Patent Description:
In general, a heat exchanger may be used as a condenser or an evaporator in a refrigeration cycle apparatus composed of a compressor, a condenser, an expansion mechanism and an evaporator.

The heat exchanger is mounted on a vehicle, a refrigerator or the like so as to perform heat exchange between refrigerant and air.

The heat exchanger may be classified into a fin tube-type heat exchanger, a microchannel-type heat exchanger and the like.

The fin tube-type heat exchanger is made of copper, and the microchannel-type heat exchanger is made of aluminum.

Because a spiral condenser, which is applied to a small-sized refrigeration cycle, includes one inlet pipe and one outlet pipe, freedom in a pass configuration is at a low level. Furthermore, the spiral condenser is disadvantageous in that it is difficult to insert a structure such as a louver (a slit, a dimple or the like) because the fin thereof is small and has a circular cross-sectional shape and efficiency is lowered because loss of air pressure is increased due to introduction of air only through one side thereof.

Because the microchannel-type heat exchanger has fine flow channels therein, there is an advantage in that efficiency is improved, compared to the fin tube-type heat exchanger. However, there is a problem in that a flow channel is deformed or blocked when the heat exchanger is bent in configuration of a refrigerant passage. The microchannel-type heat exchanger is constructed such that headers are connected to two ends of each of a plurality of tubes. However, the microchannel-type heat exchanger, in which the headers are connected to the plurality of tubes, has disadvantages in that manufacturing costs are increased and it is difficult to use when the space in a machine room is small.

<CIT>) relates to a heat exchanger and a refrigeration cycle apparatus.

<CIT>) relates to a heat exchanger structurally designed to enhance heat transfer performance.

<CIT>) relates to a U-shaped condenser for a refrigerator.

<CIT>) relates to a heat exchanger structure of a unitary air conditioner.

<CIT>) relates to a cooling device comprising an air guiding apparatus that enables the air coming from the fan to be carried the condenser.

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a condenser for a refrigerator capable of allowing plural rows of heat exchange units to be efficiently disposed in a confined space.

It is another object of the present invention to provide a condenser capable of ensuring a sufficient heat-transfer area in a machine room having a narrow space and of making it advantageous to prevent loss of air pressure.

It is a further object of the present invention to provide a condenser capable of being easily bent without reducing a flow channel when plural rows are formed in a narrow space.

Objects of the present invention are not limited to the above-mentioned objects, and other objects, which are not mentioned, will be apparent to those skilled in the art from the following description.

A condenser for a refrigerator according to the present invention is characterized by the features of claim <NUM>.

Specifically, the condenser for a refrigerator according to the present invention includes a heat exchange unit configured to receive, at one side thereof, refrigerant which has been compressed in a compressor, to perform heat exchange between the refrigerant and air and to discharge the refrigerant, which has exchanged heat with the air, to an evaporator, wherein the heat exchange unit includes a flat tube, through one end of which the refrigerant is introduced and through a remaining end of which the refrigerant is discharged, thereby performing heat exchange between the refrigerant and the air, wherein the flat tube includes at least one bent tube portion defining plural rows of tubes, which are spaced apart from each other in an up-and-down direction, and wherein the plural rows of tubes define an intersection bent surface, which has a predetermined curvature and intersects the up-and-down direction.

The bent tube surface of the intersection bent portion and a bent surface of the bent tube portion is disposed in a direction so as to intersect each other.

The flat tube may have a horizontal width, which is larger than a vertical thickness of the flat tube.

The flat tube has a longer side which is disposed parallel to the bent surface of the intersection bent portion.

The flat tube has a longer side which is disposed in a direction so as to intersect a bent surface of the bent tube portion.

The intersection bent portion has a radius of curvature which is larger than a radius of curvature of the bent tube portion.

A ratio of a radius of curvature of the intersection bent portion to a horizontal width of the flat tube may be <NUM>-<NUM>:<NUM>.

A ratio of the bent tube portion to a vertical thickness of the flat tube may be <NUM>-<NUM>:<NUM>.

A ratio of a vertical thickness of the flat tube to a pitch of the plural rows of tubes may be <NUM>:<NUM>-<NUM>.

