JP6481275B2 - Corrugated fin heat exchanger - Google Patents

Description

  The present invention relates to a corrugated fin heat exchanger that can improve cooling performance and can be used for an intercooler of a supercharged engine.

  In recent years, in an internal combustion engine such as a diesel engine mounted on a vehicle, the output of the internal combustion engine is increased by providing a turbocharger or a mechanical supercharger, and the pressure is increased by these turbochargers and the temperature is increased. An intercooler that cools the temperature of the intake air is provided to lower the temperature of the intake air, thereby improving the air intake efficiency and maintaining the combustion of the engine well.

  The intercooler includes a water cooling type and an air cooling type, and an air cooling type corrugated fin type heat exchanger is often used. As shown in FIG. 5, the intercooler 10 is a compressor of the supercharger 7. The intake pipe 4 connecting the intake manifold 7a and the intake manifold 3 cools the intake air whose temperature has risen, lowers the temperature of the intake air entering the combustion chamber, and improves the air charging efficiency. Since the efficiency is increased, combustion can be improved, fuel efficiency can be improved, and the maximum temperature and pressure can be reduced. Therefore, the thermal load and mechanical load of the engine can be reduced, and the durability of the engine can be improved.

  As shown in FIG. 6, a conventional intercooler 10 </ b> X includes an inflow side header 12 that allows intake air Ai from the compressor 7 a of the supercharger 7 to flow in, and an outflow side header that causes cooled intake air Ai to flow out to the intake manifold 3. 13 and a plurality of heat dissipating tubes 11X provided therebetween, and an external fin 14 disposed in a gap S between the heat dissipating tubes 11X through which the outside air passes in a laminated structure (core for heat exchange) of the heat dissipating tubes 11X. It is configured.

  In addition, when the intercooler is made compact, in order to increase heat transfer efficiency, between the parallel wall surfaces of the heat radiating tube, the parallel inclined fin portions inclined with respect to the wall surface (heat transfer plate) in the heat radiating tube. A corrugated fin type heat exchanger has been proposed in which (internal fins) are provided and the depth direction of the heat radiating tube is divided by the inclined fin portions to form a distribution cell (see, for example, Patent Document 1).

  With this air-cooled intercooler, in order to reduce the drift between the radiating tubes and to reduce the temperature distribution difference depending on the tube position to prevent the influence of thermal stress, A convex part with a V-shaped cross section projecting inward is formed on the outer surface part in the vicinity of the part slightly above the part so that the compressed air flowing in from the inlet pipe part is dispersed vertically by the convex part. An intercooler for a vehicle engine has also been proposed (see, for example, Patent Document 2).

  In addition, an intercooler in which the inlet side tank and the outlet side tank are connected by a large number of parallel tubes and an out fin (external fin) is provided in the gap between the tubes, and the arrangement pitch of the inner fins (internal fins) in the tube Is set to be finer near the center of the intercooler and rougher near both sides to equalize the air flow from the inlet side tank to the outlet side tank, and increase the air flow resistance in the tube at the center. An intercooler for automobiles has been proposed that can increase the heat exchange rate with inner fins and reduce the air flow resistance in the tube on both sides to ensure a sufficient air flow rate to achieve high heat exchange efficiency as a whole. (For example, refer to Patent Document 3).

  However, in this intercooler for automobiles, the air flow is suppressed from concentrating on the central tube, and heat is exchanged sufficiently even on the left and right side tubes, and heat exchange is achieved by the pitch and density of the inner fins (inner fins). It is said that it can be used with the highest heat exchange efficiency as a whole, but only the flow resistance in the tube and the heat exchange efficiency with inner fins are improved, and heat exchange with out fins (external fins) There is still room for improvement because it has not been accompanied by an increase in efficiency.

JP 2000-274251 A JP 2010-223508 A Japanese Utility Model Publication No. 2-46025

  The present invention has been made in view of the above, and the purpose of the present invention is not only to achieve a uniform flow rate between the heat transfer tubes inside the heat transfer tube, but also to each heat transfer tube. Corrugated fin type heat that can improve the cooling performance of the heat exchanger as a whole by improving the heat transfer efficiency of both internal fins and external fins, and can be used for intercoolers of supercharged engines. To provide an exchange.

