阅读说明：本技术 一种痕量水结霜可视化实验装置 (Visual experimental apparatus of trace water frosting ) 是由 植晓琴 漆映荷 邱利民 叶恒扬 胡虬钦 于 2020-12-25 设计创作，主要内容包括：本发明涉及一种痕量水结霜可视化实验装置,属于结霜实验装置的设计技术领域。包括：凝华腔,内设有用于痕量水蒸气凝华沉积以及霜层生长的凝华冷面；冷源,为痕量水蒸气凝华结霜提供冷量；温控组件,用于控制凝华冷面温度,使整个凝华结霜过程在恒温条件下发生；微质量测量组件,设置在凝华冷面底部,用于测量冷面上凝华结霜的霜层质量；显微拍摄组件,用于获得不同时间的霜层生长形貌以及测量冷面上凝华结霜的霜层厚度；进气管和出气管,连通凝华腔；配气系统,以不凝性气体为气源,通过干燥或加湿获得不同水蒸气含量的混合气体,并通过进气管。可得到不同操作条件下混合气氛中痕量水蒸气凝华结霜的规律。(The invention relates to a trace water frosting visualization experiment device, and belongs to the technical field of design of frosting experiment devices. The method comprises the following steps: a desublimation chamber, in which a desublimation cold surface for desublimation deposition of trace water vapor and frost layer growth is arranged; the cold source is used for providing cold energy for trace amount of water vapor to desublimate and frost; the temperature control component is used for controlling the temperature of the desublimated cold surface so that the whole desublimated and frosted process is carried out under the condition of constant temperature; the micro-mass measuring component is arranged at the bottom of the desublimated cold surface and is used for measuring the mass of a desublimated frost layer on the cold surface; the microscopic shooting assembly is used for obtaining the growth morphology of the frost layer at different time and measuring the thickness of the frost layer which is desublimed and frosted on the cold surface; the air inlet pipe and the air outlet pipe are communicated with the desublimation cavity; the gas distribution system takes non-condensable gas as a gas source, obtains mixed gas with different water vapor contents by drying or humidifying, and passes through the gas inlet pipe. The law of trace amount of water vapor in the mixed atmosphere for desublimation and frosting under different operating conditions can be obtained.)

1. The utility model provides a visual experimental apparatus of trace water frosting which characterized in that includes:

a desublimation chamber, in which a desublimation cold surface for desublimation deposition of trace water vapor and frost layer growth is arranged;

the cold source is used for providing cold energy for trace amount of water vapor to desublimate and frost;

the temperature control component is used for controlling the temperature of the desublimated cold surface so that the whole desublimated and frosted process is carried out under the condition of constant temperature;

the micro-mass measuring assembly is arranged at the bottom of the desublimated cold surface and is used for measuring the mass of a desublimated frost layer on the cold surface;

the microscopic shooting assembly is used for obtaining the growth morphology of the frost layer at different time and measuring the thickness of the frost layer which is desublimed and frosted on the cold surface;

the air inlet pipe and the air outlet pipe are communicated with the desublimation cavity;

the gas distribution system takes non-condensable gas such as high-purity nitrogen or helium as a gas source, obtains mixed gas with different water vapor contents by drying or humidifying, and passes through the gas inlet pipe.

2. The trace water frosting visualization experiment device according to claim 1, wherein the desublimation chamber is arranged in a vacuum box, transparent windows are correspondingly arranged on the vacuum box and the walls of the desublimation chamber, and the microscopic shooting assembly is arranged at the transparent windows for shooting.

3. The experimental device for visualizing trace water frosting as claimed in claim 1, wherein said cold source comprises a liquid nitrogen tank, a liquid inlet pipe and a liquid outlet pipe which are communicated with the liquid nitrogen tank; the desublimation cold surface is positioned at the top of the liquid nitrogen pool, and the temperature control assembly is arranged in the liquid nitrogen pool.

4. The trace water frosting visualization experiment device of claim 3, wherein the liquid nitrogen pool is provided with a liquid nitrogen inlet pipeline and a nitrogen outlet pipeline, and the orifice of the nitrogen outlet pipeline is positioned above the liquid nitrogen surface.

5. The trace water frosting visualization experiment device of claim 1, wherein the air inlet pipe and the air outlet pipe are located on the same horizontal line, are parallel to the desublimation cold surface and are located above the desublimation cold surface.

