CN107355409B - Accurate regulation and control device and method for gas-liquid two-phase flow - Google Patents

Abstract

The invention discloses a gas-liquid two-phase flow precise control device and a control method. The liquid flow measurement mechanism is installed on the liquid pipeline, the liquid pipeline flange is installed on the liquid pipeline inlet end, the gas-liquid mixing cavity outlet flange is installed on the liquid pipeline outlet end, the gas pipeline inlet end is installed with the gas pipeline flange, and the gas pipeline outlet end is installed Connected to the middle of the liquid pipeline, the gas flow measurement mechanism is installed on the gas pipeline; after the gas and liquid enter the gas-liquid mixing chamber, measure the pressure of the gas-liquid before the gas-liquid mixing, so that the gas-liquid pressure is equal, and the sum of the gas-liquid flow rate is used as the after-mixing The flow of the gas and liquid is adjusted through the liquid flow regulating valve and the gas flow regulating valve. The invention can precisely adjust the required mixed fluid, the device is convenient for maintenance, can evenly mix gas and liquid, and accurately control the flow rate of the mixed fluid and the volume ratio of gas and liquid, thereby obtaining the required mixed fluid and improving the efficiency of the gas-liquid two-phase experiment. reliability.

Description

Gas-liquid two-phase flow precise control device and control method

technical field

The invention relates to the technical field of liquid conveying power equipment, in particular to a gas-liquid two-phase flow precise control device and control method.

Background technique

As the core equipment of aerospace thermal control fluid circuit system, centrifugal pump provides circulation driving force for the work of fluid circuit. However, in practical applications, many media contain a gas-liquid two-phase mixture, and the two-phase flow condition of the centrifugal pump will affect the performance of the centrifugal pump, bringing a series of hazards to the normal operation and service life of the pump. There is gas-liquid mixed transportation in the pipelines used in actual engineering applications. In order to ensure the normal operation of the mixed transportation pipelines, a gas-liquid mixing device must be installed at the pump inlet to make the gas-liquid flow as uniform as possible. There are many gas-liquid two-phase reactions in engineering, and the mixing of gas and liquid is usually achieved through a gas-liquid mixing device to ensure the dispersion of gas in the liquid and the mixing effect between the two phases.

In the existing gas-liquid mixing device, the nozzle is not easy to disassemble. Once the gas outlet is blocked, it is difficult to detect and maintain. Since the nozzle extends into the gas-liquid mixing chamber, it also has a certain influence on the flow. In the gas-liquid two-phase flow experiment of the centrifugal pump, due to the characteristics of the flowmeter, it is difficult to accurately measure the flow rate of the mixed fluid. Many of them are the flow rate of the liquid measured before mixing, which affects the reliability of the gas-liquid two-phase experiment. .

Contents of the invention

In order to solve the problems existing in the background technology, the object of the present invention is to provide a gas-liquid two-phase flow precise control device and control method, which can realize the convenience of maintenance of the device and improve the reliability of the gas-liquid two-phase experiment.

The technical scheme adopted in the present invention is:

1. A gas-liquid two-phase flow precise control device:

The control device includes a gas pipeline, a liquid pipeline, a liquid flow measurement mechanism and a gas flow measurement mechanism; the liquid flow measurement mechanism is installed on the liquid pipeline, the liquid pipeline flange is installed at the inlet end of the liquid pipeline, and the outlet flange of the gas-liquid mixing chamber Installed at the outlet of the liquid pipeline, the inlet of the gas pipeline is equipped with a gas pipeline flange, the outlet of the gas pipeline is connected to the middle of the liquid pipeline, and the gas flow measuring mechanism is installed on the gas pipeline.

The liquid flow measuring mechanism includes a liquid pressure sensor, a liquid electromagnetic flowmeter, a liquid flow regulating valve and a liquid pressure stabilizing cavity; the liquid pressure sensor is installed on the liquid stabilizing cavity, and the annular liquid stabilizing cavity is fixedly set on In the middle of the liquid pipeline close to the gas flow measurement mechanism, the annular cavity inside the liquid pressure stabilizing cavity is directly connected with the liquid pipeline. middle of the pipe.

The gas flow measurement mechanism includes a gas flow regulating valve, a gas electromagnetic flowmeter, a gas pressure sensor and a gas pressure stabilizing cavity; the outlet end of the gas pipeline is bent downward at a right angle and connected into the gas stabilizing cavity, and the gas flow is adjusted The valve is installed at the inlet end of the gas pipeline, the gas electromagnetic flowmeter is installed in the middle of the gas pipeline, the gas stabilizing cavity is fixedly set on the outer periphery of the liquid pipeline near the outlet end, and the annular cavity inside the gas stabilizing cavity is spaced along the circumference A plurality of evenly distributed porous nozzles are connected to the liquid pipeline, and a gas pressure sensor extending into the inner annular cavity is installed on the gas stabilizing cavity.

