Multiphase carbon dioxide injection system and injection method

Abstract

Embodiments of the present application relate to an injection system and an injection method. The injection system includes an air supply device, a piston container, a plunger pump, an insulation tube, a water bath, a circulating water bath, a first temperature sensor, a second temperature sensor, a temperature controller, a pressure sensor, and a data acquisition and control system. The air supply device is used to provide a gaseous target. The piston container includes a top space connected to the air supply device and a bottom space connected to the plunger pump. The insulation tube is connected to the top space and the target container, respectively. The water bath is used to accommodate the piston container. The circulating water bath is connected to the water bath. The first temperature sensor is used to detect the real-time water temperature of the water bath. The second temperature sensor is used to detect the real-time tube temperature of the insulation tube. The temperature controller is connected to the insulation tube. The pressure sensor is used to detect the real-time pressure of the insulation tube. The data acquisition and control system is used to iteratively calculate and automatically control the real-time liquid injection rate of the plunger pump into the bottom space under a preset boost rate.

Description

Technical Field

[0001] The present application relates to an injection system and an injection method. Background Art

[0002] Current injection systems used to inject gases such as carbon dioxide, methane, or hydrogen into target containers suffer from poor injection rate control accuracy. This is especially true when the target container is a microporous volume (a few milliliters) device such as a microfluidic chip or a low-volume differential scanning calorimeter. Current injection systems and methods struggle to achieve a highly precise and controllable injection process. Summary of the Invention

[0003] In a first aspect, the present application provides an injection system. The injection system is used to inject a target substance in a predetermined phase into a target container. The target substance is one of carbon dioxide, methane, or hydrogen. The injection system includes a gas supply device, a piston container, a plunger pump, an insulation tube, a water bath, a circulating water bath, a first temperature sensor, a second temperature sensor, a temperature controller, a pressure sensor, and a data acquisition and control system. The gas supply device is used to provide the gaseous target substance. The piston container includes a cavity and a piston positioned therein. The piston divides the cavity into a top space and a bottom space. The top space is connected to the gas supply device. The plunger pump is connected to the bottom space. The insulation tube is connected to the top space and the target container, respectively. The water bath is used to accommodate the piston container. The circulating water bath is connected to the water bath. The first temperature sensor is used to detect the real-time water temperature of the water bath. The second temperature sensor is used to detect the real-time temperature of the insulation tube. The temperature controller is connected to the insulation tube. The pressure sensor is used to detect the real-time pressure of the insulation tube. The data acquisition and control system is connected to the plunger pump, the first temperature sensor, the circulating water bath, the second temperature sensor, the temperature controller, the insulation tube, and the pressure sensor, respectively. The data acquisition and control system is used to collect real-time water temperature, real-time pipe temperature and real-time pressure, and is used to maintain the water temperature in the water bath at the target water temperature by controlling the circulating water bath, maintain the pipe temperature of the insulation pipe at the target pipe temperature by controlling the temperature controller, and is used to iteratively calculate and automatically control the real-time liquid injection rate of the plunger pump into the bottom space when the piston container injects the target object of the preset phase into the target container at the preset pressurization rate.

[0004] The injection system of the embodiment of the present application can automatically control the water temperature in the water bath to be maintained at the target water temperature through the settings of the data acquisition and control system, the first temperature sensor, the circulating water bath and the water bath; can automatically control the tube temperature of the insulation tube to be maintained at the target tube temperature through the settings of the data acquisition and control system, the second temperature sensor and the temperature controller; can monitor the real-time pressure of the target container during the injection process through the settings of the data acquisition and control system, the pressure sensor and the plunger pump, and iteratively calculate the real-time liquid injection rate of the plunger pump into the bottom space of the piston container when the piston container injects the target object of the preset phase into the target container under the preset boost rate based on the real-time pressure and the real-time water temperature, and automatically control the plunger pump to inject liquid into the bottom space of the piston container at the real-time liquid injection rate. It can be seen that the injection system can automatically adjust the real-time liquid injection rate according to the real-time data (such as real-time pressure, real-time water temperature, etc.) during the injection process to ensure the optimization of the injection process. Therefore, the injection system is conducive to realizing a high-precision and controllable injection process of carbon dioxide, methane or hydrogen, etc.

[0005] The second aspect of the present application provides an injection method, which is implemented using the injection system of the first aspect of the present application. The injection method includes initial preparation, selection of injection mode, first injection and second injection. The initial preparation includes clearing the liquid in the bottom space and clearing the air in the top space. In the selected injection mode, when the target substance is carbon dioxide, the injection mode is any one of the gaseous injection mode, the gaseous-to-supercritical injection mode, the supercritical injection mode and the liquid injection mode; when the target substance is methane or hydrogen, the injection mode is the gaseous injection mode. The first injection step includes controlling the water temperature in the water bath to maintain the target water temperature, injecting the target substance into the top space through the gas supply device, so that the pressure in the top space reaches the initial pressure; wherein, in the gaseous injection mode and the gaseous-to-supercritical injection mode, the target substance in the top space is in gaseous state, and in the supercritical injection mode and the liquid injection mode, the target substance in the top space is in liquid state. The second injection step includes connecting the target container to the insulation tube, controlling the tube temperature of the insulation tube at the target tube temperature, calculating the real-time liquid injection rate under the preset pressurization rate according to the initial pressure, the volume of the piston container, the volume of the target container and the real-time pressure of the target container, and causing the plunger pump to inject liquid into the bottom space at the real-time liquid injection rate until the pressure of the target container reaches the target pressure; wherein, in the gaseous injection method, the gas-to-supercritical injection method, the supercritical injection method and the liquid injection method, the target object is injected into the target container in the form of gas, gas-to-supercritical, supercritical and liquid respectively.

