JP6920592B2 - Air conditioner - Google Patents

Description

The present invention relates to an air conditioner, and more particularly to an air conditioner using a multi-pass heat exchanger in which a pair of header flow paths are connected by a large number of heat transfer flow paths.

Generally, an air conditioner circulates a refrigerant compressed by a compressor through a heat exchanger such as a condenser or an evaporator and exchanges heat with a heat exchange fluid to cool or heat the air conditioner. At this time, the performance and energy saving of the air conditioner are greatly affected by the heat exchange efficiency of the heat exchanger. Therefore, heat exchangers are strongly required to have high efficiency.

In recent years, in order to improve the performance and energy saving of air conditioners, efforts have been made to use a multi-pass heat exchanger configured by connecting a plurality of heat transfer channels between a pair of header channels. Since the multi-pass heat exchanger can increase the number of heat transfer channels, that is, the number of passes, the heat exchange efficiency of the volume ratio can be made high.

However, when the multi-pass heat exchanger is used as an evaporator, the refrigerant flowing into the header flow path is in a gas-liquid two-phase state. Therefore, it is difficult to uniformly distribute the refrigerant in the header flow path to the entire number of heat transfer flow paths.

Therefore, in Patent Document 1, as shown in FIGS. 14 and 15, a gas-liquid separator 103 is provided on the upstream side of the refrigerant inlet 102 of the heat exchanger 101, and the refrigerant in the gas-liquid two-phase state is referred to as the gas refrigerant 104. It is disclosed that the liquid refrigerant 105 is separated from the liquid refrigerant 105, and only the liquid refrigerant 105 is supplied to the heat exchanger 101 in a single-phase state and distributed to each path. As a result, it is considered to realize uniform distribution of the refrigerant.

Japanese Patent No. 3158722

However, even if the conventional gas-liquid separator 103 separates the gas-liquid and supplies only the liquid refrigerant to the heat exchanger 101, the gas-liquid separation efficiency of the gas-liquid separator is actually poor. Therefore, the liquid refrigerant supplied to the heat exchanger is in a gas-liquid two-phase state, and it is practically difficult to uniformly distribute the refrigerant to the heat transfer flow path group.

A gas-liquid two-phase refrigerant flows into the header flow path on the inlet side of the heat exchanger 101. At this time, the gas-liquid two-phase state refrigerant is considered to be a wavy flow or a layered flow in the header flow path. Therefore, the refrigerant in a gaseous state mainly flows in the upper part of the header, and the refrigerant in a liquid state mainly flows in the lower part. Then, the gaseous refrigerant having a high flow velocity is supplied to the heat transfer flow path while entraining the liquid refrigerant in the lower part of the header. Here, the refrigerant flow state of the refrigerant in the gas-liquid two-phase state is not a uniform flow. Therefore, the refrigerant from the header flow path is not uniformly distributed to the heat transfer flow path. Therefore, the amount of heat exchange varies in the heat transfer flow path portion.

In particular, when the gas-liquid separator is installed at a position lower than the heat exchanger, the gas-liquid separation efficiency of the gas-liquid separator tends to decrease, so that the heat exchange variation in the heat transfer flow path becomes large. It was a thing.

From the above points, the refrigerant cannot be uniformly distributed to the heat transfer flow path with the conventional configuration in which the gas-liquid separator is provided, and heat exchange unevenness occurs in the heat exchange in the heat transfer flow path.

The present invention has been diligently studied in view of these points, and an object of the present invention is to provide an air conditioner that suppresses variations in heat exchange and enhances heat exchange efficiency.

In order to achieve the above object, the present invention has a compressor, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger, and in a refrigeration cycle in which a refrigerant is circulated, the throttle device and the war record indoor heat exchanger are used. A bypass flow path that includes a gas-liquid separator and a flow control valve that adjusts the flow rate of the gaseous refrigerant separated by the gas-liquid separator, and the gaseous refrigerant bypasses the indoor heat exchanger. Set up,
The indoor heat exchanger is a plate-laminated heat exchanger formed by laminating plate fins, and the plate fins connect two header flow paths and two header flow paths to the ends of the plate fins. A plurality of heat transfer channels, and at least an annular groove having a diameter larger than the diameter of the header flow path around the header flow path on the inlet side when the indoor heat exchanger is used as an evaporator among the header flow paths. The gas-liquid separator has a configuration in which the dryness of the refrigerant on the inlet side of the plate fin laminated heat exchanger is 0.1 or less. As a result, if the dryness of the refrigerant at the inlet of the heat exchanger is 0.1 or less, the liquid refrigerant existing in the lower part of the header flow path rises substantially uniformly in the annular groove portion around the header flow path due to the capillary phenomenon. , Mixes with the gas phase refrigerant and flows into the heat transfer flow path. Therefore, a refrigerant having a substantially uniform degree of dryness, which exhibits sufficient vaporization ability, flows through the heat transfer flow path. Therefore, even if the two-phase state refrigerant in the header flow path is not a uniform flow, if the dryness of the refrigerant on the inlet side of the indoor heat exchanger is 0.1 or less, the amount of heat exchange in each part of the heat transfer flow path. High heat exchange efficiency can be achieved by suppressing the variation in the heat exchange.

