JP2015094584A - Aircraft heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aircraft heat exchanger, performing heat exchange between aircraft fuel and oil, which prevents moisture in fuel from freezing due to phase transition, and prevents ice from attaching to members constituting the aircraft heat exchanger.SOLUTION: An aircraft heat exchanger 3 comprises a heat exchanger body (a matrix 30 and a shell 31). The heat exchanger body has: a temperature increase section 11 which is separated from the shell by a partition wall member 37 installed inside the shell and configured to at least locally increase a temperature of the heat exchanger body; and a heat exchange section 12 which is configured to perform heat exchange between aircraft fuel and oil. The temperature increase section has: at least one baffle 35 arranged therein; and an oil inflow port 321 arranged at a position closer to a side of the partition wall member than the baffle. The heat exchange section has an aircraft fuel outflow port. The oil passing through the temperature increase section is introduced into the heat exchange section at the position close to the aircraft fuel outflow port in the heat exchange section. The heat exchange section is configured to generate opposed flows.

Description

  The technology disclosed herein relates to an aircraft heat exchanger, and more particularly to a heat exchanger mounted on an aircraft and performing heat exchange between aircraft fuel and oil.

  Patent Document 1 describes a plate fin type heat exchanger mounted on an aircraft. This heat exchanger is used between aircraft fuel (hereinafter also simply referred to as fuel) and engine lubricating oil or lubricating oil for generators driven by the engine (hereinafter collectively referred to as oil). Perform heat exchange at. In the plate fin type heat exchanger, both the fuel flow path and the oil flow path are configured as U-turn flow paths in which the forward path and the return path are partitioned by a partition. Further, the fuel inlet and the oil inlet are both provided at the same position, so that the fuel flow direction and the oil flow direction are configured in a parallel flow type.

  Similarly to Patent Document 1, Patent Document 2 also describes a plate fin type aircraft heat exchanger. In this heat exchanger, the fuel flow path and the oil flow path are both U-turn flow paths, but the fuel inlet is provided at the same position as the oil outlet. Thus, unlike the heat exchanger of Patent Document 1, the heat exchanger of Patent Document 2 is configured as a counterflow type in which the fuel flow direction and the oil flow direction face each other. The counter flow type heat exchanger has higher heat exchange efficiency than the parallel flow type heat exchanger, and is advantageous in reducing the size and weight of the heat exchanger.

  Furthermore, Patent Document 3 describes a shell-and-tube heat exchanger as an aircraft heat exchanger that performs heat exchange between fuel and oil.

JP 2000-97582 A JP 2011-153752 A Special Table 2002-525552

  By the way, in a plate fin type heat exchanger, for example, the flow path through which the fuel flows is constituted by a set of fin gaps having a small cross-sectional area partitioned by corrugated fins. For this reason, when the fuel flows between the fin gaps, the fuel flow velocity fluctuation and pressure fluctuation increase. Even in the shell-and-tube heat exchanger, the flow path through which the fuel flows is configured by a collection of tubes having a small cross-sectional area. For this reason, as with the plate fin heat exchanger, when the fuel flows into each tube, the fuel flow velocity fluctuation and pressure fluctuation increase.

  On the other hand, in an aircraft heat exchanger, for example, during the flight of an aircraft, the temperature of the fuel may be low, and the moisture in the fuel may be in a supercooled state. According to the study of the present inventor, especially when the temperature of the aircraft fuel is in a predetermined temperature range, the water in the supercooled state undergoes a phase change and freezes, triggered by the fuel flow velocity fluctuation and pressure fluctuation. I understood. If ice adheres to the components constituting the heat exchanger due to moisture icing, moisture in the fuel freezes one after another and the ice accumulates. If ice accumulates in the vicinity of the fuel inlet composed of corrugated fins and tubes, the accumulated ice will block the inlet.

  The technology disclosed herein has been made in view of the above points, and the object of the technology is an aircraft heat exchanger that performs heat exchange between aircraft fuel and oil. It is to prevent icing due to phase change and ice adhering to the members constituting the heat exchanger.

  The inventor of the present application divides the heat exchanger main body into a temperature raising part that prevents freezing of moisture in the aircraft fuel and a heat exchange part that mainly performs heat exchange between the aircraft fuel and oil. In the heat exchanger, the heat exchanger body is locally heated to prevent freezing of water in the fuel and adhesion of ice, while in the heat exchange section, the fuel flow direction and the oil flow direction are opposed to each other. In order to improve the heat exchange efficiency.

  Specifically, the technology disclosed herein relates to an aircraft heat exchanger, and the heat exchanger is disposed between the aircraft fuel and the oil while the aircraft fuel and the oil are passing therethrough. A heat exchanger body configured to perform heat exchange.

  The heat exchanger body is configured to perform heat exchange between a temperature raising unit configured to at least locally raise the temperature of the heat exchanger body, and the aircraft fuel and the oil. The temperature raising unit has an inlet for the aircraft fuel and an inlet for the oil, and the oil flowing into the heat exchanger body through the inlet, The temperature raising part is heated.

  The heat exchanging unit has an outlet for the aircraft fuel and an outlet for the oil, and the temperature raising unit is arranged so that the flow direction of the aircraft fuel and the flow direction of the oil are opposed to each other. The passed oil is configured to be introduced into the heat exchange portion in the vicinity of the outlet for the aircraft fuel.

