Self-regulating low-temperature heat pipe heat exchange device for superconducting magnet

Abstract

The application discloses a kind of self-regulating low-temperature heat pipe heat exchange devices for superconducting magnet, it is characterized in that, including low-temperature-resistant high-strength capillary, super-low-temperature condenser, liquid-vapor evaporator and inflation tube;Among them, the low-temperature-resistant high-strength capillary is the stainless steel pipe that is passivated by cold drawing inner surface;The super-low-temperature condenser one end is used to be connected with cold lead platform, for the cold quantity transmission of the cold source end that cold lead platform is connected to the super-low-temperature condenser;The other end of the super-low-temperature condenser is connected with the cold end of low-temperature-resistant high-strength capillary, for the cold quantity transmission to the super-low-temperature fluid in low-temperature-resistant high-strength capillary;The hot end of the low-temperature-resistant high-strength capillary is connected with the liquid-vapor evaporator, for the cold quantity transmission of the super-low-temperature fluid in low-temperature-resistant high-strength capillary to the liquid-vapor evaporator;The liquid-vapor evaporator is used to transmit the cold quantity received to the superconducting magnet connected therewith.The present application realizes fast, self-regulating heat transfer under super-low-temperature.

Description

Technical Field

[0001] This invention relates to a self-circulating cryogenic heat pipe heat exchange device for superconducting magnets, and more particularly to a high-efficiency heat exchange device for superconducting magnets made of YBCO-type high-temperature superconducting materials used in cryogenic environments, belonging to the field of accelerator superconducting cryogenic application technology. Background Technology

[0002] Superconducting magnets are crucial components in accelerators for particle orbit confinement, primarily used for beam regulation of electrons and protons within the beam channel. Superconducting magnets are manufactured from Nb-Ti alloys or YBCO materials. These alloys are conventional conductors at room temperature, but when cooled to below -265°C, the superconducting magnet enters a superconducting state, becoming a superconductor and entering its operating mode. To maintain the superconducting state of the superconducting magnet, a cold source is required to ensure its operating temperature. A heat exchange device is needed between the cold source and the superconducting magnet to transfer the cooling energy from the cold source to the superconducting magnet, maintaining its cooling requirements. This heat exchange device must be able to withstand ultra-low temperatures of -265°C, possess a certain amount of heat transfer capacity and high heat transfer efficiency, and be simple in structure, easy to install, and convenient to maintain. One end of the cryogenic heat exchanger for superconducting magnets is connected to the heat-conducting end of the superconducting magnet, and the other end is connected to the helium pool or cold head of the cold source and is in an extremely low-temperature environment. During stable operation of the superconducting magnet, this cryogenic heat exchanger needs to be able to quickly transfer the cold energy from the cold source to the superconducting magnet, with an effective heat transfer efficiency within the range of 2000 W / mK. A self-circulating cryogenic heat exchanger made of stainless steel and high-conductivity copper can provide good heat transfer. Currently, the low-temperature thermal properties of the heat-conducting material between the superconducting magnet and the cold source can be achieved using copper braided tape or copper rods, but their thermal conductivity cannot meet the ultra-high heat transfer requirements of the superconducting magnet heat exchanger at extremely low temperatures. This invention enables efficient heat transfer in a self-regulating cryogenic heat exchanger for superconducting magnets at an ultra-low temperature of -265℃. Summary of the Invention

[0003] This invention provides a self-adjusting cryogenic heat exchange device for superconducting magnets, which solves the problem that current heat transfer methods with copper braided strips or copper rods cannot meet the requirements for rapid heat transfer over long distances under cryogenic conditions, and cannot meet the requirement for the heat transfer device to self-adjust its effective thermal conductivity within a certain temperature range.

[0004] The technical solution adopted in this invention is:

[0005] A self-regulating cryogenic heat pipe heat exchange device for superconducting magnets, characterized in that it comprises a cryogenically resistant high-strength capillary tube, a cryogenic condenser, a liquid-vapor evaporator, and a gas-filling pipe; wherein,

[0006] The low-temperature resistant high-strength capillary tube is a stainless steel tube that has undergone cold drawing and inner surface passivation treatment, and is used as a container for ultra-low temperature fluids.

