US20080115528A1

US20080115528A1 - Cooling module

Info

Publication number: US20080115528A1
Application number: US11/983,014
Authority: US
Inventors: Koichi Yamamoto; Hiroki Matsuo
Original assignee: Denso Corp
Current assignee: Denso Corp
Priority date: 2006-11-17
Filing date: 2007-11-06
Publication date: 2008-05-22
Also published as: CN101182975A; JP2008126720A; CN100565069C; DE102007054345A1

Abstract

A cooling module comprises an intercooler 100 and an integrated heat exchanger 1 including a condenser unit 200 for cooling a refrigerant circulated in a refrigeration cycle by heat exchange between the refrigerant and air and an oil cooler unit 300 for cooling an oil higher in temperature than the refrigerant by heat exchange between the oil and air. Condenser unit 200 and oil cooler unit 300 are vertically arranged in parallel to each other, and integrated heat exchanger 1 is arranged downstream of intercooler 100 in the air flow. The vertical length of integrated heat exchanger 1 is larger than the vertical length of intercooler 100. Oil cooler unit 300 is arranged in superposition with at least a part of intercooler 100 as viewed from the direction of air flow.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
This invention relates to a cooling module comprising a heat source unit and an integrated heat exchanger having a plurality of heat exchange units.
2. Description of the Related Art
Vehicles such as automobiles are equipped with many heat exchangers such as an oil cooler for cooling oil in the torque converter of an automatic transmission and an oil cooler for cooling engine oil, as well as a radiator for cooling water circulating through an engine and a condenser for cooling refrigerant of an air conditioning system. A hybrid vehicle also includes a radiator for cooling electronic parts, such as an inverter for controlling the electric motor.
In recent years it has been desirable to reduce the thickness and size of heat exchangers in order to safely prevent damage due to vehicle collision by reducing the installation space and assembly of heat exchangers. As a method for size reduction, an integrated heat exchanger has been proposed in which the interior of each pair of left and right headers (tanks) of a heat exchanger are partitioned by a partitioning plate so that one heat exchanger core has independent dual heat exchange functions of the condenser unit and the oil cooler unit (see, for example, U.S. Pat. No. 6,394,176).

