JP2007093105A - Freezing device and gas-liquid separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a freezing device with a gas-liquid separator for actualizing highly efficient operation when constructed to introduce a gas refrigerant separated by the gas-liquid separator into an intermediate pressure portion of a compressor, and to provide a refrigerator equipped with the device. <P>SOLUTION: The freezing device 30 comprises the compressor for compressing a refrigerant compressed by a first compression element 1A and discharging it, a radiator 2, an expansion valve 31, the air-liquid separator 4, expansion valves 12, 13 in which liquid refrigerants flowing out of the gas-liquid separator 4 circulate, heat absorbers 57, 58, a refrigerant pipe 4C for introducing the gas refrigerant into the intermediate pressure portion, and a first heat exchanger 15. The ratio of the displacement of a second compression element 1B to the displacement of the first compression element 1A of the compressor 1 is within a range of 0.6-0.8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a refrigeration apparatus including means capable of introducing gas refrigerant separated by a gas-liquid separator into an intermediate pressure portion of a compressor, and a refrigerator including such a refrigeration apparatus.

In general, a refrigeration apparatus including a compressor, a radiator, a decompression unit, and a gas-liquid separator, and a unit capable of introducing gas refrigerant separated by the gas-liquid separator into an intermediate pressure portion of the compressor is known. (See Patent Document 1). In this type of refrigeration apparatus, the gas refrigerant separated by the gas-liquid separator is introduced into the intermediate pressure portion of the compressor in a gas state, so that the efficiency of the compressor can be improved.
JP 2003-106693 A

  In this type of refrigeration apparatus, a compressor having an intermediate pressure part, for example, a compressor having a multistage compression mechanism, is applied to construct a refrigeration cycle suitable for use of the intermediate pressure part and to control the intermediate pressure. As a result, a refrigeration apparatus that can be operated with higher efficiency may be realized.

  Therefore, the present invention can be provided with a gas-liquid separator, and when the gas refrigerant separated by the gas-liquid separator can be introduced into the intermediate pressure portion of the compressor, can be operated with higher efficiency. It aims at providing a freezing apparatus and a refrigerator provided with this freezing apparatus.

  The refrigeration apparatus of the present invention has at least a first compression element and a second compression element, and the refrigerant compressed by the first compression element is compressed by the second compression element and discharged. A compressor configured, a radiator connected to the discharge side of the compressor, a first decompression unit connected to the outlet side of the radiator, and a gas-liquid mixture decompressed by the first decompression unit A gas-liquid separator in which the refrigerant in the state flows and is separated into a gas refrigerant and a liquid refrigerant, a second decompression unit through which the liquid refrigerant exiting the gas-liquid separator flows, and a second decompression unit A heat absorber connected to the outlet side, a refrigerant pipe for introducing the gas refrigerant into the intermediate pressure portion, a refrigerant discharged from the heat absorber, and a refrigerant between the radiator and the first pressure reducing means And a first heat exchanger configured to be capable of exchanging heat, and an outlet side of the first heat exchanger is the first heat exchanger. The ratio of the displacement volume of the second compression element to the displacement volume of the first compression element in the compressor is in the range of 0.6 to 0.8. It is characterized by.

  Further, the refrigeration apparatus of the present invention has at least a first compression element and a second compression element, and the refrigerant compressed by the first compression element is compressed by the second compression element and discharged. , A radiator connected to the discharge side of the compressor, a first decompression unit connected to the outlet side of the radiator, and a gas-liquid reduced in pressure by the first decompression unit A gas-liquid separator into which the refrigerant in the mixed state flows and is separated into a gas refrigerant and a liquid refrigerant, a second decompression unit through which the liquid refrigerant from the gas-liquid separator flows, and the second decompression unit A heat absorber connected to the outlet side of the gas generator, a refrigerant pipe for introducing the gas refrigerant into the intermediate pressure portion, a refrigerant discharged from the heat absorber, and the liquid refrigerant discharged from the gas-liquid separator. A second heat exchanger configured to be replaceable, and an outlet side of the second heat exchanger includes the first compression element. The ratio of the displacement volume of the second compression element to the displacement volume of the first compression element in the compressor is in the range of 0.4 to 0.6. And

  Further, the refrigeration apparatus of the present invention has a compressor having an intermediate pressure portion, and a radiator connected to the discharge side of the compressor, the refrigerant pipe on the outlet side of the radiator branches off, The refrigerant pipe is sequentially connected to the first pressure reducing means and the first heat absorber, and heats the refrigerant that has come out of the first heat absorber and the refrigerant before entering the first pressure reducing means. A third heat exchanger configured to be replaceable is provided, and the other refrigerant pipe is supplied with second decompression means and a gas-liquid mixed state refrigerant decompressed by the second decompression means. The gas-liquid separator is separated into a liquid refrigerant, the third decompression means through which the liquid refrigerant from the gas-liquid separator flows, and the second through which the refrigerant from the third decompression means flows. A heat absorber, and a refrigerant pipe capable of introducing the gas refrigerant into the intermediate pressure portion is connected to the gas-liquid separator. And a fourth heat exchanger configured to be able to exchange heat between the refrigerant discharged from the second heat absorber and the liquid refrigerant, and the refrigerant discharged from the fourth heat exchanger and the second pressure reducing means. A fifth heat exchanger configured to be capable of exchanging heat with the refrigerant before entering, the outlet side of the third heat exchanger and the outlet side of the fifth heat exchanger being the suction part of the previous compressor It is connected to.

