Determination device for measuring solubility of hydrogen in alkali liquor

Abstract

The utility model discloses a measuring device for measuring the solubility of hydrogen in alkali liquor. The measuring device comprises a first cavity, a second cavity with a liquid level reading window, three valves, a vacuum pump, a stirrer, a constant-temperature magnetic stirrer, a heating device, a thermometer, a pressure gauge and a high-pressure gas source. The first cavity is connected with a high-pressure air source through a first valve, and the other side of the first cavity is connected with the second cavity through a second valve. The second cavity is connected with the vacuum pump through a third valve. A thermometer and a pressure gauge are installed on the second cavity cover and used for accurately measuring the solution temperature and the system pressure. According to the device, dynamic balance of gas in a solution is realized by adjusting the temperature, the pressure and the stirring speed, and solubility data is obtained based on temperature and pressure changes. The device has the characteristics of simple design and easiness in operation, can be widely applied to related research on the solubility of the hydrogen in the alkali liquor, and provides important support for measuring the hydrogen dissolution amount of the alkali liquor in an alkaline electrolytic bath.

Description

TECHNICAL FIELD

[0001] The utility model relates to solubility measuring device technical field, concretely relates to a kind of measuring the solubility of hydrogen in lye determination device. BACKGROUND

[0002] Gas purity is one of the key indicators of the application and safe operation of alkaline water electrolysis technology. Among them, as the main product gas in the electrolysis process, the purity of hydrogen is directly related to the safety of the electrolytic device and the quality of the product. Because hydrogen can form an explosive mixture in the range of about 4-96% by volume fraction, the technical safety limit of the entire electrolytic cell system is set to below 2vol.%. To ensure the continuity of production and the safety of operation, the impurity content of the product gas in the electrolysis process must be strictly below this limit.

[0003] In the process of alkaline water electrolysis, the dissolution of gas in the electrolyte, the diffusion through the separation membrane (or separator), and the side reactions in the lye pipeline are the main factors leading to gas crossover. In addition, the amount of gas dissolved in the electrolyte is significantly affected by temperature and pressure. Under normal circumstances, the amount of gas dissolved increases with the increase of pressure, and decreases with the increase of temperature. Therefore, understanding the dissolution behavior and rules of gas in lye is an important way to optimize the alkaline water electrolysis process and improve safety.

[0004] However, there is very limited data on the solubility of hydrogen and oxygen in concentrated potassium hydroxide solution. Existing researches mostly focus on solubility data at room temperature or slightly above room temperature, while under actual electrolysis conditions such as high temperature and high pressure, there is a lack of systematic and standardized experimental data. This data gap greatly limits the theoretical research and engineering design of gas crossover behavior in alkaline water electrolysis technology.

[0005] Based on the above problems, it is urgent to develop an efficient and accurate gas solubility measuring device that can measure the solubility of hydrogen in potassium hydroxide solution under different temperature and pressure conditions, thereby providing theoretical basis and experimental support for the optimization of alkaline water electrolysis process. At the same time, combined with solubility data, further research can establish a gas-liquid mass transfer model to predict the dissolution behavior of hydrogen in lye under different working conditions, thereby providing more scientific guidance and protection for industrial production. UTILITY MODEL CONTENT

[0006] The utility model aims to overcome the defects in the prior art, and provides a determination device for measuring the solubility of hydrogen in lye, to improve the accuracy of the solubility of hydrogen in lye.

[0007] In order to realize the above-mentioned purpose, the technical scheme of the utility model is as follows: a measuring device for measuring solubility of hydrogen in lye, which comprises a gas chamber and a balance chamber, wherein the gas chamber is internally formed with a first cavity with a volume of V1, and the balance chamber is internally formed with a second cavity with a volume of V2,

[0008] A second valve for connecting the first cavity and the second cavity is arranged between the gas chamber and the balance chamber.

[0009] The device further comprises a high-pressure gas source for injecting a gas source into the first cavity, wherein the gas source in the high-pressure gas source is hydrogen, oxygen, nitrogen or other gas sources.

[0010] The balance chamber is provided with a pressure gauge for detecting the gas pressure in the second cavity and a thermometer for detecting the temperature in the second cavity.

