A helium liquefaction system

Abstract

The invention discloses a helium liquefaction system, comprising a helium gas source, a refrigerator heat exchange device, a low-temperature storage device, a circulation heat exchange device and a circulation drive device; the helium gas source is input into the refrigerator heat exchange device through a pipeline; the gas outlet end in the refrigerator heat exchange device is connected with the gas inlet end of the low-temperature storage device; a first channel and a second channel are arranged in the circulation heat exchange device; the gas outlet end of the low-temperature storage device is communicated with the gas inlet end of the first channel in the circulation heat exchange device; the gas outlet end of the first channel in the circulation heat exchange device is communicated with the gas inlet end of the circulation drive device; the gas outlet end of the circulation drive device is communicated with the gas inlet end of the second channel in the circulation heat exchange device; the gas outlet end of the second channel in the circulation heat exchange device is communicated with the gas inlet end of the refrigerator heat exchange device; the invention avoids the loss of cold and the leakage of gaseous helium.

Description

Technical Field

[0001] The present invention relates to the technical field of helium liquefaction, in particular to a helium liquefaction system. Background Art

[0002] Helium exists in nature mainly in natural gas or radioactive ores. In the Earth's atmosphere, the concentration of helium is very low, only 1 in 52,000. In the existing small-scale helium liquefaction process, most of them rely on refrigerators to cool the helium, and then store it in a dewar device after liquefaction. During the process of cooling and liquefying the helium, the helium in the dewar device will continuously release helium to the recovery device, which is specifically manifested in:

[0003] First, the helium released from the Dewar device is a high-purity gas, and the helium recovery process will cause new pollution to the helium, and the polluted helium needs to be purified again. Whether the helium is recovered or purified, it will consume energy, causing energy waste.

[0004] Second: If there is only a helium liquefaction device but no recovery device and purification device, the helium released from the Dewar can only be released into the atmosphere, which leads to a waste of helium resources.

[0005] Third: The temperature of helium released from the Dewar device is also relatively low, which will also cause a loss of cold energy to some extent. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a helium liquefaction system in which the helium released from the dewar does not need to flow to a recovery device, while the cold capacity in the helium is recovered as much as possible to reduce the loss.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: a helium liquefaction system, comprising a helium gas source, a refrigerator heat exchange device, a cryogenic storage device, a circulating heat exchange device and a circulating drive device; the helium gas source is input into the refrigerator heat exchange device through a pipeline; the gas outlet end in the refrigerator heat exchange device is connected with the gas inlet end of the cryogenic storage device; a first channel and a second channel are arranged in the circulating heat exchange device; the gas outlet end of the cryogenic storage device is connected with the gas inlet end of the first channel in the circulating heat exchange device; the gas outlet end of the first channel in the circulating heat exchange device is connected with the gas inlet end of the circulating drive device; the gas outlet end of the circulating drive device is connected with the gas inlet end of the second channel in the circulating heat exchange device; the gas outlet end of the second channel in the circulating heat exchange device is connected with the gas inlet end of the refrigerator heat exchange device.

[0008] The cryogenic storage device is filled with normal pressure and normal temperature helium. A normal temperature gas source inputs helium at a specific flow rate, and the helium flows into the refrigerator heat exchanger through the air inlet. Affected by the cold provided by the refrigerator, the helium temperature decreases. Under the action of the circulation drive device, the gas in the cryogenic storage container is extracted, and the low-temperature helium from the refrigerator heat exchanger enters the cryogenic storage container. At the same time, the helium extracted from the cryogenic storage container passes through the circulation heat exchanger and the circulation drive device, and then passes through the second channel of the circulation heat exchanger and flows into the refrigerator heat exchanger through another air inlet for further cooling and liquefaction; the gas temperature in the cryogenic storage device continues to decrease, and the gas temperature extracted by the circulation drive device continues to decrease. The helium temperature in the cryogenic storage device continues to decrease. When the temperature at the bottom of the container reaches the critical temperature of helium, the helium begins to liquefy and liquid begins to accumulate at the bottom of the container; the helium flows through the circulation heat exchanger twice, and the helium flowing through the first channel and the second channel is fully heat exchanged, further avoiding the loss of cold.

[0009] Preferably, the air inlet end of the refrigerator heat exchange device includes two independent air inlets; the air outlet end of the second channel in the circulating heat exchange device and the gas of the helium gas source are respectively input into the refrigerator heat exchange device through the two independent air inlets of the refrigerator heat exchange device.

[0010] Preferably, a first regulating valve is installed on the pipeline connecting the helium gas source and the refrigerator heat exchange device.

[0011] Preferably, a first flow meter is also installed on the pipeline connecting the helium gas source and the refrigerator heat exchange device, and the first flow meter is arranged behind the first regulating valve.

