Gas-liquid separator and method for determining taper angle of spiral pipe of gas-liquid separator

Abstract

The invention discloses a gas-liquid separator and a method for determining the taper angle of a spiral pipe of the gas-liquid separator. The gas-liquid separator comprises a shell, a heat insulation barrel, a low-pressure pipeline, a high-pressure pipeline and an overheating gas return pipeline; the heat insulation cylinder divides a shell cavity of the shell into an inner cavity and an outer cavity, the heat insulation cylinder is in a big-end-up conical shape, and a lower port of the heat insulation cylinder communicates with the outer cavity; the low-pressure pipeline comprises a low-pressure inlet section, a low-pressure pipe section and a low-pressure outlet section which are connected in sequence, the low-pressure inlet section penetrates out of the top of the shell, the low-pressure pipe section is of a conical spiral structure and is located in the heat insulation barrel, and the low-pressure outlet section penetrates out of the bottom of the shell; the low-pressure pipe section is provided with a liquid discharge hole; the inlet end of the overheating air return pipeline is located above the shell cavity, the outlet end of the overheating air return pipeline communicates with the low-pressure outlet section, and a control valve with the adjustable opening degree is arranged on the overheating air return pipeline. At least part of the high-pressure pipeline is located in the outer cavity and used for conducting heat exchange with the saturated gaseous refrigerant in the shell. By optimizing the structure of the gas-liquid separator, the superheat degree can be effectively adjusted.

Description

Technical Field

[0001] The present application relates to the field of thermal management technology, and in particular to a gas-liquid separator and a method for determining the taper angle of a spiral tube thereof. Background Art

[0002] In refrigeration and air-conditioning systems, the gaseous refrigerant entering the compressor is mostly a refrigerant with a certain degree of superheat. How to effectively adjust the superheat of the gaseous refrigerant entering the compressor is a problem that technicians in this field have been thinking about. Summary of the invention

[0003] The purpose of the present application is to provide a method for determining the taper angle of a gas-liquid separator and its spiral tube. By optimizing the structure of the gas-liquid separator, the distribution of the low-pressure gas inside the gas-liquid separator can be effectively controlled, thereby providing a basis for achieving the effectiveness of superheat regulation and further optimizing system performance.

[0004] In order to solve the above technical problems, the present application provides a gas-liquid separator, comprising a shell, a heat-insulating cylinder, a low-pressure pipeline, a high-pressure pipeline and an overheated return air pipeline;

[0005] The heat-insulating tube divides the shell cavity of the outer shell into an inner cavity and an outer cavity, the outer cavity surrounds the inner cavity, the heat-insulating tube is in a conical shape with a larger top and a smaller bottom, and a lower end of the heat-insulating tube is provided with a lower port; a vent hole is provided on the top of the heat-insulating tube, the upper ends of the inner cavity and the outer cavity are connected through the vent hole, and the lower ends of the inner cavity and the outer cavity are connected through the lower end of the heat-insulating tube;

[0006] The low-pressure pipeline comprises a low-pressure inlet section, a low-pressure pipe section and a low-pressure outlet section connected in sequence, the low-pressure inlet section is connected to an external pipeline, the low-pressure pipe section extends downward along a conical spiral and is located in the heat-insulating cylinder, and the low-pressure outlet section is connected to an external pipeline; the low-pressure pipe section has a drainage hole;

[0007] The inlet end of the superheated air return pipeline is located above the shell cavity, and the outlet end is connected to the low-pressure outlet section. The superheated air return pipeline is provided with a control valve with adjustable opening;

[0008] At least a portion of the high-pressure pipeline is located in the outer cavity for heat exchange with the refrigerant in the outer shell.

[0009] The gas-liquid separator is provided with a high-pressure pipeline and an overheated return gas pipeline, at least part of the high-pressure pipeline is located in the outer cavity, and saturated gaseous refrigerant will escape from the liquid refrigerant gathered in the outer cavity after gas-liquid separation in the low-pressure pipeline, and this part of the saturated gaseous refrigerant can exchange heat with at least part of the high-pressure pipeline arranged in the outer cavity to form an overheated gaseous refrigerant, and these overheated gaseous refrigerants rise in the shell cavity of the shell, gather above the shell cavity and can flow to the low-pressure outlet section through the overheated return gas pipeline to be discharged from the gas-liquid separator, and a control valve is provided on the overheated return gas pipeline, and the overheat of the gaseous refrigerant discharged through the low-pressure outlet section can be adjusted by adjusting the control valve. It can be seen that the structural setting of the gas-liquid separator can effectively realize the superheat adjustment of the discharged gaseous refrigerant, providing a basis for optimizing system performance.

[0010] In one feasible manner, the high-pressure pipeline includes a high-pressure inlet section, a high-pressure outlet section and a high-pressure pipe body, the high-pressure inlet section and the high-pressure outlet section are both connected to an external pipeline, and the high-pressure pipe body is connected between the high-pressure inlet section and the high-pressure outlet section; the high-pressure pipe body includes a first high-pressure pipe portion located in the outer cavity, and the first high-pressure pipe portion is arranged around the insulation tube.

[0011] In one achievable manner, the high-pressure pipe body further includes a second high-pressure pipe portion located in the inner cavity, the second high-pressure pipe portion extends downward along a conical spiral and is sheathed on the low-pressure pipe section.

[0012] In one achievable manner, the first high-pressure pipe portion extends downwardly along a conical spiral.

[0013] In one achievable manner, the first high-pressure pipe portion and the second high-pressure pipe portion are formed on a conical spiral tube, and the conical spiral tube includes a portion located outside the thermal insulation tube and a portion located inside the thermal insulation tube. The portion of the conical spiral tube located outside the thermal insulation tube forms the first high-pressure pipe portion, and the portion of the conical spiral tube located inside the thermal insulation tube forms the second high-pressure pipe portion.

[0014] In one achievable manner, the first high-pressure pipe section and the second high-pressure pipe section are respectively formed by two spiral high-pressure pipe sections, the high-pressure pipe section on the outside of the insulation tube spirally forms the first high-pressure pipe section, and the high-pressure pipe section on the inside of the insulation tube spirally forms the second high-pressure pipe section.

[0015] In one achievable manner, the first high-pressure pipe portion is a planar spiral structure.

[0016] In one achievable manner, the high-pressure tube body further includes a third high-pressure tube portion located in the outer cavity, and the third high-pressure tube portion is disposed at the bottom of the shell cavity of the outer shell.

[0017] In one achievable method, the outer shell includes a cylindrical shell peripheral wall, a shell bottom wall and a shell top wall, the opening aperture at the top end of the insulation cylinder is consistent with the aperture of the shell peripheral wall; the inlet end of the superheated return air pipeline is located in the insulation cylinder.

[0018] The present application also provides a method for determining the taper angle of a spiral tube of a gas-liquid separator, wherein the gas-liquid separator is any of the gas-liquid separators described above, the taper angle of the spiral tube is the taper angle α of the low-pressure pipe section, and the taper angle α of the low-pressure pipe section has a set value range. Within the value range, the comprehensive performance coefficient U of the low-pressure pipe section is selected. * The taper angle corresponding to the maximum value of is the optimal taper angle actually set for the low-pressure pipe section;

[0019] The comprehensive performance coefficient U of the low-pressure pipe section * Determined by the following formula:

[0020]

[0021] in, is the specific gravity coefficient of the low-pressure pipe section, f * is the equivalent dimensionless friction coefficient of the low-pressure pipe section, a * is the equivalent dimensionless centrifugal force of the low-pressure pipe section, A * is the dimensionless lateral area of ​​the thermal insulation cylinder; and They are respectively the equivalent dimensionless centrifugal force of the low-pressure pipe section, the equivalent dimensionless friction coefficient and the dimensionless lateral area of ​​the insulation cylinder at the reference taper angle.

[0022] The determination method is used to determine the taper angle of the low-pressure pipe section of the aforementioned gas-liquid separator. The determination of the taper angle can enable the gas-liquid separator to have a relatively better gas-liquid separation effect.

[0023] In one achievable manner, the equivalent dimensionless centrifugal force a of the low-pressure pipe section is * Determined by the following formula:

[0024] a * =k1•u l 2 / (g·D eq / 2);

[0025] u l =G(1-x) / (ρ l (1-∈));

[0026]

[0027] G=4q / (π·d i2 );

[0028] D eq =2 / (1 / D min +1 / D max ), D min =D max -2·H·tan(α / 2);

[0029] Among them, k1 is the correction coefficient, u l is the velocity of the liquid medium, D eq is the equivalent spiral diameter of the low-pressure pipe section, G is the flow density of the refrigerant, x is the dryness at the inlet of the gas-liquid separator, ρ l is the density of the liquid medium, ∈ is the porosity of the refrigerant, ρ1 is the density of the gas phase medium, σ is the surface tension of the refrigerant, q is the mass flow rate of the refrigerant, and d i is the inner diameter of the low-pressure pipe section, D max is the maximum spiral diameter of the low-pressure pipe section, D min is the minimum spiral diameter of the low-pressure pipe section, and H is the axial height of the low-pressure pipe section.

