Asymmetric Flow Sensor Pair for Contamination Detection
Solution Overview
Problem
Existing flow measurement systems in devices like heating and air conditioning units, particularly those operated with fuel gas, struggle to detect and compensate for contamination and long-term changes without recalibration, as they rely on identical sensors which cannot differentiate between shared contamination and other errors like linearity or gain drift.
Innovation Solution
Implementing two independent measuring systems with different tendencies to become dirty, where one sensor is in a bypass line and the other in a branch line, allowing for comparison of their measurements to identify deviations and output error logs or shutdown signals, enabling detection of contamination and drift through evaluation electronics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If identical sensors are installed in duplicate for redundancy, then sensor failure can be compensated, but contamination and long-term changes cannot be detected
Solution Approach 1:
The patent applies asymmetry by using two different sensor types (e.g., thermal sensor and differential pressure sensor) instead of identical sensors. This asymmetric configuration allows the sensors to respond differently to contamination, enabling detection through comparison of their divergent measurement behaviors while still providing redundancy for failure compensation.
2Measurement precision
If regular calibration and maintenance are performed, then measurement accuracy is maintained, but operational continuity is interrupted
Solution Approach 1:
The system performs self-service by continuously monitoring its own sensor health through comparison of measurements from two different sensor types. The contamination detection mechanism automatically identifies when sensors are degrading, allowing the system to maintain measurement accuracy without external calibration or maintenance interventions, thus ensuring continuous operation.
3Device complexity
If two identical sensors are used in identical configuration, then system complexity is reduced, but ability to detect contamination in both sensors is lost
Solution Approach 1:
The patent resolves this contradiction by using asymmetric sensor configurations (different sensor types or different installation positions) rather than identical sensors. This increases the ability to detect contamination through comparative analysis while maintaining manageable system complexity through the use of standard sensor technologies and straightforward comparison logic.
4Measurement precision
If sensors are placed in different locations to detect contamination, then contamination detection is enabled, but wiring complexity increases
Solution Approach 1:
The patent applies merging by housing both sensors and their associated electronics together in a common casing or on a common circuit board. This integration reduces wiring complexity by minimizing the distance and number of connections required, while still allowing the sensors to be positioned in different locations relative to the gas flow path for effective contamination detection.
Data Source
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AI summary
The invention relates to an arrangement for measuring a flow parameter on or in a device (1) through which a fluid flows by means of electronic sensors (2, 3), wherein the flow parameter is determined directly or indirectly by at least two independent measuring systems (S1, S2) and wherein the two measuring systems (S1, S2) are designed such that they differ in at least one of the following properties: type of sensor (2, 3), installation position, tendency to become dirty, long-term behavior.The invention also relates to a method for measuring a flow parameter on or in a device (1) through which a fluid flows, using electronic sensors (2, 3), in particular with an arrangement according to one of the preceding claims, wherein the flow parameter is determined directly or indirectly by at least two independent measuring systems (S1, S2), and wherein the measured values of the flow parameter and/or their temporal behavior are compared with one another in order to draw conclusions about contamination and/or temporal drift behavior of gain, linearity, and/or zero point from deviations of the measured values. The present invention is particularly suitable for controlling gas flows in heating devices operated with fuel gas and allows, for example, a reliable and stable control of the mixture ratio of fuel gas and air over long periods of time.