[0006] The injection method of the second aspect of the present application is conducive to achieving a high-precision and controllable injection process of carbon dioxide, methane or hydrogen, etc. In addition, in the injection method of the second aspect of the present application, when the target substance is carbon dioxide, the volume of the target container in the injection system and the total volume of the top space of the piston container are changed by changing the real-time water injection rate of the plunger pump into the bottom space of the piston container to increase and decrease the pressure, and the temperature of the carbon dioxide injection is automatically controlled by a circulating water bath and an insulation tube, thereby changing the phase state of the carbon dioxide, which is conducive to achieving multi-phase carbon dioxide conversion and high-precision and low-rate injection in micro-devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 Schematic diagram of the structure of an injection system according to an embodiment of the present application.

[0008] Figure 2 This is a flow chart of an injection method according to an embodiment of the present application.

[0009] Figure 3 Phase diagram of carbon dioxide under different temperature and pressure conditions.

[0010] Description of main component symbols:

[0011] Injection system 100

[0012] Air supply device 10

[0013] Gas cylinder 11

[0014] Pipeline 12

[0015] First valve 13

[0016] Piston container 20

[0017] Cavity 21

[0018] Piston 22

[0019] Head space 20a

[0020] Bottom space 20b

[0021] Plunger pump 30

[0022] Tee pipe 31

[0023] Drain valve 32

[0024] Insulation pipe 40

[0025] First branch 41

[0026] First end 41a

[0027] Second end 41b

[0028] Second branch 42

[0029] The third end 42a

[0030] Fourth end 42b

[0031] Visualization Window 42c

[0032] Cross pipe 43

[0033] Second valve 44

[0034] Water bath 50

[0035] Circulating water bath 60

[0036] First temperature sensor 71

[0037] Second temperature sensor 72

[0038] Temperature controller 73

[0039] Pressure sensor 74

[0040] Camera 75

[0041] Data acquisition and control system 80

[0042] Computer 81

[0043] Data collector 82

[0044] Target container 200 DETAILED DESCRIPTION

[0045] Carbon dioxide is a chemically inactive carbon oxide and a common greenhouse gas. It exists in different physical phases at different temperatures and pressures. These phases include solid, liquid, gaseous, and supercritical states. Due to its complex multiphase nature, different phases of carbon dioxide have diverse applications. Gaseous carbon dioxide is used as a refrigerant in refrigeration and industrial processing. Supercritical carbon dioxide possesses both gas-like diffusivity and liquid-like solubility, along with low viscosity and surface tension, making it an excellent industrial solvent for solvents, extractants, and foaming agents. However, current carbon dioxide injection systems mostly rely on a single-phase injection method, primarily due to poor temperature and pressure control, low pressure, and the lack of a visual window. Furthermore, current carbon dioxide injection systems suffer from poor control over injection rate and volume. This is primarily due to the fact that high concentrations of carbon dioxide dissolve in water to form carbonic acid, and carbon dioxide molecules can penetrate into the rubber, making high-precision compression pumps, which primarily rely on rubber seals, susceptible to damage. At the same time, in the current carbon dioxide injection system, the supercritical carbon dioxide injection system and injection process only consider larger devices. For micro-pore volume (several milliliters) devices such as microfluidics and low-capacity differential scanning calorimeters, it is difficult to achieve a high-precision controllable injection process for micro-devices.

[0046] In addition, the methane or hydrogen injection system and injection process also have the problem of difficulty in achieving a high-precision and controllable injection process.

[0047] In this regard, an embodiment of the present application provides an injection system. The injection system is conducive to achieving efficient, stable injection, and high-precision controllable injection of carbon dioxide, methane, or hydrogen. Furthermore, the injection system of the embodiment of the present application can also achieve multi-phase carbon dioxide injection (such as gaseous carbon dioxide injection, gaseous to supercritical carbon dioxide injection, supercritical carbon dioxide injection, and liquid carbon dioxide injection), and can automatically adjust the injection parameters based on the phase change of carbon dioxide. The following is a detailed description in conjunction with the drawings of the embodiment of the present application.

[0048] Figure 1 This is a schematic diagram of the structure of an injection system 100 according to one embodiment of the present application. Injection system 100 is used to inject a target substance in a predetermined phase into a target container 200. The target substance is one of carbon dioxide, methane, or hydrogen. Target container 200 can be a standard device at the core and reservoir scale, or a milliliter-scale micro-device, such as a microfluidic chip or a micro-differential scanning calorimeter.

[0049] like Figure 1As shown, the injection system 100 includes a gas supply device 10, a piston container 20, a plunger pump 30, a three-way pipe 31, a drain valve 32, an insulation pipe 40, a four-way pipe 43, a second valve 44, a water bath 50, a circulating water bath 60, a first temperature sensor 71, a second temperature sensor 72, a temperature controller 73, a pressure sensor 74, a camera 75, and a data acquisition and control system 80.

[0050] The gas supply device 10 is used to provide a gaseous target and includes a gas cylinder 11 , a pipeline 12 connected to the gas cylinder 11 and the insulation tube 40 , and a first valve 13 provided on the pipeline 12 .

[0051] The piston container 20 includes a cavity 21 and a piston 22 located within the cavity 21. The piston 22 divides the cavity 21 into a top space 20a and a bottom space 20b. The top space 20a of the piston container 20 is connected to the gas cylinder 11 of the gas supply device 10 via a pipeline 12. The bottom space 20b of the piston container 20 is connected to the plunger pump 30.