  According to a fourth aspect of the present invention, in the refrigeration apparatus according to the third aspect, the compressor includes at least a first compression element and a second compression element, and is compressed by the first compression element. The refrigerant is compressed by the second compression element and discharged, and the displacement volume of the second compression element with respect to the displacement volume of the first compression element in the compressor is The ratio is in the range of 0.4 to 0.6.

  According to a fifth aspect of the present invention, in the refrigeration apparatus according to the fourth aspect, the second heat absorber functions at a temperature lower than that of the first heat absorber.

  A sixth aspect of the invention is characterized in that in the refrigeration apparatus according to any one of the first to fifth aspects, carbon dioxide is used as a refrigerant.

  The refrigerator of this invention was equipped with the freezing apparatus as described in any one of Claim 1 thru | or 6.

  ADVANTAGE OF THE INVENTION According to this invention, when it comprises a gas-liquid separator and it comprises so that the gas refrigerant isolate | separated by this gas-liquid separator can be introduce | transduced into the intermediate pressure part of a compressor, a more efficient driving | operation is realizable. A refrigeration apparatus and a refrigerator provided with the refrigeration apparatus are provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
<Embodiment 1>
An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a refrigerant circuit diagram of a refrigeration apparatus as one embodiment of the present invention.

  The refrigeration apparatus 30 includes a compressor 1, a radiator 2 connected to the discharge side of the compressor 1, an expansion valve 31 that is a decompression unit connected to the outlet side of the radiator 2, and the expansion valve 31. The gas-liquid separator 4 connected to the outlet side of the gas through the refrigerant pipe 4A, the refrigeration expansion valve 12 and the refrigeration expansion valve 13 which are decompression means through which the liquid refrigerant separated by the gas-liquid separator 4 flows. The first heat absorber 57 and the refrigerating heat absorber 58, the refrigerant discharged from the heat absorbers 57 and 58, and the refrigerant between the radiator 2 and the expansion valve 31 are configured to be able to exchange heat. A heat exchanger 15, and the gas refrigerant separated by the gas-liquid separator 4 is sucked into the intermediate pressure portion of the compressor 1 through the refrigerant pipe 4 </ b> C and the outlet side of the first heat exchanger 15 is sucked into the compressor 1. The refrigeration cycle is configured by being connected to the unit.

  The refrigerant pipe 4 </ b> C between the gas-liquid separator 4 and the intermediate pressure part of the compressor 1 is provided with a check valve 7, and the reverse is provided between the refrigeration heat absorber 58 and the first heat exchanger 15. A check valve 52 is further provided between the first heat exchanger 15 and the suction portion of the compressor 1.

  The refrigeration expansion valve 12 and the refrigeration heat absorber 57 are provided in parallel between the branch point 9A and the junction 9B with respect to the refrigeration expansion valve 13 and the refrigeration heat absorber 58. , 13 is fully closed, the liquid refrigerant from the gas-liquid separator 4 is selectively circulated to the heat absorbers 57, 58 via the refrigerant pipe 4B. Operation is selectively performed.

  That is, when the refrigerant from the branch point 9A is circulated to the refrigeration heat absorber 57, the cold air generated in the refrigeration heat absorber 57 is circulated to the refrigeration chamber 21 via the duct 57A by a fan (not shown). Thus, the refrigeration operation is executed. On the other hand, when the refrigerant from the branch point 9A is circulated to the refrigeration heat absorber 58, the cold air generated in the refrigeration heat absorber 58 is circulated to the freezer compartment 22 via the duct 58A by a fan (not shown). Thus, the refrigeration operation is executed.

  The compressor 1 is a two-stage compressor, includes a first-stage compression unit 1A and a two-stage compression unit 1B in a hermetic container, and connects the first-stage compression unit 1A and the second-stage compression unit 1B. An intercooler 1C is provided on the refrigerant pipe. In the present embodiment, the ratio of the excluded volume of the two-stage compression unit 1B to the excluded volume of the first-stage compression unit 1A (hereinafter referred to as volume ratio) is set to 0.6 to 0.8. Yes. That is, for example, when the excluded volume of the first-stage compression unit 1A is 1 cc, the excluded volume of the second-stage compression unit 1B is set to 0.6 to 0.8 cc.

  Further, as described above, the refrigerant pipe 4C is connected so that the gas refrigerant separated by the gas-liquid separator 4 can be introduced between the intermediate pressure portion of the compressor 1, that is, between the intermediate cooler 1C and the two-stage compression portion 1B. Is done. The separated gas refrigerant is introduced into the intermediate pressure portion of the compressor 1 as indicated by a broken line arrow due to the differential pressure in the refrigerant pipe 4C. The compressor 1 is not limited to a two-stage compressor. For example, if the compressor 1 is a first-stage compressor, the refrigerant pipe 4C may be injected into an intermediate pressure portion of the first-stage compressor. It is also possible to adopt a configuration in which a plurality of compressors are connected.

