JPH11337104A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increase in a size of a heat exchanger and an increase in a consumed power according to an increase in a ventilating resistance by providing to decrease a density of louvered slits as compared with others in fins of third to first rows continued to a refrigerant inlet and a refrigerant outlet at the time of heating. SOLUTION: Many heat transfer tubes 102 are coupled by a piping via bent pipes 103, Y-shaped branch pipes 104 or T-shaped branch pipes 105 to constitute a pass. Number of arrays of the heat transfer tubes of an inverted V-shaped upper heat exchanger 22a and a front surface heat exchanger 22b are three rows. A refrigerant outlet at the time of a heating operation is disposed on a back surface oblique part 22aB of each of the exchanger 22a of the three rows of the exchangers, and a refrigerant inlet at the time of the heating operation is disposed on a lowermost leeward side (third row, a side nearest a cross flow fan 24) of the exchanger 22b. A density of louvered slits is reduced as compared with others at fins of third to first rows continued to the inlet and the outlet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a heat exchanger mounted in an indoor unit of an air conditioner.

[0002]

2. Description of the Related Art Conventionally, for the purpose of increasing the amount of heat exchange in an indoor heat exchanger, a corrugated fin having a fin surface formed into a corrugated shape or a fin surface as disclosed in Japanese Patent Application Laid-Open No. 10-185359 has been proposed. A heat exchanger in which slits are cut and raised and a refrigerant pipe arrangement is arranged in two rows is often used.

On the other hand, in recent years, in order to cope with global environmental problems, further energy saving has been required, and it has been necessary to increase the size of the heat exchanger. In the case of a heat exchanger, if the refrigerant pipes are increased in size with two rows of heat exchangers, the entire heat exchanger becomes larger, and the frontage size increases accordingly. There has been a problem that the external dimensions are increased and the cost is increased.

On the other hand, in order to increase the amount of heat exchange by suppressing the width of the frontage unit in order to prevent an increase in the size of the indoor unit, it is necessary to increase the number of rows of heat exchangers from two to three. However, if the number of rows of heat exchangers is simply changed from two to three, the size of the indoor unit can be reduced, but the ventilation resistance increases significantly in proportion to the number of rows of heat exchangers. However, there is a problem that fan power is increased and power consumption is increased, and a problem that fan noise is increased due to an increase in ventilation resistance and impairs comfort as an air conditioner.

[0005]

In order to save energy, energy saving and high performance are the most important issues along with resource saving. However, in the above prior art, the heat exchanger is increased in size and the ventilation resistance is reduced. There is a problem that power consumption increases due to the increase.

An object of the present invention is to provide a high-performance and comfortable indoor unit for an air conditioner in consideration of the global environment.

[0007]

In order to achieve the above object, an indoor unit having a top suction port and a front suction port, and a through-flow fan, a pair of suction ports, and a through-flow fan in the indoor unit are provided. An indoor heat exchanger having refrigerant pipes arranged in three rows is provided between the fins corresponding to the third row or the first row connected to the refrigerant inlet during heating and the refrigerant outlet during heating. The air conditioner room in which the density of the slits is increased in the order of other portions except for the heating refrigerant inlet row, the heating refrigerant outlet row, and the heating refrigerant inlet / outlet section in which the density of the cut and raised slits is smaller than that of the air conditioner. A unit is proposed. More preferably, the indoor heat exchanger is provided with a lower density of slits in the third or first row of fins connected to the heating-time refrigerant inlet and the heating-time refrigerant outlet as compared with the other fins. An indoor unit for an air conditioner in which the density of slits is increased by cutting and raising in the order other than the inlet row, the heating refrigerant outlet row, and the heating refrigerant inlet / outlet section is proposed.

According to the configuration of the present invention described above, by providing the cut-and-raised slits that are cut and raised on opposite sides with respect to the fin base line, the fin pitch can be widened and the airflow resistance can be reduced. By reducing the thermal resistance in the two-phase region in the pipe by improving the performance, the performance is improved as a whole, and the ventilation resistance in the portions corresponding to the refrigerant gas region and the liquid region in the tube can be significantly reduced. Accordingly, the fan airflow under the same noise condition increases, so that the heat exchange amount increases and the performance of the heat exchanger is greatly improved.

Further, when the heating capacity is constant, the temperature difference between the refrigerant and the air required at the time of heating can be reduced, so that the condensing temperature and pressure are reduced, the operating power of the refrigerant compressor is reduced, and the power consumption is reduced. Be improved.

Next, the indoor heat exchanger is provided with a cut-and-raised slit for promoting heat transfer on a fin surface located at a portion where the refrigerant in the pipe is substantially in a two-phase region, and is located at a refrigerant inlet portion during heating. The ratio of the slits is smaller in the fin shape in the portion corresponding to the in-pipe refrigerant gas area and the in-pipe refrigerant liquid area located in the heating-time refrigerant outlet section than in the fin shape in the two-phase area, and the ventilation resistance is low, preferably. Since the plate has a flat shape, the increase in airflow resistance can be suppressed to a small value. Also, the heat resistance of the air-side fins is improved in a well-balanced manner in accordance with the magnitude of the heat resistance in the pipe, so that the heat transfer performance is improved. Therefore, the fan airflow under the same noise condition increases, so that the performance of the heat exchanger is greatly improved.

The indoor heat exchanger is formed into a fin shape having a high heat transfer coefficient, for example, a corrugated fin, at a location where the refrigerant in the pipe is substantially in a two-phase region. The fin shape at the portion corresponding to the refrigerant gas region and the in-tube refrigerant liquid region located at the outlet of the refrigerant at the time of heating has a waveform with respect to the inflow airflow such that the ventilation resistance is lower than that of the fin shape in the two-phase region. Since the corners are small, and preferably flat, the increase in airflow resistance can be kept small. Therefore, the fan airflow under the same noise condition increases, so that the performance of the heat exchanger is greatly improved.

In the indoor heat exchanger, the fin located at a portion where the refrigerant in the pipe is substantially in a two-phase region has a fin shape provided with a heat transfer promoting means, and the refrigerant gas in the pipe located at the inlet of the refrigerant at the time of heating is provided. The fin shape in the region corresponding to the refrigerant liquid region in the pipe located at the region and the refrigerant outlet portion at the time of heating has a lower ventilation resistance than that of the fin shape in the two-phase region, and preferably has a flat shape, so that the ventilation resistance is reduced. Can be kept small. Therefore, the fan airflow under the same noise condition increases, so that the performance of the heat exchanger is greatly improved.

