Patent Publication Number: US-7222501-B2

Title: Evaporator

Description:
TECHNICAL FIELD 
   The present invention relates to an evaporator for an air conditioner of a vehicle having a plurality of tube rows, and in particular to an evaporator which is capable of decreasing the whole dimension and maximizing a heat exchange efficiency in such a manner that there is provided a two-row tube structure connected between upper and lower header units of an evaporator, and a header unit, tube and wrinkle portion are improved. 
   BACKGROUND ART 
   Generally, as shown in  FIG. 1 , an evaporator having a plurality of tube rows includes header units  101  and  102  provided in upper and lower sides, respectively, tubes  200  provided in two rows, one row in a front side and another row in a rear side, with respect to a flow of air, and a wrinkle fin  400  provided between the tubes. In the above structure, a heat exchange is implemented between a fluid flowing therein and air flowing between the tubes. 
   In the improvement of the thusly constituted evaporator, it is a primary object to decrease the whole dimension and enhance a heat exchange efficiency. 
   The conventional two-row tube evaporator which is improved based on the above object has the following disadvantages or problems. 
   First, the header unit adapted to connect two-row tubes is formed of a tank member and a header plate which are fabricated by a die casting or pressing fabrication method. Therefore, the assembling productivity is decreased compared to the materials extruded, and the fabrication cost is increased. 
   A path space of a fluid is partitioned by inserting a baffle into the interior of the header unit. In this case, since other baffle is assembled in the front and rear spaces portioned along the two-row tubes, the assembling productivity is decreased. 
   In addition, when assembling the tank member and header plate of the header unit, both sides of the header plate are laterally bent in the direction of the tank member and are temporarily welded (preferably, TIG welding) and then blazing-welded. In this case, the work process is increased. A defect rate is increased due to the transformation by the temporary welding operation. 
   Furthermore, since the front and rear two-row tubes are separately provided, when the air which have flown between the first-row tube flows between the second-row tube, since the air is crossed, thus decreasing a ventilation. 
   In addition, the conventional tubes are designed to have rounded lateral sides based on its inherent fabrication property during an extrusion formation. In the above construction, a condensation water produced during a heat exchange is not easily separated, namely flows in a lateral side, thus decreasing a heat exchange efficiency. 
   In the conventional header unit, since the portion into which a tube is inserted is formed flat, the condensation water from the tubes do not easily flow, namely gathers by a surface tension and capillary phenomenon. 
   DISCLOSURE OF INVENTION 
   Accordingly, it is an object of the present invention to overcome the problems encountered in the conventional art. 
   It is another object of the present invention to provide an evaporator which is capable of decreasing the whole dimension of an evaporator and enhancing a heat exchange performance, and in detail it is possible to enhance a productivity and decrease a fabrication cost by using the elements fabricated by an extruded material and press processed material. 
   It is further another object of the present invention to provide an evaporator which is implemented by a direct assembling and welding operation, omitting a temporarily welding, in such a manner that a groove is formed in a tank member in a header structure, and a header plate is inserted into the groove. 
   It is still further another object of the present invention to provide an evaporator which is capable of enhancing a heat radiating state and decreasing a pressure loss of air by forming a connection portion between a front tube portion and a rear tube portion. 
   It is still further another object of the present invention to provide an evaporator which is capable of implementing an easier discharge of a condensation water through a tube gathered from a surrounding of the tube and preventing a condensation water from being gathered in the header unit and a wrinkle portion provided between the tubes from being transformed, by improving the shapes of both side ends of the tube and the shape of the header plate. 
   It is still further another object of the present invention to provide an evaporator which is capable of increasing a cooling effect by forming an evaporator using the upper and lower header units and tubes and forming a path structure of a refrigerant based on a certain division ratio. 
