Cooling and heating combined supply device and system based on transcritical carbon dioxide

Abstract

The invention discloses a combined cooling and heating device and system based on transcritical carbon dioxide, and relates to the technical field of refrigeration. Gaseous CO2 at a refrigeration equipment end is output to a heat exchanger group, enters a low-pressure oil separation tank after heat exchange, then enters a compressor unit and is converted into high-temperature and high-pressure transcritical CO2 through the compressor unit, and the high-temperature and high-pressure transcritical CO2 passing through a high-pressure oil separation tank enters a heating equipment end and then is output to the heat exchanger group for heat exchange. The liquid CO2 is subjected to pressure reduction in a pressure reducer, and the liquid CO2 enters a refrigeration equipment end after passing through a liquid separation tank; gaseous CO2 and liquid CO2 in the system are cyclically converted between the refrigeration equipment end and the heating equipment end. Change of carbon dioxide is achieved through the plate heat exchanger and the compressor unit, various physical characteristics of carbon dioxide are fully utilized, refrigerating and heating inside the unit are achieved, the refrigerating and heating efficiency is greatly improved, the production cost is reduced, and the characteristics of energy conservation, emission reduction, environmental protection and high efficiency are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of refrigeration technology, and in particular relates to a combined cooling and heating device based on transcritical carbon dioxide, and a combined cooling and heating system based on transcritical carbon dioxide. Background Art

[0002] A carbon dioxide heat pump is a heat pump system that can achieve both heating and cooling. Its working principle is to transfer energy by transferring heat from a low-temperature heat source to a high-temperature heat source. The carbon dioxide heat pump achieves the functions of cooling and heating through the temperature change of the refrigerant during the compression and expansion process.

[0003] Transcritical CO2 heat pump combined heat and cooling technology is a new energy utilization technology developed on the basis of CO2 heat pump. Its working principle is to realize both low-temperature heating and high-temperature cooling by circulating the working fluid near the critical point of CO2, thus achieving the purpose of combined heat and cooling.

[0004] When carbon dioxide is used as a refrigerant, the system pressure is very high. The saturated pressure of carbon dioxide at 0°C is 7 times higher than that of R22. Its suction and exhaust pressures are 10MPa and 3MPa higher than those of R22 respectively. It has an abnormal solubility under supercritical pressure and shows its acidic nature when water is present. Under supercritical conditions, carbon dioxide is an effective solvent for various types of hydrocarbons. Because the exhaust of the carbon dioxide compressor is in a supercritical state, lubricating oil will be carried over under any conditions due to the solubility of supercritical carbon dioxide.

[0005] As a natural and environmentally friendly refrigerant, carbon dioxide has many advantages. (1) Carbon dioxide is a natural gas that will not damage the atmosphere. Compared with traditional CFC refrigerants, the use of carbon dioxide can better achieve environmental protection effects. (2) Carbon dioxide is not toxic or flammable, and will not pose any threat to the environment and human health during use. (3) It is low-cost, easy to obtain, stable, and has high-efficiency refrigeration performance. (4) The ozone depletion potential of carbon dioxide is ODP = 0, and the global warming potential is GWP = 1.

[0006] Transcritical carbon dioxide heat pump combined heating and cooling technology is a system engineering composed of multiple links. The degree of perfection of system integration technology will directly affect the performance and stability of the entire system. Summary of the invention

[0007] The purpose of the present invention is to provide a combined cooling and heating device and system based on transcritical carbon dioxide, which realizes the cyclic conversion of gaseous CO2 into liquid CO2 between the refrigeration equipment end and the heating equipment end through a plate heat exchanger, a pressure reducer and a compressor unit, fully utilizes the various physical properties of carbon dioxide, and realizes refrigeration and heating inside the unit.

