초록 ▼

A refrigeration device includes a compression mechanism, a radiator, a first expansion mechanism, a second expansion mechanism, an evaporator, a first internal heat exchanger, a branch pipe a third expansion mechanism, and a second internal heat exchanger. The first internal heat exchanger causes he

A refrigeration device includes a compression mechanism, a radiator, a first expansion mechanism, a second expansion mechanism, an evaporator, a first internal heat exchanger, a branch pipe a third expansion mechanism, and a second internal heat exchanger. The first internal heat exchanger causes heat to be exchanged between refrigerant that flows from the radiator to the inflow side of the first expansion mechanism, and refrigerant that flows from the evaporator to the compression mechanism. The branch pipe branches from a third refrigerant pipe for connecting the radiator and the second expansion mechanism, and merges with the second refrigerant pipe. A third expansion mechanism is provided to the branch pipe. The second internal heat exchanger causes heat to be exchanged between refrigerant that flows out from the first expansion mechanism, and refrigerant that flows out from the third expansion mechanism.

대표청구항 ▼

1. A refrigeration device comprising: a compression mechanism configured to compress a refrigerant;a radiator connected to a refrigerant discharge side of said compression mechanism;a first expansion mechanism connected to an exit side of said radiator;a second expansion mechanism connected to a ref

1. A refrigeration device comprising: a compression mechanism configured to compress a refrigerant;a radiator connected to a refrigerant discharge side of said compression mechanism;a first expansion mechanism connected to an exit side of said radiator;a second expansion mechanism connected to a refrigerant outflow side of said first expansion mechanism;an evaporator connected to the refrigerant outflow side of said second expansion mechanism and to a refrigerant intake side of said compression mechanism;a first internal heat exchanger configured to cause heat to be exchanged between refrigerant flowing in a first refrigerant pipe and refrigerant flowing in a second refrigerant pipe, the first refrigerant pipe connecting the exit side of said radiator and an inflow side of said first expansion mechanism, and the second refrigerant pipe connecting the exit side of said evaporator and the refrigerant inflow side of said compression mechanism;a branch pipe branching from a third refrigerant pipe and merging with said second refrigerant pipe, said third refrigerant pipe connecting the exit side of said radiator and a refrigerant inflow side of said second expansion mechanism;a third expansion mechanism provided in said branch pipe;a second internal heat exchanger configured to cause heat to be exchanged between refrigerant flowing out from said first expansion mechanism and refrigerant flowing out from said third expansion mechanism; anda liquid receiver arranged between the refrigerant outflow side of said first expansion mechanism and an inflow port for refrigerant flowing through said first refrigerant pipe of said second internal heat exchanger,said branch pipe merging with said second refrigerant pipe so that refrigerant flowing out from said third expansion mechanism and undergoing heat exchange in said second internal heat exchanger merges with refrigerant flowing through said second refrigerant pipe before flowing into said first internal heat exchanger. 2. The refrigeration device according to claim 1, wherein said branch pipe merges with a part of said second refrigerant pipe, which is connected to an entry side of said first internal heat exchanger. 3. The refrigeration device according to claim 1, wherein said branch pipe merges with a part of said second refrigerant pipe, which is connected to an exit side of said first internal heat exchanger. 4. The refrigeration device according to claim 1, further comprising: a control unit configured to control the third expansion mechanism so that a degree of superheating of refrigerant flowing to the refrigerant intake side of said compression mechanism from a merging point of said branch pipe with said second refrigerant pipe is within a predetermined range. 5. The refrigeration device according to claim 1, further comprising: a control unit configured to perform refrigerant cooling control, refrigerant flowing through the first refrigerant pipe being cooled by said first internal heat exchanger so that refrigerant flowing out from said first expansion mechanism does not reach a state near the critical point when the refrigerant cooling control is performed. 6. The refrigeration device according to claim 5, wherein said first expansion mechanism and said second expansion mechanism are controlled so that refrigerant flowing out from said first expansion mechanism does not reach a state near the critical point when the refrigerant cooling control is performed. 7. The refrigeration device according to claim 5, wherein refrigerant flowing through said first refrigerant pipe is cooled by said first internal heat exchanger so that a pressure of refrigerant flowing out from said first expansion mechanism is equal to or lower than a critical pressure minus 0.3 MPa when the refrigerant cooling control is performed. 8. The refrigeration device according to claim 7, further comprising: a temperature detector arranged to detect a refrigerant temperature in a vicinity of an exit of said radiator or in a vicinity of a refrigerant inflow port of said first expansion mechanism; whereinrefrigerant flowing through said first refrigerant pipe is cooled by said first internal heat exchanger so that the pressure of the refrigerant out from said first expansion mechanism is equal to or lower than the critical pressure minus 0.3 MPa when the temperature detected by said temperature detector is equal to or above a predetermined temperature, when the refrigerant cooling control is performed. 9. The refrigeration device according to claim 5, wherein said control unit includes a control switching section for switching between normal control and said refrigerant cooling control. 10. The refrigeration device according to claim 1, wherein said branch pipe merges with a part of said second refrigerant pipe, which is connected to an exit side of said first internal heat exchanger. 11. A refrigeration comprising: a compression mechanism configured to compress a refrigerant;a radiator connected to a refrigerant discharge side of side of said compression mechanism;a first expansion mechanism connected to an exit side of said radiator;a second expansion mechanism connected to a refrigerant outflow side of said first expansion mechanism;an evaporator connected to the refrigerant outflow side of said second expansion mechanism and to a refrigerant intake side of said compression mechanism;a first internal heat exchanger configured to cause heat to be exchanged between refrigerant flowing in a first refrigerant pipe and refrigerant flowing in a second refrigerant pipe, the first refrigerant pipe connecting the exit side of said radiator and an inflow side of said first expansion mechanism, the second refrigerant pipe connecting the exit side of said evaporator and the refrigerant inflow side of said compression mechanism;a branch pipe branching from a third refrigerant pipe and merging with said second refrigerant pipe, said third refrigerant pipe connecting the exit side of said radiator and a refrigerant inflow side of said second expansion mechanism;a third expansion mechanism provided in said branch pipe;a second internal heat exchanger configured to cause heat to be exchanged between refrigerant flowing out from said first expansion mechanism and refrigerant flowing out from said third expansion mechanism; anda liquid receiver arranged between the refrigerant outflow side of said first expansion mechanism and an inflow port for refrigerant flowing through said first refrigerant pipe of said second internal heat exchanger,said branch pipe merging with said second refrigerant pipe so that refrigerant flowing from said third expansion mechanism and undergoing heat exchange in said second internal heat exchanger merges with refrigerant flowing through said second refrigerant pipe after passing through said first internal heat exchanger. 12. The refrigeration device according to claim 11, wherein said branch pipe merges with a part of said second refrigerant pipe, which is connected to an entry side of said first internal heat exchanger. 13. The refrigeration device according to claim 11, further comprising: a control unit configured to control the third expansion mechanism so that a degree of superheating of refrigerant flowing to the refrigerant intake side of said compression mechanism from a merging point of said branch pipe with said second refrigerant pipe is within a predetermined range. 14. The refrigeration device according to claim 11, further comprising: a control unit configured to perform refrigerant cooling control, the refrigerant flowing through the first refrigerant pipe being cooled by said first internal heat exchanger so that the refrigerant flowing out from said first expansion mechanism does not reach a state near the critical point when the refrigerant cooling control is performed.