Double-contact type carbon capture absorption bed and regulation and control method

Abstract

The invention discloses a double contact type carbon capture absorption bed and a regulation and control method, the absorption bed comprises a hollow cylindrical shell and at least two absorbent injection pipes installed in the cylindrical shell, and the method comprises the following steps: detecting flue gas inlet and outlet volume flow and inlet and outlet carbon concentration in real time, and obtaining the current absorbent inlet volume flow; determining the carbon capture rate according to the flue gas inlet and outlet volume flow and the inlet and outlet carbon concentration; determining the molar ratio of the absorption bed according to the flue gas inlet and outlet volume flow and the current absorbent inlet volume flow; if the molar ratio of the absorption bed is smaller than the preset molar ratio threshold value, the current absorbent inlet volume flow rate is adjusted according to the preset step length till the carbon capture rate reaches the preset demand interval. Therefore, the absorbent is accurately and effectively regulated and controlled, and the carbon recovery efficiency of the flue gas is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon capture, and in particular to a double-contact carbon capture absorption bed and a control method. Background Art

[0002] As the global industrialization process is advancing rapidly, the industrial scale of various countries continues to expand, which makes the demand for energy more intense. From manufacturing to transportation, from daily life electricity to large-scale industrial production, the energy consumption of various activities is increasing day by day. The continued growth in emissions has triggered a series of climate problems. Global warming is becoming increasingly prominent, glaciers are melting faster, sea levels are rising, extreme climate events are becoming more frequent, etc. These have become global challenges that all mankind needs to overcome urgently.

[0003] In response Among the many solutions to emission problems, carbon capture, utilization and storage (CCUS) is considered to be the core path to large-scale carbon reduction from fossil energy. , make rational use of it, and safely seal up the unusable parts, etc.

[0004] However, since the absorbent needs to be adjusted in real time according to the flue gas conditions during the carbon capture process, the existing technology usually performs regulation through manual adjustment, which makes it impossible to capture carbon accurately and efficiently. Summary of the invention

[0005] The present invention provides a double-contact carbon capture absorption bed and a control method, which solves the technical problem that the absorbent needs to be adjusted in real time according to the flue gas conditions during the carbon capture process, and the control is usually performed manually in the prior art, which makes it impossible to accurately and efficiently capture carbon.

[0006] The present invention provides a double-contact carbon capture absorption bed, comprising a liquid pump, a hollow cylindrical shell and at least two absorbent injection pipes installed in the cylindrical shell;

[0007] The interior of the hollow cylindrical shell is divided into an inlet section, a reaction section and an outlet section;

[0008] The absorbent injection pipe is installed at the inlet section, and is used to receive the absorbent transported by the liquid pump and inject it into the reaction section, so as to perform double-stage carbon capture on the flue gas entering from the inlet section, and discharge the purified gas from the outlet section.

[0009] Optionally, the absorbent injection pipe is provided with at least one nozzle;

[0010] The numbers of nozzles of two adjacent absorbent injection pipes are different, and the total number of the nozzles is an odd number.

[0011] Optionally, the cross-sectional shape of the hollow cylindrical shell is a square;

[0012] The height ratios among the inlet section, the reaction section and the outlet section are as follows: 3:14:7.

[0013] Optionally, the absorbent is aqueous ammonia prepared by mixing 10% by mass NH3 and 90% by mass H2O.

[0014] The present invention also provides a control method for a double-contact carbon capture absorption bed, which is applied to a control terminal in communication connection with any of the double-contact carbon capture absorption beds described above, and the method comprises:

[0015] Real-time detection of flue gas inlet and outlet volume flow and inlet and outlet carbon concentration, and acquisition of current absorbent inlet volume flow;

[0016] Determining the carbon capture rate according to the flue gas inlet and outlet volume flow and the inlet and outlet carbon concentration;

[0017] Determining the absorption bed molar ratio according to the flue gas inlet and outlet volume flow rates and the current absorbent inlet volume flow rate;

[0018] If the absorption bed molar ratio is less than a preset molar ratio threshold, the current absorbent inlet volume flow rate is adjusted according to a preset step size until the carbon capture rate reaches a preset demand range.