  According to this configuration, the heat exchanger main body that performs heat exchange between the aircraft fuel and the oil includes the temperature raising part and the heat exchange part. The temperature raising unit is a part that locally raises the temperature of the heat exchanger body, and is provided with an inlet for aircraft fuel. The temperature raising unit raises the temperature state of the heat exchanger body, so that the water in the supercooled state freezes even if the flow rate fluctuation or pressure fluctuation occurs when the fuel flows into the heat exchanger body. To suppress that. Moreover, even if moisture freezes, ice is prevented from adhering to members constituting the heat exchanger body. Thus, by preventing freezing of water in the fuel and adhesion of ice, it is possible to prevent the ice from accumulating in the temperature raising portion. As a result, the fuel inlet is prevented from being blocked.

  The temperature raising unit has an oil inlet. Hot oil immediately after flowing into the heat exchanger body locally raises the temperature of the temperature raising portion. In the temperature raising unit, the local temperature rise of the heat exchanger body is mainly performed. Increasing the temperature of the heat exchanger body in contact with the aircraft fuel is more effective than preventing the temperature of the aircraft fuel itself from preventing freezing of water in the fuel and adhesion of ice. Because. However, since the temperature raising portion is also a part of the heat exchanger body, heat exchange between the aircraft fuel and the oil can be performed also in this temperature raising portion.

  The heat exchange unit exchanges heat between aircraft fuel and oil. The heat exchange unit has an aircraft fuel outlet and an oil outlet. The oil that has passed through the temperature raising section is introduced into the heat exchange section in the vicinity of the aircraft fuel outlet. The heat exchange unit is configured such that the flow direction of the aircraft fuel and the flow direction of the oil are opposed to each other. In the “near the outlet”, oil is introduced near the fuel outlet so that the flow of the aircraft fuel and the oil can be made opposite in the entire heat exchange section. It means to do.

  When both the fuel inlet and the oil inlet are provided in the temperature raising section, for example, as described in Patent Document 1, normally, the fuel flow direction and the oil in the heat exchanger The flow direction is parallel. This reduces the heat exchange efficiency of the heat exchanger.

  On the other hand, in the above-described configuration, the fuel inlet and the oil inlet are provided at the same position, but the oil passes through the temperature raising part and then enters the heat exchange part near the fuel outlet. be introduced. In the heat exchange section, the heat exchange efficiency of the heat exchanger is increased by making the fuel flow direction and the oil flow direction counterflow.

  Thus, in the aircraft heat exchanger, moisture freezing and ice accumulation in the aircraft fuel are prevented, and the efficiency of heat exchange between the aircraft fuel and oil is increased. This is advantageous for reducing the size and weight of the aircraft heat exchanger.

  In the above-described configuration, the heat exchanger main body has a cylindrical shell configured to partition an oil flow path through which the oil flows by closing both end openings by an end plate, and the heat exchanger main body is disposed in the shell. And a plurality of tubes constituting a fuel flow path through which the aircraft fuel flows by communicating with the outside of the shell via the end plate, A partition member configured to separate the temperature raising portion and the heat exchanging portion is disposed.

  That is, the heat exchanger having the characteristic configuration disclosed herein can be configured by a shell and tube type heat exchanger body. In the shell and tube type heat exchanger main body, a partition member that separates the temperature raising portion and the heat exchange portion is disposed in the shell that divides the oil flow path.

  And in this shell and tube type heat exchanger body, the temperature raising part is provided between the end plate and the partition member adjacent to the end plate, and between the end plate and the partition member. In between, at least one baffle is disposed, and an inlet for allowing the oil to flow into the shell is provided at a position closer to the partition member than the baffle, and the inlet is provided through the inlet. The oil that has flowed into the shell crosses the baffle and then flows in the cylinder axial direction of the shell toward the end plate.

  In the shell-and-tube type heat exchanger body, the member whose temperature should be raised most is an end plate corresponding to an inflow port for aircraft fuel. In order to effectively raise the temperature of the end plate, it is necessary to sufficiently bring the oil that has flowed into the shell (that is, the temperature raising portion) into contact with the end plate. For example, if an inlet is provided close to the end plate, the oil flowing into the shell flows along the surface of the end plate, and the effect of raising the temperature of the end plate is reduced.

  On the other hand, in the above configuration, at least one baffle is disposed between the partition member and the end plate, and the oil inlet is provided closer to the partition member side than the baffle. As a result, the oil that has flowed into the shell in the radial direction of the shell through the inflow port flows across the baffle toward the end plate in the cylindrical axis direction of the shell. Thus, the oil comes into sufficient contact with the end plate, and as a result, the temperature of the end plate can be effectively increased.

  The shell and tube type heat exchanger main body is provided on the outer side of the shell and communicates with the temperature raising portion and the heat exchange portion separated by the partition wall member, so that one of the oil flow paths is provided. It is good also as having a bypass passage which constitutes a portion.

  In this way, the oil that has passed through the temperature raising part can be introduced to the vicinity of the outlet of the fuel flow path in the heat exchange part provided in the shell through the bypass passage provided outside the shell. It becomes possible.

  The temperature raising part is provided between the partition member and the end plate, and a tip of the tube constituting an inlet for the aircraft fuel is supported by the end plate that partitions the temperature raising part. The tip of the tube may be embedded in the end plate without penetrating the end plate.

  When the end of the tube penetrates the end plate and protrudes from the surface of the end plate, the temperature of the end of the tube can be lower than the temperature of the end plate even if the end plate is heated. Therefore, moisture in the aircraft fuel freezes at the tip of the tube, or ice adheres to the tip of the tube. Moreover, when the tip of the tube protrudes from the surface of the end plate, the inlet is likely to be blocked by accumulated ice.

  On the other hand, by embedding the tip of the tube in the end plate, there is no relatively low temperature portion, and water in the aircraft fuel is prevented from freezing. Further, since there is no portion protruding from the surface of the end plate, the adhesion of ice is also prevented. As a result, the fuel inlet is more effectively prevented from being blocked.

