JP6194177B2 - Air-cooled heat exchanger for aircraft - Google Patents

Description

  The present invention relates to an air-cooled plate fin heat exchanger mounted on an aircraft, and more particularly to an air-cooled heat exchanger for an aircraft that is installed facing the outside of the apparatus for introducing cooling air.

  Aircraft is equipped with various air-cooled heat exchangers, including engine oil coolers and air conditioner heat exchangers. There are many departments. Moreover, as the structure of such an air-cooled heat exchanger for an aircraft, a plate fin type structure is often adopted mainly from the viewpoint of weight and heat exchange efficiency. A typical plate fin type heat exchanger is a cross flow type (refer to patent documents 1 and 2).

  As shown in FIG. 3, the cross-flow type plate fin heat exchanger includes corrugated fins 1A disposed between the side bars 2A and 2A on both sides of the fluid flow direction, and side bars 2B and 2B on the both sides of the fluid flow direction. Corrugated fins 1B that are arranged between them and whose fluid flow direction is orthogonal to the corrugated fins 1A are alternately stacked together with the side bars 2A, 2A and 2B, 2B on both sides via the tube plate 3, and the stacking direction The two end portions are closed by end plates 4 and 4. The end plates 4 and 4 are generally referred to as side plates, but are referred to as end plates (end plates) here in order to clarify the difference in positional relationship with the side bars 2.

  When this heat exchanger is air-cooled, the space between the side bars 2A, 2A in which one of the two orthogonal corrugated fins 1A, 1B is arranged becomes the air flow passage 5A, and the side bar in which the other is arranged The space between 2B and 2B becomes the cooled fluid flow passage 5B. Thus, the air flow passage 5A and the cooled fluid flow passage 5B are stacked while being alternately orthogonal to each other via the tube plate 3. The heat exchanger end faces on both ends in the fluid flow direction in the air flow passage 5A are exposed end faces for opening both ends of the air flow passage 5A, whereas both ends in the fluid flow direction in the cooled fluid flow passage 5B. The end face of the heat exchanger on the side is closed by headers 6 and 6 for distributing and supplying the fluid to be cooled and collecting the collected fluid.

  Such a plate fin type heat exchanger is made of an aluminum-based metal and uses a lot of thin plates, so that it has excellent heat exchange performance and is lightweight. It is frequently used in exchangers (see Patent Document 3). However, in the case of an air-cooled heat exchanger for an aircraft, the exposed end surface on the air inflow side of the heat exchanger faces the outside of the aircraft in connection with the introduction of outside air into the air flow passage 5A. There is a danger of flying objects such as When a flying object such as ice or a bird collides with the exposed end face, the corrugated fin 1A in the air flow passage 5A among the members exposed on the exposed end face is deformed, which becomes a problem.

That is, on the exposed end surface of the heat exchanger, as can be seen from FIG. 3, the tip edge portion of the corrugated fin 1 </ b> A in the air flow passage 5 </ b> A is exposed. The plate thickness is generally as thin as 0.1 mm. For this reason, when a flying object collides with the exposed end surface of the heat exchanger, the tip of the corrugated fin 1A easily deforms, and the deformation causes a bad influence on the heat exchange performance.

  As a measure for preventing damage to the corrugated fin 1A on the exposed end face located on the air inflow side of the heat exchanger, a protective member such as a thick guard fin is usually attached to the exposed end face. There is a risk that the heat exchange performance will be reduced. In addition, the number of parts increases, which adversely affects manufacturing costs and causes weight increase, which is one of the biggest problems in aircraft.

  Protective members such as guard fins are damaged not only during use after mounting the heat exchanger on the fuselage, but also during handling and storage during the heat exchanger assembly process, transport process, mounting process on the fuselage, etc. Therefore, a guard fin or a similar protective member may be attached to the opposite exposed end surface located on the air outflow side of the heat exchanger.

  As can be seen, one of the weak points of air-cooled heat exchangers for aircraft consisting of cross-flow type plate fin heat exchangers is deformation damage at the corrugated fin end in the air flow passage at the exposed end surface of the air flow passage. It is.