Further, in the air conditioner, the indoor heat exchanger includes a fin surface located between a row of heat transfer tubes serving as a refrigerant inlet for heating and a row of heat transfer tubes adjacent thereto, and a refrigerant outlet for heating. The fin surface located between the heat transfer tube row and the adjacent heat transfer tube row is provided with a separation slit for thermally separating the rows. Exchange performance is improved.

[0014]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an internal structure of an air conditioner indoor unit according to the present invention, and FIG. 2 shows an overall plan structure of a fin 100 according to the present invention. FIG. 3 shows a processing step of the upper heat exchanger fins, and FIG. 4 shows a processing step of the front heat exchanger. FIG.
3 is a sectional view taken along the line AA in FIG. 3, and FIG. 6 is a sectional view taken along the line BB in FIG. FIG. 7 is a configuration diagram of a refrigeration cycle of a heat pump air conditioner including the indoor unit, and FIG. 8 is a TS diagram schematically illustrating a state change of a refrigerant circulating in the refrigeration cycle of the air conditioner. It is.

FIG. 1 shows the internal structure of an indoor unit for an air conditioner according to an embodiment of the present invention. The indoor unit 20 includes the indoor heat exchanger 2 disposed in the box 201.
1. Once-through fan 24 and fan casing 202
The upper part of the box 201 is provided with an upper suction port 203.
However, a front surface suction port 204 is provided on the front surface thereof, and a blowout port 205 is provided below the front surface suction port 204.
Reference numeral 120 in the figure indicates a rotatable wind direction plate. The indoor heat exchanger 21 is composed of an upper heat exchanger 22a arranged in an inverted V-shape and a front heat exchanger 22b arranged in front of the cross-flow fan. Indoor heat exchanger 2
Reference numeral 1 denotes a plurality of heat transfer fins 100 arranged side by side at predetermined intervals and a plurality of hairpin bent heat transfer tubes 102 which are inserted and fixed at right angles to the heat transfer fins, and through which a refrigerant flows. ing. These many heat transfer tubes 102 are connected to each other by a pipe 106 via a bend pipe 103, a Y-shaped branch tube 104, or a T-shaped branch tube 105 to form a path. The number of heat transfer tube rows of the inverted V-shaped upper heat exchanger 22a and the front heat exchanger 22b is three. Of these three-row heat exchangers, the rear inclined portion 22aB of the upper heat exchanger 22a is provided with a refrigerant outlet during the heating operation, and the lowest row of the front heat exchanger 22b (third row, A refrigerant path is configured on the (closer side) such that a refrigerant inlet during the heating operation is arranged.

These refrigerant paths are divided into a first path included in the upper heat exchanger 22a and a second path included in the front heat exchanger 22b with the throttle mechanism 25 interposed therebetween. In other words, according to the present invention, the upper heat exchanger 22a and the front heat exchanger 22b preferably constitute separate heat exchangers in which the fins 100 are separated from each other and are independent from each other. The pipes are connected so as to function as a heater 22a and a cooling dehumidifier 22b, respectively.

More specifically, in the present embodiment, the refrigerant flow path of the upper heat exchanger 22a is configured such that most of the windward side row serving as the refrigerant outlet during the heating operation is configured as one path, and the rest is configured as two paths. It is configured as a path (two parallel paths). The refrigerant flow path of the front heat exchanger 22b is provided with a refrigerant inlet portion in a leeward row during a heating operation and is configured with two paths (two parallel paths).

Fins 10 constituting upper heat exchanger 22a
0 indicates that the refrigerant path is 1 as shown in FIGS. 2, 3 and 5.
The fins of the leeward heat transfer tube row 108u, which serve as refrigerant outlets during heating and are configured in the path, are flat fins, and the fins in the second and third rows located on the leeward side thereof are cutouts for promoting heat transfer. The fin structure has a raised slit 200. Cut-and-raised slit 20 provided on the fin surface
The cross-sectional shape of the slit 2 is a cut-and-raised slit 2 that is cut and raised on the opposite side of the reference fin surface 100 as shown in FIG.
00a and 200b.

Fins 10 constituting front heat exchanger 22b
2, fins in the lowest row 109d (third row) serving as refrigerant inlets during heating are flat plate fins, and second and first fins located on the windward side thereof as shown in FIG. 2, FIG. 4 and FIG. The fins in the row have a fin structure provided with cut-and-raised slits for promoting heat transfer.

The fins 100 of the upper heat exchanger 22a
As shown in FIG. 3, a heat transfer tube row 108u on the windward side where the refrigerant path is configured as one path and a heat transfer pipe row 108d on the leeward side where the refrigerant path is configured as two paths are thermally connected. A separation slit 110 is provided so as to be able to be separated. Similarly, the lowermost row 109d of the front heat exchanger 22b
A separation slit 110 for thermally dividing the third row is provided between the third row and the windward row 109u (the second row) as shown in FIG.

The separation slit 110 is formed by cutting the fin 100. In consideration of the handling at the time of processing the fin, as shown in FIGS. It is preferable to perform the cutting so that the cutting portions 110b are alternately arranged so that the non-cut portion 110a is left in a part of the fin 100. Instead of cutting, for example, it is also possible to form a thin slit which is also intermittent, or to form a groove to reduce the cross-sectional area of the fin, thereby thermally separating the fin.

Next, the configuration of a refrigeration cycle of an air conditioner having the indoor unit will be described. In FIG.
Reference numeral 20 denotes an indoor unit, and reference numeral 10 denotes an outdoor unit. These indoor and outdoor units 10 and 20 are connected by a piping unit 27. The outdoor unit 10 includes an outdoor heat exchanger 13 and a fan 17. The refrigeration cycle is configured by connecting the refrigerant compressor 11 to the indoor heat exchanger 21 through the four-way valve 12, the outdoor heat exchanger 13, and the pressure reducer 16, and further through the refrigerant pipe 27. It is configured such that high-pressure refrigerant circulates inside. As the high-pressure refrigerant, refrigerant R3 for protecting the ozone layer is used.
2. A mixed refrigerant is preferable in which the pressure at the same condensing temperature is higher than that of the conventional refrigerant R22 by appropriately mixing R125, R134a, and the like. More preferably, R32
And R125 in a ratio of 1: 1 by mass to a refrigerant R41
It is better to use 0A.

