Preparation method of high-altitude water for icing wind tunnel simulation

Abstract

According to the preparation method of the high-altitude water for icing wind tunnel simulation, tetrahydrofuran and matrix water are mixed according to the mass ratio of 0%-20%, and the low-icing-temperature high-altitude simulation water for icing wind tunnel simulation is obtained. The tetrahydrofuran is added to introduce a hydrogen bond acceptor into the deionized water, so that the purity of the deionized water is not influenced, the icing temperature of the water can be regulated in a wide range, the supercooled icing temperature effect of the high-altitude ultrapure water is achieved, and the prepared icing wind tunnel high-altitude simulation water has the advantages of stable physical form, no layering and the like, and has a wide application prospect. The preparation process has the characteristics of simplicity in operation, high practicability and the like. The problem that the supercooling state of high-altitude high-purity water cannot be simulated on the ground is solved, and a solution is provided for simulating high-altitude water in an ice wind tunnel and preparing supercooled ultrapure water on the ground.

Description

Technical Field

[0001] The invention relates to a technology in the field of wind tunnel simulation, in particular to a method for preparing high-altitude water for ice wind tunnel simulation. Background Art

[0002] The icing wind tunnel is a large-scale special wind tunnel with complex performance. It is a ground test equipment for studying the icing morphology, icing tolerance and anti-icing (de-icing) technology of the windward surfaces of different components and the external sensing parts of the detection instruments when the aircraft is flying under icing meteorological conditions. Since the water in the air is ultrapure water lacking condensation nuclei (the most common are compounds such as chlorine, nitrogen, carbon, magnesium, sodium, and calcium), the supercooled water formed will not freeze even at -15℃ to -20℃ and will remain in liquid state. Therefore, in order to simulate supercooled water in the air in the ground environment, higher requirements are placed on the purity of water. However, the carbon dioxide concentration in the ground environment is high and when the water is ultrapure (18.2MΩ·cm), carbon dioxide is very soluble in water, thus affecting the purity of the water. This is because carbon dioxide is a weakly acidic gas. After dissolving in water, it will form carbonic acid, which will cause the purity of the water to decrease, affecting the purity of the ultrapure water, and then affecting the freezing temperature of the ultrapure water, which makes it impossible for the ground wind tunnel test to simulate the freezing state of water in the air. Therefore, there is an urgent need to develop high-altitude water for ground ice wind tunnel simulation, that is, to simulate the supercooled temperature of high-altitude water on the ground. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a method for preparing high-altitude water for ice wind tunnel simulation. By adding tetrahydrofuran to introduce hydrogen bond acceptors into deionized water, it is possible to achieve a wide range of regulation of the freezing temperature of water without affecting the purity of deionized water, thereby achieving the supercooled freezing temperature effect of high-altitude ultrapure water. The prepared water for ice wind tunnel high-altitude simulation has the advantages of stable physical form and no stratification, and the preparation process has the characteristics of simple operation and strong practicality. The invention solves the problem that the ground cannot simulate the supercooled state of high-altitude high-purity water, and provides a solution for ice wind tunnel simulation of high-altitude water and the preparation of simulated supercooled ultrapure water on the ground.

[0004] The present invention is achieved through the following technical solutions:

[0005] The invention relates to a method for preparing high-altitude water for ice wind tunnel simulation. The method comprises mixing tetrahydrofuran and base water in a mass ratio of 0.1% to 20% to obtain high-altitude simulated water with a low freezing temperature for ice wind tunnel simulation.

[0006] The mixing is preferably uniformly mixed under magnetic stirring and dispersion.