[0030] In one possible implementation, k1 = 1.125-0.065n, n = H / s,

[0031] n is the equivalent number of spiral turns of the low-pressure pipe section, s is the equivalent spiral pitch of the low-pressure pipe section, L is the pipe length of the low-pressure pipe section,

[0032] In one achievable manner, the equivalent dimensionless friction coefficient f of the low-pressure pipe section is * Determined by the following formula:

[0033]

[0034] Re=ρud i / μ;

[0035] u=G / ρ;

[0036] Where Re is the Reynolds number, ρ is the homogeneous density, μ is the homogeneous viscosity, u is the homogeneous velocity, μ1 is the viscosity of the gas phase medium, and μ l is the viscosity of the liquid medium.

[0037] In one achievable manner, the equivalent dimensionless friction coefficient f * It is determined according to the following formula:

[0038] Where k is a constant.

[0039] In one achievable manner, the dimensionless lateral area A of the thermal insulation cylinder is * Determined by the following formula:

[0040]

[0041]

[0042] D max3 =D max +P,D min3 =D mi< +P;

[0043] Wherein, A1 is the single side area of ​​the insulation cylinder, D max3 is the maximum diameter of the insulation tube, D min3 is the minimum diameter of the insulation tube, P is the preset distance, and H is the axial height of the low-pressure pipe section.

[0044] In one achievable method, the preset distance P is set to 3d i .

[0045] In one achievable manner, the taper angle α of the low-pressure pipe section has a value range of α min ≤α<α max ;

[0046] α min =25°;

[0047] α max =2·arctan(D max / (2·H));

[0048] Among them, D max is the maximum spiral diameter of the low-pressure pipe section, and H is the axial height of the low-pressure pipe section.

[0049] In one achievable manner, when the value of the taper angle α of the low-pressure pipe section corresponding to the equivalent number of spiral turns n of the low-pressure pipe section is greater than a preset value, the value of the taper angle α is excluded; and,

[0050] The taper angle α of the low-pressure pipe section corresponds to an equivalent spiral pitch s of the low-pressure pipe section that is smaller than the inner diameter d of the low-pressure pipe section. i , the value of the taper angle α is also excluded. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a schematic structural diagram of a first embodiment of a gas-liquid separator provided in the present application;

[0052] Figure 2 for Figure 1 A perspective view of the gas-liquid separator shown;

[0053] Figure 3 for Figure 1 The schematic diagram of the structure of the gas-liquid separator shown is shown with the outer shell hidden;

[0054] Figure 4 for Figure 3 Schematic diagram of the structure of the middle heat insulation cylinder and high-pressure pipeline;

[0055] Figure 5 for Figure 3 Structural diagram of medium and low pressure pipelines and superheated air return pipelines;

[0056] Figure 6 for Figure 5 A schematic cross-sectional view of the structure shown;

[0057] Figure 7 This is a schematic structural diagram of a second embodiment of the gas-liquid separator provided in this application;

[0058] Figure 8 for Figure 7 A perspective view of the gas-liquid separator shown;

[0059] Fig. 9 for Figure 7 The schematic diagram of the structure of the gas-liquid separator shown in FIG. 1 is shown with the outer shell hidden;

[0060] Fig.10 for Fig. 9 Schematic diagram of the structure of the middle heat insulation cylinder and high-pressure pipeline;

[0061] Fig.11 for Fig.10 A partial cross-sectional schematic diagram of the structure shown;

[0062] Fig.12 A schematic structural diagram of a third embodiment of the gas-liquid separator provided in this application;

[0063] Fig.13 for Fig.12 A perspective view of the gas-liquid separator shown;

[0064] Fig.14 for Fig.12 The schematic diagram of the structure of the gas-liquid separator shown in FIG. 1 is shown with the outer shell hidden;

[0065] Fig.15 for Fig.14 Schematic diagram of the structure of the middle heat insulation cylinder and high-pressure pipeline;

[0066] Fig.16 This is a schematic structural diagram of a fourth embodiment of the gas-liquid separator provided in the present application;

[0067] Fig.17 for Fig.16A perspective view of the gas-liquid separator shown;

[0068] Fig.18 for Fig.16 The schematic diagram of the structure of the gas-liquid separator shown in FIG. 1 is shown with the outer shell hidden;

[0069] Fig.19 for Fig.18 Schematic diagram of the structure of the middle heat insulation cylinder and high-pressure pipeline;

[0070] Fig. 20 for Fig.19 A partial cross-sectional schematic diagram of the structure shown;

[0071] Fig.21 A schematic structural diagram of a fifth embodiment of the gas-liquid separator provided in the present application;

[0072] Fig. 22 for Fig.21 A perspective view of the gas-liquid separator shown;

[0073] Fig.23 for Fig. 22 The schematic diagram of the structure of the gas-liquid separator shown in FIG. 1 is shown with the outer shell hidden;

[0074] Fig.24 for Fig.23 Schematic diagram of the structure of the middle heat insulation cylinder and high-pressure pipeline;

[0075] Fig.25 This is a simplified model diagram of the internal structure of the shell of the gas-liquid separator provided in this application.

[0076] Description of reference numerals:

[0077] Shell 10, shell peripheral wall 11, shell top wall 12, shell bottom wall 13, inner cavity 101, outer cavity 102;

[0078] Insulation tube 20, vent hole 21;

[0079] Low-pressure pipeline 30, low-pressure inlet section 31, low-pressure pipe section 32, drainage hole 321, low-pressure outlet section 33,

[0080] High-pressure pipeline 40, high-pressure inlet section 41, high-pressure outlet section 42, high-pressure pipe body 43, first high-pressure pipe section 431A, third high-pressure pipe section 433A; first high-pressure pipe section 431B, second high-pressure pipe section 432B, first high-pressure pipe section 431C, second high-pressure pipe section 432C, first high-pressure pipe section 431D, second high-pressure pipe section 432D, first high-pressure pipe section 431E, second high-pressure pipe section 432E, third high-pressure pipe section 433E;

[0081] Superheated air return line 50, control valve 51. DETAILED DESCRIPTION

[0082] The embodiment of the present application provides a gas-liquid separator, which can perform heat exchange on the gaseous refrigerant in the gas-liquid separator and effectively control the distribution of the low-pressure gas through structural optimization, thereby effectively adjusting the superheat of the low-pressure outlet and optimizing the system performance.

[0083] The gas-liquid separator provided in the embodiment of the present application comprises an outer shell, an insulating cylinder, a low-pressure pipeline, a high-pressure pipeline and an overheated return air pipeline; the insulating cylinder divides the shell cavity of the outer shell into an inner cavity and an outer cavity, the outer cavity surrounds the inner cavity, the insulating cylinder is in a conical shape with a larger upper portion and a smaller lower portion, and a lower port is provided at the lower end of the insulating cylinder; a vent is provided at the top of the insulating cylinder, the upper ends of the inner cavity and the outer cavity are connected through the vent, and the lower ends of the inner cavity and the outer cavity are connected through the lower port of the insulating cylinder; the low-pressure pipeline comprises a low-pressure inlet section, a low-pressure pipe section and a low-pressure outlet section connected in sequence, the low-pressure inlet section is connected to an external pipeline, the low-pressure pipe section extends downward along a conical spiral and is located in the insulating cylinder, and the low-pressure outlet section is connected to an external pipeline; the low-pressure pipe section has a drainage hole; the inlet end of the overheated return air pipeline is located above the shell cavity, the outlet end is connected to the low-pressure outlet section, and a control valve with an adjustable opening is provided on the overheated return air pipeline; at least part of the high-pressure pipeline is located in the outer cavity for heat exchange with the refrigerant in the outer shell.

[0084] During use of the gas-liquid separator, the gas-liquid two-phase refrigerant flows in through the low-pressure inlet section of the low-pressure pipeline, and the high-pressure liquid-phase refrigerant can flow in the high-pressure pipeline; after the gas-liquid two-phase refrigerant enters the low-pressure pipeline, the flow state of the gas-liquid two-phase refrigerant is a spiral flow state because the low-pressure pipe section located on the inner side of the insulation cylinder has a conical spiral structure. Under the action of centrifugal force, the liquid refrigerant can be discharged from the drain hole, and the discharged liquid refrigerant can flow downward along the inner wall of the insulation cylinder, and is discharged through the lower port of the insulation cylinder under the action of gravity and gathered in the outer cavity. In this process, the gaseous refrigerant can flow along the low-pressure pipe section to the low-pressure outlet section and be discharged outside the gas-liquid separator, thereby realizing gas-liquid separation.

