Device and method for measuring the liquid levels of two liquid surfaces respectively

Abstract

The present invention relates to a method for measuring the liquid levels of two liquid surfaces, and the method includes: opening the exhaust valve, and then introducing gas into the storage tank through a gas source and a blowpipe assembly; controlling the gas flow rate by a gas flow controller to be a first constant flow rate, so that after the gas flow velocity is stable, a bubble overflows from one end of the blowpipe assembly inserted into the storage tank every 2 to 3 seconds, and then recording the measurement result of the first pressure sensor; after stopping introducing gas into the storage tank, closing the exhaust valve, and recording the measurement result of the temperature sensor; controlling the gas flow rate by the gas flow controller to be a second constant flow rate N, introducing gas into the storage tank at the second constant flow rate N for a first duration, then stopping introducing gas into the storage tank, and recording the measurement result of the temperature sensor and the measurement result of the second pressure sensor. The above method can maintain the advantages of the air-blowing method for measuring the liquid level, and can measure the liquid levels of the aqueous phase liquid surface and the floating oil layer liquid surface.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical instruments, and particularly to a device and method for measuring the liquid levels of two liquid surfaces respectively. Background Art

[0002] Measuring the liquid level of the liquid in a storage tank is a necessary technology for the operation and management of a chemical plant. For liquid materials involving radioactivity, high toxicity, and strong corrosion, if a contact measurement device is used, there is a risk that the probe will be damaged by irradiation, corroded, or the moving parts will be blocked by scale, and it is very difficult to repair after damage. Therefore, a contact measurement device is generally not suitable, and non-contact measurement technologies such as the air-blowing method, ultrasonic waves, and gamma rays are used instead. Among them, when measuring the liquid level by the air-blowing method, only the air-blowing pipe inserted into the measured storage tank contacts the liquid material, and there are no moving parts, which has the advantages of simple structure, high precision, and easy maintenance, and is an ideal method.

[0003] However, for an aqueous phase liquid material with floating oil, there are two phase interfaces, namely an oil-gas interface and an oil-water interface. Since the floating oil layer is thin and easy to float, the positions of both phase interfaces may change. Therefore, if the traditional air-blowing method is used to measure the liquid levels of the two phase interfaces simultaneously, it is difficult to determine the position of the pipe orifice of the air-blowing pipe in the floating oil layer. Therefore, the traditional air-blowing method is not suitable for simultaneously measuring the liquid levels of the two phase interfaces.

[0004] Under this background, how to maintain the above advantages of the air-blowing method for measuring the liquid level and simultaneously measure the liquid level of the aqueous phase liquid surface and the liquid level of the floating oil layer surface has become a problem to be solved. Summary of the Invention

[0005] Based on this, in view of the technical problem of how to maintain the above advantages of the air-blowing method for measuring the liquid level and simultaneously measure the liquid level of the aqueous phase liquid surface and the liquid level of the floating oil layer surface, it is necessary to provide a device and method for measuring the liquid levels of two liquid surfaces respectively, which can maintain the advantages of simple structure, high precision, and easy maintenance of the air-blowing method for measuring the liquid level, and moreover, can simultaneously measure the liquid level of the aqueous phase liquid surface and the liquid level of the floating oil layer surface.

[0006] A device for measuring the liquid levels of two liquid surfaces respectively is used to measure the liquid level of the aqueous phase liquid surface and the liquid level of the floating oil layer surface in a storage tank. The device for measuring the liquid levels of two liquid surfaces respectively includes:

[0007] An air-blowing pipe assembly, one end of which is connected to a gas source, and the other end is inserted into the storage tank and extends below the aqueous phase liquid surface to introduce gas into the storage tank;

[0008] A gas flow controller, which is arranged on the air-blowing pipe assembly and is used to control the flow rate of the gas;

[0009] A first pressure sensor is disposed in the blowpipe assembly to detect the air pressure in the blowpipe assembly;

[0010] A second pressure sensor is disposed in the storage tank and is used to detect the air pressure in the storage tank;

[0011] An exhaust valve is disposed in the storage tank and is used to seal or exhaust the storage tank; and

[0012] A temperature sensor is disposed in the storage tank and is used to detect the temperature of the gas in the storage tank.

[0013] In one embodiment, the blowpipe assembly includes a first pipe, a second pipe, and a third pipe. One end of the first pipe, one end of the second pipe, and one end of the third pipe are connected and communicated with each other; the other end of the first pipe is connected to the gas source, and the gas flow controller is disposed in the first pipe; the other end of the second pipe is inserted into the storage tank and extends below the water phase liquid level; the first pressure sensor is disposed in the third pipe.

