JP2001304783A - Outdoor heat exchanger, indoor heat exchanger, and air conditioner - Google Patents

Abstract

[PROBLEMS] To use an R32 single refrigerant or a R32 composition-rich mixed refrigerant to reduce the diameter of a heat transfer tube of a heat exchanger of an air conditioner, and to use a heat exchanger (13, 15). By specifying a specific configuration, it is possible to reduce the size while suppressing a decrease in performance. SOLUTION: The average inner diameter d of the heat transfer tube (13p) of the outdoor heat exchanger (13) is set to 6.0 mm ≦ d ≦ 6.5 mm, and the average inner diameter d of the heat transfer tube (15p) of the indoor heat exchanger (15) is set to 5.4. mm ≦ d ≦ 5.9 mm. When, for example, slit fins or louver fins are used for the plate fins (13f, 15f), the fin pitch P1 of the outdoor heat exchanger (13) is set to 1.2 mm ≦ P1 ≦ 2.0 mm, and the fin pitch P1 of the indoor heat exchanger is set. 1.0mm ≤ P1 ≤ 1.8m
m.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outdoor heat exchanger, an indoor heat exchanger, and an air conditioner provided with these heat exchangers, and more particularly, to a technique for miniaturizing an outdoor heat exchanger and an indoor heat exchanger. It is about.

[0002]

2. Description of the Related Art Conventionally, an outdoor heat exchanger and an indoor heat exchanger of an air conditioner generally have a plate fin coil type air heat exchanger in which heat transfer tubes arranged vertically and horizontally are passed through many plate fins and fixed. An exchanger is used. As the refrigerant of the air conditioner, for example, R22 or R4
07C or the like is used.

[0003] The air heat exchanger uses an inner grooved heat transfer tube as a heat transfer tube, or uses a slit fin or a louvered fin as a plate fin to improve the heat transfer performance as compared with the conventional heat transfer tube. Improvements have been made, thereby reducing the diameter of the heat transfer tubes. For example, in an air conditioner using R22, while a heat transfer tube having an outer diameter of 9.52 mm was used before, an outer diameter of an outdoor heat exchanger is now 8.0 mm, and an indoor heat exchanger is currently used. Heat transfer tubes with an outer diameter of 7.0 mm are being used. By reducing the diameter of the heat transfer tube in this way, the size of the air heat exchanger can be reduced, and the size of the air conditioner can be reduced.

On the other hand, in order to further reduce the diameter of the heat transfer tube in the future, it is necessary to increase the number of passes in order to prevent an increase in pressure loss in the heat exchanger due to an increase in flow velocity. However, if the number of passes is increased, it becomes difficult for the refrigerant to flow from the flow divider to each pass, and there is a possibility that the refrigerant may drift. Further, when the fin pitch is reduced in accordance with the reduction in the diameter of the heat transfer tube, frost formation in the outdoor heat exchanger and dew formation or icing in the indoor heat exchanger are likely to occur. From the above,
In practice, it has been extremely difficult to reduce the diameter of the heat transfer tube without sacrificing performance.

[0005]

From the viewpoint of preventing global warming, the applicant of the present application uses R32 or a refrigerant mixture thereof, and reduces the filling amount of the refrigerant by utilizing the characteristics of the refrigerant. This has led to the development of a technology that allows the heat transfer tube to be reduced in diameter, and has already filed an application for this technology (Japanese Patent Application No. Hei 11
No. 054289).

[0006] The heat exchanger of the above application specifies the inner diameter when the heat transfer tube is reduced in diameter corresponding to R32, and its main purpose is to reduce the filling amount of the refrigerant as described above. I have. If this technology is used, it is thought that it is possible to make the air heat exchanger smaller by reducing the diameter of the heat transfer tubes without increasing the number of passes. However, the air heat exchanger is actually made smaller. In doing so, it is necessary to specify the specific configuration of the fins and heat transfer tubes so that the performance does not decrease.

The present invention has been made in view of the above, and an object of the present invention is to reduce the diameter of a heat transfer tube of a heat exchanger of an air conditioner by using an R32 single refrigerant or an R32 refrigerant. Using a mixed refrigerant containing a lot of
An object of the present invention is to specify a specific configuration of a heat exchanger and reduce the size of the heat exchanger while suppressing a decrease in performance.

[0008]

According to the present invention, R is used as a refrigerant.
The heat transfer tubes of the air heat exchanger are reduced in diameter using 32 or a mixed refrigerant thereof, and the fin pitch according to the type of the plate fin, and the step pitch and the row pitch of the heat transfer tubes are specified. .

-Constitution- Specifically, the first to eleventh solving means adopted by the present invention are plate fin coils used in an air conditioner (1) for performing a vapor compression refrigeration cycle using R32 or a mixed refrigerant thereof. It is assumed that the outdoor heat exchanger is of the shape, and the average inner diameter d of the heat transfer tubes is 6.0 mm ≦ d ≦ 6.5 mm.

A first solution is to set the plate fin (13f) as a slit fin or a louver fin and set the fin pitch P1 to 1.2 mm ≦ P1 ≦ 2.0 mm. These fins (13f) are plate fins provided with a plurality of small cut-and-raised portions.Slit fins have cut-and-raised portions parallel to the plane of the plate fin, and louver fins have a cut-and-raised portion of the plate fin. It is inclined with respect to a plane.

[0011] The second solution taken by the present invention is:
The plate fin (13f) is a flat fin or a waffle fin, and the fin pitch P1 is set to 0.8 mm ≦ P1 ≦ 1.7 mm. In addition, these fins (13f)
The plate is not cut and raised, the flat fin is a flat plate fin, and the waffle fin is a plate fin formed into a corrugated shape.

Further, a third solution taken by the present invention is:
The plate fin (13f) is a slit fin or a louver fin having a larger area cut and raised from the windward to the leeward, and the fin pitch P1 is set to 1.0 mm ≦ P1 ≦ 1.85 mm.

A fourth solution taken by the present invention is:
The product A of the step pitch P2 of the heat transfer tube (13p) and the row pitch P2 is 220 m
m ² ≦ A ≦ 420 mm ² .

Further, a fifth solution taken by the present invention is:
In the fourth solution, the step pitch of the heat transfer tube (13p)
The product A of P2 and the row pitch P3 is further limited to 250 mm ² ≦ A ≦ 39
Are those set to 0mm ^2.

Further, a sixth solution taken by the present invention is:
The plate fin according to the fourth or fifth solution,
(13f) is a slit fin or a louver fin, and a seventh solution is that the fin pitch P1 is set to 1.2 mm ≦ P1 ≦ 2.0 mm in the sixth solution.

An eighth solution taken by the present invention is:
The plate fin according to the fourth or fifth solution,
(13f) is a flat fin or a waffle fin, and the ninth solution is that the fin pitch P1 is set to 0.8 mm ≦ P1 ≦ 1.7 mm in the eighth solution.

According to a tenth aspect of the present invention, in the above-mentioned fourth or fifth aspect, the plate fin (13f) is cut and raised from the windward side to the leeward side to increase the area of the slit fin. Alternatively, a louver fin is used, and an eleventh solution is the fin pitch P1 set to 1.0 mm ≦ P1 ≦ 1.85 mm in the tenth solution.