In FIG. 7, a solid arrow 41 is shown.
Indicates the flow direction of the refrigerant during the heating operation, and the broken arrow 42 indicates the flow direction of the refrigerant during the cooling operation. The arrow 26 in the figure indicates the airflow in the indoor unit 20,
An arrow 18 indicates an airflow in the outdoor unit 10.

In the indoor heat exchanger having the above structure, the refrigerant flowing inside the pipe and the air flowing outside the pipe exchange heat via fins provided outside the pipe, and the refrigerant inside the pipe undergoes a phase change.

For example, consider the case where the indoor heat exchanger functions as a condenser during the heating operation. The in-pipe refrigerant sent from the compressor to the indoor heat exchanger flows into the indoor heat exchanger in a state of a high-temperature and high-pressure gas refrigerant from a refrigerant inlet connected to the third row of heat transfer tubes of the front heat exchanger. While flowing through the pipes in the third row, it exchanges heat with air through the fins, and is substantially cooled to a saturation temperature determined by the pressure in the pipes, condensed and liquefied, and becomes a gas-liquid two-phase refrigerant. The heat flows into the heat transfer tubes, further proceeds to the first row, and flows into the heat transfer tubes in the leeward third row of the upper heat exchanger via the throttle valve 25 which is fully open except during the dehumidifying operation. During this time, the gas-liquid two-phase refrigerant in the pipe exchanges heat with air while the temperature is kept almost constant, but as the heat exchange progresses, the latent heat of condensation is lost and the ratio of the liquid refrigerant increases, and the upper heat exchanger When flowing out of the second row, almost all of the liquid is liquefied. The refrigerant in the pipe, which has been completely liquefied through the second row of the upper heat exchanger, flows into the heat transfer pipe connected to the circuit provided in the first path provided in the uppermost first row of the upper heat exchanger, and has a low temperature. It exchanges heat with air and is supercooled to a temperature 5 to 15 ° C. lower than the saturation temperature determined by the pressure. The supercooled liquid refrigerant flows out of the indoor heat exchanger into the cycle system to form a refrigeration cycle.

As described above, in the course of heat exchange, the temperature of the refrigerant in the tube gradually decreases while changing its phase with the gas refrigerant region, the two-phase refrigerant region, and the liquid refrigerant region, while air flowing outside the tube flows from the inlet to the outlet. The temperature gradually rises in the opposite direction to the refrigerant and is discharged from the indoor unit into the room to be used for heating.

At this time, as described above, in one embodiment according to the present invention, the refrigerant passage of the three-row heat exchanger is provided in the liquid refrigerant region so that the low-temperature outlet liquid refrigerant exchanges heat with the lowest-temperature inlet air. The hot gas inflow path is placed in the third row on the leeward side so that the hot gas refrigerant inside the pipe, where the temperature is the highest, and the outlet air, where the temperature is high, exchange heat with the hottest gas refrigerant in the pipe where the temperature is the highest. As a result, the heat exchange efficiency is greatly improved because of the counter flow path configuration.

According to the configuration of one embodiment of the present invention in the heat exchange process, the square refrigerant layer changes in the square refrigerant layer change process in the process of heat exchange between the in-pipe refrigerant and the outside pipe air. The heat resistance Rt (k / w) at the heat exchanger section corresponding to
It is expressed by the following equation as the sum of the air-side thermal resistance and the pipe-side thermal resistance.

Rt = 1 / (ho * Ao) + 1 / (hi * Ai) (1) where Ao and Ai represent the air-side and tube-side heat transfer areas, and ho and hi represent the air-side and tube-side heat. Represents the transmission rate tail. The air-side heat transfer coefficient of the double-sided slit fin according to the present embodiment is approximately ho = 70 to 100 W / m ² K, and the heat transfer coefficient inside the tube depends on the state of the refrigerant in the tube.
The following values are estimated when using an in-pipe processed pipe.

Gas area; hi, g = 300 to 500 W / m ² K liquid area; hi, l = 800 to 1000 W / m ² K two-phase area; hi, s = about 6000 to 12000 W / m ² K and refrigerant It is expected to change greatly depending on the state.

The ratio of the air-side heat resistance and the tube-side heat resistance in the total heat resistance Rt according to the state of the refrigerant in the tube is roughly as follows. Air side thermal resistance Tube inner thermal resistance Overall 1 / (ho * Ao) 1 / (hi * Ai) Rt Gas area 16% 84% 100% Liquid area 35% 65% 100% Two phase area 85% 15% 100% These Characteristically, when the state of the refrigerant in the pipe is in the gas area and the liquid area, the thermal resistance of the refrigerant in the pipe is dominant, and the ratio of the thermal resistance on the air side is small, especially in the gas area. While the tendency is remarkable, it can be seen that when the refrigerant in the pipe occupying most of the heat exchanger is in the two-phase region, the air-side thermal resistance is dominant.

Therefore, in order to improve the performance of the heat exchanger, it is important to reduce the thermal resistance in the two-phase region of the refrigerant in the pipe, which accounts for most of the heat exchange amount. Reduction is an important issue.

As means for reducing the thermal resistance on the air side, generally, a fin pitch is reduced, a fin width along an air flow direction is increased to increase a heat transfer area, or a surface shape of the air side fin is devised to improve the heat transfer. There is a method of promoting heat and improving the heat transfer coefficient ho. However, conventionally, if the heat transfer area is simply increased by reducing the fin pitch or the like, the use amount of the fin material is increased and the cost is increased, and the air flow resistance is greatly increased.

Further, in the conventional heat exchanger, when the size of the heat exchanger is increased to three rows, a fin structure having a high heat transfer coefficient for improving performance has a small ratio of heat resistance on the air side in the gas or liquid region in the pipe. In this case, the thermal resistance on the air side is meaninglessly improved, and there is a problem that the ventilation resistance is greatly increased.

However, according to the above configuration of the present invention,
As shown in FIG. 5, cut-and-raised slits are provided on opposite sides of the fin base line, and the fin pitch is widened by using double-raised slit fins, so that heat resistance and air flow in the two-phase region are increased. In addition to reducing the resistance, the fins at the portions corresponding to the gas and liquid regions in the pipe are preferably flat fins, which have a lower ventilation resistance than the fin shape in the two-phase region. Resistance can be greatly reduced. As described above, in the portion corresponding to the refrigerant gas region and the liquid region in the pipe, the ratio of the thermal resistance on the air side to the whole is small, so even if the fin pitch is widened, the deterioration of the overall thermal resistance is slight, The effect of increasing the fan airflow and improving the exchange heat quantity by reducing the ventilation resistance is greater. Therefore, the fan airflow under the same noise condition increases,
The amount of heat exchange increases and the performance of the heat exchanger is greatly improved.

