JP2010008002A - Refrigerating cycle apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating cycle apparatus, restraining the occurrence of decomposition and polymerization due to chemical reaction of a refrigerant having double bond of carbon even when using a mixed refrigerant containing a high boiling point refrigerant and a low boiling point refrigerant having double bond of carbon in a composition. <P>SOLUTION: This refrigerating cycle apparatus using a mixed refrigerant containing a high boiling point refrigerant and a low boiling point refrigerant having double bond of carbon in a composition, includes: a refrigerant separator which separates the mixed refrigerant into a high boiling point component refrigerant and a low boiling point component refrigerant; a first expansion device, which pressure-reducing the high boiling point component refrigerant; a high and low pressure heat exchanger, which performs heat exchange between the high boiling point component refrigerant pressure-reduced by the first expansion device and the condensed mixed refrigerant; a first compression element, which compresses the high boiling point component refrigerant; a second expansion device, which pressure-reduces the low boiling point component refrigerant; an evaporator, which evaporates the low boiling point component refrigerant: a second compression element, which compresses the low boiling point component refrigerant; and a joining part where the compressed high boiling point component refrigerant and the low boiling point component refrigerant join each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus such as a refrigeration apparatus, an air conditioning apparatus, or a hot water supply apparatus, and more particularly to a refrigeration cycle apparatus that uses a mixed refrigerant containing a refrigerant having a carbon double bond as a refrigerant.

  As part of preventing global warming, refrigerants (working fluids) used in refrigeration cycle equipment such as refrigeration and refrigeration equipment, air conditioning equipment, and hot water supply equipment are currently mainly used in refrigeration and air conditioning applications. Study is underway to replace the HFC refrigerants such as R410A (mixed refrigerant of R32 and R125) and R134a with refrigerants that have a significantly lower global warming potential (expressed as GWP than Global Warming Potential). .

  One of the candidate refrigerants is a halogenated hydrocarbon having a carbon double bond in its composition. One example is HPF-1234yf in which four of six hydrogens of propylene (R1270), a hydrocarbon having one carbon double bond in the molecule, are replaced with fluorine (CF3CF = CH2). being called. Although such a refrigerant is a kind of HFC refrigerant, an unsaturated hydrocarbon having a carbon double bond is called an olefin, and therefore, in order to distinguish it from a conventional HFC refrigerant having no double bond, the olefin O May be used to represent HFO.

  This HFO-1234yf refrigerant has a GWP of 4, and has a very low GWP compared to R410A with a GWP of 2088 and R134a with a 1430, and is expected to contribute to the prevention of global warming.

  HFO-1234yf is extremely close to R134a, which is a HFC refrigerant, as a heat physical property as a refrigerant. In an automotive air conditioner (car air conditioner) that currently uses the R134a refrigerant alone, the refrigerant is replaced with HFO-1234yf. However, performance problems do not become obvious. However, HFO-1234yf has a low refrigeration capacity in home and commercial air conditioning equipment or hot water supply equipment using HFC mixed refrigerants R410A and R407C having a boiling point lower than that of R134a. Therefore, it is necessary to increase the volume flow rate (refrigerant circulation amount). When the volumetric flow rate is increased, the flow rate of the refrigerant flowing through the circuit in the same circuit (refrigeration cycle) increases, so that the pressure loss of the refrigerant in the refrigeration cycle increases and the operating efficiency of the refrigeration cycle deteriorates.

  Therefore, it is considered that the refrigerant HFO-1234yf is not used alone but is used in the refrigeration cycle as a mixed refrigerant with a refrigerant (high-pressure refrigerant) having a boiling point lower than that of HFO-1234yf. The refrigerant candidates to be mixed include, for example, R32, R41, R125 and the like, and it is conceivable to mix with a plurality of refrigerants instead of one kind.

Conventionally, a compressor, a condenser, a main expansion device, and an evaporator are connected in order for the purpose of obtaining a refrigeration system that avoids the environmental problem of ozone layer destruction using HFC mixed refrigerant and that has high operating efficiency. A high-boiling point that contains a large amount of high-boiling point refrigerant, provided with a functional film that is connected to the outlet of the condenser and facilitates passage of a specific type of refrigerant in the mixed refrigerant, in a refrigeration apparatus that uses an HFC mixed refrigerant as a refrigerant A refrigerant separator that separates into a component refrigerant liquid and a low-boiling component refrigerant liquid that contains a large amount of low-boiling-point refrigerant supplied to the main expansion device, and decompresses the high-boiling component refrigerant liquid separated by the refrigerant separator A sub-expansion device, a high-low pressure heat exchanger that exchanges heat between the high-boiling component refrigerant decompressed by the sub-expansion device and the high-pressure liquid at the outlet of the condenser, and a high-boiling component heat-exchanged by the high-low pressure heat exchanger Return the refrigerant to the compressor And scan circuit is provided refrigeration apparatus has been proposed (e.g., see Patent Document 1).
Japanese Patent No. 3334418

  A substance having a carbon double bond has a problem in the stability of the substance, and may be decomposed and polymerized depending on the environment and atmosphere. Generally, the conditions for decomposition and polymerization include high temperature, high pressure and catalyst.

  In a compressor of a refrigeration cycle using a substance having a carbon double bond as a refrigerant, there is a concern about decomposition and polymerization of the refrigerant having a carbon double bond in the sliding portion of the compression element, and measures to suppress these are necessary. It is.

  In the refrigeration apparatus described in Patent Document 1, the high boiling point component refrigerant flowing out from the bypass pipe of the refrigerant separator is depressurized by the secondary expansion device, and then heated by the high pressure side in the high and low pressure heat exchanger and before the accumulator inlet. And merges with the low boiling point component refrigerant from the evaporator. In other words, since it is merged before the compressor (upstream side), a mixed refrigerant containing a refrigerant having a carbon double bond is used particularly when the inside of the sealed container is a compressor that becomes a high-pressure atmosphere of a refrigeration cycle. Then, there is a problem that the refrigerant having a carbon double bond in the mixed refrigerant may be decomposed and polymerized in the sliding portion of the compressor, and the stability of the refrigerant cannot be maintained.

  The present invention has been made to solve the above-described problems, and is at least one of a halogenated hydrocarbon having a carbon double bond in the composition and a hydrocarbon having a carbon double bond in the composition. Refrigeration capable of suppressing the occurrence of decomposition and polymerization due to the chemical reaction of the refrigerant even when using a mixed refrigerant comprising a high-boiling refrigerant containing the refrigerant and at least one low-boiling refrigerant having a lower boiling point than the high-boiling refrigerant The purpose is to provide a cycle.

