A low-temperature pipeline flow optical window surface defrosting device based on flow purging

Abstract

The application discloses a low-temperature pipeline flow optical window surface defrosting device based on flow purging, and relates to the field of window flow control of low-temperature pipeline flow. The device comprises an inlet section, a contraction section, an expansion section, a window section, a collection section and an outlet section which are sequentially communicated. The inlet section is communicated with a gas source. One side of the window section close to the low-temperature pipeline is an open side, and the other side of the window section away from the low-temperature pipeline is a sealed side provided with a first observation window. The device can not only eliminate the condensation of fog and frost on the surface of optical glass, but also effectively overcome the corrosion problem of corrosive gas to the optical glass.

Description

Technical Field

[0001] This invention relates to the field of window flow control for cryogenic pipeline flow, and more specifically, to a defogging and defrosting device for the optical window surface of cryogenic pipeline flow based on flow purging. Background Technology

[0002] In the field of aerodynamics, many aerodynamic devices require operation at low temperatures based on design requirements. To observe the flow field structure of the core internal sections of these devices, optical observation windows need to be installed on the walls. However, the significant temperature difference between the inside and outside of the device can cause gas atomization and condensation on the window surface, affecting the testing results of optical measurement equipment, especially for optical experiments with high cleanliness requirements. Furthermore, for some aerodynamic devices operating in corrosive gases, the impact of corrosive gases on the performance of the optical observation window is a technical problem that urgently needs to be addressed during the design of the window.

[0003] In existing technologies, traditional methods for eliminating fogging and condensation on optical windows typically employ double-layer optical windows and heat or replace the gas in the interlayer. However, this method offers limited protection against corrosive gases, which can still cause corrosion to the optical glass. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a low-temperature pipeline flow defogging device for optical windows based on flow purging. This device not only eliminates condensation on the surface of optical glass but also effectively overcomes the corrosion problem of optical glass caused by corrosive gases.

[0005] To achieve the above-mentioned objectives, the present invention provides a defogging and defrosting device for the optical window surface of a cryogenic pipeline based on flow purging. The device includes: an inlet section, a contraction section, an expansion section, a window section, a collection section, and an outlet section connected in sequence; the inlet section is connected to a gas source; the side of the window section closest to the cryogenic pipeline is an open surface, and the side of the window section furthest from the cryogenic pipeline is a sealed surface with a first observation window.

[0006] This invention utilizes an airflow channel formed by sequentially connected inlet section, contraction section, expansion section, window section, collection section, and outlet section. The airflow is used to blow away fog and frost from the surface of the optical window. The blowing air source is a non-corrosive gas from an external source, which can protect the optical window and prevent the corrosion of the optical glass by corrosive gases in the low-temperature pipeline.

[0007] One or more technical solutions provided by this invention have at least the following technical effects or advantages:

[0008] This device can be used for low-temperature flow display and testing research, and can reduce condensation on the observation window and improve the optical visibility of the optical window.

[0009] This device can protect the optical windows of various pneumatic equipment, eliminating the contamination and erosion of optical window glass by polluting and corrosive gases, and improving operating efficiency. Attached Figure Description

[0010] The accompanying drawings, which are provided to further illustrate embodiments of the invention and constitute a part of this invention, are not intended to limit the scope of the invention.

[0011] Figure 1 This is a schematic diagram of a defogging device for the surface of an optical window in a cryogenic pipeline based on flow purging.

[0012] Figure 2 This is a schematic diagram of the use of a defogging device for the surface of an optical window in a cryogenic pipeline based on flow purging.

[0013] Among them, 1-window section, 2-expansion section, 3-contraction section, 4-inlet section, 5-collection section, 6-outlet section, 7-this device, 8-first observation window, 9-second observation window, 10-low temperature pipeline. Detailed Implementation

[0014] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, where there is no conflict, the embodiments of the present invention and the features thereof can be combined with each other.

