JP2004162944A - Air-cooled type heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-cooled type heat exchanger of a compact constitution, having high cooling performance and minimizing the generation of uneven distribution of the heat in the cooling air flowing toward a downstream side. <P>SOLUTION: An inter-cooler 12 is divided into a first radiation part 20 and a second radiation part 21, and mounted at the front and back of a channel of the cooling air from a cooling fan 5, an inflow-side tank 22 is mounted at an upper position of the first radiation part 20, an inflow pipe 23 from a supercharger 15 is connected to the inflow-side tank 22, the first radiation part 20 is mounted at a downstream side of the cooling air with respect to the second radiation part 21, and lower end parts of the first and second radiation parts are connected to a communication tank 24. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air-cooled heat exchanger that cools a fluid to be cooled by cooling air, and particularly needs to greatly reduce the temperature of a high-temperature fluid to be cooled, such as supercharged air supplied to a diesel engine. The present invention relates to an air-cooled heat exchanger suitable for cooling a fluid to be cooled.
[0002]
[Prior art]
For example, as a construction machine, a hydraulic shovel is provided with a diesel engine as a power source, and drives a hydraulic pump by the engine to operate various actuators by a discharge pressure from the hydraulic pump. For this purpose, a radiator and an oil cooler are provided for cooling the engine cooling water and for cooling the hydraulic oil circulating in the hydraulic circuit. Further, in order to improve the output of the engine and purify the exhaust gas, the air supplied to the cylinder of the engine is supercharged, and an intercooler is provided to cool the supercharged air. .
[0003]
As described above, the radiator is a heat exchanger that uses engine cooling water, the oil cooler is hydraulic oil, and the intercooler is turbocharged air. In general, these heat exchangers are arranged in series so as to be arranged back and forth along a flow path of cooling air by a cooling fan driven by an engine. Here, of these heat exchangers, the one to be cooled to the lowest temperature is the supercharged air as the fluid to be cooled by the intercooler. Further, the radiator is desirably arranged at a position closest to the engine from the viewpoint of ease of routing of the pipes and the like in order to use the engine cooling water as the fluid to be cooled.
[0004]
Therefore, a cooling fan driven by the engine is provided at the rear position of the radiator by forming an outside air intake portion and an exhaust portion in a cover in the engine room, arranging the intercooler, the oil cooler, and the radiator in order from a position near the outside air intake portion. A configuration in which is provided is conventionally known (for example, see Patent Document 1). Therefore, the outside air taken in from the outside air intake section is cooled by the suction force of the cooling fan in the order of the intercooler, the oil cooler, and the radiator.
[0005]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 9-125972 (page 2, FIG. 5)
[0006]
[Problems to be solved by the invention]
By the way, in order to improve the output of a diesel engine and to purify exhaust gas, the supercharged air supplied to the engine needs to have a high compression and a low temperature. The supercharged air is compressed by the supercharger. At the time of this high compression, the supercharged air becomes hot due to adiabatic compression. Therefore, in the intercooler, it is necessary to improve the cooling capacity for the supercharged air as the fluid to be cooled, and to make it possible to significantly reduce the temperature. Further, since the temperature becomes abnormally high in the vicinity of the inflow portion of the intercooler, the temperature after the cooling air has passed through this position of the intercooler may partially become extremely high. As a result, there is a risk that the cooling function of the oil cooler or radiator, which is another heat exchanger disposed at the subsequent position, may be affected, and a member including rubber, plastic, or the like is provided at a portion located behind the intercooler. In such a case, there is a problem that they may be damaged by heat.
[0007]
In particular, in recent years, the demand for purification of exhaust gas has become extremely strong, and the regulations have tended to be strengthened. In order to clear the regulations, it is necessary to reduce the amount of supercharged air introduced into the intercooler. The temperature reaches 200 ° C. or higher, and it is necessary to cool this down to about 80-60 ° C. For this purpose, it is necessary to remarkably widen the heat radiating portion of the intercooler and increase the size of the cooling fan. Therefore, these installation space problems also occur. In particular, when the size of the upper revolving unit on which the heat exchanger including the intercooler is installed is limited, as in the case of a small turning hydraulic excavator, the size of the intercooler cannot be increased unnecessarily.
[0008]
The present invention has been made in view of the above points, and has as its object a small and compact configuration, high cooling capacity, and uneven distribution of heat in the cooling air flowing downstream. It is an object of the present invention to provide an air-cooled heat exchanger in which the temperature is reduced as much as possible.
