Trace impurity purification system

Abstract

According to the trace impurity purification system provided by the invention, during purification of the first adsorber, helium passes through the second pneumatic control valve, the first adsorber and the pneumatic switch valve, and during regeneration of the first adsorber, the second pneumatic control valve and the third pneumatic switch valve are closed; high-pressure normal-temperature helium enters the first heat exchanger through the first pneumatic control valve and the second pneumatic switch valve, and enters the helium low-temperature system low-pressure pipeline after being subjected to heat exchange through the first heat exchanger. Low-temperature and high-pressure helium in the first adsorber enters a third heat exchanger through a sixth pneumatic switch valve and then enters a helium recovery air bag through a fifth pneumatic control valve, the vacuum pump performs vacuum extraction, according to the logic, when the second adsorber works, the first adsorber regenerates, and the operation is repeated, so that the helium is recovered. Automatic control over trace impurity purification, purification system regeneration switching and the like is achieved, automatic continuous operation of a large helium low-temperature system can be achieved, and the automation degree of the system is improved.

Description

Technical Field

[0001] The present application relates to the field of low-temperature refrigeration and adsorption technology, and in particular to a trace impurity purification system. Background Art

[0002] Since the beginning of the 20th century, advances in science and technology have led to the development of low-temperature superconducting technology. This technology is inseparable from large-scale helium cryogenic systems, with the two complementing and promoting each other. Helium purity is a crucial factor in ensuring reliable operation in these large-scale helium cryogenic systems. Therefore, 80K and 10K adsorbers are typically installed in helium cryogenic systems to adsorb trace amounts of impurities such as nitrogen, oxygen, argon, hydrogen, and neon from high-purity helium. Once the adsorbers are saturated with impurity gases, reactivation and regeneration of the adsorbate are essential to ensure continued operation of the large-scale helium cryogenic system.

[0003] Traditional large-scale helium cryogenic systems, especially cryogenic refrigeration systems, generally employ a closed cycle, while liquefaction systems generally employ an open cycle. In a closed cycle, after purification, other impurities in the circulating helium are almost negligible. For long-term helium refrigeration systems, a single purification system (adsorber) can meet these requirements, eliminating the need for a switchover system. Regeneration of the purification system can be scheduled during a complete system overhaul. Therefore, automated control of the purification system's regeneration is not an issue. For long-term, continuous open-cycle operation, which requires constant replenishment of high-purity helium that meets national standards, a switchover trace impurity purification system (adsorber) is essential. However, regeneration can be scheduled during system overhauls or occasionally performed manually during online operation, eliminating the need for automated control. In natural gas helium extraction projects, high-purity helium from refining plants sometimes fails to meet national standards. Therefore, automated control systems for switchover trace impurity purification and regeneration of the purification system (adsorber) are particularly important in these continuously automated natural gas helium extraction projects. Summary of the Invention

[0004] In view of this, it is necessary to provide an automated trace impurity purification system that can realize continuous operation of a large helium cryogenic system to address the current technical problem of low degree of automatic control of trace impurity purification and purification system (adsorber) regeneration.

[0005] To solve the above problems, this application adopts the following technical solutions:

[0006] One of the purposes of this application is to provide a trace impurity purification system, comprising:

[0007] A first adsorber (AD1), a second adsorber (AD2), a pneumatic regulating valve (CV04) provided at the air inlet of the first adsorber (AD1), a pneumatic switch valve (CV05) provided at the air outlet of the first adsorber (AD1), a pneumatic regulating valve (CV06) provided at the air inlet of the second adsorber (AD2), a pneumatic switch valve (CV07) provided at the air outlet of the second adsorber (AD2), a first pneumatic regulating valve (CV01), a second pneumatic regulating valve (CV04), a third pneumatic regulating valve (CV05), and a pneumatic regulating valve (CV06) provided at the air inlet of the second adsorber (AD2). a throttle valve (CV06), a fourth pneumatic regulating valve (CV10), a fifth pneumatic regulating valve (CV11), a first pneumatic switch valve (CV02), a second pneumatic switch valve (CV03), a third pneumatic switch valve (CV05), a fourth pneumatic switch valve (CV07), a fifth pneumatic switch valve (CV08), and a sixth pneumatic switch valve (CV09); one end of the fourth pneumatic regulating valve (CV10) is connected to a vacuum pump and the other end is connected to the third heat exchanger (HEX03) for vacuum extraction by the vacuum pump;