The multi-hole spray head includes a flexible hose, a first quick-connect joint, a second quick-connect joint, a spray hole and an airfoil straight pipe, one end of the flexible hose is connected to the gas stabilizing cavity through the second quick-connect joint, and the flexible hose The other end is connected to the liquid pipeline through the first quick-connect joint, the other end of the flexible hose is connected to the airfoil straight pipe, and the airfoil straight pipe extends into the liquid pipeline. The airfoil straight pipe passes through the liquid pipe and enters the gas-liquid mixing chamber. Spray holes are arranged on the airfoil straight pipe. The porous nozzle is easy to disassemble, which is convenient for inspection and maintenance.

A gas-liquid mixing cavity is formed in the inner cavity near the outlet end of the liquid pipeline. The gas enters the annular cavity inside the gas stabilizing cavity through the gas pipeline, and then enters the gas-liquid mixing cavity through the flexible hose and the airfoil straight tube in turn. The liquid enters the gas-liquid mixing chamber from the liquid pipe.

There are three rows of nozzle holes arranged side by side on the multi-hole nozzle, each nozzle hole in the middle row is oriented horizontally to the axis of the liquid pipeline, and each nozzle hole in the two rows on both sides is oriented at an angle of about 15 degrees to the axis of the liquid pipeline. Improve the gas-liquid mixing degree in the center of the gas-liquid mixing chamber.

The porous nozzles are installed on both sides of the gas stabilizing chamber, and there are four porous nozzles on each side of the gas stabilizing chamber, and the porous nozzles on both sides are arranged in a staggered manner to reduce the impact of the gas injected from the rear circle on the porous nozzles of the front circle. The probability of airfoil straight pipe improves the uniformity of the mixed gas under the premise of ensuring sufficient gas mixing.

The shape of the end of the airfoil straight pipe near the center of the liquid pipeline is wing-shaped, and the airfoil straight pipe as a whole is gradually transformed from a round pipe to an airfoil-shaped flat pipe to reduce fluid flow loss.

The ratio of the internal cross-sectional area of the gas pipeline, the sum of the internal cross-sectional areas of all porous nozzles and the sum of the hole areas of all nozzle holes is 1:1:1, so that the area ratio is stable under pressure.

2. A method for precise control of gas-liquid two-phase flow:

Using the above-mentioned device, the gas is introduced from the inlet end of the gas pipeline, and the gas enters the annular cavity inside the gas stabilizing cavity through the gas pipeline, and then enters the gas-liquid mixing cavity through the flexible hose and the airfoil straight tube in turn, from the liquid The inlet end of the pipeline is fed with liquid, and the liquid enters the gas-liquid mixing chamber through the liquid pipeline;

The pressure of the liquid before gas-liquid mixing is measured by the liquid pressure sensor on the liquid pressure stabilizing tube, and the pressure of the gas before gas-liquid mixing is measured and adjusted according to the gas pressure sensor on the gas stabilizing cavity, so that the gas pressure and the liquid pressure are equal. When the gas and liquid are mixed, the gas is not compressed, and the gas flow and liquid flow are obtained according to the measurement of the gas electromagnetic flowmeter and the liquid electromagnetic flowmeter. The valve and gas flow regulating valve regulate the flow of gas and liquid, so as to obtain a mixed fluid with precise flow control.

Since the gas is not compressed when the gas and liquid are mixed, when the pressure of the gas and the liquid are equal, it is considered that the gas and the liquid are mixed in equal volumes. According to the gas volume fraction of the required mixed fluid, the flow rate of gas and liquid is calculated, and the flow rate of gas and liquid is adjusted through the valve to obtain the required mixed fluid. In the present invention, by setting equal gas Mach number and gas-liquid pressure, the two flow rates can be directly added when the gas-liquid is output, thereby realizing precise adjustment of the required mixed fluid.

If the Mach number of the gas is less than 0.3, the gas is considered incompressible.

The beneficial effects of the present invention are:

The device of the invention is convenient for maintenance, can uniformly mix gas and liquid, and accurately control the flow rate of the mixed fluid and the volume ratio of gas and liquid, thereby obtaining the required mixed fluid and improving the reliability of the gas-liquid two-phase experiment.

