JP2006327350A - Air-conditioner for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-conditioner for a vehicle which improves a heat radiation performance of a radiator by making an effective use of condensate, and which reduces the power of a compressor through prevention of an pressure increase on the high-pressure side. <P>SOLUTION: The air-conditioner for the vehicle is provided with: the compressor for compressing a refrigerant; the radiator for dissipating a high-temperature high-pressure refrigerant; an internal heat exchanger; an expansion mechanism; an evaporator; and a vapor-liquid separator. The internal heat exchanger performs heat exchange between a low-temperature high-pressure refrigerant and a refrigerant on the low-pressure side, and the vapor-liquid separator separates a low-pressure refrigerant coming out of the evaporator into a gas and a liquid. The air-conditioner for the vehicle has a vapor-compression-type refrigeration cycle which is formed by connecting them one by one, and the condensate generated from the evaporator or from the vapor-liquid separator, or from both of them, is discharged to the radiator. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle air conditioner, and more particularly to a vehicle air conditioner that can effectively use condensed water generated in a refrigeration cycle using a refrigerant such as carbon dioxide.

From the viewpoint of consideration of global environmental problems, the use of CFC-based refrigerants that have been adopted as refrigerants for refrigeration cycles in vehicle air conditioners is beginning to be regulated, and carbon dioxide refrigerants have been proposed as countermeasures for de-Freonization. The carbon dioxide refrigerant is a refrigerant that operates in a supercritical region exceeding the critical pressure due to its physical properties, and the operating pressure is about 7 MPa or more. Therefore, the amount of work by the compressor in the refrigeration cycle increases, and the coefficient of performance of the refrigeration cycle tends to decrease. In order to compensate for these disadvantages, the condensed water generated in the gas-liquid separator is sprinkled on an internal heat exchanger that exchanges heat between the high-pressure side refrigerant and the low-pressure side refrigerant provided in the refrigeration cycle. Thus, a technique for improving the internal heat exchange efficiency and improving the refrigeration performance coefficient has been proposed (Patent Document 1).
JP 2004-28460 A

  However, in order to exchange heat by applying condensed water to the internal heat exchanger, it is necessary to improve a sufficient contact area and heat transfer rate. That is, in order to exert a sufficient internal heat exchange effect, it is necessary to expand the heat transfer area of the pipe of the internal heat exchanger and improve the thermal conductivity. Carbon dioxide refrigerant is in a supercritical state where the high-pressure side exceeds the critical pressure due to its physical properties, so a material and structure that can withstand the high pressure are required. It becomes difficult to improve the rate.

  On the other hand, the radiator provided in the refrigeration cycle is usually configured as a heat exchanger having a sufficiently large contact area and good heat transfer.

  Therefore, the problem of the present invention is that the above-mentioned problem when the condensed water is used to improve the efficiency of the internal heat exchanger, and the heat exchanger is a heat exchanger having a sufficiently large contact area and high heat transfer performance. Focusing on the effective use of condensed water for the radiator, thereby improving the heat dissipation performance of the radiator and preventing the increase of the pressure on the high-pressure side, thereby reducing the compressor power, that is, An object of the present invention is to provide a vehicle air conditioner that can be improved.

  In order to solve the above problems, an air conditioner for a vehicle according to the present invention has a compressor that compresses a refrigerant, a radiator that dissipates the refrigerant that has become a high temperature and a high pressure due to compression by the compressor, and a radiator that dissipates heat. An internal heat exchanger that exchanges heat between the low-temperature and high-pressure refrigerant and the low-pressure side refrigerant, an expansion mechanism that decompresses and expands the low-temperature and high-pressure refrigerant that has become colder by the internal heat exchanger, and a refrigerant that is decompressed and expanded by the expansion mechanism And a vapor compression refrigeration cycle in which a low-pressure refrigerant exiting the evaporator is separated into a gas and a liquid, and these are sequentially connected in a loop with a refrigerant flow path. The vehicle air conditioner is characterized in that condensed water generated from the outer surfaces of the evaporator, the gas-liquid separator, or both of them is discharged to the radiator. That is, in the present invention, the generated condensed water is effectively used for improving the heat radiation efficiency of the radiator, not the internal heat exchanger.

  As the vapor compression refrigeration cycle, a supercritical vapor compression refrigeration cycle in which the pressure of the refrigerant on the high pressure side is in a supercritical region can be applied. In particular, the present invention is effective when the refrigerant used in the vapor compression refrigeration cycle is carbon dioxide.

