CN212205125U - Cascade compression refrigeration system and refrigerating and freezing device having the same - Google Patents

Abstract

The utility model provides a cascading compression refrigeration system and a refrigerating and freezing device having the same. The cascading compression refrigerating system comprises a high-temperature stage refrigeration circulation loop for circulating a first refrigerant and a refrigeration cycle for circulating a second refrigerant. Low temperature stage refrigeration circuit. The high temperature stage refrigeration cycle circuit includes an evaporation part, and the low temperature stage refrigeration cycle circuit includes a low temperature stage compressor, a heat release part, a condensation part, a low temperature stage evaporator, a heat absorption part and an expansion device. The evaporation part is thermally connected to the condensation part. The heat release part is arranged between the discharge port of the low temperature stage compressor and the condensation part, the heat absorption part is arranged between the low temperature stage evaporator and the suction port of the low temperature stage compressor, and the heat release part is thermally connected to the heat absorption part. The expansion device includes a throttling device and an expansion vessel. The throttling device is arranged between the low temperature stage evaporator and the expansion vessel. The expansion vessel is provided between the throttle device and the heat release part. Raising the suction temperature of the low-temperature stage compressor can reduce the load on the evaporator.

Description

Cascade compression refrigeration system and refrigerating and freezing device having the same

technical field

The utility model relates to the field of refrigeration, in particular to a cascade compression refrigeration system and a refrigeration and freezing device having the same.

Background technique

At present, the temperature range of the variable temperature compartment of refrigerators on the market is mostly adjusted between 8 and -18 °C, and the overall design is relatively conventional. With the gradual improvement of people's living standards, such temperature zone refrigerators can no longer meet everyone's needs. It is necessary to design high-end refrigerators with a wider temperature range and more complete functions that can meet more needs of users. For the preservation of ingredients, there is a demand for ultra-low temperature compartments in the high-end user market. -60°C basically covers the most suitable storage temperature for daily meat, fruits and vegetables in glass, and provides the possibility for long-term preservation and storage of ingredients.

Utility model content

In order to meet the market demand, the inventor proposes to use an independent refrigeration system to cool the variable temperature compartment based on the two-stage cascade system, so that the variable temperature compartment can reach extremely low temperature and meet the diverse needs of users. However, the inventor found that due to the large load and high heat of the low-temperature compressor, the temperature of the compressor rises too fast, which is easy to cause compressor protection. Based on this, the present invention provides a cascade compression refrigeration system and a refrigerating and freezing device having the same, which at least partially solve the above problems.

In one aspect, the present invention provides a cascade compression refrigeration system, comprising a high-temperature-level refrigeration cycle for circulating a first refrigerant and a low-temperature-level refrigeration cycle for circulating a second refrigerant;

The high temperature stage refrigeration cycle circuit includes an evaporation part, and the low temperature stage refrigeration cycle circuit includes a low temperature stage compressor, a heat release part, a condensation part, a low temperature stage evaporator, a heat absorption part and an expansion device;

the evaporating part is thermally connected with the condensing part, so that when the first refrigerant flows through the evaporating part, the heat released by the second refrigerant when flowing through the condensing part is absorbed;

The heat release part is arranged between the discharge port of the low temperature stage compressor and the condensation part, the heat absorption part is arranged between the low temperature stage evaporator and the suction port of the low temperature stage compressor, The heat release part is thermally connected to the heat absorption part, so that when the second refrigerant flows, the second refrigerant entering the heat absorption part absorbs the first refrigerant entering the heat release part. The heat released by the refrigerant;

The expansion device includes a throttling device and an expansion vessel; the throttling device is arranged between the low-temperature stage evaporator and the expansion vessel, or the throttling device is arranged between the heat absorbing part and the expansion vessel between the containers; the expansion container is arranged between the throttle device and the heat release part, or the expansion container is arranged between the throttle device and the condensation part.

Optionally, the low-temperature stage refrigeration cycle circuit further includes a plate heat exchanger having the heat absorption part and the heat release part.

