Carbon capture system and desorption tower device thereof

Abstract

The utility model discloses a carbon capture system and a desorption tower device thereof, the desorption tower device comprises a cylinder body, and a demister, a liquid distributor, a filler layer and a heat exchange device which are arranged in the cylinder body and are sequentially arranged from top to bottom along the height direction, the top of the cylinder body is provided with a carbon dioxide gas outlet, and the bottom of the cylinder body is provided with a carbon dioxide gas outlet. A rich liquor inlet is formed in the position, close to the top, of the side wall of the barrel, a barren liquor outlet is formed in the bottom of the barrel and connected with a reboiler, one end of the reboiler is connected with the barren liquor outlet, the other end of the reboiler is connected with the heat exchange device, and the heat exchange device is connected with the barrel. Barren liquor flowing out of the barren liquor outlet is heated by the reboiler and then can be subjected to primary heat exchange with rich liquor flowing through the heat exchange device in the barrel. Waste heat recovery can be fully utilized, desorption of carbon dioxide is achieved, and regeneration energy consumption of the absorbent is effectively reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery packaging structure technical field, especially relates to a carbon capture system and its desorption tower device. BACKGROUND

[0002] At present, under the carbon neutralization target, the demand of carbon dioxide emission reduction is increasing year by year. Carbon dioxide capture, utilization and storage (CCUS, carbon dioxide emitted in the production process is captured and purified, and then reused and stored in new production process) is the most direct and effective method to reduce carbon dioxide emissions of coal-fired power plants, steel plants and cement plants in the short term.

[0003] Among them, the chemical absorption method has the advantages of high carbon dioxide absorption rate, large absorption load and complete removal, and has been popularized and applied. The essence of decarburization by chemical absorption method is to use alkaline absorbent to contact with carbon dioxide in flue gas and react chemically to form unstable salt. Then, under certain conditions, the unstable salt is reversely decomposed to release carbon dioxide, so as to separate and enrich carbon dioxide from flue gas, and regenerate the absorbent.

[0004] The main problem limiting the further large-scale popularization and application of this technology is the high investment and operation cost. One of the main reasons is that the operation energy consumption is too high, and the regeneration energy consumption of the absorbent accounts for about 70% of the whole system energy consumption. How to reduce the regeneration energy consumption of the chemical absorption carbon capture technology by various means is the current research problem. SUMMARY

[0005] In view of the defects of the prior art, the carbon capture system and the desorption tower device provided in the embodiment of the utility model can fully utilize waste heat recovery, realize desorption of carbon dioxide, and effectively reduce the regeneration energy consumption of the absorbent.

[0006] The specific technical scheme of the embodiment of the utility model is as follows:

[0007] A desorption tower device, the desorption tower device comprises: a cylinder, and a demister, a liquid distributor, a filler layer and a heat exchange device arranged in the cylinder in sequence from top to bottom along the height direction, a carbon dioxide gas outlet is arranged at the top of the cylinder, a rich liquid inlet is arranged on the side wall of the cylinder close to the top, a lean liquid outlet is arranged at the bottom of the cylinder, the lean liquid outlet is connected with a reboiler, one end of the reboiler is connected with the lean liquid outlet, the other end of the reboiler is connected with the heat exchange device, and the lean liquid flowing out of the lean liquid outlet can be subjected to one-time heat exchange with the rich liquid flowing through the heat exchange device in the cylinder after being heated by the reboiler.

[0008] In a preferred embodiment, the heat exchange device comprises a plurality of spiral coils, which are arranged in sequence along the height direction of the cylinder body, and the plurality of spiral coils are arranged in parallel.

[0009] In a preferred embodiment, any one of the plurality of spiral coils comprises a coil body, an inlet pipe for leading the lean liquid into the coil body, and an outlet pipe for leading the lean liquid out of the coil body, a flow dividing mechanism is arranged upstream of the inlet pipe along the flow direction of the lean liquid, the flow dividing mechanism is configured to divide the lean liquid heated by the reboiler into corresponding spiral coils, and a flow combining mechanism is arranged downstream of the outlet pipe, the flow combining mechanism is configured to combine the lean liquid after heat exchange with the rich liquid and then lead the combined lean liquid out.

[0010] In a preferred embodiment, the desorption tower device further comprises a control system, and a valve electrically connected to the control system, the valve is arranged on the inlet pipe and configured to adjust the flow rate of the lean liquid into the coil body.

[0011] In a preferred embodiment, the desorption tower device further comprises a pressure transmitter electrically connected to the control system, the pressure transmitter is configured to monitor the pressure of the lean liquid flowing into the coil body.

[0012] In a preferred embodiment, the desorption tower device further comprises a temperature detection member electrically connected to the control system, the temperature detection member is configured to detect the temperature of the lean liquid flowing into the coil body.

[0013] In a preferred embodiment, the coil body is formed by spirally winding a stainless steel pipe, the outermost diameter of the coil body is close to the diameter of the cylinder body, and a predetermined gap is formed between two adjacent pipes in the radial direction of the coil body, the predetermined gap is configured to flow the rich liquid.

[0014] In a preferred embodiment, the plurality of spiral coils comprises an upper spiral coil, a middle spiral coil, and a lower spiral coil, which are arranged in sequence along the height direction from top to bottom.

[0015] A carbon capture system, comprising the desorption tower device as described in any one of the above.