  The refrigeration cycle apparatus according to the present invention comprises a high-boiling refrigerant containing at least one of a halogenated hydrocarbon having a carbon double bond in the composition or a hydrocarbon having a carbon double bond in the composition, and the high boiling point A mixed refrigerant containing at least one low-boiling refrigerant having a lower boiling point than the refrigerant is connected to the outlet side of the condenser that condenses the mixed refrigerant, and the mixed refrigerant condensed in the condenser is mostly high-boiling refrigerant. A refrigerant separator that separates the high-boiling component refrigerant contained in the refrigerant into a low-boiling component refrigerant that contains a large amount of the low-boiling refrigerant; a first expansion device that depressurizes the high-boiling component refrigerant separated by the refrigerant separator; High-low pressure heat exchanger that is arranged between the condenser and the refrigerant separator and exchanges heat between the high-boiling component refrigerant decompressed by the first expansion device and the mixed refrigerant before being condensed in the condenser and flowing into the refrigerant separator And this high and low pressure A first compression element that compresses the high-boiling component refrigerant heat-exchanged by the exchanger, a second expansion device that depressurizes the low-boiling component refrigerant separated by the refrigerant separator, and the second expansion device. An evaporator that evaporates the low-boiling component refrigerant that has been depressurized by exchanging heat with air, a second compression element that compresses the low-boiling component refrigerant evaporated by the evaporator, and upstream of the inlet of the condenser, A merging portion where the high-boiling component refrigerant compressed by the first compression element and the low-boiling component refrigerant compressed by the second compression element merge.

  The refrigeration cycle apparatus according to the present invention is a high-boiling component containing a large amount of high-boiling refrigerant having a carbon double bond in a mixed refrigerant containing a refrigerant having a carbon double bond condensed in a condenser by a refrigerant separator. Before the refrigerant and the low-boiling-point refrigerant containing a large amount of low-boiling-point refrigerant are separated and condensed by the high-boiling-point refrigerant and the condenser decompressed by the first expansion device in the high-low pressure heat exchanger before flowing into the refrigerant separator The high-boiling component refrigerant heat-exchanged by the high-low pressure heat exchanger is compressed by the first compression element, and the low-boiling-point refrigerant evaporated by the evaporator is compressed by the second compression element. Since it is configured to compress, the high-boiling component refrigerant having a carbon double bond, which has a problem in stability, is sucked only into the first compression element. Therefore, the first compression element is configured such that the refrigerant having a carbon double bond is difficult to decompose and polymerize, so that the refrigerant having the carbon double bond in the high-boiling component refrigerant having a problem in stability. It is possible to provide a highly reliable refrigeration cycle apparatus capable of suppressing the occurrence of decomposition and polymerization due to a chemical reaction and maintaining the stability of the mixed refrigerant.

Embodiment 1 FIG.
First, the refrigerant | coolant used for the refrigerating-cycle apparatus 100 in this embodiment is demonstrated. The refrigerant targeted in this embodiment includes a high-boiling-point refrigerant containing at least one of a halogenated hydrocarbon having a carbon double bond in its composition or a hydrocarbon having a carbon double bond in its composition, It is a mixed refrigerant containing at least one low boiling point refrigerant having a lower boiling point than that of the high boiling point refrigerant.

  As already mentioned, an example of a halogenated hydrocarbon having a carbon double bond in its composition is that of the six hydrogens of propylene (R1270), a hydrocarbon having one carbon double bond in the molecule. Of these, four are replaced with fluorine (CF3CF = CH2), which is called HFO-1234yf. Although such a refrigerant is a kind of HFC refrigerant, an unsaturated hydrocarbon having a carbon double bond is called an olefin, and therefore, in order to distinguish it from a conventional HFC refrigerant having no double bond, the olefin O May be used to represent HFO.

  This HFO-1234yf refrigerant has a GWP (global warming potential) of 4, and has an extremely low GWP compared to R410A with GWP of 2088 and R134a with 1430, and is expected to contribute to the prevention of global warming.

  The hydrocarbon having a carbon double bond in the composition is, for example, R1270 (propylene). In addition, although GWP of R1270 is 3, smaller than HFO-1234yf, combustibility is larger than HFO-1234yf.

  The high-boiling refrigerant used in the refrigeration cycle apparatus 100 in this embodiment is at least one of a halogenated hydrocarbon having a carbon double bond in the composition and a hydrocarbon having a carbon double bond in the composition. Shall be included.

  Examples of the low boiling point refrigerant having a lower boiling point than the high boiling point refrigerant to be mixed with the high boiling point refrigerant are R32, R41, R125 and the like which are HFC refrigerants. Carbon dioxide, which is a natural refrigerant, may be mixed as a low boiling point refrigerant. However, it is assumed that the GWP of the mixed refrigerant can maintain a predetermined low value (for example, 150 or less).

  The low boiling point refrigerant includes at least one of R32, R41, R125 or carbon dioxide.

  Although it has already been described that a substance having a carbon double bond in the composition has a problem in stability and there is a possibility of decomposition and polymerization, a little more explanation will be given by taking HFO-1234yf as an example.

  A substance having a double bond has the possibility of decomposition and polymerization, and generally the conditions for decomposition and polymerization are high temperature, high pressure and a catalyst. Those having a larger proportion of the number of fluorine atoms instead of hydrocarbons may be more easily polymerized. For example, Roy J. Plunkett (June 26, 1910-May 12, 1994, an American chemist), in 1938, introduced tetrafluoroethylene (four hydrogens of ethylene into fluorine). It was discovered that all of them had undergone a polymerization reaction spontaneously in a cylinder, and a fluororesin was produced by chance.

  HFO-1234yf is one in which six of the six hydrogen atoms of propylene (R1270), which is a hydrocarbon having one carbon double bond in its molecule, are replaced by fluorine. The possibility of polymerization is considered to be quite high. The mechanochemical reaction is a chemical reaction that occurs when the target substance is activated (mechanochemical activity) by applying mechanical energy such as impact or friction to the target substance.

  Hereinafter, a high-boiling refrigerant containing at least one of a halogenated hydrocarbon having a carbon double bond in the composition or a hydrocarbon having a carbon double bond in the composition, and at least one having a lower boiling point than the high-boiling refrigerant An example of the refrigerant circuit of the refrigeration cycle apparatus in the present embodiment using the mixed refrigerant containing the above low boiling point refrigerant will be described.

  FIGS. 1 to 3 are diagrams showing Embodiment 1, FIG. 1 is a refrigerant circuit diagram of a refrigeration cycle apparatus 100 according to the present invention, FIG. 2 is a longitudinally enlarged sectional view of a refrigerant separator 6, and FIG. FIG. 3 is a model diagram showing a cross section of a compressor 200 in which an element 1a and a second compression element 1b are accommodated in one sealed container 50.

  An example of the refrigerant circuit of the refrigeration cycle apparatus 100 will be described with reference to FIG. The refrigerant circuit of the refrigeration cycle apparatus 100 has the refrigerant separator 6 as a starting point, the first refrigerant circuit 30a through which the high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant flows, and the refrigerant separator 6 as the starting point. And a common refrigerant circuit 30c through which the mixed refrigerant 20 flows between the refrigerant separator 6 and the merging section 40.

