Helium purification method and helium purification system

Abstract

The application discloses a helium purification method and a helium purification system, wherein the helium purification method uses an adsorber in a state of being ready to be adsorbed to adsorb and purify crude helium, replaces another adsorber in a state of being ready to be adsorbed after the adsorption to a saturated state, communicates the adsorber in the saturated state with an adsorber in a vacuum state to equalize pressure, and then performs vacuumizing and reheating on the adsorber after the equalization of pressure, so that impurity gas in the adsorber is precipitated through low pressure and high temperature, the adsorber can be used again, and helium can be continuously purified through at least three adsorbers, without waiting for replacement of the adsorber, thereby improving the purification efficiency of the helium; meanwhile, the adsorber in the saturated state is equalized in pressure with the adsorber in the vacuum state, intermediate helium which is not completely adsorbed is recycled and reused, the discharge of the helium is reduced, and the helium yield is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of helium purification, in particular to a helium purification method and a helium purification system. BACKGROUND

[0002] Helium has strong chemical inertness, very low boiling point and low solubility in blood, and has irreplaceable role in national defense, industry and technology fields such as aerospace, nuclear weapons, submarines, saturation diving, nuclear magnetic resonance, semiconductors, mobile phones, liquid crystal screens, optical fibers and large scientific devices, but the purity of helium in natural gas which can be extracted is less than 10%, and the purity of recovered helium is also difficult to meet the use demand due to the penetration of various impurity gases, so it is necessary to purify helium.

[0003] In the prior art, the adsorber is usually used to purify helium, but the adsorption capacity of the adsorber for waste gas is limited, so the adsorber needs to be replaced every certain period of time, and the adsorption purification process of helium is interrupted many times, which leads to low helium purification efficiency, and at the same time, there is a part of intermediate helium which is not completely adsorbed in the adsorber when the adsorber is replaced each time, and the intermediate helium is discharged into the atmosphere with the replacement of the adsorber, which leads to waste of helium and low utilization rate of helium. SUMMARY

[0004] The main purpose of the present application is to provide a helium purification method and a helium purification system, which aims to solve the problems of low helium purification efficiency and low helium utilization rate in the existing helium purification method.

[0005] To achieve the above-mentioned purpose, the present application provides a helium purification method, comprising the following steps:

[0006] purifying and adsorbing the crude helium through an adsorber in a standby adsorption state to form refined helium and output;

[0007] continuously purifying and adsorbing until the adsorber is filled with impurities and enters a saturated state;

[0008] purifying and adsorbing the crude helium through another adsorber in a standby adsorption state;

[0009] communicating the adsorber in the saturated state with an adsorber in a vacuum state, and flowing the intermediate helium which is not completely adsorbed in the adsorber in the saturated state into the adsorber in the vacuum state, so that the adsorber in the vacuum state enters a semi-charge state;

[0010] vacuumizing the adsorber in the saturated state, and reheating the adsorber to discharge the impurities in the adsorber, so that the adsorber in the saturated state enters a vacuum state;

[0011] injecting the refined helium into the adsorber in the half-pressurized state until pressurized to a preset pressure range, so as to make the adsorber enter a state of being ready for adsorption;

[0012] returning to performing the step of continuously adsorbing until the adsorber of the purification adsorption device is filled with impurities and enters a saturated state, until all the helium purification is completed.

[0013] Preferably, the step of purifying the crude helium by the adsorber in the state of being ready for adsorption to form refined helium and outputting includes:

[0014] cooling the crude helium at room temperature;

[0015] inputting the cooled crude helium into the adsorber in the state of being ready for adsorption, wherein the temperature of the adsorber is lower than the room temperature;

[0016] the adsorber adsorbs impurities in the crude helium to form refined helium;

[0017] outputting the refined helium after being warmed to the room temperature.

[0018] Preferably, the step of continuously purifying adsorption until the adsorber is filled with impurities and enters a saturated state includes:

[0019] the adsorber continuously purifies the crude helium to form refined helium;

[0020] detecting the purity of helium in the refined helium, and determining that the adsorber enters a saturated state when the purity of helium in the refined helium is lower than a preset purity range.

