Molecular sieve adsorption purification regulation and control method and system

Abstract

The invention belongs to the technical field of molecular sieve performance detection, and relates to a regulation and control method and system for molecular sieve adsorption purification, and the detection method comprises the following steps: S1, constructing a molecular sieve adsorption capacity curve; s2, calculating the residual adsorption time of the molecular sieve; s3, regulating and controlling adsorption and purification of the molecular sieve: comparing the residual adsorption time of the molecular sieve with the regeneration time required by the molecular sieve in the regeneration stage, and regulating and controlling the adsorption and purification process of the molecular sieve. The method provided by the invention can judge whether adsorption of the molecular sieve reaches saturation or not in real time, and adjust the purification process according to the adsorption result, so that accurate regulation and control of the molecular sieve adsorption purification process are realized, and stable operation of the molecular sieve purification process is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of molecular sieve performance detection, and relates to a regulation method and system for molecular sieve adsorption purification, which is used for the regulation of the adsorption purification work of a large air separation device. Background Art

[0002] Large air separation devices generally use the deep freezing method to separate air. However, since water, carbon dioxide, etc. in the air freeze and precipitate successively under low-temperature conditions, they will block the gas channels and sieve holes of the trays. At the same time, acetylene and hydrocarbons accumulate excessively in the rectification column, so explosions will occur. To improve the safety, reliability, and economy of the operation of large air separation devices, it is necessary to purify the air and remove impurities such as water, carbon dioxide, acetylene, and hydrocarbons in the air, and the purification is mainly carried out in molecular sieves. Molecular sieves have the characteristics of high adsorption capacity, strong selectivity, and high temperature resistance, and achieve air purification by adsorbing impurities in the air. However, the adsorption capacity of molecular sieves is limited. When a certain molecule is adsorbed to saturation, there is no adsorption capacity, and continuous adsorption will cause the molecular sieve to penetrate, affecting the safe and stable operation of the air separation device. In the prior art, when the adsorption amount of the molecular sieve approaches the saturated adsorption amount, the molecular sieve needs to be sent for regeneration to restore its adsorption capacity and then adsorption is carried out again. Therefore, in order to ensure the performance of the molecular sieve and the purification effect, it is necessary to detect the actual adsorption amount of the molecular sieve in real time to determine whether to continue adsorption or carry out regeneration.

[0003] In addition, in actual work, in order to ensure continuous gas supply, the molecular sieve purification process adopted by large air separation devices generally sets two molecular sieves to be used alternately, with one molecular sieve in the adsorption stage and the other in the regeneration stage. Therefore, the ideal purification process is that the adsorption stage and the regeneration stage can be completed simultaneously, or the regeneration stage is completed first and the adsorption stage is completed later. This can not only ensure the continuous progress of the purification process, but also reduce the time consumption and improve the purification efficiency.

[0004] Therefore, in the actual purification process, it is necessary to detect the adsorption performance of the molecular sieve, determine the adsorption time in the adsorption stage through the adsorption performance of the molecular sieve, compare the regeneration time in the regeneration stage, and ensure that the adsorption time is greater than or equal to the regeneration time. In the prior art, the adsorption time is generally determined by the theoretical saturated adsorption amount of the molecular sieve. However, due to the influence of factors such as air flow rate, molecular sieve packing density, and external environment during operation, there is a deviation between the actual adsorption amount of the molecular sieve and the theoretical saturated adsorption amount. And at this time, if the theoretical saturated adsorption amount is still used for calculation, there will be fluctuations in the actual adsorption time, which will make it difficult to control the regeneration time. Often, there is a large difference between the actual adsorption stage and the regeneration stage, or the adsorption is already saturated but the regeneration has not ended, resulting in unstable operation of the purification process and difficult regulation. Summary of the Invention

[0005] In view of the technical problem of unstable operation in the existing molecular sieve purification process, the present invention provides a regulation method and system for molecular sieve adsorption purification.

