A supercritical CO2 rapid preparation device and method with intelligent pressure regulation

Abstract

The present invention belongs to the technical field of supercritical CO2 preparation, and specifically relates to a device and method for rapid supercritical CO2 preparation with intelligent pressure regulation. The device includes: a gas cylinder; a supercritical CO2 generation unit, including a condensation storage tank, a condenser, a gas booster pump, an information processing system, a double-cylinder plunger pump, and a balance buffer container. The output end of the condenser is connected to the condensation storage tank, the input end of the gas booster pump is connected to the outlet of the gas cylinder, and the output end is connected to the input port of the condensation storage tank. The gas booster pump is provided with a booster pump control valve. The information processing system is used to monitor the pressure and temperature inside the condensation storage tank in real time, and compare it with the input preset value in real time to regulate the pressure inside the condensation storage tank and cooperate with the condenser to achieve CO2 liquefaction. The double-cylinder plunger pump is connected in series between the condensation storage tank and the balance buffer container. This device puts the CO2 phase change conditions in a dynamic stable state, thereby improving the efficiency of supercritical CO2 preparation.

Description

Technical Field

[0001] The present invention belongs to the technical field of supercritical CO2 preparation, and in particular relates to a device and method for rapidly preparing supercritical CO2 with intelligent pressure regulation. Background Art

[0002] Supercritical carbon dioxide (scCO2) has important application value in the fields of energy, chemical engineering, materials science, and environmental protection due to its unique physicochemical properties (such as strong diffusivity, low viscosity, and near-zero surface tension). It has attracted particular attention in Brayton cycle power generation, efficient extraction, and precision material preparation. However, the stable preparation of scCO2 is highly dependent on the precise coordinated control of system pressure and temperature, among which the stable control of pressure directly affects the phase change efficiency and equipment operation safety. Due to the strong compressibility of gas, the pressure of liquid is easier to stably control than that of gas. Therefore, in the process of preparing scCO2 in the laboratory, it is often necessary to liquefy CO2 first, and then increase the pressure and temperature to cause it to transition to a supercritical state (the critical point of phase transition is 31.04°C, 7.38MPa).

[0003] Traditional laboratory scCO2 preparation devices often have the following deficiencies: First, the liquefaction of CO2 often directly condenses it into a liquid state through low-temperature condensation under low-pressure conditions, or relies on high-pressure liquefaction only under normal temperature conditions, causing the booster pump to be running for a long time, resulting in energy waste; second, the adjustment of the boost pressure is mostly through manual control, and the control accuracy is difficult to ensure, which can easily lead to pressure overshoot, causing the critical conditions of phase change to shift, resulting in insufficient phase change, and high manual overtime costs. Due to the above-mentioned defects and deficiencies, the supercritical CO2 preparation efficiency of traditional preparation devices is low, and it is difficult to meet the nonlinear and strongly coupled dynamic control requirements of the CO2 liquefaction and supercritical phase change process. Frequent high-pressure fluctuations may also cause equipment seal failure or fatigue damage. Therefore, there is an urgent need for a supercritical CO2 rapid preparation device and method with intelligent pressure regulation. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a supercritical CO2 rapid preparation device and method with intelligent pressure regulation, which can realize the nonlinear and strongly coupled dynamic control requirements in the process of CO2 liquefaction and then supercritical phase change, so that the CO2 phase change conditions are in a dynamically stable state, thereby improving the efficiency of supercritical CO2 preparation and ensuring the safe operation of the equipment.

[0005] The technical solution of the present invention is:

[0006] A supercritical CO2 rapid production device with intelligent pressure regulation includes a gas cylinder and a supercritical CO2 generation unit. The gas cylinder is used to store a CO2 gas source. The supercritical CO2 generation unit includes:

[0007] The condensation storage tank is connected to the gas cylinder and is used to receive CO2 and liquefy the CO2 through pressurization and cooling treatment;

[0008] The double-cylinder plunger pump and the balancing buffer container are connected between the condensate storage tank and the balancing buffer container. The double-cylinder plunger pump is used to pump the liquefied CO2 in the condensate storage tank to the balancing buffer container and pressurize the liquefied CO2 during the pumping process. The balancing buffer container is used to realize the transformation of the liquefied CO2 into supercritical CO2 through temperature increase treatment;

[0009] A gas booster pump is connected between the gas cylinder and the condensate storage tank to boost the pressure of the CO2 entering the condensate storage tank;

[0010] The condenser, whose output ends are respectively connected to the condensation storage tank and the double-cylinder plunger pump, is used to cool the CO2 in the condensation storage tank and the double-cylinder plunger pump;

[0011] A temperature regulator is connected to the balancing buffer container and is used to control the temperature of the balancing buffer container;

[0012] The intelligent pressure and temperature regulation component includes an information acquisition module and an information processing system. The information acquisition module is used to collect the internal pressure and temperature of the condensation storage tank and the balancing buffer container in real time and transmit them to the information processing system. The information processing system is used to compare the acquired pressure and temperature with the input preset values, and control the gas booster pump and the double-cylinder plunger pump to regulate the internal pressure of the condensation storage tank and the balancing buffer container respectively according to the pressure comparison information, and control the condenser and the temperature regulator to regulate the internal temperature of the condensation storage tank, the double-cylinder plunger pump and the balancing buffer container respectively according to the temperature comparison information.

