A separation system for ejector preposition in a CO2 refrigeration unit

Abstract

The present invention relates to a separation system for ejector preposition in a CO2 refrigeration unit, belonging to the technical field of separators, and comprising an intermediate-temperature compressor, an oil separator, an air cooler, a heat exchanger, a separator, a pressure regulating valve, an ejector, a flash tank, a low-temperature evaporator, an intermediate-temperature evaporator and a low-temperature compressor. The separator includes a separator cylinder body, an outer wall of the separator cylinder body is provided with a refrigerant inlet, an impact plate is arranged at a position corresponding to the refrigerant inlet in the separator cylinder body, an upper guide plate is arranged above the impact plate, and a gaseous refrigerant outlet is arranged above the separator cylinder body; a lower guide plate is arranged below the impact plate; a liquid refrigerant outlet is arranged below the lower guide plate. The separator added before the ejector in the present invention can separate the gas and liquid in the high-pressure section without losing any system energy efficiency, make the refrigerant entering the high-pressure gas inlet of the ejector be in a gaseous state, ensure the efficiency of the ejector, and thus ensure the energy efficiency of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of separators, and more particularly, to a separation system for ejector preposition in a CO2 refrigeration unit. Background Art

[0002] Freon, as an artificial refrigerant, is widely used in household appliances and industrial processes. Diffusing into the atmosphere will damage the ozone layer, and the world is looking for green and environmentally friendly refrigerants. In the long term, CO2 refrigerants conform to the development trend of green and environmentally friendly natural working fluid refrigerants. When using a CO2 refrigeration system, energy efficiency is an inevitable topic. After several generations of technological updates, the use of ejectors has further improved the energy efficiency of CO2 refrigeration units. In a carbon dioxide refrigeration system, the fluid cooled by the gas cooler is usually a gas-liquid two-phase mixture. If it directly enters the ejector, the gas-liquid two-phase fluid will affect the working efficiency of the ejector and may even cause the ejector to fail. The use characteristic of the ejector is that the high-pressure inlet needs to be high-pressure gas, and if there is liquid mixing, it will affect the ejection effect. At present, there is no separation system set before the ejector in the refrigeration systems in the industry. Therefore, it is necessary to design a separation system that can separate gas from liquid before the ejector to ensure that the gas enters the ejector. Summary of the Invention

[0003] In view of the above-mentioned technical problems, a separation system for ejector preposition in a CO2 refrigeration unit is provided. The present invention is applied to the high-pressure section of the CO2 refrigeration unit, and the separator is located between the outlet of the gas cooler and the inlet of the ejector. It prevents the liquid in the gas-liquid two-phase refrigerant cooled by the gas cooler from entering the high-pressure inlet of the ejector and causing the decline of the ejector effect.

[0004] The technical means adopted by the present invention are as follows:

[0005] A separation system for ejector preposition in a CO2 refrigeration unit, comprising a medium-temperature compressor, an oil separator, an air cooler, a heat exchanger, a separator, a pressure regulating valve, an ejector, a flash tank, a low-temperature evaporator, a medium-temperature evaporator and a low-temperature compressor. The output end of the medium-temperature compressor is connected to the oil separator, the output end of the oil separator is connected to the air cooler, the output end of the air cooler is connected to the first inlet of the heat exchanger, the first outlet of the heat exchanger is connected to the inlet of the separator. The separator is used to separate the refrigerant into gas and liquid. The gas output end of the separator is connected to the ejector, the liquid output end of the separator is connected to the flash tank. The output end of the ejector is connected to the flash tank. The flash tank includes a gas outlet and a liquid outlet. Among them, the gas outlet is connected to the second inlet of the heat exchanger, and the second outlet of the heat exchanger is connected to the medium-temperature compressor; the liquid outlet of the flash tank is respectively connected to the low-temperature evaporator and the medium-temperature evaporator. The refrigerant enters the low-temperature compressor after passing through the low-temperature evaporator, mixes with the refrigerant passing through the medium-temperature evaporator, and enters the medium-pressure gas inlet of the ejector.

[0006] Further, the separator includes a separator cylinder body. The outer wall of the separator cylinder body is provided with a refrigerant inlet. At the position corresponding to the refrigerant inlet in the separator cylinder body, an impact plate is provided. Above the impact plate is an upper diversion plate. A gas refrigerant outlet is provided above the separator cylinder body; a lower diversion plate is provided below the impact plate; a liquid refrigerant outlet is provided below the lower diversion plate.

