Coolant leak detection system in electronic equipment

Abstract

Coolant Leak Detection System in Electronic Equipment The invention relates to a system (6) for detecting coolant leaks in electronic equipment, suitable for electronic equipment installed on aircraft, comprising a gas detection sensor (8), said coolant emitting at least one volatile organic compound, the volatile organic compound(s) having an associated radio absorption spectrum, an absorbance peak of said absorption spectrum corresponding to a wavelength referred to as the wavelength absorbed by said volatile organic compound. This sensor (8) comprises at least one optical wave emitter (12, 12') with an emission wavelength chosen according to a wavelength absorbed by the volatile organic compound(s) of said coolant. Figure for the abstract: Figure 2

Description

Title of the invention: Coolant leak detection system in electronic equipment

[0001] The present invention relates to a system for detecting coolant leaks in electronic equipment, adapted for electronic equipment installed on aircraft.

[0002] The invention lies in the field of maintenance of embedded electronic equipment, in particular in aircraft.

[0003] Electronic equipment on board aircraft is subjected to extreme temperature and pressure conditions.

[0004] As is known, embedded electronic equipment is mounted in or on circuits containing a cooling fluid, which is a heat transfer fluid, whose function is to dissipate the heat produced by the operation of the electronic components. The use of a cooling fluid is necessary to ensure proper operation and prevent damage to the electronic components embedded in electronic equipment.

[0005] In general, the cooling fluid is composed of water mixed with an additive, for example ethylene glycol or propylene glycol, which increases its boiling point and / or increases resistance to freezing.

[0006] In the field of aeronautics, standardized specifications require that various characteristics be met by the cooling fluids used.

[0007] Such coolants are generally corrosive and can damage electronic components if they come into direct contact with them, for example, in the case of micro-leaks. This can lead to malfunctions or failures, and therefore a need for maintenance. If a coolant leak is not detected, maintenance must be performed after fault detection, on the ground, without any real knowledge of the cause of the failure. Furthermore, a coolant leak is difficult, if not impossible, to reproduce on the ground due to the difficulty of replicating similar temperature and pressure conditions.

[0008] There is therefore a need to detect any leakage of coolant, particularly in flight.

[0009] To this end, the invention proposes, according to one aspect, a system for detecting coolant leaks in electronic equipment, adapted for electronic equipment installed on aircraft, which comprises a gas detection sensor, said cooling fluid emitting at least one volatile organic compound, the volatile organic compound or each volatile organic compound having an associated radioelectric absorption spectrum, an absorbance peak of said absorption spectrum corresponding to a wavelength said to be the wavelength absorbed by said volatile organic compound, said gas detection sensor comprising at least one optical wave emitter of emission wavelength chosen according to a wavelength absorbed by the volatile organic compound or one of the volatile organic compounds of said cooling fluid.

[0010] Advantageously, the proposed coolant leak detection system performs coolant leak detection by detecting at least one volatile organic compound emitted by the coolant.

[0011] The coolant leak detection system according to the invention may also have one or more of the following characteristics, taken independently or according to all technically feasible combinations.

[0012] Said emission wavelength is equal to the wavelength absorbed by the or one of the volatile organic compounds emitted by the cooling fluid.

[0013] The cooling fluid emits a number N of volatile organic compounds, each having a distinct absorbed wavelength, the gas detection sensor comprising N optical wave emitters, each having an emission wavelength equal to a wavelength absorbed by one of said volatile organic compounds.

[0014] The gas detection sensor further comprises a reference optical wave emitter, having an emission wavelength distinct from the or each wavelength absorbed by the or one of the volatile organic compounds emitted by the cooling fluid.

[0015] The gas detection sensor includes an optical wave emitter adapted to operate in a band of wavelengths, the emission of an emission wavelength contained in said band of wavelengths being controllable via an external control.

[0016] The gas detection sensor further comprises an optical wave reflection device and a photoreceptor module, the photoreceptor module being a transducer configured to transform reflected optical waves from optical waves emitted by one of said optical wave emitters into an electrical signal.

[0017] The gas detection sensor is inserted into a container, having at least one hole.

[0018] The system further comprises an electronic calculation module, configured to detect the presence of at least one volatile organic compound in said cooling fluid as a function of an electrical characteristic of said electrical signal.

[0019] The electrical characteristic is a voltage or power of the electrical signal.

