Centrifugal compressor system and compressor head control method thereof

Abstract

The invention discloses a centrifugal compressor system and a compressor head control method thereof. When a first compressor is started and operates to meet the compressor head condition, whether the compressor head anti-surge condition is met or not is judged firstly, when the anti-surge condition is not met, the opening degree of a first-stage throttling valve and the opening degree of a second-stage throttling valve are actively adjusted, the refrigerant liquid level height of a condenser is reduced, the refrigerant amount between the condenser and an evaporator is balanced, and therefore the suction and exhaust pressure difference of the compressor is reduced, the surge frequency of the compressor is reduced, the actual operation frequency in the compressor head process is higher than the surge frequency, the surge phenomenon in the compressor head process is avoided, the first compressor normally operates in the compressor head period, the operation efficiency of the system is not affected, and the problem that noise is generated due to opening of a hot air bypass pipeline is solved.

Description

technical field [0001] The invention relates to the technical field of compressors, in particular to a centrifugal compressor system and a control method for adding machine heads. 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 Instantaneous drop, lower than the allowable minimum working condition, the flow direction of the airflow in the compressor deviates greatly from the installation angle of the blade inlet, resulting in a serious "rotational separation" of the airflow in the blade passage, making the gas flow in the blade passage The stagnation causes the pressure of the compressor to drop suddenly, but the pressure of the outlet system does not drop instantaneously, which makes the gas with...

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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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