In-Chamber Condenser

TECHNICAL FIELD

The present invention relates to an interior condenser, and more particularly to an interior condenser accommodated in an HVAC unit of a vehicle air-conditioning heat pump system.

BACKGROUND ART

As this type of condenser, for example, there is known a heat exchanger used in a refrigerant circuit of a vehicle air-conditioning system, and including a heat exchange core composed of vertically-stacked tubes and fins, a refrigerant inflow/outflow-side tank where one end portions of the tubes are connected to a side portion, a refrigerant turn-side tank where the other end portions of the tubes are connected to a side portion, a partition wall that separates an inner portion of the refrigerant inflow/outflow-side tank into a refrigerant inflow chamber and a refrigerant outflow chamber, a refrigerant inlet tube connected to the refrigerant inflow/outflow-side tank to communicate with the refrigerant inflow chamber, and a refrigerant outlet tube connected to the refrigerant inflow/outflow-side tank to communicate with the refrigerant outflow chamber (for example, see Patent Document 1).

The core is composed of a forward-side core section in which a refrigerant performs heat exchange after passing through the refrigerant inflow/outflow-side tank from the refrigerant inlet tube, and a return-side core section in which the refrigerant performs heat exchange after passing through the forward-side core section and the refrigerant turn-side tank, and employs a so-called counter flow-type refrigerant horizontal flow in which the refrigerant flows in a horizontal direction sequentially from the forward-side core section to the return-side core section, thereby enabling effective heat exchange between air ventilating the core and the refrigerant.

PRIOR ART DOCUMENT
Patent Document

Patent Document 1: Japanese Patent No. 4334311

SUMMARY OF THE INVENTION
Problems to be Solved by the Invention

When the heat exchanger of the above conventional technique is accommodated in an HVAC (Heating Ventilation & Air Conditioning) unit of a vehicle air-conditioning heat pump system and used as an interior condenser whose so-called subcool degree S.C (deg) is increased, a refrigerant temperature can be effectively decreased in the core, and a liquid refrigerant can be increased. Accordingly, the liquid refrigerant can be reliably caused to flow into an expansion valve provided downstream of the condenser in the refrigerant circuit.

However, in the conventional technique, the refrigerant outlet tube is connected above a lower end portion of the core, so that the liquid refrigerant may be accumulated in a tube located below the refrigerant outlet tube, or may flow back in the tube. A refrigerant flow in the return-side core section is thereby deteriorated, resulting in an uneven refrigerant temperature distribution in a low-temperature region (subcool region) particularly near the refrigerant outlet tube in the return-side core section. Therefore, a temperature of air blown off from an air outlet of the vehicle air-conditioning system into a vehicle interior may differ, for example, between a driver-seat air outlet and a passenger-seat air outlet, and a blowoff air temperature in the HVAC unit may become uneven.

Also, in the conventional technique, the refrigerant inlet tube is connected to the side portion of the refrigerant inflow/outflow-side tank at a misaligned position above the refrigerant outlet tube, so that a high temperature region (superheat region) near the refrigerant inlet tube having a relatively high temperature in the forward-side core section, and the low temperature region (subcool region) near the refrigerant outlet tube having a relatively low temperature in the return-side core section exist at a misaligned position without overlapping each other. Therefore, a temperature offset through heat exchange between sensible heat portions of the superheat region in the forward-side core section and the subcool region in the return-side core section is not smoothly performed. As a result, the unevenness in the refrigerant temperature distribution in the subcool region particularly near the refrigerant outlet tube in the return-side core section, and eventually, variation in the blowoff air temperature may be further increased.

The present invention has been made based on the above circumstances, and an object of the present invention is to provide an interior condenser capable of reducing variation in a blowoff air temperature at respective air outlets in an HVAC unit.

Means for Solving the Problems

In order to achieve the above object, an interior condenser of the present invention is an interior condenser which is accommodated in an HVAC unit of a vehicle air-conditioning heat pump system, the interior condenser including: a heat exchange core that is composed of stacked tubes and fins; a refrigerant inflow/outflow-side tank to which one end portions of the tubes are connected; a refrigerant turn-side tank to which the other end portions of the tubes are connected; a partition wall that separates an inner portion of the refrigerant inflow/outflow-side tank into a refrigerant inflow chamber and a refrigerant outflow chamber; a refrigerant inlet tube that is connected to the refrigerant inflow/outflow-side tank to communicate with the refrigerant inflow chamber; and a refrigerant outlet tube that is connected to the refrigerant inflow/outflow-side tank to communicate with the refrigerant outflow chamber, wherein the refrigerant outlet tube is connected to the refrigerant inflow/outflow-side tank at a position below the core.

