Structure for preventing centrifugal compressor from reverse rotation

Abstract

The present invention provides the structure for preventing centrifugal compressor from reverse rotation. The structure includes suction pipe connected to the suction port of the compressor, exhaust pipe connected to the exhaust port of the compressor, flow path pipe with shunt valve connected between the suction pipe and the exhaust pipe for mutual communication, and power off sensor set in the power cord. The shunt valve is made to open or shut via controlling the power off sensor and the high temperature and high pressure medium is made to flow from the exhaust port to the suction port for pressure balance between them. In case that the power supply is turned off and the compressor stops suddenly owing to power-off or abnormal compressor, the present invention can prevent the reverse rotation of the rotating shaft, abnormal flow of the medium gas inside the compressor, abnormal noise and corresponding effect on the compressor parts.

Description

technical field [0001] The invention relates to a centrifugal compressor, in particular to a structure for preventing reverse rotation of the centrifugal compressor. Background technique [0002] In general, compressors can use mechanical operation to compress fluid. Compressors are roughly divided into reciprocating type, scroll type, centrifugal type (axial flow type) and vane type (rotary type). Among them, the centrifugal compressor (also called axial flow compressor) uses the rotational force of the impeller to suck the fluid in the axial direction, and then discharge it in the centrifugal direction for compression. According to the number of impellers and compression chambers, it is divided into primary compression type and The secondary compression type, according to the arrangement of the impellers, is divided into back-to-back type and face-to-face type. [0003] Such as figure 1 As shown, the face-to-face secondary compression centrifugal compressor includes a mo...

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Problems solved by technology

[0008] However, the compressor with the above structure has the following problems: First, during the normal compression process in which the compressor compresses the medium in the low-temperature and low-pressure state through the suction port SP to form a high-temperature and high-pressure state, a power failure or abnormal drive of the compressor occurs When the power supply is cut off to make the compressor suddenly stop driving, in order to balance the pressure between the discharge port DP side of the high-pressure part and the suction port SP side of the low-pressure part in the compressor, the flow medium channel 12 through the compressor will flow from The phenomenon of rapid countercurrent flow of the medium from the discharge port DP to the suction port SP. In the above process, through the pressure difference between the suction port SP and the discharge port DP and the rapid countercurrent flow of the medium, the primary compressor fixed at both ends of the rotating shaft 7 The impeller 8A and the secondary compression impeller 8B are momentarily subjected to reverse torque, and the rotating shaft 7 is also rotating in the reverse direction. At this time, the primary compression impeller 8A, the secondary compression impeller 8B and the rotating shaft 7 are reversely rotating, which not only reduces the normal rotation of the rotating shaft 7 The performance of the first radial bearing 9A and the second radial bearing 9B that stably supports the dynamic pressure air of the axial flow self-gravity during rotation, and the components constituting the first radial bearing 9A and the second radial bearing 9B are also the same damaged

Secondly, if a power failure occurs or the power supply is cut off due to abnormal driving, the compressor will suddenly stop driving, and the medium that flows back sharply from the high-pressure discharge port DP to the low-pressure suction port SP will make abnormally loud noises and shorten the overall life of the compressor.

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