Optionally, the throttling device is a pressure reducing valve.

Optionally, the evaporation part and the condensation part are integrally formed into a condensation evaporator;

The evaporation part includes an evaporation tube, the condensation part includes a condensation tube, and the condensation evaporator further includes a fin, and the evaporation tube and the condensation tube are mounted on the fin.

Optionally, the evaporation part is disposed on the lower side of the condensation part, and the refrigerant volume of the evaporation part is larger than the refrigerant volume of the condensation part.

Optionally, the high temperature stage refrigeration cycle further includes a high temperature stage compressor and a high temperature stage evaporator,

Both the outlet of the high temperature stage evaporator and the outlet of the evaporating part are in communication with the suction port of the high temperature stage compressor; or

The outlet of the evaporation part communicates with the suction port of the high temperature stage compressor, and the outlet of the high temperature stage evaporator communicates with the inlet of the evaporation part.

On the other hand, the present invention also provides a refrigerating and freezing device, comprising any of the above-mentioned cascade compression refrigeration systems.

Optionally, the refrigerating and freezing device further includes a box body, and a storage compartment is arranged in the box body;

When the target temperature of the storage compartment is lower than the preset temperature, the high-temperature refrigeration cycle is first opened, so that the evaporating part provides cooling capacity to the storage compartment, so that the storage compartment can be The temperature of the compartment reaches the preset temperature, and then both the high temperature stage refrigeration cycle and the low temperature stage refrigeration cycle are turned on, so that the low temperature stage evaporator provides cooling capacity to the storage compartment to The temperature of the storage compartment is brought to the target temperature.

Optionally, the refrigerating and freezing device includes a box body, and the box body is provided with a first storage compartment and a second storage compartment; and

the evaporation portion is configured to provide cooling to the first storage compartment and/or to provide cooling to the second storage compartment;

The low temperature stage evaporator is configured to provide cooling to the second storage compartment.

Optionally, a third storage compartment is further provided in the box, and the high-temperature evaporator is configured to provide cooling capacity into the third storage compartment.

In the cascade compression refrigeration system of the present invention and the refrigerating and freezing device having the same, because of the heat absorption part, the heat release part and the expansion device, the heat absorption part is used to promote the second refrigerant flowing through it to absorb, flow, and discharge. The heat of the second refrigerant in the hot part increases the temperature of the second refrigerant in the low-temperature stage refrigeration cycle before flowing into the suction port of the compressor, and makes the second refrigerant enter between the condensing parts to properly cool down, so that the low-temperature stage can be improved. The suction temperature of the compressor can reduce the load of the evaporation section, protect the low-temperature stage compressor, and improve the system efficiency. The expansion vessel can prevent the pressure difference from being too large when the low-temperature stage compressor starts and damage the compressor, and at the same time, it can ensure the pressure difference when it is shut down, and the pressure reducing valve can maintain the pressure difference.

Further, in the cascade compression refrigeration system of the present invention and the refrigerating and freezing device having the same, an independent refrigeration system is used to refrigerate the temperature-changing compartment, so that the temperature-changing compartment can reach an extremely low temperature, and at the same time, when the ultra-low temperature area is not required. It can also be set to a conventional temperature zone to meet the diverse needs of users.

Further, in the cascade compression refrigeration system of the present invention and the refrigerating and freezing device having the same, when the ultra-low temperature is set, in order to reduce energy consumption, the temperature-changing compartment needs to be pre-cooled to -18°C by a high-temperature refrigeration system, Close the variable temperature damper, and then open the low temperature refrigeration system to cool the variable temperature compartment separately.

The above and other objects, advantages and features of the present invention will be more apparent to those skilled in the art from the following detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings.

