Low temperature rectification column system and method of reducing reboiler power loss

Abstract

The application relates to the technical field of rectification equipment, and provides a low-temperature rectification tower system and a method for reducing power loss of a reboiler. The low-temperature rectification tower system comprises a low-temperature rectification tower, a reboiler and a wire, a vacuum cover and a heat conduction device. The wire is electrically connected with the reboiler to convey electric energy to the reboiler; the vacuum cover has a vacuum cavity, and the low-temperature rectification tower and the reboiler are arranged in the vacuum cavity; and the heat conduction device is used for transmitting the heat emitted by the wire to the vacuum cavity to the low-temperature rectification tower. The low-temperature rectification tower system provided by the embodiment of the application can utilize the heat accumulated outside the wire, transmit the heat to the low-temperature rectification tower, promote the outward heat transmission of the wire, improve the heat dissipation condition of the wire and reduce the power loss of the wire.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rectification equipment, and in particular to a low-temperature rectification tower system and a method for reducing power loss of a reboiler. BACKGROUND

[0002] In related technologies, a low-temperature rectification tower needs to maintain a stable low-temperature environment through thermal insulation measures. A vacuum cover is usually provided outside the rectification tower, and the vacuum cover is pumped to have a high vacuum degree to reduce heat exchange between the low-temperature rectification tower and the outside world. The reboiler is a heating device for vaporizing the distillation liquid of the low-temperature rectification tower, and is usually located at the bottom of the tower or outside the bottom of the tower. The low-temperature rectification tower and the reboiler are arranged underground, and the reboiler is connected to a power supply device located on the ground through a wire. As the service life of the reboiler increases, heat continuously accumulates on the wire, the temperature of the wire rises, the resistance of the wire increases, and the voltage loss and power loss of the wire significantly increase. For example, the low-temperature rectification tower for low-separation-coefficient isotope separation of carbon and boron has a height of hundreds of meters, and the reboiler wire for power supply is long and located at the bottom of the tower or outside the bottom of the tower. The voltage drop of the wire during long-distance transmission in a high vacuum and the sudden drop in the heat dissipation capacity of the vacuum will cause the heat of the wire to accumulate and the resistance of the wire to rise, and ultimately cause the power loss of the wire to increase. SUMMARY

[0003] Therefore, the embodiments of the present application aim to provide a low-temperature rectification tower system and a method for reducing power loss of a reboiler, which can reduce the power loss of the reboiler. The low-temperature rectification tower system comprises:

[0004] a low-temperature rectification tower;

[0005] a reboiler and a wire, the wire being electrically connected to the reboiler to supply electric energy to the reboiler;

[0006] a vacuum cover having a vacuum cavity, the low-temperature rectification tower and the reboiler being arranged in the vacuum cavity;

[0007] a heat conduction device for transferring heat emitted by the wire to the low-temperature rectification tower.

[0008] In some embodiments, the heat conduction device comprises:

[0009] a heat conduction medium, both ends of the heat conduction medium being connected to the low-temperature rectification tower and the wire, respectively.

[0010] In some embodiments, the heat conduction device further comprises:

[0011] a fixing plate, the fixing plate being provided on the low-temperature rectification tower and located between the low-temperature rectification tower and the inner wall of the vacuum cover, and the heat conduction medium being arranged on the fixing plate.

[0012] In some embodiments, the fixing plate has a limiting opening, the heat-conducting medium has a heat-conducting body and a heat-conducting ring connected to each other, the heat-conducting ring is arranged on the periphery of the limiting opening, the wire is arranged in the limiting opening and in contact with the heat-conducting ring, and the two ends of the heat-conducting body are connected to the heat-conducting ring and the low-temperature rectifying tower, respectively.

[0013] In some embodiments, a plurality of the fixing plates are arranged in the up-down direction and each of the fixing plates is provided with the heat-conducting medium.

[0014] In some embodiments, the heat-conducting device further comprises:

[0015] A clamping block is connected to the fixing plate and the vacuum cover to arrange the fixing plate and the vacuum cover in a spaced manner.