[0052] The three output ports of the three-way pipe 31 are connected to the plunger pump 30 , the bottom space 20 b of the piston container 20 , and the drain valve 32 , respectively.

[0053] The heat-insulating tube 40 is connected to the head space 20 a of the piston container 20 and the target container 200 , respectively.

[0054] Specifically, the insulation tube 40 includes a first branch 41 and a second branch 42. The first branch 41 includes a first end 41a and a second end 41b opposite each other, with the first end 41a connected to the headspace 20a of the piston container 20. The second branch 42 includes a third end 42a and a fourth end 42b opposite each other, with the fourth end 42b being used to connect to the target container 200.

[0055] The four output ports of the cross-tube 43 are connected to the pipeline 12, the pressure sensor 74, the second end 41b, and the fourth end 42b, respectively. A second valve 44 is provided on the second branch pipe 42. The insulation pipe 40 includes a visualization window 42c located between the cross-tube 43 and the second valve 44.

[0056] The insulation pipe 40 may be an electrically heated insulation pipe, but is not limited thereto.

[0057] The water bath 50 is used to accommodate the piston container 20. The circulating water bath 60 is connected to the water bath 50.

[0058] The first temperature sensor 71 is used to detect the real-time water temperature of the water bath 50. The second temperature sensor 72 is used to detect the real-time pipe temperature of the insulation pipe 40. The temperature controller 73 is connected to the insulation pipe 40. The pressure sensor 74 is used to detect the real-time pressure of the insulation pipe 40.

[0059] Camera 75 is used to record real-time images of the target within insulation tube 40 through visualization window 42c during the injection process of the target into target container 200. This is used for automated identification and confirmation of the injection status and provides feedback to the computer to control the injection rate of the plunger pump. Camera 75 can be an industrial camera, but is not limited thereto.

[0060] The data acquisition and control system 80 is connected to the first temperature sensor 71 and the circulating water bath 60 respectively, so as to collect the real-time water temperature of the water bath 50 detected by the first temperature sensor 71, and control the circulating water bath 60 based on the real-time water temperature to maintain the water temperature in the water bath 50 at the target water temperature.

[0061] The data acquisition and control system 80 is also connected to the second temperature sensor 72, the temperature controller 73 and the insulation pipe 40 respectively, so as to collect the real-time pipe temperature of the insulation pipe 40 detected by the second temperature sensor 72, and control the temperature controller 73 based on the real-time pipe temperature to maintain the pipe temperature of the insulation pipe 40 at the target pipe temperature.

[0062] The data acquisition and control system 80 is also connected to the pressure sensor 74 and the plunger pump 30 respectively, so as to collect the real-time pressure detected by the pressure sensor 74, and iteratively calculate the real-time liquid injection rate of the plunger pump 30 into the bottom space 20b of the piston container 20 when the piston container 20 injects the target object of the preset phase into the target container 200 at the preset boost rate based on the real-time pressure and the real-time water temperature, and automatically control the plunger pump 30 to inject liquid into the bottom space 20b of the piston container 20 at the real-time liquid injection rate.

[0063] The data acquisition and control system 80 is also connected to the camera 75 to acquire real-time images recorded by the camera 75 and identify the phase state of the target object in the insulation tube 40 in real time.

[0064] Figure 1 In the illustrated embodiment, the data acquisition and control system 80 includes a computer 81 and a data acquisition device 82 connected to the computer 81. The data acquisition device 82 is connected to the pressure sensor 74 and the camera 75 to collect data from the pressure sensor 74 and the camera 75. The computer 81 is connected to the first temperature sensor 71 and the second temperature sensor 72 to collect data from the first temperature sensor 71 and the second temperature sensor 72, and is also connected to the plunger pump 30, the insulation tube 40, the circulating water bath 60, and the temperature controller 73 to control their respective operating processes.

[0065] In other embodiments, any one of the first temperature sensor 71 and the second temperature sensor 72 can be connected to the data acquisition device 82 , and the data acquisition device 82 collects data from the first temperature sensor 71 or the second temperature sensor 72 and transmits the data to the computer 81 .

[0066] In other embodiments, the data collector 82 may be omitted. Each of the first temperature sensor 71 , the second temperature sensor 72 , the pressure sensor 74 , and the camera 75 is directly connected to the computer 81 to directly collect data through the computer 81 .

[0067] In summary, the injection system 100 of the embodiment of the present application can automatically control the water temperature in the water bath 50 to maintain at the target water temperature through the settings of the data acquisition and control system 80, the first temperature sensor 71, the circulating water bath 60 and the water bath 50. The pipe temperature of the insulation pipe 40 can be automatically controlled to maintain at the target pipe temperature through the settings of the data acquisition and control system 80, the second temperature sensor 72 and the temperature controller 73. The real-time pressure of the target container 200 during the injection process can be monitored through the settings of the data acquisition and control system 80, the pressure sensor 74 and the plunger pump 30, and the real-time liquid injection rate of the plunger pump 30 into the bottom space 20b of the piston container 20 when the piston container 20 injects the target object of the preset phase into the target container 200 at the preset boost rate can be iteratively calculated based on the real-time pressure and the real-time water temperature, and the plunger pump 30 can be automatically controlled to inject liquid into the bottom space 20b of the piston container 20 at the real-time liquid injection rate.

[0068] As can be seen, the injection system 100 can automatically adjust the real-time injection rate based on real-time data during the injection process (such as real-time pressure and real-time water temperature), ensuring the optimization of the injection process. Therefore, the injection system 100 is conducive to achieving a high-precision and controllable injection process of carbon dioxide, methane, or hydrogen.