[0006] The present invention collects the carbon dioxide adsorption capacity corresponding to different inlet temperatures of the molecular sieve, constructs an actual curve equation; further calculates the remaining adsorption time of the molecular sieve according to the real-time carbon dioxide adsorption capacity; and compares it with the time to complete regeneration, can judge in real time whether the adsorption of the molecular sieve reaches saturation, and adjusts the purification process according to the adsorption result, realizing the precise regulation of the molecular sieve adsorption purification process and ensuring the stable operation of the molecular sieve purification process.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The present invention provides a regulation method for molecular sieve adsorption purification, including the following steps:

[0009] S1. Construct a molecular sieve adsorption capacity curve

[0010] S1.1. Set the working temperature of the molecular sieve, introduce air into the molecular sieve until the carbon dioxide concentration after adsorption by the molecular sieve is 1 ppm, record the total adsorption time; and obtain the maximum adsorption capacity of the molecular sieve for adsorbing carbon dioxide at each working temperature according to the following formula:

[0011] Q max = C × D × T

[0012] Where: Q max is the maximum adsorption capacity, unit Nm 3 ; C is the air flow rate, unit Nm 3 / h; D is the content of carbon dioxide in the introduced air; T is the total adsorption time, unit h.

[0013] S1.2. With the working temperature as the abscissa and 90% - 95% of the maximum adsorption capacity as the ordinate, construct a molecular sieve adsorption capacity curve through regression analysis;

[0014] S2. Calculate the remaining adsorption time of the molecular sieve

[0015] S2.1. In the molecular sieve adsorption purification, introduce air into the molecular sieve, and collect the inlet temperature value T 实际 of the molecular sieve, the introduced air flow rate, and the content of carbon dioxide in the air at each time point according to the set adsorption time interval ΔT;

[0016] S2.2. Substitute the inlet temperature value T 实际Substitute it into the molecular sieve adsorption capacity curve in step S1, and calculate the real-time maximum adsorption capacity Q of the molecular sieve at each time point. 实时 ;

[0017] S2.3. Calculate the actual adsorption amount Q of the molecular sieve for adsorbing carbon dioxide. 实际 ;

[0018] Q 实际 = C×D×ΔT

[0019] C is the air flow rate, with the unit Nm 3 / h; D is the carbon dioxide content in the air;

[0020] S2.4. Calculate the remaining adsorption time of the molecular sieve according to the following formula:

[0021] T 剩余 =(Q 实时 -Q 累积 ) / A 瞬时

[0022] Where:

[0023] T 剩余 is the remaining adsorption time of the molecular sieve, with the unit min; Q 累积 is the sum of the actual adsorption amounts Q of the molecular sieve for adsorbing carbon dioxide at all time points, with the unit Nm 实际 ; A The ratio of the sum of the actual adsorption amounts Q of the molecular sieve for adsorbing carbon dioxide in the previous 1 minute at the current time point to the time, with the unit Nm 3 瞬时 / min; 实际 3 剩余 / min;

[0024] S3. Regulation of molecular sieve adsorption purification

[0025] Compare the remaining adsorption time T 剩余 of the molecular sieve with the regeneration time T 再生 required by the molecular sieve in the regeneration stage, and regulate the adsorption purification work of the molecular sieve according to the comparison result.

[0026] If T 再生 < T 剩余 , it indicates that the time required for the molecular sieve to reach the adsorption saturation amount is greater than the regeneration time required by the molecular sieve in the regeneration stage, the operation is stable, and the molecular sieve continues to adsorb and purify;

[0027] If T 再生 ≥ T 剩余 , it indicates that the time required for the molecular sieve to reach the adsorption saturation amount is less than or equal to the regeneration time required by the molecular sieve in the regeneration stage, the operation is unstable, and the adsorption purification work of the molecular sieve needs to be regulated.

[0028] Further defined, the range of the working temperature is 7°C to 18°C.

[0029] Further defined, the regeneration time T required for the molecular sieve in the regeneration stage 再生 includes the pressure relief time, equalization time, heating time, and cold blow time.

[0030] Further defined, if T 再生 ≥T 剩余 When this is the case, the adsorption purification work is regulated by extending the remaining adsorption time of the molecular sieve or shortening the regeneration time required for the molecular sieve in the regeneration stage.

[0031] Further defined, the extension of the remaining adsorption time of the molecular sieve is achieved by reducing the inlet air flow rate, reducing the carbon dioxide content in the air, or lowering the inlet temperature of the molecular sieve.

[0032] Further defined, the shortening of the regeneration time required for the molecular sieve in the regeneration stage is achieved by increasing the heating temperature of the molecular sieve, increasing the cold blow gas volume of the molecular sieve, or manually switching.