The refrigeration apparatus 30 of the present embodiment has a small environmental load as a refrigerant, and is charged with carbon dioxide refrigerant (CO ₂ ), which is a natural refrigerant, in consideration of flammability and toxicity. Further, as the oil as the lubricating oil of the compressor 2, for example, mineral oil (mineral oil), alkylbenzene oil, ether oil, ester oil, PAG (polyalkylene glycol), POE (polyol ester) and the like are used.

  Thus, since the refrigeration apparatus 30 uses carbon dioxide as a refrigerant, the high-pressure part of the refrigeration cycle may be operated in a supercritical state. In this case, the refrigeration apparatus 30 is operated as a transcritical cycle. become.

  In the refrigeration apparatus 30 of the present embodiment, in FIG. 1, the operation from the discharge side of the two-stage compression unit 1B through the radiator 2 to the inlet of the expansion valve 31 is operated as a high-pressure part of the refrigeration cycle. From the discharge side of the compression unit 1A through the intermediate cooler 1C to the suction unit of the two-stage compression unit 1B, from the outlet of the expansion valve 31 to the suction unit of the two-stage compression unit 1B through the gas-liquid separator 4, and each expansion Up to the inlets of the valves 12 and 13 are operated as an intermediate pressure part of the refrigeration cycle. Then, the outlets of the expansion valves 12 and 13, the heat absorbers 57 and 58, and the first heat exchanger 15 to the suction portion of the first stage compression unit 1 </ b> A are operated as a low pressure portion of the refrigeration cycle.

  Next, the operation of the refrigeration apparatus 30 in the present embodiment will be described with reference to FIG. As described above, the refrigeration apparatus 30 is selectively selected from a refrigeration operation mainly using the refrigeration expansion valve 13 and the refrigeration heat absorber 58 and a refrigeration operation mainly using the refrigeration expansion valve 12 and the refrigeration heat absorber 57. To be executed.

  First, the freezing operation will be described. The refrigeration operation is an operation in which the refrigeration expansion valve 12 is closed and the refrigeration heat absorber 58 functions at a predetermined temperature (for example, around −26 ° C.).

  When the compressor 1 is operated, the refrigerant discharged from the compressor 1 is radiated by the radiator 2 and cooled. Thereafter, the refrigerant discharged from the radiator 2 reaches the expansion valve 31, where the refrigerant is decompressed to be in a gas-liquid mixed state (gas / liquid two-phase mixture), and the same gas is supplied from the refrigerant pipe 4 </ b> A of the gas-liquid separator 4. It is introduced into the liquid separator 4. In the gas-liquid separator 4, the refrigerant is separated into a gas refrigerant and a liquid refrigerant, and the gas refrigerant flows through the refrigerant pipe 4 </ b> C, passes through the check valve 7, and is then introduced into the intermediate pressure portion of the compressor 1. On the other hand, the liquid refrigerant separated by the gas-liquid separator 4 is circulated through the refrigerant pipe 4B and reaches the refrigeration expansion valve 13 from the branch point 9A.

  Since the refrigeration apparatus 30 is configured to perform two-stage expansion with the expansion valve 31 and the refrigeration expansion valve 12 or the refrigeration expansion valve 13, as described above, the expansion valve 31 outlet side, each expansion valve 12, 13 between the inlet side, between the discharge side of the first stage compression unit 1A of the compressor 1 and the suction part of the second stage compression unit 1B, and in the refrigerant pipe 4C, is an intermediate pressure portion in the main refrigeration cycle. .

  When the liquid refrigerant is circulated from the branch point 9A to the refrigeration expansion valve 13 and depressurized, the liquid refrigerant evaporates in the refrigeration heat absorber 58 and absorbs heat from the surroundings, and then in the first heat exchanger 15. Heat is exchanged with the refrigerant flowing between the expansion valve 31 and the radiator 2, and the heat is returned to the suction portion of the compressor 1.

  Next, the refrigeration operation will be described. The refrigeration operation is an operation in which the refrigeration expansion valve 13 is closed and the refrigeration heat absorber 57 is made to function at a higher temperature (for example, around −5 ° C.) than during the refrigeration operation.

  In this case, when the compressor 1 is operated, the refrigerant discharged from the compressor 1 is radiated by the radiator 2 and cooled. Thereafter, the refrigerant discharged from the radiator 2 reaches the expansion valve 31, where the refrigerant is decompressed to be in a gas-liquid mixed state (gas / liquid two-phase mixture), and the same gas is supplied from the refrigerant pipe 4 </ b> A of the gas-liquid separator 4. It is introduced into the liquid separator 4. In the gas-liquid separator 4, the refrigerant is separated into a gas refrigerant and a liquid refrigerant, and the gas refrigerant flows through the refrigerant pipe 4 </ b> C, passes through the check valve 7, and is then introduced into the intermediate pressure portion of the compressor 1. On the other hand, the liquid refrigerant separated by the gas-liquid separator 4 is circulated through the refrigerant pipe 4B and reaches the refrigeration expansion valve 12 from the branch point 9A.

