JP2016169901A - Fin tube heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fin tube heat exchanger which maintains heat exchange performance while improving the frost resistance in a fin tube heat exchange part disposed at an uppermost stream position when viewed in an air circulation direction.SOLUTION: A fin tube heat exchanger 100 includes: a first fin tube heat exchange part 10 having plate fins 11 and tubes 12; a second fin tube heat exchange part 20 having plate fins 21 and tubes 22; and a third fin tube heat exchange part 30 having louver fins 31 and tubes 32. The first fin tube heat exchange part 10 is disposed in an uppermost stream position in a circulation direction FD. The second fin tube heat exchange part 20 is disposed adjacent to the first fin tube heat exchange part 10. The third fin tube heat exchange part 30 is disposed at a lowermost stream position. A fin pitch FP1 between the plate fins 11 is wider than a fin pitch FP2 between the plate fins 21. Louvers are formed in the louver fins 31.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a finned tube heat exchanger.

As a conventional heat exchanger, there is known a finned tube heat exchanger including a tube through which a refrigerant flows and a plate fin in which a tube hole into which the tube is inserted is formed (for example, see Patent Document 1). ).
The heat exchanger disclosed in Patent Document 1 is an outdoor heat exchanger of a heat pump air conditioner using air as a heat source. Patent Document 1 discloses that the fin interval of the fin group on the air inflow side is arranged sparser than the fin interval of the fin group on the air outflow side.

JP-A-63-3182

By arranging the fin interval of the fin group on the air inflow side to be sparser than the fin interval of the fin group on the air outflow side, water vapor in the air becomes a frost layer in the fin group on the air inflow side and the gap between the fins is blocked. Defects are suppressed.
However, since the fin interval of the fin group on the air inflow side becomes sparse, the heat exchange amount of the fin group on the air inflow side is reduced accordingly, and the heat exchange performance of the heat exchanger is lowered.

  The present invention has been made in view of such circumstances, and is disposed at the most upstream position in the air flow direction in a finned tube heat exchanger that circulates a refrigerant inside and performs heat exchange with air. An object of the present invention is to maintain heat exchange performance while improving frost resistance in the fin tube heat exchange section.

In order to solve the above-described problems, the fin tube heat exchanger of the present invention employs the following means.
The finned tube heat exchanger according to one aspect of the present invention is a finned tube heat exchanger that exchanges heat with air by circulating a refrigerant therein, along an arrangement direction orthogonal to the flowing direction of the air. A plurality of first plate fins arranged in parallel at a first arrangement interval; and a first tube inserted into a first tube hole formed in the first plate fin and allowing the refrigerant to flow therethrough. 1 fin tube heat exchange section, a plurality of second plate fins arranged in parallel at a second arrangement interval along the arrangement direction, and inserted into a second tube hole formed in the second plate fin A second fin tube heat exchange part having a second tube for circulating the refrigerant therein, and a plurality of third plate fins arranged in parallel at a third arrangement interval along the arrangement direction; A third fin tube heat exchanging portion that is inserted into a third tube hole formed in the third plate fin and has a third tube through which the refrigerant flows, and at the most upstream position in the flow direction. The first fin tube heat exchanging portion is disposed, the second fin tube heat exchanging portion is disposed adjacent to the first fin tube heat exchanging portion, and the third fin tube heat exchanging portion is located at the most downstream position in the flow direction. An exchange portion is arranged, the first plate fin and the second plate fin are formed in a flat plate shape, and the first arrangement interval is wider than the second arrangement interval. A cut and raised portion is formed.

According to the finned tube heat exchanger according to one aspect of the present invention, the plurality of first plate fins included in the first finned tube heat exchanging unit disposed at the most upstream position in the flow direction of the air exchanged with the refrigerant. The 1st arrangement interval is wider than the 2nd arrangement interval of a plurality of 2nd plate fins which the 2nd fin tube heat exchange part arranged adjacent to the 1st fin tube heat exchange part has.
Therefore, in the 1st fin tube heat exchange part into which the air of the state which is not dehumidified flows, obstruction | occlusion of the flow path between fins by frost formation is suppressed, and frost resistance can be improved.