[0008] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0009] The present invention is a combined cooling and heating device based on transcritical carbon dioxide, comprising a base, a refrigeration equipment end, a heating equipment end, a low-pressure air inlet and a CO2 medium. A compressor unit, a heat exchanger unit, a pressure reducer, an oil storage tank, a low-pressure oil separator tank, a high-pressure oil separator tank and a liquid separator tank are arranged on the base; the oil storage tank is connected to the lubricating oil circuit system of the compressor unit through an oil storage pipe; the gaseous CO2 medium at the outlet of the refrigeration equipment end is connected to the heat exchanger unit through the low-pressure air inlet through the first low-pressure pipeline, and the gaseous CO2 medium enters the low-pressure air inlet through the first heat exchange pipeline after heat exchange in the heat exchanger unit. high-pressure oil separator tank; the outlet of the low-pressure oil separator tank is connected to the inlet of the compressor unit through a second low-pressure pipeline; the compressor unit is connected to the inlet of the high-pressure oil separator tank through the compressor outlet pipe, and the outlet of the high-pressure oil separator tank is a transcritical CO2 outlet; the transcritical CO2 outlet is connected to the heating equipment end, and the heating equipment end is connected to the heat exchanger group through the high-pressure liquid inlet pipe port through the second heat exchange pipeline and then to the pressure reducer; the pressure reducer is connected to the liquid separator tank through the liquid inlet pipe; the outlet of the liquid separator tank is a liquid separator outlet, which is connected to the inlet of the refrigeration equipment end through the liquid separator outlet and the third low-pressure pipeline.

[0010] Furthermore, the base also includes a container body, and the base is fixed inside the container body; a power distribution cabinet is also fixed on the base.

[0011] Furthermore, the compressor group includes a first group of compressors and a second group of compressors; the first group of compressors is an array of several compressors consisting of series-connected transcritical carbon dioxide compressors; the second group of compressors is an array of several compressors consisting of series-connected transcritical carbon dioxide compressors.

[0012] Furthermore, an electric valve is provided on the first low-pressure pipeline; and a manual valve is provided on the compressor outlet pipe.

[0013] Furthermore, the heating equipment end includes a flash dryer or a flash water condenser, and the high-temperature and high-pressure transcritical CO2 outputs heat energy through the heating equipment end to form sub-high-temperature and high-pressure liquid CO2.

[0014] Furthermore, a gas outlet is also provided on the top of the liquid separation tank, and the gas outlet is connected to the first low-pressure pipeline through a gas outlet pipeline.

[0015] Furthermore, the liquid inlet pipe, the first low-pressure pipeline, the second low-pressure pipeline, the third low-pressure pipeline, the first heat exchange pipeline and the second heat exchange pipeline are all provided with pressure sensors and temperature sensors.

[0016] Furthermore, the refrigeration equipment end includes an air cooler, and the air cooler is a carbon dioxide heat exchanger.

[0017] Furthermore, the pressure reducer group is a capillary pressure reducer.

[0018] Furthermore, the heat exchanger group is a plate exchanger.

[0019] A combined cooling and heating system based on transcritical carbon dioxide, wherein the gaseous CO2 medium at the outlet of the refrigeration equipment end is output to the heat exchanger group, enters the low-pressure oil separator tank after heat exchange, and then enters the compressor group, the obtained gaseous CO2 is converted into high-temperature and high-pressure transcritical CO2 by the compressor group, and the high-temperature and high-pressure transcritical CO2 passes through the high-pressure oil separator tank and enters the heating equipment end; the sub-high-temperature and high-pressure liquid CO2 output from the heating equipment end is output to the heat exchanger group for heat exchange, and the liquid CO2 that has been cooled and reduced in temperature and pressure after heat exchange enters a pressure reducer for decompression and forms low-temperature and low-pressure liquid CO2, and the low-temperature and low-pressure liquid CO2 passes through the liquid separator tank and enters the refrigeration equipment end; the gaseous CO2 in the system is converted into liquid CO2 in a cyclic manner between the refrigeration equipment end and the heating equipment end.

[0020] Furthermore, the low-pressure lubricating oil obtained after oil treatment in the low-pressure oil separator tank and the liquid separator tank enters the oil storage pipe and returns to the oil circuit system of the compressor unit; the high-pressure lubricating oil obtained after oil treatment in the high-pressure oil separator tank enters the oil storage tank.

[0021] The present invention has the following beneficial effects:

[0022] The present invention realizes the cyclic conversion of gaseous CO2 into liquid CO2 between the refrigeration equipment end and the heating equipment end through a plate heat exchanger, a pressure reducer and a compressor unit, fully utilizes the various physical properties of carbon dioxide, realizes refrigeration and heating inside the unit, greatly improves the efficiency of refrigeration and heating, reduces production costs, and realizes the characteristics of energy saving, emission reduction, environmental protection and high efficiency.

