JPH11183076A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger for an air conditioner in which pressure loss in an air side is low even when the space of fins is decreased, so that the heat exchanger can be made compact. SOLUTION: A heat exchanger comprises a pipe 11 in which refrigerant flows, and fins 12b for increasing a heat exchanging efficiency between the refrigerant and air flowing outside the pipe 11. The fins 12b are provided at pitch of 1.1 to 1.4 mm. A fin 12 has louvers 16b for passing air. Two louvers 16b are provided with space b between adjacent fin holes 14. Assuming that the width of the louver 16b is a, the space b is (4.5 to 7)a. An angle formed by the extension of the louver 16b and a straight line for connecting the centers of the fin holes 14 is preferably 10 deg. to 30 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat exchanger,
Particularly, the present invention relates to a heat exchanger suitable for use in an air conditioner for both cooling and heating.

[0002]

2. Description of the Related Art FIG. 6 is a sectional view showing an example of an indoor unit of an air conditioner. The indoor unit 1 includes a suction grill 2, an air filter 3, a casing 4, three heat exchangers 5, It comprises drain pans 6a and 6c, a tangential fan 7, a louver 8 and a flap 9.

When the air conditioner is operated for cooling, the tangential fan 7 of the indoor unit 1 rotates, and the air in the room is cooled through the suction grill 2, the air filter 3 and the heat exchanger 5, and is cooled. The wind direction is determined by the flap 9 and the air is blown into the room. The refrigerant compressed and discharged by the compressor of the outdoor unit (not shown) radiates heat in the condenser and is liquefied.
This refrigerant liquid is distributed to the heat exchanger 5 of the indoor unit 1, absorbs heat while passing through the pipe 11 provided in the heat exchanger 5, cools the air flowing outside the pipe 11, and then returns to the outdoor unit. Returned to compressor.

[0004] During the heating operation, the tangential fan 7 of the indoor unit 1 rotates, and the indoor air is heated through the suction grill 2, the air filter 3 and the heat exchanger 5,
The wind direction is determined by the louver 8 and the flap 9 and the air is blown into the room. The refrigerant discharged from the compressor of the outdoor unit (not shown) is distributed to the heat exchanger 5 and condenses in the pipe 11 provided in the heat exchanger 5 to warm the air. This refrigerant liquid evaporates in the outdoor heat exchanger of the outdoor unit, absorbs heat from outdoor air, gasifies and returns to the compressor.

[0005] In the indoor unit 1 of the air conditioner having the above structure, there is a demand for downsizing in order to obtain a large capacity without changing the size, that is, the external dimensions. Therefore, the performance of the heat exchanger 5 is improved. Need to be measured. FIG. 7 shows the heat exchanger 5
Is shown. The pipe 11 of the heat exchanger 5 is formed of a thin copper tube having a thickness of 0.3 to 0.4 mm. A fin 12 formed of an aluminum material or the like having a thickness of 0.1 to 0.2 mm is interposed outside the pipe 11. For this reason, the fin 12 has a fin hole 14 for inserting the pipe 11 as shown in FIG. In order to reduce the thermal resistance (contact resistance) between the pipe 11 and the fin 12, the pipe 11 is expanded and the fin 1
The gap with 2 has been eliminated.

[0006]

Although the refrigerant flows inside the pipe 11 and the wind is forced to flow through the fins 12, the heat transfer coefficient on the air side is much smaller than the heat transfer of the refrigerant.
Therefore, the fins 12 are provided with cutouts 16a having the shapes and dimensions as shown in FIGS. 8 to 10 to increase the surface area, and make the airflow turbulent by making the shape a curved surface to improve the heat transfer coefficient. The measured fins 12a are used.

In order to make the heat exchanger 5 more compact, the gap between the fins (fin pitch) is
When the diameter is reduced from 1.3 mm to 1.3 mm as shown in FIG. 9, the surface area of the fin increases, but the pressure loss on the air side increases, and there is a problem that the expected effect is not obtained.

