Oxygen generator with oxygen output concentration monitoring and pre-compensation functions

Abstract

The invention relates to the technical field of oxygen generators, in particular to an oxygen generator with oxygen output concentration monitoring and pre-compensation functions. The oxygen generator comprises a lower buffer valve, a lower buffer communication valve, an upper buffer valve, a lower buffer valve, a data acquisition module, a data processing module and an adjusting module, wherein the data acquisition module is used for acquiring pressure data and oxygen concentration at an outlet of the oxygen generator; the data processing module is used for obtaining the high-pressure degree of each circulation according to the pressure data and the oxygen concentration at the outlet of each cycle of each circulation of oxygen discharge, and then determining the high-pressure duration and the current compensation demand degree; acquiring a slow voltage-sharing demand factor according to the current compensation demand degree and the duration of the high-voltage duration; and the adjusting module is used for adjusting opening and closing of the valve according to the slow pressure equalizing demand. According to the invention, the influence of temperature on the adsorption efficiency of the zeolite molecular sieve is reduced, the concentration of oxygen produced by the oxygen generator is maintained, and the pre-compensation of the oxygen concentration is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of oxygen concentrators, and in particular to an oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions. Background Art

[0002] Oxygen plays an indispensable role in hospital emergency care, anesthesia, surgery, and treatment, and is crucial for medical care. Compared to other oxygen production technologies, pressure swing adsorption (PSA) oxygen production technology is not only simple and efficient, but also offers excellent controllability, allowing users to flexibly respond to diverse needs. PSA oxygen production technology also features low energy consumption, effectively reducing operating costs, further highlighting its superior performance in oxygen production and becoming the primary oxygen source used in hospitals.

[0003] The oxygen concentrator needs to go through multiple cycles during the oxygen production process. Each cycle includes two oxygen exhaust cycles. Since oxygen enters the tower from the air inlet, it takes time for it to be adsorbed and then discharged, which causes the pressure and oxygen concentration to fluctuate in each oxygen exhaust cycle. Pressure swing adsorption utilizes the adsorption effect of zeolite molecular sieve on nitrogen at high pressure and low temperature. Under normal circumstances, the air compressor will compress the air into high-pressure gas. High temperature will be generated during the compression process. The gas temperature will be reduced by cooling, and then the oxygen production cycle will be executed.

[0004] When the demand for oxygen is large, the air compressor will increase the pressure of the oxygen generator, thereby improving the adsorption efficiency and reducing the adsorption time required for each cycle. During this process, the oxygen and nitrogen molecules in the air will collide with the zeolite molecular sieve, and the pressure in the tower will increase. When the temperature rises, the adsorption amount of nitrogen will decrease, and when one tower is adsorbing and the other tower is desorbing, the remaining oxygen after adsorption will enter the other tower through the upper buffer valve, and in the pressure equalization stage, a large amount of other heated gases will directly enter the other tower, thereby heating the zeolite therein, reducing the adsorption efficiency, which is not conducive to maintaining the concentration of oxygen produced by the oxygen generator. Summary of the Invention

[0005] In order to solve the problem that the existing oxygen concentrator is not conducive to maintaining the concentration of oxygen produced by the oxygen concentrator, the purpose of the present invention is to provide an oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions. The technical solution adopted is as follows: The present invention provides an oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions, the oxygen concentrator comprising a lower buffer valve, a lower buffer connecting valve, an upper buffer valve, a data acquisition module, a data processing module and a regulating module: Data acquisition module, used to collect pressure data and oxygen concentration at the outlet of the oxygen concentrator; The data processing module is used to obtain the high pressure level of each cycle based on the distribution characteristics of the pressure data at the outlet of each cycle of the oxygen exhaust and the change characteristics of the oxygen concentration; determine the high pressure duration and the current compensation requirement based on the relative change between the high pressure level of each cycle and the previous cycle; and obtain the pressure equalization requirement factor based on the current compensation requirement and the duration of the high pressure duration; The regulating module is used to determine the opening time of the upper pressure equalizing valve in advance in the next cycle if the slow pressure equalizing demand factor is less than the preset demand threshold; if the slow pressure equalizing demand factor is greater than or equal to the preset demand threshold, the lower buffer connecting valve is opened in the pressure equalization stage of the next cycle, and the upper buffer valve and the lower buffer valve are used to weaken the pressure equalization.

[0006] Preferably, the division of each cycle period includes: For any loop: Calculating the pressure increments at every two adjacent moments in any cycle; The preceding moment of two adjacent moments corresponding to the first time the pressure increment takes a negative value is used as a dividing point to divide the arbitrary cycle into a first period and a second period.