[0016] In a preferred embodiment, the carbon capture system further comprises an absorption tower, a lean-rich liquid heat exchanger, a rich liquid flow channel, a lean liquid flow channel and a reboiler, the absorption tower comprises a shell, a flue gas outlet is arranged at the top of the shell, a rich liquid outlet is arranged at the bottom of the shell, an absorption liquid inlet is arranged on the sidewall of the shell near the top, and a flue gas inlet is arranged on the sidewall of the shell near the bottom; the lean-rich liquid heat exchanger comprises a first flow channel for flowing rich liquid and a second flow channel for flowing lean liquid, the first flow channel has a first inlet and a first outlet, the second flow channel has a second inlet and a second outlet, the rich liquid flow channel is used for guiding the rich liquid flowing out of the rich liquid outlet into the first flow channel, and after heat exchange with the lean liquid in the second flow channel, the rich liquid is guided into the desorption tower; the lean liquid outlet of the desorption tower device is sequentially connected with the reboiler, the heat exchange device, the second flow channel and the absorption liquid inlet through the lean liquid flow channel, and the lean liquid heated by the reboiler can be subjected to primary heat exchange with the rich liquid flowing through the heat exchange device, and subjected to secondary heat exchange with the rich liquid in the first flow channel when passing through the lean-rich liquid heat exchanger, and then returned to the absorption tower.

[0017] The technical scheme of the utility model has the following remarkable beneficial effects:

[0018] In the desorption process of the desorption tower device provided in the embodiment, the lean liquid heated by the reboiler enters the heat exchange device to heat the rich liquid flowing through the heat exchange device, the heat provided by the reboiler is effectively utilized, the heat generated by the reboiler is hardly wasted and lost, the waste heat recovery is fully utilized at the source, the desorption state of the rich liquid (rich carbon dioxide absorption liquid) is achieved, the desorption of carbon dioxide is realized, the regeneration energy consumption of the absorbent is effectively reduced, and the problem of effectively controlling the regeneration energy consumption of the carbon capture technology is solved.

[0019] Specific embodiments of the utility model are disclosed in detail with reference to the following description and drawings, which indicate the principles of the utility model can be used in the following ways. It should be understood that the embodiments of the utility model are not limited in scope. The embodiments of the utility model include many changes, modifications and equivalents within the scope of the appended claims and clauses. The features described and / or shown for one embodiment can be used in the same or similar way in one or more other embodiments, combined with the features in other embodiments, or replaced by the features in other embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings described herein are for purposes of illustration only and are not intended to limit the scope of the present disclosure in any way. Additionally, the shapes and proportions of the various components in the drawings are not intended to be to scale with one another but are merely intended to help provide a general understanding of the present disclosure. Those of skill in the art will recognize that many variations in the shapes and proportions of the various components are possible, which are within the scope of the present disclosure.

[0021] Figure 1 A structural schematic diagram of a desorption tower device provided in an embodiment of the present application;

[0022] Figure 2 A structural schematic diagram of a heat exchange device provided in a desorption tower device provided in an embodiment of the present application;

[0023] Figure 3 A structural schematic diagram of a carbon capture system provided in an embodiment of the present application.

[0024] Reference signs of the present application:

[0025] 2, absorption tower;

[0026] 20, housing;

[0027] 21, flue gas outlet;

[0028] 22, rich liquid outlet;

[0029] 23, absorption liquid inlet;

[0030] 24, flue gas inlet;

[0031] 4, rich liquid pump;

[0032] 41, first pipeline;

[0033] 42, second pipeline;

[0034] 5, lean and rich liquid heat exchanger;

[0035] 51, first inlet;

[0036] 52, first outlet;

[0037] 53, second inlet;

[0038] 54, second outlet;

[0039] 6, lean liquid pump;

[0040] 63, third pipeline;

[0041] 64, fourth pipeline;

[0042] 65, fifth pipeline;

[0043] 7. Reboiler;

[0044] 8. Desorption column device;

[0045] 80. Cylinder body;

[0046] 81. Heat exchange device;

[0047] 810. Coil body;

[0048] 811. Upper spiral coil;

[0049] 812. Middle spiral coil;

[0050] 813. Lower spiral coil;

[0051] 814. Distributing mechanism;

[0052] 815. Converging mechanism;

[0053] 816. Inlet pipe;

[0054] 817. Outlet pipe;

[0055] 12. Valve;

[0056] 13. Pressure transmitter;

[0057] 14. Temperature detecting member;

[0058] 82. Carbon dioxide gas outlet;

[0059] 83. Rich liquid inlet;

[0060] 84. Lean liquid outlet;

[0061] 91. Demister;

[0062] 92. Liquid distributor;

[0063] 93. Filling layer;

[0064] 10. Cooler;

[0065] 11. Condenser. DETAILED DESCRIPTION

[0066] The technical scheme of the present application will be described in detail below in combination with the drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present application and not used to limit the scope of the present application. After reading the present application, the modification of various equivalent forms of the present application by those skilled in the art falls within the scope defined by the appended claims.