[0012] Preferably, a second regulating valve is installed on the pipeline connecting the air outlet end of the first channel in the circulation heat exchange device and the air inlet end of the circulation drive device.

[0013] Preferably, a second flow meter is also installed on the pipeline connecting the air outlet end of the first channel in the circulation heat exchange device and the air inlet end of the circulation drive device; the second flow meter is arranged behind the second regulating valve.

[0014] Preferably, the low temperature storage device is a Dewar flask.

[0015] Preferably, the refrigerator heat exchange device is a GM model refrigerator.

[0016] In the initial state, the low-temperature storage device is filled with normal-pressure and normal-temperature helium. A normal-temperature gas source inputs helium at a specific flow rate, and the helium flows into the refrigerator heat exchanger through the air inlet. Affected by the cold provided by the refrigerator heat exchanger, the helium temperature decreases. Under the action of the circulation drive device, the gas in the low-temperature storage container is extracted, and the low-temperature helium from the refrigerator heat exchanger enters the low-temperature storage container. Because the recovery device and the purification device are generally operated under high-pressure conditions (>50bar), and the reflux process is carried out at a lower pressure (<0.5bar), the energy consumption of the circulation drive device per unit mass of helium is much less than the sum of the recovery device and the purification device. At the same time, the helium extracted from the low-temperature storage container flows into the second regulating valve and the second flow meter through the first channel of the circulation heat exchanger, then through the circulation drive device, and then through the second channel of the circulation heat exchanger, and then through another air inlet into the refrigerator heat exchanger for further cooling and liquefaction.

[0017] According to the above cycle, the temperature of the gas in the cryogenic storage device continues to decrease, and the temperature of the gas extracted by the circulation drive device continues to decrease. The temperature of the helium in the cryogenic storage device continues to decrease. When the temperature at the bottom of the container reaches the critical temperature of the helium, the helium begins to liquefy, and liquid begins to accumulate at the bottom of the container. At this time, adjust the first regulating valve and observe the first flow meter so that the rate at which the circulation drive device extracts gas from the cryogenic storage device is greater than the rate at which the gas evaporates from the cryogenic storage device due to heat leakage, so that helium from the room temperature gas source continues to enter, and the helium in the cryogenic storage device will continue to cool down and liquefy. In the above process, the helium flows through the circulating heat exchange device twice, and the helium flowing through the first channel and the second channel fully exchanges heat, further avoiding the loss of cold capacity.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] A. Helium flows through the circulating heat exchange device twice, and the helium flowing through the first channel and the second channel fully exchanges heat, avoiding the loss of cold capacity and reducing the leakage of gaseous helium;

[0020] B. Adjust the first regulating valve and observe the first flow meter to make the rate at which the circulation drive device extracts gas from the low-temperature storage device greater than the rate at which gas evaporates from the low-temperature storage device due to heat leakage, and the adjustment is accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the helium liquefaction system of the present invention.

[0022] Figure numbers: 1. Helium gas source; 2. First regulating valve; 21. First flow meter; 3. Refrigerator heat exchange device; 4. Low temperature storage device; 5. Circulation drive device; 6. Second regulating valve; 62. Second flow meter. DETAILED DESCRIPTION

[0023] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described in conjunction with the accompanying drawings of the specification.

[0024] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0025] See also Figure 1 The present embodiment discloses a helium liquefaction system, a helium liquefaction system, comprising a helium gas source 1, a refrigerator heat exchange device 3, a low-temperature storage device 4, a circulation heat exchange device and a circulation drive device 5; the air inlet end of the refrigerator heat exchange device 3 comprises two independent air inlets; the helium gas source 1 is input into an independent air inlet of the refrigerator heat exchange device 3 through a pipeline; the air outlet end in the refrigerator heat exchange device 3 is connected to the air inlet end of the low-temperature storage device 4; a first channel and a second channel are arranged in the circulation heat exchange device; the air outlet end of the low-temperature storage device 4 is connected to the air inlet end of the first channel in the circulation heat exchange device; the air outlet end of the first channel in the circulation heat exchange device is connected to the air inlet end of the circulation drive device 5; the air outlet end of the circulation drive device 5 is connected to the air inlet end of the second channel in the circulation heat exchange device; the air outlet end of the second channel in the circulation heat exchange device is connected to another independent air inlet of the refrigerator heat exchange device 3.

[0026] The first regulating valve 2 and the first flow meter 21 are respectively installed on the pipeline connecting the helium gas source 1 and the refrigerator heat exchange device 3 by bolts; the first flow meter 21 is arranged behind the first regulating valve 2.

[0027] A second regulating valve 6 and a second flow meter 62 are respectively installed on the pipeline connecting the air outlet end of the first channel in the circulation heat exchange device and the air inlet end of the circulation drive device 5 by bolts; the second flow meter 62 is arranged behind the second regulating valve 6.

