Piston type gas-liquid phase equilibrium dynamic observation device and use method thereof

Abstract

The invention provides a piston type gas-liquid phase equilibrium dynamic observation device and a use method thereof, the observation device comprises: a cylinder, an inner cavity of which is divided into an observation cavity gas area, an observation cavity liquid area, a pressure control piston and a pressure control cavity; the first storage bottle is communicated with the observation cavity gas area; the pressure control device pushes the pressure control piston by changing the pressure of the pressure control cavity so as to change the pressure of the observation cavity liquid area and the observation cavity gas area; the temperature control device is used for controlling the temperature of the cylinder; the parallel light source is used as experiment exciting light to irradiate the cylinder; and the data acquisition device is used for acquiring the temperature, the pressure and the image of the observation area, and acquiring the emitted light intensity of the observation area through the images of the observation cavity gas area and the observation cavity liquid area. According to the invention, through temperature and pressure control and real-time image acquisition, the phase equilibrium fraction distribution condition under the conditions of temperature, pressure, composition and time is obtained based on the relationship between the fluid exciting light-emission light intensity and the fluid composition condition.

Description

Technical Field

[0001] The present invention relates to the technical field of dynamic observation of phase equilibrium of fluid gas, liquid and supercritical state, and in particular to a piston-type gas-liquid phase equilibrium dynamic observation device and a method for using the same. Background Art

[0002] The mutual conversion characteristics of fluids between gas, liquid and supercritical states are important properties for scientific research and engineering calculations. The accurate calculation and prediction of such properties rely on precise experimental measurements. The observation of gas-liquid phase equilibrium of fluids needs to be carried out at specific temperature and pressure. When facing multi-component mixed fluids, in addition to temperature and pressure, the composition ratio of the mixed fluid also needs to be measured.

[0003] Generally speaking, the observation of fluid phase equilibrium can be divided into direct sampling analysis and indirect observation analysis according to whether sampling is required. In the direct sampling process, the temperature and pressure in the phase equilibrium and solubility limit state are first determined, and then the fluid that has reached the phase equilibrium or solubility limit is sampled through the sampling device, and the sample components are analyzed by chromatography or other analytical methods to determine the composition of the mixed fluid. For the indirect observation analysis method, the existing experimental measurement methods can generally be divided into the equal volume saturation analysis method with known ratio and the visual synthesis method with unknown mixed fluid composition ratio. In the equal volume saturation method, the calibration of the experimental area volume is a necessary measurement step and one of the main ways to introduce errors. In addition, the basic thermodynamic properties such as the density of the fluid must also be known, which limits the application of the equal volume saturation method to a certain extent. When observing the phase equilibrium of the fluid by the visual synthesis method, it is necessary to accurately judge the transition point where the phase change completely occurs, which depends on the operating accuracy of the experimental operator, and the error is very large and difficult to quantify.

[0004] In the prior art, there is a device and method for measuring phase equilibrium of fluids with different volatility characteristics. The device includes a gas sample bottle, a gas cavity, a balance kettle, a gas buffer cavity and a pressure-stabilizing gas cylinder connected in sequence through pipelines. The gas cavity, the balance kettle and the gas buffer cavity are all placed in a constant temperature bath with circulating fan blades; a vacuum pump is connected to the pipeline between the gas sample bottle and the gas cavity through a pipeline; a syringe pump is connected to the balance kettle and the gas buffer cavity through a pipeline; a data acquisition system is connected to the gas cavity and the balance kettle respectively to measure and collect data from the two. The device is used to measure the phase equilibrium of single-component or multi-component fluids at different temperatures and pressures.

[0005] However, the phase equilibrium measurement device in the prior art cannot dynamically observe the changes in the components of the fluid during the process from the non-equilibrium state to the equilibrium state. Summary of the invention

[0006] The present invention provides a piston-type gas-liquid phase equilibrium dynamic observation device and a method for using the same, so as to solve the defect that the phase equilibrium measurement device in the prior art cannot dynamically observe the change of components of the fluid in the process of changing from a non-equilibrium state to an equilibrium state, and realize dynamic observation.