Preferably, the core is composed of a forward-side core section in which a refrigerant performs heat exchange after passing through the refrigerant inflow/outflow-side tank from the refrigerant inlet tube, and a return-side core section in which the refrigerant performs heat exchange after passing through the forward-side core section and the refrigerant turn-side tank, and the refrigerant inlet tube and the refrigerant outlet tube are connected to the refrigerant inflow/outflow-side tank at a point-symmetrical position with respect to the partition wall as a symmetrical axis, and at a position overlapping each other as viewed from a direction perpendicular to the partition wall.

Preferably, the refrigerant inlet tube and the refrigerant outlet tube are connected to the refrigerant inflow/outflow-side tank at a line-symmetrical position with respect to the partition well as the symmetrical axis.

Advantageous Effects of the Invention

According to the present invention, since the refrigerant outlet tube is connected to the refrigerant inflow/outflow-side tank at a position below the core, the refrigerant flowing through the core can be sequentially guided to the refrigerant inflow/outflow-side tank and the refrigerant outlet tube by gravity, thereby preventing accumulation of a liquid refrigerant in a tube due to the tube being located below the refrigerant outlet tube, and backward flow of the liquid refrigerant in the tube. Therefore, the refrigerant can be caused to smoothly flow through all the tubes, thereby suppressing unevenness in a refrigerant temperature distribution in a subcool region particularly near the refrigerant outlet tube in the return-side core section, and eventually suppressing unevenness in a refrigerant temperature distribution in the entire core. Accordingly, variation in a blowoff air temperature at respective air outlets in the HVAC unit can be reduced.

Also, according to the present invention, since the refrigerant inlet tube and the refrigerant outlet tube are connected to the refrigerant inflow/outflow-side tank at a point-symmetrical position with respect to the partition wall as a symmetrical axis, and at a position overlapping each other as viewed from a direction perpendicular to the partition wall, the core can be formed such that a superheat region near the refrigerant inlet tube having a relatively high temperature in the forward-side core section, and the subcool region near the refrigerant outlet tube having a relatively low temperature in the return-side core section overlap each other in at least one portion. Therefore, the unevenness in the refrigerant temperature distribution in the entire core can be effectively suppressed by a temperature offset through heat exchange between sensible heat portions of the superheat region in the forward-side core section and the subcool region in the return-side core section. The variation in the blowoff air temperature at the respective air outlets in the HVAC unit can be effectively reduced.

Also, according to the present invention, since the refrigerant inlet tube and the refrigerant outlet tube are connected to the refrigerant inflow/outflow-side tank at a line-symmetrical position with respect to the partition wall as the symmetrical axis, the core can be formed such that the superheat region and the subcool region completely overlap each other. Therefore, the unevenness in the refrigerant temperature distribution in the entire core can be more effectively suppressed by the temperature offset through the heat exchange between the sensible heat portions of the superheat region in the forward-side core section and the subcool region in the return-side core section. The variation in the blowoff air temperature at the respective air outlets in the HVAC unit can be more effectively reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view illustrating a schematic configuration of a condenser according to one embodiment of the present invention.

FIG. 2 is a bottom view of the condenser in FIG. 1 as viewed from below.

FIG. 3 is a sectional view of the condenser in FIG. 1 in a direction of A-A.

FIG. 4 is a graph illustrating a maximum temperature difference ΔTmax (° C.) of outlet air ventilating a conventional condenser and the condenser of the present embodiment in relation to an increase in a subcool degree S.C (deg).

FIG. 5 is a front view illustrating a schematic configuration of a condenser according to another embodiment of the present invention.

FIG. 6 is a bottom view of the condenser in FIG. 5 as viewed from below.

FIG. 7 is a side view of the condenser in FIG. 5 as viewed from a right side.

FIG. 8 is a sectional view of the condenser in FIG. 5 in a direction of B-B.

MODE FOR CARRYING OUT THE INVENTION

In the following, a condenser 1 according to one embodiment of the present invention is described by reference to the drawings.

