A method for generating a uniform stream of ice particles in liquid nitrogen cooled background

Abstract

The application discloses a kind of liquid nitrogen cold background uniform ice particle flow generation methods, including cold source system, liquid supply system and gas mixing device, the cold source system includes nitrogen source, liquid nitrogen storage tank, cold nitrogen generation device and pipeline portion, the liquid supply system includes water storage tank, booster pump, water atomizing nozzle, particle size screening device and water supply pipeline, the gas mixing device includes mixing uniform air duct, spray rake, cold nitrogen nozzle, liquid droplet-containing gas flow outlet gas pipeline and electric heat tracing device.In the application, by using the mode of generating particles and icing segmentation, the particle size of water particles can be controlled to control the particle size of ice particles, forming an ice particle gas stream with controllable particle size;A special spray rake structure and mixing uniform air duct are designed to form a more uniform and stable ice particle-containing flow field;Liquid nitrogen is used as the system cold source, which is more energy-saving for long-time wind tunnel test with large flow rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of ice wind tunnel environment simulation, and particularly relates to a liquid nitrogen cold background uniform ice particle flow generation method. BACKGROUND

[0002] When aircraft deicing research or meteorological research is carried out on the ground, it is necessary to simulate an ice particle-containing airflow environment to test icing conditions on the ground.

[0003] Ice wind tunnels are widely used in aircraft deicing system design and atmospheric meteorological research. When designing a deicing system, ice wind tunnel tests need to be carried out on the ground to test aircraft icing conditions and the working performance of the deicing system. In meteorological research, ice and snow crystal growth phenomena also need to be researched in the ground ice wind tunnel.

[0004] Long experimental processes are required for ice wind tunnel tests, and most existing ice wind tunnels use a refrigeration machine as the main cold source. For a large wind tunnel, the required refrigeration power is very large due to the large flow rate of the flow field, and the energy consumption required for long-term ice wind tunnel tests is very considerable.

[0005] Most existing ice wind tunnels use an injection method to inject water mist or supercooled water droplets into the wind tunnel flow field through dry air injection, and the spray rake structure affects the airflow velocity and airflow in the test section. At the same time, the dry air jet can weaken the airflow deflection angle and the spatial uniformity of the airflow turbulence, and also reduce the airflow velocity, affecting the quality of the wind tunnel flow field. At the same time, due to the uncontrollability of the injection nozzle, the particle size range of the sprayed water mist is wide, and accurate particle size control cannot be achieved. SUMMARY

[0006] The purpose of the present application is to design a liquid nitrogen cold background high-uniform ice particle flow generation method applied to wind tunnel tests, to solve the problems of existing icing wind tunnel injection airflow affecting the quality of the wind tunnel flow field and the particle size being uncontrollable, and to achieve the effect of obtaining a controllable particle size ice particle uniform airflow under a liquid nitrogen cold background.

[0007] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0008] A liquid nitrogen cold background uniform ice particle flow generation method, comprising a cold source system, a liquid supply system and a gas mixing device, the cold source system comprising a nitrogen source, a liquid nitrogen storage tank, a cold nitrogen gas generation device and a pipeline part, the liquid supply system comprising a water storage tank, a booster pump, a water atomizing nozzle, a particle size screening device and a water supply pipeline, and the gas mixing device comprising a uniform mixing air duct, a spray rake, a cold nitrogen gas nozzle, a liquid droplet-containing airflow outlet pipeline and an electric heat tracing device.

[0009] Preferably, the pressure sensor one, the pressure sensor two, the flow regulating valve one, the flow sensor one, the flow sensor two, the temperature sensor, the electronic regulating valve three and the temperature and humidity sensor are further included.

[0010] Preferably, the cold source system working process comprises the following steps:

[0011] S1.1, the nitrogen source outputs medium-pressure nitrogen, which is adjusted to the required pressure by the electronic regulating valve one to form a stable-pressure nitrogen flow;

[0012] S1.2, the liquid nitrogen in the liquid nitrogen tank is adjusted by the flow regulating valve two and then sprayed into the cold nitrogen generating device to mix with the nitrogen flow to form a cold nitrogen flow with the required temperature as the system cold source.

[0013] Preferably, the liquid supply system working process comprises the following steps:

[0014] S2.1, the nitrogen source outputs medium-pressure nitrogen, which is adjusted to the required pressure by the electronic regulating valve two to form a stable-pressure nitrogen flow and is delivered to the water atomizing nozzle;

[0015] S2.2, the pure water in the water storage tank is delivered to the water atomizing nozzle by the booster pump;

[0016] S2.3, the water atomizing nozzle generates a water particle flow with the required particle size in the particle size screening device.

