The present disclosure relates to a refrigeration cycle apparatus.
There has been a refrigeration cycle apparatus including a heat exchanger as described in, for example, PTL 1 (Japanese Unexamined Patent Application Publication No. 11-256358). Like the heat exchanger of the refrigeration cycle apparatus described in PTL 1, a heat transfer tube may use a copper pipe.
A heat exchanger like one described in PTL 1 is expensive because the heat transfer tube uses the copper pipe.
In this way, the refrigeration cycle apparatus including the heat exchanger has an object to decrease the material cost.
A refrigeration cycle apparatus according to a first aspect includes a flammable refrigerant containing at least 1,2-difluoroethylene; an evaporator that evaporates the refrigerant; and a condenser that condenses the refrigerant; at least one of the evaporator and the condenser is a heat exchanger that includes a plurality of fins made of aluminum or an aluminum alloy and a plurality of heat transfer tubes made of aluminum or an aluminum alloy, and that causes the refrigerant flowing inside the heat transfer tubes and a fluid flowing along the fins to exchange heat with each other; and the refrigerant repeats a refrigeration cycle by circulating through the evaporator and the condenser.
With the refrigeration cycle apparatus, since the plurality of fins made of aluminum or an aluminum alloy and the plurality of heat transfer tubes made of aluminum or an aluminum alloy are included, for example, as compared to a case where a heat transfer tube uses a copper pipe, the material cost of the heat exchanger can be decreased.
A refrigeration cycle apparatus according to a second aspect is the refrigeration cycle apparatus according to the first aspect, in which each of the plurality of fins has a plurality of holes, the plurality of heat transfer tubes penetrate through the plurality of holes of the plurality of fins, and outer peripheries of the plurality of heat transfer tubes are in close contact with inner peripheries of the plurality of holes.
A refrigeration cycle apparatus according to a third aspect is the refrigeration cycle apparatus according to the first aspect, in which the plurality of heat transfer tubes are a plurality of flat tubes, and flat surface portions of the flat tubes that are disposed next to each other face each other.
A refrigeration cycle apparatus according to a fourth aspect is the refrigeration cycle apparatus according to the third aspect, in which each of the plurality of fins is bent in a waveform, disposed between the flat surface portions of the flat tubes disposed next to each other, and connected to the flat surface portions to be able to transfer heat to the flat surface portions.
A refrigeration cycle apparatus according to a fifth aspect is the refrigeration cycle apparatus according to the third aspect, in which each of the plurality of fins has a plurality of cutouts, and the plurality of flat tubes are inserted into the plurality of cutouts of the plurality of fins and connected thereto to be able to transfer heat to the plurality of fins.
In this refrigeration cycle apparatus, the refrigeration cycle apparatus can decrease the material cost of the heat exchanger when a refrigerant having a sufficiently low GWP, a refrigeration capacity (may also be referred to as a cooling capacity or a capacity) and a coefficient of performance (COP) equal to those of R410A is used.
Any one of various refrigerants such as refrigerant A, refrigerant B, refrigerant C, refrigerant D, and refrigerant E, details of these refrigerant are to be mentioned later, can be used as the refrigerant.
(2-2) Use of refrigerant
The refrigerant according to the present disclosure can be preferably used as a working fluid in a refrigerating machine.
The composition according to the present disclosure is suitable for use as an alternative refrigerant for HFC refrigerant such as R410A, R407C and R404 etc, or HCFC refrigerant such as R22 etc.
The tracer compound may be present in the refrigerant composition at a total concentration of about 10 parts per million (ppm) to about 1000 ppm. Preferably, the tracer compound is present in the refrigerant composition at a total concentration of about 30 ppm to about 500 ppm, and most preferably, the tracer compound is present at a total concentration of about 50 ppm to about 300 ppm.
Hereinafter, the refrigerants A to E, which are the refrigerants used in the present embodiment, will be described in detail.
In addition, each description of the following refrigerant A, refrigerant B, refrigerant C, refrigerant D, and refrigerant E is each independent. The alphabet which shows a point or a line segment, the number of an Examples, and the number of a comparative examples are all independent of each other among the refrigerant A, the refrigerant B, the refrigerant C, the refrigerant D, and the refrigerant E. For example, the first embodiment of the refrigerant A and the first embodiment of the refrigerant B are different embodiment from each other.
When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 85% or more relative to that of R410A, and a COP of 92.5% or more relative to that of R410A; furthermore, the refrigerant has an RCL of 40 g/m3 or more.
