Pressure swing adsorption device for simulating oxygen production process

Abstract

The utility model discloses a pressure swing adsorption device for simulating an oxygen production process. The pressure swing adsorption device comprises a first compressor, a storage tank, an impurity removal device, a first regulating valve, a second compressor, a first adsorption tower and a second adsorption tower, wherein the first compressor is connected with the storage tank through the impurity removal device, the storage tank is respectively connected with openings at the lower ends of the first adsorption tower and the second adsorption tower, the openings at the lower ends of the first adsorption tower and the second adsorption tower are respectively communicated with the atmosphere through valves, and the openings at the upper ends of the first adsorption tower and the second adsorption tower are connected through the first regulating valve; openings in the upper ends of the first adsorption tower and the second adsorption tower are respectively connected with a second compressor through valves. According to the utility model, a computer can conveniently carry out analogue simulation design, and six-step technological process circulation can be realized, so that an approximately real simulation process is realized, the experiment cost of related experiments is reduced, and reference data is provided for a pressure swing adsorption oxygen production process.

Description

Technical Field

[0001] The utility model relates to a pressure swing adsorption device for simulating an oxygen production process, belonging to the technical field of chemical process production control. Background Art

[0002] Oxygen, as an important natural resource, is the basis for the survival of organisms. Its main production is obtained through air separation. Due to the special properties of oxygen atoms, oxygen is widely used as a combustion aid and oxidant in metallurgy, chemical industry and other industries, and is also an essential gas in the medical industry. Therefore, how to achieve the cost of reducing the energy consumption of oxygen production and increasing the product output without changing the product purity and equipment stability has always been a hot topic. The pressure swing adsorption method is a new type of air separation oxygen production method developed in the late 1960s. The main principle is that the dipole moment of nitrogen molecules is greater than that of oxygen molecules, and the force between the cations in the adsorbent and the dipole moment of nitrogen molecules is greater than that of oxygen molecules, so that the equilibrium adsorption capacity of oxygen molecules on the adsorbent is higher than that of oxygen, and finally the purpose of nitrogen and oxygen separation is achieved. Pressure swing adsorption has developed rapidly in recent years due to its unique advantages, such as simple device, high degree of automation, convenient operation, low investment and low energy consumption. At present, most of the small and medium-sized air separation oxygen production devices in China have adopted pressure swing adsorption.

[0003] Pressure swing adsorption is a common method for small and medium-sized oxygen production processes. The study of its process is very meaningful. The study of pressure swing adsorption oxygen production requires the construction of a relevant experimental platform, and the construction of a related small-scale laboratory experiment may be dangerous. In recent years, the process industry has become more and more demanding on the degree of informatization and safety, so it is necessary to study the simulation process of the pressure swing adsorption process. Summary of the invention

[0004] The utility model provides a pressure swing adsorption device for simulating an oxygen production process, through which support is provided for building a virtual simulation platform thereof.

[0005] The technical solution of the utility model is:

[0006] A pressure swing adsorption device for simulating an oxygen production process comprises a first compressor 1, a storage tank 5, an impurity removal device, a first regulating valve 12, a second compressor 16, a first adsorption tower 17, and a second adsorption tower 18; wherein the first compressor 1 is connected to the storage tank 5 through the impurity removal device, the storage tank 5 is connected to the lower openings of the first adsorption tower 17 and the second adsorption tower 18 respectively, the lower openings of the first adsorption tower 17 and the second adsorption tower 18 are also connected to the atmosphere through valves respectively, the upper openings of the first adsorption tower 17 and the second adsorption tower 18 are connected through the first regulating valve 12, and the upper openings of the first adsorption tower 17 and the second adsorption tower 18 are also connected to the second compressor 16 through valves respectively.

[0007] The impurity removal device includes a primary filtering device 2, a secondary filtering device 3, a cold dryer 4, and an oil-water separation device 19. A second regulating valve 20 is arranged on the air inlet end pipeline of the first compressor 1. The primary filtering device 2, the secondary filtering device 3, the cold dryer 4, and the oil-water separation device 19 are sequentially connected to the pipeline connecting the first compressor 1 and the storage tank 5.