FIG. 1 is a front view schematically illustrating a schematic configuration of the condenser 1. FIG. 2 is a bottom view of the condenser 1 in FIG. 1 as viewed from below. FIG. 3 is a sectional view of the condenser 1 in FIG. 1 in a direction of A-A.

For example, the condenser 1 is an interior condenser that is incorporated in a refrigerant circuit constituting a heat pump cycle of an unillustrated vehicle air-conditioning heat pump system, and accommodated in an unillustrated HVAC (Heating Ventilation & Air Conditioning) unit of the vehicle air-conditioning heat pump system.

In the condenser 1, a plurality of tubes 2 forming a refrigerant channel are arranged in a vertical direction, and a colligated fin (fin) 4 is bonded between the respective tubes 2. The fin 4 forms an air ventilation channel in the condenser 1, thereby promoting heat exchange between a refrigerant flowing through the respective tubes 2 and outside air. The tubes 2 and the fins 4 are alternately arrayed and stacked in the vertical direction, to form a heat exchange core 6, the upper and lower end portions of which are covered with side plates 8.

While a refrigerant inflow/outflow-side tank 10, to which right end portions of the tubes 2 are connected, is arranged at a right end portion of the core 6, a refrigerant turn-side tank 12, to which left end portions of the tubes 2 are connected, is arranged et a left end portion of the core 6.

As shown in FIGS. 2 and 3, an inner portion of the refrigerant inflow/outflow-side tank 10 is completely separated into a refrigerant inflow chamber 16 and a refrigerant outflow chamber 18 by a partition wall 14 that is extended in an array direction of the tubes 2, i.e., a longitudinal direction of the refrigerant inflow/outflow-side tank 10. Meanwhile, an inner portion of the refrigerant turn-side tank 12 is also separated into a refrigerant inflow chamber 24 and a refrigerant outflow chamber 26 by a partition wall 22 that is extended in the array direction of the tubes 2, i.e., a longitudinal direction of the refrigerant turn-side tank 12, and through which a plurality of communication holes 20 are pierced.

Also, a refrigerant inlet tube 28 and a refrigerant outlet tube 30 are connected to a bottom end portion 10a of the refrigerant inflow/outflow-side tank 10. The refrigerant inlet tube 28 communicates with the refrigerant inflow chamber 16, and the refrigerant outlet tube 30 communicates with the refrigerant outflow chamber 18.

Also, the core 6 is composed of a forward-side core section 6A into which the refrigerant flows after passing through the refrigerant inflow chamber 16 of the refrigerant inflow/outflow-side tank 10 from the refrigerant inlet tube 28, and a return-side core section 6B into which the refrigerant flows after passing through the refrigerant inflow chamber 24, the communication holes 20, and the refrigerant outflow chamber 26 of the refrigerant turn-side tank 12 from the forward-side core section 6A.

The condenser 1 having the above configuration employs a so-called counter flow type in which the refrigerant flows in a horizontal direction sequentially from the forward-side core section 6A to the return-side core section 6B, thereby enabling effective heat exchange between air ventilating the core 6 and the refrigerant flowing through the core 6.

Here, in the present embodiment, the refrigerant inlet tube 28 and the refrigerant outlet tube 30 are connected to the bottom end portion 10a of the refrigerant inflow/outflow-side tank 10 as described above, and the bottom end portion 10a of the refrigerant inflow/outflow-side tank 10 is located below a bottommost tube 2a out of the respective tubes 2. In other words, the refrigerant inlet tube 28 and the refrigerant outlet tube 30 are connected to the refrigerant inflow/outflow-side tank 10 at a position below the core 6.

Also, as shown in FIG. 3, the refrigerant inlet tube 28 and the refrigerant outlet tube 30 are connected to the refrigerant inflow/outflow-side tank 10 at a line-symmetrical position with respect to the partition wall 14 as a symmetrical axis with distances d from the partition wall 14 to tube centers of the refrigerant inlet tube 28 and the refrigerant outlet tube 30 being almost the same.

Moreover, an inner diameter Do of the refrigerant outlet tube 30 is set to an inner diameter Di of the refrigerant inlet tube 28 or more in advance.

