Patent Publication Number: US-8973647-B2

Title: Heat exchanger and air conditioner having the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Korean Patent Application No. 2009-0112433, filed on Nov. 20, 2009 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     Embodiments relate to a heat exchanger having heat exchange fins configured in a flow structure having high heat exchange efficiency and low pressure loss and an air conditioner having the same. 
     2. Description of the Related Art 
     Generally, a heat exchanger is an apparatus used in equipment, such as an air conditioner or a refrigerator, having a refrigeration cycle. The heat exchanger includes a plurality of heat exchange fins arranged at intervals and a refrigerant pipe extending through the heat exchange fins to guide a refrigerant. In the heat exchanger, external air passes through the heat exchange fins to perform heat exchange between the air and the heat exchange fins, thereby achieving cooling or heating. 
     The heat exchange efficiency of the heat exchanger may be increased or decreased according to the shape of the heat exchange fins. Also, flow resistance of internal air or external air passing through the heat exchanger may be increased or decreased according to the shape of the heat exchange fins. 
     Consequently, the structure of the heat exchange fins may be changed to increase the heat exchange efficiency of the heat exchanger and to unify flow distribution of air. 
     SUMMARY 
     It is an aspect to provide a heat exchanger configured in a structure to form a flow pattern having high heat exchange efficiency and low pressure loss and an air conditioner having the same. 
     Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention. 
     In accordance with one aspect, a heat exchanger includes a plurality of refrigerant pipes in at least one row arranged at intervals in a longitudinal direction thereof and plate-shaped heat exchange fins contacting the refrigerant pipes such that the heat exchange fins are arranged at intervals to allow air to flow therebetween, wherein each of the heat exchange fins includes a guide protrusion disposed between each two of the refrigerant pipes, the guide protrusion includes first inclined planes inclined upward along opposite sides of a center line of the refrigerant pipe row and second inclined planes inclined downward from upper ends of the first inclined planes, and the first inclined planes and the second inclined planes are provided with louver members to accelerate heat exchange with air flowing along the guide protrusion. 
     The guide protrusion may be provided adjacent to the refrigerant pipes with guide planes to guide flow of air introduced from an inlet side to dead zones located at rears of the refrigerant pipes. 
     Each of the guide planes may include an arc plane facing an outer circumference of each of the refrigerant pipes and a straight plane extending from one end of the arc plane. 
     Each of the heat exchange fins may be provided around the center line of the refrigerant pipe row with a flat drainage plane to drain condensed water. 
     Each of the heat exchange fins may be provided at opposite side edges thereof with flat anti-frost planes to delay frost formation. 
     The louver members provided at the second inclined planes may be disposed in a two-column structure. 
     The two-column louver members may be disposed adjacent to the refrigerant pipes, and the second inclined planes may have flat planes between the two-column louver members. 
     In accordance with another aspect, a heat exchanger includes a refrigerant pipe to guide a refrigerant and heat exchange fins contacting the refrigerant pipe such that the heat exchange fins are arranged at intervals to allow air to flow therebetween, wherein each of the heat exchange fins, disposed between two longitudinally separated refrigerant pipes, includes a flat drainage plane provided around a center line connecting centers of the refrigerant pipes to drain condensed water, flat anti-frost planes provided at opposite side edges of each of the heat exchange fins to delay frost formation, and a guide protrusion symmetric about the center line to induce three-dimensional flow of the air, the guide protrusion having convex shapes of a triangular section protruding between the flat drainage plane and the flat anti-frost planes, and wherein the guide protrusion is provided at upper and lower ends thereof with guide planes to guide flow of the air to dead zones located at rears of the refrigerant pipes, and the guide protrusion is provided at an inclined plane thereof with a louver member lengthily formed in a longitudinal direction thereof to accelerate heat exchange. 
     The inclined plane may include first inclined planes inclined upward along opposite sides of a center line of the refrigerant pipe row and second inclined planes inclined downward from upper ends of the first inclined planes, and the louver member may include a plurality of first louver members disposed at the first inclined planes in one column and a plurality of second louver members disposed at the second inclined planes in two columns. 
     Each of the guide planes may include an arc plane facing an outer circumference of each of the refrigerant pipes and a straight plane extending from one end of the arc plane. 
