WO2021205536A1

WO2021205536A1 - Refrigeration cycle device

Info

Publication number: WO2021205536A1
Application number: PCT/JP2020/015651
Authority: WO
Inventors: 伊東　大輔
Original assignee: 三菱電機株式会社
Priority date: 2020-04-07
Filing date: 2020-04-07
Publication date: 2021-10-14
Also published as: JPWO2021205536A1; JP7341326B2; EP4134601A1; EP4134601A4

Abstract

This refrigeration cycle device (100) comprises: a compressor; a four-way valve; a first heat exchanger (3) including a first outflow/inflow section (3A) and a second outflow/inflow section (3B) into and out of which a non-azeotropic mixed refrigerant flows, and first pipe sections (31A) and second pipe sections (32A) that are serially connected to each other between the first outflow/inflow section and the second outflow/inflow section and through which the non-azeotropic mixed refrigerant flows; a decompression device; and a second heat exchanger (6). The non-azeotropic mixed refrigerant includes a refrigerant which has the property of causing a disproportionation reaction and a refrigerant which does not have the property of causing a disproportionation reaction. The four-way valve switches between a first state in which the non-azeotropic mixed refrigerant flows through the compressor, the first heat exchanger, the decompression device, and the second heat exchanger in this order and a second state in which the non-azeotropic mixed refrigerant flows through these components in the opposite direction from when in the first state. When in the first state, the non-azeotropic mixed refrigerant flows through the first outflow/inflow sections, the first pipe sections, the second pipe sections, and the second outflow/inflow section in this order within the first heat exchanger. When in the second state, the non-azeotropic mixed refrigerant flows through the second outflow/inflow section, the second pipe sections, the first pipe sections, and the first outflow/inflow section in this order within the first heat exchanger. The area expansion rate of first inner circumferential surfaces in the first pipe sections is higher than the area expansion rate of second inner circumferential surfaces in the second pipe sections.

Description

Refrigeration cycle equipment

This disclosure relates to a refrigeration cycle device.

HFO1123 is known as a refrigerant having a low global warming potential (GWP: Global Warming Potential) (low GWP refrigerant). On the other hand, HFO1123 has a property of causing a disproportionation reaction (autolysis reaction) and is flammable.

International Publication No. 2020/003494 (Patent Document 1) discloses a refrigeration cycle apparatus in which a non-azeotropic mixed refrigerant containing R32, CF3I, and HFO1123 is sealed. In the refrigeration cycle apparatus of Patent Document 1, each weight ratio of R32, CF3I, and HFO1123 in the non-azeotropic mixed refrigerant sealed in the refrigeration cycle apparatus is specified. As a result, HFO1123 is mixed with CF3I and R32, the disproportionation reaction of HFO1123 is suppressed, the temperature gradient of the non-azeotropic mixed refrigerant is suppressed, and the performance deterioration is suppressed.

International Publication No. 2020/003494

The magnitude relationship of the densities of R32, CF3I, and HFO1123 changes depending on whether they are in the liquid phase state or the gas phase state. When each is in a liquid phase state, the density of CF3I is higher than that of R32 and HFO1123, respectively. On the other hand, when each is in the gas phase, the density of CF3I is lower than the density of R32 and HFO1123, respectively. Therefore, in a non-azeotropic mixed refrigerant containing R32, CF3I, and HFO1123, CF3I is less likely to mix with R32 and HFO1123. When CF3I is not sufficiently mixed with R32 and HFO1123, CF3I is less likely to contribute to the action of suppressing the disproportionation reaction of HFO1123, and the contribution of CF3I to the action is greater than the contribution of R32 to the action. It gets lower.

A main object of the present disclosure is the disproportionation reaction of a refrigerant having a characteristic of causing a disproportionation reaction and a refrigerant having a characteristic of causing a disproportionation reaction because the refrigerant having a characteristic of causing a disproportionation reaction is easily mixed. It is an object of the present invention to provide a refrigerating cycle apparatus in which the occurrence of the above is less likely to occur and the deterioration of the performance is suppressed.

The refrigeration cycle device according to the present disclosure is a refrigeration cycle device in which a non-azeotropic mixed refrigerant is used. The refrigeration cycle device is in series with the compressor, the flow path switching section, the first inflow / outflow section and the second inflow / outflow section where the non-azeotropic mixed refrigerant flows in / out, and the first inflow / outflow section and the second inflow / outflow section. It is provided with a first heat exchanger including a first pipe portion and a second pipe portion connected to the above and through which a non-azeotropic mixed refrigerant flows, a decompression device, and a second heat exchanger. The non-azeotropic mixed refrigerant includes a refrigerant having a characteristic of causing a disproportionation reaction and a refrigerant having no characteristic of causing a disproportionation reaction. The flow path switching section has a first state in which the non-azeotropic mixed refrigerant flows through the compressor, the first heat exchanger, the decompression device, and the second heat exchanger in the order described, and a first state in which the non-azeotropic mixed refrigerant flows. Switches from the second state, which flows in the opposite direction. In the first state, the non-azeotropic mixed refrigerant flows in the first heat exchanger in the order of the first inflow / outflow portion, the first pipe portion, the second pipe portion, and the second inflow / outflow portion. In the second state, the non-azeotropic mixed refrigerant flows in the first heat exchanger in the order of the second inflow / outflow portion, the second pipe portion, the first pipe portion, and the first inflow / outflow portion. The first pipe portion has a first inner peripheral surface on which irregularities are formed. The second pipe portion has a second inner peripheral surface on which irregularities are formed. The area expansion ratio of the first inner peripheral surface of the first pipe portion is higher than the area expansion ratio of the second inner peripheral surface of the second pipe portion.

The refrigeration cycle apparatus according to the present disclosure is in the middle of heat exchange between the first refrigerant circuit in which the first refrigerant circulates, the second refrigerant circuit in which the second refrigerant circulates, and the first refrigerant and the second refrigerant. Equipped with a heat exchanger. The first refrigerant circuit includes a compressor that compresses the first refrigerant, a flow path switching section, a third heat exchanger that exchanges heat between the first refrigerant and air, and a depressurization that reduces the pressure of the first refrigerant. It includes an apparatus and a first flow path through which a first refrigerant passes in an intermediate heat exchanger. In the second refrigerant circuit, heat exchange is performed between the pump that boosts and conveys the second refrigerant, the second flow path through which the second refrigerant passes in the intermediate heat exchanger, and the second refrigerant and air. Includes 4 heat exchangers. The first refrigerant is a non-azeotropic mixed refrigerant containing a refrigerant having a characteristic of causing a disproportionation reaction and a refrigerant having a characteristic of not causing a disproportionation reaction. The intermediate heat exchanger includes a fifth inflow / outflow section and a sixth inflow / outflow section in which the first refrigerant flows in and out of the first flow path. The fifth inflow / outflow section is arranged above the sixth inflow / outflow section. In the flow path switching section, the first state in which the non-azeotropic mixed refrigerant flows through the compressor, the third heat exchanger, the decompression device, and the intermediate heat exchanger in the order described in this description, and the first state in which the non-azeotropic mixed refrigerant flows are Switch to the second state that flows in the opposite direction. In the first state, the non-azeotropic mixed refrigerant flows in the intermediate heat exchanger from the fifth inflow / outflow portion toward the sixth inflow / outflow portion. In the second state, the non-azeotropic mixed refrigerant flows in the intermediate heat exchanger from the sixth inflow / outflow portion toward the fifth inflow / outflow portion.

According to the present disclosure, a refrigerant having a characteristic of causing a disproportionation reaction and a refrigerant having a characteristic of causing a disproportionation reaction are likely to be mixed, and the disproportionation reaction of a refrigerant having a characteristic of causing a disproportionation reaction is carried out. It is possible to provide a refrigeration cycle apparatus that is less likely to occur and whose performance deterioration is suppressed.