[0028] The low temperature storage device 4 is a Dewar flask.

[0029] The refrigerator heat exchange device 3 is a GM refrigerator.

[0030] The working principle of this embodiment is as follows: in the initial state, the low-temperature storage device 4 is filled with helium at normal pressure and temperature. A normal-temperature gas source inputs helium at a specific flow rate, and the helium flows into the refrigerator heat exchanger 3 through the air inlet. Affected by the cold provided by the refrigerator heat exchanger 3, the helium temperature decreases. Under the action of the circulation drive device 5, the gas in the low-temperature storage container is extracted, and the low-temperature helium from the refrigerator heat exchanger 3 enters the low-temperature storage container. Because the recovery device and the purification device are generally carried out under high-pressure conditions (>50bar), and the reflux process is carried out at a lower pressure (<0.5bar), the energy consumption of the circulation drive device per unit mass of helium is much less than the sum of the recovery device and the purification device. At the same time, the helium extracted from the low-temperature storage container flows into the second regulating valve 6 and the second flow meter 62 through the first channel of the circulation heat exchanger, and then flows into the refrigerator heat exchanger 3 through another air inlet through the circulation drive device 5, and then through the second channel of the circulation heat exchanger for further cooling and liquefaction.

[0031] According to the above cycle, the temperature of the gas in the low-temperature storage device 4 is continuously reduced, and the temperature of the gas extracted by the circulation drive device 5 is continuously reduced. The temperature of helium in the low-temperature storage device 4 is continuously reduced. When the temperature at the bottom of the container reaches the critical temperature of helium, the helium begins to liquefy, and liquid begins to accumulate at the bottom of the container. At this time, adjust the first regulating valve 2, and observe the first flow meter 21, so that the rate at which the circulation drive device 5 extracts gas from the low-temperature storage device 4 is greater than the rate at which the gas evaporates due to heat leakage in the low-temperature storage device 4, so that helium from the normal temperature gas source continuously enters, and the helium in the low-temperature storage device 4 will also continue to cool down and liquefy. In the above process, the helium flows through the circulation heat exchange device twice, and the helium flowing through the first channel and the second channel fully exchanges heat, further avoiding the loss of cold capacity.

[0032] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0033] The embodiments described above only represent implementation methods of the invention. The protection scope of the present invention is not limited to the embodiments described above. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A helium liquefaction system, characterized in that: The invention comprises a helium gas source, a refrigerator heat exchange device, a low-temperature storage device, a circulation heat exchange device and a circulation drive device; the helium gas source is input into the refrigerator heat exchange device through a pipeline; the gas outlet end of the refrigerator heat exchange device is connected with the gas inlet end of the low-temperature storage device; the circulation heat exchange device is provided with a first channel and a second channel; the gas outlet end of the low-temperature storage device is connected with the gas inlet end of the first channel in the circulation heat exchange device; the gas outlet end of the first channel in the circulation heat exchange device is connected with the gas inlet end of the circulation drive device; the gas outlet end of the circulation drive device is connected with the gas outlet end of the circulation drive device; the gas outlet end of the circulation drive device is connected with the gas outlet end of the circulation drive device; the gas outlet end of the circulation drive device is connected with the gas outlet end of the circulation drive device; the gas outlet end of the circulation drive device is connected with the gas outlet end of the circulation drive device; the gas outlet end of the circulation drive device is connected with the gas outlet end of the circulation drive device; the gas outlet end of the circulation drive device is connected with the gas inlet ... The end is connected with the air inlet end of the second channel in the circulating heat exchange device; the outlet end of the second channel in the circulating heat exchange device is connected with the air inlet end of the refrigerator heat exchange device, and a first regulating valve is installed on the pipeline connecting the helium gas source and the refrigerator heat exchange device; a first flow meter is also installed on the pipeline connecting the helium gas source and the refrigerator heat exchange device, and the first flow meter is arranged behind the first regulating valve; a second regulating valve is installed on the pipeline connecting the outlet end of the first channel in the circulating heat exchange device and the air inlet end of the circulating drive device.

2. A helium liquefaction system according to claim 1, characterized in that: The air inlet end of the refrigerator heat exchange device includes two independent air inlets; the air outlet end of the second channel in the circulating heat exchange device and the gas of the helium gas source are respectively input into the refrigerator heat exchange device through the two independent air inlets of the refrigerator heat exchange device.

3. A helium liquefaction system according to claim 1, characterized in that: A second flow meter is also installed on the pipeline connecting the air outlet end of the first channel in the circulation heat exchange device and the air inlet end of the circulation drive device; the second flow meter is arranged behind the second regulating valve.

4. A helium liquefaction system according to claim 1, characterized in that: The low temperature storage device is a Dewar flask.

5. A helium liquefaction system according to claim 1, characterized in that: The refrigerator heat exchange device is a GM model refrigerator.

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