Moreover, according to the finned-tube heat exchanger concerning 1 aspect of this invention, a cut-and-raised part is in the some 3rd plate fin which the 3rd finned-tube heat exchange part arrange | positioned in the most downstream position of the distribution direction of air has. Is formed. Since the third plate fin provided with the cut-and-raised portion renews the temperature boundary layer developed on the upstream side with the cut-and-raised portion, heat transfer between the air and the refrigerant can be promoted by a so-called leading edge effect. Thereby, the heat exchange performance of the 1st fin tube heat exchange part which falls in order to improve frost resistance can be improved with the 3rd plate fin of the 3rd fin tube heat exchange part.
Here, the leading edge effect refers to an effect that heat transfer is performed with high efficiency by reducing the thickness of the temperature boundary layer in the vicinity of the inlet (front edge portion) blown in the heat transfer body.

  Thus, according to the finned-tube heat exchanger according to one aspect of the present invention, in the finned-tube heat exchanger that exchanges heat with the air by circulating the refrigerant inside, the fin tube heat exchanger is positioned at the most upstream position in the air flow direction. Heat exchange performance can be maintained while improving frost resistance in the fin tube heat exchange section to be arranged.

In the finned tube heat exchanger according to one aspect of the present invention, the third arrangement interval may be wider than the second arrangement interval.
By doing in this way, the pressure loss of the air by the 3rd plate fin in which a cut-and-raised part is formed can be reduced, the amount of air circulation in the fin tube heat exchanger can be secured, and the heat exchange performance can be improved. .

In the finned tube heat exchanger configured as described above, the third arrangement interval may be wider than the first arrangement interval.
By doing in this way, the pressure loss of the air by the 3rd plate fin in which a cut-and-raised part is formed can further be reduced, and the circulation quantity of the air in a fin tube heat exchanger can be secured further.

  According to the present invention, in the finned tube heat exchanger that circulates a refrigerant inside and performs heat exchange with air, the frosting resistance in the finned tube heat exchanging portion disposed at the most upstream position in the air flowing direction is improved. Heat exchange performance can be maintained while improving.

It is a perspective view which shows one Embodiment of a finned-tube heat exchanger. It is the elements on larger scale which looked at the finned-tube heat exchanger shown in FIG. 1 from upper direction. It is the elements on larger scale which looked at the 3rd fin tube heat exchange part shown in Drawing 1 from the front. It is AA arrow sectional drawing of the 3rd plate fin shown in FIG. It is the elements on larger scale which looked at the fin tube heat exchanger of the 1st comparative example from the upper part. It is the elements on larger scale which looked at the fin tube heat exchanger of the 2nd comparative example from the upper part. It is a figure which shows the change by the operation time of heat exchange amount.

Below, fin tube heat exchanger 100 concerning one embodiment of the present invention is explained with reference to drawings.
The finned tube heat exchanger 100 of the present embodiment is a device that circulates a refrigerant inside and performs heat exchange with air, and is used, for example, as an outdoor heat exchanger of a heat exchange system.
An example of a heat exchange system is an air conditioning system in which one or more indoor heat exchangers are connected to one outdoor heat exchanger. Another example of the heat exchange system is a heat pump hot water supply system using a CO ₂ refrigerant.

Another example of the heat exchange system is a refrigeration system for transporting a refrigerated vehicle having an internal heat exchanger used as an evaporator and an external heat exchanger used as a condenser.
The finned-tube heat exchanger 100 of this embodiment is used as an internal heat exchanger used as an evaporator in a transport refrigeration system.

  As shown in the perspective view of FIG. 1, the finned tube heat exchanger 100 of the present embodiment is arranged at the most upstream position in the flow direction FD of a fan (not shown) that blows air and the air blown by the fan. The first fin tube heat exchange unit 10, the second fin tube heat exchange unit 20 disposed adjacent to the first fin tube heat exchange unit 10 on the downstream side in the flow direction FD, and the most downstream position in the flow direction FD And the third finned tube heat exchanging unit 30.

  The first fin tube heat exchange unit 10 is formed on the plate fins 11 and a plurality of plate fins 11 (first plate fins) arranged in parallel along the arrangement direction AD orthogonal to the air flow direction FD. And a tube 12 (first tube) to be inserted into the tube hole 11a (first tube hole).

