Molecular Sieve Performance Detection Method for Pulse Oxygen Generator

Abstract

The present invention relates to the technical field of oxygen generators, and discloses a method for detecting the performance of molecular sieves of a pulse oxygen generator, aiming to solve the problems of complex process and poor accuracy in the existing detection of molecular sieve performance. The solution mainly includes: obtaining the first gas flow rate in the air inlet channel of the oxygen generator and the second gas flow rate in the exhaust channel; determining the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate. And obtaining the first gas flow rate in the air inlet channel of the oxygen generator and the third gas flow rate in the oxygen outlet channel; determining the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate. The present invention simplifies the performance detection process of the molecular sieve, improves the accuracy of performance detection, and is particularly suitable for portable pulse oxygen generators.

Description

Technical Field

[0001] The present invention relates to the technical field of oxygen generators, and more particularly to a method for detecting the performance of molecular sieves of a pulse oxygen generator. Background Art

[0002] The basic principle of an oxygen generator is to utilize the adsorption property of molecular sieves. Through physical principles, with a large-displacement oil-free compressor as the power, nitrogen and oxygen in the air are separated, and finally high-concentration oxygen is obtained and stored in an oxygen tank. That is, air is pressurized by a compressor, and the compressed air is filtered through a molecular sieve. Since the molecular sieve only adsorbs nitrogen with larger particles and oxygen can pass through, the separation of nitrogen and oxygen in the air is thus achieved. Oxygen generators are suitable for oxygen therapy and oxygen health care for various groups of people, and have the characteristics of rapid oxygen production, high oxygen concentration, stable oxygen production capacity, low operating power, small volume, and convenient use.

[0003] The molecular sieve therein is a kind of zeolite, which is particularly dry and adsorbs nitrogen with small pores. As the usage time increases, the performance of the molecular sieve will gradually decline. There may be various reasons for the decline in its performance. For example, the compressed air entering the molecular sieve will carry impurities such as dust and oil. The long-term adsorption of these impurities by the molecular sieve will lead to a decrease in the adsorption capacity. The molecular sieve cannot be exposed to moisture. If the air contains a large amount of water, it will also cause the performance of the molecular sieve to decline. When the performance of the molecular sieve declines, it will affect the oxygen production performance of the oxygen generator and cause a decrease in the oxygen concentration. Therefore, after an oxygen generator is used for a period of time, the problem of replacing and maintaining the molecular sieve will be faced. However, when to prompt the user to replace the molecular sieve is a difficult problem for the design of the oxygen generator.

[0004] The prior art mainly adopts the following several methods to determine the performance of the molecular sieve:

[0005] 1. Determine the performance of the molecular sieve according to the cumulative working time of the molecular sieve. Specifically, by recording the cumulative working time of the molecular sieve, when a certain cumulative time value is reached, such as 5000 hours, the user is prompted to replace the molecular sieve. However, this one-size-fits-all method does not consider the individual differences in the usage environments of each oxygen generator. The usage environments of different machines are different. Some individual usage environments are relatively harsh, and its accuracy is poor. For example, in an environment with serious air pollution, large air dust, and long-term humid weather, the molecular sieve will age prematurely. Before the prompt replacement time, the performance of the molecular sieve has seriously declined, resulting in a decrease in the oxygen output of the oxygen generator, affecting the equipment function and user experience. Some users have a better usage environment. When the cumulative set time is reached, the performance of the molecular sieve has not seriously declined and meets the oxygen output requirements. However, prompting the user to replace the molecular sieve that can still be used at this time will cause waste of resources and unnecessary increase in the user's usage cost.

[0006] 2. Detect the oxygen concentration through an oxygen concentration sensor. If the output oxygen concentration decreases, it prompts the user to replace the molecular sieve. However, there may be various situations when the output oxygen concentration decreases, and its accuracy is poor. For example, faults such as compressor aging and oxygen concentration sensor drift cause the output oxygen concentration to decrease. At this time, the performance of the molecular sieve has not decreased, but the system prompts to replace the molecular sieve, resulting in waste of the molecular sieve and unnecessary increase in the user's usage cost.

[0007] 3. Adopt professional detection methods to detect the adsorption performance of the molecular sieve, such as gas chromatography, gravimetry, frequency response method, etc. to measure the adsorption performance of zeolite molecular sieve. However, this method requires adding a large number of professional instruments and process steps and is not suitable for use inside the oxygen generator. Summary of the Invention

[0008] The present invention aims to provide a method for detecting the performance of the molecular sieve of an oxygen generator to simplify the performance detection process of the molecular sieve and improve the accuracy of the molecular sieve performance detection.

[0009] The technical solution adopted by the present invention to solve the above technical problems is as follows:

[0010] On the one hand, a method for detecting the performance of the molecular sieve of a pulse oxygen generator is provided, including:

[0011] Obtain the first gas flow rate of the intake air passage and the second gas flow rate of the exhaust passage of the oxygen generator;

[0012] Determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate.