[0008] When the first adsorber (AD1) is purified, helium passes through the second pneumatic regulating valve (CV04), the first adsorber (AD1), and the pneumatic switch valve (CV05). When the first adsorber (AD1) is regenerated, the second pneumatic regulating valve (CV04) and the third pneumatic switch valve (CV05) are closed, and high-pressure and room-temperature helium passes through the first pneumatic regulating valve (CV01) and the second pneumatic switch valve (CV03) into the first heat exchanger (HEX01). After heat exchange in the first heat exchanger (HEX01), it enters the low-pressure pipeline of the helium cryogenic system. The low-temperature and high-pressure helium in the first adsorber (AD1) enters the third heat exchanger (HEX03) through the sixth pneumatic switch valve (CV09), and then enters the helium recovery bag through the fifth pneumatic regulating valve (CV11). One end of the fourth pneumatic regulating valve (CV10) is connected to the vacuum pump and the other end is connected to the third heat exchanger (HEX03) for vacuum extraction by the vacuum pump.

[0009] When the second adsorber (AD2) is purified, helium passes through the third pneumatic control valve (CV06), the second adsorber (AD2), and the pneumatic switch valve (CV07). When the second adsorber (AD2) is regenerated, the third pneumatic control valve (CV06) and the pneumatic switch valve (CV07) are closed, and high-pressure and room-temperature helium passes through the first pneumatic control valve (CV01) and the first pneumatic switch valve (CV02) into the second heat exchanger (HEX02). After heat exchange in the second heat exchanger (HEX02), it enters the low-pressure pipeline of the helium cryogenic system. The low-temperature and high-pressure helium in the second adsorber (AD2) passes through the fifth pneumatic switch valve (CV08) into the third heat exchanger (HEX03), and then passes through the fifth pneumatic control valve (CV11) into the helium recovery bag. One end of the fourth pneumatic control valve (CV10) is connected to the vacuum pump, and the other end is connected to the third heat exchanger (HEX03) for vacuum extraction by the vacuum pump.

[0010] In some embodiments, the invention further comprises a compressor (110), a heat exchanger group (120) composed of a plurality of heat exchangers connected in series, a turbine expander group (130) and a liquid helium dewar (140), one end of the compressor (110) is connected to one end of the heat exchanger group (120) through a pipeline, the other end of the compressor (110) is connected to the liquid helium dewar (140) through a pipeline, and the liquid helium dewar (140) is connected to the other end of the heat exchanger group (120) through a pipeline, and the turbine expander group (130) is arranged on the pipeline.

[0011] In some embodiments, the heat exchanger group (120) is composed of a plurality of heat exchangers connected in series.

[0012] In some embodiments, the turboexpander assembly (130) is composed of two turboexpanders connected in series.

[0013] In some embodiments, a first low-temperature thermometer (T1) and a second low-temperature thermometer (T2) are respectively provided on the first adsorber (AD1) and the second adsorber (AD2).

[0014] In some embodiments, a pressure sensor (P1) is further provided on the pipeline between the second pneumatic regulating valve (CV04) and the first adsorber (AD1).

[0015] In some embodiments, a pressure sensor (P2) is further provided on the pipeline between the third pneumatic regulating valve (CV06) and the second adsorber (AD2).

[0016] This application adopts the above technical solution, and its beneficial effects are as follows:

[0017] The trace impurity purification system provided by the present application is as follows: when the first adsorber (AD1) is purified, helium passes through the second pneumatic regulating valve (CV04), the first adsorber (AD1) and the pneumatic switch valve (CV05); when the first adsorber (AD1) is regenerated, the second pneumatic regulating valve (CV04) and the third pneumatic switch valve (CV05) are closed, and high-pressure and room-temperature helium passes through the first pneumatic regulating valve (CV01) and the second pneumatic switch valve (CV03) into the first heat exchanger (HEX01); after heat exchange in the first heat exchanger (HEX01), the helium enters the low-pressure pipeline of the helium cryogenic system. The low-temperature, high-pressure helium in the first adsorber (AD1) then enters the third heat exchanger (HEX03) through the sixth pneumatic on / off valve (CV09), and then enters the helium recovery bag through the fifth pneumatic control valve (CV11). The fourth pneumatic control valve (CV10) is connected to the vacuum pump at one end and the third heat exchanger (HEX03) at the other end for vacuum extraction by the vacuum pump. According to the aforementioned logic, when the second adsorber (AD2) is operating, the first adsorber (AD1) is regenerating, and this cycle repeats, achieving automatic control of trace impurity purification and regeneration switching of the purification system (adsorber). This enables automatic and continuous operation of a large helium cryogenic system, improving the system's level of automation. A vaporizer, HEX03, is installed in the regeneration pipeline for the low-temperature helium in the main adsorber portion, eliminating the need for an electrically heated heater, reducing power consumption and improving system reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 A schematic structural diagram of a trace impurity purification system provided in one embodiment of the present invention.