[0014] In one embodiment, the connection between the pipe wall of the blowpipe assembly and the storage tank is in sealing fit.

[0015] In one embodiment, the gas flow controller is a gas mass flow controller.

[0016] In one embodiment, the device for measuring the liquid levels of the two liquid surfaces further includes a fourth pipe. One end of the fourth pipe is connected and communicated with the storage tank, and the second pressure sensor is disposed in the fourth pipe.

[0017] In one embodiment, the device for measuring the liquid levels of the two liquid surfaces further includes a fifth pipe. One end of the fifth pipe is connected and communicated with the storage tank, and the exhaust valve is disposed on the fifth pipe.

[0018] In one embodiment, one end of the temperature sensor is inserted into the storage tank, and the other end is located outside the storage tank, and the connection between the temperature sensor and the storage tank is in sealing fit.

[0019] In one embodiment, the exhaust valve is a remotely controllable electric valve, pneumatic valve, or hydraulic valve.

[0020] A method for measuring the liquid levels of the two liquid surfaces is implemented by using the device for measuring the liquid levels of the two liquid surfaces described in any one of the above. The method for measuring the liquid levels of the two liquid surfaces includes the following steps:

[0021] Open the exhaust valve, and then introduce gas into the storage tank through the gas source and the blowpipe assembly;

[0022] Control the flow rate of the gas to be a first constant flow rate through the gas flow controller, so that after the flow rate of the gas is stable, a bubble overflows from the end of the blowpipe assembly inserted into the storage tank every 2 to 3 seconds, and then record the measurement result of the first pressure sensor;

[0023] After stopping the gas supply to the storage tank, close the exhaust valve and record the measurement result of the temperature sensor;

[0024] Control the flow rate of the gas to be a second constant flow rate through the gas flow controller. After introducing the gas into the storage tank at the second constant flow rate for a first time period, stop introducing the gas into the storage tank, and then record the measurement result of the temperature sensor and the measurement result of the second pressure sensor.

[0025] In one embodiment, the step of recording the measurement result of the temperature sensor and the measurement result of the second pressure sensor specifically is: when the measurement result of the temperature sensor is stable, record the measurement result of the temperature sensor and the measurement result of the second pressure sensor.

[0026] The above device and method for measuring the liquid levels of the double liquid surfaces, which are implemented by using the device for measuring the liquid levels of the double liquid surfaces, include the following steps: S1: Open the exhaust valve, and then introduce gas into the storage tank through the gas source and the blowpipe assembly; S2: Control the flow rate of the gas to be a first constant flow rate through the gas flow controller, so that after the flow rate of the gas is stable, a bubble overflows from the end of the blowpipe assembly inserted into the storage tank every 2 to 3 seconds, and then record the measurement result of the first pressure sensor; S3: After stopping the gas supply to the storage tank, close the exhaust valve and record the measurement result T of the temperature sensor 1 ; S4: Control the flow rate of the gas to be a second constant flow rate N through the gas flow controller. After introducing the gas into the storage tank at the second constant flow rate N for a first time period Δt, stop introducing the gas into the storage tank, and then record the measurement result T of the temperature sensor 2 and the measurement result of the second pressure sensor. Among them, steps S1 to S2 are the process of measuring the hydraulic pressure value P at the pipe orifice of the end of the blowpipe assembly inserted into the storage tank by the air blowing method 12 The process can obtain the formula P 12 =ρ 1 gh 1 +ρ 2 gh 2 . Steps S3 and S4 are the method of obtaining formula ② P 0 *V air =n 0 *R*T 1 and formula ③ P c *V air = (n0 + N * Δt) * R * T 2 Combined with the volume formula ④V inside the storage tank air +(h 0 + h 1 + h 2 ) * S = V. According to the four - variable linear equation formed by these four formulas ①②③④, the value of h 1、 h 2、 V air、 n 0 The unique solution can be obtained, and thus the liquid level of the aqueous phase can be obtained as h 0 + h 1 , and the liquid level of the floating oil layer is h 0 + h 1 + h 2 . It can be seen that for the above device and method for measuring the liquid levels of the double liquid surfaces, only the air - blowing pipe assembly inserted into the storage pipe contacts the liquid material, and there are no moving parts, so that the advantages of simple structure, high precision, and easy maintenance during the liquid - level measurement by the air - blowing method can be maintained. Moreover, the liquid levels of the aqueous phase liquid surface and the floating oil layer liquid surface can be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram when the device for measuring the liquid levels of the double liquid surfaces in an embodiment measures the liquid levels of the aqueous phase liquid surface and the floating oil layer liquid surface of the liquid material in the storage tank;

[0028] Figure 2 Flowchart of the method for measuring the liquid levels of the double liquid surfaces in an embodiment.