[0007] Further, a separator upper end cover is provided above the separator cylinder body, and a separator lower end cover is provided below the separator cylinder body. The gas refrigerant outlet is arranged on the separator upper end cover, and the liquid refrigerant outlet is arranged on the separator lower end cover.

[0008] Further, the impact plate is vertically arranged. On the side of the impact plate facing the refrigerant inlet, multiple groups of auxiliary diversion plates are provided. The auxiliary diversion plates are arranged in a herringbone shape. Specifically, each group of auxiliary diversion plates forms a herringbone structure, and the left and right two auxiliary diversion plates of each group are staggered in the height direction. The cross-section formed by all the auxiliary diversion plates can completely cover the projection shape of the refrigerant inlet on the impact plate;

[0009] The back of the impact plate is connected with a middle diversion plate, and the middle diversion plate is welded to the inner side of the separator cylinder body.

[0010] Further, the middle diversion plate is a circular plate, and uniformly distributed through holes are opened on the circular plate. The sum of the cross-sectional areas of all the through holes needs to be greater than the cross-sectional area of the refrigerant inlet. The middle diversion plate not only has the functions of guiding and separating, but also serves as the back support and strengthening of the impact plate.

[0011] Furthermore, the lower deflector is a circular plate with a notch. The outer diameter of the lower deflector matches the inner diameter of the separator cylinder, and it is welded to the inner side of the separator cylinder. The notch is arranged on the outer circumferential surface of the circular plate for guiding the refrigerant. Thus, the liquid refrigerant flows into the lower layer and enters the system through the liquid refrigerant outlet pipe. At the same time, another key function of setting the lower deflector is to guide the gaseous refrigerant from above it to the middle and upper deflectors in the upper layer, avoiding the impact of high-pressure gaseous refrigerant on the liquid refrigerant level in the lower layer, which may cause the liquid level to be unstable and affect the monitoring data of the liquid level sensor.

[0012] Furthermore, the upper deflector is a circular plate, and evenly distributed through holes are opened on the circular plate. The sum of the cross-sectional areas of all the through holes needs to be larger than the cross-sectional area of the refrigerant inlet.

[0013] Furthermore, the positions of the round holes of the upper deflector and the middle deflector are all staggered and do not overlap.

[0014] Furthermore, a filter screen is arranged between the upper deflector and the upper end cover of the separator. The filter screen is made of stainless steel. Usually, the height of the stainless steel filter screen is about 100 mm, and the mesh number of the filter screen is usually about 100 mesh to 150 mesh. The height of the filter screen and the mesh number of the filter screen can also be adjusted according to different working conditions.

[0015] Furthermore, the separator fixing part is arranged on the outer side of the separator cylinder and is welded to the separator cylinder connection. The size and quantity of the separator fixing part can be adjusted according to different working conditions.

[0016] Compared with the prior art, the present invention has the following advantages: The separator added in front of the ejector in the present invention allows the refrigerant to enter the separator through the refrigerant inlet and directly flow towards the impact plate, enabling the liquid to naturally fall through the gaps around the lower deflector and flow into the lower end cover of the separator, and then enter the pressure regulating valve through the liquid refrigerant outlet. The gaseous refrigerant is guided by the lower deflector, passes through the middle deflector and the upper deflector, passes through the filter screen, and enters the ejector through the gaseous refrigerant outlet. Thus, the gas and liquid in the refrigerant from the air cooler are separated, ensuring that only gaseous refrigerant enters the ejector and guaranteeing the efficiency of the ejector. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a schematic diagram of the system of the present invention.

[0019] Figure 2 This is a schematic diagram of the external structure of the separator of the present invention.

[0020] Figure 3 This is an exploded view of the structure of the present invention.

