JP2009257741A - Refrigerating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating device, capable of suppressing frost formation or improving defrosting efficiency, in a refrigerating cycle of 0 ozone depletion potential. <P>SOLUTION: An air-conditioning device 1 comprises a refrigerant circuit 10; a single refrigerant made of a refrigerant represented by a molecular formula: C<SB>3</SB>H<SB>m</SB>F<SB>n</SB>(m=1-5, n=1-5 and m+n=6), and having a single double bond in the molecular structure, or a refrigerant mixture including the refrigerant; an outdoor air distribution fan 21; and a control section 4b for switching an operation state to an operation state, to make the outdoor heat exchanger 4 function as a radiator, when prescribed conditions are satisfied in the operating state in which the outdoor heat exchanger 4 functions as an evaporator. The outdoor heat exchanger 4 has a plurality of outdoor heat exchange fins, and ventilation resistance, when the airflow passes between the outdoor heat exchange fins at a windward side is lower than that at a leeward side. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a refrigeration apparatus.

  Conventionally, chlorofluorohydrocarbons, fluorohydrocarbons, azeotropic compositions thereof, and the like are known as heat media (refrigerants) used in the refrigeration cycle. As these refrigerants, for example, R-11 (trichloromonofluoromethane), R-22 (monochlorodifluoromethane), R502 (R-22 + chloropentafluoroethane) and the like are mainly used.

  However, it has been pointed out that the destruction of the ozone layer has a negative impact on the global ecosystem, and there is an international agreement that the use of refrigerants with high risk of destroying the ozone layer is restricted. .

  On the other hand, as described in Patent Document 1 (Japanese Patent Laid-Open No. 4-110388) shown below, the applicant, even if leaked into the atmosphere from the refrigeration cycle, the ozone layer depletion coefficient (ODP: Ozone) A refrigerant having a Depletion Potential) of 0 and capable of exhibiting the same ability as a refrigerant conventionally used in a refrigeration cycle has been devised. Specifically, the refrigerant | coolant which does not contain a chlorine atom and a bromine atom is proposed.

By the way, as a refrigerant which is a refrigerant having an ozone depletion coefficient of 0, it is represented by a molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure or a mixed refrigerant containing this refrigerant can be used. However, when this refrigerant is used in a refrigeration apparatus, no consideration has yet been given to a technique capable of suppressing frost formation or improving defrosting efficiency.

The present invention has been made in view of the above, an object of the present invention, there is provided a ozone depletion is 0, molecular formula: C ₃ H _m F _n (where, m = 1 to 5, n = 1 to 5 and m + n = 6), and the arrival in a refrigeration cycle using a single refrigerant composed of a refrigerant having one double bond in the molecular structure or a mixed refrigerant containing this refrigerant. An object of the present invention is to provide a refrigeration apparatus capable of suppressing frost or improving defrosting efficiency.

The refrigeration apparatus of the first invention includes a refrigerant circuit, a working refrigerant, an outdoor air blowing mechanism, and a control unit. The refrigerant circuit has at least a compression mechanism, an indoor heat exchanger, an expansion mechanism, and an outdoor heat exchanger. The working refrigerant is expressed by a molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6) in which a refrigeration cycle is performed by circulating in the refrigerant circuit. And either a single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant. The outdoor air blowing mechanism supplies an air flow to the outdoor heat exchanger. In the operation state in which the outdoor heat exchanger functions as an evaporator, the control unit can switch to the operation state in which the outdoor heat exchanger functions as a radiator when a predetermined condition is satisfied. The outdoor heat exchanger has a plurality of outdoor heat exchange fins, and the ventilation resistance when the air flow passes between the outdoor heat exchange fins is lower on the windward side than on the leeward side.

  In this refrigeration apparatus, a working refrigerant having an ozone depletion coefficient of 0 can be used.

  In general, when an outdoor heat exchanger functions as an evaporator in a refrigeration apparatus, frost formation may occur on the windward side of the outdoor heat exchanger depending on the surrounding environment and operating conditions. On the other hand, in this refrigeration apparatus, the outdoor heat exchanger has lower wind resistance on the windward side than on the leeward side, so that frost grows to cover the windward side even if frost formation occurs. The time required until the time can be lengthened. For this reason, the operation | movement which functions an outdoor heat exchanger as an evaporator can be continued for a longer time. And when the degree of frost formation of an outdoor heat exchanger increases and it will be in the state which satisfy | fills predetermined conditions, a control part can function an outdoor heat exchanger as a heat radiator. For this reason, it becomes possible to thaw with the heat of the refrigerant | coolant which circulates the frost adhering to an outdoor heat exchanger.

  This makes it possible to defrost frost attached to the outdoor heat exchanger while setting the ozone layer destruction coefficient to 0, and the frost attached to the outdoor heat exchanger covers the windward side of the outdoor heat exchanger. Thus, it is possible to continue the operation of functioning as an evaporator by increasing the time required until a longer time.

  In the refrigeration apparatus of the second invention, in the refrigeration apparatus of the first invention, the outdoor heat exchanger is an outdoor in which the pitch of the outdoor heat exchange fins arranged on the leeward side of the air flow is arranged on the leeward side of the air flow. It is wider than the pitch of heat exchanger fins.

  In this refrigeration apparatus, the pitch of the outdoor heat exchanger fins on the windward side of the outdoor heat exchanger can be made wider than that on the leeward side, whereby frost adhesion and growth on the windward side of the outdoor heat exchanger can be suppressed. Further, by reducing the pitch of the outdoor heat exchange fins on the leeward side of the outdoor heat exchanger from that on the leeward side, it is possible to improve the heat exchange capacity on the leeward side of the outdoor heat exchanger where frost formation is less likely to occur. Thereby, adhesion of frost can be suppressed while suppressing a decrease in heat exchange capacity.

  In the refrigeration apparatus of the third invention, in the refrigeration apparatus of the second invention, the pitch of the outdoor heat exchange fins arranged on the leeward side of the air flow is the pitch of the outdoor heat exchange fins arranged on the leeward side of the air flow. It is 1.3 to 1.5 times.

  In this refrigeration apparatus, frost adhesion can be suppressed more reliably while suppressing a decrease in heat exchange capacity.

  In the refrigeration apparatus of the fourth aspect of the invention, in the refrigeration apparatus of the first aspect of the invention, the outdoor heat exchanger has the outdoor heat exchanger fins arranged on the leeward side of the air flow and has cut and raised pieces. The outdoor heat exchange fin arranged on the upper side does not have a cut and raised piece.

  In this refrigeration apparatus, frost adhesion and growth can be suppressed by making the outdoor heat exchanger fin on the windward side of the outdoor heat exchanger into a shape that does not cut and raise. Moreover, the heat exchange capability in the lee side of the outdoor heat exchanger which is hard to generate | occur | produce frost can be improved by setting it as the shape which provided the cut-and-raised piece in the outdoor heat exchanger fin in the leeward side of an outdoor heat exchanger. Thereby, adhesion of frost can be suppressed while suppressing a decrease in heat exchange capacity.

  In the refrigeration apparatus of the fifth invention, in the refrigeration apparatus of any one of the first to fourth inventions, the indoor heat exchanger has a plurality of indoor heat exchange fins. The surface interval of the outdoor heat exchange fin is wider than the surface interval of the indoor heat exchange fin.

  In this refrigeration apparatus, in the indoor heat exchanger in which frost formation is difficult to occur, the heat exchange capacity can be improved by making the surface interval between the indoor heat exchange fins smaller than the surface interval between the outdoor heat exchange fins. Moreover, in the outdoor heat exchanger in which frost formation is likely to occur, adhesion and growth of frost can be suppressed by increasing the surface spacing of the outdoor heat exchange fins more than the surface spacing of the indoor heat exchange fins. Thereby, it becomes possible to suppress adhesion and growth of frost in the outdoor heat exchanger while ensuring the capability of the indoor heat exchanger.

  The refrigeration apparatus according to a sixth aspect of the present invention is the refrigeration apparatus according to any one of the first to fifth aspects of the present invention, further comprising an indoor air blowing mechanism that supplies an air flow to the indoor heat exchanger. In an operation state in which the outdoor heat exchanger functions as an evaporator, the control unit is configured so that the air flow rate generated by the outdoor fan mechanism is faster than the air flow rate generated by the indoor fan mechanism. Control at least one of the mechanisms.

  In this refrigeration apparatus, when the outdoor heat exchanger that is in a state in which frost easily adheres to the outdoor heat exchanger functions as an evaporator, frost formation and frost growth in the outdoor heat exchanger are more effectively suppressed. Is possible.

  In the refrigeration apparatus of the seventh invention, in the refrigeration apparatus of any one of the first to sixth inventions, a connection state in which the outdoor heat exchanger is connected to the suction side of the compression mechanism, and the outdoor heat exchanger is connected to the discharge side of the compression mechanism And a switching mechanism capable of switching the connection state to be connected to. The control unit switches between an operation state in which the outdoor heat exchanger functions as an evaporator and an operation state in which the outdoor heat exchanger functions as a radiator by switching the connection state of the switching mechanism.

  In this refrigeration apparatus, the frost attached while the outdoor heat exchanger is functioning as an evaporator is used by operating the outdoor heat exchanger connected to the discharge side of the compression mechanism, thereby using the heat of the discharged refrigerant. Can be thawed.

In the refrigeration apparatus of the eighth invention, in the refrigeration apparatus of any one of the first to seventh inventions, when the outdoor heat exchanger functions as an evaporator, the temperature or temperature in the vicinity of the inlet of the working refrigerant of the outdoor heat exchanger Further, an evaporation inlet detection unit that detects a state quantity that can be converted into the value is further provided. The working refrigerant is represented by the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and has one double bond in the molecular structure. It is a non-azeotropic refrigerant mixture including a single refrigerant. The control unit determines whether or not a predetermined condition is satisfied based on a value detected by the evaporation inlet detection unit.

  In this refrigeration apparatus, the mixed refrigerant has the property that the temperature rises as it moves through the evaporator under the same pressure. For this reason, when the outdoor heat exchanger is caused to function as an evaporator, the temperature on the inlet side of the working refrigerant is the lowest temperature, which is the portion where frost formation and frost growth are most likely to occur. Here, since the predetermined condition is determined based on the state quantity of the portion where frost formation is likely to occur in this way, it is possible to more reliably suppress frost formation and frost growth in the outdoor heat exchanger.

A refrigeration apparatus according to a ninth aspect of the present invention includes at least a compressor, an indoor heat exchanger, an expansion mechanism, and an outdoor heat exchanger, and a refrigerant circuit capable of performing switching between a cooling operation and a heating operation, and a refrigerant A refrigeration cycle is carried out by circulating in the circuit. The molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and the molecular structure Either a single refrigerant composed of a refrigerant having one double bond therein or a mixed refrigerant containing a refrigerant, and a blower mechanism for supplying an air flow to the outdoor heat exchanger are provided. The outdoor heat exchanger has a plurality of fins, and the pitch of the fins arranged on the leeward side of the air flow formed by the air blowing mechanism is larger than the pitch of the fins arranged on the leeward side of the air flow. wide.

  In this refrigeration apparatus, by reducing the ventilation resistance on the windward side, frost formation can be made difficult when functioning as an evaporator.

A refrigeration apparatus according to a tenth aspect of the invention includes at least a compressor, an indoor heat exchanger, an expansion mechanism, and an outdoor heat exchanger, and a refrigerant circuit capable of performing switching between a cooling operation and a heating operation, and a refrigerant A refrigeration cycle is carried out by circulating in the circuit. The molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and the molecular structure Either a single refrigerant composed of a refrigerant having one double bond therein or a mixed refrigerant containing the refrigerant, and a blower mechanism for supplying an air flow to the outdoor heat exchanger are provided. The indoor heat exchanger has a plurality of indoor fins. The outdoor heat exchanger has a plurality of outdoor fins. The spacing between the outdoor fins is wider than the spacing between the indoor fins.

  In this refrigeration apparatus, it is possible to make it difficult for frost formation in the outdoor heat exchanger to occur.

A refrigeration apparatus according to an eleventh aspect of the invention includes a refrigerant circuit having at least a compressor, an indoor heat exchanger, an expansion mechanism, and an outdoor heat exchanger, and capable of performing switching between a cooling operation and a heating operation, and a refrigerant A refrigeration cycle is carried out by circulating in the circuit. The molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and the molecular structure Either a single refrigerant composed of a refrigerant having one double bond therein or a mixed refrigerant containing a refrigerant, an indoor air blowing mechanism that sends air to the indoor heat exchanger, and an outdoor air fan that sends air to the outdoor heat exchanger And a mechanism. The air flow speed generated by the outdoor air blowing mechanism is faster than the air flow speed generated by the indoor air blowing mechanism.