[0013] Preferably, the input end of the double-cylinder plunger pump is connected to the output port of the condensation storage tank through an input pipe, and the output end of the double-cylinder plunger pump is connected to the input port of the balance buffer container through an output pipe. Pipe insulation components are provided on the input pipe and the output pipe, and the pipe insulation components are used to insulate the input pipe and the output pipe.

[0014] Preferably, the information acquisition module includes a first temperature transmitter and a second pressure transmitter connected to the condensation storage tank, the first temperature transmitter is used to monitor the temperature in the condensation storage tank in real time, and the second pressure transmitter is used to monitor the pressure in the condensation storage tank in real time.

[0015] Preferably, a pressure regulating valve and a first pressure transmitter are sequentially arranged between the gas cylinder and the gas booster pump, the pressure regulating valve is used to control the outflow speed and pressure of the gas in the gas cylinder, and the first pressure transmitter is electrically connected to the information processing system for real-time monitoring of the pressure value of the gas source at the inlet end of the gas booster pump.

[0016] Preferably, the information acquisition module also includes a third pressure transmitter and a second temperature transmitter connected to the balancing buffer container, and the third pressure transmitter and the second temperature transmitter are both electrically connected to the information processing system. The third pressure transmitter is used to monitor the pressure in the balancing buffer container in real time, and the second temperature transmitter is used to monitor the temperature in the balancing buffer container in real time.

[0017] Preferably, the input end of the gas booster pump is provided with an inlet one-way valve, and the output end is provided with an outlet one-way valve.

[0018] Preferably, the input port and the output port of the condensation storage tank and the input port and the output port of the balancing buffer container are all provided with stop valves.

[0019] Preferably, according to the above-mentioned intelligent pressure-regulated supercritical CO2 rapid production device, the method for preparing supercritical CO2 includes the following steps:

[0020] S1. Start the condenser to pre-cool the condensate storage tank and the double-cylinder plunger pump, so that the internal temperature of the condensate storage tank and the internal cavity temperature of the double-cylinder plunger pump reach the low temperature required for CO2 liquefaction; start the temperature regulator to increase the internal temperature of the equilibrium buffer container, so that the internal temperature of the equilibrium buffer container reaches the high temperature required for CO2 to transition from liquefaction to a supercritical state;

[0021] S2, control the gas cylinder to release CO2, which is pressurized by the gas booster pump and enters the condensation storage tank, and the condenser provides low temperature conditions inside the condensation storage tank to achieve the liquefaction of CO2;

[0022] S3. When the pressure and temperature in the condensation tank are stable, start the double-cylinder plunger pump to suck the liquid CO2 in the condensation tank. Adjust the pressure of the double-cylinder plunger pump to be greater than the critical pressure for CO2 to transform into a supercritical state. Pump the liquefied CO2 into the equilibrium buffer container. By coordinating with the internal temperature of the equilibrium buffer container, the CO2 is transformed from a liquid state to a supercritical state.

[0023] S4. Use the information acquisition module to collect the internal pressure and temperature of the condensation storage tank and the balance buffer container in real time, and transmit them to the information processing system. The information processing system compares the obtained pressure and temperature with the input preset values, and controls the gas booster pump and the double-cylinder plunger pump to regulate the internal pressure of the condensation storage tank and the balance buffer container respectively according to the pressure comparison information, and controls the condenser and the temperature regulator to regulate the internal temperature of the condensation storage tank, the double-cylinder plunger pump and the balance buffer container respectively according to the temperature comparison information, so that the CO2 phase change conditions in the device are in a dynamic stable state, so as to realize the continuous preparation of supercritical CO2.