  The first refrigerant circuit 30a and the second refrigerant circuit 30b are connected in parallel to the common refrigerant circuit 30c so that the starting point is the refrigerant separator 6 and the end point is the junction 40.

  Before describing the overall configuration of the refrigerant circuit of the refrigeration cycle apparatus 100, the refrigerant separator 6 will be described first.

  As shown in FIG. 2, the refrigerant separator 6 includes an inlet pipe 7 connected to the high-pressure pipe 15a of the high-low pressure heat exchanger 15 provided in the common refrigerant circuit 30c. The refrigerant separator 6 also includes an outlet pipe 8 connected to the second expansion device 3b of the second refrigerant circuit 30b.

  A flange 9 is provided between the inlet pipe 7 and the outlet pipe 8, and a functional membrane 11 made of a porous membrane or a hollow fiber membrane held by the holder 10 is provided on the flange 9. That is, the outlet pipe 8 is installed on the downstream side of the functional film 11.

  The refrigerant separator 6 includes a bypass pipe 12 connected to the first expansion device 3a of the first refrigerant circuit 30a on the downstream side of the inlet pipe 7 and upstream of the functional membrane 11.

  The functional membrane 11 of the refrigerant separator 6 is a membrane through which low-boiling refrigerant can easily pass but high-boiling refrigerant is difficult to pass through, and the high-boiling refrigerant easily passes through the functional membrane 11 of the refrigerant separator 6. It is a configuration that does not. The refrigerant separator 6 separates the mixed refrigerant 20 into a high boiling point component refrigerant 20a containing a large amount of high boiling point refrigerant and a low boiling point component refrigerant 20b containing a large amount of low boiling point refrigerant.

  Here, the refrigerant separator 6 uses the functional membrane 11 to separate the high-boiling component refrigerant 20a and the low-boiling component refrigerant 20b, but utilizes the density difference between the high-boiling refrigerant and the low-boiling refrigerant. It may be a thing.

  For example, the refrigerant separator 6 is configured as a gas-liquid separator that separates a high-pressure mixed refrigerant that has been condensed by the condenser 2 and passed through the high-low pressure heat exchanger 15 into a liquid refrigerant and a gas refrigerant. In a state where the mixed refrigerant in the gas-liquid separator is kept in gas-liquid equilibrium, the liquid refrigerant tends to be a refrigerant containing a higher boiling point refrigerant than the gas refrigerant, that is, the above-described high boiling point component refrigerant 20a. Conversely, the gas refrigerant becomes a refrigerant containing a large amount of low-boiling refrigerant, that is, the low-boiling component refrigerant 20b.

  Utilizing such a tendency, the liquid refrigerant is mainly supplied to the first refrigerant circuit 30a and the gas refrigerant is mainly supplied to the second refrigerant circuit 30b from the refrigerant separator 6 constituted by the gas-liquid separator. With this configuration, the mixed refrigerant can be separated into a high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant and a low-boiling component refrigerant 20b containing a large amount of low-boiling refrigerant.

  First, the configuration of the common refrigerant circuit 30c through which the mixed refrigerant 20 flows will be described. The common refrigerant circuit 30c has a high boiling point refrigerant 20a containing a large amount of high boiling point refrigerant compressed by the first compression element 1a (described later) and a large amount of low boiling point refrigerant compressed by the second compression element 1b (described later). Condenser 2 that condenses mixed refrigerant 20 after merging at merging portion 40 on the downstream side of this merging portion 40 (downstream side of the refrigerant flow), starting from merging portion 40 where low-boiling component refrigerant 20b that is included is merged. Is provided.

  On the downstream side of the outlet of the condenser 2 that condenses the mixed refrigerant 20, a high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant separated by the refrigerant separator 6 and decompressed by a first expansion device 3a (described later) is provided. A high-low pressure heat exchanger 15 that exchanges heat with the mixed refrigerant 20 after the outlet of the condenser 2, that is, the high-pressure mixed refrigerant 20 after condensation is provided.

  The high-low pressure heat exchanger 15 includes a high-pressure pipe 15a through which the mixed refrigerant 20 after the outlet of the condenser 2 flows, and a high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant decompressed by a first expansion device 3a (described later). And a flowing low-pressure pipe 15b. These high-pressure pipes 15a and low-pressure pipes 15b are configured as, for example, double pipes, and the central portion is the low-pressure pipe 15b and the periphery thereof is the high-pressure pipe 15a so as to exchange heat with each other. The high and low pressure heat exchanger 15 may be constituted by a double pipe having a high pressure pipe 15a at the center and a low pressure pipe 15b around the center.

  The outlet side of the condenser 2 is connected to the high-pressure pipe 15 a (upstream side) of the high-low pressure heat exchanger 15.

  On the downstream side of the high-pressure pipe 15a of the high-low pressure heat exchanger 15, the high-pressure liquid of the mixed refrigerant 20 condensed in the condenser 2, the liquid of the high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant, and the low-boiling refrigerant are increased. It connects with the inlet piping 7 of the refrigerant | coolant separator 6 isolate | separated into the liquid of the low boiling point component refrigerant | coolant 20b containing.

  The common refrigerant circuit 30c is connected to the inside of the refrigerant separator 6 via the condenser 2, the high / low pressure heat exchanger 15, and the inlet pipe 7 of the refrigerant separator 6 (the mixed refrigerant 20 contains a large amount of high-boiling refrigerant). This is a portion that reaches a space before being separated into the high-boiling component refrigerant 20a containing the low-boiling-point refrigerant 20b and the low-boiling component refrigerant 20b containing many low-boiling refrigerants.

  Next, the configuration of the first refrigerant circuit 30a will be described. In the refrigerant separator 6, the high boiling point refrigerant liquid in the mixed refrigerant 20 does not easily pass through the functional film 11 of the refrigerant separator 6, so that the high boiling point component refrigerant 20 a containing a large amount of high boiling point refrigerant is used as the first refrigerant. The refrigerant flows out from the bypass pipe 12 connected to the first expansion device 3a of the circuit 30a to the first refrigerant circuit 30a.

  The high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant flowing out from the bypass pipe 12 to the first refrigerant circuit 30a is decompressed and expanded by the first expansion device 3a.

  In the first expansion device 3a, for example, the opening degree can be changed, that is, the amount of throttle can be changed, and the flow rate of the high boiling point component refrigerant 20a flowing through the first refrigerant circuit 30a can be controlled (adjustable). A type expansion valve is used.

  The low-pressure, high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant decompressed and expanded by the first expansion device 3a enters the low-pressure pipe 15b of the high-low pressure heat exchanger 15 and flows through the high-pressure pipe 15a of the high-low pressure heat exchanger 15. Heat exchange is performed with the high-pressure liquid of the mixed refrigerant 20 after condensation, and the refrigerant evaporates. At this time, the latent heat of vaporization of the high boiling point component refrigerant 20a is recovered by the mixed refrigerant 20 flowing through the high pressure pipe 15a.