[0019] Optionally, the flue gas inlet and outlet volume flow rate includes a flue gas inlet volume flow rate and a flue gas outlet volume flow rate, and the inlet and outlet carbon concentration includes a flue gas inlet carbon concentration and a flue gas outlet carbon concentration; and determining the carbon capture rate according to the flue gas inlet and outlet volume flow rate and the inlet and outlet carbon concentration includes:

[0020] Calculating a first product value between the flue gas inlet volume flow rate and the flue gas inlet carbon concentration;

[0021] Calculating a second product between the flue gas outlet volume flow rate and the flue gas outlet carbon concentration;

[0022] calculating a first ratio between the second multiplier value and the first multiplier value;

[0023] The difference between the preset value and the first ratio is calculated to obtain the carbon capture rate.

[0024] Optionally, determining the absorption bed molar ratio according to the flue gas inlet and outlet volume flow rates and the current absorbent inlet volume flow rate comprises:

[0025] Determining the absorbent inlet mass flow rate according to the current absorbent inlet volume flow rate and absorbent density;

[0026] Determining the smoke inlet mass flow rate according to the smoke inlet volume flow rate and smoke density;

[0027] Calculate the ratio between the absorbent inlet mass flow rate and the absorbent molar mass to obtain the number of absorbent moles;

[0028] Calculate the ratio between the smoke inlet mass flow rate and the smoke molar mass to obtain the smoke mole number;

[0029] The ratio between the molar number of the absorbent and the molar number of the flue gas is calculated to obtain the molar ratio of the absorption bed.

[0030] Optionally, the method further comprises:

[0031] Acquiring structural data of the hollow cylindrical shell;

[0032] Determining the total pressure drop of the absorption bed according to the structural data and the preset average absorption data;

[0033] A liquid pump whose structural parameters meet the total pressure drop of the absorption bed is selected as a new liquid pump.

[0034] Optionally, the structural data includes cross-sectional dimensions and shell height, and the average absorption data includes average density of inlet and outlet working fluids and average flow rate of the absorption bed; and determining the total pressure drop of the absorption bed according to the structural data and preset average absorption data includes:

[0035] Substituting the average density of the inlet and outlet working fluids into the gravity pressure drop calculation formula to determine the gravity pressure drop of the absorption bed;

[0036] Substituting the shell height, the average flow velocity of the absorption bed and the cross-sectional dimensions into the resistance loss formula along the way to determine the resistance loss along the absorption bed;

[0037] The total pressure drop of the absorption bed is obtained by superimposing the pressure drop at the absorption bed weight position and the resistance loss along the absorption bed.

[0038] Optionally, the method further comprises:

[0039] Periodically obtain average absorption update data;

[0040] When the difference between the average absorption update data and the preset average absorption data is greater than the preset data threshold, the average absorption update data is used as the new average absorption data, and the step of determining the total pressure drop of the absorption bed based on the structural data and the preset average absorption data is jumped to execute.

[0041] It can be seen from the above technical solutions that the present invention has the following advantages:

[0042] The present invention provides a double-contact carbon capture absorption bed and a control method, wherein the absorption bed includes a liquid pump, a hollow cylindrical shell and at least two absorbent injection pipes installed in the cylindrical shell; the interior of the hollow cylindrical shell is divided into an inlet section, a reaction section and an outlet section; the absorbent injection pipe is installed in the inlet section, and is used to receive the absorbent transported by the liquid pump and inject it into the reaction section, so as to perform double-stage carbon capture on the flue gas entering from the inlet section, and discharge the purified gas from the outlet section. Thus, through the design and arrangement of the absorbent injection pipe, the ammonia water can be evenly contacted with the flue gas, the role of the absorbent is fully exerted, and the waste of the absorbent is reduced. At the same time, through the double-stage carbon capture method, the carbon dioxide in the flue gas can be more fully absorbed, and the carbon capture efficiency is effectively improved.