[0016] In some embodiments, the heat-conducting device comprises:

[0017] A reflecting plate is arranged between the low-temperature rectifying tower and the vacuum cover to reflect the heat of the wire to the low-temperature rectifying tower, and the wire is arranged between the reflecting plate and the low-temperature rectifying tower.

[0018] The low-temperature rectifying tower system provided by the embodiments can utilize the heat accumulated outside the wire, transfer the heat to the low-temperature rectifying tower, promote the heat transfer of the wire to the outside to improve the heat dissipation of the wire, and reduce the power loss of the wire.

[0019] The embodiments also provide a method for reducing the power loss of a reboiler, the reboiler is provided with a wire to supply electric energy for heat exchange with a low-temperature rectifying tower, and the method comprises the following steps:

[0020] Determining the heat accumulation rate under the working condition of the wire;

[0021] Setting a heat-conducting device according to the heat accumulation rate.

[0022] In some embodiments, the step of determining the heat accumulation rate under the working condition of the wire comprises:

[0023] Determining the wire power under the working condition of the wire;

[0024] Determining the heat dissipation power of the vacuum cavity to the wire;

[0025] Determining the heat accumulation rate according to the wire power and the heat dissipation power.

[0026] In some embodiments, the step of determining the wire power under the working condition of the wire comprises:

[0027] Obtaining the current of the wire under the working condition ;

[0028] obtaining the resistivity of the wire under working conditions ρ ;

[0029] calculating the wire power of the wire , specifically, calculating the wire power according to the following function relationship :

[0030]

[0031] wherein, L denotes the length of the wire, S denotes the cross-sectional area of the wire.

[0032] In some embodiments, the step of determining the heat dissipation power of the vacuum cavity to the wire comprises:

[0033] obtaining the heat dissipation area of the wire , the temperature of the wire under working conditions , the temperature of the rectifying tower under working conditions ;

[0034] calculating the heat dissipation power of the wire , specifically, calculating the heat dissipation power of the wire according to the following function relationship :

[0035]

[0036] wherein, is the emissivity of the wire, is the Stefan-Boltzmann constant.

[0037] The method for reducing the power loss of the reboiler provided by the embodiments of the present application has the same beneficial effects as the low-temperature rectifying tower system described above. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a schematic diagram of a low-temperature rectifying tower system in an embodiment of the present application;

[0039] Figure 2 is an enlarged schematic diagram of A in Figure 1 ;

[0040] Figure 3 is a schematic diagram of a low-temperature rectifying tower system in another embodiment of the present application;

[0041] Figure 4 is a flowchart of a method for reducing the power loss of a reboiler in an embodiment of the present application.

[0042] Reference Signs List

[0043] 100, low-temperature rectifying column system; 10, low-temperature rectifying column; 20, wire; 30, vacuum cover; 40, heat conduction device; 411, heat conduction body; 412, heat conduction ring; 42, fixing plate; 42a, limiting opening; 43, clamping block; 44, reflecting plate. DETAILED DESCRIPTION

[0044] The embodiments of the present application will be further described below in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but cannot be used to limit the scope of the present application.

[0045] It should be noted that the orientation or position relationship such as "upward and downward direction", "circumferential direction" and the like in the embodiments of the present application is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The present application will be further described in detail below in conjunction with the drawings and specific embodiments.

[0046] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the term "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above-mentioned term in the embodiments of the present application can be understood according to the specific circumstances.

[0047] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be that the first feature and the second feature are in direct contact, or the first feature and the second feature are in indirect contact through an intermediate medium.

[0048] In the description of the present specification, the description referring to the terms "some embodiments", "exemplarily" and the like means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are contained in at least one embodiment or example of the embodiments of the present application. In the present specification, the exemplary description of the above-mentioned terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0049] In the related art, the low-temperature rectification tower and the reboiler are arranged underground, and the reboiler is located at the bottom of the tower or outside the tower. The reboiler is connected with a power supply device located on the ground through a wire. As the use time of the reboiler increases, the heat continuously accumulates on the wire, the temperature of the wire increases, the resistance of the wire increases, and the voltage loss and power loss of the wire significantly increase.

