JP2001201236A - Refrigerator-freezer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve lower power consumption by upgrading the total adiabatic efficiency of a compressor to improve an actual efficiency of the refrigeration cycle, concerning a refrigerator-freezer. SOLUTION: The refrigerator-freezer comprises first and second compression elements 16 and 17, a condenser 19, a first expansion device 20, an evaporator 21 for high temperature, a demister 22, a second expansion device 23 and an evaporator 24 for low temperature. Communication is conducted between the side of a liquid refrigerant outlet 25 of the demister 22 and the second expansion device 23, and between the side of a gas refrigerant outlet 26 of the demister 22 and the first compression element 16. As a result, a circuit for high temperature and a circuit for low temperature are formed as separate single stage compression cycle, and operation is made under appropriate pressure condtions that allow avoiding of an extreme low compression ratio, thereby improving the total adiabatic efficiency. This can improve actual efficiency of the refrigeration cycle, thereby reducing power consumption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator having two compression elements and two evaporators.

[0002]

2. Description of the Related Art In recent years, a refrigerator having a refrigerator compartment and a freezer compartment has been required to save energy and improve the accuracy of temperature control in each compartment. Among them, a refrigerator-freezer system that includes two compression elements, two evaporators, a gas-liquid separator, and the like, and forms a two-stage compression refrigeration cycle to save energy has been proposed.

[0003] As such a refrigerator-freezer system,
For example, there is one shown in US Pat.

Hereinafter, the above-described conventional refrigerator-freezer system will be described with reference to the drawings.

FIG. 5 is a refrigerant circuit diagram of a conventional two-stage compression refrigeration cycle. FIG. 6 is a sectional view of a gas-liquid separator used in a conventional two-stage compression refrigeration cycle.

5 and 6, reference numeral 1 denotes a first expansion valve, 2 denotes a freezer evaporator, 3 denotes a low-stage compressor, 4 denotes a high-stage compressor,
Denotes a condenser, 6 denotes a second expansion valve, and 7 denotes a refrigerator evaporator, which are sequentially connected by a pipe 8. Reference numeral 9 denotes a gas-liquid separator 9 which is provided between the refrigerator evaporator 7 and the first expansion valve 1 and performs intermediate cooling between the low-stage compressor 3 and the high-stage compressor 4. Has formed a refrigerator system with a freezer compartment and a refrigerator compartment. The gas-liquid separator 9 includes a main container 10 and an inlet 11 provided at an upper portion thereof, an outlet 12 provided at an intermediate portion, an outlet 13 provided at a lower portion, and a net 14.
It is composed of Refrigerant accumulates as a liquid refrigerant 15 in the lower part of the gas-liquid separator 9 and accumulates as a saturated gas in the upper part.

The operation of the refrigerator-freezer system configured as described above will be described below.

When the low-stage compressor 3 is operated, the low-stage compressor 3 sucks and compresses the refrigerant gas and discharges it to the pipe 8. The refrigerant gas discharged from the low-stage compressor 3 to the pipe 8 is mixed with the refrigerant gas from the outlet 12 of the gas-liquid separator 9, sucked from the suction side of the high-stage compressor 4, and compressed again. The refrigerant gas compressed by the high-stage compressor 4 is passed through a pipe 8 to a condenser 5.
Sent to The refrigerant gas radiates heat in the condenser 5 to be condensed into liquid refrigerant, and then decompressed by the second expansion valve 6. And it flows into the refrigerator evaporator 7, and a part evaporates there. At this time, the refrigerator evaporator 7 exerts a cooling effect by removing heat from the surroundings, and cools the refrigerator. The gas-liquid two-phase refrigerant that has exited the refrigerator evaporator 7 is supplied to the inlet 11.
The gas flows into the gas-liquid separator 9 and solid impurities are removed by the net 14. The liquid refrigerant 1 is provided at the bottom of the gas-liquid separator 9.
5 is stored, and a saturated gas refrigerant is stored in the upper part of the gas-liquid separator 9 to separate a gaseous phase and a liquid phase. Then, only the liquid refrigerant flows out from the outlet 13 of the gas-liquid separator 9 in the direction of the first expansion valve 1, where it is decompressed, flows into the freezer compartment evaporator 2, and evaporates. At this time, by removing heat from the surroundings, the freezing room evaporator 2 exerts a cooling action, and cools the freezing room.
Then, the low-temperature gas refrigerant that has exited the freezer evaporator 2 is sucked into the low-stage compressor 3 again.

