Gas-liquid two-phase pipe flow noise elimination experiment system and experiment method thereof

Abstract

The invention relates to the technical field of gas-liquid two-phase pipe flow, and discloses a gas-liquid two-phase pipe flow noise elimination experiment system and an experiment method.The experiment system comprises a liquid inlet system, a gas-liquid mixing input pipe, an observation section, an attenuator and a circulation system which are sequentially and circularly connected, and a gas inlet system is connected to the gas inlet end of the gas-liquid mixing input pipe; the observation section and the attenuator are connected with an acquisition device; the liquid inlet system is used for providing water flow with adjustable pressure and flow for the pipeline; the gas inlet system comprises a carbon dioxide gas tank; the gas-liquid mixing input pipe is used for realizing gas-liquid fusion; the attenuator is used for suppressing pressure pulsation and noise; and the acquisition device is used for performing video data acquisition on the observation section and acquiring noise and pressure of the attenuator. The specific size experiment design of the attenuator is targeted, the pressure pulsation characteristics and noise suppression conditions of different attenuators under different working conditions are monitored, and the noise suppression working conditions of different T-shaped gas-liquid two-phase pipe flows are simulated and demonstrated through the experiment system.

Description

Technical Field

[0001] The invention relates to the technical field of gas-liquid two-phase pipe flow, and in particular to a gas-liquid two-phase pipe flow noise elimination experimental system and an experimental method thereof. Background Art

[0002] Gas-liquid two-phase flow can cause severe pipeline vibration and generate loud noise. The vibration noise caused by pipeline fluid transmission is an important factor that directly affects the noise performance of ships, and pipeline vibration noise control is also an important part of the research on ship vibration reduction and noise reduction engineering. After the harmful gases in the combustion compartment of the ship's generator are treated, the remaining gas is a mixed gas composed of carbon dioxide and oxygen, of which the content of carbon dioxide is 90%. These gases will be mixed into the seawater through a T-shaped pipe. During the dissolution of carbon dioxide, a complex gas-liquid two-phase flow will be formed, which will generate serious noise pollution. This is one of the main two-phase flow working scenarios of ships.

[0003] Since the gas-liquid flow rate, flow pattern, attenuator shape, size, and location of the T-type pipeline have a significant impact on the pressure pulsation and noise of the T-type gas-liquid two-phase pipeline, the attenuation law between the T-type pipeline and the corresponding attenuator is studied to eliminate or suppress the noise generated by the gas-liquid two-phase flow. Therefore, it is necessary to establish a gas-liquid two-phase pipe flow noise elimination experimental system. Summary of the invention

[0004] In order to overcome or alleviate one or more of the above technical problems, the purpose of the present invention is to provide a gas-liquid two-phase pipe flow noise elimination experimental system and an experimental method thereof, which has a flexible and detachable observation section and a U-shaped pipe for convenient installation of pulsation attenuators at various points. Each part is flexibly detachable, which is convenient for adjustment during the experiment and adaptable to a variety of different experimental schemes.

[0005] The present invention provides the following technical solutions:

[0006] On the one hand, the present invention provides a gas-liquid two-phase pipe flow noise elimination experimental system, which includes a liquid inlet system, a gas-liquid mixing input pipe, an observation section, an attenuator and a circulation system which are cyclically connected in sequence, the gas inlet system is connected to the gas inlet end of the gas-liquid mixing input pipe, and the observation section and the attenuator are connected to a collection device;

[0007] The liquid inlet system is used to provide water flow with adjustable pressure and flow rate to the pipeline, and the corresponding flow rate and pressure parameters are set according to the requirements of different stages of the experiment;

[0008] The air intake system includes a carbon dioxide gas tank, which is used to supply a carbon dioxide gas flow with a certain pressure and flow rate, and the flow rate and pressure can be adjusted according to experimental requirements;

[0009] The gas-liquid mixing input pipe is used to achieve gas-liquid fusion;

[0010] The observation section is used to observe the flow characteristics of the gas-liquid mixture; the attenuator is used to suppress pressure pulsation and noise, and the pipe section where the attenuator is located is a U-shaped pipe;

[0011] The acquisition device is used to collect video data of the observation section and to collect noise and pressure of the attenuator.