  As described above, in the above-described aircraft heat exchanger, the heat exchanger main body is divided into a temperature raising part and a heat exchange part. In the temperature raising section, the temperature of the heat exchanger body is locally raised by the high-temperature oil immediately after flowing into the heat exchanger body, so that moisture in the aircraft fuel freezes and ice adheres. To prevent. On the other hand, in the heat exchange section, the flow direction of the aircraft fuel and the flow direction of the oil are configured to be opposite flows, so that the heat exchange efficiency between the aircraft fuel and the oil is increased, and the size of the aircraft heat exchanger is reduced. It is advantageous for weight reduction.

FIG. 1 is a conceptual diagram showing a characteristic configuration of the technology disclosed herein. FIG. 2 is a perspective view illustrating the external appearance of a plate fin type aircraft heat exchanger. FIG. 3 is a cross-sectional view illustrating the configuration of the fuel flow path of the plate fin heat exchanger. FIG. 4 is a cross-sectional view illustrating the configuration of the oil flow path of the plate fin heat exchanger. FIG. 5 is a cross-sectional view illustrating a configuration of an oil flow path different from that in FIG. FIG. 6 is a perspective view illustrating the appearance of a shell and tube heat exchanger. FIG. 7 is a longitudinal sectional view of a shell and tube heat exchanger. FIG. 8 is an enlarged sectional view showing the vicinity of the fuel inlet in the shell-and-tube heat exchanger.

  Hereinafter, embodiments of an aircraft heat exchanger will be described with reference to the drawings. The description of the following embodiment is an example. FIG. 1 is a conceptual diagram showing a configuration of an aircraft heat exchanger 1. Hereinafter, the aircraft heat exchanger 1 is also simply referred to as a heat exchanger 1. The heat exchanger 1 and the heat exchanger body are substantially the same. The heat exchanger 1 is mounted on an aircraft and exchanges heat between aircraft fuel and engine lubricant or generator lubricant driven by the engine. The heat exchanger 1 cools oil with fuel. Fuel can be extremely cold under various usage environments, including during flight of an aircraft. In that case, the moisture in the fuel can be supercooled. The fuel in such a state may freeze in the vicinity of the inlet of the heat exchanger 1 due to, for example, fluctuations in flow velocity or pressure when flowing into the heat exchanger 1. Moreover, when the temperature of the member which comprises the heat exchanger 1 is low, ice may adhere to the member with the low temperature. When ice adheres, freezing may occur one after another and ice may gradually accumulate. The accumulated ice will also block the fuel inlet of the heat exchanger 1. The heat exchanger 1 shown in FIG. 1 increases the heat exchange efficiency of the heat exchanger 1 while preventing the freezing of water in the fuel and the adhesion of ice.

  The heat exchanger 1 shown in FIG. 1 is divided into a temperature raising unit 11 surrounded by a one-dot chain line and a heat exchange unit 12 other than that. The temperature raising unit 11 has a fuel inlet. The temperature raising portion 11 is a portion where the temperature of the fuel is low and the vicinity of the fuel inflow port is subject to freezing of moisture in the fuel because the fuel flow velocity fluctuation and pressure fluctuation are large.

  In the heat exchanger 1 shown in FIG. 1, the fuel flows from the right side of the paper in the heat exchanger 1 and flows from the right to the left in the heat exchanger 1, as indicated by the white arrow, It flows out from the left side of the paper in the exchanger 1. The fuel passes through the temperature raising unit 11 in the heat exchanger 1, is then introduced into the heat exchange unit 12, and then flows out from the heat exchange unit 12. The fuel outlet is provided in the heat exchange section 12.

  As will be described later, the temperature raising unit 11 also locally raises the temperature of the heat exchanger 1 in order to prevent freezing of water in the fuel and adhesion of ice. The heat of the heat exchanger 1 uses the heat of oil. The temperature raising unit 11 is provided with an oil inlet. As indicated by a black arrow in FIG. 1, high-temperature oil first flows into the temperature raising unit 11, so that the temperature raising unit 11 can be effectively heated. Thus, even when a flow rate fluctuation or a pressure fluctuation occurs when the low-temperature fuel flows into the inflow port, the freezing of moisture in the fuel is suppressed due to the high temperature state. Moreover, it is also suppressed that ice adheres near the inflow port. Furthermore, even if ice adheres, the ice is quickly peeled off or disappears due to a high temperature state. In this way, ice accumulation is avoided and, as a result, it is avoided that the inlet is blocked by the accumulated ice. In the temperature raising unit 11, the temperature of the heat exchanger 1 is raised rather than increasing the temperature of the fuel, thereby preventing freezing of water in the fuel and adhesion of ice.

  The heat exchange unit 12 is a part that mainly performs heat exchange between fuel and oil. When the fuel inlet and the oil inlet are provided at the same position, normally, the fuel flow direction and the oil flow direction are the same in the heat exchanger, and the heat exchanger has a parallel flow. Become a mold.

  On the other hand, in the heat exchanger 1 shown in FIG. 1, the oil that has passed through the temperature raising unit 11 is introduced into the heat exchange unit 12 in the vicinity of the fuel outlet in the heat exchange unit 12. By doing so, in the heat exchanging section 12, the flow direction of the oil is directed from the left to the right in the drawing with respect to the flow direction of the fuel from the right to the left in the drawing. become. Thus, the heat exchange efficiency is increased by configuring the heat exchanger 1 in a counterflow type. This makes it possible to reduce the size and weight of the heat exchanger 1 and is advantageous as a heat exchanger mounted on an aircraft.