[0033] A detection system for implementing the regulation method of the molecular sieve adsorption purification described above, comprising:

[0034] Data acquisition module: used to collect the working temperature of the molecular sieve, inlet temperature value, air flow rate, carbon dioxide content in the air, total adsorption time, and adsorption time interval;

[0035] Data analysis module: used to calculate the maximum adsorption capacity based on the air flow rate, carbon dioxide content in the air, and total adsorption time, and calculate 90% - 95% of the maximum adsorption capacity; used to construct a molecular sieve adsorption capacity curve based on the working temperature of the molecular sieve and 9% - 95% of the maximum adsorption capacity; used to calculate the actual adsorption amount Q of the molecular sieve adsorbing carbon dioxide based on the air flow rate, carbon dioxide content in the air, and adsorption time interval 实际 ; used to calculate the real-time adsorption capacity Q of the molecular sieve based on the inlet temperature value and the molecular sieve adsorption capacity curve 实时 ; used to calculate the remaining adsorption time T of the molecular sieve according to the formula 剩余 ;

[0036] Comparison module: used to compare T 剩余 with the regeneration time T required for the molecular sieve in the regeneration stage 再生 and feedback the comparison result to the control module;

[0037] And a control module, used to regulate the adsorption purification work of the molecular sieve according to the comparison result fed back by the comparison module.

[0038] Further limited, the data acquisition module respectively includes a temperature sensor and a flow meter; the temperature sensor is located at the inlet of the molecular sieve, and the flow meter is located at the outlet of the molecular sieve.

[0039] Further limited, the data acquisition module further includes a carbon dioxide content detection and analyzer A arranged at the air suction port of the molecular sieve and a carbon dioxide content detection and analyzer B arranged at the air outlet port of the molecular sieve.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] 1. By collecting relevant operating parameters, calculating the maximum adsorption capacity corresponding to the molecular sieve at different working temperatures, constructing a molecular sieve adsorption capacity curve through regression analysis, and then calculating the actual cumulative value of the molecular sieve adsorbing carbon dioxide by collecting parameters such as the inlet temperature in real time during the molecular sieve purification process, calculating the remaining adsorption time of the molecular sieve in real time, and comparing it with the regeneration time required for the molecular sieve in the regeneration stage, the molecular sieve in the adsorption stage can be ensured to reach saturated adsorption after the regeneration of another molecular sieve is completed, realizing the precise control of the molecular sieve adsorption purification process.

[0042] 2. Through real-time monitoring, the present invention effectively avoids the penetration of the molecular sieve, not only realizes the purpose of safe and stable operation of the system, but also can supervise the service life of the molecular sieve.

[0043] 3. By constructing a molecular sieve adsorption capacity curve, the present invention can well judge the rate of decline of the molecular sieve adsorption performance through regular measurement, and can also judge whether the adsorption capacity of the molecular sieve can meet the process operation requirements, and finally realize the purpose of planned filling or replacement of the molecular sieve, ensuring the normal operation of the molecular sieve adsorption purification process. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the regulation method for the molecular sieve adsorption purification of the present invention;

[0045] Figure 2 It is to construct a molecular sieve adsorption capacity curve through regression analysis. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with specific embodiments and the accompanying drawings. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0047] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0048] It should be noted that the terms "first", "second", etc. in the description and claims of the present application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0049] See Figure 1 , the present invention provides a method for regulating molecular sieve adsorption purification, comprising the following steps:

[0050] S1. Construct a molecular sieve adsorption capacity curve

[0051] S1.1. Set the working temperature of the molecular sieve, introduce air into the molecular sieve until the carbon dioxide concentration after adsorption by the molecular sieve is 1 ppm, record the total adsorption time, and obtain the maximum adsorption capacity of the molecular sieve for carbon dioxide.

[0052] S1.2. Take the working temperature as the abscissa and 90% - 95% of the maximum adsorption capacity as the ordinate, and construct a molecular sieve adsorption capacity curve through regression analysis.

[0053] In this step, the working temperature of the molecular sieve is set according to the performance of the molecular sieve. Generally, the range of the working temperature is 7°C - 18°C, which can meet the requirements of large-scale air separation plants for the working temperature of molecular sieves.

[0054] The maximum adsorption capacity is the adsorption capacity corresponding to the carbon dioxide concentration equal to 1 ppm after adsorption by the molecular sieve. At this time, the maximum adsorption capacity is calculated according to the following formula.

[0055] Q max = C × D × T

[0056] Q max is the maximum adsorption capacity, with the unit Nm 3 ;

[0057] C is the air flow rate, with the unit Nm 3 / h;

[0058] D is the content of carbon dioxide in the introduced air;

[0059] T is the total adsorption time, with the unit h.