[0085] The gas-liquid separator is also provided with a high-pressure pipeline, at least part of which is located in the outer cavity. After the gas-liquid separation in the low-pressure pipeline, saturated gaseous refrigerant will escape from the liquid refrigerant gathered in the outer cavity. This part of the saturated gaseous refrigerant can be heat-exchanged with at least part of the high-pressure pipeline arranged in the outer cavity to form an overheated gaseous refrigerant. These overheated gaseous refrigerants rise in the shell cavity of the shell, gather above the shell cavity, and can flow to the low-pressure outlet section through the overheated return gas pipeline to be discharged from the gas-liquid separator. A control valve is provided on the overheated return gas pipeline. By adjusting the control valve, the superheat of the gaseous refrigerant discharged through the low-pressure outlet section can be adjusted. It can be seen that the structural setting of the gas-liquid separator can effectively realize the superheat adjustment of the discharged gaseous refrigerant, providing a basis for optimizing system performance.

[0086] In the above-mentioned gas-liquid separator, there can be a variety of specific implementation methods according to the setting of the high-pressure pipeline. In order to enable personnel in this technical field to better understand the application scheme, the application is further described in detail below in conjunction with the drawings and specific implementation methods.

[0087] Please refer to Figures 1 to 6 , Figure 1 This is a schematic structural diagram of a first embodiment of a gas-liquid separator provided in the present application; Figure 2 for Figure 1 A perspective view of the gas-liquid separator shown; Figure 3 for Figure 1 The schematic diagram of the structure of the gas-liquid separator shown is shown with the outer shell hidden; Figure 4 for Figure 3 Schematic diagram of the structure of the middle heat insulation cylinder and high-pressure pipeline; Figure 5 for Figure 3 Structural diagram of medium and low pressure pipelines and superheated air return pipelines; Figure 6 for Figure 5 Schematic cross-section of the structure shown.

[0088] In this embodiment, the gas-liquid separator includes a shell 10 , a heat-insulating cylinder 20 , a low-pressure pipeline 30 , a high-pressure pipeline 40 and a superheated gas return pipeline 50 .

[0089] In a specific implementation, the housing 10 may include a cylindrical housing peripheral wall 11 , a housing top wall 12 and a housing bottom wall 13 , and the housing top wall 12 and the housing bottom wall 13 respectively block the upper end opening and the lower end opening of the housing peripheral wall 11 .

[0090] In this embodiment, the heat-insulating cylinder 20 is disposed in the shell cavity of the outer shell 10. The heat-insulating cylinder 20 is in a conical shape with a larger upper portion and a smaller lower portion. The heat-insulating cylinder 20 divides the shell cavity of the outer shell 10 into an inner cavity 101 and an outer cavity 102. The outer cavity 102 is disposed around the inner cavity 101. It can be understood that at least part of the inner cavity 101 is the cylinder cavity of the heat-insulating cylinder 20. The upper and lower ends of the heat-insulating cylinder 20 are connected, and the lower end of the heat-insulating cylinder 20 has a lower port, and the lower ends of the inner cavity 101 and the outer cavity 102 can be connected through the lower port of the heat-insulating cylinder 20.

[0091] In this embodiment, the low-pressure pipeline 30 includes a low-pressure inlet section 31, a low-pressure pipe section 32 and a low-pressure outlet section 33 connected in sequence. The low-pressure inlet section 31 is connected to an external pipeline. In a specific implementation, the low-pressure inlet section 31 can pass through the top of the outer shell 10. The low-pressure pipe section 32 is spirally wound in the insulation tube 20 to form a conical spiral structure. Specifically, the low-pressure pipe section 32 extends downward along the conical surface spiral, and the conical surface here is a virtual conical surface. The low-pressure outlet section 33 is connected to an external pipeline. In a specific implementation, the low-pressure outlet section 33 can pass through the bottom of the outer shell 10. It can be understood that the upper end and the lower end of the low-pressure pipe section 32 are respectively connected to the low-pressure inlet section 31 and the low-pressure outlet section 33. One end of the low-pressure inlet section 31 extending out of the shell 10 is conveniently connected to an external pipeline to introduce a gas-liquid two-phase refrigerant. One end of the low-pressure outlet section 33 extending out of the shell 10 is conveniently connected to an external pipeline to discharge the gaseous refrigerant after gas-liquid separation out of the gas-liquid separator.

[0092] The above-mentioned structural form of the low-pressure pipe section 32 is conducive to achieving gas-liquid separation. When the gas-liquid two-phase low-pressure refrigerant flows in the low-pressure pipe section 32, the liquid refrigerant will be thrown to the pipe wall portion of the low-pressure pipe section 32 away from the axial center line of the insulation tube 20 under the action of centrifugal force, and the gaseous refrigerant will gather in the pipe wall portion of the low-pressure pipe section 32 close to the axial center line of the insulation tube 20 and flow along the low-pressure pipe section 32 to the low-pressure outlet section 33. In order to facilitate the timely discharge of the separated liquid refrigerant from the low-pressure pipeline 30, a drainage hole 321 is provided on the low-pressure pipe section 32.

[0093] In one implementation, a plurality of drainage holes 321 may be provided, and the plurality of drainage holes 321 are arranged along the extension direction of the low-pressure pipe section 32, so that the liquid refrigerant thrown onto the wall of the low-pressure pipe section 32 can be discharged in time, which can reduce the secondary entrainment phenomenon and is beneficial to improving the gas-liquid separation efficiency of the gas-liquid separator.

[0094] Specifically, the drainage hole 321 is located below the center line of the low-pressure pipe section 32 and on the pipe wall of the low-pressure pipe section 32 facing away from the axial center line of the heat-insulating cylinder 20. In other words, the drainage hole 321 is arranged as far as possible on the path where the liquid phase medium is thrown toward the pipe wall under the action of centrifugal force, which is more conducive to the discharge of the separated liquid phase medium as soon as possible and is also more conducive to reducing the secondary entrainment phenomenon.

[0095] In a specific implementation, the low-pressure inlet section 31, the low-pressure pipe section 32 and the low-pressure outlet section 33 can be wound by a single pipe, or can be arranged in sections and then fixed.

[0096] In a specific implementation, the low-pressure inlet section 31 of the low-pressure pipeline 30 passes through the upper end of the shell peripheral wall 11 close to the shell top wall 12 , and the low-pressure outlet section 33 passes through the shell bottom wall 13 .

[0097] In this embodiment, the inlet end of the superheated air return pipeline 50 is located above the shell cavity of the outer shell 10, and the outlet end of the superheated air return pipeline 50 is connected to the low-pressure outlet section 33. In this way, the superheated gaseous refrigerant gathered above the shell cavity in the gas-liquid separator can enter the superheated air return pipeline 50, flow through the superheated air return pipeline 50 to the low-pressure outlet section 33, and be discharged from the low-pressure outlet section 33.

[0098] The superheated air return pipeline 50 is also provided with a control valve 51 with an adjustable opening, and the control valve 51 can adjust the flow rate of the gaseous refrigerant entering the superheated air return pipeline 50 .

[0099] In a specific implementation, in order to facilitate the positioning of the superheated air return pipeline 50 and the arrangement and subsequent maintenance of the control valve 51, the superheated air return pipeline 50 can be inserted into the top wall 12 of the outer shell 10, and at least part of the superheated air return pipeline 50 is located outside the outer shell 10, and the control valve 51 is installed on the part of the superheated air return pipeline 50 located outside the outer shell 10.

[0100] In a specific implementation, the aperture of the upper port of the insulation tube 20 can be consistent with the aperture of the shell peripheral wall 11 of the outer shell 10. In this way, the upper end of the outer cavity 102 separated by the insulation tube 20 will not be connected to the insulation tube 20. In order to facilitate the gaseous refrigerant in the outer cavity 102 to enter the superheated return air pipeline 50, at this time, the top of the insulation tube 20 can be circumferentially provided with ventilation holes 21.

[0101] In applications, a plurality of vent holes 21 may be provided, and the plurality of vent holes 21 may be evenly arranged along the circumference of the heat insulation cylinder 20 .

[0102] In specific configuration, the upper end of the heat-insulating tube 20 may be flush with the upper end of the shell peripheral wall 11 , and the axial center line of the heat-insulating tube 20 may coincide with the axial center line of the shell 10 , so as to effectively utilize the space.

