Drain plug comprising a device for measuring a parameter of a fluid

Abstract

This drain plug (47) of a filter cartridge (31) of an aircraft circuit configured to circulate a fluid (25), characterized in that it comprises a measuring device (61) configured to measure at least one parameter of the fluid (25) circulating in the filter cartridge (31).

Description

[0001] DESCRIPTION

[0002] TITLE: Drain plug comprising a device for measuring a parameter of a fluid

[0003] Technical field

[0004] The present invention relates to monitoring the quality of an oil or fuel in a turbomachine.

[0005] In particular, the present invention relates to monitoring the quality of oil or fuel in a turbomachine without the properties of the oil or fuel being able to be altered by other components present in the oil or fuel.

[0006] Generally, the invention applies to all types of aircraft oil or fuel circuits.

[0007] Previous techniques

[0008] Turbomachines, for example those of an aircraft, include rotating elements which require a system comprising lubricating oil in order to evacuate the calories due to thermal dissipation and to reduce friction and wear on the surfaces of the elements in contact.

[0009] Lubricating oil carries particles and chemical components which reflect the state of wear of the elements in contact with the oil, and therefore the general state of the turbomachine.

[0010] Additionally, the lubricating oil itself has heat dissipation and lubricating properties that can vary over time and deteriorate.

[0011] Currently, a circuit in which such lubricating oil circulates has several sensors for monitoring certain properties of the oil. The parameters studied are, for example, the oil level, temperature and oil pressure.

[0012] 1 schematically represents an oil circuit 1 of a turbomachine 3 of an aircraft 5, the oil circuit 1 comprising a reservoir 7, a feed pump 9, a filter cartridge 11, an air / oil exchanger 13 and a recuperator 15, also called a sump. In this embodiment, temperature and pressure sensors 17 are positioned in the middle of the oil circuit 1, namely upstream of the oil recuperator 15 and downstream of the air / oil exchanger 13. This positioning is not ideal for measuring large temperature variations before the exchangers 13 nor for ignoring debris present in the oil.

[0013] It is also possible to detect debris contained in the oil but not the quality of the oil itself directly within the oil circuit.

[0014] An oil quality analysis is currently carried out on an ad hoc basis on certain turbomachines during a maintenance task by chemical analysis in a laboratory. The parameters studied which attest to the quality of an oil are for example the density, dynamic viscosity, permittivity and electrical conductance of said oil. Thus, an oil quality problem cannot be detected during the flight of an aircraft. In addition, laboratory measurement involves immobilizing the aircraft, a complex sampling procedure, the latter having to be as homogeneous as possible and not including any external contaminants, and a waiting time for the results of several weeks.

[0015] At the same time, the turbomachine oil is drained regularly and replaced with new oil, often without knowledge of its quality before draining, potentially leading to the destruction of oil that is still of good quality.

[0016] Statement of the invention

[0017] The present invention therefore aims to overcome the aforementioned drawbacks and to provide a means of measuring parameters of a fluid such as an oil or fuel directly in the circuit in which the fluid circulates, and with a guarantee of a reliable and unaltered measurement in order to anticipate the aging and renewal of said fluid.

[0018] The present invention relates to a drain plug for a filter cartridge of an aircraft circuit configured to circulate a fluid, characterized in that it comprises a measuring device configured to measure at least one parameter of the fluid circulating in the filter cartridge.

[0019] Thus, the measuring device offers on-board measurement without adding mass and can also be easily replaced in the event of a breakdown. It also allows fluid parameter measurements once the fluid has been filtered of its impurities by the filter cartridge. The measuring device ultimately reduces measurement costs and optimizes the time intervals between each fluid renewal.

[0020] Advantageously, the measuring device comprises a temperature sensor configured to measure the temperature of the fluid circulating in the filter cartridge.

[0021] Advantageously, the measuring device comprises a fluid quality sensor configured to measure the density and / or dynamic viscosity, and / or permittivity and / or electrical conductance of the fluid flowing in the filter cartridge.

[0022] In one embodiment, the fluid quality sensor comprises a quartz tuning fork resonator comprising two metal sensing elements configured to extend parallel to each other in an enclosure defined by the filter cartridge when the drain plug is positioned to plug a drain hole of the filter cartridge, such that the sensing elements are in contact with the fluid flowing through the filter cartridge.

[0023] Advantageously, the drain plug comprises a protective tube extending longitudinally around the sensitive elements, the protective tube comprising at least one opening configured to allow contact between the fluid circulating in the filter cartridge and the sensitive elements.

[0024] Advantageously, the drain plug further comprises a means for wirelessly transmitting data from the measuring device and / or wirelessly powering the measuring device, preferably a radio-identification chip. In a particular embodiment, the wireless transmission and / or powering means is positioned at a longitudinal end of the drain plug, so that the wireless transmission and / or powering means is positioned outside an enclosure defined by the filter cartridge, said drain plug comprising an electrically insulating material positioned between the wireless transmission and / or powering means and the rest of the drain plug.