[0069] The present application also provides an injection method. The injection method can be implemented using the above-mentioned injection system 100. Figure 2 As shown, the injection method of one embodiment of the present application includes the following steps S10 to S40. According to different requirements, the order of some steps or sub-steps of the injection method can be changed, and some steps or sub-steps can be omitted or combined.

[0070] Step S10: Initial preparation.

[0071] Specifically, step S10 includes clearing the liquid from the bottom space 20 b of the piston container 20 and clearing the air from the top space 20 a of the piston container 20 .

[0072] Please refer to Figure 1Step S10 specifically includes closing the second valve 44, opening the first valve 13, and injecting the gaseous target from the gas supply device 10 into the top space 20a of the piston container 20 to a predetermined pressure greater than one standard atmospheric pressure. Next, closing the first valve 13 and opening the drain valve 32 to drain the liquid from the bottom space 20b of the piston container 20 until no more liquid remains. Next, closing the drain valve 32 and opening the second valve 44 to release the gas to one standard atmospheric pressure, and then closing the second valve 44.

[0073] In some embodiments, the preset pressure is 0.5 MPa to 1.0 MPa, but is not limited thereto.

[0074] In some embodiments, the liquid inlet of the plunger pump 30 is connected to a container filled with water, and the liquid injected into the piston container 20 by the plunger pump 30 is water, but is not limited thereto.

[0075] Step S20: Select an injection method.

[0076] Specifically, multiple optional injection methods are stored in the data acquisition and control system 80. If the target substance to be injected into the target container 200 is carbon dioxide, the optional injection methods are any one of gaseous injection, gas-to-supercritical injection, supercritical injection, and liquid injection.

[0077] It should be noted that, in the embodiment of the present application, the gaseous injection method refers to the target object being injected into the target container 200 in a gaseous phase; the gaseous-to-supercritical injection method refers to the target object being injected into the target container 200 in a gaseous phase in the initial stage of injection, and being injected into the target container 200 in a supercritical phase in the later stage of injection; the supercritical injection method refers to the target object being injected into the target container 200 in a supercritical phase; and the liquid injection method refers to the target object being injected into the target container 200 in a liquid phase.

[0078] It should also be noted that since the critical temperature of methane is -82.6°C and the critical temperature of hydrogen is -240°C, it is difficult to maintain these temperatures using the water bath 50 and the circulating water bath 60. Therefore, when the target substance to be injected into the target container 200 is methane or hydrogen, the optional injection method is gaseous injection. However, the critical temperature of carbon dioxide is 31.3°C, and the water bath 50 and the circulating water bath 60 can maintain the various temperature ranges of carbon dioxide in the gaseous, liquid, and supercritical states. Therefore, if the target substance to be injected into the target container 200 is carbon dioxide, the optional injection method is any one of gaseous injection, gas-to-supercritical injection, supercritical injection, and liquid injection.

[0079] Step S30: the first step of injection.

[0080] Specifically, step S30 includes controlling the water temperature in the water bath 50 to maintain at the target water temperature, injecting the target object into the top space 20a of the piston container 20 through the air supply device 10, so that the pressure in the top space 20a of the piston container 20 reaches the initial pressure.

[0081] More specifically, please refer to Figure 1 The first step of injection specifically includes: using the circulating water bath 60 and the first temperature sensor 71 through the data acquisition and control system 80 to control the water temperature in the water bath 50 to maintain it at the target water temperature, then opening the first valve 13, and injecting the gas in the gas cylinder 11 into the top space 20a of the piston container 20, so that the pressure in the top space 20a of the piston container 20 reaches the initial pressure, and then closing the first valve 13.

[0082] It should be noted that during the first injection step, by setting the target water temperature and initial pressure, the target object in the top space 20a of the piston container 20 is in gaseous state in the gas injection mode and the gas-to-supercritical state injection mode; and the target object in the top space 20a of the piston container 20 is in liquid state in the supercritical state injection mode and the liquid injection mode.

[0083] More specifically, please refer to Figure 3 If the injection method selected in step S20 is the gaseous injection method of carbon dioxide, then in step S30, the target water temperature is set to be in the temperature range where the carbon dioxide phase is in the gaseous phase, and the initial pressure is set to be in the pressure range where the carbon dioxide phase is in the gaseous phase, so as to ensure that the carbon dioxide injected into the piston container 20 is in the gaseous phase. Figure 3 The figure only illustrates the phase state of carbon dioxide in the range of -70°C to 70°C, but the target water temperature is not limited to 70°C. In addition, considering the operating temperatures of the water bath 50 and the circulating water bath 60, the target water temperature is not lower than -10°C.

[0084] If the injection method selected in step S20 is the gas-to-supercritical injection method for carbon dioxide, then in step S30, the target water temperature is set to be within the temperature range when the carbon dioxide phase is in the supercritical state (or the target water temperature is set to be within the temperature range where the carbon dioxide gas phase temperature range overlaps with the supercritical state temperature range), and the initial pressure is set to be within the pressure range when the carbon dioxide is in the gas phase, so as to ensure that the carbon dioxide injected into the piston container 20 is in the gaseous state and can be subsequently converted to the supercritical state by pressurization and injected into the target container 200. It can be understood that Figure 3 Only the phase state of carbon dioxide in the range of -70℃ to 70℃ is shown, but the target water temperature is not limited to 70℃.