[0007] Preferably, the high pressure level of each cycle is obtained according to the distribution characteristics of the pressure data at the outlet of each cycle of the oxygen exhaust and the variation characteristics of the oxygen concentration, including: For any loop: For any cycle, the ratio of the maximum value of the pressure data in the cycle to the duration of the same cycle is used as the pressure high pressure coefficient of the cycle; curve fitting is performed on the oxygen concentration at all times in the cycle to obtain a fitting curve, the first point and the last point of the fitting curve are connected by a straight line to obtain the slope of the straight line; the negative correlation mapping value of the slope is used as the concentration high pressure coefficient of the cycle; The high pressure degree of any cycle is obtained by integrating the pressure high pressure coefficients and concentration high pressure coefficients of all periods of any cycle.

[0008] Preferably, the step of integrating the pressure high pressure coefficient and the concentration high pressure coefficient of all periods of the arbitrary cycle to obtain the high pressure degree of the arbitrary cycle comprises: For any period, the product of the pressure high-pressure coefficient and the concentration high-pressure coefficient of the period is recorded as the first eigenvalue of the period; A normalized result of an average value of the first characteristic values ​​of all periods of the arbitrary cycle is determined as the high pressure level of the arbitrary cycle.

[0009] Preferably, determining the high pressure duration period according to the relative change between the high pressure level of each cycle and the previous cycle includes: A cycle before and adjacent to the current cycle is taken as a starting cycle, and n cycles are sequentially obtained from back to front as reference cycles. If the average value of the high pressure levels of the n reference cycles is less than a preset high pressure threshold, the n reference cycles are used as the high pressure duration period; if the average value of the high pressure levels of the n reference cycles is greater than or equal to the preset high pressure threshold, n+1 cycles are obtained as reference cycles. When the average value of the high pressure levels of the n+1 reference cycles is less than the preset high pressure threshold, the n+1 reference cycles are used as the high pressure duration period; when the average value of the high pressure levels of the n+1 reference cycles is greater than or equal to the preset high pressure threshold, n+2 cycles are obtained as reference cycles, and so on, until the average value of the high pressure levels of all the obtained reference cycles is less than the preset high pressure threshold, and all the obtained reference cycles are used as the high pressure duration period; Wherein, n is the preset number.

[0010] Preferably, obtaining the current compensation demand includes: The difference between the average value of the high pressure levels of all reference cycles and the high pressure level of the current cycle is used as the current compensation requirement.

[0011] Preferably, obtaining the pressure balancing demand factor according to the current compensation demand and the duration of the high-voltage duration period includes: The pressure balancing demand factor is calculated according to the current compensation demand and the duration of the high-pressure duration. The current compensation demand and the duration of the high-pressure duration are both positively correlated with the pressure balancing demand factor.

[0012] Preferably, the calculating of the pressure balancing demand factor according to the current compensation demand and the duration of the high-voltage duration period includes: The normalized result of the product of the current compensation demand degree and the duration of the high-voltage duration period is determined as the pressure balancing demand factor.

[0013] Preferably, determining the opening time of the upper pressure equalizing valve in advance for the next cycle includes: The product of half of the duration of one cycle and the buffering and equalizing pressure demand factor is rounded up to an integer, and recorded as the first duration; The time corresponding to when the next cycle reaches the first time length is determined as the opening time of the upper pressure equalizing valve for opening in advance in the next cycle.

[0014] Preferably, the calculating of the pressure increments between every two adjacent moments in any cycle includes: The difference between the pressure data at the latter moment and the pressure data at the previous moment in any two adjacent moments in the arbitrary cycle is taken as the pressure increment corresponding to the two adjacent moments.