SUMMARY OF THE INVENTION

In a vehicle having an intercooler (heat source unit) for cooling combustion air (intake air) introduced into an internal combustion engine, the intercooler is often arranged under the bumper where air can be introduced from the vehicle front. The heat exchange capacity of the intercooler changes according to the running load, and under a maximum load, air downstream of the intercooler reaches a temperature about 30° C. higher than atmospheric temperature. In the case where the atmospheric temperature is 30° C., for example, the air temperature downstream of the intercooler in the air flow reaches a maximum of 60° C., thereby generating conditions surpassing the condensation temperature (about 40 to 45° C.) of the refrigerant of the condenser unit.
Under these conditions, the arrangement of the condenser unit downstream of the intercooler in the air flow poses the problem that the heat exchange performance of the condenser unit is extremely reduced.
Especially, in the case where the condenser unit of the integrated heat exchanger includes a condensing portion for condensing a gas-phase refrigerant by heat exchange between the gas-phase refrigerant and air, and a supercooling portion for further cooling the refrigerant by heat exchange between the condensed refrigerant and air, the arrangement of the supercooling portion downstream of the intercooler in the air flow causes the refrigerant to boil in the supercooling portion. As a result, the expansion valve arranged downstream of the condenser unit in the refrigerant flow runs short of refrigerant, thereby deteriorating cooling performance. Another problem is that the gas-phase refrigerant flows into the expansion valve and noise is generated from the expansion valve.
In view of the problems described above, the object of this invention is to provide a cooling module in which an integrated heat exchanger having a condenser unit and another heat exchange unit arranged downstream of a heat source unit in the air flow, and in which the heat exchange performance of the condenser unit is secured.
In order to achieve the object described above, according to a first aspect of the invention, there is provided a cooling module comprising a heat source unit 100 and an integrated heat exchanger 1 including a condenser unit 200 for cooling a refrigerant circulated in a refrigeration cycle by heat exchange between the refrigerant and air and another heat exchange unit 300 for cooling another fluid by heat exchange between another fluid higher in temperature than the refrigerant and air, wherein condenser unit 200 and heat exchange unit 300 are vertically juxtaposed, wherein integrated heat exchanger 1 is arranged downstream of heat source unit 100 in the air flow, wherein the vertical length of integrated heat exchanger 1 is larger than the vertical length of heat source unit 100, and wherein another heat exchange unit 300 is arranged in superposition with at least a part of heat source unit 100 as viewed from the direction of air flow.
As described above, another heat exchange unit 300 for cooling another fluid higher in temperature than the refrigerant in the condenser unit 200 is arranged downstream of the heat source unit 100 in the air flow, i.e. at the area high in air temperature. Therefore, the condenser unit 200 can be arranged at an area comparatively low in air temperature. As a result, heat exchange performance of the condenser unit 200 can be secured.
The condenser unit 200 of the cooling module according to the first aspect described above may be comprised of a condensing portion 210 for condensing the refrigerant and supercooling portion 220 in order to supercool the refrigerant flowing in from the condensing portion 210.
According to a second aspect of the invention, there is provided a cooling module comprising a heat source unit 100 and an integrated heat exchanger 1 including a condenser unit 200 for cooling a refrigerant circulated in a refrigeration cycle by heat exchange between the refrigerant and air and another heat exchange unit 300 for cooling another fluid by heat exchange between another fluid higher in temperature than the refrigerant and air, wherein the condenser unit 200 and another heat exchange unit 300 are vertically juxtaposed, wherein the integrated heat exchanger 1 is arranged downstream of the heat source unit 100 in the air flow, wherein the vertical length of the integrated heat exchanger 1 is larger than the vertical length of the heat source unit 100, wherein the condenser unit 200 includes a condensing portion 210 for condensing the refrigerant and a supercooling portion 220 for supercooling the refrigerant flowing in from the condensing portion 210, and wherein the supercooling portion 220 is arranged not to be superposed with the heat source unit 100 as viewed from the direction of the air flow.
In the condenser unit 200, the supercooling portion 220 which is required to be kept at a low temperature is arranged downstream of the heat source unit 100 in the air flow, i.e. at an area high in air temperature, therefore, heat exchange performance of condenser unit 200 can be secured. In the process, refrigerant which may boil at the supercooling portion 220 can be suppressed, and therefore, insufficient refrigerant flow rate which otherwise might occur in the expansion valve arranged downstream of the condenser unit 200 in the refrigerant flow can be suppressed, thereby making it possible to suppress deterioration of cooling performance. Also, since the inflow of the gas-phase refrigerant into the expansion valve can be suppressed, the generation of noise from the expansion valve can be suppressed.
Also, according to a third aspect of the invention, there is provided a cooling module wherein the supercooling portion 220 is arranged on the side of the condensing portion 210 far from another heat exchange unit 300 in a vertical direction.
In the integrated heat exchanger 1, the supercooling portion 220, the condensing portion 210 and another heat exchange unit 300 are increased in temperature in that order. By arranging another heat exchange unit 300 highest in temperature at a distance from the supercooling portion 220 lowest in temperature, heat transfer from another heat exchange unit 300 to supercooling portion 220 can be avoided. As a result, heat exchange performance of the condenser unit 200 can be more positively obtained.
In the cooling module according to the first to third aspects described above, the condenser unit 200 may be configured of a plurality of stacked first tubes 2 a with the refrigerant passed therethrough and another heat exchange unit 300 configured of a plurality of second tubes 2 b stacked in the same direction as the first tubes 2 a with another fluid passed therethrough, while the integrated heat exchanger 1 may have a pair of header tanks 5 arranged at the longitudinal ends, respectively, of the first and second tubes 2 a, 2 b and communicating with a plurality of the first and second tubes 2 a, 2 b by extending in the direction in which the first and second tubes 2 a, 2 b are stacked, so that the condenser unit 200 and other heat exchange unit 300 may be integrated by header tanks 5.
The heat source unit may also be an intercooler (100) arranged downstream of a supercharger for pressurizing the intake air of the internal combustion engine in the intake air flow to cool the intake air by heat exchange between the intake air and air.
Further, another heat exchange unit may be an oil cooler unit 300 for cooling the oil of on-vehicle devices.
Incidentally, reference numerals attached to the respective means described above represent correspondence with the specific means, respectively, described in the embodiments below.
The present invention may be more fully understood from the description of preferred embodiments of the invention, as set forth below, together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the cooling module mounted on the vehicle according to an embodiment of the invention.

