Refrigerant Purity Detection via Infrared Absorption Filtering
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Solution Overview
Problem
Existing methods for detecting refrigerant purity and composition in air conditioning systems face inaccuracies due to temperature changes, pressure variations, aging, and contamination, leading to instability in measurement results.
Innovation Solution
A device with a broadband filter and narrowband filters is used to measure absorption spectra, allowing for the calculation of relative purity and concentration of refrigerants by forming quotients of measured absorption values, and solving a linear system of equations to determine unknown concentrations, while excluding absorption wavelengths of hydrocarbons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If infrared absorption measurement is used to detect refrigerant purity, then refrigerant composition can be identified, but measurement accuracy deteriorates due to temperature changes, pressure variations, aging, and contamination
Solution Approach 1:
The patent changes the measurement parameters by using multiple infrared wavelength ranges (first wavelength range for refrigerant identification, second wavelength range for purity determination) and comparing absorption values across different wavelengths. This multi-parameter approach compensates for temperature and pressure variations, improving both accuracy and reliability of measurements.
Solution Approach 2:
The patent introduces a reference substance with known absorption characteristics as an intermediary. By measuring the absorption of the reference substance and comparing it with the unknown refrigerant sample, the system eliminates the effects of environmental factors like temperature and pressure changes, thereby improving measurement stability and accuracy.
2Measurement precision
If multiple filters and measurement ranges are used to improve detection accuracy, then refrigerant composition can be precisely identified, but device complexity increases
Solution Approach 1:
The patent segments the infrared spectrum into distinct wavelength ranges: a first wavelength range for identifying refrigerant composition and a second wavelength range for determining purity. This segmentation allows each range to be optimized for specific measurement purposes, improving accuracy while maintaining manageable system complexity through structured measurement protocols.
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
This method provides stable and accurate detection of refrigerant purity and composition, minimizing the impact of environmental and aging-related inaccuracies, and effectively identifies contaminants like R134a in HFO1234yf systems.
Implementation Method 1
a gas cell is filled with the refrigerant to be tested (test refrigerant) and irradiated with infrared radiation. A sensor on the opposite side then receives the radiation, with different portions of radiation being absorbed more strongly than others, depending on the refrigerants present in the gas cell.
Implementation Method 2
The device has at least one broadband filter in the beam path from the infrared source through the gas cell into the sensor. The passband of the broadband filter does not have an absorption wavelength of a hydrocarbon and accordingly has a passband of 8 μm - 14 μm.
Data Source
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AI summary
The invention relates to a device (10) for identifying refrigerants, comprising a gas cell (12), which has a test gas inlet and a test gas outlet, an infrared source (20) that radiates through the gas cell, and at least one sensor that detects the infrared radiation that passes through the gas cell, which device is improved in that at least one wide-band filter (28), (30) is provided between the infrared source (20) and the sensor (22), the passband of the at least one wide-band filter comprising the absorption spectra of the refrigerants to be detected and not comprising the absorption spectrum of hydrocarbons, and in that the gas cell (12) is connected to a cartridge (26), which contains the refrigerant to be detected in pure form as a reference gas. The invention further relates to a corresponding method for identifying refrigerants.