Next, the operation of the refrigeration cycle in the heat pump type air conditioner having the above-described configuration will be described. First, in the refrigeration cycle configuration of the heat pump type air conditioner shown in FIG. 7, during the heating operation, the high-temperature and high-pressure refrigerant gas discharged from the compressor 11 of the outdoor unit 10 is indicated by a solid-line arrow 41. As described above, the air is sent to the indoor heat exchanger 21 of the indoor unit 20 acting as a condenser through the four-way valve 12 and the refrigerant pipe 27 and cooled by the air blown by the indoor flow fan 24 (air and heat). Exchange), it becomes a high pressure and low temperature liquid refrigerant.

The refrigerant that has been cooled and turned into a high-pressure / low-temperature liquid returns to the outdoor unit 10 through the refrigerant pipe 27 and is decompressed and expanded by the decompressor 16, thereby becoming a low-pressure / low-temperature refrigerant and evaporating. Into the outdoor heat exchanger 13 acting as a heat exchanger. The refrigerant flowing into the outdoor heat exchanger 13 is heated by the air blown by the outdoor fan 17, evaporates, returns to the compressor 11 through the four-way valve 12, is compressed again, and is circulated as described above. Repeat cycle. At this time, in the indoor heat exchanger 21, the air heated by the high-temperature and high-pressure refrigerant gas is discharged into the room to be air-conditioned to heat the room.

On the other hand, during the cooling operation, the high-pressure and high-temperature refrigerant gas discharged from the compressor 11 of the outdoor unit 10 passes through the four-way valve 12 and acts as a condenser, as indicated by the dashed arrow 42. It is sent to the outdoor heat exchanger 13. In the outdoor heat exchanger 13, the refrigerant is cooled by the air blown by the outdoor fan 17, becomes a high-pressure / low-temperature liquid refrigerant, is decompressed and expanded by the decompressor 16, and becomes a low-pressure / low-temperature refrigerant. The low pressure and low temperature refrigerant is supplied to the refrigerant pipe 27.
And flows into the indoor heat exchanger 21 of the indoor unit 20 that functions as an evaporator. Here, after being heated and evaporated by the air blown by the indoor fan 24,
The refrigerant returns to the compressor 11 through the four-way valve 12 of the outdoor unit 10 through the refrigerant pipe 27, where it is compressed again and the above-described circulation cycle is repeated. At this time, the indoor heat exchanger 2
In 1, cooling is performed by discharging air cooled by a low-pressure and low-temperature refrigerant into a room to be air-conditioned.

Next, the state change of the refrigerant circulating in the refrigeration cycle is schematically shown in FIG. In addition,
In FIG. 8, the horizontal axis is the entropy S (kJ / kg) of the refrigerant.
K), and the vertical axis indicates the temperature T (° C.) of the refrigerant. The refrigerant temperature Tc is a condensation temperature corresponding to the pressure in the condenser,
The refrigerant temperature Te is an evaporation temperature corresponding to the pressure in the evaporator. Symbols A and C indicate the inlet and outlet of the heat exchanger acting as a condenser, respectively, and symbols D and E indicate the inlet and outlet of the heat exchanger acting as an evaporator, respectively. . Further, in FIG. 8, the section AB1 indicates a refrigerant overheating area, the section B1-B2 indicates a saturation area, and the section B2-C indicates a supercooling area.

First, the case of the heating operation will be described.
In this case, the indoor heat exchangers 22 that are thermally separated from each other
The throttle mechanism 25 for dehumidifying operation provided between the a and 22b is set fully open so as not to cause flow resistance.
Next, when the compressor 11 is started, the high-temperature and high-pressure superheated refrigerant gas (point A in FIG. 8) discharged from the compressor 11 is supplied to the indoor unit 2 via the four-way valve 12 and the piping unit 27.
The heat is then sent to the indoor heat exchanger 21 of No. 0 and split into two paths from the heat transfer tubes in the third row on the air side most downstream of the front heat exchanger 22a constituting the indoor heat exchanger. Front heat exchanger 22
b flows out of the upper heat exchanger 22a through the throttle mechanism 25.
Flows into the air and exchanges heat with air to become a low-temperature liquid refrigerant,
The air flows out of the indoor heat exchanger 21 through the first heat transfer tube row on the air side of the rear inclined portion 22aB of the upper heat exchanger 22a. At this time, the room air 26 flowing outside the indoor heat exchanger 21 is warmed by heat exchange with the refrigerant in the pipe, and is used for heating the room to be air-conditioned (see FIG. 7).

At this time, since the air-side fins are raised and used as slit fins, the heat resistance on the air side is improved, and the refrigerant in the pipe is in a saturated region (section B1-B2 in FIG. 8). Is heated until it reaches a temperature substantially equal to the refrigerant condensing temperature Tc in the pipe, and reaches the leeward third row 109d thermally divided by the separation slit 110. In the third row 109d on the leeward side, the superheated 70
With the superheated refrigerant (point A in FIG. 8) of ８０80 ° C. (= Tc + 30 ° C. to 40 ° C.), the heating efficiency is improved until the temperature becomes even higher, and the heating capacity is improved. Although a temperature difference occurs between the rows sandwiching the separation slit 110, the heat transfer loss through the fins 100 due to the temperature difference between the rows of heat transfer tubes is thermally divided by the separation slit 110. It is suppressed and the heating capacity is improved.

The refrigerant path of the front heat exchanger 22b is 2
Since it is composed of a path, the flow rate of the refrigerant in the pipe is high. As a result, the heat transfer coefficient in the superheated refrigerant region is improved, so that the thermal resistance Rt, g inside the pipe is improved, the temperature difference between the pipe refrigerant temperature and the pipe wall is kept small, and the temperature of the fins is reduced. The air that has risen to near the temperature and has flowed into the third row is efficiently heated and heated. Further, since the fins in the third row are flat fins, the ventilation resistance is reduced, the air volume is increased, and the heating capacity is improved.