The condenser for a refrigerator may further include an inflow header configured to supply the refrigerant, which has been compressed in the compressor, to the heat exchange unit, and an outflow header through which the refrigerant, which has exchanged heat with the air in the heat exchange unit, flows, wherein the inflow header is connected to the one end of the flat tube, and the outflow header is connected to the remaining end of the flat tube.

The condenser for a refrigerator may further include a fin connecting the plural rows of tubes to each other in order to transfer heat.

The plural rows of tubes may define two heat exchange surfaces, which face each other.

The bent surface of the bent tube portion may be parallel to the up-and-down direction.

The intersection bent surface may be perpendicular to the up-and-down direction.

A direction in which the air flows may be parallel to the bent surface of the intersection bent portion and intersects the bent surface of the bent tube portion.

A refrigerator according to the present invention includes a body having a storage compartment for storing foodstuffs, a door configured to open and close the body, and a condenser configured to condense refrigerant for cooling the storage compartment, wherein the condenser includes a heat exchange unit configured to receive, at one side thereof, the refrigerant, which has been compressed in a compressor, to perform heat exchange between the refrigerant and air and to discharge the refrigerant, which has exchanged heat with the air, to an evaporator, wherein the heat exchange unit includes a flat tube, through one end of which the refrigerant is introduced and through a remaining end of which the refrigerant is discharged, thereby performing heat exchange between the refrigerant and the air, wherein the flat tube includes at least one bent tube portion defining plural rows of tubes, which are spaced apart from each other in an up-and-down direction, and wherein the plural rows of tubes define an intersection bent surface which has a predetermined curvature and intersects the up-and-down direction.

The flat tube may have a longer side which is disposed parallel to the bent surface of the intersection bent portion.

The condenser for a refrigerator according to the present invention offers one or more of the following effects.

First, there is an advantage in that it is possible to ensure a sufficient heat-transfer area in a confined space in a machine room and to make it advantageous to prevent loss of air pressure.

Second, there is an advantage in that heat transfer units are disposed in multiple rows, thereby optimizing space utilization, suppressing deformation of a bent portion and preventing reduction of a flow channel.

Third, there is an advantage in that a single flat tube is bent in a zigzag fashion in an up-and-down direction so as to define plural rows and the plural rows of tubes are further bent in another direction, thereby enabling a confined space in a machine room to be efficiently utilized without interfering with airflow.

Fourth, there is an advantage of counteracting stresses applied to a flat tube of a heat exchange unit and of preventing breakage of the heat exchange unit since a bending direction of a bent portion is alternately changed when the heat exchange unit is disposed in multiple rows in the case of requiring a large amount of heat exchange.

However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. The present disclosure is defined only by the categories of the claims. In certain embodiments, detailed descriptions of device constructions or processes well known in the art may be omitted to avoid obscuring appreciation of the disclosure by a person of ordinary skill in the art.

Spatially-relative terms such as "below", "beneath", "lower", "above", or "upper" may be used herein to describe one element's relationship to another element as illustrated in the Figures. It will be understood that spatially-relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in one of the figures is turned over, elements described as "below" or "beneath" other elements would then be oriented "above" the other elements. The exemplary terms "below" or "beneath" can, therefore, encompass both an orientation of above and below. Since the device may be oriented in another direction, the spatially-relative terms may be interpreted in accordance with the orientation of the device.

The terminology used in the present disclosure is for the purpose of describing particular embodiments only and is not intended to limit the disclosure. As used in the disclosure and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless context clearly indicates otherwise.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience of description and clarity. Also, the size or area of each constituent element does not entirely reflect the actual size thereof.

Angles or directions used to describe the structures of light emitting devices according to embodiments are based on those shown in the drawings. Unless there is, in the specification, no definition of a reference point to describe angular positional relations in the structures of the light emitting devices, the associated drawings may be referred to.

<FIG> is a block diagram illustrating a refrigerant cycle of a refrigerator according to a first embodiment of the present invention. <FIG> is a perspective view of the refrigerator according to the first embodiment of the present invention. <FIG> is a perspective view of the machine room shown in <FIG>.