   To achieve the above objects, in an evaporator including upper and lower header units which each have a two-row refrigerant flow path, a plurality of tubes which connect the upper and lower header units and are formed of an aluminum material and are arranged in two rows in front and rear sides with respect to the flowing direction of air and are stack-arranged in parallel in the direction orthogonal to the flowing direction of air for flowing a refrigerant therethrough, and a wrinkle fin which is provided between the neighboring tubes for enhancing a heat transfer area of air passing through the tubes and is formed of an aluminum material, there is provided the header unit which includes a tank member having a U-shaped cross section and a vertical groove in an inner center portion in a longitudinal direction, and a groove formed in an inner surface of both side ends in a longitudinal direction; a partition member which divides an inner space of the tank member in a width-wise direction by inserting a lower side end into the vertical groove of the tank member; a header plate which is engaged between the grooves of both sides of the tank member and covers an opened portion of the tank member for sealing and has a plurality of tube holes for inserting the tubes; an intermediate baffle which is formed based on the shape of the inner portion of the tank member and partitions the inner space of the tank member; and a finishing baffle which is formed based on the shape of the inner portion of the tank member and covers the inner space for sealing when the same is assembled to both side ends of the tank member. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     The present invention will become better understood with reference to the accompanying drawings which are given only by way of illustration and thus are not limitative of the present invention, wherein; 
       FIG. 1  is a view illustrating a conventional evaporator; 
       FIG. 2  is a perspective view illustrating the construction of an evaporator according to the present invention; 
       FIG. 3  is a partial perspective view illustrating an assembled state according to the present invention; 
       FIG. 4  is a cross sectional view illustrating a header plate according to the present invention; 
       FIG. 5  is a partial perspective view illustrating a disassembled state according to the present invention; 
       FIG. 6  is a cross sectional view illustrating the construction of a tank member according to the present invention; 
       FIG. 7  is a partial cross sectional view illustrating an assembled state of  FIG. 6 ; 
       FIG. 8  is a perspective view illustrating a baffle according to the present invention; 
       FIG. 9  is a view illustrating the construction of an adaptor according to the present invention; 
       FIG. 10  is an enlarged cross sectional view of  FIG. 9 ; 
       FIG. 11  is a perspective illustrating a partition member according to the present invention; 
       FIG. 12  is a view illustrating the construction of a tube according to the present invention; 
       FIG. 13  is a view illustrating the construction of a tube according to another embodiment of the present invention; 
       FIG. 14  is a view illustrating the construction of a tube according to further another embodiment of the present invention; 
       FIG. 15  is a view illustrating the construction according to a first embodiment of the present invention; 
       FIG. 16  is a view of a description of a path according to a first embodiment of the present invention; 
       FIG. 17  is a view illustrating the construction according to a second embodiment of the present invention; 
       FIG. 18  is a view of a description of a path according to a second embodiment of the present invention; 
       FIG. 19  is a graph of a measurement value of a radius that a header plate according to the present invention has; 
       FIG. 20  is a graph of a measurement value of a heat radiating state in a connection portion of a tube according to the present invention; and 
       FIG. 21  is a graph of a measurement value of an air pressure loss state in a connection portion of a tube according to the present invention. 
   

   BEST MODE FOR CARRYING OUT THE INVENTION 
   The construction and operation of the present invention will be described with reference to the accompanying drawings. 
   As shown in  FIG. 2 , an evaporator according to the present invention includes a pair of upper and lower header units  101  and  102  each having an inlet pipe  151  and an outlet pipe  152 , two-row tubes  200  connecting the header units, and a wrinkle fin  400  provided between the tubes. 
   The header unit  100  includes a tank member  110 , a header plate  120 , a baffle  130 , and a partition member  140 . 
   Here, the tank member  110  is extruded to have a U shaped cross section in such a manner that width-wise both ends  111  are oriented in the same direction. If necessary, the W-shaped cross section as shown in the drawings is obtained by bending the U shaped center portion inwardly. 
   The header plate  120  is assembled between both side ends of the tank member for thereby sealing the inner space, and the left and right sides are close to the inner side of the both side ends. The header plate  120  has a plurality of tube holes  121 . 
   The baffle  130 :  131 ,  132  is formed based on the width-wise shape formed by the tank member  110  and the header plate  120 , so that the inner pace is partitioned in the longitudinal direction. The partition member  140  is formed based on the length-wise shape of the inner space formed by the header unit  100  and the header plate  120 , so that it is possible to partition the inner space in the width direction. 