Japanese Utility Model 6-24691 Japanese Utility Model Publication 6-45162 JP 2009-36193 A

  The object of the present invention is to replace the corrugated fin end damage in the air flow passage at the exposed end face, despite the fact that it consists of a plate fin type heat exchanger of high efficiency and lightweight cross flow type. While suppressing the decrease in efficiency, it can be reliably prevented without increasing the number of parts and manufacturing cost, and it is possible to reliably prevent damage to the end of the corrugated fin not only during use but also during handling and storage. The object is to provide an air-cooled heat exchanger for aircraft that is extremely rational.

  In order to achieve the above object, the present inventor has paid attention to the configuration of the exposed end surface characteristic of an air-cooled heat exchanger for an aircraft composed of a cross-flow type plate fin heat exchanger. That is, at this exposed end face, as shown in FIG. 3, a side for forming the corrugated fin 1A in the air flow passage 5A and the cooled fluid flow passage 5B between the end plates 4 and 4 at both ends in the stacking direction. The bars 2B are alternately arranged, more specifically, the end surfaces of the corrugated fins 1A in the fluid flow direction and the side surfaces of the side bars 2B are alternately arranged.

  Here, the height T of the side bar 2B is approximately the same as the height H of the corrugated fin 1A, and is usually several mm. The corrugated fin 1A having a height H of several millimeters is very thin, on the order of 0.1 mm, and is therefore fragile regardless of the height H. However, the side bar 2B having a height T of several millimeters is inherently In addition to its high strength, the dimension (depth) in the air flow direction, that is, the material width Wb is also secured to the same level as the height T, and it is integrated with other members by brazing. Therefore, sufficient mechanical strength is shown in the air flow direction. In fact, even if a flying object collides with the exposed end surface on the air inflow side of the heat exchanger, the damage to the side bar 2B is small. Further, the arrangement interval of the side bars 2B substantially coincides with the height H of the corrugated fin 1A and is about several mm.

  The inventor who pays attention to such an exposed end surface configuration is that the side bar 2B is effective against the corrugated fin 1A depending on the positional relationship of the end surface of the corrugated fin 1A with respect to the side surface of the side bar 2B in the air flow direction (depth direction). It was found that it can function as a safe protection grid.

The air-cooled heat exchanger for aircraft according to the present invention has been made based on such knowledge, and two orthogonal corrugated fins arranged between the side bars on both sides are connected to the side bars on both sides via the tube plate. The tubes are alternately stacked, both ends in the stacking direction are closed by end plates, air flows between tube plates in which one of two orthogonal corrugated fins is disposed, and the other is disposed in the tube It consists of a plate fin type air-cooled heat exchanger in which a fluid to be cooled flows between the plates, and at least one end surface in the air flow direction of the air-cooled heat exchanger, the tip surface of the corrugated fin for the air flow path is Retreats from the side of the side bar for the fluid flow path to the inside of the air flow path, and at the front end face and end plate of the side bar on both sides of the air flow path Air flow direction end face, Ri projecting end face der located on the side bar side flush with the cooled fluid passage, and, projecting from the distal end surface of the corrugated fins in the air flow path to the air flow direction outward The side surface of the side bar for the fluid flow path to be cooled, the front end surface of the side bar on both sides of the air flow path, and the end surface of the end plate in the air flow direction protrude outwardly in the air flow direction curved toward the adjacent air flow path. are the feature points on constituting the arc-shaped curved der Rukoto.

  In a conventional air-cooled heat exchanger for an aircraft comprising a cross-flow type plate fin type heat exchanger, the end surface of the air flow direction is the tip surface of the corrugated fin for the air flow path and the side bar for the cooled fluid flow path. If the projectile or obstacle collides with the air flow direction end face in this case, the tip of the corrugated fin, which is fragile, is limited and concentrated. It is inevitable to deform and damage.