[0008] The outlet end of the storage tank 5 is connected to the first ball valve 6 through a pipeline, and the outlet of the first ball valve 6 is divided into a first branch and a second branch. The first branch is connected to the second ball valve 7 and then connected to the lower opening of the first adsorption tower 17. The lower opening of the first adsorption tower 17 is also connected to the fourth ball valve 9 through a pipeline. The second branch is connected to the third ball valve 8 and then connected to the lower opening of the second adsorption tower 18. The lower opening of the second adsorption tower 18 is also connected to the fifth ball valve 10 through a pipeline. The pipeline formed by merging the outlet ends of the fourth ball valve 9 and the fifth ball valve 10 is connected to the atmosphere through the sixth ball valve 11; the upper opening of the first adsorption tower 17 is divided into a third branch and a fourth branch, and the upper opening of the second adsorption tower 18 is divided into a fifth branch and a sixth branch. The third branch is connected to the fifth branch through a first regulating valve 12, the fourth branch is connected to the seventh ball valve 13, and the sixth branch is connected to the eighth ball valve 14. The pipeline formed by merging the outlet ends of the seventh ball valve 13 and the eighth ball valve 14 is connected to the second compressor 16 through a ninth ball valve 15.

[0009] The beneficial effects of the utility model are as follows: the utility model can facilitate computer simulation design, can realize a six-step process cycle, thereby realizing a simulation process close to the real one, reducing the experimental cost of related experiments, and providing reference materials for the pressure swing adsorption oxygen production process. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the overall process structure of the utility model;

[0011] Figure 2 It is the process of boosting and reducing pressure in the process flow of the utility model;

[0012] Figure 3 It is the adsorption and desorption process in the process flow of the utility model;

[0013] Figure 4 This is the pressure equalization process in the process flow of the utility model, the adsorption tower 17 reduces the pressure, and the adsorption tower 18 increases the pressure;

[0014] Figure 5 It is the pressure reduction and pressure increase process in the process flow of the utility model;

[0015] Figure 6 It is the desorption and adsorption process in the process flow of the utility model;

[0016] Figure 7 This is the pressure equalization process in the process flow of the utility model, the adsorption tower 17 increases the pressure, and the adsorption tower 18 decreases the pressure;

[0017] Figure 8 It is a diagram of the pressure change in the adsorption tower at each stage during the KingSCADA simulation of pressure swing adsorption oxygen production;

[0018] The numbers in the figure are: 1-first compressor, 2-primary filtering device, 3-secondary filtering device, 4-cold dryer, 5-storage tank, 6-first ball valve, 7-second ball valve, 8-third ball valve, 9-fourth ball valve, 10-fifth ball valve, 11-sixth ball valve, 12-first regulating valve, 13-seventh ball valve, 14-eighth ball valve, 15-ninth ball valve, 16-second compressor, 17-first adsorption tower, 18-second adsorption tower, 19-oil-water separation device, 20-second regulating valve. DETAILED DESCRIPTION

[0019] The utility model is further described below in conjunction with the accompanying drawings and embodiments, but the content of the utility model is not limited to the described scope.

[0020] Example 1: Figure 1-8 As shown, a pressure swing adsorption device for simulating an oxygen production process includes a first compressor 1, a storage tank 5, an impurity removal device, a first regulating valve 12, a second compressor 16, a first adsorption tower 17, and a second adsorption tower 18; wherein the first compressor 1 is connected to the storage tank 5 through the impurity removal device, the storage tank 5 is connected to the lower end openings of the first adsorption tower 17 and the second adsorption tower 18 respectively, the lower end openings of the first adsorption tower 17 and the second adsorption tower 18 are also connected to the atmosphere through valves respectively, the upper end openings of the first adsorption tower 17 and the second adsorption tower 18 are connected through the first regulating valve 12, and the upper end openings of the first adsorption tower 17 and the second adsorption tower 18 are also connected to the second compressor 16 through valves respectively.

[0021] Furthermore, the impurity removal device includes a primary filtering device 2, a secondary filtering device 3, a cold dryer 4, and an oil-water separation device 19. A second regulating valve 20 is arranged on the air inlet end pipeline of the first compressor 1. The primary filtering device 2, the secondary filtering device 3, the cold dryer 4, and the oil-water separation device 19 are sequentially connected to the pipeline connecting the first compressor 1 and the storage tank 5.