[0007] The present invention provides a piston-type gas-liquid phase equilibrium dynamic observation device, comprising: The cylinder has an inner cavity as the observation area, which is divided from top to bottom into the observation cavity gas area, the observation cavity liquid area, the pressure control piston and the pressure control cavity; A first storage bottle, used for storing a first fluid to be measured; the first storage bottle is connected to the gas area of ​​the observation chamber; A pressure control device, connected to the pressure control chamber, wherein the pressure control device changes the pressure of the pressure control chamber by pushing the pressure control piston, thereby changing the pressure of the liquid area of ​​the observation chamber and the gas area of ​​the observation chamber; A temperature control device for controlling the temperature of the cylinder; A parallel light source is used as experimental excitation light to illuminate the cylinder, and the intensity of the experimental excitation light is determined; The data acquisition device is used to collect the temperature, pressure and image of the observation area, and obtain the emission light intensity of the observation area through the images of the gas area of ​​the observation chamber and the liquid area of ​​the observation chamber.

[0008] A piston-type gas-liquid phase equilibrium dynamic observation device provided by the present invention also includes: A first weighing device, used to obtain the mass of the first fluid to be measured; A high-pressure delivery pump, one end of which is connected to the first storage bottle and the other end of which is connected to the gas area of ​​the observation chamber, the high-pressure delivery pump is used to pump the first fluid to be measured; a first filling valve, a preheater and a closed valve of the area to be measured are arranged in sequence between the high-pressure delivery pump and the gas area of ​​the observation chamber; wherein the first filling valve is opened when the first fluid to be measured is filled; the temperature of the preheater is the experimental target temperature; The second filling valve is used to fill the second fluid to be measured and measure the filling mass of the second fluid to be measured before and after the filling.

[0009] According to a piston-type gas-liquid phase equilibrium dynamic observation device provided by the present invention, a first temperature detector is arranged between the preheater and the closed valve of the area to be measured.

[0010] According to a piston-type gas-liquid phase equilibrium dynamic observation device provided by the present invention, the pressure control device comprises: High-pressure gas cylinders, which store high-pressure gas; a pressure reducing valve, disposed downstream of the high-pressure gas cylinder; A high-pressure gas filling valve has one end connected to the pressure reducing valve and the other end connected to the pressure control chamber.

[0011] According to a piston-type gas-liquid phase equilibrium dynamic observation device provided by the present invention, the pressure control device further comprises: a flushing valve, disposed downstream of the pressure reducing valve, and the flushing valve is connected in parallel with the high-pressure gas filling valve; An exhaust pressure regulating valve is arranged downstream of the flushing valve, and the exhaust pressure regulating valve is used for vacuuming the system after flushing.

[0012] According to a piston-type gas-liquid phase equilibrium dynamic observation device provided by the present invention, a first pressure sensor is arranged on the pipeline between the high-pressure gas filling valve and the pressure control chamber.

[0013] According to a piston-type gas-liquid phase equilibrium dynamic observation device provided by the present invention, the data acquisition device comprises: An image acquisition device, used for acquiring experimental images of the observation area; A temperature collection digital meter, used to collect temperature data of the observation area; A pressure collection digital meter, used to collect pressure data of the observation area; A data acquisition computer is used to acquire the experimental image, the temperature data and the pressure data.

[0014] According to a piston-type gas-liquid phase equilibrium dynamic observation device provided by the present invention, the temperature control device includes a constant temperature bath and a sealing device, wherein the sealing device is arranged on the outside of the cylinder and the sealing device is arranged in the constant temperature bath.

[0015] A piston-type gas-liquid phase equilibrium dynamic observation device provided by the present invention also includes a second temperature detector and a second pressure sensor, which are respectively used to detect the temperature and pressure in the observation area.