On the other hand, the saturated gas refrigerant in the upper part of the gas-liquid separator 9 flows out of the outlet 12 and mixes with the refrigerant gas discharged from the low-stage compressor 3, and the temperature of the refrigerant gas sucked by the high-stage compressor 4 And efficiency can be improved. Further, since the temperature of the discharge gas of the high-stage compressor 4 is also reduced, overheating of the compressor can be prevented, and poor lubrication and deterioration of the lubricating oil due to a decrease in the viscosity of the lubricating oil can be prevented.

As described above, the two-stage compression refrigeration cycle has a higher theoretical efficiency than the one-stage compression refrigeration cycle, and the reliability of the compressor is improved.

[0011]

However, in the above-mentioned conventional configuration, the low-stage compressor 3 has a small compression ratio and therefore a small theoretical compression power, but the shaft power actually required is low. It becomes considerably large due to sliding loss and the like that occur fixedly. That is, since the total adiabatic efficiency, which is the ratio of the theoretical compression power to the shaft power, is deteriorated, the efficiency of the actual refrigeration cycle may be considerably lower than the efficiency of the theoretical refrigeration cycle.

SUMMARY OF THE INVENTION The present invention solves the conventional problems, and provides a refrigeration apparatus that improves the overall adiabatic efficiency of a compressor, improves the efficiency of an actual refrigeration cycle, consumes less power, and has high efficiency. The purpose is to:

Further, in the above-mentioned conventional configuration, since the refrigerant circulating in the cycle is in the order of cooling the refrigerator compartment and then cooling the refrigerator compartment, when the balance of the cooling load between the refrigerator compartment and the refrigerator compartment changes, In particular, when the cooling load of the freezing compartment increases, the freezing compartment becomes insufficient in refrigeration capacity, and the efficiency of the refrigeration cycle may deteriorate.

Another object of the present invention is to provide a freezing and refrigerating apparatus in which each of the freezing compartments in different temperature zones, such as a freezing compartment and a refrigerating compartment, does not have insufficient refrigeration capacity or excessive freezing capacity. It is an object of the present invention to provide a refrigerating / refrigerating apparatus which can appropriately cool the inside of the apparatus, and which has high efficiency and low power consumption. Further, in the above-described conventional configuration, only one of the freezer evaporator 2 and the refrigerator compartment evaporator 7 cannot be cooled. Therefore, when performing defrosting to prevent the performance of the evaporator from deteriorating, the freezer compartment and the refrigerating compartment are not used. However, there is a disadvantage that the temperatures in the respective compartments may increase during the defrosting. Another object of the present invention is for high temperature (for cold room)
An object of the present invention is to provide a refrigerating and refrigerating apparatus that can stop cooling on only one side when defrosting an evaporator or a low-temperature (for a freezing room) evaporator and prevent a rise in the internal temperature of the refrigerator. Further, in the above-described conventional configuration, since the low-stage compressor 3 and the high-stage compressor 4 are connected in series, the maximum compressor capacity is reduced as compared with a compressor of the same size which is connected in parallel, and the door is opened and closed. It is not possible to cope when the cooling load in the freezer compartment or the refrigerator compartment due to the difference in the food put in the refrigerator or in the refrigerator compartment increases, and the temperature of each part in the refrigerator becomes uneven or the temperature in the refrigerator rises There was a drawback that there is.

Another object of the present invention is to make the temperature of each part of the freezer compartment and the refrigerator compartment uniform in response to the change of the cooling load in the refrigerator compartment, and to further increase the cooling load of the freezer compartment and the refrigerator compartment. And an efficient refrigeration apparatus capable of rapid cooling.