  The high-boiling component refrigerant 20a containing a large amount of the high-boiling refrigerant heat-exchanged and evaporated by the high-low pressure heat exchanger 15 is then sucked into the first compression element 1a, where it is compressed from low pressure to high pressure. The high-pressure, high-boiling component refrigerant 20a compressed by the first compression element 1a is discharged from the first compression element 1a to the junction 40.

  The first refrigerant circuit 30a passes from the bypass pipe 12 of the refrigerant separator 6 to the junction 40 via the first expansion device 3a, the low-pressure pipe 15b of the high-low pressure heat exchanger 15, and the first compression element 1a. It is a part to reach.

  Next, the configuration of the second refrigerant circuit 30b will be described. In the refrigerant separator 6, the low boiling point refrigerant liquid in the mixed refrigerant 20 easily passes through the functional film 11 of the refrigerant separator 6. Therefore, the low boiling point refrigerant 20 b containing a large amount of low boiling point refrigerant is used as the second refrigerant. The refrigerant flows out from the outlet pipe 8 connected to the second expansion device 3b of the circuit 30b to the second refrigerant circuit 30b.

  The low boiling point component refrigerant 20b containing a large amount of low boiling point refrigerant that has flowed out of the outlet pipe 8 into the second refrigerant circuit 30b is decompressed and expanded by the second expansion device 3b. Similarly to the first expansion device 3a, the second expansion device 3b can change, for example, the opening degree, that is, the amount of low-boiling component refrigerant 20b flowing through the second refrigerant circuit 30b can be changed by changing the throttle amount. An electronic expansion valve that can be controlled (adjustable) is used.

  The low-pressure low-boiling component refrigerant 20b containing a large amount of low-boiling refrigerant decompressed and expanded by the second expansion device 3b is evaporated by exchanging heat with air in the evaporator 4.

  The second compression element 1b sucks and compresses the low-boiling component refrigerant 20b containing a large amount of the low-boiling refrigerant evaporated by the evaporator 4. The high-pressure low-boiling component refrigerant 20b compressed by the second compression element 1b is discharged from the second compression element 1b to the junction 40.

  The second refrigerant circuit 30b is a part from the outlet pipe 8 of the refrigerant separator 6 to the junction 40 via the second expansion device 3b, the evaporator 4, and the second compression element 1b.

  Next, the operation of the refrigerant circuit of the refrigeration cycle apparatus 100 shown in the figure will be described. A high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant compressed and discharged by the first compression element 1a, and a low-boiling component refrigerant 20b containing a lot of low-boiling refrigerant compressed and discharged by the second compression element 1b The mixed refrigerant 20 is merged at the merging portion 40, and the mixed refrigerant 20 in a high-temperature and high-pressure gas state flows into the condenser 2 of the common refrigerant circuit 30c, where it is cooled and condensed by room temperature air or the like. Liquefaction.

  The high-pressure liquid of the mixed refrigerant 20 condensed and liquefied by the condenser 2 flows into the high-pressure pipe 15a of the high-low pressure heat exchanger 15 and is decompressed by the first expansion device 3a flowing through the low-pressure pipe 15b of the high-low pressure heat exchanger 15. Heat exchange is performed with the expanded high-boiling component refrigerant 20a. As a result, the latent heat of vaporization of the decompressed high boiling point component refrigerant 20a flowing through the first refrigerant circuit 30a can be recovered, and loss due to separation and flowing of the high boiling point component refrigerant 20a through the first refrigerant circuit 30a is reduced. .

  The mixed refrigerant 20 liquefied in the condenser 2 is further deprived of heat by the high and low pressure heat exchanger 15 to the high boiling point component refrigerant 20a decompressed and expanded by the first expansion device 3a flowing through the low pressure pipe 15b of the high and low pressure heat exchanger 15. The crack temperature is lowered, that is, the latent heat of vaporization of the high-boiling component refrigerant 20a is recovered, and usually it is supercooled. Thereafter, the refrigerant flows into the refrigerant separator 6 from the inlet pipe 7.

  Then, the low-boiling component refrigerant 20b containing a large amount of the low-boiling refrigerant that has passed through the functional membrane 11 in the refrigerant separator 6 flows out from the outlet pipe 8 to the second refrigerant circuit 30b.

  Further, the high-boiling component refrigerant 20a containing a large amount of the high-boiling refrigerant that is the remainder of the mixed refrigerant 20 that could not pass through the functional membrane 11 flows out from the bypass pipe 12 of the refrigerant separator 6 to the first refrigerant circuit 30a.

  The low boiling point component refrigerant 20b flowing out from the outlet pipe 8 is decompressed by the second expansion device 3b, flows into the evaporator 4, generates a low temperature by the evaporator 4, and the low boiling point component refrigerant 20b evaporates. It is gasified and sucked into the second compression element 1b.

  The high boiling point component refrigerant 20a flowing out from the bypass pipe 12 of the refrigerant separator 6 to the first refrigerant circuit 30a is depressurized by the first expansion device 3a, and then is supplied to the low pressure pipe 15b of the high / low pressure heat exchanger 15. Inflow. Then, after being heated and evaporated by the high-pressure liquid of the mixed refrigerant 20 flowing through the high-pressure pipe 15a of the high-low pressure heat exchanger 15, it is sucked into the first compression element 1a.

  The refrigeration cycle apparatus 100 includes a control unit (not shown) configured by a microcomputer in which a predetermined operation program is incorporated, and each part (first expansion device 3a, second expansion device 3b) of the refrigeration cycle apparatus 100. And the first compression element 1a and the second compression element 1b).

  The control unit is configured such that the suction pressure Ps1 when the high-boiling-point refrigerant 20a flowing through the first refrigerant circuit 30a is sucked into the first compression element 1a is the low-boiling-point refrigerant 20b flowing through the second refrigerant circuit 30b. The first expansion device 3a is controlled so as to be equal to or higher than the suction pressure Ps2 when sucked into the second compression element 1b.

  That is, the control unit controls the first expansion device 3a so that the relationship between the suction pressure Ps1 of the first compression element 1a and the suction pressure Ps2 of the second compression element 1b satisfies Ps1 ≧ Ps2.

  The suction pressure Ps2 to the second compression element 1b is the evaporation pressure of the evaporator 4, and the temperature of the air that exchanges heat with the low-boiling component refrigerant 20b that flows through the evaporator 4 in the evaporator 4 and the air blowing state of the air, It is determined by external factors such as the capacity of the evaporator 4 and heat exchange performance. In this way, the control unit detects Ps2 determined by the external factor, and controls the first expansion device 3a so that Ps1 ≧ Ps2.

  Since the refrigerant circulation amount flowing through the second refrigerant circuit 30b is also a factor that determines the suction pressure Ps2 of the second compression element 1b, that is, the evaporation pressure of the evaporator 4, the control unit is only the first expansion device 3a. Alternatively, the second expansion device 3b may also be controlled so that Ps1 ≧ Ps2.