  In this refrigeration apparatus, it is possible to make it difficult for frost formation in the outdoor heat exchanger to occur.

A refrigeration apparatus according to a twelfth aspect of the present invention includes a refrigerant circuit having at least a compressor, an indoor heat exchanger, an expansion mechanism, and an outdoor heat exchanger, and capable of switching between a cooling operation and a heating operation, and a refrigerant A refrigeration cycle is carried out by circulating in the circuit. The molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and the molecular structure Either a single refrigerant composed of a refrigerant having one double bond therein or a mixed refrigerant containing a refrigerant, and a blower mechanism for supplying an air flow to the outdoor heat exchanger are provided. The outdoor heat exchanger has a plurality of fins, and the ventilation resistance when the air flow passes between the fins is lower on the leeward side than on the leeward side.

  In this refrigeration apparatus, frost formation on the windward side can be made difficult to occur.

  In the refrigeration apparatus of the thirteenth invention, in any one of the refrigeration apparatuses of the first to twelfth inventions, the working refrigerant is a single refrigerant made of 2,3,3,3-tetrafluoro-1-propene.

  In this refrigeration apparatus, the ozone depletion coefficient can be set to 0, and the operation in the refrigeration cycle can be made favorable.

  In the refrigeration apparatus according to the fourteenth aspect, in the refrigeration apparatus according to any one of the first to twelfth aspects, the working refrigerant is a mixed refrigerant of 2,3,3,3-tetrafluoro-1-propene and difluoromethane, or , 2,3,3,3-tetrafluoro-1-propene and pentafluoroethane mixed refrigerant.

  In this refrigeration apparatus, the ozone depletion coefficient is set to 0, and the operation in the refrigeration cycle can be improved even if the refrigerant temperature tends to change during the phase change.

  In the refrigeration apparatus of the first invention, it is possible to defrost frost adhering to the outdoor heat exchanger while setting the ozone layer depletion coefficient to 0, and frost adhering to the outdoor heat exchanger becomes a wind of the outdoor heat exchanger. It is possible to continue the operation of functioning as an evaporator by increasing the time required to cover the upper side for a longer time.

  In the refrigeration apparatus of the second invention, it is possible to suppress the adhesion of frost while suppressing a decrease in heat exchange capacity.

  In the refrigeration apparatus according to the third aspect of the present invention, it is possible to more reliably suppress adhesion of frost while suppressing a decrease in heat exchange capability.

  In the refrigeration apparatus according to the fourth aspect of the invention, it is possible to suppress adhesion of frost while suppressing a decrease in heat exchange capacity.

  In the refrigeration apparatus of the fifth aspect of the invention, it is possible to suppress frost adhesion and growth in the outdoor heat exchanger while ensuring the capacity of the indoor heat exchanger.

  In the refrigeration apparatus of the sixth aspect of the invention, it is possible to more effectively suppress frost formation and frost growth in the outdoor heat exchanger.

  In the refrigeration apparatus according to the seventh aspect of the invention, the discharged refrigerant has the frost adhered in a state where the outdoor heat exchanger functions as an evaporator, and is operated by connecting the outdoor heat exchanger to the discharge side of the compression mechanism. It becomes possible to thaw using heat.

  In the refrigeration apparatus according to the eighth aspect of the invention, the predetermined condition is determined based on the state quantity of the portion where frost formation is likely to occur, so it is possible to more reliably suppress frost formation and frost growth in the outdoor heat exchanger.

  In the refrigeration apparatus of the ninth aspect, by reducing the ventilation resistance on the windward side, frost formation can be made difficult when functioning as an evaporator.

  In the refrigeration apparatus of the tenth aspect, frost formation in the outdoor heat exchanger can be made difficult to occur.

  In the refrigeration apparatus of the eleventh aspect, frost formation in the outdoor heat exchanger can be made difficult to occur.

  In the refrigeration apparatus of the twelfth aspect, frost formation on the windward side can be made difficult to occur.

  In the refrigeration apparatus of the thirteenth aspect of the invention, the ozone depletion coefficient can be set to 0, and the operation in the refrigeration cycle can be improved.

  In the refrigeration apparatus according to the fourteenth aspect of the invention, the ozone layer destruction coefficient is set to 0, and the operation in the refrigeration cycle can be improved even if the refrigerant temperature tends to change during the phase change.

The figure which shows the example of the refrigerant circuit which can apply this invention. The ph diagram which shows the example of the refrigerating cycle of the single refrigerant | coolant of this invention. The Ts diagram which shows the example of the refrigerating cycle of the single refrigerant | coolant of this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the example of the refrigerant circuit which can apply this invention. The figure which shows the heat exchanger of 1st Embodiment. The figure which shows the example of the fin of the modification (3) of 1st Embodiment. The figure which shows the example of the refrigerant circuit of the modification (8) of 1st Embodiment. The figure which shows the other example of the refrigerant circuit of the modification (8) of 1st Embodiment. The figure which shows the heat exchanger of 1st reference embodiment. The figure which shows the heat exchanger of the modification of 1st reference embodiment. The figure which shows the heat exchanger of the modification of 1st reference embodiment. The figure which shows the heat exchanger of the modification of 1st reference embodiment. The figure which shows the heat exchanger of the modification of 1st reference embodiment. The ph diagram in the heat exchanger for comparing with the modification of 1st reference embodiment. The ph diagram in the heat exchanger of the modification of 1st reference embodiment. The figure which shows the mode of frost formation of the heat exchanger of 2nd reference embodiment. The figure which shows the mode of the defrost of the heat exchanger of 2nd reference embodiment. The figure which shows the conventional refrigerant | coolant communication piping. The figure which shows the conventional refrigerant | coolant communication piping. The figure which shows the refrigerant | coolant communication piping of 3rd reference embodiment. The figure which shows the refrigerant | coolant communication piping of the modification of 3rd reference embodiment. The figure which shows the refrigerant | coolant communication piping of the modification of 3rd reference embodiment. The figure which shows the refrigerant | coolant communication piping of the modification of 3rd reference embodiment. The figure which shows the conventional reheat dehumidification heat exchanger. The figure which shows the reheat dehumidification heat exchanger of 4th reference embodiment. The figure which shows the heat exchanger tube of 5th reference embodiment. The figure which shows the heat exchanger tube of the modification of 5th reference embodiment. The figure which shows the conventional heat exchanger. The figure which shows the heat exchanger of the modification of 5th reference embodiment. The figure which shows the conventional heat exchanger. The figure which shows the heat exchanger of the modification of 5th reference embodiment. The figure which shows the conventional heat exchanger tube material. The figure which shows the heat exchanger tube material of 6th reference embodiment. The figure which shows the heat exchanger tube material of 6th reference embodiment. The figure which shows the heat exchanger tube of the modification of 6th reference embodiment. The figure which shows the heat exchanger of 7th reference embodiment. The figure which shows the heat exchanger of 8th reference embodiment. The figure which shows the heat exchanger of 8th reference embodiment.

  Hereinafter, a plurality of embodiments will be described as examples of embodiments of the present invention.

  As long as there is no contradiction with each other, embodiments described below can adopt embodiments in which different embodiments are freely combined, and embodiments by this combination are also included in the present invention. In addition, as this combination, it is more preferable to employ a combination that exhibits not only individual effects but also synergistic effects.

<1> Example of refrigeration cycle Hereinafter, before showing an example of an embodiment of the present invention, an example of a refrigeration cycle to which the present invention is applied will be described.

  In addition, the refrigeration cycle shown below shows the example of the refrigeration cycle to which this invention is applied, Comprising: The refrigeration cycle which can apply this invention is not limited to the following refrigeration cycles.

  In the following description, the heat exchanger indicated by member number 4 means an outdoor heat exchanger installed in a space other than the air-conditioned space such as outdoors, and the heat exchanger indicated by member number 6 It means an indoor heat exchanger installed in an air-conditioned space such as a room.

(1-A) Cooling Application Refrigeration Cycle FIG. 1 shows an example of a refrigerant circuit 10A included in an air conditioner 1 that performs a cooling-only refrigeration cycle.

  The refrigerant circuit 10 includes a compressor 2, a condenser 4 installed outdoors, an expansion valve 5, and an evaporator 6 installed indoors in this order, and the refrigerant circulates in the interior. Perform a refrigeration cycle. The compressor 2 is driven by a motor 2a.

  Here, the refrigerant that operates in the refrigerant circuit 10A may be a single refrigerant or a mixed refrigerant.

  As such a refrigerant, for example, a single refrigerant made of HFO-1234yf (2,3,3,3-tetrafluoro-1-propene) can be used.

In place of this refrigerant, for example, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6) is used, and two in the molecular structure. A single refrigerant composed of a refrigerant having one double bond can be used. For example, HFO-1225ye (1,2,3,3,3-pentafluoro-1-propene, chemical formula: CF ₃ —CF═CHF), HFO-1234ze (1,3,3,3-tetrafluoro-1- Propene, chemical formula: CF ₃ —CH═CHF), HFO-1234ye (1,2,3,3-tetrafluoro-1-propene, chemical formula: CHF ₂ —CF═CHF), HFO-1243zf (3, 3, 3 - trifluoro-1-propene, chemical _{formula: CF 3 -CH = CH 2)} , 1,2,2- trifluoro-1-propene (chemical _{formula: CH 3 -CF = CF 2)} , 2- fluoro-1-propene (Chemical formula: CH ₃ —CF═CH ₂ ) or the like can be used.

  Moreover, you may use the mixed refrigerant | coolant containing the above-mentioned refrigerant | coolant. For example, there is a mixed refrigerant of HFO-1234yf (2,3,3,3-tetrafluoro-1-propene) and HFC-32 (difluoromethane). Here, as a composition of this mixed refrigerant, the ratio of HFO-1234yf is 70% by mass or more and 94% by mass or less, and the ratio of HFC-32 is 6% by mass or more and 30% by mass or less, preferably HFO-1234yf. The proportion is 77% by mass or more and 87% by mass or less, and the proportion of HFC-32 is preferably 13% by mass or more and 23% by mass or less. More preferably, the proportion of HFO-1234yf is 77% by mass or more and 79% by mass or less. Is preferably 21% by mass to 23% by mass (for example, a mixed refrigerant of 78% by mass of HFO-1234yf and 22% by mass of HFC-32). Further, there is a mixed refrigerant of HFO-1234yf (2,3,3,3-tetrafluoro-1-propene) and HFC-125 (pentafluoroethane). Here, the composition of the mixed refrigerant is such that the ratio of HFO-1234yf is 90% by mass or less and the ratio of HFC-125 is 10% by mass or more, preferably, the ratio of HFO-1234yf is 80% by mass or more and 90% by mass. %, The ratio of HFC-125 is preferably 10% by mass or more and 20% by mass or less. In addition, other HFC refrigerants such as HFC-134 (1,1,2,2-tetrafluoroethane), HFC-134a (1,1,1,2-tetrafluoroethane), HFC-143a (1, 1,1-trifluoroethane), HFC-152a (1,1-difluoroethane), HFC-161 (fluoroethane), HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane) HFC-236ea (1,1,1,2,3,3-hexafluoropropane), HFC-236fa (1,1,1,3,3,3-hexafluoropropane), HFC-365mfc (1,1 , 1,3,3-pentafluorobutane) or the like may be used. In addition, other refrigerants such as hydrocarbons, not HFC refrigerants, such as methane, ethane, propane, propene, butane, isobutane, pentane, 2-methylbutane, cyclopentane, dimethyl ether, bis-trifluoromethyl-sulfide, A mixed refrigerant with carbon dioxide, helium or the like may be used.

Further, refrigerants represented by molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5 and m + n = 6) and having one double bond in the molecular structure Or a molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and a double bond in the molecular structure And other refrigerants such as the above-mentioned HFC refrigerants and hydrocarbons, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and a mixed refrigerant composed of three or more components including at least one refrigerant having one double bond in the molecular structure may be used. For example, there is a mixed refrigerant of HFO-1234yf, HFC-32, and HFC-125 (for example, a mixed refrigerant of 52% by weight of HFO-1234yf, 23% by mass of HFC-32, and 25% by weight of HFC-125). .

  In the refrigerant circuit 10A filled with the above refrigerant, the refrigerant discharged from the compressor 2 is condensed in the condenser to become liquid refrigerant, and the liquid refrigerant is decompressed by the expansion valve 5 and becomes gas refrigerant through the evaporator. The refrigeration cycle is executed by returning to the compressor 2.