[0016]

In order to achieve this object, the present invention provides a first compression element, a second compression element, a discharge side of the first compression element and a discharge side of the second compression element. A condenser connected to the pipe, a first expansion device connected to the outlet side of the condenser, a high-temperature evaporator connected to the outlet side of the first expansion device, the high-temperature evaporator, and the first evaporator; A gas-liquid separator connected to the suction side of the compression element by a pipe, a second expansion device connected to the gas-liquid separator by a pipe, and a connection between the second expansion device and the suction side of the second compression element. A liquid refrigerant outlet side of the gas-liquid separator and the second expansion device communicate with each other, and the gas refrigerant outlet side of the gas-liquid separator and the first compression element It was a communication structure.

As a result, the overall adiabatic efficiency of the compressor can be improved, the efficiency of the actual refrigeration cycle can be improved, and a refrigeration apparatus with low power consumption and high efficiency can be provided.

Further, the present invention has a configuration in which a first bypass passage communicating the inlet side and the outlet side of the high-temperature evaporator is provided, and a first on-off valve provided in the first bypass passage. is there.

Thus, the inside of each refrigerator can be properly cooled without any shortage of freezing capacity or excessive freezing capacity in one of the refrigerators of different temperature zones such as the freezing room and the refrigerator room of the freezing and refrigerating apparatus. It is possible to provide a refrigerating / refrigerating apparatus which can be made highly efficient and consumes less power.

The present invention also relates to a second opening / closing valve provided between the branch point of the first bypass passage and the high-temperature evaporator, and between the gas-liquid separator and the suction side of the second compression element. The configuration includes the third on-off valve provided.

Thus, it is possible to provide a refrigerating and refrigerating apparatus capable of stopping the cooling of only one side when defrosting the high-temperature evaporator or the low-temperature evaporator and preventing the internal temperature from rising.

The present invention also provides a second bypass passage communicating the suction side of the first compression element and the suction side of the second compression element, a fourth on-off valve provided in the second bypass passage,
A fifth on-off valve provided between the first compression element and the gas-liquid separator is provided.

This makes it possible to equalize the temperature of each part in the refrigerator in response to a change in the cooling load in the freezer compartment and the refrigerator compartment, and to cope with a remarkable increase in the cooling load in the freezer compartment and the refrigerator compartment. It is possible to provide an efficient freezing and refrigeration device capable of performing cooling.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a first compression element, a second compression element, a piping together with a discharge side of the first compression element and a discharge side of the second compression element. A condenser connected, a first expansion device connected to the outlet side of the condenser by piping, a high-temperature evaporator connected to the outlet side of the first expansion device, a high-temperature evaporator, and the first compression unit. A gas-liquid separator pipe-connected to the suction side of the element, a second expansion device pipe-connected to the gas-liquid separator, and between the second expansion device and the suction side of the second compression element. A low-temperature evaporator connected to a pipe, the liquid refrigerant outlet side of the gas-liquid separator communicates with the second expansion device, and the gas refrigerant outlet side of the gas-liquid separator communicates with the first compression element. The circuit for high temperature and the circuit for low temperature have separate single-stage compression cycles, respectively. Forming Te, by operating under appropriate pressure conditions as not to extremely low compression ratio, it is possible to prevent the overall adiabatic efficiency. Therefore, there is an effect that the efficiency of the actual refrigeration cycle can be improved and the power consumption can be reduced.

According to a second aspect of the present invention, in addition to the first aspect, a first bypass passage communicating the inlet side and the outlet side of the high-temperature evaporator is provided, and the first bypass passage is provided in the first bypass passage. In addition to the operation of the invention according to claim 1, the cooling load on the low-temperature side in the refrigerators of different temperature zones, such as a freezing room and a refrigerator room, is provided. When the pressure becomes relatively large, the first on-off valve is opened, so that the refrigerant mainly flows through the first bypass passage rather than the high-temperature evaporator, and the cooling capacity is reduced by the low-temperature evaporation on the freezer compartment side (low-temperature side). It will be mainly demonstrated in a container. Therefore, it is possible to cope with the imbalance between the cooling loads of the freezing room and the refrigeration room.
It is possible to appropriately cool the inside of each refrigerator, and to reduce the power consumption with high efficiency, without causing either one of the refrigeration capacity to be insufficient or the refrigeration capacity to be excessive.