In order to achieve the above object, the corrugated fin heat exchanger of the present invention is formed by laminating a plurality of flat heat transfer tubes that allow the first fluid to flow therethrough with a gap through which the second fluid passes. In addition, an external fin is provided in the gap, an internal fin is provided in the heat transfer tube, and a space between the first fluid and the second fluid is interposed between the wall surface of the heat transfer tube, the internal fin, and the external fin. In the corrugated fin type heat exchanger for exchanging heat in the heat transfer tube, either by changing the pitch of the internal fins, whether or not a resistance increasing member is inserted into the heat transfer tube, or a combination thereof, The flow resistance with respect to the first fluid inside is changed, and the flow rate of the first fluid passing through the inside of the heat transfer tube is equalized between the heat transfer tubes. The flow resistance to the first fluid inside the heat tube is set near the inlet portion where the intake pipe is connected to the inflow header of the first fluid, or the intake pipe is connected to the outflow side header of the first fluid. The heat transfer efficiency between the first fluid and the heat transfer tube in the internal fin is increased by configuring a large portion in the vicinity of the outlet portion and a small portion in the portion away from the inlet portion or the portion away from the outlet portion. The heat transfer efficiency between the second fluid and the heat transfer tube in the external fin is the same as that of the heat transfer tube having the large flow resistance and the heat transfer tube having the low flow resistance. In the vicinity of the inlet portion or in the vicinity of the outlet portion so that it is larger than the heat transfer efficiency between the second fluid and the second fluid. Ku constitute small at a site remote from the outlet.

  According to this configuration, in the heat transfer tube, the flow velocity of the first fluid flowing through the inside can be made uniform between the heat transfer tubes, and the heat transfer tubes can be connected to the internal fins and the heat transfer surface as a whole. Heat transfer efficiency can be increased. In addition, since the increase in the flow resistance with respect to the first fluid in the heat transfer tube is often due to the increase in the heat transfer area, the first heat transfer efficiency between the first fluid and the heat transfer tube is the first. The decrease in the first heat transfer efficiency due to the decrease in the flow rate of the fluid can be covered by the increase in the first heat transfer efficiency due to the configuration of the heat transfer tube and the internal fins. By increasing the second heat transfer efficiency between the two fluids and the heat transfer tube and matching the balance between the first heat transfer efficiency and the second heat transfer efficiency, the first fluid and the first heat transfer tube as a whole The overall heat transfer efficiency between the two fluids can be improved.

In the corrugated fin heat exchanger, the pitch of the internal fins, the shape of the internal fins, the presence or absence of a resistance increasing member inserted into the heat transfer tube, or the resistance increase inserted. The flow resistance to the first fluid inside the heat transfer tube is changed by any one or a combination of changes in the shape of the member , and the inlet with respect to the pitch which is the size of the interval between the external fins Near the outlet or near the outlet, and larger at the part away from the vicinity of the inlet or the part away from the vicinity of the outlet . It is configured to change the heat transfer efficiency between.

  According to this configuration, by combining these configurations, the flow resistance to the first fluid inside the heat transfer tube is easily increased in the vicinity of the inlet portion or in the vicinity of the outlet portion and separated from the inlet portion. The second heat transfer efficiency with the second fluid in the external fin can be increased in the vicinity of the inlet part or in the vicinity of the outlet part. It can be made small in a part away from the part or a part away from the outlet.

  In the above-described corrugated fin heat exchanger, if the corrugated fin heat exchanger is an intercooler of an engine with a supercharger, the first fluid is intake air and the second fluid is outside air, Intercooler with high cooling performance can be provided.

  According to the corrugated fin heat exchanger of the present invention, not only can the flow velocity between the heat transfer tubes inside the heat transfer tubes be made uniform, but also the internal fins and the external fins in each heat transfer tube can be made uniform. By improving both heat transfer efficiencies, the cooling performance of the entire heat exchanger can be improved. Therefore, when this corrugated fin heat exchanger is used for an intercooler of a supercharged engine, the intake efficiency can be improved and the engine performance can be improved.