  The plate fins 11 are plate-like members formed in a flat plate shape with a metal member such as aluminum. The plate fin 11 is a member in which a cut and raised portion is not formed on the surface like a louver fin 31 described later. The cross-sectional shape of the plate fin 11 can be an uneven shape such as a mountain shape, an M shape, or a waveform. Further, ribs may be provided on the surface of the plate fin 11.

  The second fin tube heat exchange section 20 is formed on the plate fins 21 and a plurality of plate fins 21 (second plate fins) arranged in parallel along the arrangement direction AD orthogonal to the air flow direction FD. A tube 22 (second tube) to be inserted into the tube hole 21a (second tube hole).

  The plate fins 21 are plate-like members formed in a flat plate shape with a metal member such as aluminum. The plate fin 21 is a member in which a cut-and-raised portion is not formed on the surface like the plate fin 11. The cross-sectional shape of the plate fin 21 can be an uneven shape such as a mountain shape, an M shape, or a waveform. Further, a rib may be provided on the surface of the plate fin 21.

The third fin tube heat exchange section 30 is formed on the louver fins 31 and a plurality of louver fins 31 (third plate fins) arranged in parallel along the arrangement direction AD orthogonal to the air flow direction FD. A tube 32 (third tube) to be inserted into the tube hole 31a (third tube hole).
The louver fin 31 is a plate-like member formed of a metal member such as aluminum, and has a louver 33 (cut-and-raised portion) described later.

The tube 12, the tube 22, and the tube 32 are used as part of a refrigerant circuit for circulating a refrigerant in a heat exchange system formed by the finned tube heat exchanger 100 and an indoor heat exchanger (not shown).
The tube 12, the tube 22, and the tube 32 are formed of a metal member such as copper. The tube 12, the tube 22, and the tube 32 are processed to be plastically deformed by enlarging the diameter with a jig (not shown) in a state where they are inserted into the tube holes 11 a, 21 a, 31 a, It will be in the state contact | adhered to 21a and 31a. As a result, the tube 12 and the plate fin 11, the tube 22 and the plate fin 21, the tube 32 and the louver fin 31 are in close contact with each other, and heat exchange between the refrigerant and the air is performed satisfactorily.

The tube 12, the tube 22, and the tube 32 are connected to each other by a U-bend (not shown) that forms a U-shaped flow path to form one continuous refrigerant circuit. .
Note that a plurality of refrigerant circuits may be formed by the tube 12, the tube 22, and the tube 32 so that the refrigerant branches on the upstream side and merges on the downstream side.

  In the first fin tube heat exchanger 10, the three tube holes 11a are formed at equal intervals in the height direction. Moreover, in the 2nd fin tube heat exchange part 20, the three tube holes 21a are formed so that it may become equal intervals in a height direction. In the third finned tube heat exchanger 30, the three tube holes 31a are formed at equal intervals in the height direction.

As shown in FIG. 1, the position of the tube hole 11a formed in the plate fin 11 and the position of the tube hole 21a formed in the adjacent plate fin 21 are shifted from each other in the height direction ( (Offset) state. Similarly, the position of the tube hole 21a formed in the plate fin 21 and the position of the tube hole 31a formed in the adjacent louver fin 31 are shifted (offset) from each other in the height direction. It is in a state.
By doing in this way, compared with the case where the position of the tube hole 11a and the position of the tube hole 21a are matched in the height direction, and the position of the tube hole 21a and the position of the tube hole 31a are matched in the height direction, The heat exchange performance of the fin tube heat exchanger 100 can be improved.

The partial enlarged view of FIG. 2 is the figure which looked at the finned-tube heat exchanger 100 shown in FIG. 1 from upper direction.
As shown in FIG. 2, the plurality of plate fins 11 of the first fin tube heat exchange unit 10 arranged at the most upstream position in the flow direction FD are along the arrangement direction AD in which the arrangement intervals are orthogonal to the flow direction FD. The first fin pitch FP1 (first arrangement interval) is continuously arranged.