According to a third aspect of the present invention, in addition to the first or second aspect, a second on-off valve provided between a branch point of the first bypass passage and the high-temperature evaporator. And a third on-off valve provided between the gas-liquid separator and the suction side of the second compression element, and the function of the invention according to claim 1 or 2 is provided. In addition, by opening the first and third on-off valves and the third on-off valve and closing the second on-off valve, the refrigerant does not flow to the high-temperature evaporator side but flows to the first bypass passage, and its cooling capacity is reduced to the freezing room side. (Low temperature side) Only the low temperature evaporator is exhibited. Therefore, it is possible to cope with a large imbalance in the cooling load between the freezing compartment and the refrigerator compartment,
Further, while performing the cooling operation by the low-temperature evaporator, the high-temperature evaporator in which the cooling operation is stopped can be defrosted. Further, by opening the second on-off valve and closing the first on-off valve and the third on-off valve, the refrigerant flows into the gas-liquid separator through the high-temperature evaporator, and then does not flow to the low-temperature evaporator side. Since it is sucked into one compression element, its cooling capacity is exerted only on the high-temperature evaporator on the refrigerator compartment side (high-temperature side). Therefore, it is possible to cope with a large imbalance in the cooling load between the freezing compartment and the refrigerating compartment, and it is possible to perform defrosting on the low-temperature evaporator in which the cooling operation is stopped while performing the cooling operation with the high-temperature evaporator. Has an action.

The invention described in claim 4 is the same as the invention described in claim 1, 2 or 3,
A second bypass passage communicating between the suction side of the first compression element and the suction side of the second compression element, a fourth on-off valve provided in the second bypass passage, the first compression element and the gas-liquid separator And a fifth on-off valve provided between the fourth and fifth on-off valves, the fifth on-off valve, the fifth on-off valve and the fifth on-off valve. By opening the on-off valve, the first compression element and the suction side of the second compression element communicate with each other to perform two-stage parallel single-stage compression operation.The refrigerant exerts a cooling action in the high-temperature evaporator, and then the low-temperature evaporator side. , And is sucked into the first compression element and the second compression element, so that the refrigeration compartment side (high temperature side) is rapidly cooled. Also,
By opening the first and fourth on-off valves and the fourth on-off valve and closing the fifth on-off valve, the suction side of the first compression element and the second compression element communicate with each other to perform two-cylinder parallel single-stage compression operation, and the refrigerant evaporates for high temperature. It does not flow to the cooler side, but flows to the first bypass passage, and its cooling capacity is exhibited only to the low-temperature evaporator on the freezer compartment side (low-temperature side). Therefore, rapid cooling operation on the freezer compartment side is performed. That is, the temperature of each part in the freezer compartment and the refrigerator compartment can be made uniform in response to changes in the cooling load in the refrigerator compartment, and the cooling load in the freezer compartment and the refrigerator compartment can be significantly increased and rapid cooling can be performed. It has the effect of being able to.

[0028]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a refrigerator according to the present invention. The same components as those of the related art are denoted by the same reference numerals, and detailed description is omitted.

(Embodiment 1) FIG. 1 shows a refrigerant circuit diagram of a refrigeration apparatus according to Embodiment 1 of the present invention. FIG. 2 is a pressure-enthalpy diagram of a refrigeration cycle in the refrigeration apparatus of the embodiment.