[0007] One end of the ultra-low temperature condenser is connected to the cooling platform to transfer the cold energy from the cold source end connected to the cooling platform to the ultra-low temperature condenser; the other end of the ultra-low temperature condenser is connected to the cold end of the low temperature resistant high-strength capillary tube to transfer the cold energy to the ultra-low temperature fluid inside the low temperature resistant high-strength capillary tube.

[0008] The hot end of the low-temperature resistant high-strength capillary is connected to the liquid vapor evaporator to transfer the cooling capacity of the ultra-low temperature fluid in the low-temperature resistant high-strength capillary to the liquid vapor evaporator.

[0009] The liquid vapor evaporator is used to transfer the received cooling energy to the superconducting magnet connected thereto;

[0010] The inflation tube is connected to the inlet and outlet of the low-temperature resistant high-strength capillary via an adapter, and is used to fill or discharge the low-temperature resistant high-strength capillary with cryogenic fluid.

[0011] Furthermore, the low-temperature resistant high-strength capillary tube is a stainless steel tube that has undergone passivation treatment of the inner surface at room temperature and cold quenching treatment at -196℃.

[0012] Furthermore, the low-temperature resistant high-strength capillary is a reciprocating serpentine stainless steel tube.

[0013] Furthermore, the cold end of the low-temperature resistant high-strength capillary is welded to the ultra-low temperature condenser by vacuum brazing; wherein the ultra-low temperature condenser is made of high-conductivity copper material, the brazing temperature is 180°C, and the welding material is a mixture of lead, tin and aluminum, wherein the proportion of lead is 20%, the proportion of tin is 40%, and the proportion of aluminum is 40%.

[0014] Furthermore, the hot end of the low-temperature resistant, high-strength capillary is welded to the liquid vapor evaporator by vacuum brazing; the liquid vapor evaporator is made of high-conductivity copper material, the brazing temperature is 120°C, and the welding material is a mixture of lead, tin, and aluminum, wherein the lead content is 20%, the tin content is 60%, and the aluminum content is 20%.

[0015] Furthermore, the ultra-low temperature condenser has a fixing groove on the back and a cooling front fixing groove on the front; the ultra-low temperature condenser connects the cooling platform to the top of the ultra-low temperature condenser through the fixing groove.

[0016] Furthermore, a heater and a temperature measuring element are fixed on the cooling platform.

[0017] Furthermore, the liquid vapor evaporator is connected to the superconducting magnet via a clamp.

[0018] Furthermore, it also includes a fixing frame, wherein the ultra-low temperature condenser is fixed to one end of the fixing frame and the liquid vapor evaporator is fixed to the other end of the fixing frame.

[0019] Furthermore, the distance between the hot end and the cold end of the low-temperature resistant high-strength capillary is not less than 100mm.

[0020] A self-regulating cryogenic heat pipe heat exchange device for superconducting magnets includes a cryogenic high-strength capillary tube, a cryogenic condenser, a liquid vapor evaporator, and a gas filling pipe. The cryogenic high-strength capillary tube is a cold-drawn stainless steel tube with a passivated inner surface, serving as a container for the cryogenic fluid. The cryogenic condenser facilitates heat transfer from the cold source to the cryogenic fluid within the capillary tube. The liquid vapor evaporator transfers the cold energy from the cryogenic fluid to the superconducting magnet. The gas filling pipe is used for filling or releasing the fluid within the self-regulating cryogenic heat pipe heat exchange device. The cryogenic high-strength capillary tube undergoes passivation treatment on its inner surface at room temperature, followed by cryogenic treatment at -196°C, and then reciprocating serpentine forming in a mold. The ultra-low temperature condenser and liquid vapor evaporator are combined with the molded low-temperature resistant high-strength capillary tube and welded together by vacuum brazing. The ultra-low temperature condenser is located at one end of the molded low-temperature resistant high-strength capillary tube, and the liquid vapor evaporator is located at the other end. After welding, a second cryogenic treatment at -196℃ and a helium mass spectrometer leak test are required. The gas filling pipe is welded to the adapter, and then subjected to a cryogenic treatment at -196℃ and a helium mass spectrometer leak test. The adapter is a three-way structure, with the other two ports connected to the inlet and outlet of the capillary tube. The overall dimensions of the self-circulating low-temperature heat pipe heat exchanger are 190mm in height and a rectangular area with dimensions of 74.4mm long and 10mm wide. The self-circulating low-temperature heat pipe heat exchanger includes a temperature sensor, a heater, and a pressure sensor. The pressure sensor is installed on the room temperature section of the gas filling pipe, and the room temperature signal interface transmits the signal to an external pressure testing instrument. Temperature sensors and heaters transmit temperature, voltage, and current signals to a room temperature signal interface via a dedicated sensor connection cable. The signals are then transmitted from the room temperature signal interface to an external testing instrument, enabling remote monitoring, reading, storage, and display of the signals.

