JP2002071208A - Heat exchanger and indoor machine and outdoor machine for air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger that can effectively make heat exchange even in such a state where air flows at different flow velocities and a refrigerant flows in the heat exchanger in different states, particularly, when the heat exchanger is used as an evaporator, and to provide an indoor machine and an outdoor machine for air conditioner. SOLUTION: The heat exchanger 10 provided with a heat transfer tube 3 and plate fins 2 formed outside the tube 3 is constituted of a plurality of blocks. The blocks are attached at the same height in the gravitational direction and, at the same time, horizontally arranged in a lateral direction which intersects the flowing direction of air. The heat exchanger 10 is used as the indoor machines 20 and 30 or outdoor machine 50 of an air conditioner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an indoor unit and an outdoor unit for a heat exchanger and an air conditioner.

[0002]

2. Description of the Related Art In a heat pump type air conditioner, for example, a heat exchanger is used in which a plurality of heat transfer tubes in which a plurality of thin aluminum sheets are laminated to form plate-like fins are arranged. In this heat exchanger, a refrigerant is caused to flow and heat is exchanged with indoor air. As shown in, for example, JP-A-6-129732, a plurality of flow paths are provided at an inlet header. A so-called multi-pass structure is known, which is composed of heat transfer tubes that are branched into a heat exchanger and merge at an outlet header while evaporating or condensing in a heat exchanger (prior art 1).

In Japanese Utility Model Laid-Open Publication No. 6-55067,
A plurality of heat transfer tubes are arranged side by side in the upwind and downwind directions with respect to the air flow direction, and by connecting these heat transfer tubes in the middle, the inside of each heat transfer tube evaporates into a gas-liquid two-phase flow refrigerant. A structure for preventing a difference in degree (thirst degree) from occurring is shown (prior art 2).

Further, Japanese Patent Application Laid-Open No. 6-129732 discloses a heat exchanger for improving the performance by securing a uniform amount of circulating refrigerant by increasing the number of passes. This heat exchanger is arranged substantially in parallel, and vertically arranges a continuous first-pass refrigerant pipe and a second-pass refrigerant pipe through which the refrigerant flows, and provides cooling fins on the heat transfer tube to achieve multi-pass. In this heat exchanger, the diameter of the first-pass refrigerant pipe disposed above is made larger than the diameter of the second-pass refrigerant pipe disposed below (prior art 3).

[0005]

In the branch structure of the refrigerant flow path shown in the above-mentioned prior art 1, it cannot be said that the temperature distribution of the heat exchanger is uneven and the heat exchanger does not always work efficiently. That is, the refrigerant that has entered the inlet header does not always flow uniformly in a plurality of channels due to manufacturing variations or inclinations of the inlet header shape. It becomes uneven.

[0006] In the above-mentioned multi-pass structure, how the refrigerant two-phase flow is mixed and how the refrigerant is evenly distributed determines the performance of the heat exchanger. The performance of a distributor using a header or the like is not always sufficient. For example, even if the adjustment is sufficiently performed in the specific operating state of the rated state, the state of the refrigerant flowing into the distributor (branch path) varies in various operations that are actually performed. The performance will also be different. For this reason, for example, when a heat exchanger is used as an evaporator, a difference occurs in the refrigerant flow rate in each flow path of the evaporator, so that the capacity as the evaporator cannot be fully utilized, and the cooling performance of the air conditioner is reduced. Let me do it.

[0007] This also causes the outlet side of the evaporator, that is, the suction pressure of the compressor to decrease. Accordingly, the compression ratio of the compressor increases, and as a result, the efficiency of the refrigeration cycle may decrease.

Further, in the above-mentioned prior art 2, although the difference in heat exchange efficiency of the heat exchanger before and after the leeward side and the leeward side can be eliminated, the direction of air flow in the heat exchanger is in the vertical and horizontal directions. However, it is not always possible to eliminate the difference in the air flow velocity in the heat exchanger, and that the heat exchange efficiency of the entire heat exchanger is not sufficiently considered.