[0013] Further, the oxygen generator includes at least two molecular sieves. Before determining the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate, it further includes:

[0014] Create a corresponding relationship between the pressure value of the molecular sieve and the flow rate correction value, where the flow rate correction value is the oxygen flow rate of the exhaust passage of the oxygen generator when the performance of the molecular sieve is normal;

[0015] Obtain the current pressure value of any one of the molecular sieves of the oxygen generator;

[0016] Based on the corresponding relationship, determine the flow rate correction value corresponding to the current pressure value, and correct the second gas flow rate according to the flow rate correction value.

[0017] Further, it further includes:

[0018] Judge whether the current pressure value of any one of the molecular sieves of the oxygen generator is within the first preset range. If so, determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate; otherwise, re-obtain the first gas flow rate, the second gas flow rate, and the current pressure value.

[0019] Further, it further includes:

[0020] Obtain the current temperature value of any one of the molecular sieves of the oxygen generator;

[0021] Judge whether the current temperature value is within a second preset range. If so, determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate. Otherwise, re-obtain the first gas flow rate, the second gas flow rate, and the current temperature value.

[0022] Further, the obtaining of the first gas flow rate of the air inlet channel of the oxygen generator at least includes:

[0023] Obtain the compressor parameters and altitude of the oxygen generator, and the compressor parameters at least include the specification parameters and rotation speed of the compressor;

[0024] Calculate the air density according to the altitude, and calculate the first gas flow rate of the air inlet channel of the oxygen generator according to the compressor parameters and the air density.

[0025] Further, determining the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate specifically includes:

[0026] Calculate a first ratio of the first gas flow rate to the second gas flow rate. The smaller the first ratio, the worse the performance of the molecular sieve, and the larger the first ratio, the better the performance of the molecular sieve; or

[0027] Calculate a second ratio of the second gas flow rate to the first gas flow rate. The smaller the second ratio, the better the performance of the molecular sieve, and the larger the second ratio, the worse the performance of the molecular sieve;

[0028] This method further includes: calculating the first ratio or the second ratio multiple times according to a preset period. If within a continuous preset number of times, the first ratio is less than a first threshold, or the second ratio is greater than a second threshold, then issue a prompt that the molecular sieve cannot work properly.

[0029] On the other hand, provide another method for detecting the performance of the molecular sieve of a pulse oxygen generator, including:

[0030] Obtain the first gas flow rate of the air inlet channel of the oxygen generator and the third gas flow rate of the oxygen outlet channel;

[0031] Determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate.

[0032] Further, the oxygen generator includes at least two molecular sieves. Before determining the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate, it further includes:

[0033] Create a correspondence between the pressure value for creating the molecular sieve and the flow correction value, where the flow correction value is the oxygen flow rate in the exhaust passage of the oxygen generator when the performance of the molecular sieve is normal;

[0034] Obtain the current pressure value of any one molecular sieve of the oxygen generator;

[0035] Based on the correspondence, determine the flow correction value corresponding to the current pressure value, and correct the third gas flow rate according to the flow correction value.

[0036] Furthermore, it further includes:

[0037] Judge whether the current pressure value of any one molecular sieve of the oxygen generator is within a first preset range. If so, determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate. Otherwise, re-obtain the first gas flow rate, the third gas flow rate, and the current pressure value.

[0038] Furthermore, it further includes:

[0039] Obtain the current temperature value of any one molecular sieve of the oxygen generator;

[0040] Judge whether the current temperature value is within a second preset range. If so, determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate. Otherwise, re-obtain the first gas flow rate, the second gas flow rate, and the current temperature value.

[0041] Furthermore, obtaining the first gas flow rate in the intake passage of the oxygen generator at least includes:

[0042] Obtain the compressor parameters and altitude of the oxygen generator, where the compressor parameters at least include the specification parameters and rotation speed of the compressor;

[0043] Calculate the air density according to the altitude, and calculate the first gas flow rate in the intake passage of the oxygen generator according to the compressor parameters and the air density.

[0044] Furthermore, determining the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate specifically includes:

[0045] Calculate a third ratio of the first gas flow rate to the third gas flow rate. The smaller the third ratio, the better the performance of the molecular sieve, and the larger the third ratio, the worse the performance of the molecular sieve; or

[0046] Calculate a fourth ratio of the third gas flow rate to the first gas flow rate. The smaller the fourth ratio, the worse the performance of the molecular sieve, and the larger the fourth ratio, the better the performance of the molecular sieve;

[0047] The method further includes: calculating the third ratio or the fourth ratio multiple times according to a preset period. If the third ratio is greater than a third threshold value within a continuous preset number of times, or the fourth ratio is less than a fourth threshold value within a continuous preset number of times, a prompt that the molecular sieve cannot work properly is issued.

