Liquid oxygen and air evaporation and mixing device

Abstract

The present invention discloses a liquid oxygen-air evaporation and mixing device. The liquid oxygen-air evaporation and mixing device of the present invention comprises a pipeline, a spoke-shaped distribution plate perpendicular to the central axis of the pipeline, a ring groove is arranged in the circumference of the distribution plate, a plurality of liquid oxygen pipelines are arranged inside the distribution plate, the liquid oxygen pipelines are provided with through holes, and a liquid oxygen injection pipe is installed on the through holes. The liquid oxygen-air evaporation and mixing device of the present invention has a reliable structure and a simple processing technology, and can quickly complete the rapid evaporation of liquid oxygen with a liquid oxygen flow rate of 50kg / s~100kg / s, an air flow rate of 200kg / s~300kg / s, and a pressure of more than 16MPa, as well as rapid mixing of liquid oxygen vapor and high-pressure air, and can obtain oxygen-enriched air with uniform components and concentrations at the outlet of the device for large-flow high-temperature combustion wind tunnel tests.

Description

Technical Field

[0001] The invention belongs to the technical field of high-temperature combustion wind tunnels, and in particular relates to a liquid oxygen-air evaporation and mixing device. Background Art

[0002] Large-flow high-temperature combustion wind tunnels usually use liquid oxygen, air and liquid or gaseous fuels for combustion to obtain the high-enthalpy test gas required for the test. For high-temperature combustion wind tunnels with nozzle outlet diameters of more than 1.5m, the liquid oxygen and air supply pressures are usually as high as 16MPa or more, the liquid oxygen flow rate is as high as 100kg / s, and the air flow rate is as high as 300kg / s~400kg / s. In order to facilitate the organization of combustion, a feasible method is to use air to directly evaporate and mix liquid oxygen to form a uniform gaseous oxygen-rich air (the oxygen content in oxygen-rich air is greater than 21% in air) to facilitate subsequent gas-gas combustion (for gaseous fuels) or gas-liquid combustion (for liquid fuels) with fuel. The advantage of this method is that the evaporation of liquid oxygen can be completed without external working fluid or energy input. However, since liquid oxygen has extremely strong oxidizing properties, how to quickly complete evaporation and mixing to form uniform oxygen-rich air under the premise of ensuring safety under large flow and high pressure conditions is the key to the design of the mixing device.

[0003] Traditional liquid oxygen evaporation devices generally take the form of coils or sheet heat exchangers, which are not convenient for integrating the two processes of evaporation and mixing with air, and there are also safety issues under high pressure and large flow. For example, the Chinese Patent Literature Library discloses a liquid oxygen vaporizer device with application number CN201410347497.4, which uses multiple thin round tubes to pass liquid oxygen, and passes air into the cavity, and heats the liquid oxygen through convection heat transfer, which can achieve liquid oxygen vaporization with a flow rate of 0.5kg / s~1.5kg / s. Because the liquid oxygen vaporizer device adopts a thin tube method, the two processes of liquid oxygen vaporization and air mixing are separated, which is difficult to apply to occasions where the liquid oxygen flow rate reaches 50kg / s~100kg / s and the pressure is above 16MPa.

[0004] Currently, there is an urgent need to develop a liquid oxygen-air evaporation and mixing device that can quickly evaporate a large flow of liquid oxygen into liquid oxygen vapor and quickly mix the liquid oxygen vapor with air. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a liquid oxygen-air evaporation and mixing device.

[0006] The liquid oxygen-air evaporation and mixing device of the present invention is characterized in that the liquid oxygen-air evaporation and mixing device comprises a pipeline, and according to the air flow direction, the pipeline comprises an air inlet pipe section, a diffusion cone section and a permeation and mixing section in sequence from front to back, and the air inlet pipe section, the diffusion cone section and the permeation and mixing section have the same central axis; the air inlet pipe section and the permeation and mixing section are both straight circular pipe sections, the inner diameter of the air inlet pipe section is smaller than the inner diameter of the permeation and mixing section, and the air inlet pipe section and the permeation and mixing section are transitionally connected by the diffusion cone section;