[0021] Compared with the prior art, the advantages of the present invention are as follows:

[0022] The self-circulating low-temperature heat pipe heat exchange device of the present invention operates in a temperature range of -263℃ to -196℃, and the effective thermal conductivity at ultra-low temperatures reaches 5000W / mK, realizing rapid heat transfer at ultra-low temperatures. It is made of high-conductivity copper and stainless steel materials, and is supplemented with measuring devices for low-temperature temperature, low-temperature heating and pressure, providing a stable and adjustable heat exchange device for the cooled superconducting magnet at ultra-low temperature operating temperature.

[0023] The present invention uses an air-filling pipe to fill the self-regulating low-temperature heat exchanger with external fluid, or to extract the fluid from the self-regulating low-temperature heat exchanger, thereby changing the amount of fluid filling the self-regulating low-temperature heat exchanger.

[0024] With a certain amount of external fluid filling, the increase in cold end temperature of this invention will automatically trigger an increase in the effective thermal conductivity of this invention, and the decrease in cold end temperature will automatically trigger a decrease in the effective thermal conductivity of this invention, thereby realizing the self-regulation of its effective thermal conductivity.

[0025] The present invention adopts a fixed structure, which facilitates the operation of the self-regulating low-temperature heat exchange device in a temperature range of -263℃ to -196℃. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0027] Figure 2 This is a front view of the present invention.

[0028] Figure 3 This is the left view of the present invention.

[0029] 1-Ultra-low temperature condenser, 2-Liquid vapor evaporator, 3-Low temperature resistant high-strength capillary tube, 4-Gas filling pipe, 5-Fixing bracket, 6-Adapter, 7-Cooling platform. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings.