[0067] It is to be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. Where, when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or intervening elements can also be present. As used herein the terms "vertical", "horizontal", "upper", "lower", "left", "right", and the like are used for clarity to provide relative positional information and are not intended to denote an absolute orientation with the illustrated position.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0069] Prior art: "A composite carbon dioxide desorption tower" technology, the tower body top purification gas outlet below the setting has demister, below the demister setting has the first liquid inlet distributor, the first liquid inlet distributor below setting has multilayer packing layer, adjacent packing layer between setting interlayer liquid distributor and tower tray, bottom packing layer setting has the second liquid inlet distributor, the second liquid inlet distributor below setting multilayer tower plate, bottom tower plate below setting gas-liquid mixing inlet pipe, tower kettle bottom setting liquid outlet pipe, liquid passes through liquid outlet pipe and enters reboiler heating desorption, after desorption gas-liquid mixed fluid passes through gas-liquid mixing inlet pipe and enters tower body, after desorption carbon dioxide liquid out reboiler. When the actual operation condition required production carbon dioxide is less, the rich amine liquid flow required at this time is small, can only use the tower plate part of the tower body to strip desorption, uses the packing part as demister, thereby greatly reduces the carbon dioxide gas liquid carrying capacity of tower top out of tower;It can also overcome the problems of partial flow and small operation flexibility of the packing tower, and can enhance the adaptability to different performance alcohol amine solutions.

[0070] The composite carbon dioxide desorption tower also uses the traditional absorption agent heating mode, uses the reboiler to heat and desorb the regenerated liquid, increases the investment of the early-stage equipment, and causes excessive energy consumption and waste, thereby increasing the cost of the whole project, and the large-scale increase of the weight and height of the equipment of the desorption tower greatly increases the construction cost and operation cost.

[0071] The carbon capture system and desorption tower device thereof can fully utilize waste heat recovery, realize desorption of carbon dioxide, and effectively reduce the regeneration energy consumption of the absorption agent.

[0072] Please refer to Figures 1 to 2In the embodiments of the present application, a desorption tower device 8 is provided, which can include a cylinder 80, and a demister 91, a liquid distributor 92, a packing layer 93 and a heat exchange device 81 arranged in the cylinder 80 in sequence from top to bottom along the height direction. The top of the cylinder 80 is provided with a carbon dioxide gas outlet 82. The side wall of the cylinder 80 is provided with a rich liquid inlet 83 near the top. The bottom of the cylinder 80 is provided with a lean liquid outlet 84. The lean liquid outlet 84 is connected to a reboiler 7. One end of the reboiler 7 is connected to the lean liquid outlet 84, and the other end is connected to the heat exchange device 81. The lean liquid flowing out of the lean liquid outlet 84 can be heated by the reboiler 7 and can be subjected to one-time heat exchange with the rich liquid flowing through the heat exchange device 81 in the cylinder 80.

[0073] The desorption tower device 8 is used for desorbing carbon dioxide in the rich liquid flowing into it. Specifically, the desorption tower device 8 can include a hollow cylinder 80, and a demister 91, a liquid distributor 92, a packing layer 93 and a heat exchange device 81 arranged in the cylinder 80. Among them, along the height direction, the demister 91, the liquid distributor 92, the packing layer 93 and the heat exchange device 81 can be arranged in sequence from top to bottom.

[0074] The top of the cylinder 80 is provided with a carbon dioxide gas outlet 82 for discharging desorbed carbon dioxide. The side wall of the cylinder 80 is provided with a rich liquid inlet 83 near the top, which is used to introduce rich liquid into the cylinder 80. The bottom of the cylinder 80 is provided with a lean liquid outlet 84, which is used to discharge the lean liquid obtained after the rich liquid is desorbed.

[0075] The demister 91 is used to remove the atomized rich liquid, water vapor and the like in the upward flowing carbon dioxide. Further, the downstream of the carbon dioxide gas outlet 82 can be provided with a cooling device, such as a condenser 11, which is used to cool the discharged carbon dioxide to control its temperature within a predetermined temperature range. In addition, the condenser 11 can also be used to further condense the rich liquid and water vapor that may not be removed by the demister 91 in the carbon dioxide, to prevent them from being discharged with the carbon dioxide gas.

[0076] The liquid distributor 92 is used to uniformly distribute the rich liquid entering the desorption tower device 8, or to re-distribute the rich liquid, so as to improve the effect of the packing layer 93. Specifically, the structure of the liquid distributor 92 can be a groove type distributor. When the liquid distributor 92 is a groove type distributor, it can include one or more rectangular or circular distribution grooves. Liquid first enters the distribution grooves, and then is uniformly distributed into the tower through small holes, overflow weirs or the like on the groove bottom or groove wall. The groove type distributor can be divided into a one-stage groove type, a two-stage groove type, etc. The multi-stage groove type distributor can improve the uniformity of liquid distribution. Overall, the groove type distributor has large operation flexibility, can adapt to large liquid flow changes, and has good liquid distribution uniformity. Of course, the structure of the liquid distributor 92 can also be other forms, for example, a pipe type distributor, a nozzle type distributor, a disc type distributor, or a combination of the above-mentioned distributors to obtain a combined distributor, etc. For example, the groove type distributor and the pipe type distributor can be combined. The liquid is preliminarily distributed through the groove type distributor, and then is finely distributed through the pipe type distributor, so as to improve the uniformity and reliability of liquid distribution. Of course, the specific form of the liquid distributor 92 can also be flexibly designed and combined according to different process requirements and tower conditions.

[0077] The packing layer 93 is mainly used to increase the contact surface of the gas-liquid two phases, and to accelerate the mass transfer efficiency. The rich liquid flows downward on the packing surface in a film shape, and mass transfer and heat transfer are performed between the gas and liquid two phases.

[0078] The packing layer 93 can include packing and a limiting mechanism for limiting the packing. The limiting mechanism can be fixed to the inner side wall of the cylinder body 80.

