WO2014068687A1

WO2014068687A1 - Parallel flow heat exchanger and air conditioner using same

Info

Publication number: WO2014068687A1
Application number: PCT/JP2012/078090
Authority: WO
Inventors: 一樹吉村; 久保田　淳; 石井　英二
Original assignee: 株式会社日立製作所
Priority date: 2012-10-31
Filing date: 2012-10-31
Publication date: 2014-05-08
Also published as: JP5957535B2; JPWO2014068687A1

Abstract

The purpose of the present invention is to provide a parallel flow heat exchanger that, with a simple structure, induces a swirl flow inside a header tube and evenly distributes refrigerant to flat tubes. This parallel flow heat exchanger is provided with: first and second header tubes; a plurality of flat tubes connected to the first and second header tubes; an inflow tube which is connected to the first header tube and into which refrigerant flows; and an outflow tube which is connected to the second header tube and out of which refrigerant flows. The inflow tube is disposed such that the center axis of the inflow tube is offset with respect to the center axis of the first header tube.

Description

Parallel flow heat exchanger and air conditioned air using the same

The present invention relates to a parallel flow heat exchanger and an air conditioner using the same.

A parallel flow type heat exchanger that has a plurality of flat tubes between two header tubes and performs heat exchange by refrigerant flow in the header and flat tubes is widely used in automobile radiators, air conditioners for cooling, etc. There is.

In order to perform heat exchange efficiently in the parallel flow type heat exchanger, it is necessary to evenly distribute the refrigerant to each flat tube in the header tube. However, particularly when the refrigerant is a gas-liquid two-phase flow, the inside of the header pipe becomes a complicated flow field, and uniform distribution is difficult. For example, the pressure distribution is dispersed due to the flow colliding with the flat tube protruding into the header tube. In addition, when the flow form in the header pipe is a laminar flow, the height of the refrigerant gas-liquid interface fluctuates. Due to these phenomena, the refrigerant distribution amount to each flat tube is biased. As a result, the performance of the heat exchanger is degraded.

On the other hand, in patent document 1, in order to "divide equally to each heat transfer tube, increase the effective heat transfer area where the refrigerant actually evaporates, and improve the performance", "in-header internal velocity of the refrigerant, upstream "Slow down sequentially from the header on the side to the header on the downstream side" and "increase the spiral angle of the spiral groove provided inside the header sequentially from the header on the upstream side to the header on the downstream side" Disclosed is a heat exchanger in which the groove depth is progressively lowered from the upstream header to the downstream header.

However, in the spiral groove provided inside the header of the heat exchanger disclosed in Patent Document 1, there is a possibility that the swirling flow for causing the refrigerant to evenly flow to each heat transfer pipe is insufficient.

Unexamined-Japanese-Patent No. 5-223490

In the present invention, it is an object of the present invention to provide a parallel flow type heat exchanger in which a swirl flow is induced in a header pipe and a refrigerant is evenly distributed to each flat pipe with a simple structure.

The parallel flow type heat exchanger according to the present invention includes the first header pipe and the second header pipe, the plurality of flat pipes connecting the first header pipe and the second header pipe, and the first header pipe, and the refrigerant flows therein. The inflow pipe is arranged such that the central axis of the inflow pipe is offset with respect to the central axis of the first header pipe.

According to the present invention, it is possible to provide a parallel flow type heat exchanger that induces swirling flow in a header pipe and distributes the refrigerant evenly to each flat pipe with a simple structure.

The figure which shows the conventional parallel flow-type heat exchanger. FIG. 2 is a diagram showing a parallel flow type heat exchanger in Embodiment 1. FIG. 6 is a view showing a turning induction structure by an inflow pipe in the first embodiment. The figure which shows the refrigerant | coolant flow field in the header pipe | tube in FIG. FIG. 6 is a diagram showing a refrigerant flow field in a header pipe in Embodiment 1. FIG. 7 is a three-dimensional view of a parallel flow heat exchanger in Embodiment 2. FIG. 7 is a view showing a connection relationship between an inflow pipe and a header pipe in a second embodiment. FIG. 7 is a view showing a connection relationship between an inflow pipe and a header pipe in a second embodiment. FIG. 7 is a view showing a parallel flow type heat exchanger in a third embodiment. FIG. 7 is a view showing a parallel flow type heat exchanger in a third embodiment. FIG. 16 is a view showing a header pipe in a fourth embodiment. FIG. 16 is a view showing a swirl flow guide plate in a fourth embodiment. FIG. 18 is a diagram showing a parallel flow type heat exchanger in a fifth embodiment. The refrigeration cycle block diagram of a home-use air conditioner. The block diagram of a refrigerating cycle at the time of adopting a reheat dehumidification system.