[0043] In the invention, the flue gas inlet and outlet volume flow and inlet and outlet carbon concentration are detected in real time, and the current absorbent inlet volume flow is obtained; the carbon capture rate is determined according to the flue gas inlet and outlet volume flow and the inlet and outlet carbon concentration; the absorption bed molar ratio is determined according to the flue gas inlet and outlet volume flow and the current absorbent inlet volume flow; if the absorption bed molar ratio is less than the preset molar ratio threshold, the current absorbent inlet volume flow is adjusted according to the preset step length until the carbon capture rate reaches the preset demand range. In this way, the absorbent is accurately and effectively regulated to improve the carbon recovery efficiency of flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0045] Figure 1 A schematic diagram of the structure of a double-contact carbon capture absorption bed provided in an embodiment of the present invention;

[0046] Figure 2 A nozzle arrangement diagram of a double-contact carbon capture absorption bed provided in an embodiment of the present invention;

[0047] Figure 3 A flow pattern diagram of a double-contact carbon capture absorption bed provided by an embodiment of the present invention;

[0048] Figure 4 A flow chart of the steps of a control method of a double-contact carbon capture absorption bed provided by an embodiment of the present invention;

[0049] Figure 5 A schematic diagram of a curve of CO2 capture rate of a double-contact carbon capture absorption bed at different molar ratios provided in an embodiment of the present invention;

[0050] Figure 6 A schematic diagram of the results of carbon capture rate and flue gas flow provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0051] The embodiment of the present invention provides a double-contact carbon capture absorption bed and a control method, which are used to solve the technical problem that since the absorbent needs to be adjusted in real time according to the flue gas conditions during the carbon capture process, the control is usually performed manually in the prior art, and carbon capture cannot be performed accurately and efficiently.

[0052] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] See also Figure 1 , Figure 1 A schematic structural diagram of a double-contact carbon capture absorption bed provided in an embodiment of the present invention.

[0054] The present invention provides a double-contact carbon capture absorption bed, comprising a liquid pump, a hollow cylindrical shell 1 and at least two absorbent injection pipes 2 installed in the cylindrical shell;

[0055] The interior of the hollow cylindrical housing 1 is divided into an inlet section, a reaction section and an outlet section;

[0056] The absorbent injection pipe 2 is installed at the inlet section, and is used to receive the absorbent transported by the liquid pump and inject it into the reaction section, so as to perform double-stage carbon capture on the flue gas entering from the inlet section, and discharge the purified gas from the outlet section.

[0057] Optionally, the cross-sectional shape of the hollow cylindrical housing 1 is a square;

[0058] The height ratios among the inlet section, the reaction section and the outlet section are as follows: 3:14:7.

[0059] The cross-sectional dimensions of the hollow cylindrical housing 1 may be 60*60-100*100 mm, preferably 80 mm×80 mm, and the total height is 1200 mm;

[0060] The height of the inlet section is 150 mm, the height of the reaction section is 700 mm, and the height of the outlet section is 350 mm.

[0061] In the embodiment of the present application, the absorbent is sprayed into the tower from the bottom nozzle 21 of the double-contact carbon capture gas-liquid two-phase absorption reaction bed through a liquid pump to form a liquid column. The flue gas to be treated enters the tower body from the inlet section (i.e., the bottom of the double-contact carbon capture gas-liquid two-phase absorption reaction bed). During the rising process, the flue gas contacts with the rising absorption liquid sprayed out from the absorbent injection pipe 2 in the downstream, and at the same time, contacts with the absorption liquid falling from the highest point in the countercurrent. During the rising process, the absorption liquid contacts with the rising flue gas twice in the downstream and countercurrent. The flow pattern inside the double-contact carbon capture absorption bed is as follows: Figure 2 As shown. Multiple groups of double-contact carbon capture absorption beds can be arranged in the new absorption tower of the carbon capture system. The main advantage is that it can effectively prevent flue gas corridors, ensure that each surface has sufficient flue gas filling, increase the gas-liquid contact area, improve the mass transfer efficiency, and ensure that the reaction can operate stably for a long time.

