阅读说明：本技术 一种散水率测试装置及测试方法 (Water-dispersing rate testing device and method ) 是由 郑永 黄河 田富竟 张亚新 袁柏华 孙永鹏 于 2020-12-02 设计创作，主要内容包括：本发明提供了一种散水率测试装置及测试方法,用到包括内壁为光滑镜面的箱体、干燥气体置换装置、敏感元件位于箱体内部的露点测试仪、气压传感器等零部件,通过本发明提供的测试方法,解决了低露点环境下测试材料散发水分质量速率的问题,从而为低温风洞试验设备选材,尤其是保温层与胶粘剂等非金属材料的选材提供了技术支撑。(The invention provides a water-dispersing rate testing device and a testing method, which are used for a box body with a smooth mirror surface on the inner wall, a dry gas replacing device, a dew-point tester with a sensitive element positioned in the box body, an air pressure sensor and other parts.)

1. A water-dispersing rate testing device is characterized by comprising a box body (3) with a smooth mirror surface on the inner wall; the dry gas replacement device is connected with the box body (3) and is used for transferring gas in the box body; and a sealing door (4) arranged at any side of the box body; and a dew point tester (5) with a sensitive element positioned inside the box body (3).

2. The water dispersing rate testing device of claim 1, wherein the dry gas replacing device is any one of a dry gas source device (1) and a vacuum pump set (2) or a combination of the two.

3. The water dispersion rate testing device according to claim 2, characterized in that the dry air source device (1) is connected with air supply pipelines arranged on one side of the box body, the air supply pipelines are distributed in a staggered manner, the air supply pipelines are distributed at two ends of one side of the box body in a staggered manner, and the outlet positions of the air supply pipelines are higher than the inner wall of the box body (3); and an air return pipeline is arranged on one side of the box body (3).

4. A water-spreading rate test method, characterized in that the water-spreading rate test device of any one of claims 1 to 3 is used, and the test steps are as follows:

the method comprises the following steps: cleaning the inner walls of the test sample piece (7) and the box body (3) to ensure that the test sample piece (7) and the box body inner wall have no oil stain or dust;

step two: installing a test sample piece (7) in the box body (3), so that the test sample piece (7) is arranged in an overhead or suspended mode and is not directly attached to the bottom of the box body, and a gas circulation space is reserved;

step three: the sealing door (4) is closed, and the box body (3) is checked and ensured to be in a good sealing state;

step four: starting a dry gas replacement device to replace gas in the box body (3); simultaneously starting a dew point tester (5), obtaining dew point parameters in the box body (3) through the dew point tester (5), and closing the dry gas replacement device after the target dew point value is reached in the box body (3);

step five: after the dry gas replacement device is closed for a period of time delta t, recording the dew point in the box body (3);

step six: calculating the mass of the water emitted by the test sample piece (7) according to the change values of the space volume in the box body (3) and the dew point, and calculating the rate of the mass of the water emitted by the test sample piece (7) in unit time per unit area according to the surface area of the material of the test sample piece (7), namely calculating the mass rate of the water emitted by the test sample piece (7) in unit time per unit area, namely

Water-spreading rate =

Wherein each symbol represents:

Δ m: a change in moisture mass;

Δ t: the duration corresponding to the change in moisture mass;

s: the surface area of the material.

5. The method for testing water dispersion rate according to claim 4, wherein in the step one, the test sample piece (7) and the inner wall of the box body (3) are cleaned and treated in a way that: and (3) cleaning the test sample piece (7) and the inner wall of the box body (3) by dipping non-woven fabrics in anhydrous alcohol.

6. The water-spreading rate testing method according to claim 4, wherein in the second step, the concrete mode that the test sample piece (7) is arranged in the box body (3) in an overhead mode is as follows: a support is arranged in the box body (3), and a test sample piece (7) is placed on the support, so that a space is reserved below the test sample piece (7).

7. The water-dispersing rate testing method of claim 4, wherein in the third step, the concrete way of suspending the test sample piece (7) in the box body (3) is as follows: the test sample piece (7) is connected with the top of the box body (3), or the test sample piece (7) is connected with the side wall of the box body (3), so that the test sample piece (7) is hung in the box body (3) in a hanging mode.

8. The water dispersing rate test method of claim 4, wherein in the fourth step, the specific way of starting the dry gas replacement device to replace the gas in the box body (3) is as follows: and starting the drying gas source device (1) to fill the drying gas in the box body and discharge the drying gas until the target dew point value is reached.