[0012] According to some embodiments, the liquid intake system includes a water pump; the air intake system includes a gas flow meter; the gas-liquid mixing input pipe is T-shaped; the circulation system includes a pressurized water tank that provides continuous power; and the observation section is selected from a transparent material.

[0013] According to some embodiments, the angle at which the liquid and gas input pipelines of the gas-liquid mixing input pipe intersect is selected from 45°, 90° or 135°.

[0014] On the other hand, the present invention also provides an experimental method for the above-mentioned gas-liquid two-phase pipe flow noise elimination experimental system, which is characterized by comprising the following steps:

[0015] S1: Formulate different experimental schemes to observe different gas-liquid flow ratios, examine the changes in the flow pattern in the gas-liquid mixed input pipe under different gas phase inflow angles, and examine the attenuation of pipeline noise and pressure pulsation in the pipe before and after the installation of the attenuator. Assemble the liquid inlet system, gas inlet system, gas-liquid mixed input pipe, observation section, attenuator and circulation system in the gas-liquid two-phase pipe flow noise elimination experimental system according to different experimental schemes;

[0016] S2: Arrange pressure sensors and noise sensors on the U-shaped pipe and arrange cameras in the observation section;

[0017] S3: Start the various equipment of the gas-liquid two-phase pipe flow noise elimination experimental system to start the test, use a high-speed camera to capture video information of the observation section, and analyze the flow pattern corresponding to the T-type gas-liquid two-phase pipe flow at different gas-liquid flow rates and different gas phase inflow angles through the collected video information; analyze the pressure pulsation characteristics of a single attenuator under different installation forms, as well as the pressure pulsation characteristics of the same attenuator in series.

[0018] According to some embodiments, step S1 comprises the following steps:

[0019] S11: To observe the flow pattern changes in the gas-liquid mixed inlet pipe at different gas-liquid flow ratios at a specified gas-liquid inlet pressure, the gas-liquid conversion velocity in the plug flow or slug flow region is selected and converted into gas-liquid flow, and a gas-liquid flow and corresponding conversion velocity table is established; the gas-liquid flow is calculated as follows:

[0020]

[0021] Q l =J l 3600A m (2)

[0022] In the formula, Q is the volume flow rate, J is the converted velocity, ρ a is the air density at room temperature and atmospheric pressure, ρ g is the density of CO2 under actual working conditions, subscripts g and l represent gas phase and liquid phase respectively, A m Represents the cross-sectional area of ​​a three-dimensional main pipe;

[0023] S12: In order to investigate the change of flow pattern in the gas-liquid mixed inlet pipe under different gas phase inlet angles, various gas phase inlet angles were selected;

[0024] S13: In order to investigate the attenuation of the pipeline noise of the gas-liquid mixed input pipe and the pressure pulsation in the pipe before and after the installation of the attenuator, different attenuator arrangements are designed.

[0025] According to some embodiments, in step S13, the different attenuator arrangements include one attenuator set on a U-shaped pipe or multiple attenuators connected in series along the U-shaped pipe, a single attenuator is located on the left or right side of the U-shaped pipe, and its state is upright or inverted.

[0026] According to some embodiments, in step S12, the gas phase inlet has a plurality of different inflow angles including 45°, 90° or 135°.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention provides a gas-liquid two-phase pipe flow noise elimination experimental system and an experimental method thereof. The liquid inlet system of the experimental system provides a water flow with adjustable pressure and flow rate for the pipeline, and the corresponding flow rate and pressure parameters are set according to the requirements of different stages of the experiment; the experimental system has a flexible and detachable observation section and a U-shaped pipeline for convenient installation of a pulsation attenuator at various points. Each part is flexible and detachable, which is convenient for adjustment during the experiment and adapts to a variety of different experimental schemes.