[0060] Preferably, the total adsorption time is the time taken by the molecular sieve from the start of adsorption until the carbon dioxide concentration after adsorption equals 1 ppm. The content of carbon dioxide in the incoming air is at the ppm level.

[0061] In this embodiment, the molecular sieve adsorption capacity curve is constructed with 90% - 95% of the maximum adsorption capacity. This is because in actual operation, considering the fluctuations in adsorption capacity caused by environmental factors and other influences, while ensuring accurate regulation, it can maximize the avoidance of the molecular sieve being saturated during actual operation and causing breakdown. Preferably, the molecular sieve adsorption capacity curve is constructed with 90% of the maximum adsorption capacity.

[0062] S2. Calculate the remaining adsorption time of the molecular sieve

[0063] S2.1. In the molecular sieve adsorption purification, air is passed into the molecular sieve, and at each time point according to the set adsorption time interval ΔT, the inlet temperature value T of the molecular sieve, 实际 the incoming air flow rate, and the content of carbon dioxide in the air are collected respectively;

[0064] S2.2. Substitute the inlet temperature value T 实际 into the molecular sieve adsorption capacity curve in step S1 to calculate the real - time maximum adsorption capacity Q of the molecular sieve at each time point 实时 ;

[0065] S2.3. Calculate the actual adsorption amount Q of the molecular sieve for adsorbing carbon dioxide 实际 ;

[0066] Q 实际 = C × D × ΔT

[0067] C is the air flow rate, with the unit Nm 3 / h; D is the content of carbon dioxide in the air;

[0068] S2.4. Calculate the remaining adsorption time of the molecular sieve according to the following formula:

[0069] T 剩余 = (Q 实时 - Q 累积 ) / A 瞬时

[0070] Where:

[0071] T 剩余 is the remaining adsorption time of the molecular sieve, with the unit min;

[0072] Q 累积 is the sum of the actual adsorption amounts Q of the molecular sieve for adsorbing carbon dioxide at all time points 实际 , with the unit Nm 3;

[0073] A 瞬时 is the ratio of the sum of the actual adsorption amount Q of molecular sieve adsorbing carbon dioxide within the first 1 minute before the current time point to time, with the unit of Nm 实际 / min; 3 / min;

[0074] S3. Regulation of Molecular Sieve Adsorption and Purification

[0075] Compare the remaining adsorption time T of the molecular sieve 剩余 with the regeneration time T required for the molecular sieve in the regeneration stage 再生 and regulate the adsorption and purification work of the molecular sieve according to the comparison result.

[0076] If T 再生 < T 剩余 , it indicates that the time required for the molecular sieve to reach the adsorption saturation amount is greater than the regeneration time required for the molecular sieve in the regeneration stage, the operation is stable, and the molecular sieve continues to adsorb and purify;

[0077] If T 再生 ≥ T 剩余 , it indicates that the time required for the molecular sieve to reach the adsorption saturation amount is less than or equal to the regeneration time required for the molecular sieve in the regeneration stage, the operation is unstable, and the adsorption and purification work of the molecular sieve needs to be regulated.

[0078] The regeneration time T required for the molecular sieve in the regeneration stage 再生 includes the pressure relief time, equalization time, heating time, and molecular sieve cold blow time.

[0079] In the present invention, if T 再生 ≥ T 剩余 , the adsorption and purification work is regulated by extending the remaining adsorption time of the molecular sieve or shortening the regeneration time required for the molecular sieve in the regeneration stage.

[0080] In the present invention, the remaining adsorption time of the molecular sieve is extended by reducing the inlet gas flow rate, reducing the carbon dioxide content in the air, or lowering the inlet temperature of the molecular sieve.

[0081] In the present invention, the regeneration time required for the molecular sieve in the regeneration stage is shortened by increasing the heating temperature of the molecular sieve, increasing the gas volume of the molecular sieve cold blow, or manually switching under conditions.

[0082] Example 1

[0083] Taking two molecular sieves set in a certain large air separation plant as an example, the detection method is specifically described.

[0084] In order to ensure continuous gas supply, the molecular sieve purification process adopted by large air separation plants generally sets two molecular sieves to be used alternately. One molecular sieve is in the adsorption stage, and the other molecular sieve is in the regeneration stage (the process of driving away the adsorbed substances and restoring the adsorption capacity is called "regeneration").

[0085] The regeneration stage of the molecular sieve includes operations of "pressure relief, pressure equalization, heating, and cold blow".