  When the liquid refrigerant is circulated from the branch point 9A to the refrigeration expansion valve 12 and depressurized, the liquid refrigerant evaporates in the refrigeration heat absorber 57 and absorbs heat from the surroundings, and then in the first heat exchanger 15. Heat is exchanged with the refrigerant flowing between the expansion valve 31 and the radiator 2, and the heat is returned to the suction portion of the compressor 1. In the refrigeration apparatus 30 in the present embodiment, the refrigeration cycle as described above is formed during both the refrigeration operation and the refrigeration operation.

  Further, in the refrigeration apparatus 30, in addition to the refrigeration operation and the refrigeration operation, a refrigeration operation is performed as necessary. This refrigeration operation means that the expansion valves 12 and 13 are not fully closed, and the refrigeration heat absorber 57 and the refrigeration heat absorber 58 are set to a predetermined temperature (for example, the refrigeration heat absorber 57 is set to around −5 ° C., This is an operation for causing the refrigeration heat absorber 58 to function at around −26 ° C., and can be performed particularly when the refrigeration apparatus 30 is started up or under a high load.

  In addition, since the operation | movement substantially the same as the time of the said freezing operation and the refrigerating operation is performed at the time of this freezing / refrigeration operation, detailed description is abbreviate | omitted.

  In the refrigeration apparatus 30, the gas refrigerant separated by the gas-liquid separator 4 cannot be used for cooling even if it is circulated through the expansion valves 12, 13 and the heat absorbers 57, 58. Is returned to the suction section of the first-stage compression section 1A, the compression efficiency in the compressor 1 is lowered. Therefore, in the present embodiment, the gas refrigerant separated by the gas-liquid separator 4 is passed through the refrigerant pipe 4C between the intermediate pressure portion of the compressor 1, that is, between the intermediate cooler 1C and the two-stage compression portion 1B. Therefore, the compression efficiency in the compressor 1 can be improved. In particular, since carbon dioxide refrigerant is enclosed in the refrigerant circuit in the refrigeration apparatus 30, the ratio of gas and liquid separated by the gas-liquid separator 4 is higher than that of conventionally used fluorocarbon refrigerants, etc. The amount of gas increases, and the efficiency is further improved by introducing the large amount of gas into the intermediate pressure portion of the compressor 1.

  And in the refrigeration apparatus 30 in this Embodiment, while providing the 1st heat exchanger 15 between the heat radiator 2 and the expansion valve 31, the compressor 1 by which volume ratio was set to 0.6-0.8. Therefore, an appropriate amount of gas refrigerant separated by the gas-liquid separator 4 can be sucked into the two-stage compression unit 1B, and a highly efficient two-stage compression two-stage expansion refrigeration cycle can be realized.

  Next, an application example of the refrigeration apparatus 30 of the present embodiment to a refrigerator will be described with reference to FIG. FIG. 2 shows a schematic configuration diagram of a refrigerator provided with the refrigeration apparatus 30.

  The refrigerator 40 includes a refrigeration room 41 in the upper stage and a freezing room 42 in the lower stage. And the inner partition walls 61 and 62 are provided in the inner part of each chamber 41 and 42, respectively, In the air path 44 partitioned by the inner partition walls 61 and 62, the refrigeration heat absorber mentioned above is provided. 57, the refrigerating heat absorber 58, and the fans 63 and 64 are installed.

  During each operation described above, that is, during the freezing operation, the fan 64 is operated, during the freezing and refrigerating operation, the fans 63 and 64 are operated, and during the refrigerating operation, the fan 63 is operated. Thereby, each chamber 41 and 42 can be cooled.

Since the refrigerator 40 of the present embodiment has the above-described configuration, high cooling performance and high-efficiency operation by a two-stage compression and two-stage expansion refrigeration cycle are possible.
<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 shows a refrigerant circuit diagram of the refrigeration apparatus 50 in this case. In this embodiment, the same reference numerals as those in FIGS. 1 and 2 have the same or similar functions and effects. When compared with the refrigeration apparatus 30, the refrigeration apparatus 50 according to the present embodiment includes the second heat exchanger 19 instead of the first heat exchanger 15, and further includes the compressor 10 instead of the compressor 1. Is different.

  The second heat exchanger 19 is configured to exchange heat between the refrigerant flowing through the refrigerant pipe 4B between the outlet side of the gas-liquid separator 4 and the branch point 9A and the refrigerant from the junction 9B.

  The compressor 10 has a volume ratio different from that of the compressor 1. That is, the compressor 10 is a two-stage compressor, and includes the first-stage compression unit 10A and the second-stage compression unit 10B in the hermetic container, and connects the first-stage compression unit 10A and the second-stage compression unit 10B. The intermediate cooler 10C is provided on the outer refrigerant pipe, and the volume ratio is set to 0.4 to 0.6. For example, if the excluded volume of the first-stage compression unit 10A is 1 cc, the excluded volume of the second-stage compression unit 10B is set to 0.4 to 0.6 cc.

