CN216078678U - Bleed conduit leakage gas collecting and guiding device - Google Patents

Abstract

The utility model relates to a device for collecting and guiding leaked gas of a high-pressure bleed air guide pipe of an airplane, which comprises: a bleed conduit; and a thermal insulation layer surrounding the bleed air conduit; wherein an air interlayer is formed between the air guide conduit and the heat insulating layer, and a plurality of leakage detection holes are arranged on the heat insulating layer; the air guide device is characterized in that a flow guide ring is further arranged between the air guide pipe and the heat insulation layer, the flow guide ring is arranged between at least two leakage detection holes in the multiple leakage detection holes in the longitudinal direction of the air guide pipe, when the flow guide ring extends from the outer wall of the air guide pipe to the inner wall of the heat insulation layer, at the moment, a flow path between the at least two leakage detection holes through an air interlayer is isolated by the flow guide ring, the flow guide ring is composed of multiple flow guide sheets, and at least one flow guide sheet of the multiple flow guide sheets is overturned to enable the flow path to be communicated with each other along with the increase of the pressure of gas leaked from the air guide pipe. The problem that the temperature of a leaking gas core area of the bleed air guide pipe is low due to the shock wave phenomenon can be prevented, and therefore timeliness and accuracy of detecting leaking gas are improved.

Description

Bleed conduit leakage gas collecting and guiding device

Technical Field

The utility model relates to the technical field of aviation, in particular to a device for collecting and guiding leaked gas of a high-pressure bleed air guide pipe in an airplane.

Background

The high-pressure bleed air guide pipe of the airplane is filled with high-temperature high-pressure gas, and once the high-temperature high-pressure gas leaks due to the breakage of the guide pipe, the high-temperature high-pressure gas can damage the composite material structure of the airplane body and surrounding electronic equipment, and the safety of the airplane is affected. In order to warn against damage in time in the event of a gas leak, a detection opening is usually arranged on the outside of the hot bleed air duct and an overheating detection device is arranged in the vicinity above the detection opening. If the high-pressure bleed air guide pipe leaks, when the temperature sensed by the detection device reaches the melting point of the eutectic salt solution, the detection device can send alarm information to timely isolate the leakage area of the guide pipe, so that the negative influence of high-temperature gas leakage on flight safety is avoided.

In order to allow the leaking gas to be rapidly ejected from the detection holes and sensed by the detection device, the leaking gas from the bleed air duct needs to be collected and guided in stages. In the early stage of leakage, leaked gas needs to be collected in a small closed area in time, so that the gas can flow out from the detection hole rapidly under the driving of pressure, and the leakage can be detected and responded in time; and in the later stage of leakage, leakage gas needs to be guided timely, so that the situation that the detection hole pressure ratio is too large to cause shock wave formation, and the shock wave can cause the temperature of a core region of the leakage gas to be too low, thereby influencing the detection accuracy and timeliness of the leakage detection device.

Chinese utility model patent CN1707236B mentions the use of a cuff with a container. The cuff is secured to a circumferential cut-out in the insulation of the conduit to form a reservoir for the hot air leaking from the conduit.

US8708554B2 proposes a leak detection system consisting of a sleeve, a flat air conducting chamber, a leak detection wire and a straight air conducting tube.

Chinese patent CN103775831B proposes a system for detecting leakage of high temperature pressure air pipeline of aircraft, which is an integral structure formed by connecting a plurality of detection units distributed continuously along the axial direction of the pipeline in series, and collects and guides the leakage air by arranging vent holes on the surface of the heat insulation layer of the high temperature conduit.

Japanese patent JP5647553B2 proposes a gas leakage prevention detecting device that obtains a gas leakage situation by arranging an inner and outer double-layer sealed chamber at a conduit connection portion to collect leakage gas and measuring a change in the concentration of the gas in the sealed chamber with time by means of a concentration detecting device.

However, the bleed air duct leak detection devices according to these prior art solutions do not allow for separate early collection and late diversion for different leak phases. Thus, there is room for improvement in existing bleed duct leak detection techniques.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects in the prior art, the utility model provides a device for collecting and guiding leaked gas of a high-pressure bleed air guide pipe of an airplane, which comprises: a bleed conduit; and a thermal insulation layer surrounding the bleed air conduit; wherein an air interlayer is formed between the bleed air conduit and the thermal insulation layer, and a plurality of leakage detection holes are arranged on the thermal insulation layer; the thermal insulation layer is characterized in that a flow guide ring is further arranged between the air guide pipe and the thermal insulation layer and is arranged between at least two leakage detection holes in the plurality of leakage detection holes in the longitudinal direction of the air guide pipe, the flow guide ring extends from the outer wall of the air guide pipe to the inner wall of the thermal insulation layer, at the moment, a flow path between the at least two leakage detection holes through the air interlayer is blocked by the flow guide ring, the flow guide ring is composed of a plurality of flow guide sheets, and when the pressure of gas leaked from the air guide pipe reaches a preset value, at least one flow guide sheet of the plurality of flow guide sheets is overturned to enable the flow path to be communicated.