[0021] Preferably, the preset pressure range is 2.0 Mpa-2.5 Mpa.

[0022] To achieve the above-mentioned purposes, the present application also provides a helium purification system applied to the above-mentioned helium purification method, the helium purification system includes at least three sets of purification adsorption devices, the purification adsorption device includes a shell, a heat exchanger and an adsorber, the adsorbers of the at least three sets of purification adsorption devices are all communicated with each other, the shell is filled with cooling liquid, the heat exchanger and the adsorber are both installed in the shell and communicated with each other, the heat exchanger is used for cooling the crude helium and warming the refined helium, and the cooling liquid is used for cooling the heat exchanger and the adsorber.

[0023] Preferably, at least three sets of the purification adsorption devices are connected in parallel on a helium gas inlet pipeline and input the crude helium gas through the helium gas inlet pipeline, at least three sets of the purification adsorption devices are connected in parallel on a helium gas outlet pipeline and output the refined helium gas through the helium gas outlet pipeline, a helium gas inlet valve is arranged between the helium gas inlet pipeline and each of the purification adsorption devices, and a helium gas outlet valve is arranged between the helium gas outlet pipeline and each of the purification adsorption devices.

[0024] Preferably, a pressurizing pipeline is further connected in parallel on the helium gas outlet pipeline, each of the adsorbers is communicated with the pressurizing pipeline, and a pressurizing valve is arranged between the pressurizing pipeline and each of the adsorbers.

[0025] Preferably, any two of the adsorbers are communicated through an equalizing pipeline, and an equalizing valve and a first flow adjusting valve are arranged on the equalizing pipeline.

[0026] Preferably, at least three sets of the adsorbers are connected in parallel on a reheating inlet pipeline and input normal-temperature nitrogen gas through the reheating inlet pipeline, at least three sets of the adsorbers are connected in parallel on a reheating outlet pipeline and output low-temperature nitrogen gas through the reheating outlet pipeline, the normal-temperature nitrogen gas is used for reheating the adsorbers in the saturated state, a reheating inlet valve is arranged between the reheating inlet pipeline and each of the adsorbers, and a reheating outlet valve is arranged between the reheating outlet pipeline and each of the adsorbers.

[0027] Preferably, each of the adsorbers is connected in parallel on a waste gas outlet pipeline, and a waste gas outlet valve is arranged between the waste gas outlet pipeline and each of the adsorbers.

[0028] In the technical scheme of the present application, the crude helium is purified by adsorption through an adsorber in a state of being ready to be adsorbed, the adsorber is replaced by another adsorber in a state of being ready to be adsorbed after being saturated, then the saturated adsorber is communicated with an adsorber in a state of being in vacuum to equalize pressure, there is intermediate helium not completely adsorbed in the saturated adsorber, part of the intermediate helium is caused to flow into the adsorber in a state of being in vacuum through equalization of pressure to make the adsorber enter a semi-charge state, then the adsorber after equalization of pressure is vacuumized and reheated, impurity gas in the adsorber is caused to be precipitated through low pressure and high temperature, so that the adsorber can be used again, the adsorber in a semi-charge state is pressurized to a preset pressure range to make it enter a state of being ready to be adsorbed, the purification precision of helium is improved under the preset pressure range, the purified helium has a higher concentration, the adsorber can be used to replace another adsorber entering a saturated state for purification, and the adsorber in a state of being in vacuum in the present cycle can be used to equalize pressure for another adsorber entering a saturated state. The present application communicates adsorbers in different states and uses them cyclically, so that helium can be continuously purified through at least three adsorbers without waiting for replacement of adsorbers, thereby improving the purification efficiency of helium; meanwhile, the intermediate helium not completely adsorbed is recovered and reused through equalization of pressure between the saturated adsorber and the adsorber in a state of being in vacuum, thereby reducing the discharge of helium and improving the yield of helium. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on the drawings shown.

[0030] FIG. 1 The flowchart of the helium purification method of an embodiment of the present application;

[0031] FIG. 2 The detailed flowchart of step S100 of the helium purification method of an embodiment of the present application;

[0032] FIG. 3 The pipeline schematic diagram of the helium purification system of an embodiment of the present application.

