Method and device for controlling helium inlet pressure through variable-temperature surge tank

Abstract

The invention provides a method and device for controlling helium inlet pressure through a variable-temperature surge tank, and relates to the field of low-temperature systems.The device comprises a helium circulating system and a temperature adjusting system, the temperature adjusting system comprises a buffer tank, a coiled tube heat exchanger and a cold water bath unit, and the buffer tank is connected with the cold water bath unit; the cold water bath unit is arranged at the outlet end of the buffer tank and is used for cooling the helium to normal temperature so as to ensure that the helium temperature does not exceed a preset value. According to the method and the device for controlling the helium inlet pressure through the variable-temperature surge tank, the problem that the normal temperature and the normal pressure of pressurized helium cannot be recovered or pressure fluctuation exists is solved.

Description

Technical Field

[0001] The invention relates to the field of cryogenic systems, and in particular to a method and a device for controlling helium inlet pressure through a variable temperature pressure regulating tank. Background Art

[0002] In cryogenic refrigeration and superconducting technology, helium is widely used as a cooling medium. The temperature at the sample needs to be very stable, and the temperature fluctuation is usually less than 0.1% of the sample temperature. The fluctuation of the helium pressure entering the system will affect the stability of the temperature. Although the existing technology adjusts the helium pressure through a compressor or a buffer tank, the helium pressure often cannot be restored to normal temperature and pressure after pressurization, and there are pressure fluctuations. These problems affect the stability and efficiency of the system.

[0003] The invention with patent number: 201110391699.5 discloses a helium circulation cooling system, including: a helium cylinder, a filtering and decompression unit, a low-pressure buffer device, a pressurizing device, a high-pressure buffer device, a device to be cooled and a heat exchanger, wherein: the output end of the helium cylinder is connected to the helium supply input side of the low-pressure buffer device through the filtering and decompression unit; the cold air output end of the heat exchanger is connected to the circulating gas input side of the low-pressure buffer device; the low-pressure buffer device, the pressurizing device, and the high-pressure buffer device are connected in sequence to the helium and perform corresponding treatments in sequence; the hot helium output end of the device to be cooled is connected to the gas input end of the heat exchanger.

[0004] Since the above system involves multiple buffer devices and boosting devices, when the heat load of the equipment to be cooled changes, the response speed of the system may be affected to a certain extent. This may cause the system to be unable to provide sufficient cooling capacity in a short period of time, thereby affecting the normal operation of the equipment.

[0005] In addition, existing pressure regulation methods (such as compressor control or large gas storage tank buffer) have limitations and cannot quickly and effectively control pressure fluctuations when the load fluctuates greatly or the system temperature changes. Even if a pressure regulating tank is set, the volume of the pressure regulating tank will be very large. Therefore, a new pressure regulation solution is urgently needed to ensure that helium can stably return to normal temperature and pressure after pressurization and eliminate pressure fluctuations. Summary of the invention

[0006] The purpose of the present invention is to provide a method and device for controlling the inlet pressure of helium through a variable temperature pressure regulating tank, and the use of a smaller volume buffer tank solves the problem that the helium cannot return to normal temperature and pressure after pressurization or there is pressure fluctuation. The main innovation of the scheme includes the combined regulation of the coil heat exchanger, cold water bath and heater to ensure the stability of the helium pressure in the system.

[0007] To achieve the above object, the present invention provides a device for controlling the inlet pressure of helium through a variable temperature pressure regulating tank, comprising a helium circulation system and a temperature regulating system, wherein the temperature regulating system comprises a buffer tank, a coiled heat exchanger and a cold water bath unit, wherein the buffer tank and the cold water bath unit are connected;

[0008] The coils of the coil heat exchanger are filled with cold water, and a heating wire is arranged on the outside of the coil heat exchanger. The coil heat exchanger is located in the buffer tank and is used to adjust the temperature of the helium in the buffer tank, thereby adjusting the helium pressure in the buffer tank and the gas supply pipeline;