[0048] The beneficial effects of the present invention are as follows: The method for detecting the performance of the molecular sieve of the pulse oxygen generator according to the present invention determines the performance of the molecular sieve through the flow ratio relationship between the air inlet channel and the air outlet channel of the oxygen generator, or the flow ratio relationship between the air inlet channel and the oxygen outlet channel. This not only simplifies the performance detection process of the molecular sieve but also improves the accuracy of the performance detection of the molecular sieve. In addition, the present invention also corrects the flow rate of the air outlet channel or the oxygen outlet channel according to the pressure of the molecular sieve, avoiding the influence of the backwashing process on the performance detection of the molecular sieve, further improving the accuracy of the performance detection of the molecular sieve, and at the same time avoiding resource waste and unnecessary increase in the user's usage cost. Description of the Drawings

[0049] Figure 1 It is a schematic structural diagram of the pulse oxygen generator according to the embodiment of the present invention;

[0050] Figure 2 It is a schematic flow chart of a method for detecting the performance of the molecular sieve of a pulse oxygen generator according to the embodiment of the present invention;

[0051] Figure 3 It is a schematic diagram showing the relationship between the pressure and the adsorption amount in the molecular sieve tower according to the embodiment of the present invention;

[0052] Figure 4 It is a schematic diagram showing the relationship between the temperature and the oxygen concentration in the molecular sieve tower according to the embodiment of the present invention;

[0053] Figure 5 It is a schematic flow chart of another method for detecting the performance of the molecular sieve of a pulse oxygen generator according to the embodiment of the present invention. Detailed Embodiments

[0054] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0055] The present invention provides two methods for detecting the performance of the molecular sieve of a pulse oxygen generator. The main technical solutions include: One is to obtain the first gas flow rate of the air inlet channel of the oxygen generator and the second gas flow rate of the air outlet channel, and determine the performance of the molecular sieve according to the ratio relationship between the first gas flow rate and the second gas flow rate. The other is to obtain the first gas flow rate of the air inlet channel of the oxygen generator and the third gas flow rate of the oxygen outlet channel, and determine the performance of the molecular sieve according to the ratio relationship between the first gas flow rate and the third gas flow rate.

[0056] It can be understood that the air entering the oxygen generator is mainly discharged in two parts. One part is the oxygen-rich gas that enters the oxygen tank through the oxygen outlet channel, and the other part of the gas is discharged through the exhaust channel, and its main component is nitrogen. Combining with the working principle of the oxygen generator, it can be known that the better the adsorption performance of the molecular sieve, the more oxygen-rich gas can be obtained from the same amount of air, and the less gas is discharged through the exhaust channel; the worse the adsorption performance of the molecular sieve, the less oxygen-rich gas can be obtained from the same amount of air, and the more gas is discharged through the exhaust channel. The oxygen content in normal air is 20.9%. Under the ideal working condition of the molecular sieve, 20.9% of the oxygen in the air entering the oxygen generator can pass through the molecular sieve and enter the oxygen tank, while the remaining 79.1% of the gas is adsorbed by the molecular sieve tower and enters the exhaust channel during desorption. Based on this, the present invention determines the performance of the molecular sieve through the flow ratio relationship between the air inlet channel and the exhaust channel of the oxygen generator, or the flow ratio relationship between the air inlet channel and the oxygen outlet channel, so as to simplify the performance detection process of the molecular sieve and improve the accuracy of performance detection.

[0057] Embodiment 1

[0058] The method for detecting the performance of the molecular sieve of the pulse oxygen generator described in this embodiment is as Figure 1 shown. The pulse oxygen generator applied includes at least: a controller, a memory, a compressor, a first molecular sieve, a second molecular sieve, a first control valve, a second control valve, a third control valve, and a pressure equalizing throttle valve. Among them, the controller is used to control the opening and closing of the first control valve, the second control valve, the third control valve, and the pressure equalizing throttle valve, the memory is used to store data, the first control valve is used to control the intake and exhaust of the first molecular sieve, the second control valve is used to control the intake and exhaust of the second molecular sieve, the pressure equalizing throttle valve is used to balance the pressure inside the first molecular sieve and the second molecular sieve, and to help the molecular sieve quickly complete the desorption of nitrogen, the pressure equalizing throttle valve is also used to control part of the oxygen for back blowing.

[0059] It should be noted that according to different actual needs, the pulse oxygen generator in this embodiment may also include other components, such as a filtering mechanism, a silencing mechanism, a heat dissipation mechanism, a human-computer interaction mechanism, etc., and this embodiment does not limit this.

