CROSS-REFERENCE TO RELATED APPLICATION- This application claims priority to and the benefit of Korean Patent Application Nos. 10-2011-0048077 and 10-2011-0084194 filed May 20 and Aug. 23, 2011, respectively, the entire contents of which application is incorporated herein for all purposes by this reference. 
BACKGROUND OF INVENTION- 1. Field of Invention 
- The present invention relates to a condenser for a vehicle and an air conditioning system for a vehicle. More particularly, the present invention relates to a condenser for a vehicle that uses a coolant to condense a refrigerant and an air conditioning system for a vehicle that prevent heat deterioration of a compressor to improve overall cooling performance. 
- 2. Description of Related Art 
- Generally, an air conditioning unit for a vehicle maintains suitable cabin temperature regardless of ambient temperature and realizes a comfortable indoor environment. 
- Such an air conditioning unit includes a compressor compressing a refrigerant, a condenser condensing and liquefying the refrigerant compressed by the compressor, an expansion valve quickly expanding the refrigerant condensed and liquefied by the condenser, and an evaporator evaporating the refrigerant expanded by the expansion valve such that cooling air is supplied to the cabin in which the air conditioning unit is installed by using evaporation latent heat. 
- Herein, the condenser cools the compressed gaseous refrigerant of a high temperature/pressure by using outside air flowing into the vehicle when running and condenses it into a liquid refrigerant of low a temperature. 
- Such a condenser is generally connected through a pipe to a receiver-drier which is provided for improving condensing efficiency through gas-liquid separation and removing moisture in the refrigerant. 
- A condenser for a vehicle is a fin-tube type that is cooled by outside air, and the overall size thereof needs to be increased so as to increase cooling performance such that there is a drawback that it is too large to fit in a narrow engine compartment. 
- In order to solve such a problem, a water-cooled condenser that uses a coolant as refrigerant is applied to the vehicle. 
- However, the water-cooled condenser, compared with the air-cooled condenser, has a lower refrigerant condensing temperature by about 5-15° C., and accordingly the difference between the condensing temperature and the ambient temperature is small. Therefore, condensing efficiency may be deteriorated due to a small sub-cooling effect, and accordingly cooling efficiency may also be deteriorated. 
- In addition, the size of a radiator or capacity of a cooling fan may be increased so as to increase the condensing efficiency or cooling efficiency of the water-cooled condenser for the vehicle. Therefore, the cost and weight may increase and connections between the receiver-drier and the condenser may be complex. 
- When the coolant is cooled by water in a conventional air conditioning system, the coolant that is cooled by outside air exchanges heat with the coolant of the condenser to increase the coolant temperature at the outlet of the condenser, and therefore there is a problem that power consumption is increased. 
- Also, when a sub-cooling area is increased through a heat exchange amount increment of coolant so as to improve cooling performance in a conventional air conditioning system, super-heating is increased above a base temperature and the interior temperature of the compressor is increased, and therefore an electrically driven compressor can be deteriorated by the heat and simultaneously there is a problem that a liquid refrigerant that is not gasified flows therein and the compressor is damaged. 
- Also, when evaporator enthalpy is increased by a sub-cooling area increment in a conventional air conditioning system, cooling performance is improved, but the suction amount of the compressor is reduced by a specific volume increment according to an inlet/outlet coolant temperature increment of the compressor, the evaporation amount of the evaporator is reduced, and therefore there is a limit in improving cooling performance thereof. 
- The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
SUMMARY OF INVENTION- The present invention has been made in an effort to provide a condenser for a vehicle having advantages of reducing the number of components and simplifying the layout of a connecting pipe, reducing cost and weight, and reducing volume of a receiver drier to increase a radiating area such that the cooling efficiency and overall performance are improved. 
- The present invention has been made in an effort to provide a condenser for vehicle in which an accumulator is integrally formed, and only gaseous refrigerant is supplied to a compressor such that damage to the compressor is prevented and durability of the compressor is improved. 
- The present invention has been made in an effort to provide an air conditioning system for a vehicle of which heat exchange efficiency is improved through heat exchange using potential heat of a middle temperature/high pressure liquid refrigerant and a low temperature/low pressure liquefying mixed refrigerant, and therefore a sub-cool area and temperature are increased to improve overall cooling performance of the system of an environmentally-friendly vehicle in which an electrically driven compressor is applied. 
- The present invention has been made in an effort to provide an air conditioner for a vehicle in which, when a gas refrigerant is supplied to the electrically driven compressor and a sub-cool area is increased, the flow rate of the refrigerant is increased through an opening rate increment of the expansion valve, and superheat of the refrigerant is reduced below a predetermined value such that an increment of the interior temperature is prevented and heat deterioration of the electrically drivencompressor509 is prevented after the electrically driven compressor compresses the refrigerant. 