It is a block diagram which shows the refrigeration cycle apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the heat exchanger of the refrigeration cycle apparatus which concerns on Embodiment 1. FIG. It is sectional drawing of the upper heat transfer tube of the heat exchanger shown in FIG. It is sectional drawing of the lower heat transfer tube of the heat exchanger shown in FIG. It is a partial cross-sectional view of the upper heat transfer tube of the 1st modification of the refrigerating cycle apparatus which concerns on Embodiment 1. FIG. It is a partial cross-sectional view of the lower heat transfer tube of the 1st modification of the refrigerating cycle apparatus which concerns on Embodiment 1. FIG. It is a partial cross-sectional view of the upper heat transfer tube of the 2nd modification of the refrigerating cycle apparatus which concerns on Embodiment 1. FIG. It is a partial cross-sectional view of the lower heat transfer tube of the 2nd modification of the refrigerating cycle apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the modification of the heat exchanger of the refrigerating cycle apparatus which concerns on Embodiment 1. FIG. It is a partial cross-sectional view of the upper heat transfer tube of the 3rd modification of the refrigeration cycle apparatus which concerns on Embodiment 1. FIG. It is a partial cross-sectional view of the lower heat transfer tube of the 3rd modification of the refrigeration cycle apparatus which concerns on Embodiment 1. FIG. It is a partial cross-sectional view of the upper heat transfer tube of the 4th modification of the refrigeration cycle apparatus which concerns on Embodiment 1. FIG. It is a partial cross-sectional view of the lower heat transfer tube of the 4th modification of the refrigeration cycle apparatus which concerns on Embodiment 1. FIG. It is a block diagram which shows the refrigeration cycle apparatus which concerns on Embodiment 2. It is a figure which shows the heat exchanger of the refrigeration cycle apparatus which concerns on Embodiment 2. When a mixed refrigerant of a liquid phase containing R32, CF3I, HFO1123, and an incompatible oil and having a liquid temperature of 10 ° C. flows in a circular tube having a smooth inner peripheral surface and extending in the horizontal direction, respectively. It is a schematic diagram which shows the distribution of a component. When a mixed refrigerant of a liquid phase containing R32, CF3I, HFO1123, and an incompatible oil and having a liquid temperature of 60 ° C. flows in a circular tube having a smooth inner peripheral surface and extending in the horizontal direction, respectively. It is a schematic diagram which shows the distribution of a component. Ease of distribution of each component when the mixed refrigerant of the gas phase containing R32, CF3I, HFO1123, and incompatible oil flows through a circular tube having a smooth inner peripheral surface and extending in the horizontal direction. It is a schematic diagram which shows.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings below, the same or corresponding parts are given the same reference number and the explanation is not repeated.

Embodiment 1.
The refrigeration cycle device 100 according to the first embodiment is configured as, for example, a RAC (Room Air Conditioner). As shown in FIG. 1, the refrigeration cycle device 100 includes an outdoor unit 110 and an indoor unit 120. The outdoor unit 110 includes a compressor 1, a four-way valve 2 (flow path switching unit), an outdoor heat exchanger 3 (first heat exchanger), an expansion valve 4A (pressure reducing device), and an expansion valve 4B (pressure reducing device). ), The receiver 5 (refrigerant container), the control device 10, the outdoor fan 11, and the temperature sensor 13. The indoor unit 120 includes an indoor heat exchanger 6 (second heat exchanger) and an indoor fan 12.

Refrigeration cycle device 100 includes non-azeotropic boiling including R32 (difluoromethane (CH ₂ F ₂ )), CF _{3I (trifluoroiodomethane (CF 3} I)), and HFO 1123 (trifluoroethylene (CF _{2 = CHF)).} A mixed refrigerant is used.

The weight ratio of R32 in the non-azeotropic mixed refrigerant sealed in the refrigeration cycle apparatus 100 is, for example, 43 wt% or less. The weight ratio of CF3I in the non-azeotropic mixed refrigerant sealed in the refrigeration cycle apparatus 100 is, for example, equal to or less than the weight ratio of R32. The weight ratio of HFO1123 in the non-azeotropic mixed refrigerant sealed in the refrigeration cycle apparatus 100 is, for example, 14 wt% or more. From the viewpoint of suppressing the disproportionation reaction, when the weight ratio of HFO1123 is 60 wt% or more, the weight ratio of CF3I is preferably 2 wt% or more, more preferably about 5 wt%. That is, when the weight ratio of HFO1123 is 60 wt% or more, the weight ratio of CF3I is 2 wt% or more and 5 wt% or less. When the weight ratio of HFO1123 is 60 wt% or more, the disproportionation reaction of HFO1123 is suppressed when the weight ratio of CF3I is more than 2 wt%, and the disproportionation reaction of HFO1123 when the weight ratio of CF3I is about 5 wt%. Is sufficiently suppressed. For example, the weight ratio between HFO1123, R32, and CF3I is HFO1123: R32: CF3I = 65 wt%: 30 wt%: 5 wt%. Weight ratio of R32 so that the regulations on refrigerants (for example, Montreal Protocol or F-gas regulations) are satisfied even if the amount of non-azeotropic mixed refrigerant used increases with the increase in the number of refrigeration cycle devices shipped. It is desirable to further reduce GWP by setting 30 wt% or less. The GWP of R32 is 675, the GWP of CF3I is about 0.4, and the GWP of HFO1123 is about 0.3. The GWP of the non-azeotropic mixed refrigerant is lower than the GWP of R32.

The standard boiling points of R32, CF3I, and HFOR1123 are −52 ° C., −22 ° C., and −59 ° C., respectively. Due to the different boiling points of each, the concentration distribution described later occurs in the non-azeotropic mixed refrigerant of the gas phase.

The total weight ratio of HFO1123, R32 and CF3I in the non-azeotropic mixed refrigerant sealed in the refrigeration cycle apparatus 100 is preferably 99.5 wt% or more, more preferably 99.7 wt% or more. Most preferably, it is 99.9 wt% or more.

As long as the reduction of GWP is not hindered, the non-cobo-boiling mixed refrigerant is a refrigerant other than R32, CF3I, and HFO1123 (for example, R1234yf (for example, 2,3,3,3-tetrafluoropropene (CF ₃ CF = CH)). ₂ )), R1234ze (E) (trans-1,3,3,3-tetrafluoropropene (trans-CF ₃ CH = CHF), R290 (propane (C ₃ H ₈ )), CO ₂ (carbon dioxide), Alternatively, it may contain R1132 (trans-1,2, difluoroethylene). R1132 has a property of causing an disproportionate reaction (self-decomposition reaction).

For the compressor 1, an incompatible oil that is incompatible with the non-azeotropic mixed refrigerant is used as the lubricating oil. The incompatible oil comprises at least one selected from the group consisting of, for example, alkylbenzene oils, mineral oils, naphthalene mineral oils and polyalphaolefin oils.

The four-way valve 2 has a first port connected to the discharge port of the compressor 1, a second port connected to the suction port of the compressor 1 via the receiver 5, and an upper outflow of the outdoor heat exchanger 3. It has a third port connected to the inlet 3A and a fourth port connected to the upper inflow / outflow section 6A of the indoor heat exchanger 6. The four-way valve 2 has a first state in which the outdoor heat exchanger 3 acts as a condenser and the indoor heat exchanger 6 acts as an evaporator, and the indoor heat exchanger 6 acts as a condenser and the outdoor heat exchanger 3 evaporates. It is formed to switch between the second state, which acts as a vessel. The first state is realized during the cooling operation and the second state is realized during the heating operation.

As shown in FIG. 2, the outdoor heat exchanger 3 is, for example, a fin tube heat exchanger. The outdoor heat exchanger 3 includes an upper inflow / outflow section 3A (first inflow / outflow section) and a lower inflow / outflow section 3B (second inflow / outflow section), and an upper inflow / outflow section 3A and a lower inflow / outflow section 3B. A plurality of upper heat transfer tubes 31A (first tube section) and a plurality of lower heat transfer tubes 31B (second tube section) connected in series with each other were connected to each upper heat transfer tube 31A and each lower heat transfer tube 31B. It has a plurality of fins 32.

The upper inflow / outflow section 3A is arranged above the lower inflow / outflow section 3B. The upper inflow / outflow portion 3A is connected to the third port of the four-way valve 2 via an extension pipe. The lower inflow / outflow portion 3B is connected to the expansion valve 4A. Each of the plurality of upper heat transfer tubes 31A is arranged above each of the plurality of lower heat transfer tubes 31B. Each of the plurality of upper heat transfer tubes 31A is arranged above the center of the outdoor heat exchanger 3 in, for example, the vertical direction A. Each of the plurality of lower heat transfer tubes 31B is arranged below the center of the outdoor heat exchanger 3 in, for example, the vertical direction A. Each upper heat transfer tube 31A and each lower heat transfer tube 31B extends along a direction B intersecting the vertical direction A.

One end of the direction B of the upper heat transfer tube 31A arranged at the lowermost position among the plurality of upper heat transfer tubes 31A is, for example, one end of the direction B of the lower heat transfer tube 31B arranged at the uppermost position among the plurality of lower heat transfer tubes 31B. Is connected in series via a bent portion 31C. One end of each of the upper heat transfer tubes 31A other than the lowermost upper heat transfer tube 31A arranged in the direction B of the plurality of upper heat transfer tubes 31A is connected in series with each other via the bent portion 31C. One end of the direction B of each of the lower heat transfer tubes 31B other than the lower heat transfer tube 31B arranged at the uppermost of the plurality of lower heat transfer tubes 31B is connected in series with each other via the bent portion 31C. In the outdoor heat exchanger 3, the upper inflow / outflow section 3A, the plurality of upper heat transfer tubes 31A, the plurality of lower heat transfer tubes 31B, and the lower inflow / outflow section 3B are connected in series in the order described.

The plurality of fins 32 are arranged side by side at intervals in the direction B. Each of the plurality of upper heat transfer tubes 31A and the plurality of lower heat transfer tubes 31B penetrates each fin 32.

As shown in FIG. 2, the indoor heat exchanger 6 is, for example, a fin tube heat exchanger. The indoor heat exchanger 6 includes an upper inflow / outflow section 6A (third inflow / outflow section) and a lower inflow / outflow section 6B (fourth inflow / outflow section) through which the non-azeotropic mixed refrigerant flows in and out, and an upper inflow / outflow section 6A and a lower inflow / outflow section 6B. A plurality of upper heat transfer tubes 61A (third tube section) and a plurality of lower heat transfer tubes 61B (fourth tube section) connected in series with each other were connected to each upper heat transfer tube 61A and each lower heat transfer tube 61B. It has a plurality of fins 62.