It is a figure which shows the structure of the intercooler of embodiment which concerns on this invention. It is a figure which shows the structure of the heat exchanger tube which changed the pitch of the internal fin. It is a figure which shows the structure of the heat exchanger tube which changed the shape of the internal fin. It is a figure which shows the structure of the heat exchanger tube which changed the shape of the resistance increase member inserted in an internal fin. It is a figure which shows the example of arrangement | positioning of the intercooler in an internal combustion engine. It is a figure which shows the structure of the prior art intercooler.

  Hereinafter, a corrugated fin heat exchanger according to an embodiment of the present invention will be described with reference to the drawings. Here, an intercooler of an engine with a supercharger will be described as an example, but the present invention is not limited to this intercooler, and can be applied to other corrugated fin heat exchangers. In the drawings, the engine 1 such as the intake throttle valve, the EGR passage, the exhaust throttle valve, and the exhaust gas after-treatment device is provided in the engine 1, but the equipment that is not necessary for the description of the present invention is not shown. It is.

  Initially, the engine by which the corrugated fin type heat exchanger of embodiment of this invention is arrange | positioned is demonstrated. As shown in FIG. 5, in the engine 1, the engine body 2 is provided with an intake manifold 3 and an intake pipe 4, and an exhaust manifold 5 and an exhaust pipe 6. The exhaust pipe 6 is provided with a turbine 7 b of a turbocharger 7 driven by exhaust gas G, and a compressor 7 a connected to the turbine 7 b is provided in the intake pipe 4. And the intercooler 10 which is a corrugated fin type heat exchanger of embodiment of this invention is arrange | positioned between the compressor 7a and the intake manifold 3. As shown in FIG.

  As shown in FIG. 1, the intercooler 10 includes gaps through which the outside air Ao as the second fluid passes through a plurality of flat heat radiation tubes (heat transfer tubes) 11 that circulate the intake air Ai as the first fluid therein. S is provided and laminated, external fins 14 are provided in the gaps S, internal fins 15 are provided inside the heat radiating tube 11, and air intake Ai is provided via the wall surface 11 s of the heat radiating tubes 11, the internal fins 15, and the external fins 14. Heat exchange with the outside air Ao. In FIG. 1, in consideration of the complexity of the drawing, the dotted line in the longitudinal direction (the flow direction of the intake air Ai) indicating the internal fins 15 is omitted.

  In the present invention, furthermore, the intake air inside the heat radiating tube 11 is set so that the flow velocity V of the intake air Ai passing through the heat radiating tube 11 is equalized between the heat radiating tubes 11, that is, the same flow velocity. The flow resistance to Ai is large in the vicinity of the inlet portion 12a where the intake pipe 4 is connected to the inflow side header 12 or in the vicinity of the outlet portion 13a where the intake pipe 4 is connected to the outflow side header 13, and the inlet portion 12a. It is configured to be small at a part away from the outlet or a part away from the outlet portion 13a.

  The flow resistance with respect to the intake air Ai in the inside of the heat radiating tube 11 is configured to change stepwise or continuously to a part away from the vicinity of the inlet part 12a or a part away from the vicinity of the outlet part 13a. To do. Thereby, the flow velocity between the heat radiating tubes 11 is made more finely uniform.

  More specifically, the vicinity of the inlet portion 12a and the vicinity of the outlet portion 13a will be described. In the portion of the inflow side header 12 of the heat radiating tube 11, when there is a portion facing the inlet portion 12a, the vicinity of the inlet portion 12a. In addition, there is no portion facing the inlet portion 12a, and a portion that is several (for example, two to five) away from the inlet portion 12a is a portion away from the vicinity of the inlet portion 12a. Moreover, in the part of the outflow side header 13 of the heat radiating tube 11, when there is the part which the exit part 13a has opposed, it is set as the vicinity of the exit part 13a, there is no part which this exit part 13a is facing, and the exit part 13a. A part having a distance of several (for example, 2 to 5) is set as a part away from the vicinity of the outlet portion 13a.

  In order to change the flow resistance with respect to the intake air Ai in the inside of the heat radiating tube 11, for example, a change in the pitch of the internal fins 15 as shown in FIGS. 1 and 2 and a change in the shape of the internal fins 15 as shown in FIG. 4, either the presence or absence of insertion of the resistance increasing member 17 into the heat radiating tube 11 as shown in FIG. 4, the change in the shape of the inserted resistance increasing member 17, or a combination thereof is used.