- A condenser for a vehicle that is disposed between the compressor and the expansion valve and circulates coolant that is supplied from a radiator to condense refrigerant through heat exchange with refrigerant that is supplied from a compressor in an air conditioning system including an expansion valve that expands liquid refrigerant, an evaporator that evaporates the expanded refrigerant through heat exchange with air, and a compressor that receives gaseous refrigerant from the evaporator to compress the gaseous refrigerant, may include a main radiating portion that is formed by laminating a plurality of plates, is connected to the radiator to circulate coolant, and circulates refrigerant that is supplied from the compressor to condense the refrigerant through heat exchange, a receiver drier portion that receives the condensed refrigerant through the main radiating portion, separates gas and liquid of the refrigerant, eliminates water, and is integrally formed at one side end of the main radiating portion to exhaust only liquid refrigerant, a supercooling radiator that is integrally formed at a lower portion of the main radiating portion between the main radiating portion and the receiver drier portion, circulates a low temperature and low pressure gas refrigerant that is supplied from the evaporator, and supercools the refrigerant that flows therein through the receiver drier portion through heat exchange with the low temperature and low pressure gas refrigerant, and an accumulator portion that receives the low temperature and low pressure refrigerant passing the supercooling radiator and is integrally formed with the main radiating portion and the other end portion of the supercooling radiator to be connected to the supercooling radiator such that the gas refrigerant is exhausted to the compressor. 
- The main radiating portion may guide the coolant and the refrigerant to flow in opposite directions such that the coolant and the refrigerant exchange heat efficiently. 
- The main radiating portion may have a first connection passage through which the condensed refrigerant flows in the receiver drier portion. 
- The supercooling radiator may have a second connection passage through which the refrigerant of which liquid and gas is separated and water is eliminated is supplied from the receiver drier portion. 
- The supercooling radiator may have a refrigerant passage through which refrigerant that flows through the second connection passage from the receiver drier portion flows and a gas refrigerant passage through which low temperature/pressure that is supplied from the evaporator flows, wherein the condensed refrigerant of the refrigerant passage and the gas refrigerant of the gas refrigerant passage exchange heat from each other to be supercooled. 
- The supercooling radiator may have a third connection passage through which the low temperature and low pressure gas refrigerant that is supplied from the evaporator is supplied to the accumulator portion. 
- The heat transfer prevention portion may be formed between the main radiating portion and the supercooling radiator to prevent heat exchange of the refrigerant passing the main radiating portion with the supercooled refrigerant flowing from the supercooling radiator. 
- The heat transfer prevention portion may have a plurality of brazing communication holes that are formed in a length direction on one side surface between the main radiating portion and the supercooling radiator, wherein N2 gas is charged through the brazing communication holes. 
- The main radiating portion, the receiver drier portion, the supercooling radiator, and the accumulator portion respectively may have upper and lower covers to be disposed between the upper cover and the lower cover. 
- The upper cover may have a coolant inlet and a coolant outlet through which coolant flows in or is exhausted corresponding to one side and the other side of the main radiating portion, wherein a refrigerant inlet through which refrigerant is supplied from the compressor is formed at a side of the coolant outlet, and a gas refrigerant outlet that is connected to the compressor is formed at one side corresponding to the accumulator portion. 
- The lower cover may have a refrigerant outlet that is formed at one end portion in an opposite side of the receiver drier portion corresponding to the refrigerant inlet to be connected to the expansion valve and a gas refrigerant inlet that is formed at one side of the supercooling radiator near the receiver drier portion, wherein the low temperature and low pressure gas refrigerant is supplied from the evaporator through the gas refrigerant inlet. 
- The receiver drier portion may have a first mounting space that is formed therein and an insertion hole is formed in a lower cover corresponding to the first mounting space. 
- A drier may be inserted into the first mounting space through the insertion hole. 
- A fixing cap may be mounted in the insertion hole to prevent separation of the drier that is inserted into the first mounting space and to prevent the escape of the refrigerant in the receiver drier portion. 
- The accumulator portion may have a second mounting space in which an accumulator is disposed. 
- The radiator may be a lower temperature type to be connected to a reservoir tank, and a cooling fan is disposed at a rear side thereof. 
- The condenser may include a heat exchanger of which a plurality of plates are laminated. 
- An air conditioning system for a vehicle that includes an expansion valve that expands fluid refrigerant, an evaporator that evaporates the expanded refrigerant through heat exchange with air, and an electrically driven compressor that receives the gaseous refrigerant from the evaporator to compress the gaseous refrigerant, wherein they are connected through a refrigerant line, may include a water cooler condenser that circulates a coolant that is supplied from a radiator through a cooling line and condenses the refrigerant through heat exchange with the refrigerant that is supplied from the electrically driven compressor, and a heat exchanger that is disposed on the refrigerant line between the water cooler condenser and the evaporator, wherein a liquid state refrigerant of a middle temperature and a high pressure passing the water cooler condenser exchanges heat with a low temperature/pressure refrigerant passing the evaporator in the heat exchanger. 