[0007] The matrix water is preferably deionized water. Technical Effects

[0008] The present invention achieves a wide range of control of the freezing temperature of the wind tunnel high-altitude simulation water to reach the freezing temperature of ultrapure water without reducing the purity of the water by inhibiting the freezing hydrogen bond control strategy. Compared with the prior art, the wind tunnel high-altitude simulation water of the present invention does not affect the purity of deionized water, and can achieve deionized water freezing at -15°C. The prepared wind tunnel high-altitude simulation water has the advantages of stable physical form and no stratification, and the preparation process has the characteristics of simple operation and strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The diagrams are the resistance and conductivity test device diagram (a), the freezing temperature test device diagram (b) and the sample placement diagram during the freezing temperature test;

[0010] Figure 2 The conductivity and resistivity diagrams are for tap water, ultrapure water-0min and ultrapure water-10min;

[0011] Figure 3 The cooling process diagrams of tap water, ultrapure water-0min and ultrapure water-10min;

[0012] Figure 4 The actual picture of the prepared deionized water and the 0.1%-20% tetrahydrofuran / deionized water solution;

[0013] Figure 5 The conductivity and resistivity diagrams of deionized water and 0.1%-20% tetrahydrofuran / deionized water solution;

[0014] Figure 6 Freezing temperature diagram for deionized water and 0.1%-20% tetrahydrofuran / deionized water solution. DETAILED DESCRIPTION Example 1

[0015] This embodiment tests the purity (conductivity and resistivity) and freezing temperature of comparative tap water as follows:

[0016] Step 1: Add 20g of tap water into the container as a comparative example, and test the conductivity and resistivity of the tap water at 25°C;

[0017] Step 2: Add 10 g of tap water into a 20 mL container;

[0018] Step 3: Add 5 mL of paraffin oil into the above container (to prevent air dust from entering during the freezing temperature test and thus affecting the test results);

[0019] Step 4: Test the freezing temperature of tap water;

[0020] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to measure the purity and freezing temperature of tap water respectively.

[0021] like Figure 1-Figure 3 As shown, after actual testing, the conductivity of tap water is 2.518μS / cm; the resistivity of tap water is 397kΩ·cm; and the freezing temperature of tap water is -7.3℃. Example 2

[0022] This embodiment tests the purity of ultrapure water prepared by the ultrapure water machine of the comparative example in terms of conductivity, resistivity and freezing temperature after being stored in the air for different periods of time as follows:

[0023] Step 1, add 20g of ultrapure water prepared by an ultrapure water machine into a container, record ultrapure water-0min (tetrahydrofuran accounts for 0% of matrix water), and immediately test the conductivity and resistivity of the ultrapure water prepared by the ultrapure water machine at 25°C;

[0024] Step 2: Add 10 g of ultrapure water prepared by an ultrapure water machine into a 20 mL container;

[0025] Step 3: Add 5 mL of paraffin oil into the above container;

[0026] Step 4: Test the freezing temperature of ultrapure water prepared by the ultrapure water machine;

[0027] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to measure the purity and freezing temperature of ultrapure water -0min respectively.

[0028] like Figure 1-Figure 3 As shown, after actual testing, the ultrapure machine equipment shows that the online purity of water is 18.2MΩ·cm; the conductivity of ultrapure water prepared by the ultrapure water machine is 0.469μS / cm; the resistivity of ultrapure water prepared by the ultrapure water machine is 2130kΩ·cm; the freezing temperature of ultrapure water prepared by the ultrapure water machine is -12.0°C. Therefore, when the ultrapure water is immediately exposed to air when it is taken, its purity decreases from 18.2MΩ·cm to 2130kΩ·cm (carbon dioxide in the air immediately dissolves into the ultrapure water), and compared with the results of Example 3, its freezing temperature will also increase. Example 3

[0029] This embodiment tests the purity (conductivity and resistivity) and freezing temperature of ultrapure water prepared by the comparative ultrapure water machine and placed in air for 10 minutes as follows:

[0030] Step 1: Add 20 g of ultrapure water that has been left for 10 minutes into a container, record ultrapure water-10min (tetrahydrofuran accounts for 0% of the matrix water), and test the conductivity and resistivity of the ultrapure water that has been left for 10 minutes at 25°C;

[0031] Step 2: Add 10 g of ultrapure water that has been left for 10 minutes into a 20 mL container;

[0032] Step 3: Add 5 mL of paraffin oil into the above container;

[0033] Step 4: Test the freezing temperature of ultrapure water after it has been left for 10 minutes;

[0034] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to measure the purity and freezing temperature of ultrapure water -10min respectively.