  FIG. 2 is a ph diagram when the refrigeration cycle is performed using HFO-1234yf (2,3,3,3-tetrafluoro-1-propene) as a single refrigerant in the refrigerant circuit 10A. Show. FIG. 3 is a Ts diagram when the refrigeration cycle is performed using HFO-1234yf (2,3,3,3-tetrafluoro-1-propene) as a single refrigerant in the refrigerant circuit 10A. Show.

  In the cooling-only refrigeration cycle, the refrigerant circulates in the order of A → B → C → D → A in the portion indicated by points A to D in the refrigerant circuit 10A in FIG. 2 and 3 are the same in that the refrigerant circulates in the order of A → B → C → D → A.

  The behavior of the refrigerant shown in FIG. 2 and FIG. 3 is an example when used in the cooling-only refrigeration cycle, and points A, B, C, and D are points in the cooling-only refrigeration cycle shown in FIG. Show. In the drawings showing other refrigerant circuits, the points A, B, C, D,... Are shown, but these are not the same state but different ones. It shows the points based on the circuit.

(1-B) Heating-only refrigeration cycle FIG. 4 shows an example of the refrigerant circuit 10B of the air-conditioning apparatus 1 that performs the heating-only refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  Here, the discharge side of the compressor 2 is connected to a condenser 6 installed indoors. Further, the refrigerant evaporated in the evaporator 4 installed outdoors is sucked into the compressor 2.

  The refrigerant circuit 10A is provided with a temperature sensor 4a capable of detecting the temperature in the vicinity of the evaporator 4 installed outdoors, and a control unit 4b for controlling the operation of the refrigerant circuit 10A. This control part 4b performs control which stops the driving | operation in the refrigerant circuit 10B, when the temperature which the temperature sensor 4a detects becomes below the atmospheric pressure equivalent temperature of a refrigerant | coolant. Thereby, the situation where frost formation to the evaporator 4 installed outdoors can be avoided.

(1-C) Cooling / heating switching refrigeration cycle FIG. 5 shows an example of a refrigerant circuit 10C of the air-conditioning apparatus 1 that performs the cooling / heating switching refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  Here, there is a four-way switching valve 3 for switching the four connection objects of the discharge side, the suction side, the indoor heat exchanger (condenser, evaporator), and the outdoor heat exchanger (evaporator, condenser) of the compressor 2. Is provided. Other configurations are the same as those of the refrigerant circuit 10A described above.

  In the four-way switching valve 3 shown in FIG. 5, the connection state when the cooling operation is performed is indicated by a solid line, and the connection state when the heating operation is performed is indicated by a dotted line.

(1-D) Accumulator refrigeration cycle FIG. 6 shows an example of a refrigerant circuit 10D of the air conditioner 1 that performs the accumulator refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  Here, an accumulator 7 is provided between the four-way switching valve 3 and the suction side of the compressor 2. In this accumulator refrigeration cycle, the risk of liquid compression occurring in the compressor 2 is reduced. Other configurations are the same as those of the refrigerant circuit 10C described above.

(1-E) Receiver Refrigeration Cycle FIG. 7 shows an example of the refrigerant circuit 10E included in the air conditioner 1 that performs the receiver refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  Here, a receiver 8 is provided between the outdoor heat exchanger 4 (condenser and evaporator) and the expansion valve 5. In this receiver refrigeration cycle, the receiver 8 can absorb the change in the amount of circulating refrigerant corresponding to the load fluctuation around the refrigerant circuit 10D. Other configurations are the same as those of the refrigerant circuit 10A described above.

(1-F) Liquid Gas Heat Exchanger Refrigeration Cycle FIG. 8 shows an example of the refrigerant circuit 10F included in the air conditioner 1 that performs the liquid gas heat exchanger refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  Here, the part through which the liquid refrigerant from the outdoor heat exchanger 4 (condenser) to the expansion valve 5 passes, the part through which the gas refrigerant from the indoor heat exchanger 6 to the suction side of the compressor 2 passes, A liquid gas heat exchange circuit 9 having a liquid gas heat exchanger 9a for performing heat exchange between the two is provided. Here, it is possible to avoid the liquid compression by increasing the circulation amount of the liquid refrigerant to improve the refrigerating capacity and applying appropriate superheat to the refrigerant sucked in the compressor 2. Other configurations are the same as those of the refrigerant circuit 10A described above.

(1-G) Supercooling Refrigeration Cycle FIG. 9 shows an example of a refrigerant circuit 10G included in the air conditioner 1 that performs the supercooling refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  Here, a subcooling circuit 11 is provided in which a part of the refrigerant decompressed in the expansion valve 5 is branched and returned to the suction side of the compressor 2. The supercooling circuit 11 is provided with a supercooling expansion valve 11b that depressurizes the branched refrigerant. And the supercooling circuit 11 has the supercooling heat exchanger 11a which heat-exchanges between the refrigerant | coolant branched and pressure-reduced by the supercooling expansion valve 11b, and the refrigerant | coolant which goes to the evaporator 6 without branching. Yes. Since the enthalpy of the refrigerant going to the evaporator 6 can be further reduced in this way, the coefficient of performance (COP) can be improved. Other configurations are the same as those of the refrigerant circuit 10C described above.

(1-H) Oil Separation Refrigeration Cycle FIG. 10 shows an example of the refrigerant circuit 10H included in the air conditioner 1 that performs the oil separation refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  Here, an oil separation circuit 12 is provided for returning a circuit branched from the discharge side of the compressor 2 to the four-way switching valve 3 to the suction side of the compressor 2. The oil separation circuit 12 is provided with an oil separator 12a that separates the refrigeration oil from the discharged refrigerant, a filter 12b that passes the refrigeration oil recovered in the oil separator 12a, and a capillary tube 12c that decompresses the oil. Thereby, exhaustion of refrigerating machine oil due to an increase in the temperature of the discharged refrigerant can be avoided. Other configurations are the same as those of the refrigerant circuit 10C described above.

(1-I) Hot gas bypass refrigeration cycle FIG. 11 shows an example of the refrigerant circuit 10I of the air conditioner 1 that performs the hot gas bypass refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  The refrigerant circuit 10I is provided with a hot gas bypass circuit 13 that mixes a part of the gas refrigerant discharged from the compressor 2 in the refrigerant circuit 10I with the refrigerant passing through the expansion valve 5 and going to the evaporator 6. ing. The hot gas bypass circuit 13 is provided with a hot gas bypass expansion valve 13 a that can adjust the bypass amount of the refrigerant discharged from the compressor 2. By adjusting the flow rate by the hot gas bypass expansion valve 13a, the state of the refrigerant sucked by the compressor 2 can be stabilized even when the load on the evaporator 6 is reduced. Other configurations are the same as those of the refrigerant circuit 10C described above.

(1-J) Two-stage compression refrigeration cycle FIG. 12 shows an example of the refrigerant circuit 10J of the air conditioner 1 that performs the two-stage compression refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  The refrigerant circuit 10J is provided with a two-stage compression circuit 14 that compresses the refrigerant in two stages using a two-stage compression type compressor as the compressor 2. The two-stage compression circuit 14 is condensed by a low-stage compressor, an intermediate cooler 14a for cooling the refrigerant discharged from the low-stage compressor, a receiver 14b for collecting the refrigerant flowing out of the intermediate cooler 14a, and the condenser 4. There are provided an expansion valve 5a for depressurizing the refrigerant toward the receiver 14b, a high stage compressor for sucking and compressing the gas refrigerant accumulated in the receiver 14b, and an expansion valve 5b for depressurizing the refrigerant toward the evaporator 6 from the receiver 14b. ing. The refrigerant cooled by the intermediate cooler 1a accumulates in the receiver 14b. Further, the refrigerant condensed by the condenser 4 and decompressed by the expansion valve 5a also accumulates in the receiver 14b and is mixed with the refrigerant cooled by the intermediate cooler 14a. The gas refrigerant in the receiver 14b is sucked into the high-stage compressor, but since the sucked refrigerant is cooled, an excessive temperature rise in the high-stage discharge pipe can be prevented, and deterioration and depletion of the refrigerator oil can be prevented. Can be prevented. Moreover, the pressure ratio per stage can be reduced. Other configurations are the same as those of the refrigerant circuit 10C described above.

(1-K) Multi Refrigeration Cycle FIG. 13 shows an example of the refrigerant circuit 10K included in the air conditioner 1 that performs the multi refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  The refrigerant circuit 10K is provided with a plurality of evaporators 6 installed indoors and a multi-refrigerant circuit 15 installed in parallel. Other configurations are the same as those of the refrigerant circuit 10C described above.

(1-L) Steam Bypass Refrigeration Cycle FIG. 14 shows an example of a refrigerant circuit 10L included in the air conditioner 1 that performs the steam refrigeration cycle. As the refrigerant used here, any one of the single refrigerant and the mixed refrigerant exemplified as the refrigerant used in the above-described cooling-only refrigeration cycle can be used.

  The refrigerant circuit 10L includes an accumulator 17b that separates the refrigerant that has been condensed by the condenser 6 and decompressed by the expansion valve 5 and before flowing into the evaporator 4 into a gas refrigerant and a liquid refrigerant. The evaporator 4 that evaporates only the liquid refrigerant excluding the gas refrigerant out of the refrigerant, the expansion valve 17a that depressurizes the gas refrigerant among the refrigerant in the accumulator 17b, and the flow of the refrigerant decompressed by the expansion valve 17a There is provided a steam bypass circuit 17 provided with a check valve 17c that allows only the flow toward the suction side. Here, since the gas refrigerant is removed from the refrigerant flowing into the evaporator 4, it is possible to reduce the gas refrigerant that does not contribute to heat exchange with the air or the like in the evaporator 4, which is a particular problem when the refrigerant is used. Thus, the pressure loss in the evaporator 4 can be reduced. Other configurations are the same as those of the refrigerant circuit 10C described above.

  In addition to this, the vapor bypass circuit 17 is arranged in the same way as the accumulator 17b in the portion where the pressure loss due to the evaporated refrigerant becomes remarkable in the middle of the evaporator 4 to evaporate. The gas refrigerant may be extracted from the middle of the vessel 4. In this case, the gas refrigerant after being evaporated in the evaporator 4 can be extracted, and the pressure loss in the evaporator 4 can be reduced more effectively.

<1> First Embodiment <1-1> Fin pitch of heat exchanger The structure and arrangement of the heat exchanger in the first embodiment described below are described above as examples of the refrigeration cycle (1-A) to (1). -L), any refrigeration cycle capable of switching between cooling operation and heating operation can be applied. Further, even if the cycle is not a switchable between the cooling operation and the heating operation, for example, as in the refrigeration cycle of (1-B), compression is performed with the valve opening degree of the expansion valve 5 fully opened when performing the heating operation. The present invention can also be applied to a refrigeration cycle that can switch between the case of sending a high-temperature and high-pressure refrigerant discharged from the machine 2. And the heat exchanger of 1st Embodiment is the single refrigerant | coolant and mixing which were illustrated in the column of said (1-A) in the refrigeration cycle in any one of (1-A)-(1-L) mentioned above. Any one of the refrigerants can be employed as a heat exchanger in a refrigeration apparatus that is used as a working refrigerant. In addition, as a single refrigerant | coolant here, the single refrigerant | coolant which consists of 2,3,3,3-tetrafluoro-1-propene can be used, for example.

  Examples of the outdoor unit having the heat exchanger according to the first embodiment include the following.

  As shown in FIG. 15, the outdoor unit 23 is an upwind side of an air flow formed by a machine group 20 such as a compressor arranged in a machine room, a blower 21 and a motor 21 m arranged in the blower room, and the blower 21. And a heat exchanger 22b disposed on the leeward side. Here, the fin pitch of the heat exchanger 22a arranged on the leeward side is larger than the fin pitch of the heat exchanger 22b arranged on the leeward side. Thereby, when functioning as an evaporator, it is possible to disperse frost that tends to occur intensively on the leeward side, and to suppress the growth of the frost that has formed.

<1-2> Modification of First Embodiment (1)
The fin pitch of the outdoor heat exchanger may be designed to be wider than the fin pitch of the indoor heat exchanger. In this case, when functioning as an evaporator during heating operation, the evaporation temperature may be 0 ° C. or lower in any of the single refrigerant and the mixed refrigerant exemplified in the section (1-A). However, frost formation is less likely to occur in the outdoor heat exchanger.

  In addition, the single refrigerant and the mixed refrigerant exemplified in the above (1-A) column have a specific volume larger than that of R-410A that has been conventionally used, so that the pressure loss due to the gasified refrigerant in the evaporator is significant. Temperature drop in the evaporator can be more problematic. Even in this case, it is possible to make it difficult to form frost by adopting the outdoor heat exchanger that hardly forms frost as described above.