6. The experimental device for visualizing trace water frosting as claimed in claim 5, wherein the mixed gas after gas distribution enters the de-sublimation chamber from the gas inlet pipe and is blown in horizontally along the edge of the de-sublimation cold surface, and the gas outlet pipe receives the partially condensed mixed gas at the other end of the de-sublimation cold surface and then sends the partially condensed mixed gas to the recovery device.

7. The trace water frosting visualization experiment device of claim 1, wherein the temperature component comprises a temperature sensor attached to the lower surface of the desublimated cold surface and a heater with adjustable power.

Technical Field

The invention relates to the technical field of design of frosting experiment devices, in particular to a trace water frosting visualization experiment device.

Background

The air transportation industry and the air manufacturing industry are strategic industries for promoting the economic development of China. In recent years, the air transportation industry of China is rapidly developed, however, the air manufacturing industry is still in a relatively laggard situation, and the rapid development is urgently needed to realize the aim of constructing the air strong country and the civil aviation strong country. The starting point for the aerospace manufacturing industry is advanced aircraft design, while fine design requires aerodynamic data at the actual reynolds number of the flight as important support.

The large low-temperature wind tunnel uses high-purity liquid nitrogen as a refrigerant, and the high-purity liquid nitrogen is evaporated in the wind tunnel to cool and test nitrogen, so that the test range of the low-temperature wind tunnel is greatly increased compared with a normal-temperature wind tunnel. During the operation of the low-temperature wind tunnel, trace water vapor in test gas may be desublimated and deposited on the proportional model, and even small-degree roughness generated by desublimation and frost formation can also obviously influence the aerodynamic characteristics of the model, thereby forming the internationally recognized problem of low-temperature wind tunnel frost pollution.

The frost pollution is a problem which needs to be solved in the operation of the current low-temperature wind tunnel, and in order to fundamentally inhibit frosting or more effectively defrost, an experiment of frosting trace amount of water vapor in a mixed atmosphere under a low-temperature condition needs to be firstly carried out to know the law of the frosting. The Chinese patent with the publication number of CN108469450A discloses a visual experimental device for a multifunctional steam condensation heat exchange and frosting process, which can be used for researching the phenomena of variable steam pressure condensation heat transfer and frosting. The Chinese patent with publication number CN111624220A discloses a novel low-temperature frosting test device, which uses a semiconductor refrigeration sheet for refrigeration, and improves the frosting efficiency by adding a breathable screen plate, so that the frosting phenomenon is more obvious. However, no experimental device capable of obtaining the trace amount of water vapor desublimation and frosting rule in the mixed atmosphere under the low-temperature condition is developed at present.

Disclosure of Invention

The invention aims to provide a trace water frosting visualization experiment device which can obtain the rule that trace water vapor in a mixed atmosphere frosts under a low-temperature condition.

In order to achieve the above object, the present invention provides a trace amount water frosting visualization experiment apparatus, comprising:

a desublimation chamber, in which a desublimation cold surface for desublimation deposition of trace water vapor and frost layer growth is arranged;

the cold source is used for providing cold energy for trace amount of water vapor to desublimate and frost;

the temperature control component is used for controlling the temperature of the desublimated cold surface so that the whole desublimated and frosted process is carried out under the condition of constant temperature;

the micro-mass measuring assembly is arranged at the bottom of the desublimated cold surface and is used for measuring the mass of a desublimated frost layer on the cold surface;

the microscopic shooting assembly is used for obtaining the growth morphology of the frost layer at different time and measuring the thickness of the frost layer which is desublimed and frosted on the cold surface;

the air inlet pipe and the air outlet pipe are communicated with the desublimation cavity;

the gas distribution system takes non-condensable gas such as high-purity nitrogen or helium as a gas source, obtains mixed gas with different water vapor contents by drying or humidifying, and passes through the gas inlet pipe.

Among the above-mentioned technical scheme, the mixed atmosphere that contains trace amount of vapor through the distribution enters into the chamber of sublimating through the intake pipe, and trace amount of vapor in the mixed atmosphere takes place the desublimation on the cold face of constant temperature low temperature in the chamber of sublimating, forms the ice crystal, and then develops at any time and form the frost layer, and remaining mist passes through the outlet duct and discharges. The cold volume of the constant temperature low temperature cold surface is obtained from the cold source, and simultaneously, the temperature control component is used for controlling the temperature of the low temperature cold surface, so that the low temperature cold surface is kept at the specified temperature in the whole process of desublimation and frosting. The appearance and thickness of the frost layer are obtained through a microscopic shooting assembly, the quality of the frost layer is obtained through a micro-quality measuring assembly, and the law of trace amount of water vapor in mixed atmosphere for desublimation and frosting under different operating conditions is obtained.