Furthermore, in the above-mentioned prior art 3, since the contribution of heat exchange in the gas-side separated gas side path is extremely small, it is not always considered that heat exchange is performed uniformly. I didn't say it.

It is an object of the present invention, in view of the above prior art, that there is a difference in the air flow velocity passing through the heat exchanger, especially when the heat exchanger is used as an evaporator even in various different inflow states of the refrigerant. Another object of the present invention is to provide a heat exchanger, an indoor unit for an air conditioner, and an outdoor unit, which have a good heat exchange effect.

[0011]

Means for Solving the Problems To achieve the above object, an invention of a heat exchanger according to the present invention is directed to a heat exchanger including a heat transfer tube and a plate fin formed outside the heat transfer tube. The heat exchanger is composed of a plurality of blocks, each of which is mounted at the same height in the direction of gravity, and arranged in a horizontal direction in the left-right direction so as to intersect with the direction of air flow.

More specifically, the heat transfer tube of each block has a flow path that branches or merges near the entrance / exit of each block.

An air purifying filter is interposed between the blocks.

In order to achieve the above object, an invention of an air conditioner indoor unit according to the present invention is directed to an air conditioner indoor unit having a heat exchanger and a blower fan, wherein a plurality of heat exchangers are provided. Each block is mounted at the same height in the direction of gravity, and is arranged horizontally horizontally across the air flow direction. Each block branches or merges near the entrance / exit of each block. And a front surface of each block is arranged in a direction perpendicular to a tangent to a discharge port of the blower fan.

In order to achieve the above object, an invention of an outdoor unit for an air conditioner according to the present invention is characterized in that the heat exchanger is composed of a plurality of blocks, and each block is mounted at the same height level in the direction of gravity. At the same time, the blocks are arranged on the sides surrounding the central fan, and the blocks are arranged in a plurality of rows at intervals before and after in the flow direction of the air, and the heat transfer tubes of each block are branched or near the entrance of each block. It has a merging flow path.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a heat exchanger, an indoor unit for an air conditioner and an outdoor unit of the present invention will be described with reference to the drawings.

FIG. 1 is a front view of a first embodiment of an air conditioner indoor unit according to the present invention, and FIG. 2 is a perspective view thereof. As shown in FIG. 1, the indoor unit 20 is a wall-mounted type, and includes a heat exchanger 10 including a plate fin 2 and a heat transfer tube 3 in a casing 1. The heat exchanger 10 has three blocks 10A, 10B, and 10C (the number of blocks is arbitrary).
And each of these blocks 10A, 10A
B and 10C are attached at the same height (same level) when they are set up in the direction of gravity (vertical direction), intersect with the direction of air flow, and are arranged in the horizontal direction without any back and forth.

A plate fin 2 is formed outside the meandering heat transfer tube 3, and each block 10A, 10B, 1
The heat transfer tube 3 of 0C forms a refrigerant channel. In each of the blocks 10A, 10B, and 10C, a lower branch 4 and an upper branch 5 are connected near the lower end and the upper end of the heat transfer tube 3 serving as a refrigerant inlet / outlet, respectively. The upper branch path 4 and the upper branch path 5 serve as flow paths for branching or merging the flow of the liquid refrigerant or gas refrigerant from an outdoor unit (not shown) (in the following description, for convenience, regardless of the flow direction of the refrigerant, the lower side). Branch road or upper branch road). An air purifying filter 6 for removing dust in the air is interposed between the blocks 10A and 10B and between the blocks 10B and 10C. The indoor air flows into the indoor unit 20 from the front of each of the blocks 10A, 10B, and 10C, and the blocks 10A, 10B, and 10C.
After that, air is blown into the room from the air outlet 7.