1 and 2, reference numeral 16 denotes a first compression element, 17 denotes a second compression element, and the first compression element 16 and the second compression element 17 are housed in a closed container 18. Reference numeral 19 denotes a condenser connected to the discharge side of the first compression element 16 and the discharge side of the second compression element 17 by piping. 20
Is a first expansion device connected to the outlet side of the condenser 19 by piping,
Reference numeral 1 denotes a high-temperature evaporator connected to the outlet of the first expansion device 20 by piping. 22 is a high-temperature evaporator 21 and the first compression element 1
6 is a gas-liquid separator connected to the suction side of 6
3 is a second expansion device connected to the gas-liquid separator 22 by piping,
Reference numeral 24 denotes a low-temperature evaporator connected to a pipe between the second expansion device 23 and the suction side of the second compression element 17. Gas-liquid separator 2
2, the liquid refrigerant outlet 25 side communicates with the second expansion device 23,
The gas refrigerant outlet 26 side of the gas-liquid separator 22 and the first compression element 1
6 communicate with each other.

The operation of the refrigeration apparatus having the above-described configuration will be described below.

When the first compression element 16 and the second compression element 17 are operated, they inhale and compress the refrigerant gas and are sent to the condenser 19 via the pipe. The refrigerant gas radiates heat in the condenser 19 and is condensed into liquid refrigerant.
The pressure is reduced by 0. Then, it flows into the high-temperature evaporator 21 and a part thereof is evaporated there. At this time, by removing heat from the surroundings, the high-temperature evaporator 21 exhibits a cooling action,
The inside of the refrigerator on the high-temperature side such as a refrigerator compartment is cooled. The gas-liquid two-phase refrigerant that has exited the high-temperature evaporator 21 flows into the gas-liquid separator 22, where the liquid refrigerant is stored at the bottom of the gas-liquid separator 22, and is stored at the upper part of the gas-liquid separator 22. The saturated gas refrigerant accumulates, and the gas phase and the liquid phase are separated. Then, only the liquid refrigerant flows out from the liquid refrigerant outlet 25 of the gas-liquid separator 22 in the direction of the second expansion device 23, where the pressure is reduced and flows into the low-temperature evaporator 24 to evaporate. At this time, by removing heat from the surroundings, the low-temperature evaporator 24 exhibits a cooling effect, and cools the inside of the refrigerator on the low-temperature side such as a freezing room. Then, the low-temperature gas refrigerant that has exited the low-temperature evaporator 24 is sucked into the second compression element 17 again. On the other hand, the saturated gas refrigerant in the upper part of the gas-liquid separator 22 is supplied to the gas refrigerant outlet 26.
And is sucked into the second compression element 16 again.

As described above, the high-temperature circuit and the low-temperature circuit are formed as separate single-stage compression cycles, and are operated under appropriate pressure conditions such as two-stage compression that does not result in an extremely low compression ratio. Efficiency can be prevented from becoming worse. Therefore, the efficiency of the actual refrigeration cycle is improved,
Power consumption can be reduced.

As described above, the freezing and refrigeration apparatus of this embodiment is
The first compression element 16, the second compression element 17, a condenser 19 connected to the discharge side of the first compression element 16 and the discharge side of the second compression element 17, and a pipe connection to an outlet side of the condenser 19. A first expansion device 20, a high-temperature evaporator 21 connected to the outlet side of the first expansion device 20 by piping, and a high-temperature evaporator 2
, A gas-liquid separator 22 connected to the suction side of the first compression element 16, a second expansion device 23 connected to the gas-liquid separator 22 by piping, a second expansion device 23, and a second compression element. 17 is connected to the liquid refrigerant outlet 25 of the gas-liquid separator 22 and the second expansion device 23, and the gas refrigerant of the gas-liquid separator 22 is connected to the low-temperature evaporator 24. Since the outlet 26 side and the first compression element 16 are configured to communicate with each other, the high-temperature circuit and the low-temperature circuit are formed as separate single-stage compression cycles, respectively, to achieve an extremely low compression ratio such as two-stage compression. By operating under an appropriate pressure condition, the total adiabatic efficiency can be prevented from deteriorating. Therefore, the efficiency of the actual refrigeration cycle can be improved, and the power consumption can be reduced.

(Embodiment 2) FIG. 3 shows a refrigerant circuit diagram of a refrigeration apparatus according to Embodiment 2 of the present invention.

