A voltage-stabilizing gas path structure and a flow rate adjustment method

Abstract

The present invention discloses a voltage-stabilized gas circuit structure and a flow rate adjustment method, which include a nitrogen discharge unit, a molecular sieve tower group, an oxygen storage unit, and a flow rate adjustment component connected in sequence; the molecular sieve tower group includes a plurality of groups of molecular sieve towers, and both ends of each group of molecular sieve towers are provided with a first control valve and a first gas resistance; the first control valve is connected to the nitrogen discharge unit, the first gas resistance is connected to the oxygen storage unit, and a check valve and a second gas resistance are also arranged between the first gas resistance and the oxygen storage unit; the flow rate adjustment component includes a first pressure sensor, a third gas resistance, a second pressure sensor, and a third pressure sensor arranged in sequence. The first gas resistance and the second gas resistance are provided to stabilize the pressure in each molecular sieve tower in the molecular sieve tower group, the check valve is provided to prevent the oxygen in the oxygen storage unit from flowing back into each molecular sieve tower and causing oxygen loss, and the first pressure sensor, the second pressure sensor, and the third pressure sensor are cooperatively arranged to perform closed-loop dynamic control on the pressure and flow rate of the oxygen output by the oxygen generator, so as to prevent the change of gas concentration caused by the pressure fluctuation.

Description

Technical Field

[0001] The present invention relates to the technical field of oxygen production, and particularly relates to a pressure-stabilizing gas path structure and a flow rate adjustment method. Background Art

[0002] The oxygen production concentration and oxygen output flow rate of a PSA oxygen generator are important parameters of the oxygen generator's performance. To increase the oxygen production amount of the oxygen generator, multiple molecular sieve towers are usually set up for nitrogen-oxygen separation of compressed air to generate oxygen. Then, the oxygen separated from multiple molecular sieve towers is collected into an oxygen storage tank. A pressure reducing valve is set at the rear end of the oxygen storage tank, and then oxygen with a certain pressure is output. Nitrogen is discharged after being silenced by a nitrogen discharge silencer.

[0003] Molecular sieves separate oxygen and nitrogen in compressed air through the physical property of adsorbing nitrogen. However, the adsorption performance of molecular sieves is affected by gas pressure, and the pressure will change when each molecular sieve tower accesses compressed air, discharges nitrogen, or discharges oxygen. If the pressure in the molecular sieve tower is too small, it will affect the adsorption performance of the molecular sieve. If the pressure in the molecular sieve tower is too large, it will affect the entry of compressed air into the molecular sieve tower, thereby increasing the load of the air compressor. Moreover, during the process of the separated oxygen flowing from the molecular sieve tower into the oxygen storage tank, some losses will occur due to the pressure change of the molecular sieve tower. In an ideal state, the pressure and flow rate of the gas in the pipeline at the rear end of the oxygen storage tank are in a direct proportional relationship. The greater the pressure, the greater the flow rate. Precision and non-precision mechanical spring pressure reducing valves on the market generally have problems of pressure fluctuation. The pressure fluctuation will cause an increase or decrease in the flow rate, thereby causing a change in the gas concentration.

[0004] Therefore, how to maintain the pressure of each molecular sieve tower during oxygen production and reduce the increase or decrease in the oxygen output flow rate caused by pressure fluctuation, which leads to a decrease in oxygen concentration, has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] The technical problem to be solved by the present invention is that the pressure will change when the molecular tower accesses compressed air, discharges nitrogen, or discharges oxygen. The pressure fluctuation will cause an increase or decrease in the flow rate, thereby causing a change in the gas concentration. The purpose is to provide a pressure-stabilizing gas path structure and a flow rate adjustment method. By setting multiple groups of molecular towers, a first control valve and a first gas resistance are set at both ends of each group of molecular towers. A one-way valve and a second gas resistance are set between the first gas resistance and the oxygen storage unit. The pressure in each molecular tower in the molecular tower group is stabilized through the first gas resistance and the second gas resistance. The one-way valve is set to prevent the oxygen in the oxygen storage unit from flowing back into each molecular tower, causing oxygen loss. A flow rate adjustment component is set to perform closed-loop dynamic control on the pressure and flow rate of the oxygen output of the oxygen generator, preventing the change in gas concentration caused by pressure fluctuation.