     The second louver members provided at the second inclined plane disposed at an inlet side to which air flows and the first louver members provided at the first inclined plane disposed at an outlet side from which the air flows may be inclined downward in a flow direction of the air, and the first louver members provided at the first inclined plane disposed at the inlet side and the second louver members provided at the second inclined plane disposed at the outlet side may be inclined upward in the flow direction of the air. 
     The flat drainage plane may have a width of about 0.1 mm to about 2 mm, each of the flat anti-frost planes may have a width of about 0.1 mm to about 2.0 mm, the guide protrusion may have a convex height of about 0.8 mm to about 1.5 mm, the louver members may have a pitch of about 0.8 mm to about 1.5 mm, and the first and second louver members may have angles of about 25 degrees to about 40 degrees to the respective inclined planes. 
     In accordance with another aspect, a heat exchanger includes a plurality of refrigerant pipes in at least one row arranged at intervals in a longitudinal direction thereof, plate-shaped heat exchange fins contacting the refrigerant pipes such that the heat exchange fins are arranged at intervals to allow air to flow therebetween, and a guide protrusion disposed at each of the heat exchange fins between each two of the refrigerant pipes, wherein the guide protrusion includes first inclined planes inclined upward along opposite sides of a flat drainage plane provided around a center line of the refrigerant pipe row and second inclined planes inclined downward from upper ends of the first inclined planes, the first inclined planes and the second inclined planes are provided with louver members provided in a longitudinal direction thereof such that the louver members are disposed in parallel, the louver members including first louver members disposed at the first inclined planes in one column and second louver members disposed at the second inclined planes in two columns, the guide protrusion including the first inclined planes and the second inclined planes is provided at upper and lower ends thereof with an arc plane facing an outer circumference of each of the refrigerant pipes and a straight plane extending from one end of the arc plane, and each of the heat exchange fins is provided at opposite side edges thereof adjacent to the lower ends of the second inclined planes with flat anti-frost planes to delay frost formation. 
     In accordance with a further aspect, an air conditioner has a heat exchanger including a refrigerant pipe to guide a refrigerant and heat exchange fins contacting the refrigerant pipe such that the heat exchange fins are arranged at intervals to allow air to flow therebetween, wherein each of the heat exchange fins, disposed between two longitudinally separated refrigerant pipes, includes a flat drainage plane provided around a center line connecting centers of the refrigerant pipes to drain condensed water, flat anti-frost planes provided at opposite side edges of each of the heat exchange fins to delay frost formation, and a guide protrusion symmetric about the center line to induce three-dimensional flow of the air, the guide protrusion having convex shapes of a triangular section protruding between the flat drainage plane and the flat anti-frost planes, and wherein the guide protrusion is provided at upper and lower ends thereof with guide planes to guide flow of the air to dead zones located at rears of the refrigerant pipes, and the guide protrusion is provided at an inclined plane thereof with a louver member lengthily formed in a longitudinal direction thereof to accelerate heat exchange. 
     The inclined plane may include first inclined planes inclined upward along opposite sides of a center line of the refrigerant pipe row and second inclined planes inclined downward from upper ends of the first inclined planes, and the louver member may include a plurality of first louver members disposed at the first inclined planes in one column and a plurality of second louver members disposed at the second inclined planes in two columns. 
     Each of the guide planes may include an arc plane facing an outer circumference of each of the refrigerant pipes and a straight plane extending from one end of the arc plane. 
     The second louver members provided at the second inclined plane disposed at an inlet side to which air flows and the first louver members provided at the first inclined plane disposed at an outlet side from which the air flows may be inclined downward in a flow direction of the air, and the first louver members provided at the first inclined plane disposed at the inlet side and the second louver members provided at the second inclined plane disposed at the outlet side may be inclined upward in the flow direction of the air. 