  Note that when a non-azeotropic refrigerant mixture is employed as one of the single refrigerant and the mixed refrigerant exemplified in the section (1-A) above, the refrigerant temperature rises in the evaporation step. The refrigerant temperature at the refrigerant inlet of the vessel is the lowest. For this reason, you may employ | adopt the structure which widened the fin pitch especially in the inlet_port | entrance of an evaporator.

  Further, for example, the windward fin pitch of the outdoor heat exchanger (two rows) can be 1.6 mm, and the leeward fin pitch can be 1.4 mm. On the other hand, the performance can be improved by setting the windward fin pitch of the indoor heat exchanger to 1.2 mm and the leeward fin pitch to 1.1 mm, which is narrower than the outdoor heat exchanger. Furthermore, when there is much frost formation of an outdoor heat exchanger, it is good also as a structure which made the fin pitch common to only two rows about an indoor heat exchanger.

(2)
You may control so that the wind speed of the air blower which forms an air flow with respect to an outdoor heat exchanger becomes larger than the air speed of the air blower which forms an air flow with respect to an indoor heat exchanger. In addition, the fan may be designed in advance so as to have such a wind speed relationship, or the rating of the fan motor may be determined. Also in this case, as described above, frost formation in the outdoor heat exchanger can be reduced.

(3)
For the plurality of fins of the outdoor heat exchanger, the ventilation resistance of the fins arranged on the leeward side of the air flow is made smaller than the ventilation resistance of the fins arranged on the leeward side of the air flow. It may be configured. For example, as shown in FIG. 16, the shape of the fin 4Fa on the leeward side is made flat, and the shape of the fin 4Fb on the leeward side is provided with a cut portion and a slit S. Also in this case, as described above, frost formation in the outdoor heat exchanger can be reduced. Here, it is sufficient that the wind resistance on the windward side is smaller than the wind resistance on the leeward side, and the fin pitches on the windward side and the leeward side may be the same, or the windward side may be narrow. .

(4)
The fins of the outdoor heat exchanger may be formed with a film having lubricity by being subjected to surface treatment. On the fin having such a sliding property, the water droplet slides down without staying in place. Therefore, also in this case, it is possible to reduce frost formation in the outdoor heat exchanger as described above.

(5)
The problem of frost formation as described above is that when a refrigerant having a low evaporation pressure is employed as a working refrigerant in a refrigeration cycle, the temperature drop due to the pressure loss of the refrigerant in the evaporator is large and may be well below 0 ° C. Depending on the nature, it may be noticeable. In addition, when a non-azeotropic refrigerant mixture is employed, the refrigerant temperature at the evaporator inlet is the lowest and may be much lower than 0 ° C., so that the problem that frost formation is likely to occur in this part becomes significant. . These problems can be improved in the first embodiment and its modifications.

(6)
In the first embodiment, when the heating operation state and the defrosting operation state are switched by switching the connection state of the four-way switching valve 3, or when the opening degree of the expansion valve 5 is adjusted, the heating operation state and the removal operation state are removed. The case where the frost operation state is switched has been described.

  Here, such switching may be automatically controlled by the control unit 4b or the like. For example, the control unit 4b or the like determines whether or not the heating operation state has been continuously performed for a predetermined time or more, and performs control to switch to the defrosting operation state when the heating operation state has continued for a predetermined time. You may do it.

  Further, the switching from the heating operation state to the defrosting operation state is performed, for example, whether or not the refrigerant temperature passing through the outdoor heat exchanger 4 is continuously performed for a predetermined time or more in a state where the refrigerant temperature is 0 ° C. or less. It is good also as a judgment standard.

  Thereby, while being able to thaw | defrost the frost adhering to the outdoor heat exchanger 4, the time required for the frost adhering to the outdoor heat exchanger 4 to cover the windward side of the outdoor heat exchanger 4 is lengthened. Can do. For this reason, the heating operation state in which the outdoor heat exchanger 4 functions as a refrigerant evaporator can be continued for a longer time without interposing the defrosting operation state.

(7)
In the said 1st Embodiment, the case where the fin pitch of the windward side was simply larger than the fin pitch of the leeward side about the outdoor heat exchanger 4 was demonstrated.

  Here, for example, the difference between the leeward side and the leeward side of the fin pitch of the outdoor heat exchanger 4 is designed so that the fin pitch on the leeward side is 1.3 to 1.5 times the fin pitch on the leeward side. May be. For example, the fin pitch on the leeward side may be about 1.4 to 1.6 mm, and the fin pitch on the leeward side may be about 1.2 mm.

(8)
In the said 1st Embodiment, the case where it did not specifically limit about a single refrigerant | coolant and a mixed refrigerant was demonstrated.

  For example, when the above-described mixed refrigerant is used in a refrigeration apparatus, for example, as shown in FIG. 17, in the heating operation state in which the outdoor heat exchanger 4 functions as a refrigerant evaporator, the upstream side in the refrigerant flow direction is You may make it provide the temperature sensor T4a which can detect the temperature of the refrigerant | coolant which passes. Then, the control unit 4b may switch between the heating operation state and the defrosting operation state based on the temperature detected by the temperature sensor T4a. The mixed refrigerant has a property that the temperature rises as it moves in the outdoor heat exchanger 4 that functions as an evaporator under the same pressure. For this reason, in the heating operation state in which the outdoor heat exchanger 4 functions as an evaporator, the temperature on the refrigerant inlet side is the lowest temperature, which is the portion where frost formation and frost growth are most likely to occur. On the other hand, here, the temperature sensor T4a detects the temperature of the refrigerant passing through the portion where frost formation is likely to occur, and the heating operation state and the defrosting operation state are switched based on the detected value. it can. For this reason, it is possible to more reliably suppress frost formation and frost growth in the outdoor heat exchanger 4. At least in the heating operation state, the air flow speed that the outdoor blower fan 21 supplies to the outdoor heat exchanger 4 is faster than the air flow speed that the indoor blower fan 25 supplies to the indoor heat exchanger 6. As such, the control unit 4b may be controlled.

  Examples of the mixed refrigerant here include a mixed refrigerant of 2,3,3,3-tetrafluoro-1-propene and difluoromethane, and 2,3,3,3-tetrafluoro-1-propene and pentafluoro. A mixed refrigerant with ethane may be used.

  In addition, the temperature of the refrigerant | coolant inlet in case the outdoor heat exchanger 4 functions as an evaporator is not restricted to the detected value by the said temperature sensor T4a. For example, as shown in FIG. 18, the temperature sensor T6a that detects the temperature of the refrigerant that flows between the indoor heat exchanger 6 and the expansion valve 5, and the refrigerant that flows between the indoor heat exchanger 6 and the expansion valve 5 A pressure sensor P6a for detecting the pressure and a pressure sensor P4a for detecting the pressure of the refrigerant flowing between the outdoor heat exchanger 4 and the expansion valve 5 are provided, and the outdoor heat exchanger 4 is utilized using the values detected by these. The temperature at the inlet side of the refrigerant may be obtained by conversion.

<2> First Reference Embodiment <2-1> Flow Direction of Refrigerant in Heat Exchanger The structure of the flow direction of refrigerant in the heat exchanger of the first reference embodiment described below is described above as an example of a refrigeration cycle. The present invention can be applied to any of the refrigeration cycles (1-A) to (1-L). Moreover, in any refrigeration cycle of (1-A) to (1-L), it can be applied as a heat exchanger described as an evaporator, or can be applied as a heat exchanger described as a condenser. . And the heat exchanger of 1st reference embodiment is the single refrigerant | coolant illustrated in the column of the said (1-A) in the refrigeration cycle in any one of (1-A)-(1-L) mentioned above. Or any of the mixed refrigerants can be employed as a heat exchanger in a refrigeration apparatus in which a working refrigerant is used.

  As the heat exchanger of the first reference embodiment, for example, as in the heat exchanger 18A shown in FIG. 19, fins 18a and fins 18b are provided, and these are connected by a heat transfer tube through which a refrigerant flows. Can be. The fins 18a are arranged on the windward side in the air flow direction generated when the blower 18c is driven. Further, the fin 18b is disposed on the leeward side. Note that a plurality of fins 18a and 18b are provided so as to overlap in the depth direction in the drawing. The heat transfer tube reciprocates between the front side and the depth side of the drawing with respect to the fin 18b through the U-shaped tube, and then extends to the fin 18a side through the U-shaped tube. Also in the fin 18a, the heat transfer tube reciprocates between the front side and the depth side of the drawing via the U-shaped tube and extends to the outside of the heat exchanger. Here, a case where the heat exchanger functions as a condenser will be described as an example. Here, the refrigerant flows into the heat exchanger 18 from the fins 18b arranged on the downstream side of the air flow by the blower 18c, passes through the fins 18a arranged on the upstream side of the air flow, and passes through the heat exchanger. It is configured to flow outside. Thus, heat exchange efficiency can be reduced by making the flow of a refrigerant and the flow of air into a counter flow.

  In particular, when a non-azeotropic mixed refrigerant is employed as one of the single refrigerant and the mixed refrigerant exemplified in the section (1-A) above, in the two-phase region on the Ph diagram. The pressure-equivalent saturation temperature has a temperature gradient between the liquid refrigerant side (part with low dryness) and the gas refrigerant side (part with high dryness). Moreover, as the refrigerant pressure increases, the temperature gradient becomes steeper, and the difference between the refrigerant heat exchanger inlet temperature and the outlet temperature of the heat exchanger increases. For this reason, in particular, in the two-phase region (liquid rich portion) near the outlet when the heat exchanger functions as a condenser, such a counterflow is also used to secure a temperature difference between the air temperature and the refrigerant temperature. The structure is preferred.

<2-2> Modification of First Reference Embodiment (1)
As shown in FIG. 20, the heat exchanger 18 </ b> A may be a heat exchanger 18 </ b> B disposed on the upstream side of the air flow with respect to the refrigerant inlet of the heat exchanger.

  In particular, when a refrigerant is used in which the pressure loss due to the gas refrigerant gasified by evaporation is significant, the condenser adopts an arrangement in which the refrigerant flow and the air flow face each other, while the evaporator uses the refrigerant flow. An arrangement in which the air flow is parallel may be employed.

(2)
As shown in FIG. 21, the heat exchanger 18A guides the refrigerant flowing into the fin 18b on the leeward side to the fin 18a side once disposed on the windward side through the U-shaped tube, and then again the U-shaped tube. It is good also as a heat exchanger 18C comprised so that it may flow through the fin 18a on the leeward side via the U-shaped pipe through the fin 18b on the leeward side.

(3)
As shown in FIG. 22, the heat exchanger 18 </ b> A uses a connection pipe other than the U-shaped pipe in the portion of the heat exchanger of the modification (2) that flows from the leeward fin 18 a to the leeward fin 18 b. It is good also as comprised heat exchanger 18D.

(4)
As shown in FIG. 23, the heat exchanger 18A branches the refrigerant flowing into the heat exchanger and flows the refrigerant flowing into the fin 18b on the leeward side to the depth side of the figure, It is good also as the heat exchanger 18E comprised so that it may guide to the near side of a figure through the fin 18a of a windward side, and after making each refrigerant | coolant flow merge, it may flow out from a heat exchanger. In particular, when a high capacity is required in the heat exchanger and the refrigerant circulation amount is large, it is necessary to further reduce the pressure loss when functioning as an evaporator, and the configuration of this modification is particularly effective.

(5)
In the first reference embodiment and the modified examples (1) to (5), a non-azeotropic mixed refrigerant is employed as one of the single refrigerant and the mixed refrigerant exemplified in the section (1-A). In the two-phase region of the Ph diagram, the number of refrigerant flow divisions (number of passes), the length from branching to merging of each pass, so that the temperature gradient and pressure loss are equal, It is preferable to configure by adjusting the tube diameter of each heat transfer tube.

  For example, as shown in FIG. 24, when the liquid refrigerant undergoes a phase change to a gas refrigerant in the evaporator, the pressure equivalent saturation temperature increases toward the outlet of the heat exchanger under the same pressure. Since a sufficient temperature difference cannot be secured between the temperature and the increased refrigerant temperature, a decrease in evaporation performance may be a problem. For example, when the air temperature is 20 ° C., a temperature difference between the refrigerant temperature and the air temperature of about 15 ° C. (20 ° C.−5 ° C.) can be secured in the vicinity of the inlet. Only a temperature difference of about 7 ° C. (20 ° C.-13 ° C.) can be secured. In such a case, by adopting the heat exchanger configured as described above, as shown in FIG. 25, the temperature difference between the air temperature and the refrigerant temperature from the inlet to the outlet of the heat exchanger. Can be made difficult to reduce, and a decrease in heat exchange efficiency can be avoided. For example, when the air temperature is 20 ° C., the temperature difference between the refrigerant temperature and the air temperature can be kept about 15 ° C. (20 ° C.−5 ° C.) in the vicinity of the inlet and the outlet.