[0015] The present invention has at least the following beneficial effects: The oxygen concentrator with oxygen output concentration monitoring and pre-compensation function provided by the present invention is based on the existing oxygen concentrator, and adds a lower buffer valve, a lower buffer connecting valve, a data acquisition module, a data processing module and a regulating module. The data acquisition module is used to collect pressure data and oxygen concentration at the outlet during the exhaust process of oxygen. The data processing module determines the high pressure degree of each cycle according to the distribution characteristics of the pressure data at the outlet of each cycle and the change characteristics of the oxygen concentration in the process of exhausting oxygen, and then selects the high pressure duration period and determines the current compensation requirement. Combined with the current compensation requirement and the duration of the high pressure duration period, the high pressure degree of each cycle is obtained. The regulating module determines whether the oxygen concentrator is in a high-load state based on the magnitude of the slow equalizing pressure demand factor. When the slow equalizing pressure demand factor is less than the preset demand threshold, the opening time of the upper equalizing pressure valve is determined to be opened in advance in the next cycle. When the slow equalizing pressure demand factor is greater than or equal to the preset demand threshold, the lower buffer connecting valve is opened in the pressure equalization stage of the next cycle, and the upper buffer valve and the lower buffer valve are used to weaken the pressure equalization. The present invention avoids the temperature increase in the double towers of the oxygen concentrator by adjusting the opening and closing of the valves, reduces the influence of temperature on the adsorption efficiency of the zeolite molecular sieve, maintains the concentration of oxygen produced by the oxygen concentrator, and realizes pre-compensation of the oxygen concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions and advantages of the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 A mechanical structure diagram of an oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions provided by an embodiment of the present invention; Figure 2 A flow chart of a method performed by an oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions provided by an embodiment of the present invention; Figure 1In the figure, 1 is the oxygen release valve of tower a; 2 is the gas outlet of tower a; 3 is the tower body of tower a; 4 is the gas inlet of tower a; 5 is the waste gas outlet; 6 is the waste gas valve of tower a, 7 is the air inlet valve of tower a; 8 is the flow control valve; 9 is the feed inlet; 10 is the air inlet valve of tower b; 11 is the lower pressure equalizing valve; 12 is the waste gas valve of tower b; 13 is the gas inlet of tower b; 14 is the tower body of tower b; 15 is the gas outlet of tower b; 16 is the upper pressure equalizing valve; 17 is the upper buffer valve; 18 is the oxygen release valve of tower b; 19 is the oxygen outlet; 20 is the oxygen concentration monitor; 21 is the lower buffer valve; 22 is the lower buffer connecting valve. DETAILED DESCRIPTION

[0018] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions proposed in accordance with the present invention is described in detail below with reference to the accompanying drawings and preferred embodiments.

[0019] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0020] The following describes in detail a specific solution of an oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions provided by the present invention with reference to the accompanying drawings.

[0021] Example of an oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions: See also Figure 1 , which shows an oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions provided by an embodiment of the present invention, the oxygen concentrator includes a tower oxygen release valve 1, a tower gas outlet 2, a tower body 3, a tower gas inlet 4, an exhaust gas outlet 5, a tower exhaust valve 6, a tower air inlet valve 7, a flow control valve 8, a feed port 9, a tower air inlet valve 10, a lower pressure equalizing valve 11, a tower exhaust valve 12, a tower gas inlet 13, a tower body 14, a tower gas outlet 15, an upper pressure equalizing valve 16, an upper buffer valve 17, a tower oxygen release valve 18, an oxygen outlet 19, an oxygen concentration monitor 20, a lower buffer valve 21, a lower buffer connecting valve 22, a data acquisition module, a data processing module and a regulation module, wherein the data acquisition module, the data processing module and the regulation module are not shown in the figure.

[0022] Among them, the tower bodies of towers a and b contain zeolite adsorption materials for adsorbing nitrogen entering the compressed gas through the gas inlets of each tower. The upper buffer valve 17 contains a buffer valve to gradually divert the airflow to prevent all the oxygen from entering another tank and leaking.

[0023] The main steps of oxygen production in an oxygen concentrator are: First, initialize and close all valves.

[0024] (1) Tower a adsorption: Open the a tower air inlet valve 7, the a tower oxygen release valve 1 and the b tower exhaust valve 12. The compressed air enters the a tower body 3 through the feed port 9 and the a tower gas inlet 4. The zeolite molecular sieve in the a tower body 3 adsorbs nitrogen to obtain oxygen. The oxygen is divided into two paths. One path is discharged from the a tower gas outlet 2, enters the oxygen outlet 19 through the a tower oxygen release valve 1, and reaches the oxygen process tank for buffering. The other part enters the b tower body 14 through the upper buffer valve 17 and the b tower gas outlet 15, desorbs the zeolite molecular sieve that has adsorbed nitrogen in the b tower body 14, and is discharged from the b tower exhaust valve 12 and the exhaust outlet 5.

[0025] (2) Pressure equalization stage: After about 60 seconds of adsorption in tower a, all valves are closed, and the lower pressure equalizing valve 11 and the upper pressure equalizing valve 16 are opened, so that the high-pressure gas in tower a enters the tower body 14 of tower b through the lower pressure equalizing valve 11 and the upper pressure equalizing valve 16. This step is to recover the high-concentration oxygen at the top of the zeolite molecular sieve and reduce the energy consumption of the compressor during the pressurization process.