FIG. 2 is a sectional view showing the integrated heat exchanger 1 according to an embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the invention is explained below with reference to FIGS. 1 and 2. A cooling module according to this embodiment used in a vehicle driven by an internal combustion engine as a drive source is taken as an example. FIG. 1 is a diagram showing the cooling module according to this embodiment mounted on the vehicle.
As shown in FIG. 1, the cooling module according to this embodiment, mounted at the front end of a vehicle, includes an integrated heat exchanger 1 having a condenser unit 200 and an oil cooler unit 300, and an intercooler 100. The intercooler 100 is an air-cooled heat exchanger arranged downstream of a supercharger (not shown) for pressurizing the intake air of the internal combustion engine to cool the intake air by heat exchange between the intake air and air. Incidentally, the intercooler 100 corresponds to the heat source unit according to the invention.
The integrated heat exchanger 1 is arranged downstream of the intercooler 100 in the air flow (in the rear of the vehicle). The length of the integrated heat exchanger 1 in the vertical direction (vertical direction on the vehicle) is larger than the vertical length of the intercooler 100. According to this embodiment, the vertical length of the intercooler 100 is larger than the vertical length of the supercooling portion 220 of the condenser unit 200 described later and the vertical length of the oil cooler unit 300. Also, the lower end of the integrated heat exchanger 1 and the lower end of the intercooler 100 are located at the same vertical position.
FIG. 2 is a sectional view showing the integrated heat exchanger 1 according to this embodiment. As shown in FIG. 2, the integrated heat exchanger 1 according to this embodiment includes one core unit 4 having a plurality of tubes 2 and fins 3 and a pair of header tanks 5 assembled at the left and right ends, respectively, of the core unit 4.
Tubes 2, in which a heat medium (the refrigerant or the oil in this embodiment) flows, each assume such a flat form that the direction of air flow (perpendicular to the page) coincides with the direction along the long diameter thereof. A plurality of tubes 2 are arranged in parallel to each other in the vertical direction in such a manner that the longitudinal direction thereof coincide with the horizontal direction. Fins 3 assume a corrugated form and are coupled to the flat surfaces on both sides of each tube 2. Fins 3 increase the heat transmission area with air and promote heat exchange between the heat medium and the air. Also, an insert 6 extending substantially in parallel to the length of tubes 2 to reinforce core unit 4 is arranged at each end of core unit 4.
Header tanks 5 extend in the direction perpendicular to the length of tubes 2 at the longitudinal ends of the tubes (left and right ends in this embodiment) and communicate with the plurality of the tubes 2. The header tanks 5 each include a core plate 5 a coupled to the tubes 2 inserted therein and a tank body 5 b making up the inner space of the tank with the core plate 5 a. The header tank 5 located on the left side in FIG. 2 is called a first header tank 51, and the header tank located on the right side in FIG. 2 a second header tank 52.
The core unit 4 is comprised of a condenser unit 200 for cooling the refrigerant by heat exchange between the refrigerant circulated in the vehicle refrigeration cycle (air conditioning system) and air, and an oil cooler unit 300 for cooling the oil in the torque converter for the automatic transmission of the vehicle. According to this embodiment, the condenser unit 200 is arranged on the upper side, and the oil cooler unit 300 on the lower side. The plurality of tubes 2 which make up the condenser unit 200 in which the refrigerant flows are called first tubes 2 a, and tubes 2 which make up oil cooler unit 300 in which the oil flows are called second tubes 2 b. Oil cooler unit 300 corresponds to the other heat exchange unit according to the invention.
A tube arranged in the boundary between the condenser unit 200 and the oil cooler unit 300 (between first tubes 2 a and second tubes 2 b) makes up a dummy tube 6 through which no heat medium flows. According to this embodiment, dummy tube 6 has the longitudinal ends thereof closed.