[0006] The present invention is realized through the following technical solutions:

[0007] The first aspect of the present invention provides a voltage-stabilized gas path structure, which includes a nitrogen discharge unit, a molecular sieve tower group, an oxygen storage unit, and a flow rate adjustment component connected in sequence;

[0008] The molecular sieve tower group includes several groups of molecular sieve towers, and a first control valve and a first gas resistance are arranged at both ends of each group of molecular sieve towers;

[0009] The first control valve is connected to the nitrogen discharge unit, the first gas resistance is connected to the oxygen storage unit, and a one-way valve and a second gas resistance are also arranged between the first gas resistance and the oxygen storage unit;

[0010] The flow rate adjustment component includes a first pressure sensor, a third gas resistance, a second pressure sensor, and a third pressure sensor arranged in sequence.

[0011] In the present invention, by setting multiple groups of molecular sieve towers, a first control valve and a first gas resistance are arranged at both ends of each group of molecular sieve towers. The first control valve is set to control the nitrogen discharge speed, ensure the air pressure stability during nitrogen discharge, and ensure the air pressure stability inside the molecular sieve tower. A one-way valve and a second gas resistance are arranged between the first gas resistance and the oxygen storage unit. The pressure inside each molecular sieve tower in the molecular sieve tower group is stabilized through the first gas resistance and the second gas resistance. The one-way valve is set to prevent the oxygen in the oxygen storage unit from flowing back into each molecular sieve tower and causing oxygen loss. The first pressure sensor, the third gas resistance, the second pressure sensor, and the third pressure sensor cooperate with each other to perform closed-loop dynamic control on the pressure and flow rate of the oxygen output by the oxygen generator, and prevent the change of gas concentration caused by the pressure fluctuation.

[0012] Further, the aperture of the second gas resistance is larger than that of the first gas resistance.

[0013] Further, the oxygen storage unit specifically includes: a first oxygen storage bin, a second control valve, and a second oxygen storage bin arranged in sequence.

[0014] Further, the first pressure sensor is used to monitor the outlet air pressure of the oxygen storage unit, the second pressure sensor is used to monitor the gas pressure after the third gas resistance stabilizes the flow, and the third pressure sensor is used to detect the ambient atmospheric pressure.

[0015] Further, a fourth pressure sensor is also arranged on the molecular sieve tower.

[0016] Further, each molecular sieve tower is internally filled with molecular sieve.

[0017] The second aspect of the present invention provides a flow rate adjustment method using the voltage-stabilized gas path structure described in the first aspect, including the following specific steps:

[0018] S1. Obtain the target outlet air pressure value P0, the monitoring data P2 of the second pressure sensor, and the monitoring data P3 of the third pressure sensor in real time;

[0019] S2. Obtain the pressure difference value P between P2 and P3 23 , and determine the pressure difference value P 23 and the magnitude of P0. According to the determination result, adjust the control voltage VF of the second control valve to obtain the adjusted P2′;

[0020] S3. Obtain the pressure difference value P between P2′ and P3 2′3 , and determine the pressure difference value P 2′3 and the magnitude of P0, until the difference between the pressure difference value P 2′3 and P0 is within the target range; otherwise, execute step S2.

[0021] The closed-loop dynamic control of the pressure and flow rate of the oxygen output of the oxygen generator is realized through the flow rate adjustment component and the flow rate adjustment method.

[0022] Further, the adjustment of the control voltage of the second control valve according to the determination result specifically includes:

[0023] The magnitude relationship between the pressure difference value P 23 and P0 includes greater than, less than, and equal to;

[0024] Determine the magnitude relationship between the pressure difference value P 23 and P0, and adjust the change trend of the control voltage VF according to the magnitude relationship, and output the change trend of the control voltage VF:

[0025] When the magnitude relationship between the pressure difference value P 23 and P0 is greater than, the change trend of the output control voltage VF is downward;

[0026] When the magnitude relationship between the pressure difference value P 23 and P0 is less than, the change trend of the output control voltage VF is upward;

[0027] When the magnitude relationship between the pressure difference value P 23 and P0 is equal to, the change trend of the output control voltage VF is to remain unchanged.