[0026] (3) Tower B adsorption: Close the lower equalizing valve 11 and the upper equalizing valve 16, open the B tower air inlet valve 10, the B tower oxygen release valve 18 and the A tower exhaust valve 6; compressed air enters the B tower body 14 through the feed port 9 and the B tower air inlet valve 10, and the zeolite molecular sieve in the B tower body 14 adsorbs nitrogen to obtain oxygen. The oxygen is divided into two paths, one path is discharged from the B tower gas outlet 15, enters the oxygen outlet 19 through the B tower oxygen release valve 18, and reaches the oxygen process tank for buffering. The other part enters the A tower body 3 through the upper buffer valve 17 and the A tower gas outlet 2, desorbs the zeolite molecular sieve that has adsorbed nitrogen in the A tower body 3, and is discharged from the A tower exhaust valve 6 and the exhaust outlet 5.

[0027] (4) Second pressure equalization stage: After about 60 seconds of adsorption in tower B, all valves are closed, and the lower pressure equalizing valve 11 and the upper pressure equalizing valve 16 are opened, so that the high-pressure gas in tower B enters the tower body 3 of tower A through the lower pressure equalizing valve 11 and the upper pressure equalizing valve 16.

[0028] (5) Steps (1) (2) (3) (4) constitute a cycle. Repeat the above steps and oxygen can be produced in all stages except the pressure equalization stage.

[0029] The oxygen concentrator provided in this embodiment with oxygen output concentration monitoring and pre-compensation functions includes, in addition to the above components, a data acquisition module, a data processing module and a regulation module; Among them, the data acquisition module is used to collect pressure data and oxygen concentration at the outlet of the oxygen concentrator; The data processing module is used to obtain the high pressure level of each cycle based on the distribution characteristics of the pressure data at the outlet of each cycle of the oxygen exhaust and the change characteristics of the oxygen concentration; determine the high pressure duration and the current compensation requirement based on the relative change between the high pressure level of each cycle and the previous cycle; and obtain the pressure equalization requirement factor based on the current compensation requirement and the duration of the high pressure duration; The regulating module is used to determine the opening time of the upper pressure equalizing valve 16 in advance of the next cycle if the slow pressure equalizing demand factor is less than the preset demand threshold; if the slow pressure equalizing demand factor is greater than or equal to the preset demand threshold, the lower buffer connecting valve 22 is opened in the pressure equalizing stage of the next cycle, and the upper buffer valve 17 and the lower buffer valve 21 are used to weaken the pressure equalization.

[0030] The method implemented by the oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions provided in this embodiment is as follows: Figure 2 shown.

[0031] During each oxygen exhaust cycle, oxygen enters the tower from the air inlet, undergoes adsorption, and then is discharged, requiring time. Consequently, the pressure and oxygen concentration fluctuate within each oxygen exhaust cycle. The oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions provided in this embodiment utilizes the paramagnetic effect of oxygen. The oxygen concentration monitor 20 in the data acquisition module monitors the oxygen concentration during each oxygen exhaust cycle, and the pressure monitor in the data acquisition module collects pressure data at the outlet. In this embodiment, the oxygen concentration and pressure data collection frequency is set to 0.1 seconds. In specific applications, the implementer can adjust this frequency based on specific circumstances.

[0032] For the compression stage, the method that can solve the problem of pressurization and collision heating is: reducing the problem caused by the cycle time; the method for solving the incomplete desorption in the other tower is: opening the upper equalizing valve 16 in advance so that it can enter the other tower without passing through the buffer valve to achieve pre-desorption. For the equalizing stage, at the moment of opening the upper and lower equalizing valves, the gas above and below the tower quickly flows into the other side, causing the pressure change on the other side to be extremely obvious. The gas molecules collide with the zeolite molecular sieve in the low pressure. When the temperature rises and the next cycle of filtration is carried out, the temperature of the zeolite molecular sieve is high, which reduces the adsorption efficiency. Therefore, if the heating time is longer, the more it is necessary to slow down the amount of gas for equalizing pressure. Specifically, in the equalizing stage, the upper and lower equalizing valves are not opened, the lower buffer connecting valve is opened, and the upper and lower pressure relief valves are used to slowly equalize the pressure, or even unevenly, to avoid two-way impact on the zeolite molecular sieve.