In the above configuration, when the air conditioner is operated as a cooling device, the indoor unit 20 is provided with a two-phase refrigerant of gas and liquid which has been adiabatically expanded and cooled to a low temperature by an outdoor unit (not shown). However, as indicated by the arrow, 3 from the lower pipe 8A to the lower branch 4
After branching into books, each block 10A, 10B, 10C
And is heated and gasified by heat exchange with indoor air, merges in the upper branch passage 5, and flows from the upper pipe 8B to a compressor (not shown) into an outdoor unit.

On the other hand, when the air conditioner is operated as a heater, a high-temperature gas refrigerant flows into the indoor unit 20 from the upper pipe 8B in a direction opposite to the arrow and is branched into three.
It flows into each of the blocks 10A, 10B, and 10C, exchanges heat with indoor air, is cooled and liquefied, merges in the lower branch passage 5, and flows from the lower pipe 8A to an outdoor unit (not shown).

During the cooling operation, each of the blocks 10A, 10A
The influence of gravity acts greatly on the liquid refrigerant flowing through the heat transfer tubes 3 of B and 10C. That is, when used as an evaporator, the blocks 10A, 10B, and 10C are mounted at the same height in the vertical direction, so that the air flow velocity in the vertical direction (indicated by A) is uneven as shown in FIG. Even if there is a distribution, the height of the liquid refrigerant in each of the blocks 10A, 10B, and 10C is almost evenly averaged even if the height instantaneously occurs due to the gravitational effect, and the same height is maintained. It rises in the heat transfer tube 3.

In various operation states, that is, in operation states other than the rated operation, the refrigerant is equalized by gravity to be used as an evaporator, and stable refrigerant distribution performance is always maintained. As a result, the performance between the blocks of the heat exchanger 10 is stabilized, and the outlet side of the heat exchanger 10, that is, the suction pressure of the compressor is prevented from lowering. Efficiency is improved. Therefore, the efficiency of the refrigeration cycle is improved.

The distribution of the gas refrigerant is easier than in the case of distributing the two-phase refrigerant, and there is no need to generate a large pressure loss in the upper branch portion in order to improve the distribution of the gas refrigerant. Therefore, when the heat exchanger 10 acts as a condenser during the heating operation, the distribution of the gas refrigerant at the inlet of the heat exchanger 10 is favorably performed. For this reason, even in an operation other than the rated operation, an increase in the discharge pressure of the heat exchanger 10 inlet side, that is, the compressor can be prevented, and the efficiency of the refrigeration cycle can be improved.

Generally, as shown in FIG. 2, the distribution of the wind speed in the wall-mounted indoor unit 20 differs greatly in the vertical direction (direction indicated by A) and in the horizontal direction (direction indicated by B).
There is little difference in distribution and it is almost uniform. As a result, the local heat load distribution in each of the blocks 10A, 10B, and 10C becomes substantially the same. Therefore, the heat exchanger 10
The difference in heat exchange efficiency based on the difference in air flow velocity can be eliminated, and the heat exchange efficiency of the entire heat exchanger can be improved.

Further, in general, the higher the performance of the air cleaning filter 6, the more easily the clogging occurs, and the greater the pressure loss. Therefore, when the air purification filter 6 is placed on the front surface of the heat exchanger 10, the heat exchange performance is reduced in the portion where the air purification filter 6 is placed due to a decrease in the flow velocity. In the present embodiment, since the air cleaning filter 6 is interposed between the blocks 10A and 10B and between the blocks 10B and 10C, even if the air cleaning filter 6 is clogged, the heat exchange performance is improved. It does not decline.

FIG. 3 is a plan view of a second embodiment of the indoor unit according to the air conditioner of the present invention, and FIG. 4 is a perspective view showing a connection state of a branch road. The same reference numerals are given and the description is omitted.

