JP2011063084A - Heat exchanger used for air conditioner for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce pressure loss in a heat exchanger in which a medium is delivered, and stably exchange heat by delivering the medium with a desired pressure. <P>SOLUTION: A cabin-exterior heat exchanger 24 is provided on a front portion of an automobile 18. For example, the cabin-exterior heat exchanger 24 includes a first port 44 for introducing a coolant during heater operation and a second port 46 for discharging the coolant which is introduced inwardly from the first port 44 toward the outside. Subsequently, a path diameter D2 of the second port 46 is set to be approximately twice or more and 2.8 times or less as long as a path diameter D1 of the first port 44. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat exchanger that is used in an air conditioner for automobiles that has both a cooling function and a heating function, and that is used in an air conditioner for vehicles for cooling and heating air blown into the passenger compartment of the automobile.

  The present applicant has proposed an automotive air conditioner capable of performing a cooling operation for supplying cool air to the vehicle interior and a heating operation for supplying warm air to the vehicle interior by switching the flow direction of the refrigerant. (See Patent Document 1).

  In this automotive air conditioner, for example, during heating operation, the refrigerant compressed by the compressor is supplied to a heat exchanger arranged indoors under the switching action of the switching valve, and heat exchange is performed by the heat exchanger. Then, it is supplied to another heat exchanger arranged in front of the automobile, evaporated, and then circulated to the compressor again. Moreover, at the time of air_conditionaing | cooling operation, a refrigerant | coolant is distribute | circulated in the opposite direction to the time of heating operation by switching the switching valve mentioned above.

JP 2003-170733 A

  The present invention has been made in connection with the above-mentioned proposal, and it is intended to reduce pressure loss when heat exchange is performed by circulating a medium, and stable heat exchange is performed by circulating the medium at a desired pressure. It aims at providing the heat exchanger used for the air-conditioner for motor vehicles which can be performed.

In order to achieve the above object, the present invention provides a heat exchanger for use in an automotive air conditioner that cools or heats air supplied into a vehicle cabin.
The heat exchanger includes a housing;
A first passage provided on a side of the housing and supplied with a medium for heat exchange during heating operation;
A second passage that is provided on the side of the housing in the same manner as the first passage, and discharges the medium circulated in the housing to the outside during the heating operation;
With
The inner diameter of the second passage is set so as to exceed approximately twice the inner diameter of the first passage.

  According to the present invention, the side of the housing constituting the heat exchanger is provided with the first passage through which the medium is supplied for heat exchange during the heating operation, and the medium circulated in the housing is externally provided. And a second passage for discharging, and the inner diameter of the second passage is set to exceed approximately twice the inner diameter of the first passage.

  Therefore, after the medium is introduced from the first passage and heat exchange is performed through the housing, the inner diameter of the second passage is approximately double the inner diameter of the first passage during the heating operation led out from the second passage. By setting so as to exceed, pressure loss during heating operation can be reduced, the medium can be circulated downstream at a desired pressure, and pressure loss during cooling operation is not increased. . As a result, in the heat exchanger that can cool or heat the air supplied to the passenger compartment of the automobile, pressure loss during heating operation can be reduced, and heating performance can be improved, and also during cooling operation, It becomes possible to maintain the desired cooling performance without deteriorating the cooling performance.

  Further, it is more preferable that the inner diameter of the second passage is set to be smaller than about 2.8 times the inner diameter of the first passage.

  Further, the inner diameter of the first passage may be set to 5 mm, and the inner diameter of the second passage may be set to a range exceeding 10 mm and less than 14 mm.

  Furthermore, the first passage may be a first port or pipe formed on the side of the housing, and the second passage may be a second port or pipe formed on the side of the housing.

  According to the present invention, the following effects can be obtained.