[0033] After collecting the pressure data and oxygen concentration at each moment, since the air entering the oxygen concentrator is cooled by the refrigerated dry cooler, the oxygen temperature at the outlet will be reset due to the low temperature of the newly incoming air. The temperature will only affect the temperature generated by the collision of oxygen molecules with the zeolite molecular sieve during pressure equalization and before the start of the next cycle, as well as the temperature generated by the collision of gas molecules caused by drastic pressure changes. After a period of screening, the zeolite molecular sieve is cooled by the newly incoming air, thereby restoring the normal oxygen concentration.

[0034] For a cycle, if the demand for oxygen production is higher, the air compressor will increase the compression pressure. If the pressure of the cycle increases before reaching the peak, it indicates that there is a demand for a high oxygen volume. Therefore, in this embodiment, each cycle is first divided into periods based on the change in pressure data, and then the current pre-compensation demand is determined based on the pressure changes in different periods.

[0035] Next, this embodiment will be described by taking one cycle as an example. Other cycles can be processed using the method provided in this embodiment.

[0036] Specifically, for any loop: The difference between the pressure data at the later moment and the pressure data at the previous moment in each of two adjacent moments in the cycle is used as the pressure increment for the corresponding two adjacent moments. Using this method, the pressure increment for each of the two adjacent moments in the cycle can be obtained, and there is a corresponding pressure increment for each of the two adjacent moments. The previous moment of the two adjacent moments corresponding to the first negative value among all the pressure increments obtained based on the cycle is used as the dividing point, and the cycle is divided into a first period and a second period using this dividing point. The first period is the stage when air is just injected into the tower body. At this time, the pressure rises from atmospheric pressure after equalization to high pressure. In the second period, after the filtered oxygen fills the tower body, the pressure continues to rise slowly due to the small outlet.

[0037] When the pressure of the compressor increases, the air will fill the tower body faster than normal and enter the second cycle. Therefore, the time of the first cycle is shorter than normal. And because the outlet is small, the pressure will continue to rise after filling the tower body, and the filtered oxygen will be released more slowly.

[0038] Under normal circumstances, as the air slowly fills the tower, the zeolite molecular sieve slowly contacts the air, thereby adsorbing as many nitrogen molecules as possible. However, when the pressure increases, the air flow rate into the tower is faster than normal, and the probability of nitrogen molecules colliding with the air in the zeolite molecular sieve decreases, resulting in a decrease in the oxygen concentration. Therefore, the rate of increase of the oxygen concentration will slow down.

[0039] For any loop: For any period within the sub-cycle, the ratio of the maximum pressure data within the period to the duration of the period is used as the pressure high-pressure coefficient for that period. A curve fit is performed on the oxygen concentration at all times within the period to obtain a fitted curve. The first and last points of the fitted curve are connected by a straight line to obtain the slope of the line. The smaller the slope, the lower the probability of nitrogen molecules being absorbed after multiple collisions compared to normal conditions, resulting in a decrease in oxygen concentration. Therefore, the negative correlation mapping value of the slope is used as the concentration high-pressure coefficient for that period. In this embodiment, the negative correlation mapping value of the slope is obtained by taking the inverse of the slope as the negative correlation mapping value of the slope. It should be noted that the slope will not be zero. The product of the pressure high-pressure coefficient and the concentration high-pressure coefficient for that period is recorded as the first eigenvalue of that period. Using the above method, the first eigenvalue of each period of the sub-cycle can be obtained.

[0040] Next, the pressure high-pressure coefficient and concentration high-pressure coefficient of all periods of the cycle are combined to obtain the high-pressure degree of the cycle. Specifically, the normalized average value of the first eigenvalues ​​of all periods of the cycle is determined as the high-pressure degree of the cycle. It should be noted that there are many methods for normalizing data. In this embodiment, the maximum and minimum value normalization method is used to normalize the average value of the first eigenvalue, so that the normalized value is (0, 1). As other implementation methods, other existing data normalization methods can also be used, and they will not be detailed here.

[0041] By adopting the above method, a high pressure level can be obtained in each cycle.