Description of drawings

Hereinafter, some specific embodiments of the present invention will be described in detail by way of example and not limitation with reference to the accompanying drawings. The same reference numbers in the figures designate the same or similar parts or parts. It will be understood by those skilled in the art that the drawings are not necessarily to scale. In the attached picture:

1 is a schematic diagram of a cascade compression refrigeration system according to an embodiment of the present invention;

2 is a schematic diagram of a cascade compression refrigeration system according to an embodiment of the present invention;

Fig. 3 is the schematic diagram of the condensation evaporator in the cascade compression refrigeration system shown in Fig. 2;

4 is a schematic diagram of a refrigeration and freezing device according to an embodiment of the present invention;

5 is a schematic diagram of a refrigeration and freezing apparatus according to an embodiment of the present invention.

Detailed ways

FIG. 1 is a schematic diagram of a cascade compression refrigeration system according to an embodiment of the present invention. As shown in FIG. 1 , the present invention provides a cascade compression refrigeration system, which includes a high-temperature-stage refrigeration cycle for circulating a first refrigerant and a low-temperature-stage refrigeration cycle for circulating a second refrigerant. The high temperature stage refrigeration cycle includes an evaporation part 31, and the low temperature stage refrigeration cycle includes a low temperature stage compressor 41, a heat release part, a condensing part 32, a low temperature stage evaporator 43, a heat absorption part and an expansion device. The evaporating part 31 is thermally connected with the condensing part 32 , so that when the first refrigerant flows through the evaporating part 31 , it absorbs the heat released by the second refrigerant when flowing through the condensing part 32 . That is to say, the second refrigerant of the low-temperature-stage refrigeration cycle is condensed by the cooling capacity generated by the high-temperature-stage refrigeration cycle, so that the low-temperature-stage evaporator 43 reaches an ultra-low temperature.

The heat release part is arranged between the discharge port of the low temperature stage compressor 41 and the condensing part 32, the heat absorption part is arranged between the low temperature stage evaporator 43 and the suction port of the low temperature stage compressor 41, and the heat release part and the heat absorption part heat up. connected so that the second refrigerant entering the heat absorbing part absorbs the heat released by the second refrigerant entering the heat releasing part when the second refrigerant flows. The heat release part and the heat absorption part make the second refrigerant in the low temperature stage refrigeration cycle warm up before flowing into the suction port of the compressor, and make the second refrigerant enter between the condensing parts 32 to properly cool down, so that the low temperature stage compressor can be improved. The suction temperature of 41 can reduce the load of the evaporation part 31, protect the low-temperature stage compressor 41, and improve the system efficiency.

The expansion device includes a throttling device 45 and an expansion vessel 46 . The inlet of the throttling device 45 is arranged on the pipeline between the outlet of the low-temperature stage evaporator 43 and the suction port of the low-temperature stage compressor 41, the inlet of the expansion vessel 46 is connected to the outlet of the throttling device 45, and the outlet of the expansion vessel 46 is arranged at the outlet of the throttling device 45. On the pipeline between the discharge port of the low temperature stage compressor 41 and the inlet of the condensing part 42 . For example, the throttling device 45 is arranged between the outlet of the low-temperature stage evaporator 43 and the expansion vessel 46 , or the throttling device 45 is arranged between the outlet of the heat absorption part and the expansion vessel 46 . The expansion vessel 46 is arranged between the throttling device 45 and the heat release part, or the expansion vessel 46 is arranged between the throttling device 45 and the inlet of the condensation part 32 . The throttling device 45 is preferably a pressure reducing valve, optionally, the throttling device 45 can also be other types of throttling devices. The expansion vessel 46 can prevent the pressure difference from being too large when the low-temperature stage compressor 41 is started and damage the compressor, and at the same time can ensure the pressure difference when the compressor is shut down, and the pressure reducing valve can maintain the pressure difference.

In some embodiments of the present invention, as shown in FIG. 1 , the high temperature stage refrigeration cycle further includes a high temperature stage compressor 21 , a condenser 22 , a high temperature stage evaporator 25 and a high temperature stage throttling device. The outlet of the evaporation part 31 communicates with the suction port of the high temperature stage compressor 21 , and the outlet of the high temperature stage evaporator 25 communicates with the inlet of the evaporation part 31 . The high temperature stage throttling device may be provided on the inlet side of the high temperature stage evaporator 25 . Further, there may be two high-temperature stage throttling devices, which are a first throttling device provided on the inlet side of the high-temperature stage evaporator 25 and a second throttling device provided on the inlet side of the evaporation part 31 . The outlet of the high temperature stage evaporator 25 communicates with the inlet of the evaporation part 31 through the second throttle device.