<3> Second Reference Embodiment <3-1> Refrigerant Inlet and Refrigerant Outlet of Heat Exchanger The structure and arrangement of the heat exchanger in the second reference embodiment described below have been described above as an example of a refrigeration cycle (1- Of A) to (1-L), any refrigeration cycle capable of switching between cooling operation and heating operation can be applied. And the heat exchanger of 2nd reference embodiment is the single refrigerant | coolant illustrated in the column of the said (1-A) in the refrigeration cycle in any one of (1-A)-(1-L) mentioned above, Any of the mixed refrigerants can be employed as a heat exchanger in the refrigeration apparatus in which the working refrigerant is used.

  As shown in FIG. 26, the heat exchanger 19 of the second reference embodiment is provided with fins 19a and fins 19b. These are the single refrigerants exemplified in the section (1-A) above. One of the mixed refrigerants may be connected by a heat transfer tube. The fins 19a are arranged on the windward side in the direction of air flow generated when the blower 19c is driven. Further, the fin 19b is arranged on the leeward side. Note that a plurality of fins 19a and 19b are provided so as to overlap in the depth direction in the drawing. Here, both the inlet and outlet of the refrigerant to the heat exchanger 19 are provided on the windward side of the air flow by the blower 19c. The inlet is located slightly above the middle of the height of the heat exchanger 19. The exit is located slightly below the entrance. The heat exchanger tube extending from the inlet of the heat exchanger 19 extends in the depth direction in the figure, and then is folded back by the U-shaped tube, and is repeatedly folded back by the U-shaped tube on the front side of the diagram, It extends to above 19. After reaching the vicinity of the upper end of the fin 19a, the heat transfer tube extends to the fin 19b disposed on the downstream side via the U-shaped tube, and extends downward while repeating the proper folding in the fin 19b. . After reaching the vicinity of the lower end of the fin 19b, the heat transfer tube extends to the windward fin 19a through the U-shaped tube, and extends to the vicinity of the outlet while repeating similar folding in the fin 19a. Here, the notch structure 19d which has the space of the width of the height direction narrower than the pitch of the height direction of a heat exchanger tube between the inlet and the outlet is adopted for the windward fin 19a.

  The heat exchanger 19 is provided as an outdoor heat exchanger in a refrigeration cycle capable of switching between cooling operation and heating operation.

  And it functions as an evaporator of a refrigerant | coolant at the time of heating operation. At this time, as shown in FIG. 26, frost formation may occur on the windward side of the heat exchanger 19 as an evaporator. In such a case, if the heat exchangeable portion of the surface of the heat exchanger 19 is filled and further frost grows, the ventilation resistance increases, thereby inhibiting heat exchange. There is. Therefore, in the refrigeration cycle in which the cooling / heating can be switched, as shown in FIG. Here, in the defrost operation, for example, the connection state of the four-way switching valve 3 is switched so that the indoor heat exchanger functions as a refrigerant evaporator and the outdoor heat exchanger functions as a refrigerant condenser. Sometimes a similar refrigeration cycle is performed. However, here, the operation of the indoor blower that supplies the air flow to the indoor heat exchanger is stopped in order to avoid sending cool air into the room during the heating operation. Since the refrigerant circulation direction is reversed by performing the defrost operation in this way, the windward side of the heat exchanger 19 functioning as an evaporator during the heating operation is the heat exchanger 19 functioning as a condenser during the defrost operation. It becomes the inlet side of the refrigerant. As a result, the high temperature and high pressure hot gas just discharged from the compressor 2 can be sent during the defrost operation to efficiently melt the frost against the windward side where frost formation is likely to occur during the heating operation. Further, the inlet of the hot gas refrigerant of the heat exchanger 19 at the time of defrosting operation is located slightly above the middle in the height direction of the heat exchanger 19, and then the heat transfer tube is located above the heat exchanger 19. Since it extends, the frost above the central vicinity of the heat exchanger 19 into which the hot gas refrigerant has flowed can be intensively melted. If it does so, the drain water produced when this frost melt | dissolves will flow down below, and the frost below can also be melt | dissolved in that case. As described above, the design is such that the inlet and the outlet of the hot gas refrigerant at the time of the defrost operation are close to each other, so that the effect of facilitating melting of the lower frost and the notch structure 19d are adopted. Therefore, heat is shut off between the entrance and exit, and the heat exchange efficiency of the heat exchanger 19 can be improved during heating operation. Moreover, even when the heat exchanger 19 functions as a condenser, the notch structure 19d eliminates the problem that it is difficult to supercool the refrigerant at the outlet by preventing heat conduction.

  In particular, when a non-azeotropic mixed refrigerant is employed as one of the single refrigerant and the mixed refrigerant exemplified in the section (1-A) above, in the two-phase region on the Ph diagram. The pressure-equivalent saturation temperature has a temperature gradient between the liquid refrigerant side (part with low dryness) and the gas refrigerant side (part with high dryness). For this reason, when the heat exchanger 19 is caused to function as an evaporator during the heating operation, the refrigerant temperature on the inlet side of the refrigerant is low, so that frost formation is likely to occur on the inlet side. On the other hand, in the heat exchanger 19 of the second reference embodiment, during defrost operation, the hot gas refrigerant is sent upward from the portion where frost formation is likely to occur, and drain water generated by melting with the frost above is supplied. The drain water can be supplied to a portion where frost formation is likely to occur due to its own weight, and the frost can be melted positively.

<4> Third Reference Embodiment <4-1> Refrigerant Communication Pipe The refrigerant connection pipe of the third reference embodiment described below is any one of (1-A) to (1-L) described above as an example of a refrigeration cycle. This can also be applied to the refrigeration cycle. In addition, about 3rd reference embodiment, it is not restricted to the refrigerant | coolant mentioned above, For example, even if it uses R-410A, R-407, R-134a, etc., the same kind of effect will be acquired.

  Conventionally, as shown in FIGS. 28 and 29, in the refrigerant communication pipes 930 and 935 connecting the indoor unit and the outdoor unit, the relatively thin liquid refrigerant communication pipes 932 and 937 and the relatively thick gas, respectively. Refrigerant communication pipes 933 and 938 are grouped together by refrigerant communication pipes 931 and 936. Here, for example, the liquid refrigerant communication pipe 932 is φ6.35, and the gas refrigerant communication pipe 933 is φ12.7. The liquid refrigerant communication pipe 937 has a diameter of 6.35, and the gas refrigerant communication pipe 938 has a diameter of 15.9.

  However, the larger the diameter of the gas refrigerant communication tube, the more difficult it is to bend during installation. Furthermore, the gas refrigerant communication tube may be flattened or buckled by bending, and the quality may be deteriorated. Moreover, it is necessary to provide a larger piping hole as the pipe diameter is larger, and restrictions are likely to be placed in the installation. In particular, when a refrigerant having a very large specific volume such as the refrigerant described above is employed, the pressure loss becomes significant in the gas refrigerant communication pipe, so the diameter of the gas refrigerant communication pipe and the pipe in the machine is increased. There was nothing else to deal with.

  On the other hand, these problems can be solved by adopting the refrigerant communication pipe of the following form as the refrigerant communication pipe of the third reference embodiment.

  As shown in FIG. 30, an expansion valve 5 is provided in the refrigerant communication pipe for connecting the indoor unit and the outdoor unit, the pipe on the side where the compressor 2 is connected to the indoor heat exchanger, and the outdoor heat exchanger. In such a case, the refrigerant communication pipe 30A can be employed for the pipe structure between the expansion valve and the indoor heat exchanger. This refrigerant communication pipe 30A employs a refrigerant communication pipe 31, one liquid refrigerant communication pipe L1 having a circular cross section, and two gas refrigerant communication pipes G1 and G2 having a circular cross section. Thus, by dividing the gas refrigerant communication pipes G1 and G2 into a plurality of pipes from the conventional one, the pipe diameter per pipe can be reduced, and the above problems can be solved. For example, the liquid refrigerant communication pipe L1 has a diameter of φ6.35, and the gas refrigerant communication pipes G1 and G2 have two diameters of φ9.52. The gas refrigerant communication pipe L1 may employ a flexible pipe to further improve the bending workability.

<4-2> Modification of Third Reference Embodiment (1)
As in the refrigerant communication pipe 30B shown in FIG. 31, the refrigerant communication pipe 31, one liquid refrigerant communication pipe L2 having a circular cross section, and three gas refrigerant communication pipes G3, G4, and G5 having a circular cross section are employed. May be. Here, the liquid refrigerant communication pipe L2 is arranged in a surplus position when the other three gas refrigerant communication pipes G1, G2, and G3 are arranged in the refrigerant communication distribution pipe 31 so as to contact each other. Here, for example, the pipe diameter of the liquid refrigerant communication pipe L2 is φ6.35, and the pipe diameters of the gas refrigerant communication pipes G3, G4, and G5 can be three φ9.52.

(2)
As shown in the refrigerant communication pipe 30C shown in FIG. 32, the refrigerant communication pipe 31, one liquid refrigerant communication pipe L3 having a circular cross section, and four gas refrigerant communication pipes G6, G7, G8, G9 having a circular cross section. May be adopted. Here, the liquid refrigerant communication pipe L3 has the same pipe diameter as the other four gas refrigerant communication pipes G6, G7, G8, and G9. Thereby, manufacturing cost can be reduced. Here, for example, the pipe diameter of the liquid refrigerant communication pipe L3 is φ6.35, and the pipe diameters of the gas refrigerant communication pipes G6, G7, G8, and G9 can be four φ6.35.

(3)
Like the refrigerant communication pipe 30D shown in FIG. 33, the refrigerant communication pipe 31, one liquid refrigerant communication pipe L4 having a circular cross section, and five gas refrigerant communication pipes G11, G12, G13, G14 having a circular cross section. G15 may be adopted. Here, the gas refrigerant communication pipe G13 having the largest cross-sectional shape is located in the center, and the liquid refrigerant communication pipe L4 and the other four gas refrigerant communication pipes G10, G11, G12, and G14 have the same pipe diameter. Yes, and arranged so as to contact the periphery of the gas refrigerant communication pipe G13. Here, for example, the diameter of the liquid refrigerant communication pipe L4 is φ6.35, and the gas refrigerant communication pipes G11, G12, G13, G14, and G15 have four pipe diameters of φ6.35 and φ9.52 of 1. It can be a book.

<5> Fourth Reference Embodiment <5-1> Indoor Heat Exchanger for Reheat Dehumidification Operation The refrigerant connection pipe of the fourth reference embodiment described below is the above-described (1-A) to ( It can be applied to any refrigeration cycle of 1-L). And the heat exchanger of 4th reference embodiment is the single refrigerant | coolant illustrated in the column of the said (1-A) in the refrigeration cycle in any one of (1-A)-(1-L) mentioned above, Any of the mixed refrigerants can be employed as a heat exchanger in the refrigeration apparatus in which the working refrigerant is used.

  Conventionally, as shown in FIG. 34, in order to reduce the indoor humidity without cooling the room, for example, a part of the indoor heat exchanger 940 is made to function as the reheat units 941 and 942 and the expansion valve 944 A configuration is adopted in which the decompressed refrigerant is evaporated by causing the other part of the indoor heat exchanger to function as the evaporator 943.

  However, when the above refrigerant having a low evaporation pressure is adopted, the specific volume is larger than that of the conventional R-410A or the like, so that the pressure loss becomes significant and the degree of temperature drop in the evaporator is large. turn into.

  On the other hand, as a heat exchanger of the fourth reference embodiment, for example, by adopting an indoor heat exchanger 40 shown in FIG. 35, these problems can be improved. Here, the indoor heat exchanger 40 has two evaporators 46 and 47 that function as an evaporator during the reheat dehumidifying operation, while one reheat unit 45 that functions as a condenser during the reheat dehumidifying operation. Thus, the area and capacity of the evaporating part are improved as compared with the prior art. Thereby, even if it is a case where a refrigerant | coolant with a large specific volume is used, the pressure loss in an evaporation part can be reduced. Then, the refrigerant condensed in the reheating unit 45 is branched into two and decompressed by the expansion valves 48 and 49, respectively, and then sent to the respective evaporation units 46 and 47. The reheat dehumidifying operation described above can be used during heating or cooling.

  In addition, when a non-azeotropic refrigerant mixture is adopted as the refrigerant, there is a temperature gradient in the evaporation process in the two-phase region of the ph diagram, and the temperature gradually rises. For this reason, the effect by the indoor heat exchanger 40 of the said 4th reference embodiment becomes more remarkable. In addition, when there is one refrigerant path, there is a possibility that the in-machine dew condensation problem due to refrigerant drift during cooling operation may occur. However, in the fourth reference embodiment, the refrigerant flow is divided into two paths, so that one path The pressure loss can be reduced as compared with the case where the same length is passed through.

