1. A carbon dioxide internal heat exchanger is characterized by comprising a shell, a heat insulation pipe (1041), a cylinder (105), a first pipeline (106), a second pipeline (107), a gas-liquid separation assembly, an oil return assembly and the like.

The housing is provided with an outlet (117), a low pressure inlet (1021), a high pressure outlet (1022), a high pressure inlet (1031) and a low pressure outlet (1032).

The heat insulation pipe (1041) is positioned in the shell;

the cylinder (105) is positioned in the heat insulation pipe (1041), the top end of the cylinder (105) is connected with the shell, and the bottom of the cylinder (105) is provided with an oil storage chamber (1052).

The first pipeline (106) is positioned in the cylinder body (105), the top end of the first pipeline (106) is connected with the low-pressure inlet (1021), and the bottom end of the first pipeline (106) is positioned at the upper half part of the cylinder body (105).

The second pipeline (107) is wound on the surface of the cylinder body (105), and two ends of the second pipeline (107) are respectively connected with the high-pressure outlet (1022) and the high-pressure inlet (1031).

The gas-liquid separation assembly is positioned in the cylinder body (105) and comprises a gas inlet pipe (1081) and a gas outlet pipe (1082), and the top of the gas outlet pipe (1082) is connected with an outlet (117) of the upper end cover (102) through a joint (1083); the gas-liquid separation assembly is positioned above the oil return assembly.

The oil return assembly comprises an oil return groove (1091), and the oil return groove (1091) is provided with an oil return hole (111).

2. The carbon dioxide internal heat exchanger as recited in claim 1, wherein the housing comprises an outer tube (101), an upper end cap (102) and a lower end cap (103); the top of the outer pipe (101) is fixedly connected with an upper end cover (102), and the bottom of the outer pipe (101) is fixedly connected with a lower end cover (103); the upper end cover (102) is provided with an outlet (117), a low-pressure inlet (1021) and a high-pressure outlet (1022), and the lower end cover (103) is provided with a high-pressure inlet (1031) and a low-pressure outlet (1032); the top end of the cylinder body (105) is connected with the upper end cover (102); the heat insulation pipe (1041) is arranged in the outer pipe (101), and the heat insulation pipe (1041) is connected with the upper end cover (102) and the lower end cover (103) through grooves respectively.

3. The carbon dioxide internal heat exchanger according to claim 2, wherein the oil return hole (111) has a diameter of 0.3 to 0.6 mm; the distance between the oil return hole (111) and the bottom of the oil storage chamber (1052) is not more than 2 mm; the top of the air inlet pipe (1081) is located 10-15mm below the upper end cover (102); a gap (115) of 2-4mm is arranged between the heat insulation pipe (1041) and the outer pipe (101).

4. The carbon dioxide internal heat exchanger as recited in claim 1, wherein the cylindrical surface of the outer contour of the cylinder (105) is provided with a spiral groove (1051), and the second pipe (107) is wound in the spiral groove (1051).

5. The carbon dioxide internal heat exchanger as recited in claim 1, further comprising a filter (112), wherein the filter (112) is located at a lower portion of the housing, and a bottom end of the filter (112) is connected to a lower end of the housing.

6. The carbon dioxide internal heat exchanger as recited in claim 1, further comprising a bracket (110), the gas-liquid separation module being fixed inside the cylinder (105) by the bracket (110); the gas-liquid separation assembly also comprises a joint (1083), and the top of the gas outlet pipe (1082) is connected with the outlet (117) through the joint (1083); the oil return assembly also comprises an oil return groove cover (1092); a gap (115) is arranged between the heat insulation pipe (1041) and the outer pipe (101) and used as a buffer area for storing fluid, and the fluid in the buffer area does not flow; the upper part of the heat insulation pipe (1041) is provided with a sealing groove (1042) and a sealing element (113), and the sealing element (113) is embedded into the sealing groove (1042) to realize sealing.