Description of drawings

Fig. 1 is a schematic diagram of the device structure of the present invention;

Fig. 2 is a front view of the device structure of the present invention;

Fig. 3 is a partial enlarged view of the device of the present invention;

Fig. 4 is a schematic cross-sectional structure diagram of a gas-liquid mixing chamber;

Fig. 5 is an axial schematic diagram of a multi-hole nozzle.

In the figure: 1. Gas pipeline flange, 2. Gas flow regulating valve, 3. Gas electromagnetic flowmeter, 4. Gas pipeline, 5. Gas pressure sensor, 6. Liquid pressure sensor, 7. Liquid electromagnetic flowmeter, 8, Liquid flow regulating valve, 9. Liquid pipeline flange, 10. Liquid pipeline, 11. Liquid pressure stabilizing cavity, 12. Gas stabilizing cavity, 13. Gas-liquid mixing cavity outlet flange, 14. Flexible hose, 15 , the first quick-connect joint, 16, the second quick-connect joint, 17, the multi-hole nozzle, 18, the gas-liquid mixing chamber, 19, the nozzle hole, 20, the airfoil straight pipe.

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, the device of the present invention comprises a gas pipeline 4, a liquid pipeline 10, a liquid flow measuring mechanism and a gas flow measuring mechanism; the liquid flow measuring mechanism is installed on the liquid pipeline 10, and the liquid pipeline flange 9 is installed on the liquid pipeline 10 inlet end, the outlet flange 13 of the gas-liquid mixing chamber is installed at the outlet end of the liquid pipeline 10, the gas pipeline flange 1 is installed at the inlet end of the gas pipeline 4, the outlet end of the gas pipeline 4 is connected to the middle of the liquid pipeline 10, and the gas flow measuring mechanism is installed at the gas pipeline 10 Pipeline 4 on.

As shown in Figure 1, Figure 2 and Figure 3, the liquid flow measurement mechanism includes a liquid pressure sensor 6, a liquid electromagnetic flowmeter 7, a liquid flow regulating valve 8 and a liquid pressure stabilizing chamber 11; the liquid pressure sensor 6 is installed in the liquid pressure stabilizing On the cavity 11, an annular liquid pressure stabilizing cavity 11 is fixedly set in the middle of the liquid pipeline 10 close to the gas flow measuring mechanism. The liquid flow regulating valve 8 is installed near the inlet end of the liquid pipeline 10 , and the liquid electromagnetic flowmeter 7 is installed in the middle of the liquid pipeline 10 .

As shown in Figure 1, Figure 2 and Figure 3, the gas flow measuring mechanism includes a gas flow regulating valve 2, a gas electromagnetic flowmeter 3, a gas pressure sensor 5 and a gas pressure stabilizing cavity 12; the outlet end of the gas pipeline 4 is bent downward at a right angle Fold and connect to extend into the gas stabilizing chamber 12, the gas flow regulating valve 2 is installed at the inlet end of the gas pipeline 4, the gas electromagnetic flowmeter 3 is installed in the middle of the gas pipeline 4, and the gas stabilizing cavity 12 is fixedly set in the liquid Pipeline 10 is close to the outer periphery near the outlet end. The annular cavity inside the gas pressure stabilizing cavity 12 is connected to the liquid pipeline 10 through a plurality of porous nozzles 17 evenly spaced along the circumference. The gas stabilizing cavity 12 is equipped with a The gas pressure sensor 5 of its inner annular cavity.

As shown in Figures 3 and 4, the multi-hole nozzle 17 includes a flexible hose 14, a first quick connector 15, a second quick connector 16, a spray hole 19 and an airfoil straight pipe 20, and one end of the flexible hose 14 passes through the second The quick connector 16 is connected to the gas pressure stabilizing cavity 12, the other end of the flexible hose 14 is connected to the liquid pipeline 10 through the first quick connector 15, and the other end of the flexible hose 14 is connected to the airfoil straight pipe 20, and the airfoil straight pipe 20 extends into the liquid pipeline 10, and the airfoil straight pipe 20 passes through the liquid pipeline 10 and enters the gas-liquid mixing chamber 18. The airfoil straight pipe 20 is provided with spray holes 19.

A gas-liquid mixing cavity 18 is formed in the inner cavity near the outlet end of the liquid pipeline 10, and the gas enters the annular cavity inside the gas stabilizing cavity 12 through the gas pipeline 4, and then enters through the flexible hose 14 and the airfoil straight tube 20 in turn. To the gas-liquid mixing chamber 18 , the liquid enters the gas-liquid mixing chamber 18 from the liquid pipeline 10 .

As shown in Figure 5, three rows of spray holes 19 are arranged side by side on the multi-hole spray head 17, each spray hole 19 holes in the middle row are oriented to be horizontal with the axis of the liquid pipeline 10, and each spray hole 19 holes in the two rows on both sides are oriented to be aligned with the liquid pipeline. The 10 axis has an included angle of about 15 degrees.