[0009] The temperature and flow rate of the cold water set in the coil remain unchanged;

[0010] The helium pressure value is obtained by a first pressure gauge and a second pressure gauge arranged on the helium circulation system, and the power of the heating wire is adjusted by using the helium pressure value, so as to accurately control the temperature of the helium in the buffer tank, and then adjust the helium pressure in the buffer tank;

[0011] The cold water bath unit is arranged at the outlet end of the buffer tank, and the gas supply pipeline is located in the cold water bath unit, which is used to cool the helium to room temperature to ensure that the helium temperature does not exceed a preset value.

[0012] Preferably, the helium circulation system is further provided with a primary heat exchanger and a secondary heat exchanger;

[0013] The primary heat exchanger and the secondary heat exchanger are located at one end of the second pressure gauge, and a low-temperature throttle valve and a sample table are provided at one end of the secondary heat exchanger;

[0014] The outer side of the secondary heat exchanger is provided with a primary cold screen, one side of the primary cold screen is provided with a secondary cold screen, and the low-temperature throttle valve and the sample stage are located in the secondary cold screen;

[0015] The sample stage is connected to a first pressure gauge.

[0016] Preferably, a refrigerator is provided on one side of the primary cold screen and the secondary cold screen, and both the primary cold screen and the secondary cold screen are connected to the refrigerator.

[0017] Preferably, a vacuum cover is provided on the outer side of the primary cold screen and the secondary cold screen, and the primary heat exchanger, the secondary heat exchanger, the low-temperature throttle valve and the sample stage are also located in the vacuum cover.

[0018] Preferably, a flow meter and a second valve are provided between the second pressure gauge and the cold water bath unit.

[0019] Preferably, a first valve is provided between the first pressure gauge and the buffer tank.

[0020] Preferably, a circulation pump is further provided between the first pressure gauge and the second pressure gauge, and the circulation pump is connected in parallel with the buffer tank and the cold water bath unit.

[0021] Preferably, the inlet end of the buffer tank is connected to a first pressure gauge, and the outlet end of the cold water bath unit is connected to a second pressure gauge.

[0022] A method for controlling the helium inlet pressure by a variable temperature pressure regulating tank comprises the following steps:

[0023] The helium passes through the second pressure gauge, and then passes through the primary heat exchanger and the secondary heat exchanger in sequence. Under the regulation of the primary cold screen and the secondary cold screen, the helium becomes liquid.

[0024] After the helium becomes liquid, it flows through the first pressure gauge. When pressure fluctuations occur in the gas supply pipeline, or the helium fails to return to normal temperature and pressure after pressurization, the helium flows into the buffer tank through the bypass pipeline. The helium in the buffer tank is regulated in temperature through the coil heat exchanger, causing the gas volume to change, thereby regulating the helium pressure.

[0025] The coil heat exchanger adjusts the helium temperature in the buffer tank, affects the helium volume, and then adjusts the helium pressure. When the helium pressure is too high, the power of the coil heat exchanger is increased to heat the helium, causing it to expand and release the pressure. When the pressure is too low, the power of the coil heat exchanger is reduced and the cold water in the coil is used to reduce the helium temperature, shrink its volume, and replenish the helium pressure.

[0026] A cold water bath unit is added at the outlet of the buffer tank, and a section of the gas supply pipeline is immersed in the cold water bath unit. After the helium is cooled to room temperature, it is mixed with the helium in the main circulation gas supply pipeline and enters the next cycle.

[0027] Therefore, the present invention adopts the above-mentioned method and device for controlling the helium inlet pressure through a variable temperature pressure regulating tank, and the technical effects are as follows:

[0028] (1) Precise control of pressure and temperature: The temperature change of helium in the buffer tank is precisely controlled through the coordinated work of the heater and the temperature control system, thereby effectively adjusting the volume of helium, ensuring the stability of pipeline pressure, and avoiding the negative impact of pressure fluctuations.