  That is, a first passage through which a medium is supplied to perform heat exchange at the side of the housing constituting the heat exchanger during heating operation, and the medium that circulates in the housing is discharged to the outside. And the medium is introduced from the first passage and led out from the second passage by setting the inner diameter of the second passage so as to exceed approximately twice the inner diameter of the first passage. During the heating operation, the pressure loss in the heat exchanger can be reduced, the medium can be circulated downstream at the desired pressure, and the pressure loss during the cooling operation is not increased. As a result, in the heat exchanger that can cool or heat the air supplied to the passenger compartment of the automobile, pressure loss during heating operation can be reduced, and heating performance can be improved, and also during cooling operation, Desired cooling performance can be maintained.

1 is an overall configuration diagram of an automotive air conditioner to which a heat exchanger according to the present embodiment is applied. FIG. 2 is an enlarged view in the vicinity of a shutter in the automobile air conditioner of FIG. 1. It is an external appearance perspective view which shows the outdoor heat exchanger in the air conditioner for motor vehicles of FIG. It is a characteristic curve figure showing the relation between the passage diameter of the 2nd port of the outdoor heat exchanger at the time of heating operation, and pressure loss. It is a schematic circuit block diagram which shows the time of heating operation of the motor vehicle air conditioner of FIG. FIG. 6 is a schematic circuit configuration diagram showing the cooling operation of FIG. 5. FIG. 7A is a comparison diagram showing the relationship between pressure loss in the conventional heat exchanger during heating operation and the heat exchanger of the present invention, and FIG. 7B shows the conventional heat exchanger during cooling operation and the heat of the present invention. It is a comparison figure which shows the relationship of the pressure loss in an exchanger.

  A preferred embodiment of a heat exchanger used in an automotive air conditioner according to the present invention will be described in detail below with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates an automotive air conditioner using a heat exchanger according to an embodiment of the present invention.

  As shown in FIGS. 1 and 2, the automotive air conditioner 10 includes a compressor 12 that sucks and compresses a refrigerant (medium), a four-way valve 14 that controls a supply direction of the refrigerant, and the four-way valve 14. The accumulator 16 disposed in the refrigerant passage toward the compressor 12, the indoor heat exchanger 22 disposed in the unit 20 communicating with the interior of the automobile 18, and the front portion of the automobile 18. An outdoor heat exchanger (heat exchanger) 24, and two first and second electromagnetic valves 26, 28 that can be adjusted in opening and disposed between the indoor heat exchanger 22 and the outdoor heat exchanger 24. And a control device 30 for driving and controlling the compressor 12, the first and second electromagnetic valves 26, 28, and the like.

  An indoor fan 32 is disposed in close proximity to the indoor heat exchanger 22. Further, a defroster outlet 34, a face outlet 36, and a foot outlet 38 are provided on the indoor side of the unit 20, and each outlet 34, 36, 38 is configured to be opened and closed by a damper 40.

  Further, as shown in FIG. 3, the outdoor heat exchanger 24 includes a main body (housing) 42 having a flow path through which a refrigerant flows, and, for example, the main body 42 when a heating operation is performed. A first port (first passage) 44 through which the refrigerant is introduced, and a second port (second passage) through which the refrigerant introduced from the first port 44 is led out through the inside of the main body portion 42. 46. Note that the first port 44 functions as an outlet-side port through which the refrigerant that has flowed through the interior of the 42 under the switching action of the four-way valve 14 during cooling operation. Functions as an inlet-side port through which the refrigerant is introduced into the main body 42.

  The first and second ports 44 and 46 are provided, for example, on the same side surface of the main body 42 and are formed in a tubular shape protruding from the side surface while being spaced apart from each other. Pipes (first passage, second passage) 47a and 47b through which refrigerant flows are connected to the first and second ports 44 and 46, respectively (see FIG. 3).

  For example, when the passage diameter D1 of the first port 44 is set to 5 mm, the passage diameter D2 of the second port 46 exceeds 10 mm and is within 14 mm. (10 <D2 ≦ 14). In other words, the passage diameter D2 of the second port 46 is set to a size that is substantially greater than twice the passage diameter D1 (inner diameter) of the first port 44 and is approximately 2.8 times or less. (2 × D1 <D2 ≦ 2.8 × D1).