[0009]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides an air-cooled heat source including an inflow portion and an outflow portion of a fluid to be cooled, and a radiator through which a cooling air passes to cool the fluid to be cooled passing therethrough. An exchange, wherein a first heat radiator is disposed downstream of the flow of the cooling air and a second heat radiator is disposed upstream thereof so as to intersect with the flow path of the cooling air; One side of the heat radiating section is connected to an inflow section of the fluid to be cooled, and one side of the second heat radiating section is connected to an outflow section of the fluid to be cooled. Is characterized in that it is configured to communicate with the communication part.
[0010]
Here, the fluid to be cooled in the heat exchanger may be any of a liquid and a gas, and in particular, a fluid that needs to significantly lower the temperature of the cooled fluid in a high temperature state, for example, a supercharger As an intercooler or the like using supercharged air supplied from a diesel engine to a diesel engine. In particular, in order to enhance the purification of exhaust gas from an engine mounted on a construction machine such as a hydraulic shovel, highly-compressed supercharged air having a temperature of 200 ° C. or higher is supplied to an engine cylinder. It is convenient to cool to the optimum temperature for cooling, ie, 80 to 60 ° C.
[0011]
Because of the air-cooled heat exchanger, cooling air is generally supplied by a cooling fan. The cooling fan may be dedicated to the heat exchanger of the present invention having the first and second heat radiating portions, but the cooling air from the single cooling fan is separated from the heat exchanger of the present invention by other means. To the air-cooled heat exchanger. In this case, the heat exchanger of the present invention and the other air-cooled heat exchanger may be arranged right and left or up and down with respect to the flow path of the cooling air, or may be arranged before and after. The point is that the temperature is selected based on the inflow temperature of each medium to be cooled and the set temperature that must be lowered. Further, another heat radiating section may be arranged between the first heat radiating section and the second heat radiating section.
[0012]
In the first and second heat radiating portions, the fluid to be cooled is caused to flow in the vertical direction or in the horizontal direction. In any case, the flow direction in the first heat exchanger and the flow direction in the second heat exchanger are opposite. The communication part between both heat radiating parts can be constituted by a communication tank, and the flow path in each heat radiating part can be connected to the communication tank, and the transition from the first heat radiating part to the second heat radiating part is possible. A configuration in which the flow path is bent into a U-shape or the like can be adopted.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, FIGS. 1 to 3 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes an engine room in a building of a construction machine, for example, a hydraulic shovel, in which a diesel engine 2 is installed, and a hydraulic pump 3 is connected to the engine 2. It is provided. Reference numeral 4 denotes a heat exchange device installed on the side of the engine 2 opposite to the side where the hydraulic pump 3 is connected. The heat exchange device 4 is provided with a cooling air supplied by a cooling fan 5 driven by the engine 2 to cool the fluid to be cooled. Cooling is performed.
[0014]
In a cover constituting the engine room 1, an outside air intake 6 is opened in front of and obliquely forward of the installation part of the heat exchange device 4, and an exhaust part 7 is opened in the installation part side of the engine 2. . Therefore, when the cooling fan 5 is driven, as shown by an arrow in FIG. 1, the outside air is taken in from the outside air intake unit 6, passes through the heat exchange device 4, and is discharged to the outside of the engine room 1 by the exhaust unit 7. A wind channel is formed. In FIG. 1, reference numeral 8 denotes a shroud for guiding the flow path of the cooling air from the cooling fan 5 toward the heat exchange device 4.
[0015]
Here, the heat exchange device 4 includes a plurality of heat exchangers. In the configuration shown in FIG. 2, a radiator 10 that uses engine cooling water as a fluid to be cooled, an oil cooler 11 that uses hydraulic oil as a fluid to be cooled, And an intercooler 12 that uses supercharged air supplied to the engine 2 as a fluid to be cooled. In the cooling air flow path of the cooling fan 5, the radiator 10 and the oil cooler 11 are arranged before and after, and the intercooler 12 is arranged so as to be arranged side by side with the radiator 10 and the oil cooler 11.
