阅读说明：本技术 适用于极寒地区的二氧化碳复叠热泵系统 (Carbon dioxide overlapping heat pump system suitable for extremely cold area ) 是由 刘勇 于 2020-05-07 设计创作，主要内容包括：一种适用于极寒地区的二氧化碳复叠热泵系统,包括制热循环和制冷循环。其中,制热循环包括蒸发冷凝器(52),第一换热器(21)通过换向阀(51)分别与第一压缩机(41)、第二换热器(22)和蒸发冷凝器(52)连通,蒸发冷凝器(52)与第一换热器(21)之间设有第二毛细管(32),蒸发冷凝器(52)与第二换热器(22)之间设有第三换热器(23),第三换热器(23)与蒸发冷凝器(52)之间设有第二压缩机(42)。制冷循环包括第一换热器(21)、第一压缩机(41)和第二换热器(22),第二换热器(22)与第一毛细管(31)连通,第一毛细管(31)与第一换热器(21)连通。该二氧化碳复叠热泵系统可以在制冷工况和制热工况之间转换,应用范围广泛,解决了现有复叠热泵系统功能单一的问题,尤其适用于极寒地区。(A carbon dioxide cascade heat pump system suitable for extremely cold regions comprises a heating cycle and a refrigerating cycle. The heating cycle comprises an evaporative condenser (52), the first heat exchanger (21) is respectively communicated with the first compressor (41), the second heat exchanger (22) and the evaporative condenser (52) through a reversing valve (51), a second capillary tube (32) is arranged between the evaporative condenser (52) and the first heat exchanger (21), a third heat exchanger (23) is arranged between the evaporative condenser (52) and the second heat exchanger (22), and a second compressor (42) is arranged between the third heat exchanger (23) and the evaporative condenser (52). The refrigeration cycle comprises a first heat exchanger (21), a first compressor (41) and a second heat exchanger (22), wherein the second heat exchanger (22) is communicated with a first capillary tube (31), and the first capillary tube (31) is communicated with the first heat exchanger (21). The carbon dioxide overlapping heat pump system can be switched between a refrigerating working condition and a heating working condition, is wide in application range, solves the problem that the existing overlapping heat pump system is single in function, and is particularly suitable for extremely cold regions.)

1. The utility model provides a carbon dioxide overlapping heat pump system suitable for extremely cold district which characterized in that: comprises a heating cycle and a refrigerating cycle; the heating cycle comprises an evaporative condenser (52), a second capillary tube (32) is arranged between the evaporative condenser (52) and a first heat exchanger (21), the evaporative condenser (52) is communicated with the first heat exchanger (21) through a reversing valve (51), a third heat exchanger (23) is arranged between the evaporative condenser (52) and a second heat exchanger (22), and a second compressor (42) is arranged between the third heat exchanger (23) and the evaporative condenser (52); the refrigeration cycle comprises a first heat exchanger (21), wherein the first heat exchanger (21) is provided with a water inlet and a water outlet, the first heat exchanger (21) is communicated with a first compressor (41) through the reversing valve (51), the first heat exchanger (21) is communicated with a second heat exchanger (22) through the reversing valve (51), the second heat exchanger (22) is communicated with a first capillary tube (31), and the first capillary tube (31) is communicated with the first heat exchanger (21).

2. The carbon dioxide cascade heat pump system suitable for extremely cold regions according to claim 1, characterized in that: a first control valve (61) is arranged between the evaporative condenser (52) and the reversing valve (51) and between the second capillary tube (32) and the first heat exchanger (21); and second control valves (62) are arranged between the first capillary tube (31) and the first heat exchanger (21) and between the second heat exchanger (22) and the reversing valve (51).

3. The carbon dioxide cascade heat pump system suitable for extremely cold regions according to claim 2, characterized in that: the first control valve (61) and/or the second control valve (62) are solenoid valves.

4. The carbon dioxide cascade heat pump system suitable for extremely cold regions according to any one of claims 1 to 3, characterized in that: the reversing valve (51) is a four-way reversing valve.

5. The carbon dioxide cascade heat pump system suitable for extremely cold regions according to claim 4, characterized in that: a first liquid storage tank (71) is arranged between the first compressor (41) and the reversing valve (51).

