A centrifugal compressor system and a method for controlling the feeding head thereof

Abstract

The invention discloses a centrifugal compressor system and a control method for adding head. When the first compressor starts and runs to meet the condition of adding head, it first judges whether the anti-surge condition of adding head is met. In surge condition, by actively adjusting the opening of the first-stage throttle valve and the second-stage throttle valve, the liquid level of the refrigerant in the condenser is reduced, and the amount of refrigerant between the condenser and the evaporator is balanced, thereby reducing the suction of the compressor. The exhaust pressure difference, thereby reducing the surge frequency of the compressor, ensures that the actual operating frequency is higher than the surge frequency during the process of adding heads, avoiding the surge phenomenon during the process of adding heads, and the first compressor during the process of adding heads Normal operation does not affect the operating efficiency of the system, and there is no problem of noise caused by opening the hot gas bypass pipeline.

Description

technical field [0001] The present invention relates to the technical field of compressors, and in particular, to a centrifugal compressor system and a method for controlling a machine head thereof. Background technique [0002] Centrifugal compressors are prone to surge during operation, which seriously affects the safety and stability of the system. Studies have shown that the internal causes of surge are closely related to the structure of the impeller and the medium gas in the blade passage. When the inlet gas flow rate Instantaneously decreases, and when it is lower than the allowable minimum working condition, the airflow direction in the compressor deviates greatly from the installation angle of the blade inlet, causing the airflow in the blade channel to appear serious "rotational separation", so that the gas in the blade channel The stagnation causes the pressure of the compressor to drop suddenly, but the pressure of the outlet system does not drop instantaneously,...

AI Technical Summary

Problems solved by technology

[0007] In order to solve the existing technical problems of reducing the surge frequency of the compressor through the hot gas bypass, which leads to the reduction of system operation efficiency and the generation of noise, the present invention proposes a centrifugal compressor system and its adding head control method, based on the control logic Adjust the liquid level of the condenser to balance the amount of refrigerant between the condenser and the evaporator to reduce the suction and discharge pressure difference of the compressor, thereby reducing the surge frequency of the compressor and making the actual operation during the process of adding the machine head The frequency is lower than the surge frequency, avoiding surge phenomenon, does not affect the operating efficiency of the system, and there is no problem of noise generated by opening the hot gas bypass pipeline

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