Apparatus and method for identifying a refrigerant fluid contained in a tank or in measuring cell of a system for recharging an air-conditioning plant

Abstract

The present disclosure describes an apparatus for identifying a refrigerant fluid contained in a tank or in a measuring cell of a system for recharging an air-conditioning plant. The apparatus includes at least one infrared source configured to emit at least radiations with a first emitting intensity at a first wavelength and a second emitting intensity at a second wavelength. A first photodetector is configured to detect a first intensity of infrared radiations at the first wavelength, and a second photodetector is configured to detect a second intensity of infrared radiations at the second wavelength. A processing unit is configured to: calculate a ratio between the first intensity detected by the first photodetector and the second intensity detected by the second photodetector; and according to the Lambert-Beer law, obtain from said ratio a physical magnitude representative of the refrigerant fluid.

Claims

1. An apparatus for identifying a refrigerant fluid contained in a tank or in a measuring cell of a system for recharging an air-conditioning plant, comprising: at least one infrared source configured to emit at least radiations with a first emitting intensity at a first wavelength and a second emitting intensity at a second wavelength, the at least one infrared source structured and arranged to send infrared radiations within the refrigerant fluid contained in the tank or the measuring cell; a first photodetector configured to detect a first intensity of infrared radiations at the first wavelength; a second photodetector configured to detect a second intensity of infrared radiations at the second wavelength, wherein said second photodetector is separate from said first photodetector, and wherein said first photodetector and said second photodetector are arranged to receive the infrared radiations coming from said refrigerant fluid; a processing unit configured to: calculate a ratio between the first intensity detected by the first photodetector and the second intensity detected by the second photodetector; and according to the Lambert-Beer law, obtain from said ratio a physical magnitude representative of the refrigerant fluid; wherein said first photodetector and said second photodetector are arranged to receive the infrared radiations coming from said refrigerant fluid contained within a common interior of the tank or the measuring cell.

2. The apparatus according to claim 1, wherein said first photodetector and said second photodetector each include a corresponding optical filter configured to allow the passage of the infrared radiation having respectively the first wavelength or the second wavelength.

3. The apparatus according to claim 1, wherein the processing unit receives a first signal from the first photodetector that is representative of the first intensity and a second signal from the second photodetector that is representative of the second intensity, and calculates a ratio between the first signal and the second signal that is indicative of the ratio between the first intensity and the second intensity.

4. The apparatus according to claim 1, wherein the physical magnitude obtained from said ratio is a molar concentration of said refrigerant fluid.

5. A method for identifying a refrigerant fluid contained in a tank or in a measuring cell of a system for recharging an air-conditioning plant, comprising the steps of: emitting in a direction of the refrigerant fluid infrared radiations with a first emitting intensity at a first wavelength and a second emitting intensity at a second wavelength; detecting a first intensity of infrared radiations at the first wavelength by a first photodetector after the infrared radiations have passed through the refrigerant fluid; detecting a second intensity of infrared radiations at the second wavelength by a second photodetector after the infrared radiations have passed through the refrigerant fluid, wherein said second photodetector is structured and arranged separately from said first photodetector; calculating a ratio between the first intensity detected upon the exit of the refrigerant fluid and the second intensity detected upon the exit of the refrigerant fluid; and according to the Lambert-Beer law, obtaining from said ratio a physical magnitude representative of the refrigerant fluid; wherein said first photodetector and said second photodetector receive said infrared radiations coming from the refrigerant fluid contained within a common interior of the tank or the measuring cell.

6. The method according to claim 5, wherein the first photodetector and the second photodetector each include a corresponding optical filter configured to allow the passage of the infrared radiation having respectively the first wavelength or the second wavelength.

7. The method according to claim 5, further comprising receiving, via a processor, a first signal from the first photodetector that is representative of the first intensity and a second signal from the second photodetector that is representative of the second intensity, and calculating a ratio between the first signal and the second signal that is indicative of the ratio between the first intensity and the second intensity.

8. A non-transitory computer readable medium tangibly embodying computer-executable instructions that when executed by a processor cause the processor to perform operations comprising: emitting in a direction of a refrigerant fluid contained in a tank or a measuring cell infrared radiations with a first emitting intensity at a first wavelength and a second emitting intensity at a second wavelength; detecting a first intensity of infrared radiations at the first wavelength by a first photodetector after the infrared radiations have passed through the refrigerant fluid in the tank or the measuring cell; detecting a second intensity of infrared radiations at the second wavelength by a second photodetector after the infrared radiations have passed through the refrigerant fluid in the tank or the measuring cell, said second photodetector structured separately from said first photodetector; calculating a ratio between the first intensity detected upon the exit of the refrigerant fluid and the second intensity detected upon the exit of the refrigerant fluid; and according to the Lambert-Beer law, obtaining from said ratio a physical magnitude representative of the refrigerant fluid; wherein said first photodetector and said second photodetector are arranged to receive the infrared radiations coming from said refrigerant fluid contained within a common interior of the tank or the measuring cell.