A part of the upper heat exchanger 22a arranged in an inverted V shape above the once-through fan 24, that is, the inverted V-shaped rearwardly inclined portion 22aB has three rows of heat transfer tubes. And the refrigerant path at the heating outlet is the uppermost stream 1 on the air side.
It is arranged in the column. Therefore, the air that has passed through the first row where the refrigerant temperature in the pipe is low and the air temperature rise is small is removed from the second row and the third row where the pipe is a gas-liquid two-phase refrigerant and the heat transfer coefficient in the pipe is high.
Since the heating and the temperature can be further increased in the heat exchanger section in the row, the air is not blown into the room at a low temperature as in the conventional two-row heat exchanger, and the heating capacity is improved. Further, since the fins in the first row are flat fins, the ventilation resistance is reduced, the air flow is increased, and the heating capacity is improved.

The fin 100 at the inverted V-shaped rear downward inclined portion 22aB of the upper heat exchanger 22a has a heat transfer tube row 108u on the windward side in which the refrigerant path is configured as one path, and the refrigerant path has two paths. The leeward side heat transfer tube row 108 configured
d so as to be thermally separated from each other.
Is provided. By providing the separation slit 110, the heat transfer tube row 108u on the leeward side where the refrigerant path is configured as one path and the heat transfer pipe row 108d on the leeward side where the refrigerant path is configured as two paths are thermally separated. Have been. The heat transfer tube row 108u on the leeward side of the one pass serves as a refrigerant outlet during the heating operation. Therefore, as shown by a section B2-C in FIG.
The refrigerant temperature is lower than the refrigerant temperature Tc of 08d, and a temperature difference occurs between the heat transfer tube arrays. However, since the separation slit 110 is provided, heat conduction loss via the fins 100 due to a temperature difference between the heat transfer tube rows is suppressed, and the heating capacity is further improved.

Next, the cooling operation will be described. In the cooling operation, the refrigerant flow direction is reversed from that in the heating, so that the heating outlet is the cooling inlet and the heating inlet is the cooling outlet. In the case of this cooling operation, first, the indoor heat exchangers 22a, 22
Throttle mechanism 25 for dehumidifying operation provided in the middle of 2b
Is also set to full open so as not to cause flow resistance.

Next, when the compressor 11 is started, the compressor 1
High-temperature and high-pressure superheated refrigerant gas discharged from No. 1 (A in FIG. 8)
) Is sent to the outdoor heat exchanger 13 and the outdoor unit 1
Heat exchange with the cooling air 18 flowing through the heat exchanger 13
The refrigerant is cooled and liquefied. The liquefied high-pressure / low-temperature liquid refrigerant (point C in FIG. 8) is reduced in pressure to the evaporation pressure via the throttle mechanism 16 to become a low-temperature gas-liquid two-phase refrigerant (point D in FIG. 8). The air flows into the indoor heat exchanger 22 of the indoor unit 20, which acts as a cooling unit, and cools the air there. afterwards,
This refrigerant gradually evaporates by the amount of heat taken from the air, reaches the outlet of the heat exchanger 22, at which the refrigerant again becomes gaseous refrigerant (point E in FIG. 8), is sent to the compressor 11, and is compressed again. It is discharged from the machine 11 and circulates.

In the cooling operation, when the indoor heat exchanger 21 of the indoor unit 20 functions as an evaporator, the pressure of the refrigerant in the pipe is low unlike the case where the indoor heat exchanger 21 functions as a condenser during the heating operation. Therefore, in particular, when the refrigerant path at the cooling outlet (heating inlet) is set to two passes, the flow velocity of the refrigerant gas in the pipe becomes high, and a large pressure loss is conventionally caused on the refrigerant side, and the cooling performance is greatly reduced. However, in the air conditioner according to the present invention, since the high-pressure refrigerant R410A is used as the refrigerant, the flow velocity in the pipe is low because the density of the refrigerant gas in the pipe is large. As a result, pressure loss is reduced and cooling performance is improved.

During the cooling operation, the saturation temperature of the refrigerant decreases toward the outlet of the heat exchanger due to the pressure loss of the refrigerant in the pipe, so that the downstream side of the front heat exchanger 22b located at the outlet of the refrigerant flow path during cooling operates. The refrigerant evaporation temperature in the row tube (in the vicinity of point E in FIG. 8) is the lowest. For this reason, a large amount of moisture is condensed on the fin surface of the third row on the air downstream side of the front heat exchanger 22b. Although there was a problem that the fan noise increased significantly and the fan noise increased, in the embodiment of the present invention, the fins in the third row were flat fins. At the same time, the ventilation resistance is reduced and the fan noise is improved, while the air flow is increased and the cooling capacity is improved. In the first and second rows, the air-side fins are raised to form slit fins, so that the drainage action of water droplets condensing on the fin surface is improved, so that the ventilation resistance when dew is formed is further improved.

As in the case of the above-described heating operation, the refrigerant evaporation temperature in the first path, which is the refrigerant passage of the upper heat exchanger 22a, and the refrigerant evaporation temperature in the second path, which is the refrigerant passage of the front heat exchanger 22b. A temperature difference occurs in the refrigerant evaporation temperature. For this reason, conventionally, heat is transferred between the upper heat exchanger 22a and the front heat exchanger 22b through the integrated fins 100 by heat conduction, and the cooling capacity is reduced due to the heat conduction loss. Had a problem.

However, in the present invention, as described above, the indoor heat exchanger 21 is constituted by the two heat exchangers 22a and 22b which are thermally separated from each other. Since heat conduction loss due to a temperature difference with the front heat exchanger 22b is unlikely to occur, the cooling capacity is improved. In addition, since the refrigerant outlet at which the refrigerant evaporation temperature is the lowest is disposed at the most downstream side of the air flow of the lower three-row heat exchanger 22b, the cool air cooled in order from the air upstream row is further cooled to a lower refrigerant evaporation temperature. Can be cooled by the air lee side row, and a significant improvement in cooling capacity can be expected.

Next, the operation during the dehumidifying operation will be described. In the case of this dehumidifying operation, first, the four-way valve 12 is set to the same position as in the cooling operation, and the pressure reducer 16 is set to the fully open position.