[0060] Based on the above pulse oxygen generator, the method for detecting the performance of the molecular sieve of the pulse oxygen generator provided in this embodiment is as Figure 2 shown, and includes the following steps:

[0061] Step 101, obtain the first gas flow rate of the air inlet channel of the oxygen generator and the second gas flow rate of the exhaust channel;

[0062] As Figure 1As shown in the figure, in this embodiment, a first flow sensor may be provided in the air intake passage of the oxygen generator, and a second flow sensor may be provided in the exhaust passage. When the oxygen generator is operating, the controller obtains the first gas flow rate detected by the first flow sensor and the second gas flow rate detected by the second flow sensor.

[0063] To save costs, the first gas flow rate in this embodiment can also be obtained by the following method:

[0064] Obtain the compressor parameters and altitude of the oxygen generator; calculate the air density according to the altitude, and calculate the first gas flow rate in the air intake passage of the oxygen generator according to the compressor parameters and the air density.

[0065] It can be understood that the air inlet of the compressor is usually directly air or filtered air. The factors related to the first gas flow rate mainly include the air density at the air inlet of the compressor and the compressor parameters. Among them, the compressor parameters include the specification parameters and the rotation speed of the compressor. Based on this, the first gas flow rate can be calculated according to the compressor parameters and altitude of the oxygen generator in this embodiment. Specifically, the air density at different altitudes is obtained through public data query. For example, from 0 to 5000 meters, there is an air density corresponding to every 50 meters, and then the corresponding relationship between altitude and air density is established. After obtaining the altitude of the oxygen generator, the corresponding air density can be obtained according to this corresponding relationship, and then the first gas flow rate can be calculated through the specification parameters of the compressor, the rotation speed of the compressor, and the air density. The specific calculation method belongs to the prior art and will not be elaborated here. In this way, the first gas flow rate can be obtained without setting the first flow sensor, thereby reducing the hardware cost.

[0066] Step 102: Determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate.

[0067] Combined with the working principle of the oxygen generator, the better the adsorption performance of the molecular sieve, the more oxygen can be obtained from the same amount of air, and the less gas is discharged through the exhaust passage; the worse the adsorption performance of the molecular sieve, the less oxygen can be obtained from the same amount of air, and the more gas is discharged through the exhaust passage. Based on this, the performance of the molecular sieve is determined according to the proportional relationship between the first gas flow rate and the second gas flow rate in this embodiment.

[0068] Specifically, the first ratio of the first gas flow rate to the second gas flow rate can be calculated. The smaller the first ratio, the worse the performance of the molecular sieve; the larger the first ratio, the better the performance of the molecular sieve. For example, if the first ratio is X1, then X1 = L1 / L2. The smaller the first ratio X1, the larger the second gas flow rate L2, that is, the more gas is discharged from the exhaust passage, indicating that the performance of the molecular sieve is worse at this time; the larger the first ratio X1, the smaller the second gas flow rate L2, that is, the less gas is discharged from the exhaust passage, indicating that the performance of the molecular sieve is better at this time.

[0069] In this embodiment, the second ratio of the second gas flow rate to the first gas flow rate can also be calculated. The smaller the second ratio, the better the performance of the molecular sieve; the larger the second ratio, the worse the performance of the molecular sieve. For example, if the second ratio is X2, then X2 = L2 / L1. The smaller the second ratio X2, the smaller the second gas flow rate L2, that is, the less gas is discharged from the exhaust passage, indicating that the performance of the molecular sieve is better at this time; the larger the second ratio X2, the larger the second gas flow rate L2, that is, the more gas is discharged from the exhaust passage, indicating that the performance of the molecular sieve is worse at this time.

[0070] In actual application, the performance of the molecular sieve can also be judged hierarchically according to the preset range in which the first ratio or the second ratio is located. For example, when the first ratio X1 is within the third preset range, it is determined that the performance of the molecular sieve is normal; when the first ratio X1 is within the fourth preset range, it is determined that the performance of the molecular sieve has declined and it cannot supply oxygen at a high concentration; when the first ratio X1 is within the fifth preset range, it is determined that the molecular sieve cannot be used normally. Or when the second ratio X2 is within the sixth preset range, it is determined that the performance of the molecular sieve is normal; when the second ratio X2 is within the seventh preset range, it is determined that the performance of the molecular sieve has declined and it cannot supply oxygen at a high concentration; when the second ratio X2 is within the eighth preset range, it is determined that the molecular sieve cannot be used normally.

[0071] Among them, the third preset range, the fourth preset range, and the fifth preset range can be preset ranges that continuously decrease, and the sixth preset range, the seventh preset range, and the eighth preset range can be preset ranges that continuously increase. Their specific values can be set according to actual needs, and this embodiment does not limit this. For example, the third preset range is 1.17 - 1.26, the fourth preset range is 1.11 - 1.17, and the fifth preset range is 1.00 - 1.11; the sixth preset range is 0.79 - 0.85, the seventh preset range is 0.85 - 0.90, and the eighth preset range is 0.90 - 1.00.

