Patent Publication Number: US-10766340-B2

Title: Air conditioner system for vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. National Stage of International Application No. PCT/KR2015/006355, filed Jun. 23, 2015, which claims the benefit and priority of KR 10-2014-0096562 filed Jul. 29, 2014, KR 10-2014-0098066 filed Jul. 31, 2014 and KR 10-2014-0098074 filed Jul. 31, 2014. The entire disclosures of each of the above applications are incorporated herein by reference. 
     TECHNICAL FIELD 
     The present invention relates to an air conditioner system for a vehicle, and more particularly, to an air conditioner system for a vehicle, in which an air-cooled condenser mounted on a refrigerant circulation line between a water-cooled condenser and an expansion valve and a blower fan for blowing air to the air-cooled condenser are arranged on one side of the water-cooled condenser in a state of being disposed in a row in the air flow direction and are arranged within the width of the one side of the water-cooled condenser. 
     BACKGROUND ART 
     In general, as shown in  FIG. 1 , an air conditioner system for a vehicle has a refrigeration cycle that includes: a compressor  1  for compressing and discharging refrigerant; a condenser  2  for condensing the refrigerant of high pressure discharged from the compressor  1 ; an expansion valve  3  for throttling the refrigerant condensed and liquefied in the condenser  2 ; and an evaporator  4  for exchanging heat between the liquefied refrigerant of low pressure throttled by the expansion valve  3  and air blown to the interior of the vehicle and evaporating the refrigerant to cool the air discharged to the interior of the vehicle due to heat absorption by evaporative latent heat, and that the compressor  1 , the condenser  2 , the expansion valve  3  and the evaporator  4  are connected with each other via refrigeration pipes. The air conditioner system cools the interior of the vehicle through the following refrigerant circulation process. 
     When a cooling switch (not shown) of the air conditioner system is turned on, first, the compressor  1  inhales and compresses gas-phase refrigerant of low-temperature and low-pressure while driving by driving power of an engine or a motor, and then sends the refrigerant in the gaseous phase of high-temperature and high-pressure to the condenser  2 . Then, the condenser  2  condenses the gas-phase refrigerant into liquid-phase refrigerant of high-temperature and high-pressure by exchanging heat with outdoor air. After that, the liquid-phase refrigerant of high-temperature and high-pressure sent from the condenser  2  rapidly expands by a throttling action of the expansion valve  3  and is sent to the evaporator  4  in a wet-saturated state of low-temperature and low-pressure. The evaporator  4  exchanges heat between the refrigerant and air blown to the interior of the vehicle by a blower (not shown). Then, the refrigerant is evaporated in the evaporator  4  and discharged in a gaseous phase of low-temperature and low-pressure. After that, the gas-phase refrigerant is inhaled into the compressor  1 , and then, recirculates the refrigeration cycle as described above. 
     In the refrigerant circulation process, as described above, the air blown by the blower (not shown) is cooled by evaporative latent heat of the liquid-phase refrigerant circulating inside the evaporator  4  and discharged to the interior of the vehicle in a cooled state so as to cool the interior of the vehicle. 
     Meanwhile, the condenser  2  which is an air-cooled condenser is mounted at the front side of the vehicle to cool the refrigerant using traveling wind from the front of the vehicle. 
     However, if the air-cooled condenser is mounted at the front side of the vehicle, a cooling module package mounted at the front side of the vehicle becomes excessively bigger. Moreover, when the vehicle idles, because air of high-temperature in an engine room flows backward toward the front side of the vehicle and is induced into the air-cooled condenser, temperature of the air induced into the air-cooled condenser gets higher, and it causes deterioration in air-conditioning performance. 
     Recently, in order to enhance air-conditioning performance, a water-cooled condenser  20  and an internal heat exchanger  25  are applied to an air conditioner system. Referring to  FIG. 2 , the water-cooled condenser  20  heat-exchanges the refrigerant discharged to the compressor  1  with coolant to condense the refrigerant. 
     That is, coolant circulating inside a water-cooled radiator  50  mounted in an engine room of the vehicle is supplied into the water-cooled condenser  20  and exchanges heat with the gas-phase refrigerant discharged from the compressor  1 , so that the gas-phase refrigerant is cooled and condensed to be changed into a liquid-phase refrigerant. 
     The water-cooled radiator  50  exchanges heat between the coolant flowing inside the water-cooled radiator  50  and the air by a water pump (WP) to cool electronic units of the vehicle, such as a battery, an inverter, a motor and so on. 
     Moreover, the internal heat exchanger  25  exchanges heat between the refrigerant discharged from the water-cooled condenser  20  and the refrigerant discharged from the evaporator  4 . 
     Therefore, the refrigerant discharged from the water-cooled condenser  20  enhances air-conditioning performance through supercooling because being further cooled in the internal heat exchanger  25  and flowing to the expansion valve  3 . 
     In the meantime, a receiver drier  30  which separates the refrigerant passing through the water-cooled condenser  20  into gas-phase refrigerant and liquid-phase refrigerant is mounted. 
     Furthermore, not shown in the drawings, but, the water-cooled condenser  20  is partitioned into a condensing region and a supercooling region through a baffle (not shown). In this instance, the refrigerant passing through the condensing region of the water-cooled condenser  20  is induced into the receiver drier  30 , and the refrigerant induced into the receiver drier  30  flows to the supercooling region of the water-cooled condenser  20  to be supercooled, and then, is induced into the internal heat exchanger  25 . 
     However, in the conventional air conditioner system, when the vehicle idles or when the outdoor temperature rises, temperature of the coolant passing the water-cooled radiator  50  also rises. In this instance, when temperature of the coolant rises, temperature of the refrigerant of the water-cooled condenser  20  which exchanges heat with the coolant also rises so that the refrigerant is induced into the internal heat exchanger  25 . After that, the refrigerant is induced into the expansion valve  3  and the evaporator  4 , and it causes deterioration in air-conditioning performance. 
     Additionally, due to the limit of the outdoor temperature which cools the coolant of the water-cooled radiator  50 , temperature of the coolant of the water-cooled radiator  50  is high and the water-cooled condenser  20  does not provide sufficient condensation in the condensing region, and hence, gas-liquid separation is not achieved smoothly in the receiver drier  30  due to high quality of the refrigerant induced into the receiver drier  30 . Finally, because not only the liquid-phase refrigerant but also the gas-phase refrigerant are induced to the supercooling region of the water-cooled condenser  20 , the receiver drier  30  cannot carry out its performance well. 
     In addition, because the water-cooled condenser  20 , the receiver drier  30  and the internal heat exchanger  25  are arranged disorderedly, the package becomes excessively bigger and it is not easy to mount them inside the engine room of the vehicle. 
     DISCLOSURE 
     Technical Problem 
     Accordingly, the present invention has been made in an effort to solve the above-mentioned problems occurring in the prior arts, and it is an object of the present invention to provide an air conditioner system for a vehicle, in which an air-cooled condenser mounted on a refrigerant circulation line between a water-cooled condenser and an expansion valve and a blower fan for blowing air to the air-cooled condenser are arranged on one side of the water-cooled condenser in a state of being disposed in a row in the air flow direction and are arranged within the width of the one side of the water-cooled condenser, thereby enabling the enhancement of installability and assemblability inside an engine room by simplifying and reducing the package, reducing noise of the blower fan and securing adequate cooling performance because of the blower fan disposed between two air-cooled heat exchangers even when inflowing air is insufficient, such as in an idling condition, and securing the original function of the receiver drier and utilizing the air-cooled condenser as a supercooling region to enhance air-conditioning performance because sufficiently liquefied refrigerant is induced into the receiver drier due to installation of the air-cooled condenser. 