7. The carbon dioxide internal heat exchanger as recited in claim 1, wherein the second pipe (107) has a certain distance between adjacent spiral pipes and forms a spiral passage (116) with the heat insulating pipe (1041) and the cylindrical body (105), and the second pipe (107) and the spiral passage (116) form a double spiral fluid region inside and outside, and the central axes of the two coincide.

8. The carbon dioxide internal heat exchanger as recited in claim 7, wherein the size of the spiral passage (116) is changed by adjusting the size of the second pipe (107) and the spiral groove (1051) to adjust the heat exchange efficiency of the inner and outer fluid domains.

9. A carbon dioxide heat pump cycle system comprising the carbon dioxide internal heat exchanger according to any one of claims 1 to 8.

10. The carbon dioxide heat pump cycle system according to claim 9, further comprising an expansion valve (2), an evaporator (3), a compressor (4), and a gas cooler (5); along the flow path of the gas, the low pressure outlet (1032), the compressor (4), the gas cooler (5) and the high pressure inlet (1031) are connected in sequence, and the high pressure outlet (1022), the expansion valve (2), the evaporator (3) and the low pressure inlet (1021) are connected in sequence.

Background

The global temperature rising trend is obviously increased in recent decades, and the automobile emission and the leakage of air-conditioning refrigerant play a role in promoting global warming.

With the global acceleration of the development of new energy vehicles, the problem of refrigerant leakage is urgently solved. At present, the refrigerant of the vehicle air conditioner is generally R134a, but the unique molecular structure of the refrigerant can cause the greenhouse effect to be intensified. Thus, CO₂And enters the sight of cooling researchers in various countries as alternative cooling.

However, the carbon dioxide used as an air conditioning system has the defects of low refrigeration efficiency, insufficient gas-liquid separation and difficult realization of oil return, thereby greatly influencing the application of the carbon dioxide heat pump air conditioner on vehicles.

Disclosure of Invention

The invention aims to provide a carbon dioxide internal heat exchanger and a carbon dioxide heat pump circulating system aiming at the defects of the prior art.

The purpose of the invention is realized by the following technical scheme: a carbon dioxide internal heat exchanger comprises a shell, a heat insulation pipe 1041, a cylinder 105, a first pipeline 106, a second pipeline 107, a gas-liquid separation assembly and an oil return assembly;

the housing is provided with an outlet 117, a low pressure inlet 1021, a high pressure outlet 1022, a high pressure inlet 1031 and a low pressure outlet 1032;

an insulating tube 1041 is located within the housing;

the cylinder 105 is positioned in the heat insulation pipe 1041, the top end of the cylinder 105 is connected with the shell, and the bottom of the cylinder 105 is provided with an oil storage chamber 1052;

the first pipeline 106 is positioned in the cylinder 105, the top end of the first pipeline 106 is connected with the low-pressure inlet 1021, and the bottom end of the first pipeline 106 is positioned at the upper half part of the cylinder 105;

the second pipeline 107 is wound on the surface of the cylinder body 105, and two ends of the second pipeline 107 are respectively connected with the high-pressure outlet 1022 and the high-pressure inlet 1031;

the gas-liquid separation assembly is positioned in the cylinder body 105 and comprises a gas inlet pipe 1081 and a gas outlet pipe 1082, and the top of the gas outlet pipe 1082 is connected with the outlet 117 of the upper end cover 102 through a connector 1083; the gas-liquid separation assembly is positioned above the oil return assembly;

the oil return component comprises an oil return groove 1091, and the oil return groove 1091 is provided with an oil return hole 111.

Further, the housing includes an outer tube 101, an upper end cap 102, and a lower end cap 103; the top of the outer tube 101 is fixedly connected with an upper end cover 102, and the bottom of the outer tube 101 is fixedly connected with a lower end cover 103; the upper end cover 102 is provided with an outlet 117, a low-pressure inlet 1021 and a high-pressure outlet 1022, and the lower end cover 103 is provided with a high-pressure inlet 1031 and a low-pressure outlet 1032; the top end of the cylinder 105 is connected with the upper end cover 102; the heat insulating pipe 1041 is provided in the outer pipe 101, and the heat insulating pipe 1041 is connected to the upper end cap 102 and the lower end cap 103 via grooves, respectively.