In other embodiments, as shown in FIG. 1 , the outlet of the evaporation part 31 communicates with the suction inlet of the high temperature stage compressor 21 , and the outlet of the high temperature stage evaporator 25 communicates with the inlet of the evaporation part 31 . There are two high temperature stage throttling devices, respectively a first throttling device 24 provided on the inlet side of the high temperature stage evaporator 25 and a second throttling device 26 provided on the inlet side of the evaporation part 31 . In addition, the outlet of the high temperature stage evaporator 25 and the outlet of the second throttle device 26 are both communicated with the inlet of the evaporation part 31 . The inlets of the first throttling device 24 and the second throttling device 26 are connected to the outlet of the condenser 22 through the control valve 23 . The control valve 23 may allow the first refrigerant to enter the first throttle device 24 or the second throttle device 26 selectively, or to allow the first refrigerant to enter the first throttle device 24 and the second throttle device 26 simultaneously.

In still other embodiments, both the outlet of the high temperature stage evaporator 25 and the outlet of the evaporation part 31 communicate with the suction port of the high temperature stage compressor 21 . There are two high-temperature stage throttling devices, respectively a first throttling device arranged on the inlet side of the high-temperature stage evaporator 25, and a second throttling device arranged on the inlet side of the evaporation part 31. The first throttling device and The inlet of the second throttling device is connected to the outlet of the condenser 22 through a control valve. The control valve may allow the first refrigerant to selectively enter the first throttle device or the second throttle device, or to allow the first refrigerant to enter the first throttle device and the second throttle device simultaneously.

Further, as shown in FIG. 2 , both the first throttling device 24 and the second throttling device 26 are capillary tubes. Between the condenser 22 and the control valve 23, a dew removal pipe 27 is also provided. The low-temperature stage refrigeration cycle circuit further includes a low-temperature stage throttling device 42 , which is arranged between the condensing part 32 and the low-temperature stage evaporator 43 . The expansion device in FIG. 2 may be arranged inside the cryogenic stage compressor 41 . Preferably, the expansion device may be provided outside the cryogenic stage compressor 41 .

In some embodiments of the present invention, the low temperature stage refrigeration cycle further includes a plate heat exchanger 44 having a heat absorption part and a heat release part. That is to say, the plate heat exchanger 44 is arranged in the low-temperature stage refrigeration cycle to facilitate the heat transfer between the heat absorption part and the heat release part. In some alternative embodiments of the present invention, the heat transfer can also be carried out by means of winding, the heat absorption part and the heat release part are both refrigerant pipes, and the heat absorption part can be wound on the heat release part.

In some embodiments of the present invention, as shown in FIG. 2 and FIG. 3 , the evaporation part 31 and the condensation part 32 are integrally formed into a condensation evaporator 30 . The evaporation part 31 includes an evaporation tube, the condensation part 32 includes a condensation tube, and the condensation evaporator 30 further includes a fin 33 , and the evaporation tube and the condensation tube are mounted on the fin 33 . Further, the evaporation part 31 is provided on the lower side of the condensation part 32 , and the refrigerant volume of the evaporation part 31 is larger than the refrigerant volume of the condensation part 32 . Specifically, the condensing evaporator 30 is set as three rows of tubes along the vertical direction, two in and two out, the upper row of tubes is the condensation part 32, and the second refrigerant of the low-temperature stage refrigeration cycle is routed inside; the lower two rows of tubes As the evaporation part 31, the first refrigerant of the high temperature stage refrigeration cycle is taken. When the cryogenic mode is turned on, the lower two rows of evaporating parts 31 cool the upper row of condensing parts 32 , thereby reducing the condensation temperature of the low-temperature stage refrigeration cycle and improving the cooling capacity of the low-temperature stage evaporator 43 .