[0062] Specifically, the flue gas to be treated enters the hollow cylindrical shell 1 from the inlet section. The height of the inlet section is 150 mm, and its design is conducive to the uniform distribution of the flue gas, so that the flue gas can smoothly enter the reaction section. The liquid pump transports the absorbent to the absorbent injection pipe 2, and the absorbent is injected from the injection pipe to the reaction section. The height of the reaction section is 700 mm. In this area, the absorbent is fully in contact with the flue gas, a chemical reaction occurs, and two-stage carbon capture is achieved. The first stage of capture is the initial contact between the absorbent and the flue gas, and most of the carbon dioxide is absorbed; the second stage of capture is a further reaction in the reaction section, so that the remaining carbon dioxide is more fully absorbed and the carbon capture efficiency is improved. After the two-stage carbon capture, the purified gas is discharged from the outlet section. The height of the outlet section is 350 mm, and its design is conducive to the stable discharge of the purified gas. At the same time, the purified gas can be further tested and processed to ensure that the emission meets environmental protection requirements.

[0063] In addition, during the operation of the carbon capture absorption bed, various parameters must be monitored in real time. The monitoring content includes flue gas flow, temperature, pressure, absorbent flow, concentration, and carbon dioxide content in the purified gas. By monitoring these parameters, the carbon capture effect and equipment operation status can be understood in a timely manner.

[0064] Optionally, the absorbent injection pipe 2 is provided with at least one nozzle 21;

[0065] The numbers of nozzles 21 of two adjacent absorbent spraying pipes 2 are different, and the total number of nozzles 21 is an odd number.

[0066] See also Figure 3 , Figure 3 It is a schematic diagram of the opening position of the nozzle 21 in the embodiment of the present invention.

[0067] In this embodiment, the absorbent injection pipes 2 are placed at intervals to increase the flue gas passing position and ensure sufficient reaction between the flue gas and the absorbent. Figure 3 As shown, the number of nozzles 21 of two adjacent absorbent injection pipes 2 is different, for example, the number of nozzles 21 opened in the upper pipe is 2, and the number of nozzles 21 opened in the lower pipe is 1, and the total number is an odd number.

[0068] The absorbent injection pipes 2 may be placed one above the other or side by side, and this embodiment of the present application does not limit this.

[0069] Optionally, the absorbent is aqueous ammonia prepared by mixing 10% by mass NH3 and 90% by mass H2O.

[0070] In this embodiment, ammonia water can be prepared in a special liquid preparation tank. According to the mass ratio, first inject a calculated amount of deionized water into the liquid preparation tank, turn on the stirring device to make the water flow evenly. Then slowly inject liquid ammonia into the water through a special pipeline. During the injection process, the flow rate is strictly controlled to prevent safety hazards and uneven mixing caused by too fast mixing. For example, according to the calculation to prepare 1000kg of 10% ammonia water by mass, 900kg of deionized water and 100kg of liquid ammonia need to be accurately measured. Continue stirring for a period of time, such as 30 minutes, so that and Mix thoroughly. Use a density meter to measure the density of ammonia water and compare it with the standard density table to preliminarily determine the accuracy of the concentration. Chemical analysis methods can also be used, such as titrating ammonia water with a standard sulfuric acid solution and calculating the ammonia content by the amount of sulfuric acid consumed to ensure that the mass fraction of ammonia water is indeed 10%.

[0071] In the embodiment of the present application, a double-contact carbon capture absorption bed is provided, including a liquid pump, a hollow cylindrical shell and at least two absorbent injection pipes installed in the cylindrical shell; the interior of the hollow cylindrical shell is divided into an inlet section, a reaction section and an outlet section; the absorbent injection pipe is installed in the inlet section, and is used to receive the absorbent transported by the liquid pump and inject it into the reaction section, so as to perform double-stage carbon capture on the flue gas entering from the inlet section, and discharge the purified gas from the outlet section. Therefore, through the design and arrangement of the absorbent injection pipe, the ammonia water can be evenly contacted with the flue gas, the role of the absorbent is fully exerted, and the waste of the absorbent is reduced. At the same time, through the double-stage carbon capture method, the carbon dioxide in the flue gas can be more fully absorbed, and the carbon capture efficiency is effectively improved.

[0072] See also Figure 4 , Figure 4 A flow chart of the steps of a method for regulating a double-contact carbon capture absorption bed provided in an embodiment of the present invention.