   At this time, as an important feature of the tank member  110  and the header plate  120  of the present invention, the tank member  110  having a U shaped cross section (or W shaped cross section as shown in the drawings) in the extrusion method, and the header plate  120  is fabricated based on the pressing method. Thereafter, as shown in  FIG. 7 , the width-wise both ends of the header plate  120  are fixedly inserted into the inner side of the both side ends  111  of the tank member  110  and then are blaze-welded. 
   The features of the tank member  110  for enhancing the assembling property will be described. 
   As shown in  FIGS. 3 through 6 , a groove  111   b  is formed in the both side ends  111  of the tank member  110  in the lengthy direction, and then the both side ends of the header plate  120  can be fixedly inserted into the groove. 
   Therefore, it is possible to temporarily fix the header plate  120  to the tan member  110  in the above manner. In the present invention, the conventional temporary welding is omitted by the above fixing means. 
   The tank member  110  has a vertical groove  112  in the center of the bottom for implementing an easier assembling of the partition member  140 . The thickness portion of the partition member  140  is inserted into the vertical groove  112 . 
   The features of the header plate  120  for enhancing the assembling property will be described. 
   As shown in  FIG. 4 , the thusly assembled header plate  120  is formed to be curved in a baffle shape for enhancing a coupling property with the tank member  110  and a ventilation performance. 
   As shown in  FIG. 6 , the curving degree is that the radius R is 75˜85 mm. 
   Therefore, the intermediate baffle and the finishing baffle which will be described later will contact with the inner surface of the header plate. Here, the intermediate baffle and the finishing baffle each have the radius R of 75˜85 mm. 
   The value of the radius R is determined based on the experiment of  FIG. 19 . Namely, when the evaporator is installed, the flowing speed of the air by a fan is changed from 2.5 m/s, 2.0 m/s, 1.5 m/s and the radius is changed from 60 mm to 105 mm, in result, it is known that the best ventilation performance is obtained when the radius R is 75˜85 mm. 
   In addition, a bent portion  123   a  is formed in the center of the header plate  120  in the longitudinal direction, simultaneously, and a bent protrusion  123   b  is formed in the outer lateral surface. In the above construction, the lower end of the partition member  140  is inserted into the vertical groove  112  formed in the center of the bottom of the tank member  110 , and the upper end of the same is inserted into the bent groove  123   a.    
   A horizontal groove  125  is formed in the header plate  120  and crosses at both side ends. The upper end of the baffle  130  assembled in the both side ends of the tank member  110  is inserted into the horizontal groove  125 . Therefore, the baffle  130  is not escaped to the outside of the tank member. 
   The features of the baffle  130  for enhancing an assembling property will be described. 
   As shown in  FIG. 2 , the baffle  130  includes more than at least one intermediate baffle  131  for partitioning the space of the interior of the header unit  100 , and a pair of finishing baffles  132  for sealing the internal space at both side ends of the header unit  100 . 
   In addition, as shown in  FIG. 8 , the baffles  130  may have a cut groove  134  in a certain portion for assembling with the partition member  140 . One of the baffles  132  has a pair of pipe holes  133  for connecting a fluid inlet pipe  151  and a fluid outlet pipe  152 . 
   When connecting the fluid inlet pipe  151  and the fluid outlet pipe  152  using the pipe holes  133 , it is preferred to dispose the adaptor  300  of  FIG. 2  for enhancing a connection convenience and sealing force. 
   As shown in  FIG. 9 , the adaptor  300  includes a pair of insertion pipe portions  310  inserted into the pipe hole  133  of the finishing baffle  132 , a pair of connection pipe portions  330  for connecting the pipes, and a pair of trough holes  301  which pass from the insertion pipe portion  310  to the connection pipe portion  330 . 
   As shown in  FIG. 10 , when connecting the insertion pipe portion  310  of the pipe connection adaptor  300  to the finishing baffle  132 , a circular rim  320  is formed in the outer diameter portion. Therefore, it is inserted into the pipe hole  133  of the finishing baffler  132  until it is stopped by the circular rim  320 , and the end portion of the same is expanded and fixedly cocked. 