According to the above configuration, the present invention can provide an air conditioner having high heat exchange efficiency by suppressing heat exchange variation even if the two-phase state refrigerant in the header flow path does not flow uniformly.

Refrigerant circuit diagram of the air conditioner according to the first embodiment of the present invention The figure which shows the relationship between the dryness of the heat exchanger inlet and the heat exchanger capacity in the indoor heat exchanger of the air conditioner. Perspective view showing the appearance of the indoor heat exchanger of the air conditioner An exploded perspective view showing the indoor heat exchanger of the air conditioner in a separated state. Top view of plate fins constituting the indoor heat exchanger of the air conditioner Enlarged plan view showing the header area of the plate fins constituting the indoor heat exchanger of the air conditioner. An exploded view showing a part of the structure of the plate fins that make up the indoor heat exchanger of the air conditioner in an enlarged manner. Perspective view showing the header flow path portion of the indoor heat exchanger of the air conditioner cut out. Cross-sectional view of the header flow path in the indoor heat exchanger of the air conditioner Explanatory drawing explaining the refrigerant flow in the header flow path part in the indoor heat exchanger of the air conditioner Refrigerant circuit diagram of the air conditioner according to the second embodiment of the present invention Refrigerant circuit diagram of the air conditioner according to the third embodiment of the present invention Refrigerant circuit diagram of the air conditioner according to the fourth embodiment of the present invention. Refrigerant circuit diagram of conventional air conditioner Detailed view of the gas-liquid separation type heat exchanger of a conventional air conditioner

The first invention has a compressor, an outdoor heat exchanger, and a squeezing device indoor heat exchanger, and in a refrigeration cycle in which a refrigerant is circulated, a gas-liquid separator between the squeezing device and the war memorial indoor heat exchanger. And a flow rate adjusting valve for adjusting the flow rate of the gaseous refrigerant separated by the gas-liquid separator, a bypass flow path for the gaseous refrigerant to bypass the indoor heat exchanger is provided, and the indoor heat is provided. The exchanger is a plate-laminated heat exchanger formed by laminating plate fins, and the plate fins connect two header flow paths and two header flow paths to the ends of the plate fins. It has a heat transfer flow path and at least an annular groove larger than the diameter of the header flow path around the header flow path on the inlet side when the indoor heat exchanger is used as an evaporator. The gas-liquid separator is configured to reduce the dryness of the refrigerant on the inlet side of the plate fin laminated heat exchanger to 0.1 or less. As a result, even if the two-phase state refrigerant in the header flow path is not a uniform flow, if the dryness of the refrigerant at the heat exchanger inlet is 0.1 or less, the liquid state refrigerant existing in the lower part of the gas state Raises substantially uniformly in the annular groove portion around the header flow path located between the heat transfer flow path and the heat transfer flow path, mixes with the gaseous refrigerant, and flows into the heat transfer flow path. Therefore, a refrigerant having a substantially uniform dryness, which exhibits sufficient vaporization ability, flows through the heat transfer flow path. Therefore, it is possible to realize high heat exchange efficiency by suppressing variation in the amount of heat exchange in each part of the heat transfer flow path.

The second invention has a compressor, an outdoor heat exchanger, a squeezing device, and an indoor heat exchanger, and in a refrigeration cycle in which a refrigerant is circulated, gas-liquid separation is performed between the squeezing device and the war memorial indoor heat exchanger. A device is provided to include a flow rate adjusting valve for adjusting the flow rate of the gaseous refrigerant separated by the gas-liquid separator, and a second throttle device between the gas-liquid separator and the indoor heat exchanger. An injection circuit for supplying the gaseous refrigerant to the compressor is provided, and the indoor heat exchanger is a plate laminated heat exchanger formed by laminating plate fins, and the plate fins of the plate fins. Two header flow paths at the ends, a plurality of heat transfer flow paths connecting the two header flow paths, and at least the header on the inlet side of the header flow paths when the indoor heat exchanger is used as an evaporator. The gas-liquid separator has an annular groove larger than the diameter of the header flow path around the flow path, and the gas-liquid separator sets the dryness of the refrigerant on the inlet side of the plate fin laminated heat exchanger to 0.1. The configuration is as follows.