     Technical Solution 
     To achieve the above objects, the present invention provides an air conditioner system for a vehicle including: a compressor for compressing refrigerant; a water-cooled condenser which exchanges heat between coolant and the refrigerant flowing after being discharged from the compressor to condense the refrigerant; an expansion valve adapted for expanding the refrigerant flowing after being discharged from the water-cooled condenser; an evaporator for evaporating the refrigerant flowing after being discharged from the expansion valve; a refrigerant circulation line which connects the compressor, the water-cooled condenser, the expansion valve and the evaporator with one another in order; an air-cooled condenser which is connected on the refrigerant circulation line between the water-cooled condenser and the expansion valve in order to further cool the refrigerant by exchanging heat between the refrigerant and air; and a blower fan for moving air toward the air-cooled condenser, wherein the air-cooled condenser and the blower fan are mounted to be arranged on one side of the water-cooled condenser in a state where they are arranged in a row in a flow direction of the air and are arranged within a width of one side of the water-cooled condenser. 
     Advantageous Effects 
     According to the present invention, because the air-cooled condenser mounted on the refrigerant circulation line between the water-cooled condenser and the expansion valve and the blower fan for blowing air to the air-cooled condenser are arranged on one side of the water-cooled condenser in a state of being disposed in a row in the air flow direction and are arranged within the width of the one side of the water-cooled condenser, the air conditioner system for a vehicle can enhance installability and assemblability inside the engine room by simplifying and reducing the package. 
     Moreover, the air conditioner system for the vehicle according to the present invention can reduce noise of the blower fan and secure adequate cooling performance because the blower fan is disposed between two air-cooled heat exchangers even when inflowing air is insufficient, such as in an idling condition. 
     Furthermore, because sufficiently liquefied refrigerant is induced into the receiver drier due to installation of the air-cooled condenser, the air conditioner system for the vehicle according to the present invention can secure the original function of the receiver drier and utilize the air-cooled condenser as a supercooling region to enhance air-conditioning performance. 
     Additionally, because the air-cooled condenser is mounted at the front side of the water-cooled condenser, the air conditioner system according to the present invention reuses the air passing through the air-cooled condenser to cool the water-cooled condenser, thereby enhancing cooling performance and improving fuel efficiency by reducing power consumption of the compressor. 
     In addition, because the air-cooled condenser is arranged at the front of the water-cooled condenser, the air conditioner system according to the present invention is easy to construct the package, provides the package in various designs, and enhances installability inside the engine room of the vehicle. 
     Moreover, because the air-cooled condenser is mounted not at the front side of the vehicle but on the cowl panel to supply the outdoor air of the cowl panel to the air-cooled condenser, thereby simplifying and reducing the package of the entire air conditioner system, reducing the refrigerant amount and manufacturing costs by making the refrigerant circulation line short, and enhancing air-conditioning performance by effectively supplying air to the air-cooled condenser. 
     Furthermore, because the air-cooled condenser is mounted on the cowl panel of the vehicle, the air-cooled condenser can escape the influence of the high-temperature air of the engine room which flows backward toward the front side of the vehicle at the time of idling of the vehicle, thereby lowering temperature of the air induced into the air-cooled condenser and enhancing air-conditioning performance. 
     Additionally, because the air-cooled condenser is connected to the outlet of the water-cooled condenser, the air conditioner system according to the present invention further cool the refrigerant inside the air-cooled condenser even though temperature of the refrigerant rises due to temperature rise of the coolant supplied to the water-cooled condenser, thereby enhancing air-conditioning performance. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a configurative diagram of a general air conditioner system for a vehicle. 
         FIG. 2  is a configurative diagram showing a state where a water-cooled condenser, receiver drier and an internal heat exchanger are applied to a conventional air conditioner system for a vehicle. 
         FIG. 3  is a configurative diagram of an air conditioner system for a vehicle according to a first preferred embodiment of the present invention. 
         FIG. 4  is a perspective view of the air conditioner system for the vehicle according to the first preferred embodiment of the present invention. 
         FIG. 5  is an arrangement diagram of essential parts of the air conditioner system for the vehicle according to the first preferred embodiment of the present invention. 
         FIG. 6  is a perspective view showing a state where one air-cooled condenser is mounted in  FIG. 4 . 
         FIG. 7  is an arrangement diagram showing essential parts of  FIG. 6 . 
         FIG. 8  is a configurative diagram of an air conditioner system for a vehicle according to a second preferred embodiment of the present invention. 
         FIG. 9  is a configurative diagram of an air conditioner system for a vehicle according to a third preferred embodiment of the present invention. 
         FIG. 10  is a detail diagram of a water-cooled condenser, a receiver drier, an air-cooled condenser and an internal heat exchanger of  FIG. 9 . 
         FIG. 11  is an arrangement diagram of essential parts of the air conditioner system for the vehicle according to the third preferred embodiment of the present invention. 
         FIG. 12  is an arrangement diagram showing a state where a blower fan is arranged between the air-cooled condenser and the water-cooled condenser in  FIG. 11 . 
         FIG. 13  is a configurative diagram of an air conditioner system for a vehicle according to a fourth preferred embodiment of the present invention. 
         FIG. 14  is a perspective view of the air conditioner system for the vehicle according to the fourth preferred embodiment of the present invention. 
         FIG. 15  is a plan view of  FIG. 14 . 
         FIG. 16  is an arrangement diagram of essential parts of the air conditioner system for the vehicle according to the fourth preferred embodiment of the present invention. 
         FIG. 17  is an arrangement diagram showing a state where a blower fan is arranged between an air-cooled condenser and a water-cooled condenser in  FIG. 16 . 
         FIG. 18  is a schematic diagram showing an air conditioner system according to a fifth preferred embodiment of the present invention is installed in a vehicle. 
         FIG. 19  is a detailedly sectional view of the air conditioner system according to the fifth preferred embodiment of the present invention. 
         FIG. 20  is a sectional view showing a state where a connection duct is mounted on a mounting part of a cowl panel in  FIG. 19 . 
         FIG. 21  is a sectional view showing a state where the connection duct is mounted on the mounting part of the cowl panel and an air-cooled condenser is arranged below the cowl panel in the vertical direction in  FIG. 19 . 
         FIG. 22  is a sectional view showing a state where a water-cooled condenser and an internal heat exchanger is omitted from the air conditioner system of  FIG. 19 . 
     