[0079] The desorption tower device 8 belongs to a differential contact type gas-liquid mass transfer equipment. The rich liquid entering the cylinder body 80 flows downward on the packing surface in a film shape. The gas flows upward in a continuous phase, and the liquid flows in a reverse direction, and mass transfer and heat transfer are performed between the gas and liquid two phases. The component concentration and temperature of the two phases continuously change along the tower height.

[0080] The desorption process is generally an endothermic reaction. Increasing the temperature is beneficial to the reaction to proceed in the desorption direction, so that the carbon dioxide escapes from the absorption liquid. For example, the rich liquid can be heated to a certain temperature range, such as 80-120°C, by using the heat exchange device 81, so as to promote the desorption of carbon dioxide.

[0081] For example, the liquid distributor 92 can be a groove type distributor, and the heat exchange device 81 can be a shell and tube heat exchanger. Figure 2As shown, the heat exchange device 81 is used to heat the lean liquid in the desorption tower device 8, ensuring that the lean liquid has a sufficient temperature to exchange heat with the rich liquid and increase the temperature of the rich liquid. The process of carbon dioxide absorption is usually a reversible chemical reaction. When the rich liquid is heated, the solubility of carbon dioxide in the absorbent decreases. The carbon dioxide molecules originally dissolved in the absorbent gain enough energy to escape from the liquid phase into the gas phase, thereby achieving carbon dioxide desorption, which promotes the desorption of the rich liquid.

[0082] Specifically, the heat exchange device 81 can be a multi-stage embedded heat exchange system. Specifically, the heat exchange device 81 can be constructed as a multi-stage spiral coil, but it can also be constructed as other types of multi-stage coils, such as serpentine coils; or, the heat exchange device 81 can have other structures. In this embodiment, a multi-stage spiral coil is used as an example for illustration.

[0083] The heat exchange device 81 may include a coil body 810, an inlet pipe 816 for introducing fluid (e.g., high-temperature lean liquid) into the coil body 810, and an outlet pipe 817 for discharging fluid (lean liquid after heat exchange with rich liquid) out of the coil body 810. An installation port for mounting the coil body 810 may be provided on the side wall of the cylinder 80, through which the coil body 810 can be sealed and fixed to the cylinder 80. Of course, the specific manner in which the heat exchange device 81 is installed in the cylinder 80 is not limited to the examples described above, and this application does not impose specific limitations here.

[0084] Along the flow direction of the lean liquor, a diversion mechanism 814 is provided upstream of the inlet pipe 816. The diversion mechanism 814 is used to distribute the lean liquor heated by the reboiler 7 to the corresponding spiral coil. A confluence mechanism 815 is provided downstream of the outlet pipe 817. The confluence mechanism 815 merges the lean liquor after heat exchange with the rich liquor and then discharges it.

[0085] A third pipe is provided between the lean liquid outlet 84 and the inlet pipe 816, and the reboiler 7 is installed on the third pipe for heating the lean liquid flowing through the reboiler 7.

[0086] The lean liquid flowing out from the bottom of the desorption tower 8 is a liquid with a low carbon dioxide content after the desorption process. By heating it with a reboiler 7, the small amount of residual carbon dioxide and other gases in the lean liquid can be further desorbed, thereby improving the quality of the lean liquid and making it more suitable for recycling back to the absorption tower 2 to continue absorbing carbon dioxide. This is beneficial to improving the efficiency and stability of the entire carbon dioxide absorption-desorption system.

[0087] The desorption process is an endothermic process that requires sufficient heat to promote the desorption of carbon dioxide and other gases from the rich liquid. The reboiler 7 provides heat to the lean liquid, and the heated lean liquid flows into the heat exchange device 81 to provide heat for the desorption process. The lean liquid exchanges heat with the rich liquid to provide the required energy for the desorption of carbon dioxide from the rich liquid, maintaining the desorption reaction in the desorption column device 8.

[0088] Overall, in the carbon capture desorption process provided in the embodiments of the present application, the heated lean liquid from the reboiler 7 enters the heat exchange device 81 to heat the rich liquid flowing through the heat exchange device 81. The heat provided by the reboiler 7 is effectively utilized, and the heat generated by the reboiler 7 is rarely wasted or lost. The waste heat is fully utilized at the source to achieve the desorption state of the rich liquid (carbon dioxide-rich absorption liquid), realize the desorption of carbon dioxide, effectively reduce the regeneration energy consumption of the absorbent, and solve the problem of effective control of the regeneration energy consumption of the carbon capture technology.

[0089] In the embodiments, the temperature and flow rate of the lean liquid can be controlled by the reboiler 7, and the temperature and liquid level at the bottom of the desorption column device 8 can be adjusted, thereby optimizing the operating conditions of the desorption column device 8. Stable bottom temperature and liquid level help to ensure gas-liquid balance and mass transfer effect in the desorption column device 8, making the desorption process more stable and efficient, and reducing problems such as incomplete desorption of carbon dioxide or unstable quality of lean liquid caused by operation fluctuations.

[0090] The coil body 810 of the heat exchange device 81 can be formed by bending a metal pipe that is corrosion-resistant and has good heat exchange performance into a spiral shape, thereby ensuring that the coil body 810 has a longer length and thus a larger heat exchange area. The outermost diameter of the coil body 810 is close to the diameter of the cylinder 80. For example, when the heat exchange device 81 is embedded in the cylinder 80, the outermost diameter of the coil body 810 can be slightly larger than the diameter of the cylinder 80. Of course, in the embodiments of the present application, the outermost diameter of the coil body 810 can also be equal to or slightly smaller than the diameter of the cylinder 80.