[0103] In this embodiment, the high-pressure pipeline 40 includes a high-pressure inlet section 41, a high-pressure outlet section 42 and a high-pressure pipe body 43; wherein the high-pressure inlet section 41 and the high-pressure outlet section 42 both pass through the housing 10, the high-pressure pipe body 43 is located in the housing 10, one end of the high-pressure inlet section 41 extends out of the housing 10 to facilitate the external pipeline, and the other end is located in the housing 10 to facilitate connection with the high-pressure pipe body 43, one end of the high-pressure outlet section 42 extends out of the housing 10 to facilitate the external pipeline, and the other end is located in the housing 10 to facilitate connection with the high-pressure pipe body 43. It can be understood that the high-pressure pipe body 43 is connected between the high-pressure inlet section 41 and the high-pressure outlet section 42.

[0104] In this embodiment, the high-pressure pipe body 43 is entirely located outside the heat-insulating tube 20 , that is, the high-pressure pipe body 43 is located in the outer cavity 102 .

[0105] The high-pressure pipe body 43 includes a first high-pressure pipe portion 431A and a third high-pressure pipe portion 433A. The first high-pressure pipe portion 431A is arranged around the heat-insulating cylinder 20, and the third high-pressure pipe portion 433A is located at the bottom of the shell cavity of the housing 10, that is, at the bottom of the heat-insulating cylinder 20.

[0106] In a specific implementation, the first high-pressure pipe portion 431A may extend downward along a conical spiral, and the first high-pressure pipe portion 431A may be formed by spirally winding a high-pressure pipe along the outer wall of the heat-insulating cylinder 20 .

[0107] In a specific implementation, the third high-pressure pipe portion 433A may be a planar curved structure. Figures 2 to 4 As shown, the third high-pressure pipe portion 433A is generally a planar spiral structure, and the third high-pressure pipe portion 433A can be formed by a high-pressure pipe winding from the inside to the outside in a plane. In other implementations, the third high-pressure pipe portion 433A can also be other winding structures, such as bending back and forth to form a serpentine structure.

[0108] In actual applications, the first high-pressure pipe section 431A and the third high-pressure pipe section 433A are sequentially connected between the high-pressure inlet section 41 and the high-pressure outlet section 42. That is, the gaseous high-pressure refrigerant flowing in from the high-pressure inlet section 41 first flows through the first high-pressure pipe section 431A, then flows through the third high-pressure pipe section 433A, and is finally discharged from the high-pressure outlet section 42.

[0109] In a specific implementation, the high-pressure inlet section 41, the first high-pressure pipe portion 431A, the third high-pressure pipe portion 433A and the high-pressure outlet section 42 can be wound by a single pipe, or can be separately arranged and then fixed.

[0110] The working principle of the gas-liquid separator provided in this embodiment is as follows:

[0111] During operation, the gas-liquid two-phase low-pressure refrigerant flows into the low-pressure pipeline 30 from the low-pressure inlet section 31 near the top of the gas-liquid separator, and flows along the conical spiral low-pressure pipe section 32. Under the action of gravity and centrifugal force, due to the high density of the low-pressure liquid refrigerant, most of it will adhere to the lower pipe wall on the outer side of the low-pressure pipe section 32 (the side away from the axial center line of the insulation tube 20), and be discharged through the drainage hole 321. Under the action of gravity, it can flow downward along the inner wall of the insulation tube 20 and be discharged from the lower port of the insulation tube 20 to the outer cavity 102, and gather at the bottom of the outer cavity 102; at the same time, due to the low-pressure gaseous refrigerant in the low-pressure pipe section 32, most of it gathers on the inner side of the low-pressure pipe section 32 (the side close to the axial center line of the insulation tube 20) of the pipe wall due to its low density, and flows along the low-pressure pipe section 32 to the low-pressure outlet section 33, and is discharged through the low-pressure outlet section 33 to achieve gas-liquid separation.

[0112] During operation, liquid high-pressure refrigerant flows from the high-pressure inlet section 41 into the high-pressure pipe body 43 and then flows out from the high-pressure outlet section 42; the aforementioned low-pressure liquid refrigerant after gas-liquid separation will have saturated gaseous refrigerant escape during the aggregation process, and the liquid refrigerant gathered at the bottom of the outer cavity 10 can exchange heat with the third high-pressure pipe section 433A located at the bottom, and saturated gaseous refrigerant or superheated gaseous refrigerant will also escape. After the two parts of gaseous refrigerant escape, they gather in the outer cavity 102 and flow upward. During the upward flow, they can exchange heat with the first high-pressure pipe section 431A jacketed on the outside of the insulation tube 20. The superheated gaseous refrigerant generated after the heat exchange continues to flow upward and gathers at the upper part of the outer cavity 102, and can enter the inner side of the insulation tube 20 through the vent 21 at the top of the insulation tube 20, and enter the superheated return air pipeline 50 from the inlet end of the superheated return air pipeline 50, and finally be discharged from the low-pressure outlet section 33.

[0113] In practical applications, the flow rate of the superheated gaseous refrigerant discharged from the superheated gas return pipeline 50 can be adjusted by adjusting the opening of the control valve 51 on the superheated gas return pipeline 50, thereby achieving the adjustment of the superheat. It can be understood that when the opening of the control valve 51 becomes larger, the amount of the superheated gaseous refrigerant flowing out increases, and the superheat of the low-pressure outlet of the gas-liquid separator increases. Conversely, when the opening of the control valve 51 becomes smaller, the amount of the superheated gaseous refrigerant flowing out decreases, and the superheat of the low-pressure outlet of the gas-liquid separator decreases.

[0114] From the above, it can be seen that the gas-liquid separator provided in this embodiment can heat the saturated gaseous refrigerant that escapes the liquid refrigerant after separation by optimizing its own structure to form superheated gaseous refrigerant, and can control the flow rate of this part of the superheated gaseous refrigerant discharged through the low-pressure outlet, thereby achieving effective regulation of the superheat, and further optimizing the system performance.

[0115] Please refer to Figures 7 to 11 , Figure 7 This is a schematic structural diagram of a second embodiment of the gas-liquid separator provided in this application; Figure 8 for Figure 7 A perspective view of the gas-liquid separator shown; Fig. 9 for Figure 7 The schematic diagram of the structure of the gas-liquid separator shown in FIG. 1 is shown with the outer shell hidden; Fig.10 for Fig. 9 Schematic diagram of the structure of the middle heat insulation cylinder and high-pressure pipeline; Fig.11 for Fig.10 Schematic diagram of a partial cross section of the structure shown.

[0116] In this embodiment, the gas-liquid separator includes a shell 10 , a heat-insulating cylinder 20 , a low-pressure pipeline 30 , a high-pressure pipeline 40 and a superheated gas return pipeline 50 .

[0117] The structures of the housing 10, the heat insulation tube 20, the low pressure pipeline 30 and the overheated return air pipeline 50 can refer to the aforementioned Figures 1 to 6 The structure of the connection between the low pressure pipeline 30 and the superheated return air pipeline 50 in this embodiment is similar to that in the first embodiment shown in FIG. Figure 5 and Figure 6 The same is shown and no further explanation is given.

[0118] In this embodiment, the high-pressure pipeline 40 includes a high-pressure inlet section 41 , a high-pressure outlet section 42 and a high-pressure pipe body 43 . The high-pressure inlet section 41 and the high-pressure outlet section 42 also pass through the outer shell 10 .

[0119] Different from the high-pressure pipe body 43 in the aforementioned first embodiment, in this embodiment, the high-pressure pipe body 43 includes a first high-pressure pipe portion 431B and a second high-pressure pipe portion 432B, and a third high-pressure pipe portion located at the bottom of the shell cavity of the housing 10 is not provided. Among them, the first high-pressure pipe portion 431B is located outside the heat-insulating cylinder 20 and is arranged around the heat-insulating cylinder 20, and the second high-pressure pipe portion 432B is located inside the heat-insulating cylinder 20 and is arranged around the heat-insulating cylinder 20. In other words, the first high-pressure pipe portion 431B is located in the outer cavity 102, and the second high-pressure pipe portion 432B is located in the inner cavity 101.

[0120] In a specific implementation, the first high-pressure pipe portion 431B may extend downward along a conical spiral, and the first high-pressure pipe portion 431B may be formed by spirally winding a high-pressure pipe along the outer wall of the heat-insulating cylinder 20 .

[0121] In a specific implementation, the second high-pressure pipe portion 432B can also extend downward along the conical spiral, and the second high-pressure pipe portion 432B can be formed by spirally winding the high-pressure pipe along the inner wall of the heat-insulating cylinder 20. The aforementioned low-pressure pipe section 32 is located on the inner side of the second high-pressure pipe portion 432B of the spiral structure, or in other words, the second high-pressure pipe portion 432B is sheathed on the low-pressure pipe section 32.