COP=(refrigerating capacity or heating capacity)/power consumption
COP=(refrigerating capacity or heating capacity)/power consumption
In a first embodiment, an air conditioning apparatus 10 that is an example of a refrigeration cycle apparatus is described. The refrigeration cycle apparatus represents any of all apparatuses that are operated with refrigeration cycles. The refrigeration cycle apparatuses include an air conditioner, a dehumidifier, a heat pump warm-water supply apparatus, a refrigerator, a refrigeration apparatus for freezing, a cooling apparatus for manufacturing process, and so forth.
The air conditioning apparatus 10 is a separate air conditioning apparatus including an outdoor unit (not illustrated) and an indoor unit (not illustrated) and configured to switch the operation between cooling operation and heating operation.
As illustrated in
An inflow pipe 36, an outflow pipe 37, and an injection pipe 38 are connected to the gas-liquid separator 25. The inflow pipe 36 is open at an upper portion of the inner space of the gas-liquid separator 25. The outflow pipe 37 is open at a lower portion of the inner space of the gas-liquid separator 25. The injection pipe 38 is open at an upper portion of the inner space of the gas-liquid separator 25. In the gas-liquid separator 25, the refrigerant which has flowed in from the inflow pipe 36 is separated into a saturated liquid and a saturated gas, the saturated liquid flows out from the outflow pipe 37, and the saturated gas flows out from the injection pipe 38. The inflow pipe 36 and the outflow pipe 37 are connected to the bridge circuit 31. The injection pipe 38 is connected to an intermediate connection pipe 47 of the compressor 21.
The refrigerant in the saturated gas state which has flowed out from the injection pipe 38 is injected into a compression chamber with an intermediate pressure of a compression mechanism 32 via an intermediate port. In this embodiment, the inflow pipe 36, the outflow pipe 37, the injection pipe 38, and the gas-liquid separator 25 supply the refrigerant in the saturated liquid state, which is included in the refrigerant which has flowed out from the outdoor heat exchanger 23 during cooling operation and which has been decompressed to have the intermediate pressure in the refrigeration cycle, to the indoor heat exchanger 27, to constitute an injection circuit 15 for supplying the refrigerant in the saturated gas state to the compressor 21.
The bridge circuit 31 is a circuit in which a first check valve CV1, a second check valve CV2, a third check valve CV3, and a fourth check valve CV4 are connected in a bridge form. In the bridge circuit 31, a connection end located on the inflow side of the first check valve CV1 and on the inflow side of the second check valve CV2 is connected to the outflow pipe 37. A connection end located on the outflow side of the second check valve CV2 and on the inflow side of the third check valve CV3 is connected to the indoor heat exchanger 27. The refrigerant pipe that connects the connection end to the indoor heat exchanger 27 is provided with the indoor expansion valve 26 of which the opening degree is changeable. A connection end located on the outflow side of the third check valve CV3 and on the outflow side of the fourth check valve CV4 is connected to the inflow pipe 36. A connection end located on the outflow side of the first check valve CV1 and on the inflow side of the fourth check valve CV4 is connected to the outdoor heat exchanger 23.
During cooling operation, the four-way valve 22 is set in a state (a state indicated by solid lines in
During heating operation, the four-way valve 22 is set in a state (a state indicated by broken lines in
The outdoor heat exchanger 23 is constituted of a microchannel heat exchanger (also referred to as micro heat exchanger) having formed therein a microchannel 13 that serves as a flow path of a refrigerant. The microchannel 13 is a fine flow path (a flow path having a very small flow path area) fabricated by using, for example, micro-fabricating technology. In general, a heat exchanger having the microchannel 13 that is a flow path having a diameter of several millimeters or less which exhibits an effect of surface tension is called microchannel heat exchanger.
Specifically, as illustrated in
An outdoor fan 28 is provided near the outdoor heat exchanger 23. In the outdoor heat exchanger 23, the outdoor air supplied by the outdoor fan 28 flows through gaps formed by the flat tubes 16 and the metal plates 19. The outdoor air flows in the width direction of the flat tubes 16.
In the outdoor heat exchanger 23, the one header 17 is connected to the third port P3 of the four-way valve 22, and the other header 18 is connected to the bridge circuit 31. In the outdoor heat exchanger 23, the refrigerant which has flowed into one of the headers 17 and 18 is distributed to the plurality of microchannels 13, and the refrigerant which has passed through each of the microchannels 13 is joined in the other one of the headers 17 and 18. Each microchannel 13 serves as a refrigerant flow path through which the refrigerant flows. In the outdoor heat exchanger 23, the refrigerant flowing through each microchannel 13 exchanges heat with the outdoor air.