     The flat drainage plane may have a width of about 0.1 mm to about 2 mm, each of the flat anti-frost planes may have a width of about 0.1 mm to about 2.0 mm, the guide protrusion may have a convex height of about 0.8 mm to about 1.5 mm, the louver members may have a pitch of about 0.8 mm to about 1.5 mm, and the first and second louver members may have angles of about 25 degrees to about 40 degrees to the respective inclined planes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a perspective view illustrating a heat exchanger according to an embodiment; 
         FIG. 2  is a sectional view taken along line I-I of  FIG. 1 ; 
         FIG. 3  is a view illustrating a heat exchange fin located between refrigerant pipes according to an embodiment; 
         FIG. 4  is a sectional view taken along line II-II of  FIG. 3 ; 
         FIG. 5  is a partially enlarged sectional view of  FIG. 4 ; and 
         FIG. 6  is a view illustrating flow distribution of air discharged through heat exchange fins according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
       FIG. 1  is a perspective view illustrating a heat exchanger according to an embodiment.  FIG. 2  is a sectional view taken along line I-I of  FIG. 1 .  FIG. 3  is a view illustrating a heat exchange fin located between refrigerant pipes according to an embodiment.  FIG. 4  is a sectional view taken along line II-II of  FIG. 3 .  FIG. 5  is a partially enlarged sectional view of  FIG. 4 . 
     Referring to  FIG. 1 , a heat exchanger  10  includes a refrigerant pipe  20  to guide a refrigerant and plate-shaped heat exchange fins  30  contacting the refrigerant pipe  20  such that the heat exchange fins are arranged at predetermined intervals to allow air to flow therebetween. 
     The refrigerant pipe  20  is a passage through which the refrigerant flows. The refrigerant may be a chemical compound such as CFC or R-134. The refrigerant is compressed or expanded and circulated in an air conditioner (not shown) to perform cooling or heating. 
     The refrigerant pipe  20  may be bent several times such that the refrigerant pipe  20  may have a long length in a limited space. The refrigerant pipe  20  may contact the heat exchange fins  30 . 
     The refrigerant pipe  20  may include first-row refrigerant pipes  20   a  and  20   b  (see  FIG. 2 ) and second-row refrigerant pipes  20   c  and  20   d  (see  FIG. 2 ) contacting the heat exchange fins  30 . The first-row refrigerant pipes  20   a  and  20   b  and the second-row refrigerant pipes  20   c  and  20   d  may be arranged in a zigzag fashion to maximize heat exchange performance. 
     The heat exchange fins  30  may contact the refrigerant pipe  20 . The heat exchange fins  30  may be arranged at predetermined intervals D (see  FIG. 6 ). 
     Since the refrigerant pipe  20  and the heat exchange fins  30  are disposed so as to come into contact, and each of the heat exchange fins  30  has a maximum area in a limited space, heat discharging or absorbing parts are increased. 
     Heat of the refrigerant flowing in the refrigerant pipe  20  is transmitted to air flowing in the vicinity of the heat exchange fins  30  through the refrigerant pipe  20  and the heat exchange fins  30 , with the result that the heat is easily discharged outside. 
     This effect is the same when heat of air flowing in the vicinity of the heat exchange fins  30  is transmitted to the refrigerant through the heat exchange fins  30  and the refrigerant pipe  20 . 
     The plate-shaped heat exchange fins  30  are arranged in parallel to a flow direction F of air at predetermined intervals. The refrigerant pipe  20 , in which the refrigerant flows, is perpendicularly fitted in the respective plate-shaped heat exchange fins  30 . 
     Consequently, air naturally flows along the surfaces of the heat exchange fins  30  without great resistance of the heat exchange fins  30  to accelerate heat exchange. 
     Referring to  FIG. 2 , each heat exchange fin  30  is provided with a guide protrusion  40 , which is located between two refrigerant pipes  20  disposed vertically to guide flow of air introduced from an inlet side thereof. 
     That is, on the assumption that the refrigerant pipes arranged at the first row in the flow direction F of air are first-row refrigerant pipes  20   a  and  20   b  and the refrigerant pipes arranged at the second row in the flow direction F of air are second-row refrigerant pipes  20   c  and  20   d , the guide protrusions  40  may be provided between the first-row refrigerant pipes  20   a  and  20   b  and between second-row refrigerant pipes  20   c  and  20   d.    
     The guide protrusion  40  has the same shape but different locations. Hereinafter, therefore, only the guide protrusion  40  provided at the heat exchange fin  30  between the first-row refrigerant pipes  20   a  and  20   b  will be described. 