4 is a schematic diagram of a refrigeration and freezing device according to an embodiment of the present invention. As shown in FIG. 4 , an embodiment of the present invention further provides a refrigeration and freezing device, which includes the cascade compression refrigeration system in any of the above embodiments. The refrigerating and freezing device can be a small household refrigerating and freezing device for storing food, medicine, or other items, for example, it can be a refrigerator or a freezer.

In some embodiments of the present invention, the refrigerating and freezing apparatus further includes a box body 50 , and a storage compartment, such as a second storage compartment 52 , is arranged in the box body 50 . When the target temperature of the storage compartment is lower than the preset temperature, the high-temperature refrigeration cycle is first opened, so that the evaporation part 31 provides cooling capacity to the storage compartment, so that the temperature of the storage compartment reaches the preset temperature, Afterwards, both the high temperature stage refrigeration cycle and the low temperature stage refrigeration cycle are turned on, so that the low temperature stage evaporator 43 provides cooling capacity to the storage compartment, so that the temperature of the storage compartment reaches the target temperature. That is to say, in the refrigerating and freezing device of the present invention, when it is set to ultra-low temperature, in order to reduce energy consumption, it is necessary to pre-cool the temperature-changing compartment to -18°C through the high-temperature refrigeration system, close the variable-temperature damper, and then open the low-temperature refrigeration system. System, separate refrigeration for the variable temperature compartment. The preset temperature can be -18°C, and the corresponding preset temperature can also be set according to the capacity of the high-temperature refrigeration cycle. When the storage compartment is set to a normal temperature, the storage compartment is cooled by using a high-temperature refrigeration cycle loop through a conventional air duct. When the condensing evaporator 30 is defrosted, the low temperature stage compressor 41 can be stopped first, and when the temperature of the condensing evaporator 30 reaches the start-up temperature, the low temperature stage compressor 41 can be started again.

In some embodiments of the present invention, as shown in FIG. 4 and FIG. 5 , the box body 50 is provided with a first storage compartment 51 , a second storage compartment 52 and an air duct damper system. The evaporation part 31 is configured to provide cooling capacity to the first storage compartment 51 and/or to provide cooling capacity to the second storage compartment 52 . The low temperature stage evaporator 43 is configured to provide cooling to the second storage compartment 52 . The first storage compartment 51 may be a freezing compartment, and the second storage compartment 52 may be a changing room. The ultra-low temperature control of the second storage compartment 52 can be operated by the low temperature stage refrigeration cycle circuit, or the high temperature stage refrigeration cycle circuit can be pre-cooled to a preset temperature first, and then the low temperature stage refrigeration cycle circuit can be opened. Further, a third storage compartment 53 is also provided in the box body 50 , and the high-temperature stage evaporator 25 of the cascade compression refrigeration system is configured to provide cooling capacity to the third storage compartment 53 . The third storage compartment 53 may be a refrigerator compartment. An independent refrigeration system is used to cool the variable-temperature compartment, so that the variable-temperature compartment can reach extremely low temperature. At the same time, when the ultra-low temperature area is not required, it can also be set to a conventional temperature area to meet the diverse needs of users. The condensing evaporator 30 may be disposed at the bottom of the box body 50 , that is, the condensing evaporator 30 is placed at the bottom of the first storage compartment 51 . The low temperature stage evaporator 43 and the high temperature stage evaporator 25 may be respectively disposed at the rear of the corresponding storage compartments. Optionally, the condensing evaporator 30 , the low temperature stage evaporator 43 and the high temperature stage evaporator 25 may be disposed at the rear of the corresponding storage compartments, respectively.

By now, those skilled in the art will recognize that although various exemplary embodiments of the present invention have been shown and described in detail herein, without departing from the spirit and scope of the present invention, Numerous other variations or modifications consistent with the principles of the present invention are directly identified or derived from the disclosure of the present invention. Accordingly, the scope of the present invention should be understood and deemed to cover all such other variations or modifications.