The indoor heat exchanger 27 is constituted of a microchannel heat exchanger. The indoor heat exchanger 27 has the same structure as the outdoor heat exchanger 23, and hence the description on the structure of the indoor heat exchanger 27 is omitted. An indoor fan 29 is provided near the indoor heat exchanger 27. In the indoor heat exchanger 27, the refrigerant flowing through each microchannel 13 exchanges heat with the indoor air supplied by the indoor fan 29. In the indoor heat exchanger 27, the one header 17 is connected to the fourth port P4 of the four-way valve 22, and the other header 18 is connected to the bridge circuit 31.
In the present embodiment, the outdoor heat exchanger 23 and the indoor heat exchanger 27 are constituted of microchannel heat exchangers. The capacity of the inside of the microchannel heat exchanger is smaller than that of a heat exchanger of another structure type having equivalent performance (for example, cross-fin type fin-and-tube heat exchanger). Hence, the total capacity of the inside of the refrigerant circuit 20 can be decreased compared with a refrigeration cycle apparatus using a heat exchanger of another structure type.
Regarding resistance to pressure and resistance to corrosion, “0.9 mm≤flat-tube thickness (a vertical height h16 of the flat tube 16 illustrated in
In the present embodiment, the refrigerant circuit 20 is filled with a refrigerant for performing a vapor compression refrigeration cycle. The refrigerant is a mixed refrigerant containing 1,2-difluoroethylene, and can use any one of the above-described refrigerants A to E.
As illustrated in
Each of the flat perforated tubes 193 includes side surface portions serving as heat transfer surfaces, and a plurality of inner flow paths 193 a through which the refrigerant flows. The flat perforated tubes 193 are arranged in a plurality of stages at intervals in a state in which a side surface portion of a flat perforated tube 193 vertically faces a side surface portion of another flat perforated tube 193 disposed next to the former flat perforated tube 193. The insertion fins 194 are a plurality of fins each having a shape illustrated in
Here, a case where a coupling portion 194b of the insertion fin 194 is disposed on the leeward side has been described. In this case, the coupling portion 194b is a portion of the insertion fin 194 linearly coupled without a cutout 194a. In the outdoor heat exchanger 125, however, the coupling portion 194b of the insertion fin 194 may be disposed on the windward side. When the coupling portion 194b is disposed on the windward side, the wind is dehumidified first by the insertion fin 194 and then the wind hits the flat perforated tubes 193.
Here, a case where the heat exchanger illustrated in
Regarding resistance to pressure and resistance to corrosion, “0.9 mm≤flat-tube thickness (a vertical height h193 of the flat perforated tube 193 illustrated in
In the present embodiment, the refrigerant circuit including the outdoor heat exchanger 125 is filled with a refrigerant for performing a vapor compression refrigeration cycle. The refrigerant is a mixed refrigerant containing 1,2-difluoroethylene, and can use any one of the above-described refrigerants A to E.
An inner-surface grooved tube 201 is inserted into through holes 211a of a plurality of plate fins 211 that are illustrated in
The inner-surface grooved tube 201 is used for a plate fin-and-tube heat exchanger of a refrigeration cycle apparatus, such as either of an air conditioner and a refrigeration air conditioning apparatus. The plate fin-and-tube heat exchanger is included in a refrigerant circuit of the refrigeration cycle apparatus. The refrigerant circuit of the refrigeration cycle apparatus includes a compressor, an evaporator, a condenser, and an expansion valve. In heating operation, the plate fin-and-tube heat exchanger functions as an evaporator in the refrigerant circuit of the refrigeration cycle apparatus. In cooling operation, the plate fin-and-tube heat exchanger functions as a condenser in the refrigerant circuit of the refrigeration cycle apparatus.
The inner-surface grooved tube 201 having a pipe outer diameter D201 of a pipe of 4 mm or more and 10 mm or less is used. The original tube of the inner-surface grooved tube 201 uses a material of aluminum or an aluminum alloy. The method of forming an inner-surface grooved shape of the inner-surface grooved tube 201 may be component rolling, rolling, or the like, however, is not limited thereby.
As illustrated in
Next, limitations on numerical values of the inner-surface groove shape of the inner-surface grooved tube 201 are described.