6. The carbon dioxide cascade heat pump system suitable for extremely cold regions according to claim 5, characterized in that: a second liquid storage tank (72) is arranged between the first capillary tube (31) and the first heat exchanger (21).

7. The carbon dioxide cascade heat pump system suitable for extremely cold regions according to claim 6, characterized in that: a third liquid storage tank (73) is arranged between the second capillary tube (32) and the first heat exchanger (21).

8. The carbon dioxide cascade heat pump system suitable for extremely cold regions according to claim 7, characterized in that: and a first expansion valve (8) is arranged between the second heat exchanger (22) and the third heat exchanger (23).

Technical Field

The invention belongs to the technical field of heat pumps, and particularly relates to a carbon dioxide cascade heat pump system suitable for extremely cold regions.

Background

The heat pump is a device capable of transferring the heat energy of a low-level heat source to a high-level heat source, and generally obtains low-grade heat energy from air, water or soil in the nature, applies work through electric power, and then provides the high-grade heat energy which can be utilized for people.

The carbon dioxide cascade heat pump system can be applied to heating and is provided with two sets of circulating systems, one set of circulating systems is used for gas circulation of a low-temperature section through carbon dioxide, the other set of circulating systems is used for liquid circulation of a high-temperature section through Freon and the like, and the two sets of circulating systems can be connected together through an evaporative condenser and realize heat exchange and heating effects under the heating working condition of the evaporative condenser.

Fig. 4 shows a conventional cascade heat pump system, which is mainly applied to the fields of food freezing and refrigeration, preservation of crop seeds, supermarket refrigeration systems, and the like. It has two sets of circulation systems: one of the circulation systems comprises an expansion valve 11, an outdoor heat exchanger 12, an internal heat exchanger 13, a compressor 14 and an evaporative condenser 15 for heating; another set of circulation system comprises a compressor 14, an evaporative condenser 15, an expansion valve 11 and a main heat exchanger 16. The two systems share one evaporative condenser 15, i.e., the two systems are coupled together by one evaporative condenser 15. The refrigeration working medium respectively circulates in the two systems, and the heat exchange and refrigeration effects are realized when the evaporative condenser 15 is under the refrigeration working condition.

However, energy consumed in the existing cascade heat pump system can only be used for cooling or heating, and the function is single, so that the application range of the cascade system is limited.

Disclosure of Invention

The invention provides a carbon dioxide overlapping heat pump system suitable for extremely cold regions, and aims to solve the technical problem that an overlapping heat pump system in the prior art is single in function.

In order to solve the technical problems, the invention provides the following specific technical scheme:

a carbon dioxide cascade heat pump system suitable for extremely cold regions comprises a heating cycle and a refrigerating cycle. The heating cycle comprises an evaporative condenser, a second capillary tube is arranged between the evaporative condenser and a first heat exchanger, the evaporative condenser is communicated with the first heat exchanger through a reversing valve, a third heat exchanger is arranged between the evaporative condenser and the second heat exchanger, and a second compressor is arranged between the third heat exchanger and the evaporative condenser; the refrigeration cycle comprises a first heat exchanger, the first heat exchanger is provided with a water inlet and a water outlet, the first heat exchanger is communicated with a first compressor through a reversing valve, the first heat exchanger is communicated with a second heat exchanger through the reversing valve, the second heat exchanger is communicated with a first capillary tube, and the first capillary tube is communicated with the first heat exchanger.

Further, first control valves are arranged between the evaporative condenser and the reversing valve and between the second capillary tube and the first heat exchanger; and second control valves are arranged between the first capillary tube and the first heat exchanger and between the second heat exchanger and the reversing valve.

Further, the first control valve and/or the second control valve is a solenoid valve.

Further, the reversing valve is a four-way reversing valve.

Further, a first liquid storage tank is arranged between the first compressor and the reversing valve.

Further, a second liquid storage tank is arranged between the first capillary tube and the first heat exchanger.

Further, a third liquid storage tank is arranged between the second capillary tube and the first heat exchanger.