  The passage diameter D2 of the second port 46 is set based on a change in pressure loss at the second port 46 during the heating operation. Details thereof will be briefly described with reference to FIG. In FIG. 4, in the heating operation state of the automotive air conditioner 10, the passage diameter D1 of the first port 44 in the outdoor heat exchanger 24 is set to 5 mm, for example, and the passage diameter D2 of the second port 46 is changed. FIG. 6 is a characteristic curve diagram showing a change in pressure loss that occurs on the second port 46 side in the case.

  As can be understood from FIG. 4, the relationship between the passage diameter D2 of the second port 46 and the pressure loss is gradually reduced as the passage diameter of the second port 46 is increased. Specifically, since it is understood that the rate of change in pressure loss decreases from around the passage diameter D2 of the second port 46 exceeding 10 mm, the passage diameter D2 exceeds 10 mm, that is, the first port 44 It is preferable to set so as to exceed approximately twice the passage diameter D1.

  In other words, when the passage diameter D2 of the second port 46 is set to 10 mm or less (D2 ≦ 10), it is understood that the pressure loss suddenly increases. Therefore, the passage diameter D2 is set within this range. It is not preferable to set within.

  In addition, since it is understood that the rate of change of the pressure loss becomes smaller around the passage diameter D2 of the second port 46 set to about 14 mm, the passage diameter D2 is within 14 mm, that is, the first port. It is preferable to set it to be within approximately 2.8 times the passage diameter D1 at 44. Even when the passage diameter D2 is set to 14 mm or more as described above, the pressure loss is small and the rate of change is small as can be understood from FIG. 6, and therefore the passage diameter D2 may be set within this range.

  As shown in FIGS. 1 and 2, the engine 48 of the automobile 18 includes a water jacket 52 to which cooling water flowing by a water pump 50 is supplied. A radiator 54 disposed close to the outdoor heat exchanger 24 is connected to the water jacket 52 via a thermostat 56. The thermostat 56 and the water pump 50 are connected by a bypass passage 58.

  As shown in FIG. 2, a pair of outdoor fans 60 are arranged close to the radiator 54. The outdoor fans 60 are connected to the control device 30 via lead wires 62 and are driven and controlled by the control device 30.

  The outdoor fan 60 is provided so as to idle in a non-driving state in which a driving signal from the control device 30 is not input.

  A heater core 64 disposed in the unit 20 is connected to the water jacket 52 via a water valve 66. A damper 68 is disposed between the indoor heat exchanger 22 and the heater core 64 to block the heater core 64 from the indoor heat exchanger 22.

  On the other hand, a plurality of shutters 72 for opening and closing the duct 70 are disposed in the duct 70 that communicates the outdoor heat exchanger 24 and the radiator 54 with the outside of the automobile 18. Each shutter 72 is rotatably provided to the duct 70 via a support shaft 74 under a driving action by a driving unit (not shown). In addition, this drive part consists of an actuator with the stepping motor which drives under an electricity supply effect, for example.

  In the outdoor heat exchanger 24 described above, the case has been described in which the passage diameter D1 of the first port 44 and the passage diameter D2 of the second port 46 are set to substantially constant diameters, but the present invention is not limited thereto. For example, when the first and second ports 44 and 46 are caulked and connected to other piping (not shown), the passage diameters D1 and D2 are assumed to be partially reduced. The In other words, the first and second ports 44 and 46 are partially reduced in diameter in the radial direction.

  In general, the pressure loss increases due to a portion (minimum diameter portion) where the diameter of the passage through which the fluid flows is the smallest. Therefore, in the above case, the passage diameter D1 due to the pressure loss of the fluid. , D2 is set in a region where the diameter is reduced radially inward and becomes the smallest.

  Further, for example, compared to the passage diameters D1 and D2 of the first and second ports 44 and 46, the inner peripheral diameters of the pipes 47a and 47b connected to the first and second ports 44 and 46 are set smaller. In this case, the inner peripheral diameter of the other pipe 47b connected to the second port 46 is almost twice the inner peripheral diameter of the one pipe 47a connected to the first port 44. It may be formed so as to exceed.