[0122] In this embodiment, the first high-pressure pipe portion 431B and the second high-pressure pipe portion 432B are formed on a conical spiral pipe. Fig.10 and Fig.11 , a part of the conical spiral tube is located inside the insulation tube 20, and the other part is located outside the insulation tube 20. It can be understood that the conical spiral tube is half embedded in the insulation tube 20, and the part of the conical spiral tube located outside the insulation tube 20 forms the first high-pressure tube part 431B, and the part of the conical spiral tube located inside the insulation tube 20 forms the second high-pressure tube part 432B. The two ends of the conical spiral tube are respectively connected to the high-pressure inlet section 41 and the high-pressure outlet section 42. This arrangement can simplify the structure of the high-pressure pipeline 40.

[0123] The working principle of the gas-liquid separator provided in this embodiment is as follows:

[0124] During operation, the gas-liquid two-phase low-pressure refrigerant flows into the low-pressure pipeline 30 from the low-pressure inlet section 31 near the top of the gas-liquid separator, and the liquid high-pressure refrigerant flows into the first high-pressure pipe section 431B and the second high-pressure pipe section 432B at the same time from the high-pressure inlet section 41, and is finally discharged from the high-pressure outlet section 42.

[0125] The gas-liquid two-phase low-pressure refrigerant flows along the conical spiral low-pressure pipe section 32. Under the action of gravity and centrifugal force, due to the high density of the low-pressure liquid refrigerant, most of it will adhere to the lower pipe wall on the outer side of the low-pressure pipe section 32 (the side away from the axial center line of the insulation tube 20) and be discharged through the drainage hole 321. Most of the liquid refrigerant discharged through the drainage hole 321 can flow to the pipe wall of the second high-pressure pipe section 432B and exchange heat with the high-pressure refrigerant flowing through the second high-pressure pipe section 432B. The heat exchange formed Part of the gaseous refrigerant rises, and the liquid refrigerant retained on the second high-pressure pipe portion 432B flows downward under the action of gravity and is discharged from the lower port of the insulation tube 20 to the outer cavity 102, and gathers at the bottom of the outer cavity 102; at the same time, the low-pressure gaseous refrigerant in the low-pressure pipe section 32 has a smaller density, and most of it gathers on the inner side of the low-pressure pipe section 32 (close to the side of the axial center line of the insulation tube 20) of the pipe wall, and flows along the low-pressure pipe section 32 to the low-pressure outlet section 33, and is discharged through the low-pressure outlet section 33, thereby realizing gas-liquid separation.

[0126] The aforementioned low-pressure liquid refrigerant after gas-liquid separation will have saturated gaseous refrigerant escaping during the gathering process, and the liquid refrigerant gathered at the bottom of the outer cavity 10 will also escape saturated gaseous refrigerant. After escaping, these two parts of gaseous refrigerant gather in the outer cavity 102 and flow upward. During the upward flow, they can exchange heat with the first high-pressure pipe part 431B on the outer side of the insulation cylinder 20. The superheated gaseous refrigerant generated after the heat exchange continues to flow upward and gathers at the upper part of the outer cavity 102, and can enter the inner side of the insulation cylinder 20 through the vent hole 21 at the top of the insulation cylinder 20, and enter the superheated gas return pipeline 50 from the inlet end of the superheated gas return pipeline 50, and finally be discharged from the low-pressure outlet section 33. By controlling the opening of the control valve 51 on the superheated gas return pipeline 50, the superheat of the low-pressure outlet of the gas-liquid separator can be adjusted.

[0127] Please refer to Figures 12 to 15 , Fig.12 A schematic structural diagram of a third embodiment of the gas-liquid separator provided in this application; Fig.13 for Fig.12 A perspective view of the gas-liquid separator shown; Fig.14 for Fig.12 The schematic diagram of the structure of the gas-liquid separator shown in FIG. 1 is shown with the outer shell hidden; Fig.15 for Fig.14 Schematic diagram of the structure of the middle insulation cylinder and high-pressure pipeline.

[0128] In this embodiment, the gas-liquid separator includes a shell 10 , a heat-insulating cylinder 20 , a low-pressure pipeline 30 , a high-pressure pipeline 40 and a superheated gas return pipeline 50 .

[0129] The structures of the housing 10, the heat insulation tube 20, the low pressure pipeline 30 and the overheated return air pipeline 50 can refer to the aforementioned Figures 1 to 6 The structure of the connection between the low pressure pipeline 30 and the superheated return air pipeline 50 in this embodiment is similar to that in the first embodiment shown in FIG. Figure 5 and Figure 6 The same is shown and no further illustration is given.

[0130] In this embodiment, the high-pressure pipeline 40 includes a high-pressure inlet section 41 , a high-pressure outlet section 42 and a high-pressure pipe body 43 . The high-pressure inlet section 41 and the high-pressure outlet section 42 also pass through the outer shell 10 .

[0131] Different from the high-pressure tube body 43 in the aforementioned first embodiment, the high-pressure tube body 43 in this embodiment includes a first high-pressure tube portion 431C and a second high-pressure tube portion 432C, and there is no third high-pressure tube portion arranged at the bottom of the shell cavity of the housing 10.

[0132] The first high-pressure pipe portion 431C is located outside the heat-insulating tube 20 and is arranged around the heat-insulating tube 20, and the second high-pressure pipe portion 432C is located inside the heat-insulating tube 20 and is arranged around the heat-insulating tube 20. In other words, the first high-pressure pipe portion 431C is located in the outer cavity 102, and the second high-pressure pipe portion 432C is located in the inner cavity 101.

[0133] Compared with the aforementioned second embodiment, the specific structures of the first high-pressure pipe portion 431C and the second high-pressure pipe portion 432C in this embodiment are different.

[0134] In this embodiment, the first high-pressure pipe portion 431C is a planar spiral structure, that is, the first high-pressure pipe portion 431C is at an axial height of the heat-insulating tube 20, and radially surrounds from the inside to the outside to form a planar spiral structure of more than two circles. The second high-pressure pipe portion 432C extends downward along the conical spiral and is sheathed on the low-pressure pipe section 32.

[0135] Based on the structures of the first high-pressure pipe part 431C and the second high-pressure pipe part 432C, the first high-pressure pipe part 431C and the second high-pressure pipe part 432C are respectively wound by two independent pipe sections. In a specific implementation, the first high-pressure pipe part 431C and the second high-pressure pipe part 432C can be wound by the same pipe, that is, a part of the pipe is wound to form the first high-pressure pipe part 431C, and the other part is wound to form the second high-pressure pipe part 432C.

[0136] The working principle of the gas-liquid separator provided in this embodiment is consistent with the working principle of the gas-liquid separator of the aforementioned second embodiment, and will not be repeated here.

[0137] Please refer to Figures 16 to 20 , Fig.16 This is a schematic structural diagram of a fourth embodiment of the gas-liquid separator provided in the present application; Fig.17 for Fig.16 A perspective view of the gas-liquid separator shown; Fig.18 for Fig.16 The schematic diagram of the structure of the gas-liquid separator shown in FIG. 1 is shown with the outer shell hidden; Fig.19 for Fig.18 Schematic diagram of the structure of the middle heat insulation cylinder and high-pressure pipeline; Fig. 20 for Fig.19 Schematic diagram of a partial cross section of the structure shown.

[0138] In this embodiment, the gas-liquid separator includes a shell 10 , a heat-insulating cylinder 20 , a low-pressure pipeline 30 , a high-pressure pipeline 40 and a superheated gas return pipeline 50 .

[0139] The structures of the housing 10, the heat insulation tube 20, the low pressure pipeline 30 and the overheated return air pipeline 50 can refer to the aforementioned Figures 1 to 6 The structure of the connection between the low pressure pipeline 30 and the superheated return air pipeline 50 in this embodiment is similar to that in the first embodiment shown in FIG. Figure 5 and Figure 6 The same is shown and no further illustration is given.

[0140] In this embodiment, the high-pressure pipeline 40 includes a high-pressure inlet section 41 , a high-pressure outlet section 42 and a high-pressure pipe body 43 . The high-pressure inlet section 41 and the high-pressure outlet section 42 also pass through the outer shell 10 .

[0141] Different from the high-pressure pipe body 43 in the aforementioned first embodiment, the high-pressure pipe body 43 in this embodiment includes a first high-pressure pipe portion 431D and a second high-pressure pipe portion 432D, and there is no third high-pressure pipe portion arranged at the bottom of the shell cavity of the housing 10.

[0142] The first high-pressure pipe portion 431D is located outside the heat-insulating tube 20 and is arranged around the heat-insulating tube 20, and the second high-pressure pipe portion 432D is located inside the heat-insulating tube 20 and is arranged around the heat-insulating tube 20. In other words, the first high-pressure pipe portion 431D is located in the outer cavity 102, and the second high-pressure pipe portion 432D is located in the inner cavity 101.