[0029] Description of the reference numerals in the drawings:

[0030] Air - blowing pipe assembly 100; First pipe 110; Second pipe 120; Third pipe 130;

[0031] Gas flow controller 200;

[0032] First air - pressure sensor 300;

[0033] Second air - pressure sensor 400; Fourth pipe 410;

[0034] Exhaust valve 500; Fifth pipe 510;

[0035] Temperature sensor 600;

[0036] Storage tank 20; Aqueous - phase liquid material 31; Floating oil layer 32. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0039] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0040] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over", and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "below", "beneath", and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0042] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for illustrative purposes and do not represent the only implementation.

[0043] Please refer to Figure 1 , an embodiment of the present application provides a device for measuring the liquid levels of two liquid surfaces respectively, which is used to measure the liquid level of the aqueous liquid surface L1 and the floating oil layer liquid surface L2 of the liquid in the storage tank 20. Among them, the liquid in the storage tank 20 includes an aqueous liquid 31 and a floating oil layer 32. The floating oil layer 32 floats on the aqueous liquid 31. The aqueous liquid surface L1 is the liquid surface of the aqueous liquid 31, and the floating oil layer liquid surface L2 is the liquid surface of the floating oil layer 32.

[0044] The device for measuring the liquid levels of two liquid surfaces respectively includes: a blowpipe assembly 100, a gas flow controller 200, a first pressure sensor 300, a second pressure sensor 400, an exhaust valve 500 and a temperature sensor 600. One end of the blowpipe assembly 100 is connected to a gas source (not shown, for example, it can be a high-pressure gas source), and the other end is inserted into the storage tank 20 and extends below the aqueous liquid surface L1 to introduce gas into the storage tank 20. The gas flow controller 200 is arranged on the blowpipe assembly 100 and is used to control the flow rate of the gas introduced into the storage tank 20. The first pressure sensor 300 is arranged on the blowpipe assembly 100 to detect the air pressure in the blowpipe assembly 100. The second pressure sensor 400 is arranged on the storage tank 20 and is used to detect the air pressure in the storage tank 20. The exhaust valve 500 is arranged on the storage tank 20 and is used to close or exhaust the storage tank 20. The temperature sensor 600 (for example, it can be a thermocouple) is arranged on the storage tank 20 and is used to detect the temperature of the gas in the storage tank 20.

[0045] Please refer to Figure 2 , an embodiment of the present application provides a method for measuring the liquid levels of two liquid surfaces respectively, and this method is implemented by using the above-mentioned device for measuring the liquid levels of two liquid surfaces respectively. The method includes the following steps:

[0046] S1: Open the exhaust valve 500, and then introduce gas into the storage tank 20 through the gas source and the blowpipe assembly 100.

[0047] Since one end of the blowpipe assembly 100 is connected to a gas source (not shown), and the other end is inserted into the storage tank 20 and extends below the aqueous liquid surface L1, the gas from the gas source can be introduced into the storage tank 20 through the blowpipe assembly 100.

[0048] Since the exhaust valve 500 is opened before the gas is introduced into the storage tank 20, and the other end of the air blowing pipe assembly 100 (i.e., the end inserted into the storage tank 20) ​​extends below the water phase liquid level L1, the gas from the gas source flows out from the other end of the air blowing pipe assembly 100 (i.e., the end inserted into the storage tank 20) ​​and first enters the water phase liquid 31 and then overflows through the floating oil layer 32, and finally is discharged into the atmosphere through the exhaust valve 500, thereby preventing pressure buildup in the storage tank 20.

[0049] S2: The gas flow rate is controlled to be a first constant flow rate through the gas flow controller 200, so that after the gas flow rate is stabilized, a bubble overflows from one end of the blowing pipe assembly 100 inserted into the storage tank 20 every 2 to 3 seconds, and then the measurement result of the first air pressure sensor 300 is recorded.

[0050] Specifically, the first air pressure sensor 300 is disposed on the air blowing pipe assembly 100, and is used to measure the air pressure in the air blowing pipe assembly 100. Therefore, the air pressure in the air blowing pipe assembly 100 can be obtained according to the measurement result of the first air pressure sensor 300.

