Testing device for gas-liquid two-phase flow mixing

Abstract

A testing device for gas-liquid two-phase flow mixing comprises a box body, a gas phase distribution chamber, a gas-liquid mixing chamber and a gas-liquid collecting chamber which are sequentially arranged from bottom to top are arranged in the box body, and the gas phase distribution chamber and the gas-liquid mixing chamber are separated through a first middle partition plate with a plurality of first through holes; the gas-liquid mixing chamber and the gas-liquid collecting chamber are separated by a second middle partition plate with a plurality of second through holes; the bottom of the gas-phase distribution chamber is provided with a gas-phase inlet through which a gas-phase medium enters, and the side wall of the lower part of the gas-liquid mixing chamber is provided with a liquid-phase inlet through which a liquid-phase medium enters; the gas-liquid collecting chamber is provided with a gas-liquid outlet; the wall surface of the box body is a transparent surface, so that the high-definition camera can record the flowing condition of gas and liquid in the box body through the transparent surface; and the gas phase uniform distribution unit is arranged in the gas phase distribution chamber and is used for uniformly distributing the gas phase entering from the gas phase inlet in the gas phase distribution chamber. According to the utility model, the gas-liquid two-phase flow mixing condition can be conveniently researched.

Description

A test apparatus for gas-liquid two-phase flow mixing Technical Field

[0001] This utility model belongs to the field of experimental device technology, specifically relating to an experimental device for gas-liquid two-phase flow mixing. Background Technology

[0002] In recent years, the oil refining and chemical industry has gradually moved towards large-scale operations. With this trend, both domestic and international developers are placing increasing emphasis on environmental protection and energy conservation. In the reforming aromatics sector, to reduce energy consumption in units such as compressors and furnaces, domestic and international process contractors are developing high-performance catalysts to lower the hydrogen-to-hydrogen ratio during unit operation, thereby achieving energy conservation and consumption reduction.

[0003] For wound tube heat exchangers used in aromatic reforming units, the reaction feed flows through the tubes and consists of gaseous circulating hydrogen and liquid feed oil. The gas and liquid phases enter the tube box of the wound tube heat exchanger through separate pipes. After thorough mixing by a gas-liquid distributor, the gas phase carries the liquid phase into each heat exchange tube, where it exchanges heat with the reaction effluent in the shell side of the heat exchanger. At this point, the entrainment capacity, mixing condition, and uniform distribution of the gas and liquid phases to each heat exchange tube are crucial and significantly affect the heat exchanger's performance. Existing gas-liquid distribution technology can meet the operational requirements of equipment at current market hydrogen-to-hydrogen ratios. However, as the hydrogen-to-hydrogen ratio gradually decreases, this technology may encounter problems with the gas phase's inability to carry the liquid phase upwards, and the mixing condition of the gas and liquid phases within the gas-liquid distributor requires further verification. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a test device for gas-liquid two-phase flow mixing in light of the current state of the technology, so as to facilitate the study of gas-liquid two-phase flow mixing.

[0005] The technical solution adopted by this utility model to solve the above-mentioned technical problems is: a test device for gas-liquid two-phase flow mixing, characterized in that it includes:

[0006] The enclosure contains, from bottom to top, a gas phase distribution chamber, a gas-liquid mixing chamber, and a gas-liquid collection chamber. The gas phase distribution chamber and the gas-liquid mixing chamber are separated by a first intermediate partition, which has multiple through holes of the same thickness. The gas-liquid mixing chamber and the gas-liquid collection chamber are separated by a second intermediate partition, which has multiple through holes of the same thickness. The bottom of the gas phase distribution chamber has a gas phase inlet for gaseous media, and the lower side wall of the gas-liquid mixing chamber has a liquid phase inlet for liquid media. The gas-liquid collection chamber has a gas-liquid outlet for gas-liquid output. The walls of the enclosure are transparent, allowing a high-definition camera to record the gas-liquid flow inside the enclosure.

[0007] A gas phase uniform distribution unit is provided in the gas phase distribution chamber to ensure that the gas phase entering from the gas phase inlet is uniformly distributed in the gas phase distribution chamber.