[0085] If the injection method selected in step S20 is the supercritical injection method of carbon dioxide, then in step S30, the target water temperature is set to be in the temperature range when carbon dioxide is in liquid state, and the initial pressure is set to be in the pressure range when carbon dioxide is in liquid state, so as to ensure that the carbon dioxide injected into the piston container 20 is in liquid state, and can be converted into a supercritical state by heating in the subsequent second injection process and injected into the target container 200. It should be noted that, since the molecular weight of carbon dioxide stored in liquid carbon dioxide is greater than that stored in gaseous carbon dioxide under the same volume, in the supercritical injection method of carbon dioxide, the gaseous carbon dioxide needs to be pressurized first to be converted into liquid carbon dioxide and stored in the piston container 20. Understandably, Figure 3 Only the phase state of carbon dioxide in the range of -70°C to 70°C is shown. Considering the working temperatures of the water bath 50 and the circulating water bath 60, the target water temperature is not lower than -10°C.

[0086] If the injection method selected in step S20 is the liquid injection method of carbon dioxide, then in step S30, the target water temperature is set to be in the temperature range when carbon dioxide is in liquid state, and the initial pressure is set to be in the pressure range when carbon dioxide is in liquid state, so as to ensure that the carbon dioxide injected into the piston container 20 is in liquid state. Similarly, since the molecular weight of carbon dioxide stored in liquid carbon dioxide is greater than that stored in gaseous carbon dioxide under the same volume, under the liquid injection method of carbon dioxide, the gaseous carbon dioxide needs to be pressurized to be converted into liquid carbon dioxide to be stored in the piston container 20. It can be understood that Figure 3 Only the phase state of carbon dioxide in the range of -70°C to 70°C is shown. Considering the working temperatures of the water bath 50 and the circulating water bath 60, the target water temperature is not lower than -10°C.

[0087] If the injection method selected in step S20 is the gaseous injection method of methane, then in step S30, based on the phase diagram of methane at different temperatures and pressures, the target water temperature can be set to be in the temperature range where the methane phase is gaseous, and the initial pressure can be set to be in the pressure range where the methane phase is gaseous, so as to ensure that the methane injected into the piston container 20 is in a gaseous state.

[0088] If the injection method selected in step S20 is the gaseous injection method of hydrogen, then in step S30, based on the phase diagram of hydrogen at different temperatures and pressures, the target water temperature can be set to be in the temperature range where the hydrogen phase is gaseous, and the initial pressure can be set to be in the pressure range where the hydrogen phase is gaseous, so as to ensure that the hydrogen injected into the piston container 20 is in gaseous state.

[0089] In addition, during the first injection step, the phase change of the target object in the insulation tube 40 is observed in real time through the camera 75 and the visualization window 42c.

[0090] Step S40: Second step injection.

[0091] For details, please refer to Figure 1 Step S40 includes: connecting the target container 200 to the insulation tube 40, controlling the temperature of the insulation tube 40 at a target temperature, iteratively calculating a real-time liquid injection rate at a preset pressurization rate based on the initial pressure, the volume of the piston container 20, the volume of the target container 200, and the real-time pressure of the target container 200, and causing the plunger pump 30 to inject liquid into the bottom space 20b of the piston container 20 at the real-time liquid injection rate until the pressure of the target container 200 reaches the target pressure. In the gaseous injection method, the gas-to-supercritical injection method, the supercritical injection method, and the liquid injection method, the target material is injected into the target container 200 in the form of gas, gas-to-supercritical, supercritical, and liquid, respectively.

[0092] More specifically, step S40 includes connecting the target container 200 to the fourth end 42b of the second branch 42 of the insulation tube 40, turning on the temperature controller 73, and then controlling the data acquisition and control system 80 to maintain the temperature of the insulation tube 40 at the target temperature based on the real-time tube temperature detected by the second temperature sensor 72. The second valve 44 is then opened, at which point the pressure in the system formed by the headspace 20a of the piston container 20, the insulation tube 40, and the target container 200 is uniform. The data acquisition and control system 80 then controls the plunger pump 30 to inject liquid into the bottom space 20b of the piston container 20 at a real-time injection rate at a preset pressure increase rate. This causes the liquid in the bottom space 20b of the piston container 20 to compress the headspace 20a of the piston container 20, increasing the pressure in the target container 200 to the target pressure at a constant preset pressure increase rate. Once the pressure in the target container 200 reaches the target pressure, the second valve 44 is closed, achieving quantitative gas molar quantity. Meanwhile, after the pressure of the target container 200 reaches the target pressure, the plunger pump 30 may be switched to a constant pressure mode so that the target container 200 is continuously maintained at the target pressure.

[0093] Furthermore, in step S40 , the phase change of the target object in the heat preservation tube 40 can be observed in real time through the camera 75 and the visualization window 42 c .

[0094] The relationship between the preset pressure increase rate and the real-time liquid injection rate is described in detail below. The following formula is obtained from the state equation of actual gas (non-ideal gas) PV = ZnRT:

[0095] P0V0=Z0nRT (Formula 1);

[0096] P1V1=Z1nRT (Formula 2);

[0097] P2(V1-V4)=Z2nRT (Formula 3);

[0098] V4=V L t(Formula 4);

[0099] Where P0 is the initial pressure;

[0100] V0 is the volume of the head space of the piston container and the insulation tube;

[0101] Z0 is the gas compressibility factor at the initial pressure P0; Z0 is calculated by the data acquisition and control system based on the initial pressure P0 and the real-time water temperature of the water bath corresponding to the initial pressure P0 by importing the Peng-Robinson equation;

[0102] n is the number of moles of gas;

[0103] R is the ideal gas constant;

[0104] T is the absolute temperature of the gas;