  More specifically, as shown in FIG. 2, the pitch Pi, which is the size of the interval between the internal fins 15, is densely adjacent to the inlet portion 12a or the outlet portion 13a and from the inlet portion 12a or the outlet portion 13a. The resistance by the internal fin 15 with respect to the flow of the intake air Ai is changed by making it sparse at a distant part. That is, the pitch Pa in the vicinity of the inlet portion 12a or the outlet portion 13a is set to be smaller than the pitch Pi of a portion away from the inlet portion 12a or the outlet portion 13a.

  According to this, in the heat radiating tube 11 in which the pitch Pa of the internal fins 15 on the inflow side of the outside air Ao is made dense, the flow cross-sectional area of the flow cell 16 partitioned by the internal fins 15 becomes small. While the flow resistance of the intake air Ai passing through (the resistance received when the intake air Ai flows through the flow cell 16) is increased and the flow velocity V is decreased, the heat radiation tube 11 having a sparse pitch Pi of the internal fins 15 The flow cross-sectional area of the flow cell 16 partitioned by the fins 15 increases, the flow resistance of the intake air Ai passing through the flow cell 16 decreases, and the flow velocity V increases.

  Alternatively, as shown in FIG. 3, the pitch Pa of the internal fins 15 is changed by changing the shape of the internal fins 15 in a cross section perpendicular to the flow of the intake air Ai so that the area of the internal fins 15 in contact with the intake air Ai changes. The flow resistance can be easily changed without changing Pi.

  Further, as shown in FIG. 4, the resistance increase member 17 may be additionally inserted into the flow cell 16 to change the flow resistance of the flow cell 16. The flow resistance of the flow cell 16 may be changed by inserting the member 17. In addition, it is preferable that this resistance increasing member 17 increases the contact part with the internal fin 15 and the wall surface 11s, and releases the heat of the intake air Ai to the outside air Ao via the resistance increasing member 17, the internal fin 15 or the wall surface 11s. Thus, the first heat transfer efficiency between the intake air Ai and the heat radiating tube 11 can be improved.

  The relative positions of the inlet portion 12a and the outlet portion 13a are affected by the location of the intercooler 10 and the like, both are on the upper side, both are on the center side, both are on the lower side, and one is on the upper side. The other changes variously, such as the lower side.

  However, since the object of the present invention is to equalize the flow velocity between the heat radiating tubes 11, the flow velocity inside each heat radiating tube 11 can be measured or calculated experimentally or by calculation of fluid calculation simulation. The amount of increase in the internal flow resistance in each heat radiating tube 11 for equalizing these flow velocities, the amount of change in the pitch of the internal fins 15 for realizing the increased flow resistance, and the like can be easily obtained. .

  Moreover, the processing of the change of the pitch Pa and Pi of the internal fin 15 inside the heat radiating tube 11 and the change of the shape of the internal fin 15 and the processing of the resistance increasing member 17 are performed by inserting the internal fin 15 into the heat radiating tube 11. It can be easily performed by processing before the process.

  At the same time, the heat transfer efficiency with the outside air Ao in the external fin 14 is large in the vicinity of the inlet portion 12a or in the vicinity of the outlet portion 13a, and small in a portion away from the inlet portion 12a or a portion away from the outlet portion 13a. To do. The heat transfer efficiency with the outside air Ao in the external fin 14 is configured to be changed stepwise or continuously to a part away from the vicinity of the inlet part 12a or to a part away from the vicinity of the outlet part 13a. . Thereby, the heat transfer efficiency between the intake air Ai and the outside air Ao in the heat radiating tube 11 can be changed more finely.

  In order to change the second heat transfer efficiency between the external fin and the outside air Ao, for example, the pitch of the external fins 14 as shown in FIG. Either the presence / absence of an area increasing member (not shown) or a change in the shape of the arranged heat transfer area increasing member, or a combination thereof is used.

  This heat transfer area increasing member is an auxiliary member for increasing the surface area of the external fin 14, and not only has a large contact area with the outside air Ao, but also a contact surface with the external fin 14 or the wall surface 11 s of the heat radiating tube 11. It is also important to improve the second heat transfer efficiency by making the value as large as possible.