[0033] Explanation of reference numerals:

[0034] Reference Name Reference Name 1 Helium purification system 31 Pressurization valve 10 Purification adsorption device 40 Pressure equalization line 11 Housing 41 Pressure equalization valve 12 Heat exchanger 42 First flow rate adjustment valve 13 Adsorber 50 Reheating intake line 20 Helium intake line 51 Reheating intake valve 21 Helium intake valve 60 Reheating exhaust line 22 Helium exhaust line 61 Reheating exhaust valve 23 Helium exhaust valve 70 Exhaust gas exhaust line 30 Pressurization line 71 Exhaust gas exhaust valve

[0035] The purposes, functional features and advantages of the present application will be further illustrated with reference to the embodiments and the drawings. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments will be described clearly and completely below in combination with the drawings in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0037] It should be noted that all the directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directionality indications also change accordingly.

[0038] In addition, the descriptions such as “first”, “second” and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as “first”, “second” can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of “plurality” is at least two, such as two, three, etc., unless otherwise specifically limited.

[0039] In the present application, unless otherwise specifically defined and limited, the terms “connection”, “fixation” and the like should be understood broadly, for example, “fixation” can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0040] In addition, the technical solutions of each embodiment of the present application can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor is it within the protection scope required by the present application. It should be understood that the specific embodiments described herein are only used to explain the present application, and not to limit the present application.

[0041] The present application provides a helium gas purification method.

[0042] Please refer to FIG. 1 The helium gas purification method of the present embodiment comprises the following steps:

[0043] S100: Purifying and adsorbing the crude helium gas through an adsorber in a state of being ready to be adsorbed to form refined helium gas and output;

[0044] The impurity gas does not exist in the adsorber 13 in the state of waiting for adsorption, and the adsorber 13 is in a low-temperature state and has a pressure in a preset pressure range, which is higher than the atmospheric pressure, so that the adsorber 13 can easily adsorb the large impurity gas in the helium gas;

[0045] S200: continuously purifying and adsorbing until the adsorber is filled with impurities and enters a saturated state;

[0046] The crude helium gas is continuously purified and adsorbed by the adsorber 13 until the adsorber 13 cannot effectively purify the crude helium gas and enters a saturated state;

[0047] S300: purifying and adsorbing the crude helium gas by another adsorber in a state of waiting for adsorption;

[0048] The crude helium gas is input into another adsorber 13 in a state of waiting for adsorption, and the purification and adsorption of the crude helium gas are continued;

[0049] S400: connecting the adsorber in the saturated state with an adsorber in a vacuum state, and uniformly flowing the intermediate helium gas not completely adsorbed in the adsorber in the saturated state to the adsorber in the vacuum state, so that the adsorber in the vacuum state enters a semi-charge state;

[0050] The adsorber 13 in the saturated state obtained in step S200 is connected with an adsorber 13 without impurities but in a vacuum state to continue the pressure equalization. It can be understood that the adsorber 13 in the saturated state contains part of the intermediate helium gas not completely adsorbed. The purity of this part of the intermediate helium gas does not meet the requirements of the refined helium gas, but it is still higher than that of the crude helium gas. The difficulty of its secondary purification is lower than that of the crude helium gas. Therefore, uniformly flowing it to the adsorber 13 in the vacuum state not only can improve the purification efficiency of the helium gas, but also can reduce the emission of the helium gas and improve the yield of the helium gas;

[0051] S500: vacuumizing the adsorber in the saturated state and reheating the adsorber to discharge the impurities in the adsorber, so that the adsorber in the saturated state enters a vacuum state;

[0052] The adsorber 13 in the saturated state after the uniform flow in step S400 is vacuumized, and the adsorber 13 is reheated to facilitate the discharge of the impurity gas in the adsorber 13. After the discharge, the adsorber 13 in the saturated state enters a vacuum state without impurities;

[0053] S600: injecting the refined helium gas into the adsorber in the semi-charge state until the pressure is increased to a preset pressure range, so that the adsorber enters a state of waiting for adsorption;

[0054] In step S400, the semi-vacuum adsorber 13 formed by the vacuum state adsorber 13 after equalization is injected with refined helium gas until the pressure reaches the preset pressure range to enter the adsorption state, and the adsorber 13 is cleaned and can be directly used for purification adsorption;

[0055] S700: return to step S200 until all the helium gas purification is completed.