[0029] The experimental method provided by the present invention takes into account the various different configurations of attenuators that affect noise elimination, specifically utilizes the specific size experimental design of the H-type attenuator, uses pressure and noise sensors to monitor the pressure pulsation characteristics and noise suppression of different attenuators under different working conditions, so that people can simulate and demonstrate the noise suppression working conditions of different T-type gas-liquid two-phase pipe flows through the experimental device, and provide a basis for the noise reduction research of gas-liquid two-phase mixed equipment in actual working conditions such as ships, petroleum, and chemicals. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1A system structure block diagram of a gas-liquid two-phase pipe flow noise elimination experimental system provided in an embodiment of the present invention.

[0031] Figure 2 This is a diagram of the installation position of the pulsation attenuator provided in an embodiment of the present invention.

[0032] Figure 3 Schematic diagram of two T-shaped gas-liquid two-phase mixing pipelines provided in embodiments of the present invention.

[0033] Figure 4a A schematic diagram of the dimensions of a pulsation attenuator provided in an embodiment of the present invention.

[0034] Figure 4b A table of geometric dimensions of a pulsation attenuator provided in an embodiment of the present invention.

[0035] Figure 5 A side view of a pulsation attenuator provided in an embodiment of the present invention installed on both sides of a U-shaped tube.

[0036] Figure 6 A schematic diagram of the upstream, midstream and downstream of a U-shaped pipeline provided in an embodiment of the present invention.

[0037] Figure 7 Table 1 provides gas-liquid volume flow rates and corresponding conversion rates for embodiments of the present invention.

[0038] Figure 8 The angle that needs to be changed for the T-type gas-liquid two-phase mixing pipeline in Table 2 provided in the embodiment of the present invention.

[0039] Fig. 9 Table 3 provides the working condition numbers of different arrangements of a single attenuator in the embodiments of the present invention.

[0040] Fig.10 Table 4 provides operating condition numbers of different arrangements of the same attenuators in series in an embodiment of the present invention.

[0041] Fig.11 Insertion loss of a single attenuator installed according to an embodiment of the present invention.

[0042] Fig.12 The sound pressure level attenuation under installation of a single attenuator provided by an embodiment of the present invention.

[0043] Fig.13 The insertion loss of the same attenuator provided by the embodiment of the present invention when installed in series.

[0044] Fig.14 The sound pressure level attenuation of the same attenuator installed in series provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The present invention is described in detail below in conjunction with the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplify the present invention and do not constitute any limitation on the protection scope of the present invention. All reasonable changes and combinations within the scope of the inventive concept of the present invention fall within the protection scope of the present invention.

[0046] The present invention will be further described below in conjunction with the accompanying drawings.

[0047] Example 1

[0048] like Figure 1 The gas-liquid two-phase pipe flow noise elimination experimental system provided in this embodiment includes a liquid inlet system, a gas-liquid mixing input pipe, an observation section, an attenuator and a circulation system which are connected in a circular manner in sequence. The air inlet system is connected to the air inlet end of the gas-liquid mixing input pipe, and a collection device is connected to the observation section and the attenuator.

[0049] The inlet system provides water flow with adjustable pressure and flow rate to the pipeline, and the corresponding flow rate and pressure parameters are set according to the needs of different stages of the experiment. The main components include water pumps.

[0050] The air intake system consists of a carbon dioxide gas tank, which can supply a carbon dioxide (CO2) gas flow with a certain pressure and flow rate. The flow rate and pressure can also be adjusted according to the experimental requirements.

[0051] The gas-liquid mixing input pipe is used to achieve gas-liquid fusion, and its main components include a T-type mixing pipe, that is, a three-way pipe section.

[0052] The observation section is used to observe flow characteristics; the pipe section where the attenuator is located is a U-shaped pipe, and the attenuator is used to suppress pressure pulsation;

[0053] The acquisition device is used to collect video data of the observation section and to collect the noise and pressure of the attenuator.