As a result, the flow rate and flow velocity of the liquid refrigerant supplied to the inlet side of the indoor heat exchanger can be adjusted by the second throttle device, and the flow rate adjusting valve provided in the throttle device and the injection circuit can perform gas-liquid separation. .. In addition, the pressure inside the gas-liquid separator is set higher than the suction pressure of the compressor with the throttle device and the second throttle, so even if there is a head difference between the gas-liquid separator and the indoor heat exchanger, the refrigerant can be used. It can be transported, that is, the gas-liquid separator can be provided at a lower position than the indoor heat exchanger.

In the second invention, the third invention is heat exchange between the refrigerant flowing between the gas-liquid separator and the second drawing device and the refrigerant flowing between the indoor heat exchanger and the compressor. It is configured to include an internal heat exchanger to perform the above.

As a result, the dryness of the refrigerant having a large amount of liquid components separated by the gas-liquid separator can be made smaller or supercooled by the internal heat exchanger. Since the dryness of the refrigerant on the inlet side of the indoor heat exchanger can be further reduced, variations in heat exchange in the heat transfer flow path can be suppressed, and high heat exchange efficiency can be exhibited. In addition, the gas-liquid separator can be installed at a position lower than that of the plate fin laminated heat exchanger, which is an indoor heat exchanger, and the degree of freedom of installation can be increased.

A fourth invention has a compressor, an outdoor heat exchanger, a drawing device, and an indoor heat exchanger, and in a refrigeration cycle in which a refrigerant is circulated, the indoor heat exchanger is formed by laminating plate fins. In a type heat exchanger, the plate fins include two header flow paths at the ends of the plate fins, a plurality of heat transfer flow paths connecting the two header flow paths, and at least the header flow paths of the header flow paths. When the indoor heat exchanger is used as an evaporator, it has an annular groove larger than the diameter of the header around the header flow path on the inlet side, and flows between the outdoor heat exchanger and the throttle device. An internal heat exchanger that exchanges heat between the refrigerant and the refrigerant flowing between the indoor heat exchanger and the compressor is provided, and the internal heat exchanger is located on the inlet side of the plate fin laminated heat exchanger. The structure is such that the dryness of the refrigerant is 0.1 or less. As a result, the dryness of the refrigerant on the inlet side of the plate fin laminated heat exchanger can be reduced in a simple form. Therefore, the degree of dryness can be set to 0.1 or less, heat exchange variation in the heat transfer flow path can be suppressed, and high heat exchange efficiency can be exhibited.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

The air conditioner of the present disclosure is not limited to the configuration of the air conditioner described in the following embodiment, and includes a heat exchanger configuration equivalent to the technical idea described in the following embodiment. It is a waste.

Further, in this embodiment, the case of the cooling operation will be described as an example, but the description is not limited to the cooling operation. For example, a refrigeration cycle may be used in which a four-way valve is further provided and the cooling operation and the heating operation can be switched.

(Embodiment 1)
FIG. 1 is a diagram showing a refrigeration cycle of an air conditioner according to the first embodiment of the present invention. FIG. 2 is a diagram showing the relationship between the dryness of the refrigerant on the inlet side of the indoor heat exchanger and the heat exchanger capacity in the present invention.

In FIG. 1, this air conditioner constitutes a refrigerant circuit 6 by sequentially connecting a compressor 1, an outdoor heat exchanger 2, a throttle device 3, and an indoor heat exchanger 5 with pipes. Further, a gas-liquid separator is provided between the throttle device 3 and the outdoor heat exchanger 2. The gas-phase refrigerant pipe 8 connects a portion of the gas-liquid separator 4 where the gaseous refrigerant flows out and between the indoor heat exchanger 5 and the compressor 1. The gas phase refrigerant pipe 8 is provided with a flow rate adjusting valve 9 for adjusting the flow rate of the flowing refrigerant. The liquid refrigerant separated by the gas-liquid separator 4 flows through the liquid-refrigerant pipe 7 and flows into the indoor heat exchanger 5. The gaseous refrigerant separated by the gas-liquid separator 4 flows through the gas-phase refrigerant pipe 8 and flows into the compressor 1.

The indoor heat exchanger 5 is composed of a multi-pass heat exchanger configured by connecting a pair of header flow paths with a large number of heat transfer flow paths. Further, in the present embodiment, the one using a plate fin laminated heat exchanger configured by laminating plate fins having a heat transfer flow path through which a refrigerant flows is disclosed.

Hereinafter, the configuration of the indoor heat exchanger 5 will be described with reference to FIGS. 3 to 10.