    
    
     MODE FOR INVENTION 
     Reference will be now made in detail to the preferred embodiment of the present invention with reference to the attached drawings. 
     As shown in the drawings, an air-conditioner system for a vehicle according to a first preferred embodiment of the present invention is configured of a compressor  100 , a water-cooled condenser  110 , an expansion valve  140  and an evaporator  150  which are connected to a refrigerant pipe P in order, and includes an air-cooled condenser  120 , a receiver drier  160  and an internal heat exchanger  130  mounted between the water-cooled condenser  110  and the expansion valve  140  in the above-mentioned system. 
     First, the compressor  100  inhales and compresses gas-phase refrigerant of low-temperature and low-pressure discharged from the evaporator  150  and discharges the gas-phase refrigerant into a gaseous state of high-temperature and high-pressure while receiving a driving power from a driving power supply source, such as, an engine or a motor. 
     The water-cooled condenser  110  exchanges heat between the gas-phase refrigerant of high-temperature and high-pressure, which flows after being discharged from the compressor  100 , and coolant, and then, condenses the refrigerant into liquid-phase refrigerant and discharges the condensed refrigerant. 
     The water-cooled condenser  110  includes: a refrigerant flow channel  111  in which the refrigerant discharged from the compressor  100  flows; and a coolant flow channel  112  in which coolant circulating a water-cooled radiator  200  mounted inside a vehicle engine room flows, and the refrigerant flow channel  111  and the coolant flow channel  112  are configured to be able to exchange heat with each other. 
     That is, the water-cooled condenser  110  may be a plate-type heat exchanger (not shown) with laminated plates. In case of the plate-type heat exchanger, a plurality of coolant flow channels  112  and a plurality of refrigerant flow channels  111  are arranged by turns to exchange heat with each other. 
     The water-cooled condenser  110  is mounted adjacent to a partition wall  300  which partitions an engine room of the vehicle and the inside of the vehicle. 
     In the meantime, the water-cooled condenser  110  may have one of various well-known forms. For example, the water-cooled condenser  110  may be configured such that the coolant flow channel  112  is formed in a tank type and the refrigerant flow channel  111  is mounted inside the coolant flow channel  112  to be able to exchange heat with each other. 
     The water-cooled radiator  200  is connected with the coolant flow channel  112  of the water-cooled condenser  110  through a coolant pipe  205 , and a water pump  210  for circulating the coolant is mounted on the coolant pipe  205 . 
     Therefore, when the water pump  210  is operated, the coolant circulating in the coolant pipe  205  is cooled by heat exchange with air while passing through the water-cooled radiator  200 , and then, the cooled coolant is supplied to the coolant flow channel  112  of the water-cooled condenser  110  to exchange heat with the refrigerant flowing in the refrigerant flow channel  111  of the water-cooled condenser  110 . 
     In the meantime, the water-cooled radiator  200  is used to cool electronic units of the vehicle, such as a battery, an inverter, a motor and so on, by exchanging heat between the air and the coolant flowing in the water-cooled radiator  200 . 
     Moreover, the expansion valve  140  rapidly expands the liquid-phase refrigerant, which flows after being discharged from the water-cooled condenser  110 , by the throttling action and sends the refrigerant to the evaporator  150  in a wet-saturated state of low-temperature and low-pressure. 
     In other words, the liquid-phase refrigerant discharged from the water-cooled condenser  110  passes the air-cooled condenser  120 , the receiver drier  160  and the internal heat exchanger  130  in order, and then, is supplied to the expansion valve  140  to be expanded. 
     In the meantime, in a case that the receiver drier  160  is mounted at the front of the air-cooled condenser  120 , the liquid-phase refrigerant discharged from the water-cooled condenser  110  passes through the receiver drier  160 , the air-cooled condenser  120  and the internal heat exchanger  130  in order, and then, is supplied to the expansion valve  140  to be expanded. 
     The evaporator  150  evaporates the liquid-phase refrigerant of low-pressure, which flows after being discharged from the expansion valve  140 , by heat-exchanging with the air blown to the interior of the vehicle inside an air-conditioning case  155  so that the air discharged to the interior of the vehicle is cooled due to heat absorption by evaporative latent heat of the refrigerant. 
     Continuously, the gas-phase refrigerant of low-temperature and low-pressure evaporated and discharged in the evaporator  150  is inhaled to the compressor  100  again, and then, recirculates the refrigerant cycle as described above. 
     Furthermore, in the refrigerant circulation process, the air blown by a blower (not shown) flows into the air-conditioning case  155 , and is cooled by evaporative latent heat of the liquid-phase refrigerant circulating the inside of the evaporator  150  while passing the evaporator  150 . Therefore, the interior of the vehicle is cooled when the refrigerant in the cooled state is discharged to the interior of the vehicle. 
     Additionally, the air-cooled condenser  120  which exchanges heat between the refrigerant and the air to additionally cool the refrigerant and a blower fan  125  which moves the air toward the air-cooled condenser  120  are mounted on the refrigerant circulation line (R) between the water-cooled condenser  110  and the expansion valve  140 . 
     In the meantime, the receiver drier  160  which separates the refrigerant into gas-phase refrigerant and liquid-phase refrigerant and stores the liquid-phase refrigerant may be connected to the refrigerant circulation line (R) which connects a condensing region  120   a  and a supercooling region  120   b  of the air-cooled condenser  120  or may be connected to the refrigerant circulation line (R) which connects two air-cooled condensers  120 . 
     Of course, as shown in  FIG. 9 , the receiver drier  160  may be mounted on the refrigerant circulation line between the water-cooled condenser  110  and the air-cooled condenser  120 . 
     However, the air-cooled condenser  120  and the blower fan  125  are arranged and mounted on one side of the water-cooled condenser  110  in a state where they are arranged in a row in the air flow direction, and are mounted to be arranged within a width (W) of one side of the water-cooled condenser  110 . 
