CN112119271A

CN112119271A - Refrigeration cycle device

Info

Publication number: CN112119271A
Application number: CN201880093146.1A
Authority: CN
Inventors: 石山宗希; 田中航祐; 藤田训弘; 阿部贵史
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2018-05-15
Filing date: 2018-05-15
Publication date: 2020-12-22
Anticipated expiration: 2038-05-15
Also published as: EP3795928A4; WO2019220541A1; JP7000566B2; JPWO2019220541A1; CN112119271B; EP3795928A1

Abstract

Provided is a refrigeration cycle device having improved period efficiency as compared with a conventional refrigeration cycle device. A refrigeration cycle device (100) is provided with a refrigerant circuit that includes a compressor (1), a first heat exchanger (3), and a second heat exchanger (4) and in which a refrigerant circulates. The refrigerant circuit is arranged to be able to switch between a first state in which the first heat exchanger (3) functions as a condenser and the second heat exchanger (4) functions as an evaporator, and a second state in which the second heat exchanger (4) functions as a condenser and the first heat exchanger (3) functions as an evaporator. The first heat exchanger (3) includes a first heat transfer pipe (6) through which a refrigerant flows. The first heat transfer pipe (6) has a flow of refrigerant when functioning as a condenserAnd a first pipe section (61) located downstream of the intermediate position in the direction of flow. The first heat exchanger (3) further includes a first content member (7) disposed inside the first pipe portion (61). The inner diameter D of the first pipe part (61)₁And equivalent diameter M₁Satisfies D in the first and second states₁/2.5<M₁<D₁The relation of/1.5.

Description

Refrigeration cycle device

Technical Field

The present invention relates to a refrigeration cycle apparatus including a first heat exchanger and a second heat exchanger, and more particularly, to a refrigeration cycle apparatus which is provided so as to be capable of switching between a first state in which the first heat exchanger functions as a condenser and the second heat exchanger functions as an evaporator and a second state in which the second heat exchanger functions as a condenser and the first heat exchanger functions as an evaporator.

Background

The refrigerant circulating through the refrigeration cycle apparatus is condensed from a gas single-phase state to a liquid single-phase state via a gas-liquid two-phase state while flowing from one end to the other end of the heat transfer pipe of the condenser, and is evaporated from the gas-liquid two-phase state to the gas single-phase state while flowing from one end to the other end of the heat transfer pipe of the evaporator.

When the heat transfer tube of the condenser is configured to have a uniform structure between one end and the other end thereof, the heat transfer performance between the refrigerant flowing inside the heat transfer tube and the heat medium such as air flowing outside the heat transfer tube (hereinafter referred to as "tube heat transfer performance") varies depending on the position in the extending direction of the heat transfer tube. The heat transfer performance in the tube in a first portion located on the downstream side including the other end of the heat transfer tube of the condenser is lower than the heat transfer performance in the tube in a second portion located on the upstream side of the first portion and on the downstream side of the one end. This is because the flow rate of the refrigerant in the liquid single-phase state flowing through the first portion of the condenser is lower than the flow rate of the refrigerant in the gas-liquid two-phase state flowing through the second portion of the condenser.

The following heat exchanger is disclosed in japanese patent laid-open No. 2000-55509 (patent document 1): in order to improve the in-tube heat transfer performance at a portion located on the downstream side of the heat transfer tube of the condenser and to improve the heat exchanger performance in an operating state functioning as the condenser, an insert body is provided in the heat transfer tube on the refrigerant outlet side in the case of the condenser.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open No. 2000-55509

Disclosure of Invention

Problems to be solved by the invention

However, in the case where the heat exchanger functions as an evaporator, the refrigerant in a gas-liquid two-phase state or a gas single-phase state flows through the heat transfer pipe into which the insert is inserted. Therefore, when the heat exchanger functions as an evaporator, the pressure loss of the refrigerant flowing through the portion of the heat transfer pipe where the insert is inserted becomes significantly larger than the pressure loss of the refrigerant flowing through the portion of the heat transfer pipe where the insert is not inserted. Therefore, the heat exchanger performance in the case where the heat exchanger functions as an evaporator is significantly lower than that in the case where the heat exchanger without the interposition member functions as an evaporator. As a result, in the refrigeration cycle apparatus provided so as to be able to switch between an operating state in which the heat exchanger functions as a condenser and an operating state in which the heat exchanger functions as an evaporator, it is difficult to improve the period efficiency.

A main object of the present invention is to provide a refrigeration cycle apparatus having improved period efficiency as compared with the above refrigeration cycle apparatus.

Means for solving the problems

A refrigeration cycle device is provided with a refrigerant circuit which includes a compressor, a flow path switching valve, a first heat exchanger, a second heat exchanger, and a decompression section and in which a refrigerant circulates. The refrigerant circuit is arranged to be capable of switching between a first state and a second stateIn the first state, the first heat exchanger functions as a condenser and the second heat exchanger functions as an evaporator, and in the second state, the second heat exchanger functions as a condenser and the first heat exchanger functions as an evaporator. The first heat exchanger and the second heat exchanger include heat transfer tubes through which a refrigerant flows. The heat transfer pipe has a first tube portion located on a downstream side of an intermediate position of the first heat transfer pipe in a flow direction of the refrigerant when the first heat exchanger functions as a condenser. The first heat exchanger further includes a first content member disposed inside the first tube part. Inner diameter D of first pipe part₁And a flow path cross-sectional area A using the first pipe part₁And the wet circumference length S of the first pipe part₁And the equivalent diameter M calculated from the following relation (1)₁The following relational expression (2) is satisfied in the first state and the second state.

M₁＝4×A₁/S₁…(1)

D₁/2.5<M₁<D₁/1.5…(2)

ADVANTAGEOUS EFFECTS OF INVENTION

Since the first heat exchanger of the refrigeration cycle device of the present invention includes the first tube portion having the equivalent diameter M satisfying the above-described relational expression (2), it exhibits high heat exchange performance when functioning as a condenser. Further, since the first heat exchanger includes the first tube portion having the equivalent diameter M satisfying the above relational expression (2), the heat exchanger exhibits a higher heat exchange performance when functioning as an evaporator than a conventional heat exchanger including a heat transfer tube having an equivalent diameter M not satisfying the above relational expression (2). As a result, according to the present invention, it is possible to provide a refrigeration cycle apparatus having improved period efficiency as compared with a refrigeration cycle apparatus including a conventional heat exchanger including a heat transfer pipe having an equivalent diameter M that does not satisfy the above relational expression (2).

Drawings

Fig. 1 is a schematic configuration diagram of a refrigeration cycle apparatus according to embodiment 1.

Fig. 2 is a schematic cross-sectional view of a heat transfer pipe of the first heat exchanger in the first state of the refrigeration cycle apparatus according to embodiment 1.

Fig. 3 is a schematic sectional view as viewed from an arrow III-III in fig. 2.

Fig. 4 is a schematic sectional view as viewed from arrows IV-IV in fig. 2.

Fig. 5 is a graph showing the relationship between the period efficiency of the first heat exchanger and the equivalent diameter of the first tube portion of the first heat exchanger in the refrigeration cycle apparatus according to embodiment 1.

