Laundry treatment appliance comprising a controller
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Solution Overview
Problem
Laundry care appliances often heat washing liquid to temperatures higher than needed, potentially damaging sensitive textiles and failing to achieve uniform heating, leading to inefficient washing processes.
Innovation Solution
A laundry care appliance with a controller that activates a heating element to reach a target temperature, then uses a pump to circulate the heated washing liquid into the laundry drum, ensuring even temperature distribution by rotating the drum to facilitate efficient heat transfer and controlled cooling, thus maintaining a minimal temperature difference between the laundry and washing liquid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the heating element heats the washing liquid to a high temperature to ensure adequate washing, then the washing effectiveness is improved, but the risk of damaging sensitive textiles increases
Solution Approach 1:
The heating element pre-heats the washing liquid to the target temperature before the washing cycle begins. This preliminary heating action ensures that the washing liquid is already at the optimal temperature when the washing process starts, avoiding the need to overheat the liquid during washing and thereby preventing textile damage while ensuring effective washing.
Solution Approach 2:
A temperature sensor continuously monitors the temperature of the washing liquid and provides feedback to the control unit. The control unit adjusts the heating element's operation based on this feedback to maintain the washing liquid at the target temperature, preventing overheating that could damage textiles while ensuring adequate washing temperature is achieved.
2Reliability
If the heating element heats the washing liquid to a temperature above the desired laundry core temperature, then adequate washing is ensured, but uniform temperature distribution in the laundry is not achieved
Solution Approach 1:
The heating element heats the washing liquid to the target temperature before the washing cycle begins. This preliminary heating ensures uniform temperature distribution throughout the washing liquid and laundry, avoiding the need to overheat the liquid during washing which would create temperature gradients and uneven heating of the laundry.
Solution Approach 2:
The control unit periodically activates the heating element in heating phases followed by mixing phases where the pump circulates the washing liquid. This periodic heating and mixing action ensures uniform temperature distribution throughout the washing liquid and laundry, preventing localized overheating while maintaining adequate washing temperature.
3Reliability
If the heating element operates continuously to maintain high temperature, then washing effectiveness is improved, but energy consumption increases
Solution Approach 1:
The heating element operates intensively during a preliminary heating phase before the washing cycle to bring the washing liquid to the target temperature. During the subsequent washing phase, the heating element operates only intermittently or not at all, as the pre-heated washing liquid maintains adequate temperature through the washing process, significantly reducing energy consumption while preserving washing effectiveness.
Solution Approach 2:
The control unit implements periodic heating phases followed by washing phases where heating is reduced or stopped. This periodic operation pattern allows the washing liquid to maintain adequate temperature through thermal inertia and pump circulation, reducing overall energy consumption while ensuring effective washing during the active washing phases.
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 uniform heating of laundry, reduces the risk of textile damage, shortens washing times, meets hygiene requirements, and enhances laundry care success by maintaining consistent temperatures throughout the process.
Implementation Method 1
washing liquid in a tub of the laundry care appliance is heated by a heating element
Implementation Method 2
a pump which is designed to pump washing liquid through the drain opening into the liquid line and to supply the pumped-out washing liquid through the inlet opening again to the tub
Implementation Method 3
the laundry drum is rotated by the drum drive, so that the washing liquid introduced by the pumping process hits the laundry and, due to the centrifugal force caused by the rotation of the laundry drum, penetrates the laundry and effectively wets it
Implementation Method 4
the washing liquid introduced by the pumping process hits the laundry and, due to the centrifugal force caused by the rotation of the laundry drum, penetrates the laundry and effectively wets it. This ensures efficient heat transfer from the heated washing liquid to the laundry
Data Source
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AI summary
The present invention relates to a laundry treatment appliance (100) comprising a washing tub (105) for receiving wash liquid, wherein the washing tub (105) has an outlet opening (111) and an inlet opening (113) which are fluidically connected by a liquid line (115), a laundry drum (107) for receiving laundry, a drum drive (123) for rotating the laundry drum (107), a temperature sensor for detecting a temperature of wash liquid in the washing tub (105), a heating element for heating the wash liquid, a pump (117) which is designed to pump away wash liquid through the outlet opening (111) into the liquid line (115) and to once again feed the pumped-away wash liquid through the inlet opening (113) to the washing tub (105) in order to wet the laundry in the laundry drum (107), and a controller (119) for controlling the pump (117), the drum drive (123) and the heating element during a washing process (144). The controller (119) is designed to activate the heating element during a heating phrase (145) of the wash process (144) until the detected temperature of the wash liquid in the washing tub (105) reaches a target temperature value (146). The controller (119) is designed to activate the drum drive (123) during a thorough-mixing phase (147) of the wash process (144), which thorough-mixing phase follows the heating phase (145), in order to rotate the laundry drum (107), and to activate the pump (117) in order to transfer the wash liquid by pumping and to wet the laundry which is accommodated in the laundry drum (107) with the heated wash liquid which is transferred by pumping, wherein the controller (119) is designed to determine a first temperature value at the beginning of a reference time period (153) of the thorough-mixing phase (147) and a second temperature value at the end of the reference time period (153) of the thorough-mixing phase (147), wherein the controller (119) is designed to terminate the thorough-mixing phase (147) when the temperature difference between the first temperature value and the second temperature value falls below a temperature threshold value in order to ensure a uniform temperature distribution in the wash liquid and in the laundry.