   The features of the partition member  140  for enhancing the assembling property will be described. 
   The tank member  110  has a partition member  140  for partitioning the inner space into two rows, namely, left and right rows. 
   As shown in  FIG. 11 , the partition member  140  may include a cut groove  2 ( 143 ) in an intermediate portion needed for assembling with the intermediate baffle  131 . A cut groove  141  may be formed in the end portion for assembling with the finishing baffle  132 . 
   A through hole  142  may be formed in one side of the intermediate portion for communicating the left and right spaces. The partition member  140  enhances the strength of the tank member  110  and prevents a distortion. 
   The features of the tube  200  according to the present invention will be described. 
   The tubes  200  adapted to connect the header units  101  and  102  include a front tube  210  and a rear tube  220 , and a connection portion  230  for connecting the front tube  210  and the rear tube  220 . The tube  200  is preferably fabricated based on the extrusion molding method for implementing a desired construction of the connection portion  230 . 
   As shown in  FIG. 14 , the tube  200  has a width W of 30˜50 mm, and a thickness T of 1.5˜3.0 mm, and the connection portion  230  has a width TW of 1˜3 mm, and a thickness TT of 0.5˜3.0 mm. 
   The width TW and the thickness TT of the connection portion  230  are determined based on the experiments of  FIGS. 20 and 21 . 
   Concerning the experiment of the heat radiation degree of  FIG. 20 , when the width TW of the connection portion was 1.0˜3.0 mm, and the height of the wrinkle fin  400  was 5.5 mm, 7.5 mm, and 9.5 mm, respectively, there was less change in the heat radiation degree, and when the range of the same exceeded 3.0 mm, there was a decrease in the heat generation performance. 
   In addition, concerning the experiment on the air pressure loss of  FIG. 21 , when the width TW of the connection portion was 1.0˜3.0 mm, even though the thickness TT of the connection portion  230  was changed, there were less pressure loss and change. When the range exceeded 3.0 mm, the pressure loss was increased. 
   When the thickness TT was 0.0 mm (there was not connection portion), it was known that there was higher pressure loss in the connection portion compared to when there was the connection portion. 
   When the front tube portion  210  and the rear tube portion  220  are connected and blocked using the connection portion  230 , the air flowing between the optional tubes do not flow between the tubes in the next compartment, so that the flowing speed of the air is increased, and the cooling performance is increased. 
   In other words, since the wrinkle fins are formed between the tubes, when the air flowing between the optional tubes receives a certain resistances by the wrinkle fins, the air is guided in the lateral direction. However, in the present invention, there is the connection portion  230  between the front tube portion  210  and the rear tube portion  220 , therefore, the flow of the air in the lateral direction is prevented. 
   As shown in  FIG. 12 , the tube  200  according to the present invention includes a plane portion  240  in the lateral outer side, and a rounding processing portion in the corner of the plane portion  240 . 
   When the plane portion  240  is formed in the outer lateral surface of the tube  200 , the air flowing in the surrounding portions of the tube makes an eddy flow in the end portion. This eddy flow prevents the condensation water from being sprayed. 
   Therefore, in the present invention, it is possible to prevent the condensation water from being gathered by a capillary phenomenon or surface tension force between the wrinkle fins and tubes. The condensation water directly falls at the plane portion  240  of the end portion and is discharged. 
   If the corners of both sides of the plane portion  240  are too angled, the angled portions may cause an eddy flow and prevents the flow of air. Therefore, it is needed to have the rounding processing portion  250  having a certain rounding degree. At this time, the radius R of the rounding curvature of the rounding processing portion  250  is preferably in a range of 0.5 mm˜1.0 mm. 
   The radius of 0.5 mm˜1.0 mm is related to the brazing welding of the wrinkle fin  400  formed between the tubes  200 . 
   Namely, when the wrinkle fins between the tubes are brazing-welded, if the radius is too large, the end of the wrinkle fin  400  does not contact with the tube. Therefore, even when a clad material is melted during the brazing welding, the welding is not performed up to the end portion. If the radius is too small, the eddy flow is too increased in the flow of air. 