[0024] Compared with the prior art, the intelligent pressure-regulated supercritical CO2 rapid production device and method of the present invention has the following beneficial effects:

[0025] This device uses intelligent pressure and temperature regulating components to realize intelligent boost control of "overpressure protection pump shutdown and low-pressure self-start compensation", thereby reducing boost energy loss. It adopts a double-cylinder plunger pump to realize the alternating operation mechanism of "main pump liquid supply-auxiliary pump backfill", promotes the operation demand of stable automatic liquid supply, and through low-temperature pre-cooling of the condensation storage tank and the double-cylinder plunger pump, it can effectively realize the nonlinear and strongly coupled dynamic control requirements of the CO2 liquefaction and then supercritical phase change process, avoids the problem of critical point offset in the supercritical CO2 generation process, and makes the CO2 phase change conditions in a dynamically stable state, thereby improving the efficiency of supercritical CO2 preparation, saving energy and labor costs, and extending the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a supercritical CO2 rapid production device with intelligent pressure regulation in an embodiment of the present invention.

[0027] Description of reference numerals:

[0028] 1. Gas cylinder, 2. Pressure regulating valve, 3. First pressure transmitter, 4. Gas booster pump, 401. Booster pump control valve, 402. Inlet check valve, 403. Outlet check valve, 5. PLC communication module, 6. First stop valve, 7. Condensate storage tank, 8. First temperature transmitter, 9. Second pressure transmitter, 10. Condenser, 11. Second stop valve, 12. Pipeline insulation assembly, 111. Input pipe, 13. Double-cylinder plunger pump, 14. Third stop valve, 141. Output pipe, 15. Balance buffer container, 16. Temperature regulator, 17. Third pressure transmitter, 18. Second temperature transmitter, 19. Fourth stop valve, 191. Delivery pipe, 20. Information processing system, 21. Core clamping equipment. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0031] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] See also Figure 1 As shown, in order to realize the nonlinear and strongly coupled dynamic control requirements in the process of CO2 liquefaction first and then supercritical phase change, the CO2 phase change conditions are in a dynamic stable state, the efficiency of supercritical CO2 preparation is improved, and energy and labor costs are saved. This embodiment provides a supercritical CO2 rapid preparation device and method with intelligent pressure regulation, including a gas cylinder 1 and a supercritical CO2 generation unit, and the supercritical CO2 generation unit includes a condensation component, a gas booster pump 4, a temperature regulator 16, an intelligent pressure and temperature regulation component, a double-cylinder plunger pump 13 and a balance buffer container 15. The condensation component includes a condensation storage tank 7 and a condenser 10. The intelligent pressure and temperature regulation component includes an information acquisition module and an information processing system 20.

[0033] The gas cylinder 1 is used to store the CO2 gas source. The input end of the gas booster pump 4 is connected to the outlet of the gas cylinder 1, and the output end is connected to the input port of the condensation storage tank 7. The gas booster pump 4 is provided with a booster pump control valve 401. The output end of the condenser 10 is respectively connected to the condensation storage tank 7 and the double-cylinder plunger pump 13, which is used to realize the cooling treatment of the inside of the condensation storage tank 7 and the double-cylinder plunger pump 13, so that the internal temperature of the condensation storage tank 7 and the double-cylinder plunger pump 13 is maintained at the liquefaction temperature of CO2. The input end of the double-cylinder plunger pump 13 is connected to the output port of the condensate storage tank 7, and the output end is connected to the input port of the balancing buffer container 15. The double-cylinder plunger pump 13 is used to pump the liquefied CO2 in the condensate storage tank 7 to the balancing buffer container 15 and pressurize the liquefied CO2 during the pumping process. The balancing buffer container 15 is connected to the temperature regulator 16, and the temperature regulator 16 increases the temperature inside the balancing buffer container 15 to achieve the conversion of liquefied CO2 into supercritical CO2. At the same time, the balancing buffer container 15 further stores supercritical CO2 to balance and buffer the fluid pressure in the device. The information processing system 20 adopts PLC programmable control, which includes a processing center, a control module and a PLC communication module 5. The internal pressure and temperature of the condensation storage tank 7 and the balancing buffer container 15 are monitored in real time through the information acquisition module, and are transmitted to the processing center in real time through the interaction of the PLC communication module 5. The processing center is used to process, record and store the monitored pressure and temperature information in real time, and compare the pressure information and temperature information with the preset values. The control module is connected to the booster pump control valve 401, the condenser 10, the double-cylinder plunger pump 13 and the temperature regulator 16, and is used to control the booster pump control valve 401 and the double-cylinder plunger pump 13 to regulate the internal pressure of the condensation storage tank 7 and the balancing buffer container 15 according to the pressure comparison information, and control the condenser 10 and the temperature regulator 16 to regulate the internal temperature of the condensation storage tank 7, the double-cylinder plunger pump 13 and the balancing buffer container 15 according to the temperature comparison information, so that the CO2 phase change conditions in the device are in a dynamic stable state, so as to realize the continuous preparation of supercritical CO2.