     In this instance, one air-cooled condenser  120  and one blower fan  125  may be mounted on one side of the water-cooled condenser  110  as shown in  FIGS. 6 and 7  or two air-cooled condensers  120  and one blower fan  125  may be mounted on one side of the water-cooled condenser  110  as shown in  FIGS. 4 and 5 . 
     In the case that the two air-cooled condensers  120  are mounted, they are mounted to be spaced apart from each other at a predetermined interval in the air flow direction of the air passing through the air-cooled condenser  120 , and the blower fan  125  is mounted between the two air-cooled condensers  120 . 
     That is, the blower fan  125  is not externally mounted but is internally mounted between the two air-cooled condensers  120 , thereby reducing noise of the blower fan  125 , cooling the two air-cooled condensers  120  with the one blower fan  125 , and reducing the total package size. 
     Meanwhile, in the case that the one air-cooled condenser  120  is mounted, as shown in  FIGS. 6 and 7 , it is preferable that the blower fan  125  be mounted above the air-cooled condenser  120  in the air flow direction of the air passing through the air-cooled condenser  120 . 
     As described above, because the air-cooled condenser  120  and the blower fan  125  are disposed within the width (W) of the water-cooled condenser  110 , the air conditioner system according to the present invention enables enhancement of installability and assemblability inside an engine room by simplifying and reducing the package. Moreover, because the blower fan  125  is arranged between the two air-cooled heat exchangers  120 , the air conditioner system according to the present invention can reduce noise of the blower fan  125  and secure adequate cooling performance even though inflowing air is insufficient under an idling condition. 
     In the meantime, the width (W) of the water-cooled condenser  110  is the sum of the width of the air-cooled condenser  120  and the width of the blower fan  125 . 
     Here, the width (W) of the water-cooled condenser  110  is the width (W) of the water-cooled condenser  110  in the air flow direction of the air passing through the air-cooled condenser  120 , and the width of the air-cooled condenser  120  is the sum of two air-cooled condensers  120  in the case that the air-cooled condensers  120  are mounted. 
     Moreover, in the case that the two air-cooled condensers  120  are mounted, the refrigerant discharged from the water-cooled condenser  110  is simultaneously supplied to the two air-cooled condensers  120 . 
     Furthermore, the receiver drier  160  which separates the refrigerant circulating the refrigerant circulation line (R) into gas-phase refrigerant and liquid-phase refrigerant and stores the liquid-phase refrigerant is arranged on one side of the air-cooled condenser  120 . 
     Additionally, the air-cooled condenser  120  includes: a condensing region  120   a  which exchanges heat between the refrigerant and the air; and a supercooling region  120   b  which reexchanges heat between the refrigerant passing the condensing region  120   a  and the air. 
     Now, the structure of the air-cooled condenser  120  will be described in brief. The air-cooled condenser  120  includes: a pair of header tanks spaced apart from each other at a predetermined interval and mounted side by side; a plurality of tubes of which both end portions are joined to the header tanks to communicate the header tanks with each other; and a radiation fin interposed between the tubes. 
     In order to divide the air-cooled condenser  120  into the condensing region  120   a  and the supercooling region  120   b,  a baffle is disposed inside the header tank to divide the inside of the header tank into an upper part and a lower part. 
     In the meantime, the water-cooled condenser  110  is connected with the condensing region  120   a  of the air-cooled condenser  120 . 
     Moreover, an inlet of the receiver drier  160  is connected with the condensing region  120   a  of the air-cooled condenser  120  and an outlet is connected with the supercooling region  120   b  of the air-cooled condenser  120 , so that the refrigerant condensed in the water-cooled condenser  110  is condensed in the condensing region  120   a  of the air-cooled condenser  120  again and is supercooled in the supercooling region  120   b  of the air-cooled condenser  120  after passing through the receiver drier  160 . 
     As described above, after the refrigerant sufficiently condensed in the water-cooled condenser  110  is cooled in the condensing region  120   a  of the air-cooled condenser  120  again, the refrigerant is supplied to the receiver drier  160 . The sufficiently liquefied refrigerant is supplied to the receiver drier  160  so that the receiver drier  160  secures its original function, thereby discharging only the liquid-phase refrigerant to the downstream side (outlet side) of the receiver drier  160 , and reducing discharge pressure of the compressor  100  and reducing power consumption of an air conditioner because the system is filled with an adequate refrigerant amount according to the system capacity. 
     Furthermore, because the air-cooled condenser  120  can be utilized as the supercooling region, temperature of the refrigerant lowers further so that the refrigerant can flow into the internal heat exchanger  130  to enhance cooling performance. In this instance, because temperature of the refrigerant flowing into the compressor  100  also drops, the air conditioner system according to the present invention can prevent a temperature rise of the refrigerant discharged from the compressor  100  and enhance durability and stability of the system. 
     In the meantime, when the vehicle idles or when the outdoor temperature rises, temperature of the coolant circulating the water-cooled radiator  200  also rises. The coolant with elevated temperature is supplied to the water-cooled condenser  110  so that temperature of the refrigerant flowing in the water-cooled condenser  110  rises. 
     In the present invention, the air-cooled condenser  120  is mounted at the downstream side of the refrigerant flow direction of the water-cooled condenser  110  in order to further cool the refrigerant by the air-cooled condenser  120  even though temperature of the refrigerant flowing in the water-cooled condenser  110  rises. Accordingly, because temperature of the refrigerant lowers further, the refrigerant can flow into the internal heat exchanger  130  to enhance cooling performance. Consequentially, because temperature of the refrigerant induced into the compressor  100  also drops, the air conditioner system according to the present invention can prevent a temperature rise of the refrigerant discharged from the compressor  100 . 