(8-1) Number of Grooves: 30 or More and 100 or Less
The number of grooves is properly determined with regard to heat transfer performance, individual weight, and so forth, in combination with respective specifications (described later) of the inner-surface groove shape, and is preferably 30 or more and 100 or less. If the number of grooves is less than 30, groove moldability likely decreases. If the number of grooves is more than 100, a grooving tool (grooving plug) is likely chipped. In either case, volume productivity of the inner-surface grooved tube 201 likely decreases.
Furthermore, when the inner-surface grooved tube 201 is used for the outdoor heat exchanger and the indoor heat exchanger included in the refrigerant circuit of the refrigeration cycle apparatus, it is preferably satisfied that the number of grooves of the inner-surface grooved tube 201 of the outdoor heat exchanger >the number of grooves of the inner-surface grooved tube 201 of the indoor heat exchanger. Accordingly, in-pipe pressure loss of the inner-surface grooved tube 201 can be decreased, and heat transfer performance thereof can be increased.
(8-2) Groove Lead Angle θ201: 10 Degrees or More and 50 Degrees or Less
The groove lead angle θ201 is preferably 10 degrees or more and 50 degrees or less. If the groove lead angle θ201 is less than 10 degrees, heat transfer performance of the inner-surface grooved tube 201 (heat exchanger) likely decreases. If the groove lead angle θ201 is more than 50 degrees, it may be difficult to suppress deformation of the in-pipe fin 203 due to ensuring of volume productivity and expansion of the diameter of the inner-surface grooved tube 201.
Furthermore, when the inner-surface grooved tube 201 is used for the outdoor heat exchanger and the indoor heat exchanger included in the refrigerant circuit of the refrigeration cycle apparatus, it is preferably satisfied that the groove lead angle of the inner-surface grooved tube 201 of the outdoor heat exchanger <the number of grooves of the inner-surface grooved tube 201 of the indoor heat exchanger. Accordingly, in-pipe pressure loss of the inner-surface grooved tube 201 can be decreased, and heat transfer performance thereof can be increased.
(8-3) Bottom Thickness T201: 0.2 mm or More and 1.0 mm or Less
The bottom thickness T201 is preferably 0.2 mm or more and 1.0 mm or less. If the bottom thickness T201 is outside the range, it may be difficult to manufacture the inner-surface grooved tube 201. If the bottom thickness T201 is 0.2 mm or less, the strength of the inner-surface grooved tube 201 likely decreases, and it is likely difficult to keep the strength of resistance to pressure.
(8-4) Fin Height h201: 0.1 mm or More and (Bottom Thickness T201×1.2) mm or Less
The fin height h201 is preferably 0.1 mm or more and (bottom thickness T201×1.2) mm or less. If the fin height h201 is less than 0.1 mm, heat transfer performance of the inner-surface grooved tube 201 (heat exchanger) likely decreases. If the fin height h201 is more than (bottom thickness T201×1.2) mm, it may be difficult to suppress significant deformation of the in-pipe fin 203 due to ensuring of volume productivity and expansion of the diameter of the inner-surface grooved tube 201.
Furthermore, when the inner-surface grooved tube 201 is used for the outdoor heat exchanger and the indoor heat exchanger included in the refrigerant circuit of the refrigeration cycle apparatus, it is preferably satisfied that the fin height h201 of the inner-surface grooved tube 201 of the outdoor heat exchanger >the fin height h201 of the inner-surface grooved tube 201 of the indoor heat exchanger. Accordingly, in-pipe pressure loss of the inner-surface grooved tube 201 can be decreased, and heat transfer performance of the outdoor heat exchanger can be further increased.
(8-5) Thread Vertex Angle δ201: 5 Degrees or More and 45 Degrees or Less
The thread vertex angle δ201 is preferably 5 degrees or more and 45 degrees or less. If the thread vertex angle δ201 is less than 5 degrees, it may be difficult to suppress deformation of the in-pipe fin 203 due to ensuring of volume productivity and expansion of the diameter of the inner-surface grooved tube 201. If the thread vertex angle δ201 is more than 45 degrees, maintenance of heat transfer performance of the inner-surface grooved tube 201 (heat exchanger) and the individual weight of the inner-surface grooved tube 201 likely become excessive.
(8-6) Fin-root Radius r201: 20% or More and 50% or Less of Fin Height h201
The fin-root radius r201 is preferably 20% or more and 50% or less of the fin height h201. If the fin-root radius r201 is less than 20% of the fin height h201, fin inclination due to the pipe expansion likely becomes excessive, and volume productivity likely decreases. If the fin-root radius r201 is more than 50% of the fin height h201, the effective heat transfer area of the refrigerant gas-liquid interface likely decreases, and heat transfer performance of the inner-surface grooved tube 201 (heat exchanger) likely decreases.