[0028] Further, it also includes obtaining the monitoring data P3 of the third pressure sensor and the monitoring data P4 of the fourth pressure sensor, and adjusting the pressure of the molecular sieve tower according to the pressure difference between P3 and P4.

[0029] Further, it also includes obtaining the monitoring data P1 of the first pressure sensor and the monitoring data P2 of the second pressure sensor;

[0030] Adjust the third air resistance according to the pressure difference between P1 and P2 as the reference value for the third air resistance voltage stabilization.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] 1. By setting multiple groups of molecular towers, with a first control valve and a first air resistance provided at both ends of each group of molecular towers, a one-way valve and a second air resistance are provided between the first air resistance and the oxygen storage unit. The pressure inside each molecular tower in the molecular tower group is stabilized by the first air resistance and the second air resistance. The one-way valve is provided to prevent the oxygen in the oxygen storage unit from flowing back into each molecular tower, causing oxygen loss. A flow rate adjustment component is provided to perform closed-loop dynamic control on the pressure and flow rate of the oxygen output from the oxygen generator, preventing changes in gas concentration caused by pressure fluctuations.

[0033] 2. It can cooperate with the mechanical structure to dynamically control the oxygen output pressure of the oxygen storage bin, so that the oxygen output of the oxygen generator always remains in a stable state, completely solving the problem of reduced oxygen concentration caused by increased or decreased oxygen output flow rate due to pressure fluctuations commonly existing in precision and non-precision mechanical spring pressure reducing valves on the market.

[0034] 3. It can solve the influence of the resistance caused by the user's overly long pipeline on the gas flow rate, that is, if the resistance reaches a certain level, it will remind the user that the pipeline is blocked, helping to find and solve the problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts. In the drawings:

[0036] Figure 1 Schematic diagram of the voltage-stabilizing gas path structure in the embodiment of the present invention Figure 1 ;

[0037] Figure 2 Schematic diagram of the voltage-stabilizing gas path structure in the embodiment of the present invention Figure 2 .

[0038] Markings in the drawings and corresponding component names:

[0039] 10. Molecular tower group; 11. Molecular tower; 12. First control valve; 13. First air resistance; 14. One-way valve; 15. Second air resistance; 20. Nitrogen discharge unit; 21. Nitrogen discharge bin; 30. Oxygen storage unit; 31. First oxygen storage bin; 32. Second control valve; 33. Second oxygen storage bin; 40. Flow rate adjustment component; 41. First pressure sensor; 42. Third air resistance; 43. Second pressure sensor; 44. Third pressure sensor; 45. Fourth pressure sensor; 46. Third control valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings. The illustrative embodiments and descriptions thereof of the present invention are only used to explain the present invention and do not limit the present invention.

[0041] Embodiment 1

[0042] As Figure 1 and Figure 2 shown, this embodiment provides a voltage-stabilized gas path structure, which includes a nitrogen discharge unit 20, a molecular sieve tower group 10, an oxygen storage unit 30, and a flow rate adjustment component 40 connected in sequence;

[0043] The molecular sieve tower group 10 includes several groups of molecular sieve towers 11, and a first control valve 12 and a first gas resistance 13 are provided at both ends of each group of molecular sieve towers 11;

[0044] The first control valve 12 is connected to the nitrogen discharge unit 20, the first gas resistance 13 is connected to the oxygen storage unit 30, and a one-way valve 14 and a second gas resistance 15 are also provided between the first gas resistance 13 and the oxygen storage unit 30;

[0045] The flow rate adjustment component 40 includes a first pressure sensor 41, a third gas resistance 42, a second pressure sensor 43, and a third pressure sensor 44 arranged in sequence.