[0023] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 Schematic diagram of the structure of the combined heat and cold supply device based on transcritical carbon dioxide of this embodiment;

[0026] Figure 2 for Figure 1 The left view of the structure;

[0027] Figure 3 for Figure 1 A top view of the structure;

[0028] Figure 4 for Figure 1 The main view of the structure;

[0029] Figure 5 for Figure 1 The rear view of the structure;

[0030] Figure 6 for Figure 1 The right side view of the structure;

[0031] Figure 7 is a schematic diagram of the structure of a heat exchanger group;

[0032] Figure 8 This is a diagram of a combined cooling and heating system based on transcritical carbon dioxide in this embodiment;

[0033] Fig. 9 It is a structural schematic diagram of the low-pressure oil separator tank;

[0034] Fig.10 for Fig. 9 Schematic diagram of the half-section structure;

[0035] Fig.11 It is a structural schematic diagram of the high-pressure oil separator tank;

[0036] Fig.12 for Fig.11 Schematic diagram of the half-section structure;

[0037] Fig.13 Schematic diagram of the structure of the combined heat and cold supply device based on transcritical carbon dioxide of this embodiment;

[0038] Fig.14 It is a structural schematic diagram of the liquid separation tank;

[0039] Fig.15 for Fig.14Schematic diagram of the half-section structure. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] like Figure 1-3 As shown, this embodiment is a combined cooling and heating device based on transcritical carbon dioxide, including a base 1, a refrigeration equipment end, a heating equipment end, a low-pressure air inlet 18 and a CO2 medium, and a compressor unit, a heat exchanger unit 11, a pressure reducer 10, an oil storage tank 7, a low-pressure oil separation tank 8, a high-pressure oil separation tank 6 and a liquid separation tank 9 are arranged on the base 1.

[0042] The base 1 also includes a container body, and the base 1 is fixed inside the container body; a power distribution cabinet 3 is also fixed on the base 1; the base 1 is a rectangular frame made of I-beams, and a bracket for supporting the layout of each pipeline of the liquid inlet pipe 1001, the first low-pressure pipeline 1801, the second low-pressure pipeline 801, the third low-pressure pipeline 1701, the first heat exchange pipeline and the second heat exchange pipeline 1501 is also provided on the base 1.

[0043] The compressor unit includes a first compressor group 2A and a second compressor group 2B; the first compressor group 2A is an array of several compressors composed of series-connected transcritical carbon dioxide compressors; the second compressor group 2B is an array of several compressors composed of series-connected transcritical carbon dioxide compressors. The compressor is one of the most important links in the entire circulation system, and the transcritical state is completed through the process of compression and expansion of carbon dioxide. According to the requirements of the site, carbon dioxide is required to have the characteristics of low pressure to high pressure, a wide range of use, high thermal efficiency, and stable exhaust pressure. Therefore, DORIN professional transcritical carbon dioxide compressors were selected, and at the same time, the power of the entire device can be adjusted according to the number of transcritical carbon dioxide compressors.

[0044] The refrigeration equipment end includes an air cooler, which is a carbon dioxide heat exchanger used for refrigeration.

[0045] The heating equipment end includes a flash dryer or a flash water condenser. The high-temperature and high-pressure transcritical CO2 outputs heat energy through the heating equipment end to form sub-high-temperature and high-pressure liquid CO2.

[0046] The pressure reducer 10 is a capillary pressure reducer. In this embodiment, a capillary device is used for pressure reduction, and the tube mouth is composed of a stainless steel tube. The pressure reduction principle of the capillary is: after the high-pressure liquid carbon dioxide enters the capillary, the cross-sectional area of ​​the flow channel becomes narrower, the fluid flow rate increases, and thus a violent friction is generated between the fluid and the capillary wall, resulting in a continuous decrease in pressure; due to the influence of flow friction resistance, the pressure drop changes linearly; the length of the capillary and the number of turns of the inner diameter present different liquid supply capacities.

[0047] like Figure 7 As shown, the heat exchanger group 11 is a plate exchanger. The heat exchanger is one of the important links in the entire circulation system. The role of heat exchange in the entire circulation system is to recover part of the heat in the high-pressure fluid and transfer it to the low-pressure fluid, thereby improving the system's energy efficiency ratio (COP) and cooling capacity. Therefore, it is critical to select a heat exchanger with high energy efficiency ratio. The cold and hot fluids are introduced into the flow channel in a staggered form of one cold and one hot, respectively, so that the cold and hot fluids can fully exchange heat in the heat exchanger, greatly improving the energy-saving effect, and the cold and hot fluids are counter-currently hedged.

[0048] like Figure 4-6 As shown, the gaseous CO2 medium output from the outlet of the refrigeration equipment is connected to the gaseous CO2 inlet of the heat exchanger group 11 through the low-pressure air inlet 18 and the first low-pressure pipeline 1801. After heat exchange in the heat exchanger group 11, the gaseous CO2 medium enters the low-pressure oil separation tank 8 from the gaseous CO2 outlet of the heat exchanger group 11 through the first heat exchange pipeline.