In the present embodiment, the refrigerant circuit including the plate fin-and-tube heat exchanger using the inner-surface grooved tube 201 is filled with a refrigerant for performing a vapor compression refrigeration cycle. The refrigerant is a mixed refrigerant containing 1,2-difluoroethylene, and can use any one of the above-described refrigerants A to E.
The air conditioning apparatus 10 that is the refrigeration cycle apparatus according to the first embodiment, the refrigeration cycle apparatus according to the second embodiment, and the refrigeration cycle apparatus according to the third embodiment each include a flammable refrigerant containing at least 1,2-difluoroethylene, an evaporator that evaporates the refrigerant, and a condenser that condenses the refrigerant. The refrigeration cycle apparatuses are constituted such that the refrigerant repeats a refrigeration cycle by circulating through the evaporator and the condenser.
According to the first embodiment, the outdoor heat exchanger 23 is one of the evaporator and the condenser, and the indoor heat exchanger 27 is the other one of the evaporator and the condenser; and the outdoor heat exchanger 23 and the indoor heat exchanger 27 each include the metal plates 19 serving as a plurality of fins made of aluminum or an aluminum alloy, and the flat tubes 16 serving as a plurality of heat transfer tubes made of aluminum or an aluminum alloy. The outdoor heat exchanger 23 and the indoor heat exchanger 27 are each a heat exchanger that causes the refrigerant flowing inside the heat transfer tubes 16 and the air which is a fluid flowing along the metal plates 19 to exchange heat with each other. The flat tube 16 includes a flat surface portion 16a illustrated in
According to the second embodiment, the outdoor heat exchanger 125 is one of the evaporator and the condenser, and includes the plurality of insertion fins 194 made of aluminum or an aluminum alloy, and the flat perforated tubes 193 serving as a plurality of heat transfer tubes made of aluminum or an aluminum alloy. The outdoor heat exchanger 125 is a heat exchanger that causes the refrigerant flowing inside the flat perforated tube 193 and the air which is a fluid flowing along the insertion fin 194 to exchange heat with each other. The flat perforated tube 193 have the flat surface portions 193b illustrated in
According to the third embodiment, the heat exchanger including the plurality of plate fins 211 made of aluminum or an aluminum alloy, and the inner-surface grooved tubes 201 serving as a plurality of heat transfer tubes made of aluminum or an aluminum alloy is one of the evaporator and the condenser. The heat exchanger is a heat exchanger that causes the refrigerant flowing inside the inner-surface grooved tube 201 and the air which is a fluid flowing along the plate fins 211 to exchange heat with each other. Each of the plurality of plate fins 211 has the plurality of through holes 211a. In the heat exchanger, the plurality of inner-surface grooved tubes 201 penetrate through the plurality of through holes 211a of the plurality of plate fins 211. The outer peripheries of the plurality of inner-surface grooved tubes 201 are in close contact with the inner peripheries of the plurality of through holes 211a.
In the above-described refrigeration cycle apparatus, the heat exchanger includes the metal plates 19, the insertion fins 194, or the plate fins 211 serving as a plurality of fins made of aluminum or an aluminum alloy; and the flat tubes 16, the flat perforated tubes 193, or the inner-surface grooved tubes 201 serving as a plurality of heat transfer tubes made of aluminum or an aluminum alloy. Since the refrigeration cycle apparatus has such a configuration, for example, as compared to a case where a heat transfer tube uses a copper pipe, the material cost of the heat exchanger can be decreased.
The embodiments of the present disclosure have been described above, and it is understood that the embodiments and details can be modified in various ways without departing from the idea and scope of the present disclosure described in the claims.
PTL 1: Japanese Unexamined Patent Application Publication No. 11-256358
Number | Date | Country | Kind |
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2017-242183 | Dec 2017 | JP | national |
2017-242185 | Dec 2017 | JP | national |
2017-242186 | Dec 2017 | JP | national |
2017-242187 | Dec 2017 | JP | national |
PCT/JP2018/037483 | Oct 2018 | JP | national |
PCT/JP2018/038746 | Oct 2018 | JP | national |
PCT/JP2018/038747 | Oct 2018 | JP | national |
PCT/JP2018/038748 | Oct 2018 | JP | national |
PCT/JP2018/038749 | Oct 2018 | JP | national |
Number | Date | Country | |
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Parent | 16955207 | Jun 2020 | US |
Child | 16913500 | US |