[0015] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0016] Example 1;

[0017] Please refer to Figures 1-2 , Figure 1 This is a schematic diagram of a defogging device for the surface of an optical window in a cryogenic pipeline based on flow purging. Figure 2 This is a schematic diagram illustrating the use of a flow-purge-based defogging device for the surface of an optical window in a cryogenic pipeline. The present invention provides a flow-purge-based defogging device for the surface of an optical window in a cryogenic pipeline, the device comprising:

[0018] The inlet section 4, the contraction section 3, the expansion section 2, the window section 1, the collection section 5, and the outlet section 6 are connected in sequence; the inlet section is connected to the gas source; the side of the window section closest to the low-temperature pipe 10 is the open side, and the side of the window section away from the low-temperature pipe is the sealed side with the first observation window 8.

[0019] The window section is a semi-enclosed structure. Its bottom and side walls are solid, while its top surface is an open surface that contacts the main airflow in the cryogenic pipeline. The high-speed airflow from the expansion section outlet of the defogging / frost removal device on the window surface is primarily used to blow away condensation or frost from the optical window, isolating it from free flow. The airflow direction within the window section matches the airflow direction within the cryogenic pipeline.

[0020] The window section primarily utilizes the high-speed airflow from the expansion section outlet of the defogging and defrosting device on the window surface to blow away condensation or frost from the optical window, isolating the airflow running inside the low-temperature pipe from contact with the optical window. The design length of the window section is mainly based on the window glass dimensions, with a length of 1-1.2 times the window glass diameter and a height of 0.05-0.3 times the window diameter. The wall surface is a smooth plane. The design dimensions of other sections of this device are primarily based on the design dimensions of the window section, designed according to relevant proportions.

[0021] The expansion section is designed with an expansion-type structure, mainly used to adjust the airflow velocity reaching the window area and match the core flow field. The outlet height of the expansion section is the same as the height of the window section, the inlet height of the expansion section is 0.1 to 1 times the outlet height, and the length is 2 to 5 times the cross-sectional height of the expansion section. The profile curve of the wall can adopt a bicubic curve, quintic curve, or other profile curve with continuous curvature, or it can be designed using the profile curve of the nozzle.

[0022] The window surface defrosting device's shrink section is a shrink-type structure with a square cross-section perpendicular to the airflow. It is mainly used to accelerate the airflow and reduce the airflow turbulence. The inlet and outlet heights of this section must be consistent with the connected front and rear sections.

[0023] The cryogenic pipeline has mounting holes on one side of its pipe wall for installing the device. These mounting holes facilitate installation. A boss is located above the inlet of the contraction section to mate with the wall of the mounting hole, and a similar boss is located at the outlet section to mate with the wall of the mounting hole. After the device is installed in the mounting hole, the bosses fit tightly against the hole, and a seal is then applied to complete the installation.

[0024] The walls of the contraction section, expansion section, and collection section near the cryogenic pipe are all flush with the wall of the cryogenic pipe where the mounting hole is located. This design aims to match the direction of the purge airflow within the device with the airflow within the cryogenic pipe, thus preventing interference between the two airflows.

[0025] A second observation window 9 is installed on the other side of the cryogenic pipeline at a position corresponding to the mounting hole. The second observation window provides illumination, while observation is performed through the first observation window, facilitating the acquisition of high-quality images.

[0026] The contraction section is used to accelerate the airflow entering from the inlet section. The inlet and outlet heights of this section must be consistent with the adjacent preceding and following sections. The outlet height of the contraction section is consistent with the inlet height of the expansion section. The inlet height of the contraction section is 1-4 times the outlet height, and the length of the contraction section is 2-5 times the inlet height. The surface profile can be a bicubic curve, quintic curve, or other surface profile with continuous curvature.

[0027] The expansion section is used to adjust the airflow velocity reaching the first observation window area to match the flow field velocity in the cryogenic pipe.

[0028] The inlet section includes a first straight section and a first corner section. One end of the first straight section is connected to the gas source, and the other end is connected to one end of the first corner section. The other end of the first corner section is connected to the contraction section. The inlet of the inlet section extends to the outside of the cryogenic pipeline. The purge gas flow originates from the gas source, passes through the first straight section of the inlet section, enters the first corner section, and then enters the contraction section. The inlet section is mainly used to uniformly introduce gas into the gas supply system, and its cross-section perpendicular to the flow direction is square.