[0031] like Figure 1 The diagram shows a self-regulating cryogenic heat pipe heat exchange device for a superconducting magnet according to the present invention. The device consists of a cryogenic condenser 1, a liquid vapor evaporator 2, a cryogenic high-strength capillary tube 3, a gas filling pipe 4, a mounting frame 5, a converter 6, and a cooling platform 7. The cryogenic condenser 1 has a cooling platform 7 at its top, a mounting groove at its back, and a cooling front-end mounting groove for the cryogenic high-strength capillary tube 3 at its front, as shown. Figure 2 As shown. The cryogenic condenser 1 is rectangular in shape, 74.4 mm long, 10 mm wide, and 35 mm high. The front groove is 1.6 mm deep, and the back groove is 5 mm deep and 40 mm long. The cryogenic condenser 1 is connected to the cooling platform 7 via a fixing groove on the back. The cooling platform 7 is equipped with a cryogenic heater and a cryogenic temperature measuring element. Simultaneously, the cooling platform 7 is connected to the cold source end for heat transfer, such as... Figure 2The cold conduction platform 7 conducts the low temperature from the cold source end to the ultra-low temperature condenser, which then conducts the low temperature to the low-temperature resistant high-strength capillary tube 3. The cold end of the low-temperature resistant high-strength capillary tube 3 is welded to the front groove of the ultra-low temperature condenser 1 (made of high-conductivity copper material) using vacuum brazing. The brazing temperature is required to reach 180°C to weld the stainless steel to the high-conductivity copper. To ensure the brazing temperature of 180°C, the welding material is a mixture of lead, tin, and aluminum, with lead accounting for 20%, tin for 40%, and aluminum for 40%. The hot end of the low-temperature resistant high-strength capillary tube 3 is located in the front groove of the liquid vapor evaporator 2. Vacuum brazing is also employed, requiring a brazing temperature of 120℃. Since the liquid vapor evaporator 2 is connected to the superconducting magnet to transfer the received cold energy, and the temperature environments of the liquid vapor evaporator 2 and the superconducting magnet are the same, the welding temperature of the low-temperature resistant high-strength capillary tube 3 to the liquid vapor evaporator 2 corresponds to the coefficient of thermal expansion of the superconducting magnet material, thus ensuring welding stability. To ensure a brazing temperature of 120℃, a mixture of lead, tin, and aluminum is selected as the welding material, with lead accounting for 20%, tin for 60%, and aluminum for 20%. The outer diameter of the low-temperature resistant high-strength capillary tube 3 is 3.18 mm, and the wall thickness is 0.64 mm. The distance between the hot and cold ends of the low-temperature resistant high-strength capillary tube 3 is required to be 100 mm. The liquid vapor evaporator 2 has a rectangular projection, with a length of 74.4 mm, a width of 10 mm, and a height of 45 mm, and a front groove depth of 1.6 mm. The liquid vapor evaporator 2 is connected to the hot end of the superconducting magnet via a clamp for heat transfer. Before assembling the self-regulating low-temperature heat pipe device, the ultra-low temperature condenser 1 and the liquid vapor evaporator 2 need to be connected via the fixing bracket 5, followed by the installation of the low-temperature resistant high-strength capillary tube 3, and the installation of the adapter 6 and the gas charging pipe 4, as follows. Figure 3As shown; the converter 6 is located at the bottom of the liquid vapor evaporator 2, and the gas charging pipe 4 is located at the top of the converter 6 and points vertically upward. The mounting bracket 5 allows for adjustment of the distance between the cryogenic condenser 1 and the liquid vapor evaporator 2. Before installing the cryogenic condenser 1 and the cooling platform 7, a complete cold shock is required at a temperature of -196℃, and the cold contraction amount and cold contraction force of the low-temperature resistant high-strength capillary tube 3 are measured. After the cold shock is completed, the self-regulating low-temperature heat pipe heat exchange device is cooled down, and the cooling platform 7 exchanges heat with the cryogenic condenser 1. The cryogenic condenser 1 is gradually cooled, and heat is transferred to the liquid vapor evaporator 2 through the low-temperature resistant high-strength capillary tube 3. After 12 hours of cooling, the liquid vapor evaporator 2 is slowly cooled to the operating temperature. At the same time, the cooling rate of the liquid vapor evaporator 2 is controlled by the thermometer and heater on the liquid vapor evaporator 2. Once the temperature stabilizes and reaches the set temperature, the changes in temperature and heating capacity of the ultra-low temperature condenser and liquid vapor evaporator cause the effective thermal conductivity of the low-temperature heat pipe heat exchange device to adjust spontaneously, achieving self-regulation of the low-temperature heat pipe heat exchange device. The thermometers and heaters of the cooling platform 7 and the liquid vapor evaporator 2 transmit electrical signals to the ambient temperature monitoring instrument through transmission lines. Temperature, heating capacity, and pressure change data signals are transmitted to a remote computer through optical fiber for real-time display and automatic data processing.

[0032] All components of the self-regulating cryogenic heat pipe heat exchange device for the superconducting magnet in this application require cryogenic quenching at -196℃. After all components have been cryogenically quenched and assembled, an overall helium mass spectrometer leak test and X-ray flaw detection are performed. After the overall inspection, a second overall cryogenic quenching is required, involving filling the device with working gas to a pressure of 2.0 MPa, holding the pressure for 1 hour without leakage, and then connecting it to the cryogenic end of the cold source and the hot end of the superconducting magnet. A thermometer, heater, and pressure sensor at the room temperature end are then installed. The overall signals and data are read and displayed remotely by a computer. The mounting bracket 5 is made of 304 stainless steel, while the cryogenic high-strength capillary tube 3, the gas filling pipe 4, and the converter 6 are made of 316L stainless steel. The cryogenic condenser 1 and the liquid vapor evaporator 2 are made of high-conductivity copper with an RRR of 100.