  As described above, the heat exchanger 1 disclosed herein includes the temperature raising unit 11 that raises the temperature state with oil and the heat exchange unit 12 that is configured in a counterflow type, thereby freezing water in the fuel. In addition, it is characterized by achieving both prevention of ice accumulation and improvement of heat exchange efficiency. Hereinafter, a plate fin type heat exchanger and a shell and tube type heat exchanger having this characteristic configuration will be described in detail with reference to the drawings.

(Example of plate fin type heat exchanger)
FIG. 2 illustrates the appearance of a plate fin type heat exchanger 2 having the above-described characteristic configuration as a reference form. This heat exchanger 2 also performs heat exchange between aircraft fuel and oil. In FIG. 2, reference numeral 21 denotes a core, reference numeral 23 denotes a header attached to the core 21 and allows fuel to flow into and out of the core 21, and reference numeral 24 denotes a header attached to the core 21 and oil flows into the core 21. The header 25 to be discharged, which is described in detail later, is a mixing header for oil that is attached to the core 21 and has passed through the temperature raising portion 11 of the core 21. In the following, for convenience of explanation, as shown in FIG. 2, an X axis, a Y axis, and a Z axis are defined. That is, the X axis extends in a direction connecting the right front side and the left back side of the paper, the Y axis extends in a direction connecting the left hand side of the paper and the right back side, and the Z axis extends in a direction connecting the bottom side and the top side of the paper. .

  The core 21 is configured by alternately laminating the fuel flow paths 210 shown in FIG. 3 and the oil flow paths 220 shown in FIG. 4 via tube plates not explicitly shown in the drawing. In FIG. 3, the oil header 24 and the mixing header 25 are not shown, and in FIG. 4, the fuel header 23 is not shown. The core 21 can be manufactured by integrating members described later, for example, by brazing.

  As shown in FIG. 3, the fuel flow path 210 is partitioned by a tube plate and a side bar 211. The inside of the fuel flow path 210 is partitioned in the Y-axis direction by a partition member 212 extending in the X-axis direction. Thus, the fuel flow path 210 is configured as a two-pass flow path that includes an outward path 210a and a return path 210b extending in the X-axis direction. The inflow port 213 and the outflow port 214 of the fuel flow path 210 are opened side by side in the Y-axis direction on the side surface of the core 21 facing the X axis (the surface on the right side in FIG. 3). The inflow port 213 and the outflow port 214 of the fuel flow path 210 are separated by the partition member 212.

  The temperature raising portion 11 in the core 21 is a portion surrounded by a one-dot chain line, and this portion is a portion corresponding to the vicinity of the fuel inlet 213. In the core 21, the part other than the temperature raising unit 11 is a heat exchange unit 12.

  In the illustrated example, the fuel header 23 is partitioned into an inflow side and an outflow side. The inflow side of the header 23 communicates with the inflow port 213 in the fuel flow path 210 of each layer, and the outflow side of the header 23 communicates with the outflow port 214 in the fuel flow path 210 of each layer. Further, a port 231 through which fuel flows is attached to the header 23 in communication with the inflow side, and a port 232 through which fuel flows out is attached to the outflow side. The fuel header may be separated from the inflow side header and the outflow side header, unlike the illustrated example.

  Corrugated fins 215 and 216 that increase the heat transfer area are disposed in the fuel flow path 210. The corrugated fins 215 and 216 are cut out in a rectangular shape or a triangular shape, and are disposed in the entire U-turn portion that connects the forward path 210a, the backward path 210b, and the forward path 210a and the backward path 210b. In the core 21, the corrugated fins 215 arranged in the temperature raising unit 11 and the corrugated fins 216 arranged in the heat exchange unit are different in type. The corrugated fins 215 disposed in the temperature raising unit 11 are corrugated fins having lower heat exchange efficiency than the corrugated fins 216 disposed in the heat exchange unit 12. Specifically, although the corrugated fin is conceptually illustrated in FIG. 3, the corrugated fin 215 is a plain corrugated fin having a relatively wide pitch. In contrast, the corrugated fins 216 are herringbone corrugated fins having a relatively narrow pitch. In addition, the corrugated fin 215 arrange | positioned at the temperature rising part 11 and the corrugated fin 216 arrange | positioned at the heat exchange part 12 can respectively select an appropriate kind of corrugated fin.

  As indicated by the white arrow in FIG. 3, the fuel that has flowed into the header 23 via the inflow side port 231 flows into the core 21 from the inlet 213, and then flows in the forward path 210a in the X-axis direction. . Thereafter, the fuel is reversed at the U-turn portion and flows in the reverse path 210b in the direction opposite to the X-axis direction. Thus, the fuel flows out from the outlet 214 and reaches the header 23. In the meantime, the fuel exchanges heat with oil mainly in the heat exchange section 12 to cool the oil, while the temperature of the fuel increases. Here, at the fuel inflow port 213, the fuel flows into the gaps between the fins having a small cross-sectional area defined by the corrugated fins 215, so that large flow velocity fluctuations and pressure fluctuations occur. At this time, if the moisture in the fuel is in a supercooled state, the moisture freezes due to fluctuations in flow velocity and pressure, and ice adheres to the vicinity of the inlet 213. When icing near the inflow port in this way, the moisture of the fuel in contact with the ice freezes one after another, and ice accumulates. As a result, the inflow port 213 is blocked by the accumulated ice.

  In contrast to the fuel channel 210 having the above-described configuration, the oil channel 220 is configured as shown in FIG. That is, the oil flow path 220 is partitioned by the tube plate and the side bar 221. Unlike the fuel flow path 210, a flow path member 223 extending in the Y-axis direction is disposed inside the oil flow path 220. The flow path member 223 is disposed in the oil flow path 220 in the X-axis direction. It is divided into two areas. The temperature raising unit 11 is separated from the heat exchange unit 12 by the flow path member 223 in the X-axis direction, and communicates with the heat exchange unit 12 in the Y-axis direction.