[0086] In implementation, the two molecular sieves are respectively denoted as molecular sieve MS1 and molecular sieve MS2.

[0087] At the air inlets of the two molecular sieves, carbon dioxide content detection and analysis instruments A are respectively set to detect the carbon dioxide content at the air inlets, that is, the carbon dioxide content before the molecular sieve purification.

[0088] At the air outlets of the two molecular sieves, carbon dioxide content detection and analysis instruments B are both set to detect the carbon dioxide content after passing through the molecular sieve, that is, the carbon dioxide content after the molecular sieve purification.

[0089] At the inlet of molecular sieve MS1, an inlet temperature measurement point T1 is set to detect the inlet temperature of molecular sieve MS1.

[0090] At the inlet of molecular sieve MS2, an inlet temperature measurement point T2 is set to detect the inlet temperature of molecular sieve MS2.

[0091] Now it is set that molecular sieve MS1 is in the adsorption stage and molecular sieve MS2 is in the regeneration stage. When molecular sieve MS1 starts to adsorb, control the inlet temperature of molecular sieve MS1 to remain constant. At this time, molecular sieve MS2 is in the regeneration stage; if after the regeneration of molecular sieve MS2 ends, make the stage where molecular sieve MS2 is located pause at the pressure boosting stage; when the carbon dioxide content detection and analysis table B at the outlet of molecular sieve MS1 rises to 0.8 ppm (reaching 80% of the control index of 1 ppm), the molecular sieves are switched, that is, molecular sieve MS1 turns into the regeneration stage and molecular sieve MS2 turns into the adsorption stage.

[0092] Specifically, the regulation process of molecular sieve adsorption purification is as follows:

[0093] S1. Construct a molecular sieve adsorption capacity curve

[0094] S1.1. Set the working temperature of the molecular sieve, introduce air into the molecular sieve until the carbon dioxide concentration after adsorption by the molecular sieve is 1 ppm, record the total adsorption time; and obtain the maximum adsorption capacity of the molecular sieve for adsorbing carbon dioxide at each working temperature according to the following formula.

[0095] In this embodiment, when constructing the molecular sieve adsorption capacity curve, the molecular sieve adsorption environment is in an ideal state. For example, factors such as working temperature, flow rate, and carbon dioxide content are all kept constant.

[0096] Preferably, the working temperature is set at an increment of 1 °C within the range of 7 °C to 18 °C, air is introduced, and the molecular sieve adsorbs carbon dioxide in the air. When the carbon dioxide concentration after adsorption by the molecular sieve is detected to be equal to 1 ppm, the total adsorption time is recorded and substituted into Q max = C × D × T to calculate the maximum adsorption capacity of the molecular sieve for adsorbing carbon dioxide. The results are shown in Table 1. At the same time, 90% of the maximum adsorption capacity is calculated, and the results are shown in Table 1.

[0097] Table 1 Results of the maximum adsorption capacity of the molecular sieve for adsorbing carbon dioxide at different working temperatures

[0098] Operating temperature (°C) <![CDATA[Maximum adsorption capacity (Nm 3 )]]> <![CDATA[Maximum adsorption capacity 90% (Nm 3 )]]> 7 875.82 788.238 8 871.86 784.674 9 863.28 776.952 10 853.38 768.042 11 838.86 754.974 12 819.72 737.748 13 797.94 718.146 14 775.5 697.95 15 750.42 675.378 16 722.04 649.836 17 692.34 623.106 18 660.096 594.086

[0099] S1.2: With the working temperature as the abscissa and 90% of the maximum adsorption capacity as the ordinate, a molecular sieve adsorption capacity curve is constructed through regression analysis.

[0100] In this embodiment, the molecular sieve adsorption capacity curve is constructed with 90% of the maximum adsorption capacity. This is because in actual operation, considering the fluctuations in the adsorption capacity caused by environmental factors and other factors, while ensuring accurate regulation, it can avoid the breakdown of the molecular sieve caused by adsorption oversaturation in actual operation to the greatest extent.

[0101] See Figure 2 , the working temperature in Table 1 and 90% of the maximum adsorption capacity are plotted in a coordinate system, and a molecular sieve adsorption capacity curve is constructed through regression analysis. Its equation is as follows:

[0102] Q = -1.245T 2 + 13.171T + 758.81

[0103] In the equation, Q is the adsorption capacity of the molecular sieve, and T is the working temperature of the molecular sieve.