The upper inflow / outflow section 6A is arranged above the lower inflow / outflow section 6B. The upper inflow / outflow portion 6A is connected to the fourth port of the four-way valve 2 via an extension pipe. The lower inflow / outflow portion 6B is connected to the expansion valve 4B via an extension pipe. Each of the plurality of upper heat transfer tubes 61A is arranged above each of the plurality of lower heat transfer tubes 61B. Each of the plurality of upper heat transfer tubes 61A is arranged above the center of the indoor heat exchanger 6 in, for example, the vertical direction A. Each of the plurality of lower heat transfer tubes 61B is arranged below the center of the indoor heat exchanger 6 in, for example, the vertical direction A. Each upper heat transfer tube 61A and each lower heat transfer tube 61B extend along a direction B intersecting the vertical direction A.

One end of the direction B of the upper heat transfer tube 61A arranged at the lowermost position among the plurality of upper heat transfer tubes 61A is, for example, one end of the direction B of the lower heat transfer tube 61B arranged at the uppermost position among the plurality of lower heat transfer tubes 61. Is connected in series via a bent portion 61C. One end of each of the upper heat transfer tubes 61A other than the lowermost upper heat transfer tube 61A arranged in the direction B of the plurality of upper heat transfer tubes 61A is connected in series with each other via a bent portion 61C. One end of each of the lower heat transfer tubes 61B other than the lower heat transfer tube 61B arranged at the uppermost of the plurality of lower heat transfer tubes 61B in the direction B is connected in series with each other via the bent portion 61C. In the indoor heat exchanger 6, the upper inflow / outflow section 6A, the plurality of upper heat transfer tubes 61A, the plurality of lower heat transfer tubes 61B, and the lower inflow / outflow section 6B are connected in series in the order described.

The plurality of fins 62 are arranged side by side at intervals in the direction B. Each of the plurality of upper heat transfer tubes 61A and the plurality of lower heat transfer tubes 61B penetrates each fin 62.

As shown in FIGS. 3 and 4, each upper heat transfer tube 31A and each lower heat transfer tube 31B are configured as circular tubes.

As shown in FIG. 3, each upper heat transfer tube 31A has a first inner peripheral surface 33A in which irregularities are formed. The first inner peripheral surface 33A is a surface in contact with the non-azeotropic mixed refrigerant flowing inside the upper heat transfer tube 31A. A plurality of first groove portions 34A are formed on the first inner peripheral surface 33A. The configurations of the first groove portions 34A are, for example, equal to each other. The first groove portions 34A are arranged so as to be spaced apart from each other in the circumferential direction of the upper heat transfer tube 31A. Each first groove portion 34A extends spirally with respect to the central axis O of the upper heat transfer tube 31A. The width of each of the first groove portions 34A in the circumferential direction is formed so as to become narrower toward the outer circumference in the radial direction of the upper heat transfer tube 31A, for example.

As shown in FIG. 4, each lower heat transfer tube 31B has a second inner peripheral surface 33B on which irregularities are formed. The second inner peripheral surface 33B is a surface in contact with the non-azeotropic mixed refrigerant flowing inside the lower heat transfer tube 31B. A plurality of second groove portions 34B are formed on the second inner peripheral surface 33B. The configurations of the second groove portions 34B are, for example, equal to each other. The second groove portions 34B are arranged so as to be spaced apart from each other in the circumferential direction of the lower heat transfer tube 31B. Each second groove 34B extends spirally with respect to the central axis O of the lower heat transfer tube 31B. The width of each of the second groove portions 34B in the circumferential direction is formed so as to become narrower toward the outer circumference of the lower heat transfer tube 31B in the radial direction, for example.

The outer shape of each upper heat transfer tube 31A is the same as the outer shape of each lower heat transfer tube 31B, for example. The outer diameter of each upper heat transfer tube 31A is equal to, for example, the outer diameter of each lower heat transfer tube 31B. The inner diameter of each upper heat transfer tube 31A is equal to, for example, the inner diameter of each lower heat transfer tube 31B.

The area of each of the first inner peripheral surface 33A of the upper heat transfer tube 31A and the second inner peripheral surface 33B of the lower heat transfer tube 31B is equal to the inner diameter of the first inner peripheral surface 33A and the second inner peripheral surface 33B, but the groove portion. Is larger than the area of the inner peripheral surface where is not formed. In other words, the area expansion ratio of the first inner peripheral surface 33A of the upper heat transfer tube 31A and the second inner peripheral surface 33B of the lower heat transfer tube 31B is 1 or more. The area expansion ratios of the first inner peripheral surface 33A and the second inner peripheral surface 33B are the same as the inner diameters of the first inner peripheral surface 33A and the second inner peripheral surface 33B when the lengths in the directions B are equal to each other and the inner diameter is the same as the inner diameter of the first inner peripheral surface 33A and the second inner peripheral surface 33B. The ratio is based on the area of the inner peripheral surface that is equal but has no groove.

The area expansion rate of the first inner peripheral surface 33A of the upper heat transfer tube 31A (first tube portion) is higher than the area expansion rate of the second inner peripheral surface 33B of the lower heat transfer tube 31B (second tube portion). As shown in FIG. 3, the number of rows of the first groove portion 34A is defined as the number of the first groove portions 34A arranged side by side in the circumferential direction in the cross section perpendicular to the axial direction of the upper heat transfer tube 31A. .. As shown in FIG. 4, the number of rows of the second groove portion 34B is defined as the number of the second groove portions 34B arranged side by side in the circumferential direction in the cross section perpendicular to the axial direction of the lower heat transfer tube 31B. .. The number of rows of the first groove portion 34A is larger than the number of rows of the second groove portion 34B. In other words, the width of each first groove portion 34A in the circumferential direction is narrower than the width of each second groove portion 34B in the circumferential direction. In the upper heat transfer tube 31A and the lower heat transfer tube 31B shown in FIGS. 3 and 4, the first inner peripheral surface of the upper heat transfer tube 31A is due to the above-mentioned magnitude relationship of the number of rows between the first groove portion 34A and the second groove portion 34B. The above magnitude relationship of the area expansion ratio between 33A and the second inner peripheral surface 33B of the lower heat transfer tube 31B is realized.

In this case, the depth of each first groove 34A (details will be described later) is equal to, for example, the depth of each second groove 34B. The lead angle of each first groove 34A (details will be described later) is, for example, equal to the lead angle of each second groove 34B. The tube wall thickness of each upper heat transfer tube 31A (details will be described later) is, for example, equal to the tube wall thickness of each lower heat transfer tube 31B.

As shown in FIGS. 3 and 4, each upper heat transfer tube 61A and each lower heat transfer tube 61B are configured as circular tubes.

As shown in FIG. 3, each upper heat transfer tube 61A has a third inner peripheral surface 63A in which irregularities are formed. The inner peripheral surface 63A is a surface in contact with the non-azeotropic mixed refrigerant flowing inside the upper heat transfer tube 61A. A plurality of groove portions 64A are formed on the third inner peripheral surface 63A. The configurations of the grooves 64A are, for example, equal to each other. The groove portions 64A are arranged so as to be spaced apart from each other in the circumferential direction of the upper heat transfer tube 61A. Each groove portion 64A is spirally formed with respect to the central axis O of the upper heat transfer tube 61A. The width of each groove 64A in the circumferential direction is formed so as to become narrower toward the outer circumference of the upper heat transfer tube 61A in the radial direction, for example.

As shown in FIG. 4, each lower heat transfer tube 61B has a fourth inner peripheral surface 63B in which irregularities are formed. The fourth inner peripheral surface 63B is a surface in contact with the non-azeotropic mixed refrigerant flowing inside the lower heat transfer tube 61B. A plurality of groove portions 64B are formed on the fourth inner peripheral surface 63B. The configurations of the grooves 64B are, for example, equal to each other. The groove portions 64B are arranged so as to be spaced apart from each other in the circumferential direction of the lower heat transfer tube 61B. Each groove portion 64B is formed in a spiral shape with respect to the central axis O of the lower heat transfer tube 61B. The width of each groove 64B in the circumferential direction is formed so as to become narrower toward the outer circumference of the lower heat transfer tube 61B in the radial direction, for example.

The outer shape of each upper heat transfer tube 61A is the same as the outer shape of each lower heat transfer tube 61B, for example. The outer diameter of each upper heat transfer tube 61A is equal to, for example, the outer diameter of each lower heat transfer tube 61B. The inner diameter of each upper heat transfer tube 61A is equal to, for example, the inner diameter of each lower heat transfer tube 61B.