Next, the twelfth to twenty-second aspects of the present invention will be described.
The solution of the present invention is based on the assumption that a plate fin coil type indoor heat exchanger used in an air conditioner (1) that performs a vapor compression refrigeration cycle using R32 or a mixed refrigerant thereof, and that the average inner diameter d of the heat transfer tube (15p) is 5.4 mm ≤ d ≤ 5.9 mm.

The twelfth solution is that the plate fin (15f) is a slit fin or a louver fin and the fin pitch P1 is set to 1.0 mm ≦ P1 ≦ 1.8 mm.

A thirteenth solution adopted by the present invention is that a plate fin (15f) is a flat fin or a waffle fin and a fin pitch P1 is 0.6 mm ≦ P1 ≦ 1.5 m
It is set to m.

A fourteenth solution taken by the present invention is that a plate fin (15f) is cut and raised from the windward side to the leeward side, and has a fin pitch P1 of 0.8 mm as a slit fin or a louver fin having a larger area. ≤P1≤1.65
It is set to mm.

A fifteenth solution taken by the present invention is that the product A of the step pitch P2 and the row pitch P3 of the heat transfer tube (15p) is
180 mm ² ≦ A ≦ 250 mm ² .

According to a sixteenth aspect of the present invention, in the fifteenth aspect, the product A of the step pitch P2 and the row pitch P3 of the heat transfer tube (15p) is further limited to 190 mm ² ≦
A ≦ 240 mm ² is set.

According to a seventeenth aspect of the present invention, in the fifteenth or sixteenth aspect, the plate fin (15f) is a slit fin or a louver fin. In the seventeenth solution, the fin pitch P1 is set to 1.0 mm ≦ P1 ≦ 1.85 mm.

According to a nineteenth aspect of the present invention, in the fifteenth or sixteenth aspect, the plate fin (15f) is a flat fin or a waffle fin. In the nineteenth solution, the fin pitch P1 is set to 0.6 mm ≦ P1 ≦ 1.5 mm.

According to a twenty-first solution of the present invention, in the fifteenth or sixteenth solution, the plate fin (15f) is cut and raised from the windward side to the leeward side to increase the area of the slit fin. Alternatively, the fin pitch P1 is set to 0.8 mm ≦ P1 ≦ 1.65 mm in the twenty-first solution means in the twenty-second solution means.

Next, the twenty-third to thirty-first aspects of the present invention will be described.
Is a compressor (11), an outdoor heat exchanger (13), a pressure reducing mechanism (14), and an indoor heat exchanger (15) so as to perform a vapor compression refrigeration cycle using R32 or a mixed refrigerant thereof. ) Are premised on an air conditioner provided with a refrigerant circuit (10) connected in order.

According to a twenty-third solution, the outdoor heat exchanger (13) is provided with the outdoor heat exchanger according to any one of claims 1 to 11.

According to a twenty-fourth solution of the present invention, the indoor heat exchanger (15) includes the indoor heat exchanger according to any one of claims 12 to 22.

According to a twenty-fifth aspect of the present invention, the outdoor heat exchanger (13) includes the outdoor heat exchanger according to any one of claims 1 to 11, and the indoor heat exchanger (15). The indoor heat exchanger according to any one of claims 12 to 22 is provided.

The twenty-sixth to thirty-first aspects of the present invention
In the air conditioner (1) of the twenty-third, twenty-fourth, or twenty-fifth air conditioners, the refrigerant used is specified.

A twenty-sixth solution is to use R32 as a refrigerant.

The twenty-seventh solution adopted by the present invention is that R32 is used as a refrigerant in an amount of 75% by mass to 100% by mass.
A mixed refrigerant rich in R32 containing less than R32 is used.

According to a twenty-eighth solution of the present invention, a mixed refrigerant of R32 and R125 is used as the refrigerant, and the mixed refrigerant contains R32 of 75% by mass or more and less than 100% by mass. It is.

According to a twenty-ninth aspect of the present invention, a mixed refrigerant of R32 and R134a is used as the refrigerant, and the mixed refrigerant contains R32 of 75% by mass or more and less than 100% by mass. It is.

A thirtieth solution adopted by the present invention is to use a mixed refrigerant of R32 and a hydrocarbon-based refrigerant (HC-based refrigerant) as a refrigerant, and the mixed refrigerant is used in the case where R32 is 75%.
It is to be contained in an amount of not less than 100% by mass and not more than 100% by mass.

According to a thirty-first aspect of the present invention, in the thirtieth aspect, the hydrocarbon-based refrigerant is any one of propane, butane, and isobutane.

-Operation- In each of the above solutions, R32 or a mixed refrigerant thereof is used. R32 is R2 as shown in FIG.
2 and R407c have a larger latent heat ratio, and when the capacity is the same, the mass flow rate of the refrigerant is only about 60% of R22. And if the same heat exchanger is used, the pressure loss is reduced to about 40% of R22. For this reason, even if the heat transfer tube is made thinner by an amount corresponding to the reduced pressure loss, the pressure loss generated in the heat exchanger can be suppressed to the same level as R22,
Within this range, it is not necessary to increase the number of passes.

-Setting of dimensions of heat transfer tube-Here, it is assumed that, for example, in the outdoor heat exchanger (13), a heat transfer tube (13p) having an outer diameter of 8.0 mm is used at R22. The heat transfer tube (13p) generally represents the outer diameter as a nominal size. However, when considering the pressure loss in the tube, it is preferable to represent the heat transfer tube with the average inner diameter. Heat transfer tube with outer diameter of 8.0mm (13p)
Has an average inner diameter of about 7.3 mm to 7.8 mm, although it varies depending on the shape, thickness, and expansion ratio of the inner surface groove. on the other hand,
From the relation of friction loss of the circular pipe, the pressure loss is almost proportional to the 1 / 5th power of the average inner diameter of the heat transfer tube (13p). It can be made about 0.83 times by 1/5 power, and it can be made 6.0 mm to 6.5 mm in terms of average inner diameter.

The above can be considered almost similarly for the indoor heat exchanger (15). In other words, if a heat transfer tube (15p) with an outer diameter of 7.0 mm is used for R22, the average inner diameter is in the range of 6.6 mm to 7.0 mm, and for R32, the average inner diameter is 5.4 mm to 5.9 mm. Can be.

Setting of Fin Pitch R32 has a saturation temperature / pressure gradient ratio of about 60% (63%) of R22 as shown in FIG. The decrease is about 60% of R22
(63%). For this reason, if the pressure loss is the same, the evaporation temperature will be higher than when R22 is used.

In addition, since the evaporation temperature rises as described above, when R32 is used, even if the fin pitch P1 is narrowed as compared with the case where R22 is used, the formation of frost, dew, or icing can be suppressed. it can. Specifically, the fin pitch P1 can be reduced to about 55% to 60% in the case of a slit fin or a louver fin, or about 40% to 45% in the case of a flat fin or a waffle fin. Can be narrowed (Fig. 3,
See FIG. 8). If the fin pitch P1 is set to a value smaller than the conventional value and larger than these values, it is possible to simultaneously reduce the size and improve the performance.

-Setting of step pitch and column pitch- Further, a plate fin coil type air heat exchanger (13, 1
5) is the step pitch P of the heat transfer tubes (13p, 15p) arranged vertically and horizontally.
The performance changes with 2 and the row pitch P3. Heat exchanger (13,1
If the number of stages and the number of rows in 5) are the same, the product of the step pitch P2 and the row pitch P3 is almost proportional to the heat transfer area per fin. When the step pitch P2 and the row pitch P3 are the same and the diameter of the heat transfer tube is small, the gap is widened and the fin efficiency is reduced.
Also, the number of heat transfer tubes (13p, 15p) is the same and the step pitch P2
When the row pitch P3 is reduced, the heat transfer area is reduced, so that the heat exchange performance is reduced. Therefore, step pitch P2 and row pitch
P3 is preferably set to a value suitable for the diameter of the heat transfer tube used.