[0016]
Here, the temperature difference between the engine cooling water that is the fluid to be cooled by the radiator 10 and the hydraulic oil that is the fluid to be cooled by the oil cooler 11 is usually about several degrees to several tens degrees Celsius between the inflow side and the outflow side. . On the other hand, the intercooler 12 uses supercharged air supplied to the engine 2 as a fluid to be cooled. The engine 2 is a diesel engine, and the air sucked into the cylinder of the engine 2 is compressed in a supercharger by a turbine driven by the flow rate of exhaust gas discharged from the engine 2 toward the muffler 14. It has become. When air is pressurized by the supercharger 15, the temperature instantaneously rises due to adiabatic compression, and the higher the compression, the higher the temperature. The reason for supplying the supercharged air with high compression is to achieve complete combustion in the engine 2 and to purify exhaust gas. Further, for purifying the exhaust gas, it is necessary to suppress the supply temperature of the supercharged air to the engine 2 to be low. Assuming that the environmental standards to be fully satisfied in the future are satisfied, the temperature of the supercharged air becomes high at 200 ° C. or more when pressurized, and the temperature is increased to about 80 to 60 ° C. when supplied to the engine 2. Is required to be reduced.
[0017]
As described above, in the intercooler 12, the inflow temperature is extremely high, and the outflow temperature is considerably lower than the fluid to be cooled in the radiator 10 and the oil cooler 11. That is, the intercooler 12 requires a higher cooling capacity than the radiator 10 and the oil cooler 11. Further, if the heat exchange efficiency in the temperature region of 200 ° C. or higher is excessively increased, the downstream air is heated and becomes hot air. Since it is damaged, the temperature does not drop too sharply when passing through the intercooler 12 so that the hot air does not flow downstream.
[0018]
From the above, as shown in FIG. 3, the heat radiating portion of the intercooler 12 is divided into the first heat radiating portion 20 and the second heat radiating portion 21. The first and second heat radiating sections 20 and 21 are arranged before and after the flow path of the cooling air by the cooling fan 5. An inflow-side tank 22 is provided at an upper position of the first radiator 20, and an inflow pipe 23 from the supercharger 15 is connected to the inflow-side tank 22. The first heat radiating section 20 is disposed downstream of the cooling air. The lower ends of the first heat radiating section 20 and the second heat radiating section 21 are connected to a communication tank 24 constituting a communication section. Further, an outflow side tank 25 is connected to an upper end of the second heat radiating section 25, and an outflow pipe 26 from the intake manifold 13 of the engine 2 is connected to the outflow side tank 25. The outflow pipe 26 drawn out of the outflow side tank 25 passes through the position of the inflow side tank 22, but the outflow pipe 26 does not interfere with the inflow side tank 22, and the outflow pipe 26 In order to extend straight from the outflow side tank 25 and almost in parallel with the inflow pipe 23, a pipe escape portion such as a sloped structure at a portion of the inflow side tank 22 opposite to a portion to which the inflow pipe 23 is connected is used. 22a (FIG. 2) are formed. Thereby, the routing of the inflow pipe 23 and the outflow pipe 26 becomes compact.
[0019]
Accordingly, the supercharged air, which is the fluid to be cooled, is cooled in the first heat radiating section 20 while forming a downward flow from above to below, but is mixed in the communication tank 24 during the cooling. . Then, the supercharged air is transferred from the communication tank 24 to the second heat radiating section 21, and forms a rising flow in the second heat radiating section 21, and is further cooled during this time. That is, when viewed from the flow direction of the cooling air, cooling of the supercharged air starts on the downstream side, the flow path is turned back in the middle, and cooled to the supply temperature to the supercharged air engine 2 on the upstream side. .
[0020]
By configuring the intercooler 12 in this way, the supercharged air that has been highly compressed by the supercharger and has become extremely high temperature flows from the inflow pipe 23 into the inflow tank 22 on the downstream side of the cooling air. When flowing in and flowing through the first heat radiating section 20, the cooling fan 5 cools down gradually by the action of the cooling air. The temperature of the supercharged air immediately after shifting from the inflow side tank 22 to the inside of the first radiator 20 is the highest temperature. It is not necessary to lower the temperature to a temperature at which it can be supplied, but it is sufficient if the temperature can be lowered to a substantially intermediate temperature. Therefore, the rate of heat reduction per unit length in the flow path of the fluid to be cooled, which constitutes the first heat radiating section 20, can be reduced.
[0021]
The supercharged air, which is the fluid to be cooled, has a temperature approximately halfway between the temperature at the time of inflow and the temperature at the time of outflow by the first heat radiating section 20 and flows into the communication tank 24. In this way, by allowing the air to flow into the communication tank 24, the air in the part where the cooling air efficiently acts and the part in the part where the cooling air does not efficiently work out of the flow path of the supercharged air in the first heat radiating part 20 are mixed. , The temperature becomes substantially uniform throughout. The supercharged air in the communication tank 24 further moves to the second heat radiating section 21 and forms an upward flow in the second heat radiating section 21. Here, the supercharged air immediately after leaving the communication tank 24 has a temperature substantially intermediate between the time of inflow and the time of outflow, but is supplied to the cylinder of the engine 2 while rising in the second heat radiation portion 21. Cooled to the temperature needed to Here, since the second heat radiating section 21 is located on the upstream side of the cooling air, the cooling air having a lower temperature acts thereon. As a result, the supercharged air is cooled to a temperature optimum for being supplied to the intake manifold 13 of the engine 2 at a position near the outflow side tank 25 which is the most upstream side in the entire heat radiation part.