First separators 71 are arranged above and below, respectively, the dummy tube 6 in each header tank 5. As a result, the interior of each header tank 5 is divided into two parts along the length (vertical direction) thereof by the first separators 71 as a boundary.
Now, the configuration of the oil cooler unit 300 will be explained. The oil cooler unit 300 is a U-turn type with the oil flowing along the shape of a U. At the portion lower than the two first separators 71 in the first header tank 51 (hereinafter referred to as the first oil header portion 51 a), an oil inlet 31 allowing the oil to flow into the oil cooler unit 300 and an oil outlet 32 allowing the oil to flow out of the oil cooler unit 300 are arranged. The oil inlet 31 and the oil outlet 32 are arranged at the lower and upper ends, respectively, of the first oil header unit 51 a.
In order to form the U-shaped oil flow in the oil cooler unit 300, a second separator 72 is arranged in the first oil header portion 51 a. More specifically, the second separator 72 is arranged between the oil inlet 31 and the oil outlet 32 in the first oil header portion 51 a.
Now, the configuration of condenser unit 200 will be explained. A refrigerant inlet 21 for allowing the refrigerant to flow into condenser unit 200 and a refrigerant outlet 22 for allowing the refrigerant to flow out of condenser unit 200 are arranged at the portion (hereinafter referred to as the first refrigerant header portion 51 b) above the two first separators 71 of the first header tank 51. The refrigerant inlet 21 and the refrigerant outlet 22 are arranged at the lower and upper ends, respectively, of the first refrigerant header portion 51 b.
A third separator 73 is arranged at the position on the upper side in the first refrigerant header portion 51 b, and a fourth separator 74 at the same height as the third separator 73 is arranged in the portion (hereinafter referred as the second refrigerant header portion 52 b) above the two first separators 71 of the second header tank 52. The condenser unit 200 is divided into two heat exchange units by the third and fourth separators 73, 74.
A gas-liquid separator 8 is arranged on the outside (far from the core unit 4) of the second refrigerant header portion 52 b. This gas-liquid separator 8 is a receiver adapted to store the liquid-phase refrigerant by separating the gas-phase and liquid-phase refrigerants from each other.
The gas-liquid separator 8 and the second refrigerant header portion 52 b communicate with each other at two points through first and second communication passages 81, 82. Specifically, the first communication passage 81 establishes communication between the lower end portion of the second refrigerant header portion 52 b and the lower portion of the gas-liquid separator 8. Also, the second communication passage 82 establishes communication between the upper portion of the gas-liquid separator 8 and the portion of the second refrigerant header portion 52 b above the fourth separator 74.
First, the portion of the condenser unit 200 under the third and fourth separators 73, 74 makes up a condensing portion 210 for condensing the refrigerant by heat exchange between the gas-phase refrigerant flowing in from the refrigerant inlet 21 and air. The refrigerant that has flowed out of the condensing portion 210 flows into the gas-liquid separator 8 through the first communication passage 81.
The portion of the condenser unit 200 above the third and fourth separators 73, 74, on the other hand, makes up a supercooling portion 220 for cooling the liquid-phase refrigerant by heat exchange between the liquid-phase refrigerant flowing in through the second communication passage 82 from the gas-liquid separator 8 and air. The refrigerant that has been cooled by the supercooling portion 220 flows out from the refrigerant outlet 22.
Now, the configuration of the gas-liquid separator 8 will be explained. The interior of the gas-liquid separator 8 is divided into an upper space 83 and a lower space 84. The upper space 83 is connected to the second communication passage 82, and the lower space 84 to the first communication passage 81. The liquid-phase refrigerant large in specific gravity flowing in from the first communication passage 81 stays temporarily in the vertically lower part (along the direction of gravity) of the lower space 84 while the gas-phase refrigerant small in specific gravity temporarily stays in the vertically upper part (along the direction of gravity) in the lower space 84.