[0046] In the present invention, by setting multiple groups of molecular sieve towers 11, a first control valve 12 and a first gas resistance 13 are provided at both ends of each group of molecular sieve towers 11. The first control valve 12 is set to control the nitrogen discharge speed, ensure the air pressure stability during nitrogen discharge, and ensure the air pressure stability in the molecular sieve tower 11. A one-way valve 14 and a second gas resistance 15 are provided between the first gas resistance 13 and the oxygen storage unit 30. The pressure in each molecular sieve tower 11 in the molecular sieve tower group 10 is stabilized through the first gas resistance 13 and the second gas resistance 15. The one-way valve 14 is set to prevent the oxygen in the oxygen storage unit 30 from flowing back into each molecular sieve tower 11 and causing oxygen loss. The first pressure sensor 41, the third gas resistance 42, the second pressure sensor 43, and the third pressure sensor 44 are set to cooperate with each other to perform closed-loop dynamic control on the pressure and flow rate of the oxygen output by the oxygen generator, and prevent the change of gas concentration caused by the pressure fluctuation.

[0047] In some possible embodiments, the nitrogen discharge unit 20 includes a nitrogen discharge bin 21 and the first control valve 12 on the passage from each molecular sieve tower 11 to the nitrogen discharge bin 21, which can periodically discharge nitrogen from each molecular sieve tower 11 to ensure that the basic pressure in each molecular sieve tower 11 is higher than the current ambient atmospheric pressure.

[0048] In some possible embodiments, the aperture diameter of the second air resistance 15 is larger than that of the first air resistance 13. The larger aperture diameter of the second air resistance 15 can avoid blocking the process of oxygen discharging into the oxygen storage unit 30, and improve the efficiency of collecting oxygen from each molecular sieve tower 11. At the same time, the aperture diameter of the first air resistance 13 is set such that the oxygen separated from the molecular sieve tower 11 can be smoothly discharged, and can also avoid the rapid discharge of oxygen in the molecular sieve tower 11, which may cause the pressure in the molecular sieve tower 11 to decrease too quickly and affect the adsorption performance of the molecular sieve. Moreover, the branches corresponding to each molecular sieve tower 11 are also interconnected, which is conducive to setting a pressure equalization process for each molecular sieve tower 11 during the period after one of the molecular sieve towers 11 discharges nitrogen and before oxygen production, avoiding too small pressure in the molecular sieve tower 11 and prolonging the time for filling compressed air, and improving the oxygen production efficiency.

[0049] In some possible embodiments, the oxygen storage unit 30 specifically includes: a first oxygen storage bin 31, a second control valve 32, and a second oxygen storage bin 33 arranged in sequence. The first oxygen storage bin 31, as a primary oxygen storage bin, is connected to the main path where the second air resistance 15 is located. The opening degree of the second control valve 32 can be controlled and adjusted. The oxygen in the first oxygen storage bin 31 flows into the second oxygen storage bin 33 through the second control valve 32, which has a buffering effect on the oxygen pressure and can initially reduce the fluctuation of the outlet oxygen pressure.

[0050] In some possible embodiments, the first pressure sensor 41 is used to monitor the outlet pressure of the oxygen storage unit 30, the second pressure sensor 43 is used to monitor the gas pressure after the third air resistance 42 stabilizes the flow, and the third pressure sensor 44 is used to detect the ambient atmospheric pressure. The pressure difference between the first pressure sensor 41 and the second pressure sensor 43 can be used as a reference value for the third air resistance 42 to stabilize the pressure, and the pressure difference between the second pressure sensor 43 and the third pressure sensor 44 can characterize the final outlet pressure and flow rate.

[0051] In some possible embodiments, the molecular sieve tower 11 is further provided with a fourth pressure sensor 45. One of the molecular sieve towers 11 in the molecular sieve tower group 10 is connected to the fourth pressure sensor 45, which is used to monitor the pressure in the molecular sieve tower 11 to ensure the pressurized adsorption performance of the molecular sieve in the molecular sieve tower 11. The other end of the fourth pressure sensor 45 connected to the molecular sieve tower 11 is connected to a third control valve 46, and the third control valve 46 is the same as the first control valve 12.