[0017] Preferably, the gas mixing device working process comprises the following steps:

[0018] S3.1, the water particle-containing gas flow delivered from the gas outlet pipeline and the cold nitrogen gas flow delivered from the cold nitrogen nozzle are mixed in the mixing air duct;

[0019] S3.2, the water particles freeze to form ice particles;

[0020] S3.3, the ice particle-containing gas flow develops sufficiently in the mixing air duct to form a uniform ice particle flow.

[0021] Preferably, the water particle-containing gas outlet pipeline and the cold nitrogen nozzle are installed on the spraying rake, the water particle-containing gas outlet pipeline and the cold nitrogen nozzle are arranged in a cross manner to mix the liquid droplets and the cold nitrogen sufficiently, and the water particle-containing gas outlet pipeline is provided with an electric heat tracing device to prevent the pipeline from being blocked by ice.

[0022] As described above, the application has the following advantages:

[0023] 1, the application can control the particle size of the ice particles by controlling the particle size of the water particles through the mode of generating particles and freezing in stages, thereby forming an ice particle flow with controllable particle size;

[0024] 2. The application designs a special spray rake structure and a mixing air duct to form a more uniform and stable ice particle flow field;

[0025] 3. The application uses liquid nitrogen as a system cold source, which is more energy-saving for a large-flow long-time wind tunnel test. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A flow chart of a liquid nitrogen cold background uniform ice particle flow generation method according to an embodiment of the application is shown;

[0027] Figure 2 A schematic diagram of the relative positions of a droplet gas outflow pipe and a cold nitrogen gas nozzle according to an embodiment of the application is shown.

[0028] LEGEND:

[0029] 1. Nitrogen source; 2. Electronic regulating valve I; 3. Pressure sensor I; 4. Electronic regulating valve II; 5. Pressure sensor II; 6. Water storage tank; 7. Booster pump; 8. Flow regulating valve I; 9. Flow sensor I; 10. Water atomizing nozzle; 11. Particle size screening device; 12. Droplet-containing gas outflow pipe; 13. Liquid nitrogen storage tank; 14. Flow regulating valve II; 15. Flow sensor II; 16. Cold nitrogen gas generation device; 17. Temperature sensor; 18. Electronic regulating valve III; 19. Temperature and humidity sensor; 20. Spray rake; 21. Electric heat tracing device; 22. Cold nitrogen gas nozzle; 23. Mixing air duct. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0031] Please refer to Figures 1-2 , the application provides a technical solution:

[0032] A liquid nitrogen cold background uniform ice particle flow generation method, comprising a cold source system, a liquid supply system and a gas mixing device. The cold source system comprises a nitrogen source 1, a liquid nitrogen storage tank 13, a cold nitrogen gas generation device 16 and a pipe part. The liquid supply system comprises a water storage tank 6, a booster pump 7, a water atomizing nozzle 10, a particle size screening device 11 and a water supply pipe. The gas mixing device comprises a mixing air duct 23, a spray rake 20, a cold nitrogen gas nozzle 22, a droplet-containing gas outflow pipe 12 and an electric heat tracing device 21.

[0033] Specifically, as Figure 1 and Figure 2As shown, it also includes pressure sensor 13, pressure sensor 25, flow regulating valve 18, flow sensor 19, flow sensor 215, temperature sensor 17, electronic regulating valve 318, and temperature and humidity sensor 19.

[0034] The cold source system is used to generate a cold nitrogen flow to provide the cooling required for water particles to freeze. The cold source system's workflow includes the following steps:

[0035] S1.1, Nitrogen source 1 outputs medium-pressure nitrogen, which is adjusted to the required pressure by electronic regulating valve 2 to form a stable nitrogen flow.

[0036] S1.2 The liquid nitrogen in the liquid nitrogen tank is regulated by the flow regulating valve 14 and then sprayed into the cold nitrogen generating device 16 to mix with the nitrogen flow to form a cold nitrogen flow at the required temperature, which serves as the cold source for the system.

[0037] The liquid supply system workflow includes the following steps:

[0038] S2.1, Nitrogen source 1 outputs medium-pressure nitrogen, which is adjusted to the required pressure by electronic regulating valve 4 to form a stable nitrogen flow, which is then delivered to water atomizing nozzle 10;

[0039] S2.2 The purified water in the water storage tank 6 is delivered to the water atomizing nozzle 10 by the booster pump 7;

[0040] S2.3, The water atomizing nozzle 10 generates a water particle airflow of the required particle size in the particle size screening device 11;

[0041] The working process of a gas mixing device includes the following steps:

[0042] S3.1 The water-particle-containing gas flow transported in the droplet-containing gas outlet pipeline 12 and the cold nitrogen gas flow transported in the cold nitrogen nozzle 22 are mixed in the mixing duct 23;

[0043] S3.2 Water particles freeze when they encounter cold, forming ice particles;

[0044] In S3.3, within the mixing duct 23, the airflow containing ice particles fully develops to form a uniform ice particle flow.