Moreover, as for the several plate fin 21 of the 2nd fin tube heat exchange part 20 which adjoins the 1st fin tube heat exchange part 10 and is arrange | positioned in the downstream of the distribution direction FD, a mutual arrangement space | interval is orthogonal to the distribution direction FD. The second fin pitch FP2 (second arrangement interval) is continuously arranged along the arrangement direction AD.
Further, the plurality of louver fins 31 of the third fin tube heat exchange unit 30 arranged at the most downstream position in the flow direction FD has a third fin pitch along the arrangement direction AD in which the arrangement interval is orthogonal to the flow direction FD. It arrange | positions continuously so that it may become FP3 (3rd arrangement | positioning space | interval).

Here, as shown in FIG. 2, the first fin pitch FP <b> 1 that is the arrangement interval of the plurality of plate fins 11, the second fin pitch FP <b> 2 that is the arrangement interval of the plurality of plate fins 21, and the plurality of louver fins 31. The third fin pitch FP3, which is the arrangement interval, has a relationship represented by the following formula (1).
FP2 <FP1 <FP3 (1)
As specific numerical values of FP1, FP2, and FP3, various values can be adopted. For example, FP1 can be 1.4 mm, FP2 can be 1.3 mm, and FP3 can be 1.6 mm.

The reason why the first fin pitch FP1 is made wider than the second fin pitch FP2 is that the flow path between the fins is blocked by frost formation in the plate fins 11 of the first fin tube heat exchange section 10 into which air that has not been dehumidified flows. This is for suppressing frost resistance and improving frost resistance.
The reason why the third fin pitch FP3 is made wider than the second fin pitch FP2 is that air pressure loss due to the louver fins 31 of the third fin tube heat exchange section 30 provided with the louver 33 is reduced, and the fin tube This is because the amount of air flow in the heat exchanger 100 is secured to improve the heat exchange performance.

By making the third fin pitch FP3 wider than the second fin pitch FP2, the arrangement interval of the louver fins 31 of the third fin tube heat exchange unit 30 is widened, and the pressure loss of air is reduced.
However, since the area of the heat transfer surface for heat exchange between the refrigerant and the air decreases as the arrangement interval of the louver fins 31 increases, the heat exchange performance decreases.
The louver fin 31 of the present embodiment is provided with a louver 33 to maintain the heat exchange performance in order to suppress a decrease in the heat exchange performance due to an increase in the arrangement interval.

As shown in FIG. 3, a louver 33 is provided in the louver fin 31 of the third fin tube heat exchange unit 30. The louver 33 has a plurality of slits extending in the height direction formed in a plate-like member formed in a flat plate shape, and between a pair of slits adjacent in the width direction or between the slit and the end portion of the louver fin 31 in the width direction. The portion sandwiched between the two is cut and raised to protrude from the plane.
Although only a part of the enlarged louver fin 31 is shown in FIG. 3, the louver 33 is provided in each part of the louver fin 31 in the height direction (vertical direction in FIG. 3).

As shown in FIG. 4 (AA arrow cross-sectional view in FIG. 3), the louver 33 formed in the louver fin 31 is cut and raised 33a, 33b, 33c, 33d, in order from the upstream side in the flow direction FD. 33e, 33f, 33g, 33h, 33i, 33j.
As shown in FIG. 4, the cut and raised 33 e and the cut and raised 33 f protrude to the first surface 31 b side of the louver fin 31, and the cut and raised 33 a and the cut and raised 33 j protrude to the second surface 31 c side of the louver fin 31. . Further, the cut-and-raised portions 33b, 33c, 33d, 33g, 33h, 33i, and 33j protrude from both the first surface 31b side and the second surface 31c side of the louver fin 31, respectively.

  The cut-and-raised portions 33a, 33b, 33c, 33d, and 33e form flow paths that guide air from the first surface 31b side to the second surface 31c side of the louver fins 31, as indicated by arrows in FIG. The louver fins 31 that form the flow path serve as the front edge portion of the heat transfer body, so that the thickness of the temperature boundary layer is reduced and heat transfer is performed with high efficiency (front edge effect).