Referring to <FIG> and <FIG>, the refrigerator according to an embodiment of the present invention includes a body <NUM> having therein a storage compartment <NUM> for storing foodstuffs, a door <NUM> for opening and closing the body <NUM> and a refrigeration system configured to cool the storage compartment <NUM>.

The refrigeration system of the refrigerator according to the embodiment may include a compressor <NUM> configured to compress refrigerant, a condenser <NUM> in which the refrigerant exchanges heat with outdoor air and is then condensed, an expansion mechanism <NUM> configured to expand the refrigerant, and an evaporator <NUM> in which the refrigerant exchanges heat with the air in the refrigerator and is then evaporated.

The refrigerant, which is condensed in the compressor <NUM>, may exchange heat with outdoor air and be condensed while passing through the condenser <NUM>. The condenser <NUM> is positioned in the machine room S provided in the inside of the body <NUM>.

The refrigerant, which is condensed in the condenser <NUM>, may flow to the expansion mechanism <NUM> and may be expanded thereat. The refrigerant, which is expanded in the expansion mechanism <NUM>, may exchange heat with the indoor air and be evaporated while passing through the evaporator <NUM>. The evaporator <NUM> is disposed so as to exchange heat with the air in the storage compartment <NUM>.

The refrigerant, which is evaporated in the evaporator <NUM>, may be recovered to the compressor <NUM>.

The refrigerant is circulated through the refrigeration cycle, which is composed of the compressor <NUM>, the condenser <NUM>, the expansion mechanism <NUM> and the evaporator <NUM>.

A flow channel for the compressor <NUM> may be connected to the compressor <NUM> so as to guide the refrigerant, having passed through the evaporator <NUM>, to the compressor <NUM>. An accumulator <NUM>, in which the liquid refrigerant is accumulated, may be provided at the flow channel for the compressor <NUM>.

The machine room S may be positioned under the rear portion of the body <NUM>. The machine room S may be configured to extend between the two lateral sides of the body <NUM> along the rear surface of the body <NUM>.

The machine room S may include a rear cover <NUM>. The rear cover <NUM> may be provided so as to open and close the rear surface of the machine room S. The rear cover <NUM> may be provided with an air inflow portion <NUM>, through which air flows into the machine room S, and an air outflow portion <NUM>, through which the air in the machine room S flows to the outside. Each of the air inflow portion <NUM> and the air outflow portion <NUM> may be divided into a plurality of portions. The air inflow portion <NUM> and the air outflow portion <NUM> may be provided at the rear cover so as to be disposed at different positions or to face each other.

A condenser fan <NUM> may be provided in the machine room S so as to blow outdoor air to the condenser <NUM>. An evaporator fan <NUM> may be provided so as to blow the indoor air to the evaporator <NUM>.

<FIG> is a perspective view of the condenser shown in <FIG>. <FIG> is a plan view of the condenser shown in <FIG>. <FIG> is a cross-sectional view of a flat tube of the condenser shown in <FIG>, which is flattened. <FIG> is a cross-sectional view of a first heat exchange unit taken along line A-A in <FIG>.

Referring to <FIG>, the condenser <NUM> is composed of at least one heat exchange unit. The heat exchange unit may be composed of a plurality of tubes coupled to each other. Here, because the plurality of tubes are coupled to each other through welding or the like, there is a disadvantage in that manufacturing thereof is difficult.

Accordingly, in order to overcome the above disadvantage, the heat exchange unit is configured such that a single flat tube <NUM> is bent and layered.

For example, the heat exchange unit includes a flat tube <NUM> defining plural rows of tubes, an inflow pipe <NUM>, which is connected to one end of the flat tube <NUM> so as to supply the refrigerant thereto, and an outflow pipe <NUM>, which is connected to the other end of the flat tube <NUM> so as to discharge the refrigerant.

First, the cross-sectional shape and the disposition of the flat tube <NUM> will be described.

Referring particularly to <FIG>, the cross-sectional shape of the flat tube <NUM> may have various shapes in consideration of efficiency in heat exchange with air.