Hereinafter, description will be made with reference to the drawings. However, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted. In FIG. 3, reference numeral 27 denotes a first bypass passage connecting the inlet side and the outlet side of the high-temperature evaporator 19, and reference numeral 28 denotes a first on-off valve provided in the first bypass passage 27. 29 is a second on-off valve provided between the branch point of the first bypass passage 27 and the high-temperature evaporator 21;
Reference numeral 30 denotes a third on-off valve provided between the gas-liquid separator 22 and the suction side of the second compression element 16.

The operation of the refrigeration apparatus having the above-described structure will be described below.

The first on-off valve 28 is closed, and the second on-off valve 29,
When the third on-off valve 30 is opened and the first compression element 16 and the second compression element 17 are operated, the same refrigeration cycle as in the first embodiment is formed, and the same effect is obtained.

From this state, when the cooling load on the low temperature side becomes relatively large in the compartments of different temperature zones such as the freezing room and the refrigerator compartment, the first on-off valve 28 is opened, so that the refrigerant is evaporated for high temperature. It flows mainly through the first bypass passage 28 rather than the vessel 21, and its cooling capacity is mainly exerted by the low-temperature evaporator 24 on the freezer compartment side (low-temperature side). Therefore, since it is possible to cope with the imbalance of the cooling load between the freezing compartment and the refrigerating compartment, it is possible to appropriately cool the interior of each compartment without causing the refrigerating capacity to be insufficient or the refrigerating capacity to be excessive, and to achieve high efficiency. Power consumption can be reduced.

Further, by opening the first opening / closing valve 28 and the third opening / closing valve 30 and closing the second opening / closing valve 29, the refrigerant flows to the first bypass passage 27 without flowing to the high-temperature evaporator 21 side. The cooling capacity is exerted only on the low-temperature evaporator 24 on the freezing room side (low-temperature side). Therefore, it is possible to cope with a large imbalance in the cooling load between the freezing compartment and the refrigerator compartment, and to perform the defrosting operation on the high-temperature evaporator 21 in which the cooling operation is stopped while performing the cooling operation on the low-temperature evaporator 24. it can.

Further, by opening the second on-off valve 29 and closing the first on-off valve 28 and the third on-off valve 30, the refrigerant flows into the gas-liquid separator 22 through the high-temperature evaporator 21 and then to the low-temperature Since it is sucked into the first compression element 16 without flowing to the evaporator 24 side, its cooling capacity is exerted only on the high-temperature evaporator 21 on the refrigerator compartment side (high-temperature side). Therefore, it is possible to cope with a large imbalance in the cooling load between the freezing compartment and the refrigerating compartment, and to perform the defrosting operation on the low-temperature evaporator 24 in which the cooling operation is stopped while performing the cooling operation on the high-temperature evaporator 21. it can.

As described above, the freezing and refrigeration apparatus of this embodiment is
A first bypass passage 27 communicating the inlet side and the outlet side of the high temperature evaporator 21, a first on-off valve 28 provided in the first bypass passage 27, a branch point of the first bypass passage 27, and a high temperature evaporation A second on-off valve 29 provided between the vessel 21 and
Since the third opening / closing valve 30 provided between the gas-liquid separator 22 and the suction side of the second compression element 17 is provided, different temperatures of the freezing room and the refrigerating room of the refrigerating and refrigerating device are used. It is possible to appropriately cool the inside of each of the compartments, and to reduce the power consumption with high efficiency, without causing either one of the compartments in the band to have a refrigeration capacity shortage or an excess refrigeration capacity. In addition, when defrosting the high-temperature evaporator 21 or the low-temperature evaporator 24, cooling on only one side is stopped to prevent an increase in the internal temperature.

(Embodiment 3) FIG. 4 shows a refrigerant circuit diagram of a refrigeration apparatus according to Embodiment 3 of the present invention.

