Heater Blower Liquid Detection Using Startup Speed Deviation
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Solution Overview
Problem
Existing heating appliances lack the ability to detect the presence of liquid in the blower, which can lead to corrosion and other malfunctions, particularly in multi-occupancy systems where safety standards are high.
Innovation Solution
A method that utilizes existing control unit data to measure and compare blower characteristics like rotational speed and PWM signal profiles against empirical and calibration data to detect liquid presence, triggering warnings or maintenance if deviations exceed predefined thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a non-return valve is installed to prevent liquid entry, then liquid protection is improved, but the ability to detect liquid presence early is worsened
Solution Approach 1:
The patent measures physical quantities during a predefined time interval after heater startup, before liquid can cause significant damage. This preliminary detection allows the system to identify liquid presence early and trigger warnings or safety actions before corrosion or malfunctions occur, resolving the contradiction between having protective valves and enabling early detection.
2Measurement precision
If additional detection instrumentation is added, then detection capability is improved, but device complexity is worsened
Solution Approach 1:
The patent makes the control unit's existing measurements serve multiple functions: regulating blower speed and detecting liquid presence. By evaluating physical quantities already measured during normal operation within a predefined time interval after startup, the system achieves liquid detection without additional sensors or instrumentation, resolving the contradiction between detection capability and device complexity.
Solution Approach 2:
The control unit uses its own existing measurement capabilities and data to detect liquid presence, rather than relying on separate dedicated detection systems. The system essentially monitors itself by evaluating its operational parameters, which eliminates the need for additional detection equipment while maintaining detection functionality.
3Measurement precision
If empirical values and calibration data are used, then detection accuracy is improved, but data processing complexity is worsened
Solution Approach 1:
Empirical values and calibration data are prepared in advance during system setup or manufacturing, before actual operation. This preliminary preparation of reference data allows for accurate liquid detection during operation without requiring complex real-time data processing, as the comparison can be made against pre-established thresholds and curves.
Data Source
Figure 1~2
AI summary
The invention relates to a method for detecting the presence of liquid (15) in a blower (4) of a heating device (1) which is operated with a mixture of air and fuel gas supplied by the blower (4) to a burner (2), wherein at least one physical quantity characteristic of the function of the blower (4) is measured at least once during a predefinable time interval from the start of the heating device (1) and compared with empirical values and/or calibration data, and wherein a deviation (d1, d2, d3) from the empirical values and/or calibration data by a predefinable quantity is considered an indication of liquid (15) in the blower (4).A corresponding arrangement includes a control unit (5) for starting up the blower (4) by means of a pulse-width modulated current and for processing a measured actual value of the rotational speed (D) of the blower (4), wherein a comparator (12) is provided in the control unit (5) which is configured to compare the rotational speed (D) and/or the pulse width of the pulse-width modulated current with stored empirical values and to trigger a warning or fault message in the event of a deviation (d1, d2, d3) by a predefinable value. The present invention makes it possible to detect the presence of liquid in the blower of a heating device early and reliably without additional instrumentation and thereby prevent subsequent damage.