Further, a first expansion valve is arranged between the second heat exchanger and the third heat exchanger.

The invention has the following beneficial technical effects:

the carbon dioxide cascade heat pump system suitable for the extremely cold region has two working conditions of heating in winter and refrigerating in summer, heating in winter is realized through the heating cycle, refrigerating in summer is realized through the refrigerating cycle, and due to the fact that the carbon dioxide cascade heat pump system has two functions of refrigerating and heating, switching can be performed between the two working conditions of refrigerating in summer and refrigerating in winter, functions are diversified, and the application range is wider.

Drawings

FIG. 1 is a schematic diagram of a carbon dioxide cascade heat pump system suitable for use in extremely cold regions in accordance with the present invention;

FIG. 2 is a schematic flow diagram of a carbon dioxide cascade heat pump system suitable for extremely cold regions according to the present invention in a winter heating condition;

FIG. 3 is a schematic flow diagram of a carbon dioxide cascade heat pump system suitable for extremely cold regions in summer refrigeration;

fig. 4 is a schematic diagram of a carbon dioxide cascade heat pump system suitable for extremely cold regions according to the background art.

In the figure: 11-expansion valve, 12-outdoor heat exchanger, 13-internal heat exchanger, 14-compressor, 15-evaporative condenser for heating, 16-main heat exchanger, 21-first heat exchanger, 22-second heat exchanger, 23-third heat exchanger, 31-first capillary tube, 32-second capillary tube, 41-first compressor, 42-second compressor, 51-reversing valve, 52-evaporative condenser, 61-first control valve, 62-second control valve, 71-first liquid storage tank, 72-second liquid storage tank, 73-third liquid storage tank, 8-first expansion valve.

Detailed Description

The embodiments of the invention will be described and explained more fully hereinafter with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a carbon dioxide cascade heat pump system suitable for an extremely cold region of the present invention, fig. 2 is a schematic flow diagram of the carbon dioxide cascade heat pump system suitable for an extremely cold region of the present invention in a winter heating condition, and fig. 3 is a schematic flow diagram of the carbon dioxide cascade heat pump system suitable for an extremely cold region of the present invention in a summer cooling condition.

As shown in fig. 1-3, the carbon dioxide cascade heat pump system suitable for extremely cold regions of the invention comprises a refrigeration cycle and a heating cycle.

Wherein the refrigeration cycle comprises a first heat exchanger 21, the first heat exchanger 21 having a water inlet and a water outlet; the first heat exchanger 21 communicates with the first compressor 41 through a reversing valve 51; the first heat exchanger 21 is communicated with the second heat exchanger 22 through a reversing valve 51; the second heat exchanger 22 communicates with the first capillary tube 31, and the first capillary tube 31 communicates with the first heat exchanger 21.

The heating cycle comprises an evaporative condenser 52, a second capillary tube 32 is arranged between the evaporative condenser 52 and the first heat exchanger 21, the evaporative condenser 52 is communicated with the first heat exchanger 21 through a reversing valve 51, a third heat exchanger 23 is arranged between the evaporative condenser 52 and the second heat exchanger 22, and a second compressor 42 is arranged between the third heat exchanger 23 and the evaporative condenser 52.

The carbon dioxide cascade heat pump system suitable for the extremely cold area has two working conditions of winter heating and summer cooling, the winter heating is realized through the heating cycle, and the summer cooling is realized through the refrigerating cycle.

Specifically, as shown in fig. 3, when the carbon dioxide cascade heat pump system suitable for the extremely cold region is in a summer refrigeration condition, the refrigerant enters the first heat exchanger 21 through the first capillary tube 31, absorbs heat in the first heat exchanger 21, enters the first compressor 41 through the reversing valve 51 after absorbing heat, enters the second heat exchanger 22 after being compressed by the first compressor 41, and returns to the first capillary tube 31 from the second heat exchanger 22, thereby completing a cycle process. Since the refrigerant absorbs heat in the first heat exchanger 21, the heat of the water flowing through the first heat exchanger 21 is absorbed, so that the temperature of the water flowing through the first heat exchanger 21 is reduced, thereby achieving the refrigeration effect.