[0143] In this embodiment, both the first high-pressure pipe portion 431D and the second high-pressure pipe portion 432D are of conical spiral structure. Compared with the aforementioned second embodiment, the first high-pressure pipe portion 431D and the second high-pressure pipe portion 432D are formed in a different manner. In this embodiment, the first high-pressure pipe portion 431D and the second high-pressure pipe portion 432D are respectively wound by two independent high-pressure pipe sections. One high-pressure pipe section on the outside of the heat-insulating tube 20 is spirally wound to form the first high-pressure pipe portion 431D, and the other high-pressure pipe section on the inside of the heat-insulating tube 20 is spirally wound to form the second high-pressure pipe portion 432D. Fig. 20As shown, one end of a pipe section forming the first high-pressure pipe section 431D is connected to the high-pressure inlet section 41, and the other end is connected to the high-pressure outlet section 42, and one end of another pipe section forming the second high-pressure pipe section 432D is connected to the high-pressure inlet section 41, and the other end is connected to the high-pressure outlet section 42. It can be understood that the first high-pressure pipe section 431D and the second high-pressure pipe section 432D are arranged in parallel between the high-pressure inlet section 41 and the high-pressure outlet section 42.

[0144] The working principle of the gas-liquid separator provided in this embodiment is also consistent with the working principle of the gas-liquid separator of the aforementioned second embodiment, and will not be repeated here.

[0145] Please refer to Figure 21 to Figure 24 , Fig.21 A schematic structural diagram of a fifth embodiment of the gas-liquid separator provided in the present application; Fig. 22 for Fig.21 A perspective view of the gas-liquid separator shown; Fig.23 for Fig. 22 The schematic diagram of the structure of the gas-liquid separator shown in FIG. 1 is shown with the outer shell hidden; Fig.24 for Fig.23 Schematic diagram of the structure of the middle insulation cylinder and high-pressure pipeline.

[0146] In this embodiment, the gas-liquid separator includes a shell 10 , a heat-insulating cylinder 20 , a low-pressure pipeline 30 , a high-pressure pipeline 40 and a superheated gas return pipeline 50 .

[0147] The structures of the housing 10, the heat insulation tube 20, the low pressure pipeline 30 and the overheated return air pipeline 50 can refer to the aforementioned Figures 1 to 6 The structure of the connection between the low pressure pipeline 30 and the superheated return air pipeline 50 in this embodiment is similar to that in the first embodiment shown in FIG. Figure 5 and Figure 6 The same is shown and no further illustration is given.

[0148] In this embodiment, the high-pressure pipeline 40 includes a high-pressure inlet section 41 , a high-pressure outlet section 42 and a high-pressure pipe body 43 . The high-pressure inlet section 41 and the high-pressure outlet section 42 also pass through the outer shell 10 .

[0149] The high-pressure pipe body 43 in this embodiment includes a first high-pressure pipe portion 431E, a second high-pressure pipe portion 432E and a third high-pressure pipe portion 433E. The first high-pressure pipe portion 431E is located outside the heat-insulating tube 20 and is arranged around the heat-insulating tube 20, the second high-pressure pipe portion 432E is located inside the heat-insulating tube 20 and is arranged around the heat-insulating tube 20, and the third high-pressure pipe portion 433E is located at the bottom of the shell cavity of the outer shell 10. In other words, the first high-pressure pipe portion 431E and the third high-pressure pipe portion 433E are both located in the outer cavity 102, and the second high-pressure pipe portion 432E is located in the inner cavity 101.

[0150] Compared with the first embodiment, the high-pressure pipe body 43 of this embodiment is additionally provided with a second high-pressure pipe portion 432E located inside the thermal insulation tube 20; compared with the second to fourth embodiments, the high-pressure pipe body 43 of this embodiment is additionally provided with a third high-pressure pipe portion 433E located at the bottom of the shell cavity of the outer shell 10.

[0151] Specifically, in this embodiment, the first high-pressure pipe portion 431E and the second high-pressure pipe portion 432E are similar to the aforementioned fourth embodiment, and are both tapered spiral structures as a whole, and are respectively formed by two high-pressure pipe sections extending spirally along a cone surface. The shape of the third high-pressure pipe portion 433E in this embodiment is similar to that of the aforementioned first embodiment, and is also a planar spiral structure. In other implementations, the third high-pressure pipe portion 433E may also be a planar winding structure bent in a snake shape, etc.

[0152] In specific applications, the high-pressure inlet section 41, the high-pressure outlet section 42, the first high-pressure pipe section 431E, the second high-pressure pipe section 432E and the third high-pressure pipe section 433E can be wound by a high-pressure pipe. In other implementations, each part of the high-pressure pipeline 40 of this embodiment can also be separately arranged and then fixed.

[0153] The working principle of the gas-liquid separator provided in this embodiment is similar to that of the gas-liquid separator of the aforementioned second embodiment, with the difference that, due to the provision of a third high-pressure pipe portion 433E, the liquid refrigerant gathered at the bottom of the shell cavity of the outer shell 10 can exchange heat with the third high-pressure pipe portion 433E to form a gaseous saturated refrigerant or a superheated saturated refrigerant.

[0154] In the above embodiments, the radial distance between the heat insulating cylinder 20 and the low-pressure pipe section 32 of the low-pressure pipeline 30 is 1 to 3 times the diameter of the low-pressure pipe section 32 to maximize the use of space.

[0155] The embodiment of the present application also provides a method for determining the taper angle of the spiral tube of the aforementioned gas-liquid separator. In the gas-liquid separator provided in the present application, the main component for performing the gas-liquid separation function is the low-pressure pipe section 32 of the low-pressure pipeline 30. It can be understood that the taper angle of the low-pressure pipe section 32 affects the relevant parameters of the spiral channel of the low-pressure pipe section 32, and correspondingly affects the gas-liquid separation effect. In order to achieve a better gas-liquid separation effect, the embodiment of the present application provides a method for determining the taper angle of the spiral tube of the aforementioned gas-liquid separator. Here, the taper angle of the spiral tube is the taper angle α of the low-pressure pipe section 32 of the low-pressure pipeline 30, which can be combined with Fig.25 understand, Fig.25 A simplified model diagram showing the internal structure of the gas-liquid separator shell.

[0156] In this embodiment, the taper angle α of the low-pressure pipe section 32 of the low-pressure pipeline 30 of the gas-liquid separator has a set value range. Within the value range, the comprehensive performance coefficient U of the low-pressure pipe section 32 is selected. *The taper angle corresponding to the maximum value of is the optimal taper angle actually set for the low-pressure pipe section 32, and the structure of the low-pressure pipe section 32 is set according to this optimal taper angle.

[0157] The comprehensive performance coefficient U of the low-pressure pipe section 32 * Determined by the following formula:

[0158]

[0159] in, is the specific gravity coefficient of the low pressure pipe section 32, f * is the equivalent dimensionless friction coefficient of the low-pressure pipe section 32, a * is the equivalent dimensionless centrifugal force of the low-pressure pipe section 32, A * is the dimensionless lateral area of ​​the thermal insulation tube 20; and They are respectively the equivalent dimensionless centrifugal force of the low-pressure pipe section 32 , the equivalent dimensionless friction coefficient, and the dimensionless lateral area of ​​the insulation cylinder 20 at the reference taper angle.

[0160] Specific gravity coefficient of low pressure pipe section 32 It can be selected based on experience, and the specific value can be in the range of 0.6 to 0.9.

[0161] The reference taper angle may be determined according to actual application scenarios, for example, it may be the minimum value of the taper angle α of the low-pressure pipe section 32 .

[0162] Considering that a drainage hole 321 is provided on the low-pressure pipe section 32 to facilitate the escape of the liquid phase medium under the action of centrifugation, in the process of the low-pressure two-phase medium running downward along the low-pressure pipe section 32, the liquid phase medium keeps escaping, and the dryness of the medium flowing in the low-pressure pipe section 32 gradually increases. The larger the dryness, the better the gas-liquid separation ability. However, the dryness is an important indicator to characterize the separation ability of the gas-liquid separator, and its calculation is relatively complicated. To simplify the calculation, this application mainly evaluates it through dimensionless centrifugal force and dimensionless friction coefficient. It can be considered that the centrifugal force and the dryness of the medium are positively correlated, that is, the greater the centrifugal force, the greater the dryness of the medium flowing out of the low-pressure pipe section 32; but the greater the centrifugal force, the greater the friction coefficient, and the greater the pressure drop generated by the system, which is not good for the system; the dimensionless centrifugal force and the dimensionless friction coefficient are not real values, and the relatively optimal taper angle is mainly obtained through relative comparison under different taper angles.