     Meanwhile, the receiver drier  160  serves to separate the refrigerant discharged from the condensing region  120   a  of the air-cooled condenser  120  into gas-phase refrigerant and liquid-phase refrigerant and store the liquid-phase refrigerant. That is, the receiver drier  160  enhances cooling efficiency by separating the gas-phase refrigerant which is not liquefied in the condensing region  120   a  of the air-cooled condenser  120  or by absorbing moisture contained in the refrigerant. 
     Therefore, a desiccant (not shown) is disposed inside the receiver drier  160  in order to remove the gas-phase refrigerant and moisture. Of course, a filter (not shown) may be mounted to remove impurities contained in the refrigerant passing through the desiccant. 
     In the meantime, the air-cooled condenser  120  and the receiver drier  160  may be formed separately from each other or formed integrally. 
     Additionally, the internal heat exchanger  130  which exchanges heat between the refrigerant discharged from the air-cooled condenser  120  and the refrigerant discharged from the evaporator  150  is mounted on the refrigerant circulation line (R) between the air-cooled condenser  120  and the expansion valve  140 . 
     In this instance, the internal heat exchanger  130  is arranged on one side of the receiver drier  160 . Hence, the water-cooled condenser  110 , the air-cooled condenser  120 , the blower fan  125 , the receiver drier  160  and the internal heat exchanger  130  are arranged in a row. 
     The internal heat exchanger  130  is a heat exchanger for refrigerant-to-refrigerant heat exchange.  FIG. 4  is a schematic diagram of the internal heat exchanger  130 , and the internal heat exchanger  130  may be a plate type heat exchanger or a dual tube type heat exchanger. 
     Therefore, while flowing in the internal heat exchanger  130 , the refrigerant passing through the air-cooled condenser  120  exchanges heat with the refrigerant of low temperature, which is discharged from the evaporator  150  and flows in the internal heat exchanger  130 , so as to be further supercooled. After that, the supercooled refrigerant induced into the expansion valve  140 . As described above, when temperature of the refrigerant gets lower, it increases an enthalpy difference of the evaporator  150  to enhance air-conditioning performance. 
     Moreover, because temperature of the refrigerant which passes the internal heat exchanger  130  and is induced into the compressor  100  after being discharged from the evaporator  150  also gets lower, temperature of the refrigerant discharged from the compressor  100  does not exceed the upper limit. 
     Hereinafter, the refrigerant flowing process of the air conditioner system for the vehicle according to the first preferred embodiment of the present invention will be described, and as shown in  FIGS. 3 and 4 , the example that two air-cooled condensers  120  are mounted will be described. 
     First, the gas-phase refrigerant of high-temperature and high-pressure compressed and discharged in the compressor  100  flows into the refrigerant heat-exchanging part  111  of the water-cooled condenser  110 . 
     The gas-phase refrigerant flowing into the refrigerant flow channel  111  of the water-cooled condenser  110  exchanges heat with coolant flowing into the coolant flow channel  112  of the water-cooled condenser  110  while circulating in the water-cooled radiator  200 , and in the above process, the refrigerant is cooled and changed into a liquid phase. 
     The liquid-phase refrigerant discharged from the water-cooled condenser  110  is cooled once more through heat exchange with the air while flowing in the condensing regions  120   a  of the two air-cooled condensers  120  so as to be condensed again, and in the case that one air-cooled condenser is mounted as shown in  FIG. 6 , the liquid-phase refrigerant is condensed while flowing in the condensing region of the one air-cooled condenser. The condensed liquid-phase refrigerant is induced into the receiver drier  160 . 
     The gas-phase refrigerant contained in the liquid-phase refrigerant is separated in the receiver drier  160  so that the liquid-phase refrigerant is located below and the gas-phase refrigerant is located above inside the receiver drier  160 . 
     Continuously, the liquid-phase refrigerant discharged from the receiver drier  160  is induced into the supercooling region  120   b  of the two air-cooled condensers  120  to be cooled further (supercooled) through heat exchange with the air, and then, is induced into the internal heat exchanger  130 . 
     The refrigerant flowing into the internal heat exchanger  130  is further supercooled while exchanging heat with the refrigerant flowing in the internal heat exchanger  130 , and then, flows into the expansion valve  140  to be decompressed and expanded. 
     The refrigerant decompressed and expanded in the expansion valve  140  becomes into an atomized state of low-temperature and low-pressure and flows into the evaporator  150 . The refrigerant flowing into the evaporator  150  is evaporated through heat exchange with the air blown to the interior of the vehicle, and at the same time, cools the air blown to the interior of the vehicle due to heat absorption due to evaporative latent heat of the refrigerant. 
     After that, the refrigerant of low-temperature and low-pressure discharged from the evaporator  150  flows into the internal heat exchanger  130 . In this instance, the refrigerant exchanges heat with the refrigerant which is discharged from the air-cooled condenser  120  and flows in the internal heat exchanger  130 . After that, the refrigerant flows into the compressor  100 , and then, recirculates the refrigeration cycle as described above. 
       FIG. 8  illustrates an air conditioner system for a vehicle according to a second preferred embodiment of the present invention, and only parts which are different from the parts of the first preferred embodiment will be described. Also, in the second preferred embodiment, two air-cooled condensers  120  are mounted, but the entire of one air-cooled condenser  120  becomes a condensing region and the entire of the other one becomes a supercooling region. 
     In this instance, an inlet of a receiver drier  160  is connected with one of the two air-cooled condensers  120 , and an outlet of the receiver drier  160  is connected with the other air-cooled condenser  120 . 
     Therefore, liquid-phase refrigerant discharged after exchanging heat with coolant in a water-cooled condenser  110  is induced into one of the air-cooled condenser  120  and is cooled once more through heat exchange with the air to be condensed again, and then, the condensed liquid-phase refrigerant is induced into the receiver drier  160 . 