According to the technical scheme of the utility model, the gas leaked from the air guide pipe is collected by the multiple groups of flow deflectors positioned in the air interlayer, and the flow of the leaked gas in the air interlayer is guided in the later period of leakage, so that the device can improve the warning timeliness and accuracy of the leakage detection system.

According to another aspect of the utility model, the deflector ring in the bleed air duct leakage gas collection and deflector arrangement comprises a plurality of flexible deflector vanes, each deflector vane being wedge-shaped in a cross-section perpendicular to said bleed air duct, and the plurality of wedge-shaped deflector vanes forming the deflector ring against each other when the deflector vanes are perpendicular to the outer surface of the bleed air duct.

The guide vane is wedge-shaped and the guide vane edge abut against each other but are not fixedly connected to each other, so that they can form a ring in a state perpendicular to the outer wall surface of the bleed air duct.

According to a further aspect of the utility model, the bleed air duct leakage gas collection and flow guide device is characterized in that each of said flexible baffles of the bleed air duct leakage gas collection and flow guide device has an outer periphery secured to the inner surface of said insulation layer and the baffles are turned around said outer periphery so that the inner periphery of said baffles exits said bleed air duct.

The arrangement of the flexible baffle is such that the baffle can be flipped up if a significant pressure difference occurs between the pressures of adjacent air sandwich sections, the inner periphery of the baffle being separated from the outer wall surface of the bleed duct, the adjacent baffle edges being separated from each other, thereby enabling the airflow to flow through the baffle ring into the adjacent air sandwich sections.

According to a further aspect of the utility model, the width of the outer periphery is greater than the width of the inner periphery of the baffle in a longitudinal cross-section along the longitudinal axis of the bleed conduit.

Preferably the baffle tapers from the outer periphery to the inner periphery at a wide base in a direction along the longitudinal axis of the bleed conduit, the inner periphery of the baffle forming substantially line contact with the outer wall surface of the bleed conduit when the baffle is perpendicular to the outer wall surface of the bleed conduit.

In this way the contact area between the guide vane and the outer wall surface of the bleed air duct is minimised, thereby minimising the amount of heat that is conducted away from the outer wall surface of the bleed air duct by the guide vane.

According to a further aspect of the utility model, each guide vane has the same shape.

According to a further aspect of the utility model, the probe holes in the insulating layer are evenly distributed in the longitudinal direction of the bleed air duct.

According to yet another aspect of the utility model, the deflector ring is preferably constructed of 12 to 20 flexible deflector plates.

According to yet another aspect of the utility model, the deflector ring is made of a thermally insulating material.

According to a further aspect of the utility model the bleed duct leakage gas collection and diversion arrangement comprises a pre-leak mode in which the inner circumference of the diversion ring on adjacent sides of the leakage aperture in the bleed duct abuts the outer wall surface of the bleed duct and a post-leak mode in which the inner circumference of the diversion ring on adjacent sides of the leakage aperture in the bleed duct leaves the outer wall surface of the bleed duct.

The utility model provides a flexible guide ring arranged in an air interlayer between a heat insulating layer and a bleed air guide pipe, wherein the guide ring is fixedly arranged on the inner wall surface of the heat insulating layer and positioned in the middle of each detection hole on the heat insulating layer. The structure is made of flexible materials and can deform under the stress condition. The flexible guide ring is equally divided into a plurality of guide vanes, each guide vane can respectively move under the action of external force, and the communication and the closed state of the air interlayer are controlled. When the leakage process begins, the pressure in the air interlayer is very low, the flexible flow guide ring does not deform, and gas can be quickly collected and sprayed out from the detection hole; when the leakage occurs for a period of time, the pressure in the air interlayer rises, the flexible flow guide ring is stressed to deform, the leaked gas is guided into the adjacent air interlayer, and the pressure ratio at the detection hole is ensured not to exceed the critical pressure ratio for forming the shock wave.