FIG. 3 is a perspective view showing the appearance of the indoor heat exchanger 5, and FIG. 4 is an exploded perspective view showing the indoor heat exchanger 5 in a separated state. FIG. 5 is a plan view of the plate fins constituting the indoor heat exchanger 5, and FIG. 6 is an enlarged plan view of the periphery of the header region of the plate fins constituting the indoor heat exchanger 5. FIG. 7 is an enlarged exploded view showing a part of the configuration of the plate fins 22a constituting the indoor heat exchanger 5, and FIG. 8 shows the header flow path A28 and the header flow path B30 in the indoor heat exchanger 5 cut out. A perspective view, FIG. 9 is a cross-sectional view of the header flow path A28 in the indoor heat exchanger 5, and FIG. 10 is an explanatory view illustrating a refrigerant flow in the header flow path A28 in the indoor heat exchanger 5.

As shown in FIG. 3, the indoor heat exchanger 5 is composed of a plurality of plate fins 22a having a rectangular plate shape. A plurality of plate fins 22a are sandwiched between the end plate 23a and the end plate 23b in the stacking direction of the plate fins 22a. The end plate 23a and the end plate 23b are connected and fixed by fastening means 21 such as bolts, and sandwich the plurality of plate fins 22a. At one end of the end plate 23a, holes 24a and holes 25a are provided which are connected to the header flow path A and the header flow path B, which are formed by stacking plate fins described later, respectively.
As shown in FIG. 4, the pipe A24b is connected to the hole 24a, and the pipe B25b is connected to the hole 25a. When the indoor heat exchanger 5 is used as an evaporator, the pipe A24b serves as an inlet and the pipe B25b serves as an outlet.
Further, as shown in FIG. 4, the plate fins 22a are laminated to form the plate fin laminated body 22. A hole forming the header flow path A28 and a hole forming the header flow path B30 are provided on the end side of the plate fin 22a. The hole forming the header flow path A28 and the hole forming the header flow path B30 are connected by a refrigerant flow path 31. The refrigerant flow path 31 will be described in more detail with reference to FIGS. 5 to 8.

FIG. 5 is a plan view of one plate fin 22a. One end side of the plate fin 22a is a header region H where header flow paths gather, and a region from the header region H to the end opposite to the header region H is a heat transfer region P where thin refrigerant flow paths gather. In the heat transfer region P, there are a plurality of parallel refrigerant flow paths 31. The refrigerant flow path 31 is connected to the header flow path A28 and the header flow path B30 in the header region H. The refrigerant flow path 31 is folded around the end on the side opposite to the header region H. A plurality of refrigerant flow paths 31 are lined up in parallel between the folded portion and the header region H. The plurality of refrigerant flow paths 31 are divided into a header flow path A-side refrigerant flow path 31a connected to the header flow path A28 and a header flow path B-side refrigerant flow path 31b connected to the header flow path B30. The number of refrigerant flow paths 31 in the header flow path A side refrigerant flow path 31a is smaller than that in the header flow path B side refrigerant flow path 31b. The plate fin 22a is provided with a slit groove 35 from the header region H to the folded back. The slit groove 35 provides a heat transfer gap between the regions of the header flow path A28 and the header flow path A side refrigerant flow path 31a and the regions of the header flow path B30 and the header flow path B side refrigerant flow path 31b. Here, the flow of the refrigerant is such that the header flow path A28 serves as an inlet when the indoor heat exchanger 5 is used as an evaporator, and the header flow path A28 serves as an outlet when the indoor heat exchanger 5 is used as a condenser. It becomes. When the indoor heat exchanger 5 is used as an evaporator, the header flow path B30 serves as an outlet, and when the indoor heat exchanger 5 is used as a condenser, the header flow path B30 serves as an inlet.

The slit groove 35 is provided in order to reduce the heat exchange that occurs between the header flow path A28 and the header flow path B30 and to improve the heat exchange efficiency. Therefore, the slit groove 35 may not be provided.

FIG. 6 is an enlarged plan view of the header region H of the plate fins 22a. As shown in FIG. 6, an annular groove 28b having an outer circumference wider than the diameter of the header flow path A28 is provided on the outer circumference of the header flow path A28. The annular groove 28b includes a connecting flow path 28c connected to the header flow path A side refrigerant flow path 31a. Similarly, an annular groove 30b is provided on the outer periphery of the header flow path B30. The annular groove 30b includes a connecting flow path 30c connected to the header flow path B side refrigerant flow path 31b.

FIG. 7 is an exploded perspective view of the plate fin 22a. As shown in FIG. 7, the plate fin 22a is configured by brazing and joining the first plate-shaped member 26a and the second plate-shaped member 26b so as to face each other. Around the header flow path A28, an annular ridge 28a that bulges outward with respect to the joint surface is provided. Similarly, an annular ridge portion 30a that bulges outward with respect to the joint surface is also provided around the header flow path B30.