[0029] The height of the inlet section is the same as that of the contraction section. The corners are rounded. The radius of the inner surface arc is 0.2 to 1 times the width of the cross section, the radius of the outer surface arc is 1.2 to 1.5 times the width of the cross section, and the length of the straight part of the inlet section is 1 to 2 times the height of the cross section.

[0030] The collection section is used to collect the airflow injected by the device. Located downstream of the first observation window (optical window), the collection section has a square cross-section perpendicular to the airflow direction. It is mainly used to collect the airflow injected by the surface defogging device, reducing the impact of the injected airflow on the main airflow in the low-temperature pipeline. The collection section has a square cross-section with openings at both ends. Considering the airflow diffusion effect, the height of the collection section cross-section should be higher than the outlet height of the window section by 1.2-2 times, and the length of the collection section is 1.5-3 times the height of the collection section cross-section.

[0031] The outlet section includes a second straight section and a second corner section. One end of the second corner section connects to the collection section, and the other end connects to one end of the second straight section. The other end of the second straight section connects to the extraction system. It is mainly used to uniformly discharge the gas injected by the device, and the cross-section perpendicular to the flow direction is square. The inlet cross-section dimensions of the outlet section are the same as those of the collection section outlet cross-section. The corners are rounded, with the inner surface radius of the rounded arc being 0.2–0.5 times the cross-sectional height, the outer surface radius being 1.2–1.5 times the cross-sectional height, and the length of the straight section being 1–2 times the cross-sectional height.

[0032] The expansion section outlet height is the same as the window section height, the contraction section outlet height is the same as the expansion section inlet height, and the collection section inlet height is higher than the window section outlet height.

[0033] In Example 2;

[0034] Based on Embodiment 1, Embodiment 2 of the present invention further provides a design method for a defogging and defrosting device for the surface of an optical window in a cryogenic pipeline based on flow purging. This method can design a device with the aforementioned effects. The window segment of this device is designed primarily to protect the optical windows of various pneumatic devices, eliminate condensation on the observation window, and improve the optical visibility of the optical window. Therefore, the overall size of the device can be determined by first determining the window segment size according to the problem to be studied, and then, based on relevant proportions, giving the geometric dimensions and parameters of other parts of the device. This example uses a pneumatic device with a circular optical window as a reference to carry out the device design. The specific implementation steps of this method are as follows:

[0035] 1) Design the device structure: The device is designed to include: an inlet section, a contraction section, an expansion section, a window section, a collection section and an outlet section connected in sequence; the inlet section is connected to the gas source; the side of the window section closest to the low-temperature pipe is the open side, and the side of the window section away from the low-temperature pipe is the sealed side with the first observation window.

[0036] 2) Determine the window segment dimensions: Set the optical window of the pneumatic equipment, i.e., the first observation window, to be circular, with a glass diameter of 100mm. Based on the design principle that the window segment length is 1-1.2 times the glass diameter and the window segment height is 0.05-0.3 times the window diameter, determine the window segment length to be 110mm and the window segment height to be 10mm.

[0037] 3) Determine the cross-sectional dimensions of the expansion section based on the window section dimensions: Based on the principle that the height of the window section is consistent with the outlet height of the expansion section, the outlet height of the expansion section is determined to be 10mm. Based on the principle that the inlet height of the expansion section is 0.1 to 1 times the outlet height, the inlet height of the expansion section is determined to be 2.5mm. Based on the principle that the length is 2 to 5 times the outlet height of the expansion section, the length of the expansion section is determined to be 30mm. The surface curve of the wall adopts a bicubic curve design.

[0038] 4) Determine the size of the contraction section based on the size of the expansion section: Based on the design principle that the outlet height of the contraction section is the same as the inlet height of the expansion section, the outlet height of the contraction section is determined to be 2.5mm. Based on the design principle that the inlet height of the contraction section is 1-4 times the outlet height, the inlet height of the contraction section is determined to be 5mm. Based on the design principle that the length of the contraction section is 2-5 times the inlet height of the contraction section, the length of the contraction section is determined to be 15mm. According to the design requirements of the contraction section wall, the profile curve of the contraction section wall is determined to be a bicubic curve.