As shown in fig. 2, when the carbon dioxide cascade heat pump system suitable for the extremely cold region is in the heating working condition in winter, the refrigeration working medium is divided into a low-temperature section refrigeration working medium and a high-temperature section refrigeration working medium. The low-temperature section refrigerating working medium enters the second heat exchanger 22, enters the third heat exchanger 23 after absorbing heat, enters the second compressor 42 after exchanging heat, enters the evaporative condenser 52 after being compressed by the second compressor 42, and returns to the third heat exchanger 23 after releasing heat, thereby completing a cycle process of the low-temperature section refrigerating working medium; the high-temperature section refrigerating working medium enters the evaporative condenser 52 through the second capillary tube 32, absorbs heat, enters the first compressor 41 through the reversing valve 51, is compressed by the first compressor 41, enters the first heat exchanger 21, releases heat, and returns to the second capillary tube 32, so that a circulation process of the high-temperature section refrigerating working medium is completed. Because the high-temperature section refrigerating working medium releases heat in the first heat exchanger 21, the released heat is absorbed by the water flowing through the first heat exchanger 21, so that the temperature of the water is increased, and the heating effect is achieved.

In conclusion, the carbon dioxide cascade heat pump system suitable for the extremely cold region has two functions of refrigeration and heating, can switch between two working conditions of refrigeration in summer and heating in winter, and is diversified in function and wider in application range.

Further, a first control valve 61 is arranged between the evaporative condenser 52 and the reversing valve 51 and between the second capillary tube 32 and the first heat exchanger 21, and a second control valve 62 is arranged between the first capillary tube 31 and the first heat exchanger 21 and between the second heat exchanger 22 and the reversing valve 51, so that switching between a summer cooling working condition and a winter heating working condition is facilitated.

Further, the first control valve 61 and the second control valve 62 are solenoid valves, and the direction valve 51 is a four-way direction valve, which is advantageous for realizing automatic control.

Further, a first liquid storage tank 71 is disposed between the first compressor 41 and the reversing valve 51, a second liquid storage tank 72 is disposed between the first capillary tube 31 and the first heat exchanger 21, a third liquid storage tank 73 is disposed between the second capillary tube 32 and the first heat exchanger 21, and a first expansion valve 8 is disposed between the second heat exchanger 22 and the third heat exchanger 23. The first liquid storage tank 71, the second liquid storage tank 72 and the third liquid storage tank 73 can play a role in storing the refrigerant and can also play a role in pressure relief and liquid separation.

As shown in fig. 3, as a specific embodiment, the carbon dioxide cascade heat pump system suitable for the extremely cold region of the present invention includes a refrigeration cycle and a heating cycle, wherein:

the refrigeration cycle includes a first capillary tube 31, a second receiver 72, a second control valve 62, a first heat exchanger 21, a direction valve 51, a first receiver 71, a first compressor 41, and a first expansion valve 8. Specifically, the first heat exchanger 21 has four interfaces, which are respectively a first interface, a second interface, a water inlet and a water outlet, in the refrigeration cycle, hot water flows into the water inlet, cold water flows out of the water outlet, the first interface of the first heat exchanger 21 is communicated with the reversing valve 51, and the second interface of the first heat exchanger 21 is communicated with the second liquid storage tank 72; the reversing valve 51, the first compressor 41 and the first liquid storage tank 71 are connected into a loop, one second control valve 62 of the two second control valves 62 is arranged on a pipeline communicated between the second liquid storage tank 72 and the first heat exchanger 21, and the other second control valve 62 is arranged on a pipeline communicated between the second heat exchanger 22 and the reversing valve 51.