Fig. 6 is a graph showing the relationship between the circulation amount of the refrigerant and the equivalent diameter of the first tube portion of the first heat exchanger in the refrigeration cycle device according to embodiment 1.

Fig. 7 is a schematic cross-sectional view of the heat transfer tube of the first heat exchanger in the first state of the refrigeration cycle apparatus according to embodiment 3.

Fig. 8 is a schematic sectional view as viewed from arrows VIII-VIII in fig. 7.

Fig. 9 is a schematic cross-sectional view of the heat transfer tubes of the first heat exchanger in the second state of the refrigeration cycle apparatus according to embodiment 3.

Fig. 10 is a schematic sectional view as seen from an arrow X-X in fig. 9.

Fig. 11 is a schematic cross-sectional view of a heat transfer pipe of the first heat exchanger in the first state of the refrigeration cycle apparatus according to embodiment 4.

Fig. 12 is a schematic sectional view as viewed from an arrow XII-XII in fig. 11.

Fig. 13 is a schematic cross-sectional view of the heat transfer tubes of the first heat exchanger in the second state of the refrigeration cycle apparatus according to embodiment 4.

Fig. 14 is a schematic sectional view as viewed from arrows XIV-XIV in fig. 13.

Fig. 15 is a schematic cross-sectional view of the heat transfer tube of the first heat exchanger in the first state of the refrigeration cycle apparatus according to embodiment 5.

Fig. 16 is a schematic sectional view as seen from arrows XVI-XVI in fig. 15.

Fig. 17 is a flowchart of the intermittent operation of the refrigeration cycle apparatus according to embodiment 5.

Fig. 18(a) is a graph showing the relationship between the operating time and the compressor frequency in the intermittent operation of the refrigeration cycle apparatus according to embodiment 5, and fig. 18(b) is a graph showing the relationship between the operating time and the indoor temperature in the intermittent operation of the refrigeration cycle apparatus according to embodiment 5.

Fig. 19 is a schematic cross-sectional view of the heat transfer tubes of the first heat exchanger in the first state of the refrigeration cycle apparatus according to embodiment 6.

Fig. 20 is a schematic sectional view as viewed from arrows XX-XX in fig. 19.

Fig. 21 is a schematic cross-sectional view of a heat transfer pipe of the first heat exchanger in the first state of the refrigeration cycle apparatus according to embodiment 7.

Fig. 22 is a schematic sectional view as viewed from arrows XXII to XXII in fig. 21.

Fig. 23 is a schematic cross-sectional view of a heat transfer pipe of the first heat exchanger in the first state of the modification of the refrigeration cycle apparatus according to embodiment 1.

Fig. 24 is a schematic sectional view seen from arrows XXIV-XXIV in fig. 23.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding portions are denoted by the same reference numerals, and description thereof will not be repeated.

Embodiment 1.

< construction of refrigeration cycle apparatus >

As shown in fig. 1, the refrigeration cycle apparatus 100 of embodiment 1 includes a refrigeration circuit including a compressor 1, a four-way valve 2 as a flow path switching valve, a first heat exchanger 3, a second heat exchanger 4, and a pressure reducing unit 5, and through which a refrigerant circulates. The refrigeration cycle apparatus 100 is provided so as to be able to switch, by the four-way valve 2, between a first state in which the first heat exchanger 3 functions as a condenser and the second heat exchanger 4 functions as an evaporator, and a second state in which the first heat exchanger 3 functions as an evaporator and the second heat exchanger 4 functions as a condenser. In the first state, the refrigerant flows through the compressor 1, the first heat exchanger 3, the decompression section 5, and the second heat exchanger 4 in this order in the direction F1. In the second state, the refrigerant flows through the compressor 1, the second heat exchanger 4, the pressure reducing unit 5, and the first heat exchanger 3 in this order along the direction F2. The first heat exchanger 3 is, for example, an indoor heat exchanger disposed indoors. The second heat exchanger 4 is, for example, an outdoor heat exchanger disposed outdoors. In this case, the first state is realized during the heating operation, and the second state is realized during the cooling operation.

As shown in fig. 1, the first heat exchanger 3 includes a plurality of first heat transfer pipes 6 through which a refrigerant flows, and exchanges heat between the refrigerant flowing inside the first heat transfer pipes 6 and a heat medium, such as air, flowing outside the first heat transfer pipes 6. The first heat exchanger 3 includes a heat exchange portion 30, a distributor 31, and a distributor 32, and the heat exchange portion 30 includes a plurality of first heat transfer pipes 6 and fins not shown. Each of the plurality of first heat transfer pipes 6 of the first heat exchanger 3 has, for example, a mutually equivalent structure.

As shown in fig. 1 and 2, each of the plurality of first heat transfer pipes 6 of the first heat exchanger 3 has a first end portion 6A and a second end portion 6B provided with an inflow/outflow port for the refrigerant. The first end portions 6A of the plurality of first heat transfer pipes 6 are connected to the distributor 31. Each of the second end portions 6B of the plurality of first heat transfer pipes 6 is connected to the distributor 32. Each of the plurality of first heat transfer pipes 6 has an inner peripheral surface 6C and an outer peripheral surface 6D. In the first heat exchanger 3, the refrigerant flows through a region surrounded by the inner peripheral surface 6C of each first heat transfer pipe 6. In the first state, the refrigerant is condensed from a gas single-phase state to a liquid single-phase state via a gas-liquid two-phase state in the process of flowing from the second end 6B to the first end 6A of each of the plurality of first heat transfer pipes 6. In the second state, the refrigerant evaporates from a gas-liquid two-phase state to a gas single-phase state in the process of flowing from the first end portion 6A to the second end portion 6B of each of the plurality of first heat transfer pipes 6.

As shown in fig. 2, each of the plurality of first heat transfer pipes 6 of the first heat exchanger 3 can be divided into: the third tube portion 63 located upstream of the intermediate position of the first heat transfer tube 6 in the refrigerant flowing direction F1 in the first state, the fourth tube portion 62 located downstream of the third tube portion 63 in the direction F1 including the intermediate position, and the first tube portion 61 located downstream of the fourth tube portion 62 in the direction F1. The first duct portion 61 is located on the downstream side of the intermediate position of the first heat transfer pipe 6 in the direction F1. The flow direction F1 of the refrigerant in the first heat transfer pipe 6 is along the axial direction of the first heat transfer pipe 6. The first heat transfer pipe 6 may extend linearly or may be bent in the axial direction. The material constituting the first heat transfer pipe 6 contains copper (Cu), for example.

The first heat exchanger 3 comprises, for example, a plurality of first content members 7. Each first containing member 7 is disposed inside each first pipe portion 61. The first content members 7 have, for example, mutually equivalent structures.

As shown in fig. 2, the first receiving member 7 has a third end portion 7A and a fourth end portion 7B. The third end portion 7A of the first containing member 7 is disposed closer to the first end portion 6A of the first heat transfer pipe 6 than the fourth end portion 7B. The end portion of the first pipe portion 61 on the fourth pipe portion 62 side is a portion that is disposed on the same cross section perpendicular to the axial direction of the first heat transfer pipe 6 as the fourth end portion 7B of the first accommodating member 7.