  A partition member 222 extending in the X-axis direction is disposed in the heat exchange unit 12, whereby the oil flow path 220 in the heat exchange unit 12 is respectively in the X-axis direction, like the fuel flow path 210. It is configured as a two-pass flow path including a forward path 220a and a return path 220b. The inflow port 224 and the outflow port 225 of the oil passage 220 are opened side by side in the X direction on the side surface of the core 21 facing the Y axis (the lower surface in FIG. 4). An inlet 224 of the oil passage 220 is provided in the temperature raising unit 11. Further, the inlet 224 and the outlet 225 of the oil passage 220 are separated by the passage member 223.

  On the side surface opposite to the side surface of the core 21 where the inflow port 224 and the outflow port 225 are opened, a second outflow port 226 and a second inflow port 227 are provided side by side in the X-axis direction. The second outlet 226 is an opening through which oil after passing through the temperature raising unit 11 once flows out of the core 21. The second inlet 227 is an opening through which oil flows again into the core 21. The second outlet 226 and the second inlet 227 are also separated by the flow path member 223.

  Similarly to the fuel header 23, the oil header 24 is partitioned into an inflow side and an outflow side. The inflow side of the header 24 communicates with the inflow port 224 in the oil flow path 220 of each layer, and the outflow side of the header 24 communicates with the outflow port 225 of the oil flow path 220 of each layer. A port 241 through which fuel flows is attached to the header 24 so as to communicate with the inflow side, and a port 242 through which fuel flows out is attached to the outflow side. It should be noted that the oil header may also be configured separately by an inflow side header and an outflow side header.

  The mixing header 25 communicates with the second outlet 226 in the oil passage 220 of each layer and also communicates with the second inlet 227 in the oil passage 220 of each layer. The oil flowing into the mixing header 25 from the oil flow path 220 of each layer is mixed in the mixing header 25 and then distributed into the oil flow path 220 of each layer through the second inlet 227. Thereby, equalization of the temperature of oil is achieved.

  Corrugated fins 228 that expand the heat transfer area are also disposed in the oil flow path 220. The corrugated fins 228 are disposed in the entire oil flow path 220 by being cut out in a triangular shape or a rectangular shape. As the corrugated fin 228 in the oil flow path 220, an appropriate type of corrugated fin can be adopted. Although conceptually shown in FIG. 4, a serrated corrugated fin is employed here.

  As indicated by black arrows in FIG. 4, the oil that has flowed into the header 24 via the inflow side port 241 flows into the core 21 from the inlet 224, that is, into the temperature raising unit 11, and then the flow path member 223. Flows in the Y-axis direction through the flow path partitioned by. Then, after passing through the temperature raising unit 11, the fuel is introduced into the vicinity of the fuel outlet 214 in the heat exchange unit 12, and then flows into the mixing header 25 through the second outlet 226. The oil mixes with the oil that has passed through the temperature raising portion 11 of the oil flow path 220 of each layer in the mixing header 25. The oil whose temperature is substantially equalized in this way flows again into the core 21 through the second inlet 227.

  After that, the oil flows in the forward path 220a in the heat exchange section 12 in the X-axis direction, then reverses in the U-turn section, and this time flows in the backward path 220b in the opposite direction in the X-axis direction. The oil then flows out from the outlet 225 and reaches the header 24. In the heat exchange unit 12, the fuel flow direction and the oil flow direction face each other.

  Thus, in the plate fin type heat exchanger 2, since the oil inlet 224 is provided in the temperature raising part 11, the oil flow path 220 and the fuel flow path are heated by the high-temperature oil immediately after flowing into the core 21. It is possible to increase the temperature state of the tube plate that divides 210 and the corrugated fin 215 disposed in the fuel flow path 210. In general, in the vicinity of the inlet 213 in the fuel flow path 210, the water in the fuel is likely to freeze or adhere to the ice. Therefore, by increasing the temperature of the metal part in contact with the fuel, the moisture in the fuel is increased. Is prevented from freezing. Further, it is possible to effectively prevent ice from adhering to the metal part. Even if ice adheres to the corrugated fins 215 or the like, the ice is peeled off or disappears due to the high temperature state. As a result, the accumulation of ice in the vicinity of the fuel inlet 213 is reliably prevented. Therefore, it is avoided that the fuel inlet 213 is blocked by the accumulated ice.

  Note that when the moisture in the fuel freezes near the fuel inlet 213 and the ice flows into the fuel flow path 210, the ice is forced to flow due to the pressure of the fuel flowing in the fuel flow path 210. Ice hardly adheres to the corrugated fins 215, 216, etc. Therefore, ice does not accumulate in the middle of the fuel flow path 210. Further, in the fuel flow path 210, since the fuel flow velocity fluctuation and pressure fluctuation are small, it is difficult for water in the fuel to freeze.

Here, as shown in FIG. 4, in the oil flow path 220, the width W _{1 of the} flow path partitioned by the flow path member 223 is compared with the width W ₂ of the forward path 220 a and the return path 220 _b in the heat exchange unit 12. It is narrowed. Thereby, the flow rate of oil when passing through this flow path becomes relatively high. Since the flow path set to be narrow corresponds to the oil flow path in the temperature raising unit 11, the oil flow rate is relatively high in the temperature raising unit 11. This increases the heat transfer coefficient from the oil to the members constituting the core 21 (described above, the tube plate and the corrugated fins 215) in the temperature raising unit 11, and increases the temperature state of the temperature raising unit 11. Become advantageous.