[0044]

According to the first means for solving the above problems, in the plate fin coil type outdoor heat exchanger used in the air conditioner (1) for performing a vapor compression refrigeration cycle using R32 or its mixed refrigerant, the heat transfer tube (13p ) Of 6.0m
m ≦ d ≦ 6.5 mm. Also, plate fins (13
f) is a slit fin or a louver fin, and the fin pitch P1 is 1.2 mm ≦ P1 ≦ 2.0 mm. This is the fin pitch in the air heat exchanger using the conventional R22.
P1 is generally about 2.0mm, less than 2.0m
m is set to be larger than 60%.

As described above, the diameter of the heat transfer tube (13p) is made smaller than that of the conventional heat transfer tube. The pressure loss does not increase as compared to. Also the fin pitch
Since P1 is specified in the above range, if the fin pitch P1 is set to a value on the upper limit side of the range, frost formation is less likely to occur. The operation can be continued for a long time. vice versa,
If the fin pitch P1 is set to the lower limit of the range,
The size of the outdoor heat exchanger (13) can be further reduced while suppressing frost formation to the same level as before. Therefore, if the fin pitch P1 is set within the above range, it is possible to reduce the size while ensuring the performance.

In the second solution, the first solution
Instead of using a slit fin or a louver fin to set the fin pitch P1 to 1.2 mm ≦ P1 ≦ 2.0 mm in the solution of the above, using a flat fin or a waffle fin to set the fin pitch P1 to 0.8 mm ≦ P1 ≦ 1.7 mm ,
The average inner diameter d of the heat transfer tube (13p) is set to 6.0 mm ≦ d ≦ 6.5 mm as in the first solution. Therefore, similarly to the first solution, frost formation is suppressed while suppressing pressure loss, and downsizing can be achieved while ensuring performance.

In the third solution, the plate fin (13f) is cut and raised from the windward side to the leeward side, and has a fin pitch P1 of 1.0 mm ≦ P1 ≦ 1.85 mm as a slit fin or a louver fin having a large area. And
This is because the characteristics of the plate fin (13f) are intermediate between a normal slit fin or a louver fin and a flat fin or a waffle fin. Therefore, the fin pitch P1 is also smaller than that of the first and second solutions. It is determined as an intermediate value. Therefore, similarly to the first and second solutions, frost formation is suppressed while suppressing pressure loss, and downsizing can be achieved while ensuring performance.

In the third solution, frost formation is less likely to occur on the windward side where frost formation is likely to occur at low temperatures, and on the leeward side, the heat transfer performance can be enhanced by slits and louvers. Therefore, it is possible to improve the performance as a whole.

Further, in the fourth solution, in the outdoor heat exchanger (13), the average inner diameter d of the heat transfer tube (13p) is 6.0 mm.
≦ d ≦ 6.5 mm, and the product A of the step pitch P2 and the row pitch P3 of the heat transfer tube (13p) is set to 220 mm ² ≦ A ≦ 420 mm ² . Within this range, the heat transfer tube (13p) is reduced in diameter while obtaining the same or better performance as when using a heat transfer tube with an outer diameter of 8.0 mm in R22. The outdoor heat exchanger (13) having the above performance can be reduced in size (see FIG. 7).

Further, in the fifth solution means, the fourth solution means
In the above solution, the product A of the step pitch P2 and the row pitch P3 of the heat transfer tube (13p) is further limited to 250 mm ² ≦ A ≦ 390 mm ² . As a result, it is possible to further reduce the size while reducing the diameter, and further enhance the capability.

In addition, the above-described sixth, eighth, and tenth solving means can secure the same or higher performance as before while enabling the heat transfer tube to be reduced in size by reducing the diameter of the heat transfer tube.

In the sixth, eighth, and tenth means, the slit fin or the louver fin is used as the plate fin (13f). P1 is preferably 1.2 mm ≦ P1 ≦ 2.0 mm. In the eighth solution using flat fins or waffle fins, the fin pitch P1 is set to 0.8 mm ≦ P1 ≦ 1.7 mm as in the ninth solution. Is preferred. Further, in the tenth solution using slit fins or louver fins having a larger area cut and raised from the windward to the leeward, the fin pitch P1 is set to 1.0 mm ≦ P1 ≦ 1.85 mm as in the eleventh solution. Is preferred. When the fin pitch P1 is set as described above,
As in the first, second, and third solutions, it is possible to increase the performance while enabling downsizing.

In the twelfth solution, R32
Alternatively, in a plate fin coil type indoor heat exchanger used in an air conditioner (1) that performs a vapor compression refrigeration cycle using the mixed refrigerant, the average inner diameter d of the heat transfer tube (15p)
Is set to 5.4 mm ≦ d ≦ 5.9 mm. The plate fin (15f) is a slit fin or a louver fin, and the fin pitch P1 is set to 1.0 mm ≦ P1 ≦ 1.8 mm.
This is because the fin pitch P1 is generally about 1.8 mm in a conventional air heat exchanger using R22, and is less than 1.8 mm.
m is set to be larger than 55%.

As described above, the diameter of the heat transfer tube (15p) is smaller than that of the conventional heat transfer tube.
2, the pressure loss does not increase as compared with the case where a heat transfer tube having an outer diameter of 7.0 mm is used. In addition, since the fin pitch P1 is specified in the above range, if the fin pitch P1 is set to the upper limit value of the range, dew condensation or icing is less likely to occur, and the fin pitch P1 is set to the lower limit value of the range. If the fin pitch P1 is set, the indoor heat exchanger (15) can be made more compact while dew formation or icing is suppressed to the same level as before. Therefore, it is possible to reduce the size while ensuring the performance.

In the thirteenth solution, flat fins or waffles are used instead of the fin pitch P1 of 1.0 mm ≦ P1 ≦ 1.8 mm using slit fins or louver fins in the twelfth solution. The fin pitch P1 is set to 0.6 mm ≦ P1 ≦ 1.5 mm using fins, and the average inner diameter d of the heat transfer tube (15p) is set to 5.4 mm ≦ d ≦ 5.9 mm as in the twelfth solution. Therefore, similarly to the twelfth solution, dew formation or icing is suppressed while suppressing pressure loss, and downsizing can be achieved while ensuring performance.

Further, in the fourteenth solution, the plate fin (15f) is cut and raised from the windward to the leeward, and as a slit fin or a louver fin having a large area, the fin pitch P1 is set to 0.8 mm ≦ P1 ≦ 1.65 mm. And This is for the same reason as the above-mentioned third solution. Since the characteristics of the plate fin (15f) are intermediate between a normal slit fin or louver fin and a flat fin or waffle fin, the fin pitch is small. P1 is also set to an intermediate value between the twelfth solving means and the thirteenth solving means. Therefore, similarly to the twelfth and thirteenth solutions, dew formation or icing is suppressed while suppressing pressure loss, and the size can be reduced while ensuring performance.