[0051] Since the gas from the gas source flows out from one end of the air blowing pipe assembly 100 inserted into the storage tank 20 at a constant flow rate (i.e., the first constant flow rate mentioned above), and a bubble overflows every 2 to 3 seconds, the bubbles are minute and the gas flow rate is low, so the gas loss along the way in the air blowing pipe assembly 100 can be ignored. Therefore, when the gas from the gas source flows out from one end of the air blowing pipe assembly 100 inserted into the storage tank 20 at the first constant flow rate, and a bubble overflows every 2 to 3 seconds at one end of the air blowing pipe assembly 100 inserted into the storage tank 20, it can be considered that the air pressure in the air blowing pipe assembly 100 is approximately equal to the air pressure value obtained according to the measurement result of the first air pressure sensor 300, and is also approximately equal to the hydraulic pressure value at the pipe mouth of one end of the air blowing pipe assembly 100 inserted into the storage tank 20. Therefore, the air pressure value obtained according to the measurement result of the first air pressure sensor 300 is approximately equal to the hydraulic pressure value at the pipe mouth of one end of the air blowing pipe assembly 100 inserted into the storage tank 20, which is recorded as P 12 .

[0052] It can be seen that step S1 to step S2 is to measure the hydraulic pressure value P at the end of the blowing pipe assembly 100 inserted into the storage tank 20 by the blowing method. 12 process. From this we can get formula ①:

[0053] P 12 =ρ 1 gh 1 +ρ 2 gh 2 ;

[0054] Where g is gravity, ρ 1is the density of the aqueous phase liquid, h 1 is the distance from the liquid level L1 of the aqueous phase to the nozzle at one end of the air blowing pipe assembly 100 inserted into the storage tank 20, ρ 2 is the density of the floating oil layer, h 2 is the height from the liquid level L1 of the aqueous phase to the liquid level L2 of the floating oil layer (i.e., the thickness of the floating oil layer).

[0055] It should be noted that during the process of controlling the gas flow rate by the gas flow controller 200, the gas flow velocity is constantly changing. It is necessary to gradually adjust the gas flow rate and observe the situation of bubbles overflowing from the end of the air blowing pipe assembly 100 inserted into the storage tank 20 while adjusting the gas flow rate. If the bubbles overflow too fast, the gas flow rate needs to be reduced; if the bubbles overflow too slowly, the gas flow rate needs to be increased until, at a constant flow rate (i.e., the above-mentioned first constant flow rate), a bubble overflows from the end of the air blowing pipe assembly 100 inserted into the storage tank 20 every 2 to 3 seconds. Among them, the value of the first constant flow rate can be a volume flow rate of about 3 - 10 cm 3 / s (or the range of this volume flow rate can also be converted into the corresponding range of mass flow rate).

[0056] It can be understood that since the gas flow velocity is constantly changing during the process of controlling the gas flow rate by the gas flow controller 200, after the gas flow rate is adjusted to the first constant flow rate, it is also necessary to wait until the gas flow velocity is stable. If a bubble overflows from the end of the air blowing pipe assembly 100 inserted into the storage tank 20 every 2 to 3 seconds, it can be considered that the air pressure in the air blowing pipe assembly 100 is approximately equal to the air pressure value obtained according to the measurement result of the first pressure sensor 300, and is also approximately equal to the hydraulic pressure value at the nozzle at the end of the air blowing pipe assembly 100 inserted into the storage tank 20.

[0057] S3: After stopping supplying gas to the storage tank 20, close the exhaust valve 500 and record the measurement result T of the temperature sensor 600 1 .

[0058] Specifically, after step S2 and in step S3, stop supplying gas to the storage tank 20. Before the exhaust valve 500 is closed, the storage tank 20 is in communication with the atmosphere. Therefore, in this step, when the exhaust valve 500 is closed, the air pressure in the storage tank 20 is equal to the atmospheric pressure P 0 . Record the measurement result T of the temperature sensor 600 at this time 1 , that is, the gas temperature value in the storage tank 20. According to the ideal gas state equation, formula ② can be obtained:

[0059] P 0 *V air =n 0 *R*T 1 ,

[0060] Among them, P 0 is the air pressure in the storage tank 20 (i.e., the air pressure of the gas above the floating oil layer 32), V air is the volume of the gas in the storage tank 20 (i.e., the volume of the gas above the floating oil layer 32), R is the molar gas constant, n 0 is the amount of substance of the gas in the storage tank 20 (i.e., the amount of substance of the gas above the floating oil layer 32).

[0061] S4: Control the gas flow rate to the second constant flow rate N through the gas flow controller 200. After introducing gas into the storage tank 20 at the second constant flow rate N for the first time period Δt, stop introducing gas into the storage tank 20, and then record the measurement result T of the temperature sensor 600 2 and the measurement result of the second air pressure sensor 400.

[0062] It should be noted that at the first time period Δt, the measured value of the second air pressure sensor 400 should be within the reliable reading range of its measuring range to ensure reliable measurement results.