[0049] like Fig. 9 and Fig.10 As shown, the low-pressure oil separator tank 8 includes a third tank body, and a second air outlet 301, a second bell-mouth fluid structure 305 located inside the third tank body, an air inlet 302, a third filter screen 306, and a third oil outlet 304 are sequentially arranged from the top to the bottom of the third tank body. The gaseous CO2 enters the third tank body 3 through the air inlet 302, and the gaseous CO2 is collected through the second bell-mouth fluid structure 305 and enters the compressor unit through the second air outlet 301. The low-pressure lubricating oil located inside the third tank body enters the oil storage tank through the third oil outlet 304. The function of the third filter screen 306 is to completely separate the gaseous CO2 and the lubricating oil.

[0050] The outlet of the low-pressure oil separator 8 is connected to the inlet of the compressor unit through the second low-pressure pipeline 801; the compressor unit is connected to the inlet of the high-pressure oil separator 6 through the compressor outlet pipe 201, and the outlet of the high-pressure oil separator 6 is the transcritical CO2 outlet 16.

[0051] like Fig.11 and Fig.12As shown, the high-pressure oil separator tank 6 includes a second tank body, on which a second liquid outlet 203, a plurality of second liquid inlets 202, a first bell-mouth fluid structure 205 located inside the second tank body, a second filter screen 206, a second oil outlet 207 and a first sewage outlet 204 are sequentially arranged from the top to the bottom of the second tank body, and one second liquid inlet 202 corresponds to a group of compressor arrays; high-temperature and high-pressure transcritical CO2 enters through the second liquid inlet 202 of the high-pressure oil separator tank 6, and the high-temperature and high-pressure transcritical CO2 formed in the second tank body is collected through the first bell-mouth fluid structure 205 and flows out through the second liquid outlet 203, and the high-pressure lubricating oil in the second tank body enters the oil storage tank 7 through the second oil outlet 207.

[0052] The first bellmouth fluid structure 205 is connected to the second liquid outlet 201. The first drain port 204 is at the bottom of the high-pressure oil separator tank to remove the accumulated oil impurities. At the same time, it is convenient to empty the oil and relieve the pressure of the unit during the later maintenance and repair. The second oil outlet 207 is at the bottom of the high-pressure oil separator tank 6. After separation, the lubricating oil returns from the oil outlet to the oil inlet of the oil storage tank 7 to replenish the oil to the compressor unit. The second oil outlet 207 is connected to the oil inlet of the oil storage tank 7.

[0053] like Fig.13 As shown, the compressor unit further includes a compressor oil replenishing pipe. When the lubricating oil in the entire system device is reduced, the lubricating oil is compensated through the compressor oil replenishing pipe.

[0054] The transcritical CO2 outlet 16 is connected to the heating equipment end, and the heating equipment end is connected to the heat exchanger group 11 through the high-pressure liquid inlet pipe 15 and the second heat exchange pipe 1501, and then connected to the pressure reducer 10; the pressure reducer 10 is connected to the liquid separation tank 9 through the liquid inlet pipe 1001;

[0055] The outlet of the liquid separator tank 9 is the liquid separator outlet 17, which is connected to the refrigeration equipment end inlet through the liquid separator outlet 17 and the third low-pressure pipeline 1701. The top of the liquid separator tank 9 is also provided with an air outlet, which is connected to the first low-pressure pipeline 1801 through the air outlet pipeline 901.

[0056] like Fig.14 and 15 As shown, the liquid separator tank 9 includes a first tank body, on which a first air outlet 103, a first liquid inlet 101, a first filter screen 106, a first liquid outlet 102 and a first oil outlet 104 are sequentially arranged from the top to the bottom of the first tank body; low-temperature and low-pressure liquid CO2 with lubricating oil enters through the first liquid inlet 101, passes through the first filter screen 106 located inside the first tank body 1, and is output to the refrigeration equipment end through the first liquid outlet 102, and the separated lubricating oil enters the oil storage pipe through the first oil outlet 104.

[0057] The first low-pressure pipeline is also provided with an electric valve 12 to control the intake of gaseous carbon dioxide to ensure the supply of the entire unit. A manual valve 5 is provided on the pipeline connecting the compressor unit and the compressor outlet pipe 201, that is, a manual valve 5 is connected to the pipeline connecting each transcritical carbon dioxide compressor and the compressor outlet pipe 201.