[0104] For the constructed molecular sieve adsorption capacity curve, the correlation coefficient R 2 is 0.9996, with a high degree of correlation and more accurate results.

[0105] S2: Calculate the remaining adsorption time of the molecular sieve

[0106] During the actual operation process, when the inlet and outlet valves of the molecular sieve MS1 are opened simultaneously, the molecular sieve MS1 is in the actual adsorption state at this time.

[0107] The air flow rate is controlled at 300000 Nm 3Around / h, the content of CO2 is detected by the carbon dioxide content detection analyzer A set at the air intake of the molecular sieve. During the adsorption and purification of the molecular sieve MS1, according to the adsorption time interval ΔT, the inlet temperature value T of the molecular sieve is collected at each time point 实际 , the air flow rate introduced, and the content of carbon dioxide in the air; calculate the actual adsorption amount Q of the molecular sieve for adsorbing carbon dioxide 实际 , in unit Nm 3 .

[0108] The actual adsorption amount Q 实际 is calculated from the air flow rate C (Nm 3 / h) of the air entering the molecular sieve, the content of carbon dioxide D (ppm) in the air, and the adsorption time interval ΔT (s) at the current adsorption time point.

[0109] Q 实际 = C × D × ΔT

[0110] Substitute the inlet temperature value T 实际 into the molecular sieve adsorption capacity curve in step S1, and calculate the real-time maximum adsorption capacity Q of the molecular sieve at each time point 实时 , and calculate the remaining adsorption time of the molecular sieve MS1 according to the following formula:

[0111] T 剩余 = (Q 实时 - Q 累积 ) / A 瞬时

[0112] Wherein:

[0113] T 剩余 is the remaining adsorption time of the molecular sieve, in unit min;

[0114] Q 累积 is the sum of the actual adsorption amounts Q of the molecular sieve for adsorbing carbon dioxide at all time points 实际 , in unit Nm 3 ;

[0115] A 瞬时 is the ratio of the sum of the actual adsorption amounts Q of the molecular sieve for adsorbing carbon dioxide in the previous 1 min at the current time point to the time, in unit Nm 实际 / min. 3 .

[0116] During implementation, the adsorption time interval ΔT is 1 s to 2 s. Preferably, the time interval ΔT is 1 s; that is, when the molecular sieve adsorption times are 1 s, 2 s, 3 s... respectively, the inlet temperature value T 实际 and the actual adsorption amount Q of the molecular sieve for adsorbing carbon dioxide corresponding to each moment are collected respectively 实际 .

[0117] Exemplarily, when the molecular sieve adsorption time is 10 s, the inlet temperature value T 实际 is 14.5 °C. Substituting it into the molecular sieve adsorption capacity curve to calculate the real-time maximum adsorption capacity Q 实时 = 673.51 Nm 3 ; meanwhile, the carbon dioxide content detection analyzer A installed at the air suction port detects that the carbon dioxide content is 600 ppm, and the air flow rate is 300,000 Nm 3 / h. Calculate the actual adsorption amount Q 实际 = 600×10 -6 ×300,000×1 / 3600 = 0.05 Nm 3 .

[0118] Furthermore, when 100 s have been adsorbed, calculate the remaining adsorption time of the molecular sieve MS1. Accumulate the actual adsorption amounts Q 实际 corresponding to each adsorption time interval within 0 - 100 s to obtain Q 累积 ; then, based on 100 s, count the sum of the actual adsorption amounts Q 实际 corresponding to each adsorption time interval within the first 1 min (i.e., 41 s - 100 s) and divide it by 1 min to obtain A 瞬时 , and finally substitute the inlet temperature value T 实际 at the 100th s into the molecular sieve adsorption capacity curve to calculate the real-time maximum adsorption capacity Q 实时 ; finally, substitute Q 实时 , Q 累积 and A 瞬时 into the calculation to obtain T 剩余 .

[0119] S3. Regulation of molecular sieve adsorption purification

[0120] Compare the remaining adsorption time T 剩余 of the molecular sieve MS1 with the time T 再生 when the molecular sieve MS2 completes regeneration

[0121] The time T 再生 when the molecular sieve MS2 completes regeneration includes a pressure relief time of 6 min, an equalization time of 18 min, a heating time of 84 min, and a cold blow time of 132 min. Therefore, T 再生 = 240 min. Compare the T 剩余 calculated when 100 s have been adsorbed with T 再生 (240 min). If T 再生 < T 剩余 , it indicates that the molecular sieve MS2 completes regeneration first, which means the purification process runs stably; no operation is required at this time. If T 再生 ≥ T 剩余; It indicates that molecular sieve MS1 finishes adsorption first and needs to wait for molecular sieve MS2 to complete regeneration; this shows that the purification process runs unstably; at this time, the inlet air flow rate is reduced to extend the remaining adsorption time of the molecular sieve.