[0057] In the fifteenth solution, in the indoor heat exchanger (15), the average inner diameter d of the heat transfer tube (15p) is set to 5.4 mm.
Assuming that ≦ d ≦ 5.9 mm, the product A of the step pitch P2 and the row pitch P3 of the heat transfer tubes (15p) is 180 mm ² ≦ A ≦ 250 mm ² . Within this range, the heat transfer tube (15p) is reduced in diameter while obtaining the same or better performance as when using a heat transfer tube with an outer diameter of 7.0 mm in R22, and is equivalent to the conventional one. The indoor heat exchanger (15) having the above performance can be reduced in size (see FIG. 9).

In the sixteenth solution, the product A of the step pitch P2 and the row pitch P3 of the heat transfer tube (15p) in the twelfth solution is further limited to 190 mm ² ≦ A ≦ 240 mm ² . . As a result, it is possible to further reduce the size while reducing the diameter, and further enhance the capability.

The ability to secure a performance equal to or higher than that of the prior art while enabling downsizing by reducing the diameter of the heat transfer tube (15p) is the same as in the seventeenth, nineteenth, and twenty-first solutions. It is.

In the 17th, 19th and 21st solutions, the 17th solution using a slit fin or a louver fin for the plate fin (15f) is the first solution.
8, the fin pitch P1 is set to 1.0 mm ≦ P1 ≦ 1.
In the nineteenth solution using flat fins or waffle fins, the fin pitch P1 is preferably set to 0.6 mm ≦ P1 ≦ 1.5 mm as in the twentieth solution. Furthermore, in the twenty-first solution using slit fins or louver fins having a larger area cut and raised from the windward to the leeward, the fin pitch P1 is set to 0.8 mm ≦ P1 ≦ 1.65 mm as in the twenty-second solution. Is preferred. By doing the above,
It is possible to further improve the performance while enabling downsizing.

According to the twenty-third solution, R
The compressor (11), the outdoor heat exchanger (13), the pressure reducing mechanism (14), and the indoor heat exchanger (15) are sequentially connected so as to perform a vapor compression refrigeration cycle using 32 or a mixed refrigerant thereof. In the air conditioner having the refrigerant circuit (10) provided, the outdoor heat exchanger (13) uses the outdoor heat exchanger according to any one of claims 1 to 11 for the outdoor heat exchanger (13). It is possible to improve the performance while reducing the size.

According to the twenty-fourth solution, since the indoor heat exchanger according to any one of claims 12 to 22 is used for the indoor heat exchanger (15), the indoor heat exchanger (15) It is possible to improve the performance while reducing the size.

Further, according to the twenty-fifth means,
The outdoor heat exchanger (13) uses the outdoor heat exchanger according to any one of claims 1 to 11, and the indoor heat exchanger (15) uses the indoor heat exchanger according to any one of claims 12 to 22. Therefore, the performance can be improved while downsizing both the outdoor heat exchanger (13) and the indoor heat exchanger (15).

According to the twenty-sixth to thirty-first solutions, the refrigerant used in the air conditioner is:
It is specified as R32 or an R32-rich mixed refrigerant containing 75% by mass or more of R32. Therefore, in the air conditioner using the outdoor heat exchanger (13) or the indoor heat exchanger (15) according to the first to twenty-second solutions, it is possible to secure sufficient performance while realizing miniaturization. It becomes possible.

[0065]

Embodiment 1 Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings.

-Configuration of Air Conditioner- As shown in FIG. 1, the air conditioner according to the first embodiment
(1) is configured by connecting an indoor unit (17) and an outdoor unit (16). The refrigerant circuit of this air conditioner (1)
(10) is a refrigerant circuit forming a vapor compression refrigeration cycle by R32, and includes a compressor (11), a four-way switching valve (12), an outdoor heat exchanger (13), an expansion valve (decompression mechanism) ( 14) and the indoor heat exchanger (15) are connected via refrigerant pipes (31, 32).

In the refrigerant circuit (10), the discharge side of the compressor (11) and the first port (12a) of the four-way switching valve (12) are connected by a first gas side pipe (21). Second of the switching valve (12)
The port (12b) and the outdoor heat exchanger (13) are connected to the second gas side pipe (2
2) connected by The outdoor heat exchanger (13) and the expansion valve (14) are connected by a first liquid side pipe (25), and the expansion valve (14) and the indoor heat exchanger (15) are connected to a second liquid side pipe (25). 26). Further, the indoor heat exchanger (15) and the third port (12c) of the four-way switching valve (12) are connected to the third gas side pipe (23).
And the fourth port (12d) of the four-way switching valve (12)
And the suction side of the compressor (11) are connected by a fourth gas side pipe (24).

The compressor (11), the first gas side pipe (21), the four-way switching valve (12), the second gas side pipe (22), the outdoor heat exchanger (13), the first liquid side pipe (25) ), Expansion valve (14), and fourth gas side pipe (24)
Is housed in the outdoor unit (16) together with the outdoor blower (27). On the other hand, the indoor heat exchanger (15) is an indoor blower (28)
Together with the indoor unit (17). And
A part of the second liquid side pipe (26) and the third gas side pipe (23) constitutes a so-called communication pipe for connecting the outdoor unit (16) and the indoor unit (17).

Since the refrigerating effect per unit volume of R32 is larger than that of R22, the amount of the circulating refrigerant required to exhibit the predetermined capacity is smaller than that of R22. Therefore, in the case of R32, when the inner diameter of the heat transfer tube of the heat exchanger is fixed, the refrigerant circulation amount is small, and the pressure loss in the tube is smaller than that of R22.

Generally, when the inner diameter of the heat transfer tube of the heat exchanger is reduced, the heat transfer area decreases and the refrigerant pressure loss increases.
The performance of the entire device is reduced. However, when R32 is used, since the refrigerant-side heat transfer coefficient in the heat transfer tube is larger than R22, even if the heat transfer tube is reduced in diameter and the pressure loss in the tube is increased to about R22, as a whole, it is equal to or equal to R22. It is possible to exhibit higher performance. Further, since the heat exchangers (13, 15) are reduced in size by reducing the diameter of the heat transfer tubes, it is possible to promote the compactness of each unit (16, 17).

In the air conditioner (1) of Embodiment 1, the heat transfer tubes (13p, 15p) of the outdoor heat exchanger (13) and the indoor heat exchanger (15) are provided.
p) is reduced in diameter until the pressure loss in the pipe becomes the same level as R22. Specifically, the amount of change in the refrigerant saturation temperature corresponding to the pressure loss in the heat transfer tube is considered, and each of the heat exchangers (13, 1) is adjusted so that the amount of change in temperature becomes equal to R22.
The inner diameter of the heat transfer tube (13p, 15p) of 5) is set.

-Outdoor heat exchanger- <Dimensions of heat transfer tubes> Specifically, the heat transfer tubes (13p: see FIGS. 4 to 6) of the outdoor heat exchanger (13) have an average inner diameter d of 6.0 mm.
Nominal size (outer diameter) is 6.35mm so that it becomes 6.5mm
Standard pipes are used. This is because the latent heat ratio of R32 is larger than that of R22 or R407c as shown in FIG. 2, and when the capacity is the same, the mass flow rate of the refrigerant is about 60% of R22, and the same heat exchanger is used. If so,
Since the pressure loss is reduced to about 40% of R22, the heat transfer tube is narrowed by an amount corresponding to the reduced pressure loss.
Thus, the pressure loss is suppressed to about the same as R22 without increasing the number of passes.