[0052] In some possible embodiments, each molecular sieve tower 11 is internally filled with a molecular sieve, and the molecular sieve tower 11 is further connected to an air compressor unit, and the air compressor unit includes an air compressor for providing compressed air for the molecular sieve tower group 10.

[0053] Embodiment 2

[0054] Based on Embodiment 1, this embodiment provides a flow rate adjustment method based on a pressure stabilizing gas path structure, including the following specific steps:

[0055] S1. Obtain the target outlet pressure value P0, the monitoring data P2 of the second pressure sensor 43, and the monitoring data P3 of the third pressure sensor 44 in real time;

[0056] S2. Obtain the pressure difference value P between P2 and P3 23 , and determine the magnitude relationship between the pressure difference value P 23 and P0, and adjust the control voltage VF of the second control valve 32 according to the determination result to obtain the adjusted P2';

[0057] S3. Obtain the pressure difference value P between P2' and P3 2′3 , and determine the magnitude relationship between the pressure difference value P 2′3 and P0, until the difference between the pressure difference value P 2′3 and P0 is within the target range, otherwise execute step S2.

[0058] The closed-loop dynamic control of the pressure and flow rate of the oxygen output of the oxygen generator is realized through the flow rate adjustment component 40 in cooperation with the flow rate adjustment method.

[0059] In some possible embodiments, adjusting the control voltage of the second control valve 32 according to the determination result specifically includes:

[0060] The magnitude relationship between the pressure difference value P 23 and P0 includes greater than, less than, and equal to;

[0061] Determine the magnitude relationship between the pressure difference value P 23 and P0, and adjust the change trend of the control voltage VF according to the magnitude relationship;

[0062] Output the change trend of the control voltage VF.

[0063] When the magnitude relationship between the pressure difference value P 23 and P0 is greater than, the change trend of the output control voltage VF is downward;

[0064] When the magnitude relationship between the pressure difference value P 23 and P0 is less than, the change trend of the output control voltage VF is upward;

[0065] When the magnitude relationship between the pressure difference value P 23 and P0 is equal to, the change trend of the output control voltage VF is to remain unchanged.

[0066] In some possible embodiments, it further includes obtaining the monitoring data P3 of the third pressure sensor 44 and the monitoring data P4 of the fourth pressure sensor 45, and adjusting the pressure of the molecular sieve tower 11 according to the pressure difference between P3 and P4.

[0067] Obtain the monitoring data P1 of the first pressure sensor 41 and the monitoring data P2 of the second pressure sensor 43; use the pressure difference between P1 and P2 as the reference value for stabilizing the pressure of the third air resistance 42, and adjust the third air resistance 42.

[0068] When adjusting the pressure of the molecular sieve tower 11, it will affect the monitoring data of the first pressure sensor 41 and the second pressure sensor 43. Therefore, the obtained monitoring data are all in real-time status.

[0069] Embodiment 3

[0070] The pressure stabilizing solenoid valve is a high-speed solenoid valve or a proportional solenoid valve. If a proportional solenoid valve is selected, its opening degree is controlled by voltage, and the control method is as follows:

[0071] Assume that the opening range of the proportional solenoid valve is Vc~Vo, where Vc is the control voltage value when the opening degree of the proportional solenoid valve is 0 (i.e., the closed state), and Vo is the control voltage value when the opening degree of the proportional solenoid valve is 100 (i.e., the fully open state). Set the control parameter for the proportional solenoid valve as VF, then the dynamic control range of VF is Vc~Vo. If the control pressure difference P 23 of the oxygen outlet pressure of the oxygen generator is set to 50 kPa, and the actually detected and calculated pressure difference P 23 is 60 kPa. At this time, it is judged that the current oxygen outlet pressure is greater than the control target value, and the value of the control parameter VF for reducing the opening degree of the proportional solenoid valve will be adjusted, so as to reduce the pressure difference P 23 , and vice versa. If it is judged that the current oxygen outlet pressure is less than the control target value, the value of the control parameter VF for increasing the opening degree of the proportional solenoid valve will be increased, and finally the value of the pressure difference P 23 will be stabilized at the control target value, realizing the dynamic stable control of the oxygen outlet pressure of the oxygen generator.