The device can prevent the problem of low temperature of the core region of the leaked gas of the bleed air duct caused by the shock wave phenomenon, so the timeliness and the accuracy of the detection of the leaked gas can be improved by adopting the device.

Drawings

For a more complete understanding of the present invention, reference is made to the following description of exemplary embodiments taken in conjunction with the accompanying drawings, in which:

figure 1A shows a longitudinal cross-sectional view of a bleed air duct leakage gas collection and diversion arrangement in accordance with a preferred embodiment of the present invention in the absence of gas leakage;

figure 1B shows a cross-sectional view of the bleed air duct leakage gas collection and flow guide arrangement when gas is not leaking according to a preferred embodiment of the present invention taken along a-a in figure 1A;

figure 2A shows a longitudinal cross-sectional view of the bleed air duct leakage gas collection and diversion arrangement in an early stage of gas leakage according to a preferred embodiment of the present invention;

figure 2B shows a cross-sectional view of the bleed air duct leakage gas collection and diversion arrangement taken along a-a in figure 2A at an early stage of gas leakage according to a preferred embodiment of the present invention;

figure 3A shows a longitudinal cross-sectional view of a bleed air duct leakage gas collection and diversion arrangement according to a preferred embodiment of the present invention in the late stage of a gas leakage; and

figure 3B shows a cross-sectional view of the bleed air duct leakage gas collection and flow guide arrangement according to a preferred embodiment of the present invention in the late stage of a gas leakage, taken along a-a in figure 3A.

List of reference numerals

1 line of detection

2 insulating layer

3 leakage detection hole

4 flow guide ring

41 flow deflector

5 air-entraining duct

6 conduit leakage hole

7 air interlayer

71. 72, 73 air sandwich segment

Detailed Description

The present invention is further described in the following description with reference to specific embodiments and the accompanying drawings, wherein the details are set forth in order to provide a thorough understanding of the present invention, but it is apparent that the present invention can be embodied in many other forms different from those described herein, and it will be readily appreciated by those skilled in the art that the present invention can be implemented in many different forms without departing from the spirit and scope of the utility model.

Fig. 1A and 1B show a longitudinal section and a cross section of a bleed air duct 5 leakage gas collecting and flow guiding device according to the utility model. The collecting and flow-guiding device comprises a bleed air duct 5 and an insulating layer 2. The insulating layer 2 surrounds the bleed air duct 5 from the outside. The bleed air duct 5 and the insulating layer 2 have the same contour shape, for example, both tubular. The bleed air duct 5 and the insulating layer 2 have different diameters and are arranged substantially concentrically such that the bleed air duct 5 and the insulating layer 2 are spaced apart by a distance, thereby forming an air interlayer 7 therebetween. The distance between the bleed air duct 5 and the insulation layer 2 can be set as desired. Both the air interlayer 7 and the insulating layer 2 provide thermal insulation protection for the bleed air duct 5, avoiding damage caused by high temperature gas passing through the bleed air duct 5.

Further, the diameter of the detection holes in the collection and flow guide means comprising a plurality of leakage detection holes 3 provided in the insulating layer 2 is preferably in the range of 20-30 mm, preferably 25mm, and the detection hole spacing is for example in the range of 50-200 mm. The detection holes 3 are formed through the heat insulating layer 2, and if the bleed air duct 5 is broken to cause internal gas leakage, the gas escapes from at least one of the detection holes 3 to be measured by the detection line 1 disposed in alignment with the detection holes 3.

It is important that a deflector ring 4 is further included between the bleed air duct 5 and the insulating layer 2, and that the deflector ring 4 is arranged between at least two leak detection holes 3 of the plurality of leak detection holes 3 in the longitudinal direction of the bleed air duct 5. The deflector ring 4 is arranged to extend from the outer wall of the bleed air duct 5 to the inner wall of the insulation layer 2, the flow path between two adjacent leakage detection holes 3 through the air interlayer 7 being interrupted by the deflector ring 4.

In particular, in the section of the bleed air duct 5 shown in fig. 1A, the heat insulating layer 2 is provided with three detection holes 3, which detection holes 3 are evenly distributed in the longitudinal direction of the bleed air duct 5. And comprises four deflector rings 4, each of the four deflector rings 4 extending from the outer wall of the bleed air duct 5 to the inner wall of the insulation layer 2, and the four deflector rings 4 being evenly distributed along the longitudinal direction of the bleed air duct 5, a separate air sandwich section 71, 72 and 73 being formed between each two adjacent deflector rings 4, a probe hole 3 being provided in the insulation layer 2 of each air sandwich section 71, 72 and 73, preferably the probe hole 3 being arranged centrally in the longitudinal length of the air sandwich section 71, 72 and 73.