Assuming that a heat transfer tube having an outer diameter of 8.0 mm (average inner diameter is approximately 7.3 mm to 7.8 mm) is used in a conventional apparatus using R22, the pressure loss is 1/5 of the diameter of the heat transfer tube.
Since it is almost proportional to the power, it is about 0.5 in 0.4 1/5.
It was calculated as 83 times. The average inner diameter d of the heat transfer tube (13p) varies depending on the shape of the inner groove, the wall thickness, the expansion ratio, and the like.
It has a certain range as described above. <Structure of Fin> As shown in FIG. 2, the saturation temperature / pressure gradient ratio of R32 is about 60% (63%) of R22.
About 60% (63%). Therefore, assuming that the pressure loss is the same, the degree of decrease in the evaporation temperature is small. R32 has a thermal conductivity of about 1.6 compared to R22.
Since the heat transfer coefficient in the pipe is higher than R22 because the heat transfer coefficient is twice as high, and the temperature boundary layer is reduced by reducing the diameter, the heat transfer coefficient on the air side is also improved. The evaporation temperature will be higher than when R22 is used.

More specifically, as compared with R22, the temperature rises by about 1.5 ° C. to 2 ° C. in the suction pipe, and the performance of the heat exchanger (13) is improved to increase the temperature by about 0.5 ° C. to 1 ° C. As a whole, the evaporation temperature becomes higher at about 2 ° C. to 3 ° C. as a whole. Since the evaporation temperature rises in this manner, when R32 is used, even if the fin pitch P1 shown in FIG. it can.

FIG. 3 shows specific data on this point. FIG. 3 shows that the outside air has a dry bulb temperature of 2 ° C. and a wet bulb temperature of 1
The heating operation time from the start of the heating operation at a temperature of 20 ° C. and the indoor temperature of the dry-bulb temperature of 20 ° C. until the ventilation resistance in the outdoor heat exchanger (13) becomes five times as high as that at the start of operation due to frosting ( Hereinafter, the continuous heating operation time) is obtained under the same conditions as the ventilation resistance of R22, and is graphed. This graph shows the continuous heating operation time when the heat transfer tube (13p) of the outdoor heat exchanger (13) is 6.35 mm and the fin pitch P1 is changed to four types using slit fins, and the comparative example is φ
Set the fin pitch P1 of the slit fin to 2.
This indicates the continuous heating operation time when 0 mm is set. Note that FIG. 3 also shows continuous heating operation time when flat fins are used and the fin pitch P1 is changed to three types as data of Embodiment 2 described later.

As can be seen from this graph, when a slit fin of φ6.35 mm is used, the fin pitch P1 is 1.2 m
Even if m, the continuous heating operation time is the same as the conventional one, and if the fin pitch P1 is made larger than that, the continuous heating operation time can be extended. In addition, from the viewpoint of preventing the outdoor heat exchanger (13) from increasing in size, in the present embodiment, the upper limit of the fin pitch P1 is 2.0 mm. In other words, when using slit fins, the fin pitch P1 is 1.2 mm to 2.0 mm
Can be appropriately selected from the range. Note that this is the same even when a louver fin is used instead of the slit fin.

In the first embodiment, the plate fins are formed by arranging the slit fins shown in FIG. 4 in two rows. <Step pitch and row pitch of heat transfer tubes> Next, heat transfer tubes (13p)
The step pitch P2 and the row pitch P3 will be described. FIG.
FIG. 5 is a partial perspective view showing a state in which a number of plate fins (13f) are stacked and arranged, and shows a state in which a heat transfer tube (13p) of an outdoor heat exchanger (13) is removed. In the plate fin (13f), a through hole (13h) to be fixed through the heat transfer tube (13p) is formed by press working. And in the figure, this through hole
The vertical pitch of (13h) corresponds to the step pitch P2 of the heat transfer tubes, and the horizontal pitch of the through holes corresponds to the row pitch P3 of the heat transfer tubes.

By setting the values of the step pitch P2 and the row pitch P3 of the heat transfer tube (13p) within appropriate ranges, the heat exchanger (1p) can be used.
3) The performance can be optimized. That is, if the diameter of the heat transfer tube (13p) is reduced as in the first embodiment, the step pitch P2
If the row pitch P3 is the same, the spacing between the heat transfer tubes (13p) is increased, and the fin efficiency is reduced. For this reason, it is preferable to set the step pitch P2 and the row pitch P3 according to the heat transfer tube diameter.

Therefore, the heat transfer tube in the outdoor heat exchanger (13)
The relationship between the step pitch P2 and the row pitch P3 in (13p) and the capability will be described with reference to FIG. FIG. 7 shows an outdoor heat exchanger using R32 for the capacity when the outside diameter of the heat transfer tube (13p) is φ8.0 mm in the outdoor heat exchanger (13) using R22.
In (13), the outside diameter of the heat transfer tube (13p) is
The figure shows the ratio of the capacity (average capacity of evaporation and condensation) when the step pitch P2 and the row pitch P3 are changed assuming 6.35 mm. The vertical axis is the heat exchanger capacity ratio, and the horizontal axis is the step pitch P2 and the row. The product (area) A of the pitch P3 is defined as A. The area A is substantially proportional to the heat transfer area per fin in the heat exchanger having the same number of stages and rows.

In the first embodiment, the heat transfer tube (1
As a value that can be obtained more than 100% of the ability outer diameter with respect to the heat transfer tube of φ8.0mm when the φ6.35mm of 3p), set in the range of about 220mm ² ~420mm ² the area A ing. Further, for example, setting the area A within the range of 250mm ² ~390mm ^2, it can be capable of more than 105% in the case of Fai8.0Mm.

Setting the capacity to a range of 105% or more corresponds to setting the evaporation temperature higher by 2 ° C. to 3 ° C. than in the prior art in this embodiment. That is, the above-mentioned increase in the evaporation temperature includes an improvement in the performance of the heat exchanger (13), and for that purpose, the capacity needs to be about 105%.
By doing so, it is possible to set the step pitch and the column pitch corresponding to the improvement in performance.

-Indoor heat exchanger-Regarding the indoor heat exchanger (15) as well, the dimensional configuration of the heat transfer tubes (15p), the configuration of the fins (15f), and the step pitch of the heat transfer tubes (15p)
P2 and the row pitch P3 are determined in the same manner as the outdoor heat exchanger (13). <Dimensions of heat transfer tube> Specifically, the heat transfer tube (15p) of the indoor heat exchanger (15) is a conventional device using R22 and has an outer diameter of 7.0 m.
m (average inner diameter is approximately 6.6 mm to 7.0 mm), and the average inner diameter is set to 5.4 mm to 5.9 mm by the same method as that of the outdoor heat exchanger (13). in this case,
If it is selected from standard pipes, the nominal dimension (outer diameter dimension) should be φ6.0mm. <Fin Configuration> The fin pitch P1 is determined based on the data shown in FIG. FIG. 8 shows an outdoor heat exchanger (1).
This shows data measured in the same way as in Fig. 3 for 3). When R32 is used, a φ6.0mm heat transfer tube (15p)
Shows the continuous cooling operation time when the fin pitch P1 is changed to about 1.7 mm with the φ7.0 mm heat transfer tube when the fin pitch P1 is changed and when R22 is used. This continuous cooling time is based on the time until the ventilation resistance becomes five times due to freezing.