[0020] Figure 2 A schematic diagram of an adsorber regeneration control interface provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0022] In the description of this application, it should be understood that the terms "upper", "lower", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on this application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0024] In order to make the purpose, technical solutions and advantages of this application more clear, this application is further described in detail below with reference to the accompanying drawings and embodiments.

[0025] See also Figure 1 The embodiment of the present application provides a trace impurity purification system, comprising: a first adsorber (AD1), a second adsorber (AD2), a pneumatic regulating valve (CV04) provided at the air inlet of the first adsorber (AD1), a pneumatic switch valve (CV05) provided at the air outlet of the first adsorber (AD1), a pneumatic regulating valve (CV06) provided at the air inlet of the second adsorber (AD2), a pneumatic switch valve (CV07) provided at the air outlet of the second adsorber (AD2), a first pneumatic regulating valve (CV01), a second pneumatic regulating valve ( CV04), a third pneumatic regulating valve (CV06), a fourth pneumatic regulating valve (CV10), a fifth pneumatic regulating valve (CV11), a first pneumatic switch valve (CV02), a second pneumatic switch valve (CV03), a third pneumatic switch valve (CV05), a fourth pneumatic switch valve (CV07), a fifth pneumatic switch valve (CV08), a sixth pneumatic switch valve (CV09), one end of the fourth pneumatic regulating valve (CV10) is connected to a vacuum pump and the other end is connected to the third heat exchanger (HEX03) for vacuum extraction through the vacuum pump.

[0026] When the first adsorber (AD1) is purified, the helium passes through the second pneumatic regulating valve (CV04), the first adsorber (AD1) and the pneumatic switch valve (CV05); when the first adsorber (AD1) is regenerated, the second pneumatic regulating valve (CV04) and the third pneumatic switch valve (CV05) are closed, and the high-pressure and room-temperature helium passes through the first pneumatic regulating valve (CV01) and the second pneumatic switch valve (CV03) into the first heat exchanger (HEX01), and after heat exchange in the first heat exchanger (HEX01), enters the low-pressure pipeline of the helium cryogenic system; the low-temperature and high-pressure helium in the first adsorber (AD1) then passes through the sixth pneumatic switch valve (CV09) into the third heat exchanger (HEX03), and then passes through the fifth pneumatic regulating valve (CV11) into the helium recovery bag; one end of the fourth pneumatic regulating valve (CV10) is connected to the vacuum pump and the other end is connected to the third heat exchanger (HEX03) for vacuum extraction by the vacuum pump;

[0027] When the second adsorber (AD2) is being purified, helium passes through the third pneumatic regulating valve (CV06), the second adsorber (AD2), and the pneumatic switch valve (CV07). When the second adsorber (AD2) is being regenerated, the third pneumatic regulating valve (CV06) and the pneumatic switch valve (CV07) are closed, and high-pressure, room-temperature helium passes through the first pneumatic regulating valve (CV01) and the first pneumatic switch valve (CV02) into the second heat exchanger (HEX02). After heat exchange in the second heat exchanger (HEX02), the helium enters the low-pressure pipeline of the helium cryogenic system. The low-temperature, high-pressure helium in the second adsorber (AD2) then passes through the fifth pneumatic switch valve (CV08) into the third heat exchanger (HEX03), and then passes through the fifth pneumatic regulating valve (CV11) into the helium recovery bag. One end of the fourth pneumatic regulating valve (CV10) is connected to the vacuum pump, and the other end is connected to the third heat exchanger (HEX03) for vacuum extraction by the vacuum pump.

[0028] Specifically, during the purification process, when AD1 is operating, pneumatic control valve CV04 and pneumatic on / off valve CV05 are fully open. Simultaneously, outlet pneumatic on / off valve CV07 of adsorber AD2 is fully open, while inlet pneumatic control valve CV06 is slightly opened, approximately 4%, to achieve continuous pre-cooling of adsorber AD2. During operation of the helium cryogenic system, adsorbers AD1 and AD2 cannot be regenerated simultaneously.

