Hybrid Laundry Drying System for Lower Cooling-Water Use

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Laundry treatment apparatuses with circulation drying systems consume excessive cooling water due to low cooling efficiency, while those with exhaust drying systems face high energy consumption due to discharging hot air that is not efficiently reused.

Innovation Solution

A laundry treatment apparatus with a combined drying system that includes a circulation drying system and an exhaust drying system, where the exhaust duct is connected to a drain unit to prevent air discharge and a water supply system that cools the tub's inner surface during specific drum rotation phases to enhance drying efficiency and reduce water and energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a circulation drying system is used to dehumidify air, then drying efficiency is improved, but excessive cooling water is consumed due to low cooling efficiency

Engineering Contradiction:
Improvedrying efficiencyVSAvoidcooling water consumption
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent combines the circulation drying system and exhaust drying system into a hybrid configuration. The circulation system handles dehumidification while the exhaust system manages heat dissipation, merging the advantages of both systems to reduce cooling water consumption while maintaining drying efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The exhaust system recovers and reuses the hot air that would otherwise be discarded. By routing exhaust air through a heat exchanger to preheat incoming air and then releasing only the necessary portion, the system recovers thermal energy and reduces the need for continuous cooling water supply.

Inventive Principle:
Principle #34Discarding and recovering

2Productivity

If an exhaust drying system is used to supply hot air, then drying capability is improved, but excessive energy is consumed by discharging hot air without efficient reuse

Engineering Contradiction:
Improvedrying capabilityVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The exhaust system recovers and reuses the hot air that would otherwise be discarded. By routing exhaust air through a heat exchanger to preheat incoming air and then releasing only the necessary portion, the system recovers thermal energy and reduces the need for continuous heating, thereby reducing energy consumption.

Inventive Principle:
Principle #34Discarding and recovering

Solution Approach 2:

The system incorporates sensors and control mechanisms that monitor temperature, humidity, and air flow conditions. Based on this feedback, the control unit adjusts the operation of the heater, fan, and exhaust valve to optimize energy usage while maintaining effective drying capability.

Inventive Principle:
Principle #23Feedback

3Temperature

If cooling water is supplied to cool the tub inner surface, then heat exchange efficiency is improved, but water may reach and wet the laundry

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidlaundry wetting
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The cooling water supply structure is designed to apply cooling water locally to specific regions of the tub inner surface where heat exchange is most needed. The water application points and flow rates are optimized to achieve sufficient cooling without creating runoff that could reach the laundry, thus maintaining heat exchange efficiency while preventing harmful wetting.

Inventive Principle:
Principle #3Local quality

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

The combined drying system reduces energy and water consumption while maintaining high drying efficiency by controlling air flow and water usage, preventing water from reaching the laundry and optimizing heat exchange.

Implementation Method 1

a water supply unit configured to supply water to cool the inner circumferential surface of the tub

Methodology Applied
Scientific EffectHeat exchange: Conduction (thermal)

Implementation Method 2

a control unit configured to control revolutions per minute of the drum such that water supplied into the tub via the water supply unit does not reach laundry

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2843126B1Laundry treatment apparatus and control method thereof
Publication Date: 2017.11.08 LG ELECTRONICS INC
  • EP2843126B1 patent drawingFigure 1(a)~1(b)
  • EP2843126B1 patent drawingFigure 2
  • EP2843126B1 patent drawingFigure 3(a)~3(b)

AI summary

Disclosed is a control method of a laundry treatment apparatus 1, the control method including drying operation including a circulation process for resupplying air discharged from a tub 2 to the tub 2, an exhaust process for discharging some of the air supplied into the tub 2 from the tub 2, a suction process for supplying outside air of the tub 2 into air circulated via the circulation process and a heating process for heating the air to be supplied into the tub 2, and motion execution operation for rotating a drum 3 based on first motion during implementation of the drying operation, the drum 3 being rotatably placed in the tub 2 and being configured to store laundry therein.