  However, if the tip surface of the corrugated fin for the air flow path is retracted to the inside of the air flow path from the side of the side bar for the cooled fluid flow path, the latter protrudes relative to the former, When flying objects or obstacles collide with the end surface of the air flow direction, the impact is intensively received by the side bar for the to-be-cooled fluid flow path that is strong and strong, and retreats from the side bar to the inside of the air flow direction. It does not reach the tip of the corrugated fin. Thus, the side bar for the cooled fluid flow path on the exposed end surface functions as a protective grid for the corrugated fin for the air flow path, so that the tip of the corrugated fin can be damaged without attaching a protective member such as a guide fin. Effectively prevented.

  The exposed end face that retracts the tip face of the corrugated fin for the air flow path to the inside of the air flow path from the side surface of the side bar for the fluid flow path may be both ends in the flow direction. In either case, by making that side the air inflow side, deformation damage to the tip of the corrugated fin due to the collision of flying objects or obstacles can be prevented. In addition, damage to the tip of the fin due to an obstacle collision during handling or storage can be prevented at the exposed end surface on the air inflow side. If this evacuation structure is adopted at both ends in the flow direction, the same effect can be obtained at the exposed end surface on the air inflow side, and the exposed end surface on the air outflow side can be used for the fin tip due to obstacle collision during handling and storage. Damage can be prevented.

As the front end surface of the corrugated fin for the air flow path retreats from the side surface of the side bar for the cooled fluid flow path to the inside of the air flow path, the side surface of the side bar is outside the air flow direction from the front end surface of the corrugated fin. Project to The protruding side of the side bars are arcuate curved surface convex to the air flow direction outwardly curved toward the adjacent air passage. By doing so, the arc-shaped projecting side surface of the side bar exhibits a rectifying function (bell mouth function) with respect to the inflowing air, and suppresses the generation of turbulent flow, thereby facilitating the inflow of air into the adjacent air passages. As a result, it can be expected that not only a decrease in the air inflow efficiency due to the formation of the step due to the protruding side surface of the side bar is suppressed, but also that the air inflow efficiency is positively improved.

For members other than the side bars for the cooled fluid flow path surrounding the corrugated fins for the air flow path, such as side bars on both sides of the air flow path, end plates at both ends in the stacking direction, etc. These members should also function as part of the protective grid as projecting end surfaces located on the same plane as the side surfaces of the side bars for use. From this point of view, in the air-cooled heat exchanger for aircraft according to the present invention, the end surface of the side bar on both sides of the air flow path and the end surface in the air flow direction of the end plate are the same as the side surface of the side bar for the cooled fluid flow path. The projecting end face is located on a plane. These protruding end face, as well as the side bar of the side surface of the cooling fluid passage are arcuate curved surface convex to the air flow direction outwardly curved toward the adjacent air passage. By doing so, the air inflow efficiency to an air flow path can be raised more.

  The retracted amount of the end face of the corrugated fin at the end face in the air flow direction of the heat exchanger with respect to the side bar side is preferably 1 mm or more for the lower limit, and the upper limit is less than the dimension (depth) of the side bar in the air flow direction, Is preferable, and more preferably ½ or less of the material width Wb. The retracted amount is also a protruding amount of the side bar side surface with respect to the corrugated fin tip surface at the air flow direction end surface of the heat exchanger. If this is small, the effect of suppressing deformation damage at the tip of the corrugated fin when a flying object or an obstacle collides with the end surface of the heat exchanger in the air flow direction is small. On the other hand, if this is too large, the brazing property at the time of manufacturing the heat exchanger is lowered, and the reduction of the mechanical strength of the heat exchanger becomes a problem.

  That is, the heat exchanger is manufactured by brazing. In the brazing process, the component members are heated in a state of being pressurized in the laminating direction. However, if the retracted amount of the corrugated fin tip end surface relative to the side bar side surface at the end surface in the air flow direction of the heat exchanger is large, The overlap margin between the corrugated fin and the side bar is reduced, the pressure applied during brazing is not sufficiently transmitted in the stacking direction, and the brazing property is lowered, resulting in a decrease in the mechanical strength of the heat exchanger. In particular, if the retracted amount is greater than the dimension (depth) of the sidebar in the air flow direction, that is, the material width Wb or more, the overlap margin between the corrugated fins and the sidebar disappears, and the brazeability is extremely deteriorated. It is particularly important that the amount be less than the dimension (depth) of the sidebar in the air flow direction, that is, less than the material width Wb.