[0050] Therefore, in order to solve the above problems, the embodiments of the present application provide a low-temperature rectification tower system 100, which comprises a low-temperature rectification tower 10, a reboiler and a wire, a vacuum cover 30 and a heat conduction device 40. The wire 20 is electrically connected with the reboiler to supply electric energy to the reboiler; the vacuum cover 30 has a vacuum cavity, and the low-temperature rectification tower 10 and the reboiler are arranged in the vacuum cavity; and the heat conduction device 40 is used for transferring the heat emitted by the wire 20 to the low-temperature rectification tower 10. Figures 1-3

[0051] The low-temperature rectification tower 10 is used for performing a rectification process at low temperature. By providing a low-temperature environment sufficient for liquefying the material to be separated, the low-temperature rectification tower 10 separates different components in the material to be separated by utilizing the difference in volatility of the components in the material to be separated and continuously contacting and mass transferring the gas and liquid phases in the low-temperature environment. The reboiler is a heating device used for vaporizing the distillation liquid of the low-temperature rectification tower 10. The vacuum cover 30 is used for providing a high-vacuum environment to reduce the heat leakage of the low-temperature rectification tower 10 from the external environment, so as to stabilize the low-temperature environment and save cold energy.

[0052] The heat conduction device 40 is used for transferring the accumulated heat of the wire 20 outward, reducing the accumulated heat of the wire 20 and reducing the resistance of the wire 20 caused by the temperature increase of the wire 20. The heat conduction device 40 also utilizes the heat outside the wire 20 and transfers the heat to the low-temperature rectification tower 10, so as to reduce the power loss of the wire 20.

[0053] In order to achieve the purpose of transferring the heat outside the wire 20 to the low-temperature rectification tower 10, the heat conduction device 40 can be implemented by heat conduction or heat radiation.

[0054] In some embodiments, the heat conduction device 40 comprises a heat conduction medium, and the two ends of the heat conduction medium are connected with the low-temperature rectification tower 10 and the wire 20, respectively. Figure 1

[0055] The heat conduction medium can transfer the heat outside the wire 20 to the low-temperature rectification tower 10 by heat conduction. The material and shape of the heat conduction medium are not limited, as long as the heat outside the wire 20 can be conveniently transferred to the low-temperature rectification tower 10. For example, the material of the heat conduction medium can be metal, such as copper.

[0056] For example, the heat conduction medium can be a heat conduction heat pipe to quickly transfer heat.

[0057] The number of heat conduction media is not limited, and one, two or more heat conduction media can be arranged.​​

[0058] Exemplarily, the plurality of heat-conducting media are arranged along the outer periphery of the low-temperature rectifying tower 100 in the horizontal direction to form a heat-conducting unit.

[0059] Exemplarily, the plurality of heat-conducting units are arranged along the vertical direction.

[0060] Exemplarily, referring to Figure 1 , the heat-conducting device 40 further comprises a fixing plate 42, which is sleeved on the low-temperature rectifying tower 10 and located between the low-temperature rectifying tower 10 and the inner wall of the vacuum cover 30, and the heat-conducting media are arranged on the fixing plate 42.

[0061] The fixing plate 42 can provide a mounting position for the heat-conducting media and play a fixing role on the heat-conducting media. The fixing plate 42 is sleeved on the low-temperature rectifying tower 10, and the vacuum cover 30 is sleeved on the low-temperature rectifying tower 10 and the fixing plate 42. Exemplarily, the cross section of the fixing plate 42 along the up-down direction is annular, and the inner periphery of the fixing plate 42 is in contact with the outer wall of the low-temperature rectifying tower 10.

[0062] It can be understood that the number of heat-conducting media arranged on each fixing plate 42 is not limited and can be adaptively arranged according to requirements. Exemplarily, the fixing plate 42 is annular, and in order to improve the heat-conducting effect, a plurality of heat-conducting media can be arranged along the circumferential direction of the fixing plate 42.

[0063] The lead wire 20 extends through the fixing plate 42 to the ground and is connected with the power supply device. Exemplarily, the fixing plate 42 has a limiting opening 42a, and the lead wire 20 extends through the limiting opening 42a to the ground and is connected with the power supply device.