Optionally, in an embodiment, the desublimation chamber is disposed in a vacuum box, transparent windows are correspondingly disposed on the vacuum box and the walls of the desublimation chamber, and the photomicrograph assembly is placed at the transparent windows for photography. The micro-shooting component can acquire the appearance of the ice crystals on the surface of the frost layer through the transparent window.

The vacuum box is internally vacuumized, so that the heat leakage of the constant-temperature desublimation and frosting device can be reduced. Meanwhile, the air inlet pipe and the air outlet pipe of the desublimation cavity penetrate through the vacuum box and the desublimation cavity through pipelines to be connected with the air distribution system and the recovery device. The mixed gas after gas distribution enters the desublimation cavity from the gas inlet pipe, desublimation and frosting occur on the constant-temperature desublimation cold surface, and part of the desublimated mixed gas enters the recovery device along the gas outlet pipeline.

Preferably, the vacuum box is cylindrical and transparent windows are provided in the top and sides of the desublimation chamber and the vacuum box. The transparent window department at top, the subassembly of shooing a little is located the top of transparent window, and the subassembly of shooing a little can acquire the ice crystal appearance on frost layer surface through the transparent window. The transparent window of side supplies to set up four, and four transparent windows all are on same water flat line, and perpendicular to intake pipe and outlet duct. The microscopic shooting assembly can move from the upper part of the transparent window at the top to the upper part of the transparent window at the cylindrical surface, and the thickness of the frost layer can be accurately measured through the transparent window.

Optionally, in an embodiment, the cold source includes a liquid nitrogen tank, and a liquid inlet pipe and a liquid outlet pipe which are communicated with the liquid nitrogen tank; the desublimation cold surface is positioned at the top of the liquid nitrogen pool, and the temperature control assembly is arranged in the liquid nitrogen pool.

In order to obtain the desublimation cold surface of different temperature regions, the cold source can be replaced by other refrigerant pools, or in order to obtain the desublimation cold surface of extremely low temperature, a low-temperature refrigerator can be directly used as the cold source to provide cold for the desublimation cold surface.

Optionally, in an embodiment, the liquid nitrogen pool is provided with a liquid nitrogen inlet pipeline and a nitrogen outlet pipeline, and a pipe orifice of the nitrogen outlet pipeline is located above the liquid nitrogen level.

Optionally, in an embodiment, the air inlet pipe and the air outlet pipe are located on the same horizontal line, and are both parallel to and above the desublimated cold surface.

Optionally, in an embodiment, the distributed mixed gas enters the desublimation chamber from the gas inlet pipe and is blown horizontally along the edge of the desublimation cold surface, and the gas outlet pipe receives the partially condensed mixed gas at the other end of the desublimation cold surface and then sends the partially condensed mixed gas to the recovery device.

Optionally, in one embodiment, the temperature assembly comprises a temperature sensor attached to the lower surface of the desublimated cold surface and a heater with adjustable power. The heater power is adjusted by reading the data of the temperature sensor and comparing the data with the temperature of the appointed cold surface, so that the desublimated cold surface is controlled to keep the temperature constant in the whole experiment process.

Compared with the prior art, the invention has the advantages that:

the trace water frosting visualization experiment device can provide mixed gas configurations with different water vapor contents and a constant low-temperature desublimation cold surface with adjustable temperature, and further can obtain the trace water vapor frosting rule in mixed atmosphere under different operation conditions; meanwhile, the crystal morphology of the surface of the frost layer can be observed in real time, and the thickness and the quality of the frost layer can be measured in real time.

Drawings

FIG. 1 is a schematic structural diagram of a trace water frosting visualization experiment device in the embodiment of the invention;

fig. 2 is a schematic side structure diagram of a trace water frosting visualization experiment device in the embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described with reference to the following embodiments and accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments without any inventive step, are within the scope of protection of the invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of the word "comprise" or "comprises", and the like, in the context of this application, is intended to mean that the elements or items listed before that word, in addition to those listed after that word, do not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

Examples

Referring to fig. 1 and 2, the trace water frosting visualization experiment apparatus of the present embodiment includes a vacuum box 1, a constant temperature desublimation frosting unit, a measurement unit, and an air distribution system 3.