As shown in FIG. 7, the first plate-shaped member 26a and the second plate-shaped member 26b are overlapped and brazed to form a refrigerant flow path between the first plate-shaped member 26a and the second plate-shaped member 26b. 31 is formed. That is, around the header flow path A28, an annular groove 28b is formed between the annular ridge 28a of the first plate-shaped member 26a and the annular ridge 28a of the second plate-shaped member 26b. Further, the first plate-shaped member 26a and the second plate-shaped member 26b overlap each other to form the header flow path A side refrigerant flow path 31a. The same applies to the header flow path B side.

As shown in FIG. 8, a large number of plate fins 22a obtained by superimposing the first plate-shaped member 26a and the second plate-shaped member 26b shown in FIG. 7 are laminated to form the main body of the heat exchanger. To configure. Between the plate fins 22a, a gap through which air, which is a second fluid, flows is formed by a plurality of protrusions 32 appropriately provided between both ends of the long sides of the plate fins 22a and the refrigerant flow path 31.

The refrigerant flow path 31 is formed in the first plate-shaped member 26a and the second plate-shaped member 26b by a concave groove so that the diameter can be easily reduced.

Further, among the refrigerant flow paths 31, heat transfer between the header flow path A side refrigerant flow path 31a connected to the header flow path A28 and the header flow path B side refrigerant flow path 31b connected to the header flow path B30. A slit groove 35 is formed in order to prevent the above.

Further, in this example, the header flow path B side refrigerant flow path 31b has a larger number of refrigerant flow paths than the header flow path A side refrigerant flow 31a and faces the communication flow path 30c of the header flow path B30 as shown in FIG. The portion to be used is a non-perforated portion 36 having no refrigerant flow path, and the refrigerant flowing from the header flow path B30, which is the downstream header flow path, to the refrigerant flow path 31b on the header flow path B side when used under condensation conditions is the non-perforated portion 36. It is configured so that it collides with the wall portion of the head and flows evenly to the refrigerant flow path 31b on the header flow path B side.

The indoor heat exchanger 5 is not limited to this form. A refrigerant having a large liquid state flows in from the header flow path A28, and a gaseous refrigerant flows out from the header flow path B30. Therefore, it is preferable that the flow path cross-sectional area of the refrigerant flow path 31 increases on the header flow path B side according to the density. However, it may be changed according to the shape of the indoor heat exchanger 5.

Further, the non-perforated portion 36 may not be provided. Since it is preferable to provide the non-perforated portion 36 in order to improve the diversion of the refrigerant, it is provided in this embodiment.

In the plate fin laminated heat exchanger of the present embodiment having the above configuration, the refrigerant flows in parallel in the longitudinal direction through the refrigerant flow path 31 group inside the plate fin 22a of the plate fin laminated body 22, makes a U-turn, and is a folded header flow. It is discharged from the path A28 or the header flow path B30 through the pipe B25b or the pipe A24b.

On the other hand, air, which is the second fluid, passes through the gap formed between the stacks of the plate fins 22a constituting the plate fin laminate 22. As a result, heat exchange between the refrigerant as the first fluid and the air as the second fluid is performed.

The operation and effect of the air conditioner configured as described above will be described below.

When the indoor heat exchanger 5 is used as an evaporator, the refrigerant moves in the order indicated by the arrows in FIG. The refrigerant is compressed by the compressor 1, and the refrigerant in a high temperature and high pressure state flows to the outdoor heat exchanger 2. Then, the refrigerant in the high temperature and high pressure state exchanges heat with the outside air and dissipates heat to become the refrigerant in the liquid state in the high pressure state, and the refrigerant in the liquid state in the high pressure state flows to the throttle device 3. The liquid refrigerant in the high pressure state in the drawing device 3 is depressurized to become a low temperature and low pressure two-phase state refrigerant, and flows to the indoor heat exchanger 5. The two-phase refrigerant in the indoor heat exchanger 5 exchanges heat with the indoor air, absorbs heat, evaporates and vaporizes to become a low-temperature gaseous refrigerant, and returns to the compressor 1. At this time, an indoor fan (not shown) sends the air cooled around the indoor heat exchanger 5 into the room, and the indoor air is cooled.

Here, the refrigerant flowing through the indoor heat exchanger 5 is gas-liquid separated by the gas-liquid separator 4. However, when the refrigerant flows into the header flow path on the inlet side of the indoor heat exchanger 5, the refrigerant is not a uniform flow due to the wavy flow or the layered flow as described above, so that the refrigerant is not uniformly distributed to the refrigerant flow path. Therefore, the liquid refrigerant mixed with the gaseous refrigerant due to insufficient gas-liquid separation flows into the header flow path on the inlet side of the indoor heat exchanger 5.