The porous nozzles 17 are installed on both sides of the gas stabilizing chamber 18, and each side of the gas stabilizing chamber 18 has four porous nozzles 17, and the porous nozzles 17 on both sides are arranged in a staggered manner. And as shown in FIG. 4 , the nozzle holes on the porous nozzles 17 on both sides are arranged on the same side facing the liquid outflow direction.

The end of the airfoil straight pipe 20 close to the center of the liquid pipeline 10 is in the shape of an airfoil, and the whole airfoil straight pipe 20 gradually changes from a round pipe to a wing-shaped flat pipe.

The ratio of the internal cross-sectional area of the gas pipeline 4, the sum of the internal cross-sectional areas of all the multi-hole nozzles 17 and the sum of the hole areas of all the nozzle holes 19 is 1:1:1.

The precise flow control process of the present invention is as follows:

When working, gas with a Mach number less than 0.3 is introduced from the inlet end of the gas pipeline 4, and the gas enters the annular cavity inside the gas stabilizing cavity 12 through the gas pipeline 4, and then passes through the flexible hose 14 and the airfoil straight tube 20 in turn. Entering the gas-liquid mixing chamber 18, the gas flows from the gas pipeline flange 1 through the gas flow regulating valve 2, the gas electromagnetic flowmeter 3, the gas pipeline 4, the gas stabilizing chamber 12 and the porous nozzle 17.

The liquid is introduced from the inlet end of the liquid pipeline 10, the liquid enters the gas-liquid mixing chamber 18 through the liquid pipeline 10, and the liquid flows from the liquid pipeline flange 9 through the liquid flow regulating valve 8, the liquid pipeline 10, the liquid electromagnetic flowmeter 7 and the liquid Stable pressure chamber 11.

In the gas-liquid mixing chamber 18 , the liquid and gas are fully mixed, and finally flow out of the outlet flange 13 of the gas-liquid mixing chamber.

Measure the pressure of the liquid before the gas-liquid mixing by the liquid pressure sensor 6 on the liquid pressure stabilizing tube 11, measure and adjust the pressure of the gas before the gas-liquid mixing according to the gas pressure sensor 5 on the gas stabilizing cavity 12, so that the gas pressure and the liquid The pressure is equal, because the gas is not compressed when the gas and liquid are mixed, the gas flow and liquid flow are obtained according to the measurement of the gas electromagnetic flowmeter 3 and the liquid electromagnetic flowmeter 7, and the sum of the readings of the gas electromagnetic flowmeter 3 and the liquid electromagnetic flowmeter 7 is used as the mixture After the flow of the liquid, the flow of gas and liquid is regulated through the liquid flow regulating valve 8 and the gas flow regulating valve 2, so as to obtain a mixed fluid with precisely regulated flow.

Claims (8)