[0064] Exemplarily, the material of the fixing plate 42 is set to be a material with insulation and high thermal resistance, for example, the fixing plate 42 can be set to be a plastic material.

[0065] Exemplarily, referring to Figure 1 and Figure 2 , the fixing plate 42 has a limiting opening 42a, the heat-conducting media have a heat-conducting body 411 and a heat-conducting ring 412 connected with each other, the heat-conducting ring 412 is arranged on the periphery of the limiting opening 42a, the lead wire 20 is arranged in the limiting opening 42a and is in contact with the heat-conducting ring 412, and the two ends of the heat-conducting body 411 are connected with the heat-conducting ring 412 and the low-temperature rectifying tower 10 respectively.

[0066] The heat-conducting ring 412 is arranged on the periphery of the limiting opening 42a, so that when the lead wire 20 passes through the limiting opening 42a, the lead wire 20 can be in contact with the heat-conducting ring 412, so that the heat-conducting ring 412 can obtain heat outside the lead wire 20 and conduct the heat to the low-temperature rectifying tower 10 through the heat-conducting body 411.

[0067] Exemplarily, the fixing plate 42 is in the horizontal direction, and the thickness direction is in the up-down direction.

[0068] The number of the fixing plates 42 is not limited and can be adaptively set according to the requirement of the heat conducting medium. In some embodiments, a plurality of the fixing plates 42 are arranged in the up-down direction at intervals.

[0069] In order to reduce the heat loss of the wire 20 and the possibility of heat conduction from outside of the wire 20 to the vacuum cover 30, in some embodiments, referring to Figure 1 , the heat conducting device 40 further comprises a clamping block 43 connecting the fixing plate 42 and the vacuum cover 30 so that the fixing plate 42 and the vacuum cover 30 are arranged at intervals.

[0070] The clamping block 43 is arranged between the fixing plate 42 and the vacuum cover 30 so that the fixing plate 42 does not directly contact the vacuum cover 30, thereby reducing the possibility of heat conduction from outside of the wire 20 to the vacuum cover 30. Exemplarily, the outer periphery of the fixing plate 42 is fixed to the vacuum cover 30 through the clamping block 43, and the clamping block 43 can support and fix the outer periphery of the fixing plate 42.

[0071] The shape, size and number of the clamping block 43 are not limited and can be adaptively set according to the fixing effect and the interval effect between the fixing plate 42 and the vacuum cover 30.

[0072] Exemplarily, the contact surface of the clamping block 43 facing the vacuum cover 30 is adapted to the inner wall of the vacuum cover 30 and has as small contact area with the vacuum cover 30 as possible, so as to reduce the heat conduction between the wire 20 and the vacuum cover 30; the contact surface of the clamping block 43 facing the fixing plate 42 is adapted to the outer wall of the fixing plate 42, so that the clamping block 43 can be stably clamped between the fixing plate 42 and the vacuum cover 30. Exemplarily, the cross section of the clamping block 43 in the up-down direction can be set as a sector.

[0073] Exemplarily, the material of the clamping block 43 is set as a material with insulation and high thermal resistance, for example, the clamping block 43 can be set as a plastic material.

[0074] Exemplarily, the clamping blocks 43 can be arranged at intervals along the outer periphery of the fixing plate 42 and arranged in pairs on both sides of the low-temperature rectifying tower 10, so as to improve the fixing and supporting effect of the fixing plate 42. In some embodiments, referring to Figure 3 , the heat conducting device 40 comprises a reflecting plate 44 arranged between the low-temperature rectifying tower 10 and the vacuum cover 30, for reflecting the heat of the wire 20 to the low-temperature rectifying tower 10, and the wire 20 is arranged between the reflecting plate 44 and the low-temperature rectifying tower 10.