  The gas-liquid separator is preferably disposed in the vicinity of the evaporator. If such an arrangement is adopted, the condensed water generated from both the evaporator and the gas-liquid separator can be easily recovered together, and the condensed water can be effectively used effectively to improve the heat dissipation efficiency of the radiator. . In addition, since the condensed water recovery container is usually provided for the evaporator, the above arrangement makes it unnecessary to install a new recovery container.

  As a more specific structure, it is preferable to have a condensed water recovery container for recovering the condensed water and a conduit for guiding the condensed water from the condensed water recovery container to the discharge position to the radiator. The condensed water receiving surface of the condensed water recovery container is preferably formed in a funnel shape, so that the condensed water generated can be easily recovered.

  Moreover, it is preferable that the said conduit | pipe is inclined in the direction located below as it goes to a heat radiator side with respect to a horizontal surface. Thereby, using the dead weight of condensed water, condensed water can be easily led to the discharge position to a radiator.

  Furthermore, it is preferable to have a condensed water storage container that stores the condensed water guided by the conduit and a condensed water discharge pipe that discharges the condensed water stored in the condensed water storage container toward the radiator. With this structure, it is possible to store an appropriate amount of condensed water to be discharged toward the radiator, and it is possible to discharge condensed water to a desired position with respect to the radiator by the condensed water discharge pipe. Become.

  This condensed water discharge pipe is preferably disposed on the vehicle front side of the radiator. With such an arrangement, the front wind of the vehicle can be used for discharging condensed water, and the heat radiator can be radiated by both air and condensed water, and heat dissipation is promoted.

  Moreover, it is preferable that the condensed water discharge pipe is extended in the substantially horizontal direction. Thereby, it becomes possible to discharge condensed water over a wider range of the radiator.

  The condensed water discharge pipe is preferably provided with a discharge hole for discharging condensed water toward the radiator. A plurality of discharge holes are preferably provided. This allows condensed water to be discharged over a wide range of radiators in a uniform and desirable form.

  The discharge hole is preferably opened obliquely downward. Thereby, condensed water is discharge | released from the condensed water discharge pipe easily and smoothly.

  Furthermore, the condensed water is discharged from the discharge hole by the vehicle front wind that is the air flow from the front side of the vehicle. For example, the condensed water is condensed by using the venturi effect of the vehicle front wind. It is preferable that the water is discharged from the inside of the water discharge pipe. In such a structure, no special mechanism or operation is required for discharging condensed water. In addition, since cooling air is generated by the cooling fan even during idling, the “vehicle front air” includes this cooling air.

  According to the vehicle air conditioner of the present invention, the heat dissipation performance of the radiator that has become a high temperature and a high pressure, particularly in a refrigeration cycle that operates in a supercritical region with a critical temperature and a low critical pressure using carbon dioxide is condensed water. It is possible to provide a vehicular air conditioner that can be significantly improved by effectively using and can reduce the high-pressure side pressure and the compressor power associated therewith.

  Further, if the condensed water generated from the gas-liquid separator is collected in the same collection container as the condensed water generated from the evaporator, it is substantially unnecessary to install a new collection container. Furthermore, if the condensed water is collected in a condensed water recovery container and discharged toward the radiator through the conduit, the condensed water storage container, and the condensed water discharge pipe, the predetermined heat radiator can be easily set with a simple mechanism. Condensed water can be discharged with respect to the range, and the heat dissipation performance of the radiator can be improved efficiently.

  Furthermore, if condensed air can be sucked and discharged from inside the condensed water discharge pipe using the wind in the front of the vehicle, the condensed water can be easily and properly directed to the radiator without the need for special mechanisms or operations. Can be released. Moreover, since the heat radiator radiates heat with air and condensed water, heat radiation can be further promoted.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a vehicle air conditioner 100 according to an embodiment of the present invention, and the vehicle air conditioner 100 has a vapor compression refrigeration cycle 101 using carbon dioxide as a refrigerant. The vapor compression refrigeration cycle 101 is provided with a compressor 2 that transmits a driving force from an engine 1 as a vehicle prime mover via a belt or the like and compresses a refrigerant. The refrigerant that has become high temperature and high pressure due to compression by the compressor 2 is radiated by the radiator 3 (gas cooler). The low-temperature and high-pressure refrigerant radiated by the radiator 3 is heat-exchanged by the internal heat exchanger 4 through the internal partition and the low-pressure side refrigerant.