[0022] Furthermore, the outlet end of the storage tank 5 is connected to the first ball valve 6 through a pipeline, and the outlet of the first ball valve 6 is divided into a first branch and a second branch. The first branch is connected to the second ball valve 7 and then connected to the lower end opening of the first adsorption tower 17. The lower end opening of the first adsorption tower 17 is connected to the fourth ball valve 9 through a pipeline, and the second branch is connected to the third ball valve 8 and then connected to the lower end opening of the second adsorption tower 18. The lower end opening of the second adsorption tower 18 is connected to the fifth ball valve 10 through a pipeline, and the pipeline formed by merging the outlet ends of the fourth ball valve 9 and the fifth ball valve 10 is connected to the atmosphere through the sixth ball valve 11; the upper end opening of the first adsorption tower 17 is divided into a third branch and a fourth branch, and the upper end opening of the second adsorption tower 18 is divided into a fifth branch and a sixth branch, the third branch is connected to the fifth branch through a first regulating valve 12, the fourth branch is connected to the seventh ball valve 13, and the sixth branch is connected to the eighth ball valve 14. The pipeline formed by merging the outlet ends of the seventh ball valve 13 and the eighth ball valve 14 is connected to the second compressor 16 through a ninth ball valve 15.

[0023] The process principle of the utility model is as follows (the process flow is divided into six steps):

[0024] like Figure 2 , and the pressure is increased and decreased. The air passes through the second regulating valve 20 and enters the first compressor 1 for pressure increase. The air passes through the primary filter device 2, the secondary filter device 3, the cold dryer 4, and the oil-water separator 19 to remove impurities from the air. Then, the air enters the storage tank 5 for buffering. The buffered air passes through the first ball valve 6 and the second ball valve 7 and enters the first adsorption tower 17 for pressure increase. At this time, the second adsorption tower 18 is depressurized through the fifth ball valve 10 and the sixth ball valve 11.

[0025] like Figure 3 , and adsorption and desorption processes are carried out. When the pressure of the first adsorption tower 17 reaches the set value, adsorption begins. A part of the adsorbed gas passes through the seventh ball valve 13, the ninth ball valve 15, and the second compressor 16 to the oxygen collection point, and another part of the adsorbed gas passes through the first regulating valve 12 into the adsorption tower C18 for purging, and passes through the fifth ball valve 10 and the sixth ball valve 11 to the exhaust port.

[0026] like Figure 4, a pressure equalization process is performed. When the first adsorption tower 17 has been adsorbed for a certain period of time, only the first regulating valve 12 is kept open, and the other valves are closed. The first adsorption tower 17 and the second adsorption tower 18 are pressure-equalized, and the gas in the first adsorption tower 17 enters the second adsorption tower 18.

[0027] like Figure 5 , and a pressure reduction and pressure increase process is performed. When the pressures of the first adsorption tower 17 and the second adsorption tower 18 are close, the gas in the storage tank 5 enters the second adsorption tower 18 through the first ball valve 6 and the third ball valve 8 for pressure increase, and the first adsorption tower 17 is led to the exhaust port through the fourth ball valve 9 and the sixth ball valve 11 for pressure reduction.

[0028] like Figure 6 , desorption and adsorption process is carried out, and adsorption begins when the pressure of the second adsorption tower 18 reaches the set value. A part of the adsorbed gas passes through the eighth ball valve 14 and the ninth ball valve 15 and the second compressor 16 to the oxygen collection point, and another part of the adsorbed gas passes through the first regulating valve 12 into the first adsorption tower 17 for purging, and passes through the fourth ball valve 9 and the sixth ball valve 11 to the exhaust port for pressure reduction.

[0029] like Figure 7 , a pressure equalization process is carried out. When the second adsorption tower 18 has been adsorbed for a certain period of time, only the first regulating valve 12 is kept open, and the other valves are closed. The second adsorption tower 18 and the first adsorption tower 17 are pressure-equalized, and the gas in the second adsorption tower 18 enters the first adsorption tower 17.

[0030] In order to further verify the utility model, a simulation model of the pressure swing adsorption oxygen production process was built according to the simulink module in MATLAB. In the storage tank part, a PID control was constructed according to the gas pressure inside the storage tank. When the pressure was greater than the set value, the inlet flow at the second regulating valve 20 was reduced. When the pressure was less than the set value, the inlet flow at the second regulating valve 20 was increased. According to the switch control of different valves, two adsorption towers were realized to complete the six-step cycle. The physical relationship of the gas pressure difference on the pipeline gas flow was used to construct the pressure change of the adsorption tower at different stages, making the simulation more realistic. The PID adjustment value can be operated on the KingSCADA interface, and the pressure change diagram of the adsorption tower can also be viewed on the KingSCADA interface. The state table of each switch valve in the KingSCADA simulation process of pressure swing adsorption oxygen production is further given as follows. Specifically, the process numbers in Table 1 represent: 1-pressure increase and pressure reduction process; 2-adsorption and desorption process; 3-pressure equalization process; 4-pressure reduction and pressure increase process; 5-desorption and adsorption process; 6-pressure equalization process, where ○ indicates that the switch is open and vice versa.