  On the other hand, in the fuel flow path 210, as described above, the corrugated fins 215 disposed in the temperature raising unit 11 have a relatively low heat exchange efficiency. As a result, the temperature of the corrugated fins 215 heated in the temperature raising unit 11 can be maintained as high as possible with respect to the temperature of the fuel, so that freezing of moisture in the fuel in the temperature raising unit 11 is prevented. This is advantageous. In this example, the corrugated fins 215 arranged in the temperature raising unit 11 are corrugated fins having a relatively wide fin pitch. As a result, the cross-sectional area between the fin gaps defined by the corrugated fins is relatively wide. This alleviates changes in flow velocity and pressure when the fuel flows in, and even if water in the fuel freezes, the ice easily flows into the core 21 through the inlet. This is also advantageous in preventing the fuel inlet from being blocked by accumulated ice.

  Thus, the temperature raising unit 11 is configured to prevent icing of water in the fuel and adhesion of ice, while the heat exchanging unit 12 is configured such that the fuel flow direction and the oil flow direction face each other. Therefore, it is possible to increase the heat exchange efficiency. Here, configuring the fuel flow path 210 in two paths including the forward path 210a and the return path 210b makes it possible to arrange the fuel inflow port 213 and the outflow port 214 adjacent to each other (see FIG. 3). ). Therefore, in the oil flow path 220, the flow path member 223 is provided, and the oil flow direction in the temperature rising section 11 is set in a direction intersecting with the fuel flow direction, thereby passing through the temperature rising section 11. Oil can be automatically introduced in the vicinity of the fuel outlet in the heat exchange section 12. That is, the plate fin type heat exchanger 1 can easily realize the above-described characteristic configuration due to its layout.

  Here, as a configuration of the oil flow path 220, for example, as shown in FIG. 5, the mixing header 25 may be omitted. That is, in the configuration example of FIG. 5, the flow path member 223 is set to a short length corresponding to the temperature raising unit 11 in the Y-axis direction. Accordingly, the second outlet 226 and the second inlet 227 are omitted. A triangular corrugated fin 229 is disposed at a location adjacent to the temperature raising portion 11, in other words, in the vicinity of the outlet 214 in the fuel flow path 210, thereby increasing the temperature inside the core 21. The flow direction of the oil after passing through the portion 11 is changed from the Y-axis direction to the X-axis direction. In FIG. 5, the same components as those in the configuration example shown in FIG. Thus, by omitting the mixing header 25, the heat exchanger 2 can be further reduced in size and weight.

  Further, in the plate fin type heat exchanger, each of the fuel flow path and the oil flow path is not limited to being configured with two paths, but may be configured with one path, or may be configured with three or more paths. . However, in the case of one pass, three passes, or the like, the inlet and outlet of the fuel flow channel are not disposed adjacent to each other, so the configuration of the oil flow channel needs to be changed. For example, as in the configuration example including the mixing header 25 described above, the oil that has passed through the temperature raising unit 11 is allowed to flow into the mixing header outside the core 21 through the outlet provided in the core 21 and the fuel flow path. Oil may be allowed to flow again into the core through an inlet provided near the outlet.

(Example of shell-and-tube heat exchanger)
FIG. 6 illustrates the appearance of the shell-and-tube heat exchanger 3 having the characteristic configuration shown in FIG. The heat exchanger 3 also performs heat exchange between aircraft fuel and oil. In the following, for convenience of explanation, as shown in FIG. 6, an X axis, a Y axis, and a Z axis are defined. That is, the X axis extends in a direction connecting the right front side and the left back side of the paper, the Y axis extends in a direction connecting the left front side and the right back side of the paper, and the Z axis extends in a direction connecting the bottom side and the top side of the paper.

  The heat exchanger 3 includes a cylindrical shell 31, and both end openings of the shell 31 are connected to fuel passages (not shown). In the example of FIG. 6, the fuel flows in from the near side of the heat exchanger 3 arranged so that the cylinder axis of the shell 31 coincides with the X-axis direction, and flows through the heat exchanger 3 in the X-axis direction. It flows out from the back side of the heat exchanger 3. On the other hand, the oil flows into the shell 31 through the inflow side port 32 attached to the outer peripheral surface of the shell 31 and is attached to the outer peripheral surface of the shell side by side with the inflow side port 32, as will be described in detail later. It flows out of the shell 31 through the outflow side port 33.

  FIG. 7 is a longitudinal sectional view of the shell and tube type heat exchanger 3. Both end openings of the shell 31 are closed by end plates 310 and 311. Each of the end plates 310 and 311 defines a fuel passage and an oil passage in the shell 31 on each of the fuel inflow side (that is, the right side in FIG. 7) and the outflow side (that is, the left side in FIG. 7). Functions as a partition wall.

  In the shell 31 defined by the end plates 310 and 311, a matrix 30 including a large number of tubes 34 and baffles 35 and 36 is disposed. The matrix 30 having a configuration to be described later can be manufactured by integrating the members by brazing.

  The tube 34 is a thin tube that constitutes a fuel flow path. Each of the tubes 34 extends in the X-axis direction and is arranged at a predetermined interval in the radial direction and the circumferential direction of the shell 31. In FIG. 7, illustration of some tubes 34 is omitted for easy understanding. Both ends of each tube 34 are inserted into through holes formed in the end plates 310, 311, whereby each tube 34 is supported at both ends by the end plates 310, 311. Further, both end openings of each tube 34 communicate with fuel passages via end plates 310 and 311, respectively. Thus, in each tube 34, the end opening supported by the end plate 310 on the fuel inflow side functions as a fuel inflow port, and the end opening supported by the end plate 311 on the fuel outflow side becomes the fuel inlet. Functions as an outlet.