Hereinafter, description will be made with reference to the drawings. However, the same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description will be omitted. In FIG. 4, reference numeral 31 denotes a second bypass passage communicating the suction side of the first compression element 16 and the suction side of the second compression element 17, and 32 denotes a fourth on-off valve provided in the second bypass passage 31. Reference numeral 33 denotes a fifth on-off valve provided between the first compression element 16 and the gas-liquid separator 22.

The operation of the freezing and refrigeration apparatus having the above-described configuration will be described below.

When the first compression element 16 and the second compression element 17 are operated with the fourth on-off valve 32 closed and the fifth on-off valve 33 opened, the same effect as in the second embodiment can be obtained.

The first on-off valve 28 and the third on-off valve 30
And the second on-off valve 29, the fourth on-off valve 32, and the fifth on-off valve 33 are opened, so that the suction sides of the first compression element 16 and the second compression element 17 communicate with each other, and a two-cylinder parallel single-stage compression operation is performed. After the refrigerant exerts a cooling action in the high-temperature evaporator 21, it does not flow to the low-temperature evaporator 24 but is drawn into the first compression element 16 and the second compression element 17. Quench operation. At this time, even if the third on-off valve 30 is opened, almost no refrigerant flows to the low-temperature evaporator 24 due to the resistance of the second expansion device 23, and the same effect is obtained.

The first on-off valve 28, the third on-off valve 30,
The fourth on-off valve 32 is opened, and the second on-off valve 29 and the fifth on-off valve 3 are opened.
By closing 3, the suction side of the first compression element 16 and the suction side of the second compression element 17 communicate with each other to perform two-stage parallel single-stage compression operation, and the refrigerant does not flow to the high-temperature evaporator 21 side but to the first bypass passage 27. It flows and exerts its cooling capacity only on the low-temperature evaporator 24 on the freezer compartment side (lower temperature side), so that the freezing compartment side is rapidly cooled. At this time, when the second on-off valve 29 is opened, the refrigerant flows to the high-temperature evaporator 21 side and can also cool the refrigerator compartment side.

As described above, the freezing and refrigeration apparatus of this embodiment is
A second bypass passage 31 communicating the suction side of the first compression element 16 and the suction side of the second compression element 17, a fourth on-off valve 32 provided in the second bypass passage 31,
Fifth opening / closing valve 33 provided between the valve 6 and the gas-liquid separator 22
With this configuration, the temperature of each part in the refrigerator can be made uniform in response to changes in the cooling load in the freezer compartment and the refrigerator compartment, and the cooling load in the freezer compartment and the refrigerator compartment can be significantly increased. And rapid cooling can be performed.

[0050]

As described above, according to the first aspect of the present invention, the first compression element, the second compression element, the discharge side of the first compression element, and the piping together with the discharge side of the second compression element. A condenser connected, a first expansion device connected to the outlet side of the condenser by piping, a high-temperature evaporator connected to the outlet side of the first expansion device, a high-temperature evaporator, and the first compression unit. A gas-liquid separator pipe-connected to the suction side of the element, a second expansion device pipe-connected to the gas-liquid separator, and between the second expansion device and the suction side of the second compression element. A low-temperature evaporator connected to a pipe, the liquid refrigerant outlet side of the gas-liquid separator communicates with the second expansion device, and the gas refrigerant outlet side of the gas-liquid separator communicates with the first compression element. The circuit for high temperature and the circuit for low temperature have separate single-stage compression cycles. It formed as, by operating under appropriate pressure conditions as not to extremely low compression ratio such as a two-stage compression, it is possible to prevent the overall adiabatic efficiency. Therefore, the efficiency of the actual refrigeration cycle can be improved, and the power consumption can be reduced.

Further, the invention according to claim 2 is the same as the invention according to claim 1.
In addition to the configuration described in (1), a first bypass passage communicating the inlet side and the outlet side of the high-temperature evaporator, and a first on-off valve provided in the first bypass passage are provided. So, furthermore, either one of the refrigerators in different temperature zones such as the freezing room and the refrigerator compartment of the freezing and refrigeration apparatus does not have insufficient refrigeration capacity, and each refrigerator can be properly cooled without excessive refrigeration capacity, In addition, power consumption can be reduced with high efficiency.