Each area of the third inner peripheral surface 63A of the upper heat transfer tube 61A and the fourth inner peripheral surface 63B of the lower heat transfer tube 61B has an inner diameter equal to the inner diameter of the third inner peripheral surface 63A and the fourth inner peripheral surface 63B, but has a groove portion. Is larger than the area of the inner peripheral surface where is not formed. In other words, the area expansion ratio of the third inner peripheral surface 63A of the upper heat transfer tube 61A and the fourth inner peripheral surface 63B of the lower heat transfer tube 61B is 1 or more. The area expansion ratios of the third inner peripheral surface 63A and the fourth inner peripheral surface 63B are such that the inner diameter is equal to the inner diameter of the third inner peripheral surface 63A and the fourth inner peripheral surface 63B, but the groove portion is not formed. It is a ratio based on the area of the surface.

The area expansion rate of the third inner peripheral surface 63A of the upper heat transfer tube 61A (third tube portion) is higher than the area expansion rate of the fourth inner peripheral surface 63B of the lower heat transfer tube 61B (fourth tube portion). As shown in FIG. 3, the number of grooves 64A is defined as the number of grooves 64A arranged side by side in the circumferential direction in the cross section perpendicular to the axial direction of the upper heat transfer tube 61A. As shown in FIG. 4, the number of grooves 64B is defined as the number of grooves 64B arranged side by side in the circumferential direction in the cross section perpendicular to the axial direction of the lower heat transfer tube 61B. The number of rows of the groove portion 64A is larger than the number of rows of the groove portion 64B. In other words, the width of each groove portion 64A in the circumferential direction is narrower than the width of each groove portion 64B in the circumferential direction. In the upper heat transfer tube 61A and the lower heat transfer tube 61B shown in FIGS. 3 and 4, the third inner peripheral surface 63A and the lower heat transfer tube of the upper heat transfer tube 61A depend on the size relationship between the groove portion 64A and the groove portion 64B. The magnitude relationship of the area expansion ratio with the fourth inner peripheral surface 63B of 61B is realized.

The control device 10 controls the drive frequency of the compressor 1 so that the temperature inside the indoor unit 120 acquired by a temperature sensor (not shown) becomes a desired temperature (for example, a temperature set by the user). 1 controls the amount of refrigerant discharged per unit time. The control device 10 controls the opening degrees of the

expansion valves

4A and 4B so that the degree of superheating or the degree of supercooling of the non-azeotropic mixed refrigerant is within a desired range. The control device 10 controls the amount of air blown per unit time of the outdoor fan 11 and the indoor fan 12. The control device 10 acquires the discharge temperature Td of the non-azeotropic mixed refrigerant discharged from the compressor 1 from the temperature sensor 13. The control device 10 controls the four-way valve 2 to switch the circulation direction of the non-azeotropic mixed refrigerant.

The control device 10 controls the four-way valve 2 to switch between cooling operation (first state) and heating operation (second state).

In the cooling operation, the non-azeotropic mixed refrigerant includes the compressor 1, the four-way valve 2, the outdoor heat exchanger 3 expansion valve 4A, the receiver 5, the expansion valve 4B, the indoor heat exchanger 6, the four-way valve 2, and the receiver 5. It circulates in this order of description. A part of the non-azeotropic mixed refrigerant flowing into the receiver 5 from the expansion valve 4A is separated into a liquid phase non-azeotropic mixed refrigerant and a gas phase non-azeotropic mixed refrigerant, and is stored in the receiver 5. In the cooling operation, the outdoor heat exchanger 3 acts as a condenser and the indoor heat exchanger 6 acts as an evaporator.

In the cooling operation, the non-azeotropic mixed refrigerant flows and condenses inside the outdoor heat exchanger 3 in the order of the upper inflow / outflow section 3A, the plurality of upper heat transfer tubes 31A, the plurality of lower heat transfer tubes 31B, and the lower inflow / outflow section 3B. .. A gas-phase non-azeotropic mixed refrigerant mainly flows through the upper inflow / outflow portion 3A and the plurality of upper heat transfer tubes 31A. A liquid-phase non-azeotropic mixed refrigerant mainly flows through the plurality of lower heat transfer tubes 31B and the lower inflow / outflow portion 3B.

In the cooling operation, the non-azeotropic mixed refrigerant flows and evaporates inside the indoor heat exchanger 6 in the order of the lower inflow / outflow section 6B, the plurality of lower heat transfer tubes 61B, the plurality of upper heat transfer tubes 61A, and the upper inflow / outflow section 6A. .. A gas-liquid two-phase non-azeotropic mixed refrigerant mainly flows through the lower inflow / outflow portion 3B and the plurality of lower heat transfer tubes 31B. A vapor-phase non-azeotropic mixed refrigerant mainly flows through the plurality of upper heat transfer tubes 31A and the upper inflow / outflow portion 6A.

In the heating operation, the non-azeotropic mixed refrigerant includes the compressor 1, the four-way valve 2, the outdoor heat exchanger 3, the expansion valve 4B, the receiver 5, the expansion valve 4A, the indoor heat exchanger 6, the four-way valve 2, and the receiver 5. , Circulate in this order of description. A part of the non-azeotropic mixed refrigerant flowing into the receiver 5 from the expansion valve 4B is separated into a liquid phase non-azeotropic mixed refrigerant and a gas phase non-azeotropic mixed refrigerant, and is stored in the receiver 5. In the heating operation, the outdoor heat exchanger 3 acts as a condenser and the indoor heat exchanger 6 acts as an evaporator.

In the heating operation, the non-azeotropic mixed refrigerant flows and condenses inside the indoor heat exchanger 6 in the order of the upper inflow / outflow section 6A, the plurality of upper heat transfer tubes 61A, the plurality of lower heat transfer tubes 61B, and the lower inflow / outflow section 6B. .. A gas-phase non-azeotropic mixed refrigerant mainly flows through the upper inflow / outflow portion 6A and the plurality of upper heat transfer tubes 61A. A liquid-phase non-azeotropic mixed refrigerant mainly flows through the plurality of lower heat transfer tubes 61B and the lower inflow / outflow portion 6B.

In the heating operation, the non-azeotropic mixed refrigerant flows and evaporates inside the outdoor heat exchanger 3 in the order of the lower inflow / outflow section 3B, the plurality of lower heat transfer tubes 31B, the plurality of upper heat transfer tubes 31A, and the upper inflow / outflow section 3A. .. A gas-liquid two-phase non-azeotropic mixed refrigerant mainly flows through the lower inflow / outflow portion 3B and the plurality of lower heat transfer tubes 31B. A gas-phase non-azeotropic mixed refrigerant mainly flows through the plurality of upper heat transfer tubes 31A and the upper inflow / outflow portion 3A.

<Effect>
Table 1 shows the densities of R32, CF3I, HFO1123, and alkylbenzene oils as an example of incompatible oils. 16 to 18 are schematic views showing a state in which the mixed refrigerants of R32, CF3I, HFO1123, and the incompatible oil flow in a circular tube extending in the horizontal direction and having a smooth inner peripheral surface. .. FIG. 16 is a schematic view showing a state of the mixed refrigerant having a liquid phase and a temperature of 10 ° C. FIG. 17 is a schematic view showing a state of the mixed refrigerant having a liquid phase and a temperature of 60 ° C. FIG. 18 is a schematic view showing the state of the mixed refrigerant in the gas phase. As shown in Table 1 and FIGS. 16 to 18, the magnitude relationship of the densities of R32, CF3I, and HFO1123 varies depending on whether they are in the liquid phase state or the gas phase state.

When each refrigerant is in a liquid phase state, the magnitude relationship of each density when the temperature of each refrigerant is 10 ° C. is equal to the magnitude relationship of each density when the temperature of each refrigerant is 60 ° C. When each refrigerant is in a liquid phase state, the density of CF3I is higher than the density of R32 and HFO1123, and the densities of R32 and HFO1123 are equal, regardless of the temperature of each refrigerant.

When each refrigerant is in a liquid phase state, the magnitude relationship between the densities of each refrigerant and the incompatible oil changes depending on whether the temperature is 10 ° C or 60 ° C. .. When each of the refrigerants is in a liquid phase state and the temperature of each refrigerant and the incompatible oil is 10 ° C., the density of each refrigerant is higher than the density of the incompatible oil. On the other hand, when each of the refrigerants is in a liquid phase state and the temperature of each refrigerant and the incompatible oil is 60 ° C., the densities of R32 and HFO1123 are lower than the density of the incompatible oil, but the density of CF3I. Is higher than the density of incompatible oils.

That is, as shown in FIGS. 16 and 17, when the non-azeotropic mixed refrigerant is in the liquid phase state, CF3I is distributed below R32, HFO1123, and the incompatible oil regardless of its temperature. Cheap. As shown in FIG. 16, when the non-azeotropic mixed refrigerant is in a liquid phase state and its temperature is 10 ° C., CF3I tends to be distributed so as to be in contact with HFO1123 and R32. As shown in FIG. 17, when the non-azeotropic mixed refrigerant is in a liquid phase state and its temperature is 60 ° C., the incompatible oil is likely to be distributed between CF3I and HFO1123 in the vertical direction A.