  The low-temperature and high-pressure refrigerant whose temperature has been further lowered by the internal heat exchanger 4 is decompressed and expanded by the expansion mechanism 5 (expansion valve). The refrigerant decompressed and expanded by the expansion mechanism 5 is evaporated by the evaporator 6 disposed on the vehicle interior side (arranged on the vehicle interior side of the vehicle interior / exterior partition wall 8), and the heat absorbed by the evaporation is used for cooling the vehicle interior. Is done. The low-pressure refrigerant that has exited the evaporator 6 is separated into gas and liquid in a gas-liquid separator 7 (accumulator), the liquid refrigerant is stored, and only the gas refrigerant is substantially discharged. The low-pressure refrigerant discharged from the gas-liquid separator 7 is heat-exchanged with the high-pressure side refrigerant in the internal heat exchanger 4 as described above, and is then sucked into the compressor 2 and compressed. As described above, the refrigerant is circulated through the vapor compression refrigeration cycle 101 in which each device is arranged in a loop. In the vapor compression refrigeration cycle 101, the pressure of the high-pressure side refrigerant (carbon dioxide refrigerant) is supercritical. It is configured as a supercritical vapor compression refrigeration cycle. In addition, the arrow in FIG. 1 has shown the flow direction of the refrigerant | coolant.

  In this embodiment, the gas-liquid separator 7 is disposed in the vicinity of the vehicle interior / exterior partition wall 8 and is disposed in the vicinity of the evaporator 6. Below the evaporator 6 and the gas-liquid separator 7, there is provided a condensed water recovery container 9 for recovering the condensed water falling from the outer surfaces of the evaporator 6 and the gas-liquid separator 7, The condensed water receiving surface of the condensed water recovery container 9 is formed in a funnel shape.

  A conduit 10 that guides the condensed water from the condensed water recovery container 9 to a discharge position to the radiator 3 is connected to a discharge port opened at the bottom of the condensed water recovery container 9. The conduit 10 is inclined with respect to a horizontal plane in a direction positioned downward as it goes to the radiator 3 side. The conduit 10 is connected to a condensed water storage container 11 that stores the condensed water guided by the conduit 10. Here, the path from the gas-liquid separator 7 to the condensed water storage container 11 via the condensed water recovery container 9 and the conduit 10 is preferably insulated so that the condensed water is not easily affected by the outside air.

  A condensed water discharge pipe 12 that discharges condensed water stored in the condensed water storage container 11 toward the radiator 3 is connected to the condensed water storage container 11. The condensed water discharge pipe 12 is disposed on the vehicle front side of the radiator 3. As shown in FIG. 2, the condensed water discharge pipe 12 extends substantially in the horizontal direction on the vehicle front side of the radiator 3, and condenses from the condensed water discharge pipe 12 toward the front side of the radiator 3. Water 13 is discharged in the form of water droplets. That is, the vehicle front wind 14 is sent to the radiator 3, and the condensed water 13 is discharged from the condensed water discharge pipe 12 using the vehicle front wind 14. In FIG. 2, 15 indicates a refrigerant inlet pipe of the radiator 3, and 16 indicates a refrigerant outlet pipe.

  As shown in FIG. 3, the condensed water discharge pipe 12 is provided with a plurality of discharge holes 17 for discharging the condensed water 13 toward the radiator 3 along the extending direction of the condensed water discharge pipe 12. . The discharge hole 17 is opened obliquely downward, and utilizes the venturi effect due to the air flow around the back side of the condensed water discharge pipe 12 of the vehicle front wind 14 that is the air flow from the front side of the vehicle, The condensed water 13 is sucked out of the condensed water discharge pipe 12 and discharged without requiring any special mechanism or operation.

  In the vehicle air conditioner 100 configured as described above, the condensed water generated from the evaporator 6 and the gas-liquid separator 7 is converted into a condensed water recovery container 9, a conduit 10, a condensed water storage container 11, and a condensed water discharge pipe 12. Is emitted toward the radiator 3 via the. The radiator 3 is radiated by the front wind 14 of the vehicle and is also radiated by the discharged condensed water, and the condensed water is effectively used, so that the heat radiating performance of the radiator 3 is greatly improved. That is, the condensed water that has been discharged toward the ground surface is used extremely effectively for improving the heat dissipation performance of the radiator 3, and heat dissipation is promoted. In particular, in the refrigeration cycle 101 operated in the supercritical region using carbon dioxide, the heat radiation performance by the radiator 3 of the high-temperature and high-pressure refrigerant can be significantly improved by using condensed water, the pressure on the high-pressure side is reduced, Accordingly, the compressor power can be reduced, and the coefficient of performance of the refrigeration cycle 101 can be greatly improved.