  Further, the reheat unit 45 is disposed above the evaporation units 46 and 47 so that drain water generated in the evaporation units 46 and 47 does not enter the reheat unit 45.

<5-2>
(1)
In the configuration described above, the refrigerant that has passed through the reheat section is branched and two expansion valves 48 and 49 are provided. In particular, one expansion valve is used without branching, and the expanded refrigerant is branched. May be.

<6> Fifth Reference Embodiment <6-1> Heat Transfer Tube Shape of Heat Exchanger The refrigerant connection pipe of the fifth reference embodiment described below is the above-described (1-A) to (1- It can be applied to any refrigeration cycle of L).

  As the heat transfer tube of the fifth reference embodiment, an evaporator 50A can be employed as shown in FIG.

  In this evaporator 50A, the tube diameter of the heat transfer tube at the outlet of the gas refrigerant is made larger than the tube diameter of the heat transfer tube at the inlet of the liquid refrigerant. As a result, when any one of the single refrigerant and the mixed refrigerant exemplified in the column (1-A) having a large specific volume is employed, the pressure changes due to the phase change from the liquid refrigerant to the gas refrigerant in the evaporator. Even if the loss increases, the diameter of the pressure loss increases because the pipe diameter is widened at that portion. Here, a thin heat transfer tube is connected by a thin U-shaped tube at the end, and a configuration in which the tube diameter of the outlet is larger than the inlet is adopted in the U-shaped tube used in a portion that transitions to a thick heat transfer tube.

  Here, in which part of the evaporator 50A the diameter of the heat transfer tube is increased is determined by the balance between the elimination of the pressure loss and the reduction of the heat exchange amount by reducing the flow velocity.

<6-2> Modification of Fifth Reference Embodiment (1)
As shown in FIG. 37, a heat transfer tube 50B having a portion in which the diameter of the evaporator gradually increases from the liquid refrigerant side to the gas refrigerant side may be adopted for a part of the heat transfer tube of the evaporator.

(2)
Inside the heat transfer tube of the evaporator, a groove shape deeper on the liquid refrigerant side than on the gas refrigerant side may be provided, so that pressure loss due to the gas refrigerant may be reduced. Here, the gas refrigerant side may have a structure in which the peak height of the inner surface of the heat transfer tube is made lower, the number of grooves, the twist angle is made smaller, etc. than the liquid refrigerant side.

(3)
As a method of manufacturing the evaporator according to the modified example (2), when the heat transfer tube having a uniform groove shape is expanded from the inside, the extent of the expansion on the gas refrigerant side is larger than that on the liquid refrigerant side. Thus, the groove shape on the gas refrigerant side may be crushed and manufactured. In this way, the pressure loss can be reduced by smoothing the inner surface of the heat transfer tube on the gas refrigerant side.

(4)
Conventionally, as shown in FIG. 38, in an indoor heat exchanger 960 of a four-direction blowout ceiling embedded type indoor unit that sucks room air from the center by a centrifugal blower and blows it in a radial direction, an input pipe 962 and a path A long piping path structure is adopted in which the heat transfer tube at the end is folded back from 963 through the U-shaped tube to reach the outlet piping 964. For this reason, when any one of the single refrigerant and the mixed refrigerant exemplified in the column (1-A) having a large specific volume is used, the pressure loss becomes more remarkable.

  On the other hand, in this modification, as shown in FIG. 39, an indoor heat exchanger 60 is employed in which the substantially quadrangular prism shape is divided into two substantially equally so as to be L-shaped. The indoor heat exchanger 60 includes a first divided indoor heat exchanger 61, a second divided indoor heat exchanger 62, an inflow pipe 68, inflow paths 64 and 65, branch pipes 66 and 67, and outflow pipes 68 and 69. ing. The liquid refrigerant or the gas-liquid two-phase refrigerant flowing through the inflow pipe 68 is divided into inflow paths 66 and 67. The refrigerant branched in the inflow path 66 passes through the second branch indoor heat exchanger 62 through the branch pipe 66 and then flows in the outflow pipe 68 as a refrigerant in a gas state. The refrigerant branched in the inflow path 67 passes through the first branch indoor heat exchanger 61 through the branch pipe 67 and then flows through the outflow pipe 69. The gas refrigerant flowing through the outflow pipe 68 and the gas refrigerant flowing through the outflow pipe 69 then merge. Thereby, even if it is a case where any one of the single refrigerant | coolant and mixed refrigerant which were illustrated in the column of the said (1-A) is used as a working refrigerant, each piping path | route can be shortened and pressure loss is reduced. Can be made.

(5)
Conventionally, as shown in FIG. 40, the refrigerant is divided into a plurality of flow dividers 971 in the heat exchanger 970 and flows into the respective heat transfer tubes 972, and each flow path has a so-called hairpin shape. It flows back at the U-shaped tube 973 portion of the pipe. For this reason, the path is long and pressure loss becomes a problem.

  On the other hand, as shown in FIG. 41, like the heat exchanger 70, the refrigerant | coolant flow divided | segmented by the flow divider 71 is each guide | induced to each heat exchanger tube 72, and only toward one direction toward the header 73 in an other end. It may be configured to flow. In this case, since a folded portion such as a U-shaped tube is not provided, pressure loss can be reduced.

<7> Sixth Reference Embodiment <7-1> Welded Heat Transfer Tube The refrigerant connection pipe of the sixth reference embodiment described below is one of (1-A) to (1-L) described above as an example of a refrigeration cycle. This can also be applied to the refrigeration cycle. And the heat exchanger tube of 6th reference embodiment is the single refrigerant | coolant and mixing which were illustrated in the column of said (1-A) in the refrigeration cycle in any one of (1-A)-(1-L) mentioned above. Any of the refrigerants can be employed as a heat transfer tube in a refrigeration apparatus that is used as a working refrigerant.

  Conventionally, a seamless tube having an inner surface shape as shown in FIG. 42 is employed, and the one that increases the surface area of the heat transfer tube inner surface and improves the heat exchange performance while preventing refrigerant leakage from the heat transfer tube is used. It has been.

  On the other hand, in the heat transfer tube of the sixth reference embodiment, the inner surface as shown in FIG. 43 is used together with either the single refrigerant or the mixed refrigerant exemplified in the section (1-A). A seam pipe having a shape 80 and having a cylindrical shape by welding can be employed. Since the refrigerant employed here has a high boiling point and tends to have a low evaporation pressure, the risk of refrigerant leakage as in the conventional R-410A can be reduced. For this reason, a seam tube can be adopted as the heat transfer tube.

  Moreover, since the uneven | corrugated uneven | corrugated shape is provided in the inside of this heat exchanger tube instead of the groove | channel which repeats the same shape at fixed intervals, reduction of the pressure loss in a pipe | tube can be suppressed effectively.

<7-2> Modification of Sixth Reference Embodiment (1)
A pipe 81 having a trapezoidal shape instead of a rectangle as shown in FIG. 44 may be used, and a seam pipe 82 having different pipe diameters at one end and the other end as shown in FIG. 45 may be used. By adopting the thicker side of the seam pipe 82 on the gas refrigerant side of the evaporator, the pressure loss of the refrigerant can be reduced.

(2)
The inner surface shape of the seam tube may be a welded tube having a non-uniform uneven shape, instead of a spiral grooved tube having a groove with the same shape at regular intervals. Thereby, a heat transfer rate can also be improved.

<8> Seventh Reference Embodiment <8-1> Aluminum Laminate Heat Exchanger or Resin Heat Exchanger The refrigerant connection pipe of the seventh reference embodiment described below has been described above as an example of a refrigeration cycle (1-A) to It can be applied to any refrigeration cycle of (1-L). And the heat exchanger of 7th reference embodiment is the single refrigerant | coolant illustrated in the column of the said (1-A) in the refrigeration cycle in any one of (1-A)-(1-L) mentioned above, Any of the mixed refrigerants can be employed as a heat exchanger in the refrigeration apparatus in which the working refrigerant is used.

  As the heat exchanger of the seventh reference embodiment, an aluminum laminated heat exchanger 90 as shown in FIG. 46 can be adopted. This aluminum laminated heat exchanger 90 can be made thinner than a conventional fin-and-tube heat exchanger. Furthermore, since corrugated fins with high heat exchange efficiency are arranged between the flat tubes, the heat exchange efficiency per unit passage area is good. For this reason, when it is going to ensure the same amount of heat exchange, compared with the conventional fin and tube type thing, the size of aluminum lamination heat exchanger 90 itself can be made compact. Thereby, even if it is a small refrigerant | coolant flow rate, the efficiency of heat exchange can be improved. Moreover, the height direction dimension of a casing can also be made compact.

  Note that, in the aluminum laminated heat exchanger 90, a multi-hole tube is adopted at the connection portion between the flat tube and the header, and the effect of reducing the pressure loss when used as an evaporator becomes remarkable.

  Further, when using any one of the single refrigerant and the mixed refrigerant exemplified in the above-mentioned column (1-A), which is a low-pressure refrigerant, than the pressure resistance required for the refrigerant such as the conventional R-410A. The pressure resistance may be lower. In this case, even the aluminum laminated heat exchanger 90 employing an aluminum flat tube that is inferior in pressure resistance compared to copper piping or the like can sufficiently withstand the refrigerant pressure, and the above (1-A) to As a heat exchanger in a refrigeration apparatus in which any one of the single refrigerant and the mixed refrigerant exemplified in the section (1-A) in the refrigeration cycle of (1-L) is used as a working refrigerant. Even if it is adopted, it can be operated sufficiently.

<8-2> Modifications of Seventh Reference Embodiment (1)
As a material of the above-mentioned laminated type heat exchanger, resin or the like may be used in addition to aluminum.

(2)
As a material of the above-mentioned laminated type heat exchanger, it is preferable to use a material having a thermal conductivity of 0.2 W / mK or more.

<9> Eighth Reference Embodiment <9-1> Pass Number Switching Heat Exchanger The refrigerant connection pipe of the eighth reference embodiment described below is the above-described (1-A) to (1-L) as an example of the refrigeration cycle. It can be applied to any refrigeration cycle. And the heat exchanger of 8th reference embodiment is the single refrigerant | coolant illustrated in the column of the said (1-A) in the refrigeration cycle in any one of (1-A)-(1-L) mentioned above, Any of the mixed refrigerants can be employed as a heat exchanger in the refrigeration apparatus in which the working refrigerant is used.

  As the heat exchanger of the eighth reference embodiment, a path number switching heat exchanger 100 as shown in FIG. 47 can be adopted.

  The pass number switching heat exchanger 100 includes a first heat transfer tube 101, a second heat transfer tube 102, a heat exchange fin group 103, a flow number switching device 104, and a connection pipe 105.

  In the heat exchange fin group 103, a plurality of heat exchange fins are arranged at predetermined intervals.

  The first heat transfer tube 101 extends in the fin thickness direction while penetrating a plurality of fins from near the lower end on one end side of the heat exchange fin group 103, and then extends to the other end and then penetrates the heat exchange fin group 103 again. While being folded back to one end side, it is further folded back to the other end side, and this is repeated.

  Similarly to the first heat transfer tube 101, the second heat transfer tube 102 also extends in the fin thickness direction while penetrating a plurality of fins from slightly above the center near one end of the heat exchange fin group 103, and the other end. It is provided so that it may return to the one end side while penetrating the heat exchanging fin group 103 again, and further to the other end side, and this may be repeated.

  The flow path number switching unit 104 includes an inflow pipe 104a that is a refrigerant path that flows into the path number switching heat exchanger 100, an outflow pipe 104d that is a refrigerant path that flows out from the path number switching heat exchanger 100, and a first transmission. There are four flow path switching pipes 104b, 104c, 104e, 104f extending to the heat pipe 101 and the second heat transfer pipe 102 side. As shown in FIG. 46, the number-of-channels switch 104 divides the refrigerant flowing into the inflow pipe 104a into the flow path switching pipes 104b and 104c and joins the refrigerant that has flowed into the flow path switching pipes 104e and 104f. As shown in FIG. 47, the multi-pass connection state leading to 104d and the refrigerant flowing into the flow path switching pipe 104c while flowing the refrigerant flowing into the inflow pipe 104a only through the flow path switching pipe 104b are flowed out from the flow path switching pipe 104e. It is possible to switch between a single-pass connection state in which the refrigerant flowing into the flow path switching pipe 104f is guided to the outflow pipe 104d.