Furthermore, the diameter of the oil return hole 111 is 0.3-0.6 mm; the distance between the oil return hole 111 and the bottom of the oil storage chamber 1052 is not more than 2 mm; the top of the air inlet pipe 1081 is located 10-15mm below the upper end cover 102; a gap 115 of 2-4mm is formed between the insulating tube 1041 and the outer tube 101.

Further, a spiral groove 1051 is arranged on the outer contour cylindrical surface of the cylinder 105, and the second pipeline 107 is wound in the spiral groove 1051.

Further, a filter 112 is also included, the filter 112 is located at the lower part of the casing, and the bottom end of the filter 112 is connected with the lower end of the casing.

Further, the gas-liquid separation device also comprises a bracket 110, and the gas-liquid separation assembly is fixed inside the cylinder 105 through the bracket 110; the gas-liquid separation assembly further comprises a connector 1083, and the top of the gas outlet pipe 1082 is connected with the outlet 117 through the connector 1083; the oil return assembly further comprises an oil return groove cover 1092; a gap 115 is formed between the heat insulation pipe 1041 and the outer pipe 101, and the gap serves as a buffer region for storing fluid, and the fluid does not flow; the upper part of the heat insulation pipe 1041 is provided with a sealing groove 1042 and a sealing member 113, and the sealing member 113 is embedded into the sealing groove 1042 to realize sealing.

Further, the adjacent spiral pipes of the second pipe 107 have a certain distance therebetween, and form a spiral passage 116 with the heat insulating pipe 1041 and the cylindrical body 105, and the second pipe 107 and the spiral passage 116 form a double spiral fluid region inside and outside, and the central axes of the two overlap.

Further, the size of the spiral passage 116 is changed by adjusting the size of the second pipe 107 and the spiral groove 1051 to adjust the heat exchange efficiency of the inner and outer fluid domains.

A carbon dioxide heat pump circulating system comprises the carbon dioxide internal heat exchanger.

Further, an expansion valve 2, an evaporator 3, a compressor 4 and a gas cooler 5 are included; along the flow path of the gas, the low pressure outlet 1032, the compressor 4, and the gas cooler 5 are connected in sequence to the high pressure inlet 1031, and the high pressure outlet 1022, the expansion valve 2, the evaporator 3, and the low pressure inlet 1021 are connected in sequence.

The invention has the beneficial effects that: the carbon dioxide internal heat exchanger disclosed by the invention is designed through a space structure, and on the premise of not increasing internal flow resistance, the internal space of the carbon dioxide internal heat exchanger is fully utilized, so that the heat exchange between high-temperature high-pressure fluid and low-temperature low-pressure fluid can be realized, and the refrigeration performance in a system is further improved. Meanwhile, the functions of gas-liquid separation, oil return and the like can be realized through the structure optimization design. The invention can reduce the energy consumption of the carbon dioxide heat pump air-conditioning system in refrigeration or heating, further increase the cruising mileage of the vehicle, and can not cause adverse effect on the environment, damage the ozone layer and greenhouse effect. The carbon dioxide heat pump air conditioner refrigeration cycle system has high heat exchange efficiency and good refrigeration performance.