   According to the experiment performed in consideration with the above matter, the radius of the rounding curvature is preferably in a range of 0.5 mm˜1.0 mm. 
   As shown in  FIG. 13 , the tube  200  may include an inner fin  201  which divides the inner space into a plurality of spaces and may integrally include a plurality of partition plates  202  which divide the inner space into a plurality of spaces as shown in  FIG. 14 . 
   The inner fin  201  and the partition plate  202  are adapted to increase the heat exchange efficiency. 
   In addition, as shown in  FIG. 14 , the partition plate  202  is installed at an inclined angle, so that the refrigerant flow paths preferably have a triangle shape and an inverted triangle shape repeatedly in sequence in their cross sections. 
   As shown in  FIG. 12 , the wrinkle fin  400  of the present invention has the same width  2 (W 2 ) as the width W of the tube  200 . 
   Namely, in the conventional art, when the width W of the tube and the width  2 (W 2 ) of the wrinkle fin  400  are same, the wrinkle fin is pressed and distorted, so that the ventilation is decreased. However, in the present invention, since the ends of the tubes are formed of the plane portions  240 , the wrinkle fin  400  is not pressed, so that the ventilation is not decreased. 
   The embodiments of the evaporator fabricated using the above elements according to the present invention will be described. 
   [Embodiment 1] 
   As shown in  FIG. 15 , the embodiment 1 of the present invention is implemented based on the above described elements as a basic type. 
   Namely, there are provided upper and lower header units  101  and  102 , a two-row tube  200  connecting the header units, and a wrinkle fin  400  provided between the tubes. As described above, the upper side header unit  101  connects a refrigerant inlet pipe  151  and a refrigerant outlet pipe  152  using the adaptor  300  in one side finishing baffle  132 . 
   The interior of the upper header unit  101  is divided by the partition member  140  which is assembled in the longitudinal direction and divides the width-wise portion, and the intermediate baffle  131  which is engaged with the partition member  140  and the cut groove  143  and divides the left and right lengths at about ⅓ distance of the right side in the drawing. 
   The interior of the lower side header unit  102  is divided by the partition member  140  which is assembled in the longitudinal direction and divides the width wise portion, and the intermediate baffle  131  which is engaged with the partition member  140  and the cut groove  143  and divides the left and right lengths at about ⅓ distance of the left side in the drawing. 
   At this time, it is preferable to perform the blazing welding by coating a blazing welding clad material on both sides of the partition member, intermediate baffle, finishing baffle and header plate except for the portions of the tank member before blazing-welding the header units for thereby saving the clad materials. 
   The use of the evaporator according to the first embodiment of the present invention will be described. As shown in  FIG. 16 , the refrigerant flown into the insertion pipe portion  310  of the adaptor  300  flows in the following sequence. 
   Namely, the refrigerant is moved to the front right space of the upper header unit  101 . Since there is the intermediate baffle  131 , the refrigerant flows downwardly along the front side tube  210  and then flows to the center portion in the front right side of the lower header unit  102  and flows to the upper side along the front tube  200 . Thereafter, the refrigerant flows into the left space in the front center portion of the header unit  101  and flows to the front left portion of the lower header unit  102  along the front tube  210 . 
   The refrigerant flows to the rear side of the lower header unit  102  through the through hole  142  formed in the partition member  140  of the lower header unit  102 . 
   In the rear header unit  100 , since there is the intermediate baffle  131 , the refrigerant flows upwardly along the rear tube  220 , and in the rear side of the upper header unit  101 , the refrigerant flows to the center portion and flows to the rear side of the lower header unit  102  along the rear tube  220 . 
   In addition, in the rear side of the lower header unit  102 , the refrigerant flows to the right side and moves up along the rear tube  220  and is discharged to the outside though the connection pipe portion  330  of the adaptor  300  in the rear side of the upper header unit  101 . 
   As shown in  FIG. 16 , according to the above flow paths, since the heating distributions of the refrigerant flowing through the front tube  210  and the rear tube  220  are different, the cooling effect is enhanced. 