[0021] In the figure: 1. Medium-temperature compressor, 2. Oil separator, 3. Air cooler, 4. Parallel heat exchanger, 5. Separator, 6. Pressure regulating valve, 7. Ejector, 8. Flash tank, 9. Low-temperature evaporator, 10. Medium-temperature evaporator, 11. Low-temperature compressor, 51. Separator cylinder body, 52. Upper end cover of the separator, 53. Filter screen, 54. Upper layer flow guide plate, 55. Refrigerant inlet, 56. Impact plate, 57. Lower layer flow guide plate, 58. Liquid level sensor interface, 59. Gas refrigerant outlet, 510. Middle layer flow guide plate, 511. Separator fixing part, 512. Lower end cover of the separator, 513. Liquid refrigerant outlet. Specific embodiments

[0022] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The description of at least one exemplary embodiment below is actually only illustrative and in no way restrictive of the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0024] It should be noted that the terms used here are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0025] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the description. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0026] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation terms such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc. are generally based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary instructions, these orientation terms do not indicate and imply that the devices or elements referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention: the orientation terms "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0027] For ease of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" etc. can be used here to describe the spatial positional relationships of one device or feature to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used here.

[0028] In addition, it should be noted that the use of words such as "first", "second", etc. to define components is only for the convenience of differentiating the corresponding components. Without additional statements, the above words have no special meanings, and thus should not be construed as limiting the protection scope of the present invention.

[0029] Such as Figure 1As shown, that is, a refrigerant circuit flow chart. An embodiment of the present invention discloses a separation system for ejector preposition in a CO2 refrigeration unit, including an intermediate-temperature compressor 1, an oil separator 2, an air cooler 3, a parallel heat exchanger 4, a separator 5, a pressure regulating valve 6, an ejector 7, a flash tank 8, a low-temperature evaporator 9, an intermediate-temperature evaporator 10, and a low-temperature compressor 11. The output end of the intermediate-temperature compressor 1 is connected to the oil separator 2, the output end of the oil separator 2 is connected to the air cooler 3, the output end of the air cooler 3 is connected to the first inlet of the parallel heat exchanger 4, the first outlet of the parallel heat exchanger 4 is connected to the inlet of the separator 5. The separator 5 is used to separate the refrigerant into gas and liquid. The gas output end of the separator 5 is connected to the ejector 7, the liquid output end of the separator 5 is connected to the flash tank 8, the output end of the ejector 7 is connected to the flash tank 8. The separated liquid or misty gas can be converted into liquid through the pressure regulating valve 6. The flash tank 8 includes a gas outlet and a liquid outlet. Among them, the gas outlet is connected to the second inlet of the parallel heat exchanger 4, and the second outlet of the parallel heat exchanger 4 is connected to the intermediate-temperature compressor 1; the liquid outlet of the flash tank 8 is respectively connected to the low-temperature evaporator 9 and the intermediate-temperature evaporator 10. The refrigerant enters the low-temperature compressor 11 after passing through the low-temperature evaporator 9, is mixed with the refrigerant passing through the intermediate-temperature evaporator 10, and enters the medium-pressure gas inlet of the ejector 7.

[0030] As Figure 2 , Figure 3 As shown, the separator includes a separator cylinder body 51. The outer wall of the separator cylinder body is provided with a refrigerant inlet 55. At the position corresponding to the refrigerant inlet in the separator cylinder body, an impact plate 56 is provided. Above the impact plate is an upper diversion plate 54. A gas refrigerant outlet 59 is provided above the separator cylinder body; a lower diversion plate 57 is provided below the impact plate; a liquid refrigerant outlet 513 is provided below the lower diversion plate.

[0031] Further, a separator upper end cover 52 is provided above the separator cylinder body, and a separator lower end cover 512 is provided below the separator cylinder body. The gas refrigerant outlet is arranged on the separator upper end cover, and the liquid refrigerant outlet is arranged on the separator lower end cover.

[0032] Further, the impact plate is vertically arranged. On the side of the impact plate facing the refrigerant inlet, multiple groups of auxiliary diversion plates are provided. The auxiliary diversion plates are arranged in a herringbone shape. Specifically, each group of auxiliary diversion plates forms a herringbone structure, and the left and right two auxiliary diversion plates of each group are staggered in the height direction. The cross-section formed by all the auxiliary diversion plates can completely cover the projection shape of the refrigerant inlet on the impact plate;

[0033] The back of the impact plate is connected with a middle diversion plate 510, and the middle diversion plate is welded to the inner side of the separator cylinder body.