[0056] After waiting for the adsorber 13 in step S300 to enter the saturated state, the adsorber 13 in step S300 repeats the essence process of the adsorber 13 in step S100, and the adsorber 13 is continuously circulated, so that the helium gas can be continuously purified to improve the purification efficiency.

[0057] In the technical scheme of the present application, one adsorber 13 in the adsorption state is used to purify the crude helium gas, and after the adsorption reaches the saturated state, another adsorber 13 in the adsorption state is replaced, and then the saturated adsorber 13 is communicated with a vacuum adsorber 13 for equalization. There is intermediate helium gas that is not completely adsorbed in the saturated adsorber 13, and part of the intermediate helium gas is evenly flowed into the vacuum adsorber 13 through equalization to make it enter the semi-charge state, and then the adsorber 13 after equalization is vacuumized and reheated, and the impurity gas in the adsorber 13 is precipitated through low pressure and high temperature, so that the adsorber 13 can be used again. At the same time, the adsorber 13 in the semi-charge state is pressurized to the preset pressure range to make it enter the adsorption state, and under the preset pressure range, the purification accuracy of the helium gas is improved, and the concentration of the purified helium gas is higher. The adsorber 13 at this time can be used to replace the next adsorber 13 that enters the saturated state for purification adsorption, and the vacuum adsorber 13 in this cycle can be used for equalization of the next adsorber 13 that enters the saturated state. The present application communicates and circulates the adsorbers 13 in different states, so that at least three adsorbers 13 can realize uninterrupted circulation of the helium gas, without waiting for replacement of the adsorbers 13, thereby improving the purification efficiency of the helium gas. During the adsorption and regeneration switching process of the at least three adsorbers 13, equalization, reheating and other operations are realized to achieve high yield of helium gas purification. The adsorber is adsorbed at low temperature, regenerated after reheating, pressure reduction and vacuumization, and the regeneration effect is optimal. At the same time, the saturated adsorber 13 and the vacuum adsorber 13 are equalized to recover and reuse the intermediate helium gas that is not completely adsorbed, reduce the discharge of helium gas, and improve the yield of helium gas.

[0058] In a specific embodiment, the number of adsorbers 13 is three, and the three adsorbers 13 are respectively a first adsorber 13, a second adsorber 13 and a third adsorber 13. The first adsorber 13 and the second adsorber 13 are in the adsorption standby state, and the third adsorber 13 is in the vacuum state. The first adsorber 13 first performs helium purification adsorption until the first adsorber 13 enters the saturated state. At this time, the second adsorber 13 is switched to perform purification adsorption on helium. The first adsorber 13 is first pressure-equalized with the third adsorber 13, and the third adsorber 13 enters the semi-charge pressure state. Then, the first adsorber 13 is vacuumized and reheated to enter the vacuum state, and the impurity gas in the first adsorber 13 is discharged. Then, the third adsorber 13 is pressurized to enter the adsorption standby state. After the second adsorber 13 also adsorbs and enters the saturated state, the third adsorber 13 is replaced to perform purification adsorption. The second adsorber 13 is pressure-equalized with the first adsorber 13, and the second adsorber 13 is vacuumized and reheated to enter the vacuum state. The first adsorber 13 is pressurized to enter the adsorption standby state. In this way, through the circulation of the minimum three adsorbers 13, the purification efficiency of helium is greatly improved.

[0059] It can be understood that the number of adsorbers 13 can be multiple, but there should always be at least one in the adsorption standby state. Before the first adsorber in the adsorption standby state is saturated, one adsorber is in the adsorption standby state (i.e., after regeneration by vacuumization and pressurization through reheating during the adsorption process of the first adsorber in the adsorption standby state), and one is in the vacuum state to ensure uninterrupted operation of helium purification.