     Referring to  FIGS. 3 to 5 , the guide protrusion  40  may be symmetric about a center line C of the refrigerant pipe row  20   a  and  20   b.    
     Also, the guide protrusion  40  may have an inclined plane to guide air such that a three-dimensional flow pattern of the air is formed when the air introduced from the inlet side thereof passes through the heat exchange fin  30 . 
     The inclined plane may include first inclined planes  41  and  42  inclined upward along opposite sides of the center line C of the refrigerant pipe row  20   a  and  20   b  and second inclined planes  43  and  44  inclined downward from the upper ends of the first inclined planes  41  and  42 . Consequently, the inclined plane may have a triangular section symmetric about the center line C. 
     Also, a height from a bottom  31  of the heat exchange fin  30  to an edge  45  where the first inclined plane  41  or  42  and the second inclined plane  43  or  44  are connected to each other, i.e., a convex height H (see  FIG. 5 ), is about 0.8 mm to about 1.5 mm, which provides a critical effect as compared with other ranges. 
     Also, the first inclined planes  41  and  42  and the second inclined planes  43  and  44  may be provided with louver members  60  and  70  to break temperature boundary layers formed along the respective inclined planes  41 ,  42 ,  43  and  44 , thereby improving heat transfer performance. 
     That is, the first inclined planes  41  and  42  may be provided with pluralities of first louver members  60  formed by partially cutting and erecting the first inclined planes  41  and  42  to scatter air flowing along the first inclined planes  41  and  42  such that boundary layers are not grown. The second inclined planes  43  and  44  may be provided with pluralities of second louver members  70  formed by partially cutting and erecting the second inclined planes  43  and  44  to scatter air flowing along the second inclined planes  43  and  44  such that boundary layers are not grown. 
     The first louver members  60  provided at the first inclined planes  41  and  42  having relatively high flow rate may be lengthily provided in the longitudinal direction of the first inclined planes  41  and  42  to improve heat transfer performance. The second louver members  70  provided at the second inclined planes  43  and  44  may be disposed in a two-column structure in which the second louver members  70  are spaced apart from each other vertically. 
     That is, the second louver members  70  are spaced apart from each other vertically at the second inclined planes  43  and  44 , and therefore, the second inclined planes  43  and  44  may have flat planes between the spaced second louver members  70 . If the second louver members  70  are lengthily formed over the entirety of the second inclined planes  43  and  44  having vertically long length in the longitudinal direction of the second inclined planes  43  and  44 , a ratio of heat exchange efficiency to pressure loss is low, and the stiffness of the guide protrusion  40  is reduced. 
     Also, when the second louver members  70  are disposed in the two-column structure, the second louver members  70  may be disposed adjacent to the refrigerant pipes  20   a  and  20   b  to efficiently discharge heat conducted from the refrigerant pipes  20   a  and  20   b.    
     That is, the second louver members  70  are disposed within positions radially spaced by a predetermined distance S from semi-circumferences  21  of the respective refrigerant pipes  20   a  and  20   b , thereby increasing a ratio of heat exchange efficiency to pressure loss. 
     As shown in  FIG. 4 , the second louver members  70  provided at an inlet side  36  may be inclined such that air flowing along the second inclined plane  43  is directed below the second inclined plane  43 , and the first louver members  60  provided at the inlet side  36  may be inclined such that air flowing below the second inclined plane  43  is directed above the second inclined plane  43 . 
     Also, the first louver members  60  provided at an outlet side  37  may be inclined in the direction opposite to the first louver members  60  at the inlet side  36 , and the second louver members  70  provided at the outlet side  37  may be inclined in the direction opposite to the second louver members  70  at the inlet side  36 . 
     The inlet side  36  indicates a side to which air flows (F) about the center line C connecting the centers of the refrigerant pipes  20   a  and  20   b , and the outlet side  37  indicates a side from which air flows about the center line C connecting the centers of the refrigerant pipes  20   a  and  20   b.    
     Consequently, air flowing in the flow direction F has a three-dimensional flow pattern with respect to the guide protrusion  40  through the first and second louver members  60  and  70 , thereby improving heat transfer performance according to breakage of the boundary layers and considerably reducing pressure loss of the air. 