[0035] like Figure 1-Figure 3 As shown, after actual testing, the conductivity of ultrapure water placed for 10 minutes is 1.010μS / cm; the resistivity of ultrapure water placed for 10 minutes is 990kΩ·cm; the freezing temperature of ultrapure water placed for 10 minutes is -11.0°C. In contrast to Example 2, the purity of ultrapure water decreases due to the rapid absorption of carbon dioxide in the air after being placed for 10 minutes, and the freezing temperature rises by 1°C. Example 4

[0036] This example tests the purity (conductivity and resistivity) and freezing temperature of the deionized water of the comparative example as follows:

[0037] Step 1: Add 20 g of deionized water prepared in the laboratory into the container, record it as deionized water, and test the conductivity and resistivity of the deionized water at 25°C;

[0038] Step 2: Add 10 g of deionized water into a 20 mL container;

[0039] Step 3: Add 5 mL of paraffin oil into the above container;

[0040] Step 4: Test the freezing temperature of deionized water;

[0041] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to measure the purity and freezing temperature of deionized water respectively.

[0042] like Figure 1 , 4 , 5 and Figure 6 As shown, after actual testing, the conductivity of deionized water is 2.985μS / cm; the resistivity of deionized water is 335kΩ·cm; and the freezing temperature of deionized water is -8.3℃. Example 5

[0043] This example prepares and tests the purity (conductivity and resistivity) and freezing temperature of high-altitude simulated water containing 0.1% tetrahydrofuran / deionized water solution as follows:

[0044] Step 1, add 20g of deionized water to a container, then add 0.1% of tetrahydrofuran to the deionized water, record the simulated high-altitude water 0.1%, and test the conductivity and resistivity of the high-altitude simulated water of 0.1% tetrahydrofuran / deionized water solution at 25°C;

[0045] Step 2: Add 10 g of the above 0.1% tetrahydrofuran / deionized water solution into a 20 mL container;

[0046] Step 3: Add 5 mL of paraffin oil into the above container;

[0047] Step 4, testing the freezing temperature of high-altitude simulated water without 0.1% tetrahydrofuran / deionized water solution;

[0048] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to respectively measure the purity and freezing temperature of high-altitude simulated water of a 0.1% tetrahydrofuran / deionized water solution.

[0049] like Figure 1 , 4 , 5 and Figure 6 As shown, after actual testing, the conductivity of 0.1% tetrahydrofuran / deionized water solution is 3.546 μS / cm; the resistivity of 0.1% tetrahydrofuran / deionized water solution is 282 kΩ·cm; and the freezing temperature of 0.1% tetrahydrofuran / deionized water solution is -12.5°C. Example 6

[0050] This example prepares and tests the purity (conductivity and resistivity) and freezing temperature of high-altitude simulated water containing 0.5% tetrahydrofuran / deionized water solution as follows:

[0051] Step 1, add 20g of deionized water to the container, and then add tetrahydrofuran with a content of 0.5% of the mass of deionized water, record the simulated high-altitude water 0.5%, and test the conductivity and resistivity of the high-altitude simulated water of 0.5% tetrahydrofuran / deionized water solution at 25°C;

[0052] Step 2: Add 10 g of the above 0.5% tetrahydrofuran / deionized water solution into a 20 mL container;

[0053] Step 3: Add 5 mL of paraffin oil into the above container;

[0054] Step 4, testing the freezing temperature of high-altitude simulated water with a 0.5% tetrahydrofuran / deionized water solution;

[0055] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to respectively measure the purity and freezing temperature of high-altitude simulated water of a 0.5% tetrahydrofuran / deionized water solution.