[0034] When preparing supercritical CO2, the condenser 10 is used to adjust the cavity temperature of the condensation storage tank 7 and the double-cylinder plunger pump 13, so that the internal temperature of the condensation storage tank 7 and the internal cavity temperature of the double-cylinder plunger pump 13 reach the low temperature required for CO2 liquefaction, and the internal temperature of the equilibrium buffer container 15 is adjusted by the temperature regulator 16 to reach the high temperature at which the liquefied CO2 can be converted into a supercritical state. In the process of the condenser 10 adjusting the internal temperature of the condensation storage tank 7, the information acquisition module detects the temperature inside the condensation storage tank 7 in real time and transmits it to the information processing system through the PLC communication module 5. The information processing system 20 compares the preset temperature required for CO2 liquefaction with the real-time temperature, and controls the start and stop of the condenser 10 through the control module based on the feedback of the comparison information, to ensure that the temperature inside the condensation storage tank 7 reaches the low temperature required for CO2 liquefaction. After the temperature at each location is stabilized, the gas cylinder 1 is controlled to release CO2, and CO2 enters the condensation storage tank 7 through the gas booster pump 4. The pressure and temperature inside the condensation storage tank 7 are monitored in real time using the information acquisition module, and the pressure and temperature information obtained are transmitted to the processing center of the information processing system 20 through the PLC communication module 5 in real time to compare with the preset pressure and temperature values. Then, based on the feedback information from the processing center, the control module of the information processing system 20 drives the booster pump control valve 401 to automatically control the start and stop of the gas booster pump 4, and dynamically controls the condenser 10. Adjust the internal temperature of the condensation storage tank 7 and the double-cylinder plunger pump 13 to ensure that the internal temperature and pressure of the condensation storage tank 7 meet the liquefaction conditions of CO2, thereby realizing the liquefaction of CO2 through the low temperature and high pressure conditions inside the condensation storage tank 7, and then use the double-cylinder plunger pump 13 to suck the liquid CO2 in the condensation storage tank 7, adjust the pressure of the double-cylinder plunger pump 13 to be greater than the critical pressure for CO2 to transform into a supercritical state, and pump the liquefied CO2 into the balancing buffer container 15. By coordinating with the internal temperature of the balancing buffer container 15, the CO2 is transformed from a liquid state to a supercritical state. In addition, the information collection module will also collect the internal temperature and pressure of the balancing buffer container 15 at the same time, transmit it to the processing center through the interaction of the PLC communication module 5, compare the pressure information and temperature information with the preset value, and use the control module to realize the dynamic adjustment of the internal temperature and pressure of the balancing buffer container 15 through the temperature regulator 16 and the double-cylinder plunger pump 13 to realize the continuous preparation of supercritical CO2.

[0035] Therefore, this device uses intelligent pressure and temperature regulating components to realize intelligent boost control of "overpressure protection pump shutdown and low-pressure self-start compensation", thereby reducing boost energy loss, and adopts a double-cylinder plunger pump 13 to realize the alternating operation mechanism of "main pump liquid supply-auxiliary pump backfill", promoting the operation demand of stable automatic liquid supply, and through low-temperature pre-cooling of the condensation storage tank 7 and the double-cylinder plunger pump 13, it can effectively realize the nonlinear and strongly coupled dynamic control requirements of the CO2 liquefaction and then supercritical phase change process, avoiding the problem of critical point offset in the supercritical CO2 generation process, making the CO2 phase change conditions in a dynamically stable state, improving the efficiency of supercritical CO2 preparation, saving energy and labor costs, and extending the service life of the equipment.

[0036] See also Figure 1 As shown, further, the double-cylinder plunger pump 13 is electrically connected to the information processing system 20 to realize program control and real-time transmission, recording and storage of operating data such as pressure, flow, volume, etc. The input end of the double-cylinder plunger pump 13 is connected to the output port of the condensation storage tank 7 through the input pipe 111, and the output end of the double-cylinder plunger pump 13 is connected to the input port of the balance buffer container 15 through the output pipe 141. The input pipe 111 and the output pipe 141 are both provided with a pipeline insulation component 12, so that the pipeline insulation component 12 can be used to insulate the input pipe 111 and the output pipe 141, reducing the heat exchange of CO2 during pipeline transportation. In addition, corresponding pipeline insulation components 12 are also provided on other pipelines in the device according to experimental requirements. It is preferred that the pipeline insulation component 12 includes a pipeline insulation sleeve, etc.