[0034] Furthermore, the middle-layer deflector is a circular plate, and evenly distributed through holes are formed in the circular plate. The sum of the cross-sectional areas of all the through holes should be greater than the cross-sectional area of the refrigerant inlet. The middle-layer deflector not only has the functions of guiding and separating, but also serves as the back support reinforcement of the impact plate.

[0035] Furthermore, the lower-layer deflector is a circular plate with a notch. The outer diameter of the lower-layer deflector matches the inner diameter of the separator cylinder body, and it is welded to the inner side of the separator cylinder body. The notch is arranged on the outer circumferential surface of the circular plate and is used to guide the refrigerant blocked by the impact plate. Thus, the liquid refrigerant flows into the lower layer and enters the system through the liquid refrigerant outlet pipe. At the same time, another key function of setting the lower-layer deflector is to guide the gaseous refrigerant from above it to the middle-layer and upper-layer deflectors in the upper layer, avoiding the impact of high-pressure gaseous refrigerant on the liquid refrigerant level in the lower layer, which may cause unstable liquid level and affect the monitoring data of the liquid level sensor.

[0036] Furthermore, the upper-layer deflector is a circular plate, and evenly distributed through holes are formed in the circular plate. The sum of the cross-sectional areas of all the through holes should be greater than the cross-sectional area of the refrigerant inlet.

[0037] Furthermore, the circular hole positions of the upper-layer deflector and the middle-layer deflector are all staggered and have no overlap.

[0038] Furthermore, a filter screen 53 is arranged between the upper-layer deflector and the upper end cover of the separator. The filter screen is made of stainless steel. Usually, the height of the stainless steel filter screen is about 100 mm, and the mesh number of the filter screen is usually about 100 meshes to 150 meshes. The height of the filter screen and the mesh number of the filter screen can also be adjusted according to different working conditions.

[0039] Furthermore, separator fixing parts 511 are arranged on the outer side of the separator cylinder body and are welded to the separator cylinder body for connection. The size and quantity of the separator fixing parts can be adjusted according to different working conditions.

[0040] During the use process, the refrigerant flowing from the air cooler to the separator enters the separator through the refrigerant inlet 55 and directly flows to the impact plate 56, causing the liquid to naturally fall through the gaps around the lower-layer deflector 57 and flow into the lower end cover 512 of the separator, and then enters the pressure regulating valve through the liquid refrigerant outlet 513. The gaseous refrigerant is guided by the lower-layer deflector 57, passes through the middle-layer deflector 510 and the upper-layer deflector 54, passes through the filter screen 53, and enters the ejector through the gaseous refrigerant outlet 59. Thus, the gas and liquid in the refrigerant from the air cooler are separated, and only gaseous refrigerant enters the ejector, ensuring the efficiency of the ejector.

[0041] As an expandable implementation manner, a liquid level sensor interface 58 is further provided on the separator cylinder body 1. The liquid level sensor interface is arranged in the interval between the lower layer deflector and the lower end cover of the separator, and is used for monitoring the liquid level condition in the separator.

[0042] The specific working process of the present invention is as follows: First, the medium-temperature compressor 1 compresses the refrigerant to a high-temperature and high-pressure state. The refrigerant enters the oil separator 2. The high-temperature and high-pressure refrigerant gas enters the gas cooler 3 to be cooled down. The low-temperature and high-pressure refrigerant enters the parallel heat exchanger 4. The refrigerant in the parallel heat exchanger enters the separator 5. The gas separated in the separator enters the ejector 7. The ejector 7 injects high-pressure gas and low-pressure gas into the flash tank 8; the liquid separated in the separator enters the flash tank 8 through the pressure regulating valve 6. The gas in the flash tank 8 enters the medium-temperature compressor 1 through the parallel heat exchanger 4. The liquid in the flash tank 8 enters the low-temperature evaporator 9 and the medium-temperature evaporator 10. After passing through the low-temperature evaporator 9, the refrigerant enters the low-temperature compressor 11, mixes with the refrigerant passing through the medium-temperature evaporator 10, and enters the medium-pressure gas inlet of the ejector 7. Thus, the entire refrigeration work is completed.