[0056] like Figure 1 , 4 , 5 and Figure 6 As shown, after actual testing, the conductivity of 0.5% tetrahydrofuran / deionized water solution is 2.985 μS / cm; the resistivity of 0.5% tetrahydrofuran / deionized water solution is 335 kΩ·cm; and the freezing temperature of 0.5% tetrahydrofuran / deionized water solution is -14.3°C. Example 7

[0057] This example prepares and tests the purity (conductivity and resistivity) and freezing temperature of high-altitude simulated water containing 1% tetrahydrofuran / deionized water solution as follows:

[0058] Step 1, add 20g of deionized water to a container, and then add tetrahydrofuran at a content of 1% of the mass of deionized water, record the simulated high-altitude water 1%, and test the conductivity and resistivity of the high-altitude simulated water solution of 1% tetrahydrofuran / deionized water at 25°C;

[0059] Step 2: Add 10 g of the above 1% tetrahydrofuran / deionized water solution into a 20 mL container;

[0060] Step 3: Add 5 mL of paraffin oil into the above container;

[0061] Step 4, testing the freezing temperature of high-altitude simulated water of 1% tetrahydrofuran / deionized water solution;

[0062] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to respectively measure the purity and freezing temperature of high-altitude simulated water of a 1% tetrahydrofuran / deionized water solution.

[0063] like Figure 1 , 4 , 5 and Figure 6 As shown in the figure, after actual testing, the conductivity of 1% tetrahydrofuran / deionized water solution is 2.906μS / cm; the resistivity of 1% tetrahydrofuran / deionized water solution is 344kΩ·cm; and the freezing temperature of 1% tetrahydrofuran / deionized water solution is -15.0℃. Therefore, compared with deionized water, whose purity has not decreased and only 1% tetrahydrofuran is added, its freezing temperature drops from -8.3℃ of pure ionized water to -15.0℃, and has reached the simulated temperature of supercooled large water droplets in the high altitude. Example 8

[0064] This example prepares and tests the purity (conductivity and resistivity) and freezing temperature of high-altitude simulated water containing 2% tetrahydrofuran / deionized water as follows:

[0065] Step 1, add 20g of deionized water to the container, and then add tetrahydrofuran with a content of 2% of the mass of deionized water, record the simulated high-altitude water 2%, and test the conductivity and resistivity of the high-altitude simulated water of 2% tetrahydrofuran / deionized water solution at 25°C;

[0066] Step 2: Add 10 g of the 2% tetrahydrofuran / deionized water solution into a 20 mL container;

[0067] Step 3: Add 5 mL of paraffin oil into the above container;

[0068] Step 4, testing the freezing temperature of high-altitude simulated water of a 2% tetrahydrofuran / deionized water solution;

[0069] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to respectively measure the purity and freezing temperature of high-altitude simulated water of a 2% tetrahydrofuran / deionized water solution.

[0070] like Figure 1 , 4 , 5 and Figure 6 As shown, after actual testing, the conductivity of 2% tetrahydrofuran / deionized water solution is 2.890 μS / cm; the resistivity of 2% tetrahydrofuran / deionized water solution is 346 kΩ·cm; and the freezing temperature of 2% tetrahydrofuran / deionized water solution is -14.0°C. Example 9

[0071] This example prepares and tests the purity (conductivity and resistivity) and freezing temperature of high-altitude simulated water containing 3% tetrahydrofuran / deionized water solution as follows:

[0072] Step 1, add 20g of deionized water to the container, and then add tetrahydrofuran with a content of 3% of the mass of deionized water, record the simulated high-altitude water 3%, and test the conductivity and resistivity of the high-altitude simulated water of 3% tetrahydrofuran / deionized water solution at 25°C;

[0073] Step 2: Add 10 g of the above 3% tetrahydrofuran / deionized water solution into a 20 mL container;

[0074] Step 3: Add 5 mL of paraffin oil into the above container;

[0075] Step 4, testing the freezing temperature of high-altitude simulated water of 3% tetrahydrofuran / deionized water solution;

[0076] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to respectively measure the purity and freezing temperature of high-altitude simulated water of a 3% tetrahydrofuran / deionized water solution.