- The water cooler condenser may include a radiation portion that circulates the refrigerant that is supplied from the electrically driven compressor and condenses the refrigerant through heat exchange with the coolant, and a receiver drier portion that receives the condensed refrigerant through the radiating portion and is integrally formed with the radiating portion to be connected to the radiation portion such that gas and liquid of the refrigerant are separated and water thereof is eliminated. 
- The heat exchanger may have a double pipe structure, wherein a middle temperature and high pressure liquid state refrigerant and a low temperature/pressure refrigerant that is being gasified flow in opposite directions to exchange heat with each other. 
- An accumulator may be disposed on the refrigerant line between the electrically driven compressor and the heat exchanger so as to supply the electrically driven compressor with only gasified refrigerant among the mixed refrigerant of fluid and gas passing the heat exchanger. 
- A cooling that may be disposed at a rear side of the radiator to blow air, wherein the radiator is connected to the reservoir tank through a coolant line and coolant is circulated through the radiator by a water pump that is disposed on the coolant line. 
- The condenser for a vehicle according to various aspects of the present invention may be a laminated plate type in which a receiver drier and an accumulator are integrally formed and uses a coolant to condense a refrigerant, supercools the condensed refrigerant through heat exchange with a gas refrigerant of low temperature/pressure that is supplied from the evaporator, can eliminate a separate device for supercooling the condensed refrigerant, simplifies components and connection pipes to save cost and weight, and increases a radiating area by reducing the volume of a receiver drier such that cooling efficiency and performance of a vehicle are improved. 
- The refrigerant that is condensed in the main radiating portion may be supplied to the supercooling radiator to be supercooled by heat exchange with a low temperature/pressure gas refrigerant such that a separate device or pipe for supercooling the condensed refrigerant is not necessary and more cost is saved. 
- The receiver drier portion may be integrally formed therein to reduce the volume of the condenser and therefore condensing efficiency and cooling efficiency are improved, and overall cooling performance of the vehicle air conditioning system is improved without the increment of the radiating area and the size increment. 
- The accumulator portion may be integrally formed therein and only gas refrigerant is supplied to the compressor such that damage to the compressor caused by liquid refrigerant is prevented and the durability of the compressor is improved. 
- Accordingly, when an air conditioning system for a vehicle according to various aspects of the present invention is applied, heat exchange efficiency is improved through heat exchange using potential heat of a middle temperature/high pressure liquid refrigerant and a low temperature/low pressure liquefying mixed refrigerant, and therefore a sub-cool area and temperature are increased to improve overall cooling performance of the system of an environmentally-friendly vehicle to which the electrically driven compressor is applied. 
- When the sub-cool area is increased, the flow rate of the refrigerant may be increased through an opening rate increment of the expansion valve, and superheat of the refrigerant is reduced below a predetermined value such that an increment of the interior temperature is prevented and heat deterioration of the electrically drivencompressor509 is prevented after the electrically driven compressor compresses the refrigerant. 
- Efficiency of the evaporator may be improved through the flow rate increment of the refrigerant, and when the superheat is reduced by applying the accumulator, the liquid refrigerant that is not gasified to an overheated gas is supplied to the compressor, damage to the electrically driven compressor is prevented, and durability of the electrically driven compressor and overall durability of the air conditioning system are improved. 
- The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention. 
BRIEF DESCRIPTION OF THE DRAWINGS- FIG. 1 is a block diagram of an exemplary vehicle air conditioning system to which a condenser for a vehicle is applied according to the present invention. 
- FIG. 2 is a perspective view of an exemplary condenser for a vehicle according to the present invention. 
- FIG. 3 is a cross-sectional view along line A-A ofFIG. 2. 
- FIG. 4 is a cross-sectional view along line B-B ofFIG. 2. 
- FIG. 5 is a block diagram of an exemplary air conditioning system for a vehicle according to the present invention. 
- FIG. 6 is a graph comparing conventional art with a refrigeration cycle of an exemplary air conditioning system for a vehicle according to the present invention. 
DETAILED DESCRIPTION- Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
- FIG. 1 is a block diagram of a vehicle air conditioning system to which a condenser for a vehicle is applied according to an exemplary embodiment of the present invention,FIG. 2 is a perspective view of a condenser for a vehicle according to an exemplary embodiment of the present invention,FIG. 3 is a cross-sectional view along line A-A ofFIG. 2, andFIG. 4 is a cross-sectional view along line B-B ofFIG. 2. 
- Referring to the drawings, acondenser100 for a vehicle according to an exemplary embodiment of the present invention is applied to an air conditioning system that includes anexpansion valve101 that expands a fluid refrigerant, anevaporator103 that evaporates the expanded refrigerant through heat exchange with air, and acompressor105 the compresses the gaseous coolant from theevaporator103. 