The air-cooled heat exchanger for aircraft according to the present invention has a corrugated fin tip for an air flow path on at least one exposed end face in the air flow direction of an air-cooled heat exchanger composed of a cross-flow type plate fin heat exchanger. By adopting a configuration in which the surface is retracted to the inside of the air flow path from the side surface of the side bar for the cooled fluid flow path, the front end surface of the side bar on both sides of the air flow path, and the end surface in the air flow direction of the end plate, Since the end plate itself functions as a protective grid, damage to the end of the corrugated fin in the air flow path at the exposed end surface due to collision of flying objects during use without adding a protective member such as a guard fin, It is possible to prevent damage to the end of the corrugated fin in the air flow path at the exposed end face due to the collision of an obstacle during handling and storage. For this reason, the fall of the heat exchange efficiency accompanying end surface protection can be suppressed effectively. Further, an increase in the number of parts and an increase in manufacturing cost can be effectively avoided.

It is a conceptual diagram which shows the structure of the air-cooling type heat exchanger for aircraft which shows 1st Embodiment of this invention, and is a perspective view. It is a conceptual diagram which shows the structure of the air-cooling type heat exchanger for aircraft which shows 2nd Embodiment of this invention, and is a perspective view. It is a conceptual diagram which shows the structure of the conventional air-cooling type heat exchanger for aircraft, and is a perspective view.

  Embodiments of the present invention will be described below with reference to the drawings.

  The air-cooled heat exchanger for aircraft according to the first embodiment is used, for example, for air conditioning in an aircraft, and is attached to a fan shroud of a gas turbine engine so that outside air can be taken in. This air-cooled heat exchanger for aircraft is configured by a cross-flow type plate fin heat exchanger, similarly to the conventional air-cooled heat exchanger for aircraft shown in FIG.

  The basic structure will be described with reference to FIG. 1. The first corrugated fin 1A disposed between the side bars 2A and 2A on both sides in the fluid flow direction and the fluid disposed between the side bars 2B and 2B on the both sides in the fluid flow direction. Second corrugated fins 1B whose distribution direction is orthogonal to corrugated fins 1A are alternately stacked together with side bars 2A, 2A and 2B, 2B on both sides via tube plate 3, and both end portions in the stacking direction are end plates. 4 and 4 are occluded.

  Of the space between the adjacent tube plates 3, 3, the space between the side bars 2A, 2A in which the first corrugated fins 1A are arranged is the air flow passage 5A, and the side in which the second corrugated fins 1B are arranged. The space between the bars 2B and 2B is the cooled fluid passage 5B. Thus, the orthogonal air flow passages 5A and the cooled fluid passages 5B are alternately stacked, and both ends in the stacking direction are the air flow passages 5A.

  Both ends in the flow direction of the air flow passage 5A are open. For this reason, the heat exchanger end faces on both ends in the flow direction of the air flow passage 5A are exposed end faces. The flow direction both ends of the cooled fluid flow passage 5B perpendicular to the air flow passage 5A are arranged in the headers 6 and 6 attached to the other end face of the heat exchanger for distributing supply and collective recovery of the cooled fluid. Communicate.

  Here, the height of the side bar 2A is the same as the height H of the corrugated fin 1A, and the height T of the side bar 2B is the same as the height of the corrugated fin 1B. Further, the height of the end plate 4, the plate thickness of the corrugated fins 1A and 1B, the thickness of the tube plate 3, and the material widths Wa and Wb of the side bars 2A and 2B are appropriately determined according to the assumed aircraft performance. As a specific example, the height H is 5 mm, the height T is 3 mm, the end plate 4 is 3 mm high, and the corrugated fins 1A and 1B are 0.1 mm thick. Further, the material widths Wa and Wb of the side bars 2A and 2B are 5 mm and 3 mm, which are the same as the respective heights, and the thickness of the tube plate 3 is 1 mm. Furthermore, the overall size including the number of stages of the air flow passage 5A and the cooled object flow passage 5B is appropriately determined depending on the assumed aircraft performance.