[0045] Specifically, such as Figure 2 As shown, the droplet-containing gas outlet pipe 12 and the cold nitrogen nozzle 22 are installed on the spray rake 20. The droplet-containing gas outlet pipe 12 and the cold nitrogen nozzle 22 are arranged in a cross pattern to ensure that the droplets and cold nitrogen are fully mixed. An electric heating device 21 is installed on the droplet-containing gas outlet pipe 12 to prevent the pipe from freezing and clogging. The specially designed spray rake 20 structure and mixing air duct 23 reduce the impact of the mixing process on the flow field, so that the final ice particle flow is uniform and stable.

[0046] The application can control the particle size of ice particles by controlling the particle size of water particles through the mode of generating particles and icing segmentation, and form an ice particle airflow with controllable particle size; the application designs a special spray rake structure and a mixing air duct to form a more uniform and stable ice particle-containing flow field; the application uses liquid nitrogen as a system cold source, which is more energy-saving for a large-flow long-time wind tunnel test.

[0047] The above description of the embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those of ordinary skill in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for generating a uniform ice particle stream with a liquid nitrogen cold background, characterized in that, The system includes a cold source system, a liquid supply system, and a gas mixing device. The cold source system includes a nitrogen source (1), a liquid nitrogen storage tank (13), a cold nitrogen generating device (16), and a pipeline. The liquid supply system includes a water storage tank (6), a booster pump (7), a water atomizing nozzle (10), a particle size screening device (11), and a water supply pipeline. The gas mixing device includes a mixing duct (23), a spray rake (20), a cold nitrogen nozzle (22), a liquid droplet-containing gas outlet pipeline (12), and an electric heat tracing device (21). The droplet-containing gas outlet pipe (12) and the cold nitrogen nozzle (22) are installed on the spray rake (20). The droplet-containing gas outlet pipe (12) and the cold nitrogen nozzle (22) are arranged in a cross pattern to ensure that the droplets are fully mixed with the cold nitrogen. An electric heating device (21) is installed on the droplet-containing gas outlet pipe (12) to prevent the pipe from freezing and becoming blocked.

2. The method for generating a uniform ice particle stream with a liquid nitrogen cold background according to claim 1, characterized in that, It also includes pressure sensor 1 (3), pressure sensor 2 (5), flow control valve 1 (8), flow sensor 1 (9), flow sensor 2 (15), temperature sensor (17), electronic control valve 3 (18), and temperature and humidity sensor (19).

3. The method for generating a uniform ice particle stream with a liquid nitrogen cold background according to claim 1, characterized in that, The cold source system's workflow includes the following steps: S1.1, Nitrogen source (1) outputs medium-pressure nitrogen, which is adjusted to the required pressure by electronic regulating valve (2) to form a stable pressure nitrogen flow; S1.2 After the liquid nitrogen in the liquid nitrogen tank is regulated by the flow regulating valve (14), it is sprayed into the cold nitrogen generating device (16) to mix with the nitrogen flow to form a cold nitrogen flow at the required temperature, which serves as the cold source of the system.

4. The method for generating a uniform ice particle stream with a liquid nitrogen cold background according to claim 1, characterized in that, The liquid supply system's workflow includes the following steps: S2.1, Nitrogen source (1) outputs medium-pressure nitrogen, which is adjusted to the required pressure by electronic regulating valve two (4) to form a stable pressure nitrogen flow, which is then delivered to the water atomizing nozzle (10). S2.2 The pure water in the water storage tank (6) is delivered to the water atomizing nozzle (10) by the booster pump (7); S2.3, The water atomizing nozzle (10) generates a water particle airflow of the required particle size in the particle size screening device (11).

5. The method for generating a uniform ice particle stream with a liquid nitrogen cold background according to claim 1, characterized in that, The working process of the gas mixing device includes the following steps: S3.1 The water-particle gas flow transported in the droplet-containing gas outlet pipeline (12) and the cold nitrogen gas flow transported in the cold nitrogen nozzle (22) are mixed in the mixing duct (23); S3.2 Water particles freeze when they encounter cold, forming ice particles; S3.3 In the mixing duct (23), the airflow containing ice particles fully develops to form a uniform ice particle flow.

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