[0122] In the above implementation process, the operation steps of "pressure relief, pressure equalization, heating, and cold blowing" during the regeneration of the molecular sieve are all prior arts and will not be elaborated here.

[0123] Example 2

[0124] To implement the regulation method for the molecular sieve adsorption purification in Example 1, this example provides a detection system, including:

[0125] Data acquisition module: used to collect the working temperature of the molecular sieve, inlet temperature value, air flow rate, carbon dioxide content in the air, total adsorption time, and adsorption time interval;

[0126] Data analysis module: used to calculate the maximum adsorption capacity and 90% of the maximum adsorption capacity according to the air flow rate, carbon dioxide content in the air, and total adsorption time; used to construct a molecular sieve adsorption capacity curve according to the working temperature of the molecular sieve and 90% of the maximum adsorption capacity; used to calculate the actual adsorption amount Q of the molecular sieve adsorbing carbon dioxide according to the air flow rate, carbon dioxide content in the air, and adsorption time interval 实际 ; used to calculate the real-time adsorption capacity Q of the molecular sieve according to the inlet temperature value and the molecular sieve adsorption capacity curve 实时 ; used to calculate the remaining adsorption time T of the molecular sieve according to the formula 剩余 ;

[0127] Comparison module: used to compare T 剩余 with the regeneration time T required for the molecular sieve in the regeneration stage 再生 and feedback the comparison result to the control module;

[0128] and

[0129] Control module: used to regulate the adsorption purification work of the molecular sieve according to the comparison result feedback by the comparison module.

[0130] In this example, the data acquisition module respectively includes a temperature sensor and a flowmeter; the temperature sensor is located at the inlet of the molecular sieve, and the flowmeter is located at the outlet of the molecular sieve. The inlet temperature or working temperature of the molecular sieve is detected by the temperature sensor. The air flow rate entering the molecular sieve is monitored by the flowmeter.

[0131] In this embodiment, the data acquisition module further includes a carbon dioxide content detection and analyzer A disposed at the air inlet of the molecular sieve and a carbon dioxide content detection and analyzer B disposed at the air outlet of the molecular sieve. Preferably, the carbon dioxide content detection and analyzer A is respectively disposed at the air inlet in front of the molecular sieve to detect the carbon dioxide content in the air at the air inlet. The carbon dioxide content detection and analyzer B is disposed behind the molecular sieve to detect the carbon dioxide content after passing through the molecular sieve, so as to avoid the molecular sieve being punctured through monitoring.

[0132] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for regulating molecular sieve adsorption purification, characterized in that, It includes the following steps: S1. Construct the molecular sieve adsorption capacity curve S1.

1. Set the working temperature of the molecular sieve, introduce air into the molecular sieve until the carbon dioxide concentration is 1 ppm after adsorption, and record the total adsorption time; and obtain the maximum adsorption capacity of the molecular sieve for carbon dioxide at each working temperature according to the following formula: Q max = C × D × T Where: Q max is the maximum adsorption capacity, unit Nm 3 ; C is the air flow rate, unit Nm 3 / h; D is the content of carbon dioxide in the inlet air; T is the total adsorption time, unit h; S1.

2. With the working temperature as the abscissa and 90% - 95% of the maximum adsorption capacity as the ordinate, construct the molecular sieve adsorption capacity curve through regression analysis; S2. Calculate the remaining adsorption time of the molecular sieve S2.

1. During the molecular sieve adsorption purification, air is introduced into the molecular sieve, and at each time point, the inlet temperature value T of the molecular sieve is collected respectively according to the set adsorption time interval ΔT. 实际 The flow rate of the introduced air and the content of carbon dioxide in the air are also measured. S2.

2. Substitute the inlet temperature value T 实际 into the molecular sieve adsorption capacity curve in step S1 to calculate the real-time maximum adsorption capacity Q of the molecular sieve at each time point 实时 ; S2.

3. Calculate the actual adsorption amount Q of the molecular sieve for carbon dioxide 实际 ; Q 实际 = C × D × ΔT Where: C is the air flow rate, unit Nm 3 / h; D is the carbon dioxide content in the air; S2.

