DEVICE FOR COOLING HEAT-SENSITIVE CONTROL MEMBERS OF A PNEUMATIC OR ELECTROPNEUMATIC VALVE, AND VALVE EQUIPPED WITH SUCH A COOLING DEVICE

Abstract

The invention relates to a device (30) for cooling heat-sensitive control members (29) of a pneumatic or electropneumatic valve (20), comprising a containment casing (31) designed to contain said control members (29): a fresh air inlet (32) in said containment casing (31); an air outlet (33) of said containment casing, provided with a ventilation air tube (34) that comprises: an air acceleration column (35) which puts into fluidic communication said containment casing (31) and the air outlet (33); a primary supply (37) for supplying the acceleration column (35) with primary air; a secondary supply (38) for supplying the acceleration column (35) with secondary air, provided in said containment casing (31) such that the primary air can drive and accelerate the secondary air in the direction of the air outlet so as to produce forced air ventilation in said containment casing (31) between the air inlet (32) and the air outlet (33).

Claims

1. A device for cooling heat-sensitive control members of a pneumatic or electro-pneumatic valve capable of being arranged in an environment subjected to temperatures above the nominal operating temperatures of these control members, the device comprising: a containment casing adapted to contain said control members of said pneumatic valve, a fresh air inlet in said containment casing, an air outlet of said containment casing, which outlet is equipped with an air mover comprising: an air acceleration column placing said containment casing and said air outlet in fluid communication; a primary supply, of primary air having a temperature and pressure greater than the temperature and pressure of the fresh air, to the acceleration column, a secondary supply of secondary air, present in said containment casing, to said acceleration column, such that said primary air drives and accelerates the secondary air toward said air outlet so as to produce forced ventilation of air in said containment casing between said air inlet and said air outlet.

2. The cooling device according to claim 1, wherein said primary supply is in fluid communication with an air chamber arranged downstream of a pneumatic regulator of said valve so as to ensure forced ventilation which is not very sensitive to the operating conditions of said valve.

3. The cooling device according to claim 1, wherein said primary supply is in fluid communication with a chamber arranged downstream of a member for activating said air valve, of the activation solenoid type, so that said forced ventilation provided by said air mover is only effective when said valve is activated by said activation member.

4. A pneumatic or electro-pneumatic valve comprising a valve body comprising an air inlet, an air outlet and an air circulation duct between the air inlet and the air outlet, a closure member movably mounted in said circulation duct between at least one open position in which air may freely circulate from said inlet to said outlet, and a closed position in which the closure member prevents the passage of air from the inlet (22) to said outlet, and control members of said closure member, wherein the valve further comprises a device for cooling said control members so that said valve may be arranged in an environment, such as an aircraft engine environment, capable of being subjected to temperatures above the nominal operating temperatures of said control members, the device comprising: a containment casing adapted to contain said control members of said pneumatic valve, a fresh air inlet in said containment casing, an air outlet of said containment casing, which outlet is equipped with an air mover comprising: an air acceleration column placing said containment casing and said air outlet in fluid communication; a primary supply, of primary air having a temperature and pressure greater than the temperature and pressure of the fresh air, to the acceleration column, a secondary supply of secondary air, present in said containment casing, to said acceleration column, such that said primary air drives and accelerates the secondary air toward said air outlet so as to produce forced ventilation of air in said containment casing between said air inlet and said air outlet.

5. The valve according to claim 4, wherein said primary supply of said acceleration column of said cooling device is connected to said air circulation duct of the valve, upstream or downstream of said closure member, so that said primary air is the air circulating in said valve body.

6. The valve according to claim 4, wherein the valve further comprises an integrated pneumatic regulating member and said primary supply of said acceleration column of said cooling device is connected downstream of said regulating member.

7. The valve according to claim 4, wherein the valve comprises a member for activating the valve, of the activation solenoid type, and said primary supply of said acceleration column of said cooling device is connected downstream of said activation member so that said forced ventilation is only effective when said valve is activated by said activation member.

8. The valve according to claim 5 wherein said air inlet in said containment casing of said cooling device is connected to an air duct supplied with air from a fan of a propulsion engine of an aircraft.