[0043] For the separator located between the outlet of the gas cooler and the high-pressure gas inlet of the ejector, after the high-pressure CO2 gas passes through the gas cooler, a small amount of CO2 liquid or misty gas will enter the high-pressure gas inlet of the ejector along the pipeline. By setting a separator before the ejector, the gas can be separated and directly enter the high-pressure gas inlet of the ejector. The separated liquid or misty gas can be converted into liquid through the pressure regulating valve and enter the flash tank. It is possible to separate the gas-liquid in the high-pressure section without losing any system energy efficiency, make the refrigerant entering the high-pressure gas inlet of the ejector be gaseous, ensure the efficiency of the ejector, and thus ensure the energy efficiency of the system.

[0044] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A separation system for the pre-injection of a CO2 refrigeration unit, characterized in that: It includes a medium-temperature compressor, an oil separator, an air cooler, a heat exchanger, a separator, a pressure regulating valve, an ejector, a flash tank, a low-temperature evaporator, a medium-temperature evaporator and a low-temperature compressor, wherein the output end of the medium-temperature compressor is connected to the oil separator, the output end of the oil separator is connected to the air cooler, the output end of the air cooler is connected to the first inlet of the heat exchanger, the first outlet of the heat exchanger is connected to the inlet of the separator, the separator is used to separate the refrigerant into gas and liquid, the gas output end of the separator is connected to the ejector, the liquid output end of the separator is connected to the flash tank, the output end of the ejector is connected to the flash tank, the flash tank includes a gas outlet and a liquid outlet, wherein the gas outlet is connected to the second inlet of the heat exchanger, and the second outlet of the heat exchanger is connected to the medium-temperature compressor; the liquid outlet of the flash tank is respectively connected to the low-temperature evaporator and the medium-temperature evaporator, the refrigerant enters the low-temperature compressor after passing through the low-temperature evaporator, is mixed with the refrigerant passing through the medium-temperature evaporator, and enters the medium-pressure gas inlet of the ejector; The separator comprises a separator cylinder, the outer wall of the separator cylinder is provided with a refrigerant inlet, an impact plate is provided at a position corresponding to the refrigerant inlet in the separator cylinder, an upper guide plate is provided above the impact plate, a gas refrigerant outlet is provided above the separator cylinder; a lower guide plate is provided below the impact plate; and a liquid refrigerant outlet is provided below the lower guide plate; The impact plate is arranged vertically, and the back of the impact plate is connected with a middle-layer guide plate, and the middle-layer guide plate is welded to the inner side of the separator cylinder; The middle guide plate is a circular plate, on which evenly distributed through holes are opened, and the sum of the cross-sectional areas of all the through holes must be larger than the cross-sectional area of ​​the refrigerant inlet; The lower guide plate is a circular plate with a notch. The outer diameter of the lower guide plate matches the inner diameter of the separator cylinder. The lower guide plate is welded to the inner side of the separator cylinder. The notch is arranged on the outer circumferential surface of the circular plate to guide the refrigerant blocked by the impact plate.

2. The separation system for the pre-injection of a CO2 refrigeration unit according to claim 1 is characterized in that: A separator upper end cover is arranged above the separator cylinder, and a separator lower end cover is arranged below the separator cylinder. The gas refrigerant outlet is arranged on the separator upper end cover, and the liquid refrigerant outlet is arranged on the separator lower end cover.

3. The separation system for the pre-injection of a CO2 refrigeration unit according to claim 1 is characterized in that: A plurality of groups of auxiliary guide plates are arranged on the side of the impact plate facing the refrigerant inlet, and the auxiliary guide plates are arranged in a herringbone shape. Specifically, each group of auxiliary guide plates forms a herringbone structure, and the two left and right auxiliary guide plates of each group are staggered in the height direction. The cross-section formed by all the auxiliary guide plates can completely cover the projection shape of the refrigerant inlet on the impact plate.

4. The separation system for the pre-injection of a CO2 refrigeration unit according to claim 1 is characterized in that: The upper guide plate is a circular plate, on which evenly distributed through holes are opened, and the sum of the cross-sectional areas of all the through holes must be larger than the cross-sectional area of ​​the refrigerant inlet.

5. The separation system for the pre-injection of a CO2 refrigeration unit according to claim 1 is characterized in that: The circular hole positions of the upper guide plate and the middle guide plate are all staggered without overlap.

6. The separation system for the pre-injection of a CO2 refrigeration unit according to claim 1 is characterized in that: A filter screen is arranged between the upper guide plate and the upper end cover of the separator, and the mesh number of the filter screen is 100-150 meshes.

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