  The automotive air conditioner 10 in which the heat exchanger according to the embodiment of the present invention is used is basically configured as described above. Next, its operation and effects will be described.

  First, the operation in the case of performing a heating operation in the automotive air conditioner 10 will be described with reference to FIGS. 1 and 5.

  For example, when the outside temperature of the automobile 18 is in the heating mode range of about 10 ° C. or less, the shutter 72 rotates to close the duct 70. That is, the shutter 72 rotates around the support shaft 74 under the drive action of a drive unit (not shown) to close the duct 70.

  Next, when the driver D operates an operation panel (not shown) of the vehicle air conditioner 10 and selects the heating operation, the damper 40 operates and the defroster outlet 34, the face outlet 36, and the foot outlet 38 are opened and closed. Is appropriately set, and the four-way valve 14 is switched to the state of FIG. 5 so that the refrigerant discharged from the compressor 12 is supplied to the indoor heat exchanger 22 side.

  The refrigerant compressed and discharged by the compressor 12 is supplied to the indoor heat exchanger 22 via the four-way valve 14 and condensed. At this time, the air supplied by the indoor fan 32 is heated by the indoor heat exchanger 22 and then indoors from the defroster outlet 34, the face outlet 36 or the foot outlet 38 selected via the heater core 64. Supplied.

  Cooling water heated by the engine 48 is supplied from the water jacket 52 to the heater core 64 through the water valve 66 by the water pump 50. Therefore, the heated air supplied to the indoor heat exchanger 22 by the indoor fan 32 is further heated by passing through the heater core 64 and supplied to the room.

  On the other hand, the refrigerant supplied to the indoor heat exchanger 22 is supplied from the first electromagnetic valve 26 set to a fully opened state to the second electromagnetic valve 28 set to a predetermined opening degree, so that the mist-like low temperature is supplied. After becoming a low-pressure refrigerant, the refrigerant is supplied to the outdoor heat exchanger 24 via the first port 44 and evaporated. At that time, the evaporating refrigerant pumps cooling heat from the air around the outdoor heat exchanger 24.

  Then, the evaporated refrigerant is led out from the second port 46 of the outdoor heat exchanger 24, supplied to the accumulator 16 through the four-way valve 14, and then the gas portion of the refrigerant is sucked by the compressor 12, Cooling operation is continued.

  Next, the operation when the cooling operation is performed in the automobile air conditioner 10 will be described with reference to FIGS. 1 and 6.

  For example, when the automobile 18 is in a cooling mode region where the outside air temperature is high, the shutter 72 opens the duct 70. That is, the shutter 72 is rotated about the support shaft 74 under the driving action of a driving unit (not shown) to open the duct 70.

  Next, when the driver D operates an operation panel (not shown) of the vehicle air conditioner 10 and selects the cooling operation, the damper 40 is operated, and the defroster outlet 34, the face outlet 36, and the foot outlet 38 are opened and closed. Is appropriately set, and the four-way valve 14 is switched to the state of FIG. 6 so that the refrigerant discharged from the compressor 12 is supplied to the outdoor heat exchanger 24 side. Further, the water valve 66 is closed, and the supply of cooling water to the heater core 64 is blocked.

  The refrigerant compressed and discharged by the compressor 12 is introduced into the second port 46 of the outdoor heat exchanger 24 through the four-way valve 14, and condensed in the main body 42 of the outdoor heat exchanger 24. The air is cooled by the outside air taken in by the outdoor fan 60.

  Next, the refrigerant is supplied to the first electromagnetic valve 26 via the second electromagnetic valve 28, and after being atomized, evaporates in the indoor heat exchanger 22, thereby cooling the outside air supplied by the indoor fan 32. And cool the room. The evaporated refrigerant is supplied from the four-way valve 14 to the accumulator 16 and then the refrigerant portion is sucked in by the compressor 12 so that the cooling operation is continued.