The parallel flow type heat exchanger according to the present embodiment includes a first header pipe and a second header pipe, a plurality of flat pipes connecting the first header pipe and the second header pipe, and a refrigerant connected to the first header pipe. The inflow pipe is arranged such that the central axis of the inflow pipe is offset with respect to the central axis of the first header pipe, and the outflow pipe connected to the second header pipe and the outflow pipe through which the refrigerant flows out . According to the present embodiment, it is possible to provide a parallel flow type heat exchanger in which a stronger swirl flow is induced in the header pipe with a simple structure to distribute the refrigerant to the flat pipes more evenly.

The parallel flow heat exchanger according to the first embodiment will be described below with reference to the drawings. First, a refrigeration cycle to which the parallel flow heat exchanger of the present embodiment is applied will be described. FIG. 14 is a diagram showing the configuration of a refrigeration cycle of a home air conditioner. In FIG. 14, reference numeral 101 denotes a compressor, 102 denotes a four-way valve, 103 denotes an expansion device such as a motor operated valve, 104 denotes an outdoor heat exchanger, and 106 denotes an indoor heat exchanger.

In the air conditioner, by switching the four-way valve 102, a cooling operation (solid arrow) using the outdoor heat exchanger 104 as an evaporator and the indoor heat exchanger 106 as a condenser, an outdoor heat exchanger 104 as a condenser, indoor heat A heating operation (broken line arrow) can be performed using the exchanger 106 as an evaporator. For example, in the cooling operation, the high-temperature and high-pressure refrigerant compressed by the compressor 101 passes through the four-way valve 102, flows into the outdoor heat exchanger 104, dissipates heat by heat exchange with air, and condenses. Then, after being isenthalpically expanded by the expansion device 103 such as a motor-operated valve, the gas-liquid two-phase flow in which gas and liquid are mixed at low temperature and low pressure flows into the indoor heat exchanger 106. In the indoor heat exchanger 104, the refrigerant absorbs heat from the air through the fins attached to the refrigerant pipe and the refrigerant pipe, and the refrigerant evaporates into a gas refrigerant from the inlet to the outlet. Then, the refrigerant that has exited the indoor heat exchanger 106 returns to the compressor 101 to form a cycle. Generally, in the outdoor heat exchanger 104 and the outdoor heat exchanger 106, in order to perform heat exchange efficiently, a piping structure in which one refrigerant pipe is branched into a plurality of refrigerant pipes is required.

FIG. 15 shows a configuration diagram of a refrigeration cycle in the case of adopting a reheat dehumidifying system in which the blowoff temperature of the indoor unit is not lowered. The throttling device 105 is provided between the

indoor heat exchangers

107 and 108, and the refrigerant is decompressed by the throttling device 105 so that the portion of the indoor heat exchanger 108 acts as a condenser and the portion of the indoor heat exchanger 107 acts as an evaporator. Then, the outlet temperatures of the indoor heat exchanger 107 and the indoor heat exchanger 108 are mixed.

In general air conditioning air, a cross fin tube type heat exchanger is used for the outdoor heat exchanger 104 and the

indoor heat exchangers

106, 107, 108. However, in order to further reduce the cost of the heat exchanger, it is required to use a parallel flow type heat exchanger, which is used in a radiator of a car, a dedicated air conditioner for cooling, etc., as a condenser and an evaporator. Therefore, it becomes an issue to distribute the refrigerant evenly from the header pipe of the parallel flow heat exchanger to the plurality of flat pipes.