[0022]
As described above, the intercooler 12 cools the fluid to be cooled by using the cooling air flow path by the single cooling fan 5 twice, that is, while reciprocating the flow path. Therefore, the temperature of the extremely high temperature fluid to be cooled can be significantly reduced without increasing the size of the cooling fan 5 and without increasing the size of the intercooler 12 in the direction orthogonal to the flow path of the cooling air. . In addition, the reciprocating flow paths overlap in the front-rear direction, and the portion of the second heat radiating portion 21 that is located on the upstream side of the cooling air and has a low temperature is the portion of the first heat radiating portion 20 that has a high temperature, The portion of the second heat radiating portion 20 where the temperature is low, that is, approximately the middle temperature, is also the portion of the first heat radiating portion 21 where the temperature is almost the middle temperature. Therefore, the air temperature on the downstream side of the cooling air in the intercooler 12 as a whole has a substantially uniform temperature state without partial uneven distribution of heat. As a result, components made of rubber, plastic, or the like are arranged downstream of the cooling fan 5, and the air that has been heat-exchanged by the intercooler 12 has a temperature that does not cause thermal damage even if it comes into direct contact with them. It can be.
[0023]
Here, in the above-described first embodiment, the first heat radiating section 20 and the second heat radiating section 21 are configured to be connected by the communication tank 24. , 21 are provided with a large number of tubes forming a narrow flow path through which the supercharged air as the fluid to be cooled flows, and as shown in FIG. A structure in which the tube 30 is integrated with the heat radiating portion 21 side, and the lower end of the first heat radiating portion 20 is curved in a substantially U-shape to be transferred to the second heat radiating portion 21. You can also. In this case, the U-shaped transition portion is provided by housing the tube 30 in the reinforcing member 31, and the reinforcing member 31 can be fixed to the lower plate of the engine room 1 by the support member 32.
[0024]
Further, FIG. 2 shows an arrangement in which the units of the intercooler 12 and the radiator 10 and the oil cooler 11 are arranged side by side, but the relationship with the aspect ratio of the unit of the radiator 10 and the oil cooler 11 is shown. Therefore, when the horizontal type is used, it can be arranged at the upper position of the unit including the radiator 10 and the oil cooler 11, as in the intercooler 40 shown in FIG. It is desirable that the front shape of the heat exchanger including the heat exchangers arranged above and below is set to be substantially square.
[0025]
Therefore, the intercooler 40 arranged on the upper side is horizontally long. Therefore, the intercooler 40 is configured such that the first heat radiating portion 41 arranged on the downstream side of the cooling air and the second heat radiating portion 42 arranged on the upstream side separate the supercharged air as the fluid to be cooled from right and left. Flow in the direction. To this end, tanks 43, 44 and 45, 46 are connected to both sides of the first and second heat radiating portions 41, 42, an inflow pipe 47 is connected to the tank 43, and an outflow pipe is connected to the tank 46. 48, and the tanks 44 and 45 are connected by a communication pipe 49.
[0026]
Further, as shown in FIG. 6, the radiator 10 and the oil cooler 11 can be arranged between the first heat radiating portion 51 and the second heat radiating portion 52 constituting the intercooler 50. That is, in the flow direction of the cooling air by the cooling fan 5, the second heat radiating portion 52 of the intercooler 50 is arranged on the most upstream side, and then the oil cooler 11 and the radiator 10 are arranged in this order. The first heat radiating portion 51 is arranged on the side closest to the fifth heat radiating portion 5. As a result, the first radiator 51 of the intercooler 50 to which the highest-temperature fluid to be cooled is supplied is located at the most downstream side of the cooling air, and it is necessary to cool the coolant to the lowest temperature. The second radiator 52 of the cooler 50 is arranged on the most upstream side of the cooling air. The first heat radiating section 51 and the second heat radiating section 52 may have the same structure, or may have different structures.
