JP2008215737A - Fin tube type heat exchanger and refrigerating cycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact fin tube type heat exchanger which prevents blocking of a clearance of each fin by frost even in an operation under a condition with frost formation, and has high heat exchanging capacity. <P>SOLUTION: The plate-shaped fin 1 comprises a slit segmented region 4 approximately in parallel with the air flowing direction between heat transfer tubes 2 adjacent to each other, segmentation slits 5 are formed at an upper portion and a lower portion of the slit segmented region 4, and a fin central slit 6 is formed in the slit segmented region 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a finned tube heat exchanger and a refrigeration cycle using the finned tube heat exchanger, and more particularly to improving the heat exchanging ability of the finned tube heat exchanger under low temperature conditions.

As a conventional fin tube type heat exchanger, for example, “a plurality of plate fins arranged in parallel at a predetermined interval so that an air current flows every interval, and the above-mentioned fluid flow inside In a heat exchanger of an air conditioner configured with a plurality of heat transfer tubes inserted and arranged in a zigzag manner vertically with respect to a plurality of flat fins, between the plurality of heat transfer tubes arranged above and below The fifth slit portion provided in the flat plate fin so as to have a predetermined height at a position passing through the vertical center line of the heat transfer tube, and the opposite direction of the flow of air flow with reference to the fifth slit portion The first and second slit portions provided so as to be vertically symmetrical to the plurality of flat plate fins so that the height is gradually lower than that of the fifth slit portion, and the air flow with reference to the fifth slit portion. Flow The third and fourth slit portions provided so as to be vertically symmetrical to the plurality of flat plate fins so that the height gradually increases from a position lower than the height of the fifth slit portion as it goes in the traveling direction. Has been proposed (for example, see Patent Document 1).
Further, for example, “a plurality of flat fins 1 that are arranged in parallel at predetermined intervals and airflow flows between them, and a fluid flows inside and zigzags vertically at right angles to the plurality of flat fins 1. In order to increase the heat transfer efficiency by turbulently flowing the airflow around the heat transfer tube 2 on the front and back surfaces of the flat plate fins 1, the flow direction of the airflow A slit-like cut-and-raised group 10 is formed at a predetermined interval between the plurality of heat-transfer tubes 2 along the rear side of the heat-transfer tube 2 by mixing the airflow turbulent by the slit-like cut-and-raised group 10. In order to effectively reduce the blind spot flow area generated in the above, a louver-like cut-and-raised portion 20 is formed to be inclined with respect to the flat plate fin 1 in the middle portion of the slit-like cut-and-raised group 10 along the flow direction of the airflow. (Example Has been proposed as that field refer to Patent Document 2).

Japanese Patent Laid-Open No. 10-206085 (paragraph number 0008, FIGS. 6 and 7) JP-A-8-49870 (paragraph number 0010, FIG. 1)

  2. Description of the Related Art Conventionally, fins of a finned tube heat exchanger have been provided with a cut and raised portion called a slit by press working or the like in order to improve heat exchange capability (see, for example, Patent Documents 1 and 2). When there is no slit on the fin surface, a temperature boundary layer develops on the fin surface along the flow of gas (for example, air) that exchanges heat with the fin, and heat exchange between air and the fin is hindered. By providing the slit on the fin surface, the temperature boundary layer is divided and updated for each slit, and heat exchange between air and the fin is promoted.

  However, when the finned tube heat exchanger is used as a heat exchanger for an outdoor unit of an air conditioner under a low outdoor temperature condition where the outdoor temperature is about 2 ° C. or less, the condensed water adhering to the surface of the heat transfer tubes and fins is frozen. It may frost. In particular, a large amount of frost is formed near the slit having a high heat transfer rate, and the gap between the fins may be blocked by frost. For this reason, when using a fin tube type heat exchanger as an outdoor heat exchanger of an air conditioner, a slit could not be provided on the fin surface, and the heat exchange capability was reduced. In this case, in order to improve the heat exchange capacity during normal operation (outdoor air temperature of about 0 ° C. or more), the heat exchanger itself can be enlarged or the fan speed can be increased to increase the heat exchanger and heat The air flow to be exchanged must be increased. Therefore, there are problems such as an increase in the outdoor unit installation area, an increase in material cost of the finned tube heat exchanger, and an increase in noise due to an increase in fan power.