In the condenser 1 of the present embodiment, since the refrigerant outlet tube 30 is connected to the refrigerant inflow/outflow-side tank 10 at a position below the core 6 as described above, the refrigerant flowing through the core 6 can be sequentially guided to the refrigerant inflow/outflow-side tank 10 and the refrigerant outlet tube 30 by gravity thereby preventing accumulation of a liquid refrigerant in a tube 2 due to the tube 2 being located below the refrigerant outlet tube 30, and backward flow of the id refrigerant in the tube 2. Therefore, the refrigerant can be caused to smoothly flow through all the tubes 2, thereby suppressing unevenness in a refrigerant temperature distribution in a low-temperature region (subcool region) particularly near the refrigerant outlet tube in the return-side core section, and eventually suppressing unevenness in a refrigerant temperature distribution in the entire core 6. Accordingly, variation in a blowoff air temperature at respective air outlets such as a foot air outlet in the HVAC unit can be reduced.

Also, since the refrigerant inlet tube 28 and the refrigerant cutlet tube 30 are connected to the refrigerant inflow/outflow-side tank 10 at a line-symmetrical position with respect to the partition wall 14 as a symmetrical axis, the core 6 can be formed such that a high-temperature region (superheat region) near the refrigerant inlet tube 28 having a relatively high temperature in the forward-side core section 6A, and the low-temperature region (subcool region) near the refrigerant outlet tube 30 having a relatively low temperature in the return-side core section 6B completely overlap each other. Therefore, the unevenness in the refrigerant temperature distribution in the entire core 6 can be more effectively suppressed by a temperature offset through heat exchange between sensible heat portions of the superheat region in he forward-side core section 6A and the subcool region in the return-side core section 6B. The variation in the blowoff air temperature at the respective air outlets in the HVAC unit can be more effectively reduced.

Also, since the inner diameter Do of the refrigerant outlet tube 30 is equal to or more than the inner diameter Di of the refrigerant inlet tube 28, the refrigerant easily flows out of the refrigerant outlet tube 30, so that the refrigerant can be caused to flow more smoothly in the tubes 2. Therefore, the unevenness in the refrigerant temperature distribution in the entire core 6 can be more effectively suppressed, and the variation in the blowoff air temperature at the respective air outlets in the HVAC unit can be more effectively reduced.

The effect is specifically described by reference to a graph illustrating a maximum temperature difference ΔTmax (° C.) of outlet air that is air after ventilating the condenser 1 in relation to an increase in a subcool degree S.C (deg) in FIG. 4. In the graph, a dashed line indicates a case of a conventional counter flow-type condenser having the core 6 in which the refrigerant vertically flows, and a solid line indicates the case of the present embodiment. A case in which the condenser 1 shown in FIG. 1 is used in a state rotated clockwise through 90° is assumed as the conventional condenser, whereby the refrigerant cannot be guided by use of gravity due to the arrangement position of the refrigerant outlet tube. Thus, the refrigerant is accumulated or flows back around the refrigerant outlet tube in the return-side core section.

As is clear from the result, in the case of the present embodiment, the maximum temperature difference ΔTmax of the outlet air can be made lower by about 10° C. than that of the conventional condenser at any value of the sub-cool decree S. C. It is understood that the unevenness in the refrigerant temperature distribution in the entire core 6 can be effectively suppressed.

The present invention should not be limited to the aforementioned embodiment, and various modifications may be made therein.

For example, although the refrigerant inlet tube 28 and the refrigerant outlet tube 30 are connected to the bottom end portion 10a of the refrigerant inflow/outflow-side tank 10 in the above embodiment, the present invention is not limited to the above embodiment as long as the refrigerant outlet tube 30 is connected to the refrigerant inflow/outflow-side tank 10 at a position below the core 6.

To be more specific, a condenser of another embodiment of the present invention is described by reference to FIGS. 5 to 8. FIG. 5 is a front view schematically illustrating a schematic configuration of a condenser 32. FIG. 6 is a bottom view of the condenser 32 in FIG. 5 as viewed from below. FIG. 7 is a side view of the condenser 32 in FIG. 5 as viewed from a right side. FIG. 8 is a sectional view of the condenser 32 in FIG. 5 in a direction of B-B. The same components as those of FIG. 1 are assigned the same reference numerals, and description is omitted.

As shown in FIGS. 5 to 7, a refrigerant inflow/outflow-side tank 34 of the present embodiment has a larger longitudinal length than the refrigerant turn-side tank 12, and a side portion 34a of the refrigerant inflow/outflow-side tank 34 has a sufficient length to a lower side from the bottommost tube 2a. Therefore, the refrigerant inlet tube 28 and the refrigerant outlet tube 30 are connected to a portion of the side portion 34a of the refrigerant inflow/outflow-side tank 34 below the bottommost tube 2a, that is, connected to the refrigerant inflow/outflow-side tank 34 at a position below the core 6.

