Integrated supercharging liquefying device for ship co2 capture system

Abstract

The application belongs to the technical field of carbon management in ocean engineering and environmental engineering, and particularly relates to an integrated pressurization and liquefaction device for a ship CO2 capture system. The device comprises an external CO2 recovery device, the CO2 recovery device is connected with an air cooler, the air cooler is connected with a compressor system, the compressor system is connected with a flash economizer, the flash economizer is connected with the compressor system through a secondary economizer, the secondary economizer is connected with a CO2 storage device through a subcooler, and the CO2 storage device is connected with the air cooler. The device can reduce process fluid, reduce cost and improve efficiency.

Description

Technical Field

[0001] This invention belongs to the field of carbon management technology in marine engineering and environmental engineering, and in particular, relates to an integrated pressurized liquefaction device for ship CO2 capture systems. Background Technology

[0002] Depending on the ship type, such as container ships, LNG carriers (liquefied natural gas carriers), or other ship types, the generated CO2 (carbon dioxide) will be captured, and the corresponding CO2 pressurization and liquefaction unit will be selected to condense the CO2 and store it in a CO2 liquid storage tank.

[0003] Existing CO2 capture systems generally consist of three modules: a CO2 separation module, a CO2 liquefaction device, and a CO2 storage device.

[0004] Among them: (1) CO2 separation modules are divided into: chemical absorption, physical absorption, membrane separation, cryogenic separation, quicklime CO2 capture and calcium acetate synthesis process. Generally, chemical absorption is more commonly used in the shipbuilding industry.

[0005] (2) CO2 liquefaction unit: It generally consists of two parts: CO2 booster unit and refrigeration unit.

[0006] (3) CO2 storage equipment: mostly tanks, with varying working pressures and load weights depending on the operating status.

[0007] This invention mainly discusses and explores CO2 liquefaction devices.

[0008] Existing CO2 liquefaction units generally consist of a CO2 booster compressor (hereinafter referred to as the booster compressor) and a refrigeration unit.

[0009] The CO2 booster pressurizes the CO2 gas recovered from the CO2 recovery unit or the flash vapor from the CO2 storage device. The pressurized superheated CO2 gas is then discharged into the CO2 liquefaction unit within the refrigeration unit, where it reacts with the low-temperature, low-pressure refrigerant supplied by the refrigeration unit, releasing heat and liquefying at the operating pressure. The liquefied CO2 is then returned to the CO2 storage device.

[0010] The refrigerants used in refrigeration units are generally Freon or hydrocarbon refrigerants.

[0011] Operating pressure state point: (1) The pressure inside the CO2 storage tank is generally controlled at around 0.2 MPaA. When the pressure inside the tank exceeds 0.2 MPaA, the CO2 booster is turned on to pressurize the flash gas to 2 MPaA before it enters the liquefaction unit in the refrigeration unit.

[0012] (2) The superheated CO2 gas delivered by the CO2 booster is liquefied by the -30~-40℃ refrigerant at around -20℃ in the CO2 liquefaction unit of the refrigeration unit, and then subcooled by 5~15℃ back to the tank for storage.

[0013] In the existing technology, CO2 liquefaction devices have the following problems and disadvantages: 1. Numerous components: The CO2 booster compressor and refrigeration unit require two independent sets of moving parts and auxiliary equipment. Too many components will lead to a decrease in reliability. 2. Large footprint: The independent two-piece moving equipment skid is not suitable for the relatively compact space of the shipbuilding industry; 3. CO2 storage devices operate at pressures below the triple point, so there is a risk of solid-state blockage in the low-pressure section. 4. The refrigeration unit requires additional refrigerant, resulting in additional management requirements.

[0014] The reasons for the aforementioned problems and shortcomings in the existing technology are as follows: 1. Based on the requirements of the "pressurization" and "freezing" functional sections, two skids are generally required respectively.

[0015] 2. The critical temperature of CO2 is 31.1℃. In the shipbuilding industry, the ambient cold source is usually seawater and ambient temperature, both of which are designed to be higher than the critical temperature of CO2. Therefore, it is necessary to set up an independent refrigeration unit to remove the heat generated during the CO2 liquefaction process.

[0016] 3. After CO2 is liquefied and supercooled in the liquefier, its state point is: pressure 1.8~2MPaA, temperature -25~-35℃ before entering the CO2 storage device. A pressure transmitter is installed on the storage device. When the pressure inside the tank exceeds 0.2MPaA, the top suction valve opens, connecting to the CO2 booster pump inlet to maintain the tank pressure. Therefore, the high-pressure, low-temperature CO2 liquid supplied from the liquefier flashes to 0.2MPaA in the storage tank, below the triple point (temperature -56.6℃, pressure 0.518MPa).

[0017] 4. CO2 has a liquefaction point temperature of around -20℃ in the liquefaction unit and cannot dissipate heat naturally through the environment. The added refrigeration unit should select a suitable refrigerant according to the operating point. Generally, R507, R717, R290, R1270, etc. are selected. Summary of the Invention

[0018] This invention addresses the shortcomings of existing technologies by providing an integrated pressurization and liquefaction device for ship CO2 capture systems.

[0019] The technical solution of this invention is as follows: The ship CO2 capture system uses an integrated pressurized liquefaction unit, including an external CO2 recovery unit. The CO2 recovery unit is connected to a gas cooler, which is connected to a compressor system. The compressor system is connected to a flash economizer. The flash economizer is connected to the compressor system through a secondary economizer. The secondary economizer is connected to a CO2 storage device through a subcooler. The CO2 storage device is connected to the gas cooler.

[0020] In one embodiment, the CO2 recovery device is connected to a gas cooler, the gas cooler is connected to a compressor system, and the compressor system is connected to a flash economizer, specifically including: The compressor system includes a high-pressure stage compressor, a low-pressure stage compressor, and an oil separator; the CO2 recovery unit is connected to a confluence valve one via a throttle valve one, confluence valve one is connected to an air cooler via a confluence valve two, and confluence valve two is connected to a subcooler; the air cooler is connected to the oil separator via the low-pressure stage compressor, the oil separator is connected to a flash economizer, the flash economizer is connected to the high-pressure stage compressor via a confluence valve three, and the high-pressure stage compressor is connected to the flash economizer via a condenser.

[0021] In one embodiment, the flash economizer is connected to the compressor system via a secondary economizer, specifically including: The flash economizer is connected to splitter one. Splitter one has three connection methods: splitter one is directly connected to the secondary economizer, splitter one is connected to the secondary economizer through throttle valve five, and splitter one is connected to the air cooler through throttle valve six; the secondary economizer is connected to the low-pressure stage compressor.

[0022] In one embodiment, the secondary economizer is connected to the CO2 storage device via a subcooler, specifically including: The secondary economizer is connected to the second distributor. The second distributor has two connection methods: the second distributor is directly connected to the subcooler; the second distributor is connected to the subcooler through the seventh throttle valve; and the subcooler is connected to the CO2 storage device through the third throttle valve.

[0023] In one embodiment, the CO2 recovery device is connected to a gas cooler, the gas cooler is connected to a compressor system, and the compressor system is connected to a flash economizer, specifically including: The compressor system includes an expander and a centrifugal compressor; the CO2 recovery unit is connected to the expander via a pneumatic switch valve one, the expander is connected to the centrifugal compressor, the expander is connected to a confluence valve two, the confluence valve two is connected to a subcooler, the confluence valve two is connected to an air cooler, the air cooler is connected to the centrifugal compressor, and the centrifugal compressor is connected to a flash economizer via a condenser.

[0024] In one embodiment, the flash economizer is connected to the compressor system via a secondary economizer, specifically including: The flash economizer is connected to the first distributor. The first distributor has three connection methods: the first distributor is directly connected to the second-stage economizer, the first distributor is connected to the second-stage economizer through the fifth throttle valve, and the first distributor is connected to the air cooler through the sixth throttle valve; the second-stage economizer is connected to the centrifugal compressor.

[0025] In one embodiment, the CO2 storage device is connected to a gas cooler, specifically including: The CO2 storage device is connected to the first confluencer via the second throttle valve, the first confluencer is connected to the second confluencer, and the second confluencer is connected to the gas cooler.

[0026] In one embodiment, the CO2 storage device is connected to a gas cooler, specifically including: The CO2 storage device is connected to the first confluencer via the second throttle valve. The first confluencer is connected to the second confluencer via the expander. The second confluencer is connected to the gas cooler.

[0027] In one embodiment, an adsorption cylinder is added between the outlet of the CO2 recovery device and the throttle valve, and phase change microspheres are added to the adsorption cylinder. The preparation method of the phase change microspheres includes the following steps: PVA (polyvinyl alcohol) solution was spray-formed into microspheres, which were then dried to obtain PVA microspheres. PVA microspheres were added to an RF (resorcinol phenolic resin) solution, stirred, then allowed to stand, aged, and freeze-dried to obtain RF-coated microspheres; the RF-coated microspheres were then heat-treated to obtain carbonized microspheres. The carbonized microspheres were immersed in a saturated LiCl (lithium chloride) methanol solution at room temperature and atmospheric pressure. After immersion, the carbonized microspheres were removed, washed, and dried to obtain LiCl preloaded carbonized microspheres. C18 (n-octadecane) and C16 (n-hexadecane) are melted to obtain a phase change mixture; LiCl preloaded carbonized microspheres were placed in a container, and a phase change mixture was added to immerse the LiCl preloaded carbonized microspheres. The container was then placed in a vacuum impregnation apparatus, and a vacuum was drawn to maintain the impregnation for 0.5-2 hours. Subsequently, the vacuum was released and the pressure was restored to normal. The mixture was kept at 60-80℃ for 0.5-1 hours. After impregnation, the microspheres were removed, cooled, and obtained.

[0028] It should be noted that, using the above technical solution, the resulting phase change microspheres include an outer porous carbonaceous shell, C18 and C16 phase change materials distributed within the pores and porous structure of the porous carbonaceous shell, and a LiCl hygroscopic component loaded within the pores of the porous carbonaceous shell. The porous carbonaceous shell has a continuous framework and interconnected channels, serving as both the supporting structure for the microspheres and the load-bearing structure for the phase change material and the hygroscopic component. After being melt-impregnated into the pores and porous structure, the C18 and C16 phase change materials solidify under cooling conditions to form a phase change heat storage component. The LiCl hygroscopic component is used to adsorb trace amounts of moisture from CO2 gas. Thus, the phase change microspheres form a composite structure of a porous carbonaceous shell, phase change material, and hygroscopic component, which can absorb or release heat through the phase change material during temperature fluctuations, while reducing the risk of phase change material migration and loss, and reducing the risk of subsequent frosting or ice blockage in low-temperature components. Moreover, the LiCl and phase change material are spatially separated, avoiding the dissolution of LiCl by the liquid phase change material.

[0029] Phase change microspheres can remove moisture from CO2 gas and buffer temperature shocks, further improving the reliability and environmental adaptability of the entire pressurized liquefaction unit.

[0030] In one embodiment, the method for preparing the RF solution includes the steps of: mixing resorcinol, formaldehyde solution, sodium carbonate solution, and deionized water to obtain the RF solution; The preparation method of saturated LiCl methanol solution includes the following steps: dissolving LiCl in methanol to obtain saturated LiCl methanol solution.

[0031] When the compressor system includes a high-pressure stage compressor, a low-pressure stage compressor, and an oil separator, the working principle of the device of the present invention is as follows: CO2 gas recovered from the CO2 recovery device or flash vapor from the CO2 storage device is equalized by throttle valve one or throttle valve two, mixed with the return gas from the subcooler, cooled by the air cooler, and then enters the low-pressure stage compressor, where it is pressurized to high temperature and medium pressure CO2 gas. After heat exchange in the flash economizer, it is drawn into the high-pressure stage compressor along with the flash gas, and pressurized to a supercritical state by the high-pressure stage compressor before being discharged into the condenser.

[0032] CO2 exchanges heat with cooling water in the condenser, liquefies, and then passes through a throttling valve for flash evaporation, where gas-liquid separation is achieved in the flash evaporation economizer. The gas returns to the inlet of the high-pressure stage compressor. The liquid enters two paths to the secondary economizer for subcooling and supply; one path enters the gas cooler as a cold source.

[0033] The subcooled CO2 liquid enters the subcooler for further subcooling, cooling to a pressure of 3.29 MPaA and a temperature of -34°C (state point 26). After passing through a throttling valve, it flashes into a saturated gas-liquid mixture with a vaporization rate of 2.2%, a pressure of 1.1 MPaA, and a temperature of -37°C, and then enters the CO2 storage device. This completes the liquefaction reflux process.

[0034] When the compressor system includes an expander and a centrifugal compressor, the working principle of the device of the present invention is as follows: Flash vapor from CO2 recovery units or CO2 storage equipment is expanded and depressurized by an expander to recover pressure energy and drive a centrifugal compressor. The expanded gas is mixed with return gas from the subcooler, cooled by an air cooler, and then enters the centrifugal compressor. After three stages of compression by the centrifugal compressor (with two stages of supplementary gas from the secondary economizer, the air cooler tube layer, and the flash economizer), it reaches a supercritical state. Then, it undergoes condensation, throttling, flashing, gas-liquid separation, subcooling in the secondary economizer, and further subcooling in the subcooler, and is finally throttled into a liquid state and stored in the CO2 storage equipment.

[0035] Compared with the prior art, the beneficial effects of the present invention are: 1. Reduced process fluids: The refrigerant used in the chiller of this invention is also CO2, which avoids additional on-site management and reduces the complexity of operation and maintenance.

[0036] 2. Based on the same process fluid, the present invention combines the CO2 booster and the refrigeration unit into a single system, reducing the number of moving parts in the CO2 liquefaction unit and lowering costs and maintenance requirements.

[0037] 3. This invention optimizes the operating conditions of the CO2 entering the storage tank after liquefaction, ensuring that the CO2 operating pressure throughout the system is far from the triple point, thus avoiding the risk of blockage. The fact that the entire process state point is far from the CO2 triple point also minimizes uncertainties within the system. Simultaneously, it optimizes the compressor pressure ratio, improving operating efficiency. For the same liquefaction volume, when the compressor system includes a high-pressure stage compressor, a low-pressure stage compressor, and an oil separator, the cumulative energy saving in compressor input power is 20%; when the compressor system includes an expander and a centrifugal compressor, the cumulative energy saving in compressor input power is 25%. It can utilize the expander to recover pressure differential energy, further reducing external energy consumption. Using the natural pressure difference between the CO2 storage device and the centrifugal compressor inlet to drive the expander directly drives the centrifugal compressor, reducing external shaft power input by approximately 5%. For large ship CO2 capture systems, this energy-saving effect is equivalent to reducing the fuel consumption of the main engine or generator.

[0038] 4. This invention optimizes the system design, recovering as much heat as possible, reducing the number of moving parts, and lowering the overall input power of the system. Specifically, CO2 condensation occurs in the supercritical section, and subsequent processes are all subcooled. While optimizing shaft power, the efficiency of the condensation equipment is also improved.

[0039] 5. This invention increases the pressure of the CO2 high-pressure side to above the supercritical pressure, achieving efficient heat transfer at room temperature, further reducing the size of the equipment and making the overall system more compact.

[0040] 6. The present invention adds an adsorption cylinder between the outlet of the CO2 recovery device and the throttling valve, and adds phase change microspheres to the adsorption cylinder, which can further improve the stability and heat exchange efficiency of the device under high humidity and low temperature conditions.

[0041] 7. By replacing the high-pressure and low-pressure compressors with centrifugal compressors, the oil separator and return oil pipeline are eliminated, avoiding the risk of cross-contamination between CO2 and lubricating oil. There is also no need to replace filter elements and treat waste oil regularly, making it suitable for marine environments with more stringent requirements for safety and maintenance cycles. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the device of the present invention, which includes a low-pressure stage compressor and a high-pressure stage compressor.

[0044] Figure 2 This is a schematic diagram of the apparatus of the present invention, which includes an expander and a centrifugal compressor.

[0045] The following are labeled in the diagram: 101. Throttling valve one; 102. Throttling valve two; 103. Throttling valve three; 104. Throttling valve four; 105. Throttling valve five; 106. Throttling valve six; 107. Throttling valve seven; 201. Combiner one; 202. Combiner two; 203. Combiner three; 300. Air cooler; 400. Low-pressure stage compressor; 500. Oil separator; 600. High-pressure stage compressor; 700. Condenser; 800. Flash economizer; 900. Flow divider one; 901. Flow divider two; 1000. Secondary economizer; 2000. Subcooler; 3000. CO2 storage device; 4000. CO2 recovery device; 5000. Expander; 6000. Centrifugal compressor; 7000. Pneumatic switching valve one; 7001. Pneumatic switching valve two.

[0046] It should be noted that, Figure 11.1, 1.2, and 2-27 above are all state point markers. A state point is a state parameter of the working medium (such as CO2 or a specific working medium at a process node), including at least one of temperature, pressure, and material state form (such as gas or liquid). Specific state points are described in detail in the embodiments. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0048] Unless otherwise specified, the experimental methods used below are conventional methods. The parts, equipment, materials, and reagents used are all commercially available unless otherwise specified. The principles or mechanisms of parts or equipment that can be routinely purchased commercially are well-known, and their common names are given below, therefore they will not be elaborated further. Specifically, throttle valves 101 to 7107 are throttle valves, confluencers 201 to 3203 are confluencers, and flow dividers 900 to 2901 are flow dividers.

[0049] Example 1 Reference Figure 1 This invention provides an integrated pressurized liquefaction device for a ship CO2 capture system, as detailed below: An external CO2 recovery unit is used to recover CO2 gas. The external CO2 recovery unit 4000 is connected via piping to throttle valve 101, which is connected via piping to confluence valve 201. The CO2 storage device 3000 is connected via piping to throttle valve 102, which is connected via piping to confluence valve 201. Confluence valve 201 is connected via piping to confluence valve 202. The outlet piping of the subcooler 2000 is connected to confluence valve 202, which is connected via piping to the shell of the gas cooler 300.

[0050] The confluencer 3203 pipe is connected to the air cooler 300. The shell outlet pipe of the air cooler 300 is connected to the inlet of the low-pressure stage compressor 400. The low-pressure stage compressor 400 pipe is connected to the oil separator 500. The oil separator 500 pipe is connected to the flash economizer 800. Specifically, the exhaust port pipe of the low-pressure stage compressor 400 is connected to the oil separator 500. The oil separator 500 pipe is connected to the cooling plate inside the flash economizer 800.

[0051] The coil outlet and shell outlet of the flash economizer 800 are respectively connected to the confluencer 3 203. The confluencer 3 203 is connected to the inlet of the high-pressure stage compressor 600. The outlet of the high-pressure stage compressor 600 is connected to the shell inlet of the condenser 700.

[0052] The shell outlet pipe of condenser 700 is connected to throttle valve 4 104, and the pipe of throttle valve 4 104 is connected to the shell of flash economizer 800.

[0053] The shell gas phase pipeline of the flash economizer 800 is connected to the high-pressure stage compressor 600.

[0054] The liquid phase pipeline of the flash economizer 800 is connected to the splitter 900, and the pipeline of splitter 900 is connected to the shell of the secondary economizer 1000. The pipeline of splitter 900 is connected to throttle valve 105, and the outlet pipeline of throttle valve 105 is connected to the shell of the secondary economizer 1000. The pipeline of splitter 900 is connected to throttle valve 106, and the pipeline of throttle valve 106 is connected to the air cooler 300.

[0055] The shell outlet pipe of the secondary economizer 1000 is connected to the intermediate air inlet of the low-pressure stage compressor 400, and the air cooler 300 is connected to the aforementioned pipe.

[0056] Additionally, the shell outlet pipe of the secondary economizer 1000 is connected to the second distributor 901, the pipe of the second distributor 901 is connected to the shell inlet of the subcooler 2000, the pipe of the second distributor 901 is connected to the throttle valve 107, and the pipe of the throttle valve 107 is connected to the inlet of the subcooler 2000. Alternatively, the shell outlet of the secondary economizer 1000 can be understood as having two paths: one connected to the shell inlet of the subcooler 2000, and the other connected to the throttle valve 107.

[0057] The subcooler 2000 is connected to the confluence valve 202 via piping. The shell outlet piping of the subcooler 2000 is connected to the throttle valve 3103 via piping. The throttle valve 3103 is connected to the CO2 storage device 3000 via piping. The CO2 storage device 3000 is connected to the throttle valve 2102 via piping.

[0058] The integrated pressurized liquefaction device for the ship CO2 capture system of this invention has the following specific working process: CO2 gas recovered from CO2 recovery unit 4000 (state point 1.2) passes through throttling valve 101, or flash vapor from CO2 storage device 3000 (state point 1.1) passes through throttling valve 102, reducing its pressure to 1.05 MPaA and 34.5℃ (state point 2). It then mixes with the return gas from subcooler 2000 (state point 25) to a pressure of 1.05 MPaA and 28℃ (state point 3), before entering the shell of gas cooler 300. Inside gas cooler 300, the gas exchanges heat with the flashing CO2 in the tubes, cooling to a pressure of 1.03 MPaA and -21℃ (state point 4), before entering the suction inlet of low-pressure stage compressor 400.

[0059] The CO2 gas entering the suction inlet of the low-pressure stage compressor 400 is pressurized by the compressor and discharged from its exhaust port at a pressure of 3.3 MPaA and a temperature of 67°C (state point 5). It then enters the oil separator 500 for oil-gas separation (if required by the compressor), yielding superheated steam. The superheated steam (state point 6) from the oil-gas separated low-pressure stage compressor 400 enters the coil at the bottom of the flash economizer 800. The coil is immersed in saturated steam at -2°C and a pressure of 3.3 MPaA. The superheated steam exchanges heat with the saturated steam in the flash economizer 800, cooling to a pressure of 3.28 MPaA and a temperature of 9.5°C (state point 7). This mixture then mixes with the saturated gas flashing out of the flash economizer 800 (state point 8) and enters the high-pressure stage compressor 600 at a pressure of 3.28 MPaA and a temperature of 1.44°C (state point 9).

[0060] In the high-pressure stage compressor 600, CO2 gas is pressurized to a supercritical state: pressure 8.4 MPaA, 86℃ (state point 10), and enters the condenser 700. In the condenser 700, it exchanges heat with cooling water, is cooled and condensed into liquid CO2 at a pressure of 8.4 MPaA and a temperature of 35℃ (state point 11). After being throttled by the expansion valve 104, the liquid CO2 flashes into a saturated gas-liquid mixture with a vaporization rate of 55.7%, a pressure of 3.3 MPaA, a temperature of -2℃ (state point 12), and a dryness of 55%. Gas-liquid separation is achieved in the flash economizer 800. The gaseous state of the gas-liquid separation is gas at state point 8, which returns to the inlet of the high-pressure stage compressor 600. The liquid state of the gas-liquid separation is liquid at a pressure of 3.3 MPaA and a temperature of -2℃ (state point 13), which is supplied to the downstream end after settling.

[0061] After the saturated liquid is separated by the sedimentation of the flash economizer 800, it is divided into three paths. Among them, (1) two paths go to the secondary economizer 1000: 1) One path of liquid (state point 14) enters the shell of the secondary economizer 1000 and exchanges heat with the low-temperature and low-pressure CO2 entering the tube layer. It is cooled to a pressure of 3.3 MPaA and -21℃ (state point 21) to supply liquid to the subcooler 2000. 2) The other path of liquid (state point 15) flashes through the throttle valve 105 to become a gas-liquid mixture with a pressure of 1.64 MPaA and -26℃ (state point 16) and enters the tube layer of the secondary economizer 1000. After heat exchange with the liquid CO2 at -2℃ in the shell layer, it absorbs heat and flashes out to the outlet of the tube layer of the secondary economizer 1000 with a pressure of 1.63 MPaA and -26℃ (state point 17) and enters the gas injection port of the low-pressure stage compressor 400. (2) The third liquid supply (state point 18) flashes through the throttle valve 106 into a gas-liquid mixture with a pressure of 1.64 MPaA and a temperature of -26℃ (state point 19). It enters the tube layer of the gas cooler 300, exchanges heat with the gaseous CO2 at 28℃ in the shell layer, absorbs heat and flashes out, and flows out to the outlet of the tube layer of the gas cooler 300 with a pressure of 1.63 MPaA and a temperature of -26℃ (state point 20) to enter the gas supply port of the low-pressure stage compressor 400.

[0062] The CO2 liquid at a pressure of 3.3 MPa and a temperature of -21°C (state point 21) is divided into two streams and enters the subcooler 2000. (1) One stream of liquid (state point 22) exchanges heat with the saturated CO2 two-phase flow in the shell layer of the subcooler 2000 and is cooled to a pressure of 3.29 MPa and a temperature of -34°C (state point 26) before going to the throttle valve 103. (2) The other stream of liquid (state point 23) flashes through the throttle valve 107 and becomes a gas-liquid mixture at a pressure of 1.1 MPa and a temperature of -37.5°C (state point 24) before entering the subcooler 2000 tube layer. After exchanging heat with the liquid CO2 at a temperature of -21°C in the shell layer, it absorbs heat and flashes out of the subcooler 2000 tube layer. The outlet pressure is 1.05 MPa and a temperature of -39°C (state point 25) before entering the suction port of the low-pressure stage compressor 400.

[0063] CO2 liquid at a pressure of 3.29 MPa and a temperature of -34°C (state point 26) is throttled and flashed by throttle valve 3103 into a saturated gas-liquid mixture with a vaporization rate of 2.2%, a pressure of 1.1 MPa and a temperature of -37°C (state point 27), and enters CO2 storage device 3000.

[0064] Through the pressurization / refrigeration cycle, the CO2 returning to the CO2 storage device 3000 is essentially in a liquid state, achieving liquid-phase storage. The unit starts up when the tank pressure increases.

[0065] Example 2 Based on Example 1, a specific device is given: The low-pressure stage compressor 400 is a low-pressure stage twin-screw compressor, while the high-pressure stage compressor 600 is a high-pressure stage single-screw compressor.

[0066] Example 3 The difference from Example 1 is that an expander 5000 and a centrifugal compressor 6000 are used instead of the low-pressure stage compressor 400, oil separator 500, and high-pressure stage compressor 600 to form an integrated pressurized liquefaction structure. Among them, the centrifugal compressor 6000 is a centrifuge with a three-stage impeller.

[0067] This configuration allows the pressure energy during the expansion of CO2 liquid to drive the centrifugal compressor 6000, reducing system shaft power consumption. It also eliminates the need for the oil separator 500 and related oil circuit systems, further reducing the equipment footprint and improving the utilization rate of ship engine room space.

[0068] Reference Figure 2 This invention provides an integrated pressurized liquefaction device for a ship CO2 capture system, as detailed below: An external CO2 recovery unit 4000 is used to recover CO2 gas. The external CO2 recovery unit 4000 is connected to a pneumatic switch valve 7000, which can be opened by the CO2 recovery unit. The pneumatic switch valve 7000 is also connected to a confluencer 201. A CO2 storage device 3000 is connected to a pneumatic switch valve 7001, which can be opened by the CO2 storage device. The pneumatic switch valve 7001 is also connected to a confluencer 201.

[0069] The pipe of the first confluencer 201 is connected to the inlet of the expander 5000. The shaft of the expander 5000 is connected to the centrifugal compressor 6000. The outlet pipe of the expander 5000 is connected to the second confluencer 202. The tube layer outlet pipe of the subcooler 2000 is connected to the second confluencer 202. The pipe of the second confluencer 202 is connected to the shell of the air cooler 300.

[0070] The shell outlet pipe of the air cooler 300 is connected to the primary inlet of the centrifugal compressor 6000. It should be noted that the centrifugal compressor 6000 is a three-stage impeller centrifugal compressor, with built-in first-stage, second-stage, and third-stage impellers, and two intermediate air inlets. The first air inlet is located between the first-stage impeller and the second-stage impeller, and the second air inlet is located between the second-stage impeller and the third-stage impeller.

[0071] The primary exhaust pipe of the centrifugal compressor 6000 is connected to the cooling plate inside the flash economizer 800.

[0072] The coil outlet and shell outlet of the flash economizer 800 are respectively connected to the second air inlet of the centrifugal compressor 600, and the secondary exhaust port of the centrifugal compressor 6000 is connected to the shell inlet of the condenser 700.

[0073] The shell outlet pipe of condenser 700 is connected to throttle valve 4 104, and the pipe of throttle valve 4 104 is connected to the shell of flash economizer 800.

[0074] The shell gas phase pipeline of the flash economizer 800 is connected to the second gas supply port of the centrifugal compressor 6000.

[0075] The liquid phase pipeline of the flash economizer 800 is connected to the splitter 900, and the pipeline of the splitter 900 is connected to the shell of the secondary economizer 1000.

[0076] The 900-pipe of the distributor is connected to the 105-throttle valve, and the outlet pipe of the 105-throttle valve is connected to the shell of the 1000-stage economizer.

[0077] The distributor 1900 pipe is connected to the throttle valve 6106, and the throttle valve 6106 pipe is connected to the inlet of the air cooler 300.

[0078] The shell outlet pipe of the secondary economizer 1000 is connected to the second distributor 901. The pipe of the second distributor 901 is connected to the shell inlet of the subcooler 2000. The pipe of the second distributor 901 is connected to the throttle valve 107. The pipe of the throttle valve 107 is connected to the tube inlet of the subcooler 2000.

[0079] After the pipe layer outlet of the secondary economizer 1000 and the pipe layer outlet of the air cooler 300 are merged, they are connected together to the first air supply port of the centrifugal compressor 6000.

[0080] The shell outlet pipe of the subcooler 2000 is connected to the throttle valve 3103, the pipe of the throttle valve 3103 is connected to the CO2 storage device 3000, and the pipe of the CO2 storage device 3000 is connected to the pneumatic switch valve 27001.

[0081] The outlet pipe of the subcooler 2000 is connected to the confluence unit 202.

[0082] The working process and thermal state point of this embodiment are similar to those of Embodiment 1, but not entirely the same, as detailed below: (a) Expander 5000 part The CO2 gas recovered from the CO2 recovery unit 4000 (state point 1.2) passes through pneumatic switch valve 1 7000, or the flash vapor from the CO2 storage device 3000 (state point 1.1) passes through pneumatic switch valve 2 7001. The two streams merge at the confluencer 1 201 and then flow into the expander 5000.

[0083] In expander 5000, CO2 gas expands and decreases in pressure, while simultaneously driving centrifugal compressor 6000 to rotate. After expansion, the pressure drops to 1.05 MPa and 34.5°C (state point 2), and flows out from the outlet of expander 5000, reaching confluencer 202 along the pipeline.

[0084] The return gas from the tube outlet of subcooler 2000 (state point 25) simultaneously enters the confluencer 202, mixes with the CO2 gas from the outlet of expander 5000 (state point 2), and forms CO2 gas at a pressure of 1.05 MPaA and a temperature of 28°C (state point 3), which then enters the shell of air cooler 300.

[0085] (ii) Centrifugal compressor 6000 compression section CO2 gas (state point 4) from the shell outlet of air cooler 300 enters the first-stage inlet of centrifugal compressor 6000. After being compressed by the first-stage impeller, the CO2 gas enters the first-stage exhaust pipe.

[0086] The makeup air (state point 17, pressure 1.63 MPaA, -26℃) from the outlet of the 1000 tube layer of the secondary economizer and the makeup air (state point 20, pressure 1.63 MPaA, -26℃) from the outlet of the 300 tube layer of the air cooler merge and enter the first makeup air port of the centrifugal compressor 6000, where it mixes with the primary exhaust gas. The mixed gas is then compressed by the secondary impeller and enters the secondary exhaust pipe to obtain the secondary exhaust gas.

[0087] The cooled gas from the outlet of the flash economizer 800 coil merges with the saturated gas flashing out of the shell of the flash economizer 800 (state point 8, pressure 3.3 MPaA, -2℃) and enters the second air inlet of the centrifugal compressor 600. It mixes with the secondary exhaust gas and enters the third impeller for compression, where it is pressurized to a supercritical state: pressure 8.4 MPaA, 86℃ (state point 10) and enters the condenser 700.

[0088] (III) Condensation and Flash Section In condenser 700, CO2 gas exchanges heat with cooling water and is condensed into liquid CO2 at a pressure of 8.4 MPaA and a temperature of 35°C (state point 11). This liquid is then throttled by expansion valve 104 and flashes into a gas-liquid mixture at a pressure of 3.3 MPaA and a temperature of -2°C (state point 12), which enters flash economizer 800 for gas-liquid separation. The separated saturated gas (state point 8) returns to the second injection port of centrifugal compressor 6000, while the saturated liquid (state point 13) enters distributor 900.

[0089] (iv) Liquid supply and gas replenishment section The distributor 1900 divides the saturated liquid into three streams: The first stream of liquid (state point 14) directly enters the shell of the secondary economizer 1000 as a cooling source; The second liquid (state point 15) is throttled by the throttle valve 105 to a pressure of 1.64 MPaA and a temperature of -26°C (state point 16), and enters the tube layer of the secondary economizer 1000. After absorbing heat, it becomes a saturated gas with a pressure of 1.63 MPaA and a temperature of -26°C (state point 17), and flows into the first gas injection port of the centrifugal compressor 6000. The third liquid (state point 18) is throttled by the throttle valve 106 to a pressure of 1.64 MPaA and a temperature of -26°C (state point 19), and enters the tube layer of the air cooler 300. After absorbing heat, it becomes a saturated gas with a pressure of 1.63 MPaA and a temperature of -26°C (state point 20), and then flows into the first gas injection port of the centrifugal compressor 6000.

[0090] After exchanging heat with the low-temperature CO2 in the shell of the secondary economizer 1000, the liquid CO2 is cooled to a pressure of 3.3 MPaA and a temperature of -21°C (state point 21) and then enters the second distributor 901.

[0091] (v) Subcooling and Storage Section Flow divider 2901 splits the CO2 liquid at state point 21 into two streams: One stream of liquid (state point 22) enters the shell of subcooler 2000; Another stream of liquid (state point 23) is throttled by throttle valve 7107 to a pressure of 1.1 MPaA and a temperature of -37.5°C (state point 24), and then enters the tube layer of subcooler 2000.

[0092] In the subcooler 2000, the CO2 liquid in the shell exchanges heat with the low-temperature two-phase flow in the tube layer and is further cooled to a pressure of 3.29 MPaA and a temperature of -34°C (state point 26). It is then throttled by the throttle valve 103 to a pressure of 1.1 MPaA and a temperature of -37°C (state point 27), forming a saturated gas-liquid mixture with a vaporization rate of 5.7%, a pressure of 0.9 MPa, and a temperature of -43°C, which then enters the CO2 storage device 3000.

[0093] The return gas (state point 25, pressure 1.05 MPaA, -39℃) after absorbing heat in the tube layer of subcooler 2000 enters the confluencer 202 and mixes with the outlet gas of expander 5000 to complete the cycle.

[0094] With the above settings, this embodiment achieves a similar thermodynamic state point and liquefaction effect as Embodiment 1. It utilizes the expander 5000 to recover the pressure energy during the throttling expansion process, reduces the external shaft power input, and eliminates the need for the oil separator 500 and related oil circuits, simplifying the system structure and improving the utilization rate of the ship's engine room space.

[0095] In this embodiment, the driving force of the expander 5000 comes from the pressure difference between the CO2 storage device 3000 and the inlet of the centrifugal compressor 6000. The specific control logic is as follows: When the pressure inside the CO2 storage device 3000 reaches the set value (e.g., 11 barG), the pneumatic switch valve 7001 opens, and the flash vapor (state point 1.1) from the CO2 storage device 3000 enters the expander 5000. Expander 5000 expands high-pressure gas to a set outlet pressure (e.g., 8 barG). During the expansion process, pressure energy is converted into mechanical energy, which drives centrifugal compressor 6000 to rotate. Through this differential pressure-driven energy recovery, the system can reduce external shaft power input by about 5%, effectively improving overall energy efficiency.

[0096] The above settings can be adjusted according to the system operating conditions. After the expansion 5000 outlet pressure (state point 2) and the subcooler 2000 return gas (state point 25) are mixed, they together meet the pressure requirements of the centrifugal compressor 6000 primary inlet.

[0097] Based on the pressurized liquefaction devices provided in Examples 1 to 3, this invention further considers that: in actual operation, the CO2 gas obtained from the CO2 recovery device 4000 in the ship's CO2 capture system typically contains trace amounts of water vapor. When compressed, cooled, and throttled to a low-temperature state, this water vapor may freeze in components such as the throttle valve and heat exchanger, leading to ice blockage and affecting the continuous and stable operation of the system. Simultaneously, compressor start-up and shutdown or changes in operating conditions can cause system temperature fluctuations, adversely affecting liquefaction efficiency and equipment lifespan. Therefore, based on the device shown in Example 1, this invention also provides a phase change microsphere with moisture absorption, phase change heat storage, and structural stability characteristics. This microsphere can effectively remove moisture from the CO2 gas, buffer temperature shocks, and further improve the reliability and environmental adaptability of the entire pressurized liquefaction device.

[0098] The present invention further provides embodiments 4-5.

[0099] Example 4 Selecting raw materials: C18: n-Octadecan, purity >99%; C16: n-Hexadecane, purity >99%; Polyvinyl alcohol (PVA), industrial grade, Mw≈30000; Phenolic resin: Prepared RF (resorcinol phenolic resin) solution; LiCl: Lithium chloride, anhydrous.

[0100] Preparation using raw materials: Preparation of PVA solution: Weigh 2g of PVA and dissolve it in 100mL of deionized water; heat to 90℃ and stir for 30min until completely dissolved, then cool to room temperature to obtain a PVA solution. Form microspheres from the PVA solution using a spray-forming method; the microsphere particle size is approximately 250μm. Dry the microspheres at room temperature to obtain PVA microspheres. It should be noted that the PVA microspheres serve as a sacrificial template; their hydrophilic surface facilitates uniform coating with the subsequent RF solution. During subsequent heat treatment, complete pyrolysis forms cavities and interconnected pores.

[0101] Preparation of RF solution: Mix 0.6g resorcinol, 0.8mL 37% formaldehyde solution, 0.3mL 0.1M sodium carbonate solution, and 2mL deionized water to obtain RF solution.

[0102] PVA microspheres were added to an RF solution and stirred at room temperature for 4 hours. Then, the mixture was allowed to stand at room temperature for 24 hours to age, forming an RF gel coating layer on the outside of the PVA microspheres. The mixture was then freeze-dried to obtain RF-coated microspheres.

[0103] RF-coated microspheres were placed in a tube furnace and heat-treated under high-purity nitrogen protection. The heat treatment parameters were set as follows: heating rate 1–5 °C / min, heat treatment temperature 500–800 °C, holding time 1–4 h, and nitrogen flow rate 50–200 mL / min. Preferably, the heating rate was 2 °C / min, the heat treatment temperature was 650 °C, the holding time was 2 h, and the nitrogen flow rate was 100 mL / min. These preferred parameters are used in this embodiment.

[0104] During the heat treatment process, PVA pyrolyzes and promotes the formation of a porous structure inside the microspheres. The RF gel coating layer is transformed into a porous carbonaceous shell with certain mechanical strength, thus obtaining carbonized microspheres with cavities and pore structures inside and a porous carbonaceous shell on the outside. That is, the inside is hollow and the shell has micropores and mesopores. Preparation of saturated LiCl methanol solution: Dissolve 10g LiCl in 50mL methanol to obtain a saturated LiCl methanol solution. Immerse the carbonized microspheres in the saturated LiCl methanol solution at room temperature and atmospheric pressure for 30min, allowing the LiCl solution to enter the micropores and mesopores of the carbon shell through capillary action.

[0105] After impregnation, the carbonized microspheres were removed, and the surface was rapidly rinsed with anhydrous methanol to remove excess LiCl. Then, they were vacuum dried at 60°C for 2 hours to obtain LiCl-preloaded carbonized microspheres. It should be noted that the LiCl is mainly loaded in the micropores of the carbon shell, while the subsequently filled C18 and C16 molecules are larger and mainly occupy the mesopores and central cavity. The two are spatially separated through the pore size sieving effect, avoiding mutual interference.

[0106] C18 and C16 are mixed in a mass ratio of 7:3 and heated to 80°C until they are completely melted to form a liquid phase change mixture. It should be noted that this ratio is optimized based on the operating temperature range of the CO2 liquefaction system, and the melting peak of the phase change mixture is located in the range of 15~25°C, which matches the ambient temperature of the ship's engine room and the temperature fluctuation range during system startup.

[0107] The LiCl-preloaded carbonized microspheres prepared above were placed in a heat-resistant container, and a phase change mixture was added to the container, allowing the molten phase change mixture to immerse the LiCl-preloaded carbonized microspheres. The container was then placed in a vacuum impregnation apparatus, and a vacuum was drawn to an absolute pressure <1 kPa, maintained for 30 min to allow gas to escape from the pores and voids of the LiCl-preloaded carbonized microspheres. Subsequently, the vacuum was released and the pressure was restored to atmospheric pressure, using the pressure difference to allow the molten phase change mixture to enter the pores and voids of the LiCl-preloaded carbonized microspheres. After restoring atmospheric pressure, the mixture was kept at 80℃ for 0.5–1 h to improve impregnation uniformity. After impregnation, the LiCl-preloaded carbonized microspheres were removed, excess phase change mixture was removed from the surface, and then cooled to room temperature to solidify, yielding phase change microspheres.

[0108] The resulting phase change microspheres comprise an outer porous carbonaceous shell, C18 and C16 phase change materials distributed within the pores and porous structure of the porous carbonaceous shell, and a LiCl hygroscopic component loaded within the pores of the porous carbonaceous shell. The porous carbonaceous shell, with its continuous framework and interconnected channels, serves as both the support structure for the microspheres and the load-bearing structure for the phase change materials and hygroscopic component. The C18 and C16 phase change materials, after being melt-impregnated into the pores and porous structure, solidify under cooling conditions to form the phase change heat storage component. The LiCl hygroscopic component adsorbs trace amounts of moisture from the CO2 gas. Thus, the phase change microspheres form a composite structure of a porous carbonaceous shell, phase change materials, and hygroscopic component. This allows the phase change materials to absorb or release heat during temperature fluctuations, while reducing the risk of phase change material migration and loss, and minimizing the risk of frost or ice blockage in subsequent low-temperature components. Furthermore, the spatial separation of LiCl and the phase change materials prevents the liquid phase change materials from dissolving LiCl.

[0109] The performance of the phase change microspheres in Example 4 was verified as follows: Experimental group: Take 5g of the phase change microspheres prepared in Example 4 as microsphere samples and place them in a breathable glass container.

[0110] Control group: empty, breathable glass containers without samples.

[0111] Place the glass container in a closed humidity control test chamber. The initial environment is set as follows: 25℃, relative humidity: 85%, and 1 atm of pure CO2 gas is injected.

[0112] Then, the temperature was lowered from the initial environment: the ambient temperature was lowered to -20℃ to simulate the temperature fluctuation of the CO2 supercooling system. The cooling was completed in 45 minutes, and after cooling to -20℃, it was kept at that temperature for 60 minutes. During the process, the side walls of the glass container were observed for condensation. The results are as follows: Experimental group: No condensation, samples intact, no breakage.

[0113] Control group: Obvious water droplets condensed.

[0114] The results show that the phase change microspheres prepared in Example 4 can reduce condensation in a simulated CO2 gas environment, indicating that they have a certain moisture absorption capacity and maintain good structural stability under low temperature conditions.

[0115] Example 5 In this embodiment, the phase change microspheres prepared in Example 4 are applied to the integrated pressurized liquefaction device of Example 1, as follows: The phase change microspheres prepared in Example 4 were loaded into an independent, quick-replaceable adsorption cylinder. This cylinder was not directly connected in series in the main process pipeline, but was connected to the pipeline between the outlet of the CO2 recovery device 4000 and the throttle valve 101 through a bypass interface.

[0116] The specific structure is as follows: The adsorption cylinder is made of pressure-bearing stainless steel and has two layers of sintered stainless steel mesh with a pore size of 10μm inside. The phase change microspheres are fixed between the two layers of mesh to form a 20mm thick packing layer.

[0117] The adsorption cylinder has standard flange interfaces at both ends, which are connected to the bypass branch pipe of the main gas line via manual or pneumatic ball valves. The main gas line itself remains straight, and the bypass valve is closed during normal operation.

[0118] When adsorption dehumidification or buffering temperature fluctuations is required, open the bypass valve to allow all or part of the CO2 gas (state point 1.2) to flow through the adsorption cylinder first, and then return to the main gas path to enter the throttle valve 101. The bypass ratio can be controlled by adjusting the opening of the bypass valve.

[0119] The outside of the adsorption cylinder is wrapped with an electric heating cable and is equipped with a temperature sensor and a vent valve.

[0120] The work process is as follows: During system startup, upstream drying unit switching, or when an abnormal increase in CO2 gas moisture content is detected, the bypass valve is opened to allow all or part of the CO2 gas to flow through the adsorption cylinder. As the gas flows through the phase change microsphere packing layer, the LiCl loaded inside the phase change microsphere shell adsorbs trace amounts of water vapor, reducing the moisture content and dew point of the gas. Simultaneously, the C18 and C16 phase change core materials absorb or release heat using the latent heat of phase change, and the porous carbon aerogel shell slows down heat transfer, synergistically buffering system temperature fluctuations and preventing ice blockage in subsequent throttling valves and cryogenic equipment.

[0121] Regeneration or replacement of the adsorption cartridge: When the phase change microspheres approach saturation due to moisture absorption, close the bypass valve and cut off the airflow. The adsorption capacity can be restored using one of the following two methods: Method 1: Use the quick-connect flange interface to directly disassemble the saturated adsorption cylinder and replace it with a pre-prepared new adsorption cylinder.

[0122] Method 2: Close the inlet and outlet valves, open the vent valve to evacuate the cylinder until the absolute pressure is below 1 kPa; No additional heating is required; low pressure is used to promote moisture evaporation (the boiling point of water decreases as pressure decreases). Maintaining a vacuum at room temperature for 2-4 hours allows partial desorption of moisture adsorbed by LiCl, restoring some of the phase change microspheres' hygroscopic capacity. After completion, the vacuum system is shut off, a small amount of dry CO2 gas is introduced to restore atmospheric pressure, and the system is put back into use.

[0123] It should be noted that the regeneration efficiency of the phase change microspheres in Method 2 is limited, and a new adsorption cartridge still needs to be replaced after multiple cycles.

[0124] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. An integrated pressurized liquefaction device for ship CO2 capture systems, characterized in that, It includes an external CO2 recovery unit, which is connected to an air cooler. The air cooler is connected to a compressor system, and the compressor system is connected to a flash economizer. The flash economizer is connected to the compressor system through a secondary economizer, and the secondary economizer is connected to a CO2 storage device through a subcooler. The CO2 storage device is connected to the air cooler.

2. The integrated pressurized liquefaction device for a ship CO2 capture system according to claim 1, characterized in that, The CO2 recovery unit is connected to a gas cooler, which in turn is connected to a compressor system. The compressor system is then connected to a flash economizer. Specifically, this includes: The compressor system includes a high-pressure stage compressor, a low-pressure stage compressor, and an oil separator; the CO2 recovery unit is connected to a confluence valve one via a throttle valve one, confluence valve one is connected to an air cooler via a confluence valve two, and confluence valve two is connected to a subcooler; the air cooler is connected to the oil separator via the low-pressure stage compressor, the oil separator is connected to a flash economizer, the flash economizer is connected to the high-pressure stage compressor via a confluence valve three, and the high-pressure stage compressor is connected to the flash economizer via a condenser.

3. The integrated pressurized liquefaction device for a ship CO2 capture system according to claim 2, characterized in that, The flash economizer is connected to the compressor system via a secondary economizer, specifically including: The flash economizer is connected to splitter one. Splitter one has three connection methods: splitter one is directly connected to the secondary economizer, splitter one is connected to the secondary economizer through throttle valve five, and splitter one is connected to the air cooler through throttle valve six; the secondary economizer is connected to the low-pressure stage compressor.

4. The integrated pressurized liquefaction device for a ship CO2 capture system according to claim 1, characterized in that, The secondary economizer is connected to the CO2 storage device via a subcooler, specifically including: The secondary economizer is connected to the second distributor. The second distributor has two connection methods: the second distributor is directly connected to the subcooler; the second distributor is connected to the subcooler through the seventh throttle valve; and the subcooler is connected to the CO2 storage device through the third throttle valve.

5. The integrated pressurized liquefaction device for a ship CO2 capture system according to claim 1, characterized in that, The CO2 recovery unit is connected to a gas cooler, which in turn is connected to a compressor system. The compressor system is then connected to a flash economizer. Specifically, this includes: The compressor system includes an expander and a centrifugal compressor; the CO2 recovery unit is connected to the expander via a pneumatic switch valve one, the expander is connected to the centrifugal compressor, the expander is connected to a confluence valve two, the confluence valve two is connected to a subcooler, the confluence valve two is connected to an air cooler, the air cooler is connected to the centrifugal compressor, and the centrifugal compressor is connected to a flash economizer via a condenser.

6. The integrated pressurized liquefaction device for a ship CO2 capture system according to claim 5, characterized in that, The flash economizer is connected to the compressor system via a secondary economizer, specifically including: The flash economizer is connected to the first distributor. The first distributor has three connection methods: the first distributor is directly connected to the second-stage economizer, the first distributor is connected to the second-stage economizer through the fifth throttle valve, and the first distributor is connected to the air cooler through the sixth throttle valve; the second-stage economizer is connected to the centrifugal compressor.

7. The integrated pressurized liquefaction device for a ship CO2 capture system according to claim 2, characterized in that, CO2 storage devices are connected to gas coolers, specifically including: The CO2 storage device is connected to the first confluencer via the second throttle valve, the first confluencer is connected to the second confluencer, and the second confluencer is connected to the gas cooler.

8. The integrated pressurized liquefaction device for a ship CO2 capture system according to claim 5, characterized in that, CO2 storage devices are connected to gas coolers, specifically including: The CO2 storage device is connected to the first confluencer via the second throttle valve. The first confluencer is connected to the second confluencer via the expander. The second confluencer is connected to the gas cooler.

9. The integrated pressurized liquefaction device for a ship CO2 capture system according to claim 1, characterized in that, An adsorption cylinder is added between the outlet of the CO2 recovery unit and the throttle valve. Phase change microspheres are added to the adsorption cylinder. The preparation method of the phase change microspheres includes the following steps: PVA solution was spray-formed into microspheres, which were then dried to obtain PVA microspheres. PVA microspheres were added to an RF solution, stirred, then allowed to stand, aged, and freeze-dried to obtain RF-coated microspheres. RF-coated microspheres were heat-treated to obtain carbonized microspheres; The carbonized microspheres were immersed in a saturated LiCl methanol solution at room temperature and atmospheric pressure. After immersion, the carbonized microspheres were removed, washed, and dried to obtain LiCl preloaded carbonized microspheres. C18 and C16 are melted to obtain a phase change mixture; LiCl preloaded carbonized microspheres were placed in a container, and a phase change mixture was added to immerse the LiCl preloaded carbonized microspheres. The container was then placed in a vacuum impregnation apparatus, and a vacuum was drawn to maintain the impregnation for 0.5-2 hours. Subsequently, the vacuum was released and the pressure was restored to normal. The mixture was kept at 60-80℃ for 0.5-1 hours. After impregnation, the microspheres were removed, cooled, and obtained.

10. The integrated pressurized liquefaction device for a ship CO2 capture system according to claim 9, characterized in that, The preparation method of RF solution includes the following steps: mixing resorcinol, formaldehyde solution, sodium carbonate solution, and deionized water to obtain RF solution; The preparation method of saturated LiCl methanol solution includes the following steps: dissolving LiCl in methanol to obtain saturated LiCl methanol solution.

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