[0063] Since in step S3, the amount of substance of the gas in the storage tank 20 (i.e., the amount of substance of the gas above the floating oil layer 32) is n 0 . Therefore, after step S3, after introducing gas into the storage tank 20 at the second constant flow rate N for the first time period Δt in step S4, the amount of substance of the gas in the storage tank 20 (i.e., the amount of substance of the gas above the floating oil layer 32) becomes n 0 + N*Δt. It should be noted that here N is the mass flow rate, which has the same unit as the amount of substance. Therefore, through n 0 + N*Δt, the amount of substance of the gas in the storage tank 20 (i.e., the amount of substance of the gas above the floating oil layer 32) can be obtained.

[0064] At the same time, after introducing gas into the storage tank 20 at the second constant flow rate N for the first time period Δt, according to the measurement result of the second air pressure sensor 400, the air pressure in the storage tank 20 at this time (i.e., the air pressure of the gas above the floating oil layer 32) P c can be known. The measurement result T of the temperature sensor 600 2 is the gas temperature value in the storage tank 20 at this time. Then, according to the ideal gas state equation, formula ③ can be obtained:

[0065] P c *V air = (n 0 + N*Δt) * R * T 2 .

[0066] It can be seen that steps S3 and S4 obtain formula ② and formula ③ through the method of sealed pressurization.

[0067] In addition, according to the volume inside the storage tank 20, formula ④ can be obtained: V air +(h 0 +h 1 +h 2 )*S = V, where V is the total volume inside the storage tank 20, h 0 is the distance from the pipe orifice at one end of the air blowing pipe assembly 100 inserted into the storage tank 20 to the bottom of the storage tank 20, and S is the cross-sectional area inside the storage tank 20.

[0068] In the above four formulas ①②③④, P 12 has been obtained according to the measurement result of the first pressure sensor 300 in step S2, ρ 1 can be obtained by sampling and measuring the aqueous phase liquid material, ρ 2 can be obtained by sampling and measuring the floating oil layer, and the gravitational acceleration g is a constant. The atmospheric pressure P 0 is a constant, R is the molar gas constant, and T 1 is obtained from the measurement result of the temperature sensor 600 in step S3. P 12 has been obtained according to the measurement result of the second pressure sensor 400 in step S4, and T 2 is obtained from the measurement result of the temperature sensor 600 in step S4. V, S, h 0 are the inherent parameters of the storage tank 20, which can be calibrated in advance and are known quantities. Therefore, only h 1、 h 2、 V air、 n 0 four unknowns remain. By performing linear solution on the system of linear equations composed of the above four formulas ①②③④, h 1、 h 2、 V air、 n 0 can be obtained, and thus the liquid level of the aqueous phase liquid surface L1 is h 0 +h 1 , and the liquid level of the floating oil layer liquid surface L2 is h 0 +h 1 +h 2 .

[0069] The above device and method for measuring the liquid levels of two liquid surfaces, which are implemented by using the device for measuring the liquid levels of two liquid surfaces, include the following steps: S1: Open the exhaust valve 500, and then introduce gas into the storage tank 20 through the gas source and the blow pipe assembly 100; S2: Control the gas flow rate to be a first constant flow rate through the gas flow controller 200, so that after the gas flow rate is stable, a bubble overflows from the end of the blow pipe assembly 100 inserted into the storage tank 20 every 2 to 3 seconds, and then record the measurement result of the first pressure sensor 300; S3: After stopping introducing gas into the storage tank 20, close the exhaust valve 500, and record the measurement result T of the temperature sensor 600 1 ; S4: Control the gas flow rate to be a second constant flow rate N through the gas flow controller 200. After introducing gas into the storage tank 20 at the second constant flow rate N for a first duration Δt, stop introducing gas into the storage tank 20, and then record the measurement result T of the temperature sensor 600 2 and the measurement result of the second pressure sensor 400. Among them, steps S1 to S2 are the process of measuring the hydraulic pressure value P at the nozzle of the end of the blow pipe assembly 100 inserted into the storage tank 20 by the blowing method 12 The process of, can obtain the formula P 12 =ρ 1 gh 1 +ρ 2 gh 2 . Steps S3 and S4 are the processes of obtaining formula ② P 0 *V air =n 0 *R*T 1 and formula ③ P c *V air =(n 0 +N*Δt)*R*T 2 . Then, combined with the volume formula ④ V air +(h 0 +h 1 +h 2 )*S=V of the inside of the storage tank 20. According to the four - variable linear equation composed of these four formulas ①②③④, the unique solutions of h 1、 h 2、 V air、 n 0 can be obtained, so that the liquid level of the aqueous phase liquid surface L1 is h 0 +h 1 , and the liquid level of the floating oil layer liquid surface L2 is h 0 +h 1 +h 2It can be seen that for the above device and method for measuring the liquid levels of the two liquid surfaces, only the air blowing pipe assembly 100 inserted into the storage pipe 20 needs to be in contact with the liquid material, and there are no moving parts, so that the advantages of simple structure, high precision, and easy maintenance during the liquid level measurement by the air blowing method can be maintained. Moreover, the liquid levels of the water phase liquid surface L1 and the floating oil layer liquid surface L2 can be measured.

