Superconducting magnet system based on frequency-adjustable GM refrigerating machine and control method

Abstract

The invention discloses a superconducting magnet system based on a frequency-adjustable GM refrigerating machine. The superconducting magnet system comprises a refrigerating assembly, a superconducting magnet assembly, a monitoring assembly and a controller. The refrigeration assembly comprises a compressor and a refrigerator, the compressor is connected with the refrigerator in a matched mode, the superconducting magnet assembly comprises a superconducting coil and a cold shield, and the superconducting coil is arranged in the cold shield; the refrigerating machine comprises a first-stage cold head and a second-stage cold head, the first-stage cold head is thermally connected with the cold shield, and the second-stage cold head is thermally connected with the superconducting coil; the monitoring assembly comprises a plurality of temperature sensors, and the plurality of temperature sensors are arranged on the superconducting magnet assembly; the controller is connected with the refrigeration assembly in a matched mode, and the controller is connected with the temperature sensors in a matched mode. According to the superconducting magnet system, the working frequency of the GM refrigerating machine can be adjusted through the controller according to different working operation modes, so that the quenching risk of the superconducting magnet system is reduced, the working efficiency of the superconducting magnet system is improved, meanwhile, energy consumption is reduced, and the purpose of saving energy is achieved.

Description

technical field [0001] The invention mainly relates to the technical field of refrigerators, in particular to a superconducting magnet system and a control method based on an adjustable-frequency GM refrigerator. Background technique [0002] GM refrigerator is a device based on Simon's expansion principle to obtain ultra-low temperature, which is widely used in medical nuclear magnetic resonance and semiconductor fields. The GM refrigerator drives the piston to reciprocate along the inner wall of the cylinder through the driving device to compress and expand the helium gas, thereby achieving cooling and refrigeration. [0003] Superconducting magnets are used in nuclear magnetic resonance imaging equipment and need to work in ultra-low temperature and vacuum environments. High-temperature superconducting tapes are used as high-temperature current leads to meet equipment operation requirements. The working temperature of the superconducting magnet is 4.2K or below, and the ...

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Problems solved by technology

[0004] The current superconducting magnet system with a GM refrigerator generally uses a superconducting magnet system with little or no liquid nitrogen due to the shortage of liquid nitrogen resources. However, the cooling time of this superconducting magnet system is long, which affects the superconducting magnet system. In addition, the superconducting magnet system is prone to quenching, which affects the operation of the superconducting magnet system. Under normal operation, the operating temperature is too low, and part of the cooling capacity is wasted, resulting in large energy consumption of the system.

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