  Similarly, the cut-and-raised portions 33f, 33g, 33h, 33i, and 33j form flow paths that guide air from the second surface 31c side to the first surface 31b side of the louver fins 31, as indicated by arrows in FIG. . The louver fins 31 that form the flow path serve as the front edge portion of the heat transfer body, so that the thickness of the temperature boundary layer is reduced and heat transfer is performed with high efficiency (front edge effect).

  As described above, the louver 33 formed on the louver fin 31 has a plurality of cuts and rises that become the front edge portion of the heat transfer body, and therefore, the air passing through the flow path formed by the cut and raised to the louver fins 31. Heat transfer is promoted.

Next, the fin tube heat exchanger 101 of the first comparative example and the fin tube heat exchanger 102 of the second comparative example will be described.
As shown in FIG. 5, the fin tube heat exchanger 101 of the first comparative example is different from the fin tube heat exchanger 100 of the present embodiment in the first fin tube heat exchange unit 10 and the third fin tube heat exchange unit 30. The configuration is different.

In the fin tube heat exchanger 100 of the present embodiment, the fin pitch FP1 of the plate fins 11 of the first fin tube heat exchange unit 10 is wider than the fin pitch FP2 of the plate fins 21. On the other hand, in the fin tube heat exchanger 101 of the first comparative example, the fin pitch of the plate fins 11 of the first fin tube heat exchange unit 10 ′ is the same as the fin pitch FP2 of the plate fins 21.
Further, in the fin tube heat exchanger 100 of the present embodiment, the third fin tube heat exchange unit 30 has the louver fins 31. On the other hand, the third finned tube heat exchange part 30 ′ of the first comparative example has a plate fin 31 ′ inserted into the tube hole 31′a.

Further, in the finned tube heat exchanger 100 of the present embodiment, the fin pitch FP3 of the louver fins 31 is wider than the fin pitch FP2 of the plate fins 21. On the other hand, in the fin tube heat exchanger 101 of the first comparative example, the fin pitch of the plate fins 31 ′ of the third fin tube heat exchange unit 30 ′ is the same as the fin pitch FP 2 of the plate fins 21.
As described above, the fin tube heat exchanger 101 of the first comparative example has a fin pitch between the first fin tube heat exchange unit 10 ′, the second fin tube heat exchange unit 20 and the third fin tube heat exchange unit 30 ′. All are the same in FP2.

As shown in FIG. 6, the fin tube heat exchanger 102 of the second comparative example is different from the fin tube heat exchanger 100 of the present embodiment in the configuration of the third fin tube heat exchanger 30.
In the fin tube heat exchanger 100 of the present embodiment, the third fin tube heat exchange unit 30 has the louver fins 31. On the other hand, the third finned tube heat exchange part 30 ′ of the second comparative example has a plate fin 31 ′ inserted into the tube hole 31′a.

Further, in the fin tube heat exchanger 100 of the present embodiment, the fin pitch FP3 of the louver fins 31 is wider than the fin pitch FP2 of the plate fins 21. On the other hand, in the fin tube heat exchanger 102 of the second comparative example, the fin pitch of the plate fin 31 ′ of the third fin tube heat exchange section 30 ′ is the same as the fin pitch FP 2 of the plate fin 21.
Thus, in the fin tube heat exchanger 101 of the second comparative example, the fin pitches of the second fin tube heat exchange unit 20 and the third fin tube heat exchange unit 30 ′ are the same at FP2.

Next, the change of the heat exchange amount of the fin tube heat exchanger 100 of the present embodiment due to the operation time is compared with the fin tube heat exchanger 101 of the first comparative example and the fin tube heat exchanger 102 of the second comparative example. I will explain.
FIG. 7 shows the fin tube heat exchanger 100 of the present embodiment with a solid line, the fin tube heat exchanger 101 of the first comparative example with a broken line, and the second comparative example with respect to changes due to the operation time of the heat exchange amount. The fin tube heat exchanger 102 is indicated by a two-dot chain line.

  As shown in FIG. 7, the heat exchange amount of the finned tube heat exchanger 100 of the present embodiment indicated by the solid line gradually increases from the start of operation and reaches a maximum heat exchange amount Q1 at time T1, and thereafter gradually. It has dropped to. The reason why the amount of heat exchange has decreased after the time T1 has elapsed is that frost formation has occurred on the plate fins 11 of the first fin tube heat exchanging section 10 and the heat exchange performance has deteriorated.