[0054] As well as the installation pipe sections and tail-end processing sections between the various components. These pipe sections are all modularly designed and connected to each other through flanges, ensuring that the components can be easily combined and replaced according to different research purposes during the experiment. For example, when exploring the effectiveness of the gas-liquid mixing input section, the gas-liquid mixing input section, the liquid flow observation section and the noise test system can be retained, and the pressure pulsation attenuation pipe section and the tail-end processing section can be temporarily removed; conversely, when studying the attenuation effect of the attenuator, the attenuator pipe section needs to be installed, and the redundant observation section needs to be removed for targeted experiments.

[0055] During the specific implementation process, the main device parameters of the gas-liquid two-phase pipe flow noise elimination experimental system are selected as follows:

[0056] (1) Water pump: To simulate the high water pressure during underwater exhaust, a multi-stage centrifugal pump is used. The motor power is 4kW and the voltage can be 220V or 380V. When the flow rate Q = 3m 3 / h, the pump head H can reach 170m, the outlet is flange connected, and the outlet diameter is DN32.

[0057] (2) Gas flow meter: installed at the gas input end of the gas-liquid mixing input pipe, the gas flow meter is used to measure the flow rate of CO2.

[0058] (3) Hose: The air intake hose is made of PU and has a maximum pressure bearing capacity of 1 MPa.

[0059] (4) Gas-liquid mixing inlet pipe: Figure 3 (a) and Figure 3 (b) The gas-liquid mixing input pipe section is a customized three-way pipe section, which is used for mixing liquid and gas. It is made of stainless steel, with an input diameter of DN8. The angles at the intersection of the liquid and gas input pipes are 45°, 90°, and 135°, which can be changed. The gas-liquid mixture output diameter is DN40, and the two sides are connected to the DN25 water pipe and the DN40 observation pipe section respectively through customized flanges. The 90° gas-liquid mixing pipe section is as follows Figure 3 (a), other inclined pipes are as follows Figure 3 (b) as shown.

[0060] (5) Observation section: The observation tube is used to observe the gas-liquid two-phase flow morphology after mixing. It is made of plexiglass, has a maximum pressure of 1.6 MPa, a diameter of DN25, and is connected by flange connection.

[0061] (6) Attenuator: The main body of the attenuator pipe section is a U-shaped pipe with a diameter of DN25, such as Figure 5 Pulsation attenuators are installed on both sides of the U-shaped pipe, and the installation method is flange connection. Pressure sensors are installed in the middle and on both sides of the U-shaped pipe to obtain the pressure pulsation before and after the attenuator is installed. At the same time, the pressure upstream and downstream of the pressure pulsation attenuator are compared to judge the attenuation effect of the attenuator. The specific schematic diagram is as follows Figure 2 Four different pulse attenuators were prepared in the experiment, as shown in Figure 4(a) and Figure 4(b) shows the specific size and resonant frequency.

[0062] (7) Collection device: including high-speed camera, noise test equipment and pressure sensor in attenuator pipe section. High-speed camera is installed in the observation section to observe the flow state and flow type of transparent pipe section. Use digital high-speed camera with the maximum frequency not less than 480000fps. The noise detection equipment is microphone and preamplifier. The noise test equipment is installed downstream of attenuator pipe section to monitor and analyze the spectrum characteristics of noise under different attenuator installation schemes. The pressure sensor is piezoelectric ICP pressure sensor, installed in the U-shaped pipe section of attenuator test, with a range of 0-30MPa and a self-oscillation frequency ≥200kHz. The data acquisition equipment is iPotest series products, consisting of chassis and acquisition module. 4-channel input, each channel has AC, DC, ICP and other conditioning functions, equipped with Gigabit network port and 1 WIFI, equipped with core board with storage function. 24-bit ADC, synchronous acquisition, maximum sampling rate of 20KHz, anti-aliasing filter, built-in constant current source power supply, can be directly connected to ICP and IEPE sensors.