As shown in fig. 2, the first content member 7 has an outer peripheral surface 7D. At least a part of the outer peripheral surface 7D is disposed to face the inner peripheral surface 6C of the first pipe portion 61 with a space. The refrigerant flowing through the first pipe portion 61 flows through a region sandwiched between the inner peripheral surface 6C of the first pipe portion 61 and the outer peripheral surface 7D of the first content member 7. For example, only one refrigerant flow path is disposed in the first tube portion 61. In a cross section perpendicular to the above-described axial direction, the outer peripheral surface 7D of the first accommodating member 7 is formed in a shape similar to that formed by the inner peripheral surface 6C of the first heat transfer pipe 6, for example. The shape of the outer peripheral surface 7D of the first receiving member 7 and the shape of the inner peripheral surface 6C of the first heat transfer pipe 6 are, for example, circular.

In a cross section perpendicular to the axial direction, the length of the outer peripheral surface of the first content member 7 is defined as E₁The length of the inner circumferential surface of the first heat transfer pipe 6 is defined as E₂When the wet circumferential length of the first pipe portion 61 is S, the following relational expression (5) is established. At the shaftIn a cross section perpendicular to the line direction, the inner diameter of the first pipe portion 61 is defined as D₁The cross-sectional area of the flow path of the first pipe 61 is denoted by A₁And the equivalent diameter of the first pipe portion 61 is set to M₁When the above relation (1) is satisfied.

S₁＝E₁+E₂…(5)

As shown in FIG. 3, the equivalent diameter M of the first pipe portion 61₁The first state and the second state satisfy the following relational expression (6). Preferably, the equivalent diameter M of the first tube part 61₁The relational expression (2) is satisfied in the first state and the second state.

D₁/2.5<M₁…(6)

As shown in fig. 2, the first pipe portion 61 includes a portion through which liquid-phase refrigerant flows when the refrigeration cycle apparatus 100 is in the first state. The first tube portion 61 includes a portion through which, for example, the gas-liquid two-phase refrigerant flows when the refrigeration cycle apparatus 100 is in the second state. The fourth tube portion 62 includes a portion through which the gas-liquid two-phase refrigerant flows when the refrigeration cycle apparatus 100 is in the first state. The third pipe portion 63 includes a portion through which the gas-phase refrigerant flows when the refrigeration cycle apparatus 100 is in the first state. In fig. 2, the refrigerant is schematically shown for explaining the change in the state of the refrigerant, and for example, the refrigerant in the fourth tube portion 62 is only in a gas-liquid two-phase state, and the mixed state and the flow state of the liquid phase portion and the gas phase portion of the refrigerant in the gas-liquid two-phase state are not shown.

The length L of the first content member 7 in the axial direction of the first pipe portion₁Is the length L of the first heat transfer pipe 6₂Less than half. Length L of the first heat transfer pipe 6₂Is the length between the first end 6A and the second end 6B of the first heat transfer pipe 6 in the axial direction.

The positional displacement of the first containing member 7 with respect to the first tube portion 61 of the first heat transfer tube 6 in the above-described axial direction is restricted by an arbitrary structure. For example, when the first heat transfer pipe 6 is bent in the axial direction and the first heat transfer pipe 6 has a bending portion not shown, the first pipe portion 61 is disposed on the downstream side of the bending portion in the flow direction F1. For example, the boundary portion of the first pipe portion 61 and the fourth pipe portion 62 of the first heat transfer pipe 6 is provided in connection with the bent portion. Thus, the first receiving member 7 is positioned between the bent portion and the first end portion 6A in the axial direction.

The material constituting the first receiving member 7 may be any material, and may be, for example, a material having corrosion resistance against the refrigerant equivalent to that of the material constituting the first heat transfer pipe 6, and may include at least one selected from the group consisting of copper (Cu), rubber, and plastic.

< Effect >

The refrigeration cycle apparatus 100 includes a refrigerant circuit including a compressor 1, a four-way valve 2, a first heat exchanger 3, a second heat exchanger 4, and a pressure reducing unit 5, and through which a refrigerant circulates. The refrigerant circuit is provided so as to be able to switch between a first state in which the first heat exchanger 3 functions as a condenser and the second heat exchanger 4 functions as an evaporator, and a second state in which the second heat exchanger 4 functions as a condenser and the first heat exchanger 3 functions as an evaporator. The first heat exchanger 3 includes first heat transfer pipes 6 through which refrigerant flows. The first heat transfer pipe 6 has a first tube portion 61 located on the downstream side of the intermediate position of the first heat transfer pipe 6 in the flow direction of the refrigerant when the first heat exchanger 3 functions as a condenser. The first heat exchanger 3 further includes a first containing member 7 disposed inside the first pipe portion 61. Inner diameter D of first pipe portion 61₁And a flow passage cross-sectional area A using the first pipe portion 61₁And the wet circumference length S of the first pipe portion 61₁And the equivalent diameter M calculated from the following relation (1)₁The following relational expression (2) is satisfied in the first state and the second state.

M₁＝4×A₁/S₁…(1)

D₁/2.5<M₁<D₁/1.5…(2)

As described above, when the refrigeration cycle apparatus 100 is in the first state, the refrigerant condenses while flowing through the third tube portion 63, the fourth tube portion 62, and the first tube portion 61 of the first heat transfer tube 6 of the first heat exchanger 3 in this order, and changes from a gas single-phase state to a liquid single-phase state through a gas-liquid two-phase state. On the other hand, when the refrigeration cycle apparatus 100 is in the second state, the refrigerant evaporates while flowing through the first tube portion 61, the fourth tube portion 62, and the third tube portion 63 of the first heat transfer tube 6 of the first heat exchanger 3 in this order, and changes from a gas-liquid two-phase state to a gas single-phase state. That is, the refrigerant flowing through the first tube portion 61 is mainly in a liquid single-phase state in the first state, and is mainly in a gas-liquid two-phase state in the second state. In the first state and the second state, the refrigerant in the liquid single-phase state flows only in the first tube portion 61 of the first heat transfer tube 6, and does not substantially flow in the fourth tube portion 62 and the third tube portion 63.

Since the first containing member 7 is disposed inside the first pipe portion 61 of the first heat transfer pipe 6, the flow path cross-sectional area a of the first pipe portion 61 of the first heat transfer pipe 6 is smaller than the flow path cross-sectional areas of the fourth pipe portion 62 and the third pipe portion 63 of the first heat transfer pipe 6 in which the first containing member 7 is not disposed. Therefore, the flow velocity of the refrigerant in the liquid single-phase state when flowing through the first tube portion 61 is higher than the flow velocity of the refrigerant in the liquid single-phase state when flowing through the conventional heat transfer tube in which the first containing member 7 is not disposed. As a result, the first tube portions 61 in the first state have higher internal heat transfer performance than the conventional heat transfer tube in which the first inner tube member 7 is not disposed.