  As described above, in the refrigeration apparatus 50 according to the present embodiment, the second heat exchanger 19 is provided between the gas-liquid separator 4 and the branch point 9A, and the volume ratio is set to 0.4 to 0.6. Since the compressed compressor 10 is used, an appropriate amount of gas refrigerant separated by the gas-liquid separator 4 can be sucked into the two-stage compression unit 10B, and a highly efficient two-stage compression two-stage expansion refrigeration cycle can be achieved. realizable.

  Further, the refrigeration apparatus 50 can be applied to a refrigerator, similarly to the refrigeration apparatus 30 of the first embodiment.

The arrangement of the second heat exchanger 19 can be provided between the branch point 9A and each of the expansion valves 12 and 13, and in this case, each of the heat absorbers 57 and 58 and the junction 9B. And between the branch point 9A and each of the expansion valves 12 and 13 can be realized by heat exchange.
<Embodiment 3>
Next, a third embodiment of the present invention will be described in detail with reference to the drawings. FIG. 4 shows a refrigerant circuit diagram of the refrigeration apparatus in the present embodiment. The refrigeration apparatus 70 includes the compressor 10 and the radiator 2 connected to the discharge side of the compressor 10.

  The outlet side refrigerant pipe of the radiator 2 branches at a branch point 9C, and one refrigerant pipe 91C side is connected to the refrigeration expansion valve 12 and the refrigeration heat absorber 57, which are decompression means, sequentially. On the outlet side of the refrigeration heat absorber 57, a third refrigerant configured to be able to exchange heat between the refrigerant discharged from the refrigeration heat exchanger 57 and the refrigerant between the branch point 9C and the refrigeration expansion valve 12. A heat exchanger 16 is provided, and the outlet side of the third heat exchanger 16 is connected to the junction 9B.

  On the other hand, on the refrigerant pipe 92C side, the expansion valve 32 as decompression means, the gas-liquid separator 4 connected to the outlet side of the expansion valve 32 via the refrigerant pipe 4A, and the gas-liquid separator 4 are separated. The refrigeration expansion valve 13, which is a decompression means through which the liquid refrigerant is circulated, and the refrigeration heat absorber 58 are sequentially connected. On the outlet side of the refrigeration endothermic device 58, the refrigerant discharged from the refrigeration endothermic device 58 and the refrigerant between the gas-liquid separator 4 and the refrigeration expansion valve 13 are configured to be able to exchange heat. A fourth heat exchanger 17 is provided, and a fifth heat exchanger is provided on the outlet side of the fourth heat exchanger 17. The fifth heat exchanger 18 is configured to be able to exchange heat between the refrigerant between the branch point 9C and the expansion valve 32 and the refrigerant discharged from the fourth heat exchanger 17, and the fifth heat exchange. The outlet side of the vessel 18 is connected to the junction 9B.

  The gas refrigerant separated by the gas-liquid separator 4 is connected to the intermediate pressure part of the compressor 10 via the refrigerant pipe 4C, and the refrigerant pipe from the junction 9B is connected to the suction part of the compressor 10. The refrigeration cycle is configured.

  The refrigerant pipe 4C between the gas-liquid separator 4 and the intermediate pressure portion of the compressor 1 is provided with a check valve 7, and a check valve is provided between the fifth heat exchanger 18 and the junction 9B. 52, a check valve 53 is further provided between the junction 9B and the suction portion of the compressor 10.

  Here, the refrigeration expansion valve 12 and the refrigeration heat absorber 57 are provided in parallel between the branch point 9C and the junction 9B with respect to the refrigeration expansion valve 13 and the refrigeration heat absorber 58, and By fully closing one of the expansion valves 12 and 13, the refrigerant selectively flows through the heat absorbers 57 and 58, whereby the refrigeration operation and the freezing operation are selectively executed.

  That is, when the refrigerant from the branch point 9C is circulated to the refrigeration heat absorber 57, the cold air generated in the refrigeration heat absorber 57 is circulated to the refrigeration chamber 21 via the duct 57A by a fan (not shown). Thus, the refrigeration operation is executed. On the other hand, when the refrigerant from the branch point 9C is circulated to the refrigerating heat absorber 58, the cold air generated in the refrigerating heat absorber 58 is circulated to the freezer compartment 22 via the duct 58A by a fan (not shown). Thus, the refrigeration operation is executed.

  The compressor 10 is a two-stage compressor, and includes a first-stage compression unit 10A and a two-stage compression unit 10B in a hermetic container, and connects the first-stage compression unit 10A and the second-stage compression unit 10B. An intermediate cooler 10C is provided on the refrigerant pipe. In the present embodiment, the volume ratio is set to 0.4 to 0.6. That is, for example, when the excluded volume of the first-stage compression unit 10A is 1 cc, the excluded volume of the second-stage compression unit 10B is set to 0.4 to 0.6 cc.