[0025] Advantageously, the measuring device is configured to measure at least one parameter of an oil and / or a fuel.

[0026] The present invention also relates to a filter cartridge of an aircraft circuit configured to circulate a fluid, the filter cartridge comprising a drain plug as defined previously.

[0027] The present invention also relates to a turbomachine comprising an aircraft circuit configured to circulate a fluid, the aircraft circuit comprising a fluid filter cartridge comprising a drain plug as defined previously.

[0028] The present invention also relates to an aircraft comprising a turbomachine as defined above.

[0029] Brief description of the drawings

[0030] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

[0031] [Fig 1] which has already been mentioned, is a schematic view of an aircraft comprising a turbomachine comprising an oil circuit comprising temperature and pressure sensors according to the state of the art;

[0032] [Fig 2] is a schematic view of an aircraft comprising a turbomachine comprising an oil circuit comprising a filter cartridge according to the invention; [Fig 3] is a schematic sectional view of a filter cartridge according to figure 2;

[0033] [Fig 4] is a schematic view of a drain plug of a filter cartridge according to Fig. 3; and

[0034] [Fig 5] is a schematic view of a radio-identification chip of the cap according to Figure 4.

[0035] Detailed description of at least one embodiment

[0036] Figure 2 schematically shows an aircraft 19 comprising a turbomachine 21 comprising an aircraft circuit 23 configured to circulate a fluid 25, for example fuel or oil, preferably oil.

[0037] The circuit 23 comprises a reservoir 27, a feed pump 29, a filter cartridge 31, an air / fluid exchanger 33 and a recuperator 35, in a similar manner to the circuit 1 shown in FIG. 1.

[0038] Figure 3 schematically shows a sectional view of a filter cartridge 31, for example of tubular shape. The filter cartridge 31 comprises a radial filter wall 37 for filtering the fluid 25 entering through the radial wall 37, the fluid then being redirected towards a first longitudinal end 39 of the filter cartridge 31.

[0039] The filter cartridge 31 further comprises a transverse wall 41 located at a second longitudinal end 43, the transverse wall 41 comprising a drain hole 45.

[0040] The filter cartridge 31 also comprises a removable drain plug 47 configured to be positioned across the drain hole 45 of the transverse wall 41 so as to be able to plug said drain hole 45.

[0041] The drain plug 47 comprises a first part 49 configured to be introduced into the enclosure 51 defined by the radial 37 and transverse 41 walls of the filter cartridge 31. The drain plug 47 comprises a second part 53 configured to remain outside the enclosure 51 defined by the radial 37 and transverse 41 walls of the filter cartridge 31.

[0042] The drain plug 47 further includes an O-ring 55 configured to be positioned in the drain hole 45 to prevent any leakage of fluid 25 outside the circuit 23.

[0043] In one embodiment, the drain hole 45 is bordered by a thread 57 made of metal and intended to cooperate with a thread 59 of the first part 49 of the drain plug 47, for example made of metal.

[0044] Figure 4 schematically shows a transparent view of the drain plug 47 illustrated in Figure 3.

[0045] Advantageously, the drain plug 47 comprises a measuring device 61 configured to measure at least one parameter of the fluid 25 circulating in the filter cartridge 31.

[0046] In particular, the measuring device 61 comprises for example a temperature sensor 63 configured to measure the temperature of the fluid 25 circulating in the filter cartridge 31.

[0047] In a particular embodiment, the measuring device 61 comprises a fluid quality sensor 65 configured to measure the density and / or the dynamic viscosity, and / or the permittivity, for example by measuring the dielectric constant, and / or the electrical conductance, otherwise called the resistivity, of the fluid circulating in the filter cartridge 31, preferably at least the electrical conductance and the dynamic viscosity.

[0048] The combination of a temperature sensor 63 with an oil quality sensor 65 has the advantage of being able to take into account the effect of temperature on the viscosity of the fluid 25.

[0049] Additionally, a temperature measurement at the filter cartridge 3 1 improves the fault monitoring models on the fluid circuit 23.

[0050] For example, the fluid quality sensor 65 comprises a quartz tuning fork resonator comprising two metal sensing elements 67 configured to extend parallel to each other in the enclosure defined by the filter cartridge 31 when the drain plug 47 is positioned so as to plug the drain hole 45 of the filter cartridge 31, so that the sensing elements 67 are in contact with the fluid 25 flowing in the filter cartridge 31. This type of sensor makes it possible to measure the parameters of the fluid such as the density and / or the dynamic viscosity, and / or the permittivity, and / or the electrical conductance.Thus, the filtering carried out by the filter cartridge 31 allows the analysis of the fluid 25 not to be disturbed by metallic, ceramic or plastic particles which increase the viscosity, the density and the dielectric constant of the fluid, thus distinguishing the effects of aging of the fluid from damage to an element of the circuit 23 in which the fluid 25 circulates.

[0051] Advantageously, the first part of the drain plug 47 comprises a protective tube 69 extending longitudinally around the sensitive elements 67, the protective tube 69 comprising at least one opening 71 configured to allow contact between the fluid 25 circulating in the filter cartridge 31 and the sensitive elements 67.