[0163] Here, the comprehensive performance coefficient U of the low-pressure pipe section 32 is *It not only takes into account the influence of the gas-liquid separation capacity (centrifugal force and pressure drop) of the low-pressure pipe section 32 itself, but also takes into account the influence of the heat exchange of the low-pressure medium in the gas-liquid separator cavity and the high-pressure pipeline 40. It is specifically characterized by the dimensionless side area of ​​the insulation tube 20. The larger the heat exchange area, the better the heat exchange effect. In addition, the proportion of the influence on the gas-liquid separation capacity of the low-pressure pipe section 32 and the influence on the heat exchange of the low-pressure medium in the gas-liquid separator cavity and the high-pressure pipeline 40 is also defined, which can better and more comprehensively evaluate the performance of the gas-liquid separator.

[0164] In one implementation, the equivalent dimensionless centrifugal force a of the low-pressure pipe section 32 is * Determined by the following formula:

[0165] a * = k1·u l 2 / (g·D eq / 2);

[0166] u l =G(1-x) / (ρ l (1-∈));

[0167]

[0168] G=4q / (π·d i 2 );

[0169] D eq =2 / (1 / D min +1 / D max ), D min =D max -2·H·tan(α / 2);

[0170] Among them, k1 is the correction coefficient, u l is the velocity of the liquid medium, D eq is the equivalent spiral diameter of the low-pressure pipe section 32, G is the flow density of the refrigerant, x is the dryness at the inlet of the gas-liquid separator, ρ l is the density of the liquid medium, ∈ is the refrigerant porosity, ρ g is the density of the gas phase medium, σ is the surface tension of the refrigerant, q is the mass flow rate of the refrigerant, d i is the inner diameter of the low-pressure pipe section 32, D max is the maximum spiral diameter of the low-pressure pipe section 32, D min is the minimum spiral diameter of the low-pressure pipe section 32 , and H is the axial height of the low-pressure pipe section 32 .

[0171] When the overall dimensions of the gas-liquid separator are determined, the dimensions of the heat-insulating tube 20 can be determined, so that the maximum spiral diameter D of the low-pressure pipe section 32 located in the heat-insulating tube 20 ismax and the axial height H can be determined in advance, or the relevant dimensions of the low-pressure pipe section 32 can be determined first, and then the relevant dimensions of the insulation cylinder 20 can be determined based on the positional relationship between the two. According to the actual application scenario, the mass flow rate of the refrigerant in the system, the relevant physical parameters of the refrigerant, etc. can all be determined in advance. In this way, according to the taper angle value of a selected low-pressure pipe section 32, the equivalent dimensionless centrifugal force a relative to can be calculated. * .

[0172] In specific implementation, the above correction coefficient k1 can be obtained by the formula:

[0173] k1=1.125-0.065n is determined.

[0174] Where n = H / s, n is the equivalent number of spiral turns of the low-pressure pipe section 32 , s is the equivalent spiral pitch of the low-pressure pipe section 32 , and L is the pipe length of the low-pressure pipe section 32 .

[0175] The inner diameter d of the low pressure pipe section 32 i and the tube length L can be determined in advance.

[0176] In a specific implementation, the equivalent dimensionless friction coefficient f of the low-pressure pipe section 32 is * It can be determined by the following formula:

[0177]

[0178] Re=ρud i / μ;

[0179] u=G / ρ;

[0180] Where Re is the Reynolds number, ρ is the homogeneous density, μ is the homogeneous viscosity, u is the homogeneous velocity, μ g is the viscosity of the gas phase medium, μ l is the viscosity of the liquid medium.

[0181] Specifically, the equivalent dimensionless friction coefficient f * It can be determined according to the following formula:

[0182] Where k is a constant and can be selected according to the actual application scenario. Equivalent dimensionless friction coefficient f * It can also be calculated using other formulas.

[0183] In a specific implementation, the dimensionless side area A of the heat insulation tube 20 is * Determined by the following formula:

[0184]

[0185]

[0186] D max3 =D max +P,D min3 =D min +P;

[0187] Wherein, A1 is the single side area of ​​the heat insulation tube 20, D max3 is the maximum diameter of the insulation tube 20, D min3 is the minimum diameter of the heat-insulating tube 20 , P is the preset distance, and H is the axial height of the low-pressure pipe section 32 .

[0188] It can be understood that (1 / 2)·P is the radial distance between the heat insulation tube 20 and the low pressure pipe section 32. In actual calculation, P=3d can be selected. i , can also be adjusted according to the actual application scenario, this is just an example.

[0189] In one implementation, the taper angle α of the low-pressure pipe section 32 has a value range of α min ≤α<α max Generally speaking, if the angle is too small, the space size of the outer cavity 102 of the gas-liquid separator will be too small, which is not conducive to liquid storage and the centrifugal effect will be relatively poor. If the angle is too large, the flow resistance of the low-pressure pipe section 32 will be increased, which is not conducive to improving the comprehensive performance of gas-liquid separation.

[0190] Among them, α min It can be selected based on experience, for example, it can be 25°.

[0191] Among them, α max =2·arctan(D max / (2·H)).

[0192] When the taper angle α of the low-pressure pipe section 32 is determined, a series of values ​​can be selected within the above value range to calculate the corresponding comprehensive performance coefficient U * According to the calculation results, the comprehensive performance coefficient U is selected * The corresponding taper angle α when it is at the maximum is the optimal value of the actual setting of the low-pressure pipe section 32 .

[0193] Specifically, multiple angle values ​​may be listed in the above value range in increments of a certain degree.

[0194] In practical applications, when the equivalent number of spiral turns n corresponding to the value of the taper angle α of the low-pressure pipe section 32 is greater than the preset value, the value of the taper angle α is excluded. According to experience, a too large equivalent number of spiral turns n is not beneficial to the gas-liquid separation effect, so the preset value of the equivalent number of spiral turns n can be set as needed. If the calculated result exceeds the maximum value, the corresponding value of the taper angle α is not considered. The aforementioned preset value can be set to 15, etc. according to experience.

[0195] At the same time, the equivalent helical pitch s of the low-pressure pipe section 32 should also be considered, which should not be less than the inner diameter d of the low-pressure pipe section 32. i Therefore, in the calculation process, if the equivalent spiral pitch s of the low-pressure pipe section 32 corresponding to the value of a certain taper angle α is smaller than the inner diameter d of the low-pressure pipe section 32 i , and the value of the taper angle α is also excluded.

[0196] The method for determining the taper angle α of the low-pressure pipe section 32 of the gas-liquid separator is described below with a specific example.

[0197] The size of the gas-liquid separator is usually limited to a certain range. Based on the maximization of space utilization, the height of the low-pressure pipe section 32 is maximized. In an application example, the parameters corresponding to the application scenario can be obtained:

[0198] The maximum spiral diameter of the low pressure pipe section 32 is D max is 105 mm, the axial height H is 112 mm, the length L of the low-pressure pipe section 32 is 800 mm, and the inner diameter d of the low-pressure pipe section 32 is i The refrigerant in the system is R1234yf, the mass flow rate q is 180kg / h, the inlet dryness x is 0.5 and the saturation temperature T is 7℃.

[0199] First determine the setting range of the taper angle α of the low-pressure pipe section 32, according to the formula α max =2·arctan(D max / (2·H)) and the above parameters can be obtained max is 50°. α is selected based on experience min is 25°.

[0200] A series of selected values ​​of the taper angle α are selected in increments of 5° within the setting range, namely 25°, 30°, 35°, 40° and 45°. In other applications, in order to obtain a better solution, the increment degree can also be set to be smaller, such as incrementing 1° or 2° each time.

[0201] According to a series of selected values ​​of the taper angle α, a series of corresponding minimum spiral diameters D of the low-pressure pipe section 32 can be calculated. min , so that the equivalent spiral diameter D of the low-pressure pipe section 32 can be determined eq, equivalent helical pitch s and equivalent number of helical turns n.

[0202] Here, taking the taper angle α as 25° as an example, the minimum spiral diameter D of the low-pressure pipe section 32 can be obtained: min The equivalent spiral diameter D is 55.34 mm. eq It is 72.48mm, the equivalent spiral pitch s is 32.22mm, and the equivalent number of spiral turns n is 3.476.

[0203] According to the previously determined inner diameter d of the low-pressure pipe section 32 i The flow density G of the refrigerant can be calculated from the mass flow rate q to be 248.6 kg / (m 2 ·s).

[0204] According to the refrigerant saturation temperature of 7°C, the density of the saturated gas phase medium ρ1 can be obtained in combination with the general physical properties table as 22.1 kg / m 3 , the density of the saturated liquid medium ρ l 1153.9kg / m 3 , surface tension σ is 0.0085024N / m), combined with the above parameters, the refrigerant porosity ∈ can be calculated to be 0.917, and the liquid medium u l The speed is 1.31m / s, and the equivalent dimensionless centrifugal force a * is 4.314.

[0205] According to the above physical parameters and the inlet dryness x, the homogeneous density ρ can be obtained as 43.369 kg / m 3 , the homogeneous viscosity μ is 0.01961 Pa·s, the homogeneous velocity u is 5.734 m / s, and combined with the above-mentioned related parameters, the corresponding Reynolds number Re can be obtained as 202.87, so that the equivalent dimensionless friction coefficient f can be determined * It is 0.006457, where the constant k is selected as 0.31.