  Further, as described above, the refrigerant pipe 4C is connected so that the gas refrigerant separated by the gas-liquid separator 4 can be introduced between the intermediate pressure portion of the compressor 10, that is, between the intermediate cooler 10C and the two-stage compression portion 10B. Is done. The separated gas refrigerant is introduced into the intermediate pressure portion of the compressor 10 as indicated by a broken line arrow due to the differential pressure in the refrigerant pipe 4C. The compressor 10 is not limited to a two-stage compressor. For example, if the compressor 10 is a first-stage compressor, the refrigerant pipe 4C may be injected into the intermediate pressure portion of the first-stage compressor. It is also possible to adopt a configuration in which a plurality of compressors are connected.

The refrigeration apparatus 70 of the present embodiment has a small environmental load as a refrigerant, and is filled with carbon dioxide refrigerant (CO ₂ ) which is a natural refrigerant in consideration of flammability and toxicity. Further, as the oil as the lubricating oil of the compressor 2, for example, mineral oil (mineral oil), alkylbenzene oil, ether oil, ester oil, PAG (polyalkylene glycol), POE (polyol ester) and the like are used.

  Thus, since the refrigeration apparatus 70 uses carbon dioxide as a refrigerant, the high-pressure part of the refrigeration cycle may be operated in a supercritical state. In this case, the refrigeration apparatus 70 is operated as a transcritical cycle. become.

  In the refrigeration apparatus 70 of the present embodiment, in FIG. 4, the discharge side of the two-stage compression unit 10 </ b> B passes through the radiator 2, and enters the expansion valve 32 from the branch point 9 </ b> C and the refrigeration expansion valve 12 from the branch point 9 </ b> C. Up to the inlet of the refrigeration cycle is operated as a high-pressure part of the refrigeration cycle, and from the discharge side of the first stage compression part 10A to the suction part of the second stage compression part 10B via the intermediate cooler 10C, and from the outlet of the expansion valve 32 to the gas-liquid separator 4 to the suction part of the two-stage compression part 10B and the inlet of the refrigeration expansion valve 13 are operated as an intermediate pressure part of the refrigeration cycle. And from the exit of each expansion valve 12 and 13 through each heat absorber 57 and 58 and each heat exchanger 16, 17, and 18 to the suction part of 10 A of 1st stage compression parts, it operate | moves as a low pressure part of a refrigerating cycle.

  Next, operation | movement of the freezing apparatus 70 in this Embodiment is demonstrated with reference to FIG. As described above, the refrigeration apparatus 70 is selectively selected from a refrigeration operation mainly using the refrigeration expansion valve 13 and the refrigeration heat absorber 58 and a refrigeration operation mainly using the refrigeration expansion valve 12 and the refrigeration heat absorber 57. To be executed.

  First, the freezing operation will be described. The refrigeration operation is an operation in which the refrigeration expansion valve 12 is closed and the refrigeration heat absorber 58 functions at a predetermined temperature (for example, around −26 ° C.).

  When the compressor 10 is operated, the refrigerant discharged from the compressor 10 is radiated by the radiator 2 and cooled. Thereafter, the refrigerant discharged from the radiator 2 reaches the expansion valve 32 via the branch point 9C, where the refrigerant is decompressed to be in a gas-liquid mixed state (gas / liquid two-phase mixture), and the gas-liquid separator 4 The refrigerant pipe 4A is introduced into the same gas-liquid separator 4. In the gas-liquid separator 4, the refrigerant is separated into a gas refrigerant and a liquid refrigerant, and the gas refrigerant flows through the refrigerant pipe 4 </ b> C, passes through the check valve 7, and is then introduced into the intermediate pressure portion of the compressor 10. On the other hand, the liquid refrigerant separated by the gas-liquid separator 4 is circulated through the refrigerant pipe 4B and reaches the refrigeration expansion valve 13 from the branch point 9A.

  In this case, since the expansion valve 32 and the freezing expansion valve 13 are configured to perform two-stage expansion, as described above, between the expansion valve 32 outlet side and the freezing expansion valve 13 inlet side, Between the discharge side of the first stage compression unit 10A of the compressor 10 and the suction part of the second stage compression unit 10B, and in the refrigerant pipe 4C, it is an intermediate pressure part in the main refrigeration cycle.

  When the liquid refrigerant is circulated through the refrigeration expansion valve 13 and depressurized, the liquid refrigerant evaporates in the refrigeration heat absorber 58 and absorbs heat from the surroundings, and then the fourth heat exchanger 17 performs a gas-liquid separator. 4 and heat exchange with the refrigerant flowing between the freezing expansion valve 13, and then heat exchange with the refrigerant flowing between the branch point 9 </ b> C and the expansion valve 32 in the fifth heat exchanger 18. Then, it is further heated and returned to the suction portion of the compressor 10.

  Next, the refrigeration operation will be described. The refrigerating operation is an operation in which the expansion valve 32 and the refrigerating expansion valve 13 are closed and the refrigerating heat absorber 57 is operated at a higher temperature (for example, around −5 ° C.) than that during the refrigerating operation.