[0073] An embodiment of the present invention provides a control method for a double-contact carbon capture absorption bed, which is applied to a control terminal that is communicatively connected to the double-contact carbon capture absorption bed of any embodiment of the present invention, and the method comprises the following steps:

[0074] Step 401, real-time detection of flue gas inlet and outlet volume flow and inlet and outlet carbon concentration, and acquisition of current absorbent inlet volume flow;

[0075] In this embodiment, various parameters are monitored in real time during the operation of the carbon capture absorption bed. The monitoring contents include flue gas flow, temperature, pressure, absorbent flow, concentration, and carbon dioxide content in the purified gas. By monitoring these parameters, the carbon capture effect and the operating status of the equipment can be timely understood. For example, the flue gas inlet and outlet volume flow and inlet and outlet carbon concentration can be detected in real time through sensors and other equipment, and at the same time, the current absorbent inlet volume flow can be obtained as the data basis for subsequent regulation.

[0076] Step 402, determining the carbon capture rate according to the flue gas inlet and outlet volume flow and the inlet and outlet carbon concentration;

[0077] In an example of the present application, the flue gas inlet and outlet volume flow rate includes the flue gas inlet volume flow rate and the flue gas outlet volume flow rate, and the inlet and outlet carbon concentration includes the flue gas inlet carbon concentration and the flue gas outlet carbon concentration; step 402 includes the following sub-steps:

[0078] Calculate the first product between the flue gas inlet volume flow rate and the flue gas inlet carbon concentration;

[0079] Calculate the second product between the flue gas outlet volume flow rate and the flue gas outlet carbon concentration;

[0080] calculating a first ratio between the second multiplied value and the first multiplied value;

[0081] The difference between the preset value and the first ratio is calculated to obtain the carbon capture rate.

[0082] Specifically, the calculation method of the carbon capture rate of CO2 is as follows:

[0083]

[0084] in, is the carbon capture rate of CO2, in %; is the flue gas outlet volume flow rate, in units of ; is the flue gas inlet volume flow rate, in units of ; is the carbon concentration at the flue gas outlet, in %; is the carbon concentration at the flue gas inlet, in %.

[0085] Step 403, determining the absorption bed molar ratio according to the flue gas inlet and outlet volume flow rates and the current absorbent inlet volume flow rate;

[0086] In one example of the present application, step 403 includes the following sub-steps:

[0087] Determine the absorbent inlet mass flow rate according to the current absorbent inlet volume flow rate and absorbent density;

[0088] Determine the smoke inlet mass flow rate according to the smoke inlet volume flow rate and smoke density;

[0089] Calculate the ratio between the absorbent inlet mass flow rate and the absorbent molar mass to obtain the number of absorbent moles;

[0090] Calculate the ratio between the smoke inlet mass flow rate and the smoke molar mass to obtain the smoke mole number;

[0091] The ratio between the moles of absorbent and the moles of flue gas is calculated to obtain the molar ratio of the absorbent bed.

[0092] In this embodiment, the calculation process of each parameter is as follows:

[0093]

[0094] Where: is the flue gas inlet mass flow rate, in kg / s; is the smoke density, the unit is ; is the flue gas inlet volume flow rate, in units of .

[0095]

[0096] Where: is the absorbent inlet mass flow rate, in kg / s; is the absorbent density, and the mass fraction is , you can take ; is the absorbent inlet volume flow rate, in Nm3 / h. In this embodiment, the absorbent is ammonia water.

[0097]

[0098] Where: is the molar ratio of the double contact carbon capture absorption bed, expressed as ; is the mole number of absorbent, in mol; for The number of moles, in mol.

[0099] Step 404: If the absorption bed molar ratio is less than the preset molar ratio threshold, the current absorbent inlet volume flow rate is adjusted according to the preset step length until the carbon capture rate reaches the preset demand range.