Next, when the compressor 11 is started, the compressor 1
The high-temperature and high-pressure superheated refrigerant gas (point A in FIG. 8) discharged from the outdoor heat exchanger 13, the pressure reducer 16, and the refrigerant pipe 2
7 and is sent to the indoor heat exchanger 21 of the indoor unit 20. The high-temperature and high-pressure refrigerant gas sent to the indoor heat exchanger 21 is first supplied to the upper heat exchanger 22 acting as a condenser.
a, where the dehumidified air 26 flowing outside
Is heated through the fins 100. At the same time, the refrigerant in the pipe is cooled and liquefied by external air and reaches the throttle unit 25. The refrigerant in the cooled and liquefied pipe is supplied to the throttle unit 2.
The refrigerant is decompressed through the refrigerant gas 5 into a low-temperature, low-pressure gas-liquid two-phase refrigerant, and then flows into the lower heat exchange 22b acting as an evaporator (cooling dehumidifier). Here, the air in the room to be conditioned is cooled and dehumidified, and at the same time, the refrigerant in the pipe evaporates and flows out of the indoor heat exchanger, and is sucked into the compressor again through the four-way valve to repeat the circulation. In the front heat exchanger 22b, as in the case of the cooling operation described above, the temperature of the refrigerant in the pipe in the lowermost row of the air is the lowest, and the air in the front heat exchanger 22b is cooled in the same manner as in the cooling operation. A large amount of water will condense on the fin surface of the third row on the downstream side. However, since the fins of the third row are flat fins, water droplets condensed on the fin surface flow down without stagnating, and dew is formed. When the airflow resistance is reduced and the fan airflow is increased, the dehumidification efficiency is greatly improved.

Conventionally, the upper heat exchanger 22a and the front heat exchanger 22b which are adjacent to each other have a
00 is thermally connected. Therefore, the lower-temperature front heat exchanger 22b acting as a cooling and dehumidifier is heated via the integrated fins 100 by the higher-temperature upper heat exchanger 22a acting as a heater. Therefore, the front heat exchanger 22b acting as a cooling dehumidifier
The dehumidified moisture condensed on the surface of the substrate is re-evaporated due to the heating from the upper heat exchanger 22a, which causes a problem that the dehumidifying efficiency is reduced.

On the other hand, in the present invention, as described above, the upper heat exchanger 22a and the front heat exchanger 22b constituting the indoor heat exchanger 21 of the indoor unit 20 have at least fins 100 separated from each other. It has a separate structure that is thermally separated. Therefore, there is no heat conduction loss between the upper heat exchanger 22a acting as a high-temperature heater and the front heat exchanger 22b acting as a low-temperature cooling and dehumidifier, so that the cooling capacity can be greatly improved. . Further, there is no problem that the dehumidified moisture re-evaporates due to the heat from the upper heat exchanger 22a acting as a heater. In particular, during the cooling operation, the upper heat exchanger 22 described above is used.
In the refrigerant passage of the inverted V-shaped rear downward inclined portion 22aB of a, in the first pass portion arranged in the first row on the windward side, the refrigerant temperature in the pipe is lower than that in the adjacent two pass portion due to the pressure loss on the refrigerant side. Since the overall height is high, a temperature difference occurs between the rows in the 1-pass section and the 2-pass section. For this reason, conventionally, there was a problem that heat exchange was caused by heat exchange due to the temperature difference between the rows, and the cooling capacity was reduced. However, in the structure of the heat exchanger according to the present invention, in particular, the heat exchanger 22a, the separation slit 1 is provided between the rows of the 1-pass section and the 2-pass section.
The provision of 10 suppresses heat conduction loss between these rows, thereby improving cooling capacity.

In the indoor unit 20 according to the above-described embodiment, the upper heat exchanger 22a has a reverse V
Although arranged in a bent shape, the effect of the present invention is not limited to the above-described arrangement and form of the heat exchanger. Of course, an arc-shaped arrangement of a "U" -shaped bend may be used.

In the above embodiment, as a method of thermally partitioning by the separation slit 110, for example, FIG.
As shown in FIG. 9A, a method of intermittently cutting the fin 100 by press working or the like, a method of punching an elongated slit hole 101 as shown in FIG. 9B, or a sewing machine as shown in FIG. Needless to say, a method such as a method of providing the eye-shaped cut 102 can be appropriately selected, such as cutting while leaving a part of the connection portion. 10 (A) and FIG.
As shown in (B), a “V” -shaped or “U” -shaped groove 103 is formed on both sides or one side of the fin 100 to substantially completely partition the heat, or to reduce heat conduction. It is also possible to use a partitioning method.

In the above embodiment, the separation slit 11
The third row defined by 0 is configured as a refrigerant inlet position during heating, and is arranged in the front heat exchanger 22b that functions as a dehumidifier during dehumidification operation. However, the refrigerant inlet position at the time of heating is not limited to this. For example, the refrigerant inlet position may be arranged downstream of the airflow, for example, adjacent to the upper heat exchanger 22a acting as a heater during the dehumidifying operation. Is also good. In this case, the high-temperature air heated by the upper heat exchanger 22a serving as a reheater flows into the third row defined by the separation slit 110 serving as a dehumidifying cooler. Since the temperature difference from the refrigerant becomes large and the dehumidifying cooling can be performed efficiently, the dehumidifying efficiency is improved.

Next, the configuration of an indoor unit according to another embodiment of the present invention is shown in FIG. In the indoor unit shown in FIG. 11, the rear inclined portion 22aB of the inverted V-shaped upper heat exchanger 22a of the indoor heat exchanger 21 is provided in two rows with respect to the indoor unit shown in FIG. Is provided. According to this configuration, since the number of rows of the upper heat exchanger 22a is two, the airflow resistance in a portion far from the fan is reduced, so that there is an effect that fan noise is improved.

FIG. 12 shows a form of an indoor heat exchanger according to another embodiment of the present invention. For the indoor unit shown in FIG.
The inverted V-shaped upper heat exchanger 22a of the indoor heat exchanger 21 has three rows of front inclined parts 22aA and two rows of rear inclined parts 22aB. By reducing the number of rows of heat exchangers on the rear side where the airflow sucked by the once-through fan 24 is slower than on the front side, the wind speed distribution is uniformed and the performance is improved.

Next, the configuration of the fin of the indoor heat exchanger according to another embodiment of the present invention is shown in FIGS. The fin structure shown in FIG. 13 corresponds to the indoor unit shown in FIG.
Are selectively provided on the fin surface except for the refrigerant inlet portion at the time of heating, so that the heat exchange efficiency at the time of the heating operation and the ventilation resistance at the fin side are optimized. The fin structure shown in FIG. 14 corresponds to the indoor unit shown in FIG. 12, and the cut-and-raised slit 200 for promoting heat transfer performance is selected on the fin surface excluding the refrigerant inlet portion and the refrigerant outlet portion during heating. The heat exchange efficiency during the heating operation and the ventilation resistance on the fin side are optimized.