[0042] Furthermore, starting from the current cycle, the high-voltage duration period is selected forward. The specific selection process is as follows: Take the cycle before and adjacent to the current cycle as the starting cycle, and obtain n cycles in sequence from back to front in time as reference cycles. If the average value of the high pressure levels of the n reference cycles obtained is less than the preset high pressure threshold, then the n reference cycles are used as high pressure duration periods; if the average value of the high pressure levels of the n reference cycles obtained is greater than or equal to the preset high pressure threshold, then obtain n+1 cycles as reference cycles. When the average value of the high pressure levels of the n+1 reference cycles obtained is less than the preset high pressure threshold, then obtain the n+1 reference cycles as the high pressure duration period; when the average value of the high pressure levels of the n+1 reference cycles obtained is greater than or equal to the preset high pressure threshold, obtain n+2 cycles as reference cycles, and so on, until the average value of the high pressure levels of all reference cycles obtained is less than the preset high pressure threshold, and then all reference cycles obtained are used as high pressure duration periods. It should be noted that each reference cycle obtained is a cycle added forward as a reference cycle based on the reference cycle obtained last time, that is, the reference cycle obtained for the first time is n cycles before the current cycle, the reference cycle obtained for the second time is n+1 cycles before the current cycle, the reference cycle obtained for the third time is n+2 cycles before the current cycle, the reference cycle obtained for the fourth time is n+3 cycles before the current cycle, and so on, until the conditions are met.

[0043] It should be noted that: if all cycles before the current cycle are used as reference cycles, and the average high pressure level of all reference cycles is still greater than or equal to the preset high pressure threshold, all cycles before the current cycle will be used as reference cycles.

[0044] Wherein, n is a preset number. In this embodiment, the preset high-pressure threshold is 0.5, and n is 3. In specific applications, the implementer can set it according to specific circumstances.

[0045] After all reference cycles are obtained, the difference between the average value of the high pressure levels of all reference cycles and the high pressure level of the current cycle is used as the current compensation requirement.

[0046] Since the only cooling measure within the oxygen concentrator is the incoming dry, cold air, if the heat generated exceeds the heat consumed by the dry, cold air, the internal temperature of the oxygen concentrator will accumulate, leading to a decrease in oxygen concentration. Therefore, if the heating period is short, the produced oxygen can be pre-desorbed by passing it into another tower. During the pressure equalization phase, the nitrogen molecules are absorbed by the zeolite molecular sieve in the current tower, reducing the volume of the gas and the collisions with the zeolite molecular sieve in the other tower. This reduces the temperature rise and achieves the cooling purpose. Therefore, only air enters after the lower pressure equalization valve is opened. The generated oxygen cools the zeolite molecular sieve in the other tower, and this oxygen can be recycled in the next cycle, avoiding the oxygen concentration drop caused by the large amount of air entering the other tower during the pressure equalization phase. However, this process consumes the amount of oxygen produced, so it is necessary to minimize the loss as much as possible. In other words, when the heating effect is not obvious, this method can be used for cooling. The cooling time varies with the heating time. Based on this, this embodiment determines the slow pressure equalization requirement of the current cycle according to the current pre-compensation requirement and the duration of the high-pressure duration period, and obtains the slow pressure equalization requirement factor.

[0047] Specifically, the pressure balancing demand factor is calculated according to the current compensation demand and the duration of the high-voltage period, and both the current compensation demand and the duration of the high-voltage period are positively correlated with the pressure balancing demand factor.

[0048] Among them, the positive correlation relationship means that the dependent variable will increase as the independent variable increases, and the dependent variable will decrease as the independent variable decreases. It can be an additive relationship, a multiplicative relationship, etc., which is determined by actual application.

[0049] In this embodiment, the normalized product of the current compensation demand and the duration of the high-pressure period is used to determine the slow and equalizing pressure demand factor. The current compensation demand represents the difference in the degree of high pressure during the high-pressure period compared to the previous period without increased pressure. A larger value indicates a greater slow and equalizing pressure demand for the current cycle. The longer the high-pressure period, the greater the slow and equalizing pressure demand for the current cycle, i.e., the greater the slow and equalizing pressure demand factor.

[0050] After the data processing module determines the buffer and pressure balancing demand factor, the adjustment module will perform subsequent adjustment processing based on the buffer and pressure balancing demand factor.

[0051] Specifically, if the slow equalizing pressure demand factor is less than the preset demand threshold, it indicates that the warming effect shown by the current high-pressure duration period is not obvious, and the temperature can be lowered by one-way regulation. Therefore, it is necessary to determine the opening time of the upper equalizing pressure valve 16 in the next cycle in advance, and round up the product of half of the duration of a cycle and the slow equalizing pressure demand factor as the first duration; the time corresponding to when the next cycle reaches the first duration is determined as the opening time of the upper equalizing pressure valve 16 in the next cycle in advance. Before the end of the next cycle, the upper equalizing pressure valve 16 is opened in advance, so that the oxygen in the upper half of the tower can enter the other tower in large quantities in advance before the pressure equalization stage, rather than only slowly entering through the buffer valve, thereby achieving a cooling effect. The earlier the advance time, the more obvious the cooling effect, but the more wasteful the produced oxygen is. Therefore, it is necessary to adaptively open the upper equalizing pressure valve 16 in advance through the current pre-compensation demand.