[0037] See also Figure 1 As shown, further, the information acquisition module includes a first temperature transmitter 8 and a second pressure transmitter 9 connected to the condensate storage tank 7, the first temperature transmitter 8 is used to monitor the temperature in the condensate storage tank 7 in real time, and the second pressure transmitter 9 is used to monitor the pressure in the condensate storage tank 7 in real time. The pressure information collected by the second pressure transmitter 9 is exchanged with the processing center in real time through the PLC communication module 5, and according to the comparison information fed back by the processing center, the control module is used to automatically control the booster pump control valve 401 to realize the start and stop of the gas booster pump 4, so as to realize intelligent regulation of the internal pressure of the condensate storage tank 7.

[0038] See also Figure 1 As shown, in order to achieve the conversion of liquefied CO2 to a supercritical state in the balancing buffer container 15, the balancing buffer container 15 is connected to a temperature regulator 16, which is used to regulate the temperature of the balancing buffer container 15. The temperature regulator 16 is also electrically connected to the information processing system 20 to facilitate automatic control.

[0039] See also Figure 1As shown, further, a pressure regulating valve 2 and a first pressure transmitter 3 are sequentially arranged between the gas cylinder 1 and the gas booster pump 4. The pressure regulating valve 2 is used to control the outflow speed and pressure of the gas in the gas cylinder 1. The first pressure transmitter 3 is electrically connected to the information acquisition module for real-time monitoring of the pressure value of the gas source at the inlet end of the gas booster pump 4.

[0040] See also Figure 1 As shown, further, in order to facilitate the pre-cooling treatment of the double-cylinder plunger pump 13, the output end of the condenser 10 is also connected to the double-cylinder plunger pump 13, so as to realize the cooling of the cavity of the double-cylinder plunger pump 13, that is, to realize the pre-cooling treatment in a synchronous state with the condensation storage tank 7, so as to facilitate the maintenance of the liquefied state of CO2 during the transmission process.

[0041] See also Figure 1 As shown, further, the information acquisition module also includes a third pressure transmitter 17 and a second temperature transmitter 18 connected to the balance buffer container 15, and the third pressure transmitter 17 and the second temperature transmitter 18 are electrically connected to the information acquisition module. The information acquisition module interacts with the information processing system 20 through the PLC communication module 5 to realize real-time monitoring of the pressure and temperature in the balance buffer container 15, so as to maintain the pressure and temperature inside the balance buffer container 15 by adjusting the output pressure of the double-cylinder plunger pump 13 and the temperature regulator 16 to maintain the pressure and temperature conditions required for CO2 to be converted into a supercritical state, thereby avoiding the critical point offset in the supercritical CO2 generation process.

[0042] See also Figure 1 As shown, the gas booster pump 4 is further provided with a check valve at its input and output. Specifically, an inlet check valve 402 is provided at the input of the gas booster pump 4 to prevent gas from flowing back toward the gas source, and an outlet check valve 403 is provided at the output of the gas booster pump to prevent high-pressure gas at the outlet from flowing back into the gas booster pump 4, thereby protecting the internal components of the booster pump.

[0043] See also Figure 1 As shown, shutoff valves are further provided at the input and output ports of the condensate storage tank 7 and the input and output ports of the balancing buffer container 15. Specifically, a first shutoff valve 6 is provided at the input port of the condensate storage tank 7, a second shutoff valve 11 is provided on the input pipe 111, a third shutoff valve 14 is provided on the output pipe 141, and a fourth shutoff valve 19 is provided at the output port of the balancing buffer container 15. These shutoff valves are used to control the flow of CO2 in the device and to ensure the safety of the equipment during the experiment.

[0044] The method for preparing supercritical CO2 by the above-mentioned intelligent pressure-regulated supercritical CO2 rapid preparation device includes the following steps:

[0045] S1. Start the condenser 10 to pre-cool the condensate storage tank 7 and the double-cylinder plunger pump 13, so that the internal temperature of the condensate storage tank 7 and the internal cavity temperature of the double-cylinder plunger pump 13 reach the low temperature required for CO2 liquefaction. Start the temperature regulator 16 to increase the internal temperature of the balancing buffer container 15, so that the internal temperature of the balancing buffer container 15 reaches the high temperature required for CO2 to transition from a liquid state to a supercritical state.

[0046] S2. Control the gas cylinder 1 to release CO2. The CO2 is pressurized by the gas booster pump 4 and enters the condensation storage tank 7. The condenser 10 provides a low temperature condition for the inside of the condensation storage tank 7 to realize the liquefaction of CO2.

[0047] S3. When the pressure and temperature in the condensation storage tank 7 are stable, start the double-cylinder plunger pump 13 to suck the liquid CO2 in the condensation storage tank 7, adjust the pressure of the double-cylinder plunger pump 13 to be greater than the critical pressure for CO2 to transform into a supercritical state, and pump the liquefied CO2 into the balancing buffer container 15. By coordinating with the internal temperature of the balancing buffer container 15, the transformation of CO2 from liquid to supercritical state is achieved.