  Up to this point, the conventional air-cooled heat exchanger for aircraft shown in FIG. 3 is the same. The difference from the conventional air-cooled heat exchanger for aircraft shown in FIG. 3 is the structure of the exposed end surface that is the end surface in the air flow direction of the heat exchanger. Specifically, as shown in FIG. 1, at the exposed end faces on both ends in the air flow direction of the heat exchanger, the front end surfaces of the corrugated fins 1A arranged in the air flow passages 5A pass through the cooled fluid passages 5B. With respect to the side surface of the side bar 2B for forming and the end surfaces of the end plates 4 and 4 at both ends in the stacking direction, the side bar 2B is retracted to the inside of the flow path. Further, the end surfaces of the side bars 2A and 2A arranged on both sides of the corrugated fin 1A and the end surface in the fluid flow direction of the tube plate 3 are the same positions as the side surfaces of the side bar 2B and the end surfaces of the end plates 4 and 4. It is in.

  That is, on the exposed end faces on both ends in the air flow direction of the heat exchanger, the member surfaces except for the tip faces of the corrugated fins 1A arranged in the air flow passages 5A are on the same plane, and the corrugated fins with respect to the planes. Only the front end surface of 1A is retracted to the inside of the flow path. The retracted amount is represented by S, and is 1 mm or more and 1/2 or less of the material width Wb (3 mm) of the side bar 2B, that is, 1.5 mm or less.

  In the air-cooled heat exchanger for an aircraft of the first embodiment configured as described above, only the front end surface of the corrugated fin 1A disposed in the air flow passage 5A on the exposed end surfaces on both ends in the air flow direction is another member. The surface, that is, the side surfaces of the upper and lower side bars 2B, the front end surfaces of the side bars 2A and 2A on both sides, the end surfaces of the end plates 4 and 4, and the end surface of the tube plate 3 in the fluid flow direction are retracted to the inside of the flow path As a result, the surface of these other members protrudes outside the air flow path with respect to the tip surface of the corrugated fin 1A. As a result, even if a flying object such as a bird or ice collides with the exposed end surface on the air inflow side during use, the impact is only on the surface of the other member protruding, and the other member functions as a protective grid. Therefore, the tip of the corrugated fin 1A arranged in the air flow passage 5A is effectively protected without using another member such as a guard fin.

  Similarly, even if an obstacle collides with any exposed end surface during handling and storage in the heat exchanger assembly process, transport process, mounting process to the airframe, etc., the impact is other than the corrugated fin 1A. It will be received on the surface of the member, and damage to the tip of the corrugated fin 1A is avoided. Since other members have high mechanical strength, they do not cause any problem damage even by impact due to a collision. Since the tube plate 3 is a thin plate and has a small mechanical strength, the side bars 2A, 2A and 2B, 2B are in close contact with each other to be fixed by brazing, so there is no risk of damage due to collision. .

  The air-cooled heat exchanger for aircraft of the second embodiment shown in FIG. 2 has the same main structure as the air-cooled heat exchanger for aircraft of the first embodiment shown in FIG. That is, FIG. 1 shows that only the front end surfaces of the corrugated fins 1A arranged in the air flow passages 5A on the exposed end surfaces on both end sides in the air flow direction are retracted to the inside of the flow path with respect to the other member surfaces. This is the same as the air-cooled heat exchanger for aircraft according to the first embodiment.