As shown in the figure, the ceiling embedded cassette type indoor unit 30 has air outlets 7 at four locations on the lower surface periphery, a turbo fan 9 for blowing air at the center, and this fan 9
A heat exchanger 10 (arbitrary number of blocks) divided into eight is arranged so as to surround the periphery of. In this embodiment, the front surface of each heat exchanger 10 is installed in a direction perpendicular to a tangent line at the discharge port of the turbo fan 9.

When the heat exchanger 10 functions as an evaporator during the cooling operation, the liquid refrigerant flows in from the lower branch 4 and passes through the heat exchanger 10, and then the gas refrigerant joins in the upper branch 5. When the heat exchanger 10 acts as a condenser during the heating operation, the gas refrigerant flows in from the upper branch passage 5, becomes a liquid refrigerant after passing through the heat exchanger 10, and joins in the lower branch portion 4. .

Each of the heat exchangers 10 includes the plate fins 2 and the heat transfer tubes 3, but is not limited thereto. For example, as shown in FIG. 6, a large number of small-diameter heat transfer tubes 42 having a diameter of about 1 to 2 mm are arranged between an upper header 40 and a lower header 41 (another embodiment),
As shown in FIG. 7, the meandering refrigerant plate (flat tube) 43
The fins 44 may be joined between them by brazing or the like (still another embodiment). In the arrangement of the heat exchangers shown in FIGS. 6 and 7, as in the case of FIG.
Arrange horizontally in the left and right directions so that they stand at the same height when standing in the direction of gravity. This is the same in other embodiments.

Also in the present embodiment, the influence of gravity acts greatly on the liquid refrigerant flowing in each heat exchanger 10, and the height of the liquid refrigerant in each heat exchanger 10 at the time of evaporation is substantially equalized. Good refrigerant distribution can be obtained. For this reason,
In an operation other than the rated operation, a decrease in the heat exchanger 10 outlet side, that is, a compressor suction pressure can be prevented, and the efficiency of the refrigeration cycle is improved.

The distribution of the gas refrigerant is easier than the distribution of the two-phase refrigerant.
Refrigerant distribution at the zero inlet is relatively good. For this reason, even in an operation other than the rated operation, an increase in the discharge pressure of the heat exchanger 10 inlet side, that is, the compressor can be prevented, and the efficiency of the refrigeration cycle can be improved.

Normally, the wind speed distribution in the ceiling embedded cassette type indoor unit 20 also has a large difference in the height direction and a small difference in the horizontal direction. As a result, the local heat load distribution in each block of the heat exchanger 10 in the present embodiment becomes substantially the same. Therefore, the difference in heat exchange efficiency based on the difference in air flow velocity of the heat exchanger 10 can be eliminated, and the heat exchange efficiency of the entire heat exchanger improves.

In this embodiment, the air flow from the turbo type fan 9 hits each block of the heat exchanger 10 almost perpendicularly. As it is, it passes between the plate fins 2 without loss. As a result, the heat transfer performance on the air side of the heat exchanger 10 can be improved by the synergistic effect of the increase in the surface heat transfer coefficient at the plate fins 2 and the suppression of the rise in the wind temperature. Thereby, the heat exchange efficiency of the entire heat exchanger is improved.

Further, since there is no loss when the air flow in this portion passes between the fins, the dynamic power loss is reduced, and the fan power is also reduced. It is also effective in reducing noise.

FIG. 5 is a perspective view of an embodiment of the outdoor unit according to the air conditioner of the present invention.

An axial flow fan 9 is mounted in the center of the upper surface of the housing on the side of the exhaust port, and surrounds the fan 9 on its side surface.
0 blocks are provided. The blocks of the heat exchanger 10 are arranged in two front and rear rows (arbitrary number of rows) in the air flow direction, and are arranged with a gap formed between the front row and the rear row.

As in the above embodiment, a lower branch channel 4 and an upper branch channel 5 are provided at the upper and lower refrigerant ports of each block of the heat exchanger 10.