  The present invention has been made to solve the above-described problems, and even when operating under conditions where frost formation occurs, the gap between the fins can be prevented from being blocked by frost, and heat exchange can be performed. A fin-tube heat exchanger with high capacity and compactness is obtained. Moreover, the refrigerating cycle with high heat exchange capability using this fin tube type heat exchanger is obtained.

  In the finned tube heat exchanger according to the present invention, a plurality of plate-like fins stacked in parallel at a predetermined interval and through which gas passes, and a plurality of plate-like fins arranged through the plate-like fin in the stacking direction In the finned tube heat exchanger having the heat transfer tube, the fin includes a slit division region in a column direction substantially parallel to the gas flow direction between the heat transfer tubes adjacent in the vertical direction. A first slit is provided on the fins above and below the region, and a second slit is provided on the fin in the slit division region.

  In this invention, since the fin is provided with the slit dividing region, the fin tube type heat exchanger in which the conventional slit is provided in the fin is frosted, and even in an environment where the gap between the fins is blocked by frost and cannot be used. Since the air flow path can be secured, a high heat exchange capability can be maintained. For this reason, compared with the fin tube type heat exchanger which does not provide the slit in the fin conventionally used, a heat exchanger capacity and a compact fin tube type heat exchanger can be used. In addition, it is possible to provide a refrigeration cycle having a high heat exchange capability using the finned tube heat exchanger.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view of a main part showing a finned tube heat exchanger 20 according to Embodiment 1 of the present invention. FIG. 2 is a main part side view showing the finned tube heat exchanger 20 according to the first embodiment. 3A and 3B are cross-sectional views taken along the lines AA and BB in FIG. 1, respectively, FIG. The finned tube heat exchanger 20 according to the first embodiment will be described below with reference to these drawings.

  As shown in FIGS. 1 and 2, the plate-like fins 1 are laminated in parallel in the lamination direction (direction shown in FIG. 1) at a predetermined interval Fp (fin pitch). The heat transfer tubes 2 are penetrated and held in the laminating direction by fin collars 3 provided on the plate-like fins 1 and arranged at predetermined intervals in the step direction (direction shown in FIG. 1).

  In the plate-like fin 1, the slit division region 4 has a stepwise width L <b> 1 in the column direction (the direction shown in FIG. 1, substantially parallel to the air flow direction) at the substantially central portion of the adjacent heat transfer tube 2. Is formed. A split slit 5 corresponding to the first slit of the present invention is provided above and below the slit split region 4. In addition, a fin central portion slit 6 corresponding to the second slit of the present invention is provided at a substantially central portion in the slit division region 4. The dividing slit 5 is divided into two in the column direction (substantially parallel to the air flow) with the fin center slit 6 as a substantial center. That is, the divided slits 5 and the fin central slit 6 form three rows of slits in the row direction as a whole.

As shown in FIG. 3, the split slit 5 and the fin central portion slit 6 are cut and raised from the plate-like fin 1 and are parallel to the leg portions 5 a and 6 a and the plate-like fin 1 inclined with respect to the plate-like fin 1, respectively. It consists of cut-and-raised parts 5b and 6b, and is formed so that the side ends of the cut-and-raised parts 5b and 6b face each other in the air flow direction. The slit height H6 of the fin central slit 6 is formed lower than the slit height H5 of the divided slit 5.
As shown in FIG. 1, the leg 5 a of the split slit 5 is provided in parallel to the slit split region 4 on the slit split region 4 side, and is inclined so as to face the heat transfer tube 2 on the heat transfer tube 2 side. Is provided.