For example, when viewed in cross-section, the flat tube <NUM> may have various shapes such that the horizontal width A1 thereof is larger than the vertical thickness W1 thereof. Here, the horizontal width A1 of the flat tube <NUM> means the anteroposterior length of the flat tube <NUM>, and the vertical thickness W1 of the flat tube <NUM> means the length of the flat tube <NUM> in the up-and-down direction.

Specifically, as illustrated in <FIG>, the flat tube <NUM> includes two longer sides 50a, which face each other, and two shorter sides 50b, which are shorter than the longer sides 50a and connect the two longer sides 50a to each other, when viewed in cross-section. The two longer sides 50a and the two shorter sides 50b define a closed space. It is preferable that each of the longer sides 50a have a length <NUM> to <NUM> times each of the shorter sides 50b.

The longer sides 50a of the flat tube <NUM> extend in a direction of airflow. In other words, the longer sides 50a of the flat tube <NUM> are disposed so as to be parallel to the anteroposterior direction, and the shorter sides 50b of the flat tube <NUM> extend in an up-and-down direction so as to intersect the longer sides 50a.

Consequently, since the longer sides of the flat tube <NUM> extend in a direction of airflow, it is possible to increase the contact area between the flat tube <NUM> and air and the time for which the flat tube <NUM> contacts air, and it is possible to improve efficiency in heat exchange.

In another example, as illustrated in <FIG>, the flat tube <NUM> may have an elliptical shape such that the horizontal width A1 of the flat tube <NUM> is larger than the vertical thickness W1 of the flat tube <NUM> when viewed in cross-section.

The flat tube <NUM> causes the refrigerant to exchange heat with air, and receives the refrigerant through one end thereof and discharges the refrigerant through the other end thereof.

In order to efficiently perform heat exchange between the refrigerant and air in a confined space, the flat tube <NUM> may define plural rows of tubes <NUM>, which are spaced apart from each other in an up-and-down direction and are layered so as to have a regular pitch. For example, the flat tube <NUM> is bent so as to have at least one bent tube portion <NUM>.

Specifically, the flat tube <NUM> includes plural rows of tubes <NUM> (51a - 51n), which are disposed parallel to each other, and a bent tube portion <NUM> connecting adjacent tube rows <NUM>.

The plural rows of tubes <NUM> extend in a direction intersecting the direction of airflow. Specifically, the plural rows of tubes <NUM> extend horizontally, and are spaced apart from each other in an up-and-down direction at a regular pitch. Specifically, the flat tube <NUM> is disposed such that at least two tube rows <NUM> overlap each other when viewed from above.

A fin <NUM> is disposed between two adjacent tube rows <NUM> of the plural rows of tubes <NUM> so as to connect the adjacent tube rows <NUM> to each other and to conduct heat. The fin <NUM> connects the two adjacent tube rows <NUM> to each other to conduct heat. The plural rows of tubes <NUM>, which are layered in an up-and-down direction, define a heat exchange surface in conjunction with the fins <NUM>.

Although the length of each of the tube rows <NUM> is not limited, if the horizontal width A1 of the flat tube <NUM> is overly small, there are problems in that it is difficult to efficiently conduct heat and the number of tube rows is excessively increased, thereby increasing loss of air pressure. Accordingly, the length of each of the tube rows <NUM> is preferably <NUM> times or greater the horizontal width A1 of the flat tube <NUM>.

Each of the bent tube portions <NUM> connects the left ends or the right ends of adjacent tube rows <NUM>. Consequently, the flat tube <NUM> is configured such that the plural rows of tubes <NUM> are layered in an up-and-down direction in a zigzag fashion. Specifically, the right end of the first tub row 51a and the right end of the second tube row 51b are connected to each other via the first bent tube portion 52a, and the left end of the second tube row 51b and the left end of the third tube row 51c are connected to each other via the second bent tube portion 52b.

The bent tube portion <NUM> is formed by bending a portion of the flat tube <NUM> so as to have a predetermined curvature. The bent tube portion <NUM> is bent such that the flat tube <NUM> is disposed in a confined space and that the space in the flat tube <NUM>, in which the refrigerant flows, does not become narrow.