[0008] During the experiment, the gaseous medium is introduced into the gas distribution chamber through the gas inlet and is evenly distributed in the gas distribution chamber under the action of the gas uniform distribution unit. Then, it flows upward into the gas-liquid mixing chamber through the first through hole on the first intermediate partition. The liquid medium enters the gas-liquid mixing chamber through the liquid inlet and flows upward under the carrying effect of the gaseous medium flowing upward through the first through hole. It then flows upward into the gas-liquid collection chamber through the second through hole on the second intermediate partition and finally flows out from the gas-liquid outlet. Throughout the process, the gas-liquid flow, the droplet size distribution, and the distribution of gas and liquid in the cross-section of the gas-liquid mixing chamber and the gas-liquid collection chamber can all be recorded and analyzed using existing high-definition cameras.

[0009] Meanwhile, the design of the second intermediate partition in this invention can evenly distribute the gas-liquid two-phase medium, and is also similar to the tube sheet in existing heat exchangers, simulating the scenario of the gas-liquid two-phase medium entering the heat exchange tube through the tube sheet, making the test scenario of this invention closer to the actual application scenario.

[0010] In this invention, during testing, to prevent liquid phase leakage downwards through the first through-hole, the flow velocity of the gas phase is ensured to be greater than the velocity at the leakage point. This allows the gas phase flowing upwards through the first through-hole to support the liquid phase, preventing leakage. Therefore, the design of the first intermediate partition in this invention can evenly distribute the gas phase medium while preventing the liquid phase medium from flowing downwards.

[0011] The aforementioned transparent surface also allows the tester to easily observe the interior of the chamber.

[0012] To ensure a stable liquid phase input, the liquid phase inlet is preferably a plurality of spaced-apart small holes;

[0013] It also includes a liquid phase distribution unit, which is located on the outside of the housing corresponding to the liquid phase inlet and has a channel for the flow of liquid phase medium. The channel has a liquid phase input end for the liquid phase medium to enter and a liquid phase output end for the liquid phase medium to exit. The liquid phase output end is a plurality of horizontally extending and side-by-side liquid guide strips. The first end of each liquid guide strip is connected to the channel, and the second end of each liquid guide strip is supported at its corresponding small hole to guide the liquid phase medium in the channel into the small hole.

[0014] The aforementioned fluid guide strip can be made from existing tubing, pipettes, etc.

[0015] To ensure that the liquid medium can enter each liquid guide bar evenly, preferably, the channel is provided with a flow equalization plate, which is horizontally blocked between the liquid input end and the liquid output end, and the flow equalization plate is provided with multiple flow equalization holes for the liquid medium to pass through.

[0016] Preferably, multiple small holes spaced apart in the horizontal direction are grouped together, with at least two groups arranged at intervals in the vertical direction, and the vertical distance between the lowest small hole and the first intermediate partition is 200-300 mm. This distance ensures that the small hole is above the liquid phase on the first intermediate partition, preventing the small hole from being covered by the liquid phase, and also ensures that the liquid phase medium output from each small hole is uniformly distributed on the first intermediate partition.

[0017] In the above scheme, in order to better achieve uniform distribution of the gaseous medium, preferably, the gas distribution chamber is filled with multiple small spheres of equal diameter to form the aforementioned gas phase uniform distribution unit. Alternatively, other existing filling materials can also be used for the gas phase uniform distribution unit.

[0018] Furthermore, let the diameter of a single sphere be D1, and the diameter of a single first through hole be D2, both satisfying: D1 < 2 × D2. This is to facilitate uniform distribution of the gaseous medium.

[0019] Preferably, the diameter of the first through hole is smaller than the diameter of the second through hole, and the diameter of the second through hole corresponds to the inner diameter of the heat exchange tube in the wound tube heat exchanger.

[0020] In the above schemes, to better simulate the actual application environment, preferably, the cross-section of the gas-liquid mixing chamber is fan-shaped, which has a first straight segment, a second straight segment, and an arc segment. The first straight segment and the second straight segment are arranged at an acute angle, and the first end of the first straight segment joins the first end of the second straight segment, with the aforementioned liquid phase inlet located at the joint. The second ends of the first straight segment and the second straight segment are respectively connected to the two ends of the arc segment. Existing gas-liquid distributors are cylindrical. The fan-shaped gas-liquid mixing chamber of this invention simulates a local fan-shaped area in the circumferential direction within a cylindrical gas-liquid distributor, ensuring that the experiment is as close as possible to the real application environment while meeting the experimental requirements for detection and recording of gas-liquid two-phase flow.