[0070] In one embodiment, in step S4, the measurement result T of the temperature sensor 600 is recorded 2 The steps of recording the measurement result of the temperature sensor 600 and the measurement result of the second pressure sensor 400 are specifically as follows: After the measurement result of the temperature sensor 600 is stable, the measurement result T of the temperature sensor 600 is recorded 2 and the measurement result of the second pressure sensor 400.

[0071] It can be understood that in step S3, the air pressure in the storage tank 20 is equal to the atmospheric pressure P 0 , then it can be considered that the measurement result T of the temperature sensor 600 1 is equal to the ambient temperature T 1 .

[0072] In step S4, the measurement result T of the temperature sensor 600 2 is equal to the temperature of the gas in the storage tank 20. After the measurement result of the temperature sensor 600 is stable, that is, after the temperature of the gas in the storage tank 20 is stable.

[0073] Since the temperature of the gas in the storage tank 20 is affected by the environment, after the temperature of the gas in the storage tank 20 is stable, the temperature of the gas in the storage tank 20 is approximately equal to the ambient temperature T 1 , so that the measurement result T of the temperature sensor 600 2 is approximately equal to the ambient temperature T 1 .

[0074] Since after the measurement result of the temperature sensor 600 is stable, the measurement result T of the temperature sensor 600 is recorded 2 and the measurement result of the second pressure sensor 400, the measurement result is more accurate, and further the measurement results of the liquid levels of the water phase liquid surface L1 and the floating oil layer liquid surface L2 are accurate.

[0075] Such as Figure 1As shown, in one embodiment, the blowing pipe assembly 100 includes a first pipe 110, a second pipe 120, and a third pipe 130. One end of the first pipe 110, one end of the second pipe 120, and one end of the third pipe 130 are connected and conduct with each other, that is, the three form a tee. The other end of the first pipe 110 is connected to a gas source, and the gas flow controller 200 is arranged on the first pipe 110. The other end of the second pipe 120 is inserted into the storage tank 20 and extends below the water phase liquid level L1. The first pressure sensor 300 is arranged on the third pipe 130.

[0076] The gas from the gas source can enter from the first pipe 110 and flow into the water phase liquid 31 in the storage tank 20 through the second pipe 120. Since the gas flow controller 200 is arranged on the first pipe 110, the flow rate of the gas entering from the first pipe 110 can be controlled, that is, the flow rate of the gas entering the storage tank 20 through the second pipe 120 can be controlled.

[0077] Since one end of the first pipe 110, one end of the second pipe 120, and one end of the third pipe 130 are connected and conduct with each other, the air pressures in the first pipe 110, the second pipe 120, and the third pipe 130 are equal. Therefore, according to the measurement result of the first pressure sensor 300 arranged on the third pipe 130, the air pressure in the first pipe 110, the second pipe 120, and the third pipe 130 can be obtained, that is, the air pressure in the blowing pipe assembly 100 in the above embodiment can be obtained.

[0078] Specifically, the other end of the first pipe 110 can be connected to the outlet end of the gas flow controller 200, and the inlet end of the gas flow controller 200 is connected to the gas source. Thus, the gas flow controller 200 can control the flow rate of the gas entering the first pipe 110 through the gas source, that is, control the flow rate of the gas entering the storage tank 20 through the first pipe 110 and the second pipe 120.

[0079] The first pressure sensor 300 can be arranged at the other end of the third pipe 130, that is, the first pressure sensor 300 is arranged at the end of the third pipe 130 away from the storage tank 20.

[0080] The first pressure sensor 300 can adopt a capacitive differential pressure transmitter, and the detection result is accurate.

[0081] As Figure 1 shown, in one embodiment, the connection between the pipe wall of the blowing pipe assembly 100 and the storage tank 20 is in sealed cooperation, so as to prevent air leakage at the connection between the pipe wall of the blowing pipe assembly 100 and the storage tank 20 in step S4. Furthermore, the measurement result T of the temperature sensor 600 2 and the measurement result of the second pressure sensor 400 can be more accurate, and further the measurement results of the liquid level of the water phase liquid level L1 and the liquid level of the floating oil layer liquid level L2 are accurate.