Further, the invention according to claim 3 provides the invention according to claim 2
In addition to the invention described in the above, a second on-off valve provided between the branch point of the first bypass passage and the high-temperature evaporator, provided between the gas-liquid separator and the suction side of the second compression element And the third on-off valve is provided, so that when defrosting the high-temperature evaporator or the low-temperature evaporator, cooling on only one side is stopped to prevent an increase in the internal temperature. be able to.

The invention described in claim 4 is the first invention.
Alternatively, in addition to the invention described in claim 2 or 3, a second bypass passage communicating the suction side of the first compression element and the suction side of the second compression element, and the second bypass passage is provided in the second bypass passage. Since the fourth opening / closing valve and the fifth opening / closing valve provided between the first compression element and the gas-liquid separator are provided, the cooling load in the freezer compartment and the refrigerator compartment is further reduced. , The temperatures of the various parts in the refrigerator can be made uniform, and furthermore, it is possible to cope with a remarkable increase in the cooling load of the freezing compartment and the refrigerating compartment and to perform rapid cooling.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram of Embodiment 1 of a refrigeration apparatus according to the present invention.

FIG. 2 is a pressure-enthalpy diagram of a refrigeration cycle in the refrigeration apparatus of the embodiment.

FIG. 3 is a refrigerant circuit diagram of Embodiment 2 of the refrigeration apparatus according to the present invention.

FIG. 4 is a refrigerant circuit diagram of Embodiment 3 of the refrigeration apparatus according to the present invention.

FIG. 5 is a refrigerant circuit diagram of a conventional two-stage compression refrigeration cycle.

FIG. 6 is a cross-sectional view of a gas-liquid separator used in a conventional two-stage compression refrigeration cycle.

[Explanation of symbols]

 16 first compression element 17 second compression element 19 condenser 20 first expansion device 21 high temperature evaporator 22 gas-liquid separator 23 second expansion device 24 low temperature evaporator 25 liquid refrigerant outlet 26 gas refrigerant outlet 27 first bypass Passageway 28 First on-off valve 29 Second on-off valve 30 Third on-off valve 31 Second bypass passage 32 Fourth on-off valve 33 Fifth on-off valve

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F25B 31/00 F25B 31/00 A 47/02 47/02 A (72) Inventor Kosuke Tsuboi Higashi Osaka, Osaka Matsushita Refrigerating Machinery Co., Ltd. F-term (reference) 3L045 AA01 AA03 BA01 CA02 DA02 HA02 HA06 JA02 JA14 LA14 PA01 PA04 PA05

Claims (4)

[Claims] A first compression element, a second compression element, a condenser connected to a discharge side of the first compression element and a discharge side of the second compression element, and a pipe connected to an outlet side of the condenser. A connected first expansion device, a high-temperature evaporator connected to the outlet side of the first expansion device, and a gas-liquid separation pipe connected between the high-temperature evaporator and the suction side of the first compression element. Vessel, a second expansion device connected to the gas-liquid separator by piping,
A low-temperature evaporator connected to a pipe between the second expansion device and the suction side of the second compression element, wherein a liquid refrigerant outlet side of the gas-liquid separator communicates with the second expansion device; A refrigeration unit in which a gas refrigerant outlet side of a gas-liquid separator communicates with the first compression element. 2. The refrigerator according to claim 1, further comprising: a first bypass passage communicating between an inlet side and an outlet side of the high-temperature evaporator; and a first on-off valve provided in the first bypass passage. apparatus. 3. A second on-off valve provided between a branch point of the first bypass passage and the high-temperature evaporator, and a second on-off valve provided between the gas-liquid separator and the suction side of the second compression element. The refrigeration apparatus according to claim 2, comprising a three-way valve. 4. A second bypass passage communicating between a suction side of the first compression element and a suction side of the second compression element, a fourth on-off valve provided in the second bypass passage, and the first compression element. The refrigeration apparatus according to claim 1, further comprising a fifth on-off valve provided between the refrigeration apparatus and the gas-liquid separator.