The heat exchanger provided with the interposer described in patent document 1 does not satisfy the relational expression (2). Specifically, as shown in fig. 9 of patent document 1, the equivalent diameter M of the portion into which the interposer is inserted_rAnd inner diameter D thereof_rSatisfy the relation M_r<D_r/2.5。

In contrast, since the equivalent diameter M of the first pipe portion 61 satisfies the above relational expression (2), the time efficiency of the first heat exchanger 3 of the refrigeration cycle apparatus 100 is improved as compared with the heat exchanger of patent document 1 which does not satisfy the above relational expression (2). Fig. 5 is a graph showing the relationship among the equivalent diameter M of the first pipe portion 61, the heat exchange performance of the first heat exchanger 3 in the first state (line a in fig. 5), the heat exchange performance of the first heat exchanger 3 in the second state (line B in fig. 5), and the period efficiency of the first heat exchanger 3 (line C in fig. 5). The horizontal axis of fig. 5 represents the equivalent diameter M of the first pipe portion 61, and the vertical axis of fig. 5 represents the heat exchange performance and the period efficiency of the first heat exchanger 3.

As shown in FIG. 5, the equivalent diameter M of the first pipe portion 61₁Is set to D₁(ii) equivalent diameter M to that of the first pipe portion 61 in the case of 2.5 or less₁Is set to exceed D₁The efficiency during the first heat exchanger 3 is greatly reduced compared to the case of 2.5.

Referring to line segment B in FIG. 5, the equivalent diameter M at the first tube part 61₁Is set to D₁(ii) equivalent diameter M to that of the first pipe portion 61 in the case of 2.5 or less₁Is set to exceed D₁In comparison with the case of 2.5, the pressure loss of the refrigerant in the gas-liquid two-phase state flowing through the first tube portion 61 in the second state is significantly increased, and the heat exchange performance of the first heat exchanger 3 in the second state is significantly reduced. On the other hand, referring to line segment A in FIG. 5, the equivalent diameter M at the first pipe portion 61₁Is set to D₁(ii) equivalent diameter M to that of the first pipe portion 61 in the case of 2.5 or less₁Is set to exceed D₁In comparison with the case of 2.5, the velocity of the refrigerant in the liquid single-phase state flowing in the first tube portion 61 in the first state does not increase significantly, and therefore the heat exchange performance of the first heat exchanger 3 in the first state is not improved significantly. For the above reasons, the equivalent diameter M of the first pipe portion 61₁Is set to exceed D₁First heat exchanger 3 period efficiency and inner diameter D of 2.5_rIn the heat transfer pipe of (3) has an equivalent diameter M_rIs less than D_rThe heat exchanger of the above patent document 1 of/2.5 has a significantly improved period efficiency as compared with the heat exchanger.

Further, as shown in fig. 5, the equivalent diameter M of the first pipe portion 61₁Is set to D₁At least 1.5, the equivalent diameter M of the first pipe part 61₁Is set to be less than D₁The period efficiency of the first heat exchanger 3 is not sufficiently improved as compared with the case of/1.5. Equivalent diameter M of first pipe portion 61₁Is set to D₁At least 1.5, the equivalent diameter M of the first pipe part 61₁Is set to be less than D₁The pressure loss of the refrigerant in the gas-liquid two-phase state flowing through the first tube portion 61 in the second state is suppressed as compared with the case of/1.5. However, the equivalent diameter M of the first pipe portion 61₁Is set to D₁At least 1.5, the equivalent diameter M of the first pipe part 61₁Is set to be less than D₁In comparison with the case of 1.5, the velocity of the refrigerant in the liquid single-phase state flowing through the first tube portion 61 in the first state is not sufficiently increased, and the heat exchange performance of the first heat exchanger 3 in the first state is not sufficiently improved. For the above reasons, the equivalent diameter M of the first pipe 61₁Is set to D₁The equivalent diameter M of the first pipe portion 61 is smaller than that in the case of 1.5 or more₁Is set to be less than D₁The efficiency of the first heat exchanger 3 of/1.5 is greatly improved.

As shown in fig. 6, the refrigeration cycle apparatus 100 has the equivalent diameter M of the first pipe portion 61₁Is set to exceed D₁2.5, so equivalent diameter M to that of the first pipe portion 61₁Is set to D₁The amount of refrigerant sealed in the refrigerant circuit can be reduced as compared with the case of 2.5 or less. Equivalent diameter M of first pipe portion 61₁Is set to exceed D₁The surface area of the outer peripheral surface of the first content member 7 at/2.5 is larger than the equivalent diameter M of the first pipe portion 61₁Is set to D₁The surface area of the outer peripheral surface of the first receiving member 7 is small when/2.5 or less. Therefore, the residual particle is retained in the equivalent diameter M₁Is set to exceed D₁The refrigerant quantity ratio in the first pipe portion 61 of/2.5 resides in the equivalent diameter M₁Is set to D₁The amount of refrigerant in the first pipe portion 61 of 2.5 or less is small. As a result, the inner diameter D_rIn the heat transfer pipe of (3) has an equivalent diameter M_rIs set to D_rThe amount of refrigerant sealed in the refrigerant circuit of the refrigeration cycle apparatus 100 can be reduced as compared with the amount of refrigerant of patent document 1 below 2.5. In addition, even when the refrigerant and the oil circulate in the refrigerant circuit of the refrigeration cycle apparatus 100, the amount of the oil sealed in the refrigerant circuit can be reduced compared to the amount of the oil of patent document 1 for the same reason as the refrigerant.

In the refrigeration cycle apparatus 100, only one refrigerant flow path is disposed in the first tube portion 61. When a plurality of refrigerant flow paths are arranged in the first tube portion 61, the refrigerant is distributed to the plurality of refrigerant flow paths. In this case, the in-tube heat transfer performance of the first heat transfer tube 6 in the second state is deteriorated depending on the distribution ratio between the plurality of refrigerant flow paths. Therefore, it is necessary to set the distribution ratio between the plurality of refrigerant flow paths so that the in-tube heat transfer performance of the first heat transfer pipe 6 in the second state described above in which the refrigerant in the gas-liquid two-phase state flows through the first tube portion 61 does not deteriorate. In contrast, in the refrigeration cycle apparatus 100, the problem of deterioration of the heat transfer performance in the pipe due to the distribution ratio described above does not occur.

Further, in the heat exchanger of patent document 1, a plurality of refrigerant flow paths defined by the plurality of projections are arranged, and when the heat exchanger functions as an evaporator, a refrigerant in a gas-liquid two-phase state flows around the interposer. However, in the heat exchanger of patent document 1, the distribution ratio of the refrigerant in the gas-liquid two-phase state is not considered. Therefore, the heat exchange performance in the case where the first heat exchanger 3 functions as an evaporator is improved as compared with the heat exchange performance of the heat exchanger of patent document 1.

Embodiment 2.

The refrigeration cycle apparatus according to embodiment 2 has basically the same configuration as the refrigeration cycle apparatus 100 according to embodiment 1, but the length L of the first content member 7 in the axial direction defined as the first pipe portion 61₁(refer to fig. 6) is smaller than the length L of the first heat transfer pipe 6₂(see fig. 6) differs in one third.

At the length L of the first content member 7₁Is the length L of the first heat transfer pipe 6₂More than one third of the total weight of the composition, can be usedA portion where the refrigerant in a liquid single-phase state flows in the first heat transfer pipe 6 is restricted within the first tube portion 61. On the other hand, in this case, in the first state, the refrigerant in the gas-liquid two-phase state flows through the upstream side of the first tube portion 61, and there is a possibility that the pressure loss increases.