[0008] The present invention has been made in view of the above circumstances, and even if the gap between the fins is reduced, the pressure loss on the air side is small, so that the heat exchanger can be made compact and has excellent heat exchange efficiency. The purpose is to provide.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a fin for improving the heat exchange efficiency between the refrigerant and air flowing outside the pipe by inserting the pipe through a fin hole. Wherein the fins have a fin pitch of 1.1 mm to 1.4 mm, and the fins are provided with cuts and raised, and the cuts and raised are formed between adjacent fin holes. It is possible to solve the problem by providing a heat exchanger characterized in that two spaces are provided at an interval and the width of the cut and raised portion is a, and the interval is (4.5 to 7) a. In addition, in a heat exchanger including a pipe through which a refrigerant flows, and a fin in which the pipe is inserted into a fin hole to increase heat exchange efficiency between the refrigerant and air flowing outside the pipe. The fins are cut and raised The cut and raised portion is provided in parallel with an interval between adjacent fin holes and has an angle of 10 ° between an extension of the cut and raised portion and a straight line connecting the centers of the fin holes. The problem can be solved by using a heat exchanger characterized by being up to 30 °.

As described above, the heat exchanger of the present invention has a fin pitch of 1.1 mm to 1.4 mm, so that the heat exchanger can be made compact. Even in such a compact size, two fins are provided between adjacent fin holes at an interval, and the width of the two fins is a. At this time, since the interval is set to be (4.5 to 7) a, the pressure loss on the air side is unlikely to increase, and the air is effectively turbulent by the fins, so that heat exchange is performed. It is a highly efficient heat exchanger.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a heat exchanger according to the present invention is similar to the indoor heat exchanger 5 shown in FIG.
Is a heat exchanger using the fins 12b shown in FIGS. FIG. 1 is a front view showing an example of a fin used in the heat exchanger of the present invention, FIG. 2 is a sectional view taken along line BB of the fin shown in FIG. 1, and FIG. 3 is a fin shown in FIG. A
It is an arrow view. The heat exchanger of the present invention includes a pipe 11 through which a refrigerant flows, and a pipe 11 inserted into a fin hole 14, which contacts the outside of the pipe 11 to form a flow of the refrigerant and air flowing outside the pipe 11. And a fin 12b for improving the heat exchange efficiency between the fins 12b, wherein the fin 12b has a fin pitch p of 1.1 mm to 1.4 mm.
As shown in FIG. 1, the fin 12b is provided with a large number of cuts 16b in parallel with a straight line connecting the centers of the adjacent fin holes 14, and the cut 16b is formed between the fins 14 and the adjacent fin holes 14. The two holes are provided in parallel with each other with a space b between the holes 14 and cut and raised.
When the width of 6b is a (mm), the interval b (mm)
Is (4.5-7) a.

When the fin pitch p is less than 1.1 mm, the air resistance becomes excessive, the air volume and performance tend to decrease, and the noise tends to increase. When the fin pitch p exceeds 1.4 mm, the fin pitch p exceeds 1.4 mm.
The heat exchange efficiency tends to decrease, and it is difficult to make the heat exchanger compact. The desirable range of the fin pitch p is 1.25 to
1.35 mm. If the interval b between the cuts and raises 16b is less than 4.5a, two adjacent cuts and raises 16b
Because they are too close to each other, the air resistance is high, which is inappropriate for reducing the fin pitch, and it is difficult to effectively make the air flow turbulent. If the interval b between the cuts 16b is too large, exceeding 7a, it is difficult to effectively make the air flow turbulent. Preferably, the interval b is (5-6.5)
a.

In the present invention, the fin pitch p of the fins 12b is, for example, about 1.3 mm. FIG.
As shown in FIG. 3, by providing two cuts 16b, 16b in parallel between the fin holes 14 adjacent to the fin holes 14 which are vertically arranged in a line at a predetermined interval b, two by two, The fins 12b have a large number of
6b is provided. The width a of the cut and raised portion 16b is, for example, 1.
A fin 12b having a length of about 2 mm and an interval b between the two cut-and-raised portions 16b, for example, 6.8 mm can be used. As shown in FIG. 3, the length of the cut-and-raised portion 16b of the fin 12b is about 8 mm at the upper side and about 11 mm at the lower side. The height of the cut and raised portion 16b is, for example, about 0.6 mm as shown in FIG.