In this case, when the slit fins of φ6.0 mm are used, the continuous cooling operation time is almost the same as the conventional one even when the fin pitch P1 is set to 1.0 mm. You can extend the time. In this embodiment, the upper limit of the fin pitch P1 is 1.7 mm in order to prevent the indoor heat exchanger (15) from increasing in size. That is, the indoor heat exchanger (1
In 5), the fin pitch P1 can be appropriately selected from the range of 1.0 mm to 1.7 mm. This is the same when louver fins are used instead of slit fins. <Step pitch and row pitch of heat transfer tubes>
The step pitch P2 and the row pitch P3 of p) are also used for the outdoor heat exchanger (13).
It is determined in the same way as Fig. 9 shows the heat transfer tube (15p) with the same ventilation resistance against the capacity when the outside diameter of the heat transfer tube (15p) is φ7.0mm in the indoor heat exchanger (15) using R32.
Represents the ratio of the capacity (average capacity of evaporation and condensation) when the step pitch P2 and the row pitch P3 are varied with the outer diameter of φ6.0 mm.

In this embodiment, from this figure, the heat transfer tubes (15
as a value that can be obtained more than 100% of the ability outer diameter with respect to the heat transfer tube of φ7.0mm when the φ6.0mm of p), is set in a range of about 180mm ² ~250mm ² the area A ing. Further, for example, setting the area A within the range of 190mm ² ~240mm ^2, it can be capable of more than 105% in the case of Fai7.0Mm. The reason why the capacity is preferably set to 105% or more is for the same reason as that of the outdoor heat exchanger.

Next, the operation of the air conditioner (1) will be described based on the refrigerant circulation operation in the refrigerant circuit (10).

During the cooling operation, the four-way switching valve (12) is set on the solid line side shown in FIG. That is, the four-way switching valve (12)
The first port (12a) communicates with the second port (12b), and the third port (12c) communicates with the fourth port (12d). In this state, the gas refrigerant discharged from the compressor (11) is supplied to the first gas side pipe (21), the four-way switching valve (12) and the second gas side pipe (21).
The gas flows through the gas pipe (22) and condenses in the outdoor heat exchanger (13). The liquid refrigerant flowing out of the outdoor heat exchanger (13) flows through the first liquid side pipe (25), and is decompressed by the expansion valve (14) to become a gas-liquid two-phase refrigerant. The two-phase refrigerant flowing out of the expansion valve (14) flows through the second liquid side pipe (26), exchanges heat with the indoor air in the indoor heat exchanger (15), evaporates, and cools the indoor air. Indoor heat exchanger (1
The gas refrigerant that has flowed out of 5) flows through the third gas-side pipe (23), the four-way switching valve (12) and the fourth gas-side pipe (24), and the compressor (11)
Inhaled.

On the other hand, during the heating operation, the four-way switching valve (12) is set on the broken line side shown in FIG. That is, the four-way switching valve (1
In (2), the first port (12a) and the third port (12c) communicate with each other, and the second port (12b) and the fourth port (12d) communicate with each other. In this state, the gas refrigerant discharged from the compressor (11) flows through the first gas-side pipe (21), the four-way switching valve (12) and the third gas-side pipe (23), and passes through the indoor heat exchanger. (15). The refrigerant flowing into the indoor heat exchanger (15) exchanges heat with the indoor air to condense and heat the indoor air. The liquid refrigerant flowing out of the indoor heat exchanger (15) flows through the second liquid side pipe (26), and is decompressed by the expansion valve (14) to become a gas-liquid two-phase refrigerant. The two-phase refrigerant flowing out of the expansion valve (14) flows through the first liquid side pipe (25) and evaporates in the outdoor heat exchanger (13). Outdoor heat exchanger (13)
The gas refrigerant flowing out flows through the second gas side pipe (22), the four-way switching valve (12) and the fourth gas side pipe (24), and is sucked into the compressor (11).

-Effects of First Embodiment- According to the first embodiment, the following effects are exhibited.

That is, with respect to the outdoor heat exchanger (13), the average diameter d of the heat transfer tube (13p) is reduced to 6.0 mm ≦ d ≦ 6.5 mm. If so, the pressure loss does not increase as compared with the case where a heat transfer tube having an outer diameter of 8.0 mm is used in R22.

The plate fin (13f) is used as a slit fin or a louver fin, and the fin pitch P1 is set to 1.
Since 2 mm ≤ P1 ≤ 2.0 mm, if the fin pitch P1 is set to a value on the upper limit side of the range, frost formation is less likely to occur, so it is possible to perform the heating operation continuously for a long time, If the fin pitch P1 is set to a value on the lower limit side of the range, the outdoor heat exchanger (13) can be made more compact while suppressing frost formation to the same level as in the past. Therefore, it is possible to reduce the size while ensuring the performance.

Further, if the product A of the step pitch P2 and the row pitch P3 of the heat transfer tube (13p) is 220 mm ² ≦ A ≦ 420 mm ² , it is equal to or more than the case where the heat transfer tube having the outer diameter of 8.0 mm is used in R22. The heat transfer tube (13p) can be reduced in diameter while obtaining the capability of Therefore,
The outdoor heat exchanger (13) having performance equal to or higher than the conventional one can be miniaturized. In particular, the step pitch P2 and row pitch of the heat transfer tube (13p)
By setting the product A of P3 to 250 mm ² ≦ A ≦ 390 mm ² , it is possible to further reduce the size while reducing the diameter and further enhance the capacity.

On the other hand, regarding the indoor heat exchanger (15), the heat transfer tubes (1)
5p), the average inner diameter d is 5.4 mm ≤ d ≤ 5.9 mm, which is smaller than before.
The pressure loss does not increase as compared with the case where a heat transfer tube having an outer diameter of 7.0 mm is used in R22.

The plate fin (15f) is used as a slit fin or a louver fin, and the fin pitch P1 is set to 1.
Since 0 mm ≤ P1 ≤ 1.8 mm, if the fin pitch P1 is set at the upper limit of the range, dew condensation and icing are more unlikely to occur, and the fin pitch is set at the lower limit of the range.
If P1 is set, the size of the indoor heat exchanger (15) can be further reduced while keeping dew formation or icing on the same level as before. Therefore, it is possible to reduce the size while ensuring the performance.

Further, if the product A of the step pitch P2 and the row pitch P3 of the heat transfer tube (15p) is 180 mm ² ≦ A ≦ 250 mm ² , it is equal to or greater than the case where a heat transfer tube having an outer diameter of 7.0 mm is used in R22. The diameter of the heat transfer tube (15p) can be reduced while obtaining the capability. Therefore,
The indoor heat exchanger (15) having performance equal to or higher than the conventional one can be downsized. In particular, the step pitch P2 and row pitch of the heat transfer tubes (15p)
By setting the product A of P3 to 190 mm ² ≦ A ≦ 240 mm ² , it is possible to further reduce the size and to further increase the capacity.

As described above, according to the air conditioner of the present embodiment, it is possible to improve the performance of the device while reducing the size of both the outdoor heat exchanger (13) and the indoor heat exchanger (15). Can be. And a compact and high performance air conditioner utilizing the characteristics of R32 can be realized.

[0096]

Second Embodiment A second embodiment of the present invention is different from the air conditioner (1) of the first embodiment in that the fins (13f, 15f) of each heat exchanger (13, 15) are different. Things.