In the refrigeration cycle device according to embodiment 2, the length L of the first receiving member 7 is large₁Is less than the length L of the first heat transfer pipe 6₂One third of the above, an increase in pressure loss associated with the refrigerant in the gas-liquid two-phase state flowing through the first tube portion 61 in the first state is suppressed.

The refrigeration cycle apparatus according to embodiment 2 has the same configuration as the refrigeration cycle apparatus 100 according to embodiment 1, in addition to the above configuration, and therefore can provide the same effects as the refrigeration cycle apparatus 100.

Embodiment 3.

As shown in fig. 7 to 10, the refrigeration cycle apparatus according to embodiment 3 has basically the same configuration as the refrigeration cycle apparatus 100 according to embodiment 1, but differs in that a first containing member 71 is provided instead of the first containing member 7. The first containing member 71 is different from the first containing member 7 in that the thermal expansion rate of the material constituting the first containing member 71 is larger than the thermal expansion rate of the material constituting the first heat transfer pipe 6.

In the above-described first state, the first accommodating member 71 is thermally expanded as compared with the first heat transfer pipe 6. The temperature of the liquid single-phase refrigerant flowing through the first tube portion 61 in the first state (hereinafter referred to as a first temperature) is higher than the temperature of the gas-liquid two-phase refrigerant flowing through the first tube portion 61 in the second state (hereinafter referred to as a second temperature). Therefore, the first receiving member 71 in the first state is thermally expanded as compared with the first receiving member 71 in the second state. As a result, in the refrigeration cycle apparatus according to embodiment 3, the flow passage sectional area a of the first tube portion 61 of the first heat transfer tube 6 in the first state is smaller than the flow passage sectional area a of the first tube portion 61 of the first heat transfer tube 6 in the second state.

That is, the first one mentioned aboveEquivalent diameter M of first pipe portion 61 of first heat transfer pipe 6 in this state₃And the equivalent diameter M of the first pipe portion 61 of the first heat transfer pipe 6 in the second state₄Average equivalent diameter M₁The above relation (2) is satisfied, but the equivalent diameter M₃Specific equivalent diameter M₄Is small. That is, the refrigeration cycle apparatus according to embodiment 3 satisfies the following relational expression (7).

D₁/2.5<M₃<M₄<D₁/1.5…(7)

As described above, in the refrigeration cycle apparatus according to embodiment 3, when the first heat exchanger 3 functions as a condenser, the equivalent diameter M of the first tube portion 61 of the first heat transfer tube 6₃Is smaller than the equivalent diameter M of the first tube part 61 of the first heat transfer tube 6 when the first heat exchanger 3 functions as an evaporator₄. Therefore, the period efficiency of the refrigeration cycle apparatus of embodiment 3 is improved as compared with the period efficiency of the refrigeration cycle apparatus 100 of embodiment 1.

For example, the equivalent diameter M in the first state₁When the first content member 71 is designed to have the equivalent diameter equal to that of the refrigeration cycle apparatus 100, the equivalent diameter M in the second state₂Is smaller than the equivalent diameter of the refrigeration cycle device 100. The first heat exchanger 3 provided with the first receiving member 71 has a reduced pressure loss in the first pipe portion 61 in the second state as compared with the first heat exchanger 3 provided with the first receiving member 7, and therefore has improved heat exchange performance.

Further, the equivalent diameter M in the second state₄When the first content member 71 is designed to have the equivalent diameter equal to that of the refrigeration cycle apparatus 100, the equivalent diameter M in the first state₁Is larger than the equivalent diameter of the refrigeration cycle device 100. The first heat exchanger 3 provided with the first containing member 71 has a higher speed of the refrigerant in the liquid single-phase state in the first state than the first heat exchanger 3 provided with the first containing member 7, and therefore, the heat exchange performance is improved.

The refrigeration cycle apparatus according to embodiment 3 has the same configuration as the refrigeration cycle apparatus 100 according to embodiment 1, in addition to the above configuration, and therefore can provide the same effects as the refrigeration cycle apparatus 100. The refrigeration cycle apparatus according to embodiment 3 may have the same configuration as the refrigeration cycle apparatus according to embodiment 2, except for the above configuration.

Embodiment 4.

As shown in fig. 11 to 14, the refrigeration cycle apparatus according to embodiment 4 has basically the same configuration as the refrigeration cycle apparatus 100 according to embodiment 1, but differs in that a first containing member 72 is provided instead of the first containing member 7. The first content member 72 is different from the first content member 7 in that the material constituting the first content member 72 contains a shape memory alloy.

The first content member 72 is arranged to be deformed between the above-mentioned first state and the above-mentioned second state. The first containing member 72 is deformed so that the flow passage sectional area a of the first tube portion 61 of the first heat transfer tube 6 in the first state becomes smaller than the flow passage sectional area a of the first tube portion 61 of the first heat transfer tube 6 in the second state. That is, the equivalent diameter M of the first pipe portion 61 of the first heat transfer pipe 6 in the first state₃And the equivalent diameter M of the first pipe portion 61 of the first heat transfer pipe 6 in the second state₄Average equivalent diameter M₁The above relation (2) is satisfied, but the equivalent diameter M₃Specific equivalent diameter M₄Is small.

The temperature of the liquid single-phase refrigerant flowing through the first tube portion 61 in the first state (hereinafter referred to as a first temperature) is higher than the temperature of the gas-liquid two-phase refrigerant flowing through the first tube portion 61 in the second state (hereinafter referred to as a second temperature).

The transition temperature of the shape memory alloy constituting the first containing member 72 is equal to or lower than the first temperature and exceeds the second temperature. When the temperature of the first containing member 72 is lower than the transition temperature, the first containing member 72 is deformed by, for example, the pressure of the refrigerant in the gas-liquid two-phase state in the second state. When the temperature of the first content member 72 is equal to or higher than the transition temperature, the first content member 72 is restored from the deformed state.

The refrigeration cycle apparatus according to embodiment 4 satisfies the following relational expression (7) as in the refrigeration cycle apparatus according to embodiment 3.

D₁/2.5<M₃<M₄<D₁/1.5…(7)

As described above, in the refrigeration cycle apparatus according to embodiment 4, the equivalent diameter M of the first tube portion 61 of the first heat transfer tube 6 when the first heat exchanger 3 functions as a condenser₁Is smaller than the equivalent diameter M of the first tube part 61 of the first heat transfer tube 6 when the first heat exchanger 3 functions as an evaporator₂. Therefore, the period efficiency of the refrigeration cycle apparatus of embodiment 4 is improved as compared with the period efficiency of the refrigeration cycle apparatus 100 of embodiment 1.

For example, the equivalent diameter M in the first state₁When the first receiving member 72 is designed to have the equivalent diameter equal to that of the refrigeration cycle apparatus 100, the equivalent diameter M in the second state₂Is smaller than the equivalent diameter of the refrigeration cycle device 100. The first heat exchanger 3 provided with the first receiving member 72 has a reduced pressure loss in the first pipe portion 61 in the second state as compared with the first heat exchanger 3 provided with the first receiving member 7, and therefore has improved heat exchange performance.