[0021] Preferably, the sidewalls of the gas-liquid mixing chamber corresponding to the first and second straight segments are provided with multiple test holes that can be opened and closed at horizontal intervals; the multiple test holes spaced at horizontal intervals form a group, and there are two groups, respectively corresponding to the upper and lower parts of the gas-liquid mixing chamber. The test holes can be used to measure the gas phase velocity in different areas of the fan-shaped cross-section when a gas phase medium is introduced alone before the test (by inserting a Pitot tube into the test hole for measurement), to verify the uniformity of the gas phase distribution. During the formal test, each test hole can be plugged with a stopper or the like.

[0022] Preferably, the cross-sections of the gas phase distribution chamber and the gas-liquid collection chamber are fan-shaped, consistent with the cross-sectional shape of the gas-liquid mixing chamber; the sidewalls of the gas-liquid collection chamber corresponding to the straight segment of the fan shape are provided with the aforementioned gas-liquid outlets.

[0023] Compared with the prior art, the advantages of this utility model are as follows: By designing the interior of the chamber to have a gas phase distribution chamber, a gas-liquid mixing chamber, and a gas-liquid collection chamber, and separating the gas phase distribution chamber and the gas-liquid mixing chamber by a first intermediate partition with multiple first through holes, and separating the gas-liquid mixing chamber and the gas-liquid collection chamber by a second intermediate partition with multiple second through holes, and by providing a gas phase uniform distribution unit in the gas phase distribution chamber, the gas phase medium is introduced into the gas phase distribution chamber through the gas phase inlet during the experiment, and is evenly distributed in the gas phase distribution chamber under the action of the gas phase uniform distribution unit. The liquid phase medium enters the gas-liquid mixing chamber through the first through-hole on the first intermediate partition plate, and then flows upward into the gas-liquid mixing chamber through the liquid inlet. Under the carrying action of the gas phase medium flowing upward through the first through-hole, it flows upward into the gas-liquid collection chamber through the second through-hole on the second intermediate partition plate, and finally flows out from the gas-liquid outlet. Throughout the process, the gas-liquid flow, the droplet size distribution, and the distribution of gas and liquid in the cross-section of the gas-liquid mixing chamber and the gas-liquid collection chamber can all be recorded and analyzed using existing high-definition cameras.

[0024] Meanwhile, the design of the second intermediate partition in this invention can evenly distribute the gas-liquid two-phase medium, and is also similar to the tube sheet in existing heat exchangers, simulating the scenario of the gas-liquid two-phase medium entering the heat exchange tube through the tube sheet, making the test scenario of this invention closer to the actual application scenario.

[0025] In this invention, during testing, to prevent liquid phase leakage downwards through the first through-hole, the flow velocity of the gas phase is ensured to be greater than the velocity at the leakage point. This allows the gas phase flowing upwards through the first through-hole to support the liquid phase, preventing leakage. Therefore, the design of the first intermediate partition in this invention can evenly distribute the gas phase medium while preventing the liquid phase medium from flowing downwards. Attached Figure Description

[0026] Figure 1 is a structural schematic diagram of an embodiment of the present utility model;

[0027] Figure 2 is a structural schematic diagram of an embodiment of the present invention from another perspective;

[0028] Figure 3 is a longitudinal sectional view of an embodiment of the present invention;

[0029] Figure 4 is an enlarged view of part A in Figure 3;

[0030] Figure 5 is a cross-sectional view of an embodiment of the present utility model;

[0031] Figure 6 is an enlarged view of part B in Figure 5. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] As shown in Figures 1 to 6, this is a preferred embodiment of a test device for gas-liquid two-phase flow mixing according to the present invention. This test device is particularly suitable for gas-liquid distribution tests of reformed aromatic hydrocarbons and includes a housing 1, a gas phase uniform distribution unit 2, and a liquid phase uniform distribution unit 3.