[0020] The volatile organic compound is 2-ethyl-l-Butanol or decane.

[0021] According to another aspect, the invention relates to electronic equipment comprising a housing encapsulating at least one electronic component and a cooling circuit comprising a cooling fluid, which includes, inside said housing, a cooling fluid leak detection system as briefly described above.

[0022] Other features and advantages of the invention will become apparent from the description given below, by way of example and not limitation, with reference to the accompanying figures, among which:

[0023] [Fig-1] [Fig.1] schematically represents an aircraft equipped with a system of coolant leak detection;

[0024] [Fig.2] [Fig.2] schematically represents the functional modules of a coolant leak detection system;

[0025] [Fig.3] [Fig.3] illustrates absorption spectra of volatile organic components emitted by a cooling fluid in an application case;

[0026] [Fig.4] [Fig.4] represents a cooling fluid detection sensor according to one embodiment.

[0027] Fig. 1 schematically illustrates an aircraft 2, and electronic equipment 4 on board aircraft 2.

[0028] It is understood that the representation is schematic, in practice an aircraft comprising a plurality of on-board electronic equipment 4, for example sensors, traveling wave tube, power supplies, on-board computers, active antenna, positioned outside or inside the aircraft fuselage.

[0029] Such electronic equipment 4 is encapsulated in a housing, comprising a cooling system by circulation of a heat transfer fluid called cooling fluid, which allows the heat produced by the operation of the electronic components of the electronic equipment 4 to be evacuated.

[0030] In the field of aeronautics, the following cooling fluids are used in particular: Coolanol®, which is a silicate-based cooling fluid, and PAO (polyalpholefin), based on synthetic hydrocarbons.

[0031] Of course, the invention applies with any type of cooling fluid, as described in more detail below.

[0032] The on-board electronic equipment 4 is advantageously associated with a coolant leak detection system 6, which allows the detection of gaseous emanations from the coolant.

[0033] In other words, the coolant leak detection system 6 detects the presence of a volatile organic compound emitted by the coolant.

[0034] The coolant leak detection system 6 is particularly suitable for detecting such leaks in electronic equipment when the aircraft is in flight, any coolant leak producing an associated gas emission, in greater or lesser quantities depending on the conditions of use, in particular temperature and pressure.

[0035] For example, in one embodiment, a coolant leak detection system 6 is placed in each of the coolant-cooled electronic equipment housings so as to detect any possible leak of this coolant.

[0036] Figure 2 illustrates the main functional blocks of a detection system coolant leak 6.

[0037] The system 6 includes a gas detection sensor 8, connected to an electronic computing module 10.

[0038] Advantageously, the system 6 is adapted to detect the presence of a gas or volatile organic component emitted by the cooling fluid, and consequently to detect the presence of a cooling fluid leak in the event of the presence of such a gas.

[0039] The sensor 8 comprises one or more emitters 12 of electromagnetic waves, and more particularly of optical waves, preferably of wavelengths in the infrared range, typically between 780nm and 1mm.

[0040] Each emitter 12 is adapted to emit in an emission range centered on a given wavelength, called the emission wavelength.

[0041] The emission wavelength is advantageously chosen according to the radioelectric absorption spectrum of a volatile organic component emitted by the cooling fluid.

[0042] In the illustrated embodiment, the sensor 8 comprises two emitters 12, 12' of electromagnetic waves, and more particularly of optical waves, each having an associated emission wavelength.

[0043] For example, in one embodiment, each of the emitters 12, 12' is an infrared beam emitting device, for example a light-emitting diode LED adapted to emit an infrared beam of a given emission wavelength when an electric current passes through it.

[0044] The sensor further comprises an optical wave reflection device 14 and a photoreceptor module 16.

[0045] The photoreceptor module 16 is, in a known manner, a transducer which converts incident optical radiation (here, it is optical waves reflected by the reflection device 14) into an electrical signal.

[0046] The electrical signal thus obtained, or an electrical characteristic of this signal (e.g. voltage, power) is transmitted to the electronic calculation module 10.

[0047] This module 10 includes, for example, a processor 18 and an associated electronic memory 20.

[0048] The sensor 8 and the electronic calculation module 10 can be integrated into the same device, for example in the same housing.