[0011] Further, the device further comprises a temperature adjusting device for controlling the temperature in the second cavity and a stirring device for applying stirring to the second cavity.

[0012] Further, the temperature adjusting device is a heating device, which can be heated by a constant-temperature water bath or a heating jacket. Of course, the temperature adjusting device can also comprise a cooling device for cooling the second cavity. The stirring device is a magnetic stirrer, and a magnetic stirring rod is arranged in the second cavity. In actual use, a mechanical stirrer can also be used.

[0013] Further, the high-pressure gas source is connected to one side of the gas chamber, and a first pressure regulating valve is arranged on the connecting pipeline between the high-pressure gas source and the gas chamber.

[0014] Further, the device further comprises a vacuum pump connected to the second cavity, and a third pressure regulating valve arranged on the connecting pipeline between the vacuum pump and the second cavity.

[0015] Further, the material of the first cavity, the second cavity and the sealing cover thereof is a material that does not react with lye and has pressure resistance.

[0016] Further, the material of the first cavity, the second cavity and the sealing cover thereof is carbon steel plated with nickel, pure nickel or stainless steel, and the stainless steel includes but is not limited to 304 stainless steel, 316L stainless steel and 321 stainless steel.

[0017] Further, the side wall of the balance chamber is provided with a scale window for observing and reading the liquid volume in the second cavity.

[0018] Further, the sealing cover of the balance chamber is provided with a liquid injection pipe with a sealing valve for injecting liquid into the second cavity.

[0019] Further, the pressure of the high-pressure gas source is less than or equal to 4MPa.

[0020] The device has the advantages of simple design, easy operation, and wide application in the related research of hydrogen solubility in lye, and provides important support for measuring the amount of hydrogen dissolved in lye in an alkaline electrolytic tank.

[0021] 2. The liquid injection pipe on the sealing cover of the balance chamber is provided with a sealing valve, so that liquid samples can be conveniently injected; meanwhile, the side wall is provided with a scale window, so that the liquid volume can be observed and read, the experimental steps are simplified, and the accuracy is improved.

[0022] 3. The high-pressure gas source is connected with the first pressure regulating valve, and the vacuum pump is connected with the third pressure regulating valve, so that the user can operate within a safe pressure range and prevent overpressure. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a structural schematic view of a measuring device for measuring hydrogen solubility in lye.

[0024] In the figure: 1, gas chamber; 2, balance chamber; 3, first cavity; 4, second cavity; 5, second valve; 6, high-pressure gas source; 7, pressure gauge; 8, thermometer; 9, temperature adjusting device; 10, magnetic stirrer; 11, magnetic stirring rod; 12, first pressure regulating valve; 13, vacuum pump; 14, third pressure regulating valve; 15, sealing cover; 16, scale window; 17, liquid injection pipe. DETAILED DESCRIPTION

[0025] The specific embodiments of the present application will be further described in combination with the drawings and examples. The following examples are only used to more clearly illustrate the technical scheme of the present application, and cannot be used to limit the protection scope of the present application.

[0026] A measuring device for measuring hydrogen solubility in lye, as shown in Figure 1 The device has the advantages of simple design, easy operation, and wide application in the related research of hydrogen solubility in lye, and provides important support for measuring the amount of hydrogen dissolved in lye in an alkaline electrolytic tank.

[0027] A second valve 5 is arranged to control the opening and closing of the first chamber 3 and the second chamber 4; as shown in the figure, the second valve 5 is arranged on the upper left side of the first chamber 3, and the left side of the second valve 5 is connected to the first chamber 3. The opening and closing of the second valve 5 controls the connection or separation between the two chambers.

[0028] A pressure gauge 7 and a thermometer 8 are arranged on the balance chamber 2, the pressure gauge 7 is used to detect the gas pressure of the second chamber 4, and the thermometer 8 is used to detect the gas temperature of the second chamber 4.