The plate fin (13) of each heat exchanger (13, 15)
For the f, 15f), the flat fin of FIG. 5 is used instead of the slit fin of the first embodiment. Flat fins are generally used in room air conditioners and the like, and although the fin efficiency is lower than slit fins and louver fins, frost formation does not easily progress, and frost elimination during defrosting is improved. And the performance decrease is the fin pitch
It can be compensated by increasing the heat transfer area by filling P1.

FIG. 3 shows that the outside diameter of the outdoor heat exchanger (13) is
The change of the continuous heating operation time due to the change of the fin pitch P1 when the flat fin is used in the 6.35 mm heat transfer tube (13p) is also shown. As shown in this figure, when flat fins are used in the outdoor heat exchanger (13), the fin pitch
Even if the lower limit of P1 is set to 0.8 mm, continuous heating operation can be performed at about the same level as in the past, and if the fin pitch P1 is set wider than that, the continuous heating operation time can be extended.

The upper limit of the fin pitch P1 when using flat fins is preferably about 1.7 mm so that the fin efficiency is not lowered and the heat exchanger performance is not lowered. That is, the fin pitch may be appropriately selected from the range of 0.8 mm to 1.7 mm. Note that this is the same even when waffle fins are used instead of flat fins.

As described above, since the flat fins are generally used in the outdoor heat exchanger (13) used in the room air conditioner or the like, in this case, the fin pitch P1 can be considerably reduced, and the size is reduced. It is very advantageous.

In this embodiment, the indoor heat exchanger (15)
Similarly, flat fins are used. The fin pitch P1 of the indoor heat exchanger (15) is determined based on FIG. As shown in the figure, when flat fins are used in the indoor heat exchanger (15), continuous cooling operation can be performed at about the same level as before even if the fin pitch P1 is set to 0.6 mm. Cooling time can be extended. Also in this case, the upper limit is preferably set to about 1.5 mm and the fin pitch P1 is selected within the range so that the fin pitch P1 is not excessively widened and the fin efficiency does not decrease. This is the same even when waffle fins are used.

-Effect of Embodiment 2- In Embodiment 2, the outdoor heat exchanger (13) and the indoor heat exchanger (1
Since the upper limit and the lower limit of the fin pitch P1 are made smaller than those in the first embodiment by using flat fins or waffle fins in 5), the size can be made smaller than when slit fins or louver fins are used.

[0103]

Third Embodiment A third embodiment of the present invention is different from the first and second embodiments in that the plate fins (13f, 15f) of each heat exchanger (13, 15) are different.

Specifically, as shown in FIG. 10, the plate fins (13f, 15f) of each heat exchanger (13, 15) are gradually cut and raised from the windward side to the leeward side, and the slit fins whose area is increased. Alternatively, louver fins are used. And
By reducing the density of the slits or louvers on the windward side where frost is likely to occur at low temperatures, it is difficult to form frost and easy to defrost, and on the leeward side the density of the slits or louvers is increased to improve heat transfer performance I try to make it.

In the third embodiment as well, the average inner diameter of the heat transfer tubes (13p, 15p) is 6.0 mm ≦ d ≦ 6.5 mm in the outdoor heat exchanger (13), as in the first and second embodiments. 5.4m with exchanger (15)
m ≦ d ≦ 5.9 mm.

The range of the fin pitch P1 in each of the heat exchangers (13, 15) is preferably an intermediate range between the first and second embodiments. Specifically, the fin pitch P1 is 1.0 mm in the outdoor heat exchanger (13). ≤
P1 ≤ 1.85 mm, 0.8 mm ≤ P1 ≤ 1.65 mm for the indoor heat exchanger (15).

-Effects of Embodiment 3- According to Embodiment 3, frost formation is difficult and defrosting is easy,
Moreover, a heat exchanger (13, 15) having high heat transfer performance can be provided.
Therefore, it is possible to reduce the size of the heat exchanger (13, 15) of the first embodiment while improving the performance of the heat exchanger (13, 15) of the second embodiment.

-Modification of Embodiment 3- In the example of FIG. 10, plate fins (13f, 15f) having a large area that are gradually cut and raised from the windward side to the leeward side are used. As shown in FIG. 11, a flat fin or a waffle fin may be arranged on the windward side, and a slit fin or a louver fin may be arranged on the leeward side.

In this manner, in addition to the effect substantially equivalent to that of the example of FIG. 10 in terms of performance, a special mold for press-molding the plate fins (13f, 15f) of the third embodiment is used. Since a general mold can be used without using it, the production is easy and the increase in cost can be suppressed.

[0110]

Other Embodiments of the Invention The present invention may be configured as follows with respect to the above embodiment.

For example, in each of the above embodiments, a single refrigerant R32 has been described, but a mixed refrigerant containing R32 in an amount of about 75% by mass or more and less than 100% by mass (a mixed refrigerant rich in R32 composition) may be used. . Examples of the mixed refrigerant include R32 / R125, R32 / R134a,
Mixed refrigerants such as R32 / propane, R32 / butane, R32 / isobutane can be used. Even if these mixed refrigerants are used, the characteristics are almost the same as those of the R32 single refrigerant, so that the same effects as in the above embodiments can be obtained.

Although the above embodiment is a so-called heat pump type air conditioner capable of selectively performing a cooling operation and a heating operation, the present invention is not limited to the heat pump type air conditioner. Instead, for example, a heating-only machine or a cooling-only machine may be used.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of an air-conditioning apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a table comparing characteristics of various refrigerants.

FIG. 3 is a graph showing a continuous heating operation time when R32 is used instead of R22.

FIG. 4 is an external view of a slit fin used in the first embodiment.

FIG. 5 is an external view of a flat fin used in a second embodiment.

FIG. 6 is a perspective view showing a fin pitch, a step pitch of a heat transfer tube, and a row pitch.

FIG. 7 is a graph showing the relationship between the product of the step pitch and the row pitch and the capacity of the outdoor heat exchanger.

FIG. 8 is a graph showing a continuous cooling operation time when R32 is used instead of R22.

FIG. 9 is a graph showing the relationship between the product of the stage pitch and the row pitch and the capacity of the indoor heat exchanger.

FIG. 10 is an external view of a plate fin used in a third embodiment.

FIG. 11 is an external view of a plate fin used in a modification of the third embodiment.

[Explanation of symbols]

 (1) Air conditioner (10) Refrigerant circuit (11) Compressor (12) Four-way switching valve (13) Outdoor heat exchanger (13f) Plate fin (13p) Heat transfer tube (14) Expansion valve (pressure reducing mechanism) ( 15) Indoor heat exchanger (15f) Plate fin (15p) Heat transfer tube (16) Outdoor unit (17) Indoor unit (P1) Fin pitch (P2) Step pitch (P3) Row pitch

Claims (31)