[0048] S4. Use the information acquisition module to collect the internal pressure and temperature of the condensation storage tank 7 and the balance buffer container 15 in real time, and transmit them to the information processing system 20. The information processing system 20 compares the acquired pressure and temperature with the input preset values, and controls the gas booster pump 4 and the double-cylinder plunger pump 13 to regulate the internal pressure of the condensation storage tank 7 and the balance buffer container 15 respectively according to the pressure comparison information, and controls the condenser 10 and the temperature regulator 16 to regulate the internal temperature of the condensation storage tank 7, the double-cylinder plunger pump 13 and the balance buffer container 15 respectively according to the temperature comparison information, so that the CO2 phase change condition in the device is in a dynamic stable state, so as to realize the continuous preparation of supercritical CO2.

[0049] Specifically, when conducting relevant experiments using supercritical CO2 delivered to the core clamping device 21, the core clamping device 21 is connected to one end of the output port of the balance buffer container 15 via a delivery pipe 191, and a pipe insulation component 12 is also provided on the delivery pipe 191. The specific experimental process includes the following steps:

[0050] S1. Process pre-cooling, preheating and insulation: Start the condenser 10 and set the lower temperature value T0 to make the internal cavity space of the condensation storage tank 7 and the double-cylinder plunger pump 13 in a low temperature state in advance, that is, to reach the low temperature required for CO2 liquefaction, start the temperature regulator 16, so that the temperature in the equilibrium buffer container 15 is set to a higher temperature value T1 that can convert CO2 into a supercritical state. It should be noted that T1 is set to be greater than the critical temperature of 31.04°C, such as 35°C. Then install the pipeline insulation assembly 12 on the input pipe 111, output pipe 141 and delivery pipe 191, and ensure that it is working properly.

[0051] S2. Device data acquisition and control: Ensure that all electrical components in the device, such as the first pressure transmitter 3, the second pressure transmitter 9, the third pressure transmitter 17, the first temperature transmitter 8, the second temperature transmitter 18, and the boost pump control valve 401, can work properly. The pressure and temperature data of each part of the device process are collected and recorded in real time through the information acquisition module, and the boost target pressure value P is preset in the processing center of the information processing system 20. t That is, the pressure that can liquefy CO2 under the condition of refrigeration temperature T0, which can be expressed as P t =5MPa, and controls the PLC communication module 5 to feed back the pressure signal collected by the second pressure transmitter 9 to the processing center in real time.

[0052] S3, intelligent pressurization and CO2 liquefaction: open the first stop valve 6, control the pressure regulating valve 2 to make the gas cylinder 1 release CO2, CO2 flows through the first pressure transmitter 3, the gas booster pump 4 and enters the condensate storage tank 7. When the internal pressure P0 of the condensate storage tank 7 is less than the set pressurization target pressure value P t When the pressure in the storage tank increases to the target pressure value P, the information processing system 20 opens the booster pump control valve 401 by controlling the PLC communication module 5, thereby starting the gas booster pump 4 to pressurize the CO2 in the condensation storage tank 7. t When the pressure is equal, the control module will automatically control the boost pump control valve 401 to close, and the gas boost pump 4 will stop boosting. t Under the simultaneous action of low temperature T0, the CO2 in the condensation storage tank 7 rapidly changes phase and liquefies. When the pressure P0 in the condensation storage tank 7 drops to less than the target pressure value P t When the pressure in the condensate tank 7 is 1000 MPa, the control module will automatically control the booster pump control valve 401 to open, and the gas booster pump 4 will start again, so as to realize the intelligent control and regulation of the pressure in the condensate storage tank 7, ensure that the temperature and pressure conditions for CO2 liquefaction are maintained inside the storage tank, and ensure that the condensate storage tank 7 can provide sufficient liquid CO2 for the double-cylinder plunger pump 13.

[0053] S4, supercritical CO2 preparation: wait until the pressure in the condensation tank 7 stabilizes at the target pressure value P t When the double-cylinder plunger pump 13 is started, the liquefied CO2 is absorbed from the bottom of the condensation storage tank 7 through the inlet pipe 111 and the liquefied CO2 is converted to CO2 at a higher pressure value P h The output pipe 141 is pumped from the bottom to the balance buffer container 15. Generally, P h If the pressure is greater than the critical pressure of 7.38 MPa for liquid CO2 to transform into supercritical state, P h =8MPa, wait until the pressure and temperature in the equilibrium buffer container 15 are stable, it is considered that the CO2 in the equilibrium buffer container 15 is transformed from liquid to supercritical state, that is, the phase transition is completed, and the preparation of supercritical CO2 is completed.