[0082] Specifically, as Figure 1 shown, in this embodiment, the second pipe 120 is inserted into the storage tank 20. Therefore, the connection between the pipe wall of the second pipe 120 and the storage tank 20 is in sealed cooperation.

[0083] In one embodiment, the gas flow controller 200 is a gas mass flow controller.

[0084] As Figure 1 shown, in one embodiment, the device for measuring the liquid levels of the two liquid surfaces further includes a fourth pipe 410. One end of the fourth pipe 410 is connected to and communicated with the storage tank 20, and the second pressure sensor 400 is arranged on the fourth pipe 410, so as to facilitate the arrangement of the second pressure sensor 400.

[0085] Specifically, the second pressure sensor 400 can be arranged at the other end of the fourth pipe 410, that is, the second pressure sensor 400 is arranged at the end of the fourth pipe 410 away from the storage tank 20.

[0086] The second pressure sensor 400 can adopt a capacitive differential pressure transmitter, and the measurement result is accurate.

[0087] The connection between the fourth pipe 410 and the storage tank 20 is in sealed cooperation, so as to prevent air leakage at the connection between the fourth pipe 410 and the storage tank 20 in step S4. Furthermore, the measurement result T of the temperature sensor 600 2 and the measurement result of the second pressure sensor 400 can be more accurate, and further the measurement results of the liquid level of the aqueous phase liquid surface L1 and the liquid level of the floating oil layer liquid surface L2 are accurate.

[0088] As Figure 1 shown, in one embodiment, the device for measuring the liquid levels of the two liquid surfaces further includes a fifth pipe 510. One end of the fifth pipe 510 is connected to and communicated with the storage tank 20, and the exhaust valve 500 is arranged on the fifth pipe 510, which facilitates the arrangement of the exhaust valve 500. Moreover, since the exhaust valve 500 is arranged on the fifth pipe 510, when the exhaust valve 500 is opened, the gas in the storage tank 20 can be discharged from the other end of the fifth pipe 510 (that is, the end of the fifth pipe 510 away from the storage tank 20) after passing through the exhaust valve 500.

[0089] The connection between the fifth pipe 510 and the storage tank 20 is in sealed cooperation, so as to prevent air leakage at the connection between the fifth pipe 510 and the storage tank 20 in step S4. Furthermore, the measurement result T of the temperature sensor 600 2 and the measurement result of the second pressure sensor 400 can be more accurate, and further the measurement results of the liquid level of the aqueous phase liquid surface L1 and the liquid level of the floating oil layer liquid surface L2 are accurate.

[0090] As Figure 1As shown, in one embodiment, one end of the temperature sensor 600 is inserted into the storage tank 20, and the other end is located outside the storage tank 20, which facilitates the installation of the temperature sensor 600 on the storage tank 20. Moreover, since one end of the temperature sensor 600 is inserted into the storage tank 20, it is convenient to measure the temperature of the gas in the storage tank 20.

[0091] In one embodiment, the connection between the temperature sensor 600 and the storage tank 20 is in sealed cooperation, so as to prevent air leakage at the connection between the temperature sensor 600 and the storage tank 20 in step S4, and further enable the measurement result T of the temperature sensor 600 2 and the measurement result of the second pressure sensor 400 to be more accurate, and further make the measurement results of the liquid level of the aqueous phase liquid surface L1 and the liquid level of the floating oil layer liquid surface L2 accurate.

[0092] In one embodiment, the exhaust valve 500 is an electrically controlled valve, a pneumatic valve or a hydraulic valve that can be remotely controlled. Thus, when performing the operation of opening or closing the exhaust valve 500, it can be remotely controlled without manual operation. In this way, even if the storage tank 20 is in a high-radiation area, personnel do not need to approach the storage tank 20, and personnel can be protected from radiation.