[0091] The coil body 810 has a predetermined gap between two adjacent pipes in the radial direction, and the predetermined gap is used for the flow of rich liquid. Specifically, the predetermined gap can be about 5 centimeters. The diameter of the coil and the predetermined gap (pitch) can be determined according to the size, processing capacity, and heating requirements of the desorption column device 8, and the present application does not limit the values to be unique.

[0092] In the desorption tower device 8, the spiral coil can be divided into multiple stages, and the multiple-stage spiral coils can be arranged in layers along the height direction of the desorption tower device 8. The coils at each stage can be connected by pipelines to form a complete heat exchange device 81. Specifically, when the spiral coil includes three stages, it can be divided into an upper spiral coil 811, a middle spiral coil 812, and a lower spiral coil 813, which are arranged in the cylinder 80 in sequence along the height direction.

[0093] The arrangement of the multiple-stage spiral coils in the heat exchange device 81 enables the heating medium to be uniformly distributed in the tower, thereby achieving uniform heating of the rich liquid. The shape of the spiral coil can cause the heating medium to change direction constantly during flow, enhancing the disturbance of the fluid and improving the heat transfer effect, reducing the heating dead angle, and ensuring that the rich liquid is fully and uniformly heated throughout the tower cross-section, which is beneficial to the desorption of carbon dioxide.

[0094] The arrangement of the multiple-stage spiral coils in the heat exchange device 81 increases the contact area and contact time between the heating medium (lean liquid) and the rich liquid. The heating medium flows in the coil, and the rich liquid flows in the tower, and heat exchange is performed through the pipe wall. The multiple-stage coil allows the rich liquid to exchange heat with heating media of different temperatures multiple times during the descent, gradually increasing the temperature and improving the desorption efficiency. At the same time, the structure of the spiral coil also increases the flow rate of the fluid. According to the principles of heat transfer, an increase in flow rate can increase the convective heat transfer coefficient, further improving the heat transfer efficiency.

[0095] The structure of the spiral coil is relatively compact, and a large heat exchange area can be arranged in a limited tower space. The multiple-stage spiral coil can be reasonably designed according to the shape and size of the tower, fully utilizing the space inside the tower, reducing the volume occupied by the heat exchange device 81, improving the space utilization of the desorption tower device 8, and making the entire desorption system more compact and efficient.

[0096] In addition, an independent inlet pipeline 816 and an outlet pipeline 817 can be provided for each stage of coil to facilitate control and adjustment of the heating process. The flow rate, temperature, and other parameters of the heating medium of each stage of coil can be adjusted to accurately control the heating according to the temperature of the rich liquid and the desorption of carbon dioxide at different heights in the desorption tower device 8. For example, in the upper part of the tower, a lower heating temperature can be required due to the gradual decrease in carbon dioxide concentration; while in the lower part of the tower, a higher heating temperature is required due to the higher carbon dioxide concentration in the rich liquid. The multi-stage coil adjustment can meet the heating requirements at different heights and optimize the desorption process.

[0097] A valve 12 can be installed on the inlet pipe 816 to control the flow rate and pressure of the fluid introduced into the coil. In addition, a filter can also be provided on the inlet pipe 816 to prevent impurities in the fluid from entering the coil, affecting the heat exchange effect or blocking the pipe.

[0098] Specifically, the carbon capture system further comprises a control system. The control system can be electrically connected with devices such as the valve 12 that need to be electrically controlled, so as to control the working state and working parameters of these devices.

[0099] A pressure transmitter 13 electrically connected with the control system can be provided on the inlet pipe 816 downstream of the valve 12 in the flow direction of the fluid. The pressure transmitter 13 can be used to monitor the pressure of the fluid flowing into the coil in real time and convert it into an electrical signal, so as to enable the control system to accurately control and adjust the fluid pressure.

[0100] The pressure transmitter 13 can be used to measure the pressure value of the fluid (mainly the lean liquid in the vapor state) in the inlet pipe 816 in real time, so as to enable the control system to accurately understand the current fluid pressure condition. This is very important to ensure the stability of the heating process in the desorption tower device 8, because the stability of the vapor pressure directly affects the heating effect and the desorption efficiency of carbon dioxide.

[0101] In addition, the pressure transmitter 13 and the control system can also be used to achieve the purpose of safety protection and optimization control.

[0102] For example, when the pressure of the fluid flowing through the inlet pipe 816 exceeds or is lower than the set safety range, the pressure transmitter 13 can send a signal in time. The signal can trigger an alarm device to remind the operator to take corresponding measures to avoid safety accidents such as pipe rupture and equipment damage caused by excessive vapor pressure, or to ensure the safe and stable operation of the desorption tower device 8 due to the influence of the desorption effect caused by low pressure.

[0103] The pressure transmitter 13 transmits the measured pressure signal to the control system, and the control system can automatically adjust the opening degree of the valve 12 according to the preset pressure value. Through this closed-loop control mode, the vapor pressure can always be maintained within the optimal working range, thereby optimizing the heating process of the desorption tower device 8, improving the energy utilization efficiency, and reducing the operating cost.

[0104] Specifically, the pressure sensor inside the pressure transmitter 13 can use strain gauge, capacitive or piezoelectric principles to sense the fluid pressure. Taking the strain gauge type pressure sensor as an example, when the fluid pressure acts on the elastic element (such as the diaphragm) of the sensor, the elastic element deforms, and the strain gauge pasted on its surface also produces strain, causing the resistance value of the strain gauge to change.