[0075] The heat outside the lead wire 20 can be reflected to the low-temperature rectifying tower 10 by the reflecting plate 44, and the cold leakage of the vacuum cover 30 to the outside is reduced. Exemplarily, the material of the reflecting plate 44 is set to be a material with high reflectivity, low thermal conductivity and low outgassing rate, so as to strengthen the radiation heat transfer and reduce the influence on the vacuum degree in the vacuum cover 30. For example, the reflecting plate 44 can be set to be a multi-layer heat insulation material formed by superimposing a double-sided aluminum film and a non-woven fabric, and has high reflectivity, low thermal conductivity and low outgassing rate. Exemplarily, the reflecting plate 44 is arranged in a reflecting cylinder around the circumferential direction of the low-temperature rectifying tower 10, the axial direction of the reflecting cylinder is arranged along the height direction of the low-temperature rectifying tower 10, the reflecting cylinder is arranged in a spaced manner with the outer wall of the low-temperature rectifying tower 10, and the lead wire 20 is arranged between the reflecting cylinder and the low-temperature rectifying tower 10.

[0076] Exemplarily, the number of the reflecting plate 44 is not limited, and the reflecting plate 44 can be one, two or more. When a plurality of reflecting plates 44 are arranged, the reflecting plates 44 are arranged in a continuous manner along the radial direction of the low-temperature rectifying tower outward in sequence. The radial direction refers to the extension direction of the radius on the cross section of the low-temperature rectifying tower in the horizontal direction.

[0077] The low-temperature rectifying tower system 100 provided by the embodiment of the present application can utilize the heat accumulated outside the lead wire 20 by the heat conduction device 40, and transfer the heat to the low-temperature rectifying tower 10, so as to promote the heat transfer of the lead wire 20 to the outside, improve the heat dissipation of the lead wire 20, and reduce the power loss of the lead wire 20.

[0078] The embodiment of the present application also provides a method for reducing the power loss of the reboiler, please refer to Figure 4 The reboiler is provided with electric energy by the lead wire, and is used for heat exchange with the low-temperature rectifying tower, and the method comprises the following steps:

[0079] determining the heat accumulation rate under the working condition of the lead wire;

[0080] setting the heat conduction device according to the heat accumulation rate.

[0081] The higher the heat accumulation rate outside the lead wire is, the heat conduction device can be increased to increase the heat dissipation effect outside the lead wire. For example, the number of the heat conduction device can be increased, the position of the heat conduction device can be adjusted, when the heat conduction device comprises a heat conduction medium, a material with better heat conduction performance can be selected, or the number or the cross-sectional area of the heat conduction medium can be increased, or when the heat conduction device comprises a reflecting plate, a material with better reflecting performance can be selected, or the number of the reflecting plate can be increased or the extension length of the reflecting plate along the height direction of the low-temperature rectifying tower can be increased.

[0082] In some embodiments, the step of determining the heat accumulation rate under the working condition of the lead wire comprises:

[0083] determining the power of the lead wire under the working condition of the lead wire;

[0084] determining a heat dissipation power of the vacuum cavity to the wire;

[0085] determining a heat accumulation rate according to the wire power and the heat dissipation power.

[0086] determining a heat accumulation rate according to the wire power and the heat dissipation power. calculating the heat accumulation rate, wherein the heat accumulation rate is the wire power is the environmental heat dissipation capacity is.

[0087] The wire power can be calculated, and the environmental heat dissipation capacity can be measured or calculated. For example, a test device can be placed in the vacuum cavity, and the heat loss of the test device in a certain time is measured to obtain the heat dissipation capacity of the vacuum cavity to the test device as the heat dissipation power of the vacuum cavity to the wire 20. A certain current can also be applied to the wire in the vacuum cavity to generate a certain power, and the difference between the theoretical temperature rise and the actual temperature rise of the wire caused by the electric power in a certain time determining the heat dissipation power , wherein C is the heat capacity of the wire, m is the mass of the wire, and t is the test time.

[0088] In some embodiments, the step of determining the wire power of the wire under the working condition comprises:

[0089] obtaining the current of the wire under the working condition ;

[0090] obtaining the resistivity of the wire under the working condition ρ ;

[0091] calculating the wire power of the wire, specifically calculating the wire power according to the following function relationship :

[0092]

[0093] wherein, L represents the length of the wire, S represents the cross-sectional area of the wire.

[0094] Through this step, the wire power of the wire under the working condition can be obtained.