[0052] If the slow pressure equalization demand factor is greater than or equal to the preset demand threshold, it shows that the warming effect shown by the high pressure duration period is obvious, and after a long period of temperature accumulation, it is necessary to cool down in time, so if the pressure is equalized again at this time, the gas in the current tower will be quickly poured into another tower, thereby causing the temperature rise caused by the violent movement of gas in another tower. Therefore, if the current pre-compensation demand is too large, the weakening pressure equalization of gas can be carried out by utilizing the lower buffer valve 21 and the lower buffer connecting valve 22 installed in the oxygen concentrator using the present embodiment. Originally, opening the equalizing valve is to directly connect the two towers so that the air pressure of the two towers is equal. The speed of the pressure equalization can be slowed down by the buffer valve. Although the energy consumption of the compressor is increased, the temperature accumulation in the tower body is reduced, and the oxygen concentration is increased. Therefore, if the slow pressure equalization demand factor is greater than or equal to the preset demand threshold, in the pressure equalization stage of the next cycle, the upper and lower equalizing valves are not opened, the lower buffer connecting valve 22 is opened, and the weakening pressure equalization is realized by upper buffer valve 17 and lower buffer valve 21. In the present embodiment, the preset demand threshold is 0.5. In specific applications, the implementer can be set according to specific circumstances.

[0053] Thus, the above method is used to realize the pre-compensation of the oxygen production process of the oxygen generator.

[0054] The oxygen concentrator with oxygen output concentration monitoring and pre-compensation functions provided in this embodiment is based on the existing oxygen concentrator, and is equipped with a lower buffer valve, a lower buffer connecting valve, a data acquisition module, a data processing module, and a regulating module. The data acquisition module is used to collect pressure data and oxygen concentration at the outlet during the oxygen exhaust process. The data processing module determines the high pressure level of each cycle based on the distribution characteristics of the pressure data at the outlet of each cycle and the change characteristics of the oxygen concentration during the oxygen exhaust process, and then selects the high pressure duration period and determines the current compensation requirement. The current compensation requirement and the duration of the high pressure duration period are combined to obtain The regulating module determines whether the oxygen concentrator is in a high-load state based on the magnitude of the slow equalizing pressure demand factor. When the slow equalizing pressure demand factor is less than the preset demand threshold, the regulating module determines the opening time of the upper equalizing pressure valve in the next cycle in advance. When the slow equalizing pressure demand factor is greater than or equal to the preset demand threshold, the lower buffer connecting valve is opened in the pressure equalization stage of the next cycle, and the upper and lower buffer valves are used to weaken the pressure equalization. This embodiment avoids the temperature increase in the twin towers of the oxygen concentrator by regulating the opening and closing of the valves, reduces the influence of temperature on the adsorption efficiency of the zeolite molecular sieve, maintains the concentration of oxygen produced by the oxygen concentrator, and realizes pre-compensation of the oxygen concentration.

[0055] It should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An oxygen concentrator with oxygen output concentration monitoring and pre-compensation function, characterized in that: The oxygen concentrator includes a lower buffer valve, a lower buffer connecting valve, an upper buffer valve, a data acquisition module, a data processing module and a regulating module: Data acquisition module, used to collect pressure data and oxygen concentration at the outlet of the oxygen concentrator; A data processing module is used to obtain the high pressure level of each cycle according to the distribution characteristics of the pressure data at the outlet of each cycle of the oxygen exhaust and the change characteristics of the oxygen concentration; Determine the high pressure duration and the current compensation requirement based on the relative change between the high pressure level of each cycle and the previous cycle; and obtain the pressure equalization requirement factor based on the current compensation requirement and the duration of the high pressure duration; A regulating module, configured to determine an opening time for opening the upper pressure equalizing valve in advance in the next cycle if the slow pressure equalizing demand factor is less than a preset demand threshold; If the buffer pressure equalization demand factor is greater than or equal to the preset demand threshold, the lower buffer connecting valve is opened in the pressure equalization stage of the next cycle, and the upper buffer valve and the lower buffer valve are used to weaken the pressure equalization.

2. The oxygen concentrator with oxygen output concentration monitoring and pre-compensation function according to claim 1, characterized in that: The division of each cycle includes: For any loop: Calculating the pressure increments at every two adjacent moments in any cycle; The preceding moment of two adjacent moments corresponding to the first time the pressure increment takes a negative value is used as a dividing point to divide the arbitrary cycle into a first period and a second period.