1. A gas-liquid two-phase flow precise control device, characterized in that: the device includes a gas pipeline (4), a liquid pipeline (10), a liquid flow measurement mechanism and a gas flow measurement mechanism; the liquid flow measurement mechanism is installed on the liquid On the pipeline (10), the liquid pipeline flange (9) is installed at the inlet end of the liquid pipeline (10), the outlet flange (13) of the gas-liquid mixing chamber is installed at the outlet end of the liquid pipeline (10), and the gas pipeline (4) inlet end A gas pipeline flange (1) is installed, the outlet end of the gas pipeline (4) is connected to the middle of the liquid pipeline (10), and the gas flow measuring mechanism is installed on the gas pipeline (4); The liquid flow measuring mechanism includes a liquid pressure sensor (6), a liquid electromagnetic flowmeter (7), a liquid flow regulating valve (8) and a liquid pressure stabilizing cavity (11); the liquid pressure sensor (6) is installed in the liquid stabilizing On the cavity (11), the annular liquid pressure stabilizing cavity (11) is fixedly set in the middle of the liquid pipeline (10) close to the gas flow measurement mechanism, and the annular cavity and liquid pipeline inside the liquid pressure stabilizing cavity (11) ( 10) Direct communication, the liquid flow regulating valve (8) is installed near the inlet end of the liquid pipeline (10), and the liquid electromagnetic flowmeter (7) is installed in the middle of the liquid pipeline (10); The gas flow measurement mechanism includes a gas flow regulating valve (2), a gas electromagnetic flowmeter (3), a gas pressure sensor (5) and a gas pressure stabilizing cavity (12); the outlet end of the gas pipeline (4) is bent downward at a right angle Fold and connect into the gas stabilizing cavity (12), the gas flow regulating valve (2) is installed at the inlet end of the gas pipeline (4), the gas electromagnetic flowmeter (3) is installed in the middle of the gas pipeline (4), The gas stabilizing chamber (12) is fixedly set on the outer periphery of the liquid pipeline (10) near the outlet end, and the annular cavity inside the gas stabilizing chamber (12) passes through a plurality of porous nozzles (17) evenly spaced along the circumference. Connected to the liquid pipeline (10), the gas pressure stabilizing cavity (12) is equipped with a gas pressure sensor (5) extending into its inner annular cavity; The multi-hole nozzle (17) includes a flexible hose (14), a first quick-connect joint (15), a second quick-connect joint (16), a nozzle hole (19) and an airfoil straight pipe (20), the flexible hose (14) One end is connected to the gas stabilizing cavity (12) through the second quick-connect joint (16), and the other end of the flexible hose (14) is connected to the liquid pipeline (10) through the first quick-connect joint (15). The other end of the flexible pipe (14) is connected with the airfoil straight pipe (20), and the airfoil straight pipe (20) extends into the liquid pipeline (10) and the airfoil straight pipe (20) passes through the liquid pipeline (10) and enters the air The liquid mixing chamber (18) and the airfoil straight pipe (20) are provided with spray holes (19). 2. A gas-liquid two-phase flow precise control device according to claim 1, characterized in that: a gas-liquid mixing cavity (18) is formed in the inner cavity near the outlet end of the liquid pipeline (10), and the gas passes through the gas pipeline ( 4) Enter the annular cavity inside the gas stabilizing cavity (12), and then enter the gas-liquid mixing cavity (18) through the flexible hose (14) and wing-shaped straight tube (20) in sequence, and the liquid flows from the liquid pipeline ( 10) Enter the gas-liquid mixing chamber (18). 3. A gas-liquid two-phase flow precise control device according to claim 1, characterized in that: there are three rows of nozzle holes (19) in parallel on the porous nozzle (17), and each nozzle hole (19) in the middle row ) holes are oriented horizontally to the axis of the liquid pipeline (10), and the orientation of each nozzle hole (19) in two rows on both sides has an included angle of about 15 degrees with the axis of the liquid pipeline (10). 4. A gas-liquid two-phase flow precise control device according to claim 1, characterized in that: the porous nozzle (17) is installed on both sides of the gas stabilizing cavity (18), and the gas stabilizing cavity ( 12) There are four porous nozzles (17) on each side, and the porous nozzles (17) on both sides are arranged in a staggered manner. 5. A gas-liquid two-phase flow precise control device according to claim 1, characterized in that: the shape of the end of the airfoil straight pipe (20) close to the center of the liquid pipe (10) is wing-shaped, and the wing The straight tube (20) as a whole is gradually transformed from a round tube into a wing-shaped flat tube. 6. A gas-liquid two-phase flow precise control device according to claim 1, characterized in that: the internal cross-sectional area of the gas pipeline (4), the sum of the internal cross-sectional areas of all the porous nozzles (17) and all nozzles The sum ratio of the hole areas of the holes (19) is 1:1:1. 7. A method for precise control of gas-liquid two-phase flow applied to the device described in any one of claims 1-6, characterized in that: using the device described in any one of claims 1-6, from the gas pipeline (4) The inlet port is fed with gas, and the gas enters the annular cavity inside the gas pressure stabilizing cavity (12) through the gas pipeline (4), and then enters the gas-liquid through the flexible hose (14) and the airfoil straight tube (20) in sequence. The mixing chamber (18) is fed with liquid from the inlet of the liquid pipe (10), and the liquid enters the gas-liquid mixing chamber (18) through the liquid pipe (10); through the liquid pressure sensor (6 ) to measure the pressure of the liquid before the gas-liquid mixing, measure and adjust the gas pressure before the gas-liquid mixing according to the gas pressure sensor (5) on the gas pressure stabilizing cavity (12), so that the gas pressure and the liquid pressure are equal, due to the gas-liquid mixing When the gas is not compressed, the gas flow and liquid flow are measured by the gas electromagnetic flowmeter (3) and the liquid electromagnetic flowmeter (7), and the sum of the readings of the gas electromagnetic flowmeter (3) and liquid electromagnetic flowmeter (7) is taken as After mixing, the flow of gas and liquid is adjusted through the liquid flow regulating valve (8) and the gas flow regulating valve (2), so as to obtain a mixed fluid with precise flow control. 8. A method for precise control of gas-liquid two-phase flow according to claim 7, characterized in that: the Mach number of the gas introduced is less than 0.3.

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