[0029] (2) Rapid response to pressure fluctuations: The temperature control system can quickly respond to changes in helium pressure. By adjusting the heater power in real time, it can quickly adjust the helium temperature and stabilize the helium pressure in the system.

[0030] (3) Ensure the stability of the helium temperature in the thermostat: The design of the cold water bath ensures that the temperature of the helium at the thermostat inlet is not too high, thus avoiding the problem of system instability caused by excessively high helium temperature.

[0031] (4) Easy integration and application: The solution has a compact structure and the temperature control system is easy to integrate with the existing helium circulation system. Through reasonable design, the existing system can be easily modified to improve its stability and efficiency.

[0032] (5) Enhanced system stability and reliability: By solving the pressure fluctuation and temperature problems in the helium circulation pipeline, the stability and cooling efficiency of the system are greatly improved, ensuring long-term stable operation and avoiding the decline in cooling effect or system failure caused by pressure fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The invention discloses a device for controlling the inlet pressure of helium through a variable temperature pressure stabilizing tank.

[0034] Reference numerals

[0035] 1. Buffer tank; 2. Coil heat exchanger; 3. Cold water bath unit; 4. First pressure gauge; 5. Second pressure gauge; 6. Primary heat exchanger; 7. Secondary heat exchanger; 8. Low temperature throttle valve; 9. Sample table; 10. Primary cold screen; 11. Secondary cold screen; 12. Refrigerator; 13. Vacuum cover; 14. Flow meter; 15. Second valve; 16. First valve; 17. Circulation pump; 18. Coil; 19. Cold water circulation unit; 20. Host computer. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0037] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0038] Embodiment 1

[0039] like Figure 1 As shown, a device for controlling the helium inlet pressure through a variable temperature pressure regulating tank includes a helium circulation system and a temperature regulating system; wherein the helium circulation system is the same as the traditional method, and the temperature regulating system is an improvement on the traditional structure.

[0040] The helium circulation system includes a first valve 16, a second valve 15, a first pressure gauge 4, a second pressure gauge 5, a flow meter 14, a circulation pump 17, a low-temperature throttle valve 8, a sample table 9, a primary cold shield 10, a secondary cold shield 11, a vacuum cover 13, a primary heat exchanger 6, a secondary heat exchanger 7, and a refrigerator 12.

[0041] The temperature circulation system includes a buffer tank 1 , a coil heat exchanger 2 , a coil 18 and a cold water bath unit 3 .

[0042] The helium flows through the second pressure gauge 5 and enters the primary heat exchanger 6 and the secondary heat exchanger 7. When passing through the secondary heat exchanger 7, the helium is initially cooled down under the action of the primary cold screen 10. Further, the helium flows through the second throttle valve to reach the sample table 9. At this time, under the action of the secondary cold screen 11, the helium is cooled down again and becomes liquid. Under the action of the circulating pump 17, the liquid helium passes through the first pressure gauge 4 and the first valve 16 to reach the buffer tank 1. The buffer tank 1 is provided with a coil heat exchanger 2, which includes a coil 18 and a heating wire (not shown) arranged outside the coil 18.

[0043] The cryogenic throttle valve 8 and the sample stage 9 simulate the pressure changes in actual usage scenarios.

[0044] According to the pressure values ​​obtained by the first pressure gauge 4 and the second pressure gauge 5, the upper computer 20 is used to adjust the heating power of the heating wire (the control algorithm can be set to achieve automatic adjustment); the coil heat exchanger 2 is externally connected to a cold water circulation unit 19, wherein the cold water circulation unit 19 is a common device on the market, wherein the temperature and flow rate of the cold water are fixed values, so that the cold amount in the buffer tank 1 remains unchanged, thereby accurately controlling the temperature of the helium in the buffer tank 1, and then adjusting the helium pressure in the buffer tank 1.