  Here, as shown in an enlarged view in FIG. 8, in the end plate 310 on the fuel inflow side, the tip of the tube 34 is embedded in the end plate 310, and as shown virtually in FIG. The tip of the tube 34 is not configured to penetrate the end plate 310 and protrude from the surface of the end plate 310. This prevents ice from accumulating at the tip of the tube 34 as will be described later.

  As described above, in the shell 31 partitioned by the end plates 310 and 311, the plurality of baffles 35 and 36 are arranged at equal intervals in the X-axis direction. The plurality of baffles 35, 36 are formed with a through hole in the central portion, an annular ring baffle 35 that fits inside the inner peripheral surface of the shell 31, and a through hole that is not formed in the central portion. And a disk-shaped disk baffle 36 provided with a predetermined gap in the radial direction with respect to the inner peripheral surface of the shell 31. The ring baffle 35 and the disk baffle 36 are alternately arranged in the X-axis direction. Each tube 34 is disposed through the ring baffle 35 and the disk baffle 36.

  With such a configuration, as shown by a white arrow in FIG. 7, the fuel flows into the tube 34 through the tip opening on the fuel inflow side in the heat exchanger 3. After flowing in the X-axis direction, the fuel flows out from the heat exchanger 3 through the end opening of each tube 34 on the fuel outflow side.

  A partition member 37 is disposed in the shell 31 at a predetermined distance in the X-axis direction with respect to the end plate 310 on the inflow side. The partition member 37 has a disc shape and is fitted into the inner peripheral surface of the shell 31. Thus, the partition member 37 divides the inside of the shell 31 into two spaces that do not communicate with each other in the X-axis direction. The partition member 37 is a member that separates the temperature raising unit 11 and the heat exchange unit 12, and a space between the partition member 37 and the inflow side end plate 310 forms the temperature rising unit 11, and the partition member 37 and the outflow A space between the end plate 311 on the side constitutes the heat exchange unit 12. A ring baffle 35 is disposed between the partition member 37 and the end plate 310.

  The inflow side port 32 communicates with the temperature raising unit 11, and more specifically, communicates with the partition member 37 rather than the ring baffle 35 disposed between the partition member 37 and the end plate 310. ing. The outflow side port 33 communicates with the heat exchange unit 12, and is specifically located in the vicinity of the partition wall member 37. That is, the oil inlet 321 and the outlet 331 for the shell 31 are provided adjacent to each other with the partition wall member 37 interposed therebetween.

  In the shell 31, on the opposite side of the oil inflow port 321 and the outflow port 331 across the cylinder shaft, a second outflow port 381 for flowing oil out of the shell 31 and a second flow for flowing oil into the shell 31. Each inlet 382 is provided. The second outflow port 381 is provided between the partition member 37 and the inflow side end plate 310, and particularly in the illustrated example, the ring baffle 35 disposed between the partition wall member 37 and the end plate 310 and the inflow side end plate. The second outflow port 381 is in communication with the temperature raising unit 11. On the other hand, the second inflow port 382 is the most fuel among the plurality of baffles 35 and 36 arranged in the vicinity of the outflow side end plate 311, more specifically, the outflow side end plate 311 and in the X-axis direction. It is provided between the ring baffle 35 arranged on the outflow side. Thus, the second inlet 382 communicates with the vicinity of the fuel outlet in the heat exchange section 12.

  The second outlet 381 and the second inlet 382 communicate with each other via a bypass passage 38 provided outside the shell 31. The bypass passage 38 allows the temperature raising unit 11 and the heat exchange unit 12 to communicate with each other outside the shell 31. In the illustrated example, the bypass passage 38 extends in the X-axis direction along the outer peripheral surface of the shell 31 and is provided integrally with a cylinder constituting the shell 31. In the illustrated example, the bypass passage 38 is provided integrally with the shell 31, but the bypass passage 38 is separate from the shell 31, which connects the second outlet 381 and the second inlet 382. For example, a pipe may be used.

  With such a configuration, as shown by a black arrow in FIG. 7, the oil flows into the temperature raising portion 11 of the shell 31 through the inflow side port 32. The temperature state of the temperature raising unit 11 is increased by the high-temperature oil immediately after flowing into the heat exchanger 3. Specifically, the temperature of the end plate 310 on the inflow side increases. Here, the oil inlet 321 is located on the opposite side of the end plate 310 with the ring baffle 35 interposed therebetween, and in particular, the second outlet 381 opens between the ring baffle 35 and the end plate 310. Therefore, the oil that has flowed into the temperature raising unit 11 crosses the ring baffle 35 and flows toward the end plate 310 in the X-axis direction. Thus, by flowing the oil in a direction orthogonal to the end plate 310, the contact between the hot oil and the end plate 310 can be increased, and the temperature of the end plate 310 can be effectively increased. That is, when the oil inlet is provided closer to the end plate 310 than the ring baffle 35, and the inlet and the end plate 310 come close to each other, the radial direction of the shell 31 (that is, the Z-axis) passes through the inlet. The oil flowing in the direction) and flowing into the temperature raising unit 11 flows along the surface of the end plate 310 also in the temperature raising unit 11. Such an oil flow cannot efficiently raise the temperature of the end plate 310. On the other hand, in the above-described configuration, the oil inlet 321 is separated from the end plate 310 and the ring baffle 35 is interposed between the inlet 321 and the end plate 310 so that the oil flows in the radial direction. The flow direction of the oil can be changed to create a flow in the cylinder axis direction. As a result, the temperature increase effect of the end plate 310 can be enhanced.

  Since the temperature state of the end plate 310 is thus increased, it is possible to prevent water in the fuel from icing near the fuel inlet. Further, it is possible to prevent ice from adhering to the end plate 310 or the like. As a result, it is avoided in advance that the fuel inlet formed by the opening of the tube 34 is blocked by the accumulated ice.

