Dishwasher Wash Cycle Control for Variable Inlet Water Temperature

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Solution Overview

Problem

Conventional dishwashers achieve optimal cleaning and drying effects only under standard conditions, leading to inefficiencies and unsatisfactory results when operated under different environmental conditions, due to the dependence of wash cycle parameters on inlet water temperature.

Innovation Solution

The dishwasher's sequence control device adapts parameters of washing programs based on the inlet water temperature, ensuring consistent cleaning and drying effects across varying temperatures, allowing connection to different water sources without compromising efficiency or washing results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the dishwasher operates with fixed wash cycle parameters, then the device complexity is reduced and ease of operation is improved, but the washing result becomes unsatisfactory when operated under different environmental conditions (inlet water temperatures)

Engineering Contradiction:
Improveease of operationVSAvoidwashing result
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies dynamics by making the wash cycle parameters adaptive rather than fixed. The sequence control device automatically adjusts parameters such as heating duration, circulation time, and spray intensity based on detected inlet water temperature, allowing the system to optimize performance for each specific operating condition while maintaining simple user operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback through a temperature sensor that continuously monitors inlet water temperature and feeds this information back to the sequence control device. The control device then uses this feedback to automatically adjust wash cycle parameters, ensuring consistent washing results across varying environmental conditions without requiring user intervention.

Inventive Principle:
Principle #23Feedback

2Reliability

If the dishwasher adapts wash cycle parameters to inlet water temperature, then the washing result remains satisfactory under varying conditions, but the device complexity increases due to additional sensors and control logic

Engineering Contradiction:
Improvewashing resultVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sequence control device serves multiple functions: it manages the overall wash cycle sequence, detects inlet water temperature through an integrated sensor, processes temperature data, and automatically adjusts multiple wash parameters. This multi-functionality consolidates what could be separate complex systems into a single integrated control unit, minimizing additional complexity while achieving adaptive performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system performs self-service by automatically detecting inlet water temperature and adjusting its own operating parameters without external intervention. The sequence control device autonomously modifies heating duration, circulation pump speed, and spray intensity based on real-time temperature measurements, eliminating the need for manual user adjustments or complex external control systems.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If the dishwasher uses standard wash cycle parameters, then energy consumption is predictable and ease of operation is maintained, but energy efficiency decreases when operated with non-standard inlet water temperatures

Engineering Contradiction:
Improveease of operationVSAvoidenergy efficiency
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting wash cycle parameters based on inlet water temperature. When cold water is detected, the system extends heating duration and increases heating power; when warm water is detected, it reduces heating time and intensity. This automatic parameter adaptation optimizes energy efficiency for each specific temperature condition while maintaining consistent washing quality and requiring no user input.

Inventive Principle:
Principle #35Parameter changes

4Device complexity

If the dishwasher operates without parameter adaptation, then the device complexity is reduced, but the adaptability to different water sources and environmental conditions is limited

Engineering Contradiction:
Improvedevice complexityVSAvoidadaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system uses feedback from a temperature sensor to automatically adapt to different water sources and environmental conditions. The sensor continuously monitors inlet water temperature, and the sequence control device uses this information to adjust wash cycle parameters, enabling the dishwasher to effectively operate with various water sources (municipal supply, well water, recycled water) without requiring manual configuration or complex user setup procedures.

Inventive Principle:
Principle #23Feedback

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 adaptation maintains a satisfactory washing result while improving energy, time, and operating cost efficiency, ensuring efficient operation regardless of inlet water temperature, from 10°C to 60°C, and enabling connection to both cold and hot water sources.

Implementation Method 1

an electrical heating device is arranged in the circulation circuit, which makes it possible to bring the washing water to a specified temperature during washing

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

a circulating pump, which makes it possible to spray the washing water collecting in a lower area of the washing compartment onto the items to be washed via a spray device

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 3

the dishwasher has a drain pump, which makes it possible to pump out rinse water that is no longer required

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 4

a sensor for the temperature of the washing water is also provided

Methodology Applied
Scientific EffectTemperature sensing:

Implementation Method 5

The rinsing water then returns to the lower area of the rinsing container due to its gravity

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2228001B1Dishwasher
Publication Date: 2018.04.18 BSH HAUSGERATE GMBH
  • EP2228001B1 patent drawingFigure 1
  • EP2228001B1 patent drawingFigure 2
  • EP2228001B1 patent drawingFigure 3

AI summary

The dishwasher has a connecting device for receiving the inlet water and has a cycle controlling device, with which one or multiple rinsing cycles (PNS) are stored for controlling the process (A) of one or more rinsing cycles. The cycle controlling device is formed for adjusting a parameter (D,Z2,Z4,TRG,TKG) of one of the rinsing cycles at a temperature (TFW) of the inlet water.