- That is, thecondenser100 is disposed between thecompressor105 and theexpansion valve101, circulates coolant that is supplied from aradiator107, and condenses the refrigerant through heat exchange with the refrigerant that is supplied from thecompressor105. 
- Theradiator107 is a low temperature type to be connected to areservoir tank108 and a coolingfan109 is disposed at a rear side thereof. 
- Here, thecondenser100 for a vehicle according to an exemplary embodiment of the present invention is a laminated plate type in which a receiver drier and an accumulator are integrally formed, and uses a coolant to condense a refrigerant, supercools the condensed refrigerant through heat exchange with a low temperature/pressure gas refrigerant that is supplied from theevaporator103, can eliminate a separate device for supercooling the condensed refrigerant, simplifies components and connection pipes to save cost and weight, and increases a radiating area by reducing volume of a receiver drier such that cooling efficiency and performance of a vehicle are improved. 
- Also, an accumulator is integrally formed therein, and only gaseous refrigerant is supplied to a compressor such that damage to the compressor is prevented and durability of the compressor is improved. 
- For this, as shownFIG. 1 andFIG. 2, thecondenser100 for a vehicle according to an exemplary embodiment of the present invention includes amain radiating portion110, a receiverdrier portion130, asupercooling radiator140, and anaccumulator portion150, and these will be described as follows. 
- First, themain radiating portion110 includes upper andlower covers111 and113, and plurality ofplates115 are laminated between theupper cover111 and thelower cover113. 
- Themain radiating portion110 is connected to theradiator107 to a circulate coolant, circulate a refrigerant that is supplied from thecompressor105, and condense the refrigerant through heat exchange. 
- Here, the coolant and the refrigerant flow in opposite directions in themain radiating portion110 to effectively exchange heat. 
- That is, the coolant and the refrigerant are not mixed to respectively flow through arefrigerant passage117 and acoolant passage119 that are alternately disposed between theplates115 and do not communicate with each other in themain radiating portion110, and as shown inFIG. 3 andFIG. 4, the coolant and the refrigerant flow in opposite directions from each other to exchange heat with each other. 
- In the present exemplary embodiment, theupper cover111 has acoolant inlet121 and acoolant outlet123 that are formed at one side and the other side corresponding to themain radiating portion110, wherein the coolant flows in through the inlet from theradiator107 or is exhausted out through the outlet. 
- Also, arefrigerant inlet125 is formed at a side of thecoolant outlet123, high temperature and high pressure coolant flows in through theinlet125, and agas refrigerant outlet151 that is connected to thecompressor105 is formed at one side corresponding to theaccumulator portion150. 
- Here, therefrigerant inlet125 is formed at one side of theupper cover111 and thecoolant outlet123 is formed in an opposite direction of thecoolant inlet121 such that the coolant flows in an opposite direction to that of the refrigerant. 
- In the present exemplary embodiment, the receiverdrier portion130 receives condensed refrigerant through themain radiating portion110, and is integrally formed with one end of themain radiating portion110 to be connected to themain radiating portion110 so as to separate gas and liquid of the refrigerant and eliminate water. One will appreciate that the receiver driver portion and the main radiating portion may be monolithically formed. 
- In this case, afirst connection passage127 is formed in a lower side of themain radiating portion110 such that the refrigerant that is condensed through heat exchange with the coolant flows in the receiverdrier portion130 through thepassage127. 
- The receiverdrier portion130 reduces the volume through a receiver drier that has the same shape as thecondenser100 to be able to eliminate a separate pipe, compared to a conventional cylindrical receiver drier. 
- Meanwhile, afirst mounting space131 is formed in the receiverdrier portion130 and aninsertion hole133 is formed on thelower cover113 corresponding to thefirst mounting space131 in the present exemplary embodiment. 
- A drier135 is inserted into thefirst mounting space131 through theinsertion hole133, and the drier135 eliminates water in the refrigerant that is supplied from themain radiating portion110. 
- That is, the drier135 is disposed in the receiverdrier portion130 to be able to be replaced according to a replacement cycle through theinsertion hole133. 
- Meanwhile, a filter is integrally formed in the drier135 to filter foreign materials included in the refrigerant of the receiverdrier portion130. 
- That is, the receiverdrier portion130 eliminates water in the refrigerant through the drier135 and filters foreign materials through the filter to prevent the foreign material from being supplied to theexpansion valve101. 
- Accordingly, theexpansion valve101 is not plugged by foreign materials of the refrigerant. 
- Here, a fixingcap137 is disposed in theinsertion hole133 to prevent separation of the drier135 that is inserted into thefirst mounting space131 and to prevent leakage of the refrigerant of the receiverdrier portion130. 
- Further, the supercoolingradiator140 is integrally formed with a lower portion of themain radiating portion110 between themain radiating portion110 and the receiverdrier portion130. One will appreciate that the supercooling radiator and the main radiating portion may be monolithically formed. 