     The gas-phase refrigerant contained in the liquid-phase refrigerant is separated in the receiver drier  160  so that the liquid-phase refrigerant is located below and the gas-phase refrigerant is located above inside the receiver drier  160 . 
     Continuously, the liquid-phase refrigerant discharged from the receiver drier  160  is induced into the other air-cooled condenser  120  to be further cooled (supercooled) through heat exchange with the air, and then, is induced into the internal heat exchanger  130 . The following steps of the refrigerant flow process is the same as the first preferred embodiment. 
       FIGS. 9 to 12  illustrate an air conditioner system for a vehicle according to a third preferred embodiment of the present invention, and only parts which are different from the parts of the first and second preferred embodiments will be described. 
     In the third preferred embodiment, a receiver drier  160 , an air-cooled condenser  120  and an internal heat exchanger  130  are mounted on a refrigerant circulation line (R) to be connected in order in the refrigerant flow direction. 
     In this instance, an inlet of the receiver drier  160  is connected with the water-cooled condenser  110  and an outlet of the receiver drier  160  is connected with the air-cooled condenser  120  so that refrigerant condensed in the water-cooled condenser  110  is supercooled in the air-cooled condenser  120  after passing through the receiver drier  160 . 
     The receiver drier  160  is arranged at the left or the right of the water-cooled condenser  110 , and in  FIG. 10 , the receiver drier  160  is arranged at the right of the water-cooled condenser  110 . 
     In this instance, the receiver drier  160  may be mounted integrally with the water-cooled condenser  110 . 
     The air-cooled condenser  120  is arranged such that the air passing through the air-cooled condenser  120  faces the water-cooled condenser  110 . Therefore, the air passing through the air-cooled condenser  120  is reused to cool the water-cooled condenser  110 . For this, he air-cooled condenser  120  is arranged and mounted in front of the water-cooled condenser  110 . 
     In this instance, the air-cooled condenser  120  is arranged in a row with the water-cooled condenser  110  in the air flow direction of the air passing through the air-cooled condenser  120  and is spaced apart from the water-cooled condenser  110  at a predetermined interval. 
     Therefore, the air passing through the air-cooled condenser  120  flows to the water-cooled condenser  110  and cools the water-cooled condenser  110  while flowing along the front surface of the water-cooled condenser  110  so as to enhance cooling performance. 
     In this instance, as shown in  FIG. 15 , the front surface of the water-cooled condenser  110  which faces the air-cooled condenser  120  has a curved surface  115  to promote a flow of the air at the front side of the water-cooled condenser  110 . 
     In other words, the air passing through the air-cooled condenser  120  flows to both sides along the curved surface  115  of the water-cooled condenser  110  not to interrupt the flow of the air so that the air flows smoothly. 
     Moreover, because the front side of the water-cooled condenser  110  has the curved surface  115 , heat-exchange performance is enhanced due to an increase of a contact area with the air. 
     Meanwhile, in the case that the water-cooled condenser  110  is the plate-type heat exchanger, front sides of plates are made in a curved form and the plates having the curved front sides are laminated so that the plate-type heat exchanger (water-cooled heat exchanger) having the curved surface  115  can be manufactured. 
     Furthermore, a radiation fin (not shown) is mounted on the front side of the water-cooled condenser  110  to enhance heat-exchange efficiency of the water-cooled condenser  110 . 
     Additionally, a blower fan  125  is mounted in front of the air-cooled condenser  120  or mounted between the air-cooled condenser  120  and the water-cooled condenser  110 . 
     In the case that the blower fan  125  is mounted in front of the air-cooled condenser  120 , the blower fan  125 , the air-cooled condenser  120  and the water-cooled condenser  110  are mounted in a row in the air flow direction of the air passing through the air-cooled condenser  120 . 
     In the case that the blower fan  125  is mounted between the air-cooled condenser  120  and the water-cooled condenser  110 , the air-cooled condenser  120 , the blower fan  125  and the water-cooled condenser  110  are mounted in a row in the air flow direction of the air passing through the air-cooled condenser  120 . 
     As described above, because the blower fan  125  is mounted in front of the air-cooled condenser  120  or mounted between the air-cooled condenser  120  and the water-cooled condenser  110 , air can be induced sufficiently even when inflowing air is insufficient, such as in an idling condition, so as to secure sufficient cooling performance. 
     In the meantime, the air-cooled condenser  120  exchanges heat between the refrigerant flowing inside the air-cooled condenser  120  after being discharged from the receiver drier  160  and the air passing through the air-cooled condenser  120 . 
     As described above, in the third preferred embodiment, the whole area of the water-cooled condenser  110  is used as the condensing region, and the whole area of the air-cooled condenser  120  is used as the supercooling region. 
     In other words, because the whole area of the water-cooled condenser  110  is used as the condensing region, the refrigerant which is liquefied after being sufficiently condensed in the water-cooled condenser  110  is induced into the receiver drier  160 . Thus, the receiver drier  160  secures its original function, thereby discharging only the liquid-phase refrigerant to the downstream side of the receiver drier  160 , reducing discharge pressure of the compressor  100  and reducing power consumption of an air conditioner because the system is filled with an adequate refrigerant amount according to the system capacity. 
     Furthermore, because the whole area of the air-cooled condenser  120  can be utilized as the supercooling region, temperature of the refrigerant gets lower so that the refrigerant can flow into the internal heat exchanger  130  to enhance air-conditioning performance. In this instance, because temperature of the refrigerant induced into the compressor  100  also gets lower, the air conditioner system according to the present invention can prevent a temperature rise of the refrigerant discharged from the compressor  100  and enhance durability and stability of the system. 