[0034] The housing 1 contains, from bottom to top, a gas phase distribution chamber 11, a gas-liquid mixing chamber 12, and a gas-liquid collection chamber 13. The bottom of the gas phase distribution chamber 11 has a gas phase inlet 111 for the gas phase medium to enter. The gas phase inlet 111 is connected to the gas outlet of an existing blower (such as a centrifugal compressor) via a connecting pipe. Pressure gauges (such as digital pressure gauges) are installed on the gas phase inlet and the connecting pipe of the blower to facilitate observation and recording of the gas pressure within the connecting pipe. Simultaneously, a gas phase equalization unit 2 is provided within the gas phase distribution chamber 11 to ensure that the gas phase entering through the gas phase inlet 111 is evenly distributed within the gas phase distribution chamber 11. In this embodiment, the gas phase distribution chamber 11 is filled with multiple small balls of equal diameter to form the aforementioned gas phase equalization unit 2. As shown in Figure 3, the multiple small balls of equal diameter are constrained by a net at the center of the gas phase distribution chamber 11 in the vertical direction, thereby ensuring that the gas phase medium input from the gas phase inlet 111 is evenly distributed within the gas phase distribution chamber 11.

[0035] The gas-liquid mixing chamber 12 and the gas phase distribution chamber 11 are separated by a first intermediate partition 14, and the first intermediate partition 14 has a plurality of first through holes 140 that penetrate the thickness of the plate, so that the gas phase medium in the gas phase distribution chamber 11 can enter the gas-liquid mixing chamber 12 through the first through holes 140. In this embodiment, the aperture of a single first through hole 140 is denoted as D2, and the diameter of a single sphere is denoted as D1, both of which satisfy: D1 < 2 × D2, to facilitate uniform gas phase distribution. The lower side wall of the gas-liquid mixing chamber 12 is provided with a liquid inlet 121 for the liquid medium to enter. The liquid inlet 121 consists of multiple small holes arranged at intervals, and the multiple small holes distributed at intervals in the horizontal direction form a group, with at least two groups arranged at intervals in the vertical direction. The vertical distance between the lowest small hole and the first middle partition plate 14 is 200-300 mm (it can be any value between 200-300 mm, such as 200, 230, 260, 300 mm, etc.). The aforementioned liquid phase distribution unit 3 is located on the outside of the housing 1, corresponding to the liquid phase inlet 121, and has a channel 30 for the flow of liquid phase medium. The channel 30 has a liquid phase input end for the liquid phase medium to enter and a liquid phase output end for the liquid phase medium to exit. A flow equalization plate 32 is provided inside the channel 30, which is horizontally positioned between the liquid phase input end and the liquid phase output end. The flow equalization plate 32 has multiple flow equalization holes 320 spaced apart to allow the liquid phase medium to pass through, so that the liquid phase medium can be evenly distributed in the channel 30. In this embodiment, the liquid phase output end is a plurality of horizontally extending and side-by-side liquid guide strips 31 (in this embodiment, the liquid guide strips 31 are existing tubing). The first end of each liquid guide strip 31 is connected to the channel 30, and the second end of each liquid guide strip 31 is supported at its corresponding small hole, so as to guide the liquid phase medium in the channel 30 into the small hole, thereby allowing the liquid phase medium to flow evenly into the gas-liquid mixing chamber 12 and be carried upward by the gas phase medium. Meanwhile, the liquid phase input end of channel 30 can be connected to an external liquid storage tank through a pipeline, and a pump, flow regulating valve, flow meter, etc. are installed on the pipeline.

[0036] The gas-liquid collection chamber 13 and the gas-liquid mixing chamber 12 are separated by a second intermediate partition 15, and the second intermediate partition 15 has a plurality of second through holes 150 that penetrate the thickness of the plate. In this embodiment, the diameter of a single second through hole 150 is larger than the diameter of a single first through hole 140, and the diameter of the second through hole 150 corresponds to the inner diameter of the heat exchange tube in the wound tube heat exchanger. That is, the second intermediate partition 15 in this embodiment is similar to the tube sheet used to support the ends of the heat exchange tube in an existing wound tube heat exchanger, and can simulate the situation of gas and liquid flowing upward through the tube sheet.