A bent surface S2 of the bent tube portion <NUM>, which defines a direction in which the bent tube portion <NUM> is bent, is defined. Referring to <FIG>, the bent surface S2 of the bent tube portion <NUM> is defined as an imaginary plane defined by the center of one end of the bent tube portion <NUM>, the center of the other end of the bent tube portion <NUM> and the center C2 of the radius of curvature of the bent tube portion <NUM>.

In an example, the bent surface S2 of the bent tube portion <NUM> is disposed so as to intersect the longer side of the flat tube <NUM>. Specifically, the bent surface S2 of the bent tube portion <NUM> may be a surface parallel to a horizontal plane parallel both to an up-and-down direction and to an anteroposterior direction.

If the radius of curvature of the bent tube portion <NUM> is excessively small, the internal space in the flat tube <NUM> decreases and the refrigerant does not efficiently flow. If the radius of curvature of the bent tube portion <NUM> is excessively large, there are disadvantages in that efficiency in heat exchange is lowered, and the volume of the condenser increases.

Accordingly, it is preferable that the ratio of the radius of curvature of the bent tube portion <NUM> to the vertical thickness W1 of the flat tube <NUM> be <NUM>-<NUM>:<NUM> and that the ratio of the vertical thickness W1 of the flat tube <NUM> to the pitch of the plural rows of tubes <NUM> be <NUM>:<NUM>-<NUM>.

The length of the bent tube portion <NUM> is less than the length of one tube row <NUM>. It is preferable that the ratio of the length of the bent tube portion <NUM> to the length of the tube row <NUM> be <NUM>:<NUM> - <NUM>:<NUM>.

The inflow pipe <NUM> transmits the refrigerant, which is compressed in the compressor <NUM>, to the heat exchange unit. The inflow pipe <NUM> is connected to one end of the flat tube <NUM>. The inflow pipe <NUM> is connected to the compressor <NUM> so as to supply high-temperature and pressure refrigerant to the flat tube <NUM>. Specifically, the inflow pipe <NUM> is connected to the left end of the first tube row 51a.

An inflow header <NUM> may be disposed between the inflow pipe <NUM> and the flat tube <NUM>. The inflow header <NUM> connects the inflow pipe <NUM> having a circular section to the flat tube <NUM>, which extends in one direction, to supply the refrigerant in the inflow pipe <NUM>. One side and the other side of the inflow header <NUM> may have crosssections different from each other, and the one side of the inflow pipe <NUM> may have a shape corresponding to the sectional shape of the flat tube <NUM>.

The outflow pipe <NUM> transmits the refrigerant, which is compressed in the compressor <NUM>, to the heat exchange unit. The outflow pipe <NUM> is connected to the other end of the flat tube <NUM>. The outflow pipe <NUM> is connected to the evaporator <NUM> so as to supply the refrigerant, which is discharged from the flat tube <NUM>, to the evaporator <NUM>. Specifically, the outflow pipe <NUM> is connected to the right end of the last tube row (the nth tube row) 51n.

An outflow header <NUM> may be disposed between the outflow pipe <NUM> and the flat tube <NUM>. The outflow header <NUM> connects the outflow pipe <NUM> having a circular section to the flat tube <NUM>, which extends in one direction, to supply the refrigerant in the outflow pipe <NUM> to the flat tube <NUM>. One side and the other side of the outflow header <NUM> may have different cross-sectional shapes, and the one side of the outflow header <NUM> may have a shape corresponding to the cross-sectional shape of the flat tube <NUM>.

If the flat tube <NUM> has a plurality of bent tube portions <NUM> and is layered in one direction (specifically, in an up-and-down direction), there are problems in that it is difficult to efficiently dispose the heat exchange unit in a confined space and loss of air pressure increases.

Accordingly, the embodiment has a configuration in which plural rows of tubes <NUM> are bent in one direction. For example, the plural rows of tubes <NUM> may include at least two heat exchange surfaces and at least one intersection bent portion <NUM>.