FIG. 15 shows a cut-and-raised slit cross-sectional shape of an air-side fin according to another embodiment of the present invention. In this embodiment, the slits are cut and raised alternately on opposite sides of the fin substrate surface, and the slits 200a, 20 cut and raised on the same side.
0b is obtained by changing the cut and raised height. A bent portion 200c is provided on the substrate adjacent to the cut-and-raised slit 200 to increase the gap between the slits. With this configuration, the downstream slit is not affected by the wake of the upstream slit, so that the heat transfer coefficient is further improved. A large number of slits cut and raised and having different heights can be arranged between adjacent fins, so that the heat transfer coefficient on the air side can be secured even if the fin pitch is increased to reduce the ventilation resistance. Further, since a gap is ensured by the bent portion provided on the substrate, there is an effect that drainage of water droplets condensing on the fin surface during cooling operation or dehumidifying operation is greatly improved.

FIG. 16 shows a sectional structure of an air-side fin according to another embodiment of the present invention. In this embodiment, the entire fin is formed in a waveform along the air flow direction, and a cut-and-raised slit having a mountain-shaped cross section having a different cut-and-raised height is provided continuously to the mountain-shaped plane. That is, the fin shape corresponding to the third row or the first row connected to the heating-time refrigerant inlet and the heating-time refrigerant outlet is cut and raised, and is processed into a mountain-shaped plane having no slit. With such a configuration, the rigidity of the fins is largely improved as a whole, so that the fins are easy to handle and the productivity is greatly improved. Since the cross-sectional shape of the cut-and-raised slit 200 is formed to have a mountain-shaped cross section, the effect of further improving the heat transfer performance on the air side due to the turbulent flow effect is achieved.

FIG. 17 shows a fin structure according to another embodiment of the present invention. In this embodiment, the cross-sectional shape of the cut-and-raised slit 200 as viewed from the airflow direction is formed as a mountain shape as a whole,
Further, the cut-and-raised slit is formed by bending the cut-up slit rising portion 300 at an acute angle in two steps and changing the position of the slit rising portion to the airflow direction. With such a configuration, the slits are cut and raised between the adjacent fins, and the slits are arranged obliquely. The air flow between the fins is disturbed even if the fin pitch is widened to reduce the ventilation resistance. Side heat transfer coefficient. In addition, since the position of the rising portion 300 is changed, the distance between adjacent slits is secured, so that the drainage of water droplets condensed on the fin surface during the cooling operation or the dehumidifying operation is greatly improved. Play.

FIG. 18 shows a fin structure according to another embodiment of the present invention. In a fin having three rows of heat transfer tubes, the cut-and-raised slit is provided on a fin surface located between adjacent heat transfer tubes in each row, and cut so that the slit arrangement density is different for each row. The raised slit is formed. That is, the third or first row of the fins connected to the heating-time refrigerant inlet and the heating-time refrigerant outlet is provided with a cut and raised slit having a lower density than other fins. In addition, preferably, the slits are cut and raised in the order of the portions except for the heating-time refrigerant inlet row, the heating-time refrigerant outlet row, and the heating-time refrigerant inlet / outlet portion to increase the density of the slit. With this configuration, the thermal resistance on the air side is improved in accordance with the thermal resistance in the pipe, so that the thermal resistance between the pipe and the air side is balanced, so that the heat exchange efficiency during heating and the ventilation resistance on the fin side are appropriate. Since the airflow is further improved, the fan airflow is improved and the heating capacity is improved.

FIG. 19 shows a fin structure according to another embodiment of the present invention. In a fin with three rows of heat transfer tubes,
The entire fins are formed in a waveform, and the angle of attack of the corrugated fin surface with respect to the airflow direction is smaller in the first row, which is the liquid refrigerant area in the pipe, in the second row, in which the refrigerant in the pipe is in the two phase area,
It is enlarged in the third row. With such a configuration, the thermal resistance of the air-side fins can be appropriately changed in accordance with the thermal resistance in the pipe, so that the heating capacity is improved by reducing the ventilation resistance.

The fins for an indoor heat exchanger according to the present invention described above can of course exert the same effect when used for the outdoor heat exchanger acting as a condenser during cooling and an evaporator during heating. is there.

As described above, according to the above configuration of the indoor heat exchanger for an air conditioner according to the embodiment of the present invention, the indoor heat exchanger has three rows connected to the heating refrigerant inlet and the heating refrigerant outlet. In the fin corresponding to the first row or the first row, the cut-and-raised slits are provided with a lower density than the others, and preferably cut in the order other than the heating refrigerant inlet row, the heating refrigerant outlet row and the heating refrigerant inlet / outlet section. Since the density of the raised slits is increased, the air-side heat resistance is improved according to the heat resistance in the pipe, so that the heat exchange efficiency during the heating operation and the ventilation resistance on the fin side are optimized. Thus, an air conditioner having high heating capacity with low fan power and low fan noise can be provided.

In the cooling operation, the third row of fins corresponding to the cooling outlet has cut and raised slits with a lower density than the others, and is preferably a flat fin. Since the flow does not flow down, the ventilation resistance at the time of dew is reduced and the fan noise is improved, and the air volume is increased and the cooling capacity is improved. In the first and second rows, the air-side fins are raised to form slit fins, so that the drainage action of water droplets condensing on the fin surface is improved, so that the ventilation resistance when dew is formed is further improved.

Further, according to the above configuration of the indoor unit for an air conditioner according to the embodiment of the present invention, during the heating operation, the separation slit is provided on the fin surface between the rows having different refrigerant temperatures in the pipe. Thus, heat conduction loss between the heat transfer tubes having different temperatures via the fins does not occur, and the heating capacity is improved.

Further, when the heating capacity is constant, the temperature difference between the refrigerant and the air required for heating can be reduced, so that the condensation temperature and pressure are reduced, and the compression work is reduced. Therefore, it is possible to provide an air conditioner that consumes less power and to reduce the size of the heat exchanger.

[0071]

As described above, according to the above configuration of the indoor heat exchanger for an air conditioner according to the embodiment of the present invention,
In the indoor heat exchanger, the third row or the first row of fins connected to the heating-time refrigerant inlet and the heating-time refrigerant outlet are provided with a lower density of slits than the other fins. It is configured so that the density of the slits is increased by cutting and raising in the order other than the hour refrigerant outlet row and the heating-time refrigerant inlet / outlet part, so that the air-side thermal resistance is improved according to the pipe thermal resistance, so that the heating operation is performed. The optimization of the heat exchange efficiency at the time and the ventilation resistance on the fin side is achieved, and an air conditioner having a high heating capacity with suppressed fan power and fan noise can be provided.