[0029] In the above-mentioned gas solubility measuring device, a constant temperature magnetic stirrer 10 capable of adjusting the temperature is further included, wherein the temperature adjusting device 9 can adopt a constant temperature water bath or a heating jacket for heating. Specifically, as shown in the figure, the second chamber 4 is located on the constant temperature magnetic stirrer 10 with a constant temperature water bath, and a stirring rod is arranged in the second chamber 4. The constant temperature water bath is used to keep the lye in the second chamber 4 at the required temperature, thereby improving the accuracy of temperature control. Figure 1

[0030] In the above-mentioned gas solubility measuring device, a hydrogen high-pressure gas source 6 with adjustable gas outlet pressure is further included, which is connected to the first chamber 3, and a first pressure regulating valve 12 is arranged on the connecting pipeline between the hydrogen high-pressure gas source 6 and the first chamber 3. The gas chamber 1 is used to contain the gas to be tested. At the beginning of the test, the gas in the gas chamber 1 is provided with pressure by the high-pressure gas source 6, and the first chamber 3 reaches a certain pressure, which is connected to the balance chamber 2. When the second valve 5 is opened, the gas can enter the balance chamber 2 to contact and dissolve the liquid.

[0031] In the above-mentioned gas solubility measuring device, a vacuum pump 13 is further included, which is connected to the second chamber 4, and a third pressure regulating valve 14 is arranged on the connecting pipeline between the vacuum pump 13 and the second chamber 4.

[0032] In the above-mentioned gas solubility measuring device, the materials of the first chamber 3, the second chamber 4 and the sealing cover 15 can be carbon steel plated with nickel, pure nickel, or other materials that do not react with lye and have pressure resistance. The use of materials that do not react with lye and have pressure resistance (such as carbon steel plated with nickel or pure nickel) increases the chemical stability and safety of the system.

[0033] In the above-mentioned gas solubility measuring device, a recess for inserting the thermometer 8 is left on the top of the sealing cover 15 of the second chamber 4. This facilitates the installation of the thermometer 8 on the cover of the balance chamber 2.

[0034] ​In the above gas solubility measuring device, the side of the second cavity 4 is provided with a liquid level reading scale window 16 for reading the volume of the liquid. The side wall of the second cavity 4 is provided with a scale window 16, which facilitates observation and reading of the volume of the liquid, simplifies the experimental steps and improves accuracy. The sealing cover 15 of the balance chamber 2 is provided with a liquid injection pipe 17 with a sealing valve for injecting liquid into the second cavity 4. The liquid injection pipe 17 on the sealing cover 15 of the balance chamber 2 is provided with a sealing valve, which facilitates the injection of the liquid sample.

[0035] When using the gas solubility measuring device provided by the utility model, the operation steps are as follows:

[0036] 1) Preparation

[0037] a. Measurement volume, fill the gas chamber 1 and the balance chamber 2 with water at a constant temperature, and obtain the volume V1 and V2 of the first cavity 3 and the second cavity 4, including the volume of the connecting pipeline, by measuring the weight difference before and after filling the water. After measuring the volume of the second cavity 4, a scale is drawn at the liquid level reading window for reading the volume of the second cavity 4.

[0038] b. Connect the gas solubility measuring device as required, and set the potassium hydroxide lye to the required temperature T1 and keep it stable.

[0039] c. Open the second valve 5 and the third valve, close the first valve, and use the vacuum pump 13 to vacuum the measuring device of the first cavity 3 and the second cavity 4.

[0040] Detect the airtightness. After closing the second valve 5, if the pressure in the gas solubility measuring device does not rise within half an hour, proceed to the next test; otherwise, use soap water to detect the connection points of each component to find the air leakage point and reconnect.

[0041] d. Open the first and second valves 5, close the third valve, fill the gas solubility measuring device with the gas to be tested, and close the first valve when the gas pressure reaches the required pressure.

[0042] e. After the pressure in the gas solubility measuring device is stable for more than half an hour and the lye temperature is stable, close the second valve 5. The average pressure at this time is P1.

[0043] 2) Measure the solubility of the gas in the liquid

[0044] f. Weigh m1 mass of lye and place it in the open second cavity 4. Read the liquid mass V through the liquid level reading window. L Close the second cavity 4 cover, open the third valve, and vacuum the second cavity 4 chamber. After closing the third valve for half an hour, if the pressure does not rise, it indicates that the liquid has been completely degassed.

[0045] g. Open the second valve 5, start the magnetic stirrer 10, and wait for more than half an hour for the pressure to stabilize. The temperature of the lye T2 and the average pressure P2 at this time are recorded.