[0100] In this embodiment, the influence of the CO2 capture rate of the double contact carbon capture absorption bed under different molar ratio conditions is calculated, and the results are as follows: Figure 5 As shown. Figure 5 It can be seen that as the molar ratio increases, the amount of liquid ammonia increases, and the CO2 capture rate of the double-contact carbon capture absorber bed shows a gradually increasing trend. When the molar ratio is less than 21 molNH3 / molCO2, the CO2 capture rate of the double-contact carbon capture absorber bed basically shows a positive proportional trend. At this stage, the amount of NH3 is small and is the main influencing factor of the CO2 capture rate of the double-contact carbon capture absorber bed; when the molar ratio is greater than 21 molNH3 / molCO2, the CO2 capture rate of the double-contact carbon capture absorber bed is above 83.5%. At this time, increasing the amount of NH3 has little effect on the CO2 capture rate of the double-contact carbon capture absorber bed, and the amount of NH3 is no longer the main influencing factor. When the molar ratio is greater than 29 molNH3 / molCO2, the CO2 capture rate of the double contact carbon capture absorber fluctuates in the range of 84.2%-86.1%. The reason for the fluctuation is that the molar ratio gradually increases but the number of nozzles is fixed, so the liquid phase flow rate gradually increases, resulting in a shorter reaction time, which makes the CO2 capture rate of the double contact carbon capture absorber fluctuate within a certain range. When the molar ratio is less than 9 molNH3 / molCO2, the CO2 capture rate of the double contact carbon capture absorber is below 70%. The reason is that when the molar ratio is less than 9 molNH3 / molCO2, from the perspective of reaction equilibrium, the amount of liquid NH3 is insufficient, the positive reaction is limited, and the reaction proceeds slowly. When the molar ratio is 27.42 molNH3 / molCO2, the CO2 capture rate of the double contact carbon capture absorber is the highest, reaching 86.525%.

[0101] Therefore, if the molar ratio of the absorption bed is less than the preset molar ratio threshold, it indicates that the current ratio of the amount of absorbent (such as ammonia water) to the absorbed gas (such as carbon dioxide) has not reached the ideal state, which may affect the carbon capture effect. The current absorbent inlet volume flow is adjusted according to the preset step size. After adjusting the flow, the system will continue to monitor the carbon capture rate. Due to the change in the absorbent flow, the contact between the absorbent and the gas will change, thereby affecting the carbon capture rate. The system will continue to repeat the above operations of adjusting the flow and monitoring the carbon capture rate until the carbon capture rate reaches the preset demand range to ensure that the absorption bed is always in an efficient carbon capture working state and achieve effective capture of carbon dioxide.

[0102] In one example of the present application, the method further includes the following steps S11-S13:

[0103] S11, obtaining structural data of the hollow cylindrical shell;

[0104] S12, determining the total pressure drop of the absorption bed according to the structural data and the preset average absorption data;

[0105] Furthermore, the structural data includes the cross-sectional dimensions and the shell height, and the average absorption data includes the average density of the inlet and outlet working fluids and the average flow rate of the absorption bed; S12 may include the following sub-steps:

[0106] Substitute the average density of the inlet and outlet working fluids into the gravity pressure drop calculation formula to determine the gravity pressure drop of the absorption bed;

[0107] Substitute the shell height, average flow velocity of the absorption bed and the cross-sectional dimensions into the resistance loss formula along the way to determine the resistance loss along the absorption bed;

[0108] The total pressure drop of the absorber bed is obtained by superimposing the pressure drop at the absorption bed weight position and the resistance loss along the absorption bed.

[0109] In this embodiment, the total pressure drop of the absorption bed can be calculated by the following formula:

[0110]

[0111] in, is the total pressure drop, in Pa; is the absorption bed weight pressure drop, in Pa; It is the resistance loss along the absorption bed, the unit is Pa.

[0112] The formula for calculating the pressure drop at the gravity position is:

[0113]

[0114] in, is the injection height difference of the absorbent, in m; is the acceleration due to gravity, in units of ; is the average density of the inlet and outlet working fluids, in units of .

[0115] The formula for resistance loss along the way is:

[0116]

[0117] in, is the resistance coefficient along the way; is the average flow velocity of the absorption bed, in m / s; is the shell height, in m; is the cross-sectional dimension in m.

[0118] The cross section of the hollow cylindrical shell may also be circular, in which case d is the cross section radius.

[0119] In addition, the total pressure drop of the absorption bed can be obtained by comprehensively calculating the resistance along the pipeline, the local resistance of the pipe fittings, and the resistance generated by the internal structure of the equipment.