Further, during cooling operation, the third row of fins corresponding to the cooling outlet has cut-and-raised slits with a lower density than the others, and is preferably a flat fin, so that water droplets condensed on the fin surface may remain. Since the flow does not flow down, the ventilation resistance at the time of dew is reduced and the fan noise is improved, and the air volume is increased and the cooling capacity is improved. In the first and second rows, the air-side fins are raised to form slit fins, so that the drainage action of water droplets condensing on the fin surface is improved, so that the ventilation resistance when dew is formed is further improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a detailed structure inside an indoor unit for an air conditioner according to an embodiment of the present invention.

FIG. 2 is a plan view showing a detailed structure of a fin for an indoor heat exchanger according to an embodiment of the present invention.

FIG. 3 is a view showing a structure of a fin constituting an inverted V-shaped rear downward inclined portion of the indoor unit for an air conditioner.

FIG. 4 is a view showing a structure of a fin of a front heat exchanger of the indoor unit for an air conditioner.

FIG. 5 is a diagram showing a cross-sectional structure of a fin constituting an inverted V-shaped inclined portion of the indoor unit for an air conditioner.

FIG. 6 is a view showing a sectional structure of a fin of a front heat exchanger of the indoor unit for an air conditioner.

FIG. 7 is a configuration diagram of a refrigeration cycle including the indoor unit for an air conditioner of the present invention.

FIG. 8 is a TS diagram of a refrigeration cycle in the refrigeration cycle of the indoor unit for an air conditioner.

FIG. 9 is a partially enlarged cross-sectional perspective view of a fin showing a specific structure of a separation slit for thermally partitioning between rows of the indoor heat exchanger.

FIG. 10 is a partially enlarged cross-sectional perspective view of a fin showing a specific structure of a separation slit for thermally partitioning between rows of the indoor heat exchanger.

FIG. 11 is a cross-sectional view showing a detailed structure inside an indoor unit for an air conditioner according to another embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a detailed structure inside an indoor unit for an air conditioner according to another embodiment of the present invention.

FIG. 13 is a plan view showing a detailed structure of a fin for an indoor heat exchanger according to another embodiment of the present invention.

FIG. 14 is a plan view showing a detailed structure of a fin for an indoor heat exchanger according to another embodiment of the present invention.

FIG. 15 is a sectional view showing a detailed structure of a fin for an indoor heat exchanger according to another embodiment of the present invention.

FIG. 16 is a sectional view showing a detailed structure of a fin for an indoor heat exchanger according to another embodiment of the present invention.

FIG. 17 is a front view showing a detailed structure of a fin for an indoor heat exchanger according to another embodiment of the present invention.

FIG. 18 is a plan view showing a detailed structure of a fin for an indoor heat exchanger according to another embodiment of the present invention.

FIG. 19 is a sectional view showing a detailed structure of a fin for an indoor heat exchanger according to another embodiment of the present invention.

[Explanation of symbols]

20 indoor unit, 21 indoor heat exchanger, 22a, 2
2b: upper heat exchanger, front heat exchanger, 24: once-through fan, 201: box, 202: fan casing, 203
... upper suction port, 204: front suction port, 30: separate heat exchanger, 110: separation slit, 200: cut and raised slit.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeki Chiba 800, Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Inside the Cooling Division, Hitachi, Ltd. Hitachi, Ltd.Cooling Division (72) Inventor Ichiro Fujibayashi 800, Tomita, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture Inside the Cooling Division, Hitachi Ltd. (72) Atsushi Otsuka 800, Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Pref.Hitachi Co., Ltd.

Claims (4)

[Claims] An indoor unit having an upper surface suction port and a front surface suction port, and indoor heat exchange in which a through-flow fan and three rows of refrigerant pipes are arranged in the indoor unit between the suction ports and the through-flow fan. The indoor heat exchanger is connected to the refrigerant inlet during heating and the refrigerant outlet during heating.
In the fins corresponding to the first row or the first row, the raised and cut slits are provided with a lower density than the others, and cut and raised in the order of other parts except the heating refrigerant inlet row, the heating refrigerant outlet row, and the heating refrigerant inlet / outlet part. An air conditioner characterized by increasing the density of slits. 2. An indoor unit having a top suction port and a front suction port, and a through-flow fan in the indoor unit, and a refrigerant pipe between the two suction ports and the through-flow fan.
A cross-fin type indoor heat exchanger configured in a row, wherein the indoor heat exchanger has a fin surface located at a portion where the refrigerant in the refrigerant pipe is substantially in a gas-liquid two-phase region. In the two-phase region, a cut-and-raised slit is provided, and a fin shape at a portion corresponding to the in-pipe refrigerant gas area located at the heating-time refrigerant inlet and the in-pipe refrigerant liquid area located at the heating-time refrigerant outlet is formed. An air conditioner characterized by having a lower ratio of slits and a lower airflow resistance than a fin shape. 3. An indoor unit having a top suction port and a front suction port, a cross-flow fan in the indoor unit, and a cross fin having three rows of refrigerant pipes between the suction ports and the cross-flow fan. Indoor heat exchanger, wherein the indoor heat exchanger cuts and rises on the fin surface located at a portion where the refrigerant in the refrigerant pipe is substantially in a gas-liquid two-phase region with the fin baseline interposed therebetween. The cut-and-raised slit is provided, and the fin shape at a portion corresponding to the in-pipe refrigerant gas area located at the heating-time refrigerant inlet and the in-pipe refrigerant liquid area located at the heating-time refrigerant outlet is formed in the two-phase area. An air conditioner having a lower ventilation resistance than a fin shape, preferably a flat shape. 4. An indoor unit having a top suction port and a front suction port, a cross-flow fan in the indoor unit, and a cross in which three rows of refrigerant pipes are arranged between the suction ports and the cross-flow fan. With a fin-shaped indoor heat exchanger, the indoor heat exchanger is a fin shape located in a portion where the refrigerant in the refrigerant pipe is substantially in a gas-liquid two-phase region and a high heat transfer coefficient corrugated fin, The fin shape at the portion corresponding to the in-pipe refrigerant gas area located at the heating-time refrigerant inlet and the in-pipe refrigerant liquid area located at the heating-time refrigerant outlet has a lower ventilation resistance than the fin shape in the two-phase area. An air conditioner characterized in that the angle of attack of the waveform with respect to the inflow airflow is reduced as much as possible.