FIG. 1 is a view showing the structure of a conventional parallel flow type heat exchanger. The parallel flow type heat exchanger has

header pipes

21 and 22 in which the refrigerant branches and joins at both ends of the flat pipes 11 arranged at equal intervals, and the

header pipes

21 and 22 are inflow and

outflow pipes

31 and 32 of the refrigerant. Have. Further, the inside of the flat tube 11 is divided by a thinner flow passage. Between the flat tubes 11, fins 4 for improving the efficiency of heat exchange are installed. For example, when the refrigerant flows in from the inflow pipe 31, the refrigerant is distributed to the flat pipes 11 in the header pipe 21. Then, after joining at the header pipe 22, it flows out from the outflow pipe 32. The same applies to the case where the inflow pipe is 32 and the outflow pipe is 31.

FIG. 2 is a view showing a parallel flow type heat exchanger of the present embodiment. The basic configuration is the same as in FIG. The heat exchanger comprises a flat pipe 12,

header pipes

21 and 22, an outflow pipe 32 installed on the end face of the header pipe 22, an inflow pipe 33 installed on the side surface of the header pipe 21, and a fin installed between the flat pipes 12. It consists of four. In the present embodiment, the structure for inducing the swirling flow in the header pipe 21 by the inflow pipe 33 will be described, but it is possible to induce the swirling flow also in the header pipe 22 with the same structure. The positions of the header pipe 21 and the inflow pipe 33 and the details of the flat pipe 12 will be described with reference to FIG.

FIG. 3 is a view for explaining the positional relationship between the header pipe 21 and the inflow pipe 33 of FIG. As shown in FIG. 3, the inflow pipe 33 is installed such that the central axis 61 of the inflow pipe 33 and the longitudinal central axis 62 of the header pipe 21 are offset by a distance ε with the side surface of the header pipe 21. A swirling flow of refrigerant is induced in the pipe 21. As described later, by inducing a swirling flow of the refrigerant in the header pipe 21, the liquid refrigerant is not biased toward the inflow pipe in the header pipe 21 or in the lower part of the header pipe 21, and the upper portion in the header pipe 21 (inflow pipe end Since the liquid refrigerant can be distributed in part (1), the refrigerant can be distributed evenly to the flat tube 12. In addition, since the liquid refrigerant is also distributed in the upper part of the header pipe 21 (inflow pipe end part), there is no need to deeply insert the inflow pipe end part into the header pipe 21 to the lower inside of the header pipe 21. Can also be reduced. Further, for example, as in the flat tube 12 shown in FIG. 3, by making it an arc shape (concave shape) so that the area of the insertion portion with respect to the header tube 21 becomes small, the turning force due to the resistance of the insertion portion of the flat tube 12 Attenuation can be reduced. The same effect can be obtained by reducing the insertion length of the flat tube 12 into the header tube 21 as much as possible without limiting the flat tube 12 to an arc shape. For example, while the end face of the flat tube 12 is flat, the insertion length into the header tube 21 is shortened to the processing limit at which the header tube 21 and the flat tube 12 can be joined. And the like.

Next, in the present embodiment, the gas-liquid refrigerant flow field of the conventional structure of FIG. 1 and the structure of the present embodiment of FIG. 2 when the refrigerant is a gas-liquid two-phase flow will be respectively described. FIG. 4 is a view showing a flow field in the header pipe 21 of FIG. 1 which is a conventional structure. In FIG. 4, the heat exchanger is composed of the flat pipe 11, the header pipe 21, the inflow pipe 31, and the gas-liquid refrigerant 5, and the illustration of the fins is omitted. In the conventional structure, the refrigerant flowing from the inflow pipe forms a laminar flow in which the upper part is a gas refrigerant and the lower part is a liquid refrigerant, and flows in the header pipe 21. The flow velocity of the refrigerant is high in the vicinity of the inlet pipe inlet, and the refrigerant collides with the flat pipe 11 which is protruded into the header pipe 21 by the flow colliding. Therefore, the refrigerant easily flows into the flat tube 11 in the vicinity of the inflow tube 31 and the distribution amount is increased. On the other hand, since the liquid refrigerant flowing as a laminar flow is repelled by the wall end at the wall end face downstream of the header pipe 21, the flow stagnates, and the interface of the liquid refrigerant becomes high. For this reason, the refrigerant is likely to flow into the flat tube 11 in the vicinity of the end face of the wall. In addition, since the flat tube 11 located at the central portion of the header tube 21 has a lower interface compared to both ends of the header tube 21, the end face (inflow port) of the flat tube 11 is unlikely to contact the liquid refrigerant, The amount of inflow decreases relatively. As mentioned above, in the conventional structure, the dispersion | distribution of distribution amount will arise between the flat tubes 11. As shown in FIG.