  In the finned tube heat exchanger 20 according to the first embodiment, as the heat transfer tube 2, for example, a metal pipe having an outer shape of 7 mm, 7.94 mm, or 9.52 mm is used. As the diameter of the fin collar into which the heat transfer tube 2 is inserted, 7.55 mm, 8.54 mm, 10.2 mm, or the like is used. The arrangement pitch of the heat transfer tubes 2 in the heat transfer tube step direction is set to 20.4 mm, for example. When a plurality of heat transfer tubes 2 are arranged in the row direction, the arrangement pitch of the heat transfer tubes 2 in the row direction is set to 18 mm and 22 mm. However, all of these values are merely examples, and the present invention is not limited to these values. In the first embodiment, only one row of the heat transfer tubes 2 is arranged in the row direction, but two rows or more may be provided.

  FIG. 4 is an explanatory diagram of the air flow when the finned tube heat exchanger 20 according to Embodiment 1 of the present invention is frosted. During normal operation (outdoor air temperature is about 0 ° C. or higher), the temperature boundary layer formed on the plate fin 1 by the air flowing in from the windward side is divided and updated by the dividing slit 5 and the fin central slit 6. The heat exchange capacity of the fin tube type heat exchanger 20 is improved. Moreover, since the leg part 5a of the division | segmentation slit 5 is inclined and provided so as to oppose the heat exchanger tube 2, the air which flows the back of the heat exchanger tube 2 which is an air flow downstream is made into the flow along the heat exchanger tube 2. Can be formed. For this reason, when there is no division slit 5, the heat transfer fall by the dead water area (velocity deficit field) which occurs behind heat exchanger tube 2 can be prevented.

  However, when operating under conditions in which frost formation occurs at an outdoor air temperature of about 2 degrees or less, frost adheres from the air flow upstream side end of the split slit 5 and fin central slit 6 having high heat exchange capability. start. Then, the frost adhering to the division | segmentation slit 5 and the fin center part slit 6 grows, and between the adjacent plate-like fins 1 will be obstruct | occluded by frost formation in the division | segmentation slit 5 vicinity. However, since the slit division region 4 is provided in the fin tube type heat exchanger 20 in the first embodiment and the slit height of the fin central portion slit 6 is lower than the division slit 5, the air is shown in FIG. 4. It can flow through the air channels 7a and 7b shown. Further, even when frosting grows and the gap between adjacent plate-like fins 1 in the vicinity of the fin central slit 6 is closed by frosting, the air is shown in FIG. It can flow through 7a without any problem. The split slit 5 is divided into two in the column direction (in the direction parallel to the air flow) with the fin central slit 6 as a center, and the split slit 5 and the fin central slit 6 form three slits in the column direction as a whole. Therefore, a wide air flow path 7a can be secured.

FIG. 5 is an explanatory diagram of the air flow during frost formation of the finned tube heat exchanger 20 in which the slit division region 4 as a comparative example is not provided. When the adjacent plate-like fins 1 near the split slit 5 are blocked by frost due to frost formation, there is no air flow path in the finned tube heat exchanger 20 (air flow path 7c), and the ventilation resistance is large. Become.
FIG. 6 shows the amount of frost formation in the finned tube heat exchanger 20 provided with the slit dividing region 4 in Embodiment 1 and the finned tube heat exchanger 20 provided with no slit dividing region 4 as a comparative example. It is a characteristic view which shows the relationship between ventilation resistance. Here, the ventilation resistance is a pressure difference between the static pressure of air flowing into the finned tube heat exchanger 20 and the static pressure of air flowing out of the finned tube heat exchanger 20. In the finned tube heat exchanger 20 provided with the slit division region 4 in the first embodiment, by providing the slit division region 4, an increase in ventilation resistance due to an increase in the amount of frost formation is suppressed. For this reason, compared with the fin tube type heat exchanger 20 in which the slit division | segmentation area | region 4 is not provided, ventilation resistance is small.

