Dishwasher and control method thereof

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Solution Overview

Problem

Existing dishwashers face inefficiencies in drying cycles due to reliance on separate heating and ventilation systems, which can fail, leading to deteriorated drying performance and safety concerns when high-temperature water vapor is released.

Innovation Solution

A dishwasher with a control method that uses temperature sensors to monitor air temperature changes, determining the operational status of the supply fan and heater, and adjusting valves to maintain safe discharge temperatures, while also supplying heated outdoor air for improved drying.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high-temperature water vapor is supplied to dry dishes, then drying speed is improved, but safety risk increases due to high discharge temperature

Engineering Contradiction:

Improvedrying speedVSAvoidsafety risk from high discharge temperature

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically adjusts the discharge air temperature parameter by controlling the mixing ratio between high-temperature exhaust air and ambient air. The controller regulates the discharge fan speed and opening degree of the discharge port to maintain temperature within a safe range (below 60°C) while preserving drying effectiveness through rapid vapor removal.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Ambient air acts as an intermediary substance that is introduced into the tub to mix with high-temperature water vapor. This intermediary ambient air absorbs excess heat from the vapor through convection and mixing, reducing the temperature of discharged air while maintaining the drying function by facilitating moisture removal.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If separate heating and ventilation systems are used, then drying function is achieved, but system reliability deteriorates due to component failure

Engineering Contradiction:

Improvedrying functionVSAvoidcomponent failure risk

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The heating and ventilation functions are merged into a single integrated drying system. The exhaust fan simultaneously performs ventilation by removing moist air and heating by facilitating the drying process through controlled air circulation. This integration reduces the number of separate components that could fail independently, improving overall system reliability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The exhaust fan is designed to perform multiple functions: ventilation (removing moist air), heating (facilitating heat distribution), and drying (accelerating moisture removal). This multi-functionality reduces dependency on separate dedicated components for each function, thereby improving system reliability by minimizing the number of potential failure points.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If door is kept open after operation, then drying is completed, but user convenience deteriorates

Engineering Contradiction:

Improvedrying completionVSAvoiduser convenience

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The drying system operates autonomously to complete the drying process without requiring user intervention to open the door. The controller automatically manages the exhaust fan operation, ambient air introduction, and discharge temperature control to achieve thorough drying while the door remains closed, thereby maintaining user convenience.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The drying process continues effectively with the door closed by maintaining continuous operation of the exhaust fan and controlled introduction of ambient air. This continuous useful action achieves complete drying without interrupting the cycle to open the door, preserving user convenience while ensuring drying completion.

Inventive Principle:

Principle #20Continuity of useful action

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 solution enables rapid and efficient drying by accurately identifying component failures, ensuring safe operation, and minimizing drying time by using outdoor air for drying, thus enhancing overall performance and user convenience.

Implementation Method 1

operating a heater disposed in the heating duct

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

detecting a temperature of air supplied to a tub through a heating duct by a temperature sensor

Methodology Applied

Scientific EffectTemperature detection: Thermocouple

Data Source

PatentUS20240041294A1Dishwasher and control method thereof

Publication Date: 2024.02.08 LG ELECTRONICS INC

AI summary

The present disclosure relates to a method of controlling a dishwasher. The method of controlling a dishwasher of the present disclosure includes steps of: detecting a temperature of air supplied to a tub through a heating duct by a temperature sensor; operating a supply fan which supplies outdoor air to the heating duct; operating a heater disposed in the heating duct; determining whether the supply fan and the heater are normally operating; and determining that the supply fan and the heater are normally operating, when a temperature change detected by the temperature sensor is within a first set range.