However, in the refrigerant circuit of the present embodiment, the header flow path of the indoor heat exchanger 5 into which the gas-liquid two-phase refrigerant from the gas-liquid separator 4 flows, in this case, the annular groove 28b around the header flow path A28. Is formed. Therefore, as shown in FIG. 10, the liquid refrigerant a flowing in the lower part of the header flow path A28 rises substantially uniformly on the annular groove 28b as shown by the arrow due to the capillary phenomenon, and is mixed with the gaseous refrigerant. Then, it flows into the refrigerant flow path 31. In particular, if the width T of the annular groove 28b shown in FIG. 8 is set to about 3 mm or less and the groove depth H is set to about 1 mm or more, the liquid refrigerant in the lower part of the header flow path A28 makes the portion of the annular groove 30b substantially uniform due to the capillary phenomenon. It rises to, mixes with the refrigerant in a gaseous state, and flows into the refrigerant flow path 31.

Therefore, the refrigerant having a substantially uniform dryness, which exhibits sufficient evaporation ability, flows through the refrigerant flow path 31 connected to the header flow path A28, and the variation in the amount of heat exchange in each part of the refrigerant flow path is suppressed. High heat exchange efficiency can be achieved.

For efficient capillary action, it is preferable that the header flow path A28 is provided below the refrigerant flow path 31 when the indoor heat exchanger 5 is installed in the air conditioner.

Further, at least the annular groove 28b may be provided on the header flow path A28 side into which the liquid refrigerant flows.

FIG. 2 is a diagram showing the relationship between the dryness of the heat exchanger inlet and the heat exchanger capacity in the indoor heat exchanger 5 having the above configuration. It can be confirmed that if the dryness is 0.1 or less, the heat exchange capacity of nearly 100% can be secured.

That is, even when the gas-liquid separator 4 does not exhibit sufficient gas-liquid separation, if the separation efficiency is such that the dryness of the refrigerant is 0.1 or less, the variation in the amount of heat exchange in each part of the refrigerant flow path is suppressed. High heat exchange efficiency can be achieved.

(Embodiment 2)
FIG. 11 is a refrigerant circuit diagram of the air conditioner according to the second embodiment of the present invention.

In the present embodiment, the injection circuit 11 for supplying the gas-phase refrigerant separated by the gas-liquid separator 4 to the compressor 1 is provided. The injection circuit 11 is provided with a flow rate adjusting valve 12. Further, a throttle device 3 is provided at the inlet of the gas-liquid separator 4, and a second throttle device 13 is provided at the liquid refrigerant pipe 7 from the gas-liquid separator 4.

Other configurations and the configuration of the indoor heat exchanger 5 are the same as those in the first embodiment, and the same parts may be assigned the same number and the description thereof may be omitted.

According to the above configuration, even when the gas-liquid separator 4 is installed below the indoor heat exchanger 5, a decrease in the gas-liquid separation efficiency of the gas-liquid separator 4 is suppressed to achieve high heat exchange efficiency. It can be demonstrated.

That is, if the gas-liquid separator 4 is provided at a position lower than the indoor heat exchanger 5 in the refrigerant circuit configuration, the refrigerant separated by the gas-liquid separator 4 and having a large amount of liquid components is used in the indoor heat exchanger 5. In order to lift and supply the refrigerant up to, it is necessary for the refrigerant having a large amount of liquid components separated by the gas-liquid separator 4 to lift up to the indoor heat exchanger 5 against the liquid head in the liquid refrigerant pipe 7.

For that purpose, in the refrigerant circuit in which the injection circuit 11 is not installed, it is necessary to reduce the flow rate of the gas component side refrigerant separated by the gas-liquid separator 4 in order to secure a pressure equal to or higher than that of the liquid head. As a result, the gas-phase refrigerant is mixed on the substantially liquid refrigerant side, and the gas-liquid separation efficiency is lowered.

However, according to the configuration of the present embodiment, since the intermediate pressure of the compressor 1 is applied in the gas-liquid separator 4, the refrigerant having a large amount of liquid components is opposed to the liquid head up to the indoor heat exchanger 5. Can be lifted and supplied.

Therefore, it is not necessary to throttle the flow rate of the gas-liquid refrigerant separated by the gas-liquid separator 4, and it is possible to suppress a decrease in the gas-liquid separation efficiency of the gas-liquid separator 4.

Therefore, even if the gas-liquid separator 4 is provided at a position lower than the plate fin laminated heat exchanger which is the indoor heat exchanger 5, the dryness of the refrigerant at the inlet of the plate fin laminated heat exchanger is 0.1. It can flow in as follows. As a result, heat exchange variation in the refrigerant flow path 31 can be suppressed, and high heat exchange efficiency can be exhibited.