[0058] The liquid inlet pipe 1001, the first low-pressure pipeline 1801, the second low-pressure pipeline 801, the third low-pressure pipeline 1701, the first heat exchange pipeline and the second heat exchange pipeline 1501 are all provided with pressure sensors 14 and temperature sensors 13 to detect the changes of CO2 in various shapes in real time; the pipelines are all made of stainless steel pipes.

[0059] like Figure 8 As shown, a combined cooling and heating system based on transcritical carbon dioxide in this embodiment is shown. The gaseous CO2 medium at the outlet of the refrigeration equipment end is output to the heat exchanger group 11, enters the low-pressure oil separator 8 after heat exchange, and then enters the compressor group. The obtained gaseous CO2 is converted into high-temperature and high-pressure transcritical CO2 by the compressor group. The high-temperature and high-pressure transcritical CO2 passes through the high-pressure oil separator 6 and enters the heating equipment end.

[0060] The sub-high temperature and high pressure liquid CO2 output from the heating equipment end is output to the heat exchanger group 11 for heat exchange. The cooled and reduced pressure liquid CO2 after heat exchange enters a pressure reducer 10 for decompression and forms low temperature and low pressure liquid CO2. The low temperature and low pressure liquid CO2 passes through the liquid separator 9 and enters the refrigeration equipment end. The gaseous CO2 in the system is converted into liquid CO2 in a cycle between the refrigeration equipment end and the heating equipment end.

[0061] The working environment pressure of the low-pressure oil separator 8 is in the range of 2.0-3.0MPa; the working environment pressure of the high-pressure oil separator 6 is in the range of 8-10MPa; the working environment pressure of the liquid separator 9 is in the range of 3-4MPa. Since the overall oil circuit system operates under the system pressure, the oil circuit of the oil storage tank 7 can flow by relying on the pressure of the transcritical carbon dioxide combined heating and cooling unit system, without the need for an additional oil pump, which effectively reduces the equipment cost.

[0062] The oil storage tank 7 is connected to the lubricating oil circuit system of the compressor unit through the oil storage pipe 701; the low-pressure lubricating oil obtained after oil separation treatment by the low-pressure oil separator tank 8 and the liquid separator tank 9 enters the oil storage pipe 701 and returns to the oil circuit system of the compressor unit; the high-pressure lubricating oil obtained after oil separation treatment by the high-pressure oil separator tank 6 enters the oil storage tank 7.

[0063] The low-temperature and low-pressure gaseous carbon dioxide is heat-exchanged with the high-temperature and high-pressure liquid carbon dioxide coming out of the super carbon dioxide cooler, and the gaseous carbon dioxide is heated; the heated gaseous carbon dioxide enters the low-pressure oil separator 8, which stores the gaseous carbon dioxide and plays a role in gas-oil separation; the separated gaseous carbon dioxide enters the compressor unit and is compressed into high-temperature and high-pressure transcritical carbon dioxide; the high-temperature and high-pressure transcritical carbon dioxide enters the high-pressure oil separator 6, and oil-liquid separation is performed inside the high-pressure oil separator 6; the separated high-temperature and high-pressure transcritical carbon dioxide is flash-dried and converted into liquid carbon dioxide, which is further cooled by a closed cooling tower and a cooler to become liquid carbon dioxide (higher temperature and pressure); the (higher temperature and pressure) liquid carbon dioxide enters the heat exchanger group and exchanges heat with the low-temperature and low-pressure gaseous carbon dioxide to reduce temperature and pressure; the cooled and reduced-pressure liquid carbon dioxide enters the pressure reducer 10, and is output after further cooling and pressure reduction.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0065] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A combined cooling and heating device based on transcritical carbon dioxide, comprising a base (1), a refrigeration equipment end, a heating equipment end, a low-pressure air inlet (18) and a CO2 medium, characterized in that: A compressor unit, a heat exchanger unit (11), a pressure reducer (10), an oil storage tank (7), a low-pressure oil separation tank (8), a high-pressure oil separation tank (6) and a liquid separation tank (9) are arranged on the base (1); the oil storage tank (7) is connected to the lubricating oil circuit system of the compressor unit through an oil storage pipe (701); The gaseous CO2 medium at the outlet of the refrigeration equipment is connected to the heat exchanger group (11) through the low-pressure air inlet (18) and the first low-pressure pipeline (1801). After heat exchange in the heat exchanger group (11), the gaseous CO2 medium enters the low-pressure oil separation tank (8) through the first heat exchange pipeline; The outlet of the low-pressure oil tank (8) is connected to the inlet of the compressor unit through a second low-pressure pipeline (801); The compressor unit is connected to the inlet of the high-pressure oil separator tank (6) through the compressor outlet pipe (201), and the outlet of the high-pressure oil separator tank (6) is a transcritical CO2 outlet (16); The transcritical CO2 outlet (16) is connected to the heating equipment end, and the heating equipment end is connected to the heat exchanger group (11) through the high-pressure liquid inlet pipe (15) and the second heat exchange pipe (1501), and then connected to the pressure reducer (10); the pressure reducer (10) is connected to the liquid separation tank (9) through the liquid inlet pipe (1001); The outlet of the liquid separation tank (9) is a liquid separation outlet (17), which is connected to the inlet of the refrigeration equipment through the liquid separation outlet (17) and the third low-pressure pipeline (1701).