Drawings

FIG. 1 is a schematic view of one embodiment of a carbon dioxide heat pump cycle system according to the present invention;

FIG. 2 is a schematic external view of a carbon dioxide internal heat exchanger according to the present invention;

FIG. 3 is a schematic cross-sectional view of an embodiment of the carbon dioxide internal heat exchanger according to the present invention;

FIG. 4 is a schematic cross-sectional view of a carbon dioxide internal heat exchanger according to the present invention;

FIG. 5 is a schematic 3D external view of the inner and outer double helical fluid domains of the carbon dioxide internal heat exchanger of the present invention;

FIG. 6 is a schematic 3D cross-sectional view of the inner and outer double helical fluid domains of the carbon dioxide internal heat exchanger according to the present invention;

FIG. 7 is an enlarged view of a portion of FIG. 3 at A;

FIG. 8 is a schematic view of a gas-liquid separation assembly and an oil return assembly of the carbon dioxide internal heat exchanger according to the present invention;

in the figure, the carbon dioxide internal heat exchanger 1, the expansion valve 2, the evaporator 3, the compressor 4, the gas cooler 5, the outer tube 101, the upper end cover 102, the lower end cover 103, the cylinder 105, the first pipe 106, the second pipe 107, the bracket 110, the oil return hole 111, the filter 112, the seal 113, the gap 115, the spiral passage 116, the outlet 117, the low pressure inlet 1021, the high pressure outlet 1022, the high pressure inlet 1031, the low pressure outlet 1032, the heat insulating pipe 1041, the seal groove 1042, the spiral groove 1051, the oil storage chamber 1052, the internal spiral fluid region 107A, the external spiral fluid region 116A, the air inlet pipe 1081, the air outlet pipe 1082, the joint 1083, the oil return groove 1091, and the oil return groove cover 1092.

Detailed Description

The invention will be further explained and illustrated with reference to the drawings and the specific examples in the following description, which, however, do not limit the technical solution of the invention.

As shown in fig. 1, a carbon dioxide heat pump cycle system according to the present invention includes a carbon dioxide internal heat exchanger 1, an expansion valve 2, an evaporator 3, a compressor 4, and a gas cooler 5. In the present embodiment, when the carbon dioxide heat pump cycle system operates, firstly, high-temperature and high-pressure gas from the compressor 4 is cooled by the gas cooler 5, enters the carbon dioxide internal heat exchanger 1, is subjected to heat exchange in the carbon dioxide internal heat exchanger 1 and then flows out, is throttled by the expansion valve 2, enters the evaporator 3 to be evaporated to form a low-temperature and low-pressure gas-liquid mixture, enters the carbon dioxide internal heat exchanger 1 to be subjected to heat exchange with the high-temperature and high-pressure gas, and is subjected to gas-liquid separation in the carbon dioxide internal heat exchanger 1, the separated liquid is stored in the carbon dioxide internal heat exchanger 1, and the gas flows into the compressor 4 to be compressed into high-temperature and high-pressure gas for recycling.

The heat exchange and gas-liquid separation in the carbon dioxide internal heat exchanger 1 will be further described with reference to fig. 2 and 3.

As shown in fig. 2 and 3, in the present embodiment, the carbon dioxide internal heat exchanger 1 includes a housing, and the housing includes an outer tube 101, an upper end cap 102, and a lower end cap 103. The top of the outer tube 101 is fixedly connected with the upper end cap 102, and the bottom of the outer tube 101 is fixedly connected with the lower end cap 103. The upper end cover 102 is provided with an outlet 117, a low-pressure inlet 1021 and a high-pressure outlet 1022; the lower end cover 103 has a high pressure inlet 1031 and a low pressure outlet 1032.

The low pressure import 1021 is the gas-liquid mixture import, and in the carbon dioxide internal heat exchanger 1 was flowed into from low pressure import 1021 to the gas-liquid mixture, the high pressure export 1022 was the export of low temperature low pressure gas, and high temperature high pressure gas becomes low temperature low pressure gas after the heat exchange and flows out from high pressure export 1022. Further, the high pressure inlet 1031 is a high temperature and high pressure gas inlet, the high temperature and high pressure gas flows into the carbon dioxide internal heat exchanger 1 from the high pressure inlet 1031 for heat exchange, the low pressure outlet 1032 is a low temperature and low pressure gas outlet, and the low temperature and low pressure gas-liquid mixture flows out from the low pressure outlet 1032 as a low temperature and low pressure gas obtained by gas-liquid separation by the carbon dioxide internal heat exchanger 1. As can be seen from fig. 1 and 3, along the flow path of the fluid, the high pressure outlet 1022, the expansion valve 2, the evaporator 3, and the low pressure inlet 1021 are connected in sequence, and the low pressure outlet 1032, the compressor 4, the gas cooler 5, and the high pressure inlet 1031 are connected in sequence.