9. The non-transitory computer readable medium according to claim 8, wherein the first photodetector and the second photodetector each include a corresponding optical filter configured to allow the passage of the infrared radiation having respectively the first wavelength or the second wavelength.

10. The non-transitory computer readable medium according claim 8, wherein the processor receives a first signal from the first photodetector that is representative of the first intensity and a second signal from the second photodetector that is representative of the second intensity, and calculates a ratio between the first signal and the second signal that is indicative of the ratio between the first intensity and the second intensity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an apparatus for identifying a refrigerant fluid contained in a tank or in a measuring cell of a system for recharging an air-conditioning plant.

DETAILED DESCRIPTION

(2) Further features and advantages of the present invention will become much clearer from the indicative, albeit non-limiting description of a preferred, but not exclusive embodiment of an apparatus and of a method for identifying a refrigerant fluid contained in a tank or that in a measuring cell of a system for recharging an air-conditioning plant, as shown in FIG. 1, which shows a schematic view of an apparatus according to the present invention.

(3) With reference to FIG. 1, numeral 1 denotes an apparatus for identifying a refrigerant fluid contained in a tank or in a measuring cell 10, for example in a system for recharging an air-conditioning plant.

(4) The apparatus 1 comprises at least one infrared source S configured to emit at least radiations with a first emitting intensity I.sub.01 at a first wavelength λ.sub.1 and with a second emitting intensity I.sub.02 at a second wavelength λ.sub.2.

(5) The infrared source S is arranged in such a way as to send infrared radiations within the refrigerant fluid contained in the tank or measuring cell 10.

(6) Two infrared radiation photodetectors F.sub.1, F.sub.2 are provided on the opposite side of the refrigerant fluid as compared to the infrared source S.

(7) In particular, a first photodetector F.sub.1 is configured to detect a first intensity I.sub.1 of infrared radiations at the first wavelength λ.sub.1.

(8) A second photodetector F.sub.2 is instead configured to detect a second intensity I.sub.2 of infrared radiations at the second wavelength λ.sub.2.

(9) The two photodetectors F.sub.1, F.sub.2 are arranged in such a way as to receive the infrared radiations coming from said refrigerant fluid;

(10) The apparatus 1 also comprises a processing unit 20 which receives two signals at its inlet, each originating from one of the two photodetectors F.sub.1, F.sub.2.

(11) In particular, the first photodetector F.sub.1 provides a first signal, which is representative of the first measured intensity I.sub.1, whereas the second photodetector F.sub.2 provides a second signal, which is representative of the second measured intensity I.sub.2.

(12) The processing unit 20 is configured to calculate the ratio between the first and second signals at the inlet, which is indicative of a ratio R between the first intensity I.sub.1 detected by the first photodetector F.sub.1 and the second intensity I.sub.2 detected by the second photodetector F.sub.2.

(13) According to the Lambert-Beer law, the first intensity I.sub.1 detected by the first photodetector F.sub.1 is equal to:

(14) $I_1=I_{01}{e}^{-k_{1}L}$

(15) Similarly, the second intensity I.sub.2 detected by the second photodetector is equal to:

(16) $I_2=I_{02}{e}^{-k_{2}L}$
where k.sub.1 and k.sub.1 are the coefficients of attenuation of the refrigerant fluid, these being functions of the respective wavelengths (λ.sub.1, λ.sub.2) and pressure of the refrigerant fluid.

(17) The ratio R between such intensities is:

(18) $\frac{I_1}{I_2}=\gamma e^{-\left(k_1-k_2\right)L}$
where γ is the ratio I.sub.01/I.sub.02.

(19) On the basis of this ratio R and by applying the Lambert-Beer law, it is therefore possible to form a physical magnitude representative of the refrigerant fluid. In particular, this physical magnitude is the molar concentration of the refrigerant fluid.

(20) The apparatus described and illustrated herein comprises two photodetectors. However, it could comprise further photodetectors.

(21) The measurements shall always be intended as ratios between a pair of intensity values measured by two photodetectors of the apparatus. The physical magnitudes characteristic of the refrigerant fluid are therefore formed by systemizing the equations for the various ratios.

(22) The processing unit 20 may be formed by an electronic module, suitably programmed to perform the functions described, possibly corresponding to various hardware units and/or software routines forming part of the programmed module.

(23) Alternatively or additionally, these functions may be provided by a plurality of distributed electronic modules.

(24) The processing unit 20 may also comprise one or more processors for executing the instructions contained in memory modules.

(25) The features of the apparatus and of the method for identifying a refrigerant fluid contained in a tank or in a measuring cell of a system for recharging an air-conditioning plant according to the present invention have been clarified by the description provided, as have the advantages thereof.

(26) Thanks to the calculation of the ratio between intensities, the problem relating to deviations in intensity of the IR source caused by thermal fluctuations of the heating element from which it is formed has been solved. Thus, it is not necessary to perform an initial cleaning of the measuring cell or to make measurement corrections.