[0072] When judging the pressure difference P 23 , if the judgment result is that the pressure difference deviates from the normal value range, it can be initially judged and the user can be reminded that the pipeline is blocked.

[0073] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A voltage-stabilized gas path structure, characterized in that, It includes a nitrogen discharging unit (20), a molecular sieve tower group (10), an oxygen storage unit (30) and a flow rate regulating component (40) which are connected in sequence; The molecular sieve tower group (10) includes several groups of molecular sieve towers (11), and a first control valve (12) and a first air resistance (13) are arranged at both ends of each group of molecular sieve towers (11); Molecular sieve is filled inside each molecular sieve tower (11); The first control valve (12) is connected to the nitrogen discharging unit (20), the first air resistance (13) is connected to the oxygen storage unit (30), and a one-way valve (14) and a second air resistance (15) are further arranged between the first air resistance (13) and the oxygen storage unit (30); The aperture of the second air resistance (15) is larger than that of the first air resistance (13); The oxygen storage unit (30) specifically includes: a first oxygen storage bin (31), a second control valve (32) and a second oxygen storage bin (33) which are arranged in sequence; The flow rate regulating component (40) includes a first pressure sensor (41), a third air resistance (42), a second pressure sensor (43) and a third pressure sensor (44) which are arranged in sequence; The molecular sieve tower (11) further includes: a fourth pressure sensor (45), wherein the fourth pressure sensor (45) is used for monitoring the pressure in the molecular sieve tower (11); The first pressure sensor (41) is used for monitoring the outlet pressure of the oxygen storage unit (30), the second pressure sensor (43) is used for monitoring the gas pressure after the third air resistance (42) stabilizes the flow, and the third pressure sensor (44) is used for detecting the ambient atmospheric pressure.

2. A flow rate adjustment method using the voltage stabilizing gas path structure described in claim 1, characterized in that, It includes the following specific steps: S1. Obtain the target outlet pressure value P0, the monitoring data P2 of the second pressure sensor (43) and the monitoring data P3 of the third pressure sensor (44) in real time; S2. Obtain the pressure difference value P between P2 and P3 23 , and determine the pressure difference value P 23 and the magnitude of P0. According to the judgment result, adjust the control voltage VF of the second control valve (32) to obtain the adjusted P2'. S3. Obtain the pressure difference value P between P2' and P3 2′3 , and judge the pressure difference value P 2′3 and P0. Keep judging until the difference between the pressure difference value P 2′3 and P0 is within the target range; otherwise, execute step S2.

3. The flow rate adjustment method according to claim 2, characterized in that Adjusting the control voltage of the second control valve (32) according to the judgment result specifically includes: The pressure difference value P 23 The magnitude relationship with P0 includes greater than, less than, and equal to; Determine the pressure difference value P 23 Compare it with P0, adjust the change trend of the control voltage VF according to the comparison result, and output the change trend of the control voltage VF: Differential pressure value P 23 When the relationship between the size of P and P0 is greater than, the change trend of the output control voltage VF is downward; Differential pressure value P 23 When the relationship between its magnitude and P0 is less than, the changing trend of the output control voltage VF is upward; Differential pressure value P 23 When the magnitude relationship with P0 is equal, the change trend of the output control voltage VF is to remain constant.

4. The flow rate adjustment method according to claim 2, wherein It also includes obtaining the monitoring data P3 of the third pressure sensor (44) and the monitoring data P4 of the fourth pressure sensor (45), and adjusting the pressure of the molecular sieve tower (11) according to the pressure difference between P3 and P4.

5. The flow rate adjustment method according to claim 2, wherein It also includes obtaining the monitoring data P1 of the first pressure sensor (41) and the monitoring data P2 of the second pressure sensor (43); Taking the pressure difference between P1 and P2 as the reference value for stabilizing the pressure of the third air resistance (42), and adjusting the third air resistance (42).

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