Specifically, the plural rows of tubes <NUM> is composed of a first heat exchange surface <NUM>, a second heat exchange surface <NUM> and the intersection bent portion <NUM>. Unlike the embodiment, the condenser <NUM> may also include two or more heat exchange surfaces. Here, the heat exchange surface means an imaginary surface in which the plurality of flat tubes <NUM> intersect a direction of airflow and are layered so as to allow air to pass therethrough while exchanging heat with air.

Each of the heat exchange surface and the intersection bent portion <NUM> is one of a plurality of regions formed by dividing the plural rows of tubes <NUM> in a longitudinal direction (in a horizontal direction). The embodiment is described as being configured such that two heat exchange surfaces are positioned at two ends in a longitudinal direction and the intersection bent portion <NUM> is disposed between the two heat exchange surfaces.

The first heat exchange surface <NUM> and the second heat exchange surface <NUM> may be oriented so as to intersect each other or to face each other.

For example, the first heat exchange surface <NUM> is disposed so as to exchange heat with air, which has exchanged heat with the second heat exchange surface <NUM>. Specifically, the first exchange surface <NUM> and the second heat exchange surface <NUM> are disposed in a flow path along which external air flows, and the external air first exchanges heat with the second heat exchange surface <NUM> and secondly exchanges heat with the first heat exchange surface <NUM>.

More specifically, the machine room S is provided with the air inflow portion <NUM>, through which external air is introduced into the machine room, and the air outflow portion <NUM>, through which the air, which has exchanged heat with the heat exchange unit, is discharged, and the second heat exchange surface <NUM> is disposed closer to the air inflow portion <NUM> than the first heat exchange surface <NUM>.

The first heat exchange surface <NUM> and the second heat exchange surface <NUM> may be disposed so as to define a heat exchange surface P, which intersects a direction of airflow. The first heat exchange surface <NUM> and the second heat exchange surface <NUM> define the heat exchange surfaces, which intersect a direction of airflow and which allow air to pass therethrough while exchanging heat with the air. The first heat exchange surface <NUM> and the second heat exchange surface <NUM> may be layered in a direction of airflow. The first heat exchange surface <NUM> and the second heat exchange surface <NUM> are disposed to face each other.

The intersection bent portion <NUM> is defined as a region in which the tube rows <NUM> are bent. When the flat tube <NUM> is composed of plural tubes, which are disposed in multiple rows, the intersection bent portion <NUM> provides a bent region, thereby improving freedom in disposition and minimizing deformation of the flat tube <NUM>, thereby maintaining efficiency of heat exchange in the heat exchange unit.

The intersection bent portion <NUM> is formed by plural rows of tubes <NUM>, which are bent so as to have a predetermined curvature. The bending direction of the intersection bent portion <NUM> is preferably set in consideration of a degree of fatigue of the flat tube <NUM> and loss of air pressure due to airflow.

The intersection bent surface of the intersection bent portion <NUM> intersects an up-and-down direction and is disposed parallel to a direction of airflow. Here, the intersection bent surface defines the bending direction of the intersection bent portion <NUM>. Referring to <FIG>, the intersection bent surface S is defined as an imaginary surface defined by the center of one end of the intersection bent portion <NUM>, the center of the other end of the intersection bent portion <NUM> and the center C1 of the radius of curvature of the intersection bent portion <NUM>.

The intersection bent surface S of the intersection bent portion <NUM> and the bent surface S2 of the bent tube portion <NUM> are disposed so as to intersect each other. Specifically, the intersection bent surface S of the intersection bent section <NUM> defines a surface parallel both to an anteroposterior direction and to a horizontal direction, and the intersection bent surface S2 of the bent tube portion <NUM> defines a surface parallel to an up-and-down direction. The intersection bent surface S of the intersection bent portion <NUM> and the bent surface S2 of the bent tube portion <NUM> are disposed so as to intersect each other so as to employ a confined space in the machine room, reduce loss of air pressure and improve efficiency in heat exchange.