[0105] The pressure sensor converts the sensed pressure change into a change in a physical quantity such as resistance, capacitance, or charge, and then converts the change in the physical quantity into a standard electrical signal, such as a 4-20 milliamp current signal or a 0-10 volt voltage signal, through a circuit inside the pressure transmitter 13.

[0106] The converted electrical signal is transmitted to the control system through a wired (for example, a cable) or wireless manner. In the control system, the control system compares the received pressure signal with a preset pressure value, and then issues a control instruction to adjust the opening degree of the valve 12 in the inlet pipe 816 to maintain the stability of the fluid pressure. In addition, the control system can also display the pressure value corresponding to the electrical signal, so that the operator can intuitively observe the change of the fluid pressure.

[0107] On the inlet pipe, specifically, downstream of the pressure transmitter 13 along the flow direction of the fluid, a temperature detection member 14 can also be arranged on the inlet pipe. Considering that the fluid will undergo a certain degree of heat exchange when flowing through the inlet pipe 816, the temperature will fluctuate to a certain extent. When the temperature detection member 14 is located downstream of the pressure transmitter 13, it is relatively closer to the inlet of the coil body 810 of the heat exchange device 81, so that the temperature detected by it is closer to the fluid temperature in the heat exchange device 81.

[0108] The temperature detection member 14 can be in the form of a thermocouple, and the temperature detection member 14 can also be in other forms, which are not limited in the present application. In the embodiments of the present application, the temperature detection member 14 is mainly exemplified in the form of a thermocouple.

[0109] The temperature detection member 14 is used to accurately measure the temperature of the fluid flowing into the heat exchange device 81, and provides a temperature parameter for the heating control of the desorption tower device 8, so as to ensure the stability and efficiency of the desorption process. The temperature detection member 14 can be electrically connected with the control system. The temperature signal obtained by the temperature detection member 14 is used to control the temperature of the cylinder 80 for setting the lower part of the heat exchange device 81 to be between 110 degrees Celsius and 120 degrees Celsius.

[0110] Different desorption stages and rich liquid components require different temperature fluids to achieve the best desorption effect. The thermocouple can accurately measure the temperature of the steam in real time. After receiving the temperature signal of the thermocouple, the control system can compare it with the preset temperature to determine whether the current fluid meets the temperature requirements of the desorption process.

[0111] Since temperature is one of the important parameters affecting the desorption process. The temperature signal measured by the thermocouple can be transmitted as feedback information to the control system. The control system compares the preset temperature value with the actual measured value and automatically adjusts the opening of the valve 12 on the inlet pipe 816 or other related heat exchange devices 81 to keep the temperature of the fluid within the appropriate range, thereby optimizing the heating process of the desorption tower device 8 and improving the desorption efficiency of carbon dioxide.

[0112] Since overheating or overcooling of the fluid can cause damage to the desorption tower device 8 and related equipment. The thermocouple can detect abnormal changes in the temperature of the steam in time, and when the temperature exceeds the safe range, the control system will issue an alarm and take appropriate protective measures, such as closing the valve 12 on the inlet pipe 816, or starting a backup cooling device, etc. to prevent equipment damage due to high temperature, pipe rupture due to excessive thermal stress, or poor desorption effect due to low temperature, frozen rich liquid, etc. to ensure the safe and stable operation of the desorption system.

[0113] In addition, by analyzing the temperature data measured by the thermocouple and combining other operating parameters of the desorption tower device 8 such as pressure, flow, etc., the running state of the system can be evaluated and fault diagnosed. For example, if the fluid temperature suddenly drops, it may mean that the fluid supply system has failed, such as a reboiler 7 failure, pipe blockage or valve 12 leakage, etc. If the temperature fluctuates greatly, it may indicate that the control system has a problem or the heating device is not running stably. By discovering and solving these potential problems in time, the desorption process can be severely affected, and the reliability and efficiency of the system can be improved.

[0114] In one embodiment, the heat exchange device 81 in the desorption tower device 8 can be a multi-stage spiral coil, which is arranged in sequence along the height direction of the cylinder 80, and the multi-stage spiral coils are arranged in parallel. For example, when the multi-stage embedded heat exchange system is a three-stage embedded heat exchange system, and the heat exchange system is a multi-stage coil, it can include: an upper spiral coil 811, a middle spiral coil 812 and a lower spiral coil 813. Embedding a multi-stage embedded heat exchange system in the desorption tower device 8 can increase the contact area between the rich liquid (absorbent liquid rich in carbon dioxide) and the high-temperature lean liquid, thereby increasing the heating speed of the rich liquid.

[0115] As shown in Figure 3 The carbon capture system provided in the embodiment of the present application mainly includes the above-mentioned desorption tower device 8. The carbon capture system can achieve the technical effects realized by the embodiments of the desorption tower device 8 by setting the desorption tower device 8. For details, please refer to the specific description of the above-mentioned embodiments, which will not be repeated here.

[0116] For the carbon capture system, in addition to the desorption tower device 8, it also includes: an absorption tower 2, a lean-rich liquid heat exchanger 5, a rich liquid flow channel, a lean liquid flow channel and a reboiler 7.

