Detection of abnormal heat exchanger operating condition
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Solution Overview
Problem
Existing heat exchangers in in vitro diagnostic medical devices may not be properly primed, leading to air bubbles that reduce heat transfer and inaccurate temperature sensing, causing overheating and potential damage, requiring a detection method that is sensitive, accurate, and easily implemented on existing hardware and software.
Innovation Solution
A method and system that utilize actual current and temperature measurements to detect abnormal operating conditions by comparing them to baseline values, allowing for the declaration of fault states such as not primed, partially primed, or primed, and automatically shutting off the heat exchanger if necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If pressure sensors are added to detect abnormal flow, then detection sensitivity is improved, but device complexity increases
Solution Approach 1:
The heat exchanger uses its own operational parameters (current draw, temperature readings from existing thermistor) to detect abnormal conditions. The system monitors itself without requiring external detection devices, thereby maintaining simplicity while achieving detection capability.
Solution Approach 2:
Existing components serve multiple functions: the thermistor not only controls temperature regulation but also provides data for fault detection; the current measurement circuit not only powers the heater but also monitors for abnormal current draw indicating improper priming. This multi-functionality eliminates the need for dedicated detection hardware.
2Device complexity
If detection is delayed, then system simplicity is maintained, but heater damage risk increases
Solution Approach 1:
The system continuously monitors current draw and temperature with real-time feedback to the control logic. When abnormal conditions are detected (such as current draw exceeding thresholds or temperature rising faster than expected), the system immediately responds by shutting off the heater, preventing damage while maintaining simple hardware architecture.
Solution Approach 2:
The system establishes baseline current and temperature characteristics during normal operation and uses these pre-determined parameters to detect deviations before they cause damage. By comparing real-time measurements against predetermined safety thresholds, the system can take preventive action before overheating occurs.
3Ease of manufacture
If existing equipment is used for detection, then ease of implementation is improved, but measurement precision may be reduced
Solution Approach 1:
The system extracts multiple diagnostic parameters from existing sensors (current draw, temperature rate of change, duty cycle variations) and analyzes their relationships to detect improper priming. By monitoring how these parameters change over time and comparing against expected patterns, the system achieves accurate fault detection using only existing equipment.
Solution Approach 2:
The patent replaces mechanical detection methods (pressure sensors, flow sensors) with electrical and thermal parameter analysis. By substituting physical measurement devices with analysis of electrical current and temperature data from existing circuits, the system achieves detection capability without adding hardware complexity.
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
Enables immediate detection and prevention of overheating by accurately identifying improper priming states, ensuring the heat exchanger's safe operation and reducing equipment damage.
Implementation Method 1
heat transfer between the heating element of the heat exchanger and the fluid is reduced
Implementation Method 2
determining the heat exchanger's reference-temperature resistance and thermal coefficient of electrical resistance
Data Source
AI summary
A method for detecting an abnormal operating condition of a heat exchanger is provided. The method includes determining the actual current through a heat exchanger, using the actual current to indicate an abnormal operating condition, and declaring a fault state. A step of comparing the baseline current to the actual current includes normalizing the actual current, calculating a difference between the normalized actual current and the baseline current, and determining that difference is less than zero.