[0072] In order to further improve the accuracy of molecular sieve performance detection, this embodiment further includes: calculating the first ratio or the second ratio multiple times according to a preset period. If within a continuous preset number of times, the first ratio is less than the first threshold, or the second ratio is greater than the second threshold, a prompt that the molecular sieve cannot work properly is issued. The first ratio or the second ratio obtained through multiple detections is used for judgment respectively. And only when each judgment result indicates that the molecular sieve cannot work properly, a prompt to replace the molecular sieve is given to the user, thereby avoiding false alarms caused by errors in single data collection. Among them, the preset period can be set according to actual needs, and this embodiment does not limit this.

[0073] In practical applications, for an oxygen generator with multiple molecular sieves, it includes a corresponding molecular sieve cycle logic, that is, controlling the molecular sieves to intake and exhaust air alternately, so that multiple molecular sieves work alternately. When some molecular sieves adsorb nitrogen, the other part of the molecular sieves desorb to prepare for the next adsorption. The oxygen-rich gas filtered by the molecular sieves enters the oxygen tank for storage. In order to completely discharge the nitrogen released from the molecular sieve, a back-blowing process is also carried out between the molecular sieves through a pressure equalizing throttle valve, that is, controlling part of the oxygen to purge the desorbing molecular sieve through the pressure equalizing throttle valve. This part of the oxygen will be discharged through the exhaust passage together with the desorbed nitrogen, and when the gas pressure in the molecular sieve is different, the amount of oxygen discharged through the exhaust passage is also different. Based on this, before determining the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate, this embodiment also corrects the second gas flow rate, specifically including:

[0074] Step 111, create a corresponding relationship between the pressure value of the molecular sieve and the flow correction value, where the flow correction value is the oxygen flow rate of the exhaust passage of the oxygen generator when the molecular sieve is in normal performance;

[0075] It can be understood that the flow correction value is the oxygen flow rate of the exhaust passage of the oxygen generator when the molecular sieve is in normal performance, which mainly includes two parts: one part is that the molecular sieve cannot be completely filtered even when it is in normal performance, resulting in a small amount of oxygen being discharged from the exhaust passage, and the other part is that the back-blowing process causes part of the oxygen to be discharged from the exhaust passage together with the nitrogen. In practical applications, before the oxygen generator leaves the factory or is used, when the performance of the molecular sieve is normal and the aperture of the pressure equalizing throttle valve is fixed, the flow correction value corresponding to different pressure values of the molecular sieve can be determined through experiments, that is, by adjusting the pressure value of the molecular sieve and measuring the oxygen flow rate in the gas discharged through the exhaust passage under various pressure conditions of the molecular sieve respectively. For example, increase the pressure value of the molecular sieve in sequence from 0 - 200 KPa, and measure the oxygen flow rate in the gas discharged through the exhaust passage every 10 KPa, then the corresponding relationship between the pressure value of the molecular sieve and the flow correction value can be obtained. This embodiment stores the corresponding relationship in the memory.

[0076] Step 112: Obtain the current pressure value of any molecular sieve of the oxygen generator;

[0077] As Figure 1 shown, in this embodiment, a pressure sensor can be set in the first molecular sieve of the oxygen generator. Due to the pressure equalization effect of the pressure equalizing throttle valve, the pressures in multiple molecular sieves are almost the same. Therefore, the pressure sensor can also be set in other molecular sieves. When the oxygen generator is working, the controller obtains the current pressure value detected by the pressure sensor.

[0078] Step 113: Determine the flow rate correction value corresponding to the current pressure value based on the corresponding relationship, and correct the second gas flow rate according to the flow rate correction value.

[0079] Specifically, after obtaining the current pressure value of the molecular sieve, the controller determines the flow rate correction value corresponding to the current pressure value according to the corresponding relationship stored in the memory, corrects the second gas flow rate according to the flow rate correction value to obtain the corrected second gas flow rate, and finally determines the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the corrected second gas flow rate. For example, if the second gas flow rate obtained by the second flow sensor is L2′, and the flow rate correction value corresponding to the current pressure value Pn is Ln, then the corrected second gas flow rate L2 = L2′ - Ln.

[0080] In this embodiment, by correcting the second gas flow rate of the exhaust passage, the influence of the oxygen discharged from the exhaust passage on the performance detection of the molecular sieve in the backflush process is avoided, the accuracy of the molecular sieve performance detection is further improved, and at the same time, resource waste and unnecessary increase in user usage cost are avoided.

[0081] To further improve the accuracy of the molecular sieve performance, this embodiment further includes:

[0082] Judge whether the current pressure value of any molecular sieve of the oxygen generator is within a first preset range. If so, determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate; otherwise, re-obtain the first gas flow rate of the intake passage and the second gas flow rate of the exhaust passage of the oxygen generator.