[0117] The absorption tower 2 includes a shell 20, the top of the shell 20 is provided with a flue gas outlet 21, the bottom of the shell 20 is provided with a rich liquid outlet 22, the sidewall of the shell 20 is provided with an absorption liquid inlet 23 near the top, and the sidewall of the shell 20 is provided with a flue gas inlet 24 near the bottom; the lean-rich liquid heat exchanger 5 includes a first flow channel for flowing rich liquid and a second flow channel for flowing lean liquid, the first flow channel has a first inlet 51 and a first outlet 52, the second flow channel has a second inlet 53 and a second outlet 54, the rich liquid flow channel is used to guide the rich liquid flowing out of the rich liquid outlet 22 into the first flow channel, and after heat exchange with the lean liquid in the second flow channel, it is guided into the desorption tower; the lean liquid outlet 84 of the desorption tower device 8 is connected with the reboiler 7, the heat exchange device 81, the second flow channel and the absorption liquid inlet 23 in sequence through the lean liquid flow channel, and the lean liquid heated by the reboiler 7 can be heat exchanged with the rich liquid flowing through the heat exchange device 81 once, and then heat exchanged with the rich liquid in the first flow channel through the lean-rich liquid heat exchanger 5 twice and returned to the absorption tower 2.

[0118] Among them, the rich liquid flow channel includes a first pipeline 41 and a second pipeline 42, the first pipeline 41 is connected between the rich liquid outlet 22 and the first inlet 51, and the rich liquid pump 4 is arranged on the first pipeline 41; the second pipeline 42 is connected between the first outlet 52 and the rich liquid inlet 83.

[0119] The heat exchange device 81 has opposite inlet and outlet ends, the lean liquid flow channel includes a third pipeline 63, a fourth pipeline 64 and a fifth pipeline 65, the third pipeline 63 is connected between the lean liquid outlet 84 and the inlet end, the reboiler 7 is arranged on the third pipeline 63, the fourth pipeline 64 is connected between the outlet end and the second inlet 53, the lean liquid pump 6 is arranged on the fourth pipeline 64, and the fifth pipeline 65 is connected between the second outlet 54 and the absorption liquid inlet 23. The fifth pipeline 65 is provided with a cooler 10.

[0120] In the embodiment, the outlet pipe 817 of the heat exchange device 81 can pass through the fourth pipeline 64, pass through the fifth pipeline 65 after passing through the lean-rich heat exchanger, and then return to the absorption tower 2 as the absorption liquid, so as to realize the recycling of the absorption liquid. One end of the fourth pipeline 64 is connected with the outlet pipe 817, and the other end can be connected with the second inlet 53 of the second flow channel of the lean-rich heat exchanger 5. Since the lean liquid has already been subjected to the first heat exchange with the rich liquid in the desorption tower device 8 when flowing through the heat exchange device 81 in the desorption tower device 8, the temperature of the lean liquid has been lowered to a certain extent, but the lean liquid still has a certain amount of heat. In order to fully utilize the lean liquid after the first heat exchange, the lean liquid can be caused to flow into the lean-rich heat exchanger 5 to preheat the rich liquid before flowing into the desorption tower device 8, so as to further utilize the heat in the lean liquid, so that the waste heat recovery rate can be maximized, and the regeneration energy consumption of the absorbent can be further reduced, and the problem of effectively controlling the regeneration energy consumption of the carbon capture technology is preferably solved.

[0121] In addition, in order to cause the lean liquid (absorbent) returned to the absorption tower 2 to reach the target reaction temperature, a cooler 10 can be arranged on the fifth pipeline 65, the absorbent is subjected to cooling treatment by the cooler 10, so as to reach the target reaction temperature, thereby facilitating the absorbent to better react with carbon dioxide. For different selected absorbents, the optimal temperature for reacting with carbon dioxide is also different. Taking the absorbent as an organic amine absorbent as an example, the temperature of the absorbent can be lowered to room temperature by the condenser 11, thereby facilitating the organic amine absorbent to efficiently chemically react with carbon dioxide.

[0122] In use, the flue gas after desulfurization and denitrification enters the absorption tower 2, the flue gas enters from the flue gas inlet 24 at the bottom of the absorption tower 2, the flue gas after removing carbon dioxide is discharged from the flue gas outlet 21 at the top of the absorption tower 2, the absorption liquid rich in carbon dioxide flows out from the rich liquid outlet 22 at the bottom of the absorption tower 2, and after being subjected to heat exchange with the lean liquid from the desorption tower device 8 through the lean-rich heat exchanger 5, enters the desorption tower device 8, the heat exchange device 81 is arranged in the desorption tower device 8, and the efficient desorption of carbon dioxide can be realized according to the capacity of the absorption rich liquid and the desorption rate. The lean liquid flowing out from the lean liquid outlet 84 at the bottom of the desorption tower device 8 is subjected to temperature rising by the reboiler 7, and after being subjected to multi-stage heat exchange with the rich liquid in the desorption tower device 8, returns to the absorption tower 2 through the lean-rich heat exchanger.

[0123] In a specific application scenario, the carbon capture system provided in the embodiment of the application has the following process when desorbing carbon dioxide:

[0124] The flue gas after desulfurization and denitrification has a temperature of about 80 to 120 DEG C, is cooled to normal temperature by a washing tower, and then enters the absorption tower 2 through a flue to be in countercurrent contact with the absorption liquid from the upper part of the absorption tower 2, and the absorption liquid after absorbing carbon dioxide is sprayed into the upper part of the desorption tower device 8 after heat exchange by the lean- rich liquid heat exchanger 5. The multi-stage heat exchange device 81 embedded in the desorption tower device 8 is in full contact with the sprayed rich liquid to achieve the effect of heating and desorption of the absorption liquid. The system controls the number of heat exchange devices 81 participating in heat exchange through the desorption rate to ensure the removal rate of carbon dioxide.