[0095] In some embodiments, the step of determining the heat dissipation power of the vacuum cavity to the wire comprises:

[0096] obtaining the heat dissipation area of the wire , the temperature of the wire under the working condition , and the temperature of the rectifying tower under the working condition ;​

[0097] The heat dissipation power of the wire was calculated. Specifically, the heat dissipation power of the conductor is calculated based on the following functional relationship. :

[0098]

[0099] in, The emissivity of the conductor. This is the Stefan-Boltzmann constant. This refers to the emission area, which is the heat dissipation area of ​​the conductor. ; This indicates the emission temperature, i.e., the temperature of the conductor under operating conditions. ; This indicates the receiving temperature, i.e., the temperature of the distillation column under operating conditions. .

[0100] In this way, the heat dissipation power of the vacuum cavity on the wires can be obtained. Then, according to... The heat accumulation rate was calculated. .

[0101] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A cryogenic rectification column system characterized by, The low-temperature rectification tower system comprises: a low-temperature rectification tower; a reboiler and a wire electrically connected with the reboiler to supply electric energy to the reboiler; a vacuum cover having a vacuum cavity, the low-temperature rectification tower and the reboiler being arranged in the vacuum cavity; a heat conduction device for transferring heat emitted by the wire to the low-temperature rectification tower; wherein the heat conduction device comprises a heat conduction medium connected at two ends with the low-temperature rectification tower and the wire respectively; or the heat conduction device comprises a reflecting plate arranged between the low-temperature rectification tower and the vacuum cover for reflecting heat of the wire to the low-temperature rectification tower, the wire being arranged between the reflecting plate and the low-temperature rectification tower.

2. The cryogenic rectification column system of claim 1, wherein, The heat conduction device comprises a heat conduction medium connected at two ends with the low-temperature rectification tower and the wire respectively. The heat conduction device further comprises: a fixing plate sleeved on the low-temperature rectification tower and located between the low-temperature rectification tower and an inner wall of the vacuum cover, the heat conduction medium being arranged on the fixing plate.

3. The cryogenic rectification column system of claim 2, wherein, The fixing plate is provided with a limiting opening, the heat conduction medium is provided with a heat conduction body and a heat conduction ring connected with each other, the heat conduction ring is arranged on a periphery of the limiting opening, the wire is arranged in the limiting opening and in contact with the heat conduction ring, and two ends of the heat conduction body are connected with the heat conduction ring and the low-temperature rectification tower respectively.

4. The cryogenic rectification column system of claim 2, wherein, A plurality of fixing plates are arranged in a vertical direction, and the heat conduction medium is arranged on each fixing plate.

5. The cryogenic rectification column system of claim 2, wherein, The heat conduction device further comprises: a clamping block connected with the fixing plate and the vacuum cover to arrange the fixing plate and the vacuum cover in a spaced manner.

6. A method of reducing reboiler power loss, characterized by, The method for using the low-temperature rectification tower system of any one of claims 1 to 5, the reboiler supplying electric energy through a wire for heat exchange with the low-temperature rectification tower, the method comprising: determining a heat accumulation rate under a working condition of the wire; arranging a heat conduction device according to the heat accumulation rate.

7. The method of claim 6, wherein, The step of determining the heat accumulation rate under the working condition of the wire comprises: determining a wire power under the working condition of the wire; determining a heat dissipation power of the vacuum cavity to the wire; determining the heat accumulation rate according to the wire power and the heat dissipation power.

8. The method of claim 7, wherein, The step of determining the wire power under the working condition of the wire comprises: acquiring the current of the conductor under the working condition ; obtaining an electrical resistivity p of the wire under the working condition; The conductor power of the conductor is calculated , in particular calculated according to the following functional relationship : wherein, L represents the length of the wire and S represents the cross-sectional area of the wire.

9. The method of claim 7, wherein, The step of determining the heat dissipation power of the vacuum cavity to the wire comprises: acquiring a heat dissipation area of the wire , a temperature of the wire under working conditions , a temperature of the rectifying column under working conditions ; The heat dissipation power of the wire is calculated , specifically, the heat dissipation power of the wire is calculated according to the following function relationship : wherein ε is the emissivity of the wire, ε is the emissivity of the wire, is the Stefan-Boltzmann constant.

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