In addition, as shown in fig. 1A, the three detection holes 3 are arranged in the same straight line, and the detection line 1 is aligned with the detection holes 3 and is substantially parallel to the straight line of the detection holes 3.

As shown in fig. 1B, the baffle ring 4 is formed by a plurality of baffles 41, the baffles of which are turned to communicate the flow path when the pressure of the gas leaking from the bleed air duct 5 reaches a predetermined value. Preferably, the deflector ring 4 comprises a plurality of flexible deflectors 41, each flexible deflector 41 having an outer periphery fixed to the inner surface of the insulating layer 2, the deflectors 41 being turned up around the outer periphery so that the inner periphery of the deflector 41 leaves said bleed air duct 5 when a leakage of the air flow occurs in the bleed air duct 5.

According to a preferred embodiment, the flexible baffles 41 may be formed integrally with the insulation layer 2. In an alternative embodiment, the flow deflector 41 may also be glued to the inner surface of the heat insulating layer 2.

Each guide vane 41 is wedge-shaped in a cross-section perpendicular to the bleed air duct 5, and a number of wedge-shaped guide vanes are connected to each other to form a guide ring 4. As shown in fig. 1B, by "wedge-shaped" is meant that the circumferential length of the outer circumference of the guide vane is larger than the circumferential length of the inner circumference of the guide vane. In the preferred form shown in fig. 1B, the guide ring 4 is formed by 16 guide vanes abutting each other and each guide vane is of the same size.

It should be understood that in other alternative embodiments the deflector ring 4 may comprise other numbers of deflector plates 41, for example the number of deflector plates 41 may be greater or less than 16, in particular depending on the nature of the air flow in the bleed air duct 5, the pipe diameter, etc.

Furthermore, it can also be seen from fig. 1A that the width in longitudinal section along the longitudinal axis of the bleed air duct 5 is also greater for the outer circumference of the guide vane 41 than for the inner circumference of the guide vane 41. In longitudinal section, the inner periphery of the guide vane 41 forms a tip, so that the inner periphery of the guide vane 41 abuts in line contact against the outer periphery of the bleed air duct 5. Since the contact area between the inner peripheral edge of the baffle 41 and the outer peripheral surface of the duct is extremely small, the baffle 41 does not conduct the heat of the gas from the air guide duct 5 to the outside. It will be appreciated that in other alternatives the deflector ring 4 may be formed in other shapes, such as a laminar shape, in cross-section along the longitudinal axis of the bleed air duct 5.

The material of the deflector ring 4 may preferably be made of a material with a low thermal conductivity, such as carbon fiber prepreg or other composite materials.

Next, the operation of the collecting and guiding device according to the present invention will be described with reference to fig. 1A, 2A and 3A.

Fig. 1A and 1B show a longitudinal section and a cross section of a bleed air duct 5 leaking gas collection and flow guidance device according to a preferred embodiment of the utility model in the absence of gas leakage. As shown in figure 1A, the walls of the bleed air duct 5 are intact and no gas leakage occurs. The air interlayer 7 between the heat insulating layer 2 and the air guide pipe 5 is communicated with the outside through an exposed hole, no pressure exists in the air guide pipe 5 at the moment, and the flow guide ring 4 is perpendicular to the outer wall surface of the pipe 5, so that the inner periphery of the flow guide ring 4 is completely attached to the outer wall surface of the air guide pipe 5 as shown in fig. 1B. The air interlayer 7 is divided into a plurality of sections by the guide ring 4, and no gas flows between the sections.

Fig. 2A and 2B show a longitudinal section and a cross section of the bleed air duct 5 leakage gas collection and flow guidance device in the early stages of a gas leakage according to a preferred embodiment of the utility model. As shown in fig. 2A, when breakage of the bleed air duct 5 has just occurred and gas in the duct 5 has just leaked, the apparatus is in an initial mode of gas leakage, and gas is ejected from the leak hole 6 in the bleed air duct 55, and a high-pressure region is formed in the insulating layer 2 and the intermediate air sandwich section 72 between the 2 nd and third deflector rings 4 from the left as shown in fig. 2A, and finally ejected from the leak detection hole 3 in the insulating layer 2. High-temperature gas is sprayed to the detection line 1 through the detection hole 3, warning is generated, and a driver is reminded to cut off bleed air in time.

