This method ensures clothes are dried efficiently and within the desired time frame, saving energy by preventing over-drying and ensuring clothes are dry when the user wants them to be.
Implementation Method 1
surface temperature sensor 105 senses a temperature on the surface of the clothes
Implementation Method 2
circulation blower 101 sucks the air in the bath, and heats the air, then blows the heated air into the bath again
Implementation Method 3
heater 103
Data Source
AI summary
A control method for drying clothes is disclosed. The method finds a difference in surface temperature between clothes catching air blow and the same clothes catching no air blow, and then determines a degree of dryness in the clothes based on the difference. Based on the degree of dryness, the method determines at what time heating should start.