[0125] The lean liquid after the multi-stage heat exchange device 81 of the desorption tower device 8 is gathered in the pipeline, enters the lean- rich liquid heat exchanger 5 through the lean liquid pump 6, and exchanges heat with the absorption liquid rich in carbon dioxide from the absorption tower 2. Heat is recovered again. The lean liquid after heat exchange enters the top of the absorption tower 2 to absorb carbon dioxide again.

[0126] The rich liquid (absorption liquid rich in carbon dioxide) from the lean- rich liquid heat exchanger 5 after the first heating enters the top of the desorption tower device 8, and is heated again from top to bottom by the multi-stage heat exchange device 81 to achieve the purpose of desorption of carbon dioxide.

[0127] It should be noted that in the description of the present application, the terms "first", "second" and the like are only used for descriptive purposes and to distinguish similar objects, and there is no prior or posterior order between them, nor can it be understood or implied as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0128] The above various embodiments in the specification are described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment mainly explains the difference from other embodiments.

[0129] The above is only several embodiments of the present application, although the embodiments disclosed by the present application are as above, but the content is only for the purpose of understanding the present application and the embodiments adopted, and is not used to limit the present application. Any person skilled in the art of the present application can make any modification and change in the form and details without departing from the spirit and scope of the present application, but the patent protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. A desorption tower apparatus, characterized in that, The desorption tower device includes: a cylindrical body, and a demister, a liquid distributor, a packing layer and a heat exchange device arranged sequentially from top to bottom along the height direction inside the cylindrical body; The top of the cylinder is provided with a carbon dioxide gas outlet, the side wall of the cylinder is provided with a rich liquid inlet near the top, and the bottom of the cylinder is provided with a lean liquid outlet. The lean liquid outlet is connected to a reboiler, one end of which is connected to the lean liquid outlet and the other end of which is connected to the heat exchange device. The lean liquid flowing out of the lean liquid outlet is heated by the reboiler and can then exchange heat with the rich liquid flowing through the heat exchange device inside the cylinder.

2. The desorption tower apparatus as described in claim 1, characterized in that, The heat exchange device includes multi-stage spiral coils, which are arranged at intervals along the height direction of the cylinder and connected in parallel.

3. The desorption tower apparatus as described in claim 2, characterized in that, Any stage of the multi-stage spiral coil includes: a coil body, an inlet pipe for introducing lean liquor into the coil body, an outlet pipe for discharging lean liquor out of the coil body, a diversion mechanism provided upstream of the inlet pipe along the flow direction of the lean liquor, the diversion mechanism being used to distribute the lean liquor heated by the reboiler to the corresponding spiral coil, and a confluence mechanism provided downstream of the outlet pipe, the confluence mechanism being used to merge the lean liquor after heat exchange with the rich liquor and then discharge it.

4. The desorption tower apparatus as described in claim 3, characterized in that, The desorption tower device also includes a control system and a valve electrically connected to the control system. The valve is installed on the inlet pipe and is used to regulate the flow rate of lean liquid entering the coil body.

5. The desorption tower apparatus as described in claim 4, characterized in that, The desorption tower device also includes a pressure transmitter, which is electrically connected to the control system and is used to monitor the pressure of the lean liquid flowing into the coil body.

6. The desorption tower apparatus as described in claim 4, characterized in that, The desorption tower device also includes a temperature detection element, which is electrically connected to the control system and is used to detect the temperature of the lean liquid flowing into the coil body.

7. The desorption tower apparatus as described in claim 3, characterized in that, The coil body is made of stainless steel pipe spirally wound. The outermost diameter of the coil body is close to the diameter of the cylinder. A predetermined gap is formed between two adjacent pipes in the radial direction of the coil body. The predetermined gap is used for the flow of rich liquid.

8. The desorption tower apparatus as described in claim 2, characterized in that, The multi-stage spiral coil includes an upper spiral coil, a middle spiral coil, and a lower spiral coil, which are arranged sequentially from top to bottom along the height direction.

9. A carbon capture system, characterized in that, The carbon capture system includes the desorption tower device as described in any one of claims 1 to 8.

10. The carbon capture system as described in claim 9, characterized in that, The carbon capture system also includes: an absorption tower, a lean and rich liquid heat exchanger, a rich liquid flow channel, a lean liquid flow channel, and a reboiler. The absorption tower includes a shell, with a flue gas outlet at the top and a rich liquid outlet at the bottom. An absorbent inlet is located on the side wall of the shell near the top, and a flue gas inlet is located on the side wall of the shell near the bottom. The lean-rich liquid heat exchanger includes a first flow channel for flowing rich liquid and a second flow channel for flowing lean liquid. The first flow channel has a first inlet and a first outlet, and the second flow channel has a second inlet and a second outlet. The rich liquid flow channel guides the rich liquid flowing out of the rich liquid outlet into the first flow channel, where it exchanges heat with the lean liquid in the second flow channel before being introduced into the desorption tower. The lean liquid outlet of the desorption tower is sequentially connected to the reboiler, the heat exchange device, the second flow channel, and the absorbent inlet via the lean liquid flow channel. The lean liquid, heated by the reboiler, undergoes a primary heat exchange with the rich liquid flowing through the heat exchange device, and then undergoes a secondary heat exchange with the rich liquid in the first flow channel before returning to the absorption tower.

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