3. The oxygen concentrator with oxygen output concentration monitoring and pre-compensation function according to claim 2, characterized in that: The method of obtaining the high pressure level of each cycle according to the distribution characteristics of the pressure data at the outlet of each cycle of the oxygen exhaust and the variation characteristics of the oxygen concentration includes: For any loop: For any cycle, the ratio of the maximum value of the pressure data in the cycle to the duration of the same cycle is used as the pressure high pressure coefficient of the cycle; curve fitting is performed on the oxygen concentration at all times in the cycle to obtain a fitting curve, the first point and the last point of the fitting curve are connected by a straight line to obtain the slope of the straight line; the negative correlation mapping value of the slope is used as the concentration high pressure coefficient of the cycle; The high pressure degree of any cycle is obtained by integrating the pressure high pressure coefficients and concentration high pressure coefficients of all periods of any cycle.

4. The oxygen concentrator with oxygen output concentration monitoring and pre-compensation function according to claim 3, characterized in that: The step of synthesizing the pressure high pressure coefficient and the concentration high pressure coefficient of all periods of the arbitrary cycle to obtain the high pressure degree of the arbitrary cycle includes: For any period, the product of the pressure high-pressure coefficient and the concentration high-pressure coefficient of the period is recorded as the first eigenvalue of the period; A normalized result of an average value of the first characteristic values ​​of all periods of the arbitrary cycle is determined as the high pressure level of the arbitrary cycle.

5. The oxygen concentrator with oxygen output concentration monitoring and pre-compensation function according to claim 1, characterized in that: Determining the high pressure duration period according to the relative change between the high pressure level of each cycle and the previous cycle includes: Take the cycle before and adjacent to the current cycle as the starting cycle, and sequentially obtain n cycles as reference cycles in chronological order from back to front; if the average value of the high pressure levels of the n reference cycles is less than a preset high pressure threshold, then use the n reference cycles as the high pressure duration period; if the average value of the high pressure levels of the n reference cycles is greater than or equal to the preset high pressure threshold, obtain n+1 cycles as reference cycles; when the average value of the high pressure levels of the n+1 reference cycles is less than the preset high pressure threshold, then use the n+1 reference cycles as the high pressure duration period; when the average value of the high pressure levels of the n+1 reference cycles is greater than or equal to the preset high pressure threshold, obtain n+2 cycles as reference cycles, and so on, until the average value of the high pressure levels of all the obtained reference cycles is less than the preset high pressure threshold, and then use all the obtained reference cycles as the high pressure duration period; Wherein, n is the preset number.

6. The oxygen concentrator with oxygen output concentration monitoring and pre-compensation function according to claim 5, characterized in that: Obtaining the current compensation demand, including: The difference between the average value of the high pressure levels of all reference cycles and the high pressure level of the current cycle is used as the current compensation requirement.

7. The oxygen concentrator with oxygen output concentration monitoring and pre-compensation function according to claim 1, characterized in that: The step of obtaining the pressure balancing demand factor according to the current compensation demand and the duration of the high-voltage duration period includes: The pressure balancing demand factor is calculated according to the current compensation demand and the duration of the high-pressure duration. The current compensation demand and the duration of the high-pressure duration are both positively correlated with the pressure balancing demand factor.

8. The oxygen concentrator with oxygen output concentration monitoring and pre-compensation function according to claim 7, characterized in that: The calculating of the pressure balancing demand factor according to the current compensation demand and the duration of the high-voltage duration period includes: The normalized result of the product of the current compensation demand degree and the duration of the high-voltage duration period is determined as the pressure balancing demand factor.

9. The oxygen concentrator with oxygen output concentration monitoring and pre-compensation function according to claim 1, characterized in that: Determine the opening time of the upper pressure equalizing valve in advance for the next cycle, including: The product of half of the duration of one cycle and the buffering and equalizing pressure demand factor is rounded up to an integer, and recorded as the first duration; The time corresponding to when the next cycle reaches the first time length is determined as the opening time of the upper pressure equalizing valve for opening in advance in the next cycle.

10. The oxygen concentrator with oxygen output concentration monitoring and pre-compensation function according to claim 2, characterized in that: Calculating the pressure increments at every two adjacent moments in any cycle includes: The difference between the pressure data at the latter moment and the pressure data at the previous moment in any two adjacent moments in the arbitrary cycle is taken as the pressure increment corresponding to the two adjacent moments.

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