  By flowing the low-boiling component refrigerant 20b containing a large amount of low-boiling point refrigerant to the evaporator 4, compared to the case where the mixed refrigerant 20 is flowed to the evaporator 4 under the same conditions, the evaporation temperature (corresponding to the temperature of the air for heat exchange) can be reduced. The evaporation pressure, that is, the suction pressure Ps2 of the second compression element 1b can be increased. The discharge pressure of the second compression element 1b is the condensation pressure of the mixed refrigerant 20 in the condenser 2 (this is also the same as the evaporation pressure of the evaporator 4 and is determined by an external factor). The compression ratio becomes lower than when absorbing and compressing, and the efficiency of the second compression element 1b increases.

  Further, the suction pressure Ps1 of the first compression element 1a is controlled to Ps1 ≧ Ps2 as described above, and the discharge pressure of the first compression element 1a is similarly the condensation pressure of the mixed refrigerant 20 in the condenser 2, that is, Since it becomes the same as the discharge pressure of the 2nd compression element 1b, the compression ratio of the 1st compression element 1a becomes below or equal to the compression ratio of the 2nd compression element 1b, and the efficiency of the 1st compression element 1a is also high. it can. Therefore, the operation efficiency of the refrigeration cycle apparatus 100 is improved.

  Further, the high-boiling component refrigerant 20a decompressed by the first expansion device 3a flowing through the first refrigerant circuit 30a and the high-pressure liquid of the mixed refrigerant 20 condensed and liquefied by the condenser 2 are heated by the high-low pressure heat exchanger 15. By exchanging, the latent heat of vaporization of the high boiling point component refrigerant 20a flowing through the first refrigerant circuit 30a can be recovered.

  For this reason, the loss by flowing the high boiling point component refrigerant 20a through the first refrigerant circuit 30a is reduced. The latent heat of vaporization of the high boiling point component refrigerant 20a flowing through the first refrigerant circuit 30a is also collected by the high / low pressure heat exchanger 15 and contributes to the supercooling of the mixed refrigerant 20. Thereby, generation | occurrence | production of the loss of energy by the 1st refrigerant circuit 30a can be suppressed, and the operating efficiency of the refrigerating-cycle apparatus 100 is combined with the efficiency improvement of the 1st compression element 1a mentioned above and the 2nd compression element 1b. Can be further improved.

  Moreover, since the compression ratio of the 1st compression element 1a which compresses the high boiling point component refrigerant | coolant 20a can be made low compared with the case where the mixed refrigerant 20 is compressed, the discharge temperature of the 1st compression element 1a can be made low. . The refrigerant having a carbon double bond in the composition, which is contained in a large amount in the high-boiling component refrigerant 20a, easily causes decomposition and polymerization at a high temperature and a high pressure. Decomposition and polymerization of the refrigerant having a bond are suppressed.

Next, a method for incorporating the first compression element 1a and the second compression element 1b into the compressor will be described. There are the following two methods.
(1) A first compressor (not shown) having a first compression element 1a, a second compressor (not shown) having a second compression element 1b, and two compressors are provided.
(2) The first compression element 1a and the second compression element 1b are housed in one sealed container 50 (see FIG. 3), and one electric motor 60 (see FIG. 3) housed in the sealed container 50. Thus, both the first compression element 1a and the second compression element 1b are driven.

  In the case of (1) above, the first compressor includes the first compression element 1a inside the sealed container (not shown) and an electric motor (not shown) that drives the first compression element 1a. Therefore, it is preferable to use a compressor generally called a low-pressure shell type in which the space in which the electric motor is disposed is the suction pressure atmosphere (low-pressure atmosphere) of the high-boiling component refrigerant 20a.

  With this configuration, the high-temperature and high-pressure discharge gas of the high-boiling component refrigerant 20a discharged from the first compression element 1a does not pass through the electric motor, so that thermally and chemically unstable HFO-1234yf, propylene, etc. The high-boiling component refrigerant 20a containing a refrigerant having a carbon double bond in the composition of the above has an adverse effect on an organic material such as an insulating material of the electric motor, or conversely has a carbon double bond depending on the organic material of the electric motor. There is no risk of the refrigerant being decomposed or polymerized. The first compressor is of a low-pressure shell type so that a motor having an organic material does not come into contact with a refrigerant having a high-temperature and high-pressure carbon double bond. Thereby, decomposition | disassembly and superposition | polymerization of the refrigerant | coolant which has a carbon double bond in a composition can be suppressed, and the stability of the mixed refrigerant | coolant 20 can be maintained. Moreover, the stability of the organic material of the electric motor accommodated in the first compressor can be maintained.

  Specific examples of the compressor in which the space in which the electric motor is disposed inside the hermetic container is the suction pressure atmosphere of the high boiling point component refrigerant 20a are a reciprocating compressor (reciprocating compressor), a scroll compressor, and the like. is there.

  In the case of (2) above, as shown in the compressor 200 in FIG. 3, the first compression element 1 a and the second compression element 1 b are accommodated in one sealed container 50, Both the first compression element 1a and the second compression element 1b are driven by the single electric motor 60 that is housed, but the high-boiling-point refrigerant that is compressed and discharged by the first compression element 1a is high. It is preferable that the boiling point component refrigerant 20a be discharged directly outside the sealed container 50 without being discharged into the sealed container 50.

  As in the case of (1) above, by configuring in this way, the discharge gas of the high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant discharged from the first compression element 1a does not pass through the electric motor 60. The high-boiling component refrigerant 20a containing a refrigerant having a thermally and chemically unstable carbon double bond adversely affects organic materials such as an insulating material of an electric motor. There is no possibility that the refrigerant having a double bond is decomposed or polymerized. Thereby, decomposition | disassembly and superposition | polymerization of the refrigerant | coolant which has a carbon double bond in a composition can be suppressed, and the stability of the mixed refrigerant | coolant 20 can be maintained. Moreover, the stability of the organic material of the electric motor 60 accommodated in the compressor 200 can be maintained.

  The compressor 200 shown in the model diagram of FIG. 3 is, for example, a two-cylinder rotary compressor. The high boiling point component refrigerant 20a including the refrigerant having a carbon double bond that is compressed and discharged by the first compression element 1a is not discharged into the sealed container 50 but directly discharged out of the sealed container 50. However, although not shown, the first compression element 1a includes a discharge muffler from which a compressed gas refrigerant is temporarily discharged from its cylinder (one of the components constituting the compression chamber). The discharge muffler is connected to a refrigerant circuit outside the sealed container 50 without communicating with the inside of the sealed container 50 by a discharge pipe or the like.

  The compressor 200 shown in the model diagram of FIG. 3 is, for example, a two-cylinder rotary compressor, but it is preferable that at least the first compression element 1a be a swing rotary system (not shown).