FIG. 5 is a view showing a flow field in the header pipe 21 of FIG. 2 which is a structure of the present embodiment. In FIG. 5, the heat exchanger is composed of the flat pipe 12, the header pipe 21, the inflow pipe 33, and the gas-liquid refrigerant 5, and the illustration of the fins is omitted. In the structure of this embodiment, since the inflow pipe 33 is installed so that the swirling flow is induced in the header pipe 21, the liquid refrigerant is pulled by the swirling flow of the gas refrigerant so as to cover the entire wall surface of the header pipe 21. Liquid refrigerant flows. The flat tube 12 not only shortens the insertion length into the inside of the header tube 21 but also has an end face shape along the arc shape of the header tube 21. As a result, the flat tube does not disturb the swirling flow, and the pressure distribution in the header tube 21 becomes even. Furthermore, the liquid refrigerant forming a liquid film on the wall surface of the header pipe 21 easily flows into the flat pipe 12. However, as the refrigerant flows downstream of the header pipe 21, the swirling speed is attenuated. Therefore, the turning force can be adjusted by reducing the diameter of the inflow pipe 33 according to the length of the header pipe 21 so that the swirling flow can be maintained in the entire header pipe 21. For example, a pipe having a small diameter is used as the inflow pipe 33, a taper or an orifice is provided at the pipe outlet, and a restriction is provided at the outflow portion.

In the present embodiment, a case is described in which the water flows in from the inflow pipe provided in the header pipe provided on the lower side of the heat exchanger, flows out from the outflow pipe after joining with the header pipe provided on the upper side of the heat exchanger However, the direction of gravity is not limited, and even when the structure of the header pipe is upside down or when the longitudinal direction of the header pipe is the direction of gravity, the distribution variation reduction effect can be obtained by the swirling of the refrigerant.

Next, a second embodiment will be described using the drawings. The configuration of the heat exchanger and the swirl inducing structure are the same as in the first embodiment, and thus the description thereof is omitted. In this embodiment, the central axis of the inflow pipe is inclined in the longitudinal direction of the header pipe. Specifically, the inflow pipe insertion angle into the header pipe 21 is inclined by θ ₁ toward the downstream side of the header pipe 21.

FIG. 6 is a three-dimensional view of the parallel flow heat exchanger in the second embodiment. In FIG. 6, the heat exchanger comprises the flat pipe 12, the header pipe 21 and the inflow pipe 34, and the illustration of the fins is omitted. When installing the inflow pipe 34 in the header pipe 21, the outlet pipe 34 is inclined θ ₁ toward the inflow pipe 34 with respect to the header pipe 21 so that the outlet of the inflow pipe 34 faces the downstream side of the header pipe 21. Configure. With such a configuration, the longitudinal velocity of the refrigerant flow in the header pipe 21 becomes larger toward the downstream side of the header pipe 21, so that the sustained distance of the swirling flow becomes relatively longer, especially the refrigerant in the downstream of the header pipe 21 Distribution of each flat tube 12 is improved.

The details of this structure are shown in FIG. The heat exchanger of FIG. 7 comprises a flat pipe 12, a header pipe 21, an inflow pipe 34, a refrigerant 5, a central axis 61 of the inflow pipe 34, and a longitudinal central axis 62 of the header pipe 21; . As shown in FIG. 7, θ _{1 is} inclined to the side vertical direction of the header pipe 21.