On the other hand, the heat exchange amount of the finned tube heat exchanger 101 of the first comparative example indicated by the broken line gradually increases from the start of operation to the maximum heat exchange amount Q1 at time T1, and then gradually decreases. Yes. The maximum heat exchange amount Q1 is the same as that of the finned tube heat exchanger 100 of the present embodiment.
This is because the third fin tube heat exchanging portion 30 of the first comparative example is not a louver fin having a louver but a plate fin 31 ', but the fin pitch FP2 of the first fin tube heat exchanging portion 10' is the same as that of this embodiment. It is because it is narrower than the fin pitch FP1 of the first fin tube heat exchange unit 10.

  However, the heat exchange amount of the fin tube heat exchanger 101 of the first comparative example is less than the heat exchange amount of the fin tube heat exchanger 100 of the present embodiment after time T1. This is because the fin pitch FP2 of the first fin tube heat exchange unit 10 ′ is narrower than the fin pitch FP1 of the first fin tube heat exchange unit 10 of the present embodiment, and the plate fins 11 of the first fin tube heat exchange unit 10 ′. This is because the flow path between the fins is blocked by the frost formation and the air flow rate is reduced.

  Thus, although the fin tube heat exchanger 101 of the first comparative example exhibits the same performance as the fin tube heat exchanger 100 of the present embodiment at the maximum value of the heat exchange amount, Since the decrease is large, the decrease in heat exchange performance due to the passage of operating time is significant. Therefore, the heat exchange performance of the finned tube heat exchanger 100 of the present embodiment exceeds the heat exchange performance of the finned tube heat exchanger 101 of the first comparative example.

  Moreover, the heat exchange amount of the fin tube heat exchanger 102 of the second comparative example indicated by the chain line gradually increases from the start of operation to the maximum heat exchange amount Q2 at time T1, and then gradually decreases. Yes. The maximum heat exchange amount Q2 is lower than the maximum heat exchange amount Q1 in the finned tube heat exchanger 100 of the present embodiment. Further, the heat exchange amount after the time T1 has elapsed is less than the heat exchange amount of the finned tube heat exchanger 100 of the present embodiment.

This is because the fin pitch FP1 of the first fin tube heat exchange unit 10 of the second comparative example is wider than the fin pitch FP2 of the second fin tube heat exchange unit 20, and the third fin tube heat exchange unit 30 ′ has a louver. This is because the plate fin 31 ′ does not have. In the fin tube heat exchanger 102 of the second comparative example, the third fin tube heat exchange reduces the heat exchange performance due to the wide fin pitch of the first fin tube heat exchange unit 10 in order to increase the frost resistance. It cannot be compensated by the part 30 ′.
Thus, the heat exchange performance of the finned tube heat exchanger 100 of the present embodiment exceeds the heat exchange performance of the finned tube heat exchanger 102 of the second comparative example at all times from the start of operation.

The operation and effect of the fin tube heat exchanger 100 of the present embodiment described above will be described.
According to the finned tube heat exchanger 100 of the present embodiment, the fin pitch of the plurality of plate fins 11 included in the first finned tube heat exchanging unit 10 arranged at the most upstream position in the flow direction of the air exchanged with the refrigerant. FP1 is wider than the fin pitch FP2 of the plurality of plate fins 21 included in the second fin tube heat exchange unit 20 disposed adjacent to the first fin tube heat exchange unit 10.
Therefore, in the 1st fin tube heat exchange part 10 in which the air of the state which is not dehumidified flows in, blockade of the channel between fins by frost formation can be controlled, and frost resistance can be improved.

  Moreover, according to the fin tube heat exchanger 100 of this embodiment, the louver 33 is formed in the several louver fin 31 which the 3rd fin tube heat exchange part 30 arrange | positioned in the most downstream position of the distribution direction FD of air has. ing. The louver fin 31 provided with the louver 33 renews the temperature boundary layer developed on the upstream side with the louver 33. Therefore, heat transfer between the air and the refrigerant can be promoted by a so-called leading edge effect. Thereby, the heat exchange performance of the 1st fin tube heat exchange part 10 which falls in order to improve frost resistance can be improved with the louver fin 31 of the 3rd fin tube heat exchange part 30. FIG.