9. The water dispersing rate test method of claim 4, wherein in the fourth step, the specific way of starting the dry gas replacement device to replace the gas in the box body (3) is as follows: and starting the vacuum pump set (2), and vacuumizing the box body to enable the box body to reach a target dew point value.

10. The water scattering rate test method according to claim 4, characterized in that the box body (3) is provided with an air pressure sensor (6) with a sensitive element positioned inside the box body (3), and an air pressure parameter in the box body is obtained through the air pressure sensor (6); in the fourth step, the specific way of starting the dry gas replacement device to replace the gas in the box body (3) is as follows: starting a vacuum pump set (2) to reduce the air pressure in the box body (3), keeping for a period of time until the dew point is reduced to a target value, and closing the vacuum pump set (2); and starting the drying gas source device (1) to fill and discharge the drying gas until the target dew point value is reached in the box body.

Technical Field

The invention relates to the technical field of detection, in particular to a water-dispersing rate testing device and a water-dispersing rate testing method.

Background

The test temperature of the low-temperature wind tunnel is 110K, and under the low-temperature environment, water molecules are changed into ice particles. In the high-speed airflow of the low-temperature wind tunnel test, ice particles seriously threaten a test device and a test model, and even destroy the test device and the test model, because the content of free water molecules in the low-temperature wind tunnel test chamber needs to be controlled at an extremely low target value, the content of the free water molecules in the test chamber is generally reduced by blowing dry gas. The heat-insulating layer of the low-temperature wind tunnel test cabin is made of high polymer materials, has water absorption and water dispersion capabilities (water dispersion capabilities, the capability of materials for volatilizing water contained in the materials to the external environment), and free water molecules formed by the water dispersion of the materials can become ice particles in the low-temperature wind tunnel. In order to evaluate the water dispersing capacity of materials such as the insulating layer of the low-temperature wind tunnel test cabin, a technical scheme for testing the water dispersing capacity needs to be designed.

The existing moisture content testing method is to test the absolute moisture content of a material through a certain technical means, and the low-temperature engineering requires to test the water dispersion rate (water dispersion rate: the rate of the mass of the water dispersed by the material in unit time) of the material in a low dew point environment.

Disclosure of Invention

The invention aims to provide a water dispersing rate testing device and a testing method to evaluate the water dispersing capacity of a material.

In order to achieve the purpose, the invention provides a water-dispersing rate testing device, which comprises a box body 3, the inner wall of which is a smooth mirror surface; the dry gas replacement device is connected with the box body and is used for transferring gas in the box body; and a sealing door 4 arranged at any side of the box body; and a dew point tester 5 with a sensing element inside the box body.

Further, the dry gas replacement device is any one of or a combination of two of the dry gas source device 1 and the vacuum pump set 2.

Further, the dry air source device 1 is connected with an air supply pipeline arranged on one side of the box body, the air supply pipeline is distributed in a staggered manner, the air supply pipeline is distributed at two ends of one side of the box body in a staggered manner, and the outlet position of the air supply pipeline is higher than the inner wall of the box body 3; and an air return pipeline is arranged on one side of the box body 3.

The invention also provides a water-dispersing rate testing method, which adopts a water-dispersing rate testing device and comprises the following testing steps:

the method comprises the following steps: cleaning the inner walls of the test sample piece 7 and the box body 3 to ensure that the inner walls of the test sample piece 7 and the box body do not have oil stains or dust;

step two: installing a test sample piece 7 in the box body 3, so that the test sample piece 7 is arranged in an overhead or suspended manner and is not directly attached to the bottom of the box body, and a gas circulation space is reserved;

step three: the sealing door 4 is closed, and the box body 3 is checked and ensured to be in a good sealing state;

step four: starting a dry gas replacement device to replace gas in the box body 3; simultaneously starting a dew point tester 5, obtaining dew point parameters in the box body 3 through the dew point tester 5, and closing the dry gas replacement device after the target dew point value is reached in the box body 3;

step five: after the dry gas replacement device is closed for a period of time delta t, recording the dew point in the box body 3;

step six: calculating the mass of the water emitted by the test sample piece 7 according to the change values of the space volume in the box body 3 and the dew point, and calculating the rate of the mass of the water emitted by the test sample piece 7 in unit time per unit area according to the surface area of the material of the test sample piece 7, namely the rate

Water spreading rate = Δ m/(Δ t · S)

Wherein each symbol represents:

Δ m: a change in moisture mass;

Δ t: the duration corresponding to the change in moisture mass;

s: the surface area of the material.