Also in the present embodiment, the influence of gravity acts greatly on the liquid refrigerant flowing in each block of the heat exchanger 10,
The existing height of the liquid refrigerant in each block at the time of evaporation is substantially equalized, and good refrigerant distribution can be obtained. Therefore, similarly to the above-described embodiment, a decrease in the outlet side of the heat exchanger 10, that is, a decrease in the compressor suction pressure can be prevented, and the efficiency of the refrigeration cycle improves.

In general, when acting as an evaporator, frost adheres to the front end of the fin of the heat exchanger 10 on the front stage side, and the air volume is reduced, which tends to cause a decrease in the heating capacity. However, in the case of the present embodiment, even if frost adheres to the front end of the heat exchanger 10 fins in the front row and the ventilation resistance of that part increases, air flows from the gap between the front row and rear row of the heat exchanger 10. , Flows into the rear heat exchanger 10, so that the performance of the heat exchanger 10 as an evaporator can be maintained for a long time. Therefore, the time interval until the defrosting operation is performed is greatly increased, and the operating efficiency and the comfort during the heating operation are improved.

[0040]

According to the present invention, there is a difference in the air flow rate passing through the heat exchanger, especially when the heat exchanger is used as an evaporator even in various different inlet states of the refrigerant.
A heat exchanger, an indoor unit for an air conditioner, and an outdoor unit with good heat exchange efficiency can be provided.

[Brief description of the drawings]

FIG. 1 is a front view of a first embodiment of an indoor unit according to the air conditioner of the present invention.

FIG. 2 is a perspective view of the embodiment of FIG.

FIG. 3 is a plan view of a second embodiment of the indoor unit according to the air conditioner of the present invention.

FIG. 4 is a perspective view showing a connection state of a branch road in the embodiment of FIG. 3;

FIG. 5 is a perspective view of an embodiment of the outdoor unit according to the air conditioner of the present invention.

FIG. 6 is a side view of another embodiment of the heat exchanger according to the air conditioner of the present invention.

FIG. 7 is a side view of still another embodiment of the heat exchanger according to the air conditioner of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Casing 2 ... Plate fin 3 ... Heat transfer tube 4 ... Lower branch path 5 ... Upper branch path 6 ... Air purification filter 7 ... Air outlet 8A ... Lower piping, 8B ... Upper piping 9 ... Fan 10 ... Heat exchanger 20 , 30 ... Indoor unit 40 ... Upper header 41 ... Lower header 42 ... Small diameter heat transfer tube 50 ... Outdoor unit

Claims (5)

[Claims] 1. A heat exchanger comprising a heat transfer tube and a plate fin formed outside the heat transfer tube, wherein the heat exchanger is composed of a plurality of blocks, and each block has the same height in the direction of gravity. A heat exchanger which is mounted and arranged in a horizontal direction on the left and right sides crossing the direction of air flow. 2. The heat exchanger according to claim 1, wherein the heat transfer tube of each block has a flow path that branches or merges near the entrance / exit of each block. 3. The heat exchanger according to claim 1, wherein an air purifying filter is interposed between each block. 4. An air conditioner indoor unit having a heat exchanger and a blower fan, wherein the heat exchanger is composed of a plurality of blocks, and each block is mounted at the same height in the direction of gravity. Each block is provided in a horizontal direction intersecting the flow direction of air, each block is provided with a flow path that branches or merges near an entrance / exit portion of each block, and a front face of each block is provided with a discharge port of a blower fan. An indoor unit for an air conditioner, wherein the indoor unit is arranged in a direction perpendicular to a tangent line. 5. An outdoor unit for an air conditioner comprising a heat exchanger and a blower fan, wherein the heat exchanger comprises a plurality of blocks, each of which is mounted at the same height in the direction of gravity. The blocks are arranged on the sides surrounding the central fan, and the blocks are arranged in a plurality of rows at intervals before and after the air flow direction. Each block has a flow path that branches or merges near the entrance / exit of each block. An outdoor unit for an air conditioner, comprising: