Carbon dioxide pressurization system and method of carbon dioxide pressurization

Abstract

The application discloses a carbon dioxide pressurization system and a carbon dioxide pressurization method, and belongs to the technical field of pipeline transportation. In the system, a multistage pressurization compressor pressurizes gaseous carbon dioxide multiple times until the liquefaction pressure of the carbon dioxide is reached, and the heat generated by the gaseous carbon dioxide after each pressurization is transferred to an absorption refrigerator through a first heat exchange system for heat exchange. When the liquefaction pressure is reached, the multistage pressurization compressor transfers the heat generated by the gaseous carbon dioxide reaching the liquefaction pressure to the absorption refrigerator through a second heat exchange system for heat exchange. The second heat exchange system cools the gaseous carbon dioxide to obtain liquid carbon dioxide, and the liquid carbon dioxide is transported to a pressurization system, and the pressurization system pressurizes the liquid carbon dioxide to a supercritical pressure. The system can cool the carbon dioxide by absorbing the heat generated by the pressurization of the carbon dioxide through the absorption refrigerator, does not need to input extra energy, and can greatly reduce energy consumption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipeline transportation, in particular to a carbon dioxide pressurization system and a carbon dioxide pressurization method. BACKGROUND

[0002] Carbon capture, utilization and storage (CCUS) refers to a technology that captures and purifies carbon dioxide emitted in a production process, and then recycles or stores the carbon dioxide in a new production process. At present, it is considered that the method of transporting carbon dioxide from a capture point to a storage site through a pipeline is the most cost-effective and most reliable method for CCUS. In order to effectively transport carbon dioxide, the low-pressure carbon dioxide after capture needs to be pressurized until the carbon dioxide reaches a supercritical pressure, and then the carbon dioxide is transported through a pipeline.

[0003] In the related art, the carbon dioxide is pressurized multiple times by a multi-stage pressurization compressor until the carbon dioxide reaches a liquefaction pressure. Since the temperature of the carbon dioxide will rise during the pressurization process, the carbon dioxide needs to be cooled by a cooling system each time the carbon dioxide is pressurized. When the carbon dioxide reaches the liquefaction pressure, the carbon dioxide needs to be cooled by another cooling system, and then the carbon dioxide is pressurized to a supercritical pressure by a pressurization pump.

[0004] Since the multi-stage pressurization compressor and the pressurization pump consume a large amount of energy in pressurizing the carbon dioxide, and the carbon dioxide is additionally cooled by two cooling systems, the energy consumption is further increased, resulting in a large energy consumption in the carbon dioxide pressurization process. SUMMARY

[0005] Embodiments of the present application provide a carbon dioxide pressurization system and a carbon dioxide pressurization method, which can reduce the energy consumption in the carbon dioxide pressurization process. The technical solution is as follows:

[0006] In one aspect, a carbon dioxide pressurization system is provided, which includes a multi-stage pressurization compressor, a pressurization system, an absorption refrigeration machine, a first heat exchange system, and a second heat exchange system.

[0007] A first end of the multi-stage pressurization compressor is connected to a first end of the first heat exchange system, and a second end of the first heat exchange system is connected to a first end of the absorption refrigeration machine.

[0008] A second end of the multi-stage pressurization compressor is connected to a first end of the second heat exchange system, a second end of the second heat exchange system is connected to a second end of the absorption refrigeration machine, and a third end of the second heat exchange system is connected to the pressurization system.

[0009] The multi-stage booster compressor is configured to boost the gaseous carbon dioxide multiple times, and after each boosting, the boosted gaseous carbon dioxide is delivered to the first heat exchange system until a liquefaction pressure of the carbon dioxide is reached.

[0010] The first heat exchange system is configured to transfer heat generated by the gaseous carbon dioxide after each boosting to the absorption chiller for heat exchange.

[0011] The first heat exchange system is further configured to deliver the gaseous carbon dioxide with reduced heat to the multi-stage booster compressor.

[0012] The multi-stage booster compressor is further configured to deliver the gaseous carbon dioxide reaching the liquefaction pressure to the second heat exchange system when the liquefaction pressure is reached.

[0013] The second heat exchange system is configured to transfer heat generated by the gaseous carbon dioxide reaching the liquefaction pressure to the absorption chiller for heat exchange.

[0014] The second heat exchange system is further configured to cool the gaseous carbon dioxide to obtain liquid carbon dioxide, and deliver the liquid carbon dioxide to the booster system.

[0015] The booster system is configured to boost the liquid carbon dioxide to a supercritical pressure.

[0016] In a possible implementation, the system further includes a first cooler and a first gas-liquid separator.

[0017] A first end of the first cooler is connected to a third end of the first heat exchange system, a second end of the first cooler is connected to a first end of the first gas-liquid separator, and a second end of the first gas-liquid separator is connected to a second end of the multi-stage booster compressor.

[0018] The first heat exchange system is further configured to deliver the gaseous carbon dioxide with reduced heat to the first cooler.

[0019] The first cooler is configured to further cool the gaseous carbon dioxide with reduced heat, and deliver the cooled gaseous carbon dioxide to the first gas-liquid separator.

[0020] The first gas-liquid separator is configured to separate liquid from the cooled gaseous carbon dioxide, and deliver the separated gaseous carbon dioxide back to the multi-stage booster compressor.

[0021] In another possible implementation, the system further includes a dehydration device.

[0022] The first end of the dewatering device is connected with the second end of the first gas-liquid separator, and the second end of the dewatering device is connected with the third end of the multi-stage booster compressor.

[0023] The first gas-liquid separator is configured to, when the number of times of boosting reaches the preset number of times, transport the separated gaseous carbon dioxide to the dewatering device.

[0024] The dewatering device is configured to further dewater the separated gaseous carbon dioxide until the water content of the dewatered gaseous carbon dioxide meets the requirement, and transport the gaseous carbon dioxide meeting the requirement back to the multi-stage booster compressor.

[0025] In another possible implementation, the system further includes a third heat exchange system.

[0026] The first end of the third heat exchange system is connected with the third end of the absorption refrigerating machine, and the second end of the third heat exchange system is connected with the dewatering device.

[0027] The dewatering device is further configured to, after the dewatering agent is saturated, heat the dewatering agent, and transport the heated dewatering agent or regenerated gas to the third heat exchange system, wherein the regenerated gas is generated after the dewatering agent is heated.

[0028] The third heat exchange system is configured to transfer heat generated by the heated dewatering agent or the regenerated gas to the absorption refrigerating machine for heat exchange.

[0029] In another possible implementation, the system further includes a second cooler.

[0030] The first end of the second cooler is connected with the second end of the multi-stage booster compressor, and the second end of the second cooler is connected with the first end of the second heat exchange system.

[0031] The multi-stage booster compressor is further configured to, when the liquefaction pressure is reached, transport the gaseous carbon dioxide reaching the liquefaction pressure to the second cooler.

[0032] The second cooler is configured to cool the gaseous carbon dioxide reaching the liquefaction pressure, and transport the cooled gaseous carbon dioxide to the second heat exchange system.

[0033] In another possible implementation, the system further includes a second gas-liquid separator.

[0034] The first end of the second gas-liquid separator is connected with the third end of the second heat exchange system, and the second end of the second gas-liquid separator is connected with the booster system.

[0035] The second heat exchange system is configured to deliver the liquid carbon dioxide to the second gas-liquid separator.

[0036] The second gas-liquid separator is configured to separate the gas in the liquid carbon dioxide and deliver the separated liquid carbon dioxide to the booster system.

[0037] In another aspect, a method for boosting carbon dioxide is provided, the method comprising:

[0038] The multi-stage booster compressor boosts the gaseous carbon dioxide multiple times, and after each boosting, the boosted gaseous carbon dioxide is delivered to a first heat exchange system until a liquefaction pressure of carbon dioxide is reached.

[0039] The first heat exchange system exchanges heat generated by the gaseous carbon dioxide after each boosting with an absorption chiller.

[0040] The first heat exchange system delivers the gaseous carbon dioxide with reduced heat to the multi-stage booster compressor.

[0041] When the liquefaction pressure is reached, the multi-stage booster compressor delivers the gaseous carbon dioxide reaching the liquefaction pressure to a second heat exchange system.

[0042] The second heat exchange system exchanges heat generated by the gaseous carbon dioxide reaching the liquefaction pressure with the absorption chiller.

[0043] The second heat exchange system cools the gaseous carbon dioxide to obtain liquid carbon dioxide and delivers the liquid carbon dioxide to a booster system.

[0044] The booster system boosts the liquid carbon dioxide to a supercritical pressure.

[0045] In a possible implementation, the first heat exchange system delivers the gaseous carbon dioxide with reduced heat to the multi-stage booster compressor, comprising:

[0046] The first heat exchange system delivers the gaseous carbon dioxide with reduced heat to a first cooler.

[0047] The first cooler further cools the gaseous carbon dioxide with reduced heat and delivers the cooled gaseous carbon dioxide to a first gas-liquid separator.

[0048] The first gas-liquid separator separates the liquid in the cooled gaseous carbon dioxide and delivers the separated gaseous carbon dioxide back to the multi-stage booster compressor.

[0049] In another possible implementation, the first gas-liquid separator separates liquid from the cooled gaseous carbon dioxide, and the separated gaseous carbon dioxide is fed back to the multi-stage booster compressor, including:

[0050] When the number of pressurization reaches the preset number, the first gas-liquid separator feeds the separated gaseous carbon dioxide to a dehydration device;

[0051] The dehydration device further dehydrates the separated gaseous carbon dioxide until the water content of the dehydrated gaseous carbon dioxide meets the requirement, and feeds the gaseous carbon dioxide meeting the requirement back to the multi-stage booster compressor.

[0052] In another possible implementation, the method further includes:

[0053] When the dehydration agent is saturated, the dehydration device heats the dehydration agent, and feeds the heated dehydration agent or regenerated gas to a third heat exchange system; the regenerated gas is generated after the dehydration agent is heated.

[0054] The third heat exchange system exchanges heat with the absorption refrigeration machine by transferring heat generated by the heated dehydration agent or the regenerated gas.

[0055] In another possible implementation, when the liquefaction pressure is reached, the multi-stage booster compressor feeds the gaseous carbon dioxide reaching the liquefaction pressure to a second heat exchange system, including:

[0056] When the liquefaction pressure is reached, the multi-stage booster compressor feeds the gaseous carbon dioxide reaching the liquefaction pressure to a second cooler;

[0057] The second cooler cools the gaseous carbon dioxide reaching the liquefaction pressure, and feeds the cooled gaseous carbon dioxide to the second heat exchange system.

[0058] In another possible implementation, the second heat exchange system feeds the liquid carbon dioxide to a pressurization system, including:

[0059] The second heat exchange system feeds the liquid carbon dioxide to a second gas-liquid separator;

[0060] The second gas-liquid separator separates gas from the liquid carbon dioxide, and feeds the separated liquid carbon dioxide to the pressurization system.

[0061] The embodiment of the present application provides a carbon dioxide pressurization system, which pressurizes carbon dioxide for multiple times through a multi-stage pressurization compressor, absorbs heat generated by pressurized carbon dioxide through an absorption refrigerating machine after each pressurization, so as to cool the carbon dioxide. In addition, the absorption refrigerating machine can also absorb heat generated by carbon dioxide reaching a liquefaction pressure, so as to cool the carbon dioxide. Therefore, the system can cool the carbon dioxide by absorbing heat generated by pressurized carbon dioxide through the absorption refrigerating machine, without additional energy input, and can greatly reduce energy consumption.

[0062] It should be understood that the above general description and the following detailed description are only exemplary and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 is a schematic diagram of a carbon dioxide pressurization system provided by the embodiment of the present application;

[0064] Figure 2 is a schematic diagram of another carbon dioxide pressurization system provided by the embodiment of the present application;

[0065] Figure 3 is a flow chart of a carbon dioxide pressurization method provided by the embodiment of the present application.

[0066] The reference signs respectively represent:

[0067] 10-multi-stage pressurization compressor, 11-pressurization system, 12-absorption refrigerating machine, 13-first heat exchange system,

[0068] 14-second heat exchange system, 15-first cooler, 16-first gas-liquid separator, 17-dehydration device,

[0069] 18-second cooler, 19-second gas-liquid separator, 121-generator, 122-evaporator,

[0070] 123-absorber, 124-condenser, 131-heat exchanger, 132-second circulating pipeline,

[0071] 133-first circulating pump, 141-third cooler, 142-fourth circulating pipeline, 143-fourth circulating pump. DETAILED DESCRIPTION

[0072] In order to make the technical scheme and advantages of the present application more clear, the embodiment of the present application is further described in detail.

[0073] The terms "first", "second", "third", and "fourth" and the like in the description and in the claims of the present application and in the accompanying drawings are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. The terms "comprises", "comprising", "includes", "including", "contains", "containing" and any variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, system, product, or apparatus that comprises, includes, contains or contains one or more steps or units listed need not comprise, include, contain or contain only those one or more steps or units but can optionally include one or more additional steps or units not listed.

[0074] Figure 1 is a schematic diagram of a carbon dioxide pressurization system provided by an embodiment of the present application, referring to Figure 1 The system comprises a multi-stage pressurization compressor 10, a pressurization system 11, an absorption refrigerating machine 12, a first heat exchange system 13, and a second heat exchange system 14.

[0075] A first end of the multi-stage pressurization compressor 10 is connected to a first end of the first heat exchange system 13, and a second end of the first heat exchange system 13 is connected to a first end of the absorption refrigerating machine 12.

[0076] A second end of the multi-stage pressurization compressor 10 is connected to a first end of the second heat exchange system 14, a second end of the second heat exchange system 14 is connected to a second end of the absorption refrigerating machine 12, and a third end of the second heat exchange system 14 is connected to the pressurization system 11.

[0077] The multi-stage pressurization compressor 10 is configured to pressurize the gaseous carbon dioxide multiple times, and after each pressurization, deliver the pressurized gaseous carbon dioxide to the first heat exchange system 13 until the liquefaction pressure of the carbon dioxide is reached.

[0078] The first heat exchange system 13 is configured to transfer the heat generated by the pressurized gaseous carbon dioxide to the absorption refrigerating machine 12 for heat exchange.

[0079] The first heat exchange system 13 is further configured to deliver the gaseous carbon dioxide with reduced heat to the multi-stage pressurization compressor 10.

[0080] The multi-stage pressurization compressor 10 is further configured to, when the liquefaction pressure is reached, deliver the gaseous carbon dioxide with the liquefaction pressure to the second heat exchange system 14.

[0081] The second heat exchange system 14 is configured to transfer the heat generated by the gaseous carbon dioxide with the liquefaction pressure to the absorption refrigerating machine 12 for heat exchange.

[0082] The second heat exchange system 14 is further configured to cool the gaseous carbon dioxide to obtain liquid carbon dioxide, and deliver the liquid carbon dioxide to the pressurization system 11.

[0083] A booster system 11 is used to boost the liquid carbon dioxide to supercritical pressure.

[0084] In the embodiment of the present application, the low-pressure carbon dioxide (1-5 bar) from the carbon dioxide capture plant needs to be boosted to supercritical pressure (80-150 bar) before entering the delivery pipeline. The multi-stage booster compressor 10 boosts the captured gaseous carbon dioxide multiple times, and the outlet temperature of the multi-stage booster compressor 10 can reach above 100℃ after each boosting. Due to the limitations of sealing and materials, the carbon dioxide after each boosting needs to be cooled. The multi-stage booster compressor 10 can be a plurality of compressors connected in series, or a device that gradually increases the pressure of the gas, and is not specifically limited.

[0085] In the embodiment of the present application, after each boosting, the multi-stage booster compressor 10 delivers the boosted gaseous carbon dioxide to the first heat exchange system 13, and the first heat exchange system 13 transfers the heat generated by the gaseous carbon dioxide after each boosting to the absorption chiller 12 for heat exchange.

[0086] In one possible implementation, referring to Figure 2 The first heat exchange system 13 includes a heat exchanger 131, a first circulating pipeline 132, and a first circulating pump 133. The first end of the heat exchanger 131 is connected to the first end of the multi-stage booster compressor 10, the second end of the heat exchanger 131 is connected to the first end of the absorption chiller 12, and the first circulating pipeline 132 is arranged between the heat exchanger 131 and the absorption chiller 12. The first circulating pump 133 is arranged on the first circulating pipeline 132.

[0087] In this implementation, the multi-stage booster compressor 10 delivers the boosted gaseous carbon dioxide to the heat exchanger 131, and the heat generated by the boosted gaseous carbon dioxide is transferred to the circulating water in the first circulating pipeline 132. The circulating water after absorbing heat flows in the first circulating pipeline 132, exchanges heat with the absorption chiller 12, and then the first circulating pump 133 delivers the circulating water after heat exchange back to the heat exchanger, thereby achieving cooling of the carbon dioxide.

[0088] For the convenience of understanding, the absorption refrigerating machine 12 is introduced first. The absorption refrigerating machine 12 mainly includes a generator 121, an evaporator 122, an absorber 123 and a condenser 124, and the working principle of the absorption refrigerating machine 12 is as follows: using a working heat source (such as water vapor, hot water and gas, etc.) to heat the solution with a certain concentration delivered from the absorber 123 to the generator 121 by a solution pump, and to make most of the low-boiling-point refrigerant in the solution evaporate. The refrigerant vapor enters the condenser 124 and is condensed into refrigerant liquid by the cooling medium in the condenser 124, and then is reduced in pressure to the evaporation pressure by a throttling device. The refrigerant enters the evaporator 122 through the throttling device, absorbs the heat of the cooled system in the evaporator 122, and is activated into refrigerant vapor at the evaporation pressure. The remaining solution (high-boiling-point absorbent and a small amount of unevaporated refrigerant) in the generator 121 is reduced in pressure to the evaporation pressure by a throttling device, enters the absorber 123, and absorbs the low-pressure refrigerant vapor from the evaporator 122 to recover to the original concentration.

[0089] Among them, the absorption process is often an exothermic process, so the mixed solution needs to be cooled by cooling water in the absorber 123, and the solution with recovered concentration in the absorber 123 is pumped to the generator 121 again to continue the cycle.

[0090] The absorption refrigerating machine 12 completes the refrigeration cycle by using the characteristics that the solution can precipitate low-boiling-point vapor under certain conditions and strongly absorb low-boiling-point vapor under another condition. The absorption refrigerating machine 12 usually uses binary solution as the working medium, and the low-boiling-point component is generally called refrigerant, and the high-boiling-point component is called absorbent. There are two commonly used absorption refrigerating machines 12, namely ammonia-water absorption refrigerating machine and lithium bromide-water absorption refrigerating machine. The difference between the absorption refrigerating machine 12 and the compression refrigerating machine is that the absorption refrigerating machine 12 does not have a prime mover for compression.

[0091] In the embodiment of the application, the circulating water after absorbing heat flows in the first circulating pipeline 132 and exchanges heat with the generator 121 of the absorption refrigerating machine 12, that is, the generator 121 uses the heat absorbed by the circulating water as a working heat source to heat the refrigerant in the generator 121, so that the refrigerant exchanges heat with the circulating water in the first circulating pipeline 132. The circulating water with reduced heat is circulated back to the heat exchanger, absorbs heat again, and then transfers the heat to the generator 121, so as to realize the cooling of carbon dioxide. Among them, other forms of low-temperature heat sources, such as solar energy, boiler waste heat, etc., can also transfer heat to the generator 121 through the circulating water.

[0092] And, the absorber 123 can be cooled by cooling water, the temperature of the cooling water increases by absorbing heat, obtaining hot water, which can be used in production and living areas. In addition, the condenser 124 can also be cooled by cooling water.

[0093] In the embodiment of the present application, in order to cool the gaseous carbon dioxide to the required temperature of the multi-stage booster compressor 10, further cooling can be performed by a cooler. Correspondingly, continuing to refer to Figure 2 The system further comprises a first cooler 15 and a first gas-liquid separator 16.

[0094] The first end of the first cooler 15 is connected with the third end of the first heat exchange system 13, the second end of the first cooler 15 is connected with the first end of the first gas-liquid separator 16, and the second end of the first gas-liquid separator 16 is connected with the second end of the multi-stage booster compressor 10.

[0095] The first heat exchange system 13 is further configured to deliver the gaseous carbon dioxide with reduced heat to the first cooler 15.

[0096] The first cooler 15 is configured to further cool the gaseous carbon dioxide with reduced heat, and deliver the cooled gaseous carbon dioxide to the first gas-liquid separator 16.

[0097] The first gas-liquid separator 16 is configured to separate the liquid in the cooled gaseous carbon dioxide, and deliver the separated gaseous carbon dioxide back to the multi-stage booster compressor 10.

[0098] In the implementation mode, the first end of the first cooler 15 is connected with the third end of the heat exchanger 131, the heat exchanger 131 delivers the gaseous carbon dioxide with reduced heat to the first cooler 15, the first cooler 15 further cools the gaseous carbon dioxide with reduced heat, and when the temperature of the cooled gaseous carbon dioxide meets the boosting requirement of the multi-stage booster compressor 10, the first cooler 15 delivers the cooled gaseous carbon dioxide to the first gas-liquid separator 16.

[0099] The first gas-liquid separator 16 separates the liquid in the cooled gaseous carbon dioxide, and delivers the separated gaseous carbon dioxide back to the multi-stage booster compressor 10, so that the multi-stage booster compressor 10 boosts the carbon dioxide to the next stage.

[0100] In the embodiment of the present application, in order to further improve the cooling effect on carbon dioxide, the first cooler 15 can also be connected with the evaporator 122 of the absorption chiller 12 through a second circulating pipeline, and a second circulating pump is arranged between the second circulating pipeline and the absorption chiller 12. The gaseous carbon dioxide with reduced heat is delivered to the first cooler 15 by the heat exchanger 131, and the gaseous carbon dioxide with reduced heat further transfers heat to the circulating water in the second circulating pipeline, and the circulating water after absorbing heat flows in the second circulating pipeline and exchanges heat with the evaporator 122. The refrigerant in the evaporator 122 absorbs heat of the circulating water in the second circulating pipeline to evaporate, the temperature of the circulating water in the second circulating pipeline is reduced to obtain cooling water, and the second circulating pump delivers the cooling water back to the first cooler 15, and the cooling water absorbs heat of the gaseous carbon dioxide in the first cooler 15 again to transfer the heat to the refrigerant in the evaporator 122 again, so as to realize further cooling of carbon dioxide.

[0101] In the embodiment of the present application, in order to further improve the cooling effect on carbon dioxide, the first cooler 15 can also be connected with the evaporator 122 of the absorption chiller 12 through a second circulating pipeline, and a second circulating pump is arranged between the second circulating pipeline and the absorption chiller 12. The gaseous carbon dioxide with reduced heat is delivered to the first cooler 15 by the heat exchanger 131, and the gaseous carbon dioxide with reduced heat further transfers heat to the circulating water in the second circulating pipeline, and the circulating water after absorbing heat flows in the second circulating pipeline and exchanges heat with the evaporator 122. The refrigerant in the evaporator 122 absorbs heat of the circulating water in the second circulating pipeline to evaporate, the temperature of the circulating water in the second circulating pipeline is reduced to obtain cooling water, and the second circulating pump delivers the cooling water back to the first cooler 15, and the cooling water absorbs heat of the gaseous carbon dioxide in the first cooler 15 again to transfer the heat to the refrigerant in the evaporator 122 again, so as to realize further cooling of carbon dioxide.

[0102] It should be noted that if the temperature of the gaseous carbon dioxide after heat exchange between the first heat exchange system 13 and the absorption chiller 12 can meet the requirements of the multi-stage booster compressor 10, the gaseous carbon dioxide with reduced heat can be directly delivered to the first gas-liquid separator 16.

[0103] In the embodiment of the present application, after the carbon dioxide is boosted for a certain number of times, the carbon dioxide needs to be deeply dehydrated to meet the delivery requirements of the delivery pipeline. Accordingly, continuing to refer to Figure 2 , the system further comprises a dehydration device 17;

[0104] The first end of the dehydration device 17 is connected with the second end of the first gas-liquid separator 16, and the second end of the dehydration device 17 is connected with the third end of the multi-stage booster compressor 10.

[0105] The first gas-liquid separator 16 is used for delivering the separated gaseous carbon dioxide to the dehydration device 17 when the number of boosting reaches a preset number.

[0106] The dehydration device 17 is used for further dehydrating the separated gaseous carbon dioxide until the water content of the gaseous carbon dioxide after dehydration meets the requirements, and delivering the gaseous carbon dioxide meeting the requirements back to the multi-stage booster compressor 10.

[0107] In this implementation, the preset number of boosting cycles can be determined based on the actual dehydration pressure requirements and the pressure after more than 10 boosting cycles by the multi-stage booster compressor. However, the preset number of boosting cycles is less than or equal to the maximum number of boosting cycles. For example, if the maximum number of boosting cycles is 7, the preset number of boosting cycles could be 2 or 3.

[0108] In this embodiment, when the dehydrating agent in the dehydration device 17 adsorbs or absorbs a certain amount of water, it will reach saturation. In this case, the dehydrating agent can be regenerated. The dehydrating agent regeneration process requires heating and cooling. To further reduce energy consumption, the dehydration device 17 can be connected to the evaporator 122 of the absorption chiller 12, and the heated dehydrating agent can be cooled by the absorption chiller 12. Accordingly, the system also includes a third heat exchange system.

[0109] The first end of the third heat exchange system is connected to the third end of the absorption chiller 12, and the second end of the third heat exchange system is connected to the dehydration device 17.

[0110] The dehydration equipment 17 is also used to heat the dehydrating agent after it has become saturated, and to deliver the heated dehydrating agent or regeneration gas to the third heat exchange system; wherein, the regeneration gas is generated after the dehydrating agent is heated;

[0111] The third heat exchange system is used to transfer the heat generated by the heated dehydrating agent or regeneration gas to the absorption chiller 12 for heat exchange.

[0112] In this implementation, the third heat exchange system includes a third circulation pipe and a third circulation pump. The two ends of the third circulation pipe are connected to the dehydration device 17 and the evaporator 122, respectively, and the third circulation pump is installed on the third circulation pipe.

[0113] Dehydration equipment is categorized into solution absorption (e.g., triethylene glycol dehydration) and solid adsorption (e.g., molecular sieve adsorption). After absorbing a certain amount of water, the dehydrating agent used in solution absorption requires heating for regeneration, while the adsorbent used in solid adsorption, i.e., the dehydrating agent, also needs regeneration. For solution absorption, the dehydrating agent can be regenerated by first heating and then cooling it. For solid adsorption, the adsorbent can be regenerated by first heating it to obtain heated regeneration gas, and then cooling the heated regeneration gas.

[0114] Therefore, if the dehydration equipment uses the solution absorption method for dehydration, after the dehydrating agent is saturated, the dehydration equipment 17 heats the dehydrating agent. After heating, the circulating water in the third circulation pipe absorbs the heat generated by the dehydrating agent. The circulating water, after absorbing heat, flows in the third circulation pipe and exchanges heat with the evaporator 122. The refrigerant in the evaporator 122 absorbs the heat from the circulating water in the third circulation pipe and evaporates, lowering the temperature of the circulating water in the third circulation pipe, thus obtaining cooling water. The third circulation pump transports this cooling water back to the dehydration equipment 17, where it absorbs the heat from the dehydrating agent again and transfers this heat to the refrigerant in the evaporator 122. This cycle continues, thereby cooling the dehydrating agent and regenerating it.

[0115] If the dehydration equipment uses solid adsorption, after the adsorbent (i.e., the dehydrating agent) becomes saturated, it is heated to generate regeneration gas. The circulating water in the third circulation pipe absorbs the heat generated by the regeneration gas and flows within the pipe, exchanging heat with the evaporator 122. The refrigerant in the evaporator 122 absorbs the heat from the circulating water in the third circulation pipe and evaporates, lowering the temperature of the water and producing cooling water. The third circulation pump returns this cooling water to the dehydration equipment 17, where it absorbs heat from the regeneration gas and transfers it to the refrigerant in the evaporator 122. This cycle continues, thus cooling and regenerating the dehydrating agent.

[0116] In this embodiment, when the carbon dioxide reaches its liquefaction pressure, the multi-stage booster compressor 10 can first perform preliminary cooling of the carbon dioxide at the liquefaction pressure through the second cooler 18, and then perform further cooling through the absorption chiller 12. Accordingly, see below. Figure 2 The system also includes: a second cooler 18;

[0117] The first end of the second cooler 18 is connected to the second end of the multi-stage booster compressor 10, and the second end of the second cooler 18 is connected to the first end of the second heat exchange system 14.

[0118] The multi-stage booster compressor 10 is also used to deliver gaseous carbon dioxide that has reached liquefaction pressure to the second cooler 18 when liquefaction pressure is reached;

[0119] The second cooler 18 is used to cool the gaseous carbon dioxide that has reached liquefaction pressure and to deliver the cooled gaseous carbon dioxide to the second heat exchange system 14.

[0120] In this implementation, when carbon dioxide is pressurized to liquefaction pressure, the multi-stage booster compressor 10 delivers gaseous carbon dioxide that has reached liquefaction pressure to the second cooler 18. The second cooler 18 performs preliminary cooling on the gaseous carbon dioxide that has reached liquefaction pressure, and then delivers the cooled gaseous carbon dioxide to the second heat exchange system 14.

[0121] The second heat exchange system 14 includes a third cooler 141, a fourth circulation pipe 142, and a fourth circulation pump 143. The first end of the third cooler 141 is connected to the second end of the second cooler 18. The second end of the third cooler 141 is connected to the pressurization system 11. The third end of the third cooler 141 is connected to one end of the fourth circulation pipe 142. The other end of the fourth circulation pipe 142 is connected to the evaporator 122 of the absorption chiller 12. The fourth circulation pump 143 is installed on the fourth circulation pipe 142.

[0122] In this implementation, the second cooler 18 supplies cooled gaseous carbon dioxide to the third cooler 141. Circulating water in the fourth circulation pipe 142 absorbs heat from the cooled gaseous carbon dioxide and flows within the pipe, exchanging heat with the evaporator 122. The refrigerant in the evaporator 122 absorbs heat from the circulating water in the fourth circulation pipe 142 and evaporates, lowering the temperature of the water and producing cooling water. The fourth circulation pump 143 then pumps this cooling water back to the third cooler 141. This cooling water then absorbs heat from the carbon dioxide in the third cooler 141 and transfers this heat to the refrigerant in the evaporator 122. This cycle continues, further cooling the carbon dioxide. After being cooled by the third cooler 141, the carbon dioxide changes from a gaseous state to a liquid state.

[0123] In this embodiment, before the liquid carbon dioxide is delivered to the pressurization system 11, a gas-liquid separator can be used to separate the gas from the liquid carbon dioxide. Accordingly, see below. Figure 2 The system also includes: a second gas-liquid separator 19;

[0124] The first end of the second gas-liquid separator 19 is connected to the third end of the second heat exchange system 14, and the second end of the second gas-liquid separator 19 is connected to the pressurization system 11.

[0125] The second heat exchange system 14 is used to transport liquid carbon dioxide to the second gas-liquid separator 19;

[0126] The second gas-liquid separator 19 is used to separate the gas from the liquid carbon dioxide and transport the separated liquid carbon dioxide to the pressurization system 11.

[0127] In this implementation, after the second gas-liquid separator 19 separates the gas from the liquid carbon dioxide, the separated liquid carbon dioxide is transported to the pressurization system 11. The pressurization system 11 includes a pressurization pump, which pressurizes the liquid carbon dioxide to the required supercritical pressure, and then transports it through a delivery pipeline.

[0128] In another possible implementation, the second gas-liquid separator 19 transports the separated liquid carbon dioxide to a storage tank for storage, or directly loads it onto a vehicle or ship, without any specific limitation.

[0129] This application provides a carbon dioxide pressurization system. The system uses a multi-stage pressurization compressor to pressurize carbon dioxide multiple times. After each pressurization, an absorption chiller absorbs the heat generated during the pressurization process, thereby cooling the carbon dioxide. Furthermore, the absorption chiller can also absorb the heat generated by the carbon dioxide reaching liquefaction pressure, thus cooling the carbon dioxide. Therefore, this system can cool carbon dioxide by absorbing the heat generated during pressurization using an absorption chiller, eliminating the need for additional energy input and significantly reducing energy consumption.

[0130] In this embodiment, the waste heat from the multi-stage booster compressor, solar heating, or other forms of low-temperature waste heat are used as the driving heat source for the absorption chiller. The cooling water generated by the absorption chiller can be used for cooling the carbon dioxide liquefaction process, cooling the dehydrating agent in the dehydration equipment, and cooling the heat exchange of the first cooler. This system helps save compression work in the carbon dioxide booster process, replaces the direct compression booster scheme with a liquefaction booster scheme, and recovers and utilizes the waste heat from compression, reducing operating costs and energy consumption, improving economic efficiency, and facilitating further promotion and application.

[0131] For a supercritical carbon dioxide transmission pipeline with a capacity of 1 million tons / year, assuming a pressurization from 0.2 MPa to 15 MPa, the solution provided in this application can save approximately 1400 kW of compression power and 1.12 × 10⁻⁶ kilowatt-hours of electricity per year. 7 With an electricity cost of 0.4 yuan / kWh, the annual savings would be approximately 4.48 million yuan. The solution provided in this application solves the problem of difficult access to cold sources in the first-station carbon dioxide liquefaction pressurization scheme of supercritical carbon dioxide long-distance pipelines, and can reduce the pressurization operating cost by at least 10%. Compared with the scheme of direct pressurization through multi-stage pressurization compressors, it is more energy-efficient and advanced.

[0132] Figure 3 This is a flowchart of a carbon dioxide pressurization method provided in this application, see [link / reference]. Figure 3 The method includes:

[0133] Step 301: The multi-stage booster compressor boosts the gaseous carbon dioxide multiple times. After each boost, the boosted gaseous carbon dioxide is delivered to the first heat exchange system until the liquefaction pressure of the carbon dioxide is reached.

[0134] Step 302: The first heat exchange system transfers the heat generated by the gaseous carbon dioxide after each pressurization to the absorption chiller for heat exchange.

[0135] Step 303: The first heat exchange system returns the cooled gaseous carbon dioxide to the multi-stage booster compressor.

[0136] Step 304: When the liquefaction pressure is reached, the multi-stage booster compressor delivers gaseous carbon dioxide that has reached the liquefaction pressure to the second heat exchange system.

[0137] Step 305: The second heat exchange system transfers the heat generated by the gaseous carbon dioxide that has reached liquefaction pressure to the absorption chiller for heat exchange.

[0138] Step 306: The second heat exchange system cools the gaseous carbon dioxide to obtain liquid carbon dioxide, and then transports the liquid carbon dioxide to the pressurization system.

[0139] Step 307: The pressurization system pressurizes the liquid carbon dioxide to supercritical pressure.

[0140] In one possible implementation, the first heat exchange system returns the cooled gaseous carbon dioxide to the multi-stage booster compressor, including:

[0141] The first heat exchange system delivers the cooled gaseous carbon dioxide to the first cooler;

[0142] The first cooler further cools the gaseous carbon dioxide, which has been deheated, and then transports the cooled gaseous carbon dioxide to the first gas-liquid separator.

[0143] The first gas-liquid separator separates the liquid from the cooled gaseous carbon dioxide and sends the separated gaseous carbon dioxide back to the multi-stage booster compressor.

[0144] In another possible implementation, a first gas-liquid separator separates the liquid from the cooled gaseous carbon dioxide and returns the separated gaseous carbon dioxide to the multi-stage booster compressor, including:

[0145] When the pressurization cycle reaches the preset number, the first gas-liquid separator will transport the separated gaseous carbon dioxide to the dehydration equipment;

[0146] The dehydration equipment further dehydrates the separated gaseous carbon dioxide until the water content of the dehydrated gaseous carbon dioxide meets the requirements; the gaseous carbon dioxide that meets the requirements is then sent back to the multi-stage booster compressor.

[0147] In another possible implementation, the method also includes:

[0148] After the dehydrating agent is saturated, the dehydrating equipment heats the dehydrating agent and supplies the heated dehydrating agent or regeneration gas to the third heat exchange system; wherein, the regeneration gas is generated after the dehydrating agent is heated;

[0149] The third heat exchange system transfers the heat generated by the heated dehydrating agent or regeneration gas to the absorption chiller for heat exchange.

[0150] In another possible implementation, when the liquefaction pressure is reached, the multi-stage booster compressor delivers gaseous carbon dioxide, having reached the liquefaction pressure, to the second heat exchange system, including:

[0151] When the liquefaction pressure is reached, the multi-stage booster compressor delivers gaseous carbon dioxide that has reached the liquefaction pressure to the second cooler;

[0152] The second cooler cools the gaseous carbon dioxide that has reached liquefaction pressure and then supplies the cooled gaseous carbon dioxide to the second heat exchange system.

[0153] In another possible implementation, the second heat exchange system delivers liquid carbon dioxide to the pressurization system, including:

[0154] The second heat exchange system delivers liquid carbon dioxide to the second gas-liquid separator;

[0155] The second gas-liquid separator separates the gas from the liquid carbon dioxide and delivers the separated liquid carbon dioxide to the pressurization system.

[0156] This application provides a method for pressurizing carbon dioxide. This method uses a multi-stage pressurizing compressor to pressurize carbon dioxide multiple times. After each pressurization, an absorption chiller absorbs the heat generated during the pressurization process, thereby cooling the carbon dioxide. Furthermore, the absorption chiller can also absorb the heat generated by the carbon dioxide reaching liquefaction pressure, thus cooling the carbon dioxide. Therefore, this method can cool carbon dioxide by absorbing the heat generated during pressurization using an absorption chiller, eliminating the need for additional energy input and significantly reducing energy consumption.

[0157] It should be noted that the carbon dioxide pressurization method provided in this application embodiment belongs to the same concept as the above-mentioned carbon dioxide pressurization system embodiment. For details of the specific process, please refer to the carbon dioxide pressurization system embodiment, which will not be repeated here.

[0158] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0159] The above description is only for the purpose of enabling those skilled in the art to understand the technical solution of this application, and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A carbon dioxide booster system, characterized in that, The system includes: a multi-stage booster compressor, a booster system, an absorption chiller, a first heat exchange system, a second heat exchange system, a first cooler, a first gas-liquid separator, a dehydration device, and a third heat exchange system; The first end of the multi-stage booster compressor is connected to the first end of the first heat exchange system, the second end of the first heat exchange system is connected to the first end of the absorption chiller, the third end of the first heat exchange system is connected to the first end of the first cooler, the second end of the first cooler is connected to the first end of the first gas-liquid separator, the second end of the first gas-liquid separator is connected to the second end of the multi-stage booster compressor and the first end of the dehydration device, and the second end of the dehydration device is connected to the third end of the multi-stage booster compressor. The second end of the multi-stage booster compressor is connected to the first end of the second heat exchange system, the second end of the second heat exchange system is connected to the second end of the absorption chiller, and the third end of the second heat exchange system is connected to the booster system. The first end of the third heat exchange system is connected to the third end of the absorption chiller, and the second end of the third heat exchange system is connected to the dehydration equipment. The multi-stage booster compressor is used to boost gaseous carbon dioxide multiple times. After each boosting, the boosted gaseous carbon dioxide is delivered to the first heat exchange system until the liquefaction pressure of carbon dioxide is reached. The first heat exchange system is used to transfer the heat generated by the gaseous carbon dioxide after each pressurization to the absorption chiller for heat exchange. The first heat exchange system is further configured to directly deliver the cooled gaseous carbon dioxide to the first gas-liquid separator when the temperature of the cooled gaseous carbon dioxide meets the boosting requirements of the multi-stage boosting compressor; and to deliver the cooled gaseous carbon dioxide to the first cooler when the temperature of the cooled gaseous carbon dioxide does not meet the boosting requirements of the multi-stage boosting compressor. The first cooler is used to further cool the gaseous carbon dioxide whose heat has been reduced, and to deliver the cooled gaseous carbon dioxide to the first gas-liquid separator. The first gas-liquid separator is used to separate the liquid from the cooled gaseous carbon dioxide or the gaseous carbon dioxide after heat reduction, and to send the separated gaseous carbon dioxide back to the multi-stage booster compressor; when the booster cycle reaches a preset number, the separated gaseous carbon dioxide is sent to the dehydration equipment; The dehydration equipment is used to further dehydrate the separated gaseous carbon dioxide until the water content of the dehydrated gaseous carbon dioxide meets the requirements; the gaseous carbon dioxide that meets the requirements is then transported back to the multi-stage booster compressor. The multi-stage booster compressor is also used to deliver gaseous carbon dioxide that has reached the liquefaction pressure to the second heat exchange system when the liquefaction pressure is reached; The second heat exchange system is used to transfer the heat generated by the gaseous carbon dioxide that has reached the liquefaction pressure to the absorption chiller for heat exchange. The second heat exchange system is also used to cool gaseous carbon dioxide to obtain liquid carbon dioxide, and to transport the liquid carbon dioxide to the pressurization system; The pressurization system is used to pressurize the liquid carbon dioxide to a supercritical pressure; The dehydration equipment is also used to heat the dehydrating agent after it has become saturated, and to supply the heated dehydrating agent or regeneration gas to the third heat exchange system; wherein the regeneration gas is generated after the dehydrating agent has been heated; The third heat exchange system is used to transfer the heat generated by the heated dehydrating agent or regeneration gas to the absorption chiller for heat exchange.

2. The system according to claim 1, characterized in that, The system also includes: a second cooler; The first end of the second cooler is connected to the second end of the multi-stage booster compressor, and the second end of the second cooler is connected to the first end of the second heat exchange system. The multi-stage booster compressor is also used to deliver gaseous carbon dioxide that has reached the liquefaction pressure to the second cooler when the liquefaction pressure is reached; The second cooler is used to cool the gaseous carbon dioxide that has reached the liquefaction pressure and to deliver the cooled gaseous carbon dioxide to the second heat exchange system.

3. The system according to claim 2, characterized in that, The system also includes: a second gas-liquid separator; The first end of the second gas-liquid separator is connected to the third end of the second heat exchange system, and the second end of the second gas-liquid separator is connected to the pressurization system. The second heat exchange system is used to transport the liquid carbon dioxide to the second gas-liquid separator; The second gas-liquid separator is used to separate the gas from the liquid carbon dioxide and deliver the separated liquid carbon dioxide to the pressurization system.

4. A method for pressurizing carbon dioxide, characterized in that, The method includes: The multi-stage booster compressor boosts gaseous carbon dioxide multiple times. After each boost, the boosted gaseous carbon dioxide is delivered to the first heat exchange system until the liquefaction pressure of carbon dioxide is reached. The first heat exchange system transfers the heat generated by the gaseous carbon dioxide after each pressurization to the absorption chiller for heat exchange. When the temperature of the cooled gaseous carbon dioxide meets the boosting requirements of the multi-stage booster compressor, the first heat exchange system directly delivers the cooled gaseous carbon dioxide to the first gas-liquid separator; when the temperature of the cooled gaseous carbon dioxide does not meet the boosting requirements of the multi-stage booster compressor, the first heat exchange system delivers the cooled gaseous carbon dioxide to the first cooler. The first cooler further cools the gaseous carbon dioxide whose heat has been reduced, and then delivers the cooled gaseous carbon dioxide to the first gas-liquid separator. The first gas-liquid separator separates the heat-reduced gaseous carbon dioxide or the liquid in the cooled gaseous carbon dioxide, and sends the separated gaseous carbon dioxide back to the multi-stage booster compressor; when the booster cycle reaches a preset number, the separated gaseous carbon dioxide is sent to the dehydration equipment; The dehydration equipment further dehydrates the separated gaseous carbon dioxide until the water content of the dehydrated gaseous carbon dioxide meets the requirements; the gaseous carbon dioxide that meets the requirements is then transported back to the multi-stage booster compressor. When the liquefaction pressure is reached, the multi-stage booster compressor delivers gaseous carbon dioxide that has reached the liquefaction pressure to the second heat exchange system; The second heat exchange system transfers the heat generated by the gaseous carbon dioxide that has reached the liquefaction pressure to the absorption chiller for heat exchange. The second heat exchange system cools gaseous carbon dioxide to obtain liquid carbon dioxide, and then delivers the liquid carbon dioxide to the pressurization system; The pressurization system pressurizes the liquid carbon dioxide to supercritical pressure; The method further includes: After the dehydrating agent becomes saturated, the dehydrating equipment heats the dehydrating agent and supplies the heated dehydrating agent or regeneration gas to the third heat exchange system; wherein the regeneration gas is generated after the dehydrating agent is heated. The third heat exchange system transfers the heat generated by the heated dehydrating agent or regeneration gas to the absorption chiller for heat exchange.

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