Further, in the present embodiment, the injection circuit 11 is provided, the squeezing device 3 is provided at the inlet of the gas-liquid separator 4, and the second squeezing device 13 is provided at the liquid refrigerant pipe 7 from the gas-liquid separator 4. , The magnitude of the intermediate pressure applied in the gas-liquid separator 4 can be changed according to the installation position of the gas-liquid separator 4, and the gas-liquid separator 4 can be used without lowering the separation efficiency of the gas-liquid separator 4. The installation position can be freely selected.

(Embodiment 3)
FIG. 12 is a refrigerant circuit diagram of the air conditioner according to the third embodiment of the present invention.

In the present embodiment, an internal heat exchanger 14 is provided instead of the gas-liquid separator so that the dryness of the refrigerant having a large amount of liquid components flowing into the indoor heat exchanger 5 is suppressed to 0.1 or less.

That is, in FIG. 12, in this refrigerant circuit, the refrigerant flowing through the high-pressure side circuit between the outdoor heat exchanger 2 and the throttle device 3 and the refrigerant flowing through the low-pressure side circuit between the indoor heat exchanger 5 and the compressor 1 are present. An internal heat exchanger 14 is provided so as to perform heat exchange.

Other configurations and the configuration of the indoor heat exchanger 5 are the same as those in the first embodiment, and the same parts may be assigned the same number and the description thereof may be omitted.

The operation and effect of the air conditioner configured as described above will be described below.

The high-pressure refrigerant that has passed through the outdoor heat exchanger 2 reaches the internal heat exchanger 14, is further adiabatically expanded into a low-temperature low-pressure two-phase refrigerant by the drawing device 3, and flows through the internal heat exchanger 14 to the indoor heat exchanger 5. .. In the indoor heat exchanger 5, the refrigerant exchanges heat with the indoor air to absorb heat, evaporates and vaporizes to become a low-temperature gaseous refrigerant, returns to the compressor 1, and the indoor air is cooled to cool the room.

At this time, in the internal heat exchanger, the high-pressure side refrigerant and the low-pressure side refrigerant exchange heat, and the high-pressure side liquid refrigerant absorbs heat, so that the refrigerant temperature decreases and the degree of supercooling increases. The liquid refrigerant having a large degree of supercooling expands adiabatically in the throttle device 3 to become a two-phase refrigerant having a degree of dryness smaller than that when the internal heat exchanger 14 is not installed, and flows to the indoor heat exchanger 5.

Therefore, according to the above configuration, the degree of supercooling of the liquid refrigerant in the inlet chamber of the throttle device 3 becomes large, so that the degree of dryness of the refrigerant at the inlet of the plate fin laminated heat exchanger serving as the indoor heat exchanger 5 can be reduced. That is, the degree of dryness can be set to 0.1 or less, whereby the heat exchange variation in the refrigerant flow path can be suppressed, and high heat exchange efficiency can be exhibited.

(Embodiment 4)
FIG. 13 is a refrigerant circuit diagram of the air conditioner according to the fourth embodiment.

This embodiment is a combination of the circuit configurations of the second embodiment and the third embodiment.

That is, in FIG. 13, in this refrigerant circuit, an injection circuit 11 for supplying the gaseous refrigerant separated by the gas-liquid separator 4 to the compressor 1 is provided, and further, the outdoor heat exchanger 2 and the second drawing device 13 are provided. An internal heat exchanger 14 is provided so that the refrigerant flowing in the high-pressure side circuit between them and the refrigerant flowing in the low-pressure side circuit between the indoor heat exchanger 5 and the compressor 1 exchange heat. The injection circuit 11 is provided with a flow rate adjusting valve 12.

Other configurations and the configuration of the indoor heat exchanger 5 are the same as those in the first embodiment, and the same parts may be assigned the same number and the description thereof may be omitted.

According to the above configuration, the effect of providing the injection circuit 11 and the effect of providing the internal heat exchanger 14 are combined, and the dryness of the refrigerant having a large amount of liquid components separated by the gas-liquid separator 4 is further reduced. can do.

Therefore, the dryness of the refrigerant at the inlet of the indoor heat exchanger 5 can be further reduced to suppress the variation in the indoor heat exchanger 5 in the refrigerant flow path, and high heat exchange efficiency can be exhibited.

Further, the gas-liquid separator 4 can be installed at a position lower than that of the plate fin laminated heat exchanger which is the indoor heat exchanger 5, and the degree of freedom of installation can be increased.
(Other embodiments)
As described above, Embodiments 1 and 2 have been described as examples of the techniques disclosed in this application. However, the technique in the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, etc. have been made. It is also possible to combine the components described in the first and second embodiments to form a new embodiment.