[0120] S13. Select a liquid pump whose structural parameters meet the total pressure drop of the absorption bed as a new liquid pump.

[0121] In this embodiment, after the total pressure drop value is obtained, it is converted into the head that the liquid pump needs to overcome. At the same time, the liquid flow rate required for the normal operation of the absorption bed is clarified. Next, the liquid pump product information is consulted, and the candidate liquid pumps whose heads can meet the total pressure drop conversion head of the absorption bed and whose flow rate is not lower than the actual demand of the absorption bed. Further analyze the performance curves of these candidate liquid pumps, mark the working points of the absorption bed (the corresponding points of flow rate and head), and give priority to selecting liquid pumps whose working points fall in the high-efficiency zone, because when operating in the high-efficiency zone, the pump has low energy consumption and good economy. In addition, it is necessary to consider factors such as the applicability of the liquid pump material to the absorption bed liquid, whether the installation method meets the site conditions, and the reliability and convenience of maintenance. After comprehensive consideration, a new liquid pump with structural parameters adapted to the total pressure drop of the absorption bed is finally selected.

[0122] Optionally, the method further comprises the following steps S21-S22:

[0123] S21, periodically obtaining average absorption update data;

[0124] S22. When the difference between the average absorption update data and the preset average absorption data is greater than the preset data threshold, the average absorption update data is used as the new average absorption data, and the step of determining the total pressure drop of the absorption bed based on the structural data and the preset average absorption data is jumped to execute.

[0125] In the embodiment of the present application, due to the non-fixed flue gas flow rate and density changes, the average density of the inlet and outlet working fluid and the average flow rate of the absorption bed are likely to change, and the preset average absorption data is often an empirical value or an experimental simulation value. Therefore, the average absorption update data can be periodically obtained to obtain the average density of the inlet and outlet working fluid and the average flow rate of the absorption bed under different conditions. When the difference between the average absorption update data and the preset average absorption data is greater than the preset data threshold, it indicates that the liquid pump may not be able to meet the current demand at this time, and the step S12 can be jumped to recalculate the total pressure drop of the absorption bed, so as to reselect the liquid pump.

[0126] In this embodiment, the gas phase and liquid phase of the double contact carbon capture absorption bed are both inlet with mass flow. The gas phase inlet of the double contact carbon capture absorption bed is a simulated flue gas composed of N2 and CO2 with molar fractions of 88% and 12%, respectively, and its inlet volume flow rate is 3.75 m 3 / h. The liquid phase inlet of the double-contact carbon capture absorption bed is ammonia water, which is a mixture of 10% NH3 and 90% H2O by mass fraction. Its volume flow rate changes with the change of molar ratio. The inlet volume flow rate is from 0.014 m 3 / h at 0.002 m 3 / h is the flow rate when the step length reaches the maximum height of the liquid column of the double contact carbon capture absorption bed in the reaction section 0.132 m 3 / h, such as Figure 6 shown.

[0127] In the embodiment of the present application, the flue gas inlet and outlet volume flow and inlet and outlet carbon concentration are detected in real time, and the current absorbent inlet volume flow is obtained; the carbon capture rate is determined according to the flue gas inlet and outlet volume flow and the inlet and outlet carbon concentration; the absorption bed molar ratio is determined according to the flue gas inlet and outlet volume flow and the current absorbent inlet volume flow; if the absorption bed molar ratio is less than the preset molar ratio threshold, the current absorbent inlet volume flow is adjusted according to the preset step length until the carbon capture rate reaches the preset demand range. In this way, the absorbent is accurately and effectively regulated to improve the carbon recovery efficiency of flue gas.

[0128] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A double contact carbon capture absorption bed, characterized in that: It includes a liquid pump, a hollow cylindrical housing and at least two absorbent injection pipes installed in the cylindrical housing; The interior of the hollow cylindrical shell is divided into an inlet section, a reaction section and an outlet section; The absorbent injection pipe is installed at the inlet section, and is used to receive the absorbent transported by the liquid pump and inject it into the reaction section, so as to perform double-stage carbon capture on the flue gas entering from the inlet section, and discharge the purified gas from the outlet section.