[0031] Table 1 The status of each switch valve during the KingSCADA simulation of pressure swing adsorption oxygen production

[0032]

[0033] like Figure 8 The figure shows the pressure changes in the adsorption tower at each stage during the KingSCADA simulation of pressure swing adsorption oxygen production. The numbers in the figure represent, respectively, 1-pressure change during the depressurization process of the right adsorption tower; 2-pressure change during the desorption process of the right adsorption tower; 3-pressure change during the equalization process of the right adsorption tower (pressurization); 4-pressure change during the pressure increase process of the right adsorption tower; 5-pressure change during the adsorption process of the right adsorption tower; 6-pressure change during the equalization process of the right adsorption tower (pressure reduction). The change of the left adsorption tower is opposite to that of the right adsorption tower. The above six processes are one cycle. Figure 8 Two complete cycles are included.

[0034] By applying the above technical solution, it can be known that the utility model realizes a six-step cycle by building a pressure swing adsorption oxygen production process model through the simulink module in the MATLAB software, and adds PID control to the storage tank part, so that the internal pressure of the storage tank can be maintained at a certain value in the experiment, so that the gas flow is more stable, and a display interface is established in the KingSCADA software interface, which can adjust the PID value and the internal pressure display of the adsorption tower, and can more intuitively display the pressure change in the adsorption tower during the pressure swing adsorption oxygen production process, providing a reference for related research.

[0035] The specific implementation modes of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A pressure swing adsorption device for simulating an oxygen production process, characterized in that: A pressure swing adsorption device simulation model of an oxygen production process is constructed based on a simulink module, comprising a first compressor (1), a storage tank (5), an impurity removal device, a first regulating valve (12), a second compressor (16), a first adsorption tower (17), and a second adsorption tower (18); wherein the first compressor (1) is connected to the storage tank (5) via the impurity removal device, the storage tank (5) is connected to the lower end openings of the first adsorption tower (17) and the second adsorption tower (18), respectively, the lower end openings of the first adsorption tower (17) and the second adsorption tower (18) are also connected to the atmosphere via valves, the upper end openings of the first adsorption tower (17) and the second adsorption tower (18) are connected via the first regulating valve (12), and the upper end openings of the first adsorption tower (17) and the second adsorption tower (18) are also connected to the second compressor (16) via valves; PID control is introduced at the storage tank (5); The impurity removal device comprises a primary filtering device (2), a secondary filtering device (3), a cold dryer (4), and an oil-water separation device (19); a second regulating valve (20) is provided on the air inlet end pipeline of the first compressor (1); and the primary filtering device (2), the secondary filtering device (3), the cold dryer (4), and the oil-water separation device (19) are sequentially connected to the pipeline connecting the first compressor (1) and the storage tank (5); The outlet end of the storage tank (5) is connected to the first ball valve (6) via a pipeline. The outlet of the first ball valve (6) is divided into a first branch and a second branch. The first branch is connected to the second ball valve (7) and then connected to the lower opening of the first adsorption tower (17). The lower opening of the first adsorption tower (17) is also connected to a fourth ball valve (9) via a pipeline. The second branch is connected to the third ball valve (8) and then connected to the lower opening of the second adsorption tower (18). The lower opening of the second adsorption tower (18) is also connected to a fifth ball valve (10) via a pipeline. The fourth ball valve (9), the third ball valve (8) and the fifth ball valve (10) are connected to the first branch. The pipeline formed by merging the outlet ends of the five ball valves (10) is communicated with the atmosphere through the sixth ball valve (11); the opening at the upper end of the first adsorption tower (17) is divided into a third branch and a fourth branch; the opening at the upper end of the second adsorption tower (18) is divided into a fifth branch and a sixth branch; the third branch and the fifth branch are connected through the first regulating valve (12); the fourth branch is connected to the seventh ball valve (13); the sixth branch is connected to the eighth ball valve (14); the pipeline formed by merging the outlet ends of the seventh ball valve (13) and the eighth ball valve (14) is connected to the second compressor (16) through the ninth ball valve (15).

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