Wet air condensation device and photoelectric imaging equipment

Abstract

The invention provides a moist air condensation device and photoelectric imaging equipment, the moist air condensation device comprises a heat insulation shell, a condensation window, an annular space ring and a ventilation window, a cavity with one end open and the other end closed is formed in the heat insulation shell along the axis of the heat insulation shell; the ventilation window, the space ring and the condensation window are sequentially and coaxially embedded in one end of a cavity of the heat insulation shell, and the side wall of the other end of the heat insulation shell is provided with a humid air inlet channel communicated with the cavity of the heat insulation shell. The condensation window and the ventilation window are isolated by the annular space ring to form a water vapor condensation space. The moist air condensation device is installed at the lowest temperature position in the photoelectric cabin, the condensation window is made of a material with a large heat conductivity coefficient and small specific heat capacity, moist air in the optical cabin can penetrate through the ventilation window and is rapidly condensed into small water drops on the condensation window, and therefore the situation that the imaging quality is affected due to optical window frosting caused by the temperature difference inside and outside the optical cabin is avoided. The structure is simple, and the molded surface of the optical window cannot be influenced.

Description

Technical Field

[0001] The present invention belongs to the technical field of humidity control of optical devices, and particularly relates to a humid air condensation device and an optoelectronic imaging device. Background Art

[0002] For optoelectronic imaging devices with optical windows, due to the temperature difference inside and outside the optoelectronic imaging device at different ambient temperatures, water vapor condensation is likely to occur at the optical window. The condensation above zero degree is manifested as small liquid beads, and below zero degree as small ice particles, which are collectively referred to as window fogging here. Usually, in order to prevent fogging, a great deal of effort is required to seal the optoelectronic device to prevent external water vapor from entering the interior of the optical cabin, and the interior of the optical cabin needs to be thoroughly dried and dehumidified. In addition, heating facilities are designed on the optical window for defogging, such as plating heating wires, setting air outlets, etc. However, although these measures can prevent or remove the fog on the optical window, heating or blowing cold air easily causes the deformation of the optical window surface, thus affecting the imaging quality. Summary of the Invention

[0003] The purpose of the present invention is to solve the problem that the anti-fogging method of the optical window of the existing optoelectronic imaging device easily causes the deformation of the optical window surface, thereby affecting the imaging quality of the optoelectronic imaging device, and provides a humid air condensation device and an optoelectronic imaging device.

[0004] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0005] A humid air condensation device includes a heat-insulating housing, a breathable window, an annular spacer, and a condensation window;

[0006] A cavity with one end open and one end closed is formed along the axis inside the heat-insulating housing; the breathable window, the annular spacer, and the condensation window are coaxially and sequentially installed inside one end of the cavity, and are in sealed cooperation with the inner wall of the cavity;

[0007] The condensation window and the breathable window are plate-shaped, and the condensation window can close the open end of the cavity;

[0008] The side wall at the other end of the heat-insulating housing has a humid air inlet channel communicating with the cavity;

[0009] The thermal conductivity coefficient of the heat-insulating housing is lower than 0.5W / m·k;

[0010] The thermal conductivity coefficient of the condensation window is greater than 1.0W / m·k and the specific heat capacity is less than 0.8J / g·℃;

[0011] The annular spacer is used to separate the condensation window from the breathable window to form a water vapor condensation space;

[0012] The ventilation window is made of a breathable material and is used to allow moist air in a low-temperature working environment to pass through the ventilation window and enter the water vapor condensation space, where it condenses into water droplets on the condensation window.

[0013] Further, the heat-insulating housing includes a cylinder and a flange plate radially extending outward from the side wall of the cylinder; the flange plate is close to the opening end of the cavity of the heat-insulating housing.

[0014] The cavity includes a large-diameter hole and a small-diameter hole connected coaxially. The ventilation window, the annular spacer, and the condensation window are sequentially installed in the large-diameter hole, and the end face of the ventilation window fits against the step surface between the large-diameter hole and the small-diameter hole.

[0015] Further, the moist air inlet channels are a plurality of annular through-holes evenly distributed circumferentially on the side wall of the heat-insulating housing, and the annular through-holes communicate with the small-diameter hole of the cavity.

[0016] Further, the plurality of annular through-holes are in the same plane, and the plane is perpendicular to the axis of the heat-insulating housing.