[0049] According to one variant, the electronic computing module 10 is a remote computer, for example integrated into an on-board computing system of the aircraft, and the sensor 8 communicates with the electronic computing module 10 by means of a communication link, wired or wireless.

[0050] The electronic computing module 10 is, for example, a programmable logic component, such as an FPGA (Field Programmable Gate Array), or a dedicated integrated circuit, such as an ASIC (Application-Specific Integrated Circuit).

[0051] The electronic memory 20 is particularly suitable for storing electrical characteristics of the received signal, and for example associated reception dates.

[0052] The processor 18 is particularly suitable for performing calculations when the electronic calculation module 10 is switched on, in particular for detecting, for example by comparing electrical characteristics of the electrical signal to threshold values, the presence of a gas emitted by a chosen cooling fluid.

[0053] Optionally, module 10 includes a communication module 22, adapted to communicate with another electronic device not shown, for example using a wired communication protocol or a wireless communication protocol.

[0054] Thus, the detection of the presence of emitted cooling fluid is advantageously signaled to a remote device, for example in order to generate an alert for an operator.

[0055] Alternatively, the detection of the presence of gas emitted by a selected cooling fluid is stored in the electronic memory 20, for example in association with associated electrical signal characteristics and a detection date for further processing, for example in a subsequent maintenance phase. The electrical characteristics are, for example, the power or voltage of the received electrical signal.

[0056] In one embodiment, a first optical wave emitter 12 has an emission wavelength chosen according to the radio absorption spectrum, and in particular a wavelength absorbed by a volatile organic compound (or VOC) or gas emitted by the cooling fluid in question, i.e. the cooling fluid from which a possible leak is to be detected.

[0057] For example, if the cooling fluid is Coolanol®, one of the main gases emitted is 2-ethyl-l-Butanol, an example of whose absorption spectrum in the infrared range is illustrated in [Fig.3].

[0058] Indeed, [Fig. 3] illustrates an absorption spectrum of 2-ethyl-l-Butanol, which is a Graph representing absorbance on the ordinate, as a function of wavelength, represented on the abscissa, in micrometers (pm). As can be seen, the absorption spectrum has a main absorbance peak at approximately 3.3 µm and a secondary peak at approximately 9.7 pm.

[0059] In order to detect the presence of this gas, the emission wavelength is chosen to be equal to the wavelength corresponding to the main absorbance peak of 2-ethyl-l-Butanol, for example at 3.3qm.

[0060] In one embodiment, the second optical wave emitter 12' is a reference optical wave emitter, with a reference emission wavelength that is not a wavelength absorbed by the gas to be detected, for example equal to 3qm. This makes it possible to increase the selectivity of the sensor.

[0061] Fig. 4 schematically illustrates one embodiment of a sensor 8.

[0062] In this embodiment, the sensor comprises a container (or housing) 15, for example of cylindrical shape.

[0063] The container 15 is preferably fireproof and robust to a given level of mechanical vibration.

[0064] Inside the container 15 are placed the optical wave emitters 12, 12', the optical wave reflection device 14 and the photoreceptor module 16.

[0065] For example, the emitter 12 emits optical waves with a wavelength of 3.3qm (wavelength of the absorbance peak of the gas to be detected) and the emitter 12' emits optical waves with a wavelength of 3qm (reference emission wavelength).

[0066] For example, the container 15 includes at least one hole allowing ambient air to pass through. In the illustrated embodiment, the container 15 is cylindrical and includes a circular plate 17, which forms a lid for the container 15.

[0067] The optical wave reflection device 14, e.g. a reflective surface forming a mirror, is formed on a first inner face of the plate 17.

[0068] In addition, the plate 17 includes a series of holes, formed in its thickness, regularly spaced around a peripheral ring of this plate. The holes formed in this plate allow ambient air to pass through, in particular the air from the housing encapsulating the electronic equipment cooled by the cooling fluid, any leakage of which must be detected.

[0069] Of course, this is an example of an embodiment, multiple variants being conceivable, including other geometric shapes of container, and other arrangements and distributions of holes.

[0070] Each optical wave beam of emission wavelength is emitted by the corresponding emitter, and reflected by the reflecting device 14.

[0071] When the gas emitted by the cooling fluid is present, the laser beam emitted by the emission device 12, whose wavelength is equal to the maximum absorbance wavelength of the gas (also called the absorbed wavelength), is absorbed and the power of the reflected optical wave received by the photoreceptor module 16 is considerably reduced.