[0054] S5. Use of supercritical CO2: Open the fourth stop valve 19 and control the double-cylinder plunger pump 13 to deliver the prepared supercritical CO2 through the delivery pipe 191 to the core clamping device 21 to carry out relevant experiments according to experimental requirements.

[0055] S6. Automatic replenishment of supercritical CO2: As the supercritical CO2 is consumed during the experiment, the double-cylinder plunger pump 13 will automatically backfill and replenish the fluid while maintaining a stable output of the fluid, that is, it will absorb the liquid CO2 in the condensation tank 7. The pressure in the condensation tank 7 will drop as a result. Once it is less than the target pressure value P t , the PLC communication module 5 will automatically control the booster pump control valve 401 to open, start the gas booster pump 4 to pressurize the CO2 fluid in the condensate storage tank 7, and maintain the liquefaction conditions of CO2, thereby providing sufficient liquid CO2 for the double-cylinder plunger pump 13, ensuring that the double-cylinder plunger pump 13 can quickly pump it to the balance buffer container 15 to complete the supercritical CO2 preparation, thereby ensuring that there is a sufficient amount of supercritical CO2 during the experiment.

[0056] The advantages of this device in experimental applications are as follows:

[0057] (1) Coordinated control of refrigeration and pressurization: Breaking through the traditional single phase change mode, the composite technology of "low-temperature pre-cooling-pressurization compression-phase dynamic equilibrium control" is adopted to successfully overcome the difficulty of CO2 liquefaction under laboratory conditions, realize the rapid conversion of CO2 from gas to liquid and then to supercritical state and precise control of phase state throughout the whole process, avoid problems such as critical point offset, and significantly improve the preparation efficiency of supercritical CO2.

[0058] (2) An intelligent boost control method based on an intelligent pressure and temperature regulating component: by arranging a second pressure transmitter 9 to monitor the pressure signal in the condensate storage tank 7 in real time, and interacting with the processing center in real time through a PLC communication module, the processing center compares the obtained real-time pressure signal with the preset value, and automatically controls the opening and closing output of the boost pump control valve 401, that is, the dynamic adjustment of the internal pressure of the condensate storage tank 7 by the gas boost pump 4 is realized, thereby setting the CO2 boost target pressure threshold through a program, and realizing the intelligent boost control of "overpressure protection pump stop, low pressure self-start compensation", thereby achieving the intelligent control goals of reducing boost energy loss, eliminating manual on-duty costs and extending the service life of the equipment.

[0059] (3) Dual-pump coordinated automatic backfilling technology: A dual-cylinder plunger pump 13 is used as a pressure and flow control device in the device, and an alternating operation mechanism of "main pump supplying liquid-auxiliary pump backfilling" is adopted to break through the interruption bottleneck of traditional single pump operation and meet the operation requirements of long-term stable automatic liquid supply.

[0060] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A supercritical CO2 rapid preparation device with intelligent pressure regulation, comprising a gas cylinder (1) and a supercritical CO2 generation unit, wherein the gas cylinder (1) is used to store a CO2 gas source, and is characterized in that: The supercritical CO2 generation unit includes: A condensation storage tank (7) is connected to the gas cylinder (1) and is used to receive CO2 and liquefy the CO2 through pressurization and temperature reduction treatment; A double-cylinder plunger pump (13) and a balancing buffer container (15), wherein the double-cylinder plunger pump (13) is connected between the condensation storage tank (7) and the balancing buffer container (15), and is used to pump the liquefied CO2 in the condensation storage tank (7) to the balancing buffer container (15), and to increase the pressure of the liquefied CO2 during the pumping process. The balancing buffer container (15) is used to realize the conversion of the liquefied CO2 into supercritical CO2 through a temperature increase process; A gas booster pump (4) is connected between the gas cylinder (1) and the condensation storage tank (7) and is used to boost the pressure of CO2 entering the condensation storage tank (7); The condenser (10) has an output end connected to the condensation storage tank (7) and the double-cylinder plunger pump (13) respectively, and is used to cool the CO2 in the condensation storage tank (7) and the double-cylinder plunger pump (13); a temperature regulator (16), connected to the balancing buffer container (15), for regulating the temperature of the balancing buffer container (15); An intelligent pressure and temperature regulating component comprises an information acquisition module and an information processing system (20), wherein the information acquisition module is used to acquire the internal pressure and temperature of the condensation storage tank (7) and the balancing buffer container (15) in real time and transmit the information to the information processing system (20), and the information processing system (20) is used to compare the acquired pressure and temperature with the input preset values, and control the gas booster pump (4) and the double-cylinder plunger pump (13) to regulate the internal pressure of the condensation storage tank (7) and the balancing buffer container (15) respectively according to the pressure comparison information, and control the condenser (10) and the temperature regulator (16) to regulate the internal temperature of the condensation storage tank (7), the double-cylinder plunger pump (13) and the balancing buffer container (15) respectively according to the temperature comparison information.