  In this case, when the compressor 10 is operated, the refrigerant discharged from the compressor 10 is radiated by the radiator 2 and cooled. Thereafter, the refrigerant discharged from the radiator 2 reaches the refrigeration expansion valve 12 via the branch point 9C. When the refrigerant is circulated through the refrigeration expansion valve 12 and depressurized, the refrigerant evaporates in the refrigeration heat sink 57 and absorbs heat from the surroundings, and then the branch heat 9C and the refrigeration for the third heat exchanger 16 are absorbed. Heat is exchanged with the refrigerant flowing between the expansion valve 12 and the refrigerant returns to the suction portion of the compressor 10. In the refrigeration apparatus 30 in the present embodiment, the refrigeration cycle as described above is formed during both the refrigeration operation and the refrigeration operation.

  Further, in the refrigeration apparatus 70, in addition to the refrigeration operation and the refrigeration operation, a refrigeration operation is performed as necessary. In this refrigeration operation, the expansion valves 32, 12 and 13 are not fully closed, and the refrigeration endothermic device 57 and the refrigeration endothermic device 58 are set to a predetermined temperature (for example, the refrigeration endothermic device 57 is set to −5 ° C.). This is an operation in which the refrigeration heat absorber 58 functions in the vicinity of −26 ° C., and can be executed particularly when the refrigeration apparatus 70 is activated or under a high load.

  In addition, since the operation | movement substantially the same as the time of the said freezing operation and the refrigerating operation is performed at the time of this freezing / refrigeration operation, detailed description is abbreviate | omitted.

  In the refrigeration apparatus 70, the gas refrigerant separated by the gas-liquid separator 4 cannot be used for cooling even if it is circulated through the refrigeration expansion valve 13 and the refrigeration heat absorber 58. Returning to the suction section of the stage compression section 10A reduces the compression efficiency of the compressor 10. Therefore, in the present embodiment, the gas refrigerant separated by the gas-liquid separator 4 is passed through the refrigerant pipe 4C between the intermediate pressure portion of the compressor 10, that is, between the intermediate cooler 10C and the two-stage compression portion 10B. Therefore, the compression efficiency in the compressor 10 can be improved. Particularly, since the carbon dioxide refrigerant is sealed in the refrigerant circuit in the refrigeration apparatus 70, the ratio of gas and liquid separated by the gas-liquid separator 4 is compared with the conventionally used fluorocarbon refrigerant, etc. The gas content increases, and the efficiency is further improved by introducing the large gas content into the intermediate pressure portion of the compressor 10.

  In addition, since it was set as the structure which does not distribute | circulate a refrigerant | coolant to the gas-liquid separator 4 at the time of the said refrigerating operation, the function which introduces the gas refrigerant isolate | separated by the gas-liquid separator 4 to the intermediate pressure part of the compressor 10 cannot be utilized. However, during this refrigeration operation, the amount of gas refrigerant generated is smaller when the gas-liquid separator is used than during the refrigeration operation. Therefore, even if the operations of the expansion valve 32 and the refrigerant pipe 4C are not used, the operation efficiency is reduced. The width is suppressed.

  And in the refrigerating apparatus 70 in this Embodiment, while providing the 4th heat exchanger 17 and the 5th heat exchanger 18, the compressor 10 by which volume ratio was set to 0.4-0.6 is used. Therefore, during the refrigeration operation, an appropriate amount of gas refrigerant separated by the gas-liquid separator 4 can be sucked into the two-stage compression unit 10B, and a highly efficient two-stage compression two-stage expansion refrigeration cycle can be realized.

  Next, an application example of the refrigeration apparatus 70 of the present embodiment to a refrigerator will be described with reference to FIG. FIG. 5 shows a schematic configuration diagram of a refrigerator provided with the refrigeration apparatus 70.

  The refrigerator 40 includes a refrigeration room 41 in the upper stage and a freezing room 42 in the lower stage. And the inner partition walls 61 and 62 are provided in the inner part of each chamber 41 and 42, respectively, In the air path 44 partitioned by the inner partition walls 61 and 62, the refrigeration heat absorber mentioned above is provided. 57, the refrigerating heat absorber 58, and the fans 63 and 64 are installed.

  During each operation described above, that is, during the freezing operation, the fan 64 is operated, during the freezing and refrigerating operation, the fans 63 and 64 are operated, and during the refrigerating operation, the fan 63 is operated. Thereby, each chamber 41 and 42 can be cooled.

  Since the refrigerator 40 of the present embodiment has the above-described configuration, high cooling performance and high-efficiency operation by a two-stage compression two-stage expansion refrigeration cycle are possible particularly during refrigeration operation.

  Although the present invention has been described above by the above embodiments, the present invention is not limited to this, and various modifications can be made. For example, in each of the above embodiments, the carbon dioxide refrigerant is enclosed in the refrigerant circuit, but the present invention is not limited to this, and the present invention can be applied to other refrigerant-filled refrigerants.

  Further, the expansion valves 31, 32, 12, and 13, which are decompression means, can be changed to capillary tubes as necessary. When changing the expansion valves 12 and 13 to capillary tubes in the refrigeration apparatus 30 and the refrigeration apparatus 50, it is necessary to provide a three-way valve at the branch point 9A, or to provide an electromagnetic valve or the like before the entrance of each capillary tube. is there. Furthermore, when the expansion valves 32, 12, and 13 are changed to capillary tubes in the refrigeration apparatus 70, it is necessary to provide a three-way valve at the branch point 9C, or to provide an electromagnetic valve or the like before the entrance of each capillary tube.