[0033] The above description, in conjunction with specific embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the inventive concept of this application.

Claims

1. A self-regulating cryogenic heat pipe heat exchange device for superconducting magnets, characterized in that, This includes low-temperature resistant high-strength capillary tubes, ultra-low temperature condensers, liquid-vapor evaporators, and gas charging pipes; among which, The low-temperature resistant high-strength capillary tube is a stainless steel tube that has undergone cold drawing and inner surface passivation treatment, and is used as a container for ultra-low temperature fluids; the low-temperature resistant high-strength capillary tube is a stainless steel tube that has undergone inner surface passivation treatment at room temperature and cold quenching treatment at -196℃. One end of the ultra-low temperature condenser is connected to the cooling platform to transfer the cold energy from the cold source end connected to the cooling platform to the ultra-low temperature condenser; the other end of the ultra-low temperature condenser is connected to the cold end of the low temperature resistant high-strength capillary tube to transfer the cold energy to the ultra-low temperature fluid inside the low temperature resistant high-strength capillary tube. The hot end of the low-temperature resistant high-strength capillary is connected to the liquid vapor evaporator, and is used to transfer the cooling capacity of the ultra-low temperature fluid in the low-temperature resistant high-strength capillary to the liquid vapor evaporator. The liquid vapor evaporator is used to transfer the received cooling energy to the superconducting magnet connected thereto; The inflation tube is connected to the inlet and outlet of the low-temperature resistant high-strength capillary via an adapter, and is used to fill or discharge the low-temperature resistant high-strength capillary with cryogenic fluid. The cold end of the low-temperature resistant high-strength capillary is welded to the cryogenic condenser via vacuum brazing; wherein the cryogenic condenser is made of high-conductivity copper material, the brazing temperature is 180°C, and the welding material is a mixture of lead, tin, and aluminum, wherein lead accounts for 20%, tin accounts for 40%, and aluminum accounts for 40%; the hot end of the low-temperature resistant high-strength capillary is welded to the liquid vapor evaporator via vacuum brazing; wherein the liquid vapor evaporator is made of high-conductivity copper material, the brazing temperature is 120°C, and the welding material is a mixture of lead, tin, and aluminum, wherein lead accounts for 20%, tin accounts for 60%, and aluminum accounts for 20%.

2. The self-regulating cryogenic heat pipe heat exchanger for superconducting magnets as described in claim 1, characterized in that, The low-temperature resistant, high-strength capillary tube is a reciprocating serpentine stainless steel tube.

3. The self-regulating cryogenic heat pipe heat exchange device for superconducting magnets as described in claim 1 or 2, characterized in that, The ultra-low temperature condenser has a fixing groove on the back and a cooling front fixing groove on the front; the ultra-low temperature condenser connects the cooling platform to the top of the ultra-low temperature condenser through the fixing groove.

4. The self-regulating cryogenic heat pipe heat exchanger for superconducting magnets as described in claim 1, characterized in that, A heater and a temperature measuring element are fixed on the cooling platform.

5. The self-regulating cryogenic heat pipe heat exchanger for superconducting magnets as described in claim 1, characterized in that, The liquid vapor evaporator is connected to the superconducting magnet via a clamp.

6. The self-regulating cryogenic heat pipe heat exchanger for superconducting magnets as described in claim 1, characterized in that, It also includes a fixing frame, wherein the ultra-low temperature condenser is fixed to one end of the fixing frame and the liquid vapor evaporator is fixed to the other end of the fixing frame.

7. The self-regulating cryogenic heat pipe heat exchange device for superconducting magnets as described in claim 1, characterized in that, The distance between the hot end and the cold end of the low-temperature resistant high-strength capillary is not less than 100mm.

Images