2. The intelligent pressure-regulated supercritical CO2 rapid production device according to claim 1 is characterized in that: The input end of the double-cylinder plunger pump (13) is communicated with the output port of the condensation storage tank (7) via an input pipe (111), and the output end of the double-cylinder plunger pump (13) is communicated with the input port of the balancing buffer container (15) via an output pipe (141). Both the input pipe (111) and the output pipe (141) are provided with a pipe insulation component (12), and the pipe insulation component (12) is used to insulate the input pipe (111) and the output pipe (141).

3. The intelligent pressure-regulated supercritical CO2 rapid production device according to claim 1 is characterized in that: The information acquisition module comprises a first temperature transmitter (8) and a second pressure transmitter (9) connected to the condensation storage tank (7), wherein the first temperature transmitter (8) is used to monitor the temperature in the condensation storage tank (7) in real time, and the second pressure transmitter (9) is used to monitor the pressure in the condensation storage tank (7) in real time.

4. The intelligent pressure-regulated supercritical CO2 rapid production device according to claim 1 is characterized in that: A pressure regulating valve (2) and a first pressure transmitter (3) are sequentially arranged between the gas cylinder (1) and the gas booster pump (4). The pressure regulating valve (2) is used to control the outflow speed and pressure of the gas in the gas cylinder (1). The first pressure transmitter (3) is electrically connected to the information processing system (20) and is used to monitor the pressure value of the gas source at the inlet end of the gas booster pump (4) in real time.

5. The intelligent pressure-regulated supercritical CO2 rapid production device according to claim 3 is characterized in that: The information acquisition module further includes a third pressure transmitter (17) and a second temperature transmitter (18) connected to the balancing buffer container (15), wherein the third pressure transmitter (17) is used to monitor the pressure in the balancing buffer container (15) in real time, and the second temperature transmitter (18) is used to monitor the temperature in the balancing buffer container (15) in real time.

6. The intelligent pressure-regulated supercritical CO2 rapid production device according to claim 1 is characterized in that: The input end of the gas booster pump (4) is provided with an inlet one-way valve (402), and the output end is provided with an outlet one-way valve (403).

7. The intelligent pressure-regulated supercritical CO2 rapid production device according to claim 2, characterized in that: The input port and the output port of the condensation storage tank (7) and the input port and the output port of the balancing buffer container (15) are all provided with stop valves.

8. The method for preparing a supercritical CO2 rapid production device with intelligent pressure regulation according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, start the condenser (10) to pre-cool the condensate storage tank (7) and the double-cylinder plunger pump (13), so that the internal temperature of the condensate storage tank (7) and the internal cavity temperature of the double-cylinder plunger pump (13) reach the low temperature required for CO2 liquefaction; start the temperature regulator (16) to increase the internal temperature of the balance buffer container (15), so that the internal temperature of the balance buffer container (15) reaches the high temperature at which CO2 transitions from liquefaction to supercritical state; S2, controlling the gas cylinder (1) to release CO2, which is pressurized by the gas booster pump (4) and enters the condensation storage tank (7), and cooperates with the low temperature conditions provided by the condenser (10) inside the condensation storage tank (7) to achieve liquefaction of CO2; S3, when the pressure and temperature in the storage tank to be condensed (7) are stable, the double-cylinder plunger pump (13) is started to suck the liquid CO2 in the condensation storage tank (7), and the pressure of the double-cylinder plunger pump (13) is adjusted to be greater than the critical pressure for CO2 to transform into a supercritical state, and the liquefied CO2 is pumped into the balancing buffer container (15), and the transformation of CO2 from the liquid state to the supercritical state is achieved by coordinating with the internal temperature of the balancing buffer container (15); S4. The internal pressure and temperature of the condensation storage tank (7) and the balancing buffer container (15) are collected in real time by using the information collection module, and are transmitted to the information processing system (20). The information processing system (20) compares the obtained pressure and temperature with the input preset values, and controls the gas booster pump (4) and the double-cylinder plunger pump (13) to regulate the internal pressure of the condensation storage tank (7) and the balancing buffer container (15) respectively according to the pressure comparison information, and controls the condenser (10) and the temperature regulator (16) to regulate the internal temperature of the condensation storage tank (7), the double-cylinder plunger pump (13) and the balancing buffer container (15) respectively according to the temperature comparison information, so that the CO2 phase change condition in the device is in a dynamic stable state, so as to realize the continuous preparation of supercritical CO2.

Images