Claims (10)

1. A cascade compression refrigeration system includes a high-temperature stage refrigeration cycle circuit for circulating a first refrigerant and a low-temperature stage refrigeration cycle circuit for circulating a second refrigerant; it is characterized in that the preparation method is characterized in that,

the high-temperature-stage refrigeration circulation loop comprises an evaporation part, and the low-temperature-stage refrigeration circulation loop comprises a low-temperature-stage compressor, a heat release part, a condensation part, a low-temperature-stage evaporator, a heat absorption part and an expansion device;

the evaporation part is thermally connected with the condensation part, so that the first refrigerant absorbs heat released by the second refrigerant when flowing through the condensation part when flowing through the evaporation part;

the heat radiating part is arranged between a discharge port of the low-temperature stage compressor and an inlet of the condensing part, the heat absorbing part is arranged between an outlet of the low-temperature stage evaporator and a suction port of the low-temperature stage compressor, and the heat radiating part is thermally connected with the heat absorbing part so that the second refrigerant entering the heat absorbing part absorbs heat released by the second refrigerant entering the heat radiating part when the second refrigerant flows;

the expansion device comprises a throttling device and an expansion container; the inlet of the throttling device is arranged on a pipeline between the outlet of the low-temperature-stage evaporator and the suction inlet of the low-temperature-stage compressor, the inlet of the expansion container is communicated with the outlet of the throttling device, and the outlet of the expansion container is arranged on a pipeline between the discharge outlet of the low-temperature-stage compressor and the inlet of the condensing part.

2. The cascade compression refrigeration system of claim 1, wherein the low temperature stage refrigeration cycle further comprises a plate heat exchanger having the heat absorption portion and the heat release portion.

3. The cascade compression refrigeration system of claim 1 wherein the throttling device is a pressure relief valve.

4. The cascade compression refrigeration system of claim 1,

the evaporation part and the condensation part are integrally formed into a condensation evaporator;

the evaporation part comprises an evaporation pipe, the condensation part comprises a condensation pipe, the condensation evaporator further comprises fins, and the evaporation pipe and the condensation pipe are mounted on the fins.

5. The cascade compression refrigeration system according to claim 1 or 4,

the evaporation part is arranged on the lower side of the condensation part, and the refrigerant volume of the evaporation part is larger than that of the condensation part.

6. The cascade compression refrigeration system of claim 1, wherein the high temperature stage refrigeration cycle further comprises a high temperature stage compressor and a high temperature stage evaporator,

the outlet of the high-temperature-stage evaporator and the outlet of the evaporation part are both communicated with the suction inlet of the high-temperature-stage compressor; or

The outlet of the evaporation part is communicated with the suction inlet of the high-temperature stage compressor, and the outlet of the high-temperature stage evaporator is communicated with the inlet of the evaporation part.

7. A refrigerated freezing apparatus comprising a cascade compression refrigeration system according to any one of claims 1 to 6.

8. A cold storage and refrigeration device as recited in claim 7 further comprising a cabinet, said cabinet having a storage compartment therein;

when the target temperature of the storage chamber is lower than the preset temperature, the high-temperature refrigeration circulation loop is firstly opened, the evaporation part supplies cold energy to the storage chamber, so that the temperature of the storage chamber reaches the preset temperature, and then the high-temperature refrigeration circulation loop and the low-temperature refrigeration circulation loop are both opened, so that the low-temperature evaporator supplies cold energy to the storage chamber, and the temperature of the storage chamber reaches the target temperature.

9. A cold storage and freezing device as claimed in claim 7, further comprising a box body, wherein a first storage chamber and a second storage chamber are arranged in the box body; and is

The evaporation part is configured to provide cold for the first storage chamber and/or provide cold for the second storage chamber;

the low-temperature-stage evaporator is configured to provide cold to the second storage compartment.

10. A refrigerator-freezer according to claim 9,

and a third storage compartment is further arranged in the box body, and a high-temperature-stage evaporator of the cascade compression refrigeration system is configured to provide cold energy into the third storage compartment.

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