The carbon dioxide internal heat exchanger 1 further includes an insulating pipe 1041, a cylinder 105, a first pipe 106, and a second pipe 107. The heat insulation pipe 1041 is arranged in the outer pipe 101, and the heat insulation pipe 1041 is connected with the upper end cover 102 and the lower end cover 103 through grooves respectively; specifically, the upper and lower ends of the heat insulation pipe 1041 are embedded into the grooves on the upper end cover 102 and the lower end cover 103; the cylinder 105 is arranged in the heat insulation pipe 1041, and the top end of the cylinder 105 is connected with the upper end cover 102; the first pipe 106 is disposed in the cylinder 105, a top end of the first pipe 106 is connected to the low pressure inlet 1021, and a bottom end of the first pipe 106 is located at an upper half portion (about 1/6 of the cylinder 105) of the cylinder 105. A sealing groove 1042 and a sealing element 113 (sealing ring) are arranged at the upper part of the heat insulation pipe 1041; the sealing member 113 is inserted into the sealing groove 1042 and is tightly contacted with the inner surface of the outer pipe 101 to realize sealing.

As shown in FIG. 4, the cylindrical surface of the outer contour of the cylinder 105 is provided with a spiral groove 1051, and the bottom is provided with an oil storage chamber 1052. The cylinder 105 is also internally provided with a gas-liquid separation assembly, an oil return assembly and a support 110.

As shown in fig. 8, the gas-liquid separation assembly includes three gas inlet pipes 1081, gas outlet pipes 1082 and a joint 1083, and the oil return assembly includes an oil return groove 1091 and an oil return groove cover 1092. The air inlet pipe 1081 and the air outlet pipe 1082 are mounted on the upper portion of the oil return groove 1091, the top of the air inlet pipe 1081 is located 10-15mm below the upper end cover 102, the top of the air outlet pipe 1082 is connected with the outlet 117 of the upper end cover 102 through a connector 1083, and the air inlet pipe 1081 and the air outlet pipe 1082 are fixed inside the barrel 105 through a support 110. The second pipeline 107 is arranged in the heat insulation pipe 1041 and spirally wound on the spiral groove 1051 of the cylinder 105, and a certain distance is reserved between adjacent spiral pipes of the second pipeline 107, so that a spiral passage 116 is formed outside the second pipeline 107; the two ends of the second pipeline 107 are respectively connected with the high pressure outlet 1022 and the high pressure inlet 1031.

In the present embodiment, the low-temperature and low-pressure gas-liquid mixture enters the carbon dioxide internal heat exchanger 1 through the low-pressure inlet 1021, and then fills the entire cylinder 105, and due to gravity, the gaseous carbon dioxide flows into the top inlet pipe 1081, and the liquid carbon dioxide and the freezing oil mixture are stored in the oil storage chamber 1052 at the bottom. The gaseous carbon dioxide flowing through the inlet pipe 1081 from the top down is collected at the bottom and flows from the outlet pipe 1082 to the top, then flows from the outlet 117 of the upper end cover 102 to the spiral passage 116, is sufficiently contacted with the second pipe 107 in the spiral passage 116 and exchanges heat, and finally flows from the low pressure outlet 1032 to the compressor 4. The high-temperature and high-pressure gas enters the second pipe 107 from the high-pressure inlet 1031 at the bottom of the lower end cover 103, exchanges heat with the low-temperature and low-pressure gas in the spiral passage 116 along the second pipe 107, and then flows out from the high-pressure outlet 1022. It should be noted that, considering that there is a contamination of the foreign substances, in the present embodiment, the lower portion of the housing is provided with a filter 112 near the low pressure outlet 1032 to filter the foreign substances; the bottom end of the filter 112 is connected to the lower end cap 103.