A direction of airflow is an anteroposterior direction, which is parallel to the intersection bent surface S of the intersection bent portion <NUM> and intersects the bent surface S2 of the bent tube portion <NUM>. Accordingly, since the plural rows of tubes of the heat exchange unit are bent both in an up-and-down direction and in a horizontal direction such that the longer side 50a of the flat tube <NUM> does not intersect a direction of airflow in a predetermined space, it is possible to provide plural rows of tubes in a small space without interfering with airflow.

In other words, even when the flat tube <NUM> has a plurality of bent portions, the longer side 50a of the flat tube <NUM> is disposed parallel to a direction of airflow.

The intersection bent surface S of the intersection bent portion <NUM> is disposed parallel to the longer side of the flat tube <NUM>. Accordingly, even when the plural rows of tubes <NUM> are bent, there is no interference with airflow passing through the plural rows of tubes <NUM>.

If the radius of curvature R1 of the intersection bent portion <NUM> is excessively small, the internal space in the flat tube <NUM> becomes narrow, thereby interfering with efficient flow of the refrigerant. On the other hand, if the radius of curvature R1 of the intersection bent portion <NUM> is excessively large, efficiency in heat exchange is decreased and the volume of the condenser is increased.

Accordingly, the ratio of the radius of curvature R1 of the intersection bent portion <NUM> to the horizontal width A1 of the flat tube <NUM> is preferably <NUM>-<NUM>:<NUM>.

Because the longer side 50a of the flat tube <NUM> has a length, which is <NUM> to <NUM> times the length of the shorter side 50b, there is difference in the limitation in the radius of curvature of the bent portion depending on the length of the side of the flat tube <NUM>. Accordingly, the radius of curvature R1 of the intersection bent portion <NUM> is preferably greater than the radius of curvature R2 of the bent tube portion <NUM>.

The intersection bent portion <NUM> may have the same construction and shape as the plural rows of tubes <NUM>. However, the intersection bent portion <NUM> may be made of a material different from the flat tube <NUM> in order to realize a bent-type layered structure capable of efficiently utilizing a space. Specifically, the intersection bent portion <NUM> may be made of a softer material than the flat tube <NUM> so as to be easily bent.

The cross-sectional shape of the flat tube <NUM> is maintained as in <FIG> in the heat exchange surfaces and the intersection bent portion <NUM>.

The length of the intersection bent portion <NUM> is shorter than the length D1 of the flat tube <NUM> and the length of the first and second heat exchange surfaces. The ratio of the length of the intersection bent portion <NUM> to the length of the heat exchange surface is preferably <NUM>:<NUM> - <NUM>:<NUM>.

The length of the intersection bent portion <NUM> is greater than the horizontal width A1 of the flat tube <NUM>. The length of the intersection bent portion <NUM> may be <NUM> times the horizontal width A1 of the flat tube <NUM>.

The sum of the lengths of the first heat exchange surface <NUM>, the second heat exchange surface <NUM> and the intersection bent portion <NUM> is preferably <NUM> times or more the horizontal width A1 of the flat tube <NUM>. The reason for this is because efficient heat transfer is difficult and loss of air pressure is increased due to increased rows of tubes <NUM> if the sum of the lengths of the first heat exchange surface <NUM>, the second heat exchange surface <NUM> and the intersection bent portion <NUM> is excessively small.

<FIG> is a plan view of a condenser <NUM> according to a second embodiment of the present invention.

There is a difference between the first embodiment and the second embodiment in that the second embodiment further includes an intermediate heat exchange surface <NUM>.

Referring to <FIG>, the intermediate heat exchange surface <NUM> defines at least one row between the first heat exchange surface <NUM> and the second heat exchange surface <NUM>. The intermediate heat exchange surface <NUM>, the first heat exchange surface <NUM> and the second heat exchange surface <NUM> define plural rows of heat exchange surfaces, which intersect a direction of airflow.

The intermediate heat exchange surface <NUM> is connected to the first heat exchange surface <NUM> and the second heat exchange surface <NUM> via at least two intersection bent portions <NUM>. Although the construction of the intermediate heat exchange surface <NUM> is almost the same as the construction of the first heat exchange surface <NUM>, there are differences in that the header is not connected to the intermediate heat exchange surface <NUM> and the intersection bent portions <NUM> are connected to the two ends of the intermediate heat exchange surface <NUM>.