In addition, the central axis of the inflow pipe may be configured to be inclined in the longitudinal direction of the flat pipe. FIG. 8 shows an example of a heat exchanger in which the inflow pipe insertion angle to the header pipe 21 is inclined by θ _{2 in} the flow direction of the flat pipe. The heat exchanger of FIG. 8 is composed of the flat pipe 12, the header pipe 21, the inflow pipe 34, and the refrigerant 5, whereby the gas-liquid refrigerant flows more along the side wall surface of the header pipe 21 and the swirl flow efficiently. Can be induced.

As described above, by adjusting the installation angles θ ₁ and θ ₂ of the inflow pipe 34, it is possible to make the swirl flow act more efficiently, and to reduce the dispersion of the refrigerant distribution.

Next, a third embodiment will be described using the drawings. The configuration of the heat exchanger and the swirl inducing structure are the same as in the first embodiment, and thus the description thereof is omitted.

FIG. 9 shows an example of a heat exchanger in which the number of inflow pipes 34 inserted into the header pipe 21 is plural. The heat exchanger of FIG. 9 includes a flat pipe 12,

header pipes

21 and 22, four inflow pipes 34, an outflow pipe 32, and fins 4. The inflow pipe 34 is structured to induce a swirling flow in the header pipe 21 as described in the above embodiments. In the present embodiment, four inflow pipes 34 are provided for the header pipe 21. Thereby, compared with the case where a refrigerant | coolant flows in into the header pipe | tube 21 from one inflow pipe | tube, the dispersion | variation in the refrigerant | coolant distribution by damping | damping of a turning can be disperse | distributed to four places. As a result, it is possible to further reduce the dispersion of refrigerant distribution in each flat tube. In addition, by setting a plurality of inflow locations to header tube 21, the swirling force decreases with a decrease in the flow rate of refrigerant per inflow tube, but this can be coped with by reducing the outlet tube diameter of inflow tube 34. It is. For example, a pipe having a small diameter is used as the inflow pipe 34, a taper or an orifice is provided at the pipe outlet, and the like. Although the inflow pipes 34 are installed at four locations in FIG. 9, the use of more inflow pipes 34 can further reduce the variation in refrigerant distribution. Further, the installation position of the inflow pipe 34 is not limited to the header pipe 21 at equal intervals, and can be installed at unequal intervals to adjust the inflow rate to each flat pipe 12.

Here, the header pipe 21 may be divided into a plurality of sections, and the inflow pipe 21 of the present embodiment may be connected to each of the plurality of sections. FIG. 10 shows an example of a heat exchanger in which the partition wall 7 is provided inside the header pipe 21 as compared with the heat exchanger of FIG. By dividing the header pipe by the partition 7 according to the number of the inflow pipes 34, small rooms are formed inside the header pipe 21 and the amount of refrigerant distributed to each flat pipe 12 in each small room from each inflow pipe 34 Limited to the amount of refrigerant inflow. Thereby, it is possible to reduce the variation in distribution of the refrigerant to the flat tubes 12 more than the structure of FIG. 9. In FIG. 10, by providing partitions 7 at equal intervals in the header pipe 21 for the four inflow pipes 34, the header pipe 21 is further divided into four small rooms. As a result, since all the refrigerant flowing from each inflow pipe 34 is distributed in each small chamber, no large distribution variation occurs between the flat tubes 12 across the rooms. Further, the installation position of the partition wall 7 is not limited to the header pipe 21 at equal intervals, and can be installed at unequal intervals to adjust the inflow rate to each flat tube 12.

Next, a fourth embodiment will be described using the drawings. The configuration of the heat exchanger and the swirl inducing structure are the same as in the first and second embodiments, and therefore the description thereof is omitted. In the present embodiment, a spiral flow guide plate 8 is disposed inside the header pipe 21.

FIG. 11 is a view showing a header pipe provided with a swirl flow guide plate 8 to maintain the swirl flow. In each of the above embodiments, the swirling flow guide plate 8 serving as a swirling flow guide is inserted along the side wall surface in the header pipe 21. The heat exchanger of FIG. 11 is comprised from the flat pipe 12, the header pipe 21, the inflow pipe 34, and the rotational flow guide plate 8, and illustration of a fin is abbreviate | omitted. FIG. 12 is a detailed structural view of the swirl flow guide plate 8 of FIG.