[0063] Noise and pressure sensor layout In order to obtain the noise and pressure pulsation characteristics of the pipeline under different attenuator installation methods, a piezoelectric pressure sensor is arranged on the U-shaped pipeline, and a noise sensor is installed downstream of the U-shaped pipeline. The specific layout method is as follows Figure 6 shown.

[0064] The specific experimental methods are as follows:

[0065] S1: Develop different experimental schemes to observe different gas-liquid flow ratios, examine the changes in the flow pattern of the gas-liquid mixed input pipe under different gas phase inflow angles, and examine the attenuation of pipeline noise and pressure pulsation in the pipe before and after the installation of the attenuator. Specifically:

[0066] S11: In order to observe the flow pattern changes of the pipeline at different gas-liquid flow ratios and the gas-liquid inlet pressure of 0.25 MPa, the gas-liquid conversion velocity in the plug flow or slug flow region was selected and converted into the gas-liquid flow rate as follows: Figure 7 As shown in Table 1. In the working condition number, the number after Q or L represents the gas phase or liquid phase conversion rate of the working condition, and the unit is NL / min or m3 / h, respectively. NL / min is the standard gas volume flow rate, and the density of air at normal temperature and pressure is used as a reference. The calculation method of gas-liquid flow rate is as follows:

[0067]

[0068] Q l =J l 3600A m (2)

[0069] In the formula, Q is the volume flow rate, J is the converted velocity, ρ a is the air density at room temperature and atmospheric pressure, ρg is the density of CO2 under actual working conditions, subscripts g and l represent gas phase and liquid phase respectively, A m Represents the cross-sectional area of ​​a three-dimensional main pipe.

[0070] S12: In order to investigate the changes in the flow pattern in the tube under different gas phase inflow angles, three different gas phase inlet inflow angles of 45°, 90°, and 135° were selected. The experimental working pressure was 0.25MPa, the liquid phase conversion velocity was maintained at 1.817m / s, and the gas phase conversion velocity was maintained at 0.126m / s. The corresponding conversion velocities were also distributed in the plug or slug flow area. The specific working conditions are as follows: Figure 8 As shown in Table 2. Among them, the number after A is the gas phase inflow angle, the unit is "°".

[0071] S13: In order to investigate the attenuation of pipeline noise and pressure pulsation in the pipe before and after the installation of the attenuator, Figure 2 Several different attenuator layouts are designed for the attenuator installation pipe section. The working conditions of the attenuator installed alone are as follows: Fig. 9 As shown in Table 3, the same attenuators are installed in series. Fig.10 As shown in Table 4, when attenuator 4 is installed upside down, its attenuation effect is poor, so there is no data related to attenuator 4. In the working condition number, "L" or "R" means that it is installed in Figure 2 The left or right side of the U-shaped tube, such as Figure 5 As shown; "U" or "D" indicates that the attenuator is upright or inverted. The inlet pressure is 0.25MPa, and the gas-liquid conversion speed is J g =0.288m / s,J l =1.817m / s, the corresponding flow type is intermittent flow with intense pressure pulsation, and the corresponding gas and liquid flow rates are, Q g =32.878NL / min, Q l =3.211m3 / h.

[0072] S2: Arrange pressure sensors and noise sensors on the U-shaped pipe, and arrange high-speed cameras in the observation section for video recording;

[0073] In order to obtain the noise and pressure pulsation characteristics of the pipeline under different attenuator installation methods, a piezoelectric pressure sensor is arranged on the U-shaped tube, and a noise sensor is installed downstream of the pipeline. The specific arrangement method is as follows: Figure 6As shown, the pressure measuring heads are respectively arranged at the upstream, midstream and downstream of the U-tube, and the pressure signals measured are represented by P1, P2 and P3 respectively, and the sound pressure level signal measured by the noise sensor is represented by SPL (Sound Pressure Level). Insertion loss needs to be introduced here to judge the attenuation effect of different attenuators and different arrangements, as shown in Formula 3. In addition, it is also necessary to judge the attenuation effect of environmental noise under different arrangements. The environmental noise of the U-tube without attenuator is subtracted from the environmental noise under different attenuator arrangements, which is used as the basis for judging the noise attenuation effect. The specific formula is shown in Formula 4:

[0074]

[0075] In the formula, K i Indicates different insertion losses; P′3 indicates the pressure measured by the pressure measuring head 3 before the attenuator is installed on the U-shaped tube; P3 indicates the pressure measured by the pressure measuring head 3 after the attenuator is installed.