Further, the equivalent diameter M in the second state₂When the first content member 72 is designed to have the equivalent diameter equal to that of the refrigeration cycle apparatus 100, the equivalent diameter M in the first state₁Is larger than the equivalent diameter of the refrigeration cycle device 100. The first heat exchanger 3 provided with the first containing member 72 has a higher speed of the refrigerant in the liquid single-phase state in the first state than the first heat exchanger 3 provided with the first containing member 7, and therefore, the heat exchange performance is improved.

The refrigeration cycle apparatus according to embodiment 4 has the same configuration as the refrigeration cycle apparatus 100 according to embodiment 1, in addition to the above configuration, and therefore can provide the same effects as the refrigeration cycle apparatus 100. The refrigeration cycle apparatus according to embodiment 4 may have the same configuration as the refrigeration cycle apparatus according to embodiment 2, except for the above configuration.

Embodiment 5.

As shown in fig. 15 and 16, the refrigeration cycle apparatus according to embodiment 5 has a configuration substantially identical to that of the refrigeration cycle apparatus 100 according to embodiment 1, but differs in that a first containing member 73 is provided instead of the first containing member 7. The first containing member 73 is different from the first containing member 7 in that the specific heat of the material constituting the first containing member 73 is larger than the specific heat of the material constituting the first heat transfer pipe 6.

The material constituting the first receiving member 73 includes, for example, aluminum (Al). The heat capacity of the first containing member 73 is larger than the heat capacity of the first pipe portion 61, for example. The first receiving member 73 may be formed of a single material or a plurality of materials. The material constituting the first containing member 73 may include a material having a specific heat equivalent to that of the material constituting the first heat transfer pipe 6 and a material having a specific heat greater than that of the material. The material constituting the first containment member 73 may include, for example, copper (Cu) and any material having a specific heat greater than Cu. In addition, the first containing member 73 may be composed of a profile member provided with an inner space divided from the outside and a filling member filled in the inner space. In this case, the material constituting the outline member may contain Cu, and the material constituting the filling member may contain any material having a specific heat larger than Cu, for example, at least any one of oil and water.

As shown in fig. 17 and fig. 18(a) and (b), the refrigeration cycle apparatus according to embodiment 5 is provided so as to be capable of intermittent operation in the first state. The intermittent operation is an operation in which the state in which the compressor 1 is driven and the state in which the compressor 1 is stopped are alternately switched. An example of the control flow of the intermittent operation in the first state will be described below with reference to a case where the refrigeration cycle apparatus performs the heating operation in the first state.

The refrigeration cycle apparatus according to embodiment 5, when starting the intermittent operation, drives the compressor 1, for example, and maintains the first state until the indoor temperature becomes equal to or higher than the target set temperature. Thereafter, when it is confirmed that the indoor temperature is equal to or higher than the target set temperature, the compressor 1 is stopped, and the circulation of the refrigerant in the refrigerant circuit is also stopped. At this time, when the heat medium that exchanges heat with the refrigerant in the first heat exchanger 3 is air or the like, the fan for supplying air to the first heat exchanger 3 is continuously driven. When the heat medium is brine or the like, the pump for supplying brine to the first heat exchanger 3 is continuously driven. The stop time of the compressor 1 is counted. The fan or the pump is driven until the stop time of the compressor 1 becomes equal to or longer than a set time. Thereafter, when it is confirmed that the stop time of the compressor 1 is equal to or longer than the set time, the fan or the pump is stopped. Thereafter, when it is confirmed that the indoor temperature is lower than the target set temperature, the drive of the compressor 1 and the fan or the pump is restarted.

When such intermittent operation is performed, the frequency of the compressor 1 is controlled as shown in fig. 18 (a). After such intermittent operation, the temperature in the room changes as shown in fig. 18 (b). In fig. 18(a) and (b), a line segment D indicates an intermittent operation state in the refrigeration cycle apparatus according to embodiment 5, and a line segment E indicates an intermittent operation state in the conventional refrigeration cycle apparatus in which the driving of the compressor, the fan, or the pump is stopped at the same time when it is confirmed that the indoor temperature is equal to or higher than the target set temperature.

As shown in fig. 18(a) and (b), in the refrigeration cycle apparatus according to embodiment 5, the number of times the compressor 1 is operated is reduced compared to the conventional refrigeration cycle apparatus, and the temperature in the room is suppressed from decreasing. In a conventional refrigeration cycle apparatus, heat in a heat transfer pipe of an indoor heat exchanger and heat in a refrigerant that has stopped driving a compressor and has accumulated inside the heat transfer pipe are lost relatively quickly by heat exchange with a heat medium present outside the heat transfer pipe. As a result, the temperature in the room after the stop of the driving of the compressor is relatively quickly lowered to be less than the target set temperature.

In contrast, in the refrigeration cycle apparatus according to embodiment 5, while the compressor 1 is driven, a part of the heat of the refrigerant flowing through the first tube portion 61 is stored in the first containing member 73. Therefore, even when the compressor 1 is stopped from being driven, the first heat transfer pipe 6 and the refrigerant accumulated in the first heat transfer pipe 6 can receive the supply of heat from the first containing member 73. As a result, in the refrigeration cycle apparatus according to embodiment 5, compared to the conventional refrigeration cycle apparatus described above, the temperature in the room is gently decreased during the intermittent operation, and therefore, the comfort during the intermittent operation is improved.

In the refrigeration cycle apparatus according to embodiment 5, the stop time of the compressor 1 can be extended as compared with the conventional refrigeration cycle apparatus, and therefore the number of times of driving the compressor 1 within a predetermined time can be reduced. As a result, the refrigeration cycle apparatus according to embodiment 5 has higher reliability than the conventional refrigeration cycle apparatus described above, because power consumption can be reduced and the load on the compressor 1 can be reduced.

The refrigeration cycle apparatus according to embodiment 5 has the same configuration as the refrigeration cycle apparatus 100 according to embodiment 1, in addition to the above configuration, and therefore can provide the same effects as the refrigeration cycle apparatus 100. The refrigeration cycle apparatus according to embodiment 5 may have a configuration similar to that of any of the refrigeration cycle apparatuses according to embodiments 2 to 4, in addition to the above configuration.

Embodiment 6.

As shown in fig. 19 and 20, the refrigeration cycle apparatus according to embodiment 6 has a configuration substantially identical to that of the refrigeration cycle apparatus 100 according to embodiment 1, but differs in the following respects: the first pipe portion 61 has a plurality of protrusions 64, and the plurality of protrusions 64 protrude from the inner circumferential surface 6C facing the outer circumferential surface 7D of the first content member 7.

The plurality of projections 64 extend in the axial direction. Each of the plurality of convex portions 64 has a fifth end portion 64A on the first end portion 6A side and a sixth end portion 64B on the second end portion 6B side in the above-described axial direction. The sixth end 64B and the fourth end 7B of the first receiving member 7 are disposed on the same cross section perpendicular to the axial direction.