Further, in the first step, the way of cleaning the test sample 7 and the inner wall of the box 3 is: and (3) cleaning the test sample piece 7 and the inner wall of the box body 3 by dipping non-woven fabrics in anhydrous alcohol.

Further, in the second step, the specific manner of the overhead installation of the test sample 7 in the box 3 is as follows: set up the support in box 3, experimental sample 7 is placed on the support for leave the space below experimental sample 7.

Further, in step three, the concrete mode that the test sample 7 is mounted in the box 3 in a suspended manner is as follows: the test sample piece 7 is connected with the top of the box body 3, or the test sample piece 7 is connected with the side wall of the box body 3, so that the test sample piece 7 is hung in the box body 3 in a suspension mode.

Further, in the fourth step, the specific manner of starting the dry gas replacement device to replace the gas in the box 3 is as follows: and starting the drying gas source device 1 to fill the drying gas in the box body and discharge the drying gas until the target dew point value is reached.

Further, in the fourth step, the specific manner of starting the dry gas replacement device to replace the gas in the box 3 is as follows: and starting the vacuum pump set 2, and vacuumizing the box body to enable the box body to reach a target dew point value.

Further, the box body 3 is provided with an air pressure sensor 6 with a sensitive element positioned inside the box body 3, and air pressure parameters in the box body are obtained through the air pressure sensor 6; in the fourth step, the specific way of starting the dry gas replacement device to replace the gas in the box body 3 is as follows: starting the vacuum pump set 2 to reduce the air pressure in the box body 3, keeping for a period of time until the dew point is reduced to a target value, and closing the vacuum pump set 2; and starting the drying gas source device 1, filling the drying gas and discharging the drying gas until the target dew point value in the box body is reached.

The invention has the following beneficial effects:

the invention has two methods of vacuumizing and discharging drying gas while filling to reduce the dew point, and can calculate the water dispersion rate of the material within a period of time after the target dew point is reached; the invention provides a water-dispersing rate concept and a method for testing the water-dispersing rate in a low dew point environment for the first time by testing the initial and target dew points in a water-dispersing rate device, recording the elapsed time and calculating the water-dispersing amount, which is different from the absolute water content of the test material in the prior art. The problem of the mass rate of the water emitted by the test material under the low dew point environment is solved, and therefore technical support is provided for material selection of low-temperature wind tunnel test equipment, particularly material selection of a heat insulation layer.

According to the invention, the air supply pipelines distributed at the bottom of the box body in a staggered manner, so that the dry gas can be more fully blown to each position in the box body, the speed of taking away the moisture is accelerated, and the testing efficiency is improved.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic structural diagram of a preferred embodiment of the present invention;

in the figure: 1. the device comprises a dry air source device, 2 a vacuum pump set, 3 a box body, 4 a sealing door, 5 a dew point tester, 6 an air pressure sensor and 7 a test sample piece.

Detailed Description

Embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways, which are defined and covered by the claims.

Referring to fig. 1, a water-spreading rate testing device comprises a box body 3 with a smooth mirror surface on the inner wall, wherein the box body is required to polish and smooth a welding line during manufacturing; and a dry gas replacement device connected to the box 3, the dry gas replacement device transferring gas inside the box; and a sealing door 4 arranged at any side of the box body; and a dew point tester 5 with a sensing element inside the box 3.

Specifically, the dry gas replacement device is any one of or a combination of two of a dry gas source device 1 and a vacuum pump set 2. The drying gas device can select a liquid nitrogen source and a liquid nitrogen vaporizer, and the drying gas is drying nitrogen, drying air or other drying gases. The vacuum pump group is one of an oil pump, a roots pump or a combination of the oil pump and a molecular pump or other vacuum pump groups, and the lowest pressure in the tank is 70-80 Pa.

Specifically, the dry air source device 1 is connected with an air supply pipeline arranged on one side of the box body, the air supply pipeline is distributed in a staggered mode and is distributed at two ends of one side of the box body in a staggered mode, the outlet position of the air supply pipeline is higher than the inner wall of the box body, and the height of the air supply pipeline is 10-30 mm. An air return pipeline is arranged on one side of the box body 3; the preferable air supply pipeline is arranged at the top, and the air return pipeline is arranged at the side.

The sealing door of the box body is an inflatable sealing door and mainly comprises a door frame, a door plate, an inflatable sealing rubber strip, an inflation and deflation control system and the like, wherein the inflatable sealing rubber strip is embedded in a groove of a door plate framework; the instrument, the air supply pipeline and the like of the box body are sealed internally and externally by rubber. The box body can also be provided with a display screen for intensively displaying parameters such as dew point, temperature, pressure, time and the like, and dynamically monitoring the change of each parameter in the test process.