When each refrigerant is in the gas phase state, the magnitude relationship of each density when the temperature of each refrigerant is 10 ° C. is equal to the magnitude relationship of each density when the temperature of each refrigerant is 60 ° C. When each refrigerant is in the gas phase, the density of CF3I is lower than the density of R32 and HFO1123, and the density of HFO1123 is higher than the density of R32, regardless of the temperature of each refrigerant.

That is, as shown in FIG. 18, when the non-azeotropic mixed refrigerant is in the gas phase state, CF3I tends to be distributed above R32, HFO1123, and the incompatible oil regardless of the temperature. When the non-azeotropic mixed refrigerant is in the gas phase state, R32 is likely to be distributed between CF3I and HFO1123 in the vertical direction A.

Therefore, for example, in a refrigeration cycle device as a comparative example in which the inner peripheral surface of the heat transfer tube of each heat exchanger is configured as a smooth surface, the non-azeotropic mixed refrigerant is difficult to be agitated and CF3I is difficult to mix with HFO1123. , The contribution of CF3I to the action of suppressing the disproportionation reaction of HFO1123 is lower than the contribution of R32 to the action.

On the other hand, in the refrigeration cycle device 100, since the upper heat transfer tube 31A and the lower heat transfer tube 31B of the outdoor heat exchanger 3 each have a first groove portion 34A and a second groove portion 34B, refrigeration as the above comparative example is performed. The non-azeotropic mixed refrigerant is more likely to be agitated than the cycle device.

Further, in the refrigeration cycle apparatus 100, the area expansion rate of the first inner peripheral surface 33A of the upper heat transfer tube 31A is higher than the area expansion rate of the second inner peripheral surface 33B of the lower heat transfer tube 31B, so that the non-azeotropic mixed refrigerant is used. It is easier to stir in the upper heat transfer tube 31A than in the lower heat transfer tube 31B.

For example, during the cooling operation in which the outdoor heat exchanger 3 acts as a condenser, a non-azeotropic mixed refrigerant in a gas phase state in which R32 is likely to be distributed between CF3I and HFO1123 flows through the upper heat transfer tube 31A. Since the non-azeotropic mixed refrigerant flowing through the upper heat transfer tube 31A is easily agitated as described above, CF3I, HFO1123, and R32 distributed between the two are easily agitated, and CF3I is easily mixed with HFO1123. As a result, in the refrigeration cycle apparatus 100, CF3I is more likely to be mixed with R32 and HFO1123 than in the refrigeration cycle apparatus as the comparative example, so that the disproportionation reaction of HFO1123 is less likely to occur, and the performance deterioration is suppressed.

Further, in the refrigeration cycle device 100, since each of the upper heat transfer tube 61A and the lower heat transfer tube 61B of the indoor heat exchanger 6 has a groove portion 64A and a groove portion 64B, as compared with the refrigeration cycle device as the above comparative example, Non-azeotropic mixed refrigerant is easily agitated.

Further, in the refrigeration cycle apparatus 100, the area expansion rate of the inner peripheral surface of the upper heat transfer tube 61A is higher than the area expansion rate of the inner peripheral surface of the lower heat transfer tube 61B, so that the non-azeotropic mixed refrigerant is higher than the lower heat transfer tube 61B. It is easily agitated in the upper heat transfer tube 61A.

For example, during the heating operation in which the indoor heat exchanger 6 acts as a condenser, the non-azeotropic mixed refrigerant in the gas phase in which R32 is likely to be distributed between CF3I and HFO1123 flows through the upper heat transfer tube 61A, so that R32 is agitated. CF3I can be easily mixed with HFO1123. As a result, in the refrigeration cycle apparatus 100, CF3I is more likely to be mixed with R32 and HFO1123 than in the refrigeration cycle apparatus as the comparative example, so that the disproportionation reaction of HFO1123 is less likely to occur, and the performance deterioration is suppressed.

Further, in the refrigeration cycle apparatus 100, when the area expansion rate of the second inner peripheral surface 33B of the lower heat transfer tube 31B is equal to the area expansion rate of the first inner peripheral surface 33A of the upper heat transfer tube 31A, the lower heat transfer tube 61B Compared with the case where the area expansion ratio of the fourth inner peripheral surface 63B is equal to the area expansion ratio of the third inner peripheral surface 63A of the upper heat transfer tube 61A, the outdoor heat exchanger 3 and the indoor heat exchanger 6 as a whole The pressure loss of the non-co-boiling mixed refrigerant is reduced. Therefore, in the refrigeration cycle apparatus 100, the performance deterioration is suppressed more effectively.

<Modification example>
In the refrigeration cycle apparatus 100, the area expansion rate of the inner peripheral surface of the upper heat transfer tube 31A increases the area expansion of the inner peripheral surface of the lower heat transfer tube 31B only because the number of the first groove portions 34A is larger than the number of the second groove portions 34B. It is larger than the rate, but it is not limited to this. The magnitude relationship of the area expansion ratio of the inner peripheral surface between the upper heat transfer tube 31A and the lower heat transfer tube 31B is the magnitude relationship of at least one of the number, depth, and lead angle of the first groove portion 34A and the second groove portion 34B. It may be realized by.

In FIGS. 5 and 6, the magnitude relationship of the area expansion ratio of the inner peripheral surface between the upper heat transfer tube 31A and the lower heat transfer tube 31B is realized by the magnitude relationship of the depths of the first groove portion 34A and the second groove portion 34B. A first modification of the refrigeration cycle apparatus 100 is shown.

As shown in FIG. 5, the depth H1 of the first groove portion 34A includes the virtual line L1 extending the first inner peripheral surface 33A and the inner surface of the first groove portion 34A at the center of the first groove portion 34A in the circumferential direction. Defined as the distance between. The depth H1 of each first groove 34A is equal to each other.

As shown in FIG. 6, the depth H2 of the second groove portion 34B includes the virtual line L2 extending the second inner peripheral surface 33B and the inner surface of the second groove portion 34B at the center of the second groove portion 34B in the circumferential direction. Defined as the distance between. The depth H2 of each second groove 34B is equal to each other.

In the first modification, the depth H1 of the first groove portion 34A is deeper than the depth H2 of the second groove portion 34B. In this case, even if the number of the first groove portions 34A is equal to the number of the second groove portions 34B and the lead angle of the first groove portion 34A is equal to the lead angle of the second groove portion 34B, the first inner peripheral surface 33A of the upper heat transfer tube 31A The area expansion rate of the lower heat transfer tube 31B is larger than the area expansion rate of the second inner peripheral surface 33B of the lower heat transfer tube 31B. In the first modification, only one first groove portion 34A may be formed in the upper heat transfer tube 31A, and only one second groove portion 34B may be formed in the lower heat transfer tube 31B.

In FIGS. 7 and 8, the magnitude relationship of the area expansion ratio of the inner peripheral surface between the upper heat transfer tube 31A and the lower heat transfer tube 31B is realized by the magnitude relationship of the lead angles of the first groove portion 34A and the second groove portion 34B. A second modification of the refrigeration cycle apparatus 100 is shown.

As shown in FIG. 7, the lead angle θ1 of the first groove portion 34A is such that the extending direction of the first groove portion 34A is relative to the central axis O of the upper heat transfer tube 31A in the cross section along the central axis of the upper heat transfer tube 31A. It is defined as the angle formed by. The lead angles θ1 of the first groove portions 34A are equal to each other.

As shown in FIG. 8, the lead angle θ2 of the second groove portion 34B is such that the extending direction of the second groove portion 34B is relative to the central axis O of the lower heat transfer tube 31B in the cross section along the central axis of the lower heat transfer tube 31B. It is defined as the angle formed by. The lead angles θ2 of the second groove portions 34B are equal to each other.

In the second modification, the lead angle θ1 of each first groove portion 34A is larger than the lead angle θ2 of each second groove portion 34B. In this case, even if the number of the first groove portions 34A is equal to the number of the second groove portions 34B and the depth of the first groove portions 34A is equal to the depth of the second groove portions 34B, the first inner peripheral surface 33A of the upper heat transfer tube 31A The area expansion rate is larger than the area expansion rate of the second inner peripheral surface 33B of the lower heat transfer tube 31B. In the second modification, only one first groove portion 34A may be formed in the upper heat transfer tube 31A, and only one second groove portion 34B may be formed in the lower heat transfer tube 31B.

In the refrigeration cycle apparatus 100, two of the first embodiment, the first modification, and the second modification may be combined, or the first, first modification, and second modification of the first embodiment and the second modification may be combined. All of the examples may be combined. For example, the number of first groove portions 34A is larger than the number of second groove portions 34B, the lead angle θ1 of each first groove portion 34A is larger than the lead angle θ2 of each second groove portion 34B, and the lead of each first groove portion 34A. The angle θ1 may be larger than the lead angle θ2 of each second groove portion 34B.

Similarly, in the refrigeration cycle apparatus 100, the magnitude relationship of the area expansion ratio of the inner peripheral surface between the upper heat transfer tube 61A and the lower heat transfer tube 61B is at least the number, depth, and lead angle of the groove portions 64A and the groove portions 64B. It may be realized by any of the magnitude relations.