The plurality of projections 64 are arranged at intervals in the circumferential direction with respect to the axial direction. The number of the convex portions 64 arranged at intervals in the circumferential direction may be any number of 2 or more, for example, 5. Each of the plurality of projections 64 has, for example, a mutually equivalent structure. The plurality of projections 64 are fixed to the first pipe portion 61. The material constituting the plurality of projections 64 may be any material, and for example, the material has corrosion resistance equivalent to that of the material constituting the first heat transfer pipe 6 with respect to the refrigerant, and includes at least one selected from the group consisting of copper (Cu), rubber, and plastic.

The plurality of protrusions 64 contact the outer peripheral surface 7D of the first content member 7. The plurality of protrusions 64 are provided to maintain the state in which the outer peripheral surface 7D and the inner peripheral surface 6C of the first pipe portion 61 are arranged with a space therebetween. The plurality of protrusions 64 are provided such that the first pipe portion 61 and the first containing member 7 are arranged coaxially. In other words, the plurality of protrusions 64 are provided such that the axis of the first pipe portion 61 coincides with the axis of the first content member 7. The plurality of protrusions 64 suppress the positional displacement of the first content member 7 with respect to the first pipe portion 61 in the direction perpendicular to the axial direction. The plurality of projections 64 also suppress the positional displacement of the first content member 7 in the axial direction with respect to the first pipe portion 61, for example.

The ratio of the distribution of the refrigerant in the gas-liquid two-phase state by the plurality of protrusions 64 is appropriately designed so that the decrease in the heat exchange performance of the first heat exchanger 3 associated with the distribution of the refrigerant in the gas-liquid two-phase state flowing in the first tube portion 61 in the above-described second state by the plurality of protrusions 64 can be suppressed.

The cross-sectional area of the plurality of projections 64 perpendicular to the axial direction, that is, the total value of the cross-sectional areas of the projections 64 perpendicular to the axial direction is smaller than the cross-sectional area of the first content member 7 perpendicular to the axial direction.

The refrigeration cycle apparatus according to embodiment 6 satisfies the above-described relational expression (2) as in the refrigeration cycle apparatus according to embodiment 1. In addition, when the inner diameter D is adjusted₁When the first pipe portion 61 of embodiment 6 and the first pipe portion 61 of embodiment 1 are compared to each other, and the configuration of the first content member 7 is made equivalent, the flow passage cross-sectional area a of the first pipe portion 61 of embodiment 6 is smaller than the flow passage cross-sectional area a of the first pipe portion 61 of embodiment 1, and therefore, the present embodiment is not limited to thisEquivalent diameter M of first pipe portion 61 of formula 6₁Equivalent diameter M of first pipe portion 61 of embodiment 1₁Is small.

In the refrigeration cycle apparatus according to embodiment 6, the plurality of convex portions 64 keep the outer peripheral surface 7D and the inner peripheral surface 6C of the first pipe portion 61 in a spaced-apart arrangement, and therefore, vibration of the first content member 7 due to pulsation of the refrigerant is suppressed. As a result, in the refrigeration cycle apparatus according to embodiment 6, compared to the refrigeration cycle apparatus 100 according to embodiment 1, generation of noise accompanying vibration of the first content member 7 is suppressed, and comfort is improved.

In addition, since the plurality of convex portions 64 prevent the contact between the outer peripheral surface 7D of the first content member 7 and the inner peripheral surface 6C of the first pipe portion 61, the reduction of the heat transfer area in the inner peripheral surface 6C of the first pipe portion 61 is suppressed.

The refrigeration cycle apparatus according to embodiment 6 has the same configuration as the refrigeration cycle apparatus 100 according to embodiment 1, in addition to the above configuration, and therefore can provide the same effects as the refrigeration cycle apparatus 100. The refrigeration cycle apparatus according to embodiment 6 may have a configuration similar to that of any of the refrigeration cycle apparatuses according to embodiments 2 to 5, in addition to the above configuration.

As shown in fig. 19 and 20, a plurality of grooves may be disposed on the inner circumferential surface 6C of the first pipe portion 61. The plurality of grooves are arranged at intervals in the circumferential direction. Between the two circumferentially adjacent grooves, a plurality of minute protrusions 65 or a plurality of protrusions 64 are disposed so as to protrude from the bottom of the groove. That is, each of the convex portions 64 is disposed between two adjacent groove portions in the circumferential direction. In a cross section perpendicular to the axial direction, the distal end portion of each minute convex portion 65 has, for example, an intersection point at which two curved surfaces intersect with each other while forming an acute angle. The height of each convex portion 64 with respect to the inner peripheral surface 6C is higher than the height of each minute convex portion 65 with respect to the inner peripheral surface 6C. The number of the minute projections 65 arranged at intervals in the circumferential direction may be any number of 2 or more, and may exceed the number of the plurality of projections 64. Each of the plurality of minute protrusions 65 has, for example, a mutually equivalent structure.

When the plurality of minute protrusions 65 are provided in the first pipe portion 61, the heat exchange performance of the first heat exchanger 3 is improved because the heat transfer area in the inner peripheral surface 6C of the first pipe portion 61 is increased as compared with the case where the plurality of minute protrusions 65 are not provided.

Embodiment 7.

As shown in fig. 21 and 22, the refrigeration cycle apparatus according to embodiment 7 has a configuration substantially identical to that of the refrigeration cycle apparatus according to embodiment 6, but differs in that the plurality of projections 64 are disposed at intervals in the axial direction. That is, the plurality of projections 64 are arranged at intervals in the circumferential direction with respect to the axial direction, and are also arranged at intervals in the axial direction.

The number of the convex portions 64 arranged at intervals in the axial direction may be any number of 2 or more, for example, 3. Each of the plurality of projections 64 has, for example, a mutually equivalent structure.

The refrigeration cycle apparatus according to embodiment 7 satisfies the above-described relational expression (2) as in the refrigeration cycle apparatus according to embodiment 1.

In the refrigeration cycle apparatus according to embodiment 7, since the plurality of projections 64 are arranged at intervals from each other in the axial direction, the occurrence of pressure loss due to the plurality of projections 64 is suppressed as compared with the refrigeration cycle apparatus according to embodiment 6. As a result, in the refrigeration cycle apparatus according to embodiment 7, the heat exchange performance of the first heat exchanger 3 in the second state is improved and the period efficiency is improved as compared with the refrigeration cycle apparatus according to embodiment 6.

The refrigeration cycle apparatus according to embodiment 7 has the same configuration as the refrigeration cycle apparatus 100 according to embodiment 1, in addition to the above configuration, and therefore can provide the same effects as the refrigeration cycle apparatus 100. The refrigeration cycle apparatus according to embodiment 7 may have a configuration similar to that of any of the refrigeration cycle apparatuses according to embodiments 2 to 5, in addition to the above configuration.

< modification example >

In the refrigeration cycle apparatuses according to embodiments 1 to 7, the first heat exchanger 3 may include the first containing

members

7, 71, 72, and 73, and the second heat exchanger 4 may include the second containing members having the same configuration as any of the first containing

members

7, 71, 72, and 73. Fig. 23 shows a configuration in which the second heat exchanger 4 includes a second receiving member 9, and the second receiving member 9 has the same configuration as the first receiving member 7.