[0076] ΔSPL=SPL′-SPL (4)

[0077] In the formula, ΔSPL represents the attenuation effect before and after the attenuator is installed, SPL' represents the sound pressure level before the attenuator is installed in the U-shaped tube, and SPL represents the sound pressure level after the attenuator is installed.

[0078] S3: Start the various equipment of the gas-liquid two-phase pipe flow noise elimination experimental system to start the test, use a high-speed camera to capture video information of the observation section, and analyze the flow pattern corresponding to the T-type gas-liquid two-phase pipe flow at different gas-liquid flow rates and different gas phase inflow angles through the collected video information; analyze the pressure pulsation characteristics of a single attenuator under different installation forms, as well as the pressure pulsation characteristics of the same attenuator in series.

[0079] Under the condition of single attenuator installation in Table 3, the attenuator insertion loss and environmental noise attenuation effect are as follows: Fig.11 , Fig.12 As shown. Fig.11 (a)(b) It can be seen that when the attenuator is installed upside down, the attenuator cavity will be filled with liquid. Regardless of whether it is installed on the left or right side of the U-shaped tube, attenuator 3 has the best attenuation effect. The attenuation frequencies are all around 372, 733, 1097, 1449, and 1821 Hz, and the attenuation amplitude is the largest around 733 Hz, which is close to its design frequency. The attenuation effect of attenuator 3 installed on the right side at each order frequency is much worse than that installed on the left side, because when installed on the right side, the attenuator is closer to the pressure measuring head 3, and the pressure pulsation loss in the transmission is less. The attenuation effect of attenuators 1, 2, and 4 is average.

[0080] from Fig.11(c)(d) It can be seen that when the attenuator is installed upright, the attenuator cavity is filled with gas. No matter it is installed on the left or right, attenuator 4 has the best attenuation effect on pressure pulsation, and the attenuation frequencies are all around 363.5, 727, 1091, 1456, and 1818 Hz. When attenuator 4 is installed on the left, it has the best attenuation effect near 1818 Hz, and when it is installed on the right, the frequency with the best attenuation effect is around 1097 Hz, which is far from the design frequency of attenuator 4. It is also found that when attenuator 4 is installed upright on the right side of the pipeline, its attenuation effect at each frequency is much worse than that when it is installed on the left, which is also attributed to the less pressure pulsation transmission loss. Attenuator 3 has a certain attenuation effect, and the attenuation frequency is close to the frequencies of each order of attenuator 4. The attenuation effects of the remaining attenuators are poor.

[0081] from Fig.12 (a)(b) It can be seen that under the "LD" (attenuator on the left and inverted installation) working condition, attenuator 3 has the best noise reduction effect, with noise reduction frequencies at 310, 618, 924, 1232, 1530, and 1845Hz, and the sound pressure level attenuation at 924Hz is the largest; attenuator 1 has a certain noise reduction effect near the same frequency. However, under the "RD" (attenuator on the right) working condition, the noise reduction effects of each attenuator are not ideal, which shows that pressure pulsation has a certain connection with noise.

[0082] from Fig.12 (c)(d) It can be seen that no matter attenuator 4 is installed on the left or right side, it has a good noise reduction effect; under the "LU" (attenuator is on the left and installed upright) working condition, the noise reduction frequencies are 472, 707, 948, 1172, 1419, 1654, and 1870 Hz; under the "RU" working condition, the corresponding noise reduction frequencies are 306, 615, 923, 1230, 1536, and 1846 Hz; near the various order frequencies of attenuator 4 under the "RU" working condition, attenuator 3 has a certain noise reduction effect.