2. The transcritical carbon dioxide-based combined cooling and heating device according to claim 1, characterized in that: The base (1) also includes a container body, and the base (1) is fixed inside the container body; a power distribution cabinet (3) is also fixed on the base (1).

3. The combined cooling and heating device based on transcritical carbon dioxide according to claim 1, characterized in that: The compressor group comprises a first group of compressors (2A) and a second group of compressors (2B); the first group of compressors (2A) is an array of several compressors consisting of series-connected transcritical carbon dioxide compressors; the second group of compressors (2B) is an array of several compressors consisting of series-connected transcritical carbon dioxide compressors.

4. The combined cooling and heating device based on transcritical carbon dioxide according to claim 1, characterized in that: The first low-pressure pipeline is also provided with an electric valve (12); and the compressor outlet pipe (201) is provided with a manual valve (5).

5. The combined cooling and heating device based on transcritical carbon dioxide according to claim 1, characterized in that: The heating equipment end includes a flash dryer or a flash water condenser, and the high-temperature and high-pressure transcritical CO2 outputs heat energy through the heating equipment end to form sub-high-temperature and high-pressure liquid CO2.

6. The combined cooling and heating device based on transcritical carbon dioxide according to claim 1, characterized in that: The top of the liquid separation tank (9) is also provided with an air outlet, and the air outlet is connected to the first low-pressure pipeline (1801) through an air outlet pipeline (901).

7. The combined cooling and heating device based on transcritical carbon dioxide according to claim 6, characterized in that: The liquid inlet pipe (1001), the first low-pressure pipeline (1801), the second low-pressure pipeline (801), the third low-pressure pipeline (1701), the first heat exchange pipeline and the second heat exchange pipeline (1501) are all provided with a pressure sensor (14) and a temperature sensor (13).

8. The combined cooling and heating device based on transcritical carbon dioxide according to claim 1, characterized in that: The refrigeration equipment end includes an air cooler, which is a carbon dioxide heat exchanger; the pressure reducer group is a capillary pressure reducer; and the heat exchanger group is a plate exchanger.

9. A combined cooling and heating system based on transcritical carbon dioxide according to any one of claims 1 to 8, characterized in that: The gaseous CO2 medium at the outlet of the refrigeration equipment end is output to the heat exchanger group (11), enters the low-pressure oil separator tank (8) after heat exchange, and then enters the compressor group. The obtained gaseous CO2 is converted into high-temperature and high-pressure transcritical CO2 by the compressor group. The high-temperature and high-pressure transcritical CO2 passes through the high-pressure oil separator tank (6) and enters the heating equipment end. The sub-high temperature and high pressure liquid CO2 outputted from the heating device end is outputted to the heat exchanger group (11) for heat exchange, and the liquid CO2 after heat exchange with reduced temperature and pressure enters a pressure reducer (10) for decompression to form low temperature and low pressure liquid CO2, and the low temperature and low pressure liquid CO2 passes through the liquid separator (9) and then enters the refrigeration device end; The gaseous CO2 in the system is converted into liquid CO2 in a cycle between the refrigeration equipment end and the heating equipment end.

10. The combined cooling and heating system based on transcritical carbon dioxide according to claim 9, characterized in that: The low-pressure lubricating oil obtained after oil separation in the low-pressure oil separator tank (8) and the liquid separator tank (9) enters the oil storage pipe (701) and returns to the oil circuit system of the compressor unit; the high-pressure lubricating oil obtained after oil separation in the high-pressure oil separator tank (6) enters the oil storage tank (7).

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