Water level sensor for steam generator

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Solution Overview

Problem

Conventional water level sensors in steam generators of drum washing machines malfunction due to electrical connections between electrodes caused by water permeation and short distances, leading to overheating and potential fires, as well as economic losses from excessive energy consumption.

Innovation Solution

A separation-type water level sensor with a common electrode assembly and a first water level electrode assembly, each housed separately, prevents electrical connections and uses voltage values to sense water levels, with the first water level electrode sensing when the heater is exposed and the second water level electrode sensing the maximum water level, ensuring accurate water level detection and preventing overheating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If electrodes are placed close together in a conventional water level sensor, then the device complexity is reduced, but electrical connections between electrodes occur due to water permeation causing sensor malfunction

Engineering Contradiction:

Improvestructure complexityVSAvoidsensor reliability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The water level sensor is divided into multiple independent electrode assemblies, each with its own housing. The first water level electrode assembly and second water level electrode assembly are separated by a predetermined distance, preventing water film formation between electrodes while maintaining structural organization through modular design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A common electrode housing serves as an intermediary structure that houses both the common electrode and provides electrical connection terminals. This housing acts as a barrier preventing direct water contact between electrodes while facilitating proper electrical connections to the controller

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If water level sensing is implemented to prevent heater overheating, then the heater protection function is improved, but sensor malfunction due to water permeation causes false readings and continuous heating

Engineering Contradiction:

Improveheater overheating preventionVSAvoidwater level detection accuracy

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The electrodes are pre-positioned at specific heights relative to the heater, with the first water level electrode positioned to detect when water covers the heater and the second electrode positioned to detect maximum water level. This preliminary positioning ensures the heater is protected before overheating occurs

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The conventional mechanical/electrical contact-based water level sensing is replaced with an electrical field-based sensing system where voltage values are measured between electrodes. This substitution eliminates mechanical wear and reduces susceptibility to water film interference

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If multiple electrodes are installed at different heights for accurate water level detection, then measurement precision is improved, but the risk of electrical connection and short circuit increases

Engineering Contradiction:

Improvewater level detection precisionVSAvoidelectrical short circuit risk

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

Multiple electrode assemblies are segmented into separate housings positioned at different heights. The first water level electrode assembly and second water level electrode assembly are separated by a predetermined distance, with each assembly independently housed to prevent electrical short circuits while maintaining precise water level detection capability

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Housing structures with sealing elements are used to enclose electrode assemblies and prevent water permeation. These flexible sealing elements create barriers that prevent water film formation between electrodes while allowing the sensor to function in wet environments

Inventive Principle:

Principle #30Flexible shells and thin films

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 separation of electrodes and use of voltage sensing prevents sensor malfunctions, avoids water film formation, and ensures safe and efficient operation by accurately maintaining the water level, preventing heater overheating and energy wastage.

Implementation Method 1

a water level sensor for a steam generator... sensing a water level... uses voltage values of the first water level electrode

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP1883728B1Water level sensor for steam generator

Publication Date: 2017.08.02 LG ELECTRONICS INC

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AI summary

A separation-type water level sensor, and a steam generator (15) of a washing drying machine having the same. The steam generator (150) includes a case storing water for generating steam; and a separation-type water level sensor comprising a common electrode assembly (160) comprising a water common electrode (162) and a common electrode housing (161 ), and inserted into the case; and a first water level electrode assembly (170) comprising a first water level electrode (172) and a first water level electrode housing (171), separated form the common electrode assembly (160), and inserted into the case.