[0083] It can be understood that the adsorption performance of the molecular sieve will be affected by the pressure in the tower, such as Figure 3As shown, as the pressure rises, the adsorption capacity of the molecular sieve increases rapidly. When it reaches a certain pressure range, the adsorption curve is horizontal or nearly horizontal, and the adsorption capacity approaches the limit. This is because the molecular sieve has many narrow micropores, and the external surface area is much smaller than the internal surface area of the pores. When the pressure on the molecular sieve is very low, due to the enhanced interaction between the adsorbent and the adsorbed substance in the narrow micropores (micropores of molecular size), micropore filling occurs at low pressure, resulting in a sharp increase in the adsorption capacity. As the pressure continues to rise, due to the limitation of the internal surface area of the pores that the adsorbed gas can enter, the adsorption capacity tends to saturation. When the saturation pressure is reached, adsorption condensate may occur, causing the curve to rise.

[0084] Based on this, to avoid the influence of the pressure in the molecular sieve tower on the performance detection of the molecular sieve, the current pressure value of any molecular sieve is detected by a pressure sensor. When the oxygen generator is working, the controller obtains the current pressure value detected by the pressure sensor. When the current pressure value is within the first preset range, it indicates that the filtration performance of the molecular sieve is stable. At this time, the performance of the molecular sieve is determined according to the proportional relationship between the first gas flow rate and the second gas flow rate (or the corrected second gas flow rate) obtained. When the current pressure value is not within the first preset range, it indicates that the filtration performance of the molecular sieve is not stable enough. At this time, the first gas flow rate in the intake passage of the oxygen generator, the second gas flow rate in the exhaust passage, and the current pressure value in any molecular sieve are redetected according to a preset cycle until the current pressure value meets the preset conditions, and then the performance of the molecular sieve is determined according to the proportional relationship between the newly obtained first gas flow rate and the second gas flow rate, thereby avoiding the influence of the pressure in the molecular sieve tower on the performance detection of the molecular sieve and further improving the accuracy of the molecular sieve performance detection.

[0085] In addition, the adsorption performance of the molecular sieve will be affected by the pressure in the tower, such as Figure 4 shown, too low or too high temperature will affect the adsorption performance of the molecular sieve, resulting in different oxygen concentrations in the oxygen outlet passage.

[0086] Based on this, to avoid the influence of the temperature in the molecular sieve tower on the performance detection of the molecular sieve, in this embodiment, a temperature sensor can also be set in the first molecular sieve tower. Since the temperatures in multiple molecular sieves are almost the same, in actual application, the temperature sensor can also be set in other molecular sieve towers. When the oxygen generator is working, the controller obtains the current temperature value detected by the temperature sensor. When the current temperature value is within the second preset range, it indicates that the filtering performance of the molecular sieve is stable. At this time, the performance of the molecular sieve is determined according to the proportional relationship between the first gas flow rate and the second gas flow rate obtained. When the current temperature value is not within the second preset range, it indicates that the filtering performance of the molecular sieve is not stable enough. At this time, the first gas flow rate in the air inlet channel of the oxygen generator, the second gas flow rate in the exhaust channel, and the current temperature value in any one of the molecular sieves are redetected according to a preset period until the current temperature value meets the preset conditions, and then the performance of the molecular sieve is determined according to the proportional relationship between the first gas flow rate and the second gas flow rate obtained again, thereby avoiding the influence of the temperature in the molecular sieve tower on the performance detection of the molecular sieve and further improving the accuracy of the performance detection of the molecular sieve.

[0087] It should be noted that in actual application, the pressure and temperature in any one of the molecular sieve towers can be detected simultaneously. And when both the pressure and the temperature are within the corresponding preset ranges, the performance of the molecular sieve is determined according to the proportional relationship between the first gas flow rate and the second gas flow rate obtained, thereby being able to avoid the influence of both the pressure and the temperature in the molecular sieve tower on the performance detection of the molecular sieve and further improving the accuracy of the performance detection of the molecular sieve.

[0088] Among them, the first preset range and the second preset range are respectively used to represent the pressure range and the temperature range when the filtering performance of the molecular sieve is stable. In actual application, their specific values can also be different according to different specific situations. This embodiment does not limit this. For example, the first preset range can be 90 - 100 KPa, and the second preset range can be 28 - 30 °C.

[0089] To sum up, in this embodiment, the performance of the molecular sieve is determined by the flow rate proportional relationship between the air inlet channel and the exhaust channel of the oxygen generator, which not only simplifies the performance detection process of the molecular sieve but also improves the accuracy of the performance detection of the molecular sieve. And in this embodiment, the flow rate of the exhaust channel is corrected according to the pressure value of the molecular sieve, avoiding the influence of the oxygen discharged from the exhaust channel on the performance detection of the molecular sieve during the backwashing process, further improving the accuracy of the performance detection of the molecular sieve, and at the same time avoiding resource waste and unnecessary increase in the user's usage cost.