2. The double-contact carbon capture absorption bed according to claim 1, characterized in that: The absorbent injection pipe is provided with at least one nozzle; The numbers of nozzles of two adjacent absorbent injection pipes are different, and the total number of the nozzles is an odd number.

3. The double-contact carbon capture absorption bed according to claim 1, characterized in that: The cross-sectional shape of the hollow cylindrical shell is a square; The height ratios among the inlet section, the reaction section and the outlet section are as follows: 3:14:

7.

4. The double-contact carbon capture absorption bed according to claim 1, characterized in that: The absorbent is ammonia water mixed with 10% NH3 and 90% H2O by mass fraction.

5. A method for regulating a double-contact carbon capture absorption bed, characterized in that: Applied to a control terminal in communication with the double-contact carbon capture absorption bed according to any one of claims 1 to 4, the method comprising: Real-time detection of flue gas inlet and outlet volume flow and inlet and outlet carbon concentration, and acquisition of current absorbent inlet volume flow; Determining the carbon capture rate according to the flue gas inlet and outlet volume flow and the inlet and outlet carbon concentration; Determining the absorption bed molar ratio according to the flue gas inlet and outlet volume flow rates and the current absorbent inlet volume flow rate; If the absorption bed molar ratio is less than a preset molar ratio threshold, the current absorbent inlet volume flow rate is adjusted according to a preset step size until the carbon capture rate reaches a preset demand range.

6. The method according to claim 5, characterized in that The flue gas inlet and outlet volume flow rate includes a flue gas inlet volume flow rate and a flue gas outlet volume flow rate, and the inlet and outlet carbon concentration includes a flue gas inlet carbon concentration and a flue gas outlet carbon concentration; and determining the carbon capture rate according to the flue gas inlet and outlet volume flow rate and the inlet and outlet carbon concentration includes: Calculating a first product value between the flue gas inlet volume flow rate and the flue gas inlet carbon concentration; Calculating a second product between the flue gas outlet volume flow rate and the flue gas outlet carbon concentration; calculating a first ratio between the second multiplier value and the first multiplier value; The difference between the preset value and the first ratio is calculated to obtain the carbon capture rate.

7. The method according to claim 6, characterized in that The step of determining the absorption bed molar ratio according to the flue gas inlet and outlet volume flow rates and the current absorbent inlet volume flow rate comprises: Determining the absorbent inlet mass flow rate according to the current absorbent inlet volume flow rate and absorbent density; Determining the smoke inlet mass flow rate according to the smoke inlet volume flow rate and smoke density; Calculate the ratio between the absorbent inlet mass flow rate and the absorbent molar mass to obtain the number of absorbent moles; Calculate the ratio between the smoke inlet mass flow rate and the smoke molar mass to obtain the smoke mole number; The ratio between the molar number of the absorbent and the molar number of the flue gas is calculated to obtain the molar ratio of the absorption bed.

8. The method according to any one of claims 5 to 7, characterized in that: The method further comprises: Acquiring structural data of the hollow cylindrical shell; Determining the total pressure drop of the absorption bed according to the structural data and the preset average absorption data; A liquid pump whose structural parameters meet the total pressure drop of the absorption bed is selected as a new liquid pump.

9. The method according to claim 8, characterized in that The structural data includes cross-sectional dimensions and shell height, and the average absorption data includes average density of inlet and outlet working fluids and average flow rate of the absorption bed; the total pressure drop of the absorption bed is determined according to the structural data and the preset average absorption data, including: Substituting the average density of the inlet and outlet working fluids into the gravity pressure drop calculation formula to determine the gravity pressure drop of the absorption bed; Substituting the shell height, the average flow velocity of the absorption bed and the cross-sectional dimensions into the resistance loss formula along the way to determine the resistance loss along the absorption bed; The total pressure drop of the absorption bed is obtained by superimposing the pressure drop at the absorption bed weight position and the resistance loss along the absorption bed.

10. The method according to claim 9, characterized in that The method further comprises: Periodically obtain average absorption update data; When the difference between the average absorption update data and the preset average absorption data is greater than the preset data threshold, the average absorption update data is used as the new average absorption data, and the step of determining the total pressure drop of the absorption bed based on the structural data and the preset average absorption data is jumped to execute.

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