  The difference from the air-cooled heat exchanger for aircraft of the first embodiment shown in FIG. 1 is that the surface of a member other than the corrugated fin 1A arranged in the air flow passage 5A, specifically, the air flow passage. The side surface of the side bar 2B disposed above and below the corrugated fin 1A in 5A, the front end surfaces of the side bars 2A, 2A disposed on both sides, and the end surfaces of the end plates 4, 4 are the front end surface of the corrugated fin 1A. On the other hand, by projecting to the outside of the air flow path, only the front end surface of the corrugated fin 1A is retracted to the inside of the flow path with respect to the surface of the other member. The protruding surfaces of these other members, that is, the protruding side surface of the side bar 2B, the protruding end surfaces of the side bars 2A and 2A, and the protruding end surfaces of the end plates 4 and 4 are adjacent to each other. Headed to the curved flow path outside the point which is formed in an arcuate curved surface of the convex.

  In addition to simply retracting the front end surface of the corrugated fin 1A disposed in the air flow passage 5A at the exposed end surfaces on both ends of the air flow direction with respect to the surface of the other member, the other end of the corrugated fin 1A It goes without saying that the front end surface of the corrugated fin 1A can be retracted from the surface of the other member by projecting the surface of the member.

  In addition, by making the protruding surface of the other member an arcuate curved surface as described above, the inlet to the air flow passage 5A has a bell mouth shape at the exposed end surface on the air inflow side, and turbulent flow associated with the edge portion is suppressed. As a result, the inflow of air becomes smooth. Further, the outlet from the air flow passage 5A has a bell mouth shape on the exposed end surface on the air outflow side, and the turbulent flow associated with the edge portion is suppressed, whereby the outflow of air becomes smooth. As a result, it can be expected that the heat exchange efficiency is improved more than the conventional air-cooled heat exchanger for aircraft shown in FIG.

  In the conventional air-cooled heat exchanger for aircraft shown in FIG. 3, unless special measures are taken, the occurrence of turbulent flow due to the edge of other members is caused by the inflow of air into the air flow passage 5A and the air There is a concern of hindering the outflow of air from the flow passage 5A.

1A, 1B corrugated fins 2A, 2B Sidebar 3 Tube plate 4 End plate 5A Air flow path 5B Cooled fluid flow path 6 Header

Claims (3)

Two orthogonal corrugated fins arranged between the side bars on both sides are alternately stacked together with the side bars on both sides via the tube plate, and both ends in the stacking direction are closed by the end plates, and the two orthogonal It consists of a plate fin type air-cooled heat exchanger in which air flows between the tube plates where one of the corrugated fins in the direction is arranged, and the fluid to be cooled flows between the tube plates where the other is arranged,
At least one end surface of the air-cooled heat exchanger in the air flow direction, the front end surface of the corrugated fin for the air flow path is retracted from the side surface of the side bar for the fluid flow path to the inside of the air flow path,
Air flow end face of the air passage either side of the sidebar of the front end surface and the end plates, Ri projecting end face der located on the side bar side flush with the cooled fluid passage,
In addition, the side surface of the side bar for the cooled fluid flow path that protrudes outward from the front end face of the corrugated fin for the air flow path, the front end face of the side bar on both sides of the air flow path, and the end face of the end plate in the air flow direction It is adjacent air passages aircraft air-cooled heat exchanger Ru arcuate curved der convex to curved air flow outwardly toward the. 2. The air-cooled heat exchanger for an aircraft according to claim 1 , wherein a front end surface of the corrugated fin for the air flow path is a side surface of the side bar for the cooled fluid flow path, a front end face and an end of the side bar on both sides of the air flow path. An air-cooled heat exchanger for an aircraft, wherein the end face of the heat exchanger that retracts from the end face in the air flow direction to the inside of the air flow path is the both end faces in the air flow direction. 3. The air-cooled heat exchanger for an aircraft according to claim 1 , wherein the front end surface of the corrugated fin for the air flow path, the side surface of the side bar for the cooled fluid flow path, and the front end of the side bar on both sides of the air flow path An air-cooled heat exchanger for an aircraft, wherein a retraction amount of the surface and the end plate with respect to the end surface in the air flow direction is 1 mm or more and less than a dimension of the side bar in the air flow direction.

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