The fin 12b is 0.1 to 0.2 mm
Molded from an aluminum material or the like having a thickness of At this time, the aluminum material or the like is partially cut in a substantially U-shape or a substantially inverted U-shape, and the uncut portion is bent as a base to form the cut 16b. The cut and raised portions 16b are formed in order to make the flow of air flowing between the fins 12b and the fins 12b turbulent and increase the heat exchange efficiency between the refrigerant flowing through the pipe 11 and the air. The pipe 11 through which the refrigerant passes is inserted into the fin hole 14 which is a hole formed in the fin.

When a heat exchanger having the fins 12b is used as the heat exchanger 5 of the indoor unit 1 shown in FIG.
The air in the room passes through the suction grill 2 and the air filter 3 and is heat-exchanged by the heat exchanger 5 having the fins 12b. The air direction is determined by the louvers 8 and the flaps 9, and the air is blown into the room.
This heat exchanger 5 has a large number of fins 12b at a fin pitch p of 1.1 mm to 1.4 mm, and has two cuts 16b at intervals b between adjacent pipes 11. And the distance b is 1
When the width of 6b is a, it is (4.5-7) a, so that it can be made compact and has excellent heat exchange efficiency between refrigerant and air.

The heat exchanger 5 of the first embodiment is
FIG. 4 is a sectional view of only the rows. When this heat exchanger 5 is used as an evaporator, the air is cooled by the refrigerant in the pipe 11 and the water droplet 18 drips below the pipe 11 and is easily trapped between the fins 12b. The heat transfer area tends to be reduced without flowing down the heat transfer area.

The heat exchanger having the fins 12c shown in FIG. 5 improves this point. As shown in FIG. 5, the heat exchanger of the second embodiment has a fin
6b is vertical, that is, the fin hole 1 through which the pipe 11 is inserted.
The angle formed by the extension of the bottom of the cut and raised portion 16b and the straight line connecting the centers of the adjacent fin holes 14 instead of making the base of the cut and raised portion 16b parallel to the straight line connecting the centers of the four fin holes 14 (Angle on the acute angle side) θ is set to 10 ° to 30 °. Except for this point, the configuration is the same as that of the heat exchanger shown in FIG.

In the case of the heat exchanger of the second embodiment, the refrigerant flowing through the pipe 11
2c is cooled, water in the air is condensed, and water drops are dropped particularly below the pipe 11, but the water drops are caught on the cuts 16b of the fins 12c and flow down along the cuts 16b. Therefore, the water droplets flow down without being large, and the heat transfer area of the fins is not reduced.
Therefore, the heat exchanger of the second embodiment is compact,
Moreover, the heat exchanger is such that the heat transfer area of the fins is hardly reduced depending on the water droplets. If the angle θ is less than 10 °, the fin is sandwiched between the fins and does not easily flow down.
When the angle exceeds 30 °, the inclination of the cut and raised portion is small, so that it is difficult for water droplets to flow down along the cut and raised portion, and the length of the cut and shortened portion is reduced due to the arrangement between pipes.

[0019]

EXAMPLE The fin pitch p was 1.3 mm, the width a of the cut and raised 16b was 1.2 mm, and two cut and raised portions 16b were used.
Fins 12b were prepared having an interval b between 6.8 mm and having the shapes and dimensions shown in FIGS. And the indoor unit of the air conditioner was produced using the heat exchanger of this invention provided with the fin 12b. On the other hand, a conventional fin 12a having the shapes and dimensions shown in FIGS. 8 to 10 was prepared. The fins 12a have a fin pitch of 1.4 mm as shown in FIG. 9, and the fins 16a are six places counted on one side, and have a width of 1.2 as shown in FIG.
mm. And the indoor unit of the air conditioner was produced using the conventional heat exchanger provided with the fin 12a.
Further, an indoor unit was manufactured using a heat exchanger provided with flat fins. Table 1 shows the analysis results of the performance of these indoor units. However, the fin surface temperature (Tw) is 40
゜ C, the inflow air temperature (Ti) was set to 20 ° C.