Further, in the refrigeration cycle device 100, each of the upper heat transfer tube 31A, the lower heat transfer tube 31B, the upper heat transfer tube 61A, and the lower heat transfer tube 61B is configured as a circular tube, but the present invention is not limited to this. As shown in FIGS. 10 to 13, each of the upper heat transfer tube 31A, the lower heat transfer tube 31B, the upper heat transfer tube 61A, and the lower heat transfer tube 61B may be configured as a flat tube. The outer shape of the upper heat transfer tube 31A is the same as the outer shape of the lower heat transfer tube 31B. The tube wall thickness W of the upper heat transfer tube 31A is equal to, for example, the tube wall thickness W of the lower heat transfer tube 31B. The upper heat transfer tube 31A and the lower heat transfer tube 31B are formed with at least one of at least one wall portion for partitioning the internal space into a plurality of minute spaces and at least one unevenness facing the internal space. In this case, the area expansion ratios of the upper heat transfer tube 31A and the lower heat transfer tube 31B are the same as those of the upper heat transfer tube 31A and the lower heat transfer tube 31B in the length and the tube wall thickness in the direction B, but the wall portion and the unevenness are formed. It is defined as a ratio based on the area of the inner peripheral surface that is not used.

As shown in FIGS. 10 and 11, for example, a plurality of

wall portions

38A, 38B, 68A, 68B are formed in the upper heat transfer tube 31A and the lower heat transfer tube 31B. The number of

wall portions

38A, 68A formed in the upper heat transfer tube 31A (in other words, the number of minute spaces) is, for example, the number of

wall portions

38B, 68B formed in the lower heat transfer tube 31B (in other words, the number of minute spaces). ) More than.

As shown in FIGS. 12 and 13, the upper heat transfer tube 31A and the lower heat transfer tube 31B face, for example, a plurality of

wall portions

38A, 38B, 68A, 68B and each minute space partitioned by each wall portion. A plurality of

irregularities

39A, 39B, 69A, 69B are formed. Each wall portion and each unevenness extends along the direction in which the upper heat transfer tube 31A extends. The number of

irregularities

39A and 69A formed on the upper heat transfer tube 31A is larger than the number of

irregularities

39B and 69B formed on the lower heat transfer tube 31B, for example. In the upper heat transfer tube 31A and the lower heat transfer tube 31B shown in FIGS. 12 and 13, the number of

wall portions

38A and 68A is the same as the number of

wall portions

38B and 68B formed on the lower heat transfer tube 31B, for example. There may be, but there may be more.

Further, each of the outdoor heat exchanger 3 and the indoor heat exchanger 6 of the refrigeration cycle device 100 is configured as a fin tube heat exchanger, but the present invention is not limited thereto. As shown in FIG. 9, each of the outdoor heat exchanger 3 and the indoor heat exchanger 6 may be configured as a corrugated heat exchanger.

As shown in FIG. 9, the outdoor heat exchanger 3 configured as a corrugated heat exchanger has an upper header 35A (first header) connected to an upper inflow / outflow portion 3A (first inflow / outflow portion) and a lower inflow / outflow portion. A plurality of heat transfer tubes 36 connected between the lower header 35B (second header) connected to 3B (second inflow / outflow portion), the upper header 35A and the lower header 35B, and extending along the vertical direction A, and a plurality of heat transfer tubes 36. Includes corrugated fins 37. The upper header 35A is arranged above the lower header 35B. The upper header 35A is connected to each upper end of the plurality of heat transfer tubes 36. The lower header 35B is connected to each lower end of the plurality of heat transfer tubes 36. The upper header 35A and the lower header 35B distribute the non-azeotropic mixed refrigerant to the plurality of heat transfer tubes 36, or join the non-azeotropic mixed refrigerants that have flowed through the plurality of heat transfer tubes 36. The upper header 35A and the lower header 35B extend along a direction B intersecting the vertical direction A. The area expansion ratio of the inner peripheral surface of the upper header 35A is higher than the area expansion ratio of the inner peripheral surface of the lower header 35B.

As shown in FIG. 9, the outdoor heat exchanger 6 configured as a corrugated heat exchanger has an upper header 65A (third header) connected to an upper inflow / outflow portion 6A (third inflow / outflow portion) and a lower inflow / outflow portion. A plurality of heat transfer tubes 66 connected between the lower header 65B (fourth header) connected to 6B (second inflow / outflow portion), the upper header 65A and the lower header 65B, and extending along the vertical direction A, and a plurality of heat transfer tubes 66. Includes corrugated fins 67. The upper header 65A is arranged above the lower header 65B. The upper header 65A is connected to each upper end of the plurality of heat transfer tubes 66. The lower header 65B is connected to each lower end of the plurality of heat transfer tubes 66. The upper header 65A and the lower header 65B distribute the non-azeotropic mixed refrigerant to the plurality of heat transfer tubes 66, or join the non-azeotropic mixed refrigerants flowing through the plurality of heat transfer tubes 66. The upper header 65A and the lower header 65B extend along a direction B intersecting the vertical direction A. The upper header 65A has an inner peripheral surface (first inner peripheral surface) on which irregularities are formed. The lower header 65B has an inner peripheral surface (second inner peripheral surface) on which irregularities are formed. The area expansion ratio of the inner peripheral surface (first inner peripheral surface) of the upper header 65A is higher than the area expansion ratio of the inner peripheral surface (second inner peripheral surface) of the lower header 65B.

The upper header 35A and the upper header 65A have the same configurations as the upper heat transfer tube 31A and the upper heat transfer tube 61A as the first tube portion shown in each of FIGS. 3, 5, and 7. The lower header 35B and the lower header 65B have the same configurations as the lower heat transfer tube 31B and the lower heat transfer tube 61B as the second tube portion shown in FIGS. 4, 6, and 8, respectively.

In the refrigeration cycle apparatus 100, one of the outdoor heat exchanger 3 and the indoor heat exchanger 6 is the fin tube heat exchanger shown in FIG. 2, and the other of the outdoor heat exchanger 3 and the indoor heat exchanger 6 is FIG. It may be a corrugated heat exchanger shown in.

Further, in the refrigeration cycle apparatus 100, as long as at least one of the outdoor heat exchanger 3 and the indoor heat exchanger 6 has the above configuration, the outdoor heat exchanger 3 or the indoor heat exchanger 6 is used as a conventional heat exchanger. It may be configured. For example, the area expansion ratio of the first inner peripheral surface of the upper heat transfer tube 31A of the outdoor heat exchanger 3 is higher than the area expansion ratio of the second inner peripheral surface of the lower heat transfer tube 31B, and the upper heat transfer tube 61A of the indoor heat exchanger 6 The area expansion ratio of the third inner peripheral surface of the lower heat transfer tube 61B may be equal to the area expansion ratio of the fourth inner peripheral surface of the lower heat transfer tube 61B. Further, for example, the area expansion ratio of the inner peripheral surface of the upper heat transfer tube 61A of the indoor heat exchanger 6 is higher than the area expansion ratio of the inner peripheral surface of the lower heat transfer tube 61B, and the inside of the upper heat transfer tube 31A of the outdoor heat exchanger 3 The area expansion rate of the peripheral surface may be equal to the area expansion rate of the inner peripheral surface of the lower heat transfer tube 31B.

Embodiment 2.
The refrigeration cycle device 100 according to the second embodiment includes a first refrigerant circuit 130 in which the first refrigerant circulates, and a second refrigerant circuit 140 in which the second refrigerant circulates. The first refrigerant circuit 130 corresponds to an "outdoor cycle", a "heat source side cycle" or a "primary circuit". The second refrigerant circuit 140 corresponds to an "indoor side cycle", a "utilization side cycle" or a "secondary circuit".

The first refrigerant circuit 130 includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3 (third heat exchanger), an expansion device 4, and a first flow path H1 of an intermediate heat exchanger 7.

The first refrigerant is a non-azeotropic mixed refrigerant whose GWP is reduced by mixing R32, CF3I, and HFO1123. The first refrigerant has a configuration equivalent to that of the non-azeotropic mixed refrigerant according to the first embodiment. The second refrigerant is a refrigerant having a lower combustion lower limit concentration as compared with the first refrigerant, and is, for example, a CF3I single refrigerant or a mixed refrigerant such as R466A containing CF3I.

The compressor 1 compresses and discharges the first refrigerant. The compressor 1 has the same configuration as the compressor 1 in the first embodiment.

The four-way valve 2 switches the flow path of the first refrigerant. The four-way valve 2 has a first port connected to the discharge port of the compressor 1, a second port connected to the suction port of the compressor 1, and a third port connected to the outdoor heat exchanger 3. And a fourth port connected to the lower inflow / outflow portion 7B of the intermediate heat exchanger 7. The four-way valve 2 switches the flow path of the first refrigerant discharged from the compressor 1. During the cooling operation in which the first refrigerant is circulated in the direction indicated by the solid arrow in FIG. 14, the four-way valve 2 forms a flow path from the compressor 1 to the outdoor heat exchanger 3. On the other hand, during the heating operation in which the first refrigerant is circulated in the direction indicated by the broken line arrow in FIG. 14, the four-way valve 2 forms a flow path from the compressor 1 to the intermediate heat exchanger 7.