[0007] A spoke-shaped distribution plate perpendicular to the central axis of the pipeline is installed on the permeation and mixing section; a central cavity coaxial with the central axis of the pipeline is arranged on the central axis of the distribution plate; an annular groove communicating with the liquid oxygen inlet pipeline is opened along the circumferential direction of the distribution plate; the distribution plate is provided with spokes at 0°, 60°, 120°, 180°, 240°, and 300°, and the spokes are provided with liquid oxygen pipeline I, and protrusions similar to the spokes in appearance and shorter in length than the spokes are arranged at 30°, 90°, 150°, 210°, 270°, and 330°, and liquid oxygen is opened on the protrusions. Pipeline II, liquid oxygen pipeline I and liquid oxygen pipeline II have the same inner diameter, through holes I and II are respectively opened at both ends of the spokes and are parallel to the central axis of the pipeline, through holes III are opened at the protruding suspended ends and are parallel to the central axis of the pipeline, and the projection of through hole III on the adjacent spokes is located at the midpoint of through holes I and II of the adjacent spokes; through holes I, II and III have the same inner diameter, and liquid oxygen injection pipes are installed on through holes I, II and III, and a plurality of arrays of small holes are opened on the pipe wall of the liquid oxygen injection pipe, and the central axis of the small holes is perpendicular to or intersects with the central axis of the pipeline;

[0008] After liquid oxygen enters the liquid oxygen inlet pipe, it flows along the annular groove into the liquid oxygen pipe I and liquid oxygen pipe II in the distribution plate, and then is sprayed into the pipeline through the liquid oxygen injection pipe and evaporates to form liquid oxygen vapor; high-pressure air passes through the distribution plate of the infiltration and mixing section through the air inlet pipe section and the diffusion cone section, and is fully mixed with the liquid oxygen vapor before and after the distribution plate to form oxygen-enriched air with uniform composition and temperature, and the oxygen-enriched air flows out through the infiltration and mixing section.

[0009] Furthermore, the spokes of the distribution plate are provided with a plurality of parallel liquid oxygen pipelines I, and the protrusions are provided with a plurality of liquid oxygen pipelines II corresponding to the plurality of liquid oxygen pipelines I.

[0010] Furthermore, the pipeline, distribution plate and liquid oxygen injection pipe are all made of austenitic stainless steel and connected by fusion welding.

[0011] The working process of the liquid oxygen-air evaporation and mixing device of the present invention is as follows:

[0012] High-pressure air is injected from the pipeline, and before the liquid oxygen is injected, the diameter of the pipeline is expanded through the diffusion cone section to reduce the air flow rate and create a longer residence time for evaporating liquid oxygen and mixing; the liquid oxygen is injected into the distribution plate after passing through the annular groove, and the distribution is completed inside the distribution plate. The purpose of the distribution is to evenly flow the liquid oxygen into the liquid oxygen injection pipe; there are several vertical or inclined small holes on the side of the liquid oxygen injection pipe, and the liquid oxygen is injected from these small holes and completes the evaporation and mixing processes with the high-pressure air flow, so as to obtain uniform oxygen-enriched air at the outlet of the infiltration and mixing section. Among them, there are several liquid oxygen pipelines radially opened at the connection between the distribution plate and the annular groove, and holes are vertically punched on the liquid oxygen pipeline. The holes are distributed in concentric circles and connected to the liquid oxygen injection pipe. In addition to establishing a liquid oxygen channel, the distribution plate also leaves a large area between the spokes and the protrusions to establish an airflow path to ensure that the oxygen-enriched air can flow downstream.