[0037] In this embodiment, the wall of the chamber 1 is transparent (it can be made of acrylic transparent sheet) so that a high-definition camera can record the flow of gas and liquid inside the chamber 1 through the transparent surface. In actual experiments, the high-definition camera can detect and record the gas and liquid flow, droplet size distribution, and gas and liquid distribution within the chamber from the side and top of the chamber 1. To avoid droplets adhering to the wall and affecting observation, this embodiment applies a conventional high-definition hydrophobic coating to the inner wall of the chamber 1.

[0038] Furthermore, the cross-section of the housing 1 is fan-shaped (i.e., the cross-sections of the gas phase distribution chamber 11, the gas-liquid mixing chamber 12, and the gas-liquid collection chamber 13 are all fan-shaped; correspondingly, the first intermediate partition 14 and the second intermediate partition 15 are adapted fan-shaped plates). This fan shape is taken from a local fan-shaped area in the circumferential direction of an existing cylindrical gas-liquid distributor, and has a first straight segment, a second straight segment, and an arc segment. The first straight segment and the second straight segment are arranged at an acute angle, and the first end of the first straight segment and the first end of the second straight segment are joined by a short straight line, and the aforementioned liquid phase inlet 121 is provided at the joint. The second ends of the first straight segment and the second straight segment are respectively connected to the two ends of the arc segment. This ensures that the experiment closely approximates the actual application scenario while meeting the experimental requirements for detection and recording of gas-liquid two-phase flow.

[0039] Meanwhile, multiple openable and closable test holes 122 are provided at horizontal intervals on the side walls of the gas-liquid mixing chamber 12 corresponding to the first and second straight segments. These test holes 122 are arranged in two groups, one at the top and one at the bottom of the gas-liquid mixing chamber 12. Before the test, a gaseous medium is introduced separately. The test holes are designed to measure the gas phase velocity in different regions of the cross-section within the gas-liquid mixing chamber 12 (measured using an existing Pitot tube inserted into the test hole) to verify the uniformity of the gas phase distribution. During the formal test, the test holes 122 can be plugged.

[0040] In this embodiment, to collect the gas and liquid generated during the experiment, the side wall of the gas and liquid collection chamber 13 corresponding to the fan-shaped straight segment is provided with a gas and liquid outlet 131 for gas and liquid output. The gas and liquid are collected together after being output through the gas and liquid outlet 131 to facilitate subsequent processing and avoid the gas and liquid used in the experiment from being directly discharged into the external environment and causing pollution.

[0041] Meanwhile, as shown in Figure 3, in order to facilitate assembly, the box 1 in this embodiment is assembled with the first intermediate partition 14 and the second intermediate partition 15 by three units. The three units are arranged from top to bottom in sequence, and the units are separated by corresponding intermediate partitions.

[0042] During the experiment, the gaseous medium is introduced into the gas distribution chamber 11 through the gas inlet 111 and is evenly distributed in the gas distribution chamber 11 under the action of the gas uniform distribution unit 2. Then, it flows upward into the gas-liquid mixing chamber 12 through the first through hole 140 on the first intermediate partition 14. The liquid medium enters the gas-liquid mixing chamber 12 through the liquid inlet 121 and flows upward under the carrying action of the gaseous medium flowing upward through the first through hole 140. It then flows upward into the gas-liquid collection chamber 13 through the second through hole 150 on the second intermediate partition 15 and finally flows out from the gas-liquid outlet 131. Throughout the process, the gas-liquid flow, the droplet size distribution, and the distribution of gas and liquid in the cross-section of the gas-liquid mixing chamber and the gas-liquid collection chamber can all be recorded and analyzed using existing high-definition cameras.

[0043] During the experiment, to prevent the liquid phase from leaking downwards through the first through-hole 140, the flow velocity of the gas phase must be greater than the velocity at the leakage point. This ensures that the gas phase flowing upwards through the first through-hole 140 can support the liquid phase, preventing leakage. Therefore, the design of the first intermediate partition 14 in this embodiment can evenly distribute the gas phase medium while preventing the liquid phase medium from flowing downwards.