The gas-liquid separator 8 includes a communication pipe 85 for introducing the liquid-phase refrigerant in the neighborhood of the bottom portion of the lower space 84 into the upper space 83. A baffle plate 85 for improving the gas-liquid separability is arranged in the part of the lower space 84 lower than the first communication passage 81. Also, a dryer 86 containing therein a desiccant for removing moisture in the refrigerant is arranged in the lower space 84. Further, a filter 87 for removing foreign matter from the refrigerant is arranged in the upper space 83.
According to this embodiment, the first communication passage 81 is arranged below a normal liquid level (indicated by dashed line in FIG. 2) of the liquid-phase refrigerant in the lower space 84. As a result, the intrusion of the gas-liquid two-phase refrigerant into the communication pipe 85 is prevented which otherwise might be caused by involving the gas-phase refrigerant existing above the liquid level under a dynamic pressure exerted on the liquid surface of the liquid-phase refrigerant flowing into the lower space 84 from the first communication passage 81. Incidentally, intrusion of the gas-liquid two-phase refrigerant into communication pipe 85 causes the intrusion of the gas-phase refrigerant into the supercooling portion 220 and reduces the supercooled area, resulting in a lower cooling performance. According to this embodiment, in contrast, the deterioration of the cooling performance is prevented by arranging the first communication passage 81 under the normal liquid level of the liquid-phase refrigerant in the lower space 84.
Returning to FIG. 1, the oil cooler unit 300 is arranged in superposition with the intercooler 100 as viewed along the direction of air flow. The supercooling portion 220, on the other hand, is arranged not to be superposed with the intercooler 100 as viewed along the direction of air flow (longitudinal direction of the vehicle). Also, the supercooling portion 220 is arranged on the side of the condensing portion 210 vertically far from the oil cooler unit 300. According to this embodiment, the supercooling portion 220 is arranged at the upper end and the oil cooler unit 300 at the lower end of the integrated heat exchanger 1, and the condensing portion 210 is interposed between the supercooling portion 220 and the oil cooler unit 300.
By arranging the oil cooler unit 300 as described above in superposition with the intercooler 100 as viewed along the direction of air flow, i.e. downstream of the intercooler 100 in the air flow where the air temperature is high, the condenser unit 200 can be arranged at the part where the air temperature is comparatively low. As a result, the heat exchange performance of the condenser unit 200 is secured. In the process, the temperature of the heat medium (oil) passed through the oil cooler unit 300 is higher than the temperature of the heat medium (refrigerant) passed through the condenser unit 200, and therefore, the heat exchange performance of the oil cooler unit 300 is not extremely reduced.
Also, the supercooling portion 220 constituting the part of the condenser unit 200 which is required to be reduced in temperature is not arranged downstream of the intercooler 100 in the air flow, i.e. the area high in air temperature. In this way, the heat exchange performance of the condenser unit 200 is secured. In the process, refrigerant which may boil in the supercooling portion 220 is suppressed, and therefore the refrigerant flow rate in the expansion valve arranged downstream of the condenser unit 200 in the refrigerant flow is prevented from becoming insufficient, thereby making it possible to suppress the deterioration of the cooling performance. Also, since the intrusion of the gas-phase refrigerant into the expansion valve can be suppressed, the expansion valve is prevented from generating noise.
Also, in the integrated heat exchanger 1, the temperature of the supercooling portion 220, the condensing portion 210 and the oil cooler unit 300 are higher in ascending order. For this reason, the oil cooler unit 300 is arranged on the side of the condensing portion 210 far from the supercooling portion 220. Specifically, the oil cooler unit 300 highest in temperature and the supercooling portion 220 lowest in temperature are arranged at a distance from each other. Thus, the heat transfer from the oil cooler unit 300 to the supercooling portion 220 can be avoided. As a result, the heat exchange performance of the condenser unit 200 can be secured more positively.