     Meanwhile, the receiver drier  160  serves to separate the refrigerant discharged from the water-cooled condenser  110  into gas-phase refrigerant and liquid-phase refrigerant and store the liquid-phase refrigerant. That is, the receiver drier  160  enhances cooling efficiency by separating the gas-phase refrigerant which is not liquefied in the water-cooled condenser  110  or by absorbing moisture contained in the refrigerant. 
     Additionally, the internal heat exchanger  130  which exchanges heat between the refrigerant discharged from the air-cooled condenser  120  and the refrigerant discharged from the evaporator  150  is mounted on the refrigerant circulation line (R) between the air-cooled condenser  120  and an expansion valve  140 . 
     In this instance, the internal heat exchanger  130  is arranged on one side of the receiver drier  160  so that the water-cooled condenser  110 , the receiver drier  160  and the internal heat exchanger  130  are arranged in a row. 
     As shown in the drawings, the receiver drier  160  is mounted at the right of the water-cooled condenser  110  and the internal heat exchanger  130  is mounted at the right of the receiver drier  160 . 
     As described above, in the state where the water-cooled condenser  110 , the receiver drier  160  and the internal heat exchanger  130  are arranged in a row, the air-cooled condenser  120  is arranged in front of the water-cooled condenser  110 , namely, in front of the components arranged in a row, so as to enhance installability inside the engine room of the vehicle, to make the construction of the package easy and to provide various designs. 
       FIGS. 13 to 17  illustrate an air conditioner system for a vehicle according to a fourth preferred embodiment of the present invention, and only parts which are different from the parts of the first, second and third preferred embodiments will be described. 
     In the fourth preferred embodiment, an air-cooled condenser  120 , a receiver drier  160  and an internal heat exchanger  130  are mounted on a refrigerant circulation line (R) between a water-cooled condenser  110  and an expansion valve  140  to be connected in order in the refrigerant flow direction. 
     Like the third preferred embodiment, the air-cooled condenser  120  is arranged in front of the water-cooled condenser  110 . 
     Like the third preferred embodiment, the receiver drier  160  is arranged at the left or the right of the water-cooled condenser  110 , and in  FIG. 14 , is arranged at the right of the water-cooled condenser  110 . 
     An inlet of the receiver drier  160  is connected with the condensing region  120   a  of the air-cooled condenser  120  and an outlet is connected with the supercooling region  120   b  of the air-cooled condenser  120 , so that the refrigerant condensed in the water-cooled condenser  110  is condensed in the condensing region  120   a  of the air-cooled condenser  120  again and is supercooled in the supercooling region  120   b  of the air-cooled condenser  120  after passing through the receiver drier  160 . 
     In the meantime, an inlet pipe and an outlet pipe are respectively disposed in the condensing region  120   a  and the supercooling region  120   b  to respectively induce and discharge refrigerant. 
     Additionally, the internal heat exchanger  130  is mounted on the refrigerant circulation line (R) between the air-cooled condenser  120  and the expansion valve  140 . In this instance, the internal heat exchanger  130  is arranged below the water-cooled condenser  110  in a state where it is connected with the supercooling region  120   b  of the air-cooled condenser  120 . 
     As described above, in the third and fourth preferred embodiments, when viewed from the air flow direction, the air-cooled condenser  120  is arranged in the front row and the water-cooled condenser  110 , the receiver drier  160  and the internal heat exchanger  130  are arranged in the rear row so as to enhance installability inside the engine room of the vehicle by making the construction of the package easy and providing various designs. 
       FIGS. 18 to 22  illustrate an air conditioner system for a vehicle according to a fifth preferred embodiment of the present invention, and only parts which are different from the parts of the first, second, third and fourth preferred embodiments will be described. 
     In the fifth preferred embodiment, an air-cooled condenser  120  is mounted on a cowl panel  350  which is mounted between a wind shield glass  360  and an engine hood (not shown) of the vehicle, so that the outdoor air of the cowl panel  350  can be smoothly supplied to the air-cooled condenser  120 . 
     That is, the air-cooled condenser  120  exchanges heat between the air which is supplied from the outside of the cowl panel  350  and passes through the air-cooled condenser  120  and the refrigerant which flows inside the air-cooled condenser  120 . 
     In this instance, the cowl panel  350  includes a mounting part  351  for communicating the outside of the cowl panel  350  with the inside of the engine room of the vehicle, and the air-cooled condenser  120  is mounted on the mounting part  351 . 
     The mounting part  351  is formed by a through hole formed in the cowl panel  350  to be as big as the air-cooled condenser  120 . In this instance, the mounting part  351  is formed in a rectangular shape because the air-cooled condenser  120  is in a rectangular form. 
     Moreover, a blower fan  125  is mounted at the upper portion or the lower portion of the cowl panel  350  where the mounting part  351  is located in order to forcedly supply the outdoor air of the cowl panel  350  toward the air-cooled condenser  120 . 
     Therefore, when the vehicle travels, the outdoor air of the cowl panel  350  is supplied to the air-cooled condenser  120  using static pressure by traveling wind to cool the refrigerant. When the vehicle idles, the blower fan  125  is operated so that the outdoor air of the cowl panel  350  is forcedly supplied to the air-cooled condenser  120  to cool the refrigerant. 
     Meanwhile,  FIGS. 18 and 19  illustrate the water-cooled condenser  110  and the air-cooled condenser  120  which are spaced apart from each other, but the water-cooled condenser  110  may be arranged adjacent to one side (lower part) of the air-cooled condenser  120  mounted on the mounting part  351 . 