[0029] See also Figure 2Figure 1 is a schematic diagram of the adsorber regeneration control interface provided in this embodiment. First, set the adsorber regeneration interval to 100 hours on the adsorber regeneration control interface. When adsorber regeneration is reached, adsorber AD1 automatically regenerates, the regeneration button becomes pressed, and the "Regeneration" and "Regeneration End" buttons change color. Slowly open CV06 to 100% opening. Simultaneously, slowly close CV04 to an opening of 0%. When CV04 reaches 0%, immediately open pneumatic switch valve CV09 and pneumatic control valve CV11 to approximately 8% opening. Then, slowly increase the opening of CV11 until the pressure P1 of adsorber AD1 reaches 2-3 bara. Simultaneously, open pneumatic switch valve CV03 and slowly open pneumatic control valve CV01, while adjusting CV11 to maintain the pressure of adsorber AD1 at 2-3 bara. Note adsorber AD1's temperature T1. When T1 is around 100K, close CV01 and CV03. Slowly adjust the opening of CV11 until the pressure in adsorber AD1 no longer fluctuates. At the same time, turn on the vacuum pump, close CV11, and open CV10. Continue to draw the vacuum for about 40 minutes. Turn off CV10 and the vacuum pump. Open CV04 to about 4% opening, and when the pressure of adsorber AD1 reaches atmospheric pressure, close CV08. When the pressure of adsorber AD1 reaches the operating pressure, fully open CV05. At this point, regeneration is completed, and the regeneration button returns to the initial unpressed state. At the same time, "Regeneration" and "Regeneration End" change color. That is, the colors of "Regeneration" and "Regeneration End" are inconsistent on the same interface. Green font indicates that this state is in place, and red font indicates that this state has ended. When the adsorber regeneration time interval is reached again, according to the above logic, adsorber AD2 will work and adsorber AD1 will regenerate, and so on, realizing automatic control of trace impurity purification and purification system (adsorber) regeneration switching.

[0030] It can be understood that the trace impurity purification system provided in this embodiment includes a first adsorber (AD1) and a second adsorber (AD2), and the control logic and automatic control system for the purification of multiple adsorbers in parallel or 80K adsorbers and the regeneration of the purification system (adsorber) are consistent with the technical solutions of the above embodiments and will not be repeated here.

[0031] In some embodiments, the invention further comprises a compressor (110), a heat exchanger group (120) composed of a plurality of heat exchangers connected in series, a turbine expander group (130) and a liquid helium dewar (140), one end of the compressor (110) is connected to one end of the heat exchanger group (120) through a pipeline, the other end of the compressor (110) is connected to the liquid helium dewar (140) through a pipeline, and the liquid helium dewar (140) is connected to the other end of the heat exchanger group (120) through a pipeline, and the turbine expander group (130) is arranged on the pipeline.

[0032] In some embodiments, the heat exchanger group (120) is composed of a plurality of heat exchangers connected in series.

[0033] In some embodiments, the turboexpander assembly (130) is composed of two turboexpanders connected in series.

[0034] In some embodiments, the first adsorber (AD1) and the second adsorber (AD2) are provided with a first low-temperature thermometer (T1) and a second low-temperature thermometer (T2), respectively, for obtaining the temperature of the first adsorber (AD1) and the second adsorber (AD2) in real time. The first low-temperature thermometer (T1) and the second low-temperature thermometer (T2) are low-temperature thermometers in the 10K temperature range.

[0035] In some embodiments, a pressure sensor (P1) is further provided on the pipeline between the second pneumatic regulating valve (CV04) and the first adsorber (AD1) for obtaining the pressure on the pipeline in real time.

[0036] In some embodiments, a pressure sensor (P2) is further provided on the pipeline between the third pneumatic regulating valve (CV06) and the second adsorber (AD2) for obtaining the pressure on the pipeline in real time.

[0037] The trace impurity purification system provided in the aforementioned embodiments of the present application can achieve automated control of trace impurity purification and regeneration switching of the purification system (adsorber), enabling automatic and continuous operation of a large helium cryogenic system, thereby improving the system's level of automation. A vaporizer, namely HEXO3, is installed in the regeneration line of the low-temperature helium gas in the main adsorber flow, eliminating the need for an electrically heated heater, reducing power consumption and improving system reliability.

[0038] It can be understood that the various technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the various technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0039] The above are merely preferred embodiments of the present application and only specifically describe the technical principles of the present application. These descriptions are intended only to explain the principles of the present application and should not be construed in any way as limiting the scope of protection of the present application. Based on the explanations herein, any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application, as well as other specific implementations of the present application that can be conceived by those skilled in the art without inventive effort, shall be included within the scope of protection of the present application.