Also, as shown in FIG. 8, the refrigerant inlet tube 28 and the refrigerant outlet tube 30 are connected to the refrigerant inflow/outflow-side tank 34 at a line-symmetrical position with respect to the partition wall 14 as a symmetrical axis with distances d from the partition wall 14 to tube centers of the refrigerant inlet tube 28 and the refrigerant outlet tube 30 being almost the same. An inner diameter Do of the refrigerant outlet tube 30 is set to an inner diameter Di of the refrigerant inlet tube 2B or more in advance.

In the condenser 32 of the present embodiment, since the refrigerant outlet tube 30 is connected to the refrigerant inflow/outflow-side tank 34 at a position below the core 6 as described above, the accumulation of the liquid refrigerant in the tube 2, and the backward flow of the liquid refrigerant in the tube 2 can be prevented. Furthermore, the unevenness in the refrigerant temperature distribution in the entire core 6 can be suppressed by the temperature offset through the heat exchange between the sensible heat portions of the superheat region in the forward-side core section 6A and the subcool region in the return-side core section 6B, and the variation in the blowoff air temperature at the respective air outlets in the HVAC unit can be effectively reduced.

Also, in the aforementioned respective embodiments, the refrigerant inlet tube 28 and the refrigerant outlet tube 30 are connected to the refrigerant inflow/outflow-side tank 34 at the line-symmetrical position with respect to the partition wall 14 as the symmetrical axis with the distances d from the partition wall 14 to the tube centers of the refrigerant inlet tube 28 and the refrigerant outlet tube 30 being almost the same. However, the present invention is not limited thereto, and the refrigerant inlet tube 28 and the refrigerant outlet tube 30 may be connected to the refrigerant inflow/outflow-side tank 34 at a point-symmetrical position with respect to the partition wall 14 as the symmetrical axis, and at a position overlapping each other as viewed from a direction perpendicular to the partition wall 14.

In this case, the distances d from the partition wall 14 to the tube centers of the refrigerant inlet tube 28 and the refrigerant outlet tube 30 are almost the same. The core 6 can be formed such that the superheat region near the refrigerant inlet tube 28 having a relatively high temperature in the forward-side core section 6A, and the subcool region near the refrigerant outlet tube 30 having a relatively low temperature in the return-side core section 6B overlap each other in at least one portion. Therefore, the unevenness in the refrigerant temperature distribution in the entire core 6 can be more effectively suppressed by the temperature offset through the heat exchange between the sensible heat portions of the superheat region in the forward-side core section 6A and the subcool region in the return-side core section 6B. The variation in the blowoff air temperature at the respective air outlets in the HVAC unit can be effectively reduced.

Also, although the condensers 1 and 32 employing the counter flow type in which the refrigerant flows in the horizontal direction sequentially from the forward-side core section 6A to the return-side core section 6B have been described in the aforementioned respective embodiments, the condenser is not limited to the forms of the condensers 1 and 32. To be more specific, the same effects as those described above can be of course obtained even in a counter flow-type condenser, such as the conventional condenser assumed in the description of FIG. 4, in which the refrigerant vertically flows, by connecting the refrigerant outlet tube 30 to the refrigerant inflow/outflow-side tank 10 at a position below the core 6, and connecting the refrigerant inlet tube 28 and the refrigerant outlet tube 30 to the refrigerant inflow/outflow-side tank 10 at a line-symmetrical position with respect to the partition wall 14 as a symmetrical axis, or at a point-symmetrical position with respect to the partition wall 14 as the symmetrical axis, and at a position overlapping each other as viewed from a direction perpendicular to the partition wall 14.

EXPLANATION OF REFERENCE SIGNS

1, 32 Condenser (Interior condenser)

2 Tube

2
a Bottommost tube (Tube)

4 Fin

6 Core

6A Forward-side core section

6B Return-side core section

10, 34 Refrigerant inflow/outflow-side tank

12 Refrigerant turn-side tank

14 Partition well

16 Refrigerant inflow chamber

18 Refrigerant outflow chamber

28 Refrigerant inlet tube

30 Refrigerant outlet tube

In-Chamber Condenser

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CPC

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Description

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