     As shown in  FIG. 5 , angles α1 and α2 between the first and second louver members  60  and  70  and the first and second inclined planes  41  and  43  may be 25 to 40 degrees. Also, a pitch P of the first louver members  60  and the second louver members  70  may be 0.8 to 1.5 mm. 
     That is, the second louver members  70  provided at the inlet side  36  and the first louver members  60  provided at the outlet side  37  may have an angle α2 of 25 to 40 degrees with respect to the second inclined plane  43  and the first inclined plane  42  in the clockwise direction. Also, the first louver members  60  provided at the inlet side  36  and the second louver members  70  provided at the outlet side  37  may have an angle α1 of 25 to 40 degrees with respect to the first inclined plane  41  and the second inclined plane  44  in the counterclockwise direction. 
     With the angles α1 and α2 and the pitch P defined as described above, the increase in pressure drop of air is minimized at the first and second louver members  60  and  70 , and, at the same time, a heat transfer area where heat transfer is simultaneously performed is increased to increase an amount of heat discharged. 
     Meanwhile, as shown in  FIG. 3 , guide planes  50  to guide flow of air to dead zones, located at rears  35  of the refrigerant pipes  20   a  and  20   b , where little convection is performed in the flow direction F of the air may be provided at the guide protrusion  40  adjacent to the refrigerant pipes  20   a  and  20   b.    
     The guide planes  50  may be planes vertically extending from the bottom  31  of the heat exchange fin  30  to upper end edges  46  and the lower end edges  47  of the inclined planes  41 ,  42 ,  43  and  44  of the guide protrusion  40 . Each of the guide planes  50  may include an arc plane  51  and a straight plane  53  symmetric about the center line C. 
     The arc plane  51  symmetric about the center line C is formed in the shape of an arc facing the outer circumference of each of the refrigerant pipes  20   a  and  20   b . The straight plane  53  extending from one end of the arc plane  51  may be disposed in parallel to the flow direction F of air. 
     Consequently, a channel  33  to guide flow of air to the refrigerant pipes  20   a  and  20   b  is defined between the guide planes  50  of the guide protrusions  40  spaced apart from each other vertically as shown in  FIG. 2 , thereby reducing the dead zones formed at the rears  35  of the refrigerant pipes  20   a  and  20   b.    
     Meanwhile, as shown in  FIG. 3 , the heat exchange fin  30  may be provided around the center line of the refrigerant pipes  20   a  and  20   b  with a flat drainage plane  80  to rapidly drain condensed water resulting from condensation of moisture in the air due to temperature difference between the refrigerant flowing in the refrigerant pipes  20   a  and  20   b  and the moisture in the air. Also, the heat exchange fin  30  may be provided at opposite side edges thereof with flat anti-frost planes  90  to delay formation of frost on the surface of the heat exchange fin  30 , thereby improving efficiency. 
     The flat drainage plane  80  may have a width W1 of 0.1 to 2 mm. Each of the flat anti-frost planes  90  may have a width W2 of 1.0 to 2.0 mm. These ranges provide critical effects as compared with other ranges. 
       FIG. 6  is a view illustrating flow distribution of air discharged through heat exchange fins according to an embodiment of the present invention. 
     When air passes through the inlet side  36  and the outlet side  37  of each heat exchange fin  30  in the flow direction F of the air, as shown in  FIG. 6 , the pressure loss of the air is minimized by the guide protrusion  40  of each heat exchange fin  30  and the first and second louver members  60  and  70  formed at the guide protrusion  40 , which are formed within the numerical ranges of this embodiment, thereby achieving maximum heat transfer performance. Also, the flow distribution of the air discharged through the outlet side  37  is uniform, thereby achieving noise reduction. 
     As is apparent from the above description, the pressure loss of air is minimized and maximum heat transfer performance is achieved through three-dimensional flow of the air at the heat exchange fins. 
     Also, flow distribution of air at the insides and the ends of the heat exchange fins is unified, and therefore, noise is reduced. 
     In addition, the dead zone located at the rear of the refrigerant pipe is reduced, and therefore, heat exchange efficiency is further improved. 
     Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.