  Here, with respect to the outflow pair of the flow path switching pipe 104b and the flow path switching pipe 140c and the inflow pair of the flow path switching pipe 104e and the flow path switching pipe 104f, the inlet and outlet of the first heat transfer pipe 101 and The inlet and outlet of the second heat transfer tube 102 are connected to each other by connecting pipes 105.

  That is, the connection form is as follows.

  The connection pipe 105 a connects the outlet side of the flow path switching pipe 104 b and the inlet of the first heat transfer pipe 101.

  The connection pipe 105b connects the inlet of the flow path switching pipe 104e and the outlet of the first heat transfer pipe 101.

  The connection pipe 105c connects the outlet side of the flow path switching pipe 104c and the inlet of the second heat transfer pipe 102.

  The connection pipe 105d connects the inlet of the flow path switching pipe 104f and the outlet of the second heat transfer pipe 102.

  In this manner, the refrigerant flow bias can be reduced by sprinkling the refrigerant flow.

  Then, the switching by the channel number switching unit 104 switches the connection state between the channel switching tube 104c and the channel switching tube 104e by switching the connection state in the path number switching heat exchanger 100, as shown in FIG. In addition, after the refrigerant flowing into the pass number switching heat exchanger 100 is branched into two before inflow, the heat exchanged refrigerant is joined to flow out of the pass number switching heat exchanger 100, As shown in FIG. 47, the refrigerant flowing into the pass number switching heat exchanger 100 is allowed to flow in one flow without branching, and the refrigerant that has been heat-exchanged as one flow is directly passed as one flow. The heat can be discharged from the number switching heat exchanger 100.

  Since such switching is possible, for example, when the pass number switching heat exchanger 100 functions as an evaporator, any one of the single refrigerant and the mixed refrigerant exemplified in the section (1-A) above is used. If this is used as the working refrigerant, the increase in the specific volume due to evaporation is larger than that of the conventional R-410A or the like, so that it is particularly necessary to reduce the pressure loss. However, by this switching, it is possible to switch to the multi-path connection state shown in FIG. 47, so that one long flow path can be changed to two short flow paths, and pressure loss can be reduced. Furthermore, when the pass number switching heat exchanger 100 functions as a condenser, as shown in FIG. 48, the flow path in the pass number switching heat exchanger 100 is switched by switching to a single-pass connection state. The heat transfer rate can be increased by increasing the mass flow rate while ensuring a long period of time.

  In particular, in a heating operation, when the outdoor heat exchanger functions as an evaporator, in a situation where frost formation is likely to occur, a connection state in which the number of passes increases can be achieved as shown in FIG.

<10> Reference example (Reference example 1)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The design pressure of the refrigerant circuit is 2.6 MPa or less,
Refrigeration equipment.

  In the refrigerating apparatus of Reference Example 1, since the design pressure of the refrigerant circuit is 2.6 MPa or less, it is not necessary to increase the material and thickness of piping and the like in order to improve pressure resistance. Further, since the refrigerant used in the refrigerant circuit is a so-called low-pressure refrigerant, it can be operated efficiently even at a design pressure of 2.6 MPa or less. Thereby, the manufacturing cost can be reduced while the efficiency is kept good.

(Reference Example 2)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator, and capable of at least heating operation;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
A temperature detector for detecting the temperature around the evaporator;
A control unit that stops the heating operation of the refrigerant circuit when the temperature detected by the temperature acquisition unit is equal to or lower than the atmospheric pressure equivalent saturated gas temperature of the refrigerant;
A refrigeration apparatus.

  In the refrigeration apparatus of Reference Example 2, the control unit stops the heating operation of the refrigerant circuit when the temperature detected by the temperature acquisition unit is equal to or lower than the atmospheric pressure equivalent saturated gas temperature of the refrigerant. For this reason, the state where the part through which the gas refrigerant in a refrigerant circuit passes falls below atmospheric pressure can be avoided. This makes it possible to prevent air from entering the refrigerant circuit from the outside.

(Reference Example 3)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator, and having a pipe connection portion;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
The pipe connecting portion includes a joint body in which a joint hole for joining pipes is formed, a fastening member fastened to the joint body, and the fastening member before fastening the fastening member to the joint body. And a sleeve that is cut from the fastening member and bites into the outer periphery of the pipe when the fastening member is fastened to the joint body in a state where the pipe is inserted into the joint hole. And
The sleeve has a contact surface that abuts the joint body and seals the contact portion when the sleeve bites into the pipe, and the contact area of the contact portion increases when the sleeve bites into the pipe. It is a deformation induction shape that deforms the contact surface,
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 3, a so-called flareless joint is employed in which the connecting portion is not subjected to flare processing. Thereby, even if it is a case where the refrigerant | coolant which performs a refrigerating cycle in a refrigerant circuit has combustibility, the possibility of leaking outside can be reduced.

(Reference Example 4)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
A gas-liquid separation mechanism that is provided at least one position between the expansion mechanism and the evaporator or between the input side and the output side of the evaporator and separates the gas refrigerant and the liquid refrigerant; ,
A gas bypass circuit connecting a gas phase in the gas-liquid separation mechanism and a suction side of the compressor;
A refrigeration apparatus.

  In the refrigeration apparatus of Reference Example 4, gas refrigerant contained in the refrigerant flowing into the evaporator can be reduced. For this reason, the gas refrigerant which does not contribute to heat exchange with air etc. in an evaporator can be decreased, and the pressure loss in an evaporator can be reduced.

(Reference Example 5)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
A blowing mechanism for flowing air in a direction opposite to the flow direction of at least a part of the refrigerant with respect to at least one of the evaporator and the condenser;
A refrigeration apparatus.

  In the refrigeration apparatus of Reference Example 5, the heat exchange efficiency can be improved. In particular, when a non-azeotropic refrigerant mixture is used among the refrigerants of Reference Example 5, a temperature gradient is generated in the two-phase region on the Ph diagram, and therefore the effect of adopting the flow direction of Reference Example 5 Can be made more prominent.

(Reference Example 6)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
A blowing mechanism for flowing air such that the outlet side of the refrigerant of at least one of the evaporator or the condenser is on the windward side;
A refrigeration apparatus.

  In the refrigeration apparatus of Reference Example 6, the heat exchange efficiency can be improved. In particular, when a non-azeotropic refrigerant mixture is used among the refrigerants of Reference Example 6, a temperature gradient is generated in the two-phase region on the Ph diagram, and thus the effect of adopting the flow direction of Reference Example 6 is achieved. Can be made more prominent.

(Reference Example 7)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
At least one of the evaporator and the condenser has a U-shape that connects the first heat transfer tube and the second heat transfer tube, the first heat transfer tube and the second heat transfer tube having substantially the same longitudinal direction. A tube, and
When the refrigerant flows into at least one of the evaporator or the condenser, only the first heat transfer tube, the U-shaped tube, and the second heat transfer tube flow in this order, and the refrigerant flows into the evaporator. Or, when it flows out from at least one of the condensers, it further comprises a blower mechanism for flowing air so that the second heat transfer tube side is on the windward side and the first heat transfer tube is on the leeward side,
A refrigeration apparatus.

  In the refrigeration apparatus of Reference Example 7, the heat exchange efficiency can be improved. In particular, when a non-azeotropic refrigerant mixture is used among the refrigerants of Reference Example 7, a temperature gradient is generated in the two-phase region on the Ph diagram, and therefore the effect of adopting the flow direction of Reference Example 7 Can be made more prominent.

(Reference Example 8)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A non-azeotropic refrigerant mixture comprising a single refrigerant comprising a refrigerant having one double bond in the molecular structure;
With
At least one of the evaporator and the condenser has a number of branches that branches until the refrigerant flows in and out so as to eliminate a temperature change when the dryness of the refrigerant changes phase. At least one of the length of one of the divided ones and the inner diameter of one of the branched ones is adjusted,
A refrigeration apparatus.

  In the refrigerating apparatus of Reference Example 8, since the temperature change in the evaporator or condenser is small, a temperature difference with the air that is the target of heat exchange can be secured, and the decrease in heat exchange efficiency can be suppressed. it can.

(Reference Example 9)
A refrigerant circuit having at least a compressor, an indoor heat exchanger, an expansion mechanism, and an outdoor heat exchanger, and capable of performing switching between cooling operation and heating operation;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
A blower mechanism for supplying an air flow to the outdoor heat exchanger;
With
The outdoor heat exchanger has a refrigerant inlet and outlet on the windward side of the air flow formed by the blower mechanism,
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 9, when defrosting is performed by performing a refrigeration cycle in a cooling operation, the compressor acts on the windward side where frost formation is likely to occur by functioning as an evaporator during heating operation. High-temperature and high-pressure gas refrigerant from can be fed. Thereby, defrosting can be performed efficiently.

(Reference Example 10)
A refrigerant circuit having at least a compressor, an indoor heat exchanger, an expansion mechanism, and an outdoor heat exchanger, and capable of performing switching between cooling operation and heating operation;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
A blower mechanism for supplying an air flow to the outdoor heat exchanger;
With
The outdoor heat exchanger has a refrigerant inlet above the windward side of the air flow formed by the blower mechanism, and has a refrigerant outlet below the inlet.
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 10, the frost above the outdoor heat exchanger can be melted by the high-temperature and high-pressure gas refrigerant by performing defrosting, and the drain water generated by melting the frost above is used during heating operation. It can be guided by its own weight with respect to the portion where frost formation is likely to occur at the entrance of the evaporator.

(Reference Example 11)
A refrigerant circuit having at least a compressor, an indoor heat exchanger, an expansion mechanism, and an outdoor heat exchanger, and capable of performing switching between cooling operation and heating operation;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The outdoor heat exchanger has a plurality of fins having water slidability,
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 11, even when the outdoor heat exchanger functions as an evaporator during heating operation, it is difficult for water droplets to remain on the fin surface. For this reason, even if there are water droplets remaining on the fin surface, it is possible to make the water droplets difficult to freeze by sliding off the fins.

(Reference Example 12)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, an evaporator, a liquid refrigerant communication tube, and a plurality of gas refrigerant communication tubes;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
A refrigeration apparatus.

  In the refrigeration apparatus of Reference Example 12, the bending workability of the pipe can be improved while reducing the pressure loss in the gas refrigerant communication pipe.

(Reference Example 13)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, an evaporator, a liquid refrigerant communication tube, and a plurality of gas refrigerant communication tubes;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The liquid refrigerant communication pipe and the gas refrigerant communication pipe have the same pipe diameter,
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 13, it is possible to improve the bending workability of the pipe and reduce the manufacturing cost while reducing the pressure loss in the gas refrigerant communication pipe.

(Reference Example 14)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, an evaporator, a liquid refrigerant communication tube, and a plurality of gas refrigerant communication tubes;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The liquid refrigerant communication pipe and the gas refrigerant communication pipe have the same diameter.
At least the liquid refrigerant communication pipe is provided with an indication indicating that it is for liquid refrigerant,
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 14, it is possible to improve the bending workability of the pipe while reducing the pressure loss in the gas refrigerant communication pipe, to reduce the manufacturing cost, and to prevent the pipe connection mistake during construction.

(Reference Example 15)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, an evaporator, a liquid refrigerant communication tube, and a plurality of gas refrigerant communication tubes;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The gas refrigerant communication pipe is a flexible pipe.
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 15, it is possible to further improve the bending workability of the pipe while reducing the pressure loss in the gas refrigerant communication pipe.

(Reference Example 16)
A refrigerant circuit having at least a compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The indoor heat exchanger has an indoor evaporation unit, an indoor condensing unit, and an indoor expansion mechanism that depressurizes the refrigerant between the indoor evaporating unit and the indoor condensing unit,
The indoor evaporation section has a larger capacity than the indoor condensation section,
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 16, when a refrigerant having a large specific volume is used, the pressure loss in the indoor evaporation unit can be reduced.

(Reference Example 17)
A refrigerant circuit having at least a compressor, an outdoor heat exchanger, an expansion mechanism, and an indoor heat exchanger;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The indoor heat exchanger has a plurality of indoor expansion units, an indoor condensing unit, and an indoor expansion mechanism that decompresses the refrigerant between the indoor evaporating unit and the indoor condensing unit,
The indoor evaporation section has a larger capacity than the indoor condensation section,
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 17, when a refrigerant having a large specific volume is used, the pressure loss in the indoor evaporation section can be reduced, and an effect of reducing the pressure loss due to an increase in the refrigerant passage channel can be obtained.

(Reference Example 18)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The evaporator has a larger tube diameter on the outlet side than the inlet side in the refrigerant flow direction when functioning as an evaporator,
Refrigeration equipment.

  In the refrigerating apparatus of Reference Example 18, the pressure loss of the evaporator can be reduced.