[0077] like Figure 1 , 4 , 5 and Figure 6 As shown, after actual testing, the conductivity of 3% tetrahydrofuran / deionized water solution is 2.409 μS / cm; the resistivity of 3% tetrahydrofuran / deionized water solution is 415 kΩ·cm; and the freezing temperature of 3% tetrahydrofuran / deionized water solution is -11.7°C. Example 10

[0078] This example prepares and tests the purity (conductivity and resistivity) and freezing temperature of high-altitude simulated water containing 10% tetrahydrofuran / deionized water solution as follows:

[0079] Step 1, add 20g of deionized water to a container, and then add tetrahydrofuran with a content of 10% of the mass of deionized water, record the simulated high-altitude water 10%, and test the conductivity and resistivity of the high-altitude simulated water of 10% tetrahydrofuran / deionized water solution at 25°C;

[0080] Step 2: Add 10 g of the above 10% tetrahydrofuran / deionized water solution into a 20 mL container;

[0081] Step 3: Add 5 mL of paraffin oil into the above container;

[0082] Step 4, testing the freezing temperature of high-altitude simulated water with a 10% tetrahydrofuran / deionized water solution;

[0083] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to respectively measure the purity and freezing temperature of high-altitude simulated water of a 10% tetrahydrofuran / deionized water solution.

[0084] like Figure 1 , 4 , 5 and Figure 6 As shown, after actual testing, the conductivity of 10% tetrahydrofuran / deionized water solution is 2.364 μS / cm; the resistivity of 10% tetrahydrofuran / deionized water solution is 423 kΩ·cm; and the freezing temperature of 10% tetrahydrofuran / deionized water solution is -12.3°C. Embodiment 11

[0085] This example prepares and tests the purity (conductivity and resistivity) and freezing temperature of high-altitude simulated water containing 20% ​​tetrahydrofuran / deionized water as follows:

[0086] Step 1, add 20g of deionized water to a container, and then add tetrahydrofuran with a content of 20% of the mass of deionized water, record it as simulating high-altitude water 20%, and test the conductivity and resistivity of the high-altitude simulated water of 20% tetrahydrofuran / deionized water solution at 25°C;

[0087] Step 2: Add 10 g of the above 20% tetrahydrofuran / deionized water solution into a 20 mL container;

[0088] Step 3: Add 5 mL of paraffin oil into the above container;

[0089] Step 4, testing the freezing temperature of high-altitude simulated water with a 20% tetrahydrofuran / deionized water solution;

[0090] This embodiment uses a water purity measuring instrument and a freezing temperature testing device to respectively measure the purity and freezing temperature of high-altitude simulated water of a 20% tetrahydrofuran / deionized water solution.

[0091] like Figure 1 , 4 , 5 and Figure 6 As shown, after actual testing, the conductivity of 20% tetrahydrofuran / deionized water solution is 2.049 μS / cm; the resistivity of 20% tetrahydrofuran / deionized water solution is 488 kΩ·cm; and the freezing temperature of 20% tetrahydrofuran / deionized water solution is -14.0°C.

[0092] Compared with the prior art, the present method introduces a hydrogen bond acceptor into deionized water, so that it forms a hydrogen bond with water, and finally generates a macromolecular microscopic superstructure of tetrahydrofuran-water composed of hydrogen bonds, thereby inhibiting the formation of ice nuclei and ordered ice crystal structures in deionized water. The present invention introduces a unitized hydrogen bond acceptor element such as O into deionized water based on the structure of the organic hydrogen bond acceptor by using a method of adding an organic hydrogen bond acceptor substance to deionized water, thereby strengthening the hydrogen bond of the organic hydrogen bond acceptor in deionized water to inhibit ice formation.

[0093] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.

Claims

1. A method for preparing high-altitude water for ice wind tunnel simulation, characterized in that: The high-altitude simulated water with low freezing temperature for ice wind tunnel simulation is obtained by mixing tetrahydrofuran and base water in a mass ratio of 0.1% to 20%.

2. The method for preparing high-altitude water for ice wind tunnel simulation according to claim 1, characterized in that: The mixture is uniformly mixed under magnetic stirring and dispersion.

3. The method for preparing high-altitude water for ice wind tunnel simulation according to claim 1, characterized in that: The matrix water is deionized water.

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