  In the general rotary method, a cylindrical rolling piston that rotates eccentrically contacts the vane tip of a rectangular parallelepiped that enters and exits the receiving groove of the cylinder to partition the suction chamber and the compression chamber. The piston and the vane are integrated (in the case of the swing method, called a blade instead of a vane), and the vane-integrated rolling piston compresses the refrigerant by performing an eccentric oscillating motion. In the general rotary system, the rolling piston is accompanied by rotation, but in the swing rotary system, the rolling piston (vane integrated) does not rotate.

  The sliding state between the vane tip and the rolling piston has the most severe sliding state in a general rotary system. In such a severe sliding portion, the atmosphere is locally high temperature and high pressure (much higher than the pressure atmosphere of the refrigerant), and the material of the sliding portion is a metal such as iron or aluminum. The surface is activated.

  For this reason, there is an activated metal surface that can act as a catalyst to decompose and polymerize substances having carbon double bonds at high temperatures and pressures, so the decomposition of refrigerants having carbon double bonds. And polymerization tends to occur. However, in the swing rotary system, the vane and the rolling piston are integrated, and such a sliding portion does not exist. Therefore, by making the first compression element 1a a swing rotary system in which a severe sliding environment between the rolling piston and the vane does not occur, the refrigerant having a carbon double bond in the high boiling point component refrigerant 20a can be locally heated. It is possible to suppress decomposition and polymerization due to the catalytic action of the activated metal in the sliding portion under a high-pressure atmosphere. Thereby, the stability of the mixed refrigerant 20 can be maintained.

  When the compressor 200 shown in the model diagram of FIG. 3 is a two-cylinder rotary compressor, the first compression element 1a and the second compression element 1b are of a general rotary system in which the rolling piston and the vane slide. The most severe sliding portion of the first compression element 1a in contact with the high boiling point component refrigerant 20a including the refrigerant having a carbon double bond is a sliding portion between the vane and the rolling piston.

  Therefore, in order to suppress the decomposition and polymerization of the refrigerant having a carbon double bond in the high boiling point component refrigerant 20a by the catalytic action of an activated metal such as iron or aluminum at the sliding portion between the vane and the rolling piston. In addition, it is effective to apply a carbon-based or ceramic-based coating to at least one of the vane and the rolling piston of the first compression element 1a.

  The material of the rolling piston in the compressor 200 is alloy steel containing chromium or the like.

  Further, high-speed tool steel is used as a material for the vanes of the compressor 200.

  Examples of the carbon-based coating include DLC-Si (diamond-like carbon-silicon) and DLC (diamond-like carbon).

  For ceramic coating, CrN (chromium nitride), TiN (titanium nitride), TiCN (titanium carbonitride), TiAlN (titanium nitride aluminum), WC / C (tungsten carbide coating), VC (vanadium carbide), etc. There is.

  Such a coating is applied to at least one of the vane and the rolling piston of the first compression element 1a to demetalize at least one sliding surface, that is, at least the sliding surface is made of iron or aluminum. By making the structure such that the metal is not exposed, the high temperature due to the direct contact between the metals is difficult, and the metal surface is also difficult to be activated, so it is activated at the sliding part under local high temperature and high pressure. The decomposition and polymerization of the refrigerant having a carbon double bond due to the catalytic action of the metal can be suppressed, and the stability of the mixed refrigerant 20 can be maintained.

  As described above, according to this embodiment, the control unit sucks when the high-boiling-point refrigerant 20a containing a large amount of high-boiling refrigerant flowing through the first refrigerant circuit 30a is sucked into the first compression element 1a. The first expansion is performed so that the pressure is equal to or higher than the suction pressure when the low-boiling component refrigerant 20b containing a large amount of low-boiling-point refrigerant flowing through the second refrigerant circuit 30b is sucked into the second compression element 1b. The device 3a and, if necessary, the second expansion device 3b are also controlled (when the suction pressure of the first compression element 1a is Ps1 and the suction pressure of the second compression element 1b is Ps2, the control unit The first expansion device 3a and, if necessary, the second expansion device 3b are also controlled so as to satisfy the relationship of Ps1 ≧ Ps2, thereby reducing the compression ratio of the first compression element 1a. Improving the efficiency of the first compression element 1a Can.

  Also, by reducing the compression ratio of the first compression element 1a, the discharge gas temperature of the high-boiling component refrigerant 20a that is compressed and discharged by the first compression element 1a can be kept low, so the high-boiling component refrigerant 20a It is possible to provide a highly reliable refrigeration cycle apparatus 100 that can suppress decomposition and polymerization of a refrigerant having a carbon double bond therein and can maintain the stability of the mixed refrigerant 20.

  Further, the high-low pressure heat exchanger 15 exchanges heat between the decompressed high-boiling component refrigerant 20 a flowing through the first refrigerant circuit 30 a and the high-pressure mixed refrigerant 20 condensed and liquefied by the condenser 2, thereby Since the latent heat of vaporization of the high boiling point component refrigerant 20a flowing through the refrigerant circuit 30a can be recovered, loss due to flowing the high boiling point component refrigerant 20a through the first refrigerant circuit 30a is reduced. The latent heat of vaporization that the high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant flowing through the first refrigerant circuit 30a has as a refrigerating capacity is also recovered by the high-low pressure heat exchanger 15. Thereby, generation | occurrence | production of the loss of energy by the 1st refrigerant circuit 30a can be suppressed.

  Moreover, the 1st compressor which has the 1st compression element 1a, and the 2nd compressor which has the 2nd compression element 1b are provided, and the 1st compressor has the 1st compression element inside the airtight container. 1a and an electric motor (not shown) for driving the same, and a space in which the electric motor is arranged inside the sealed container is used as an intake pressure atmosphere (pressure Ps1 atmosphere) of the high boiling point component refrigerant 20a. Since the discharge gas of the high boiling point component refrigerant 20a discharged from one compression element 1a does not pass through the electric motor, the refrigerant having a carbon double bond in the high boiling point component refrigerant 20a which is thermally and chemically unstable is the electric motor. It is possible to maintain the stability of the mixed refrigerant 20 without adversely affecting the organic material such as the insulating material or conversely decomposing and polymerizing the refrigerant having a carbon double bond in the organic material of the electric motor. Highly reliable frozen rhino It is possible to provide the Le device 100.

  In addition, the first compression element 1a and the second compression element 1b are accommodated in one sealed container 50, and the first compression element 1a and the second compression element 1a are stored in the single electric motor 60 accommodated in the sealed container 50. The high-boiling component refrigerant 20a containing a refrigerant having a carbon double bond in the composition compressed and discharged by the first compression element 1a is contained in the sealed container 50. Since the discharge gas of the high boiling point component refrigerant 20a discharged from the first compression element 1a does not pass through the electric motor 60 by being configured to discharge directly to the outside of the sealed container 50 without discharging, it is thermally and chemically unstable. The refrigerant having a carbon double bond in the high-boiling component refrigerant 20a adversely affects an organic material such as an insulating material of the motor, or conversely, the refrigerant having a carbon double bond in the organic material of the motor is decomposed. Without fear of being polymerized Ri, it is possible to provide a reliable and can maintain the stability of the mixed refrigerant 20 refrigeration cycle apparatus 100.

