Inverse Brayton cryogenic box rapid refrigeration system and operation control method thereof

Abstract

The invention discloses a reverse Brayton low-temperature box rapid refrigerating system which comprises a cooler, an expansion machine, a turbine compressor, an aftercooler and a heat regenerator which are sequentially and circularly communicated through a pipeline and located in a box body, the turbine compressor and the expansion machine are driven by a high-speed motor, and the reverse Brayton low-temperature box rapid refrigerating system further comprises an electric control device which is connected with the turbine compressor and the high-speed motor; a bypass pipeline used for producing a temporary gas short circuit phenomenon is arranged between an outlet pipeline of the aftercooler and an inlet of the turbine compressor, and a bypass electromagnetic valve is arranged on the bypass pipeline and connected with the electric control device. The invention further discloses a corresponding operation control method. According to the technical scheme, the operation power of the turbine compressor and the high-speed motor is improved through the designed airflow short-circuit phenomenon in the initial starting stage of the system, and the airflow short-circuit phenomenon is ended after the operation power is improved, so that the purpose of rapid refrigeration is achieved by rapidly improving the operation power of the system.

Description

technical field [0001] The invention relates to the refrigeration technology of gas reverse Brayton cycle low temperature box, which is a kind of rapid refrigeration and stable operation invented by Henan Xinfei Refrigeration Appliance Co., Ltd. method. Background technique [0002] The structure of the existing reverse Brayton cycle refrigeration system is: including a box for providing a low-temperature storage space, a regenerator for heat exchange between low-temperature nitrogen and high-temperature nitrogen, a turbocompressor, an expander, an aftercooler, High-speed motor and cooler located in the box; the regenerator has a high temperature inlet, a high temperature outlet, a low temperature inlet and a low temperature outlet; the regenerator is provided with a foam layer, which is insulated from the outside to promote high temperature nitrogen and low temperature nitrogen better exchange of heat with each other. The turbo compressor is used to compress low-temperatu...

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Problems solved by technology

[0004] The disadvantage of the reverse Brayton cycle refrigeration system of this existing structure is: at the initial stage of system start-up, the power of the high-speed motor is low due to the limited air intake of the main engine, and the speed of increasing the power to the level of normal operation is very slow, resulting in turbo compression. The performance of the compressor cannot be developed quickly, and it takes a long time for the pressure in the box to be balanced before the performance of the turbo compressor can be fully utilized, resulting in slow cooling speed and weak quick-freezing ability of the system

[0005] And because the control is not perfect, if the high-speed motor is stopped directly under the normal working condition of the speed of about 100,000 revolutions per minute, the motor shaft will be unstable, and friction will be generated at the pneumatic bearing, which will damage the pneumatic bearing and even the motor shaft, and shorten the corresponding time. The service life of the structure, and increase the power of the high-speed motor during subsequent use, and damage to the pneumatic bearing or motor shaft will make it difficult to start the subsequent motor

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