  Further, since the gas-liquid separator 7 is disposed in the vicinity of the evaporator 6 and the condensed water generated from the evaporator 6 and the gas-liquid separator 7 is recovered by the common condensed water recovery container 9, efficient condensed water recovery is possible. Is possible. Further, since the evaporator 6 is usually provided with a condensed water receiver (recovery container), it is substantially unnecessary to newly install a recovery container. Further, the condensed water recovered in the condensed water recovery container 9 is discharged toward the radiator 3 through the conduit 10, the condensed water storage container 11, and the condensed water discharge pipe 12, so that the condensed water for discharge is condensed into the condensed water storage container. 11 can always be stored in an appropriate amount, and condensed water can be effectively discharged over a wide range of the radiator 3 via the condensed water discharge pipe 12. The heat dissipation performance can be improved more efficiently.

  Further, the condensed water can be sucked and discharged from the condensed water discharge pipe 12 using the front wind 14 of the vehicle, so that the condensed water can be discharged by a very simple mechanism without requiring any special mechanism or operation. Can be released automatically toward the radiator.

  The present invention is applicable to any vehicle air conditioner equipped with a vapor compression refrigeration cycle, and is particularly suitable for a vehicle air conditioner equipped with a vapor compression refrigeration cycle using carbon dioxide as a refrigerant.

It is a schematic structure figure seen from the vehicles side of the air-conditioner for vehicles concerning one embodiment of the present invention. It is a front view of the heat radiator part in the apparatus of FIG. It is an expanded sectional view of the condensed water discharge pipe in the apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Compressor 3 Radiator 4 Internal heat exchanger 5 Expansion mechanism 6 Evaporator 7 Gas-liquid separator 8 Car interior and exterior partition wall 9 Condensate recovery container 10 Conduit 11 Condensate storage container 12 Condensate discharge pipe 13 Condensate 14 Vehicle front wind 15 Radiator refrigerant inlet pipe 16 Radiator refrigerant outlet pipe 17 Release hole 100 Air conditioner 101 for vehicle Vapor compression refrigeration cycle

Claims (14)

  A compressor that compresses the refrigerant, a radiator that dissipates the high-temperature and high-pressure refrigerant that is compressed by the compressor, and an internal heat exchange that exchanges heat between the low-temperature and high-pressure refrigerant and the low-pressure side refrigerant that are dissipated by the radiator , An expansion mechanism that decompresses and expands the low-temperature high-pressure refrigerant that has been cooled to a lower temperature by the internal heat exchanger, an evaporator that evaporates the refrigerant decompressed and expanded by the expansion mechanism, and a low-pressure refrigerant that exits the evaporator as gas and liquid In a vehicle air conditioner having a vapor compression refrigeration cycle, which is sequentially connected in a loop with a refrigerant flow path, the evaporator or the gas-liquid separator or both A vehicle air conditioner characterized in that condensed water generated from the outer surface of the vehicle is discharged to the radiator.   The vehicle air conditioner according to claim 1, wherein the vapor compression refrigeration cycle is a supercritical vapor compression refrigeration cycle in which the pressure of a refrigerant on a high pressure side is in a supercritical region.   The vehicle air conditioner according to claim 1 or 2, wherein the refrigerant used in the vapor compression refrigeration cycle is carbon dioxide.   The vehicle air conditioner according to any one of claims 1 to 3, wherein the gas-liquid separator is disposed in the vicinity of the evaporator.   It has a condensed water collection | recovery container which collect | recovers the said condensed water, and a conduit | pipe which guides the condensed water from this condensed water collection | recovery container to the discharge | release position to the said heat radiator, The any one of Claims 1-4 characterized by the above-mentioned. The vehicle air conditioner described in 1.   6. The vehicle air conditioner according to claim 5, wherein a condensed water receiving surface of the condensed water recovery container is formed in a funnel shape.   The vehicle air conditioner according to claim 5 or 6, wherein the conduit is inclined with respect to a horizontal plane in a direction positioned downward as it goes to the radiator side.   And a condensed water storage container for storing the condensed water guided by the conduit, and a condensed water discharge pipe for discharging the condensed water stored in the condensed water storage container toward the radiator. The vehicle air conditioner according to any one of claims 5 to 7.   The vehicle air conditioner according to claim 8, wherein the condensed water discharge pipe is disposed on the vehicle front side of the radiator.   The vehicular air conditioner according to claim 8 or 9, wherein the condensed water discharge pipe is extended in a substantially horizontal direction.   The vehicle air conditioner according to any one of claims 8 to 10, wherein the condensed water discharge pipe is provided with a discharge hole for discharging condensed water toward the radiator.   The vehicle air conditioner according to claim 11, wherein a plurality of the discharge holes are provided.   The vehicle air conditioner according to claim 11 or 12, wherein the discharge hole is opened obliquely downward.   The vehicle according to any one of claims 11 to 13, wherein the condensed water is discharged from the discharge hole by a vehicle front wind that is an air flow from the front side of the vehicle. Air conditioner.

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