  Thus, according to the finned-tube heat exchanger 100 of this embodiment, in the finned-tube heat exchanger 100 that performs heat exchange with air by circulating a refrigerant inside, the fin tube heat exchanger 100 is at the most upstream position in the air flow direction FD. The heat exchange performance can be maintained while improving the frost resistance in the first fin tube heat exchange section 10 to be arranged.

In the fin tube heat exchanger 100 of the present embodiment, the fin pitch FP3 of the third fin tube heat exchange unit 30 is wider than the fin pitch FP2 of the second fin tube heat exchange unit 20.
By doing in this way, the pressure loss of the air by the louver fin 31 in which the louver 33 is formed can be reduced, the air circulation amount in the fin tube heat exchanger 100 can be secured, and the heat exchange performance can be improved.

Further, the fin pitch FP3 of the third fin tube heat exchange unit 30 is wider than the fin pitch FP1 of the first fin tube heat exchange unit 10.
By doing in this way, the pressure loss of the air by the louver fin 31 in which the louver 33 is formed can be further reduced, and the air circulation amount in the finned tube heat exchanger 100 can be further ensured.

[Other Embodiments]
In the above description, the first fin tube heat exchange unit 10, the second fin tube heat exchange unit 20, and the third fin tube heat exchange unit 30 are provided in order from the upstream side in the air flow direction FD. The aspect of this may be sufficient.
For example, one or more other heat exchange units may be arranged between the second fin tube heat exchange unit 20 and the third fin tube heat exchange unit 30. Therefore, the finned-tube heat exchanger 100 of this embodiment is applicable also to the structure which provided the multiple types of heat exchange part of 3 or more types along the distribution direction FD of air.
The fin tube heat exchanger may have a configuration in which the first fin tube heat exchange unit 10, the second fin tube heat exchange unit 20, and the third fin tube heat exchange unit 30 each have a plurality of rows.

10 1st fin tube heat exchange part 11 Plate fin (1st plate fin)
11a Tube hole (first tube hole)
12 tube (first tube)
20 Second fin tube heat exchange section 21 Plate fin (second plate fin)
21a Tube hole (second tube hole)
22 Tube (second tube)
30 3rd fin tube heat exchange part 31 Louver fin (3rd plate fin)
31a Tube hole (third tube hole)
32 tubes (third tube)
33 louvers
100 fin tube heat exchanger AD arrangement direction FD distribution direction FP1 first fin pitch (first arrangement interval)
FP2 Second fin pitch (second arrangement interval)
FP3 3rd fin pitch (3rd arrangement interval)

Claims (3)

A finned tube heat exchanger that circulates refrigerant inside and exchanges heat with air,
A plurality of first plate fins arranged in parallel at first arrangement intervals along an arrangement direction orthogonal to the air flow direction, and inserted into a first tube hole formed in the first plate fin and inside A first fin tube heat exchange section having a first tube for circulating the refrigerant in
A plurality of second plate fins arranged in parallel at the second arrangement interval along the arrangement direction, and a second tube fin inserted into a second tube hole formed in the second plate fin and circulating the refrigerant therein. A second fin tube heat exchange section having two tubes;
A plurality of third plate fins arranged in parallel at a third arrangement interval along the arrangement direction, and a third tube hole inserted into a third tube hole formed in the third plate fin and the refrigerant flowing inside. A third finned tube heat exchange section having three tubes,
The first fin tube heat exchange section is disposed at the most upstream position in the flow direction, the second fin tube heat exchange section is disposed adjacent to the first fin tube heat exchange section, and the most downstream in the flow direction. The third finned tube heat exchange part is disposed at a position;
The first plate fin and the second plate fin are formed in a flat plate shape, and the first arrangement interval is wider than the second arrangement interval,
A finned tube heat exchanger in which a cut and raised portion is formed in the third plate fin.   The fin tube heat exchanger according to claim 1, wherein the third arrangement interval is wider than the second arrangement interval.   The finned tube heat exchanger according to claim 2, wherein the third arrangement interval is wider than the first arrangement interval.

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