- The supercoolingradiator140 circulates low temperature/pressure gas refrigerant that is supplied from theevaporator103 and supercools the refrigerant that is supplied from the receiverdrier portion130 through heat exchange with the low temperature/pressure gas refrigerant. 
- The supercoolingradiator140 has asecond connection passage141 that is formed at one end upper portion corresponding to the receiverdrier portion130 such that the refrigerant of which liquid and gas is separated and the water is eliminated is supplied from the receiverdrier portion130 in the present exemplary embodiment. 
- The supercoolingradiator140 has a refrigerant passage through which refrigerant that flows in thesecond connection passage141 from the receiverdrier portion130 flows and agas refrigerant passage117 through which low temperature/pressure that is supplied from theevaporator103 flows, wherein the condensed refrigerant of therefrigerant passage117 and the gas refrigerant ofgas refrigerant passage143 exchange heat with each other. 
- That is, the supercoolingradiator140 has theplate115 that is laminated to be alternately disposed, and the condensed refrigerant passing the receiverdrier portion130 and the low temperature and low pressure gas refrigerant flows without mixing to heat exchange with each other through therefrigerant passage117 and thegas refrigerant passage143 that do not communicate with each other. 
- Here, thelower cover113 has arefrigerant outlet129 to be connected to theexpansion valve101, wherein theoutlet129 is formed at one end portion of an opposite side of the receiverdrier portion130 corresponding to therefrigerant inlet125. 
- Also, thelower cover113 has agas refrigerant inlet147 that is formed at one side of thesupper cooling radiator140 near the receiverdrier portion130, wherein the low temperature/pressure gas refrigerant is supplied from theevaporator103. 
- Here, the supercoolingradiator140 has athird connection passage145 that is formed at the other end lower portion corresponding to theaccumulator portion150, wherein the low temperature/pressure gas refrigerant that is supplied from theevaporator103 flows through thethird connection passage145 to theaccumulator portion150. 
- Thethird connection passage145 is formed at an opposite side of thesecond connection passage141 to supply the low temperature gas refrigerant that is supplied to thesuper cooling radiator140 through thegas refrigerant inlet147 to theaccumulator portion150. 
- Further, theaccumulator portion150 is integrally formed with themain radiating portion110 and the other end of thesupercooling radiator140 to be connected to thesupercooling radiator140, and receives the low temperature/pressure refrigerant passing thesupercooling radiator140 such that only the gas refrigerant is supplied to the compressor through thegas refrigerant outlet151. One will appreciate that the portions of the accumulator portion, main radiating portion, and supercooling radiator may be monolithically formed. 
- Theaccumulator portion150 has asecond mounting space155 for anaccumulator153, and theaccumulator153 supplies only gas refrigerant to thecompressor105 through thegas refrigerant outlet151. 
- That is, theaccumulator portion150 is integrally formed with themain radiating portion110 of an opposite side of the receiverdrier portion130 and the other portion of thesupercooling radiator140, wherein the gas refrigerant is supplied to thecompressor105 through theaccumulator153 to prevent the fluid refrigerant from being supplied to thecompressor105. 
- Accordingly, thecompressor105 receives only gas refrigerant from theaccumulator portion150 and therefore trouble or damage that is caused by fluid refrigerant and durability thereof is improved. 
- Meanwhile, the receiverdrier portion140 is integrally formed with one side of thesupercooling radiator140 and themain radiating portion110 in the present exemplary embodiment, and refrigerant or coolant is not supplied to a remaining portion except themain radiating portion110 and thesupercooling radiator140 and the first andsecond connection passages127 and141 in a height direction of thecondenser100. Again, one will appreciate that portions of the receiver drier portion, the supercooling radiator, and the main radiating portion may be monolithically formed. 
- Also, theaccumulator portion150 is integrally formed with the other side of themain radiating portion110 and thesupercooling radiator140, and refrigerant or coolant is not supplied to a remaining portion except thesupercooling radiator140 and thethird connection passage145 in a height direction of thecondenser100. One will appreciate that portions of the accumulator portion, the main radiating portion and the supercooling radiator may be monolithically formed. 
- In the present exemplary embodiment, a heattransfer prevention portion160 is formed between themain radiating portion110 and thesupercooling radiator140 to prevent heat transfer between the refrigerant passing themain radiating portion110 and the supercooled refrigerant passing thesupercooling radiator140. 
- The heattransfer prevention portion160 is formed by supplying N2 gas through a plurality of brazing communication holes161 that are formed during lamination of theplates115 between themain radiating portion110 and thesupercooling radiator140. 
- Here, the brazing holes161 exhaust gas that is generated by welding of theplate115 that is laminated to reduce the welding fault rate, and provide a N2 gas supply passage so as to form the heattransfer prevention portion160. 
- The brazing holes161 are closed after supplying the N2 gas for forming the heattransfer prevention portion150. 