[0020]

[Table 1]

Table 1 shows the performance as a condenser and the pressure loss of air. Temperature difference Δ between outlet and inlet of air heat exchanger
T indicates a case where the wind speed is 1 m / s. When the conventional fin 12a is used, the fin 12
The present invention using the b-type fins (18.76 k) has a simplified shape such as forming two cut-and-raised portions 16 b between the fin holes 14. The efficiency was good for 15.85 of the plate fin). In terms of temperature efficiency ε, plate fin 0.7
9 compared with 0.96 when the conventional fin 12a was used.
The present invention using the fins 12b is the most efficient.
94 was a bit bad. On the other hand, when the wind speed is 1 m / s, the pressure loss ΔPa of the air per row (row equivalent pressure loss) ΔPa is the smallest at 2.82 Pa of the plate fin,
The maximum was 7.86 Pa when 2a was used, and 5.15 Pa in the case of the present invention using the fin 12b, which was smaller than that when the conventional fin 12a was used.

When the conventional fin 12a and the fin 12b used in the present invention are blown using the same fan and the power of the fan is made the same, the capacity of the present invention using the fin 12b is larger than that of the fan. The capacity of the heat exchanger alone as a condenser (unit capacity ratio) is the same as that of the conventional fin 12.
a was increased by 18% as compared with the case where a was used. The heating capacity of the unit (unit capacity ratio) could be increased by 3%.

[0023]

As described above, according to the present invention,
A compact heat exchanger having excellent heat exchange efficiency can be obtained, and a heat exchanger having excellent heat exchange efficiency, in which the heat transfer area of the fin is hardly reduced due to condensed water droplets.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a fin used for a heat exchanger of the present invention.

FIG. 2 is a sectional view taken along line BB of the fin shown in FIG.

FIG. 3 is a view of the fin shown in FIG.

FIG. 4 is a sectional view of a main part showing an example of the heat exchanger of the present invention.

FIG. 5 is a sectional view of a main part showing another example of the heat exchanger of the present invention.

FIG. 6 is a cross-sectional view illustrating an example of an indoor unit of the air conditioner.

FIG. 7 is a cross-sectional view illustrating an example of a heat exchanger used for an indoor unit.

FIG. 8 is a front view showing a conventional fin used for a heat exchanger.

FIG. 9 is a sectional view of the fin shown in FIG. 8 taken along line BB.

FIG. 10 is a view of the fin shown in FIG.

[Explanation of symbols]

1. Indoor unit, 2. Suction grill, 3. Air filter, 4. Casing, 5. Heat exchanger, 6a, 6
c · · drain pan, 7 · tangential fan,
8. Louver, 9 flap, 11 pipe (copper tube), 12, 12a, 12b, 12c fin, 14
..Fin holes, 16, 16a, 16b
18. Water drops

Claims (3)

[Claims] 1. A heat exchanger comprising: a pipe through which a refrigerant flows; and a fin that is inserted into a fin hole to increase a heat exchange efficiency between the refrigerant and air flowing outside the pipe. The fin has a fin pitch of 1.1.
mm to 1.4 mm, the fin is provided with a cut and raised, two such cuts are provided at an interval between adjacent fin holes, and the width of the cut and raised is a Wherein the interval is (4.5 to 7) a. 2. The heat exchanger according to claim 1, wherein an angle between an extension of the cutting and raising and a straight line connecting the centers of the fin holes is 10 ° to 30 °. 3. A heat exchanger comprising: a pipe through which a refrigerant flows; and a fin through which the pipe is inserted through a fin hole to increase a heat exchange efficiency between the refrigerant and air flowing outside the pipe. The fin is provided with a cut and raised portion, the cut and raised portion is provided in parallel with an interval between adjacent fin holes, and connects an extension line of the cut and raised portion and the centers of the fin holes. An angle between the straight line and the straight line is 10 ° to 30 °.