[0016] The present invention also provides a method for using a piston-type gas-liquid phase equilibrium dynamic observation device, comprising: Placing a first fluid to be measured in a cylinder cavity to form an observation area, wherein the temperature and pressure of the cylinder cavity are kept constant; irradiating the observation area with experimental excitation light; Get the experimental excitation light intensity I1; After time t, the first fluid to be measured reaches a phase equilibrium state in the observation area; The emission light intensity I2 at the phase equilibrium state is obtained by a data acquisition device; According to the formula I2=k∙E∙X∙d∙I1, the composition fraction X at time t in the dynamic process of achieving phase equilibrium is obtained, where E is the emission efficiency of the fluid to be measured, k is the optical path attenuation coefficient, and d is the diameter of the cylinder.

[0017] The piston-type gas-liquid phase equilibrium dynamic observation device and the use method thereof provided by the present invention use the inner cavity of the cylinder as the observation area, which is divided into an observation cavity gas area, an observation cavity liquid area, a pressure control piston and a pressure control cavity from top to bottom. The first storage bottle is used to store the first fluid to be measured, and the first storage bottle is connected to the observation cavity gas area. The pressure control device is connected to the pressure control cavity. The temperature control device controls the temperature of the observation area. A parallel light source is used as an experimental excitation light to illuminate the cylinder to obtain the experimental excitation light intensity. The data acquisition device can obtain the emission light intensity of the observation area. When the dynamic observation of phase equilibrium is carried out, the pressure is freely adjusted by the pressure control piston. During the adjustment process, the emission light intensity distribution of the observation area can be obtained by real-time acquisition of images of the observation cavity gas area and the observation cavity liquid area. Since the phase equilibrium fraction is associated with the excitation light intensity and the emission light intensity, the composition fraction of the phase equilibrium dynamic process can be obtained through the excitation light intensity and the emission light intensity.

[0018] The present invention can realize dynamic observation. During the experiment, the phase equilibrium fraction distribution under the conditions of (T, P, X, t) (temperature, pressure, composition, time) is obtained through temperature and pressure control and real-time image acquisition. Compared with the traditional phase equilibrium observation device that can only measure the equilibrium conditions (T, P, X) (temperature, pressure, composition), the present invention adds the measurement of the time evolution from non-equilibrium to equilibrium.

[0019] Moreover, the calibration error can be reduced. The dissolution conditions obtained through the emission light intensity distribution image do not need to be calibrated for the experimental volume, thus reducing the error caused by repeated calibration.

[0020] In addition, the temperature, pressure and image of the observation area are collected by the data acquisition device, and the emission light intensity of the observation area is obtained by observing the images of the gas area and the liquid area of ​​the observation cavity, which can reduce the balance error judged by the naked eye and quantify the measurement error. For the balance score that reaches the limit, the emission light intensity is obtained by image processing to stabilize the balance limit, which reduces the judgment error compared to the naked eye observation of the experimental operator. The experimental image error can be determined by the pixel of the image acquisition device, and its error can quantify the minimum recognition pixel compared to the judgment of the experimental operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a structural principle diagram of the piston type gas-liquid phase equilibrium dynamic observation device provided by the present invention.

[0023] Reference numerals: 1. Observation chamber gas area; 2. Observation chamber liquid area; 3. Pressure control piston; 4. Pressure control chamber; 5. First storage bottle; 6. Pressure control device; 7. Temperature control device; 8. Parallel light source; 9. Data acquisition device; 10. First weighing device; 11. High-pressure delivery pump; 12. First filling valve; 13. Preheater; 14. Closed valve of the area to be measured; 15. Second filling valve; 16. First temperature detector; 17. First pressure sensor; 18. Sealing device; 19. Second temperature detector; 20. Second pressure sensor; 21. Third temperature detector; 22. Fourth temperature detector; 61. High-pressure gas bottle; 62. Pressure reducing valve; 63. High-pressure gas filling valve; 64. Flushing valve; 65. Exhaust pressure regulating valve; 91. Image acquisition device; 92. Temperature acquisition digital meter; 93. Pressure acquisition digital meter; 94. Data acquisition computer. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0026] Combine the following Figure 1 Describing an embodiment of the present invention, a piston-type gas-liquid phase equilibrium dynamic observation device is provided, which includes a cylinder, a first storage bottle 5, a pressure control device 6, a temperature control device 7, a parallel light source 8 and a data acquisition device 9.