A first intersection bent portion <NUM>-<NUM>, which connects the first heat exchange surface <NUM> to one end of the intermediate heat exchange surface <NUM>, is bent in a clockwise direction along the intersection bent surface S. A second intersection bent portion <NUM>-<NUM>, which connects the second heat exchange surface <NUM> to the other end of the intermediate heat exchange surface <NUM>, is bent in a counterclockwise direction along the intersection bent surface S. In other words, since the bending direction of the first intersection bent portion <NUM> (<NUM>-<NUM>) and the bending direction of the second intersection bent portion <NUM> (<NUM>-<NUM>) are opposite each other, the stress concentrated on the first heat exchange surface <NUM>, the intermediate heat exchange surface <NUM> and the second heat exchange surface <NUM> is alleviated.

Accordingly, since plural rows of heat exchange units are disposed in a confined space while the surface area of heat exchange of the heat exchange units is increased, it is possible to optimize space utilization and to prevent concentration of stress by alternately changing the bending direction.

<FIG> is a cross-sectional view of a flat tube <NUM> of a condenser according to a third embodiment of the present invention in the unfolded state.

The third embodiment has differences in the fin <NUM> and the tube bent portion <NUM>, compared to the first embodiment.

Referring to <FIG>, the diameter P2 of the bent tube portion <NUM> is larger than the pitch of the plural rows of tubes <NUM>. Specifically, the diameter P2 of the bent tube portion <NUM> is preferably <NUM> to <NUM> times the pitch of the plural rows of tubes <NUM>. The reason for this is that the adjacent bent tube portions <NUM> interfere with each other if the diameter P2 of the bent tube portion <NUM> is excessively large and because the flat tube <NUM> is damaged during a bending operation if the diameter P2 of the bent tube portion <NUM> is excessively small.

Particularly, since the diameter P2 of the bent tube portion <NUM> is larger than the pitch of the plural rows of tubes <NUM>, stress applied to the flat tube <NUM> is alleviated. Furthermore, since the fin <NUM> is also provided in the space in the bent tube portion <NUM>, it is possible to improve efficiency in heat transfer.

Here, the fin <NUM> is disposed not only between the plural rows of tubes <NUM> but also in the internal space in the bent tube portion <NUM> without a finless region.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope of the invention as disclosed in the accompanying claims.

Claim 1:
A condenser (<NUM>) for a refrigerator comprising a heat exchange unit configured to receive, at one side thereof, refrigerant which has been compressed in a compressor (<NUM>), to perform heat exchange between the refrigerant and air and to discharge the refrigerant, which has exchanged heat with the air, to an evaporator (<NUM>),
wherein the heat exchange unit includes a flat tube (<NUM>), through one end of which the refrigerant is able to be introduced and through a remaining end of which the refrigerant is able to be discharged, thereby performing heat exchange between the refrigerant and the air,
wherein the flat tube (<NUM>) includes at least one bent tube portion (<NUM>) defining plural rows of tubes (<NUM>), which are spaced apart from each other in an up-and-down direction, and
wherein the plural rows of tubes (<NUM>) include an intersection bent portion (<NUM>) and define an intersection bent surface (S), which has a predetermined curvature and intersects the up-and-down direction,
wherein the intersection bent surface (S) of the intersection bent portion (<NUM>) and a bent surface (S2) of the bent tube portion (<NUM>) are disposed in a direction so as to intersect each other,
wherein the intersection bent portion (<NUM>) has a radius of curvature (R1) which is larger than a radius of curvature (R2) of the bent tube portion (<NUM>),
wherein the flat tube (<NUM>) has a longer side (50a) which is disposed parallel to the intersection bent surface (S) of the intersection bent portion (<NUM>),
wherein said longer side is disposed in a direction so as to intersect the bent surface (S2) of the bent tube portion (<NUM>),
wherein each of the bent tube portions (<NUM>) connects the left ends or the right ends of adjacent tube rows (<NUM>), the flat tube (<NUM>) is configured such that the plural rows of tubes (<NUM>) are layered in an up-and-down direction in a zigzag fashion.