[0083] In studying the pressure pulsation characteristics of the same attenuator in series, the working conditions of the same attenuator in series in Table 4 (such as L1-R1-D) are selected for comparison. The insertion loss of the attenuator and the environmental noise attenuation effect are as follows: Fig.13 , Fig.14 As shown. Fig.13 (a) shows that when the two attenuators are installed upside down, only the series installation of attenuator 3 can achieve a certain attenuation effect, and the attenuation frequencies are 356, 715, 1089, 1447, and 1827 Hz; compared with the case of a single attenuator installed Fig.11 Comparing (a) and (b), it is found that the attenuation effect of the attenuators installed in series is not as good as that of a single attenuator.

[0084] from Fig.13(b) It can be seen that when two attenuators are installed in an upright position, attenuators 2 and 4 can effectively attenuate pressure pulsation, and the attenuation frequencies are all around 363.5, 731, 1086.25, 1466, and 1815 Hz; Fig.11 Comparing (c) and (d), it is found that the attenuation effect of attenuator 4 is slightly improved when installed in series, while the attenuation effect of attenuator 2 is greatly improved.

[0085] from Fig.14 (a) It can be seen that the noise reduction effect of the attenuator series connection is not ideal when installed inverted.

[0086] from Fig.14 (b) It can be seen that under the upright series installation, attenuator 2 has a better noise attenuation effect, with frequencies of 532, 800, 1067, 1333, 1600, and 1866 Hz; compared with the previous Fig.12 (a)(b) It is found that the noise reduction effect of attenuator 2 is similar to that of attenuator 4 under the "LU" and "RU" working conditions; when the same attenuator 4 is connected in series and installed in an upright position, it has a certain noise reduction effect, and the frequency is close to that of attenuator 2.

[0087] Based on the experimental analysis of step S3, different pressure pulsation attenuators were designed based on the sound velocity of gas or liquid media (attenuators 2, 4 and attenuators 1, 3), and data of these attenuators under different installation conditions were collected. When a single attenuator is installed upside down, the attenuator cavity will be filled with liquid, and attenuator 3 has good pressure pulsation attenuation and noise reduction effects; but because it is installed on the right, the pressure pulsation loss during transmission is less, the effect of attenuator 3 is worse than that on the left, and the corresponding noise reduction effect is not ideal; when a single attenuator is installed upright, the attenuator cavity is filled with gas, and attenuator 4 has good pressure pulsation attenuation and noise reduction effects regardless of whether it is installed on the left or right; when attenuator 4 is installed on the right side of the pipeline, due to less pressure pulsation transmission loss, the pressure pulsation attenuation effect is slightly worse, but the noise reduction effect does not change;

[0088] Under the same attenuator series working condition, when installed inverted, only the series installation of attenuator 3 can have a certain attenuation effect, and the effect of series installation is not as good as that of a single installation. At this time, the noise reduction effect of each attenuator is not ideal; when installed upright, attenuators 2 and 4 can both attenuate pressure pulsation well. The effect of attenuator 4 installed in series is slightly improved compared with a single installation, but the noise reduction effect is average. The pressure pulsation attenuation and noise reduction effects of attenuator 2 are greatly improved.

[0089] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A gas-liquid two-phase pipe flow noise elimination experimental system, characterized by: It includes a liquid inlet system, a gas-liquid mixed inlet pipe, an observation section, an attenuator and a circulation system which are cyclically connected in sequence, the gas inlet system is connected to the gas inlet end of the gas-liquid mixed inlet pipe, and the observation section and the attenuator are connected to a collection device; The liquid inlet system is used to provide water flow with adjustable pressure and flow rate to the pipeline, and the corresponding flow rate and pressure parameters are set according to the requirements of different stages of the experiment; The air intake system includes a carbon dioxide gas tank, which is used to supply a carbon dioxide gas flow with a certain pressure and flow rate, and the flow rate and pressure can be adjusted according to experimental requirements; The gas-liquid mixing input pipe is used to achieve gas-liquid fusion; The observation section is used to observe the flow characteristics of the gas-liquid mixture; the attenuator is used to suppress pressure pulsation and noise, and the pipe section where the attenuator is located is a U-shaped pipe; The acquisition device is used to collect video data of the observation section and to collect noise and pressure of the attenuator.