[0206] According to the maximum spiral diameter D of the low-pressure pipe section 32 max , minimum spiral diameter D min The maximum diameter D of the heat insulation tube 20 can be determined by the inner diameter of the low-pressure pipe section 32. max3 and minimum diameter D min3 The maximum diameter D of the heat insulation tube 20 max3 =D max +P=153mm, here P=3d i Calculate the minimum diameter D of the insulation tube 20 min3 =D min +P = 103.34 mm. According to the above formula, the single-side area of ​​the heat insulation tube 20 can be determined to be 46192.67 mm 2, and then the dimensionless side area A of the insulation tube 20 can be determined * It is 0.858053.

[0207] Here we take the reference taper angle as 25° and Can get is 4.314, is 0.006457, It is 0.858053.

[0208] Select the specific gravity coefficient of the low pressure pipe section 32 =0.8, according to the above formula, the comprehensive performance coefficient U of the low-pressure pipe section 32 at a taper angle of 25° can be obtained. * is 1.

[0209] Similarly, the comprehensive performance coefficient U corresponding to other selected values ​​of the taper angle α can be determined: * , please refer to the following Table 1. Among them, when the taper angle α is 45°, the calculated equivalent spiral pitch s of the low-pressure pipe section 32 is smaller than the inner diameter d of the pipe i , so exit the calculation.

[0210] Table 1- Correspondence table between the taper angle of the low-pressure pipe section 32 and related parameters in an application scenario

[0211]

[0212] It can be seen from Table 1 that when the taper angle is 35°, the comprehensive performance coefficient U * Highest, so in the aforementioned application scenario, the low-pressure pipe section 32 can be set according to the taper angle of 35° of the low-pressure pipe section 32, and the relevant parameters of the insulation tube 20 can be set according to the low-pressure pipe section 32, so that the gas-liquid separator has a relatively good gas-liquid separation effect.

[0213] In other application scenarios, the relevant design parameters of the low-pressure pipe section 32 of the gas-liquid separator may also be set according to the above determination method, and will not be described in detail.

[0214] Specific examples are used herein to illustrate the principles and implementation methods of the present application, and the description of the above embodiments is only used to help understand the method and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A gas-liquid separator, characterized in that: It includes the outer shell, the heat-insulating cylinder, the low-pressure pipeline, the high-pressure pipeline and the superheated return air pipeline; The heat-insulating tube divides the shell cavity of the outer shell into an inner cavity and an outer cavity, the outer cavity surrounds the inner cavity, the heat-insulating tube is in a conical shape with a larger top and a smaller bottom, and a lower end of the heat-insulating tube is provided with a lower port; a vent hole is provided on the top of the heat-insulating tube, the upper ends of the inner cavity and the outer cavity are connected through the vent hole, and the lower ends of the inner cavity and the outer cavity are connected through the lower port of the heat-insulating tube; The low-pressure pipeline comprises a low-pressure inlet section, a low-pressure pipe section and a low-pressure outlet section connected in sequence, the low-pressure inlet section is connected to an external pipeline, the low-pressure pipe section extends downward along a conical spiral and is located in the heat-insulating cylinder, and the low-pressure outlet section is connected to an external pipeline; the low-pressure pipe section has a drainage hole; The inlet end of the superheated air return pipeline is located above the shell cavity, and the outlet end is connected to the low-pressure outlet section. The superheated air return pipeline is provided with a control valve with adjustable opening; At least a portion of the high-pressure pipeline is located in the outer cavity for heat exchange with the refrigerant in the outer shell.

2. The gas-liquid separator according to claim 1, characterized in that: The high-pressure pipeline includes a high-pressure inlet section, a high-pressure outlet section and a high-pressure pipe body, the high-pressure inlet section and the high-pressure outlet section are both connected to the external pipeline, and the high-pressure pipe body is connected between the high-pressure inlet section and the high-pressure outlet section; the high-pressure pipe body includes a first high-pressure pipe portion located in the outer cavity, and the first high-pressure pipe portion is arranged around the insulation cylinder.

3. The gas-liquid separator according to claim 2, characterized in that: The high-pressure pipe body also includes a second high-pressure pipe portion located in the inner cavity, and the second high-pressure pipe portion extends downward along a conical spiral and is sheathed on the low-pressure pipe section.

4. The gas-liquid separator according to claim 3, characterized in that: The first high-pressure pipe portion extends downward along a conical spiral.

5. The gas-liquid separator according to claim 4, characterized in that: The first high-pressure pipe section and the second high-pressure pipe section are formed on a conical spiral tube, and the conical spiral tube includes a portion located outside the insulation tube and a portion located inside the insulation tube. The portion of the conical spiral tube located outside the insulation tube forms the first high-pressure pipe section, and the portion of the conical spiral tube located inside the insulation tube forms the second high-pressure pipe section.

6. The gas-liquid separator according to claim 4, characterized in that: The first high-pressure pipe section and the second high-pressure pipe section are respectively formed by two high-pressure pipe sections spirally, the high-pressure pipe section on the outside of the insulation tube spirally forms the first high-pressure pipe section, and the high-pressure pipe section on the inside of the insulation tube spirally forms the second high-pressure pipe section.

7. The gas-liquid separator according to claim 3, characterized in that: The first high-pressure pipe portion is in a planar spiral structure.

8. The gas-liquid separator according to any one of claims 2 to 7, characterized in that: The high-pressure pipe body also includes a third high-pressure pipe portion located in the outer cavity, and the third high-pressure pipe portion is arranged at the bottom of the shell cavity of the outer shell.

9. The gas-liquid separator according to any one of claims 1 to 7, characterized in that: The shell includes a cylindrical shell peripheral wall, a shell bottom wall and a shell top wall. The opening diameter of the top end of the insulation cylinder is consistent with the aperture of the shell peripheral wall. The inlet end of the superheated return air pipeline is located in the insulation cylinder.

10. A method for determining the taper angle of a spiral tube of a gas-liquid separator, characterized in that: The gas-liquid separator is the gas-liquid separator according to any one of claims 1 to 9, the taper angle of the spiral tube is the taper angle α of the low-pressure pipe section, the taper angle α of the low-pressure pipe section has a set value range, within the value range, the comprehensive performance coefficient U of the low-pressure pipe section is selected * The taper angle corresponding to the maximum value of is the optimal taper angle actually set for the low-pressure pipe section; The comprehensive performance coefficient U of the low-pressure pipe section * Determined by the following formula: in, is the specific gravity coefficient of the low-pressure pipe section, f * is the equivalent dimensionless friction coefficient of the low-pressure pipe section, a * is the equivalent dimensionless centrifugal force of the low-pressure pipe section, A * is the dimensionless lateral area of ​​the thermal insulation cylinder; and are respectively the equivalent dimensionless centrifugal force, the equivalent dimensionless friction coefficient and the dimensionless lateral area of ​​the thermal insulation cylinder of the low-pressure pipe section at the reference taper angle; The equivalent dimensionless centrifugal force a of the low-pressure pipe section * Determined by the following formula: am * s1u l 2 / (g·D eq / 2) you l =G(1-x) / (ρ l (1-∈)); G=4q / (π·d i 2 ); D eq =2 / (1 / D min +1 / D max ),D min =D max -2·H·tan(α / 2); The equivalent dimensionless friction coefficient f of the low-pressure pipe section * Determined by the following formula: Re=ρud i / m; u=G / ρ; The dimensionless lateral area A of the thermal insulation cylinder * Determined by the following formula: D max3 =D max ++P,D min3 =D min +P; Among them, k1 is the correction coefficient, u l is the velocity of the liquid medium, D eq is the equivalent spiral diameter of the low-pressure pipe section, G is the flow density of the refrigerant, x is the dryness at the inlet of the gas-liquid separator, ρ l is the density of the liquid medium, ∈ is the refrigerant porosity, ρ g is the density of the gas phase medium, σ is the surface tension of the refrigerant, q is the mass flow rate of the refrigerant, d i is the inner diameter of the low-pressure pipe section, D max is the maximum spiral diameter of the low-pressure pipe section, D min is the minimum spiral diameter of the low-pressure pipe section, H is the axial height of the low-pressure pipe section, Re is the Reynolds number, ρ is the homogeneous density, μ is the homogeneous viscosity, u is the homogeneous velocity, μ g is the viscosity of the gas phase medium, μ l is the viscosity of the liquid medium, A1 is the single-sided side area of ​​the insulation cylinder, D max3 is the maximum diameter of the insulation tube, D min3 is the minimum diameter of the insulation tube, P is the preset distance, and H is the axial height of the low-pressure pipe section.

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