[0093] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0094] The above-described embodiments only represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A method for measuring the liquid levels of two liquid surfaces respectively, which is used to measure the liquid level of the aqueous phase liquid surface and the liquid level of the floating oil layer liquid surface in a storage tank. Characterized in that, It includes the following steps: S1: Open the exhaust valve, and then introduce gas into the storage tank through the gas source and the blowpipe assembly. One end of the blowpipe assembly is connected to the gas source, and the other end is inserted into the storage tank and extends below the aqueous phase liquid surface. S2: Control the gas flow rate to a first constant flow rate through a gas flow controller, so that after the gas flow velocity is stable, a bubble overflows from the end of the blowpipe assembly inserted into the storage tank every 2 - 3 seconds, and then record the air pressure measurement result P in the blowpipe assembly 12 , from which formula ① can be obtained: P 12 =ρ 1 gh 1 +ρ 2 gh 2 , where g is the acceleration due to gravity, ρ 1 is the density of the aqueous phase liquid, h 1 is the distance from the aqueous phase liquid level to the nozzle of the end of the blowpipe assembly inserted into the storage tank, ρ 2 is the density of the floating oil layer, h 2 is the height from the aqueous phase liquid level to the floating oil layer liquid level; S3: After stopping the gas supply to the storage tank, close the exhaust valve and record the temperature measurement result T of the gas in the storage tank. 1 , from which formula ② can be obtained: P 0 *V air =n 0 *R*T 1 , where P 0 is the air pressure in the storage tank when the exhaust valve is closed in step S3, V air is the volume of the gas in the storage tank, R is the molar gas constant, and n 0 is the amount of substance of the gas in the storage tank; S4: Control the gas flow rate to a second constant flow rate N through the gas flow controller. After introducing gas into the storage tank at the second constant flow rate N for a first duration Δt, stop introducing gas into the storage tank, and then record the temperature measurement result T of the gas in the storage tank 2 and the air pressure measurement result P in the storage tank c , from which the formula ③ can be obtained: P c *V air = (n 0 + N * Δt) * R * T 2 ; According to the internal volume of the storage tank, formula ④ can be obtained: V air +(h 0 +h 1 +h 2 )*S = V, where V is the total internal volume of the storage tank, h 0 is the distance from the pipe orifice at one end of the blowpipe assembly inserted into the storage tank to the bottom of the storage tank, and S is the cross-sectional area inside the storage tank; Solving the system of four linear equations formed by the above formulas ①②③④ can obtain h 1、 h 2、 V air、 n 0 The unique solution of, thus the liquid level of the aqueous phase can be obtained as h 0 +h 1 , and the liquid level of the floating oil layer is h 0 +h 1 +h 2 .

2. A device for measuring the liquid levels of two liquid surfaces respectively, Characterized in that, It is used to implement the method for measuring the liquid levels of two liquid surfaces respectively described in claim 1; the device for measuring the liquid levels of two liquid surfaces respectively includes: A blowpipe assembly, one end of the blowpipe assembly is connected to the gas source, and the other end is inserted into the storage tank and extends below the aqueous phase liquid surface to introduce gas into the storage tank; A gas flow controller, which is arranged on the blowpipe assembly and is used to control the gas flow; A first pressure sensor, which is arranged on the blowpipe assembly to detect the air pressure in the blowpipe assembly; A second pressure sensor, which is arranged on the storage tank and is used to detect the air pressure in the storage tank; An exhaust valve, which is arranged on the storage tank and is used to seal or exhaust the storage tank; and A temperature sensor, which is arranged on the storage tank and is used to detect the temperature of the gas in the storage tank.

3. The device for measuring the liquid levels of two liquid surfaces respectively according to claim 2, Characterized in that, The blowpipe assembly includes a first pipe, a second pipe and a third pipe. One end of the first pipe, one end of the second pipe and one end of the third pipe are connected and conduct; the other end of the first pipe is connected to the gas source, and the gas flow controller is arranged on the first pipe; the other end of the second pipe is inserted into the storage tank and extends below the aqueous phase liquid surface; the first pressure sensor is arranged on the third pipe.

4. The device for measuring the liquid levels of two liquid surfaces respectively according to claim 2, Characterized in that, The connection between the pipe wall of the blowpipe assembly and the storage tank is in sealed cooperation.

5. The device for measuring the liquid levels of two liquid surfaces respectively according to claim 2, Characterized in that, The gas flow controller is a gas mass flow controller.

6. The device for measuring the liquid levels of two liquid surfaces respectively according to claim 2, Characterized in that, It further includes a fourth pipe, one end of the fourth pipe is connected and conducts with the storage tank, and the second pressure sensor is arranged on the fourth pipe.

7. The device for measuring the liquid levels of two liquid surfaces respectively according to claim 2, Characterized in that, It further includes a fifth pipe, one end of the fifth pipe is connected and conducts with the storage tank, and the exhaust valve is arranged on the fifth pipe.

8. The device for measuring the liquid levels of two liquid surfaces respectively according to claim 2, Characterized in that, One end of the temperature sensor is inserted into the storage tank, and the other end is located outside the storage tank, and the connection between the temperature sensor and the storage tank is in sealed cooperation.

9. The device for measuring the liquid levels of two liquid surfaces respectively according to claim 2, Characterized in that, The exhaust valve is a remotely controllable electric valve, pneumatic valve or hydraulic valve.

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