[0090] Embodiment 2

[0091] It can be understood that the air entering the oxygen generator is mainly discharged in two parts. One part is the oxygen-rich gas that enters the oxygen tank through the oxygen outlet channel, and the other part of the gas is discharged through the exhaust channel. That is, the gas flow rate of the air inlet channel of the oxygen generator is equal to the sum of the oxygen-rich gas flow rate entering the oxygen tank and the gas flow rate discharged through the exhaust channel. Based on this, another method for detecting the performance of the molecular sieve of a pulse oxygen generator is proposed in this embodiment. This method determines the performance of the molecular sieve through the flow rate ratio relationship between the air inlet channel and the oxygen outlet channel.

[0092] Specifically, for the method for detecting the performance of the molecular sieve of the pulse oxygen generator provided in this embodiment, the structure of the pulse oxygen generator applied is basically the same as that in Embodiment 1, which will not be elaborated here. As Figure 5 shown, this method includes the following steps:

[0093] Step 201: Obtain the first gas flow rate of the air inlet channel of the oxygen generator and the third gas flow rate of the oxygen outlet channel;

[0094] In this embodiment, a third flow sensor can be set in the oxygen outlet channel. When the oxygen generator is working, the controller obtains the first gas flow rate detected by the first flow sensor and the third gas flow rate detected by the third flow sensor.

[0095] Step 202: Determine the performance of the molecular sieve according to the ratio relationship between the first gas flow rate and the third gas flow rate.

[0096] Specifically, in this embodiment, the third ratio of the first gas flow rate to the third gas flow rate can be calculated. The smaller the third ratio, the better the performance of the molecular sieve; the larger the third ratio, the worse the performance of the molecular sieve. For example, let the third ratio be X3, then X3 = L1 / L3. The smaller the third ratio X3, the larger the third gas flow rate, that is, the more oxygen is generated, indicating that the performance of the molecular sieve is better at this time; the larger the third ratio X3, the smaller the third gas flow rate, that is, the less oxygen is generated, indicating that the performance of the molecular sieve is worse at this time.

[0097] In this embodiment, the fourth ratio of the third gas flow rate to the first gas flow rate can also be calculated. The smaller the fourth ratio, the worse the performance of the molecular sieve; the larger the fourth ratio, the better the performance of the molecular sieve. For example, let the fourth ratio be X4, then X4 = L3 / L1. The smaller the fourth ratio X4, the smaller the third gas flow rate, that is, the less oxygen is generated, indicating that the performance of the molecular sieve is worse at this time; the larger the fourth ratio X4, the larger the third gas flow rate, that is, the more oxygen is generated, indicating that the performance of the molecular sieve is better at this time.

[0098] In actual application, the performance of the molecular sieve can also be judged by grading according to the preset range in which the third ratio or the fourth ratio is located. The principle and specific implementation are similar to those in Embodiment 1, which will not be elaborated here.

[0099] Similarly, before determining the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate in this embodiment, the third gas flow rate can also be corrected. The principle and specific implementation are similar to those of Embodiment 1 and will not be elaborated here. The difference lies in the correction method. For example, if the third gas flow rate obtained by the third flow sensor is L3', and the flow rate correction value corresponding to the current pressure value Pn is Ln, then the corrected third gas flow rate L3 = L3' + Ln.

[0100] Similarly, in order to further improve the accuracy of molecular sieve performance detection, a temperature sensor can also be provided in the molecular sieve in this embodiment to detect the current temperature value of the molecular sieve, and the performance of the molecular sieve is determined according to the proportional relationship between the first gas flow rate and the third gas flow rate only when the current pressure value and / or the current temperature value of the molecular sieve meet the preset conditions. The principle and specific implementation are similar to those of Embodiment 1 and will not be elaborated here.

[0101] In summary, in this embodiment, the performance of the molecular sieve is determined by the flow rate proportional relationship between the oxygen inlet channel and the oxygen outlet channel of the oxygen generator, which not only simplifies the molecular sieve performance detection process but also improves the accuracy of molecular sieve performance detection. And in this embodiment, the flow rate of the oxygen outlet channel is corrected according to the pressure value of the molecular sieve, avoiding the influence of the oxygen discharged from the exhaust channel on the molecular sieve performance detection during the backwashing process, further improving the accuracy of molecular sieve performance detection, and at the same time avoiding resource waste and unnecessary increase in user usage costs.