[0052] In one embodiment, the second part 53 of the drain plug 47 comprises a screw head 73 for screwing the drain plug 47 into the drain hole 45, as well as a means 75 for wireless transmission of data from the measuring device and / or wireless power supply of the measuring device 61, preferably positioned at the distal longitudinal end of the sensitive elements 67, so that the means 75 for wireless transmission and / or power supply is positioned outside the enclosure 51 defined by the filter cartridge 31 in order to escape as much as possible from the temperature and pressure conditions present in the enclosure 51.

[0053] For example, the means 75 for wirelessly transmitting data from the measuring device and / or for wirelessly powering the measuring device is a radio-identification chip 75, more commonly called an RFID chip in English terms, and configured to power the measuring device 61 following the acquisition of a signal sent by a radio-identification reader of the turbomachine 21, and configured to transmit data from the measuring device 61 to said radio-identification reader of the turbomachine 21.

[0054] 5 schematically shows a radio-identification chip 75, connected on the one hand to the temperature sensor 63 and on the other hand to the fluid quality sensor 65, the radio-identification chip 75 comprising an antenna 77, a radio-frequency transmission module 79 connected to the antenna 77, a power supply module 81, a memory module 83, a signal conditioning module 85 received respectively by the temperature sensors 63 and fluid quality sensors 65, as well as a microcontroller 87 allowing the electronic management of the different modules.

[0055] Thus, in such an embodiment, a mobile radio-identification reader is used by an operator, or the turbomachine 21 comprises an on-board and powered radio-identification reader as well as a memory making it possible to power, communicate and store data with the measuring device 61, for example measurements of parameters such as temperature, and / or density and / or dynamic viscosity, and / or permittivity, and / or electrical conductance.

[0056] In a particular embodiment, the drain plug 47 comprises an electrically insulating material 89 positioned between the wireless transmission and / or power supply means 75 and the rest of the drain plug 47, for example between the screw head 73 and the wireless transmission and / or power supply means 75. The electrically insulating material 89 makes it possible to isolate the wireless transmission and / or power supply means 75 from the metal parts of the drain plug 47 and more generally from the filter cartridge 31, so as not to disturb the proper functioning of the antenna 77 and to maximize the communication reading distance.

[0057] In a variant not shown, the drain plug 47 comprises a wired transmission and power supply means, nevertheless increasing the mass and the connectivity.

Claims

CLAIMS 1. Drain plug (47) of a filter cartridge (31) of an aircraft circuit (23) configured to circulate a fluid (25), characterized in that it comprises a measuring device (61) configured to measure at least one parameter of the fluid (25) circulating in the filter cartridge (31), the measuring device (61) comprising a fluid quality sensor (65) configured to measure at least one parameter chosen from the density, the dynamic viscosity, the permittivity and the electrical conductance of the fluid (25) circulating in the filter cartridge (31).

2. Drain plug (47) according to claim 1, wherein the measuring device (61) comprises a temperature sensor (63) configured to measure the temperature of the fluid (25) circulating in the filter cartridge (31).

3. Drain plug (47) according to one of claims 1 and 2, wherein the fluid quality sensor (65) comprises a quartz tuning fork type resonator comprising two sensitive elements (67) made of metal configured to extend parallel to each other in an enclosure (5 1 ) defined by the filter cartridge (31 ) when the drain plug (47) is positioned so as to plug a drain hole (45) of the filter cartridge (3 1 ), so that the sensitive elements (67) are in contact with the fluid (25) circulating in the filter cartridge (3 1 ).

4. Drain plug (47) according to claim 3, comprising a protective tube (69) extending longitudinally around the sensitive elements (67), the protective tube (69) comprising at least one opening (71) configured to allow contact between the fluid (25) circulating in the filter cartridge (31) and the sensitive elements (67).

5. Drain plug (47) according to any one of claims 1 to 4, further comprising means (75) for wireless transmission of data from the measuring device (61) and / or for wireless powering of the measuring device (61), preferably a radio-identification chip (75).

6. Drain plug (47) according to claim 5, wherein the wireless transmission and / or power supply means (75) is positioned at a longitudinal end of the drain plug (47), such that the wireless transmission and / or power supply means (75) is positioned outside an enclosure (51) defined by the filter cartridge (31), said drain plug (47) comprising an electrically insulating material (89) positioned between the wireless transmission and / or power supply means (75) and the remainder of the drain plug (47).

7. Drain plug (47) according to any one of claims 1 to 6, the measuring device (61) of which is configured to measure at least one parameter of an oil and / or a fuel.

8. Filter cartridge (31) of an aircraft circuit (23) configured to circulate a fluid (25), the filter cartridge (31) comprising a drain plug (47) according to any one of claims 1 to 7.

9. Turbomachine (21) comprising a circuit (23) configured to circulate a fluid (25), the circuit (23) comprising a filter cartridge (31) of fluid (25) comprising a drain plug (47) according to any one of claims 1 to 7.

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