As shown in fig. 5 and 6, the inner fluid region 107A is formed inside the second pipe 107, the spiral passage 116 outside the second pipe 107 is formed as an outer fluid region 116A, and the central axes of the inner fluid region 107A and the outer fluid region 116A overlap to form an inner and outer double-spiral fluid region. The fluid in the inner fluid area 107A flows along the second pipeline 107 from bottom to top in a spiral manner, the fluid in the outer fluid area 116A flows along the spiral passage 116 from top to bottom in a spiral manner, and the fluids in the inner and outer double-spiral fluid areas are subjected to sufficient heat exchange through the second pipeline 107. The spiral groove 1051 on the cylinder 105 ensures that the flow area of a fluid domain formed after the second pipeline 107 is installed is uniform, and the increase of flow resistance caused by installation is avoided; the size of the helical passage 116 may be varied by adjusting the size of the helical groove 1051 to adjust the heat exchange efficiency of the inner and outer fluid zones.

A 2-4mm gap 115 is formed between the heat insulation pipe 1041 and the outer pipe 101, so that heat exchange between internal fluid and the external environment is reduced, and the heat exchange efficiency is improved; meanwhile, the gap 115 stores a certain fluid as a buffer region where the fluid does not flow, thereby also functioning to reduce heat exchange between the internal fluid and the external environment.

As shown in fig. 7, the bottom of the oil return groove 1091 of the oil return assembly is provided with a plurality of oil return holes 111, and the oil return holes 111 are used for connecting with the compressor 4 and collecting oil return. And in the present embodiment, the oil return hole 111 is provided at an upper portion of the filter 112. The diameter of the oil return hole 111 is 0.3-0.6mm, and the distance between the oil return hole 111 and the bottom of the oil storage chamber 1052 is not more than 2 mm. The refrigerant oil flows into the oil return groove 1091 through the oil return hole 111, and the carbon dioxide gas takes away a proper amount of the refrigerant oil when flowing through the oil return groove 1091, so that an oil return function is realized.

It should be noted that the carbon dioxide heat pump cycle system of the present invention can be applied to a new energy vehicle, and the carbon dioxide internal heat exchanger 1 of the present invention can be used alone for a new energy vehicle.

In summary, the carbon dioxide internal heat exchanger provided by the invention is designed by a space structure, and on the premise of not increasing internal flow resistance, the internal space of the carbon dioxide internal heat exchanger is fully utilized, so that heat exchange between a high-temperature high-pressure substance and a low-temperature low-pressure substance can be realized, and further, the refrigeration performance in a system is improved. Meanwhile, the functions of gas-liquid separation, oil return and the like can be realized through the structure optimization design. In addition, the carbon dioxide heat pump circulating system also has the characteristics and the beneficial effects. Meanwhile, the new energy vehicle also has the characteristics and the beneficial effects.

It should be noted that the prior art in the protection scope of the present invention is not limited to the examples given by the present invention, and all the prior art which is not contradictory to the scheme of the present invention, including but not limited to the prior patent documents, the prior publications, and the like, can be included in the protection scope of the present invention.

In addition, the combination of the features of the present invention is not limited to the combination described in the claims of the present invention or the combination described in the embodiments, and all the features described in the present invention may be freely combined or combined in any manner unless contradictory to each other.

It should also be noted that the above-mentioned embodiments are only specific embodiments of the present invention. It is apparent that the present invention is not limited to the above embodiments and similar changes or modifications can be easily made by those skilled in the art from the disclosure of the present invention and shall fall within the scope of the present invention.