     As described above, because the air-cooled condenser  120  is mounted at the front side of the vehicle but on the cowl panel  350 , a distance among the air-cooled condenser  120 , the evaporator  150  mounted in the interior of the vehicle, the water-cooled condenser  110  mounted in the engine room and the compressor  100  is reduced, thereby simplifying and reducing the package of the entire air conditioner system and reducing the refrigerant amount and manufacturing costs due to the short refrigerant circulation line (R). 
     Furthermore, because the air-cooled condenser  120  is mounted on the cowl panel  350  inside the system having the water-cooled condenser  110  and the air-cooled condenser  120 , the duct for supplying outdoor air to the air-cooled condenser  120  can be omitted or simplified in structure, thereby simplifying the package and enhancing air-conditioning performance by effectively supplying the outdoor air to the air-cooled condenser  120 . 
     Additionally, because the air-cooled condenser  120  is mounted on the cowl panel  350  of the vehicle, the air-cooled condenser  120  can escape the influence of the high-temperature air of the engine room which flows backward toward the front side of the vehicle at the time of idling of the vehicle, thereby lowering temperature of the air induced into the air-cooled condenser  120  and enhancing air-conditioning performance. 
     In addition, if the cowl panel  350  is short of an area to install the air-cooled condenser  120 , as shown in  FIG. 20 , an extension duct  352  is mounted on the mounting part  351  of the cowl panel  350 . 
     The extension duct  352  extends to a predetermined length toward the engine room from the mounting part  351 , and in this instance, the air-cooled condenser  120  is mounted inside the extension duct  352 . 
     Moreover, the blower fan  125  is also mounted inside the extension duct  352  to forcedly supply the outdoor air of the cowl panel  350  toward the air-cooled condenser  120 . 
     Furthermore, as shown in  FIG. 20 , it is preferable that the water-cooled condenser  110  and the internal heat exchanger  130  be mounted adjacent to the lower portion of the blower fan  125 . 
     In other words, because the water-cooled condenser  110  and the internal heat exchanger  130  are mounted adjacent to the lower portion of the blower fan  125 , the air used to cool the air-cooled condenser  120  when the blower fan  125  is operated can be reused to cool the water-cooled condenser  110  and the internal heat exchanger  130  so as to enhance air-conditioning performance more. That is, the refrigerant can be cooled further while the air passing through the air-cooled condenser  120  flows along the outer surfaces of the water-cooled condenser  110  and the internal heat exchanger  130 . 
     Additionally, if it is impossible to mount the air-cooled condenser  120  on the cowl panel  350  in the transverse direction, as shown in  FIG. 21 , the air-cooled condenser  120  is mounted below the cowl panel  350  in the perpendicular direction, and a connection duct  353  which connects the outside of the cowl panel  350  and the air-cooled condenser  120  with each other is mounted on the cowl panel  350  in order to supply the outdoor air of the cowl panel  350  toward the air-cooled condenser  120 . 
     The connection duct  353  is formed to change the flow of the air at an angle of 90 degrees. In this instance, the connection duct  353  is mounted in such a way that one end portion of the connection duct  353  is located at the upper portion of the cowl panel  350  and the other end portion is connected with the air-cooled condenser  120  mounted below the cowl panel  350 . 
     In addition, the blower fan  125  is mounted on one side of the air-cooled condenser to forcedly supply the outdoor air of the cowl panel  350  toward the air-cooled condenser  120  through the connection duct  353 . 
     As described above, even though the air-cooled condenser  120  is mounted below the cowl panel  350  in the perpendicular direction, the outdoor air of the cowl panel  350  can be smoothly supplied to the air-cooled condenser  120  through the connection duct  353 . 
     Meanwhile, not shown in the drawings, but in the fifth preferred embodiment, a receiver drier may be also mounted on the refrigerant circulation line (R) between the water-cooled condenser  110  and the internal heat exchanger  130  in order to separate the refrigerant into gas-phase refrigerant and liquid-phase refrigerant and store the liquid-phase refrigerant. 
       FIG. 22  is a sectional view showing a state where the water-cooled condenser and the internal heat exchanger are omitted from the air conditioner system according to the fifth preferred embodiment. Even in the air conditioner system from which the water-cooled condenser  110  and the internal heat exchanger  130  are omitted, when the air-cooled condenser  120  is mounted on the cowl panel  350 , the previously described effect can be obtained. 
     
       
         
           
               
             
               
                   
               
               
                 Explanation of reference numerals in drawings 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 100:  
                 Compressor 
               
               
                   
                 110:  
                 Water-cooled condenser 
               
               
                   
                 111:  
                 Refrigerant flow channel 
               
               
                   
                 112:  
                 Coolant flow channel 
               
               
                   
                 120:  
                 Air-cooled condenser 
               
               
                   
                 120a:  
                 Condensing region 
               
               
                   
                 120b: 
                 Supercooling region 
               
               
                   
                 125:  
                 Blower fan 
               
               
                   
                 130:  
                 Internal heat exchanger 
               
               
                   
                 140:  
                 Expansion valve 
               
               
                   
                 150:  
                 Evaporator 
               
               
                   
                 200:  
                 Water-cooled radiator 
               
               
                   
                 350:  
                 Cowl panel 
               
               
                   
                 351:  
                 Mounting part 
               
               
                   
                 352:  
                 Extension duct 
               
               
                   
                 353:  
                 Connection duct