[0060] Please refer to FIG. 2 In an embodiment, step S100 includes:

[0061] S110: cooling the crude helium gas at room temperature;

[0062] The crude helium gas is usually at room temperature when output, and needs to be cooled to improve the adsorption efficiency;

[0063] S120: inputting the cooled crude helium gas into the adsorber in the adsorption standby state, wherein the temperature of the adsorber is lower than the room temperature;

[0064] It can be understood that the cooling liquid is generally liquid nitrogen, so the temperature of the adsorber is the temperature of the liquid nitrogen;

[0065] S130: the adsorber adsorbs the impurities in the crude helium gas to form refined helium gas;

[0066] S140: outputting the refined helium gas after being warmed to room temperature.

[0067] The crude helium gas is cooled to low temperature, the adsorption efficiency and adsorption capacity of the adsorber 13 can be improved under the low temperature environment, thereby improving the purification effect of the crude helium gas, and the refined helium gas needs to be increased to normal temperature when output, thereby reducing the pressure loss in the output process, and the safety problem can be avoided.

[0068] Further, the step S200 comprises:

[0069] S210: The adsorber continuously purifies the crude helium gas to form refined helium gas;

[0070] S220: Detect the purity of helium in the refined helium gas, and when the purity of helium in the refined helium gas is lower than the preset range, it is judged that the adsorber enters the saturated state.

[0071] By detecting the concentration of helium in the refined helium gas, the adsorption of the adsorber 13 to impurities is judged, so that the adsorber 13 can be replaced in time, and the purification concentration of the refined helium gas is improved.

[0072] Specifically, the preset pressure range is 2.0Mpa-2.5Mpa. Under the pressure of 2.0Mpa-2.5Mpa, the adsorption efficiency and adsorption capacity of the adsorber 13 can be improved, thereby improving the purification effect of the crude helium gas.

[0073] Understandably, the adsorbent in the adsorber 13 can be carbon.

[0074] To achieve the above purpose, the application also provides a helium purification system 1 applied to the above-mentioned helium purification method, the helium purification system 1 comprises at least three sets of purification adsorption devices 10, the purification adsorption device 10 comprises a shell 11, a heat exchanger 12 and an adsorber 13, the adsorbers 13 of the at least three sets of purification adsorption devices 10 are communicated with each other, the shell 11 is filled with cooling liquid, the heat exchanger 12 and the adsorber 13 are installed in the shell 11 and communicated with each other, the heat exchanger 12 is used for cooling the crude helium gas and heating the refined helium gas, and the cooling liquid is used for cooling the heat exchanger 12 and the adsorber 13.

[0075] Specifically, the cooling liquid is liquid nitrogen, the heat exchanger 12 and the adsorber 13 are immersed in the cooling liquid to keep low temperature, the crude helium gas enters the shell 11 first passes through the heat exchanger 12 to be cooled, the pressure in the adsorber 13 is kept in a preset pressure range, under the condition of low temperature and high pressure, the impurity gas is more easily absorbed by the adsorbent in the adsorber 13, the refined helium gas after purification passes through the heat exchanger 12 again to be warmed to normal temperature and is output to the external collecting device, at least three sets of the purification adsorption devices 10 are used alternately, the adsorbers 13 of the three sets of the purification adsorption devices 10 are in different adsorption states and are used cyclically, so that the helium gas can be purified continuously by using at least three adsorbers 13 without waiting for replacement of the adsorber 13, thereby improving the purification efficiency of the helium gas; meanwhile, the adsorber 13 in the saturated state and the adsorber 13 in the vacuum state are pressure equalized, the intermediate helium gas which is not completely adsorbed is recycled and reused, the helium gas emission is reduced, and the helium gas yield is improved.

[0076] In an embodiment, at least three sets of the purification adsorption devices 10 are connected in parallel on the helium gas inlet pipeline 20 and input the crude helium gas through the helium gas inlet pipeline 20, at least three sets of the purification adsorption devices 10 are connected in parallel on the helium gas outlet pipeline 22 and output the refined helium gas through the helium gas outlet pipeline 22, the helium gas inlet pipeline 20 is provided with a helium gas inlet valve 21 between each purification adsorption device 10, and the helium gas outlet pipeline 22 is provided with a helium gas outlet valve 23 between each purification adsorption device 10. At least three sets of the purification adsorption devices 10 are connected in parallel on the helium gas outlet pipeline 22 and the helium gas inlet pipeline 20, when the corresponding helium gas outlet valve 23 and the helium gas inlet valve 21 of one set of the purification adsorption devices 10 are opened, the adsorber 13 of the set of the purification adsorption devices 10 is purified and adsorbed, when the adsorber 13 is saturated, the corresponding helium gas outlet valve 23 and the helium gas inlet valve 21 are disconnected, and the helium gas outlet valve 23 and the helium gas inlet valve 21 corresponding to another adsorber 13 in the adsorption state are opened to realize seamless switching, so that the helium gas is continuously purified and the purification efficiency of the helium gas is improved.

