Heating device for heating fluids and a method for operating such a heating device
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Solution Overview
Problem
Existing heating devices for fluids lack reliable detection of local overheating, which can lead to damage due to the absence of effective temperature monitoring over large areas, especially at critical temperatures above 200°C to 300°C.
Innovation Solution
A heating device with a planar support featuring distributed heating elements and a temperature sensor device with an electrically insulating sensor layer and two sensor electrodes, allowing for the detection of local excess temperatures and providing increased failsafety by monitoring the area for overheating, even if one electrode fails.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single sensor electrode is used to detect overheating, then the device complexity is reduced, but the reliability decreases due to single point of failure
Solution Approach 1:
The patent implements a sensor electrode system with redundant detection capability where at least one sensor electrode extends beyond the heating element area. This over-extension creates a safety margin that cushions against detection failures, ensuring that overheating cannot go undetected even if part of the sensor electrode is compromised or if the heating element extends slightly beyond expected boundaries.
Solution Approach 2:
The sensor electrode is divided into multiple segments: a first portion that extends beyond the heating element in a first direction and a second portion that extends beyond the heating element in a second direction. This segmentation allows different portions of the sensor electrode to monitor different areas, providing comprehensive coverage and redundant detection pathways that improve reliability without requiring a fully symmetric complex configuration.
2Area of stationary object
If the sensor electrode is extended beyond the heating element area, then the detection coverage is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The sensor electrode exhibits local quality variations along its length, with different portions serving different functions. The portions extending beyond the heating element in first and second directions have different orientations and coverage areas, allowing each local region to be optimized for its specific monitoring task rather than requiring uniform precision throughout the entire sensor electrode structure.
Solution Approach 2:
The sensor electrode configuration embraces asymmetry rather than requiring symmetric extension in all directions. The first and second portions extend in different directions with potentially different lengths and orientations, allowing the system to achieve comprehensive monitoring coverage with more practical manufacturing tolerances rather than demanding perfect symmetric positioning.
3Measurement precision
If discrete temperature sensors are used instead of a sensor layer, then the measurement precision at specific points is improved, but the device complexity and cost increase
Solution Approach 1:
The patent replaces a system of multiple discrete temperature sensors with a continuous sensor electrode that functions as both the sensing element and the structural component. This substitution eliminates the need for separate sensor mounting structures, wiring harnesses, and individual sensor housings, significantly reducing device complexity while maintaining adequate measurement precision through the continuous nature of the sensor electrode.
Solution Approach 2:
The sensor electrode serves multiple functions simultaneously: it acts as the heating element support structure, the temperature sensing element, and the electrical connection pathway. This multi-functionality eliminates the need for separate discrete temperature sensors and their associated mounting and wiring infrastructure, reducing overall device complexity while providing comprehensive temperature monitoring.
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 solution enables reliable detection and prevention of overheating, ensuring the heating device's safety and longevity by accurately monitoring temperature changes across its surface, reducing the risk of damage from localized hotspots.
Implementation Method 1
The sensor layer has the aforementioned temperature-dependent properties with regard to its electrical resistance
Implementation Method 2
heating elements are arranged in a distributed manner on the surface of the carrier
Data Source
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AI summary
A heating device for heating liquids has: a flat carrier with a surface on which heating elements are arranged in a distributed manner and are divided into several heating circuits that can be operated separately from one another, a temperature sensor device with a sensor layer that covers the surface of the heating elements, with the sensor layer, at least two sensor electrodes are applied in an electrode layer, which are electrically separated from one another and have finger-like or coil-like sensor electrode sections that run at a distance of less than 2 cm from one another, with the width of each two sensor electrode sections arranged next to each other being less than 2 cm, and one Control device for evaluating the temperature sensor device.