[0027] The inner cavity of the cylinder is the observation area, which is divided into observation cavity gas area 1, observation cavity liquid area 2, pressure control piston 3 and pressure control cavity 4 from top to bottom.

[0028] The first storage bottle 5 is used to store the first fluid to be measured; the first storage bottle 5 is connected to the observation chamber gas area 1; the first fluid to be measured can flow into the observation chamber gas area 1 through the pipeline.

[0029] The pressure control device 6 is connected to the pressure control chamber 4. The pressure control device 6 pushes the pressure control piston 3 by changing the pressure of the pressure control chamber 4, thereby changing the pressure of the observation chamber liquid area 2 and the observation chamber gas area 1.

[0030] The temperature control device 7 is used to control the temperature of the cylinder; the parallel light source 8 is used as the experimental excitation light to illuminate the cylinder, and the experimental excitation light intensity is determined by the parallel light source 8. The data acquisition device 9 is used to collect the temperature, pressure and image of the observation area, and obtain the emission light intensity of the observation area by observing the images of the gas area 1 and the liquid area 2 of the observation cavity.

[0031] In the piston-type gas-liquid phase equilibrium dynamic observation device provided in this embodiment, the experimental excitation light intensity is determined by a parallel light source, and the image data is collected by a data acquisition device and associated with the phase equilibrium fraction. When the phase equilibrium dynamic observation is performed, the pressure can be freely adjusted by controlling the pressure control piston 3 through the pressure control device 6. During the adjustment process, by real-time acquisition of images of the observation chamber gas area 1 and the observation chamber liquid area 2, the emission light intensity distribution of the observation area can be obtained, and then the composition fraction of the phase equilibrium dynamic process can be obtained.

[0032] In a feasible embodiment of the present invention, it also includes a first weighing device 10, a high-pressure delivery pump 11 and a second filling valve 15. The first weighing device 10 is used to obtain the mass of the first fluid to be tested. The first fluid to be tested is usually a light component, which is weighed by the first weighing device 10 to determine the filling mass, which is recorded as m. One end of the high-pressure delivery pump 11 is connected to the first storage bottle 5, and the other end is connected to the observation chamber gas zone 1. The high-pressure delivery pump 11 is used to pump the first fluid to be tested. The first fluid to be tested is injected into the experimental pipeline through the high-pressure delivery pump 11. The first filling valve 12, the preheater 13 and the test area closing valve 14 are arranged in sequence between the high-pressure delivery pump 11 and the observation chamber gas zone 1; wherein the first filling valve 12 is opened when the first fluid to be tested is filled. The first fluid to be tested enters the preheater 13 after passing through the first filling valve 12, and the temperature of the preheater 13 is the experimental target temperature. The first fluid to be tested after preheating passes through the test area closing valve 14 and enters the observation area.

[0033] The second filling valve 15 is used to fill the second fluid to be tested, and the filling mass of the second fluid to be tested is measured before and after the filling. The second fluid to be tested is usually a heavy component. The second fluid to be tested is filled through the second filling valve 15, and the filling mass is measured before and after the filling, which is recorded as m'.

[0034] In a feasible embodiment of the present invention, a first temperature detector 16 is provided between the preheater 13 and the closed valve 14 of the test area, and is capable of acquiring the temperature of the first fluid to be tested.

[0035] In a feasible embodiment of the present invention, the pressure control device 6 includes a high-pressure gas bottle 61, a pressure reducing valve 62 and a high-pressure gas filling valve 63. The high-pressure gas bottle 61 stores high-pressure gas; the pressure reducing valve 62 is arranged downstream of the high-pressure gas bottle 61; one end of the high-pressure gas filling valve 63 is connected to the pressure reducing valve 62, and the other end is connected to the pressure control chamber 4. A first pressure sensor 17 is arranged on the pipeline between the high-pressure gas filling valve 63 and the pressure control chamber 4.