[0105] P1 is the pressure of the system consisting of the head space of the piston container, the insulation tube and the target container when the second valve is opened;

[0106] V1 is the total volume of the headspace of the piston container, the insulation tube, and the target container;

[0107] Z1 is the gas compressibility factor when the pressure of the target container is the real-time pressure P1. Z1 is calculated by the data acquisition and control system based on the real-time pressure P1 and the real-time water temperature of the water bath corresponding to the real-time pressure P1 by importing the Peng-Robinson equation;

[0108] P2 is the target pressure;

[0109] V4 is the cumulative volume of the plunger pump, or the reduction in the volume of the top space when the plunger pump compresses the piston upward;

[0110] Z2 is the gas compressibility factor when the target container pressure is the target pressure P2. Z2 is calculated by the data acquisition and control system based on the pressure P2 and the real-time water temperature of the water bath corresponding to the pressure P2 by importing the Peng-Robinson equation;

[0111] t is the time it takes to increase the pressure of the target container from the initial pressure P0 to the real-time pressure P2 in the second injection step.

[0112] From the above formula 1 and formula 2, we can get:

[0113]

[0114] From the above formulas 3, 4 and 5, we can get:

[0115]

[0116] By taking the derivative of Formula 5 with respect to time t, we can get the preset boost rate V P and real-time injection rate V L The relationship satisfies:

[0117]

[0118] From the above formula 6, we can know that as time t changes, the constant preset boost rate V P In the second step of injection, the gas compression factor Z1 changes due to the difference in real-time water temperature and real-time pressure. Therefore, during the second injection process, the data acquisition and control system 80 needs to collect the real-time water temperature sensed by the first temperature sensor 71 and the real-time pressure sensed by the pressure sensor 74 to iteratively calculate the gas compression factor at different real-time pressures and real-time temperatures to obtain the corresponding real-time injection rate, and use the real-time injection rate to control the injection speed of the plunger pump 30.

[0119] Specifically, if the injection method selected in step S20 is the gaseous injection method of carbon dioxide, then in step S40, the target pipe temperature is set to be in the temperature range where the phase of carbon dioxide is gaseous, and the target pressure is set to be in the pressure range where the phase of carbon dioxide is gaseous, so as to ensure that the carbon dioxide injected into the target container 200 is in gaseous state.

[0120] If the injection method selected in step S20 is the gaseous-to-supercritical carbon dioxide injection method, then in step S40, the target tube temperature is set to a temperature range when the carbon dioxide phase is in a supercritical state, and the target pressure is set to a pressure range when the carbon dioxide is in a supercritical state, to ensure that the carbon dioxide injected into the target container 200 is in a supercritical state. Specifically, during the process of increasing the pressure in the target container 200 from the initial pressure to the supercritical pressure Pep (7.29 MPa), the carbon dioxide is injected into the target container 200 in a gaseous state, and during the process of increasing the pressure in the target container 200 from the supercritical pressure Pep to the target pressure, the carbon dioxide is injected into the target container 200 in a supercritical state. In step S40, the phase change of the carbon dioxide in the insulation tube 40 can be observed in real time through the camera 75 and the visualization window 42c.

[0121] If the injection method selected in step S20 is the supercritical carbon dioxide injection method, then in step S40, the target pipe temperature is set to be within the temperature range when carbon dioxide is in the supercritical state, and the target pressure is set to be within the pressure range when carbon dioxide is in the supercritical state, to ensure that the carbon dioxide injected into the target container 200 is in the supercritical state. Since in the supercritical carbon dioxide injection method, the target water temperature in step S30 is within the temperature range when carbon dioxide is in the liquid state, step S40 also includes controlling the circulating water bath 60 through the data acquisition and control system 80 to raise the water temperature in the water bath 50 to the temperature range when carbon dioxide is in the supercritical state, and simultaneously turning on the temperature controller 73 and controlling the temperature controller 73 through the data acquisition and control system 80 to raise the pipe temperature of the insulation pipe 40 to the temperature range when carbon dioxide is in the liquid state.

[0122] If the injection method selected in step S20 is the liquid injection method of carbon dioxide, then in step S40, the target pipe temperature is set to be in the temperature range when carbon dioxide is in liquid state, and the target pressure is set to be in the pressure range when carbon dioxide is in liquid state, so as to ensure that the carbon dioxide injected into the target container 200 is in liquid state.

[0123] If the injection method selected in step S20 is the gaseous injection method of methane, then in step S40, based on the phase diagram of methane at different temperatures and pressures, the target pipe temperature can be set to a temperature range where the methane phase is gaseous, and the initial pressure can be set to a pressure range where the methane phase is gaseous, to ensure that the methane injected into the target container 200 is in a gaseous state.

[0124] If the injection method selected in step S20 is the gaseous injection method of hydrogen, then in step S40, based on the phase diagram of hydrogen at different temperatures and pressures, the target pipe temperature can be set to a temperature range where the hydrogen phase is gaseous, and the target pressure can be set to a pressure range where the hydrogen phase is gaseous, to ensure that the hydrogen injected into the target container 200 is in a gaseous state.