   [Embodiment 2] 
     FIG. 17  is a view illustrating the paths structure according to the second embodiment of the present invention. 
   As shown in  FIG. 17 , the adaptor  300  is connected to an intermediate portion of the upper header unit  101 . There are provided upper and lower header units  101  and  102 , a two-row tube  200  connecting the header units, and a wrinkle fin  400  provided between the tubes. The upper and lower header units  101  and  102  are sealed using the finishing baffle  132 . 
   The interior of the upper header unit  101  is divided by a partition member  140  which is assembled in the longitudinal direction and divides the front and rear width portions, and an intermediate baffle  131  which is assembled to be engaged with the partition member  140  and the cut groove  143  and divides the left side portion by ½ or divides the right side portion by ½. In the interior of the lower header unit  102 , there is only the partition member  140  which is assembled in the longitudinal direction and divides the front and rear width portions. There is not formed an intermediate baffle in the interior of the lower header unit  102 . 
   As shown in  FIG. 18 , the refrigerant from the insertion inlet pipe  310  of the adaptor  300  flows in the following sequences. 
   Namely, the refrigerant flown into the center portion of the upper header unit  101  flows to the lower header unit  102  along the front tube  210  by the intermediate baffle  131  assembled in the left and right sides. In the front side of the lower header unit  102 , the refrigerant are spread in left and right sides and then is moved up along the front tube  210 . 
   In the upper header unit  101 , since the refrigerant flows to the outer side of the intermediate baffle  131  assembled in the left and right sides, the refrigerant is moved to the rear side of the upper header unit  101  along the through hole  142  formed in each partition member  140 . 
   In the rear side of the upper header unit  101 , the refrigerant moves down at the left and right sides along both sides of the rear tube  220  and is gathered at the center portion in the rear side of the lower header portion  102  and is moved up along the center portion of the rear tube  220 . 
   Therefore, the refrigerant moved up to the center of the upper header unit  101  is discharged to the outside along the connection pipe portion  330  in the sufficient heat-exchanged state. 
   The above described path flow is preferred when the refrigerant inlet pipe and the refrigerant outlet pipe are positioned in the center portion. The inner space of the upper header unit  101  is divided into the space a in the left side, the space b in the center and the space c in the right side by two intermediate baffles  131 . The volumes of the spaces a, b, and c are preferably 20:60:20, not 25:50:25. 
   Namely, the above ratios correspond to the values that the number of the tubes connected between the upper and lower header units  101  and  102  is divided into the center, right and center, so that the initial refrigerant flowing to the center portion performs much heat exchange. In addition, when the refrigerant is moved to the left and right sides, the heat exchange is performed, and then the volume is gradually decreased. Therefore, the ratios of the space a, b and c are most preferably 20:60:20 with respect to the length of the header unit. 
   As described above, in the evaporator according to the present invention, the tank member and header plate which are the elements of the header unit are formed of the extruded materials and processing processed materials, so that it is possible to enhance the productivity and decrease the fabrication cost. 
   In particular, in the present invention, when forming a two-row tube, the front tube and the rear tube are integrally connected using the connection portion, so that the air flowing between the tubes is not flown over to other tubes for thereby enhancing a head exchange efficiency. 
   In addition, since the ends of the tube are formed in plane, the condensation water gathered from the surrounding is effectively discharged along the tube. The wrinkle fin provided between the tubes is not easily transformed. 
   In the present invention, it is possible to adjust the number of the tubes for implementing a smooth flow of refrigerant by adjusting the position of the intermediate baffle. The assembling intervals of the tubes arranged in two rows may be determined so that the air is gathered at a portion in which the air intensively flow, thus enhancing the cooling performance. 
   Therefore, in the present invention, the heat exchange is enhanced by improving the structures, so that the whole dimension of the evaporator is decreased without decreasing the heat exchange capability. The tank member and header plate of the header unit have a certain elastic fixing force, so that a temporarily welding is omitted, and a direct assembling and blazing welding are implemented for thereby significantly enhancing the productivity. 
   The present invention is not limited to the above embodiment. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described examples are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.