2. The gas-liquid two-phase pipe flow noise elimination experimental system according to claim 1, characterized in that: The liquid inlet system includes a water pump; the air inlet system includes a gas flow meter; the gas-liquid mixing input pipe is T-shaped; the circulation system includes a pressurized water tank that provides continuous power; and the observation section is selected from a transparent material.

3. The gas-liquid two-phase pipe flow noise elimination experimental system according to claim 1, characterized in that: The angle at which the liquid and gas input pipelines of the gas-liquid mixing input pipe intersect is selected from 45°, 90° or 135°.

4. An experimental method for the gas-liquid two-phase pipe flow noise elimination experimental system as claimed in claims 1 to 3, characterized in that: The following steps are involved: S1: Formulate different experimental schemes to observe different gas-liquid flow ratios, examine the changes in the flow pattern in the gas-liquid mixed input pipe under different gas phase inflow angles, and examine the attenuation of pipeline noise and pressure pulsation in the pipe before and after the installation of the attenuator. Assemble the liquid inlet system, gas inlet system, gas-liquid mixed input pipe, observation section, attenuator and circulation system in the gas-liquid two-phase pipe flow noise elimination experimental system according to different experimental schemes; S2: Arrange pressure sensors and noise sensors on the U-shaped pipe and arrange cameras in the observation section; S3: Start the various equipment of the gas-liquid two-phase pipe flow noise elimination experimental system to start the test, use a high-speed camera to capture video information of the observation section, and analyze the flow pattern corresponding to the T-type gas-liquid two-phase pipe flow at different gas-liquid flow rates and different gas phase inflow angles through the collected video information; analyze the pressure pulsation characteristics of a single attenuator under different installation forms, as well as the pressure pulsation characteristics of the same attenuator in series.

5. The experimental method of the gas-liquid two-phase pipe flow noise elimination experimental system according to claim 4 is characterized by: Step S1 includes the following steps: S11: To observe the flow pattern changes in the gas-liquid mixed inlet pipe at different gas-liquid flow ratios at a specified gas-liquid inlet pressure, the gas-liquid conversion velocity in the plug flow or slug flow region is selected and converted into gas-liquid flow, and a gas-liquid flow and corresponding conversion velocity table is established; the gas-liquid flow is calculated as follows: Q l =J l 3600A m (2) In the formula, Q is the volume flow rate, J is the converted velocity, ρ a is the air density at room temperature and atmospheric pressure, ρ g is the density of CO2 under actual working conditions, subscripts g and l represent gas phase and liquid phase respectively, A m Represents the cross-sectional area of ​​a three-dimensional main pipe; S12: In order to investigate the change of flow pattern in the gas-liquid mixed inlet pipe under different gas phase inlet angles, various gas phase inlet angles were selected; S13: In order to investigate the attenuation of the pipeline noise of the gas-liquid mixed input pipe and the pressure pulsation in the pipe before and after the installation of the attenuator, different attenuator arrangements are designed.

6. The experimental method of the gas-liquid two-phase pipe flow noise elimination experimental system according to claim 5 is characterized by: In step S13, the different attenuator arrangements include one attenuator or multiple attenuators arranged on a U-shaped pipe connected in series along the U-shaped pipe, a single attenuator being located on the left or right side of the U-shaped pipe, and being in an upright or inverted state.

7. The experimental method of the gas-liquid two-phase pipe flow noise elimination experimental system according to claim 5 is characterized by: In step S12, the gas phase inlet has a plurality of different inflow angles including 45°, 90° or 135°.

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