As shown in fig. 23 and 24, the second heat exchanger 4 includes a plurality of second heat transfer pipes 8, and the plurality of second heat transfer pipes 8 have the same configuration as the first heat transfer pipes 6 of the first heat exchanger 3. Each of the second heat transfer pipes 8 can be divided into: the fifth tube portions 83 located upstream of the intermediate positions of the second heat transfer tubes 8 in the refrigerant flow direction F2 in the second state, the sixth tube portions 82 including the intermediate positions of the second heat transfer tubes 8 and located downstream of the fifth tube portions 83 in the direction F2, and the second tube portions 81 located downstream of the sixth tube portions 82 in the direction F2. The second tube portions 81 of the second heat transfer tubes are portions located on the downstream side of the intermediate positions of the second heat transfer tubes 8 in the refrigerant flow direction F2 when the second heat exchanger 4 functions as a condenser. The second tube portion 81 of the second heat transfer tube corresponds to the first tube portion 61 of the first heat transfer tube 6, the sixth tube portion 82 of the second heat transfer tube 8 corresponds to the fourth tube portion 62 of the first heat transfer tube 6, and the fifth tube portion 83 of the second heat transfer tube 8 corresponds to the third tube portion 63 of the first heat transfer tube 6. The second tube portion 81 of the second heat transfer tube 8 includes a portion through which the liquid-phase refrigerant flows when the refrigeration cycle apparatus is in the second state. The second tube portion 81 of the second heat transfer tube 8 includes a portion through which, for example, a gas-liquid two-phase refrigerant flows when the refrigeration cycle apparatus is in the first state.

When the second heat exchanger 4 includes a plurality of second content members 9, each of the second content members 9 is disposed inside the second tube portion 81 of each of the second heat transfer tubes 8. In this case, the equivalent diameter M to the first pipe portion 61 of the first heat transfer pipe 6₁Similarly, the cross-sectional area A of the flow path of the second pipe 81 is used₂And the wet circumference length S of the second pipe part 81₂And calculating the second heat transfer pipe according to the following relational expression (3)Equivalent diameter M of second pipe portion 81 of 8₂。

M₂＝4×A₂/S₂…(3)

And, an equivalent diameter M₂And the inner diameter D of the second pipe part 81₂The first state and the second state satisfy the following relational expression (4).

D₂/2.5<M₂<D₂/1.5…(4)

In addition, the heat exchange performance in the above-described second state of this second heat exchanger 4 is indicated by a line segment a in fig. 5, the heat exchange performance in the above-described first state is indicated by a line segment B in fig. 5, and the term efficiency is indicated by a line segment C in fig. 5.

Therefore, the tube internal heat transfer performance of the second tube portions 81 of the second heat transfer tube 8 in the second state is higher than that in the case where the second content member 9 is not disposed. The term efficiency of the second heat exchanger 4 is higher than that of a heat exchanger provided with an interposer that does not satisfy the relational expression (4). The second content member may have the same configuration as the

first content members

71, 72, and 73.

The first containing

member

7, 71, 72, 73 may be disposed inside the first tube part 61 of at least one of the plurality of first heat transfer tubes 6 of the first heat exchanger 3. The second content member 9 may be disposed inside the second tube portion 81 of at least one of the plurality of second heat transfer tubes 8 of the second heat exchanger 4.

As described above, the embodiments of the present invention have been described, but the above embodiments can be variously modified. The scope of the present invention is not limited to the above embodiments. The scope of the present invention is indicated by the appended claims, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Description of reference numerals

1 compressor, 2 four-way valve, 3 first heat exchanger, 4 second heat exchanger, 5 decompression section, 6 first heat transfer pipe, 6A first end section, 6B second end section, 6C inner peripheral surface, 6D, 7D outer peripheral surface, 7, 71, 72, 73 first content member, 7A third end section, 7B fourth end section, 8 second heat transfer pipe, 9 second content member, 30 heat exchange section, 31, 32 distributor, 61 first pipe section, 62 fourth pipe section, 63 third pipe section, 64 convex section, 64A fifth end section, 64B sixth end section, 65 micro convex section, 81 second pipe section, 82 sixth pipe section, 83 fifth pipe section, 100 refrigeration cycle device.

Claims

1. A refrigeration cycle apparatus, wherein,

the refrigeration cycle device is provided with a refrigerant circuit which comprises a compressor, a flow path switching valve, a first heat exchanger, a second heat exchanger and a decompression part and is used for circulating refrigerant,

the refrigerant circuit is provided so as to be capable of switching between a first state in which the first heat exchanger functions as a condenser and the second heat exchanger functions as an evaporator and a second state in which the second heat exchanger functions as a condenser and the first heat exchanger functions as an evaporator,

the first heat exchanger includes a first heat transfer pipe through which a refrigerant flows,

the first heat transfer pipe has a first pipe portion located on a downstream side of an intermediate position of the first heat transfer pipe in a flow direction of the refrigerant in the first state,

the first heat exchanger further includes a first content member disposed inside the first tube part,

a flow path cross-sectional area A using the first pipe part₁And a wet circumference length S of the first pipe portion₁And the equivalent diameter M calculated from the following relation (1)₁And the inner diameter D of the first pipe part₁Satisfies the following relational expression (2) in the first state and the second state,

M₁＝4×A₁/S₁…(1)

D₁/2.5<M₁<D₁/1.5…(2)。

2. the refrigeration cycle apparatus according to claim 1,

the length of the first content member in the axial direction of the first pipe portion is less than one third of the length of the first heat transfer pipe.

3. The refrigeration cycle device according to claim 1 or 2, wherein,

a thermal expansion rate of a material constituting the first containing member is larger than a thermal expansion rate of a material constituting the first heat transfer pipe,

the equivalent diameter in the first state is less than the equivalent diameter in the second state.

4. The refrigeration cycle device according to claim 1 or 2, wherein,

the material of which the first content member is made comprises a shape memory alloy,

the equivalent diameter when functioning as a condenser is smaller than the equivalent diameter in the second state.

5. The refrigeration cycle device according to any one of claims 1 to 4, wherein,

the specific heat of the material constituting the first containing member is larger than the specific heat of the material constituting the first heat transfer pipe.

6. The refrigeration cycle device according to any one of claims 1 to 5, wherein,

the first pipe portion has a plurality of protruding portions protruding from an inner peripheral surface facing an outer peripheral surface of the first content member,

the plurality of projections are in contact with the outer peripheral surface.

7. The refrigeration cycle apparatus according to claim 6, wherein,

the plurality of projections are arranged at intervals in a circumferential direction with respect to an axis of the first pipe portion.

8. The refrigeration cycle device according to any one of claims 1 to 7, wherein,

the second heat exchanger includes a second heat transfer pipe through which a refrigerant flows,

the second heat transfer pipe has a second tube portion located on a downstream side of an intermediate position of the second heat transfer pipe in a flow direction of the refrigerant in the second state,

the second heat exchanger further includes a second content member disposed inside the second tube portion of the second heat transfer pipe,

inner diameter D of the second pipe portion₂And a flow path cross-sectional area A using the second pipe portion₂And a wet circumference length S of the second pipe portion₂And the equivalent diameter M calculated from the following relation (3)₂Satisfies the following relational expression (4) in the first state and the second state,

M₂＝4×A₂/S₂…(3)

D₂/2.5<M₂<D₂/1.5…(4)。