[0027]
In FIG. 6, the inflow pipe 54 connected to the inflow tank 53 of the first radiator 51 and the outflow pipe 56 connected to the outflow tank 55 of the second radiator 52 are both in the upper position. The lower tank 57 of the first radiator 51 and the lower tank 58 of the second radiator 52 are configured to communicate with each other by a communication pipe 59. Therefore, the supercharged air forms a downward flow in the first radiating section 51 and an upward flow in the second radiating section 52. However, as shown in FIG. 7, the first heat radiating portion 61 that forms the intercooler 60 and the second heat radiating portion 62 that is arranged so as to sandwich the radiator 10 and the oil cooler 11 each supply a fluid to be cooled. It may be configured to flow in the left-right direction. In this case, a tank 64 provided at an end of the first heat radiating section 61 to which the inflow pipe 63 is connected, and a tank 66 provided at an end of the second heat radiating section 62 to which the outflow pipe 65 is connected. Are arranged on the same side, and tanks 67 and 68 are provided at opposite ends, respectively, and these two tanks 67 and 68 are connected by a communication pipe 69 provided so as to bypass the radiator 10 and the oil cooler 11. I do.
[0028]
As described above, in each of the embodiments shown in FIG. 4 to FIG. 7, similarly to the first embodiment, the high-temperature fluid to be cooled can be easily and efficiently cooled to a desired temperature. In each of these embodiments, the same or equivalent members as described in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.
[0029]
【The invention's effect】
As described above, according to the present invention, the air-cooled heat exchanger has a small and compact configuration, has a high cooling capacity, and can suppress the uneven distribution of heat in the cooling air flowing downstream. Has the effect of
[Brief description of the drawings]
FIG. 1 is an internal configuration diagram of an engine room incorporating an intercooler as an air-cooled heat exchanger according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing a configuration of the heat exchange device of FIG.
FIG. 3 is an operation explanatory view of the intercooler having the configuration of FIG. 1;
FIG. 4 is an internal configuration diagram of an engine room incorporating an intercooler as an air-cooled heat exchanger according to a second embodiment of the present invention.
FIG. 5 is a perspective view illustrating a configuration of a heat exchange device according to a third embodiment of the present invention.
FIG. 6 is an internal configuration diagram of an engine room incorporating an intercooler as an air-cooled heat exchanger according to a fourth embodiment of the present invention.
FIG. 7 is a perspective view illustrating a configuration of a heat exchange device according to a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Engine room 2 Engine 4 Heat exchange device 5 Cooling fan 6 Outside air intake part 7 Exhaust part 10 Radiator 11 Oil cooler 12, 40, 50, 60 Intercooler 20, 41, 51, 61 First radiator 21, 42, 52 , 62 second radiator 22, 53 inflow-side tank 22 a pipe relief 23, 47, 54, 63 inflow pipe 24 communication tank 25, 55 outflow-side tank 26, 48, 56, 65 outflow pipe 30 tube 43-46, 64, 66-68 Tank 49, 59, 69 Connecting piping

Claims (6)

In an air-cooled heat exchanger including an inflow portion and an outflow portion of a fluid to be cooled, and a radiating portion through which cooling air passes and cools the fluid to be cooled passing through the inside,
A first heat radiator is arranged downstream of the flow of the cooling air and a second heat radiator is arranged upstream of the flow of the cooling air so as to cross the flow path of the cooling air,
An inflow portion of the fluid to be cooled is connected to one side of the first heat radiating portion,
An outlet of the fluid to be cooled is connected to one side of the second heat radiator,
The air-cooled heat exchanger is characterized in that the other side between the two heat radiating parts is communicated by a communicating part. The air-cooled heat exchanger according to claim 1, wherein the fluid to be cooled is supercharged air supplied to an engine from a supercharger. The air-cooled heat exchanger according to claim 1 or 2, wherein another air-cooled heat exchanger is arranged between the first heat radiator and the second heat radiator. 3. The air-cooled heat exchanger according to claim 1, wherein the communication portion is formed of a communication tank to which the flow paths of both heat radiating portions are connected. An inflow-side tank to which an inflow pipe is connected is provided at an upper position of the first radiator, and an outflow-side tank to which an outflow pipe to which an outflow pipe is connected is provided at an upper position of the second radiator. Further, the communication tank is provided between lower end portions of the first and second heat radiating portions, and the outflow pipe is provided at an end of the inflow tank opposite to a connection portion of the inflow pipe. 5. The air-cooled heat exchanger according to claim 4, wherein a pipe escape portion for extracting the air is formed. The air-cooled heat exchange according to claim 1 or 2, wherein the communication part is formed by bending a transition flow path from the first heat radiation part to the second heat radiation part in a U-shape. vessel.

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