[0036] The pressure control is performed by the high-pressure gas in the high-pressure gas bottle 61. The high-pressure gas enters the gas pipeline through the pressure reducing valve 62 and enters the pressure control chamber 4 through the high-pressure gas filling valve 63. The pressure of this part is measured by the first pressure sensor 17. The high-pressure gas controls the experimental pressure in the cylinder by driving the pressure control piston 3, and the measured temperature is controlled by the temperature control device.

[0037] In a feasible embodiment of the present invention, the pressure control device 6 also includes a flushing valve 64 and an exhaust pressure regulating valve 65. The flushing valve 64 is arranged downstream of the pressure reducing valve 62, and the flushing valve 64 is connected in parallel with the high-pressure gas filling valve 63; the exhaust pressure regulating valve 65 is arranged downstream of the flushing valve 64, and the exhaust pressure regulating valve 65 is used for vacuum treatment after the system is flushed. In addition, it also includes a second temperature detector 19 and a second pressure sensor 20, which are respectively used to detect the temperature and pressure in the observation area. During the experiment, the temperature and pressure in the observation area are measured by the second temperature detector 19 and the second pressure sensor 20, and the phase equilibrium fraction distribution under different temperatures and pressures under dynamic conditions is obtained.

[0038] Before the experiment, the system needs to be volume calibrated and flushed. Through liquid volume calibration, the pipeline volume V1 from the first storage bottle 5 to the first filling valve 12, the pipeline volume V2 from the first filling valve 12 to the closed valve 14 of the test area, and the pipeline volume V3 between the closed valve 14 of the test area, the second temperature detector 19 and the second pressure sensor 20 to the cylinder are obtained. In the flushing stage, the system is cleaned more than three times with dry high-pressure gas. At this time, the flushing valve 64 is opened, and the system is evacuated through the exhaust pressure regulating valve 65 after each cleaning.

[0039] In a feasible embodiment of the present invention, the data acquisition device 9 includes an image acquisition device 91, a temperature acquisition digital meter 92, a pressure acquisition digital meter 93 and a data acquisition computer 94. The image acquisition device 91 is used to acquire the experimental image of the observation area; the temperature acquisition digital meter 92 is used to acquire the temperature data of the observation area; the pressure acquisition digital meter 93 is used to acquire the pressure data of the observation area; and the data acquisition computer 94 synchronously acquires the experimental image, temperature data and pressure data. The temperature of the constant temperature bath is acquired by the third temperature detector 21. The temperature data acquired by all temperature detectors in the system are converted into digital signals by the temperature acquisition digital meter 92, and the pressure data acquired by all pressure sensors are converted into digital signals by the pressure acquisition digital meter 93.

[0040] The temperature control device 7 includes a constant temperature bath and a sealing device 18. The sealing device 18 is arranged outside the cylinder and inside the constant temperature bath. It should be noted that the constant temperature bath can be divided into a gas constant temperature bath or a liquid constant temperature bath according to different media.

[0041] In the above embodiment, the first temperature detector 16 detects the temperature of the first fluid to be measured, which is recorded as T1; the second temperature detector 19 detects the temperature of the observation area, which is recorded as T2; the third temperature detector 21 detects the temperature of the constant temperature bath, which is recorded as T3; the temperature of the first fluid to be measured before filling is detected by the fourth temperature detector 22, which is recorded as T4. The first pressure sensor 17 is used to measure the pressure before the high-pressure gas fills the pressure control chamber 4, which is recorded as P1; the pressure of the observation area cavity is measured by the second pressure sensor 20, which is recorded as P2.

[0042] A second aspect of the present invention provides a method for using a piston-type gas-liquid phase equilibrium dynamic observation device, comprising: The first fluid to be measured is placed in the inner cavity of the cylinder to form an observation area, wherein the temperature and pressure of the inner cavity of the cylinder are kept constant.

[0043] The observation area is illuminated by experimental excitation light, and the intensity of the experimental excitation light is determined by the parallel light source 8 and is recorded as I1.

[0044] After time t, the first fluid to be measured reaches a phase equilibrium state in the observation area; The emission light intensity I2 at the phase equilibrium state is acquired by a data acquisition device and correlated with the phase equilibrium fraction.