- Thecondenser100 according to an exemplary embodiment of the present invention is a heat-exchanger type in which plurality ofplates115 are laminated. 
- That is, in thecondenser100 for a vehicle according to an exemplary embodiment of the present invention, the coolant cooled through theradiator107 is supplied to themain radiating portion110 through thecoolant inlet121. 
- The inflow coolant circulates along thecoolant passage119 that is formed between theplates115 in themain radiating portion110 and is exhausted to theradiator107 again through thecoolant outlet123. 
- At this time, the refrigerant flows from thecompressor105 into themain radiating portion110 through therefrigerant inlet125, and flows through therefrigerant line117 alternately formed with thecoolant line119. 
- Accordingly, the coolant and the refrigerant flowing in themain radiating portion110 flow in opposite directions and are heat-exchanged with each other. If the heat exchange of the coolant and the refrigerant is completed, the cooled and condensed refrigerant is supplied to the receiverdrier portion130 through the first connectingline127. 
- The condensed refrigerant circulates in the receiverdrier portion130. At this time, gas-liquid separation is performed and the moisture in the refrigerant is removed by the drier135. After that, the condensed refrigerant is supplied to the second heat-radiatingportion140 through the second connectingline141. 
- The refrigerant supplied to thesupercooling radiating portion140 circulates through therefrigerant line117 in thesupercooling radiating portion140. 
- At this time, low temperature/pressure gas refrigerant that is supplied from theevaporator103 is supplied to thesupercooling radiator140 near the receiverdrier portion130 Through thegas refrigerant inlet147 that is formed on thelower cover113. 
- Here, the gas refrigerant that is supplied to thesupercooling radiator140 flows to theaccumulator portion150 through thegas refrigerant passage143 and exchanges heat with the refrigerant flowing in therefrigerant passage117. 
- Accordingly, the gas refrigerant supercools the refrigerant that is supplied from the receiverdrier portion130 to thesupercooling radiator140 through heat exchange with the refrigerant passing themain radiating portion140 and the receiverdrier portion130. 
- That is, the refrigerant that is supplied to thesupercooling radiator140 exchanges heat with the gas refrigerant to be supercooled and is exhausted through therefrigerant outlet129 to be supplied to theexpansion valve101. 
- Meanwhile, the gas refrigerant that is supplied to thegas refrigerant inlet147 exchanges heat within the supercoolingradiator140 to be supplied to theaccumulator portion150 through thethird connection passage145. 
- The gas refrigerant that is supplied to theaccumulator portion150 is exhausted through thegas refrigerant outlet151 in a condition that the gas is separated from the remaining fluid refrigerant thereof to be supplied to thecompressor105 that is connected to thegas refrigerant outlet151. 
- Here, since the receiverdrier portion130 andaccumulator portion150 are integrally formed with one end portion of the main andsupercooling radiator110 and140, additional connection pipes for connecting the receiver-drier portion130 to the first and second heat-radiatingportions110 and120 can be eliminated. In addition, since the receiver-drier of the receiver-drier portion130 has the same shape as thecondenser100, dead volume can be minimized. 
- Also, only gas refrigerant is supplied to thecompressor105 through theaccumulator portion150 to prevent damage and faults of thecompressor105 and to improve the durability thereof. 
- Further, the heattransfer prevention portion160 prevents the heat exchange of the refrigerant in themain radiating portion110 and thesupercooling radiator140 to improve overall condensing efficiency and cooling efficiency of thecondenser100. 
- Meanwhile, for thecondenser100 for a vehicle according to an exemplary embodiment of the present invention that has been described so far with reference to the drawings, it is described as an exemplary embodiment that themain radiating portion110, the receiverdrier portion130, the supercoolingradiator140, and theaccumulator portion150 are formed between the upper andlower covers111 and113 by laminating the plurality ofplates115, but it is not limited thereto, and only the laminated structure of the plurality ofplates115 can form themain radiating portion110, the supercoolingradiator140, the receiverdrier portion130, and theaccumulator portion150 without the upper/lower covers111 and113. 
- As stated above, acondenser100 for a vehicle according to an exemplary embodiment of the present invention is a laminated plate type in which the receiver drier and the accumulator are integrally formed, and uses a coolant to condense the refrigerant and supercools the condensed refrigerant through heat exchange with the low temperature/pressure gas refrigerant that is supplied from theevaporator103 to simplify to layout of connecting pipes, to reduce components thereof, and to decrease cost and weight. 
- Also, the refrigerant that is condensed in themain radiating portion110 is supplied to thesupercooling radiator140 to be supercooled by heat exchange with the low temperature/pressure gas refrigerant such that a separate device or pipe for supercooling the condensed refrigerant is not necessary and further cost is saved. 
- Also, the receiverdrier portion140 is integrally formed therein to reduce volume of thecondenser100 and therefore condensing efficiency and cooling efficiency are improved, and overall cooling performance of the vehicle air conditioning system is improved without the increment of the radiating area and the size increment. 