  As described above, in the present embodiment, for example, the first port 44 into which the refrigerant is introduced into the main body 42 when the heating operation is performed, on the side surface of the main body 42 constituting the outdoor heat exchanger 24. A second port 46 for leading the refrigerant introduced from the first port 44 to the outside through the inside of the main body portion 42 is provided, and the first and second ports 44, 46 formed in a tubular shape are The passage diameter D2 (inner diameter) of the second port 46 is set within a range that is substantially more than twice and less than 2.8 times the passage diameter D1 (inner diameter) of the first port 44. ing.

  In general, in a heat exchanger used in an automotive air conditioner 10 having both a cooling function and a heating function, the passage diameters D1 and D2 of the first and second ports 44 and 46 assuming only a cooling operation. The ratio between the passage diameter D1 of the first port 44 and the passage diameter D2 of the second port 46 is set to 1: 1.5. In this case, there is no problem during the cooling operation, but during the heating operation, the pressure loss on the second port 46 side from which the refrigerant is derived is large, and the flow rate of the refrigerant decreases due to the increase in the pressure loss. For this reason, the heating performance is deteriorated and there is a concern that the durability of the compressor 12 may be decreased due to the decrease in the flow rate of the refrigerant.

  On the other hand, in the present invention, by setting a ratio of the passage diameter D2 of the second port 46 to the passage diameter D1 of the first port 44 into which the refrigerant is introduced during the heating operation, the heating performance during the heating operation is set. The pressure loss can be reduced while improving (see FIG. 7A). Moreover, the flow volume fall of the refrigerant | coolant concerned when a pressure loss arises can be avoided, and the durable fall of the compressor 12 can be prevented.

  Further, even during the cooling operation, the refrigerant pressure loss can be slightly reduced while maintaining the cooling performance (see FIG. 7B).

  That is, in the outdoor heat exchanger 24, the passage diameter D2 of the second port 46 is approximately twice as large as the passage diameter D1 of the first port 44 and is approximately 2.8 times or less. By setting to, the pressure loss can be reduced while improving the heating performance during the heating operation, and the pressure loss during the cooling operation can be slightly reduced.

  Note that the heat exchanger used in the automotive air conditioner according to the present invention is not limited to the above-described embodiment, and can of course have various configurations without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Automotive air conditioner 12 ... Compressor 14 ... Four-way valve 18 ... Automobile 22 ... Indoor heat exchanger 24 ... Outdoor heat exchanger 26 ... First electromagnetic valve 28 ... Second electromagnetic valve 30 ... Control device 32 ... Indoor fan 42 ... main body 44 ... first port 46 ... second port 48 ... engine 54 ... radiator 60 ... outdoor fan 64 ... heater core 70 ... duct 72 ... shutter

Claims (4)

In a heat exchanger used in an automotive air conditioner that cools or heats the air supplied to the interior of an automobile,
The heat exchanger includes a housing;
A first passage provided on a side of the housing and supplied with a medium for heat exchange during heating operation;
A second passage that is provided on the side of the housing in the same manner as the first passage, and discharges the medium circulated in the housing to the outside during the heating operation;
With
The heat exchanger for use in an automotive air conditioner, characterized in that the inner diameter of the second passage is set to exceed approximately twice the inner diameter of the first passage. The heat exchanger according to claim 1, wherein
The heat exchanger for use in an automotive air conditioner, wherein the inner diameter of the second passage is set to be smaller than about 2.8 times the inner diameter of the first passage. The heat exchanger according to claim 1 or 2,
The inner diameter of the first passage is set to 5 mm, and the inner diameter of the second passage is set within a range exceeding 10 mm and within 14 mm. Heat exchanger. The heat exchanger according to any one of claims 1 to 3,
The first passage includes a first port or pipe formed in a side portion of the housing, and the second passage includes a second port or pipe formed in a side portion of the housing. Heat exchanger used in automotive air conditioners.

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