Claims

1. Method for detecting molecular sieve performance of a pulse oxygen generator, characterized in that, it includes: Obtain the first gas flow rate of the intake passage of the oxygen generator and the second gas flow rate of the exhaust passage; Determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate, specifically including: Calculate the first ratio of the first gas flow rate to the second gas flow rate. The smaller the first ratio, the worse the performance of the molecular sieve, and the larger the first ratio, the better the performance of the molecular sieve; or Calculate the second ratio of the second gas flow rate to the first gas flow rate. The smaller the second ratio, the better the performance of the molecular sieve, and the larger the second ratio, the worse the performance of the molecular sieve; The oxygen generator includes at least two molecular sieves. Before determining the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate, it further includes: Create a correspondence between the pressure value of the molecular sieve and the flow correction value, where the flow correction value is the oxygen flow rate of the exhaust passage of the oxygen generator when the molecular sieve performance is normal; Obtain the current pressure value of any one molecular sieve of the oxygen generator; Determine the flow correction value corresponding to the current pressure value based on the correspondence, and correct the second gas flow rate according to the flow correction value.

2. The method for detecting molecular sieve performance of a pulse oxygen generator according to claim 1, characterized in that, it further includes: Judge whether the current pressure value of any one molecular sieve of the oxygen generator is within a first preset range. If so, determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate. Otherwise, re-obtain the first gas flow rate, the second gas flow rate, and the current pressure value.

3. The method for detecting molecular sieve performance of a pulse oxygen generator according to claim 1, characterized in that, it further includes: Obtain the current temperature value of any one molecular sieve of the oxygen generator; Judge whether the current temperature value is within a second preset range. If so, determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the second gas flow rate. Otherwise, re-obtain the first gas flow rate, the second gas flow rate, and the current temperature value.

4. The method for detecting molecular sieve performance of a pulse oxygen generator according to claim 1, characterized in that, This method further includes: Calculate the first ratio or the second ratio multiple times according to a preset period. If within a continuous preset number of times, the first ratio is less than a first threshold, or the second ratio is greater than a second threshold, then issue a prompt that the molecular sieve cannot work properly.

5. The method for detecting molecular sieve performance of a pulse oxygen generator according to claim 1, characterized in that, The obtaining of the first gas flow rate of the intake passage of the oxygen generator at least includes: Obtain the compressor parameters and altitude of the oxygen generator, and the compressor parameters at least include the specification parameters and rotational speed of the compressor; Calculate the air density according to the altitude, and calculate the first gas flow rate of the intake passage of the oxygen generator according to the compressor parameters and the air density.

6. Method for detecting molecular sieve performance of a pulse oxygen generator, characterized in that, it includes: Obtain the first gas flow rate of the intake air passage of the oxygen generator and the third gas flow rate of the oxygen outlet passage; Determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate, specifically including: Calculate the third ratio of the first gas flow rate to the third gas flow rate. The smaller the third ratio, the better the performance of the molecular sieve; the larger the third ratio, the worse the performance of the molecular sieve; or Calculate the fourth ratio of the third gas flow rate to the first gas flow rate. The smaller the fourth ratio, the worse the performance of the molecular sieve; the larger the fourth ratio, the better the performance of the molecular sieve; The oxygen generator includes at least two molecular sieves. Before determining the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate, it further includes: Create a correspondence relationship between the pressure value of the molecular sieve and the flow rate correction value, where the flow rate correction value is the oxygen flow rate of the exhaust passage of the oxygen generator when the performance of the molecular sieve is normal; Obtain the current pressure value of any one molecular sieve of the oxygen generator; Determine the flow rate correction value corresponding to the current pressure value based on the correspondence relationship, and correct the third gas flow rate according to the flow rate correction value.

7. The method for detecting the performance of the molecular sieve of the pulse oxygen generator according to claim 6, characterized in that, it further includes: Judge whether the current pressure value of any one molecular sieve of the oxygen generator is within the first preset range. If so, determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate; otherwise, re-obtain the first gas flow rate, the third gas flow rate and the current pressure value.

8. The method for detecting the performance of the molecular sieve of the pulse oxygen generator according to claim 6, characterized in that, it further includes: Obtain the current temperature value of any one molecular sieve of the oxygen generator; Judge whether the current temperature value is within the second preset range. If so, determine the performance of the molecular sieve according to the proportional relationship between the first gas flow rate and the third gas flow rate; otherwise, re-obtain the first gas flow rate, the third gas flow rate and the current temperature value.

9. The method for detecting the performance of the molecular sieve of the pulse oxygen generator according to claim 6, characterized in that, This method further includes: calculating the third ratio or the fourth ratio multiple times according to a preset period. If within a continuous preset number of times, the third ratio is greater than the third threshold, or the fourth ratio is less than the fourth threshold, then issue a prompt that the molecular sieve cannot work properly.

10. The method for detecting the performance of the molecular sieve of the pulse oxygen generator according to claim 6, characterized in that, The obtaining of the first gas flow rate of the intake air passage of the oxygen generator at least includes: Obtain the compressor parameters and altitude of the oxygen generator, and the compressor parameters at least include the specification parameters and rotation speed of the compressor; Calculate the air density according to the altitude, and calculate the first gas flow rate of the intake air passage of the oxygen generator according to the compressor parameters and the air density.

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