Control method and control device suitable for full-frequency-conversion compressor parallel unit

Abstract

The invention discloses a control method and a control device suitable for a full-frequency-conversion compressor parallel unit so as to optimize compressor running wasted work and guarantee system reliable running. The method comprises the following steps that the air suction pressure p of a parallel refrigeration unit is collected and compared with the frequency increasing pressure pz and the frequency reducing pressure pj; the accumulated running waste work of various compressors is read, the principle that frequency increasing is firstly conducted on the compressor with the lowest accumulated running waste work and frequency reducing is firstly conducted on the compressor with the largest accumulated running waste work is utilized for controlling running frequency changes of the various compressors. According to the control method, the running frequency of the compressors is controlled by comprising the total accumulated wasted work of compressor running, the running wasted work ofthe multiple frequency conversion compressors is homogenized, the frequency is orderly, and the system reliability is improved. The probability of faults of the compressors in the refrigeration parallel unit is reduced, the service life of the whole refrigeration parallel compressor is prolonged, and the running cost of the full-frequency-conversion compressor parallel unit is reduced.

Description

technical field [0001] The present invention relates to the technical field of refrigeration, and more specifically relates to a control method and a control device for operating frequency of compressors in parallel units of full-frequency compressors. Background technique [0002] With the continuous progress of the development of modern electronic technology, frequency conversion technology is more and more applied to the field of refrigeration technology. Inverter compressors are also increasingly used in variable-condition refrigeration systems. Parallel refrigeration units with fully variable frequency compressors are widely used because of their high reliability and low operating costs. [0003] During the operation of the fully variable frequency compressor parallel refrigeration unit, the load changes, and it is often necessary to increase or decrease the operating frequency of the compressor. The frequency of each compressor is often increased or decreased accordi...

AI Technical Summary

Problems solved by technology

The service life of variable frequency compressors is fixed, and the cost is higher than that of fixed frequency compressors. As a result, the compressor with a long running time is the first to fail or has a higher probability of failure.

In the fully variable frequency compressor refrigeration parallel unit, when any one or more compressors fail, it is not suitable to replace them. Therefore, the faulty compressor reduces the service life of the entire parallel unit and increases the operating cost of the refrigeration system; Or, after the compressor fails, if it cannot be repaired in time, the refrigeration system may not be able to resume work in time, causing damage to the valuables stored in it and causing losses; more importantly, in the above control methods, only the control object compressor The control signal sent out does not have a feedback link to detect whether the compressor is running, and the system is unreliable

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