[0072] The voltage of the electrical signal at the output of the photoreceptor module 16 is then reduced, which makes it possible to detect the presence of a gas absorbing the emission wavelength of the optical wave emitter.

[0073] Alternatively, the output power of the photoreceptor module is used for detecting the presence of this gas.

[0074] When each of the emitters 12, 12' emits optical wave beams with its own emission wavelength, it is possible, for example, to calculate, by the electronic calculation module 10, the ratio between the electrical signal voltage values ​​obtained by the photoreceptor.

[0075] Comparing this ratio to a predetermined threshold value makes it possible to detect the presence or absence of the gas emitted by the cooling fluid in question. More specifically, comparing the ratio to a threshold value makes it possible to avoid false positives in the detection of the presence of a gas emitted by the cooling fluid in question.

[0076] The case in which the cooling fluid is Coolanol® has been described above.

[0077] According to one variant, the cooling fluid considered is PAO, and the volatile organic compound emitted is mainly decane.

[0078] To detect the presence of decane, the absorption spectrum of decane is obtained, and in a manner analogous to what has been described above, the wavelength of one of the optical wave emitters is chosen to be equal to the wavelength corresponding to the main absorbance peak of decane.

[0079] In one embodiment, in the case of a cooling fluid which has a number N greater than or equal to two of volatile organic components, each having an absorbance peak of distinct wavelength, it is conceivable to provide N optical wave emitters of different wavelengths, so as to detect the presence of each of the emitted volatile organic components.

[0080] According to another embodiment, the detection system 6 uses an optical wave emitter capable of emitting in a given wide wavelength band, for example, a wavelength band containing the N peak absorbance wavelengths of the gases, and filters for selecting an emission wavelength by command. In other words, the emission of a wavelength contained within the wavelength band is controllable via an external command.

[0081] According to another variant, the selection of one or more wavelengths is carried out at reception, by digital processing by the electronic computing module 10, which is local or remote from the gas detection sensor 8.

Claims

Claims

1. System for detecting a leak of coolant in electronic equipment (4), suitable for electronic equipment (4) on board aircraft, characterized in that it comprises a gas detection sensor (8), said coolant emitting at least one volatile organic compound, the or each volatile organic compound having an associated absorption spectrum, an absorbance peak of said absorption spectrum corresponding to a wavelength called the wavelength absorbed by said volatile organic compound, said gas detection sensor (8) comprising at least one emitter (12, 12') of optical waves with an emission wavelength chosen as a function of a wavelength absorbed by the or one of the volatile organic compounds of said coolant, in which said coolant emits a number N of volatile organic compounds each having a distinct absorbed wavelength,the gas detection sensor (8) comprising N optical wave emitters, each having an emission wavelength equal to a wavelength absorbed by one of said volatile organic compounds.,

2. System according to claim 1, in which the gas detection sensor (8) further comprises an emitter (12') of reference optical waves, having an emission wavelength distinct from the or each wavelength absorbed by the or one of the volatile organic compounds emitted by the cooling fluid.

3. System according to claim 1, in which the gas detection sensor (8) comprises an optical wave emitter adapted to operate in a wavelength band, the emission of an emission wavelength contained in said wavelength band being controllable via an external command.

4. System according to one of claims 1 to 3, wherein said gas detection sensor (8) further comprises a device (14) for reflecting optical waves and a photoreceiving module (16), the photoreceiving module (16) being a transducer configured to transform reflected optical waves from the optical waves emitted by one of said optical wave emitters into an electrical signal.

5. System according to claim 4, wherein said gas detection sensor (8) is inserted into a container (15) having at least one hole.

6. System according to claim 4 or 5, further comprising an electronic calculation module (10), configured to detect a presence of at least one volatile organic compound of said cooling fluid as a function of an electrical characteristic of said electrical signal.

7. The system of claim 6, wherein said electrical characteristic is a voltage or power of the electrical signal.

8. The system of any one of claims 1 to 7, wherein said volatile organic compound is 2-ethyl-l-Butanol or decane.

9. Electronic equipment comprising a housing encapsulating at least one electronic component and a cooling circuit comprising a cooling fluid, characterized in that it comprises, inside said housing, a cooling fluid leak detection system according to claims 1 to 8.

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