It is a refrigerant circuit figure showing one embodiment of the freezing device of the present invention. It is a schematic block diagram which shows the example of application to the refrigerator of the freezing apparatus of one embodiment of this invention. It is a refrigerant circuit figure which shows the freezing apparatus of the 2nd Embodiment of this invention. It is a refrigerant circuit figure which shows the freezing apparatus of the 3rd Embodiment of this invention. It is a schematic block diagram which shows the example of application to the refrigerator of the freezing apparatus of the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 10 Compressor 2 Radiator 4 Gas-liquid separator 7, 52, 53 Check valve 12, 13, 31, 32 Expansion valve 15, 16, 17, 18, 19 Heat exchanger 21, 41 Refrigeration chamber 22, 42 Freezer room 30, 50, 70 Refrigeration equipment 40 Refrigerator 63, 64 Fan 57, 58 Heat absorber

Claims (7)

A compressor having at least a first compression element and a second compression element and configured to compress and discharge the refrigerant compressed by the first compression element by the second compression element; A radiator connected to the discharge side of the compressor, a first decompression unit connected to the outlet side of the radiator, and a refrigerant in a gas-liquid mixed state that is decompressed by the first decompression unit flows into the compressor. A gas-liquid separator that is separated into a gas refrigerant and a liquid refrigerant, a second decompression unit through which the liquid refrigerant exits from the gas-liquid separator, and an endotherm connected to the outlet side of the second decompression unit And a refrigerant pipe for introducing the gas refrigerant into the intermediate pressure part,
A first heat exchanger configured to be capable of exchanging heat between the refrigerant coming out of the heat absorber and the refrigerant between the radiator and the first decompression means,
The outlet side of the first heat exchanger is connected to the suction portion of the first compression element;
The ratio of the excluded volume of the second compression element to the excluded volume of the first compression element in the compressor is in the range of 0.6 to 0.8. A compressor having at least a first compression element and a second compression element, and configured to compress and discharge the refrigerant compressed by the first compression element by the second compression element; A radiator connected to the discharge side of the compressor, a first decompression means connected to the outlet side of the radiator, and a refrigerant that is decompressed by the first decompression means flows in a gas-liquid mixed state. A gas-liquid separator that is separated into a gas refrigerant and a liquid refrigerant, a second pressure reducing means through which the liquid refrigerant discharged from the gas-liquid separator flows, and an endothermic connection connected to the outlet side of the second pressure reducing means And a refrigerant pipe for introducing the gas refrigerant into the intermediate pressure part,
A second heat exchanger configured to be capable of exchanging heat between the refrigerant coming out of the heat absorber and the liquid refrigerant coming out of the gas-liquid separator,
The outlet side of the second heat exchanger is connected to the suction portion of the first compression element;
The ratio of the excluded volume of the second compression element to the excluded volume of the first compression element in the compressor is in the range of 0.4 to 0.6. A compressor having an intermediate pressure portion, and a radiator connected to the discharge side of the compressor, the refrigerant pipe on the outlet side of the radiator branches off,
The first pressure reducing means and the first heat absorber are sequentially connected to one refrigerant pipe, the refrigerant that has come out of the first heat absorber, the refrigerant before entering the first pressure reducing means, A third heat exchanger configured to be heat exchangeable is provided,
The other refrigerant pipe has a second decompression unit, a gas-liquid separator that is decompressed by the second decompression unit and into which a refrigerant in a gas-liquid mixed state flows and is separated into a gas refrigerant and a liquid refrigerant, A third pressure reducing means through which the liquid refrigerant discharged from the gas-liquid separator flows and a second heat absorber through which the refrigerant discharged from the third pressure reducing means flows are sequentially connected to the gas-liquid separator. Is connected to a refrigerant pipe capable of introducing the gas refrigerant into the intermediate pressure part,
The fourth heat exchanger configured to be able to exchange heat between the refrigerant discharged from the second heat absorber and the liquid refrigerant, and the refrigerant discharged from the fourth heat exchanger and the second pressure reducing unit. A fifth heat exchanger configured to exchange heat with the previous refrigerant is provided;
The refrigeration apparatus, wherein an outlet side of the third heat exchanger and an outlet side of the fifth heat exchanger are connected to a suction portion of the previous compressor. The compressor has at least a first compression element and a second compression element, and is configured to compress and discharge the refrigerant compressed by the first compression element by the second compression element. A compressor,
The refrigeration according to claim 3, wherein a ratio of an excluded volume of the second compression element to an excluded volume of the first compression element in the compressor is in a range of 0.4 to 0.6. apparatus.   The refrigeration apparatus according to claim 4, wherein the second heat absorber functions at a temperature lower than that of the first heat absorber.   The refrigeration apparatus according to any one of claims 1 to 5, wherein carbon dioxide is used as the refrigerant. A refrigerator comprising the refrigeration apparatus according to any one of claims 1 to 6.

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