  In addition, since the first compression element 1a that compresses at least the high-boiling component refrigerant 20a is of a swing rotary system, sliding between the vane tip portion and the rolling piston that are severely slid can be avoided. The decomposition of the refrigerant having a carbon double bond and the occurrence of polymerization in the high boiling point component refrigerant 20a due to the catalytic action of an activated metal such as iron or aluminum can be suppressed, and the stability of the mixed refrigerant 20 can be improved. A highly reliable refrigeration cycle apparatus 100 that can be maintained can be provided.

  When the compressor 200 shown in the model diagram of FIG. 3 is a two-cylinder rotary compressor and the first compression element 1a is a general rotary system in which a vane and a rolling piston slide, the first compression element At least one of the vane of 1a and the rolling piston is coated with a carbon-based or ceramic-based coating so that at least one sliding surface is nonmetalized, that is, at least the sliding surface is made of iron or aluminum. By adopting a structure that does not expose the metal, high temperatures due to direct contact between metals are less likely to be generated, and the metal surface is also less likely to be activated. The decomposition and polymerization of a refrigerant having a carbon double bond in the high boiling point component refrigerant 20a due to the catalytic action of It can provide high refrigeration cycle apparatus 100 reliability capable of maintaining the stability of the medium 20.

Embodiment 2. FIG.
FIG. 4 is a refrigerant circuit diagram of the refrigeration cycle apparatus 300.

  A refrigerant circuit of a refrigeration cycle apparatus 300 having a form different from that of the first embodiment will be described with reference to FIG. Note that the refrigerant used in the refrigeration cycle apparatus 300 is the same as the mixed refrigerant 20 of the first embodiment, and a description thereof will be omitted. Also, the same or corresponding parts as those in the refrigeration cycle apparatus 100 of Embodiment 1 are denoted by the same reference numerals, and the description thereof is omitted.

  The refrigerant circuit of the refrigeration cycle apparatus 300 has the refrigerant separator 6 as a starting point, the first refrigerant circuit 30a through which the high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant flows, and the refrigerant separator 6 as the starting point. And a common refrigerant circuit 30c through which the mixed refrigerant 20 flows between the refrigerant separator 6 and the merging section 40.

  The first refrigerant circuit 30a and the second refrigerant circuit 30b are connected in parallel to the common refrigerant circuit 30c so that the starting point is the refrigerant separator 6 and the end point is the junction 40.

  The configuration of the refrigerant separator 6 is the same as that in the first embodiment, and a description thereof will be omitted.

  First, the configuration of the common refrigerant circuit 30c through which the mixed refrigerant 20 flows will be described. The common refrigerant circuit 30c includes a high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant compressed by the first compression element 1a and a low-boiling component refrigerant 20b containing a large amount of low-boiling refrigerant compressed by the second compression element 1b. The condenser 2 that condenses the mixed refrigerant 20 after joining at the joining portion 40 is provided on the downstream side of the joining portion 40 that joins (downstream of the refrigerant flow).

  A refrigerant separator 6 is connected to the downstream side of the condenser 2 that condenses the mixed refrigerant 20, and the outlet of the condenser 2 uses a high-pressure liquid of the mixed refrigerant 20 condensed in the condenser 2, and a large amount of high-boiling refrigerant. The refrigerant is connected to an inlet pipe 7 of a refrigerant separator 6 that separates into a liquid of a high-boiling component refrigerant 20a containing and a liquid of a low-boiling component refrigerant 20b containing a large amount of low-boiling refrigerant.

  The common refrigerant circuit 30c is connected to the inside of the refrigerant separator 6 from the junction 40 via the condenser 2 and the inlet pipe 7 of the refrigerant separator 6 (the high-boiling component refrigerant 20a in which the mixed refrigerant 20 contains a large amount of high-boiling refrigerant) This is the part that reaches the space before separation into the low-boiling component refrigerant 20b containing a large amount of low-boiling refrigerant.

  Next, the configuration of the first refrigerant circuit 30a will be described. In the refrigerant separator 6, the high boiling point refrigerant in the mixed refrigerant 20 does not easily pass through the functional film 11 of the refrigerant separator 6. Therefore, the high boiling point component refrigerant 20 a containing a large amount of high boiling point refrigerant is used as the first refrigerant circuit 30 a. Outflow from the bypass pipe 12 connected to the first expansion device 3a to the first refrigerant circuit 30a.

  The liquid of the high boiling point component refrigerant 20a containing a large amount of the high boiling point refrigerant flowing out from the bypass pipe 12 to the first refrigerant circuit 30a is decompressed and expanded by the first expansion device 3a.

  The high-boiling component refrigerant 20a containing a large amount of high-boiling refrigerant decompressed by the first expansion device 3a evaporates by exchanging heat with air in the first evaporator 4a.

  The first compression element 1a sucks and compresses the high-boiling component refrigerant 20a containing a large amount of the high-boiling refrigerant evaporated by the first evaporator 4a. The high-pressure, high-boiling component refrigerant 20a compressed by the first compression element 1a is discharged from the first compression element 1a to the junction 40.

  The first refrigerant circuit 30a is a part from the bypass pipe 12 of the refrigerant separator 6 to the junction 40 via the first expansion device 3a, the first evaporator 4a, and the first compression element 1a. .

  Next, the configuration of the second refrigerant circuit 30b will be described. In the refrigerant separator 6, the low-boiling point refrigerant in the mixed refrigerant 20 easily passes through the functional film 11 of the refrigerant separator 6, so that the low-boiling component refrigerant 20b containing a large amount of low-boiling point refrigerant becomes the second refrigerant circuit 30b. Outflow from the outlet pipe 8 connected to the second expansion device 3b to the second refrigerant circuit 30b.

  The liquid of the low boiling point component refrigerant 20b containing a large amount of the low boiling point refrigerant flowing out from the outlet pipe 8 to the second refrigerant circuit 30b is decompressed and expanded by the second expansion device 3b.

  The low-boiling component refrigerant 20b containing a large amount of low-boiling refrigerant decompressed by the second expansion device 3b evaporates by exchanging heat with air in the second evaporator 4b.

  The second compression element 1b sucks and compresses the low-boiling component refrigerant 20b containing a large amount of the low-boiling refrigerant evaporated by the second evaporator 4b. The high-pressure low-boiling component refrigerant 20b compressed by the second compression element 1b is discharged from the second compression element 1b to the junction 40.

  The second refrigerant circuit 30b is a portion from the outlet pipe 8 of the refrigerant separator 6 to the junction 40 via the second expansion device 3b, the second evaporator 4b, and the second compression element 1b. .