Claims

1. A trace impurity purification system, characterized in that: include: A first adsorber (AD1), a second adsorber (AD2), a pneumatic regulating valve (CV04) provided at the air inlet of the first adsorber (AD1), a pneumatic switch valve (CV05) provided at the air outlet of the first adsorber (AD1), a pneumatic regulating valve (CV06) provided at the air inlet of the second adsorber (AD2), a pneumatic switch valve (CV07) provided at the air outlet of the second adsorber (AD2), a first pneumatic regulating valve (CV01), a second pneumatic regulating valve (CV04), a third pneumatic regulating valve (CV05), and a pneumatic regulating valve (CV06) provided at the air inlet of the second adsorber (AD2). a throttle valve (CV06), a fourth pneumatic regulating valve (CV10), a fifth pneumatic regulating valve (CV11), a first pneumatic switch valve (CV02), a second pneumatic switch valve (CV03), a third pneumatic switch valve (CV05), a fourth pneumatic switch valve (CV07), a fifth pneumatic switch valve (CV08), and a sixth pneumatic switch valve (CV09); one end of the fourth pneumatic regulating valve (CV10) is connected to a vacuum pump and the other end is connected to the third heat exchanger (HEX03) for vacuum extraction by the vacuum pump; When the first adsorber (AD1) is purified, the helium passes through the second pneumatic regulating valve (CV04), the first adsorber (AD1) and the pneumatic switch valve (CV05); when the first adsorber (AD1) is regenerated, the second pneumatic regulating valve (CV04) and the third pneumatic switch valve (CV05) are closed, and the high-pressure and room-temperature helium passes through the first pneumatic regulating valve (CV01) and the second pneumatic switch valve (CV03) into the first heat exchanger (HEX01), and after heat exchange in the first heat exchanger (HEX01), enters the low-pressure pipeline of the helium cryogenic system; the low-temperature and high-pressure helium in the first adsorber (AD1) enters the third heat exchanger (HEX03) through the sixth pneumatic switch valve (CV09), and then enters the helium recovery bag through the fifth pneumatic regulating valve (CV11); one end of the fourth pneumatic regulating valve (CV10) is connected to the vacuum pump and the other end is connected to the third heat exchanger (HEX03) for vacuum extraction by the vacuum pump; When the second adsorber (AD2) is purified, the helium passes through the third pneumatic regulating valve (CV06), the second adsorber (AD2) and the pneumatic switch valve (CV07); when the second adsorber (AD2) is regenerated, the third pneumatic regulating valve (CV06) and the pneumatic switch valve (CV07) are closed, and the high-pressure and room-temperature helium passes through the first pneumatic regulating valve (CV01) and the first pneumatic switch valve (CV02) into the second heat exchanger (HEX02), and after heat exchange in the second heat exchanger (HEX02), enters the low-pressure pipeline of the helium cryogenic system; the low-temperature and high-pressure helium in the second adsorber (AD2) enters the third heat exchanger (HEX03) through the fifth pneumatic switch valve (CV08), and then enters the helium recovery bag through the fifth pneumatic regulating valve (CV11); one end of the fourth pneumatic regulating valve (CV10) is connected to the vacuum pump and the other end is connected to the third heat exchanger (HEX03) for vacuum extraction by the vacuum pump.

2. The trace impurity purification system according to claim 1, characterized in that: The invention also includes a compressor (110), a heat exchanger group (120) composed of a plurality of heat exchangers connected in series, a turbine expander group (130) and a liquid helium dewar (140), wherein one end of the compressor (110) is connected to one end of the heat exchanger group (120) via a pipeline, the other end of the compressor (110) is connected to the liquid helium dewar (140) via a pipeline, and the liquid helium dewar (140) is connected to the other end of the heat exchanger group (120) via a pipeline, and the turbine expander group (130) is arranged on the pipeline.

3. The trace impurity purification system according to claim 2, characterized in that: The heat exchanger group (120) is composed of a plurality of heat exchangers connected in series.

4. The trace impurity purification system according to claim 2, characterized in that: The expansion unit (130) consists of two turbine expanders connected in series.

5. The trace impurity purification system according to claim 1, characterized in that: The first adsorber (AD1) and the second adsorber (AD2) are respectively provided with a first low-temperature thermometer (T1) and a second low-temperature thermometer (T2).

6. The trace impurity purification system according to claim 1, characterized in that: A pressure sensor (P1) is also provided on the pipeline between the second pneumatic regulating valve (CV04) and the first adsorber (AD1).

7. The trace impurity purification system according to claim 1, characterized in that: A pressure sensor (P2) is also provided on the pipeline between the third pneumatic regulating valve (CV06) and the second adsorber (AD2).

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