[0125] It should be noted that the existing multiphase carbon dioxide injection and production devices are mostly concentrated on the injection devices and processes of supercritical carbon dioxide at the core and reservoir scale. However, for micro-devices such as microfluidic chips and micro differential scanning calorimeters, uncontrollable carbon dioxide injection problems occur due to volume changes such as switching valves. In the injection system of the embodiment of the present application, the piston container is combined with a plunger pump to enlarge the volume of the equipment, effectively solving the uncontrollable problems of carbon dioxide injection caused by pipelines, back pressure valve volumes, etc. At the same time, in the injection system and injection method of the embodiment of the present application, the volume of the target container in the injection system and the total volume of the top space of the piston container are changed by changing the real-time water injection rate of the plunger pump to the bottom space of the piston container to increase and reduce pressure, and the temperature of carbon dioxide injection is automatically controlled by a circulating water bath and an insulation tube, thereby changing the phase state of carbon dioxide, which is conducive to realizing multiphase carbon dioxide conversion and high-precision, low-rate injection in micro-devices. In addition, in the injection system of the embodiment of the present application, the camera and the visualization window can monitor the phase state of carbon dioxide in real time. At the same time, the piston container greatly increases the pore volume of the micro-device, and when combined with a plunger pump, it can control the injection of multiphase carbon dioxide with high precision and low rate.

[0126] In summary, the injection system and injection method of the embodiment of the present application can automatically control the temperature and pressure conditions to achieve the control and visual identification of the multiphase state of carbon dioxide, and can realize the injection control of high-precision and low-rate carbon dioxide in trace equipment (milliliter level). Therefore, the injection system and injection method of the embodiment of the present application can be used for the injection of liquid carbon dioxide and supercritical carbon dioxide in the front end of high-precision test instruments and microfluidic chips, for carbon dioxide replacement of methane hydrate mining, relative permeability testing, and can also be used in submarine carbon dioxide hydrate storage technology. In addition, the injection system and injection method of the embodiment of the present application can also be further applied to high-precision constant-rate injection and drainage of gases such as methane and hydrogen in trace equipment.

[0127] The advantages of the injection system and injection method according to the embodiment of the present application are described in more detail below:

[0128] First, industrial camera phase recognition technology: using industrial cameras in conjunction with visualization windows to capture the phase changes of carbon dioxide at different pressures and temperatures, and using image processing technology to identify its current phase (such as gas, liquid, supercritical, etc.) in real time, providing data for the data acquisition and control system to iteratively calculate the real-time injection rate of the plunger pump to achieve gas state control.

[0129] Second, a fully automatic temperature / pressure control program: Based on the phase state provided by the industrial camera and visualization window, the temperature and pressure of the injection system are automatically adjusted through advanced algorithms, the gas compressibility factor under different phases is automatically calculated, and the real-time injection rate of the plunger pump is iteratively calculated to maintain the carbon dioxide in a specific phase or achieve an orderly phase transition and a constant rate of carbon dioxide injection.

[0130] Third, injection flow and pressure control mechanism: By precisely controlling the injection flow and pressure of carbon dioxide to adapt to different usage requirements (including micro-equipment (milliliter level) and ordinary equipment) and environmental conditions, the stability and efficiency of the injection process are ensured.

[0131] Fourth, closed-loop feedback and automatic adjustment system: establish a closed-loop feedback mechanism to automatically adjust the injection parameters (including real-time injection rate, temperature, etc.) according to the real-time data during the injection process (such as flow, pressure, temperature, etc.) to ensure the optimization of the injection process.

[0132] Fifth, integrated design of phase identification and control: Design the phase identification and injection control system as an integrated device to simplify the operating process and improve the overall efficiency and reliability of the system.

[0133] Sixth, temperature sensor and pressure sensor network: deploy a series of temperature sensors (including at least the first temperature sensor and the second temperature sensor) and pressure sensors to obtain accurate temperature and pressure data, providing real-time and accurate input for the data acquisition and control system.

[0134] Seventh, intelligent algorithms optimize injection parameters: Based on the collected temperature and pressure data and visual images, an iterative calculation method is used to continuously optimize the injection parameters based on historical and real-time data to achieve more accurate phase control and transformation.

[0135] Eighth, optimization of multi-phase conversion efficiency: Through fine-tuning technology, the efficiency of carbon dioxide conversion between different phases is optimized, energy loss is reduced, and the energy efficiency ratio of the entire injection system is improved.

[0136] Ninth, safety protection mechanism: Establish multiple safety protection measures, such as overpressure protection and overtemperature protection, to ensure the safe and stable operation of the injection system under abnormal conditions.

[0137] Tenth, scalable and customizable system design: Taking into account the different needs of different industries and research fields for carbon dioxide phase control, the system is designed to be scalable and customizable (including piston container volume and plunger pump maximum pressure), and can adjust the configuration according to the specific needs of users.

[0138] In summary, the injection system and method of the embodiments of the present application, by integrating industrial camera technology, automatic temperature / pressure regulation, injection flow pressure control, and an advanced feedback regulation system, provide an efficient, reliable, and intelligent solution for multiphase identification and temperature-controlled injection of carbon dioxide. Furthermore, the injection system and method of the embodiments of the present application can also be further applied to the high-precision, constant-rate injection and extraction of gases such as methane and hydrogen in trace equipment.

[0139] The above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent replacements of the technical solutions of the present application should not depart from the spirit and scope of the technical solutions of the present application.