In the present invention, the swirl flow is induced inside the header pipe 21 by adopting the same configuration as each of the above embodiments. However, the longer the length in the longitudinal direction of the header pipe 21 is, the more the refrigerant flows downstream in the header pipe 21, the more the header pipe wall and the refrigerant, or the shear force generated between the gas refrigerant and the liquid refrigerant As a result, the effect of reducing the distribution of refrigerant is reduced. Therefore, in the present embodiment, by disposing the spiral flow guide plate 8 inside the header pipe 21, the refrigerant is guided so as to turn the inner wall of the header pipe 21, so that the reduction of the turning force is suppressed. be able to. Further, by correcting the direction of the velocity vector by the swirling flow guide plate upstream of the header pipe 21, it is possible to suppress the phenomenon that the refrigerant flows directly into the flat tube 12 by the strong swirling flow immediately after the refrigerant flows.

FIG. 12 is a detailed structure of the swirling flow guide plate. In this embodiment, as shown in FIG. 12, the radial thickness of the swirling flow guide plate 8 is further increased from the upstream side to the downstream side of the header pipe 21. That is, the spiral flow guide plate 8 is configured such that the width of the plate from the upstream to the downstream of the header pipe gradually increases to t ₁ <t ₂ <t ₃ . Thereby, the direction of the velocity vector of the refrigerant flow can be corrected more forcibly in the swirling direction even in the downstream of the header pipe 21 where the swirling force is attenuated, and the effect of the swirling flow can be sustained longer. In addition, the pressure loss can be optimized because the thickness of the plate is changed according to the flow as compared with the case where the thickness of the swirling flow guide plate 8 is uniformly thickened and the force is applied to the flow. it can. This makes it possible to further suppress the dispersion of refrigerant distribution. Furthermore, the combination of the installation of the plurality of inflow pipes 34 and the installation of the dividing wall 7 described in the third embodiment is also effective for reducing the variation in distribution of the refrigerant.

A fifth embodiment will now be described with reference to the drawings. The configuration of the heat exchanger and the swirl inducing structure are the same as in the first embodiment, and thus the description thereof is omitted. FIG. 13 is a view showing a swing induction structure by the inflow pipe 35 disposed between the header pipes when the heat exchangers are arranged in two rows in the front and back.

In the heat exchanger of this embodiment, the heat exchangers comprising the header pipe, the flat pipe, and the fins are arranged in two rows connected in the front and back, and when the refrigerant flows from the header pipe in the front row into the header pipe in the rear row, The swirl induction structure shown in each of the above embodiments is provided (that is, the heat exchanger on the downstream side of the refrigerant flow is constituted by the parallel flow heat exchanger of each of the above embodiments). The heat exchanger of FIG. 13 has

flat tubes

12 and 13, header tubes 22 in the front row, header tubes 23 in the rear row, inflow tube (outflow tube) 35, central axis 61 of inflow tube 35, and longitudinal central axis of header tube 23. It consists of 62.

In this embodiment, the parallel flow type heat exchangers of the above embodiments, other parallel flow type heat exchangers (a plurality of header pipes 22 and a header pipe (not shown), a header pipe 22 and a header pipe ( A plurality of flat pipes 12 connecting the not shown, an inflow pipe (not shown) connected to the header pipe (not shown) into which the refrigerant flows, and an outflow pipe 35 connected to the header pipe 22 and the refrigerant flows out And a parallel flow heat exchanger) are connected. Specifically, the outflow pipe 35 of another parallel flow heat exchanger is connected to the inflow pipe 35 of the parallel flow heat exchanger of each of the above embodiments, and the outflow pipe 35 of another parallel flow heat exchanger. The refrigerant which has flowed out of the refrigerant flows into the header pipe 23 through the inflow pipe 35 of the parallel flow heat exchanger of each of the above embodiments.