9. The valve according to claim 5 wherein said secondary supply of said cooling device is connected to an air duct supplied with air from a compressor of a propulsion engine of an aircraft.

10. The valve according to claim 5 characterized in that wherein said control members comprise members of organic origin such as coatings, varnishes, membranes and in general any member capable of having thermal performance that deteriorates over time.

Description

5. LIST OF FIGURES

[0047] Further objectives, features and advantages of the invention will become apparent upon reading the following description, which is provided solely by way of non-limiting example, and which refers to the appended drawings, in which:

[0048] FIG. 1 is a functional schematic view of a valve according to an embodiment of the invention equipped with a cooling device according to an embodiment of the invention and installed within an air bleed system on a propulsion engine of an aircraft,

[0049] FIG. 2 is a functional schematic view of a valve according to an embodiment of the invention equipped with a cooling device according to an embodiment of the invention,

[0050] FIG. 3 is a detailed functional schematic view of the cooling device of FIG. 2,

[0051] FIG. 4 is a detailed functional schematic view of a cooling device according to another embodiment,

[0052] FIG. 5 is a functional schematic view of a valve according to another embodiment equipped with a cooling device according to another embodiment of the invention.

6. DETAILED DESCRIPTION OF ONE EMBODIMENT OF THE INVENTION

[0053] For the sake of illustration and clarity, scales and proportions are not strictly adhered to in the figures. Throughout the detailed description which follows with reference to the figures, unless otherwise indicated, each element of the cooling device is described as it is arranged when it equips a valve according to an embodiment of the invention.

[0054] Moreover, identical, similar or analogous elements are denoted using the same reference signs throughout the figures.

[0055] FIG. 1 schematically illustrates an air bleed system intended to supply an air conditioning pack for a cabin of an aircraft and comprising a valve according to one embodiment of the invention.

[0056] The system of FIG. 1 comprises a propulsion engine 10 of an aircraft comprising an air bleed port 11 connected by a duct 12 to an air bleed valve 20 according to an embodiment of the invention, which is better known by the acronym PRV (pressure regulating valve), itself connected to a heat exchanger 16, better known as a precooler. The air bleed valve 20 is equipped with a device 30 for cooling the control members according to one embodiment of the invention of the air bleed valve 20. The air bleed system also comprises an air bleed port 13 on the secondary flow of the engine 10, which flow is better known as fan air. This fan air circulates to the precooler 16 via a valve 17, better known by the acronym FAV (fan air valve), in order to cool the flow of hot air taken from the port 11. The air flow exiting the precooler 16 is then directed to an air conditioning system 40 of a cabin of the aircraft. The cooling device 30 is supplied with fan air via a duct 15. As described in connection with FIGS. 2 to 5, this fan air is then accelerated by an air mover, not shown in FIG. 1, to allow the cooling of the control members of the valve 20.

[0057] FIG. 2 illustrates in a little more detail the valve 20 equipped with the cooling device 30.

[0058] The valve 20 comprises a valve body 21 comprising an air inlet 22, an air outlet 23, an air circulation duct 24 between the air inlet and the air outlet, and a butterfly valve 25 forming a closure member movably mounted in the circulation duct to allow or not allow the passage of air from the air inlet 22 to the air outlet 23.

[0059] This valve 20 is equipped with a cooling device 30 for the control members of the valve.

[0060] This device comprises a containment casing 31 adapted to contain the control members of the valve 20. This casing 31 may be made of any type of material compatible with the environment in which it is intended to be installed, in particular in an engine environment.

[0061] This casing 31 defines an enclosure 36 supplied with air by a fresh air inlet 32. The casing also includes an air outlet 33 equipped with an air mover 34.

[0062] This air mover 34 comprises an air acceleration column 35 placing the enclosure 36, delimited by the casing 31, and the air outlet 33 in fluid communication.

[0063] The air mover 34 is supplied with air from both a primary supply 37 in fluid communication with a source of hot air and from a secondary supply 38 in fluid communication with the enclosure 36 delimited by the casing 31.

[0064] The secondary air present in the casing 31 is the fresh air introduced into the casing, possibly reheated in contact with the control members.

