Dryer Condensing Air Channel Control for Cooling Water Retention

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Solution Overview

Problem

Laundry dryers inefficiently utilize cooling water during the heat exchange process, leading to wasted resources due to low cooling efficiency.

Innovation Solution

A control method for the condensing apparatus in laundry dryers, which adjusts the fan's rotational speed and water supply to optimize water retention and discharge within the air channel, enhancing heat exchange efficiency without altering the structure, using distinct parameters to manage airflow and water usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the fan drives airflow upward with high rotational speed, then heat exchange efficiency is improved, but water is discharged from the air channel causing resource waste

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidwater discharge
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent applies dynamics by making the fan rotational speed adjustable rather than fixed. The control apparatus dynamically changes the fan's rotational speed between a first speed (for heat exchange) and a second speed (for water discharge prevention), allowing the system to adapt its operation mode based on the required function.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameter (rotational speed) of the fan to resolve the contradiction. By switching between different rotational speed parameters, the system can optimize for either heat exchange efficiency or water retention in the air channel, thereby preventing resource waste while maintaining effective heat exchange when needed.

Inventive Principle:
Principle #35Parameter changes

2Loss of substance

If the fan rotational speed is reduced to retain water in the air channel, then water resource utilization is improved, but heat exchange efficiency decreases

Engineering Contradiction:
Improvewater retentionVSAvoidheat exchange efficiency
Core Design Contradiction:
Loss of substanceVSProductivity

Solution Approach 1:

The system dynamically adjusts fan speed based on operational requirements. When water retention is prioritized, the fan operates at reduced speed to minimize water discharge. When heat exchange efficiency is prioritized, the fan speed increases to enhance airflow and heat transfer, demonstrating dynamic adaptation between conflicting objectives.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control apparatus implements periodic switching between different fan speed modes. The fan alternates between first rotational speed (optimized for heat exchange) and second rotational speed (optimized for water retention), creating a periodic action pattern that balances both competing requirements over time.

Inventive Principle:
Principle #19Periodic action

3Reliability

If cooling water temperature increases after heat exchange, then cooling effect is reduced, but continuing to use the same water causes waste

Engineering Contradiction:
Improvecooling effectVSAvoidwater waste
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The control apparatus monitors cooling water temperature and uses this feedback to determine when to switch fan speeds. When the water temperature reaches a threshold indicating reduced cooling effectiveness, the system responds by adjusting fan operation to prevent further water waste, thereby maintaining reliability while avoiding unnecessary resource consumption.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes operational parameters based on water temperature conditions. When cooling water temperature increases and cooling effect diminishes, the fan speed parameter is adjusted to prioritize water retention, preventing waste of partially depleted cooling resources while maintaining system reliability.

Inventive Principle:
Principle #35Parameter changes

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

Improves cooling water efficiency by ensuring full heat exchange and reducing water waste, while maintaining operational efficiency and reducing noise through controlled fan operation.

Implementation Method 1

a first parameter is set to controlling a lifting force that is generated when the fan drives an airflow to move upward

Methodology Applied
Scientific EffectLifting force generation through airflow: Bernoulli Effect

Implementation Method 2

water after heat exchange still has relatively low temperature when the water is discharged

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

By condensation of the condensing apparatus, moisture in the wet hot air is condensed into water

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

the second parameter is set to controlling the fan to reduce a rotational speed, to reduce the lifting force that is generated when the airflow is driven to move upward, so that most of the water is discharged from the air channel

Methodology Applied
Scientific EffectLifting force reduction through rotational speed control: Bernoulli Effect

Data Source

PatentEP3124686B1Laundry dryer having a condensing apparatus and control method for said condensing apparatus
Publication Date: 2018.11.28 BSH HAUSGERATE GMBH
  • EP3124686B1 patent drawingFigure 1
  • EP3124686B1 patent drawingFigure 2A~2C

AI summary

The present invention discloses a control method for a condensing apparatus (7) of a laundry dryer (1), wherein the laundry dryer (1) comprises a drying drum (6) and a condensing apparatus (7), wherein the condensing apparatus (7) has an air channel (9), a water supply apparatus (20) connected to the air channel (9), and a fan (11) for forcing wet hot air to pass through the air channel (9); and a control apparatus (100) for controlling running of the fan (11). The control method comprises: Supplying, by the water supply apparatus (20), water to the air channel (9), and setting, by the control apparatus (100), a first parameter and a second parameter to control the running of the fan (11), wherein the first parameter is set to controlling a lifting force that is generated when the fan (11) drives an airflow to move upward, so that most of the water remains in the air channel (9), and the second parameter is set to controlling the fan (11) to reduce a rotational speed, to reduce the lifting force that is generated when the airflow is driven to move upward, so that most of the water is discharged from the air channel (9). The invention also discloses a laundry dryer (1) implementing such method. By means of the invention it is ensured that cooling water is efficiently used, so that water resource is saved. Moreover, noise of a machine is also reduced because of reduction of an average air volume of a fan (11).