- Also, theaccumulator portion150 is integrally formed therein and only gas refrigerant is supplied to the compressor such that damage to the compressor caused by liquid refrigerant is prevented and the durability of the compressor is improved. 
- Thereby, overall product quality of thecondenser100 is improved. 
- FIG. 5 is a block diagram of an air conditioning system for a vehicle according to an exemplary embodiment of the present invention. 
- Referring to the drawing, heat exchange efficiency is increased through heat exchange using potential heat of a middle temperature/high pressure liquid refrigerant and a low temperature/low pressure liquid/gas mixed refrigerant to increase a sub-cool temperature and area in an environmentally-friendly vehicle in which an electrically drivencompressor505 is applied such that the overall cooling performance is improved in anair conditioning system500 for a vehicle according to an exemplary embodiment of the present invention. 
- Also, when only gaseous refrigerant is supplied to the electrically drivencompressor505 and a sub-cool area is increased, superheat of the refrigerant is reduced to a value lower than a predetermined temperature through a flow rate increment of the refrigerant and an increase of the interior temperature is prevented to prevent the heat deterioration and damage to the electrically driven compressor after compressing the refrigerant of the electrically drivencompressor505 such that the durability of the overall system is improved. 
- For this, anair conditioning system500 for a vehicle according to an exemplary embodiment of the present invention as shown inFIG. 5, is disposed in a vehicle and includes anexpansion valve501 that expands fluid refrigerant, anevaporator503 that evaporates the expanded refrigerant through theexpansion valve501 and minimizes the degree of overheat, and an electrically drivencompressor505 that receives the gaseous refrigerant from theevaporator503 and compresses the gaseous refrigerant, wherein these are connected with each other through a refrigerant line (hereinafter, “R.L”). 
- Here, theair conditioning system500 for a vehicle according to an exemplary embodiment of the present invention further includes awater cooler condenser510 and aheat exchanger520, and these will be described in more detail as follows. 
- Firstly, thewater cooler condenser510 circulates coolant that is supplied from theradiator507 through a cooling line (hereinafter, “C.L”) to condense the refrigerant through heat exchange with refrigerant that is supplied from the electrically drivencompressor505. 
- Here, theradiator507 is a low-temperature type to be connected to areservoir tank507 through the cooling line C.L, and circulates coolant through operation of awater pump506 that is disposed in the cooling line C.L to cool the coolant through heat exchange with the outside air. 
- A coolingfan509 is disposed at a rear side of theradiator507 to blow air. 
- That is, in the present exemplary embodiment, thewater cooler condenser510 is disposed between the electrically drivencompressor505 and theexpansion valve501 to circulate coolant that is supplied from theradiator507 and condenses the refrigerant through heat exchange with the refrigerant that is supplied from the electrically drivencompressor505. 
- Here, thewater cooler condenser510 includes a radiatingportion511 and a receiverdrier portion513. 
- Firstly, the radiatingportion511 circulates the refrigerant that is supplied from the electrically drivencompressor505 and condenses the refrigerant through heat exchange with the coolant. 
- The radiating portion is a fin-tube type, but may be made of a plate type in which a plurality of plates are laminated. 
- Further, the receiverdrier portion513 is integrally formed with the radiatingportion511 to be connected to the radiatingportion511, receives the condensed refrigerant of the radiatingportion511, separates gas and liquid thereof, and eliminates moisture. 
- That is, thewater cooler condenser510 that is described above condenses the refrigerant that is supplied from the electrically drivencompressor505 through the heat exchange with the cooled coolant that is supplied from theradiator507 through the radiatingportion511. 
- Thereafter, thewater cooler condenser510 makes the condensed refrigerant that exchanges heat through the radiatingportion511 pass the receiverdrier portion513, separates liquid and gas of the refrigerant, and eliminates moisture. 
- In the present exemplary embodiment, theheat exchanger520 is disposed in the refrigerant line (R.L) between thewater cooler condenser510 and theevaporator503 and makes a middle temperature/high pressure liquid state refrigerant passing thewater cooler condenser510 exchange heat with the low temperature/low pressure liquefying refrigerant passing theevaporator503. 
- Here, theheat exchanger520 is a double-pipe type, wherein the middle temperature/high pressure liquid state refrigerant and the low temperature/low pressure refrigerant flow in opposite directions to exchange heat. 
- That is, theheat exchanger520 makes the refrigerant passing thewater cooler condenser510 exchange heat with the refrigerant passing theevaporator503, and therefore heat exchange efficiency is increased. 
- Meanwhile, in the present exemplary embodiment, theevaporator503 evaporates the expanded refrigerant through heat exchange with air and maintains a uniform degree of superheat of the refrigerant to maximize the performance thereof in a condition of minimizing the degree of superheat of the refrigerant through theheat exchanger520 of a double-pipe type. 