  The 1st compression element 1a compresses the high boiling point component refrigerant | coolant 20a containing the refrigerant | coolant which has a carbon double bond in a composition, and the 2nd compression element 1b compresses the low boiling point component refrigerant | coolant 20b.

  Since the method of incorporating the first compression element 1a and the second compression element 1b into the compressor is the same as that of the first embodiment, the description thereof is omitted.

  In the present embodiment, the first compression element 1a and the second compression element 2a correspond to the high-boiling component refrigerant 20a including a refrigerant having a carbon double bond in the composition and the low-boiling component refrigerant 20b including a large amount of low-boiling refrigerant. The material and configuration of each compression element 1b can be properly used.

  Therefore, the first compression element 1a is configured as described in the first embodiment, that is, a configuration in which a refrigerant having a carbon double bond is difficult to decompose and polymerize in the composition. It is possible to provide a highly reliable refrigeration cycle apparatus 300 that can suppress the occurrence of decomposition and polymerization due to a chemical reaction of a refrigerant having a carbon double bond, and can maintain the stability of the mixed refrigerant 20.

FIG. 5 shows the first embodiment, and is a refrigerant circuit diagram of the refrigeration cycle apparatus 100. FIG. 3 is a longitudinal enlarged cross-sectional view of the refrigerant separator 6 in the refrigeration cycle apparatus 100. The model figure which shows the compressor 200 by which the 1st compression element 1a and the 2nd compression element 1b are accommodated in the inside of one airtight container 50 in a cross section. FIG. 5 shows the second embodiment, and is a refrigerant circuit diagram of the refrigeration cycle apparatus 300.

Explanation of symbols

  1a 1st compression element, 1b 2nd compression element, 2 condenser, 3a 1st expansion device, 3b 2nd expansion device, 4 evaporator, 4a 1st evaporator, 4b 2nd evaporator, 6 refrigerant separator, 7 inlet pipe, 8 outlet pipe, 9 flange, 10 retainer, 11 functional membrane, 12 bypass pipe, 15 high-low pressure heat exchanger, 15a high-pressure pipe, 15b low-pressure pipe, 20a high-boiling component refrigerant, 20b Low boiling point component refrigerant, 30a first refrigerant circuit, 30b second refrigerant circuit, 30c common refrigerant circuit, 40 junction, 50 sealed container, 60 electric motor, 100 refrigeration cycle apparatus, 200 compressor, 300 refrigeration cycle apparatus.

Claims (10)

A high-boiling-point refrigerant comprising at least one of a halogenated hydrocarbon having a carbon double bond in the composition or a hydrocarbon having a carbon double bond in the composition, and at least one or more having a lower boiling point than the high-boiling refrigerant A mixed refrigerant containing a low boiling point refrigerant of
Connected to the outlet side of the condenser for condensing the mixed refrigerant, the mixed refrigerant condensed in the condenser is a high boiling point component refrigerant containing a large amount of the high boiling point refrigerant and a low boiling point containing a large amount of the low boiling point refrigerant. A refrigerant separator that separates into component refrigerants;
A first expansion device that depressurizes the high-boiling component refrigerant separated by the refrigerant separator;
The high boiling point component refrigerant disposed between the condenser and the refrigerant separator and decompressed by the first expansion device, and the mixed refrigerant before being condensed in the condenser and flowing into the refrigerant separator. A high and low pressure heat exchanger for heat exchange;
A first compression element that compresses the high-boiling component refrigerant heat-exchanged by the high-low pressure heat exchanger;
A second expansion device that depressurizes the low-boiling-point component refrigerant separated by the refrigerant separator;
An evaporator for evaporating the low-boiling component refrigerant decompressed by the second expansion device by heat exchange with air;
A second compression element for compressing the low boiling point component refrigerant evaporated by the evaporator;
On the upstream side from the inlet of the condenser, a merging portion where the high boiling point component refrigerant compressed by the first compression element and the low boiling point component refrigerant compressed by the second compression element merge,
A refrigeration cycle apparatus comprising: A control unit that performs operation control of the refrigeration cycle apparatus includes:
When the suction pressure of the first compression element is Ps1, and the suction pressure of the second compression element is Ps2,
The refrigeration cycle apparatus according to claim 1, wherein the control unit controls the first expansion device to satisfy a relationship of Ps1 ≧ Ps2. A high-boiling-point refrigerant comprising at least one of a halogenated hydrocarbon having a carbon double bond in the composition or a hydrocarbon having a carbon double bond in the composition; and at least one or more having a lower boiling point than the high-boiling refrigerant A mixed refrigerant containing a low boiling point refrigerant of
Connected to the outlet side of the condenser for condensing the mixed refrigerant, the mixed refrigerant condensed in the condenser is a high boiling point component refrigerant containing a lot of the high boiling point refrigerant and a low boiling point containing a lot of the low boiling point refrigerant. A refrigerant separator that separates into component refrigerants;
A first expansion device that depressurizes the high-boiling component refrigerant separated by the refrigerant separator;
A first evaporator for evaporating the high-boiling component refrigerant decompressed by the first expansion device by heat exchange with air;
A first compression element that compresses the high-boiling component refrigerant evaporated by the first evaporator;
A second expansion device that depressurizes the low-boiling-point component refrigerant separated by the refrigerant separator;
A second evaporator for evaporating the low boiling point component refrigerant decompressed by the second expansion device by heat exchange with air;
A second compression element for compressing the low-boiling component refrigerant evaporated by the second evaporator;
On the upstream side from the inlet of the condenser, a merging portion where the high-boiling component refrigerant compressed by the first compression element and the low-boiling component refrigerant compressed by the second compression element merge;
A refrigeration cycle apparatus comprising:   The refrigeration cycle according to any one of claims 1 to 3, further comprising: a first compressor having the first compression element; and a second compressor having the second compression element. apparatus.   The first compressor includes the first compression element and an electric motor that drives the first compression element in a sealed container, and a space in which the electric motor is disposed in the sealed container includes the high-boiling component refrigerant. The refrigeration cycle apparatus according to claim 4, wherein an intake pressure atmosphere is provided.   The first compression element and the second compression element are accommodated in a single sealed container, and the first compression element and the second compression element are stored in a single electric motor stored in the closed container. The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the refrigeration cycle apparatus is driven.   The refrigeration cycle apparatus according to claim 6, wherein the high-boiling-point component refrigerant compressed and discharged by the first compression element is directly discharged outside the sealed container without being discharged into the sealed container.   The refrigeration cycle apparatus according to claim 6 or 7, wherein at least the first compression element is a swing rotary system.   9. The structure according to claim 1, wherein at least one of the parts constituting the sliding portion of the first compression element is configured not to expose iron or aluminum to at least a sliding surface thereof. 10. Refrigeration cycle equipment.   The refrigeration cycle apparatus according to claim 9, wherein iron or aluminum is not exposed on a sliding surface by performing a coating process on a surface of a component constituting the sliding portion.

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