[0045] After the temperature of the buffer tank 1 is adjusted, the helium becomes gaseous and flows out from the outlet of the buffer tank 1 to the cold water bath unit 3. The cold water bath unit 3 performs auxiliary cooling to cool the helium to room temperature to ensure that the helium temperature does not exceed the preset value. After that, the helium flows through the second valve 15 and the flow meter 14 to enter the next cycle.

[0046] The primary cold screen 10 and the secondary cold screen 11 are externally connected to a refrigerator 12 to achieve a cooling effect.

[0047] The primary cold shield 10, the secondary cold shield 11, the primary heat exchanger 6, the secondary heat exchanger 7, the cryogenic throttle valve 8, the sample stage 9, and the refrigerator 12 are all located in the vacuum cover 13, which effectively isolates the external heat radiation and ensures the stability of the helium in a low-temperature environment.

[0048] The circulation pump 17 is connected in parallel with the buffer tank 1 and the cold water bath unit 3. The circulation pump 17 is responsible for extracting the liquid helium from the gas supply pipeline and transporting it to the temperature control system through the pipeline. The temperature control system heats or cools the liquid helium according to the set temperature value. The temperature-regulated helium turns into gas and returns to the gas supply pipeline, completing a cycle.

[0049] A method for controlling the helium inlet pressure by a variable temperature pressure regulating tank comprises the following steps:

[0050] The helium passes through the second pressure gauge 5, and then passes through the primary heat exchanger 6 and the secondary heat exchanger 7 in sequence. Under the regulation of the primary cold screen 10 and the secondary cold screen 11, the helium becomes liquid.

[0051] After the helium becomes liquid, it flows through the first pressure gauge 4. When pressure fluctuation occurs in the gas supply pipeline, or the helium fails to return to normal temperature and pressure after pressurization, the helium flows into the buffer tank 1 through the bypass pipeline; the helium in the buffer tank 1 is regulated in temperature by the coil heat exchanger 2, causing the gas volume to change, thereby regulating the helium pressure;

[0052] The coil heat exchanger 2 adjusts the helium temperature in the buffer tank 1, affects the helium volume, and then adjusts the helium pressure; when the helium pressure is too high, the power of the coil heat exchanger 2 is increased to heat the helium, promote its expansion, and release the pressure; when the pressure is too low, the power of the coil heat exchanger 2 is reduced and the cold water in the coil 18 is used to reduce the helium temperature, shrink its volume, and replenish the helium pressure;

[0053] In order to prevent the helium temperature in the helium circulation system from being too high, a cold water bath unit 3 is added to the outlet of the buffer tank 1. A section of the gas supply pipeline is immersed in the cold water bath unit 3. After the helium is cooled to room temperature, it is mixed with the helium in the main circulation gas supply pipeline to ensure the stability of the helium temperature in the helium circulation system.

[0054] Therefore, the present invention adopts the above-mentioned method and device for controlling the inlet pressure of helium through a variable temperature pressure tank to solve the problem that the helium cannot return to normal temperature and pressure or has pressure fluctuations after pressurization. The main innovation of the scheme includes the combined regulation of the coil heat exchanger, cold water bath and heater to ensure the stability of the helium pressure in the system.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A device for controlling the inlet pressure of helium through a variable temperature pressure tank, characterized in that: It includes a helium circulation system and a temperature regulation system, wherein the temperature regulation system includes a buffer tank, a coil heat exchanger and a cold water bath unit, and the buffer tank and the cold water bath unit are connected; The coils of the coil heat exchanger are filled with cold water, and a heating wire is arranged on the outside of the coil heat exchanger. The coil heat exchanger is located in the buffer tank and is used to adjust the temperature of the helium in the buffer tank, thereby adjusting the helium pressure in the buffer tank and the gas supply pipeline; The temperature and flow rate of the cold water set in the coil remain unchanged; The helium pressure value is obtained by a first pressure gauge and a second pressure gauge arranged on the helium circulation system, and the power of the heating wire is adjusted by using the helium pressure value, so as to accurately control the temperature of the helium in the buffer tank, and then adjust the helium pressure in the buffer tank; The cold water bath unit is arranged at the outlet end of the buffer tank, and the gas supply pipeline is located in the cold water bath unit, which is used to cool the helium to room temperature to ensure that the helium temperature does not exceed a preset value.