The heating cycle comprises an evaporative condenser 52, a second capillary tube 32, a third liquid storage tank 73, a first control valve 61 and a third heat exchanger 23, specifically, the second capillary tube 32 is communicated with the third liquid storage tank 73, the third liquid storage tank 73 is communicated with a second interface of the first heat exchanger 21, the evaporative condenser 52 and the third heat exchanger 23 are respectively provided with four interfaces, the second heat exchanger 22 is provided with six interfaces, the first interface and the second interface of the evaporative condenser 52 are respectively communicated with the second capillary tube 32 and the reversing valve 51, the third interface of the evaporative condenser 52 is communicated with the second interface of the third heat exchanger 23, and the fourth interface of the evaporative condenser 52 is communicated with the second compressor 42; a first interface of the third heat exchanger 23 is communicated with a first interface of the second heat exchanger 22 through the first expansion valve 8, a third interface of the third heat exchanger 23 is communicated with a second interface of the second heat exchanger 22, and a fourth interface of the third heat exchanger 23 is communicated with the second compressor 42; the third interface of the second heat exchanger 22 is communicated with the first capillary tube 31, the fourth interface of the second heat exchanger 22 is communicated with the reversing valve 51, the fifth interface and the sixth interface of the second heat exchanger 22 are respectively an air outlet and an air inlet, one of the two first control valves 61 is arranged on a pipeline through which the third liquid storage tank 73 is communicated with the first heat exchanger 21, and the other first control valve 61 is arranged on a pipeline through which the evaporative condenser 52 is communicated with the reversing valve 51.

Preferably, the direction valve 51 is a four-way direction valve, the first control valve 61 and the second control valve 62 are both solenoid valves, the second heat exchanger 22 is an outdoor heat exchanger, and the third heat exchanger 23 is an internal heat exchanger.

In the process of operating the refrigeration cycle, the first control valve 61 is closed, the second control valve 62 is opened, the reversing valve 51 is adjusted to the refrigeration mode, the refrigerant enters the first heat exchanger 21 through the first capillary tube 31 and the second liquid storage tank 72, absorbs heat, passes through the reversing valve 51, the first liquid storage tank 71 and the first compressor 41, is compressed by the first compressor 41, enters the second heat exchanger 22, and returns to the first capillary tube 31 from the second heat exchanger 22, thereby completing a cycle process. Meanwhile, hot water enters from the water inlet of the first heat exchanger 21, and in the first heat exchanger 21, the refrigeration working medium absorbs heat of the hot water, so that the temperature of the hot water is reduced, the hot water becomes cold water and then flows out from the water outlet, and the refrigeration process is completed.

In the process of operating the heating cycle, the refrigeration working medium is divided into two parts, namely a high-temperature section refrigeration working medium and a low-temperature section refrigeration working medium, wherein the high-temperature section refrigeration working medium can be Freon or other refrigeration working media, and the low-temperature section refrigeration working medium is carbon dioxide. When the cooling working condition in summer is switched to the heating working condition in winter, the second control valve 62 needs to be closed, and the first control valve 61 needs to be opened, because the flow directions of the cooling working medium in the heating cycle and the cooling cycle are different, the reversing valve 51 needs to be adjusted to the heating mode. The low-temperature section refrigerating working medium enters the second heat exchanger 22 through the first expansion valve 8, enters the third heat exchanger 23 after absorbing outdoor heat, enters the second compressor 42 after heat exchange, enters the evaporative condenser 52 after being compressed by the second compressor 42, releases heat, and returns to the first expansion valve 8 through the third heat exchanger 23 and the second heat exchanger 22, so that a circulation process of the low-temperature section refrigerating working medium is completed; the high-temperature section refrigerant enters the evaporative condenser 52 through the second capillary tube 32, absorbs heat, enters the first compressor 41 through the reversing valve 51 and the first liquid storage tank 71, is compressed by the first compressor 41, enters the first heat exchanger 21, releases heat, and returns to the second capillary tube 32 through the third liquid storage tank 73, so that one cycle of the high-temperature section refrigerant is completed. Meanwhile, cold water enters from the water inlet of the first heat exchanger 21, the temperature of the cold water rises after the cold water absorbs heat emitted by the high-temperature section refrigerating working medium in the first heat exchanger 21, the cold water becomes hot water and then flows out from the water outlet, and therefore the heating process is completed.

The technical solutions and preferred embodiments of the present invention have been described above in clear and in detail. It is to be understood that the described embodiments are merely preferred embodiments of the invention, rather than all embodiments, and that the invention is not limited thereto. All other embodiments, which can be obtained by modifications, equivalents and/or simple variations without inventive step, are included in the scope of the present invention by those skilled in the art.