[0017] Further, the condensation window is made of quartz material, and the surface close to the ventilation window is a polished surface; the surface facing away from the ventilation window is a matte surface.

[0018] Further, the materials of the annular spacer and the heat-insulating housing are Teflon.

[0019] An optical imaging device having an optical window further includes the above-mentioned moist air condensation device.

[0020] The moist air condensation device is fixedly installed at the lowest temperature position in the optical cabin of the optoelectronic imaging device through its upper flange plate.

[0021] The moist air condensation device can quickly condense the moist air in the optical cabin into water droplets to prevent frosting on the optical window.

[0022] Further, the following method is used to design the moist air condensation device in the optical imaging device:

[0023] Step 1: According to the volume of the optical cabin of the optoelectronic imaging device, calculate the maximum water vapor condensation area S.

[0024] The maximum water vapor condensation area S = ρV / πr 2 ;

[0025] In the formula, V is the volume of the optical cabin, ρ is the maximum saturated water vapor density at the working environment temperature, and r is the radius of the liquid droplet, which is the thickness of the ice particle when the temperature is below zero.

[0026] Step 2: According to the operating environmental temperature of the optoelectronic imaging device, the internal thermal circulation path, and the influence of airflow during flight, simulate and analyze the temperature distribution inside the optical cabin. Take the area with the lowest temperature on the inner surface of the optical cabin as the optimal installation position of the humid air condensation device.

[0027] Step 3: Determine the area of the condensation window in the humid air condensation device according to the maximum water vapor condensation area S obtained in Step 1, where the area of the condensation window is larger than the maximum water vapor condensation area S.

[0028] The advantages of the present invention are as follows:

[0029] 1. The humid air condensation device designed by the present invention includes a heat-insulating housing, a condensation window, an annular spacer, and a ventilation window. The annular spacer isolates the condensation window and the ventilation window to form a water vapor condensation space. After the humid air inside the optical cabin of the optoelectronic imaging device enters the humid air condensation device, it can pass through the ventilation window and quickly condense into small water droplets on the condensation window, thus avoiding the frosting of the optical window due to the temperature difference between the inside and outside of the optical cabin and affecting the imaging quality.

[0030] 2. The present invention uses a humid air condensation device to prevent fogging of the optical window, without the need to additionally design a heating device, avoiding changes in the optical window surface profile and ensuring the imaging quality of the optical window.

[0031] 3. After adopting the humid air condensation device of the present invention in a low-temperature working environment, the humid air condensation device of the present invention quickly condenses the humid air inside the optoelectronic cabin, avoiding frosting of the optical window. After the working environment temperature rises, the fog evaporates again, and the water vapor in the humid air condensation device is released after the air inside and outside the optical cabin is exchanged. Therefore, there is no need to require the optical cabin of the optoelectronic imaging device to be strictly sealed.

[0032] 4. The device of the present invention has a low cost, does not require electric drive, and is easy to install.

[0033] The additional aspects and advantages of the present invention will be partially given in the following description, partially will become obvious from the following description, or will be understood through the practice of the present invention. Description of the Drawings

[0034] The above and / or additional aspects and advantages of the present invention will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, where:

[0035] Figure 1 is a perspective view of the humid air condensation device of the present invention;

[0036] Figure 2 is a cross-sectional view of the humid air condensation device of the present invention.

[0037] In the figure: 1 - condensation window, 2 - annular spacer, 3 - ventilation window, 4 - heat-insulating housing. Detailed implementation mode

[0038] The embodiments of the present invention will be described in detail below. The embodiments are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0039] Referring to Figure 1 and Figure 2 , this embodiment provides a humid air condensation device, which includes a condensation window 1, an annular spacer 2, a breathable window 3 and a heat-insulating housing 4. A cavity with one end open and one end closed is formed along the axis inside the heat-insulating housing 4. The breathable window 3, the annular spacer 2 and the condensation window 1 are coaxially and sequentially installed inside one end of the cavity of the heat-insulating housing 4 and are in sealed cooperation with the inner wall surface of the cavity. The condensation window 1 and the breathable window 3 are plate-shaped, and the condensation window 1 can close the open end of the cavity of the heat-insulating housing. The thermal conductivity coefficient of the heat-insulating housing is less than 0.5 W / m·k; the thermal conductivity coefficient of the condensation window is greater than 1.0 W / m·k and the specific heat capacity is less than 0.8 J / g·°C; the spacer is used to separate the condensation window from the breathable window to form a water vapor condensation space; the breathable window is made of a breathable material and is used to allow humid air in a low-temperature working environment to enter the water vapor condensation space through the breathable window and condense on the condensation window.