[Claims] A plate fin coil type outdoor heat exchanger used in an air conditioner (1) for performing a vapor compression refrigeration cycle using R32 or a refrigerant mixture thereof, wherein an average inner diameter d of a heat transfer tube (13p) is An outdoor heat exchanger in which 6.0 mm ≤ d ≤ 6.5 mm, the plate fin (13f) is a slit fin or a louver fin, and the fin pitch P1 is 1.2 mm ≤ P1 ≤ 2.0 mm. 2. A plate fin coil type outdoor heat exchanger used in an air conditioner (1) for performing a vapor compression refrigeration cycle using R32 or a refrigerant mixture thereof, wherein an average inner diameter d of the heat transfer tube (13p) is An outdoor heat exchanger in which 6.0 mm ≤ d ≤ 6.5 mm, the plate fin (13f) is a flat fin or a waffle fin, and the fin pitch P1 is 0.8 mm ≤ P1 ≤ 1.7 mm. 3. A plate fin coil type outdoor heat exchanger used in an air conditioner (1) for performing a vapor compression refrigeration cycle using R32 or a refrigerant mixture thereof, wherein the average inner diameter d of the heat transfer tube (13p) is 6.0mm ≤ d ≤ 6.5mm, and the plate fin (13f) is a slit fin or louver fin with a larger area cut and raised from windward to leeward, and the fin pitch P1 is 1.0mm ≤ P1 ≤ 1.85mm Outdoor heat exchanger. 4. A plate fin coil type outdoor heat exchanger used in an air conditioner (1) for performing a vapor compression refrigeration cycle using R32 or a refrigerant mixture thereof, wherein an average inner diameter d of the heat transfer tube (13p) is 6.0mm ≤ d ≤ 6.5mm, and the product A of the step pitch P2 and row pitch P2 of the heat transfer tubes (13p) is 220m
An outdoor heat exchanger in which m ² ≦ A ≦ 420 mm ² . 5. The step pitch P2 and the row pitch P2 of the heat transfer tubes (13p).
The product A is, the outdoor heat exchanger of claim 4, wherein a 250mm ² ≦ A ≦ 390mm ^2. 6. The outdoor heat exchanger according to claim 4, wherein the plate fin is a slit fin or a louver fin. 7. The outdoor heat exchanger according to claim 6, wherein the fin pitch P1 is 1.2 mm ≦ P1 ≦ 2.0 mm. 8. The outdoor heat exchanger according to claim 4, wherein the plate fins are flat fins or waffle fins. 9. The outdoor heat exchanger according to claim 8, wherein the fin pitch P1 is 0.8 mm ≦ P1 ≦ 1.7 mm. 10. The outdoor heat exchanger according to claim 4, wherein the plate fin (13f) is a slit fin or a louver fin having a larger area cut and raised from the windward side to the leeward side. 11. The fin pitch P1 is 1.0 mm ≦ P1 ≦ 1.85 mm
The outdoor heat exchanger according to claim 10, wherein 12. A plate fin coil type indoor heat exchanger used in an air conditioner (1) for performing a vapor compression refrigeration cycle using R32 or a refrigerant mixture thereof, wherein the average inner diameter d of the heat transfer tube (15p) is An indoor heat exchanger in which 5.4 mm ≤ d ≤ 5.9 mm, the plate fin (15f) is a slit fin or a louver fin, and the fin pitch P1 is 1.0 mm ≤ P1 ≤ 1.8 mm. 13. A plate fin coil type indoor heat exchanger used in an air conditioner (1) for performing a vapor compression refrigeration cycle using R32 or a mixed refrigerant thereof, wherein the average inner diameter d of the heat transfer tube (15p) is An indoor heat exchanger in which 5.4 mm ≤ d ≤ 5.9 mm, the plate fin (15f) is a flat fin or a waffle fin, and the fin pitch P1 is 0.6 mm ≤ P1 ≤ 1.5 mm. 14. A plate fin coil type indoor heat exchanger used in an air conditioner (1) for performing a vapor compression refrigeration cycle using R32 or a refrigerant mixture thereof, wherein the average inner diameter d of the heat transfer tube (15p) is 5.4 mm ≤ d ≤ 5.9 mm, and plate fins (15f) are slit fins or louver fins whose area is cut and raised from windward to leeward, and the fin pitch P1 is 0.8 mm ≤ P1 ≤ 1.65 mm Indoor heat exchanger. 15. A plate fin coil type indoor heat exchanger used in an air conditioner (1) for performing a vapor compression refrigeration cycle using R32 or a refrigerant mixture thereof, wherein the average inner diameter d of the heat transfer tube (15p) is 5.4mm ≤ d ≤ 5.9mm, and the product A of the step pitch P2 and row pitch P3 of the heat transfer tube (15p) is 180m
An indoor heat exchanger in which m ² ≦ A ≦ 250 mm ² . 16. Step pitch P2 and row pitch of heat transfer tubes (15p)
P3 of product A is an indoor heat exchanger of claim 15 wherein the 190mm ² ≦ A ≦ 240mm ^2. 17. The indoor heat exchanger according to claim 15, wherein the plate fin (15f) is a slit fin or a louver fin. 18. The fin pitch P1 is 1.0 mm ≦ P1 ≦ 1.8 mm
The indoor heat exchanger according to claim 17, wherein 19. The indoor heat exchanger according to claim 15, wherein the plate fins are flat fins or waffle fins. 20. Fin pitch P1 is 0.6 mm ≦ P1 ≦ 1.5 mm
20. The indoor heat exchanger according to claim 19, wherein 21. The indoor heat exchanger according to claim 15, wherein the plate fin (15f) is a slit fin or a louver fin having a larger area cut and raised from the windward to the leeward. 22. Fin pitch P1 is 0.8 mm ≦ P1 ≦ 1.65 mm
22. The indoor heat exchanger according to claim 21, wherein 23. A compressor (11), an outdoor heat exchanger (13), a pressure reducing mechanism (14), and an indoor heat exchanger (15) so as to perform a vapor compression refrigeration cycle using R32 or a refrigerant mixture thereof. ) And a refrigerant circuit (10) connected in order, wherein the outdoor heat exchanger (13) is constituted by the outdoor heat exchanger according to any one of claims 1 to 11. Air conditioner. 24. A compressor (11), an outdoor heat exchanger (13), a pressure reducing mechanism (14), and an indoor heat exchanger (15) so as to perform a vapor compression refrigeration cycle using R32 or a refrigerant mixture thereof. And a refrigerant circuit (10) connected in sequence to the indoor heat exchanger (15), wherein the indoor heat exchanger (15) is any one of claims 12 to 22.
An air conditioner comprising the indoor heat exchanger according to any one of the preceding claims. 25. A compressor (11), an outdoor heat exchanger (13), a pressure reducing mechanism (14), and an indoor heat exchanger (15) so as to perform a vapor compression refrigeration cycle using R32 or a mixed refrigerant thereof. ) Is connected to the refrigerant circuit (10) in order, the outdoor heat exchanger (13) is configured by the outdoor heat exchanger according to any one of claims 1 to 11, indoors An air conditioner wherein the heat exchanger (15) is constituted by the indoor heat exchanger according to any one of claims 12 to 22. 26. The air conditioner according to claim 23, 24 or 25, wherein R32 is used as the refrigerant. 27. A mixed refrigerant containing 75% by mass or more and less than 100% by mass of R32 as the refrigerant.
26. The air conditioner according to 3, 24 or 25. 28. The air conditioner according to claim 23, 24 or 25, wherein a mixed refrigerant of R32 and R125 is used as the refrigerant, and the mixed refrigerant contains 75% by mass or more and less than 100% by mass of R32. 29. As the refrigerant, a mixed refrigerant of R32 and R134a is used.
26. The air conditioner according to claim 23, 24 or 25, which contains at least 100% by mass. 30. A mixed refrigerant of R32 and a hydrocarbon-based refrigerant is used as the refrigerant, and the mixed refrigerant contains 75% by mass or more and less than 100% by mass of R32.
Or the air conditioner of 25. 31. The air conditioner according to claim 30, wherein the hydrocarbon-based refrigerant is any one of propane, butane, and isobutane.