Claims

1. A test apparatus for gas-liquid two-phase flow mixing, characterized in that... It includes: a housing (1), which has a gas phase distribution chamber (11), a gas-liquid mixing chamber (12), and a gas-liquid collection chamber (13) arranged sequentially from bottom to top. The gas phase distribution chamber (11) and the gas-liquid mixing chamber (12) are separated by a first intermediate partition (14), and the first intermediate partition (14) has a plurality of first through holes (140) that penetrate the thickness of the plate at intervals. The gas-liquid mixing chamber (12) and the gas-liquid collection chamber (13) are separated by a second intermediate partition (15), and the second intermediate partition (15) has a plurality of second through holes (150) that penetrate the thickness of the plate at intervals. 0); The bottom of the gas phase distribution chamber (11) has a gas phase inlet (111) for gas phase medium to enter, and the lower side wall of the gas-liquid mixing chamber (12) has a liquid phase inlet (121) for liquid phase medium to enter; The gas-liquid collection chamber (13) has a gas-liquid outlet (131) for gas-liquid output; The wall of the box (1) is a transparent surface so that the high-definition camera can record the flow of gas and liquid inside the box (1) through the transparent surface; The gas phase uniform distribution unit (2) is located in the gas phase distribution chamber (11) and is used to uniformly distribute the gas phase entering through the gas phase inlet (111) in the gas phase distribution chamber (11).

2. The experimental apparatus according to claim 1, characterized in that: The liquid inlet (121) consists of multiple spaced small holes; it also includes a liquid distribution unit (3), which is located on the outside of the housing (1) corresponding to the liquid inlet (121) and has a channel (30) for the flow of liquid medium. The channel (30) has a liquid input end for the liquid medium to enter and a liquid output end for the liquid medium to exit. The liquid output end consists of multiple horizontally extending and side-by-side liquid guide strips (31). The first end of each liquid guide strip (31) is connected to the channel (30), and the second end of each liquid guide strip (31) is supported at its corresponding small hole to guide the liquid medium in the channel (30) into the small hole.

3. The experimental apparatus according to claim 2, characterized in that: The channel (30) is provided with a flow equalization plate (32), which is horizontally blocked between the liquid phase input end and the liquid phase output end, and multiple flow equalization holes (320) for the liquid phase medium to pass through are distributed at intervals on the flow equalization plate (32).

4. The test apparatus according to claim 2, characterized in that: Multiple small holes spaced apart in the horizontal direction are grouped together, with at least two groups arranged at intervals in the vertical direction, and the vertical distance between the lowest small hole and the first middle partition plate (14) is 200-300mm.

5. The test apparatus according to claim 1, characterized in that: The gas phase distribution chamber (11) is filled with multiple small balls of equal diameter to form the gas phase uniform distribution unit (2) mentioned above.

6. The test apparatus according to claim 5, characterized in that: Let the diameter of a single ball be D1 and the diameter of a single first through hole (140) be D2. Both satisfy the condition: D1 < 2 × D2.

7. The test apparatus according to claim 1, characterized in that: The diameter of the first through hole (140) is smaller than the diameter of the second through hole (150), and the diameter of the second through hole (150) corresponds to the inner diameter of the heat exchange tube in the wound tube heat exchanger.

8. The test apparatus according to any one of claims 1 to 7, characterized in that: The cross-section of the gas-liquid mixing chamber (12) is fan-shaped, which has a first straight segment, a second straight segment and an arc segment. The first straight segment and the second straight segment are arranged at an acute angle, and the first end of the first straight segment is connected to the first end of the second straight segment. The connection point is provided with the liquid inlet (121) mentioned above. The second end of the first straight segment and the second end of the second straight segment are respectively connected to the two ends of the arc segment.

9. The test apparatus according to claim 8, characterized in that: The gas-liquid mixing chamber (12) corresponding to the first straight segment and the second straight segment is provided with multiple test holes (122) that can be opened and closed at intervals along the horizontal direction on the side wall; the multiple test holes (122) at intervals along the horizontal direction are grouped into two groups, which are respectively provided for the upper and lower parts of the gas-liquid mixing chamber (12).

10. The test apparatus according to claim 8, characterized in that: The cross-sections of the gas phase distribution chamber (11) and the gas-liquid collection chamber (13) are fan-shaped, which is consistent with the cross-sectional shape of the gas-liquid mixing chamber (12); the side wall of the gas-liquid collection chamber (13) corresponding to the straight segment of the fan shape is provided with the above-mentioned gas-liquid outlet (131).

Images