[0039] 5) Determining the inlet section dimensions based on the contraction section dimensions: The inlet section is mainly used to uniformly introduce gas into the gas supply system, including corner sections and straight sections. Based on the design principle that the inlet section height should be consistent with the inlet height of the contraction section, the inlet section cross-sectional height is determined to be 5mm. Corners are rounded, and based on the design principle that the inner surface radius of the rounded arc is 0.2-1 times the cross-sectional height and the outer surface radius is 1.2-1.5 times the cross-sectional height, the inner surface radius of the rounded arc at the corner is determined to be 2.5mm, and the outer surface radius is determined to be 30mm. Based on the principle that the length of the straight section of the inlet section is 1-2 times the cross-sectional height, the length of the straight section of the inlet section is determined to be 7.5mm.

[0040] 6) Determine the cross-sectional dimensions of the collection section based on the window section dimensions: According to the design principle that the height of the collection section cross-section should be higher than the height of the window section outlet by a ratio of 1.2-2 times, and the length of the collection section should be 1.5-3 times the height of the collection section cross-section, the height of the collection section is determined to be 15mm and the length of the collection section is 30mm.

[0041] 7) Determine the outlet section cross-sectional dimensions based on the collection section dimensions: Since the inlet cross-sectional dimensions are consistent with the outlet cross-sectional dimensions of the collection section, the outlet section height is determined to be 15mm; Based on the design requirements such as using rounded transitions at corners, with the inner surface rounded radius being 0.2-0.5 times the cross-sectional height and the outer surface rounded radius being 1.2-1.5 times the cross-sectional height, the inner surface rounded radius of the rounded transition section is determined to be 5mm and the outer surface rounded radius to be 20mm. Based on the design principle that the straight section length is 1-2 times the cross-sectional height, the straight section length is determined to be 20mm.

[0042] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0043] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A defogging and defrosting device for the surface of an optical window in a low-temperature pipeline based on flow purging, characterized in that, The device includes: The inlet section, contraction section, expansion section, window section, collection section and outlet section are connected in sequence; the inlet section is connected to the gas source; the side of the window section closest to the low temperature pipe is the open side, and the side of the window section away from the low temperature pipe is the sealed side with the first observation window. The contraction section is used to accelerate the airflow entering from the inlet section, and the expansion section is used to adjust the airflow velocity reaching the first observation window area to match the flow field velocity in the cryogenic pipe. The inlet section includes a first straight section and a first corner section. One end of the first straight section is connected to the air source, and the other end of the first straight section is connected to one end of the first corner section. The other end of the first corner section is connected to the contraction section. The outlet section includes a second straight section and a second corner section. One end of the second corner section is connected to the collection section, and the other end of the second corner section is connected to one end of the second straight section. The other end of the second straight section is connected to the extraction system.

2. The defogging and defrosting device for the surface of an optical window in a low-temperature pipeline based on flow purging according to claim 1, characterized in that, The cryogenic pipeline has mounting holes on one side of its pipe wall for installing the device.

3. The defogging and defrosting device for the surface of an optical window in a low-temperature pipeline based on flow purging according to claim 2, characterized in that, The walls of the contraction section, the expansion section, and the collection section near the cryogenic pipe are all flush with the wall of the cryogenic pipe where the mounting hole is located.

4. The defogging and defrosting device for the surface of an optical window in a low-temperature pipeline based on flow purging according to claim 2, characterized in that, A second observation window is installed on the other side of the pipe wall, corresponding to the mounting hole.

5. A defogging and defrosting device for the surface of an optical window in a low-temperature pipeline based on flow purging, as described in claim 1, is characterized in that... The collection section is used to collect the airflow injected by the device.

6. The defogging and defrosting device for the surface of an optical window in a low-temperature pipeline based on flow purging according to claim 1, characterized in that, The outlet height of the expansion section is the same as the height of the window section, the outlet height of the contraction section is the same as the inlet height of the expansion section, and the inlet height of the collection section is higher than the outlet height of the window section.

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