[0046] The amount-of-substance solubility is calculated as follows:

[0047]

[0048]

[0049] wherein is the amount of substance of hydrogen; R is the ideal gas constant 8.314 J / mol-k; Z1, Z2 are the compressibility factors of hydrogen at the respective pressure and temperature [hydrogen: ].

[0050] Example:

[0051] The conditions are: temperature T1=298.15 K (25°C)

[0052] Initial pressure P1=1000 mBar

[0053] First chamber volume V1=100 mL

[0054] Second chamber volume V2=200 mL

[0055] Lye mass m1=100 g

[0056] Lye volume V L =100 mL (assuming a density of 1 g / mL)

[0057] Final pressure P2=750 mBar

[0058] Molecular weight of hydrogen =2.016 g / mol

[0059] Compressibility factor calculation:

[0060] For hydrogen, the approximate formula for the compressibility factor Z is:

[0061]

[0062] At T1 and P1:

[0063] Z1≈0.996

[0064] At T2 and P2 (assuming T2=T1):

[0065] Z2≈0.997

[0066] Amount-of-substance solubility Calculation:

[0067]

[0068]

[0069] ≈0.0041 mol

[0070] Mole fraction solubility s calculation:

[0071]

[0072]

[0073] s ≈ 0.000082

[0074] The above only is the preferred embodiment of the present application, it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, under the premise of, can also make a number of improvements and refinements, these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A measuring device for measuring solubility of hydrogen gas in a caustic solution, characterized by, It comprises a gas chamber (1), a balance chamber (2), the gas chamber (1) forms a first cavity (3) with V1 volume inside, the balance chamber (2) forms a second cavity (4) with V2 volume inside, The second valve (5) for connecting the first cavity (3) and the second cavity (4) is arranged between the gas chamber (1) and the balance chamber (2); It also comprises a high-pressure gas source (6) for injecting gas into the first cavity (3); The balance chamber (2) is provided with a pressure gauge (7) for detecting the gas pressure in the second cavity (4) and a thermometer (8) for detecting the temperature in the second cavity (4).

2. The apparatus for measuring solubility of hydrogen in a caustic solution according to claim 1, wherein It also comprises a temperature regulating device (9) for controlling the temperature in the second cavity (4) and a stirring device for applying stirring in the second cavity (4).

3. The apparatus for measuring solubility of hydrogen in a caustic solution according to claim 2, wherein The temperature regulating device (9) is a heating device, and the stirring device is a magnetic stirrer (10), and a magnetic stirring rod (11) is arranged in the second cavity (4).

4. The apparatus for measuring solubility of hydrogen in a caustic solution according to claim 1, wherein The high-pressure gas source (6) is connected to one side of the gas chamber (1), and a first pressure regulating valve (12) is arranged on the communication pipeline between the high-pressure gas source (6) and the gas chamber (1); the gas source in the high-pressure gas source (6) is any one of hydrogen, oxygen and nitrogen.

5. The apparatus for measuring solubility of hydrogen in a caustic solution according to claim 4, wherein It also comprises a vacuum pump (13) connected with the second cavity (4) and a third pressure regulating valve (14) arranged on the communication pipeline between the vacuum pump (13) and the second cavity (4).

6. The apparatus for measuring solubility of hydrogen in a caustic solution according to claim 5, wherein The material of the first cavity (3), the second cavity (4) and the sealing cover (15) thereof is a material that does not react with lye and has pressure resistance.

7. The apparatus for measuring solubility of hydrogen in a caustic solution according to claim 6, wherein The material of the first cavity (3), the second cavity (4) and the sealing cover (15) thereof is carbon steel plated with nickel, pure nickel or stainless steel.

8. The apparatus for measuring solubility of hydrogen in a caustic solution according to claim 1, wherein The side wall of the balance chamber (2) is provided with a scale window (16) for observing and reading the liquid volume in the second cavity (4).

9. The apparatus for measuring solubility of hydrogen in a caustic solution according to claim 8, wherein The sealing cover (15) of the balance chamber (2) is provided with a liquid injection pipe (17) with a sealing valve for injecting liquid into the second cavity (4).

10. The apparatus for measuring solubility of hydrogen in a caustic solution according to claim 1, wherein The pressure of the high-pressure gas source (6) is less than or equal to 4MPa.

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