A water-dispersing rate test method adopts the water-dispersing rate test device, and the test steps are as follows:

the method comprises the following steps: cleaning the inner walls of the test sample piece 7 and the box body 3 to ensure that the inner walls of the test sample piece 7 and the box body do not have oil stains or dust;

step two: installing a test sample piece 7 in the box body 3, so that the test sample piece 7 is arranged in an overhead or suspended manner and is not directly attached to the bottom of the box body, and a gas circulation space is reserved;

step three: the sealing door 4 is closed, and the box body 3 is checked and ensured to be in a good sealing state;

step four: starting a dry gas replacement device to replace gas in the box body 3; simultaneously starting a dew point tester 5, obtaining dew point parameters in the box body 3 through the dew point tester 5, and closing the dry gas replacement device after the target dew point value is reached in the box body 3;

step five: after the dry gas replacement device is closed for a period of time delta t, recording the dew point in the box body 3;

step six: calculating the mass of the water emitted by the test sample piece 7 according to the change values of the space volume in the box body 3 and the dew point, and calculating the rate of the mass of the water emitted by the test sample piece 7 in unit time per unit area according to the surface area of the material of the test sample piece 7, namely the rate

Water spreading rate = Δ m/(Δ t · S)

Wherein each symbol represents:

Δ m: a change in moisture mass;

Δ t: the duration corresponding to the change in moisture mass;

s: the surface area of the material.

Specifically, in the first step, the inner walls of the test sample 7 and the box 3 are cleaned in the following manner: and the non-woven fabric is dipped in the anhydrous alcohol to clean the test sample piece 7 and the inner wall of the box body 3, so that no oil stain or dust is ensured.

Specifically, in the second step, the specific manner of the overhead installation of the test sample 7 in the box 3 is as follows: set up the support in box 3, experimental sample 7 is placed on the support for leave the space below experimental sample 7.

Specifically, in step three, the concrete mode that experimental sample 7 was installed in the box 3 in the air is: the test sample piece 7 is connected with the top of the box body 3, or the test sample piece 7 is connected with the side wall of the box body 3, so that the test sample piece 7 is hung in the box body 3 in a suspension mode. The test sample piece can be directly hung on the top of the box body or hung on the side position of the box body by a plurality of ropes, so that the test sample piece is suspended.

In the fourth step, the method of starting the dry gas replacement device to make the interior of the box body reach the target dew point value comprises the following steps:

specifically, in the fourth step, the specific manner of starting the dry gas replacement device to replace the gas in the box 3 is as follows: and starting the drying gas source device 1 to fill the drying gas in the box body and discharge the drying gas until the target dew point value is reached. The gas source of the dry gas source device can be liquid nitrogen, dry gas is formed after vaporization and is input into the box body, and the original gas containing moisture in the box body is overflowed and taken away, so that the target dew point value is reached.

Specifically, in the fourth step, the specific manner of starting the dry gas replacement device to replace the gas in the box 3 is as follows: and starting the vacuum pump set 2, vacuumizing the box body, pumping away the moisture in the device along with the air, and simultaneously evaporating and pumping away the moisture remained on the inner wall to enable the interior of the box body to reach a target dew point value.

Because some corners in the box 3 are difficult to be swept by dry gas, or the test sample piece is irregular shape, and moisture is difficult to be taken away, so the gas replacement adopts the mode of first evacuating, filling dry gas and discharging water vapour. Specifically, the box body 3 is provided with an air pressure sensor 6 with a sensitive element positioned inside the box body 3, and air pressure parameters in the box body are obtained through the air pressure sensor 6; in the fourth step, the specific way of starting the dry gas replacement device to replace the gas in the box body 3 is as follows: starting the vacuum pump set 2 to reduce the air pressure in the box body 3 to 70-80Pa, keeping the air pressure for a period of time until the dew point is reduced to a target value, and closing the vacuum pump set 2 at minus 50 to minus 55 ℃; and starting the drying gas source device 1, filling the drying gas and discharging the drying gas until the target dew point value in the box body is reached.

In order to verify the water displacement capacity and the sealing performance of the estimated water dispersing rate testing device, a test of the device without a load and without a test piece can be carried out and used for the calculation of a comparison test. The specific mode is as follows: and if the dew point change is within the expected set range, the replacement level of the water scattering rate testing device meets the technical requirements, and the sealing performance is good.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.