4. Calculate the remaining adsorption time of the molecular sieve according to the following formula: T 剩余 = (Q 实时 - Q 累积 ) / A 瞬时 Where: T 剩余 is the remaining adsorption time of the molecular sieve, unit min; Q 累积 is the sum of the actual adsorption amounts Q 实际 of carbon dioxide adsorbed by the molecular sieve at all time points, unit Nm 3 ; A 瞬时 is the ratio of the sum of the actual adsorption amounts Q 实际 of carbon dioxide adsorbed by the molecular sieve within the previous 1 min at the current time point to the time, unit Nm 3 / min; S3. Regulation of molecular sieve adsorption purification Compare the remaining adsorption time T of the molecular sieve 剩余 with the regeneration time T required for the molecular sieve in the regeneration stage 再生 and regulate the adsorption and purification work of the molecular sieve according to the comparison result; If T 再生 <T 剩余 , it indicates that the time required for the molecular sieve to reach the adsorption saturation capacity is greater than the regeneration time required for the molecular sieve in the regeneration stage, the operation is stable, and the molecular sieve continues to adsorb and purify; If T 再生 ≥ T 剩余 , it indicates that the time required for the molecular sieve to reach the adsorption saturation capacity is less than or equal to the regeneration time required for the molecular sieve in the regeneration stage, and the operation is unstable. Then, it is necessary to regulate the adsorption and purification work of the molecular sieve.

2. The regulation method for molecular sieve adsorption purification according to claim 1, characterized in that, In the step S1, the range of the working temperature is 7°C to 18°C.

3. The regulation method for molecular sieve adsorption purification according to claim 1, characterized in that In the step S3, the regeneration time T required for the molecular sieve in the regeneration stage 再生 includes a pressure relief time, a pressure equalization time, a heating time, and a cold blow time.

4. The regulation method for molecular sieve adsorption purification according to claim 1, wherein If T 再生 ≥ T 剩余 When this occurs, the adsorption purification operation is regulated by extending the remaining adsorption time of the molecular sieve or shortening the regeneration time required for the molecular sieve in the regeneration stage.

5. The regulation method for molecular sieve adsorption purification according to claim 4, characterized in that, To extend the remaining adsorption time of the molecular sieve, it is achieved by reducing the inlet air flow rate, reducing the carbon dioxide content in the air, or lowering the inlet temperature of the molecular sieve.

6. The regulation method for molecular sieve adsorption purification according to claim 4, wherein To shorten the regeneration time required for the molecular sieve in the regeneration stage, it is achieved by increasing the heating temperature of the molecular sieve, increasing the gas volume of cold blowing of the molecular sieve, or manually switching.

7. A detection system for implementing the regulation method of molecular sieve adsorption purification described in claim 1, characterized in that, It includes: Data acquisition module: used to collect the working temperature of the molecular sieve, inlet temperature value, air flow rate, carbon dioxide content in the air, total adsorption time, and adsorption time interval; Data analysis module: used to calculate the maximum adsorption capacity according to the air flow rate, carbon dioxide content in the air, and total adsorption time, and calculate 90% - 95% of the maximum adsorption capacity; used to construct the molecular sieve adsorption capacity curve according to the working temperature of the molecular sieve and 90% - 95% of the maximum adsorption capacity; For calculating the actual adsorption capacity Q of molecular sieve for adsorbing carbon dioxide based on air flow rate, carbon dioxide content in air, and adsorption time interval 实际 ; for calculating the real-time adsorption capacity Q of molecular sieve based on the inlet temperature value and the molecular sieve adsorption capacity curve 实时 ; for calculating the remaining adsorption time T of molecular sieve according to the formula 剩余 ; Comparison module: used to compare T 剩余 with the regeneration time T 再生 required for the molecular sieve in the regeneration stage, and feed back the comparison result to the control module; and a control module, used to regulate the adsorption purification work of the molecular sieve according to the comparison result fed back by the comparison module.

8. The detection system according to claim 7, characterized in that, The data acquisition module respectively includes a temperature sensor and a flow meter; the temperature sensor is located at the inlet of the molecular sieve, and the flow meter is located at the outlet of the molecular sieve.

9. The detection system according to claim 7, wherein The data acquisition module also includes a carbon dioxide content detection analyzer A arranged at the air inlet of the molecular sieve and a carbon dioxide content detection analyzer B arranged at the air outlet of the molecular sieve.

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