2. The device for controlling the inlet pressure of helium gas by means of a variable temperature pressure regulating tank according to claim 1, characterized in that: The helium circulation system is also provided with a primary heat exchanger and a secondary heat exchanger; The primary heat exchanger and the secondary heat exchanger are located at one end of the second pressure gauge, and a low-temperature throttle valve and a sample table are provided at one end of the secondary heat exchanger; The outer side of the secondary heat exchanger is provided with a primary cold screen, one side of the primary cold screen is provided with a secondary cold screen, and the low-temperature throttle valve and the sample stage are located in the secondary cold screen; The sample stage is connected to a first pressure gauge.

3. The device for controlling the inlet pressure of helium gas by means of a variable temperature pressure regulating tank according to claim 2, characterized in that: A refrigerator is provided on one side of the primary cold screen and the secondary cold screen, and both the primary cold screen and the secondary cold screen are connected to the refrigerator.

4. The device for controlling the inlet pressure of helium gas by means of a variable temperature pressure regulating tank according to claim 2, characterized in that: A vacuum cover is arranged outside the primary cold screen and the secondary cold screen, and the primary heat exchanger, the secondary heat exchanger, the low-temperature throttle valve and the sample stage are also located inside the vacuum cover.

5. The device for controlling the inlet pressure of helium gas by means of a variable temperature pressure regulating tank according to claim 1, characterized in that: A flow meter and a second valve are arranged between the second pressure gauge and the cold water bath unit.

6. The device for controlling the inlet pressure of helium gas by means of a variable temperature pressure regulating tank according to claim 1, characterized in that: A first valve is provided between the first pressure gauge and the buffer tank.

7. The device for controlling the inlet pressure of helium gas by means of a variable temperature pressure regulating tank according to claim 1, characterized in that: A circulation pump is also provided between the first pressure gauge and the second pressure gauge, and the circulation pump is connected in parallel with the buffer tank and the cold water bath unit.

8. The device for controlling the inlet pressure of helium gas by means of a variable temperature pressure regulating tank according to claim 1, characterized in that: The inlet end of the buffer tank is connected to a first pressure gauge, and the outlet end of the cold water bath unit is connected to a second pressure gauge.

9. A method for controlling the inlet pressure of helium gas by means of a variable temperature pressure regulating tank, characterized in that: The following steps are involved: The helium passes through the second pressure gauge, and then passes through the primary heat exchanger and the secondary heat exchanger in sequence. Under the regulation of the primary cold screen and the secondary cold screen, the helium becomes liquid. After the helium becomes liquid, it flows through the first pressure gauge. When pressure fluctuations occur in the gas supply pipeline, or the helium fails to return to normal temperature and pressure after pressurization, the helium flows into the buffer tank through the bypass pipeline. The helium in the buffer tank is regulated in temperature through the coil heat exchanger, causing the gas volume to change, thereby regulating the helium pressure. The coil heat exchanger adjusts the helium temperature in the buffer tank, affects the helium volume, and then adjusts the helium pressure. When the helium pressure is too high, the power of the coil heat exchanger is increased to heat the helium, causing it to expand and release the pressure. When the pressure is too low, the power of the coil heat exchanger is reduced and the cold water in the coil is used to reduce the helium temperature, shrink its volume, and replenish the helium pressure. A cold water bath unit is added at the outlet of the buffer tank, and a section of the gas supply pipeline is immersed in the cold water bath unit. After the helium is cooled to room temperature, it is mixed with the helium in the main circulation gas supply pipeline and enters the next cycle.

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