[0040] Specifically, the heat-insulating housing 4 includes a cylinder and a flange plate radially extending outward on the side wall of the cylinder; the flange plate is close to the open end of the cavity of the heat-insulating housing, and the flange plate is used to fix the humid air condensation device in the optical cabin of the optical imaging device. The cavity inside the heat-insulating housing 4 includes a large-diameter hole and a small-diameter hole connected coaxially. The breathable window 3, the annular spacer 2 and the condensation window 1 are sequentially installed in the large-diameter hole, and the end face of the breathable window 3 fits against the step surface between the large-diameter hole and the small-diameter hole. A plurality of annular through holes penetrating through the small-diameter hole of the heat-insulating housing 4 are circumferentially and evenly distributed on the side wall of the heat-insulating housing as a humid air inlet channel. Preferably, the plurality of annular through holes are in the same plane, and this plane is perpendicular to the axis of the heat-insulating housing 4.

[0041] Specifically, since the thermal conductivity of quartz is 10 times that of traditional glass materials, the condensation window 1 in this embodiment is made of quartz material, and the surface close to the breathable window is a polished surface with a surface roughness less than or equal to 0.012, which is convenient for humid air to quickly condense into water droplets; the surface of the condensation window 1 facing away from the breathable window is a matte surface with a surface roughness greater than 1.6.

[0042] The annular spacer 2 is used to isolate the condensation window 1 and the breathable window 3 to form a water vapor condensation space, so that humid air quickly condenses on the surface of the condensation window 1 to form water droplets and falls into the water vapor condensation space. The thermal conductivity coefficient of the annular spacer 2 is not greater than 0.3 W / m·k, which can prevent the heat in the pod from being conducted to the condensation window 1. In the embodiment of the present invention, the material of the annular spacer 2 is Teflon, and its thermal conductivity coefficient is 0.3 W / m·k.

[0043] The heat-insulating housing 4 is made of a material with a thermal conductivity coefficient lower than 0.5 W / m·k, and is used to prevent the internal radiation of the optics from heating the condensation window 1.

[0044] This embodiment also provides an optoelectronic imaging device. The optoelectronic imaging device has an optical window and further includes the above-mentioned humid air condensation device. The humid air condensation device is fixed at the position with the lowest temperature in the optical cabin of the optoelectronic imaging device through its upper flange. When the optical imaging device is in a low-temperature working environment, the humid air condensation device can quickly condense the humid air in the optical cabin into water droplets to prevent frosting on the optical window of the optical imaging device.

[0045] The process of designing the humid air condensation device in the optoelectronic imaging device is as follows:

[0046] Step 1: According to the volume of the optical cabin of the optoelectronic imaging device, calculate the maximum water vapor condensation area S according to the formula.

[0047] The maximum water vapor condensation area S = ρV / πr 2 ;

[0048] In the formula, V is the volume of the optical cabin, ρ is the maximum saturated water vapor density at the working environment temperature, r is the radius of the liquid droplet, and when the temperature is below zero, r is the thickness of the ice particle.

[0049] Step 2: According to the working environment of the optoelectronic imaging device, the internal heat circulation path, and the influence of the airflow during flight, simulate and analyze the temperature distribution in the optical cabin, and take the area with the lowest surface temperature in the optical cabin as the best installation position of the humid air condensation device.

[0050] Taking a spherical optoelectronic pod as an example, when the optoelectronic pod is flying forward and looking obliquely downward at the ground target, the position exposed at the front end is generally the area where the convective cooling is the most obvious, and this position is the best installation position of the humid air condensation device.

[0051] Step 3: Determine the area of the condensation window in the humid air condensation device according to the maximum water vapor condensation area S obtained in Step 1, where the area of the condensation window is larger than the maximum water vapor condensation area S.

[0052] In this embodiment, the condensation window 1 is made of quartz material, and the annular spacer 2 and the heat-insulating housing 4 are made of Teflon material.