[0065] The architecture of the device is such that the primary air is hotter than the secondary air.

[0066] Moreover, the primary air may drive and accelerate the secondary air toward the air outlet 33 so as to produce forced air ventilation in the containment casing 31 between the air inlet 32 and the air outlet 33.

[0067] According to the embodiment of FIG. 2, the source of fresh air supplying the air inlet 32 is the fan air taken from the secondary flow of the engine 10.

[0068] According to the embodiment of FIG. 2, the source of hot air supplying the forced air mover 34 is air tapped at an air chamber downstream of the valve regulator 40.

[0069] FIG. 3 illustrates this air tapping downstream from the regulator 40 of the valve 20 in more detail.

[0070] The regulator 40 comprises, by way of example and as shown in FIG. 3, an inlet 41 for high-pressure air which is the hot air circulating downstream of the closure member 25 of the valve and which supplies a first chamber 42 of the regulator. The regulator also comprises an inlet 43 for a control fluid supplying a second pressure chamber 44. In addition, the regulator comprises a member 47 movable as a result of the pressure of the hot air and of the control fluid. This control member 47 is configured to be able to act on a membrane 48 which delimits a pressure chamber 49 connected to the primary supply 37 of the air mover 34.

[0071] The experiments carried out by the inventors demonstrate that, for an air mover equipped with a 2 mm injector, supplied by secondary air taking in fan air and implemented downstream of a regulator calibrated at 49 psig, the ventilation gains are between 4 and 38% relative to natural ventilation (estimated from a 0 mm injector).

[0072] According to another embodiment as shown in FIG. 4, the primary supply 37 of the air mover 34 is connected to a chamber 52 downstream of a control solenoid 51. Thus, the air mover 34 is supplied with primary air only when the valve is active.

[0073] FIG. 5 illustrates a valve according to another embodiment in the form of an air compressor discharge valve.

[0074] This valve comprises control members 29 housed in the casing 31. The casing 31 is supplied with fresh air taken from the secondary flow. The air outlet 33 of the casing opens into the secondary flow. The primary air supply to the acceleration column 35 is connected directly to a chamber downstream of the closure member of the valve. Thus, the supply is only effective when the discharge valve is open and supplied by the hot air from the compressor.

[0075] In other words, in the case of the engine discharge valve illustrated in FIG. 5, the cold air is supplied by the Venturi effect by using, on the primary circuit of the air mover, the pressure discharged by the valve in the open position, and, on the secondary circuit, the cold air taken from the secondary flow. This therefore makes it possible to force the ventilation when the calorie supply is greatest, i.e. when the valve is open.

[0076] In FIG. 5, the supply of the actuator chamber of the discharge valve is not shown in the interest of clarity.

[0077] If the control member is positioned outside the discharge duct of the valve, dedicated ventilation is obtained which is only active when the valve is opened.

[0078] If the control member is positioned inside the discharge duct of the valve, the situation is similar but with the addition of recirculation of air in the secondary flow. Furthermore, the internal location in the discharge duct makes it possible to optionally benefit from natural ventilation (at a lower flow rate than when the air mover is activated) if the ventilation tapping in the secondary flow makes it possible to recover the dynamic pressure.

[0079] Another variant consists in having permanent forced ventilation by supplying the primary of the air mover regardless of the state of the discharge valve. This then involves a permanent bleed from the compression stage.

[0080] The implementation of an air mover supplied in secondary by the air of the secondary flow therefore allows integrated ventilation of the sensitive components on board the discharge valve.

[0081] The experiments carried out by the inventors have made it possible to demonstrate that for a primary air pressure of approximately 20 bar, a secondary air pressure of approximately 1.5 bar, and an injector of 1 mm, the gains in ventilation of a device according to the invention are approximately 6 g/s of fresh air in a 5 mm duct.

[0082] The invention is mainly intended to cool heat-sensitive elements associated with a pneumatic or electro-pneumatic valve intended to be installed in an engine environment. However, a device according to the invention could also be used as a moderate heating means by mixing the very hot primary flow and the cold secondary flow implemented in a device according to the invention.