[0013] The liquid oxygen-air evaporation and mixing device of the present invention has the following characteristics:

[0014] a. Complete the liquid oxygen injection of the distribution plate through the ring groove to ensure injection uniformity;

[0015] b. The through holes of the distribution plate are distributed in concentric circles, and the air flow passage areas around each liquid oxygen injection pipe are close, thereby ensuring that the flow ratio in space is evenly distributed during the evaporation and mixing of liquid oxygen with air;

[0016] c. The liquid oxygen injection pipes of the distribution plate are symmetrically distributed in front and behind the distribution plate, which overcomes the asymmetry of force and cold shrinkage caused by unilateral injection of liquid oxygen, which makes the pipeline sealing design difficult;

[0017] d. The pipeline, distribution plate and liquid oxygen injection pipe are all made of austenitic stainless steel and connected by fusion welding, without the need for complex processes such as brazing, laser welding, and electron beam welding. Each component has a simple structure and does not require large forgings or precision structural parts. A distribution plate with a slightly higher complexity can also be completed by conventional punching and milling, which reduces the difficulty and cost of processing.

[0018] The liquid oxygen-air evaporation and mixing device of the present invention has a reliable structure and a simple processing technology. It can quickly complete the rapid evaporation of liquid oxygen with a liquid oxygen flow rate of 50kg / s-100kg / s, an air flow rate of 200kg / s-300kg / s, and a pressure of more than 16MPa, as well as rapid mixing of liquid oxygen vapor with high-pressure air, and can obtain oxygen-enriched air with uniform components and concentrations at the outlet of the device for large-flow high-temperature combustion wind tunnel tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the liquid oxygen-air evaporation and mixing device of the present invention;

[0020] Figure 2It is a schematic diagram of the structure of the distribution plate in the liquid oxygen and air evaporation and mixing device of the present invention (front cross-sectional view);

[0021] Figure 3 It is a schematic diagram of the structure of the distribution plate in the liquid oxygen and air evaporation and mixing device of the present invention (side cross-sectional view).

[0022] In the figure, 1. pipeline; 2. annular groove; 3. distribution plate; 4. liquid oxygen injection pipe. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0024] Example 1

[0025] like Figure 1~Figure 3 As shown, the liquid oxygen-air evaporation and mixing device of this embodiment includes a pipeline 1. According to the air flow direction, the pipeline 1 includes an air inlet pipe section, a diffusion cone section and a permeation and mixing section from front to back in sequence. The air inlet pipe section, the diffusion cone section and the permeation and mixing section have the same central axis; the air inlet pipe section and the permeation and mixing section are both straight circular pipe sections, the inner diameter of the air inlet pipe section is smaller than the inner diameter of the permeation and mixing section, and the air inlet pipe section and the permeation and mixing section are transitionally connected by the diffusion cone section;

[0026] A spoke-shaped distribution plate 3 perpendicular to the central axis of the pipeline 1 is installed on the permeation and mixing section; a central cavity coaxial with the central axis of the pipeline 1 is arranged on the central axis of the distribution plate 3; the distribution plate 3 is provided with an annular groove 2 in the circumferential direction which is communicated with the liquid oxygen inlet pipeline; the distribution plate 3 is provided with spokes at 0°, 60°, 120°, 180°, 240°, and 300°, and the spokes are provided with liquid oxygen pipelines I, and protrusions similar in shape to the spokes and shorter in length than the spokes are provided at 30°, 90°, 150°, 210°, 270°, and 330°, and the protrusions are provided with liquid Oxygen pipeline II, liquid oxygen pipeline I and liquid oxygen pipeline II have the same inner diameter, through holes I and II are respectively opened at both ends of the spokes and are parallel to the central axis of pipeline 1, through holes III are opened at the protruding suspended ends and are parallel to the central axis of pipeline 1, and the projection of through hole III on the adjacent spokes is located at the midpoint of through holes I and II of the adjacent spokes; through holes I, II and III have the same inner diameter, and liquid oxygen injection pipes 4 are installed on through holes I, II and III, and a plurality of arrays of small holes are opened on the pipe wall of liquid oxygen injection pipe 4, and the central axis of the small holes is perpendicular to or intersects with the central axis of pipeline 1;

[0027] After the liquid oxygen enters the liquid oxygen inlet pipeline, it flows along the annular groove 2 into the liquid oxygen pipeline I and the liquid oxygen pipeline II in the distribution plate 3, and then is sprayed into the pipeline 1 through the liquid oxygen injection pipe 4 and evaporates to form liquid oxygen vapor; the high-pressure air passes through the distribution plate 3 of the infiltration and mixing section through the air inlet pipe section and the diffusion cone section, and is fully mixed with the liquid oxygen vapor before and after the distribution plate 3 to form oxygen-enriched air with uniform composition and temperature, and the oxygen-enriched air flows out through the infiltration and mixing section.