Other Embodiments

According to the embodiments described above, the other heat exchange unit makes up the oil cooler unit 300 for cooling the oil in the torque converter for the automatic transmission of the vehicle. Nevertheless, the invention is not limited to such an application, and a oil cooler unit for cooling engine oil or power steering fluid may be used.
Also, according to the embodiments described above, the supercooling portion 220 is arranged at the upper end and the oil cooler unit 300 at the lower end of the integrated heat exchanger 1. Alternatively, the supercooling portion 220 may be arranged at the lower end and the oil cooler unit 300 at the upper end of the integrated heat exchanger 1.
Further, the lower end of the integrated heat exchanger 1 and the lower end of the intercooler 100, though located at the same vertical position according to the embodiments described above, may alternatively be displaced from each other.
Also, according to the embodiments described above, the oil cooler unit 300 is arranged in superposition with the intercooler 100 in its entirety as viewed from the direction of air flow. Nevertheless, the invention is not limited to this configuration, and the oil cooler unit 300 may alternatively be arranged in superposition at least partially with the intercooler 100.
While the invention has been described by reference to specific embodiments chosen for purposes of illustration, it should be apparent that numerous modifications could be made thereto by those skilled in the art without departing from the basic concept and scope of the invention.

Claims

1. A cooling module comprising:

a heat source unit; and

an integrated heat exchanger including a condenser unit for cooling a refrigerant circulated in a refrigeration cycle by heat exchange between the refrigerant and air, and another heat exchange unit for cooling another fluid higher in temperature than the refrigerant by heat exchange between another fluid and air;

wherein the condenser unit and another heat exchange unit are vertically arranged in parallel to each other,

wherein the integrated heat exchanger is arranged downstream of the heat source unit in the air flow,

wherein the vertical length of the integrated heat exchanger is larger than the vertical length of the heat source unit, and

wherein another heat exchange unit is arranged in superposition with at least a part of the heat source unit as viewed from the direction of air flow.

2. The cooling module according to claim 1,

wherein the condenser unit includes a condensing portion for condensing the refrigerant and a supercooling portion for supercooling the refrigerant flowing in from the condensing portion.

3. A cooling module comprising:

a heat source unit; and

an integrated heat exchanger including a condenser unit for cooling a refrigerant circulated in a refrigeration cycle by heat exchange between the refrigerant and air and another heat exchange unit for cooling another fluid higher in temperature than the refrigerant by heat exchange between another fluid and air;

wherein the condenser unit and the heat exchange unit are vertically arranged in parallel to each other,

wherein the vertical length of the integrated heat exchanger is larger than the vertical length of the heat source unit,

wherein the condenser unit includes a condensing portion for condensing the refrigerant and a supercooling portion for supercooling the refrigerant flowing in from the condensing portion, and

wherein the supercooling portion is arranged not to be superposed with the heat source unit as viewed from the direction of the air flow.

4. The cooling module according to claim 3,

wherein the supercooling portion is arranged on the side of the condensing portion far from another heat exchange unit in vertical direction.

5. The cooling module according to claim 1,

wherein the condenser unit is configured of a plurality of stacked first tubes with the refrigerant passed therethrough,

wherein another heat exchange unit is configured of a plurality of second tubes stacked in the same direction as the first tubes with another fluid passed therethrough,

wherein the integrated heat exchanger has a pair of header tanks arranged at the longitudinal ends, respectively, of the first and second tubes and communicating with the plurality of the first and second tubes by extending in the direction in which the first and second tubes are stacked, and

wherein the condenser unit and another heat exchange unit are integrated with each other by the header tanks.

6. The cooling module according to claim 1,

wherein the heat source unit is an intercooler arranged in the intake air flow downstream of a supercharger for pressuring the intake air of the internal combustion engine and adapted to cool the intake air by heat exchange between the intake air and air.

7. The cooling module according to claim 1,

wherein another heat exchange unit is an oil cooler unit for cooling the oil of the on-vehicle devices.