- Accordingly, the middle temperature/high pressure refrigerant passing thewater cooler condenser510 increases the sub-cool temperature and area compared with a conventional art, and when the sub-cool area is increased, the flow rate of the refrigerant is increased by adjusting the opening rate of theexpansion valve501 to be able to reduce superheat to less than a predetermined value. 
- Meanwhile, anaccumulator530 is disposed between the electrically drivencompressor505 and theheat exchanger520 in the refrigerant line (R.L) to supply the electrically drivencompressor505 with only gaseous refrigerant of the liquid/gas refrigerant passing theheat exchanger520. 
- Theaccumulator530 stores fluid refrigerant of the gas/liquid mixed refrigerant and evaporates the fluid refrigerant to supply the gas refrigerant to the electrically drivencompressor505 such that the efficiency and durability of the electrically drivencompressor505 are improved. 
- A refrigeration cycle of anair conditioning system500 of a vehicle according to an exemplary embodiment of the present invention is described as follows, referring toFIG. 6. 
- FIG. 6 is a graph comparing a conventional art with a refrigeration cycle of an air conditioning system for a vehicle according to an exemplary embodiment of the present invention. 
- Here, the refrigeration cycle shows a relation of enthalpy according to pressure. 
- Here, ΔT and ΔT1 denote sub-cool, T is an outlet temperature of the compressor, ΔT2, ΔT3, and ΔT4 shows superheat, and Δh and Δh′ show an enthalpy of the increased evaporator. 
- First, a sub-cool in anair conditioning system500 for a vehicle according to an exemplary embodiment of the present invention is increased (ΔT1>ΔT) compared to a conventional art (ΔT). 
- That is, in the present exemplary embodiment, thewater cooler condenser510 condenses the inflow refrigerant to a middle temperature/high pressure liquid refrigerant by cooling the inflow refrigerant through heat exchange with the coolant, and the middle temperature and high pressure liquid refrigerant further exchanges heat with the low temperature/low pressure liquefying refrigerant that is exhausted from theevaporator503 through theheat exchanger520, and therefore heat exchange efficiency is increased and sub-cool temperature and area are increased compared to a conventional art. 
- Accordingly, enthalpy (Δh') of theevaporator503 is increased (Δh′>Δh) compared to evaporator enthalpy (Δh) of Conventional Art1 and Conventional Art2, wherein this signifies that the liquid refrigerant to gaseous refrigerant ratio is increased by increasing the flow rate of the refrigerant according to an opening rate increment of theexpansion valve501 and the cooling performance is thereby improved. 
- Also, in a case that the sub-cool temperature and area are increased, the flow rate of the refrigerant is increased by increasing the opening rate of theexpansion valve501 such that the superheat ΔT4 of the present exemplary embodiment is decreased compared to the superheat ΔT2 of a Conventional Art1 and the superheat ΔT3 of a Conventional Art2. 
- Accordingly, the discharge temperature T1 of thecompressor505 of the present exemplary embodiment is remarkably decreased compared to the compressor discharge temperature T2 of the Conventional Art1 and a compressor discharge temperature T3 of the Conventional Art2, wherein the temperature is decreased (T1>T2>T3). 
- Accordingly, in an environmentally friendly vehicle to which an electrically drivencompressor505, which is weak to heat compared to a conventional mechanical compressor, is applied, heat deterioration of the electrically driven compressor is prevented, and gas refrigerant is supplied to the electrically drivencompressor505 through theaccumulator530 such that the overall durability of the electrically drivencompressor505 is improved. 
- Also, since the heat deterioration problem of the electrically drivencompressor505 is resolved, there is no problem for increasing the sub-cool temperature and area in the present exemplary embodiment. 
- Accordingly, when anair conditioning system500 for a vehicle according to an exemplary embodiment of the present invention is applied, heat exchange efficiency is improved through heat exchange using potential heat of a middle temperature/high pressure liquid refrigerant and a low temperature/low pressure liquefying mixed refrigerant, and therefore the sub-cool area and temperature are increased to improve overall cooling performance of the system of an environmentally-friendly vehicle to which the electrically drivencompressor505 is applied. 
- Also, when the sub-cool area is increased, the flow rate of the refrigerant is increased through an opening rate increment of theexpansion valve501, and superheat of the refrigerant is reduced below a predetermined value such that an increment of interior temperature is prevented and heat deterioration of the electrically drivencompressor509 is prevented after the electrically drivencompressor505 compresses the refrigerant. 
- Also, efficiency of theevaporator503 is improved through the flow rate increment of the refrigerant, and when superheat is reduced by applying theaccumulator530, liquid refrigerant that is not gasified to an overheat as being supplied to thecompressor505 is prevented, damage to the electrically drivencompressor505 is prevented, and durability of the electrically drivencompressor505 and overall durability of theair conditioning system500 are improved. 
- For convenience in explanation and accurate definition in the appended claims, the terms upper or lower, rear, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 
- The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.