The constant temperature desublimation frosting unit sets up in vacuum cavity 1, including desublimation chamber 2, desublimation cold surface 8, temperature control component 10 and cold source, and the cold source is liquid nitrogen pool 9 in this embodiment, and liquid nitrogen pool 9 is equipped with liquid nitrogen inlet pipe way 6 and nitrogen gas outlet pipe way 7, and nitrogen gas outlet pipe way 7 is higher than the liquid level of liquid nitrogen. The two sides of the desublimation cavity 2 are respectively provided with an air inlet pipeline 4 and an air outlet pipeline 5 which are respectively communicated with an air inlet and an air outlet of the desublimation cavity 2 after penetrating through the side wall of the vacuum box 1, mixed atmosphere containing trace water vapor passing through the air distribution system 3 is introduced into the desublimation cavity 2, the trace water vapor in the mixed atmosphere is desublimated on a desublimation cold surface 8 to form ice crystals and grows into a frost layer along with the development of time, and part of the desublimated mixed gas is discharged from the air outlet pipeline 5.

The air inlet pipeline 4 and the air outlet pipeline 5 are on the same horizontal line and are both parallel to the desublimation cold surface 8. The mixed gas after gas distribution enters the desublimation cavity 2 from the gas inlet pipeline 4, is blown in horizontally along the edge of the desublimation cold surface 8, and the mixed gas after partial condensation is received at the other end of the desublimation cold surface 8 by the gas outlet pipeline 5 and is sent into the recovery device.

The gas distribution system 3 takes high-purity nitrogen as a gas source and comprises a standard gas pipeline and three paths of purification and permeation. The water vapor content of the high purity nitrogen is about 3-7 ppmv, and the water vapor content of the gas source can be continuously reduced through the purification path, so that the adjustable range of 1-3ppmv is realized. Through the permeation pathway, the water vapor content in the gas source can be increased, enabling higher ppmv grade gas configurations. The gas distribution system 3 also comprises a dew point meter, so that the mixed gas with different water vapor contents can be accurately configured.

The temperature control component 10 is arranged right below the desublimation cold surface 8 and is immersed in the liquid nitrogen tank 9. The temperature assembly 10 comprises a temperature sensor attached to the lower surface of the desublimation cold surface 8 and a heater with adjustable power, and the power of the heater is adjusted by reading the data of the temperature sensor and comparing the data with the temperature of the designated cold surface, so that the desublimation cold surface 8 is controlled to keep the temperature constant in the whole experimental process.

The upper surface of the desublimation chamber 2 is provided with a first transparent window 12, and the upper surface of the vacuum box 1 is provided with a second transparent window 13 which is opposite to and parallel to the first transparent window 12. The side surface of the desublimation cavity 2 in the vertical direction with the air inlet pipeline 4 and the air outlet pipeline 5 is oppositely provided with a third transparent window 15 and a fifth transparent window 17, and the side surface of the vacuum box 1 in the vertical direction with the air inlet pipeline 4 and the air outlet pipeline 5 is provided with a fourth transparent window 16 which is just opposite to and parallel to the third transparent window 15 and a sixth transparent window 18 which is just opposite to and parallel to the fifth transparent window 17. All transparent windows are glass windows.

The measuring unit comprises a microscopic photographing assembly 14 and a micro mass measuring assembly 11. The micro-shooting assembly 14 comprises a high-resolution lens and a supporting arm capable of rotating 90 degrees, can be placed above the second transparent window 14 for capturing the crystal morphology on the surface of the frost layer, and can also be placed on the left side of the fourth transparent window 16 or the right side of the sixth transparent window 18 for obtaining the thickness of the frost layer through rotating 90 degrees by the supporting arm. And the micro-mass measuring component 11 is embedded on the surface of the desublimation cold surface 8 and is used for measuring the frost layer deposition quality in real time. Further, the average density of the frost layer can be obtained by combining the thickness and the quality of the frost layer.

The embodiment provides mixed gas configurations with different water vapor contents and a constant low-temperature desublimation cold surface with adjustable temperature, so that the trace water vapor frosting rule in mixed atmosphere under different operating conditions can be obtained; meanwhile, the crystal morphology of the surface of the frost layer can be observed in real time, and the thickness, the quality and the average density of the frost layer can be measured in real time.