In the outdoor heat exchanger 3, heat exchange is performed between the first refrigerant and the outdoor air. The expansion device 4 decompresses and expands the refrigerant passing through the inside to obtain a low-temperature and low-pressure refrigerant. As the expansion device 4, for example, an electronic expansion valve can be used.

The second refrigerant circuit 140 includes the second flow path H2 of the intermediate heat exchanger 7, the pump 150, and the indoor

temperature control units

160, 170, 180. The indoor

temperature control units

160, 170, 180 are connected in parallel to each other.

The pump 150 is configured so that the direction of rotation can be switched in the forward and reverse directions. The pump 150 guides the second refrigerant in the liquid state from the pump 150 to the

indoor heat exchangers

161, 171, 181 during the cooling operation, and the second refrigerant in the liquid state from the pump 150 to the second intermediate heat exchanger 7 during the heating operation. The circulation direction of the second refrigerant is switched so as to lead to the flow path H2.

The indoor temperature control unit 160 includes an indoor heat exchanger 161 (fourth heat exchanger), a fan for sending indoor air to the indoor heat exchanger 161 (not shown), and a flow rate for adjusting the flow rate of the second refrigerant. Includes a regulating valve 162. The indoor heat exchanger 161 exchanges heat between the second refrigerant and the indoor air.

The indoor temperature control unit 170 includes an indoor heat exchanger 171, a fan (not shown) for sending indoor air to the indoor heat exchanger 171 and a flow rate adjusting valve 172 for adjusting the flow rate of the second refrigerant. The indoor heat exchanger 171 exchanges heat between the second refrigerant and the indoor air.

The indoor temperature control unit 180 includes an indoor heat exchanger 181 and a fan (not shown) for sending indoor air to the indoor heat exchanger 181 and a flow rate adjusting valve 182 for adjusting the flow rate of the second refrigerant. The indoor heat exchanger 181 exchanges heat between the second refrigerant and the indoor air.

In the present embodiment, an air conditioner having three indoor temperature control units is given as an example, but the number of indoor temperature control units is not particularly limited.

FIG. 15 is a schematic side view of the intermediate heat exchanger 7. In FIG. 15, the structure shown by the broken line shows the main internal structure related to the first flow path H1 in the intermediate heat exchanger 7. As shown in FIGS. 14 and 15, the intermediate heat exchanger 7 is configured as a plate heat exchanger. The intermediate heat exchanger 7 includes a plurality of heat transfer plates 71 laminated in the direction B intersecting the vertical direction A. A plurality of first flow paths H1 and a plurality of second flow paths H2 are alternately arranged in the direction B between the plurality of heat transfer plates 71. Each of the plurality of heat transfer plates 71 is formed with an upper through hole connected in the direction B and arranged relatively upward, and a lower through hole connected in the direction B and arranged below the upper through hole. Has been done. In the plurality of upper through holes of the intermediate heat exchanger 7, an upper distribution region 72A extending in the direction B and connecting with each first flow path H1 is formed. In the plurality of lower through holes of the intermediate heat exchanger 7, a lower distribution region 72B extending in the direction B and connecting with each first flow path H1 is formed.

The main internal structure of the intermediate heat exchanger 7 related to the second flow path H2 is the same as the main internal structure of the intermediate heat exchanger 7 related to the first flow path H1.

In the intermediate heat exchanger 7, heat exchange is performed between the first refrigerant flowing through each of the first flow paths H1 and the second refrigerant flowing through each of the second flow paths H2. The intermediate heat exchanger 7 is connected to the first refrigerant circuit 130 and the second refrigerant circuit 140 so that, for example, the first flow path H1 and the second flow path H2 are countercurrent.

The intermediate heat exchanger 7 has an upper inflow / outflow section 7A (fifth inflow / outflow section) and a lower inflow / outflow section 7B (sixth inflow / outflow section) in which the first refrigerant flows in and out of the first flow path H1, and a second flow path H2. 2 The upper inflow / outflow section 7C and the lower inflow / outflow section 7D through which the refrigerant flows in and out are further included. The upper inflow / outflow portion 7A is arranged above the lower inflow / outflow portion 7B. The upper inflow / outflow portion 7A is connected to the upper distribution region 72A in the direction B. The lower inflow / outflow portion 7B is connected to the lower distribution region 72B in the direction B. The upper inflow / outflow portion 7C is arranged above the lower inflow / outflow portion 7D.

The upper inflow / outflow section 7A is connected to the expansion device 4. The lower inflow / outflow portion 7B is connected to the fourth port of the four-way valve 2. The upper inflow / outflow portion 7C is connected to the pump 150. The lower inflow / outflow section 7D is connected to the

indoor heat exchangers

161, 171, 181.

In the refrigerating cycle device 101, the second refrigerant circulating in the second refrigerant circuit 140 is cooled by the first refrigerant circulating in the first refrigerant circuit 130 during the cooling operation. On the other hand, during the heating operation, the first refrigerant circulating in the first refrigerant circuit 130 heats the second refrigerant circulating in the second refrigerant circuit 140.

In particular, during the cooling operation, the relatively low temperature gas-liquid two-phase first refrigerant evaporates while flowing from the upper side to the lower side in the first flow path H1 of the intermediate heat exchanger 7, and changes to the gas phase. During the heating operation, the first refrigerant in the gas phase condenses while flowing from the lower side to the upper side in the first flow path H1 of the intermediate heat exchanger 7, and changes into a liquid phase.

The control device 10 controls the overall operation of the refrigeration cycle device 101. The control device 10 is shown to be attached to the compressor 1, the expansion device 4, the pump 150, the

flow control valves

152, 172, 182, and the

heat exchangers

3, 161, 171 and 181 according to the outputs of the pressure sensor, the temperature sensor and the like. Do not control the rotation speed of the fan.

The control device 10 switches the circulation direction of the first refrigerant in the first refrigerant circuit 130 by the four-way valve 2 in the refrigerant operation and the heating operation. In conjunction with this, the control device 10 exchanges heat with the first refrigerant in a countercurrent flow in the intermediate heat exchanger 7, and causes the second refrigerant circuit to be overcooled at the suction port of the pump 150. The rotation direction of the pump 150 of 140 is switched.

<Effect>
In a refrigeration cycle apparatus as a comparative example including an intermediate heat exchanger in which a relatively low temperature gas-liquid two-phase first refrigerant flows from the bottom to the top during cooling operation, the first refrigerant flowing in the lower distribution region is used. , R32, CF3I, HFO1123, and incompatible oils are more likely to be distributed as shown in FIG. 16, and CF3I is more likely to be distributed below R32 and HFO1123. In this case, the flowability (fluidity) of CF3I is hindered by the plate portion located below the lower through hole in each heat transfer plate. Further, in the first refrigerant flowing through the upper distribution region, R32, CF3I, HFO1123, and the incompatible oil are likely to be distributed as shown in FIG. 18, and CF3I is likely to be distributed above R32 and HFO1123. In this case, the fluidity of CF3I is impeded by the plate portion located above the upper through hole in each heat transfer plate.

Further, during the heating operation of the refrigeration cycle apparatus as the comparative example, R32, CF3I, HFO1123, and the incompatible oil are easily distributed as shown in FIG. 18 in the first refrigerant flowing through the upper distribution region, and CF3I Is more likely to be distributed above R32 and HFO1123. In this case, the fluidity of CF3I is impeded by the plate portion located above the upper through hole in each heat transfer plate. Further, in the first refrigerant flowing through the lower distribution region, R32, CF3I, HFO1123, and the incompatible oil are likely to be distributed as shown in FIG. 17, and CF3I is likely to be distributed below R32 and HFO1123. In this case, the flowability (fluidity) of CF3I is hindered by the plate portion located below the lower through hole in each heat transfer plate.

On the other hand, during the cooling operation of the refrigeration cycle device 101, the first refrigerant of the gas-liquid two-phase at a relatively low temperature flows through the intermediate heat exchanger 7, the upper inflow / outflow portion 7A, the upper distribution region 72A, and each first flow path. It flows in the order of H1, the lower distribution area 72B, and the lower inflow / outflow portion 7B. Therefore, in the first refrigerant flowing through the upper distribution region 72A, R32, CF3I, HFO1123, and the incompatible oil are likely to be distributed as shown in FIG. That is, CF3I tends to be distributed below R32 and HFO1123 in the upper distribution region 72A. Further, in the first refrigerant flowing through the lower distribution region 72B, R32, CF3I, HFO1123, and the incompatible oil are likely to be distributed as shown in FIG. That is, CF3I tends to be distributed above R32 and HFO1123 in the lower distribution region 72B.

Further, during the heating operation of the refrigeration cycle device 101, the first refrigerant in the gas phase having a relatively high temperature enters the intermediate heat exchanger 7, the lower inflow / outflow portion 7B, the lower distribution region 72B, each first flow path H1, and the upper distribution. It flows in the order of region 72A and upper inflow / outflow portion 7A. Therefore, in the first refrigerant flowing through the lower distribution region 72B, R32, CF3I, HFO1123, and the incompatible oil are likely to be distributed as shown in FIG. That is, CF3I tends to be distributed above R32 and HFO1123 in the lower distribution region 72B. Further, in the first refrigerant flowing through the upper distribution region 72A, R32, CF3I, HFO1123, and the incompatible oil are likely to be distributed as shown in FIG. That is, CF3I tends to be distributed below R32 and HFO1123 in the upper distribution region 72A.