[0077] In an embodiment, a pressurizing pipeline 30 is further connected in parallel on the helium gas outlet pipeline 22, each adsorber 13 is communicated with the pressurizing pipeline 30, and a pressurizing valve 31 is arranged between the pressurizing pipeline 30 and each adsorber 13. When the adsorber 13 in the half-charged state needs to be pressurized, the corresponding pressurizing valve 31 is only opened to realize pressurization without external connection of the pressurizing pipeline 30, so that the structure is simplified.

[0078] Further, any two adsorbers 13 are communicated through an equalizing pipeline 40, and the equalizing pipeline 40 is provided with an equalizing valve 41 and a first flow regulating valve 42. When the adsorber 13 in the saturated state and the adsorber 13 in the vacuum state need to be equalized, the equalizing valve 41 between the two is opened, and the flow is regulated through the first flow regulating valve 42, which simplifies the equalizing process, improves the equalizing efficiency, and enables the adsorber 13 in the vacuum state to enter the adsorption state after being rapidly equalized and pressurized, so as to prevent the purification of helium from being interrupted and improve the purification efficiency.

[0079] In an embodiment, at least three sets of adsorbers 13 are connected in parallel to a reheating gas inlet pipeline 50 and input normal-temperature nitrogen gas through the reheating gas inlet pipeline 50, and at least three sets of adsorbers 13 are connected in parallel to a reheating gas outlet pipeline 60 and output low-temperature nitrogen gas through the reheating gas outlet pipeline 60. The normal-temperature nitrogen gas is used to reheat the adsorber 13 in the saturated state, and the reheating gas inlet pipeline 50 and each adsorber 13 are provided with a reheating gas inlet valve 51, and the reheating gas outlet pipeline 60 and each adsorber 13 are provided with a reheating gas outlet valve 61. The adsorber 13 is reheated by the normal-temperature nitrogen gas, which is low in cost. When the adsorbent in the adsorber 13 is activated carbon, nitrogen gas is an inert gas and does not react with activated carbon, so that the activated carbon is not contaminated with impurity gas during the reheating process. Nitrogen gas is also an environmentally friendly gas, and its emission will not affect the environment.

[0080] Further, each adsorber 13 is connected in parallel to a waste gas outlet pipeline 70, and the waste gas outlet pipeline 70 and each adsorber 13 are provided with a waste gas outlet valve 71. When the adsorber 13 is reheated, the impurity gas in the adsorber 13 is precipitated, and only the waste gas outlet valve 71 corresponding to the adsorber 13 needs to be opened, and then the adsorber 13 can be depressurized and vacuumized through the waste gas outlet pipeline 70, which is simple and fast and improves the depressurization efficiency.

[0081] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent flow conversion, or direct or indirect application in other related technical fields, which is based on the content of the specification and drawings of the present application, is also included in the patent protection scope of the present application.