[0053] When the optoelectronic imaging device operates in a low-temperature environment, the condensation window 1 in the humid air condensation device starts to cool down first, and its temperature is the lowest in the optoelectronic imaging device. The humid air inside the optical cabin enters the small-diameter holes of the heat-insulating housing 4 through the humid air inlet channel on the heat-insulating housing 4, passes through the air-permeable window 3 and contacts the surface of the condensation window 1, condenses into small water droplets on the condensation window, and is located in the water vapor condensation space formed between the condensation window 1 and the air-permeable window 3. The humid air in the optical cabin of the optoelectronic imaging device quickly condenses in the humid air condensation device of the present invention, thus avoiding the frosting of the optical window due to the temperature difference inside and outside the optical cabin and affecting the imaging quality.

[0054] When the working temperature rises, the fog evaporates again, and the water vapor in the water vapor condensation space is released after the air inside and outside the optical cabin is exchanged.

[0055] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A humid air condensing device, characterized in that: It includes a heat-insulating shell, a ventilation window, an annular spacer and a condensation window; A cavity with one end open and the other end closed is provided in the heat-insulating shell along its axis; the air-permeable window, the annular spacer, and the condensation window are coaxially embedded in one end of the cavity in sequence and are sealed with the inner wall of the cavity; The condensation window and the ventilation window are plate-shaped, and the condensation window can close the open end of the cavity; The side wall at the other end of the heat-insulating shell has a moist air inlet channel connected to the cavity; The thermal conductivity coefficient of the heat-insulating shell is lower than 0.5 W / m·k; The thermal conductivity coefficient of the condensation window is greater than 1.0 W / m·k and the specific heat capacity is less than 0.8 J / g·°C; The annular spacer is used to separate the condensation window from the ventilation window to form a water vapor condensation space; The ventilation window is made of a breathable material and is used to allow humid air in a low-temperature working environment to pass through the ventilation window into the water vapor condensation space and condense into water droplets on the condensation window.

2. The humid air condensing device according to claim 1, characterized in that: The heat-insulating shell comprises a cylinder and a flange extending radially outwardly from the side wall of the cylinder; the flange is close to the cavity opening end of the heat-insulating shell; The cavity comprises a large diameter hole and a small diameter hole which are coaxially connected. The air permeable window, annular spacer and condensation window are sequentially installed in the large diameter hole, and the end face of the air permeable window fits with the step surface between the large diameter hole and the small diameter hole.

3. The humid air condensing device according to claim 2, characterized in that: The moist air inlet passage is a plurality of annular through holes uniformly distributed on the side wall of the heat-insulating shell around the circumference, and the annular through holes are connected with the small-diameter holes of the cavity.

4. The humid air condensing device according to claim 3, characterized in that: The plurality of annular through holes are located on the same plane, and the plane is perpendicular to the axis of the heat-insulating shell.

5. The humid air condensing device according to claim 4, characterized in that: The condensation window is made of quartz material, and the side close to the air permeable window is a polished surface, and the side away from the air permeable window is a rough surface.

6. The humid air condensing device according to claim 1, characterized in that: The annular spacer and the heat-insulating shell are made of Teflon.

7. An optical imaging device having an optical window, characterized in that: Also includes the humid air condensing device according to any one of claims 1 to 6; The moist air condensation device is fixedly mounted at the lowest temperature position in the optical cabin of the optoelectronic imaging device through its upper flange; The humid air condensing device can rapidly condense the humid air in the optical cabin into water droplets, so as to prevent frost from forming on the optical window.

8. The optoelectronic imaging device according to claim 7, characterized in that: The humid air condensing device is designed by the following method: Step 1: Calculate the maximum water vapor condensation area S according to the volume of the optical cabin of the optoelectronic imaging device; The maximum water vapor condensation area S = ρV / πr 2 ; Where V is the volume of the optical cabin, ρ is the maximum saturated water vapor density at the working environment temperature, r is the droplet radius, and r is the ice particle thickness when the temperature is below zero degrees; Step 2: According to the working environment temperature of the optoelectronic imaging device, the internal heat circulation path and the influence of the airflow during flight, the temperature distribution in the optical cabin is simulated and analyzed, and the area with the lowest surface temperature in the optical cabin is used as the optimal installation position of the humid air condensation device; Step 3: According to the maximum water vapor condensation area S obtained in step 1, determine the area of ​​the condensation window in the humid air condensation device, wherein the area of ​​the condensation window is larger than the maximum water vapor condensation area S.

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