In the present embodiment, since the heat exchangers are arranged in two rows, for example, when the header pipe is installed separately in the vertical direction with respect to the direction of gravity, when the refrigerant flows from the header pipe at the top of the front row to the header pipe at the top of the rear row The liquid refrigerant stagnates in the header tubes of the rear row, and the liquid refrigerant is less likely to be distributed to the flat tubes. Therefore, in the present invention, as shown in FIG. 13, the heat exchangers described in the above embodiments are applied to induce a swirling flow in the header pipe 23 at the upper part of the rear row, whereby the refrigerant is applied to each flat pipe 13. Distribute evenly. The refrigerant flow field of this embodiment and the effect thereof will be described. First, the refrigerant 5 having flowed into the front row is distributed to the flat tubes 12, and then flows through the flat tubes 12 and merges at the header tube 22. Next, the refrigerant 5 flows from the header pipe 22 through the inflow pipe (outflow pipe) 35 to the header pipe 23 installed in the heat exchanger in the rear row. At this time, in order to reduce the pressure loss due to the laminar flow of the refrigerant in the header pipe 23, a swirling flow is induced in the same manner as in the above embodiments. Since the gas-liquid refrigerant is in a swirling flow, the liquid refrigerant does not stay in the header pipe 23. Therefore, the pressure distribution in the header pipe 23 becomes more uniform, and the refrigerant distribution variation to the flat pipe 13 is improved. Since the end surface shape of the flat tube 13 is along the header tube (the end surface shape of the flat tube 13 is a concave shape), the stagnation of the refrigerant can be further suppressed.

11: Conventional flat tubes 12 and 13:

Flat tubes

21, 22 and 23 whose end shapes are changed: header tubes 31 and 32: inflow and

outflow tubes

33, 34 and 35: inflow and outflow tubes 4 having a swirl inducing structure : Fin 5: Gas-liquid refrigerant 61: Central axis 62 of inflow pipe: Central axis in the longitudinal direction of header pipe 7: Partition 8 provided inside header pipe: Spiral flow guide plate 101: Compressor 102: Four sides Valves 103, 105: throttle devices 104 such as motor operated valves:

outdoor heat exchangers

106, 107, 108: indoor heat exchangers

Claims

A first header pipe and a second header pipe,
A plurality of flat tubes connecting the first header pipe and the second header pipe;
An inflow pipe connected to the first header pipe and into which the refrigerant flows;
An outlet pipe connected to the second header pipe and from which the refrigerant flows out;
The parallel flow type heat exchanger, wherein the inflow pipe is arranged such that the central axis of the inflow pipe is offset with respect to the central axis of the first header pipe.
The parallel flow heat exchanger according to claim 1, wherein a central axis of the inflow pipe is inclined in a longitudinal direction of the header pipe.
The parallel flow type heat exchanger according to claim 2, wherein a central axis of the inflow pipe is inclined in a longitudinal direction of the flat pipe.
In any one of claims 1 to 3,
The inflow pipe comprises a plurality of inflow pipes,
The header pipe is divided into a plurality of sections,
A parallel flow type heat exchanger connecting the inflow pipe to each of a plurality of the sections.
The parallel flow type heat exchanger according to any one of claims 1 to 4, wherein a spiral flow guide plate is disposed inside the first header pipe.
The parallel flow type heat exchanger according to claim 5, wherein a radial thickness of the swirling flow guide plate increases from the upstream side to the downstream side of the first header pipe.
The parallel flow type heat exchanger according to any one of claims 1 to 6, wherein an end face of the first header pipe of the flat pipe connected to the first header pipe is formed in a concave shape.
A parallel flow type heat exchanger according to any one of claims 1 to 7;
Third header pipe and fourth header pipe, a plurality of second flat pipes connecting the third header pipe and the fourth header pipe, and a second inflow pipe connected to the third header pipe and into which the refrigerant flows A second parallel flow type heat exchanger having a second outlet pipe connected to the fourth header pipe and from which the refrigerant flows out;
The second outflow pipe is connected to the inflow pipe,
The parallel flow type heat exchanger in which the refrigerant which flowed out out of the 2nd outflow pipe flows into the 1st header pipe via the inflow pipe.
The compressor, the four-way valve, the indoor heat exchanger, the expansion valve, and the indoor heat exchanger are connected to each other, and at least one of the indoor heat exchanger and the outdoor heat exchanger is provided. Refrigeration cycle device with any parallel flow type heat exchanger.