Claims

1. A method of purifying helium gas, characterized by, The method is realized by an ammonia purification system, the ammonia purification system comprises at least three sets of purification adsorption devices, and the at least three sets of purification adsorption devices are in different adsorption states, wherein the adsorption states comprise a saturated state, a standby adsorption state and a half-charge state, and the ammonia purification method comprises the following steps: purifying and adsorbing the crude helium gas by an adsorber in the standby adsorption state to form refined helium gas and outputting the refined helium gas; continuously purifying and adsorbing until the adsorber is filled with impurities and enters the saturated state; purifying and adsorbing the crude helium gas by another adsorber in the standby adsorption state; communicating the adsorber in the saturated state with an adsorber in a vacuum state, and uniformly flowing the intermediate helium gas that is not completely adsorbed in the adsorber in the saturated state to the adsorber in the vacuum state, so that the adsorber in the vacuum state enters the half-charge state, wherein the purity of the intermediate helium gas is higher than that of the crude helium gas; vacuumizing the adsorber in the saturated state, and re-heating the adsorber to discharge the impurities in the adsorber, so that the adsorber in the saturated state enters the vacuum state; injecting the refined helium gas into the adsorber in the half-charge state until the pressure is increased to a preset pressure range, so that the adsorber enters the standby adsorption state; returning to the step of continuously adsorbing until the adsorbers of the purification adsorption devices are filled with impurities and enter the saturated state, until the helium gas purification is completed.

2. The helium purification method of claim 1, wherein, The step of purifying and adsorbing the crude helium gas by an adsorber in the standby adsorption state to form refined helium gas and outputting the refined helium gas comprises: cooling the crude helium gas at room temperature; inputting the cooled crude helium gas into the adsorber in the standby adsorption state, wherein the temperature of the adsorber is lower than the room temperature; the adsorber adsorbs the impurities in the crude helium gas to form refined helium gas; outputting the refined helium gas after being warmed to room temperature.

3. The helium purification method of claim 1, wherein, The step of continuously purifying and adsorbing until the adsorber is filled with impurities and enters the saturated state comprises: the adsorber continuously purifies and adsorbs the crude helium gas to form refined helium gas; detecting the purity of helium in the refined helium gas, and determining that the adsorber enters the saturated state when the purity of helium in the refined helium gas is lower than a preset purity range.

4. The helium purification method of claim 1, wherein, The preset pressure range is 2.0Mpa~2.5Mpa.

5. A helium purification system, characterized by, The helium purification system is applied to the helium purification method in any one of claims 1-4, and the helium purification system comprises at least three sets of purification adsorption devices, the purification adsorption device comprises a shell, a heat exchanger and an adsorber, the adsorbers of the at least three sets of purification adsorption devices are communicated with each other, the shell is filled with cooling liquid, the heat exchanger and the adsorber are installed in the shell and are communicated with each other, the heat exchanger is used for cooling the crude helium gas and warming the refined helium gas, and the cooling liquid is used for cooling the heat exchanger and the adsorber.

6. The helium purification system of claim 5, wherein, At least three sets of the purification adsorption devices are connected in parallel on a helium gas inlet pipeline and input the crude helium gas through the helium gas inlet pipeline, at least three sets of the purification adsorption devices are connected in parallel on a helium gas outlet pipeline and output the refined helium gas through the helium gas outlet pipeline, a helium gas inlet valve is arranged between the helium gas inlet pipeline and each of the purification adsorption devices, and a helium gas outlet valve is arranged between the helium gas outlet pipeline and each of the purification adsorption devices.

7. The helium purification system of claim 6, wherein, A pressurizing pipeline is further connected in parallel on the helium gas outlet pipeline, each of the adsorbers is communicated with the pressurizing pipeline, and a pressurizing valve is arranged between the pressurizing pipeline and each of the adsorbers.

8. The helium purification system of claim 5, wherein, Any two of the adsorbers are communicated through an equalizing pipeline, and an equalizing valve and a first flow adjusting valve are arranged on the equalizing pipeline.

9. The helium purification system of claim 5, wherein, At least three sets of the adsorbers are connected in parallel on a reheating gas inlet pipeline and input normal-temperature nitrogen gas through the reheating gas inlet pipeline, and at least three sets of the adsorbers are connected in parallel on a reheating gas outlet pipeline and output low-temperature nitrogen gas through the reheating gas outlet pipeline, the normal-temperature nitrogen gas is used for reheating the adsorbers in the saturated state, a reheating gas inlet valve is arranged between the reheating gas inlet pipeline and each of the adsorbers, and a reheating gas outlet valve is arranged between the reheating gas outlet pipeline and each of the adsorbers.

10. The helium purification system of claim 5, wherein, Each of the adsorbers is connected in parallel on a waste gas outlet pipeline, and a waste gas outlet valve is arranged between the waste gas outlet pipeline and each of the adsorbers.

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