  Further, the tip of the tube 34 is embedded in the end plate 310 as shown in FIG. 8 and does not protrude from the surface of the end plate 310 as virtually shown in FIG. As described above, the end plate 310 is heated from the inside of the shell 31. However, when the tip of the tube 34 protrudes from the outer surface of the end plate 310, the temperature of the tip of the tube 34 is changed to the end plate 310. It becomes lower than 310, and there is a possibility that ice adheres to the tip of the tube 34 and the ice accumulates. This in particular leads to blockage of the distal opening of the tube 34.

  On the other hand, embedding the distal end of the tube 34 in the end plate 310 makes it possible to maintain the temperature of the distal end of the tube 34 at a high temperature state similarly to the temperature of the end plate 310. Further, since the tip of the tube 34 is not exposed, it is possible to prevent ice from adhering to the tip of the tube 34. As a result, ice is prevented from accumulating near the fuel inflow port, and it is reliably prevented that the end opening of the tube 34 is blocked.

  The oil that has flowed through the temperature raising unit 11 once flows out of the shell 31 through the second outlet 381 that opens to the temperature raising unit 11. The oil flows in the X-axis direction through the bypass passage 38 and flows into the heat exchange unit 12 in the shell 31 through the second inflow port 382.

  The oil that flows into the fuel outflow side in the heat exchange unit 12 flows in the X-axis direction so as to face the fuel flow direction. Specifically, since the ring baffle 35 and the disk baffle 36 are alternately arranged in the heat exchanging portion 12, the oil passes through the through holes of the ring baffle 35 as indicated by black arrows in FIG. After passing in the axial direction, it flows outward in the radial direction of the shell 31, passes through the gap between the disk baffle 36 and the inner peripheral surface of the shell 31 in the X-axis direction, and then flows inward in the radial direction of the shell 31. It becomes like this. In this way, the oil flows in the heat exchange section 12 across the tubes 34 by combining the axial flow in the X-axis direction and the radial radial flow, and between the fuel flowing in the tubes 34 in the meantime. Perform heat exchange at. As described above, in the heat exchanging unit 12, in the X-axis direction, the fuel flow direction and the oil flow direction are opposed to each other, so that the heat exchange efficiency can be increased.

  Then, the oil that has flowed in the X-axis direction in the heat exchange unit 12 and has reached the vicinity of the partition wall member 37 flows out of the shell 31 through the outflow side port 33.

  The arrangement of the oil inlet 321 with respect to the shell 31 is not limited to the illustrated example. For example, the oil inlet 321 is arranged further away from the end plate 310 on the inflow side, and the end plate 310 and the partition wall member 37 are arranged. Two or more baffles may be provided between them. For example, the ring baffles 35 and the disk baffles 36 may be alternately arranged in the plurality of baffles.

  As described above, the aircraft heat exchanger described above is advantageous in reducing the size and weight of the aircraft fuel because it can prevent the icing of the aircraft fuel and the adhesion of ice and increase the heat exchange efficiency.

DESCRIPTION OF SYMBOLS 1 Aircraft heat exchanger 11 Temperature raising part 12 Heat exchange part 3 Shell and tube type heat exchanger 30 Matrix (heat exchanger main body)
31 Shell (heat exchanger body)
310 End plate 311 End plate 34 Tube 35 Ring baffle 37 Bulkhead member 38 Bypass passage

Claims (3)

A heat exchanger body configured to perform heat exchange between the aircraft fuel and the oil while the aircraft fuel and the oil are passing,
The heat exchanger body is configured to perform heat exchange between a temperature raising unit configured to at least locally raise the temperature of the heat exchanger body, and the aircraft fuel and the oil. A heat exchanging part,
The temperature raising part has an inlet for the aircraft fuel and an oil inlet, and the temperature rising part is heated by oil flowing into the heat exchanger body through the inlet,
The heat exchanging unit has an outlet for the aircraft fuel and an outlet for the oil, and the temperature raising unit is arranged so that the flow direction of the aircraft fuel and the flow direction of the oil are opposed to each other. The passed oil is configured to be introduced into the heat exchange portion in the vicinity of the outlet of the aircraft fuel,
The heat exchanger body has a cylindrical shell configured to partition an oil flow path through which the oil flows by closing both end openings by an end plate, and the heat exchanger body is disposed in the shell and the A shell and tube type having a plurality of tubes constituting a fuel flow path through which the aircraft fuel flows by communicating with the outside of the shell through an end plate;
In the shell, a partition member configured to separate the temperature raising portion and the heat exchange portion is disposed,
The temperature raising portion is provided between the end plate and the partition member adjacent to the end plate, and at least one baffle is disposed between the end plate and the partition member. ,
An inflow port through which the oil flows into the shell is provided at a position closer to the partition member than the baffle, and the oil that has flowed into the shell through the inflow port crosses the baffle; An aircraft heat exchanger configured to flow in a cylindrical axis direction of the shell toward the end plate. The aircraft heat exchanger according to claim 1,
The shell and tube type heat exchanger main body is provided on the outer side of the shell and communicates with the temperature raising portion and the heat exchange portion separated by the partition wall member, so that one of the oil flow paths is provided. An aircraft heat exchanger further comprising a bypass passage constituting the part. The aircraft heat exchanger according to claim 1 or 2,
The temperature raising part is provided between the partition member and the end plate,
The tip of the tube constituting the inflow port for the aircraft fuel is supported by the end plate that defines the temperature raising portion,
The tip of the tube is an aircraft heat exchanger embedded in the end plate without penetrating the end plate.

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