3 to 10 show a form in which the header flow path A28 and the header flow path B30 are concentrated on one end side of the indoor heat exchanger 5, but the present invention is not limited to this form. For example, the header flow path A may be provided at one end of the plate fin, and the header flow path B may be provided at the end opposite to the above-mentioned one end. In this case, the heat transfer flow path connecting the header flow path A and the header flow path B does not have to be folded back. Further, in this case, when incorporating the air conditioner, it is preferable that the header flow path A through which the refrigerant containing a large amount of liquid components passes is provided downward with respect to the gravity direction as compared with the header flow path B.

INDUSTRIAL APPLICABILITY The present invention can provide an air conditioner having high heat exchange efficiency by suppressing heat exchange variation even if the two-phase state refrigerant in the header flow path is not a uniform flow. Therefore, it can be widely used in heat exchangers and various refrigerating devices used for home and commercial air conditioners, and has great industrial value.

1 Compressor 2 Outdoor heat exchanger 3 Squeezing device 4 Gas-liquid separator 5 Indoor heat exchanger 6 Refrigerant circuit 7 Liquid refrigerant pipe 8 Gas phase refrigerant pipe 9 Flow control valve 11 Injection circuit 12 Flow control valve 13 Second throttle device 14 Internal heat exchanger 21 Fastening means 22 Plate fin laminate 22a Plate fins 23a, 23b End plates 24a, 25a Holes 24b Tube A
25b tube B
26a First plate-shaped member 26b Second plate-shaped member 28 Header flow path A
30 Header flow path B
28a, 30a Circular ridge 28b, 30b Circular groove 28c, 30c Communication flow path 31 Refrigerant flow path 31a Header flow path A side Refrigerant flow path 31b Header flow path B side Refrigerant flow path 32 Protrusion 35 Slit groove 36 Non-perforated part H Header Area P Heat transfer area

Claims (4)

It has a compressor, an outdoor heat exchanger, a squeezing device, and an indoor heat exchanger, and in a refrigeration cycle in which a refrigerant is circulated, a gas-liquid separator and the gas-liquid are provided between the squeezing device and the indoor heat exchanger. A flow control valve for adjusting the flow rate of the gaseous refrigerant separated by the separator is provided, a bypass flow path for the gaseous refrigerant bypasses the indoor heat exchanger is provided, and the indoor heat exchanger is a plate fin. A plate laminated heat exchanger formed by laminating anda large annular groove than the diameter of said header passages around the inlet side header flow path in the case of using at least the indoor heat exchanger of said header passage as an evaporator, of the annular groove The gas-liquid separator is characterized in that the width is 3 mm or less, the groove depth H is 1 mm or more, and the dryness of the refrigerant on the inlet side of the plate fin laminated heat exchanger is 0.1 or less. Air exchanger. Has a compressor and an outdoor heat exchanger and the expansion device and the indoor heat exchanger, in a refrigeration cycle for circulating a refrigerant, provided with gas-liquid separator between said indoor heat exchanger and the throttling device, the gas A flow control valve for adjusting the flow rate of the gaseous refrigerant separated by the liquid separator and a second throttle device between the gas-liquid separator and the indoor heat exchanger are included to provide the gaseous refrigerant. An injection circuit to be supplied to the compressor is provided, and the indoor heat exchanger is a plate laminated heat exchanger formed by laminating plate fins, and the plate fins have two header flows at the ends of the plate fins. The header is around a path, a plurality of heat transfer channels connecting the two header channels, and at least the header channels on the inlet side of the header channels when the indoor heat exchanger is used as an evaporator. It has an annular groove larger than the diameter of the flow path, the width of the annular groove is 3 mm or less, the groove depth H is 1 mm or more, and the gas-liquid separator is the inlet of the plate fin laminated heat exchanger. An air exchanger characterized in that the dryness of the refrigerant on the side is 0.1 or less. The second aspect of claim 2 includes an internal heat exchanger that exchanges heat between the refrigerant flowing between the gas-liquid separator and the second throttle device and the refrigerant flowing between the indoor heat exchanger and the compressor. The described air conditioner. In a refrigeration cycle that has a compressor, an outdoor heat exchanger, a throttle device, and an indoor heat exchanger and circulates a refrigerant, the indoor heat exchanger is a plate laminated heat exchanger formed by laminating plate fins. The plate fins have two header channels and two at the ends of the plate fins.
Around the plurality of heat transfer channels connecting the header channels and at least the header channels on the inlet side of the header channels when the indoor heat exchanger is used as an evaporator, the diameter of the header is larger than the diameter of the header. It has a large annular groove, the width of the annular groove is 3 mm or less, the groove depth H is 1 mm or more , the refrigerant flowing between the outdoor heat exchanger and the drawing device, the indoor heat exchanger and the above. It is provided with an internal heat exchanger that exchanges heat with the refrigerant flowing between the compressor and the internal heat exchanger, and the dryness of the refrigerant on the inlet side of the plate fin laminated heat exchanger is 0.1 or less. An air exchanger characterized by the fact that

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