  FIG. 7 is a characteristic diagram showing the relationship between the ratio L1 / L2 between the width L1 of the slit division region 4 shown in FIGS. 1 and 2 and the distance L2 between the adjacent fin collars 3, and the ventilation resistance. In the first embodiment, since the heat transfer tube 2 is inserted and held in the fin collar 3 and is provided in the plate fin 1, the distance L2 between the adjacent fin collars 3 is the adjacent plate fin in the present invention. This corresponds to the length in the step direction in the cross section perpendicular to the air flow direction formed by the heat transfer tube 2 adjacent to 1. As the value of L1 / L2 increases, the ventilation resistance decreases. This is because the flow rate of air flowing through the slit division region 4 has increased because the width L1 of the slit division region 4 has increased. Moreover, it is because the air which flows between the adjacent plate-like fins 1 is less affected by the turbulent flow generated by passing through the dividing slit 5.

  FIG. 8 is a characteristic diagram showing the relationship between the slit height H5 of the divided slit 5 and the ventilation resistance. When the slit height H5 of the divided slit 5 is larger than 1/3 of the fin pitch Fp of the adjacent plate-like fins 1, the draft resistance decreases as H5 becomes smaller. In H5 ≦ Fp / 3, the low ventilation resistance is kept almost constant. This is because the fin pitch Fp of the adjacent plate-like fins 1 is widened, so that the air flowing between the adjacent plate-like fins 1 is less affected by the turbulence generated by passing through the split slits 5. It is.

In accordance with the conditions of FIGS. 7 and 8, the width L1 of the slit divided region 4, the distance L2 between the adjacent fin collars 3, the slit height H5 of the divided slit 5, and the fin pitch Fp of the adjacent plate fins 1 are determined. Therefore, the ventilation resistance of the air which flows through the finned-tube heat exchanger 20 in Embodiment 1 can be suppressed. Therefore, even when the adjacent fins 1 are blocked by frosting in the vicinity of the split slit 5 during the frosting operation (outdoor air temperature is about 2 ° C. or less), the air flow path can be secured. An exchanger can be used.
However, if the influence of the turbulent flow generated by passing through the dividing slit 5 from the air flow is excluded too much, the temperature boundary layer formed on the plate-like fin 1 cannot be divided and renewed during normal operation ( The heat exchange capability at outdoor air temperatures of about 0 ° C. or higher) is reduced.

  FIG. 9 is a characteristic diagram showing the relationship between the ratio L1 / L2 between the width L1 of the slit division region 4 and the distance L2 between the adjacent fin collars 3, and the ratio between the tube outside heat transfer coefficient and the ventilation resistance. Here, the heat transfer coefficient outside the tube is a heat transfer coefficient when the refrigerant flowing in the heat transfer tube 2 exchanges heat with the heat transfer tube 2 → the fin collar 3 → the fin → the air. In the range of L1 / L2 ≦ 0.2, the value of (outer pipe heat transfer coefficient / ventilation resistance) increases rapidly. In the range of 0.2 <L1 / L2 <0.6, the value of (tube outside heat transfer coefficient / ventilation resistance) is gently curved. In the range of 0.6 ≦ L1 / L2, the value of (outer pipe heat transfer coefficient / ventilation resistance) decreases rapidly. In the range of L1 / L2 ≦ 0.2, since the ventilation resistance is large, the flow rate of air flowing between each plate-like fin 1 is small, and the amount of heat exchange between the fin and air is small. For this reason, the heat transfer coefficient becomes small, and the value of (outer tube heat transfer coefficient / ventilation resistance) becomes small. In the range of 0.6 ≦ L1 / L2, the air flow resistance is small and the flow rate of air flowing between the plate fins is large, but the temperature boundary layer in which the divided slits 5 are formed in the plate fins 1 is divided and updated. The amount of heat exchange between the fin and air is reduced. For this reason, the heat transfer coefficient becomes small, and the value of (outer tube heat transfer coefficient / ventilation resistance) becomes small. From FIG. 9, the range of L1 / L2 where the heat transfer coefficient is large and the ventilation resistance is small, that is, the range of L1 / L2 where the heat exchange capacity is large is 0.2 <L1 / L2 <0.6.

  Since the fin-tube heat exchanger 20 configured as described above includes the plate-like fin 1 and the slit division region 4, the fin-tube heat exchanger in which the conventional slits are provided in the fins forms frost, and each fin Even in an environment in which the gap is closed due to frost and cannot be used, an air flow path can be secured, so that the finned tube heat exchanger 20 in which slits are provided in the fins can be used. For this reason, compared with the fin tube type heat exchanger which is not providing the slit in the fin conventionally used, the heat exchanger capacity and the fin tube type heat exchanger 20 with high compactness can be used. In addition, by using the fin tube type heat exchanger 20 having a high heat exchange capability, the outdoor unit can be manufactured in a compact manner, and the outdoor unit installation area can be reduced.

  In general, the heat exchange capacity of a fin tube heat exchanger is inversely proportional to the fin pitch, which is the distance between the fins. Therefore, by using the fin tube type heat exchanger 20 having a high heat exchange capability, the fin pitch can be increased, and the material cost of the fin tube type heat exchanger 20 can be reduced by reducing the number of fins. it can. By using the fin tube type heat exchanger 20 having a high heat exchange capability, noise due to an increase in fan power can be prevented.

  Since the slit height H6 of the fin central slit 6 is formed lower than the slit height H5 of the split slit 5, it is adjacent to the vicinity of the split slit 5 during the frosting operation (the outdoor air temperature is about 2 ° C. or less). Even when the plate-like fins 1 to be closed are blocked by frost formation, air can flow through the upper portion of the fin central slit 6. For this reason, the air flow volume which flows between the plate-shaped fins 1 at the time of frost formation can be ensured more.

  Since the ratio L1 / L2 between the width L1 of the slit division region 4 and the distance L2 between the adjacent fin collars 3 is 0.2 <L1 / L2 <0.6, the frosting operation (the outdoor air temperature is about 2). The heat exchange capacity of the finned tube heat exchanger 20 can be optimally exhibited under both operating conditions during normal operation (outdoor air temperature is about 0 ° C or higher).

  Since the slit height H5 of the divided slits 5 and the fin pitch Fp of the plate fins 1 are set to H5 ≦ Fp / 3, the ventilation resistance of the air flowing between the adjacent plate fins 1 can be kept small.

  Since the leg 5a of the split slit 5 is provided in parallel to the slit split region 4 on the slit split region 4 side and inclined so as to face the heat transfer tube 2 on the heat transfer tube 2 side, the slit split region The width L1 of 4 can be ensured, and when the split slit 5 is not present, a decrease in heat transfer due to a dead water area (speed deficit area) generated on the downstream side of the heat transfer tube 2 can be prevented.

  The split slit 5 is divided into two in the row direction (direction parallel to the air flow) with the fin central portion slit 6 as the center, and the split slit 5 and the fin central portion slit 6 form three rows of slits in the row direction as a whole. Therefore, a wide air flow path 7a can be secured. For this reason, more air flow rate can flow between the plate-like fins 1 during the frosting operation.

Embodiment 2. FIG.
FIG. 10 is an example of a fragmentary sectional view showing a finned tube heat exchanger 20 according to Embodiment 2 of the present invention. FIG. 11 is an example of a cross-sectional view taken along the line CC in FIG. In the second embodiment, items not particularly described are the same as those in the first embodiment, and the same functions are described using the same reference numerals. Protrusions 8 formed by, for example, press working in parallel to the step direction are provided on both side edges of the plate-like fin 1. The cross-sectional shape of the convex portion 8 may be processed into a semicircular shape as shown in FIG. 11A, or may be processed into a triangular shape as shown in FIG.

  In the fin tube type heat exchanger 20 configured as described above, by providing the convex portions 8 on both side edges of the plate-like fin 1, the bending strength of the plate-like fin 1 can be increased and the deflection can be reduced. . For this reason, the stacking process of the plate-like fins 1 can be speeded up. Even if a bending moment is applied from the outside, the distance L2 between the slit height H5 of the divided slit 5 and the fin pitch Fp of the plate-like fin 1 and the width L1 of the slit divided region 4 and the adjacent fin collar 3 is obtained. The ratio L1 / L2 can be kept at the setting conditions at the time of assembly, and the heat exchange capacity of the finned tube heat exchanger 20 can be maintained.

Embodiment 3 FIG.
FIG. 12 is an example of a fragmentary sectional view showing a finned tube heat exchanger 20 according to Embodiment 3 of the present invention. FIG. 13 is an example of an EE cross-sectional view in FIG. At substantially the center in the step direction of the slit division region 4, convex portions 9 formed by, for example, press working in parallel with the row direction are provided on the air flow upstream side and downstream side of the fin center slit 6. . The cross-sectional shape of the convex portion 8 may be processed into a semicircular shape as shown in FIG. 13A, or may be processed into a triangular shape as shown in FIG.

  In the fin tube type heat exchanger 20 configured as described above, the convex portions 9 are provided on the air flow upstream side and the downstream side of the fin central slit 6 at the substantially central portion in the step direction of the slit dividing region 4. Therefore, the buckling strength of the plate-like fin 1 can be increased and the buckling can be reduced. For this reason, the stacking process of the plate-like fins 1 can be speeded up. Even when a compression load is applied from the outside, the distance L2 between the slit height H5 of the divided slit 5 and the fin pitch Fp of the plate-like fin 1 and the width L1 of the slit divided region 4 and the adjacent fin collar 3 is L2. The ratio L1 / L2 can be kept at the setting conditions at the time of assembly, and the heat exchange capacity of the finned tube heat exchanger 20 can be maintained.

Embodiment 4 FIG.
FIG. 14 is a cross-sectional view of a main part showing a finned tube heat exchanger 20 according to Embodiment 4 of the present invention. The leg 5a of the split slit 5 on the slit split region 4 side is provided in parallel with the leg 5a of the split slit 5 on the heat transfer tube 2 side. That is, the leg part 5a of the dividing slit 5 on the slit dividing region 4 side is provided in a shape opened to the upstream side of the air flow.
By comprising in this way, an air flow can be induced | guided | derived to the fin center part slit 6, and the further improvement of heat exchange capability can be aimed at.

Embodiment 5. FIG.
FIG. 15 is a cross-sectional view of a main part showing a finned tube heat exchanger 20 according to Embodiment 5 of the present invention. The slit portion 10 of the plate-like fin 1 is provided with a slit division region 4, a division slit 5, and a fin central portion slit 6. Further, the plate-like fin 1 flat part 11 is not provided with the slit dividing region 4, the dividing slit 5, and the fin central part slit 6. These slit portions 10 and flat portions 11 are alternately arranged between the heat transfer tubes 2.
By configuring in this way, even when the area between the plate-like fins 1 adjacent to the split slit 5 and the fin central slit 6 is blocked by frost during the frost operation (the outdoor air temperature is about 2 ° C. or less), Air can flow through the flat part. For this reason, the air flow volume which flows between the plate-like fins 1 at the time of frost formation can be ensured more, and the fall of heat exchange efficiency can be prevented.

Embodiment 6 FIG.
FIG. 16 is a cross-sectional view of a main part showing a finned tube heat exchanger 20 according to Embodiment 6 of the present invention. Split slits 5 are provided in the upper and lower portions of the slit split region 4. In addition, a fin central portion slit 6 corresponding to the second slit of the present invention is provided at a substantially central portion in the slit division region 4. The dividing slit 5 is divided into two in the column direction (direction parallel to the air flow) with the fin center slit 6 as a substantial center. Each of the divided slits 5 divided into two is further divided into two in the column direction (direction parallel to the air flow). That is, the divided slits 5 and the fin central slit 6 form five rows of slits in the row direction as a whole.
With this configuration, the ventilation resistance is slightly increased, but the ability to divide and update the temperature boundary layer formed on the plate-like fin 1 is increased, and the heat exchange capability can be further improved.

Embodiment 7 FIG.
FIG. 17 is an example of a refrigeration cycle in which any one of the fin-tube heat exchangers 20 described in the first to sixth embodiments is used as an outdoor heat exchanger. The compressor 21, the four-way valve 22, the indoor heat exchanger 23, the expansion valve 24, and the fin tube heat exchanger 20 that is an outdoor heat exchanger are sequentially connected by a refrigerant pipe to constitute a refrigeration cycle. The refrigerant flow during heating is in the direction indicated by the arrows in FIG. The gaseous refrigerant compressed by the compressor 21 passes through the four-way valve 22 and enters the indoor heat exchanger 23. The indoor heat exchanger 23 radiates heat by exchanging heat with air sent from the blower 25. The refrigerant that has exchanged heat with the indoor heat exchanger 23 becomes a supercooled liquid refrigerant and enters the expansion valve 24. The low-temperature and low-pressure refrigerant expanded by the expansion valve 24 enters a two-phase state with a low dryness, and enters the finned tube heat exchanger 20 that is an outdoor heat exchanger. The fin tube type heat exchanger 20 absorbs heat by heat exchange with the air sent out from the blower 26. The refrigerant that has absorbed heat by exchanging heat with outdoor air in the finned tube heat exchanger 20 evaporates into a gas state and enters the compressor 21.

  Thus, the fin tube type heat | fever which has the said each outstanding characteristic by using the fin tube type heat exchanger 20 in any one of this Embodiment 1- Embodiment 6 for an outdoor heat exchanger. A refrigeration cycle including the exchanger 20 can be provided. In addition, the indoor heat exchanger 23 does not need to use any of the fin tube type heat exchangers 20 described in the first to sixth embodiments, and is conventionally used, for example, a fin tube type heat exchange. A vessel is sufficient.

It is principal part sectional drawing of the fin tube type heat exchanger 20 which shows Embodiment 1 of this invention. It is a principal part side view of the finned tube type heat exchanger 20 which shows Embodiment 1 of this invention. It is AA sectional drawing and BB sectional drawing shown in FIG. 1, (a) is AA sectional drawing, (b) is BB sectional drawing. It is explanatory drawing of the air flow at the time of frost formation of the finned-tube type heat exchanger 20 which shows Embodiment 1 of this invention. It is explanatory drawing of the air flow at the time of frost formation of the finned-tube type heat exchanger 20 in which the slit division | segmentation area | region 4 is not provided. In the finned tube heat exchanger 20 provided with the slit division region 4 and the finned tube heat exchanger 20 not provided with the slit division region 4 according to the first embodiment of the present invention, the amount of frost formation and ventilation resistance It is a characteristic view which shows a relationship. It is a characteristic view which shows ratio L1 / L2 of the width | variety L1 of the slit division | segmentation area | region 4 in Embodiment 1 of this invention, and the distance L2 between the adjacent fin collars 3, and the ventilation resistance. It is a characteristic view which shows the relationship between the slit height H5 of the division | segmentation slit 5 in this Embodiment 1 and ventilation resistance. The characteristic view which shows ratio L1 / L2 of the width L1 of the slit division | segmentation area | region 4 in Embodiment 1 of this invention and the distance L2 between the adjacent fin collars 3, and the ratio of the ratio of a pipe | tube outer side heat transfer rate and ventilation resistance. It is. It is an example of principal part sectional drawing of the fin tube type heat exchanger 20 which shows Embodiment 2 of this invention. It is an example of CC sectional drawing shown in FIG. It is an example of principal part sectional drawing of the fin tube type heat exchanger 20 which shows Embodiment 3 of this invention. It is an example of EE sectional drawing shown in FIG. It is principal part sectional drawing of the finned-tube type heat exchanger 20 which shows Embodiment 4 of this invention. It is principal part sectional drawing of the finned tube type heat exchanger 20 which shows Embodiment 5 of this invention. It is principal part sectional drawing of the fin tube type heat exchanger 20 which shows Embodiment 6 of this invention. It is an example of the refrigerating cycle which used any fin tube type heat exchanger 20 as described in Embodiment 1- Embodiment 7 of this invention for the outdoor heat exchanger.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plate fin, 2 Heat exchanger tube, 3 Fin collar, 4 Slit division area, 5 Division slit, 5a Division slit leg part, 5b Division slit cut and raised part, 6 Fin center part slit, 6a Fin center part slit leg part, 6b Fin center part slit cut and raised part, 7a air flow path, 7b air flow path, 7c air flow path, 8 convex part, 9 convex part, 10 slit part, 11 flat part, 20 fin tube heat exchanger, 21 compressor , 22 Four-way valve, 23 Indoor heat exchanger, 24 Expansion valve, 25 Fan, 26 Fan, Fp Fin pitch, H5 slit height, H6 slit height, L1 Slit divided region 4 width, L2 Distance between fin collars 3 .

Claims (12)

A plurality of plate-like fins stacked in parallel at a predetermined interval, through which gas passes;
In a finned tube heat exchanger having a plurality of heat transfer tubes arranged through the plate fins in the stacking direction,
The fin includes a slit division region in a row direction substantially parallel to the gas flow direction between the heat transfer tubes adjacent in the vertical direction,
A first slit is provided on the upper and lower fins of the slit dividing region,
A fin-tube heat exchanger, wherein a second slit is provided on the fin in the slit division region.   The fin tube heat exchanger according to claim 1, wherein a slit height of the second slit is lower than a slit height of the first slit. The stepwise width of the slit division region is L1,
When the stepwise length in a cross section perpendicular to the gas flow direction formed by the adjacent heat transfer tubes and the adjacent fins is L2,
0.2 <L1 / L2 <0.6
The finned tube heat exchanger according to claim 1 or 2, wherein The predetermined interval between the fins is Fp,
When the slit height of the first slit is H5,
Fp / 3 ≧ H5
The finned tube heat exchanger according to any one of claims 1 to 3, wherein   The fin tube type heat exchanger according to any one of claims 1 to 4, wherein a convex portion is provided in a side edge portion of the fin in parallel with the step direction.   6. The finned tube heat exchanger according to any one of claims 1 to 5, wherein a convex portion is provided in the slit division region in parallel with the column direction. The first slit is
The slit leg on the slit division area side is parallel to the slit division area,
The finned tube heat exchanger according to any one of claims 1 to 6, wherein the heat transfer tube side slit leg portion is inclined so as to face the heat transfer tube. The first slit is
The slit leg on the heat transfer tube side is inclined so as to face the heat transfer tube,
The slit leg on the slit division region side and on the upstream side in the gas flow direction is inclined with respect to the slit division region and opens on the upstream side in the gas flow direction. The finned tube heat exchanger according to any one of claims 1 to 6. On the fin,
A slit portion provided with the slit division region, the first slit and the second slit;
A flat portion where no slit is provided on the fin,
The finned tube heat exchanger according to any one of claims 1 to 8, wherein the finned tube heat exchanger is alternately arranged between the heat transfer tubes. The first slit is divided into two in the column direction around the second slit,
The fin tube type heat exchanger according to any one of claims 1 to 9, wherein the first slit and the second slit form a total of three rows of slits in the row direction. The first slit is divided into two in the column direction around the second slit,
Each of the first cut and raised portions divided into two is further divided into two in the column direction,
The fin tube type heat exchanger according to any one of claims 1 to 9, wherein the first slit and the second slit form a total of five rows of slits in the row direction.   A refrigeration cycle using the finned tube heat exchanger according to any one of claims 1 to 11.

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