[0045] During the dynamic observation of phase equilibrium, the pressure can be freely adjusted by the pressure control piston 3. During the adjustment process, the distribution of the emission light intensity I2 in the observation area can be obtained by real-time acquisition of images of the observation chamber gas area 1 and the observation chamber liquid area 2. When the fluid emission efficiency E, the optical path attenuation coefficient k, and the cylinder diameter d are known, the composition fraction X at time t in the dynamic process of achieving phase equilibrium is obtained by the formula I2=k∙E∙X∙d∙I1. During the experiment, the temperature and pressure in the observation chamber are measured by the second temperature detector 19 and the second pressure sensor 20, and the phase equilibrium fraction distribution under the conditions of (T, P, X, t) (temperature, pressure, composition, time) is obtained.

[0046] The piston-type gas-liquid phase equilibrium dynamic observation device provided by the present invention can quantify the experimental error method. For the equilibrium score that reaches the limit, the emission light intensity is obtained through image processing to determine the equilibrium limit, which reduces the judgment error compared to the naked eye observation of the experimental operator. The experimental image error can be determined by the pixel of the image acquisition device, and its error can quantify the minimum recognition pixel compared to the judgment of the experimental operator.

[0047] In addition to the emission light intensity analysis method, the phase equilibrium limit score can be obtained by mass analysis for the measurement of equilibrium limit. When the equilibrium image reaches stability, it is considered that the system reaches the equilibrium limit. In this case, the total mass m of the first fluid component a (usually the light component) in the experimental area is known, and the volume V1 from the first storage bottle 5 to the first filling valve 12, the pipeline volume V2 from the first filling valve 12 to the closed valve 14 in the test area, and the pipeline volume V3 between the closed valve 14 in the test area, the second temperature detector 19, and the second pressure sensor 20 to the experimental cylinder, the pressure is equal everywhere during injection, which is P2, and the density is obtained from the state equation under the known temperature and pressure in the corresponding area, which is recorded as ρ1, ρ2, ρ3. The mass of the V1, V2, and V3 areas can be calculated to obtain m1, m2, and m3, so the mass of the first fluid to be measured in the observation area is (m-m1-m2-m3). The volume V4 of the gas zone 1 of the observation chamber and the volume V5 of the liquid zone 2 of the observation chamber can be obtained by image processing method and cylinder diameter. When the volume V4 of the gas zone 1 of the observation chamber is known, the gas mass is calculated as m4 by the state equation, and the mass fraction of component a in the liquid phase is X'=(m-m1-m2-m3-m4) / (m-m1-m2-m3-m4+m'). At this time, the equilibrium mass fraction X' can be compared with the equilibrium limit mass fraction X obtained by the emission light intensity analysis method.

[0048] Therefore, the piston-type gas-liquid phase equilibrium dynamic observation device provided by the present invention can also verify each other in multiple ways. For the state of reaching equilibrium, it can be measured by injecting mass, temperature, and pressure to determine the limit of equilibrium while reducing measurement errors, and at the same time verify each other with the dynamic measurement of the emitted light intensity.

[0049] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0050] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "mode", "specific mode", or "some modes" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or mode are included in at least one embodiment or mode of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or mode. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or modes in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or modes described in this specification and the features of the different embodiments or modes, without contradiction.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A piston-type gas-liquid phase equilibrium dynamic observation device, characterized in that: include: The cylinder has an inner cavity which is an observation area, which is divided from top to bottom into an observation cavity gas area (1), an observation cavity liquid area (2), a pressure control piston (3) and a pressure control cavity (4); A first storage bottle (5), used for storing a first fluid to be tested; The first storage bottle (5) is in communication with the observation chamber gas area (1); a pressure control device (6) connected to the pressure control chamber (4), wherein the pressure control device (6) pushes the pressure control piston (3) by changing the pressure of the pressure control chamber (4), thereby changing the pressure of the observation chamber liquid area (2) and the observation chamber gas area (1); A temperature control device (7) for controlling the temperature of the cylinder; A parallel light source (8) is used as experimental excitation light to illuminate the cylinder to obtain the experimental excitation light intensity; A data acquisition device (9) is used to acquire the temperature, pressure and image of the observation area, and to obtain the emission light intensity of the observation area through the images of the observation chamber gas area (1) and the observation chamber liquid area (2).