[0028] Furthermore, the spokes of the distribution plate 3 are provided with a plurality of parallel liquid oxygen pipelines I, and the protrusions are provided with a plurality of liquid oxygen pipelines II corresponding to the plurality of liquid oxygen pipelines I.

[0029] Furthermore, the pipeline 1, the distribution plate 3 and the liquid oxygen injection pipe 4 are all made of austenitic stainless steel and are connected by fusion welding.

[0030] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and the embodiments, and can be fully applied to various technical fields suitable for the present invention. For those familiar with the art, additional improvements and modifications can be easily realized, so without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the legends shown and described here.

Claims

1. A liquid oxygen-air evaporation and mixing device, characterized in that: The liquid oxygen-air evaporation and mixing device comprises a pipeline (1). According to the air flow direction, the pipeline (1) comprises, from front to back, an air inlet pipe section, a diffusion cone section and a permeation and mixing section. The air inlet pipe section, the diffusion cone section and the permeation and mixing section are coaxial. The air inlet pipe section and the permeation and mixing section are both straight circular pipe sections. The inner diameter of the air inlet pipe section is smaller than the inner diameter of the permeation and mixing section. The air inlet pipe section and the permeation and mixing section are transitionally connected via the diffusion cone section. A spoke-shaped distribution plate (3) perpendicular to the central axis of the pipeline (1) is installed on the mixing section; a central cavity coaxial with the central axis of the pipeline (1) is arranged on the central axis of the distribution plate (3); an annular groove (2) communicating with the liquid oxygen inlet pipeline is opened along the circumferential direction of the distribution plate (3); the distribution plate (3) is provided with spokes at positions of 0°, 60°, 120°, 180°, 240°, and 300°, the spokes are provided with liquid oxygen pipelines I, and protrusions similar in shape to the spokes and shorter in length than the spokes are arranged at positions of 30°, 90°, 150°, 210°, 270°, and 330°, the protrusions are provided with There is a liquid oxygen pipeline II, the inner diameters of the liquid oxygen pipeline I and the liquid oxygen pipeline II are the same, the two ends of the spokes are respectively provided with through holes I and II parallel to the central axis of the pipeline (1), the protruding suspended end is provided with a through hole III parallel to the central axis of the pipeline (1), the projection of through hole III on the adjacent spoke is located at the midpoint of through holes I and II of the adjacent spoke; the inner diameters of through holes I, II and III are the same, and liquid oxygen injection pipes (4) are installed on through holes I, II and III, and a plurality of arrays of small holes are provided on the wall of the liquid oxygen injection pipe (4), and the central axis of the small holes is perpendicular to or intersects with the central axis of the pipeline (1); After the liquid oxygen enters the liquid oxygen inlet pipe, it flows along the annular groove (2) into the liquid oxygen pipe I and the liquid oxygen pipe II in the distribution plate (3), and then is sprayed into the pipeline (1) through the liquid oxygen injection pipe (4) and evaporates to form liquid oxygen vapor; the high-pressure air passes through the distribution plate (3) of the permeation and mixing section through the air inlet pipe section and the diffusion cone section, and is fully mixed with the liquid oxygen vapor before and after the distribution plate (3) to form oxygen-enriched air with uniform components and temperature, and the oxygen-enriched air flows out through the permeation and mixing section.

2. The liquid oxygen-air evaporation and mixing device according to claim 1, characterized in that: The spokes of the distribution plate (3) are provided with a plurality of parallel liquid oxygen pipelines I, and the protrusions are provided with a plurality of liquid oxygen pipelines II corresponding to the plurality of liquid oxygen pipelines I.

3. The liquid oxygen-air evaporation and mixing device according to claim 1, characterized in that: The pipeline (1), distribution plate (3) and liquid oxygen injection pipe (4) are all made of austenitic stainless steel and are connected by fusion welding.

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