Therefore, in the refrigeration cycle device 101, the fluidity of CF3I in the first refrigerant in the intermediate heat exchanger 7 is higher than that in the refrigeration cycle device according to the above comparative example. Since the fluidity of CF3I in the intermediate heat exchanger 7 is high, CF3I is easily mixed with HFO1123, so that the disproportionation reaction of HFO1123 is unlikely to occur, and the deterioration of performance is suppressed.

Further, in the refrigeration cycle device 101, the fluidity of CF3I in the upper distribution region 72A arranged on the upstream side of each first flow path H1 is higher during the cooling operation than in the refrigeration cycle device according to the above comparative example. During the heating operation, the fluidity of CF3I in the lower distribution region 72B arranged on the upstream side of each first flow path H1 is high. Therefore, in the refrigeration cycle device 101, there is less variation in the flow rate of CF3I flowing through each of the first flow paths H1 as compared with the refrigeration cycle device according to the above comparative example.

The

refrigeration cycle devices

100 and 101 are not limited to RAC. The uses and capacities of the

refrigeration cycle devices

100, 101 can be set arbitrarily.

Although the embodiment of the present invention has been described above, it is possible to modify the above-described embodiment in various ways. Moreover, the scope of the present invention is not limited to the above-described embodiment. The scope of the present invention is indicated by the claims and is intended to include all modifications within the meaning and scope equivalent to the claims.

1 Compressor, 2 4-way valve, 3,6,7,161,171,181 Heat exchanger, 3A, 6A, 7A, 7C Upper inflow / outflow section, 3B, 6B, 7B, 7D Lower inflow / outflow section, 4,4A, 4B Inflator, 5 receiver, 10 control device, 11 outdoor fan, 12 indoor fan, 13 temperature sensor, 31B, 61B lower heat transfer tube, 31A, 61A upper heat transfer tube, 31C, 61C bent part, 32, 62 fins, 33A, 33B , 63A, 63B inner peripheral surface, 34A, 34B, 64A, 64B groove, 35A, 65A upper header, 35B, 65B lower header, 36,66 heat transfer tube, 37,67 corrugated fin, 71 heat transfer plate, 72A upper distribution area , 72B lower distribution area, 100,101 refrigeration cycle device, 110 outdoor unit, 120 indoor unit, 130 first refrigerant circuit, 140 second refrigerant circuit, 150 pump, 152,162,172,182 flow control valve, 160,170 , 180 Indoor temperature control unit.

Claims

A refrigeration cycle device that uses a non-azeotropic mixed refrigerant.
With a compressor,
Flow path switching part and
The first inflow / outflow section and the second inflow / outflow section through which the non-azeotropic mixed refrigerant flows in and out, and the first inflow / outflow section and the second inflow / outflow section are connected in series with each other, and the non-azeotropic mixed refrigerant is connected. A first heat exchanger including a flowing first pipe portion and a second pipe portion,
Decompression device and
Equipped with a second heat exchanger
The non-azeotropic mixed refrigerant contains a refrigerant having a characteristic of causing a disproportionation reaction and a refrigerant having no characteristic of causing a disproportionation reaction.
The flow path switching unit includes a first state in which the non-azeotropic mixed refrigerant flows through the compressor, the first heat exchanger, the decompression device, and the second heat exchanger in the order described, and the non-azeotropic mixing refrigerant. Switching between the second state in which the mixed refrigerant flows in the opposite direction to the first state,
In the first state, the non-azeotropic mixed refrigerant flows in the first heat exchanger in the order of the first inflow / outflow portion, the first pipe portion, the second pipe portion, and the second inflow / outflow portion.
In the second state, the non-azeotropic mixed refrigerant flows in the first heat exchanger in the order of the second inflow / outflow portion, the second pipe portion, the first pipe portion, and the first inflow / outflow portion.
The first pipe portion has a first inner peripheral surface on which irregularities are formed.
The second pipe portion has a second inner peripheral surface on which irregularities are formed.
A refrigeration cycle apparatus in which the area expansion ratio of the first inner peripheral surface of the first pipe portion is higher than the area expansion ratio of the second inner peripheral surface of the second pipe portion.
At least one first groove portion extending spirally is formed on the first inner peripheral surface, and at least one second groove portion extending spirally is formed on the second inner peripheral surface. Has been
The at least one first groove exceeds the at least one second groove with respect to at least one of the number, depth, and lead angle of the at least one first groove and the at least one second groove. , The refrigeration cycle apparatus according to claim 1.
The second heat exchanger is arranged between the third inflow / outflow section and the fourth inflow / outflow section where the non-azeotropic mixed refrigerant flows in / out, and the third inflow / outflow section and the fourth inflow / outflow section, and the non-azeotropic mixed refrigerant flows in and out. Including the third pipe part and the fourth pipe part through which the azeotropic mixed refrigerant flows,
In the first state, the non-azeotropic mixed refrigerant flows in the second heat exchanger in the order of the fourth inflow / outflow portion, the fourth pipe portion, the third pipe portion, and the third inflow / outflow portion.
In the second state, the non-azeotropic mixed refrigerant flows in the second heat exchanger in the order of the third inflow / outflow portion, the third pipe portion, the fourth pipe portion, and the fourth inflow / outflow portion.
The third pipe portion has a third inner peripheral surface on which irregularities are formed.
The fourth pipe portion has a fourth inner peripheral surface on which irregularities are formed.
The refrigeration cycle apparatus according to claim 1 or 2, wherein the area expansion ratio of the third inner peripheral surface of the third pipe portion is higher than the area expansion ratio of the fourth inner peripheral surface of the fourth pipe portion.
The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the first pipe portion and the second pipe portion extend in a direction intersecting the vertical direction.
The refrigeration cycle apparatus according to any one of claims 1 to 4, wherein the first heat exchanger is a fin tube heat exchanger in which the first tube portion and the second tube portion are configured as heat transfer tubes. ..
The first heat exchanger further includes a heat transfer tube having upper and lower ends and extending in the vertical direction.
Each of the first heat exchanger and the second heat exchanger is configured as a first header in which the first tube portion is connected to the upper end of the heat transfer tube, and the second tube portion is The refrigeration cycle apparatus according to any one of claims 1 to 4, which is a corrugated heat exchanger configured as a second header connected to the lower end of the heat transfer tube.
The first refrigerant circuit in which the first refrigerant circulates,
The second refrigerant circuit in which the second refrigerant circulates,
It is provided with an intermediate heat exchanger in which heat exchange is performed between the first refrigerant and the second refrigerant.
The first refrigerant circuit is
A compressor that compresses the first refrigerant and
Flow path switching part and
A third heat exchanger in which heat is exchanged between the first refrigerant and air,
A decompression device that decompresses the first refrigerant and
In the intermediate heat exchanger, the first flow path through which the first refrigerant passes is included.
The second refrigerant circuit is
A pump that boosts and conveys the second refrigerant,
In the intermediate heat exchanger, the second flow path through which the second refrigerant passes and
Including a fourth heat exchanger in which heat exchange is performed between the second refrigerant and air.
The first refrigerant is a non-azeotropic mixed refrigerant containing a refrigerant having a characteristic of causing a disproportionation reaction and a refrigerant having no characteristic of causing a disproportionation reaction.
The intermediate heat exchanger includes a fifth inflow / outflow portion and a sixth inflow / outflow portion through which the first refrigerant flows in and out of the first flow path.
The fifth inflow / outflow section is arranged above the sixth inflow / outflow section.
The flow path switching unit includes the first state in which the non-azeotropic mixed refrigerant flows through the compressor, the third heat exchanger, the depressurizing device, and the intermediate heat exchanger in the order described, and the non-azeotropic mixing. Switching between the second state in which the refrigerant flows in the opposite direction to the first state,
In the first state, the non-azeotropic mixed refrigerant flows in the intermediate heat exchanger from the fifth inflow / outflow section toward the sixth inflow / outflow section.
In the second state, the refrigeration cycle apparatus in which the non-azeotropic mixed refrigerant flows in the intermediate heat exchanger from the sixth inflow / outflow portion toward the fifth inflow / outflow portion.
The refrigeration cycle apparatus according to claim 7, wherein the intermediate heat exchanger is a plate type heat exchanger including a plurality of heat transfer plates stacked in a direction intersecting the vertical direction.
The refrigeration cycle apparatus according to any one of claims 1 to 8, wherein the non-azeotropic mixed refrigerant contains R32, CF3I, and HFO1123.
The weight ratio of the HFO 1123 in the non-azeotropic mixed refrigerant sealed in the refrigeration cycle apparatus is 60 wt% or more.
The refrigeration cycle apparatus according to claim 9, wherein the weight ratio of the CF3I in the non-azeotropic mixed refrigerant sealed in the refrigeration cycle apparatus is 2 wt% or more and 5 wt% or less.