2. The piston type gas-liquid phase equilibrium dynamic observation device according to claim 1, characterized in that: Also includes: A first weighing device (10) for obtaining the mass of the first fluid to be measured; a high-pressure delivery pump (11), one end of which is in communication with the first storage bottle (5) and the other end of which is in communication with the observation chamber gas zone (1), the high-pressure delivery pump (11) being used to pump the first fluid to be measured; a first filling valve (12), a preheater (13) and a test area closing valve (14) are sequentially arranged between the high-pressure delivery pump (11) and the observation chamber gas zone (1); wherein the first filling valve (12) is opened when the first fluid to be measured is filled; and the temperature of the preheater (13) is the experimental target temperature; The second filling valve (15) is used to fill the second fluid to be measured and measure the filling mass of the second fluid to be measured before and after the filling.

3. The piston type gas-liquid phase equilibrium dynamic observation device according to claim 2, characterized in that: A first temperature detector (16) is provided between the preheater (13) and the test area closing valve (14).

4. The piston type gas-liquid phase equilibrium dynamic observation device according to claim 1, characterized in that: The pressure control device (6) comprises: A high-pressure gas bottle (61) for storing high-pressure gas; a pressure reducing valve (62), arranged downstream of the high-pressure gas bottle (61); A high-pressure gas filling valve (63) has one end connected to the pressure reducing valve (62) and the other end connected to the pressure control chamber (4).

5. The piston type gas-liquid phase equilibrium dynamic observation device according to claim 4, characterized in that: The pressure control device (6) further comprises: a flushing valve (64), arranged downstream of the pressure reducing valve (62), and the flushing valve (64) is connected in parallel with the high-pressure gas filling valve (63); An exhaust pressure regulating valve (65) is arranged downstream of the flushing valve (64), and the exhaust pressure regulating valve (65) is used for vacuuming the system after flushing.

6. The piston type gas-liquid phase equilibrium dynamic observation device according to claim 4, characterized in that: A first pressure sensor (17) is provided on the pipeline between the high-pressure gas filling valve (63) and the pressure control chamber (4).

7. The piston type gas-liquid phase equilibrium dynamic observation device according to claim 1, characterized in that: The data acquisition device (9) comprises: An image acquisition device (91) is used to acquire an experimental image of the observation area; A temperature collection digital meter (92) is used to collect temperature data of the observation area; A pressure acquisition digital meter (93) for acquiring pressure data of the observation area; A data acquisition computer (94) is used to acquire the experimental image, the temperature data and the pressure data.

8. The piston type gas-liquid phase equilibrium dynamic observation device according to claim 1, characterized in that: The temperature control device (7) comprises a constant temperature bath and a sealing device (18), wherein the sealing device (18) is arranged on the outside of the cylinder and the sealing device (18) is arranged inside the constant temperature bath.

9. The piston type gas-liquid phase equilibrium dynamic observation device according to claim 1, characterized in that: It also includes a second temperature detector (19) and a second pressure sensor (20), which are used to detect the temperature and pressure in the observation area respectively.

10. A method for using the piston type gas-liquid phase equilibrium dynamic observation device according to any one of claims 1 to 9, characterized in that: include: Placing a first fluid to be measured in a cylinder cavity to form an observation area, wherein the temperature and pressure of the cylinder cavity are kept constant; irradiating the observation area with experimental excitation light; Get the experimental excitation light intensity I1; After time t, the first fluid to be measured reaches a phase equilibrium state in the observation area; The emission light intensity I2 at the phase equilibrium state is obtained by a data acquisition device; According to the formula I2=k∙E∙X∙d∙I1, the composition fraction X at time t in the dynamic process of achieving phase equilibrium is obtained, where E is the emission efficiency of the fluid to be measured, k is the optical path attenuation coefficient, and d is the diameter of the cylinder.

Images