(Reference Example 19)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The evaporator has an uneven groove on the inside of the tube deeper on the inlet side in the refrigerant flow direction when functioning as an evaporator than on the outlet side,
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 19, the pressure loss of the evaporator can be reduced.

(Reference Example 20)
At least the compressor, the condenser, the expansion mechanism, and the evaporator obtained by enlarging the degree of expansion on the outlet side rather than the inlet side when expanding the heat transfer tube provided with a uniform uneven shape on the inner surface side from the inside A refrigerant circuit having
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
Of manufacturing a refrigeration apparatus comprising:

  In the method for manufacturing the refrigeration apparatus of Reference Example 20, a refrigeration apparatus having an evaporator that can reduce pressure loss can be easily manufactured.

(Reference Example 21)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The evaporator has a substantially quadrangular prism shape divided into approximately equal halves,
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 21, the pressure loss of the evaporator can be reduced.

(Reference Example 22)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The evaporator does not have a portion where the bending angle of the heat transfer tube is less than 90 degrees from the inlet to the outlet.
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 22, the pressure loss of the evaporator can be reduced.

(Reference Example 23)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The evaporator has a heat transfer tube which is a seam tube.
Refrigeration equipment.

  In the refrigerating apparatus of Reference Example 23, even if a seam pipe is used by using a low-pressure refrigerant, refrigerant leakage is unlikely to occur.

(Reference Example 24)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The evaporator has a heat transfer tube which is a seam tube having a non-uniform uneven shape on the inner surface side.
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 24, the heat transfer coefficient can be improved by making the uneven shape of the inner surface of the seam tube nonuniform.

(Reference Example 25)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The piping material used for flowing the refrigerant in the refrigerant circuit contains at least one selected from aluminum and resin.
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 25, the degree of freedom of the material can be increased as well as the conventional copper pipe.

(Reference Example 26)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
At least one of the evaporator or the condenser is an aluminum laminated heat exchanger having a header, a plurality of flat tubes extending from the header, and corrugated fins disposed between the plurality of flat tubes. is there,
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 26, the heat exchanger can be thinned. In addition, in a heat exchanger of a laminated type rather than a multi-hole tube, the pressure loss at the time of evaporation can be reduced.

(Reference Example 27)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
With
The material of at least one of the evaporator or the condenser has a thermal conductivity of 0.2 W / mK or more.
Refrigeration equipment.

  In the refrigeration apparatus of Reference Example 27, the heat exchanger performance can be improved while being thinned.

(Reference Example 28)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
A flow path number changing mechanism that is provided in at least one of the evaporator and the condenser and that can change the number of flow paths that flow inside the provided heat exchanger;
A refrigeration apparatus.

  In the refrigeration apparatus of Reference Example 28, the number of refrigerant flow paths that pass through the heat exchanger can be changed according to the operating state. Therefore, when the refrigerant functioning as an evaporator, the flow path is increased to reduce pressure loss. In the case of functioning as a condenser, the heat exchange efficiency can be improved by reducing the number of flow paths and increasing the flow rate while lengthening the path.

(Reference Example 29)
A refrigerant circuit having at least a compressor, a condenser, an expansion mechanism, and an evaporator;
A refrigeration cycle is performed by circulating in the refrigerant circuit, the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and A single refrigerant composed of a refrigerant having one double bond in the molecular structure, or a mixed refrigerant containing the refrigerant;
A detector for detecting a state quantity of the refrigerant flowing through the evaporator;
A flow path number changing section that changes the number of flow paths flowing through the evaporator based on the detection value by the detection section;
A refrigeration apparatus.

  In the refrigeration apparatus of Reference Example 29, occurrence of frost formation can be suppressed.

(Reference Example 30)
The refrigerant in which the refrigeration cycle is performed by circulating in the refrigerant circuit is a single refrigerant composed of 2,3,3,3-tetrafluoro-1-propene,
The refrigeration apparatus according to any one of Reference Examples 1 to 29.

  In the refrigeration apparatus of Reference Example 30, the ozone depletion coefficient can be set to 0, and the operation in the refrigeration cycle can be improved.

(Reference Example 31)
The refrigerant in which the refrigeration cycle is performed by circulating in the refrigerant circuit is a mixed refrigerant of 2,3,3,3-tetrafluoro-1-propene and difluoromethane.
The refrigeration apparatus according to any one of Reference Examples 1 to 29.

  In the refrigeration apparatus of Reference Example 31, the ozone depletion coefficient is 0, and the operation in the refrigeration cycle can be improved even if the refrigerant temperature tends to change during the phase change.

(Reference Example 32)
The refrigerant in which the refrigeration cycle is performed by circulating in the refrigerant circuit is a mixed refrigerant of 2,3,3,3-tetrafluoro-1-propene and pentafluoroethane.
The refrigeration apparatus according to any one of Reference Examples 1 to 29.

  In the refrigerating apparatus of Reference Example 32, the ozone depletion coefficient is set to 0, and the operation in the refrigerating cycle can be improved even if the refrigerant temperature tends to change during the phase change.

If the present invention is used, the ozone depletion coefficient is 0, and the molecular formula is C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), In addition, it is possible to suppress frost formation or improve defrosting efficiency in a refrigeration cycle using a single refrigerant composed of a refrigerant having one double bond in the molecular structure or a mixed refrigerant containing this refrigerant. Therefore, it can be applied to a refrigeration cycle such as an air conditioner.

DESCRIPTION OF SYMBOLS 1 Refrigeration apparatus 2 Compressor 3 Four-way switching valve 4 Evaporator, condenser, outdoor heat exchanger 4b Control part 5 Expansion valve 6 Condenser, evaporator, indoor heat exchanger T4a Temperature sensor (evaporation inlet detection part)

JP-A-4-110388

Claims (14)

A refrigerant circuit (10) having at least a compression mechanism (2), an indoor heat exchanger (4, 6), an expansion mechanism (5), and an outdoor heat exchanger (6, 4, 19);
The refrigeration cycle is performed by circulating the refrigerant circuit (10), and is represented by the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6). And a single refrigerant composed of a refrigerant having one double bond in the molecular structure, and a working refrigerant that is one of the mixed refrigerants containing the refrigerant,
An outdoor air blowing mechanism (19c) for supplying an air flow to the outdoor heat exchanger;
In an operation state in which the outdoor heat exchanger functions as an evaporator, when a predetermined condition is satisfied, a control unit (4b) capable of switching to an operation state in which the outdoor heat exchanger functions as a radiator;
With
The outdoor heat exchanger has a plurality of outdoor heat exchange fins, and the ventilation resistance when the air flow passes between the outdoor heat exchange fins is lower on the leeward side than on the leeward side,
Refrigeration equipment (1). In the outdoor heat exchanger (19), the pitch of the outdoor heat exchange fins arranged on the leeward side of the air flow is wider than the pitch of the outdoor heat exchange fins arranged on the leeward side of the air flow. ,
The refrigeration apparatus (1) according to claim 1. The pitch of the outdoor heat exchange fins arranged on the leeward side of the air flow is 1.3 to 1.5 times the pitch of the outdoor heat exchange fins arranged on the leeward side of the air flow.
The refrigeration apparatus (1) according to claim 2. In the outdoor heat exchanger (19), the outdoor heat exchange fin disposed on the leeward side of the air flow has cut and raised pieces, and the outdoor heat disposed on the windward side of the air flow. The cross fin has no cut and raised pieces,
The refrigeration apparatus (1) according to claim 1. The indoor heat exchanger has a plurality of indoor heat exchange fins,
The surface interval of the outdoor heat exchange fin is wider than the surface interval of the indoor heat exchange fin,
The refrigeration apparatus (1) according to any one of claims 1 to 4. An indoor blower mechanism (25) for supplying an air flow to the indoor heat exchanger;
In the operation state in which the outdoor heat exchanger functions as an evaporator, the controller (4b) is configured such that the air flow speed generated by the outdoor air blowing mechanism is faster than the air flow speed generated by the indoor air blowing mechanism. Controlling at least one of the outdoor air blowing mechanism and the indoor air blowing mechanism,
The refrigeration apparatus (1) according to any one of claims 1 to 5. A switching mechanism (3) capable of switching between a connection state in which the outdoor heat exchanger is connected to the suction side of the compression mechanism and a connection state in which the outdoor heat exchanger is connected to the discharge side of the compression mechanism; Prepared,
The control unit (4b) switches the connection state of the switching mechanism, thereby operating a state in which the outdoor heat exchanger functions as an evaporator and a state in which the outdoor heat exchanger functions as a radiator. Switch,
The refrigeration apparatus (1) according to any one of claims 1 to 6. When the outdoor heat exchanger functions as an evaporator, it further includes an evaporation inlet detector (T4a) that detects a temperature in the vicinity of the inlet of the working refrigerant of the outdoor heat exchanger or a state quantity that can be converted into the temperature. ,
The working refrigerant is represented by a molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6), and has one double bond in the molecular structure. A non-azeotropic refrigerant mixture including a single refrigerant comprising
The control unit (4b) determines whether or not the predetermined condition is satisfied based on a value detected by the evaporation inlet detection unit.
The refrigeration apparatus (1) according to any one of claims 1 to 7. It has at least a compressor (2), indoor heat exchangers (4, 6), expansion mechanism (5), and outdoor heat exchangers (6, 4, 19), and switches between cooling operation and heating operation. A refrigerant circuit (10) capable of
The refrigeration cycle is performed by circulating the refrigerant circuit (10), and is represented by the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6). A working refrigerant that is either a single refrigerant composed of a refrigerant having one double bond in the molecular structure or a mixed refrigerant containing the refrigerant;
A blower mechanism (19c) for supplying an air flow to the outdoor heat exchanger;
With
The outdoor heat exchanger (19) has a plurality of fins, and the pitch of the fins arranged on the leeward side of the air flow formed by the blower mechanism is arranged on the leeward side of the air flow. Which is wider than the pitch of the fins,
Refrigeration equipment (1). It has at least a compressor (2), indoor heat exchangers (4, 6), expansion mechanism (5), and outdoor heat exchangers (6, 4, 19), and switches between cooling operation and heating operation. A refrigerant circuit (10) capable of
A refrigeration cycle is performed by circulating the refrigerant circuit (10), and is represented by a molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6). A working refrigerant that is either a single refrigerant composed of a refrigerant having one double bond in the molecular structure or a mixed refrigerant containing the refrigerant;
A blower mechanism (19c) for supplying an air flow to the outdoor heat exchanger;
With
The indoor heat exchanger has a plurality of indoor fins,
The outdoor heat exchanger has a plurality of outdoor fins,
The spacing between the outdoor fins is wider than the spacing between the indoor fins,
Refrigeration equipment (1). It has at least a compressor (2), indoor heat exchangers (4, 6), expansion mechanism (5), and outdoor heat exchangers (6, 4, 19), and switches between cooling operation and heating operation. A refrigerant circuit (10) capable of
A refrigeration cycle is performed by circulating the refrigerant circuit (10), and is represented by a molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6). A working refrigerant that is either a single refrigerant composed of a refrigerant having one double bond in the molecular structure or a mixed refrigerant containing the refrigerant;
An indoor air blowing mechanism for sending air to the indoor heat exchanger;
An outdoor air blowing mechanism for sending air to the outdoor heat exchanger;
With
The air flow speed generated by the outdoor air blowing mechanism is faster than the air flow speed generated by the indoor air blowing mechanism.
Refrigeration equipment (1). It has at least a compressor (2), indoor heat exchangers (4, 6), expansion mechanism (5), and outdoor heat exchangers (6, 4, 19), and switches between cooling operation and heating operation. A refrigerant circuit (10) capable of
The refrigeration cycle is performed by circulating the refrigerant circuit (10), and is represented by the molecular formula: C ₃ H _m F _n (where m = 1 to 5, n = 1 to 5, and m + n = 6). A working refrigerant that is either a single refrigerant composed of a refrigerant having one double bond in the molecular structure or a mixed refrigerant containing the refrigerant;
A blower mechanism (19c) for supplying an air flow to the outdoor heat exchanger;
With
The outdoor heat exchanger has a plurality of fins, and the ventilation resistance when the air flow passes between the fins is lower on the leeward side than on the leeward side,
Refrigeration equipment (1). The working refrigerant is a single refrigerant composed of 2,3,3,3-tetrafluoro-1-propene,
The refrigeration apparatus (1) according to any one of claims 1 to 12. The working refrigerant is a mixed refrigerant of 2,3,3,3-tetrafluoro-1-propene and difluoromethane, or a mixture of 2,3,3,3-tetrafluoro-1-propene and pentafluoroethane. A refrigerant,
The refrigeration apparatus (1) according to any one of claims 1 to 12.

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