Fig. 3A and 3B show a longitudinal section and a cross section of the bleed air duct 5 leakage gas collection and flow guiding device in the later stages of a gas leakage according to a preferred embodiment of the utility model. As shown in fig. 3A and 3B, when the arrangement is in the late mode of gas leakage, gas leaking out of the leakage holes 6 in the bleed air duct 5 continues to accumulate in the intermediate air sandwich section 72 between the insulation layer 2 and the flexible baffle ring 4, resulting in an increasing pressure therein. When the pressure rises to a certain value, the guide vanes 41 of the guide ring 4 deform, the flexible guide rings 4 on the two sides of the leakage hole 6 bend and turn up towards the two sides, so that a flow channel of the leaked gas in the air interlayer 7 is opened, the gas flow in the middle air interlayer section is guided towards the air interlayer sections on the two sides, the pressure ratio at the detection hole 3 is not more than the critical pressure ratio for forming shock waves, the pressure in the air interlayer 7 is not more than the back pressure required for generating supersonic speed, and the core region expansion and temperature reduction process of the leaked gas near the detection line 1 is prevented.

Although the present invention has been disclosed in terms of the preferred embodiment, it is not intended to limit the utility model, and variations and modifications may be made by one skilled in the art without departing from the spirit and scope of the utility model. Therefore, any modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope defined by the claims of the present invention, unless the technical essence of the present invention departs from the content of the present invention.

Claims (10)

1. A bleed conduit leak gas collection and diversion apparatus comprising:

a bleed conduit; and

a thermal insulation layer surrounding the bleed air conduit;

wherein an air interlayer is formed between the bleed air conduit and the thermal insulation layer, and a plurality of leakage detection holes are arranged on the thermal insulation layer;

characterized in that a deflector ring is further included between the bleed air duct and the insulating layer and is arranged in the longitudinal direction of the bleed air duct between at least two of the plurality of leakage detection holes, the deflector ring extending from the outer wall of the bleed air duct to the inner wall of the insulating layer, when the flow path between the at least two leakage detection holes through the air interlayer is interrupted by the deflector ring,

the deflector ring is formed of a plurality of deflector vanes, at least one of which is turned to communicate the flow path as the pressure of the gas leaking from the bleed air duct increases.

2. The bleed duct leak gas collection and diversion apparatus of claim 1 wherein the deflector ring comprises a plurality of flexible deflectors, the side edges of adjacent deflectors abutting each other and each deflector being wedge-shaped in cross-section perpendicular to the outer wall of the bleed duct when the deflectors are each perpendicular to the outer wall of the bleed duct, the plurality of wedge-shaped deflectors abutting each other to form the deflector ring.

3. The bleed conduit leak gas collection and deflector device of claim 2, wherein an outer periphery of each of the flexible baffles is secured to an inner surface of the insulation layer and the baffles are turned around the outer periphery so that an inner periphery of the baffles exits the bleed conduit.

4. The bleed conduit leak gas collection and deflector device of claim 3, wherein the width of the outer periphery is greater than the width of the inner periphery of the deflector in a direction along the longitudinal axis of the bleed conduit.

5. The bleed conduit leak gas collection and deflector device of claim 4, wherein the wide base of the deflector in the direction along the longitudinal axis of the bleed conduit tapers from the outer periphery to the inner periphery, the inner periphery of the deflector forming substantially line contact with the outer wall surface of the bleed conduit when the deflector is perpendicular to the outer wall surface of the bleed conduit.

6. Bleed duct leakage gas collection and flow guide arrangement according to claim 2, characterised in that each guide vane has the same shape.

7. The bleed duct leak gas collection and flow guide apparatus of claim 1, wherein the probe holes in the insulating layer are evenly distributed in the longitudinal direction of the bleed duct.

8. The bleed duct leak gas collection and diversion apparatus of claim 2 wherein the diversion ring comprises 12 to 20 flexible diversion flaps.

9. The bleed conduit leak gas collection and diversion apparatus of claim 1 wherein the deflector ring is made of a thermally insulating material.

10. The bleed air duct leak gas collection and diversion arrangement of claim 1, wherein the arrangement includes a pre-leak mode and a post-leak mode second mode,

wherein in the pre-leakage mode, the inner peripheries of the diversion rings at two adjacent sides of the leakage hole in the bleed air duct are abutted against the outer wall surface of the bleed air duct,

in the later leakage mode, the inner peripheries of the diversion rings on two adjacent sides of the leakage hole in the bleed air duct leave the outer wall surface of the bleed air duct.

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