Claims

1. An injection system, characterized in that: The injection system is used to inject a target object of a preset phase into a target container, wherein the target object is one of carbon dioxide, methane or hydrogen. The injection system includes: a gas supply device for providing the target object in a gaseous state; A piston container, comprising a cavity and a piston located in the cavity, wherein the piston divides the cavity into a top space and a bottom space, wherein the top space is connected to the air supply device; a plunger pump connected to the bottom space; an insulation pipe connected to the head space and the target container respectively; a water bath for accommodating the piston container; a circulating water bath connected to the water bath; a first temperature sensor, configured to detect the real-time water temperature of the water bath; A second temperature sensor is used to detect the real-time temperature of the insulation pipe; A temperature controller connected to the insulation tube; A pressure sensor, used to detect the real-time pressure of the insulation pipe; and A data acquisition and control system is respectively connected to the plunger pump, the first temperature sensor, the circulating water bath, the second temperature sensor, the temperature controller, the insulation tube and the pressure sensor. The data acquisition and control system is used to collect the real-time water temperature, the real-time tube temperature and the real-time pressure, and is used to maintain the water temperature in the water bath at the target water temperature by controlling the circulating water bath, maintain the tube temperature of the insulation tube at the target tube temperature by controlling the temperature controller, and is used to iteratively calculate and automatically control the real-time liquid injection rate of the plunger pump into the bottom space when the piston container injects the target object of the preset phase into the target container at a preset pressurization rate.

2. The injection system according to claim 1, wherein The insulation tube includes a visualization window, and the injection system also includes a camera. The camera is used to record the real-time image of the target object in the insulation tube through the visualization window during the process of injecting the target object into the target container. The data acquisition and control system is also connected to the camera and is used to collect the real-time image and identify the phase state of the target object in the insulation tube in real time.

3. The injection system according to claim 2, wherein: The gas supply device includes a gas cylinder, a pipeline connected to the gas cylinder and the insulation pipe, and a first valve provided on the pipeline; The insulation pipe includes a first branch pipe and a second branch pipe; The first branch pipe includes a first end and a second end opposite to each other, the first end being connected to the head space; The second branch pipe includes a third end and a fourth end opposite to each other, and the fourth end is used to connect to the target container; The injection system also includes a four-way pipe and a second valve, the four output ports of the four-way pipe are respectively connected to the pipeline, the pressure sensor, the second end and the fourth end, the second valve is arranged on the second branch pipe, and the visualization window is located between the four-way pipe and the second valve.

4. The injection system according to claim 3, characterized in that The injection system further comprises a three-way pipe and a drain valve, wherein the three output ports of the three-way pipe are respectively connected to the plunger pump, the bottom space and the drain valve.

5. The injection system according to any one of claims 2 to 4, characterized in that The data acquisition and control system is a computer; or, the data acquisition and control system includes a computer and a data acquisition instrument connected to the computer, and the data acquisition instrument is connected to at least one of the pressure sensor, the first temperature sensor, the second temperature sensor, and the camera.

6. An injection method, characterized in that: The injection method is implemented using the injection system according to any one of claims 1 to 5, and the injection method includes: Initial preparation: clearing the liquid from the bottom space and clearing the air from the head space; Select the injection method: when the target substance is carbon dioxide, the injection method is any one of gaseous injection, gaseous-to-supercritical injection, supercritical injection, and liquid injection; when the target substance is methane or hydrogen, the injection method is gaseous injection; The first step of injection is to control the water temperature in the water bath to maintain the target water temperature, and inject the target into the head space through the gas supply device so that the pressure in the head space reaches the initial pressure; wherein, in the gaseous injection method and the gas-to-supercritical injection method, the target in the head space is in a gaseous state, and in the supercritical injection method and the liquid injection method, the target in the head space is in a liquid state; and The second step is injection: connecting the target container to the insulation tube, controlling the tube temperature of the insulation tube to the target tube temperature, calculating the real-time injection rate under the preset pressurization rate according to the initial pressure, the volume of the piston container, the volume of the target container and the real-time pressure of the target container, and causing the plunger pump to inject liquid into the bottom space at the real-time injection rate until the pressure of the target container reaches the target pressure; wherein, in the gaseous injection method, the gas-to-supercritical injection method, the supercritical injection method and the liquid injection method, the target object is injected into the target container in the form of gas, gas-to-supercritical, supercritical and liquid, respectively.

7. The injection method according to claim 6, wherein: The second step of injection further includes: after the pressure of the target container reaches the target pressure, changing the plunger pump to a constant pressure mode.

8. The injection method according to claim 6, wherein: In the case where the injection system further includes the tee pipe and the drain valve, the initial preparation includes: Close the second valve, open the first valve, and inject the gaseous target in the gas supply device into the top space to a preset pressure, which is greater than one standard atmospheric pressure; then close the first valve and open the drain valve to discharge the liquid in the bottom space; then close the drain valve and open the second valve to deflate to one standard atmospheric pressure to clear the air in the top space; then close the second valve.

9. The injection method according to claim 6, wherein: In the case where the injection system further includes a camera, the injection method further includes: during the first injection step and the second injection step, observing the phase change of the target object in the insulation tube in real time through the camera and the visualization window.

10. The injection method according to any one of claims 6 to 9, characterized in that: The relationship between the preset boost rate and the real-time injection rate satisfies: Among them, V P The preset boost rate; V L is the real-time injection rate; P0 is the initial pressure; Z0 is the gas compressibility factor when the pressure of the target container is the initial pressure P0, and Z0 is calculated by the data acquisition and control system based on the initial pressure P0 and the real-time water temperature of the water bath at the initial pressure P0 by introducing the Peng-Robinson equation; Z2 is the gas compressibility factor when the pressure of the target container is the target pressure P2, and Z2 is calculated by the data acquisition and control system based on the target pressure P2 and the real-time water temperature of the water bath at the target pressure P2 by introducing the Peng-Robinson equation; t is the time taken for the pressure of the target container to increase from the initial pressure to the real-time pressure during the second injection step; V1 is the sum of the volumes of the head space of the piston container, the insulation tube, and the target container; V0 is the sum of the volume of the top space of the piston container and the volume of the insulation tube.

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