  Thereby, in the heat radiating tube 11, the flow velocity V of the intake air Ai flowing through the inside can be made uniform between the heat radiating tubes 11, and the heat transfer efficiency to the internal fin 15 and the wall surface 11s as the heat radiating tube 11 as a whole can be improved. Can be bigger. In addition, an increase in the flow resistance with respect to the intake air Ai inside the heat radiating tube 11 is often due to an increase in the heat transfer area. The decrease in the first heat transfer efficiency due to the increase in the first heat transfer efficiency due to the configuration of the heat radiation tube 11 and the internal fins 15 can be covered.

  Further, in accordance with this, the configuration of the external fins 14 increases the second heat transfer efficiency between the outside air Ao and the heat radiating tube 11 to match the balance between the first heat transfer efficiency and the second heat transfer efficiency. Thus, the overall heat transfer efficiency between the intake air Ai and the outside air Ao as the entire heat radiating tube 11 can be improved.

  Therefore, according to the intercooler 10 of the present invention, not only can the flow velocity V between the heat radiating tubes 11 inside the heat transfer tube 11 be made uniform, but also the internal fins 15 and the outside of each heat radiating tube 11 can be made uniform. Since both the heat transfer efficiencies of the fins 14 can be improved, the cooling performance of the entire heat exchanger can be improved.

1 engine (internal combustion engine)
3 Intake manifold 4 Intake pipe 7a Compressor 10, 10X Intercooler (corrugated fin heat exchanger)
11, 11X Heat radiation tube (heat transfer tube)
11s Wall surface 12 of heat radiating tube Inflow side header 12a Inlet part 13 Outlet side header 13a Outlet part 14 External fin 15 Internal fin 16 Distribution cell 17 Resistance increasing member Ai Intake (first fluid)
Ao Outside air (second fluid)
G exhaust gas

Claims (3)

A plurality of flat heat transfer tubes through which the first fluid flows are laminated with a gap through which the second fluid passes, and external fins are provided in the gaps, and internal fins are provided inside the heat transfer tubes. In the corrugated fin type heat exchanger for exchanging heat between the first fluid and the second fluid via the wall surface of the heat transfer tube, the inner fin, and the outer fin,
The flow resistance to the first fluid inside the heat transfer tube is changed by changing the pitch of the internal fins, whether or not a resistance increasing member is inserted into the heat transfer tube, or a combination thereof. ,
The flow resistance to the first fluid inside the heat transfer tube is set so that the flow rate of the first fluid passing through the inside of the heat transfer tube is equalized between the heat transfer tubes. In the vicinity of the inlet portion where the intake pipe is connected to the side header, or in the vicinity of the outlet portion where the intake pipe is connected to the outflow side header of the first fluid, the portion away from the inlet portion or the outlet In a part away from the part, it is configured to be small to increase the heat transfer efficiency between the first fluid in the internal fin and the heat transfer tube,
The heat transfer efficiency between the second fluid and the heat transfer tube in the external fin is the same as that of the heat transfer tube with the low flow resistance and the heat transfer tube with the low flow resistance. It is configured to be larger in the vicinity of the inlet part or in the vicinity of the outlet part and smaller in the part away from the inlet part or the part away from the outlet part so as to be larger than the heat transfer efficiency with two fluids. Corrugated fin type heat exchanger. Either the change in pitch of the internal fins, the change in the shape of the internal fins, the presence or absence of insertion of the resistance increasing member inside the heat transfer tube, or the change in the shape of the resistance increasing member to be inserted, or By changing the flow resistance to the first fluid inside the heat transfer tube by combination,
Regarding the pitch, which is the size of the interval between the external fins, it is short in the vicinity of the inlet part or in the vicinity of the outlet part, and away from the vicinity of the inlet part or in the vicinity of the outlet part. The corrugated fin heat exchanger according to claim 1, wherein the heat transfer efficiency between the external fin and the second fluid is changed by increasing the size of the external fin.   The corrugated fin type heat exchanger according to claim 1 or 2, wherein the corrugated fin type heat exchanger is an intercooler of a supercharged engine, the first fluid is intake air, and the second fluid is outside air. Heat exchanger.

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